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aic79xx_core.c

/*
 * Core routines and tables shareable across OS platforms.
 *
 * Copyright (c) 1994-2002 Justin T. Gibbs.
 * Copyright (c) 2000-2003 Adaptec Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * $Id: //depot/aic7xxx/aic7xxx/aic79xx.c#250 $
 */

#ifdef __linux__
#include "aic79xx_osm.h"
#include "aic79xx_inline.h"
#include "aicasm/aicasm_insformat.h"
#else
#include <dev/aic7xxx/aic79xx_osm.h>
#include <dev/aic7xxx/aic79xx_inline.h>
#include <dev/aic7xxx/aicasm/aicasm_insformat.h>
#endif


/***************************** Lookup Tables **********************************/
char *ahd_chip_names[] =
{
      "NONE",
      "aic7901",
      "aic7902",
      "aic7901A"
};
static const u_int num_chip_names = ARRAY_SIZE(ahd_chip_names);

/*
 * Hardware error codes.
 */
struct ahd_hard_error_entry {
        uint8_t errno;
      char *errmesg;
};

static struct ahd_hard_error_entry ahd_hard_errors[] = {
      { DSCTMOUT, "Discard Timer has timed out" },
      { ILLOPCODE,      "Illegal Opcode in sequencer program" },
      { SQPARERR, "Sequencer Parity Error" },
      { DPARERR,  "Data-path Parity Error" },
      { MPARERR,  "Scratch or SCB Memory Parity Error" },
      { CIOPARERR,      "CIOBUS Parity Error" },
};
static const u_int num_errors = ARRAY_SIZE(ahd_hard_errors);

static struct ahd_phase_table_entry ahd_phase_table[] =
{
      { P_DATAOUT,      MSG_NOOP,         "in Data-out phase"     },
      { P_DATAIN, MSG_INITIATOR_DET_ERR,  "in Data-in phase"      },
      { P_DATAOUT_DT,   MSG_NOOP,         "in DT Data-out phase"  },
      { P_DATAIN_DT,    MSG_INITIATOR_DET_ERR,  "in DT Data-in phase"   },
      { P_COMMAND,      MSG_NOOP,         "in Command phase"      },
      { P_MESGOUT,      MSG_NOOP,         "in Message-out phase"  },
      { P_STATUS, MSG_INITIATOR_DET_ERR,  "in Status phase" },
      { P_MESGIN, MSG_PARITY_ERROR, "in Message-in phase"   },
      { P_BUSFREE,      MSG_NOOP,         "while idle"            },
      { 0,        MSG_NOOP,         "in unknown phase"      }
};

/*
 * In most cases we only wish to itterate over real phases, so
 * exclude the last element from the count.
 */
static const u_int num_phases = ARRAY_SIZE(ahd_phase_table) - 1;

/* Our Sequencer Program */
#include "aic79xx_seq.h"

/**************************** Function Declarations ***************************/
static void       ahd_handle_transmission_error(struct ahd_softc *ahd);
static void       ahd_handle_lqiphase_error(struct ahd_softc *ahd,
                                      u_int lqistat1);
static int        ahd_handle_pkt_busfree(struct ahd_softc *ahd,
                                     u_int busfreetime);
static int        ahd_handle_nonpkt_busfree(struct ahd_softc *ahd);
static void       ahd_handle_proto_violation(struct ahd_softc *ahd);
static void       ahd_force_renegotiation(struct ahd_softc *ahd,
                                    struct ahd_devinfo *devinfo);

static struct ahd_tmode_tstate*
                  ahd_alloc_tstate(struct ahd_softc *ahd,
                               u_int scsi_id, char channel);
#ifdef AHD_TARGET_MODE
static void       ahd_free_tstate(struct ahd_softc *ahd,
                              u_int scsi_id, char channel, int force);
#endif
static void       ahd_devlimited_syncrate(struct ahd_softc *ahd,
                                      struct ahd_initiator_tinfo *,
                                    u_int *period,
                                    u_int *ppr_options,
                                    role_t role);
static void       ahd_update_neg_table(struct ahd_softc *ahd,
                                   struct ahd_devinfo *devinfo,
                                   struct ahd_transinfo *tinfo);
static void       ahd_update_pending_scbs(struct ahd_softc *ahd);
static void       ahd_fetch_devinfo(struct ahd_softc *ahd,
                                struct ahd_devinfo *devinfo);
static void       ahd_scb_devinfo(struct ahd_softc *ahd,
                              struct ahd_devinfo *devinfo,
                              struct scb *scb);
static void       ahd_setup_initiator_msgout(struct ahd_softc *ahd,
                                       struct ahd_devinfo *devinfo,
                                       struct scb *scb);
static void       ahd_build_transfer_msg(struct ahd_softc *ahd,
                                     struct ahd_devinfo *devinfo);
static void       ahd_construct_sdtr(struct ahd_softc *ahd,
                                 struct ahd_devinfo *devinfo,
                                 u_int period, u_int offset);
static void       ahd_construct_wdtr(struct ahd_softc *ahd,
                                 struct ahd_devinfo *devinfo,
                                 u_int bus_width);
static void       ahd_construct_ppr(struct ahd_softc *ahd,
                                struct ahd_devinfo *devinfo,
                                u_int period, u_int offset,
                                u_int bus_width, u_int ppr_options);
static void       ahd_clear_msg_state(struct ahd_softc *ahd);
static void       ahd_handle_message_phase(struct ahd_softc *ahd);
typedef enum {
      AHDMSG_1B,
      AHDMSG_2B,
      AHDMSG_EXT
} ahd_msgtype;
static int        ahd_sent_msg(struct ahd_softc *ahd, ahd_msgtype type,
                             u_int msgval, int full);
static int        ahd_parse_msg(struct ahd_softc *ahd,
                              struct ahd_devinfo *devinfo);
static int        ahd_handle_msg_reject(struct ahd_softc *ahd,
                                    struct ahd_devinfo *devinfo);
static void       ahd_handle_ign_wide_residue(struct ahd_softc *ahd,
                                    struct ahd_devinfo *devinfo);
static void       ahd_reinitialize_dataptrs(struct ahd_softc *ahd);
static void       ahd_handle_devreset(struct ahd_softc *ahd,
                                  struct ahd_devinfo *devinfo,
                                  u_int lun, cam_status status,
                                  char *message, int verbose_level);
#ifdef AHD_TARGET_MODE
static void       ahd_setup_target_msgin(struct ahd_softc *ahd,
                                     struct ahd_devinfo *devinfo,
                                     struct scb *scb);
#endif

static u_int            ahd_sglist_size(struct ahd_softc *ahd);
static u_int            ahd_sglist_allocsize(struct ahd_softc *ahd);
static bus_dmamap_callback_t
                  ahd_dmamap_cb; 
static void       ahd_initialize_hscbs(struct ahd_softc *ahd);
static int        ahd_init_scbdata(struct ahd_softc *ahd);
static void       ahd_fini_scbdata(struct ahd_softc *ahd);
static void       ahd_setup_iocell_workaround(struct ahd_softc *ahd);
static void       ahd_iocell_first_selection(struct ahd_softc *ahd);
static void       ahd_add_col_list(struct ahd_softc *ahd,
                               struct scb *scb, u_int col_idx);
static void       ahd_rem_col_list(struct ahd_softc *ahd,
                               struct scb *scb);
static void       ahd_chip_init(struct ahd_softc *ahd);
static void       ahd_qinfifo_requeue(struct ahd_softc *ahd,
                                  struct scb *prev_scb,
                                  struct scb *scb);
static int        ahd_qinfifo_count(struct ahd_softc *ahd);
static int        ahd_search_scb_list(struct ahd_softc *ahd, int target,
                                  char channel, int lun, u_int tag,
                                  role_t role, uint32_t status,
                                  ahd_search_action action,
                                  u_int *list_head, u_int *list_tail,
                                  u_int tid);
static void       ahd_stitch_tid_list(struct ahd_softc *ahd,
                                  u_int tid_prev, u_int tid_cur,
                                  u_int tid_next);
static void       ahd_add_scb_to_free_list(struct ahd_softc *ahd,
                                     u_int scbid);
static u_int            ahd_rem_wscb(struct ahd_softc *ahd, u_int scbid,
                             u_int prev, u_int next, u_int tid);
static void       ahd_reset_current_bus(struct ahd_softc *ahd);
static ahd_callback_t   ahd_stat_timer;
#ifdef AHD_DUMP_SEQ
static void       ahd_dumpseq(struct ahd_softc *ahd);
#endif
static void       ahd_loadseq(struct ahd_softc *ahd);
static int        ahd_check_patch(struct ahd_softc *ahd,
                              struct patch **start_patch,
                              u_int start_instr, u_int *skip_addr);
static u_int            ahd_resolve_seqaddr(struct ahd_softc *ahd,
                                  u_int address);
static void       ahd_download_instr(struct ahd_softc *ahd,
                                 u_int instrptr, uint8_t *dconsts);
static int        ahd_probe_stack_size(struct ahd_softc *ahd);
static int        ahd_scb_active_in_fifo(struct ahd_softc *ahd,
                                     struct scb *scb);
static void       ahd_run_data_fifo(struct ahd_softc *ahd,
                                struct scb *scb);

#ifdef AHD_TARGET_MODE
static void       ahd_queue_lstate_event(struct ahd_softc *ahd,
                                     struct ahd_tmode_lstate *lstate,
                                     u_int initiator_id,
                                     u_int event_type,
                                     u_int event_arg);
static void       ahd_update_scsiid(struct ahd_softc *ahd,
                                u_int targid_mask);
static int        ahd_handle_target_cmd(struct ahd_softc *ahd,
                                    struct target_cmd *cmd);
#endif

/******************************** Private Inlines *****************************/
static __inline void    ahd_assert_atn(struct ahd_softc *ahd);
static __inline int     ahd_currently_packetized(struct ahd_softc *ahd);
static __inline int     ahd_set_active_fifo(struct ahd_softc *ahd);

static __inline void
ahd_assert_atn(struct ahd_softc *ahd)
{
      ahd_outb(ahd, SCSISIGO, ATNO);
}

/*
 * Determine if the current connection has a packetized
 * agreement.  This does not necessarily mean that we
 * are currently in a packetized transfer.  We could
 * just as easily be sending or receiving a message.
 */
static __inline int
ahd_currently_packetized(struct ahd_softc *ahd)
{
      ahd_mode_state     saved_modes;
      int          packetized;

      saved_modes = ahd_save_modes(ahd);
      if ((ahd->bugs & AHD_PKTIZED_STATUS_BUG) != 0) {
            /*
             * The packetized bit refers to the last
             * connection, not the current one.  Check
             * for non-zero LQISTATE instead.
             */
            ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
            packetized = ahd_inb(ahd, LQISTATE) != 0;
      } else {
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            packetized = ahd_inb(ahd, LQISTAT2) & PACKETIZED;
      }
      ahd_restore_modes(ahd, saved_modes);
      return (packetized);
}

static __inline int
ahd_set_active_fifo(struct ahd_softc *ahd)
{
      u_int active_fifo;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      active_fifo = ahd_inb(ahd, DFFSTAT) & CURRFIFO;
      switch (active_fifo) {
      case 0:
      case 1:
            ahd_set_modes(ahd, active_fifo, active_fifo);
            return (1);
      default:
            return (0);
      }
}

/************************* Sequencer Execution Control ************************/
/*
 * Restart the sequencer program from address zero
 */
void
ahd_restart(struct ahd_softc *ahd)
{

      ahd_pause(ahd);

      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      /* No more pending messages */
      ahd_clear_msg_state(ahd);
      ahd_outb(ahd, SCSISIGO, 0);         /* De-assert BSY */
      ahd_outb(ahd, MSG_OUT, MSG_NOOP);   /* No message to send */
      ahd_outb(ahd, SXFRCTL1, ahd_inb(ahd, SXFRCTL1) & ~BITBUCKET);
      ahd_outb(ahd, SEQINTCTL, 0);
      ahd_outb(ahd, LASTPHASE, P_BUSFREE);
      ahd_outb(ahd, SEQ_FLAGS, 0);
      ahd_outb(ahd, SAVED_SCSIID, 0xFF);
      ahd_outb(ahd, SAVED_LUN, 0xFF);

      /*
       * Ensure that the sequencer's idea of TQINPOS
       * matches our own.  The sequencer increments TQINPOS
       * only after it sees a DMA complete and a reset could
       * occur before the increment leaving the kernel to believe
       * the command arrived but the sequencer to not.
       */
      ahd_outb(ahd, TQINPOS, ahd->tqinfifonext);

      /* Always allow reselection */
      ahd_outb(ahd, SCSISEQ1,
             ahd_inb(ahd, SCSISEQ_TEMPLATE) & (ENSELI|ENRSELI|ENAUTOATNP));
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

      /*
       * Clear any pending sequencer interrupt.  It is no
       * longer relevant since we're resetting the Program
       * Counter.
       */
      ahd_outb(ahd, CLRINT, CLRSEQINT);

      ahd_outb(ahd, SEQCTL0, FASTMODE|SEQRESET);
      ahd_unpause(ahd);
}

void
ahd_clear_fifo(struct ahd_softc *ahd, u_int fifo)
{
      ahd_mode_state     saved_modes;

#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_FIFOS) != 0)
            printf("%s: Clearing FIFO %d\n", ahd_name(ahd), fifo);
#endif
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, fifo, fifo);
      ahd_outb(ahd, DFFSXFRCTL, RSTCHN|CLRSHCNT);
      if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0)
            ahd_outb(ahd, CCSGCTL, CCSGRESET);
      ahd_outb(ahd, LONGJMP_ADDR + 1, INVALID_ADDR);
      ahd_outb(ahd, SG_STATE, 0);
      ahd_restore_modes(ahd, saved_modes);
}

/************************* Input/Output Queues ********************************/
/*
 * Flush and completed commands that are sitting in the command
 * complete queues down on the chip but have yet to be dma'ed back up.
 */
void
ahd_flush_qoutfifo(struct ahd_softc *ahd)
{
      struct            scb *scb;
      ahd_mode_state    saved_modes;
      u_int       saved_scbptr;
      u_int       ccscbctl;
      u_int       scbid;
      u_int       next_scbid;

      saved_modes = ahd_save_modes(ahd);

      /*
       * Flush the good status FIFO for completed packetized commands.
       */
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      saved_scbptr = ahd_get_scbptr(ahd);
      while ((ahd_inb(ahd, LQISTAT2) & LQIGSAVAIL) != 0) {
            u_int fifo_mode;
            u_int i;
            
            scbid = ahd_inw(ahd, GSFIFO);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: Warning - GSFIFO SCB %d invalid\n",
                         ahd_name(ahd), scbid);
                  continue;
            }
            /*
             * Determine if this transaction is still active in
             * any FIFO.  If it is, we must flush that FIFO to
             * the host before completing the  command.
             */
            fifo_mode = 0;
rescan_fifos:
            for (i = 0; i < 2; i++) {
                  /* Toggle to the other mode. */
                  fifo_mode ^= 1;
                  ahd_set_modes(ahd, fifo_mode, fifo_mode);

                  if (ahd_scb_active_in_fifo(ahd, scb) == 0)
                        continue;

                  ahd_run_data_fifo(ahd, scb);

                  /*
                   * Running this FIFO may cause a CFG4DATA for
                   * this same transaction to assert in the other
                   * FIFO or a new snapshot SAVEPTRS interrupt
                   * in this FIFO.  Even running a FIFO may not
                   * clear the transaction if we are still waiting
                   * for data to drain to the host. We must loop
                   * until the transaction is not active in either
                   * FIFO just to be sure.  Reset our loop counter
                   * so we will visit both FIFOs again before
                   * declaring this transaction finished.  We
                   * also delay a bit so that status has a chance
                   * to change before we look at this FIFO again.
                   */
                  ahd_delay(200);
                  goto rescan_fifos;
            }
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            ahd_set_scbptr(ahd, scbid);
            if ((ahd_inb_scbram(ahd, SCB_SGPTR) & SG_LIST_NULL) == 0
             && ((ahd_inb_scbram(ahd, SCB_SGPTR) & SG_FULL_RESID) != 0
              || (ahd_inb_scbram(ahd, SCB_RESIDUAL_SGPTR)
                  & SG_LIST_NULL) != 0)) {
                  u_int comp_head;

                  /*
                   * The transfer completed with a residual.
                   * Place this SCB on the complete DMA list
                   * so that we update our in-core copy of the
                   * SCB before completing the command.
                   */
                  ahd_outb(ahd, SCB_SCSI_STATUS, 0);
                  ahd_outb(ahd, SCB_SGPTR,
                         ahd_inb_scbram(ahd, SCB_SGPTR)
                         | SG_STATUS_VALID);
                  ahd_outw(ahd, SCB_TAG, scbid);
                  ahd_outw(ahd, SCB_NEXT_COMPLETE, SCB_LIST_NULL);
                  comp_head = ahd_inw(ahd, COMPLETE_DMA_SCB_HEAD);
                  if (SCBID_IS_NULL(comp_head)) {
                        ahd_outw(ahd, COMPLETE_DMA_SCB_HEAD, scbid);
                        ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, scbid);
                  } else {
                        u_int tail;

                        tail = ahd_inw(ahd, COMPLETE_DMA_SCB_TAIL);
                        ahd_set_scbptr(ahd, tail);
                        ahd_outw(ahd, SCB_NEXT_COMPLETE, scbid);
                        ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, scbid);
                        ahd_set_scbptr(ahd, scbid);
                  }
            } else
                  ahd_complete_scb(ahd, scb);
      }
      ahd_set_scbptr(ahd, saved_scbptr);

      /*
       * Setup for command channel portion of flush.
       */
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

      /*
       * Wait for any inprogress DMA to complete and clear DMA state
       * if this if for an SCB in the qinfifo.
       */
      while (((ccscbctl = ahd_inb(ahd, CCSCBCTL)) & (CCARREN|CCSCBEN)) != 0) {

            if ((ccscbctl & (CCSCBDIR|CCARREN)) == (CCSCBDIR|CCARREN)) {
                  if ((ccscbctl & ARRDONE) != 0)
                        break;
            } else if ((ccscbctl & CCSCBDONE) != 0)
                  break;
            ahd_delay(200);
      }
      /*
       * We leave the sequencer to cleanup in the case of DMA's to
       * update the qoutfifo.  In all other cases (DMA's to the
       * chip or a push of an SCB from the COMPLETE_DMA_SCB list),
       * we disable the DMA engine so that the sequencer will not
       * attempt to handle the DMA completion.
       */
      if ((ccscbctl & CCSCBDIR) != 0 || (ccscbctl & ARRDONE) != 0)
            ahd_outb(ahd, CCSCBCTL, ccscbctl & ~(CCARREN|CCSCBEN));

      /*
       * Complete any SCBs that just finished
       * being DMA'ed into the qoutfifo.
       */
      ahd_run_qoutfifo(ahd);

      saved_scbptr = ahd_get_scbptr(ahd);
      /*
       * Manually update/complete any completed SCBs that are waiting to be
       * DMA'ed back up to the host.
       */
      scbid = ahd_inw(ahd, COMPLETE_DMA_SCB_HEAD);
      while (!SCBID_IS_NULL(scbid)) {
            uint8_t *hscb_ptr;
            u_int  i;
            
            ahd_set_scbptr(ahd, scbid);
            next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: Warning - DMA-up and complete "
                         "SCB %d invalid\n", ahd_name(ahd), scbid);
                  continue;
            }
            hscb_ptr = (uint8_t *)scb->hscb;
            for (i = 0; i < sizeof(struct hardware_scb); i++)
                  *hscb_ptr++ = ahd_inb_scbram(ahd, SCB_BASE + i);

            ahd_complete_scb(ahd, scb);
            scbid = next_scbid;
      }
      ahd_outw(ahd, COMPLETE_DMA_SCB_HEAD, SCB_LIST_NULL);
      ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, SCB_LIST_NULL);

      scbid = ahd_inw(ahd, COMPLETE_ON_QFREEZE_HEAD);
      while (!SCBID_IS_NULL(scbid)) {

            ahd_set_scbptr(ahd, scbid);
            next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: Warning - Complete Qfrz SCB %d invalid\n",
                         ahd_name(ahd), scbid);
                  continue;
            }

            ahd_complete_scb(ahd, scb);
            scbid = next_scbid;
      }
      ahd_outw(ahd, COMPLETE_ON_QFREEZE_HEAD, SCB_LIST_NULL);

      scbid = ahd_inw(ahd, COMPLETE_SCB_HEAD);
      while (!SCBID_IS_NULL(scbid)) {

            ahd_set_scbptr(ahd, scbid);
            next_scbid = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: Warning - Complete SCB %d invalid\n",
                         ahd_name(ahd), scbid);
                  continue;
            }

            ahd_complete_scb(ahd, scb);
            scbid = next_scbid;
      }
      ahd_outw(ahd, COMPLETE_SCB_HEAD, SCB_LIST_NULL);

      /*
       * Restore state.
       */
      ahd_set_scbptr(ahd, saved_scbptr);
      ahd_restore_modes(ahd, saved_modes);
      ahd->flags |= AHD_UPDATE_PEND_CMDS;
}

/*
 * Determine if an SCB for a packetized transaction
 * is active in a FIFO.
 */
static int
ahd_scb_active_in_fifo(struct ahd_softc *ahd, struct scb *scb)
{

      /*
       * The FIFO is only active for our transaction if
       * the SCBPTR matches the SCB's ID and the firmware
       * has installed a handler for the FIFO or we have
       * a pending SAVEPTRS or CFG4DATA interrupt.
       */
      if (ahd_get_scbptr(ahd) != SCB_GET_TAG(scb)
       || ((ahd_inb(ahd, LONGJMP_ADDR+1) & INVALID_ADDR) != 0
        && (ahd_inb(ahd, SEQINTSRC) & (CFG4DATA|SAVEPTRS)) == 0))
            return (0);

      return (1);
}

/*
 * Run a data fifo to completion for a transaction we know
 * has completed across the SCSI bus (good status has been
 * received).  We are already set to the correct FIFO mode
 * on entry to this routine.
 *
 * This function attempts to operate exactly as the firmware
 * would when running this FIFO.  Care must be taken to update
 * this routine any time the firmware's FIFO algorithm is
 * changed.
 */
static void
ahd_run_data_fifo(struct ahd_softc *ahd, struct scb *scb)
{
      u_int seqintsrc;

      seqintsrc = ahd_inb(ahd, SEQINTSRC);
      if ((seqintsrc & CFG4DATA) != 0) {
            uint32_t datacnt;
            uint32_t sgptr;

            /*
             * Clear full residual flag.
             */
            sgptr = ahd_inl_scbram(ahd, SCB_SGPTR) & ~SG_FULL_RESID;
            ahd_outb(ahd, SCB_SGPTR, sgptr);

            /*
             * Load datacnt and address.
             */
            datacnt = ahd_inl_scbram(ahd, SCB_DATACNT);
            if ((datacnt & AHD_DMA_LAST_SEG) != 0) {
                  sgptr |= LAST_SEG;
                  ahd_outb(ahd, SG_STATE, 0);
            } else
                  ahd_outb(ahd, SG_STATE, LOADING_NEEDED);
            ahd_outq(ahd, HADDR, ahd_inq_scbram(ahd, SCB_DATAPTR));
            ahd_outl(ahd, HCNT, datacnt & AHD_SG_LEN_MASK);
            ahd_outb(ahd, SG_CACHE_PRE, sgptr);
            ahd_outb(ahd, DFCNTRL, PRELOADEN|SCSIEN|HDMAEN);

            /*
             * Initialize Residual Fields.
             */
            ahd_outb(ahd, SCB_RESIDUAL_DATACNT+3, datacnt >> 24);
            ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr & SG_PTR_MASK);

            /*
             * Mark the SCB as having a FIFO in use.
             */
            ahd_outb(ahd, SCB_FIFO_USE_COUNT,
                   ahd_inb_scbram(ahd, SCB_FIFO_USE_COUNT) + 1);

            /*
             * Install a "fake" handler for this FIFO.
             */
            ahd_outw(ahd, LONGJMP_ADDR, 0);

            /*
             * Notify the hardware that we have satisfied
             * this sequencer interrupt.
             */
            ahd_outb(ahd, CLRSEQINTSRC, CLRCFG4DATA);
      } else if ((seqintsrc & SAVEPTRS) != 0) {
            uint32_t sgptr;
            uint32_t resid;

            if ((ahd_inb(ahd, LONGJMP_ADDR+1)&INVALID_ADDR) != 0) {
                  /*
                   * Snapshot Save Pointers.  All that
                   * is necessary to clear the snapshot
                   * is a CLRCHN.
                   */
                  goto clrchn;
            }

            /*
             * Disable S/G fetch so the DMA engine
             * is available to future users.
             */
            if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0)
                  ahd_outb(ahd, CCSGCTL, 0);
            ahd_outb(ahd, SG_STATE, 0);

            /*
             * Flush the data FIFO.  Strickly only
             * necessary for Rev A parts.
             */
            ahd_outb(ahd, DFCNTRL, ahd_inb(ahd, DFCNTRL) | FIFOFLUSH);

            /*
             * Calculate residual.
             */
            sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
            resid = ahd_inl(ahd, SHCNT);
            resid |= ahd_inb_scbram(ahd, SCB_RESIDUAL_DATACNT+3) << 24;
            ahd_outl(ahd, SCB_RESIDUAL_DATACNT, resid);
            if ((ahd_inb(ahd, SG_CACHE_SHADOW) & LAST_SEG) == 0) {
                  /*
                   * Must back up to the correct S/G element.
                   * Typically this just means resetting our
                   * low byte to the offset in the SG_CACHE,
                   * but if we wrapped, we have to correct
                   * the other bytes of the sgptr too.
                   */
                  if ((ahd_inb(ahd, SG_CACHE_SHADOW) & 0x80) != 0
                   && (sgptr & 0x80) == 0)
                        sgptr -= 0x100;
                  sgptr &= ~0xFF;
                  sgptr |= ahd_inb(ahd, SG_CACHE_SHADOW)
                         & SG_ADDR_MASK;
                  ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr);
                  ahd_outb(ahd, SCB_RESIDUAL_DATACNT + 3, 0);
            } else if ((resid & AHD_SG_LEN_MASK) == 0) {
                  ahd_outb(ahd, SCB_RESIDUAL_SGPTR,
                         sgptr | SG_LIST_NULL);
            }
            /*
             * Save Pointers.
             */
            ahd_outq(ahd, SCB_DATAPTR, ahd_inq(ahd, SHADDR));
            ahd_outl(ahd, SCB_DATACNT, resid);
            ahd_outl(ahd, SCB_SGPTR, sgptr);
            ahd_outb(ahd, CLRSEQINTSRC, CLRSAVEPTRS);
            ahd_outb(ahd, SEQIMODE,
                   ahd_inb(ahd, SEQIMODE) | ENSAVEPTRS);
            /*
             * If the data is to the SCSI bus, we are
             * done, otherwise wait for FIFOEMP.
             */
            if ((ahd_inb(ahd, DFCNTRL) & DIRECTION) != 0)
                  goto clrchn;
      } else if ((ahd_inb(ahd, SG_STATE) & LOADING_NEEDED) != 0) {
            uint32_t sgptr;
            uint64_t data_addr;
            uint32_t data_len;
            u_int  dfcntrl;

            /*
             * Disable S/G fetch so the DMA engine
             * is available to future users.  We won't
             * be using the DMA engine to load segments.
             */
            if ((ahd_inb(ahd, SG_STATE) & FETCH_INPROG) != 0) {
                  ahd_outb(ahd, CCSGCTL, 0);
                  ahd_outb(ahd, SG_STATE, LOADING_NEEDED);
            }

            /*
             * Wait for the DMA engine to notice that the
             * host transfer is enabled and that there is
             * space in the S/G FIFO for new segments before
             * loading more segments.
             */
            if ((ahd_inb(ahd, DFSTATUS) & PRELOAD_AVAIL) != 0
             && (ahd_inb(ahd, DFCNTRL) & HDMAENACK) != 0) {

                  /*
                   * Determine the offset of the next S/G
                   * element to load.
                   */
                  sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
                  sgptr &= SG_PTR_MASK;
                  if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
                        struct ahd_dma64_seg *sg;

                        sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);
                        data_addr = sg->addr;
                        data_len = sg->len;
                        sgptr += sizeof(*sg);
                  } else {
                        struct      ahd_dma_seg *sg;

                        sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);
                        data_addr = sg->len & AHD_SG_HIGH_ADDR_MASK;
                        data_addr <<= 8;
                        data_addr |= sg->addr;
                        data_len = sg->len;
                        sgptr += sizeof(*sg);
                  }

                  /*
                   * Update residual information.
                   */
                  ahd_outb(ahd, SCB_RESIDUAL_DATACNT+3, data_len >> 24);
                  ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr);

                  /*
                   * Load the S/G.
                   */
                  if (data_len & AHD_DMA_LAST_SEG) {
                        sgptr |= LAST_SEG;
                        ahd_outb(ahd, SG_STATE, 0);
                  }
                  ahd_outq(ahd, HADDR, data_addr);
                  ahd_outl(ahd, HCNT, data_len & AHD_SG_LEN_MASK);
                  ahd_outb(ahd, SG_CACHE_PRE, sgptr & 0xFF);

                  /*
                   * Advertise the segment to the hardware.
                   */
                  dfcntrl = ahd_inb(ahd, DFCNTRL)|PRELOADEN|HDMAEN;
                  if ((ahd->features & AHD_NEW_DFCNTRL_OPTS) != 0) {
                        /*
                         * Use SCSIENWRDIS so that SCSIEN
                         * is never modified by this
                         * operation.
                         */
                        dfcntrl |= SCSIENWRDIS;
                  }
                  ahd_outb(ahd, DFCNTRL, dfcntrl);
            }
      } else if ((ahd_inb(ahd, SG_CACHE_SHADOW) & LAST_SEG_DONE) != 0) {

            /*
             * Transfer completed to the end of SG list
             * and has flushed to the host.
             */
            ahd_outb(ahd, SCB_SGPTR,
                   ahd_inb_scbram(ahd, SCB_SGPTR) | SG_LIST_NULL);
            goto clrchn;
      } else if ((ahd_inb(ahd, DFSTATUS) & FIFOEMP) != 0) {
clrchn:
            /*
             * Clear any handler for this FIFO, decrement
             * the FIFO use count for the SCB, and release
             * the FIFO.
             */
            ahd_outb(ahd, LONGJMP_ADDR + 1, INVALID_ADDR);
            ahd_outb(ahd, SCB_FIFO_USE_COUNT,
                   ahd_inb_scbram(ahd, SCB_FIFO_USE_COUNT) - 1);
            ahd_outb(ahd, DFFSXFRCTL, CLRCHN);
      }
}

/*
 * Look for entries in the QoutFIFO that have completed.
 * The valid_tag completion field indicates the validity
 * of the entry - the valid value toggles each time through
 * the queue. We use the sg_status field in the completion
 * entry to avoid referencing the hscb if the completion
 * occurred with no errors and no residual.  sg_status is
 * a copy of the first byte (little endian) of the sgptr
 * hscb field.
 */
void
ahd_run_qoutfifo(struct ahd_softc *ahd)
{
      struct ahd_completion *completion;
      struct scb *scb;
      u_int  scb_index;

      if ((ahd->flags & AHD_RUNNING_QOUTFIFO) != 0)
            panic("ahd_run_qoutfifo recursion");
      ahd->flags |= AHD_RUNNING_QOUTFIFO;
      ahd_sync_qoutfifo(ahd, BUS_DMASYNC_POSTREAD);
      for (;;) {
            completion = &ahd->qoutfifo[ahd->qoutfifonext];

            if (completion->valid_tag != ahd->qoutfifonext_valid_tag)
                  break;

            scb_index = ahd_le16toh(completion->tag);
            scb = ahd_lookup_scb(ahd, scb_index);
            if (scb == NULL) {
                  printf("%s: WARNING no command for scb %d "
                         "(cmdcmplt)\nQOUTPOS = %d\n",
                         ahd_name(ahd), scb_index,
                         ahd->qoutfifonext);
                  ahd_dump_card_state(ahd);
            } else if ((completion->sg_status & SG_STATUS_VALID) != 0) {
                  ahd_handle_scb_status(ahd, scb);
            } else {
                  ahd_done(ahd, scb);
            }

            ahd->qoutfifonext = (ahd->qoutfifonext+1) & (AHD_QOUT_SIZE-1);
            if (ahd->qoutfifonext == 0)
                  ahd->qoutfifonext_valid_tag ^= QOUTFIFO_ENTRY_VALID;
      }
      ahd->flags &= ~AHD_RUNNING_QOUTFIFO;
}

/************************* Interrupt Handling *********************************/
void
ahd_handle_hwerrint(struct ahd_softc *ahd)
{
      /*
       * Some catastrophic hardware error has occurred.
       * Print it for the user and disable the controller.
       */
      int i;
      int error;

      error = ahd_inb(ahd, ERROR);
      for (i = 0; i < num_errors; i++) {
            if ((error & ahd_hard_errors[i].errno) != 0)
                  printf("%s: hwerrint, %s\n",
                         ahd_name(ahd), ahd_hard_errors[i].errmesg);
      }

      ahd_dump_card_state(ahd);
      panic("BRKADRINT");

      /* Tell everyone that this HBA is no longer available */
      ahd_abort_scbs(ahd, CAM_TARGET_WILDCARD, ALL_CHANNELS,
                   CAM_LUN_WILDCARD, SCB_LIST_NULL, ROLE_UNKNOWN,
                   CAM_NO_HBA);

      /* Tell the system that this controller has gone away. */
      ahd_free(ahd);
}

void
ahd_handle_seqint(struct ahd_softc *ahd, u_int intstat)
{
      u_int seqintcode;

      /*
       * Save the sequencer interrupt code and clear the SEQINT
       * bit. We will unpause the sequencer, if appropriate,
       * after servicing the request.
       */
      seqintcode = ahd_inb(ahd, SEQINTCODE);
      ahd_outb(ahd, CLRINT, CLRSEQINT);
      if ((ahd->bugs & AHD_INTCOLLISION_BUG) != 0) {
            /*
             * Unpause the sequencer and let it clear
             * SEQINT by writing NO_SEQINT to it.  This
             * will cause the sequencer to be paused again,
             * which is the expected state of this routine.
             */
            ahd_unpause(ahd);
            while (!ahd_is_paused(ahd))
                  ;
            ahd_outb(ahd, CLRINT, CLRSEQINT);
      }
      ahd_update_modes(ahd);
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MISC) != 0)
            printf("%s: Handle Seqint Called for code %d\n",
                   ahd_name(ahd), seqintcode);
#endif
      switch (seqintcode) {
      case ENTERING_NONPACK:
      {
            struct      scb *scb;
            u_int scbid;

            AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                         ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  /*
                   * Somehow need to know if this
                   * is from a selection or reselection.
                   * From that, we can determine target
                   * ID so we at least have an I_T nexus.
                   */
            } else {
                  ahd_outb(ahd, SAVED_SCSIID, scb->hscb->scsiid);
                  ahd_outb(ahd, SAVED_LUN, scb->hscb->lun);
                  ahd_outb(ahd, SEQ_FLAGS, 0x0);
            }
            if ((ahd_inb(ahd, LQISTAT2) & LQIPHASE_OUTPKT) != 0
             && (ahd_inb(ahd, SCSISIGO) & ATNO) != 0) {
                  /*
                   * Phase change after read stream with
                   * CRC error with P0 asserted on last
                   * packet.
                   */
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                        printf("%s: Assuming LQIPHASE_NLQ with "
                               "P0 assertion\n", ahd_name(ahd));
#endif
            }
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                  printf("%s: Entering NONPACK\n", ahd_name(ahd));
#endif
            break;
      }
      case INVALID_SEQINT:
            printf("%s: Invalid Sequencer interrupt occurred, "
                   "resetting channel.\n",
                   ahd_name(ahd));
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_RECOVERY) != 0)
                  ahd_dump_card_state(ahd);
#endif
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
            break;
      case STATUS_OVERRUN:
      {
            struct      scb *scb;
            u_int scbid;

            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb != NULL)
                  ahd_print_path(ahd, scb);
            else
                  printf("%s: ", ahd_name(ahd));
            printf("SCB %d Packetized Status Overrun", scbid);
            ahd_dump_card_state(ahd);
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
            break;
      }
      case CFG4ISTAT_INTR:
      {
            struct      scb *scb;
            u_int scbid;

            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  ahd_dump_card_state(ahd);
                  printf("CFG4ISTAT: Free SCB %d referenced", scbid);
                  panic("For safety");
            }
            ahd_outq(ahd, HADDR, scb->sense_busaddr);
            ahd_outw(ahd, HCNT, AHD_SENSE_BUFSIZE);
            ahd_outb(ahd, HCNT + 2, 0);
            ahd_outb(ahd, SG_CACHE_PRE, SG_LAST_SEG);
            ahd_outb(ahd, DFCNTRL, PRELOADEN|SCSIEN|HDMAEN);
            break;
      }
      case ILLEGAL_PHASE:
      {
            u_int bus_phase;

            bus_phase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
            printf("%s: ILLEGAL_PHASE 0x%x\n",
                   ahd_name(ahd), bus_phase);

            switch (bus_phase) {
            case P_DATAOUT:
            case P_DATAIN:
            case P_DATAOUT_DT:
            case P_DATAIN_DT:
            case P_MESGOUT:
            case P_STATUS:
            case P_MESGIN:
                  ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                  printf("%s: Issued Bus Reset.\n", ahd_name(ahd));
                  break;
            case P_COMMAND:
            {
                  struct      ahd_devinfo devinfo;
                  struct      scb *scb;
                  struct      ahd_initiator_tinfo *targ_info;
                  struct      ahd_tmode_tstate *tstate;
                  struct      ahd_transinfo *tinfo;
                  u_int scbid;

                  /*
                   * If a target takes us into the command phase
                   * assume that it has been externally reset and
                   * has thus lost our previous packetized negotiation
                   * agreement.
                   * Revert to async/narrow transfers until we
                   * can renegotiate with the device and notify
                   * the OSM about the reset.
                   */
                  scbid = ahd_get_scbptr(ahd);
                  scb = ahd_lookup_scb(ahd, scbid);
                  if (scb == NULL) {
                        printf("Invalid phase with no valid SCB.  "
                               "Resetting bus.\n");
                        ahd_reset_channel(ahd, 'A',
                                      /*Initiate Reset*/TRUE);
                        break;
                  }
                  ahd_compile_devinfo(&devinfo, SCB_GET_OUR_ID(scb),
                                  SCB_GET_TARGET(ahd, scb),
                                  SCB_GET_LUN(scb),
                                  SCB_GET_CHANNEL(ahd, scb),
                                  ROLE_INITIATOR);
                  targ_info = ahd_fetch_transinfo(ahd,
                                          devinfo.channel,
                                          devinfo.our_scsiid,
                                          devinfo.target,
                                          &tstate);
                  tinfo = &targ_info->curr;
                  ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                              AHD_TRANS_ACTIVE, /*paused*/TRUE);
                  ahd_set_syncrate(ahd, &devinfo, /*period*/0,
                               /*offset*/0, /*ppr_options*/0,
                               AHD_TRANS_ACTIVE, /*paused*/TRUE);
                  scb->flags |= SCB_EXTERNAL_RESET;
                  ahd_freeze_devq(ahd, scb);
                  ahd_set_transaction_status(scb, CAM_REQUEUE_REQ);
                  ahd_freeze_scb(scb);

                  /* Notify XPT */
                  ahd_send_async(ahd, devinfo.channel, devinfo.target,
                               CAM_LUN_WILDCARD, AC_SENT_BDR);

                  /*
                   * Allow the sequencer to continue with
                   * non-pack processing.
                   */
                  ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                  ahd_outb(ahd, CLRLQOINT1, CLRLQOPHACHGINPKT);
                  if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0) {
                        ahd_outb(ahd, CLRLQOINT1, 0);
                  }
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                        ahd_print_path(ahd, scb);
                        printf("Unexpected command phase from "
                               "packetized target\n");
                  }
#endif
                  break;
            }
            }
            break;
      }
      case CFG4OVERRUN:
      {
            struct      scb *scb;
            u_int scb_index;
            
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                  printf("%s: CFG4OVERRUN mode = %x\n", ahd_name(ahd),
                         ahd_inb(ahd, MODE_PTR));
            }
#endif
            scb_index = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scb_index);
            if (scb == NULL) {
                  /*
                   * Attempt to transfer to an SCB that is
                   * not outstanding.
                   */
                  ahd_assert_atn(ahd);
                  ahd_outb(ahd, MSG_OUT, HOST_MSG);
                  ahd->msgout_buf[0] = MSG_ABORT_TASK;
                  ahd->msgout_len = 1;
                  ahd->msgout_index = 0;
                  ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                  /*
                   * Clear status received flag to prevent any
                   * attempt to complete this bogus SCB.
                   */
                  ahd_outb(ahd, SCB_CONTROL,
                         ahd_inb_scbram(ahd, SCB_CONTROL)
                         & ~STATUS_RCVD);
            }
            break;
      }
      case DUMP_CARD_STATE:
      {
            ahd_dump_card_state(ahd);
            break;
      }
      case PDATA_REINIT:
      {
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                  printf("%s: PDATA_REINIT - DFCNTRL = 0x%x "
                         "SG_CACHE_SHADOW = 0x%x\n",
                         ahd_name(ahd), ahd_inb(ahd, DFCNTRL),
                         ahd_inb(ahd, SG_CACHE_SHADOW));
            }
#endif
            ahd_reinitialize_dataptrs(ahd);
            break;
      }
      case HOST_MSG_LOOP:
      {
            struct ahd_devinfo devinfo;

            /*
             * The sequencer has encountered a message phase
             * that requires host assistance for completion.
             * While handling the message phase(s), we will be
             * notified by the sequencer after each byte is
             * transfered so we can track bus phase changes.
             *
             * If this is the first time we've seen a HOST_MSG_LOOP
             * interrupt, initialize the state of the host message
             * loop.
             */
            ahd_fetch_devinfo(ahd, &devinfo);
            if (ahd->msg_type == MSG_TYPE_NONE) {
                  struct scb *scb;
                  u_int scb_index;
                  u_int bus_phase;

                  bus_phase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
                  if (bus_phase != P_MESGIN
                   && bus_phase != P_MESGOUT) {
                        printf("ahd_intr: HOST_MSG_LOOP bad "
                               "phase 0x%x\n", bus_phase);
                        /*
                         * Probably transitioned to bus free before
                         * we got here.  Just punt the message.
                         */
                        ahd_dump_card_state(ahd);
                        ahd_clear_intstat(ahd);
                        ahd_restart(ahd);
                        return;
                  }

                  scb_index = ahd_get_scbptr(ahd);
                  scb = ahd_lookup_scb(ahd, scb_index);
                  if (devinfo.role == ROLE_INITIATOR) {
                        if (bus_phase == P_MESGOUT)
                              ahd_setup_initiator_msgout(ahd,
                                                   &devinfo,
                                                   scb);
                        else {
                              ahd->msg_type =
                                  MSG_TYPE_INITIATOR_MSGIN;
                              ahd->msgin_index = 0;
                        }
                  }
#ifdef AHD_TARGET_MODE
                  else {
                        if (bus_phase == P_MESGOUT) {
                              ahd->msg_type =
                                  MSG_TYPE_TARGET_MSGOUT;
                              ahd->msgin_index = 0;
                        }
                        else 
                              ahd_setup_target_msgin(ahd,
                                                 &devinfo,
                                                 scb);
                  }
#endif
            }

            ahd_handle_message_phase(ahd);
            break;
      }
      case NO_MATCH:
      {
            /* Ensure we don't leave the selection hardware on */
            AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
            ahd_outb(ahd, SCSISEQ0, ahd_inb(ahd, SCSISEQ0) & ~ENSELO);

            printf("%s:%c:%d: no active SCB for reconnecting "
                   "target - issuing BUS DEVICE RESET\n",
                   ahd_name(ahd), 'A', ahd_inb(ahd, SELID) >> 4);
            printf("SAVED_SCSIID == 0x%x, SAVED_LUN == 0x%x, "
                   "REG0 == 0x%x ACCUM = 0x%x\n",
                   ahd_inb(ahd, SAVED_SCSIID), ahd_inb(ahd, SAVED_LUN),
                   ahd_inw(ahd, REG0), ahd_inb(ahd, ACCUM));
            printf("SEQ_FLAGS == 0x%x, SCBPTR == 0x%x, BTT == 0x%x, "
                   "SINDEX == 0x%x\n",
                   ahd_inb(ahd, SEQ_FLAGS), ahd_get_scbptr(ahd),
                   ahd_find_busy_tcl(ahd,
                               BUILD_TCL(ahd_inb(ahd, SAVED_SCSIID),
                                       ahd_inb(ahd, SAVED_LUN))),
                   ahd_inw(ahd, SINDEX));
            printf("SELID == 0x%x, SCB_SCSIID == 0x%x, SCB_LUN == 0x%x, "
                   "SCB_CONTROL == 0x%x\n",
                   ahd_inb(ahd, SELID), ahd_inb_scbram(ahd, SCB_SCSIID),
                   ahd_inb_scbram(ahd, SCB_LUN),
                   ahd_inb_scbram(ahd, SCB_CONTROL));
            printf("SCSIBUS[0] == 0x%x, SCSISIGI == 0x%x\n",
                   ahd_inb(ahd, SCSIBUS), ahd_inb(ahd, SCSISIGI));
            printf("SXFRCTL0 == 0x%x\n", ahd_inb(ahd, SXFRCTL0));
            printf("SEQCTL0 == 0x%x\n", ahd_inb(ahd, SEQCTL0));
            ahd_dump_card_state(ahd);
            ahd->msgout_buf[0] = MSG_BUS_DEV_RESET;
            ahd->msgout_len = 1;
            ahd->msgout_index = 0;
            ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
            ahd_outb(ahd, MSG_OUT, HOST_MSG);
            ahd_assert_atn(ahd);
            break;
      }
      case PROTO_VIOLATION:
      {
            ahd_handle_proto_violation(ahd);
            break;
      }
      case IGN_WIDE_RES:
      {
            struct ahd_devinfo devinfo;

            ahd_fetch_devinfo(ahd, &devinfo);
            ahd_handle_ign_wide_residue(ahd, &devinfo);
            break;
      }
      case BAD_PHASE:
      {
            u_int lastphase;

            lastphase = ahd_inb(ahd, LASTPHASE);
            printf("%s:%c:%d: unknown scsi bus phase %x, "
                   "lastphase = 0x%x.  Attempting to continue\n",
                   ahd_name(ahd), 'A',
                   SCSIID_TARGET(ahd, ahd_inb(ahd, SAVED_SCSIID)),
                   lastphase, ahd_inb(ahd, SCSISIGI));
            break;
      }
      case MISSED_BUSFREE:
      {
            u_int lastphase;

            lastphase = ahd_inb(ahd, LASTPHASE);
            printf("%s:%c:%d: Missed busfree. "
                   "Lastphase = 0x%x, Curphase = 0x%x\n",
                   ahd_name(ahd), 'A',
                   SCSIID_TARGET(ahd, ahd_inb(ahd, SAVED_SCSIID)),
                   lastphase, ahd_inb(ahd, SCSISIGI));
            ahd_restart(ahd);
            return;
      }
      case DATA_OVERRUN:
      {
            /*
             * When the sequencer detects an overrun, it
             * places the controller in "BITBUCKET" mode
             * and allows the target to complete its transfer.
             * Unfortunately, none of the counters get updated
             * when the controller is in this mode, so we have
             * no way of knowing how large the overrun was.
             */
            struct      scb *scb;
            u_int scbindex;
#ifdef AHD_DEBUG
            u_int lastphase;
#endif

            scbindex = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbindex);
#ifdef AHD_DEBUG
            lastphase = ahd_inb(ahd, LASTPHASE);
            if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                  ahd_print_path(ahd, scb);
                  printf("data overrun detected %s.  Tag == 0x%x.\n",
                         ahd_lookup_phase_entry(lastphase)->phasemsg,
                         SCB_GET_TAG(scb));
                  ahd_print_path(ahd, scb);
                  printf("%s seen Data Phase.  Length = %ld.  "
                         "NumSGs = %d.\n",
                         ahd_inb(ahd, SEQ_FLAGS) & DPHASE
                         ? "Have" : "Haven't",
                         ahd_get_transfer_length(scb), scb->sg_count);
                  ahd_dump_sglist(scb);
            }
#endif

            /*
             * Set this and it will take effect when the
             * target does a command complete.
             */
            ahd_freeze_devq(ahd, scb);
            ahd_set_transaction_status(scb, CAM_DATA_RUN_ERR);
            ahd_freeze_scb(scb);
            break;
      }
      case MKMSG_FAILED:
      {
            struct ahd_devinfo devinfo;
            struct scb *scb;
            u_int scbid;

            ahd_fetch_devinfo(ahd, &devinfo);
            printf("%s:%c:%d:%d: Attempt to issue message failed\n",
                   ahd_name(ahd), devinfo.channel, devinfo.target,
                   devinfo.lun);
            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb != NULL
             && (scb->flags & SCB_RECOVERY_SCB) != 0)
                  /*
                   * Ensure that we didn't put a second instance of this
                   * SCB into the QINFIFO.
                   */
                  ahd_search_qinfifo(ahd, SCB_GET_TARGET(ahd, scb),
                                 SCB_GET_CHANNEL(ahd, scb),
                                 SCB_GET_LUN(scb), SCB_GET_TAG(scb),
                                 ROLE_INITIATOR, /*status*/0,
                                 SEARCH_REMOVE);
            ahd_outb(ahd, SCB_CONTROL,
                   ahd_inb_scbram(ahd, SCB_CONTROL) & ~MK_MESSAGE);
            break;
      }
      case TASKMGMT_FUNC_COMPLETE:
      {
            u_int scbid;
            struct      scb *scb;

            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb != NULL) {
                  u_int    lun;
                  u_int    tag;
                  cam_status error;

                  ahd_print_path(ahd, scb);
                  printf("Task Management Func 0x%x Complete\n",
                         scb->hscb->task_management);
                  lun = CAM_LUN_WILDCARD;
                  tag = SCB_LIST_NULL;

                  switch (scb->hscb->task_management) {
                  case SIU_TASKMGMT_ABORT_TASK:
                        tag = SCB_GET_TAG(scb);
                  case SIU_TASKMGMT_ABORT_TASK_SET:
                  case SIU_TASKMGMT_CLEAR_TASK_SET:
                        lun = scb->hscb->lun;
                        error = CAM_REQ_ABORTED;
                        ahd_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb),
                                     'A', lun, tag, ROLE_INITIATOR,
                                     error);
                        break;
                  case SIU_TASKMGMT_LUN_RESET:
                        lun = scb->hscb->lun;
                  case SIU_TASKMGMT_TARGET_RESET:
                  {
                        struct ahd_devinfo devinfo;

                        ahd_scb_devinfo(ahd, &devinfo, scb);
                        error = CAM_BDR_SENT;
                        ahd_handle_devreset(ahd, &devinfo, lun,
                                        CAM_BDR_SENT,
                                        lun != CAM_LUN_WILDCARD
                                        ? "Lun Reset"
                                        : "Target Reset",
                                        /*verbose_level*/0);
                        break;
                  }
                  default:
                        panic("Unexpected TaskMgmt Func\n");
                        break;
                  }
            }
            break;
      }
      case TASKMGMT_CMD_CMPLT_OKAY:
      {
            u_int scbid;
            struct      scb *scb;

            /*
             * An ABORT TASK TMF failed to be delivered before
             * the targeted command completed normally.
             */
            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb != NULL) {
                  /*
                   * Remove the second instance of this SCB from
                   * the QINFIFO if it is still there.
                         */
                  ahd_print_path(ahd, scb);
                  printf("SCB completes before TMF\n");
                  /*
                   * Handle losing the race.  Wait until any
                   * current selection completes.  We will then
                   * set the TMF back to zero in this SCB so that
                   * the sequencer doesn't bother to issue another
                   * sequencer interrupt for its completion.
                   */
                  while ((ahd_inb(ahd, SCSISEQ0) & ENSELO) != 0
                      && (ahd_inb(ahd, SSTAT0) & SELDO) == 0
                      && (ahd_inb(ahd, SSTAT1) & SELTO) == 0)
                        ;
                  ahd_outb(ahd, SCB_TASK_MANAGEMENT, 0);
                  ahd_search_qinfifo(ahd, SCB_GET_TARGET(ahd, scb),
                                 SCB_GET_CHANNEL(ahd, scb),  
                                 SCB_GET_LUN(scb), SCB_GET_TAG(scb), 
                                 ROLE_INITIATOR, /*status*/0,   
                                 SEARCH_REMOVE);
            }
            break;
      }
      case TRACEPOINT0:
      case TRACEPOINT1:
      case TRACEPOINT2:
      case TRACEPOINT3:
            printf("%s: Tracepoint %d\n", ahd_name(ahd),
                   seqintcode - TRACEPOINT0);
            break;
      case NO_SEQINT:
            break;
      case SAW_HWERR:
            ahd_handle_hwerrint(ahd);
            break;
      default:
            printf("%s: Unexpected SEQINTCODE %d\n", ahd_name(ahd),
                   seqintcode);
            break;
      }
      /*
       *  The sequencer is paused immediately on
       *  a SEQINT, so we should restart it when
       *  we're done.
       */
      ahd_unpause(ahd);
}

void
ahd_handle_scsiint(struct ahd_softc *ahd, u_int intstat)
{
      struct scb  *scb;
      u_int        status0;
      u_int        status3;
      u_int        status;
      u_int        lqistat1;
      u_int        lqostat0;
      u_int        scbid;
      u_int        busfreetime;

      ahd_update_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      status3 = ahd_inb(ahd, SSTAT3) & (NTRAMPERR|OSRAMPERR);
      status0 = ahd_inb(ahd, SSTAT0) & (IOERR|OVERRUN|SELDI|SELDO);
      status = ahd_inb(ahd, SSTAT1) & (SELTO|SCSIRSTI|BUSFREE|SCSIPERR);
      lqistat1 = ahd_inb(ahd, LQISTAT1);
      lqostat0 = ahd_inb(ahd, LQOSTAT0);
      busfreetime = ahd_inb(ahd, SSTAT2) & BUSFREETIME;

      /*
       * Ignore external resets after a bus reset.
       */
      if (((status & SCSIRSTI) != 0) && (ahd->flags & AHD_BUS_RESET_ACTIVE))
            return;

      /*
       * Clear bus reset flag
       */
      ahd->flags &= ~AHD_BUS_RESET_ACTIVE;

      if ((status0 & (SELDI|SELDO)) != 0) {
            u_int simode0;

            ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
            simode0 = ahd_inb(ahd, SIMODE0);
            status0 &= simode0 & (IOERR|OVERRUN|SELDI|SELDO);
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      }
      scbid = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scbid);
      if (scb != NULL
       && (ahd_inb(ahd, SEQ_FLAGS) & NOT_IDENTIFIED) != 0)
            scb = NULL;

      if ((status0 & IOERR) != 0) {
            u_int now_lvd;

            now_lvd = ahd_inb(ahd, SBLKCTL) & ENAB40;
            printf("%s: Transceiver State Has Changed to %s mode\n",
                   ahd_name(ahd), now_lvd ? "LVD" : "SE");
            ahd_outb(ahd, CLRSINT0, CLRIOERR);
            /*
             * A change in I/O mode is equivalent to a bus reset.
             */
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
            ahd_pause(ahd);
            ahd_setup_iocell_workaround(ahd);
            ahd_unpause(ahd);
      } else if ((status0 & OVERRUN) != 0) {

            printf("%s: SCSI offset overrun detected.  Resetting bus.\n",
                   ahd_name(ahd));
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
      } else if ((status & SCSIRSTI) != 0) {

            printf("%s: Someone reset channel A\n", ahd_name(ahd));
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/FALSE);
      } else if ((status & SCSIPERR) != 0) {

            /* Make sure the sequencer is in a safe location. */
            ahd_clear_critical_section(ahd);

            ahd_handle_transmission_error(ahd);
      } else if (lqostat0 != 0) {

            printf("%s: lqostat0 == 0x%x!\n", ahd_name(ahd), lqostat0);
            ahd_outb(ahd, CLRLQOINT0, lqostat0);
            if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0)
                  ahd_outb(ahd, CLRLQOINT1, 0);
      } else if ((status & SELTO) != 0) {
            u_int  scbid;

            /* Stop the selection */
            ahd_outb(ahd, SCSISEQ0, 0);

            /* Make sure the sequencer is in a safe location. */
            ahd_clear_critical_section(ahd);

            /* No more pending messages */
            ahd_clear_msg_state(ahd);

            /* Clear interrupt state */
            ahd_outb(ahd, CLRSINT1, CLRSELTIMEO|CLRBUSFREE|CLRSCSIPERR);

            /*
             * Although the driver does not care about the
             * 'Selection in Progress' status bit, the busy
             * LED does.  SELINGO is only cleared by a sucessfull
             * selection, so we must manually clear it to insure
             * the LED turns off just incase no future successful
             * selections occur (e.g. no devices on the bus).
             */
            ahd_outb(ahd, CLRSINT0, CLRSELINGO);

            scbid = ahd_inw(ahd, WAITING_TID_HEAD);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: ahd_intr - referenced scb not "
                         "valid during SELTO scb(0x%x)\n",
                         ahd_name(ahd), scbid);
                  ahd_dump_card_state(ahd);
            } else {
                  struct ahd_devinfo devinfo;
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_SELTO) != 0) {
                        ahd_print_path(ahd, scb);
                        printf("Saw Selection Timeout for SCB 0x%x\n",
                               scbid);
                  }
#endif
                  ahd_scb_devinfo(ahd, &devinfo, scb);
                  ahd_set_transaction_status(scb, CAM_SEL_TIMEOUT);
                  ahd_freeze_devq(ahd, scb);

                  /*
                   * Cancel any pending transactions on the device
                   * now that it seems to be missing.  This will
                   * also revert us to async/narrow transfers until
                   * we can renegotiate with the device.
                   */
                  ahd_handle_devreset(ahd, &devinfo,
                                  CAM_LUN_WILDCARD,
                                  CAM_SEL_TIMEOUT,
                                  "Selection Timeout",
                                  /*verbose_level*/1);
            }
            ahd_outb(ahd, CLRINT, CLRSCSIINT);
            ahd_iocell_first_selection(ahd);
            ahd_unpause(ahd);
      } else if ((status0 & (SELDI|SELDO)) != 0) {

            ahd_iocell_first_selection(ahd);
            ahd_unpause(ahd);
      } else if (status3 != 0) {
            printf("%s: SCSI Cell parity error SSTAT3 == 0x%x\n",
                   ahd_name(ahd), status3);
            ahd_outb(ahd, CLRSINT3, status3);
      } else if ((lqistat1 & (LQIPHASE_LQ|LQIPHASE_NLQ)) != 0) {

            /* Make sure the sequencer is in a safe location. */
            ahd_clear_critical_section(ahd);

            ahd_handle_lqiphase_error(ahd, lqistat1);
      } else if ((lqistat1 & LQICRCI_NLQ) != 0) {
            /*
             * This status can be delayed during some
             * streaming operations.  The SCSIPHASE
             * handler has already dealt with this case
             * so just clear the error.
             */
            ahd_outb(ahd, CLRLQIINT1, CLRLQICRCI_NLQ);
      } else if ((status & BUSFREE) != 0
            || (lqistat1 & LQOBUSFREE) != 0) {
            u_int lqostat1;
            int   restart;
            int   clear_fifo;
            int   packetized;
            u_int mode;

            /*
             * Clear our selection hardware as soon as possible.
             * We may have an entry in the waiting Q for this target,
             * that is affected by this busfree and we don't want to
             * go about selecting the target while we handle the event.
             */
            ahd_outb(ahd, SCSISEQ0, 0);

            /* Make sure the sequencer is in a safe location. */
            ahd_clear_critical_section(ahd);

            /*
             * Determine what we were up to at the time of
             * the busfree.
             */
            mode = AHD_MODE_SCSI;
            busfreetime = ahd_inb(ahd, SSTAT2) & BUSFREETIME;
            lqostat1 = ahd_inb(ahd, LQOSTAT1);
            switch (busfreetime) {
            case BUSFREE_DFF0:
            case BUSFREE_DFF1:
            {
                  u_int scbid;
                  struct      scb *scb;

                  mode = busfreetime == BUSFREE_DFF0
                       ? AHD_MODE_DFF0 : AHD_MODE_DFF1;
                  ahd_set_modes(ahd, mode, mode);
                  scbid = ahd_get_scbptr(ahd);
                  scb = ahd_lookup_scb(ahd, scbid);
                  if (scb == NULL) {
                        printf("%s: Invalid SCB %d in DFF%d "
                               "during unexpected busfree\n",
                               ahd_name(ahd), scbid, mode);
                        packetized = 0;
                  } else
                        packetized = (scb->flags & SCB_PACKETIZED) != 0;
                  clear_fifo = 1;
                  break;
            }
            case BUSFREE_LQO:
                  clear_fifo = 0;
                  packetized = 1;
                  break;
            default:
                  clear_fifo = 0;
                  packetized =  (lqostat1 & LQOBUSFREE) != 0;
                  if (!packetized
                   && ahd_inb(ahd, LASTPHASE) == P_BUSFREE
                   && (ahd_inb(ahd, SSTAT0) & SELDI) == 0
                   && ((ahd_inb(ahd, SSTAT0) & SELDO) == 0
                    || (ahd_inb(ahd, SCSISEQ0) & ENSELO) == 0))
                        /*
                         * Assume packetized if we are not
                         * on the bus in a non-packetized
                         * capacity and any pending selection
                         * was a packetized selection.
                         */
                        packetized = 1;
                  break;
            }

#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0)
                  printf("Saw Busfree.  Busfreetime = 0x%x.\n",
                         busfreetime);
#endif
            /*
             * Busfrees that occur in non-packetized phases are
             * handled by the nonpkt_busfree handler.
             */
            if (packetized && ahd_inb(ahd, LASTPHASE) == P_BUSFREE) {
                  restart = ahd_handle_pkt_busfree(ahd, busfreetime);
            } else {
                  packetized = 0;
                  restart = ahd_handle_nonpkt_busfree(ahd);
            }
            /*
             * Clear the busfree interrupt status.  The setting of
             * the interrupt is a pulse, so in a perfect world, we
             * would not need to muck with the ENBUSFREE logic.  This
             * would ensure that if the bus moves on to another
             * connection, busfree protection is still in force.  If
             * BUSFREEREV is broken, however, we must manually clear
             * the ENBUSFREE if the busfree occurred during a non-pack
             * connection so that we don't get false positives during
             * future, packetized, connections.
             */
            ahd_outb(ahd, CLRSINT1, CLRBUSFREE);
            if (packetized == 0
             && (ahd->bugs & AHD_BUSFREEREV_BUG) != 0)
                  ahd_outb(ahd, SIMODE1,
                         ahd_inb(ahd, SIMODE1) & ~ENBUSFREE);

            if (clear_fifo)
                  ahd_clear_fifo(ahd, mode);

            ahd_clear_msg_state(ahd);
            ahd_outb(ahd, CLRINT, CLRSCSIINT);
            if (restart) {
                  ahd_restart(ahd);
            } else {
                  ahd_unpause(ahd);
            }
      } else {
            printf("%s: Missing case in ahd_handle_scsiint. status = %x\n",
                   ahd_name(ahd), status);
            ahd_dump_card_state(ahd);
            ahd_clear_intstat(ahd);
            ahd_unpause(ahd);
      }
}

static void
ahd_handle_transmission_error(struct ahd_softc *ahd)
{
      struct      scb *scb;
      u_int scbid;
      u_int lqistat1;
      u_int lqistat2;
      u_int msg_out;
      u_int curphase;
      u_int lastphase;
      u_int perrdiag;
      u_int cur_col;
      int   silent;

      scb = NULL;
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      lqistat1 = ahd_inb(ahd, LQISTAT1) & ~(LQIPHASE_LQ|LQIPHASE_NLQ);
      lqistat2 = ahd_inb(ahd, LQISTAT2);
      if ((lqistat1 & (LQICRCI_NLQ|LQICRCI_LQ)) == 0
       && (ahd->bugs & AHD_NLQICRC_DELAYED_BUG) != 0) {
            u_int lqistate;

            ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
            lqistate = ahd_inb(ahd, LQISTATE);
            if ((lqistate >= 0x1E && lqistate <= 0x24)
             || (lqistate == 0x29)) {
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_RECOVERY) != 0) {
                        printf("%s: NLQCRC found via LQISTATE\n",
                               ahd_name(ahd));
                  }
#endif
                  lqistat1 |= LQICRCI_NLQ;
            }
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      }

      ahd_outb(ahd, CLRLQIINT1, lqistat1);
      lastphase = ahd_inb(ahd, LASTPHASE);
      curphase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
      perrdiag = ahd_inb(ahd, PERRDIAG);
      msg_out = MSG_INITIATOR_DET_ERR;
      ahd_outb(ahd, CLRSINT1, CLRSCSIPERR);
      
      /*
       * Try to find the SCB associated with this error.
       */
      silent = FALSE;
      if (lqistat1 == 0
       || (lqistat1 & LQICRCI_NLQ) != 0) {
            if ((lqistat1 & (LQICRCI_NLQ|LQIOVERI_NLQ)) != 0)
                  ahd_set_active_fifo(ahd);
            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb != NULL && SCB_IS_SILENT(scb))
                  silent = TRUE;
      }

      cur_col = 0;
      if (silent == FALSE) {
            printf("%s: Transmission error detected\n", ahd_name(ahd));
            ahd_lqistat1_print(lqistat1, &cur_col, 50);
            ahd_lastphase_print(lastphase, &cur_col, 50);
            ahd_scsisigi_print(curphase, &cur_col, 50);
            ahd_perrdiag_print(perrdiag, &cur_col, 50);
            printf("\n");
            ahd_dump_card_state(ahd);
      }

      if ((lqistat1 & (LQIOVERI_LQ|LQIOVERI_NLQ)) != 0) {
            if (silent == FALSE) {
                  printf("%s: Gross protocol error during incoming "
                         "packet.  lqistat1 == 0x%x.  Resetting bus.\n",
                         ahd_name(ahd), lqistat1);
            }
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
            return;
      } else if ((lqistat1 & LQICRCI_LQ) != 0) {
            /*
             * A CRC error has been detected on an incoming LQ.
             * The bus is currently hung on the last ACK.
             * Hit LQIRETRY to release the last ack, and
             * wait for the sequencer to determine that ATNO
             * is asserted while in message out to take us
             * to our host message loop.  No NONPACKREQ or
             * LQIPHASE type errors will occur in this
             * scenario.  After this first LQIRETRY, the LQI
             * manager will be in ISELO where it will
             * happily sit until another packet phase begins.
             * Unexpected bus free detection is enabled
             * through any phases that occur after we release
             * this last ack until the LQI manager sees a
             * packet phase.  This implies we may have to
             * ignore a perfectly valid "unexected busfree"
             * after our "initiator detected error" message is
             * sent.  A busfree is the expected response after
             * we tell the target that it's L_Q was corrupted.
             * (SPI4R09 10.7.3.3.3)
             */
            ahd_outb(ahd, LQCTL2, LQIRETRY);
            printf("LQIRetry for LQICRCI_LQ to release ACK\n");
      } else if ((lqistat1 & LQICRCI_NLQ) != 0) {
            /*
             * We detected a CRC error in a NON-LQ packet.
             * The hardware has varying behavior in this situation
             * depending on whether this packet was part of a
             * stream or not.
             *
             * PKT by PKT mode:
             * The hardware has already acked the complete packet.
             * If the target honors our outstanding ATN condition,
             * we should be (or soon will be) in MSGOUT phase.
             * This will trigger the LQIPHASE_LQ status bit as the
             * hardware was expecting another LQ.  Unexpected
             * busfree detection is enabled.  Once LQIPHASE_LQ is
             * true (first entry into host message loop is much
             * the same), we must clear LQIPHASE_LQ and hit
             * LQIRETRY so the hardware is ready to handle
             * a future LQ.  NONPACKREQ will not be asserted again
             * once we hit LQIRETRY until another packet is
             * processed.  The target may either go busfree
             * or start another packet in response to our message.
             *
             * Read Streaming P0 asserted:
             * If we raise ATN and the target completes the entire
             * stream (P0 asserted during the last packet), the
             * hardware will ack all data and return to the ISTART
             * state.  When the target reponds to our ATN condition,
             * LQIPHASE_LQ will be asserted.  We should respond to
             * this with an LQIRETRY to prepare for any future
             * packets.  NONPACKREQ will not be asserted again
             * once we hit LQIRETRY until another packet is
             * processed.  The target may either go busfree or
             * start another packet in response to our message.
             * Busfree detection is enabled.
             *
             * Read Streaming P0 not asserted:
             * If we raise ATN and the target transitions to
             * MSGOUT in or after a packet where P0 is not
             * asserted, the hardware will assert LQIPHASE_NLQ.
             * We should respond to the LQIPHASE_NLQ with an
             * LQIRETRY.  Should the target stay in a non-pkt
             * phase after we send our message, the hardware
             * will assert LQIPHASE_LQ.  Recovery is then just as
             * listed above for the read streaming with P0 asserted.
             * Busfree detection is enabled.
             */
            if (silent == FALSE)
                  printf("LQICRC_NLQ\n");
            if (scb == NULL) {
                  printf("%s: No SCB valid for LQICRC_NLQ.  "
                         "Resetting bus\n", ahd_name(ahd));
                  ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
                  return;
            }
      } else if ((lqistat1 & LQIBADLQI) != 0) {
            printf("Need to handle BADLQI!\n");
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
            return;
      } else if ((perrdiag & (PARITYERR|PREVPHASE)) == PARITYERR) {
            if ((curphase & ~P_DATAIN_DT) != 0) {
                  /* Ack the byte.  So we can continue. */
                  if (silent == FALSE)
                        printf("Acking %s to clear perror\n",
                            ahd_lookup_phase_entry(curphase)->phasemsg);
                  ahd_inb(ahd, SCSIDAT);
            }
      
            if (curphase == P_MESGIN)
                  msg_out = MSG_PARITY_ERROR;
      }

      /*
       * We've set the hardware to assert ATN if we 
       * get a parity error on "in" phases, so all we
       * need to do is stuff the message buffer with
       * the appropriate message.  "In" phases have set
       * mesg_out to something other than MSG_NOP.
       */
      ahd->send_msg_perror = msg_out;
      if (scb != NULL && msg_out == MSG_INITIATOR_DET_ERR)
            scb->flags |= SCB_TRANSMISSION_ERROR;
      ahd_outb(ahd, MSG_OUT, HOST_MSG);
      ahd_outb(ahd, CLRINT, CLRSCSIINT);
      ahd_unpause(ahd);
}

static void
ahd_handle_lqiphase_error(struct ahd_softc *ahd, u_int lqistat1)
{
      /*
       * Clear the sources of the interrupts.
       */
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      ahd_outb(ahd, CLRLQIINT1, lqistat1);

      /*
       * If the "illegal" phase changes were in response
       * to our ATN to flag a CRC error, AND we ended up
       * on packet boundaries, clear the error, restart the
       * LQI manager as appropriate, and go on our merry
       * way toward sending the message.  Otherwise, reset
       * the bus to clear the error.
       */
      ahd_set_active_fifo(ahd);
      if ((ahd_inb(ahd, SCSISIGO) & ATNO) != 0
       && (ahd_inb(ahd, MDFFSTAT) & DLZERO) != 0) {
            if ((lqistat1 & LQIPHASE_LQ) != 0) {
                  printf("LQIRETRY for LQIPHASE_LQ\n");
                  ahd_outb(ahd, LQCTL2, LQIRETRY);
            } else if ((lqistat1 & LQIPHASE_NLQ) != 0) {
                  printf("LQIRETRY for LQIPHASE_NLQ\n");
                  ahd_outb(ahd, LQCTL2, LQIRETRY);
            } else
                  panic("ahd_handle_lqiphase_error: No phase errors\n");
            ahd_dump_card_state(ahd);
            ahd_outb(ahd, CLRINT, CLRSCSIINT);
            ahd_unpause(ahd);
      } else {
            printf("Reseting Channel for LQI Phase error\n");
            ahd_dump_card_state(ahd);
            ahd_reset_channel(ahd, 'A', /*Initiate Reset*/TRUE);
      }
}

/*
 * Packetized unexpected or expected busfree.
 * Entered in mode based on busfreetime.
 */
static int
ahd_handle_pkt_busfree(struct ahd_softc *ahd, u_int busfreetime)
{
      u_int lqostat1;

      AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                   ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
      lqostat1 = ahd_inb(ahd, LQOSTAT1);
      if ((lqostat1 & LQOBUSFREE) != 0) {
            struct scb *scb;
            u_int scbid;
            u_int saved_scbptr;
            u_int waiting_h;
            u_int waiting_t;
            u_int next;

            /*
             * The LQO manager detected an unexpected busfree
             * either:
             *
             * 1) During an outgoing LQ.
             * 2) After an outgoing LQ but before the first
             *    REQ of the command packet.
             * 3) During an outgoing command packet.
             *
             * In all cases, CURRSCB is pointing to the
             * SCB that encountered the failure.  Clean
             * up the queue, clear SELDO and LQOBUSFREE,
             * and allow the sequencer to restart the select
             * out at its lesure.
             */
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            scbid = ahd_inw(ahd, CURRSCB);
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL)
                   panic("SCB not valid during LQOBUSFREE");
            /*
             * Clear the status.
             */
            ahd_outb(ahd, CLRLQOINT1, CLRLQOBUSFREE);
            if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0)
                  ahd_outb(ahd, CLRLQOINT1, 0);
            ahd_outb(ahd, SCSISEQ0, ahd_inb(ahd, SCSISEQ0) & ~ENSELO);
            ahd_flush_device_writes(ahd);
            ahd_outb(ahd, CLRSINT0, CLRSELDO);

            /*
             * Return the LQO manager to its idle loop.  It will
             * not do this automatically if the busfree occurs
             * after the first REQ of either the LQ or command
             * packet or between the LQ and command packet.
             */
            ahd_outb(ahd, LQCTL2, ahd_inb(ahd, LQCTL2) | LQOTOIDLE);

            /*
             * Update the waiting for selection queue so
             * we restart on the correct SCB.
             */
            waiting_h = ahd_inw(ahd, WAITING_TID_HEAD);
            saved_scbptr = ahd_get_scbptr(ahd);
            if (waiting_h != scbid) {

                  ahd_outw(ahd, WAITING_TID_HEAD, scbid);
                  waiting_t = ahd_inw(ahd, WAITING_TID_TAIL);
                  if (waiting_t == waiting_h) {
                        ahd_outw(ahd, WAITING_TID_TAIL, scbid);
                        next = SCB_LIST_NULL;
                  } else {
                        ahd_set_scbptr(ahd, waiting_h);
                        next = ahd_inw_scbram(ahd, SCB_NEXT2);
                  }
                  ahd_set_scbptr(ahd, scbid);
                  ahd_outw(ahd, SCB_NEXT2, next);
            }
            ahd_set_scbptr(ahd, saved_scbptr);
            if (scb->crc_retry_count < AHD_MAX_LQ_CRC_ERRORS) {
                  if (SCB_IS_SILENT(scb) == FALSE) {
                        ahd_print_path(ahd, scb);
                        printf("Probable outgoing LQ CRC error.  "
                               "Retrying command\n");
                  }
                  scb->crc_retry_count++;
            } else {
                  ahd_set_transaction_status(scb, CAM_UNCOR_PARITY);
                  ahd_freeze_scb(scb);
                  ahd_freeze_devq(ahd, scb);
            }
            /* Return unpausing the sequencer. */
            return (0);
      } else if ((ahd_inb(ahd, PERRDIAG) & PARITYERR) != 0) {
            /*
             * Ignore what are really parity errors that
             * occur on the last REQ of a free running
             * clock prior to going busfree.  Some drives
             * do not properly active negate just before
             * going busfree resulting in a parity glitch.
             */
            ahd_outb(ahd, CLRSINT1, CLRSCSIPERR|CLRBUSFREE);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MASKED_ERRORS) != 0)
                  printf("%s: Parity on last REQ detected "
                         "during busfree phase.\n",
                         ahd_name(ahd));
#endif
            /* Return unpausing the sequencer. */
            return (0);
      }
      if (ahd->src_mode != AHD_MODE_SCSI) {
            u_int scbid;
            struct      scb *scb;

            scbid = ahd_get_scbptr(ahd);
            scb = ahd_lookup_scb(ahd, scbid);
            ahd_print_path(ahd, scb);
            printf("Unexpected PKT busfree condition\n");
            ahd_dump_card_state(ahd);
            ahd_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb), 'A',
                         SCB_GET_LUN(scb), SCB_GET_TAG(scb),
                         ROLE_INITIATOR, CAM_UNEXP_BUSFREE);

            /* Return restarting the sequencer. */
            return (1);
      }
      printf("%s: Unexpected PKT busfree condition\n", ahd_name(ahd));
      ahd_dump_card_state(ahd);
      /* Restart the sequencer. */
      return (1);
}

/*
 * Non-packetized unexpected or expected busfree.
 */
static int
ahd_handle_nonpkt_busfree(struct ahd_softc *ahd)
{
      struct      ahd_devinfo devinfo;
      struct      scb *scb;
      u_int lastphase;
      u_int saved_scsiid;
      u_int saved_lun;
      u_int target;
      u_int initiator_role_id;
      u_int scbid;
      u_int ppr_busfree;
      int   printerror;

      /*
       * Look at what phase we were last in.  If its message out,
       * chances are pretty good that the busfree was in response
       * to one of our abort requests.
       */
      lastphase = ahd_inb(ahd, LASTPHASE);
      saved_scsiid = ahd_inb(ahd, SAVED_SCSIID);
      saved_lun = ahd_inb(ahd, SAVED_LUN);
      target = SCSIID_TARGET(ahd, saved_scsiid);
      initiator_role_id = SCSIID_OUR_ID(saved_scsiid);
      ahd_compile_devinfo(&devinfo, initiator_role_id,
                      target, saved_lun, 'A', ROLE_INITIATOR);
      printerror = 1;

      scbid = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scbid);
      if (scb != NULL
       && (ahd_inb(ahd, SEQ_FLAGS) & NOT_IDENTIFIED) != 0)
            scb = NULL;

      ppr_busfree = (ahd->msg_flags & MSG_FLAG_EXPECT_PPR_BUSFREE) != 0;
      if (lastphase == P_MESGOUT) {
            u_int tag;

            tag = SCB_LIST_NULL;
            if (ahd_sent_msg(ahd, AHDMSG_1B, MSG_ABORT_TAG, TRUE)
             || ahd_sent_msg(ahd, AHDMSG_1B, MSG_ABORT, TRUE)) {
                  int found;
                  int sent_msg;

                  if (scb == NULL) {
                        ahd_print_devinfo(ahd, &devinfo);
                        printf("Abort for unidentified "
                               "connection completed.\n");
                        /* restart the sequencer. */
                        return (1);
                  }
                  sent_msg = ahd->msgout_buf[ahd->msgout_index - 1];
                  ahd_print_path(ahd, scb);
                  printf("SCB %d - Abort%s Completed.\n",
                         SCB_GET_TAG(scb),
                         sent_msg == MSG_ABORT_TAG ? "" : " Tag");

                  if (sent_msg == MSG_ABORT_TAG)
                        tag = SCB_GET_TAG(scb);

                  found = ahd_abort_scbs(ahd, target, 'A', saved_lun,
                                     tag, ROLE_INITIATOR,
                                     CAM_REQ_ABORTED);
                  printf("found == 0x%x\n", found);
                  printerror = 0;
            } else if (ahd_sent_msg(ahd, AHDMSG_1B,
                              MSG_BUS_DEV_RESET, TRUE)) {
#ifdef __FreeBSD__
                  /*
                   * Don't mark the user's request for this BDR
                   * as completing with CAM_BDR_SENT.  CAM3
                   * specifies CAM_REQ_CMP.
                   */
                  if (scb != NULL
                   && scb->io_ctx->ccb_h.func_code== XPT_RESET_DEV
                   && ahd_match_scb(ahd, scb, target, 'A',
                                CAM_LUN_WILDCARD, SCB_LIST_NULL,
                                ROLE_INITIATOR))
                        ahd_set_transaction_status(scb, CAM_REQ_CMP);
#endif
                  ahd_handle_devreset(ahd, &devinfo, CAM_LUN_WILDCARD,
                                  CAM_BDR_SENT, "Bus Device Reset",
                                  /*verbose_level*/0);
                  printerror = 0;
            } else if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_PPR, FALSE)
                  && ppr_busfree == 0) {
                  struct ahd_initiator_tinfo *tinfo;
                  struct ahd_tmode_tstate *tstate;

                  /*
                   * PPR Rejected.
                   *
                   * If the previous negotiation was packetized,
                   * this could be because the device has been
                   * reset without our knowledge.  Force our
                   * current negotiation to async and retry the
                   * negotiation.  Otherwise retry the command
                   * with non-ppr negotiation.
                   */
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("PPR negotiation rejected busfree.\n");
#endif
                  tinfo = ahd_fetch_transinfo(ahd, devinfo.channel,
                                        devinfo.our_scsiid,
                                        devinfo.target, &tstate);
                  if ((tinfo->curr.ppr_options & MSG_EXT_PPR_IU_REQ)!=0) {
                        ahd_set_width(ahd, &devinfo,
                                    MSG_EXT_WDTR_BUS_8_BIT,
                                    AHD_TRANS_CUR,
                                    /*paused*/TRUE);
                        ahd_set_syncrate(ahd, &devinfo,
                                    /*period*/0, /*offset*/0,
                                    /*ppr_options*/0,
                                    AHD_TRANS_CUR,
                                    /*paused*/TRUE);
                        /*
                         * The expect PPR busfree handler below
                         * will effect the retry and necessary
                         * abort.
                         */
                  } else {
                        tinfo->curr.transport_version = 2;
                        tinfo->goal.transport_version = 2;
                        tinfo->goal.ppr_options = 0;
                        /*
                         * Remove any SCBs in the waiting for selection
                         * queue that may also be for this target so
                         * that command ordering is preserved.
                         */
                        ahd_freeze_devq(ahd, scb);
                        ahd_qinfifo_requeue_tail(ahd, scb);
                        printerror = 0;
                  }
            } else if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_WDTR, FALSE)
                  && ppr_busfree == 0) {
                  /*
                   * Negotiation Rejected.  Go-narrow and
                   * retry command.
                   */
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("WDTR negotiation rejected busfree.\n");
#endif
                  ahd_set_width(ahd, &devinfo,
                              MSG_EXT_WDTR_BUS_8_BIT,
                              AHD_TRANS_CUR|AHD_TRANS_GOAL,
                              /*paused*/TRUE);
                  /*
                   * Remove any SCBs in the waiting for selection
                   * queue that may also be for this target so that
                   * command ordering is preserved.
                   */
                  ahd_freeze_devq(ahd, scb);
                  ahd_qinfifo_requeue_tail(ahd, scb);
                  printerror = 0;
            } else if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_SDTR, FALSE)
                  && ppr_busfree == 0) {
                  /*
                   * Negotiation Rejected.  Go-async and
                   * retry command.
                   */
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("SDTR negotiation rejected busfree.\n");
#endif
                  ahd_set_syncrate(ahd, &devinfo,
                              /*period*/0, /*offset*/0,
                              /*ppr_options*/0,
                              AHD_TRANS_CUR|AHD_TRANS_GOAL,
                              /*paused*/TRUE);
                  /*
                   * Remove any SCBs in the waiting for selection
                   * queue that may also be for this target so that
                   * command ordering is preserved.
                   */
                  ahd_freeze_devq(ahd, scb);
                  ahd_qinfifo_requeue_tail(ahd, scb);
                  printerror = 0;
            } else if ((ahd->msg_flags & MSG_FLAG_EXPECT_IDE_BUSFREE) != 0
                  && ahd_sent_msg(ahd, AHDMSG_1B,
                               MSG_INITIATOR_DET_ERR, TRUE)) {

#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("Expected IDE Busfree\n");
#endif
                  printerror = 0;
            } else if ((ahd->msg_flags & MSG_FLAG_EXPECT_QASREJ_BUSFREE)
                  && ahd_sent_msg(ahd, AHDMSG_1B,
                              MSG_MESSAGE_REJECT, TRUE)) {

#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("Expected QAS Reject Busfree\n");
#endif
                  printerror = 0;
            }
      }

      /*
       * The busfree required flag is honored at the end of
       * the message phases.  We check it last in case we
       * had to send some other message that caused a busfree.
       */
      if (printerror != 0
       && (lastphase == P_MESGIN || lastphase == P_MESGOUT)
       && ((ahd->msg_flags & MSG_FLAG_EXPECT_PPR_BUSFREE) != 0)) {

            ahd_freeze_devq(ahd, scb);
            ahd_set_transaction_status(scb, CAM_REQUEUE_REQ);
            ahd_freeze_scb(scb);
            if ((ahd->msg_flags & MSG_FLAG_IU_REQ_CHANGED) != 0) {
                  ahd_abort_scbs(ahd, SCB_GET_TARGET(ahd, scb),
                               SCB_GET_CHANNEL(ahd, scb),
                               SCB_GET_LUN(scb), SCB_LIST_NULL,
                               ROLE_INITIATOR, CAM_REQ_ABORTED);
            } else {
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf("PPR Negotiation Busfree.\n");
#endif
                  ahd_done(ahd, scb);
            }
            printerror = 0;
      }
      if (printerror != 0) {
            int aborted;

            aborted = 0;
            if (scb != NULL) {
                  u_int tag;

                  if ((scb->hscb->control & TAG_ENB) != 0)
                        tag = SCB_GET_TAG(scb);
                  else
                        tag = SCB_LIST_NULL;
                  ahd_print_path(ahd, scb);
                  aborted = ahd_abort_scbs(ahd, target, 'A',
                               SCB_GET_LUN(scb), tag,
                               ROLE_INITIATOR,
                               CAM_UNEXP_BUSFREE);
            } else {
                  /*
                   * We had not fully identified this connection,
                   * so we cannot abort anything.
                   */
                  printf("%s: ", ahd_name(ahd));
            }
            printf("Unexpected busfree %s, %d SCBs aborted, "
                   "PRGMCNT == 0x%x\n",
                   ahd_lookup_phase_entry(lastphase)->phasemsg,
                   aborted,
                   ahd_inw(ahd, PRGMCNT));
            ahd_dump_card_state(ahd);
            if (lastphase != P_BUSFREE)
                  ahd_force_renegotiation(ahd, &devinfo);
      }
      /* Always restart the sequencer. */
      return (1);
}

static void
ahd_handle_proto_violation(struct ahd_softc *ahd)
{
      struct      ahd_devinfo devinfo;
      struct      scb *scb;
      u_int scbid;
      u_int seq_flags;
      u_int curphase;
      u_int lastphase;
      int   found;

      ahd_fetch_devinfo(ahd, &devinfo);
      scbid = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scbid);
      seq_flags = ahd_inb(ahd, SEQ_FLAGS);
      curphase = ahd_inb(ahd, SCSISIGI) & PHASE_MASK;
      lastphase = ahd_inb(ahd, LASTPHASE);
      if ((seq_flags & NOT_IDENTIFIED) != 0) {

            /*
             * The reconnecting target either did not send an
             * identify message, or did, but we didn't find an SCB
             * to match.
             */
            ahd_print_devinfo(ahd, &devinfo);
            printf("Target did not send an IDENTIFY message. "
                   "LASTPHASE = 0x%x.\n", lastphase);
            scb = NULL;
      } else if (scb == NULL) {
            /*
             * We don't seem to have an SCB active for this
             * transaction.  Print an error and reset the bus.
             */
            ahd_print_devinfo(ahd, &devinfo);
            printf("No SCB found during protocol violation\n");
            goto proto_violation_reset;
      } else {
            ahd_set_transaction_status(scb, CAM_SEQUENCE_FAIL);
            if ((seq_flags & NO_CDB_SENT) != 0) {
                  ahd_print_path(ahd, scb);
                  printf("No or incomplete CDB sent to device.\n");
            } else if ((ahd_inb_scbram(ahd, SCB_CONTROL)
                    & STATUS_RCVD) == 0) {
                  /*
                   * The target never bothered to provide status to
                   * us prior to completing the command.  Since we don't
                   * know the disposition of this command, we must attempt
                   * to abort it.  Assert ATN and prepare to send an abort
                   * message.
                   */
                  ahd_print_path(ahd, scb);
                  printf("Completed command without status.\n");
            } else {
                  ahd_print_path(ahd, scb);
                  printf("Unknown protocol violation.\n");
                  ahd_dump_card_state(ahd);
            }
      }
      if ((lastphase & ~P_DATAIN_DT) == 0
       || lastphase == P_COMMAND) {
proto_violation_reset:
            /*
             * Target either went directly to data
             * phase or didn't respond to our ATN.
             * The only safe thing to do is to blow
             * it away with a bus reset.
             */
            found = ahd_reset_channel(ahd, 'A', TRUE);
            printf("%s: Issued Channel %c Bus Reset. "
                   "%d SCBs aborted\n", ahd_name(ahd), 'A', found);
      } else {
            /*
             * Leave the selection hardware off in case
             * this abort attempt will affect yet to
             * be sent commands.
             */
            ahd_outb(ahd, SCSISEQ0,
                   ahd_inb(ahd, SCSISEQ0) & ~ENSELO);
            ahd_assert_atn(ahd);
            ahd_outb(ahd, MSG_OUT, HOST_MSG);
            if (scb == NULL) {
                  ahd_print_devinfo(ahd, &devinfo);
                  ahd->msgout_buf[0] = MSG_ABORT_TASK;
                  ahd->msgout_len = 1;
                  ahd->msgout_index = 0;
                  ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
            } else {
                  ahd_print_path(ahd, scb);
                  scb->flags |= SCB_ABORT;
            }
            printf("Protocol violation %s.  Attempting to abort.\n",
                   ahd_lookup_phase_entry(curphase)->phasemsg);
      }
}

/*
 * Force renegotiation to occur the next time we initiate
 * a command to the current device.
 */
static void
ahd_force_renegotiation(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      struct      ahd_initiator_tinfo *targ_info;
      struct      ahd_tmode_tstate *tstate;

#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
            ahd_print_devinfo(ahd, devinfo);
            printf("Forcing renegotiation\n");
      }
#endif
      targ_info = ahd_fetch_transinfo(ahd,
                              devinfo->channel,
                              devinfo->our_scsiid,
                              devinfo->target,
                              &tstate);
      ahd_update_neg_request(ahd, devinfo, tstate,
                         targ_info, AHD_NEG_IF_NON_ASYNC);
}

#define AHD_MAX_STEPS 2000
void
ahd_clear_critical_section(struct ahd_softc *ahd)
{
      ahd_mode_state    saved_modes;
      int         stepping;
      int         steps;
      int         first_instr;
      u_int       simode0;
      u_int       simode1;
      u_int       simode3;
      u_int       lqimode0;
      u_int       lqimode1;
      u_int       lqomode0;
      u_int       lqomode1;

      if (ahd->num_critical_sections == 0)
            return;

      stepping = FALSE;
      steps = 0;
      first_instr = 0;
      simode0 = 0;
      simode1 = 0;
      simode3 = 0;
      lqimode0 = 0;
      lqimode1 = 0;
      lqomode0 = 0;
      lqomode1 = 0;
      saved_modes = ahd_save_modes(ahd);
      for (;;) {
            struct      cs *cs;
            u_int seqaddr;
            u_int i;

            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            seqaddr = ahd_inw(ahd, CURADDR);

            cs = ahd->critical_sections;
            for (i = 0; i < ahd->num_critical_sections; i++, cs++) {
                  
                  if (cs->begin < seqaddr && cs->end >= seqaddr)
                        break;
            }

            if (i == ahd->num_critical_sections)
                  break;

            if (steps > AHD_MAX_STEPS) {
                  printf("%s: Infinite loop in critical section\n"
                         "%s: First Instruction 0x%x now 0x%x\n",
                         ahd_name(ahd), ahd_name(ahd), first_instr,
                         seqaddr);
                  ahd_dump_card_state(ahd);
                  panic("critical section loop");
            }

            steps++;
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0)
                  printf("%s: Single stepping at 0x%x\n", ahd_name(ahd),
                         seqaddr);
#endif
            if (stepping == FALSE) {

                  first_instr = seqaddr;
                  ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
                  simode0 = ahd_inb(ahd, SIMODE0);
                  simode3 = ahd_inb(ahd, SIMODE3);
                  lqimode0 = ahd_inb(ahd, LQIMODE0);
                  lqimode1 = ahd_inb(ahd, LQIMODE1);
                  lqomode0 = ahd_inb(ahd, LQOMODE0);
                  lqomode1 = ahd_inb(ahd, LQOMODE1);
                  ahd_outb(ahd, SIMODE0, 0);
                  ahd_outb(ahd, SIMODE3, 0);
                  ahd_outb(ahd, LQIMODE0, 0);
                  ahd_outb(ahd, LQIMODE1, 0);
                  ahd_outb(ahd, LQOMODE0, 0);
                  ahd_outb(ahd, LQOMODE1, 0);
                  ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
                  simode1 = ahd_inb(ahd, SIMODE1);
                  /*
                   * We don't clear ENBUSFREE.  Unfortunately
                   * we cannot re-enable busfree detection within
                   * the current connection, so we must leave it
                   * on while single stepping.
                   */
                  ahd_outb(ahd, SIMODE1, simode1 & ENBUSFREE);
                  ahd_outb(ahd, SEQCTL0, ahd_inb(ahd, SEQCTL0) | STEP);
                  stepping = TRUE;
            }
            ahd_outb(ahd, CLRSINT1, CLRBUSFREE);
            ahd_outb(ahd, CLRINT, CLRSCSIINT);
            ahd_set_modes(ahd, ahd->saved_src_mode, ahd->saved_dst_mode);
            ahd_outb(ahd, HCNTRL, ahd->unpause);
            while (!ahd_is_paused(ahd))
                  ahd_delay(200);
            ahd_update_modes(ahd);
      }
      if (stepping) {
            ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
            ahd_outb(ahd, SIMODE0, simode0);
            ahd_outb(ahd, SIMODE3, simode3);
            ahd_outb(ahd, LQIMODE0, lqimode0);
            ahd_outb(ahd, LQIMODE1, lqimode1);
            ahd_outb(ahd, LQOMODE0, lqomode0);
            ahd_outb(ahd, LQOMODE1, lqomode1);
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            ahd_outb(ahd, SEQCTL0, ahd_inb(ahd, SEQCTL0) & ~STEP);
            ahd_outb(ahd, SIMODE1, simode1);
            /*
             * SCSIINT seems to glitch occassionally when
             * the interrupt masks are restored.  Clear SCSIINT
             * one more time so that only persistent errors
             * are seen as a real interrupt.
             */
            ahd_outb(ahd, CLRINT, CLRSCSIINT);
      }
      ahd_restore_modes(ahd, saved_modes);
}

/*
 * Clear any pending interrupt status.
 */
void
ahd_clear_intstat(struct ahd_softc *ahd)
{
      AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                   ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
      /* Clear any interrupt conditions this may have caused */
      ahd_outb(ahd, CLRLQIINT0, CLRLQIATNQAS|CLRLQICRCT1|CLRLQICRCT2
                         |CLRLQIBADLQT|CLRLQIATNLQ|CLRLQIATNCMD);
      ahd_outb(ahd, CLRLQIINT1, CLRLQIPHASE_LQ|CLRLQIPHASE_NLQ|CLRLIQABORT
                         |CLRLQICRCI_LQ|CLRLQICRCI_NLQ|CLRLQIBADLQI
                         |CLRLQIOVERI_LQ|CLRLQIOVERI_NLQ|CLRNONPACKREQ);
      ahd_outb(ahd, CLRLQOINT0, CLRLQOTARGSCBPERR|CLRLQOSTOPT2|CLRLQOATNLQ
                         |CLRLQOATNPKT|CLRLQOTCRC);
      ahd_outb(ahd, CLRLQOINT1, CLRLQOINITSCBPERR|CLRLQOSTOPI2|CLRLQOBADQAS
                         |CLRLQOBUSFREE|CLRLQOPHACHGINPKT);
      if ((ahd->bugs & AHD_CLRLQO_AUTOCLR_BUG) != 0) {
            ahd_outb(ahd, CLRLQOINT0, 0);
            ahd_outb(ahd, CLRLQOINT1, 0);
      }
      ahd_outb(ahd, CLRSINT3, CLRNTRAMPERR|CLROSRAMPERR);
      ahd_outb(ahd, CLRSINT1, CLRSELTIMEO|CLRATNO|CLRSCSIRSTI
                        |CLRBUSFREE|CLRSCSIPERR|CLRREQINIT);
      ahd_outb(ahd, CLRSINT0, CLRSELDO|CLRSELDI|CLRSELINGO
                          |CLRIOERR|CLROVERRUN);
      ahd_outb(ahd, CLRINT, CLRSCSIINT);
}

/**************************** Debugging Routines ******************************/
#ifdef AHD_DEBUG
uint32_t ahd_debug = AHD_DEBUG_OPTS;
#endif
void
ahd_print_scb(struct scb *scb)
{
      struct hardware_scb *hscb;
      int i;

      hscb = scb->hscb;
      printf("scb:%p control:0x%x scsiid:0x%x lun:%d cdb_len:%d\n",
             (void *)scb,
             hscb->control,
             hscb->scsiid,
             hscb->lun,
             hscb->cdb_len);
      printf("Shared Data: ");
      for (i = 0; i < sizeof(hscb->shared_data.idata.cdb); i++)
            printf("%#02x", hscb->shared_data.idata.cdb[i]);
      printf("        dataptr:%#x%x datacnt:%#x sgptr:%#x tag:%#x\n",
             (uint32_t)((ahd_le64toh(hscb->dataptr) >> 32) & 0xFFFFFFFF),
             (uint32_t)(ahd_le64toh(hscb->dataptr) & 0xFFFFFFFF),
             ahd_le32toh(hscb->datacnt),
             ahd_le32toh(hscb->sgptr),
             SCB_GET_TAG(scb));
      ahd_dump_sglist(scb);
}

void
ahd_dump_sglist(struct scb *scb)
{
      int i;

      if (scb->sg_count > 0) {
            if ((scb->ahd_softc->flags & AHD_64BIT_ADDRESSING) != 0) {
                  struct ahd_dma64_seg *sg_list;

                  sg_list = (struct ahd_dma64_seg*)scb->sg_list;
                  for (i = 0; i < scb->sg_count; i++) {
                        uint64_t addr;
                        uint32_t len;

                        addr = ahd_le64toh(sg_list[i].addr);
                        len = ahd_le32toh(sg_list[i].len);
                        printf("sg[%d] - Addr 0x%x%x : Length %d%s\n",
                               i,
                               (uint32_t)((addr >> 32) & 0xFFFFFFFF),
                               (uint32_t)(addr & 0xFFFFFFFF),
                               sg_list[i].len & AHD_SG_LEN_MASK,
                               (sg_list[i].len & AHD_DMA_LAST_SEG)
                             ? " Last" : "");
                  }
            } else {
                  struct ahd_dma_seg *sg_list;

                  sg_list = (struct ahd_dma_seg*)scb->sg_list;
                  for (i = 0; i < scb->sg_count; i++) {
                        uint32_t len;

                        len = ahd_le32toh(sg_list[i].len);
                        printf("sg[%d] - Addr 0x%x%x : Length %d%s\n",
                               i,
                               (len & AHD_SG_HIGH_ADDR_MASK) >> 24,
                               ahd_le32toh(sg_list[i].addr),
                               len & AHD_SG_LEN_MASK,
                               len & AHD_DMA_LAST_SEG ? " Last" : "");
                  }
            }
      }
}

/************************* Transfer Negotiation *******************************/
/*
 * Allocate per target mode instance (ID we respond to as a target)
 * transfer negotiation data structures.
 */
static struct ahd_tmode_tstate *
ahd_alloc_tstate(struct ahd_softc *ahd, u_int scsi_id, char channel)
{
      struct ahd_tmode_tstate *master_tstate;
      struct ahd_tmode_tstate *tstate;
      int i;

      master_tstate = ahd->enabled_targets[ahd->our_id];
      if (ahd->enabled_targets[scsi_id] != NULL
       && ahd->enabled_targets[scsi_id] != master_tstate)
            panic("%s: ahd_alloc_tstate - Target already allocated",
                  ahd_name(ahd));
      tstate = malloc(sizeof(*tstate), M_DEVBUF, M_NOWAIT);
      if (tstate == NULL)
            return (NULL);

      /*
       * If we have allocated a master tstate, copy user settings from
       * the master tstate (taken from SRAM or the EEPROM) for this
       * channel, but reset our current and goal settings to async/narrow
       * until an initiator talks to us.
       */
      if (master_tstate != NULL) {
            memcpy(tstate, master_tstate, sizeof(*tstate));
            memset(tstate->enabled_luns, 0, sizeof(tstate->enabled_luns));
            for (i = 0; i < 16; i++) {
                  memset(&tstate->transinfo[i].curr, 0,
                        sizeof(tstate->transinfo[i].curr));
                  memset(&tstate->transinfo[i].goal, 0,
                        sizeof(tstate->transinfo[i].goal));
            }
      } else
            memset(tstate, 0, sizeof(*tstate));
      ahd->enabled_targets[scsi_id] = tstate;
      return (tstate);
}

#ifdef AHD_TARGET_MODE
/*
 * Free per target mode instance (ID we respond to as a target)
 * transfer negotiation data structures.
 */
static void
ahd_free_tstate(struct ahd_softc *ahd, u_int scsi_id, char channel, int force)
{
      struct ahd_tmode_tstate *tstate;

      /*
       * Don't clean up our "master" tstate.
       * It has our default user settings.
       */
      if (scsi_id == ahd->our_id
       && force == FALSE)
            return;

      tstate = ahd->enabled_targets[scsi_id];
      if (tstate != NULL)
            free(tstate, M_DEVBUF);
      ahd->enabled_targets[scsi_id] = NULL;
}
#endif

/*
 * Called when we have an active connection to a target on the bus,
 * this function finds the nearest period to the input period limited
 * by the capabilities of the bus connectivity of and sync settings for
 * the target.
 */
void
ahd_devlimited_syncrate(struct ahd_softc *ahd,
                  struct ahd_initiator_tinfo *tinfo,
                  u_int *period, u_int *ppr_options, role_t role)
{
      struct      ahd_transinfo *transinfo;
      u_int maxsync;

      if ((ahd_inb(ahd, SBLKCTL) & ENAB40) != 0
       && (ahd_inb(ahd, SSTAT2) & EXP_ACTIVE) == 0) {
            maxsync = AHD_SYNCRATE_PACED;
      } else {
            maxsync = AHD_SYNCRATE_ULTRA;
            /* Can't do DT related options on an SE bus */
            *ppr_options &= MSG_EXT_PPR_QAS_REQ;
      }
      /*
       * Never allow a value higher than our current goal
       * period otherwise we may allow a target initiated
       * negotiation to go above the limit as set by the
       * user.  In the case of an initiator initiated
       * sync negotiation, we limit based on the user
       * setting.  This allows the system to still accept
       * incoming negotiations even if target initiated
       * negotiation is not performed.
       */
      if (role == ROLE_TARGET)
            transinfo = &tinfo->user;
      else 
            transinfo = &tinfo->goal;
      *ppr_options &= (transinfo->ppr_options|MSG_EXT_PPR_PCOMP_EN);
      if (transinfo->width == MSG_EXT_WDTR_BUS_8_BIT) {
            maxsync = MAX(maxsync, AHD_SYNCRATE_ULTRA2);
            *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
      }
      if (transinfo->period == 0) {
            *period = 0;
            *ppr_options = 0;
      } else {
            *period = MAX(*period, transinfo->period);
            ahd_find_syncrate(ahd, period, ppr_options, maxsync);
      }
}

/*
 * Look up the valid period to SCSIRATE conversion in our table.
 * Return the period and offset that should be sent to the target
 * if this was the beginning of an SDTR.
 */
void
ahd_find_syncrate(struct ahd_softc *ahd, u_int *period,
              u_int *ppr_options, u_int maxsync)
{
      if (*period < maxsync)
            *period = maxsync;

      if ((*ppr_options & MSG_EXT_PPR_DT_REQ) != 0
       && *period > AHD_SYNCRATE_MIN_DT)
            *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
            
      if (*period > AHD_SYNCRATE_MIN)
            *period = 0;

      /* Honor PPR option conformance rules. */
      if (*period > AHD_SYNCRATE_PACED)
            *ppr_options &= ~MSG_EXT_PPR_RTI;

      if ((*ppr_options & MSG_EXT_PPR_IU_REQ) == 0)
            *ppr_options &= (MSG_EXT_PPR_DT_REQ|MSG_EXT_PPR_QAS_REQ);

      if ((*ppr_options & MSG_EXT_PPR_DT_REQ) == 0)
            *ppr_options &= MSG_EXT_PPR_QAS_REQ;

      /* Skip all PACED only entries if IU is not available */
      if ((*ppr_options & MSG_EXT_PPR_IU_REQ) == 0
       && *period < AHD_SYNCRATE_DT)
            *period = AHD_SYNCRATE_DT;

      /* Skip all DT only entries if DT is not available */
      if ((*ppr_options & MSG_EXT_PPR_DT_REQ) == 0
       && *period < AHD_SYNCRATE_ULTRA2)
            *period = AHD_SYNCRATE_ULTRA2;
}

/*
 * Truncate the given synchronous offset to a value the
 * current adapter type and syncrate are capable of.
 */
void
ahd_validate_offset(struct ahd_softc *ahd,
                struct ahd_initiator_tinfo *tinfo,
                u_int period, u_int *offset, int wide,
                role_t role)
{
      u_int maxoffset;

      /* Limit offset to what we can do */
      if (period == 0)
            maxoffset = 0;
      else if (period <= AHD_SYNCRATE_PACED) {
            if ((ahd->bugs & AHD_PACED_NEGTABLE_BUG) != 0)
                  maxoffset = MAX_OFFSET_PACED_BUG;
            else
                  maxoffset = MAX_OFFSET_PACED;
      } else
            maxoffset = MAX_OFFSET_NON_PACED;
      *offset = MIN(*offset, maxoffset);
      if (tinfo != NULL) {
            if (role == ROLE_TARGET)
                  *offset = MIN(*offset, tinfo->user.offset);
            else
                  *offset = MIN(*offset, tinfo->goal.offset);
      }
}

/*
 * Truncate the given transfer width parameter to a value the
 * current adapter type is capable of.
 */
void
ahd_validate_width(struct ahd_softc *ahd, struct ahd_initiator_tinfo *tinfo,
               u_int *bus_width, role_t role)
{
      switch (*bus_width) {
      default:
            if (ahd->features & AHD_WIDE) {
                  /* Respond Wide */
                  *bus_width = MSG_EXT_WDTR_BUS_16_BIT;
                  break;
            }
            /* FALLTHROUGH */
      case MSG_EXT_WDTR_BUS_8_BIT:
            *bus_width = MSG_EXT_WDTR_BUS_8_BIT;
            break;
      }
      if (tinfo != NULL) {
            if (role == ROLE_TARGET)
                  *bus_width = MIN(tinfo->user.width, *bus_width);
            else
                  *bus_width = MIN(tinfo->goal.width, *bus_width);
      }
}

/*
 * Update the bitmask of targets for which the controller should
 * negotiate with at the next convenient oportunity.  This currently
 * means the next time we send the initial identify messages for
 * a new transaction.
 */
int
ahd_update_neg_request(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
                   struct ahd_tmode_tstate *tstate,
                   struct ahd_initiator_tinfo *tinfo, ahd_neg_type neg_type)
{
      u_int auto_negotiate_orig;

      auto_negotiate_orig = tstate->auto_negotiate;
      if (neg_type == AHD_NEG_ALWAYS) {
            /*
             * Force our "current" settings to be
             * unknown so that unless a bus reset
             * occurs the need to renegotiate is
             * recorded persistently.
             */
            if ((ahd->features & AHD_WIDE) != 0)
                  tinfo->curr.width = AHD_WIDTH_UNKNOWN;
            tinfo->curr.period = AHD_PERIOD_UNKNOWN;
            tinfo->curr.offset = AHD_OFFSET_UNKNOWN;
      }
      if (tinfo->curr.period != tinfo->goal.period
       || tinfo->curr.width != tinfo->goal.width
       || tinfo->curr.offset != tinfo->goal.offset
       || tinfo->curr.ppr_options != tinfo->goal.ppr_options
       || (neg_type == AHD_NEG_IF_NON_ASYNC
        && (tinfo->goal.offset != 0
         || tinfo->goal.width != MSG_EXT_WDTR_BUS_8_BIT
         || tinfo->goal.ppr_options != 0)))
            tstate->auto_negotiate |= devinfo->target_mask;
      else
            tstate->auto_negotiate &= ~devinfo->target_mask;

      return (auto_negotiate_orig != tstate->auto_negotiate);
}

/*
 * Update the user/goal/curr tables of synchronous negotiation
 * parameters as well as, in the case of a current or active update,
 * any data structures on the host controller.  In the case of an
 * active update, the specified target is currently talking to us on
 * the bus, so the transfer parameter update must take effect
 * immediately.
 */
void
ahd_set_syncrate(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
             u_int period, u_int offset, u_int ppr_options,
             u_int type, int paused)
{
      struct      ahd_initiator_tinfo *tinfo;
      struct      ahd_tmode_tstate *tstate;
      u_int old_period;
      u_int old_offset;
      u_int old_ppr;
      int   active;
      int   update_needed;

      active = (type & AHD_TRANS_ACTIVE) == AHD_TRANS_ACTIVE;
      update_needed = 0;

      if (period == 0 || offset == 0) {
            period = 0;
            offset = 0;
      }

      tinfo = ahd_fetch_transinfo(ahd, devinfo->channel, devinfo->our_scsiid,
                            devinfo->target, &tstate);

      if ((type & AHD_TRANS_USER) != 0) {
            tinfo->user.period = period;
            tinfo->user.offset = offset;
            tinfo->user.ppr_options = ppr_options;
      }

      if ((type & AHD_TRANS_GOAL) != 0) {
            tinfo->goal.period = period;
            tinfo->goal.offset = offset;
            tinfo->goal.ppr_options = ppr_options;
      }

      old_period = tinfo->curr.period;
      old_offset = tinfo->curr.offset;
      old_ppr        = tinfo->curr.ppr_options;

      if ((type & AHD_TRANS_CUR) != 0
       && (old_period != period
        || old_offset != offset
        || old_ppr != ppr_options)) {

            update_needed++;

            tinfo->curr.period = period;
            tinfo->curr.offset = offset;
            tinfo->curr.ppr_options = ppr_options;

            ahd_send_async(ahd, devinfo->channel, devinfo->target,
                         CAM_LUN_WILDCARD, AC_TRANSFER_NEG);
            if (bootverbose) {
                  if (offset != 0) {
                        int options;

                        printf("%s: target %d synchronous with "
                               "period = 0x%x, offset = 0x%x",
                               ahd_name(ahd), devinfo->target,
                               period, offset);
                        options = 0;
                        if ((ppr_options & MSG_EXT_PPR_RD_STRM) != 0) {
                              printf("(RDSTRM");
                              options++;
                        }
                        if ((ppr_options & MSG_EXT_PPR_DT_REQ) != 0) {
                              printf("%s", options ? "|DT" : "(DT");
                              options++;
                        }
                        if ((ppr_options & MSG_EXT_PPR_IU_REQ) != 0) {
                              printf("%s", options ? "|IU" : "(IU");
                              options++;
                        }
                        if ((ppr_options & MSG_EXT_PPR_RTI) != 0) {
                              printf("%s", options ? "|RTI" : "(RTI");
                              options++;
                        }
                        if ((ppr_options & MSG_EXT_PPR_QAS_REQ) != 0) {
                              printf("%s", options ? "|QAS" : "(QAS");
                              options++;
                        }
                        if (options != 0)
                              printf(")\n");
                        else
                              printf("\n");
                  } else {
                        printf("%s: target %d using "
                               "asynchronous transfers%s\n",
                               ahd_name(ahd), devinfo->target,
                               (ppr_options & MSG_EXT_PPR_QAS_REQ) != 0
                             ?  "(QAS)" : "");
                  }
            }
      }
      /*
       * Always refresh the neg-table to handle the case of the
       * sequencer setting the ENATNO bit for a MK_MESSAGE request.
       * We will always renegotiate in that case if this is a
       * packetized request.  Also manage the busfree expected flag
       * from this common routine so that we catch changes due to
       * WDTR or SDTR messages.
       */
      if ((type & AHD_TRANS_CUR) != 0) {
            if (!paused)
                  ahd_pause(ahd);
            ahd_update_neg_table(ahd, devinfo, &tinfo->curr);
            if (!paused)
                  ahd_unpause(ahd);
            if (ahd->msg_type != MSG_TYPE_NONE) {
                  if ((old_ppr & MSG_EXT_PPR_IU_REQ)
                   != (ppr_options & MSG_EXT_PPR_IU_REQ)) {
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                              ahd_print_devinfo(ahd, devinfo);
                              printf("Expecting IU Change busfree\n");
                        }
#endif
                        ahd->msg_flags |= MSG_FLAG_EXPECT_PPR_BUSFREE
                                     |  MSG_FLAG_IU_REQ_CHANGED;
                  }
                  if ((old_ppr & MSG_EXT_PPR_IU_REQ) != 0) {
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                              printf("PPR with IU_REQ outstanding\n");
#endif
                        ahd->msg_flags |= MSG_FLAG_EXPECT_PPR_BUSFREE;
                  }
            }
      }

      update_needed += ahd_update_neg_request(ahd, devinfo, tstate,
                                    tinfo, AHD_NEG_TO_GOAL);

      if (update_needed && active)
            ahd_update_pending_scbs(ahd);
}

/*
 * Update the user/goal/curr tables of wide negotiation
 * parameters as well as, in the case of a current or active update,
 * any data structures on the host controller.  In the case of an
 * active update, the specified target is currently talking to us on
 * the bus, so the transfer parameter update must take effect
 * immediately.
 */
void
ahd_set_width(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
            u_int width, u_int type, int paused)
{
      struct      ahd_initiator_tinfo *tinfo;
      struct      ahd_tmode_tstate *tstate;
      u_int oldwidth;
      int   active;
      int   update_needed;

      active = (type & AHD_TRANS_ACTIVE) == AHD_TRANS_ACTIVE;
      update_needed = 0;
      tinfo = ahd_fetch_transinfo(ahd, devinfo->channel, devinfo->our_scsiid,
                            devinfo->target, &tstate);

      if ((type & AHD_TRANS_USER) != 0)
            tinfo->user.width = width;

      if ((type & AHD_TRANS_GOAL) != 0)
            tinfo->goal.width = width;

      oldwidth = tinfo->curr.width;
      if ((type & AHD_TRANS_CUR) != 0 && oldwidth != width) {

            update_needed++;

            tinfo->curr.width = width;
            ahd_send_async(ahd, devinfo->channel, devinfo->target,
                         CAM_LUN_WILDCARD, AC_TRANSFER_NEG);
            if (bootverbose) {
                  printf("%s: target %d using %dbit transfers\n",
                         ahd_name(ahd), devinfo->target,
                         8 * (0x01 << width));
            }
      }

      if ((type & AHD_TRANS_CUR) != 0) {
            if (!paused)
                  ahd_pause(ahd);
            ahd_update_neg_table(ahd, devinfo, &tinfo->curr);
            if (!paused)
                  ahd_unpause(ahd);
      }

      update_needed += ahd_update_neg_request(ahd, devinfo, tstate,
                                    tinfo, AHD_NEG_TO_GOAL);
      if (update_needed && active)
            ahd_update_pending_scbs(ahd);

}

/*
 * Update the current state of tagged queuing for a given target.
 */
void
ahd_set_tags(struct ahd_softc *ahd, struct scsi_cmnd *cmd,
           struct ahd_devinfo *devinfo, ahd_queue_alg alg)
{
      struct scsi_device *sdev = cmd->device;

      ahd_platform_set_tags(ahd, sdev, devinfo, alg);
      ahd_send_async(ahd, devinfo->channel, devinfo->target,
                   devinfo->lun, AC_TRANSFER_NEG);
}

static void
ahd_update_neg_table(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
                 struct ahd_transinfo *tinfo)
{
      ahd_mode_state    saved_modes;
      u_int       period;
      u_int       ppr_opts;
      u_int       con_opts;
      u_int       offset;
      u_int       saved_negoaddr;
      uint8_t           iocell_opts[sizeof(ahd->iocell_opts)];

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      saved_negoaddr = ahd_inb(ahd, NEGOADDR);
      ahd_outb(ahd, NEGOADDR, devinfo->target);
      period = tinfo->period;
      offset = tinfo->offset;
      memcpy(iocell_opts, ahd->iocell_opts, sizeof(ahd->iocell_opts)); 
      ppr_opts = tinfo->ppr_options & (MSG_EXT_PPR_QAS_REQ|MSG_EXT_PPR_DT_REQ
                              |MSG_EXT_PPR_IU_REQ|MSG_EXT_PPR_RTI);
      con_opts = 0;
      if (period == 0)
            period = AHD_SYNCRATE_ASYNC;
      if (period == AHD_SYNCRATE_160) {

            if ((ahd->bugs & AHD_PACED_NEGTABLE_BUG) != 0) {
                  /*
                   * When the SPI4 spec was finalized, PACE transfers
                   * was not made a configurable option in the PPR
                   * message.  Instead it is assumed to be enabled for
                   * any syncrate faster than 80MHz.  Nevertheless,
                   * Harpoon2A4 allows this to be configurable.
                   *
                   * Harpoon2A4 also assumes at most 2 data bytes per
                   * negotiated REQ/ACK offset.  Paced transfers take
                   * 4, so we must adjust our offset.
                   */
                  ppr_opts |= PPROPT_PACE;
                  offset *= 2;

                  /*
                   * Harpoon2A assumed that there would be a
                   * fallback rate between 160MHz and 80Mhz,
                   * so 7 is used as the period factor rather
                   * than 8 for 160MHz.
                   */
                  period = AHD_SYNCRATE_REVA_160;
            }
            if ((tinfo->ppr_options & MSG_EXT_PPR_PCOMP_EN) == 0)
                  iocell_opts[AHD_PRECOMP_SLEW_INDEX] &=
                      ~AHD_PRECOMP_MASK;
      } else {
            /*
             * Precomp should be disabled for non-paced transfers.
             */
            iocell_opts[AHD_PRECOMP_SLEW_INDEX] &= ~AHD_PRECOMP_MASK;

            if ((ahd->features & AHD_NEW_IOCELL_OPTS) != 0
             && (ppr_opts & MSG_EXT_PPR_DT_REQ) != 0
             && (ppr_opts & MSG_EXT_PPR_IU_REQ) == 0) {
                  /*
                   * Slow down our CRC interval to be
                   * compatible with non-packetized
                   * U160 devices that can't handle a
                   * CRC at full speed.
                   */
                  con_opts |= ENSLOWCRC;
            }

            if ((ahd->bugs & AHD_PACED_NEGTABLE_BUG) != 0) {
                  /*
                   * On H2A4, revert to a slower slewrate
                   * on non-paced transfers.
                   */
                  iocell_opts[AHD_PRECOMP_SLEW_INDEX] &=
                      ~AHD_SLEWRATE_MASK;
            }
      }

      ahd_outb(ahd, ANNEXCOL, AHD_ANNEXCOL_PRECOMP_SLEW);
      ahd_outb(ahd, ANNEXDAT, iocell_opts[AHD_PRECOMP_SLEW_INDEX]);
      ahd_outb(ahd, ANNEXCOL, AHD_ANNEXCOL_AMPLITUDE);
      ahd_outb(ahd, ANNEXDAT, iocell_opts[AHD_AMPLITUDE_INDEX]);

      ahd_outb(ahd, NEGPERIOD, period);
      ahd_outb(ahd, NEGPPROPTS, ppr_opts);
      ahd_outb(ahd, NEGOFFSET, offset);

      if (tinfo->width == MSG_EXT_WDTR_BUS_16_BIT)
            con_opts |= WIDEXFER;

      /*
       * Slow down our CRC interval to be
       * compatible with packetized U320 devices
       * that can't handle a CRC at full speed
       */
      if (ahd->features & AHD_AIC79XXB_SLOWCRC) {
            con_opts |= ENSLOWCRC;
      }

      /*
       * During packetized transfers, the target will
       * give us the oportunity to send command packets
       * without us asserting attention.
       */
      if ((tinfo->ppr_options & MSG_EXT_PPR_IU_REQ) == 0)
            con_opts |= ENAUTOATNO;
      ahd_outb(ahd, NEGCONOPTS, con_opts);
      ahd_outb(ahd, NEGOADDR, saved_negoaddr);
      ahd_restore_modes(ahd, saved_modes);
}

/*
 * When the transfer settings for a connection change, setup for
 * negotiation in pending SCBs to effect the change as quickly as
 * possible.  We also cancel any negotiations that are scheduled
 * for inflight SCBs that have not been started yet.
 */
static void
ahd_update_pending_scbs(struct ahd_softc *ahd)
{
      struct            scb *pending_scb;
      int         pending_scb_count;
      int         paused;
      u_int       saved_scbptr;
      ahd_mode_state    saved_modes;

      /*
       * Traverse the pending SCB list and ensure that all of the
       * SCBs there have the proper settings.  We can only safely
       * clear the negotiation required flag (setting requires the
       * execution queue to be modified) and this is only possible
       * if we are not already attempting to select out for this
       * SCB.  For this reason, all callers only call this routine
       * if we are changing the negotiation settings for the currently
       * active transaction on the bus.
       */
      pending_scb_count = 0;
      LIST_FOREACH(pending_scb, &ahd->pending_scbs, pending_links) {
            struct ahd_devinfo devinfo;
            struct ahd_initiator_tinfo *tinfo;
            struct ahd_tmode_tstate *tstate;

            ahd_scb_devinfo(ahd, &devinfo, pending_scb);
            tinfo = ahd_fetch_transinfo(ahd, devinfo.channel,
                                  devinfo.our_scsiid,
                                  devinfo.target, &tstate);
            if ((tstate->auto_negotiate & devinfo.target_mask) == 0
             && (pending_scb->flags & SCB_AUTO_NEGOTIATE) != 0) {
                  pending_scb->flags &= ~SCB_AUTO_NEGOTIATE;
                  pending_scb->hscb->control &= ~MK_MESSAGE;
            }
            ahd_sync_scb(ahd, pending_scb,
                       BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
            pending_scb_count++;
      }

      if (pending_scb_count == 0)
            return;

      if (ahd_is_paused(ahd)) {
            paused = 1;
      } else {
            paused = 0;
            ahd_pause(ahd);
      }

      /*
       * Force the sequencer to reinitialize the selection for
       * the command at the head of the execution queue if it
       * has already been setup.  The negotiation changes may
       * effect whether we select-out with ATN.  It is only
       * safe to clear ENSELO when the bus is not free and no
       * selection is in progres or completed.
       */
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      if ((ahd_inb(ahd, SCSISIGI) & BSYI) != 0
       && (ahd_inb(ahd, SSTAT0) & (SELDO|SELINGO)) == 0)
            ahd_outb(ahd, SCSISEQ0, ahd_inb(ahd, SCSISEQ0) & ~ENSELO);
      saved_scbptr = ahd_get_scbptr(ahd);
      /* Ensure that the hscbs down on the card match the new information */
      LIST_FOREACH(pending_scb, &ahd->pending_scbs, pending_links) {
            u_int scb_tag;
            u_int control;

            scb_tag = SCB_GET_TAG(pending_scb);
            ahd_set_scbptr(ahd, scb_tag);
            control = ahd_inb_scbram(ahd, SCB_CONTROL);
            control &= ~MK_MESSAGE;
            control |= pending_scb->hscb->control & MK_MESSAGE;
            ahd_outb(ahd, SCB_CONTROL, control);
      }
      ahd_set_scbptr(ahd, saved_scbptr);
      ahd_restore_modes(ahd, saved_modes);

      if (paused == 0)
            ahd_unpause(ahd);
}

/**************************** Pathing Information *****************************/
static void
ahd_fetch_devinfo(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      ahd_mode_state    saved_modes;
      u_int       saved_scsiid;
      role_t            role;
      int         our_id;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      if (ahd_inb(ahd, SSTAT0) & TARGET)
            role = ROLE_TARGET;
      else
            role = ROLE_INITIATOR;

      if (role == ROLE_TARGET
       && (ahd_inb(ahd, SEQ_FLAGS) & CMDPHASE_PENDING) != 0) {
            /* We were selected, so pull our id from TARGIDIN */
            our_id = ahd_inb(ahd, TARGIDIN) & OID;
      } else if (role == ROLE_TARGET)
            our_id = ahd_inb(ahd, TOWNID);
      else
            our_id = ahd_inb(ahd, IOWNID);

      saved_scsiid = ahd_inb(ahd, SAVED_SCSIID);
      ahd_compile_devinfo(devinfo,
                      our_id,
                      SCSIID_TARGET(ahd, saved_scsiid),
                      ahd_inb(ahd, SAVED_LUN),
                      SCSIID_CHANNEL(ahd, saved_scsiid),
                      role);
      ahd_restore_modes(ahd, saved_modes);
}

void
ahd_print_devinfo(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      printf("%s:%c:%d:%d: ", ahd_name(ahd), 'A',
             devinfo->target, devinfo->lun);
}

struct ahd_phase_table_entry*
ahd_lookup_phase_entry(int phase)
{
      struct ahd_phase_table_entry *entry;
      struct ahd_phase_table_entry *last_entry;

      /*
       * num_phases doesn't include the default entry which
       * will be returned if the phase doesn't match.
       */
      last_entry = &ahd_phase_table[num_phases];
      for (entry = ahd_phase_table; entry < last_entry; entry++) {
            if (phase == entry->phase)
                  break;
      }
      return (entry);
}

void
ahd_compile_devinfo(struct ahd_devinfo *devinfo, u_int our_id, u_int target,
                u_int lun, char channel, role_t role)
{
      devinfo->our_scsiid = our_id;
      devinfo->target = target;
      devinfo->lun = lun;
      devinfo->target_offset = target;
      devinfo->channel = channel;
      devinfo->role = role;
      if (channel == 'B')
            devinfo->target_offset += 8;
      devinfo->target_mask = (0x01 << devinfo->target_offset);
}

static void
ahd_scb_devinfo(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
            struct scb *scb)
{
      role_t      role;
      int   our_id;

      our_id = SCSIID_OUR_ID(scb->hscb->scsiid);
      role = ROLE_INITIATOR;
      if ((scb->hscb->control & TARGET_SCB) != 0)
            role = ROLE_TARGET;
      ahd_compile_devinfo(devinfo, our_id, SCB_GET_TARGET(ahd, scb),
                      SCB_GET_LUN(scb), SCB_GET_CHANNEL(ahd, scb), role);
}


/************************ Message Phase Processing ****************************/
/*
 * When an initiator transaction with the MK_MESSAGE flag either reconnects
 * or enters the initial message out phase, we are interrupted.  Fill our
 * outgoing message buffer with the appropriate message and beging handing
 * the message phase(s) manually.
 */
static void
ahd_setup_initiator_msgout(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
                     struct scb *scb)
{
      /*
       * To facilitate adding multiple messages together,
       * each routine should increment the index and len
       * variables instead of setting them explicitly.
       */
      ahd->msgout_index = 0;
      ahd->msgout_len = 0;

      if (ahd_currently_packetized(ahd))
            ahd->msg_flags |= MSG_FLAG_PACKETIZED;

      if (ahd->send_msg_perror
       && ahd_inb(ahd, MSG_OUT) == HOST_MSG) {
            ahd->msgout_buf[ahd->msgout_index++] = ahd->send_msg_perror;
            ahd->msgout_len++;
            ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                  printf("Setting up for Parity Error delivery\n");
#endif
            return;
      } else if (scb == NULL) {
            printf("%s: WARNING. No pending message for "
                   "I_T msgin.  Issuing NO-OP\n", ahd_name(ahd));
            ahd->msgout_buf[ahd->msgout_index++] = MSG_NOOP;
            ahd->msgout_len++;
            ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
            return;
      }

      if ((scb->flags & SCB_DEVICE_RESET) == 0
       && (scb->flags & SCB_PACKETIZED) == 0
       && ahd_inb(ahd, MSG_OUT) == MSG_IDENTIFYFLAG) {
            u_int identify_msg;

            identify_msg = MSG_IDENTIFYFLAG | SCB_GET_LUN(scb);
            if ((scb->hscb->control & DISCENB) != 0)
                  identify_msg |= MSG_IDENTIFY_DISCFLAG;
            ahd->msgout_buf[ahd->msgout_index++] = identify_msg;
            ahd->msgout_len++;

            if ((scb->hscb->control & TAG_ENB) != 0) {
                  ahd->msgout_buf[ahd->msgout_index++] =
                      scb->hscb->control & (TAG_ENB|SCB_TAG_TYPE);
                  ahd->msgout_buf[ahd->msgout_index++] = SCB_GET_TAG(scb);
                  ahd->msgout_len += 2;
            }
      }

      if (scb->flags & SCB_DEVICE_RESET) {
            ahd->msgout_buf[ahd->msgout_index++] = MSG_BUS_DEV_RESET;
            ahd->msgout_len++;
            ahd_print_path(ahd, scb);
            printf("Bus Device Reset Message Sent\n");
            /*
             * Clear our selection hardware in advance of
             * the busfree.  We may have an entry in the waiting
             * Q for this target, and we don't want to go about
             * selecting while we handle the busfree and blow it
             * away.
             */
            ahd_outb(ahd, SCSISEQ0, 0);
      } else if ((scb->flags & SCB_ABORT) != 0) {

            if ((scb->hscb->control & TAG_ENB) != 0) {
                  ahd->msgout_buf[ahd->msgout_index++] = MSG_ABORT_TAG;
            } else {
                  ahd->msgout_buf[ahd->msgout_index++] = MSG_ABORT;
            }
            ahd->msgout_len++;
            ahd_print_path(ahd, scb);
            printf("Abort%s Message Sent\n",
                   (scb->hscb->control & TAG_ENB) != 0 ? " Tag" : "");
            /*
             * Clear our selection hardware in advance of
             * the busfree.  We may have an entry in the waiting
             * Q for this target, and we don't want to go about
             * selecting while we handle the busfree and blow it
             * away.
             */
            ahd_outb(ahd, SCSISEQ0, 0);
      } else if ((scb->flags & (SCB_AUTO_NEGOTIATE|SCB_NEGOTIATE)) != 0) {
            ahd_build_transfer_msg(ahd, devinfo);
            /*
             * Clear our selection hardware in advance of potential
             * PPR IU status change busfree.  We may have an entry in
             * the waiting Q for this target, and we don't want to go
             * about selecting while we handle the busfree and blow
             * it away.
             */
            ahd_outb(ahd, SCSISEQ0, 0);
      } else {
            printf("ahd_intr: AWAITING_MSG for an SCB that "
                   "does not have a waiting message\n");
            printf("SCSIID = %x, target_mask = %x\n", scb->hscb->scsiid,
                   devinfo->target_mask);
            panic("SCB = %d, SCB Control = %x:%x, MSG_OUT = %x "
                  "SCB flags = %x", SCB_GET_TAG(scb), scb->hscb->control,
                  ahd_inb_scbram(ahd, SCB_CONTROL), ahd_inb(ahd, MSG_OUT),
                  scb->flags);
      }

      /*
       * Clear the MK_MESSAGE flag from the SCB so we aren't
       * asked to send this message again.
       */
      ahd_outb(ahd, SCB_CONTROL,
             ahd_inb_scbram(ahd, SCB_CONTROL) & ~MK_MESSAGE);
      scb->hscb->control &= ~MK_MESSAGE;
      ahd->msgout_index = 0;
      ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
}

/*
 * Build an appropriate transfer negotiation message for the
 * currently active target.
 */
static void
ahd_build_transfer_msg(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      /*
       * We need to initiate transfer negotiations.
       * If our current and goal settings are identical,
       * we want to renegotiate due to a check condition.
       */
      struct      ahd_initiator_tinfo *tinfo;
      struct      ahd_tmode_tstate *tstate;
      int   dowide;
      int   dosync;
      int   doppr;
      u_int period;
      u_int ppr_options;
      u_int offset;

      tinfo = ahd_fetch_transinfo(ahd, devinfo->channel, devinfo->our_scsiid,
                            devinfo->target, &tstate);
      /*
       * Filter our period based on the current connection.
       * If we can't perform DT transfers on this segment (not in LVD
       * mode for instance), then our decision to issue a PPR message
       * may change.
       */
      period = tinfo->goal.period;
      offset = tinfo->goal.offset;
      ppr_options = tinfo->goal.ppr_options;
      /* Target initiated PPR is not allowed in the SCSI spec */
      if (devinfo->role == ROLE_TARGET)
            ppr_options = 0;
      ahd_devlimited_syncrate(ahd, tinfo, &period,
                        &ppr_options, devinfo->role);
      dowide = tinfo->curr.width != tinfo->goal.width;
      dosync = tinfo->curr.offset != offset || tinfo->curr.period != period;
      /*
       * Only use PPR if we have options that need it, even if the device
       * claims to support it.  There might be an expander in the way
       * that doesn't.
       */
      doppr = ppr_options != 0;

      if (!dowide && !dosync && !doppr) {
            dowide = tinfo->goal.width != MSG_EXT_WDTR_BUS_8_BIT;
            dosync = tinfo->goal.offset != 0;
      }

      if (!dowide && !dosync && !doppr) {
            /*
             * Force async with a WDTR message if we have a wide bus,
             * or just issue an SDTR with a 0 offset.
             */
            if ((ahd->features & AHD_WIDE) != 0)
                  dowide = 1;
            else
                  dosync = 1;

            if (bootverbose) {
                  ahd_print_devinfo(ahd, devinfo);
                  printf("Ensuring async\n");
            }
      }
      /* Target initiated PPR is not allowed in the SCSI spec */
      if (devinfo->role == ROLE_TARGET)
            doppr = 0;

      /*
       * Both the PPR message and SDTR message require the
       * goal syncrate to be limited to what the target device
       * is capable of handling (based on whether an LVD->SE
       * expander is on the bus), so combine these two cases.
       * Regardless, guarantee that if we are using WDTR and SDTR
       * messages that WDTR comes first.
       */
      if (doppr || (dosync && !dowide)) {

            offset = tinfo->goal.offset;
            ahd_validate_offset(ahd, tinfo, period, &offset,
                            doppr ? tinfo->goal.width
                                : tinfo->curr.width,
                            devinfo->role);
            if (doppr) {
                  ahd_construct_ppr(ahd, devinfo, period, offset,
                                tinfo->goal.width, ppr_options);
            } else {
                  ahd_construct_sdtr(ahd, devinfo, period, offset);
            }
      } else {
            ahd_construct_wdtr(ahd, devinfo, tinfo->goal.width);
      }
}

/*
 * Build a synchronous negotiation message in our message
 * buffer based on the input parameters.
 */
static void
ahd_construct_sdtr(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
               u_int period, u_int offset)
{
      if (offset == 0)
            period = AHD_ASYNC_XFER_PERIOD;
      ahd->msgout_index += spi_populate_sync_msg(
                  ahd->msgout_buf + ahd->msgout_index, period, offset);
      ahd->msgout_len += 5;
      if (bootverbose) {
            printf("(%s:%c:%d:%d): Sending SDTR period %x, offset %x\n",
                   ahd_name(ahd), devinfo->channel, devinfo->target,
                   devinfo->lun, period, offset);
      }
}

/*
 * Build a wide negotiateion message in our message
 * buffer based on the input parameters.
 */
static void
ahd_construct_wdtr(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
               u_int bus_width)
{
      ahd->msgout_index += spi_populate_width_msg(
                  ahd->msgout_buf + ahd->msgout_index, bus_width);
      ahd->msgout_len += 4;
      if (bootverbose) {
            printf("(%s:%c:%d:%d): Sending WDTR %x\n",
                   ahd_name(ahd), devinfo->channel, devinfo->target,
                   devinfo->lun, bus_width);
      }
}

/*
 * Build a parallel protocol request message in our message
 * buffer based on the input parameters.
 */
static void
ahd_construct_ppr(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
              u_int period, u_int offset, u_int bus_width,
              u_int ppr_options)
{
      /*
       * Always request precompensation from
       * the other target if we are running
       * at paced syncrates.
       */
      if (period <= AHD_SYNCRATE_PACED)
            ppr_options |= MSG_EXT_PPR_PCOMP_EN;
      if (offset == 0)
            period = AHD_ASYNC_XFER_PERIOD;
      ahd->msgout_index += spi_populate_ppr_msg(
                  ahd->msgout_buf + ahd->msgout_index, period, offset,
                  bus_width, ppr_options);
      ahd->msgout_len += 8;
      if (bootverbose) {
            printf("(%s:%c:%d:%d): Sending PPR bus_width %x, period %x, "
                   "offset %x, ppr_options %x\n", ahd_name(ahd),
                   devinfo->channel, devinfo->target, devinfo->lun,
                   bus_width, period, offset, ppr_options);
      }
}

/*
 * Clear any active message state.
 */
static void
ahd_clear_msg_state(struct ahd_softc *ahd)
{
      ahd_mode_state saved_modes;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      ahd->send_msg_perror = 0;
      ahd->msg_flags = MSG_FLAG_NONE;
      ahd->msgout_len = 0;
      ahd->msgin_index = 0;
      ahd->msg_type = MSG_TYPE_NONE;
      if ((ahd_inb(ahd, SCSISIGO) & ATNO) != 0) {
            /*
             * The target didn't care to respond to our
             * message request, so clear ATN.
             */
            ahd_outb(ahd, CLRSINT1, CLRATNO);
      }
      ahd_outb(ahd, MSG_OUT, MSG_NOOP);
      ahd_outb(ahd, SEQ_FLAGS2,
             ahd_inb(ahd, SEQ_FLAGS2) & ~TARGET_MSG_PENDING);
      ahd_restore_modes(ahd, saved_modes);
}

/*
 * Manual message loop handler.
 */
static void
ahd_handle_message_phase(struct ahd_softc *ahd)
{ 
      struct      ahd_devinfo devinfo;
      u_int bus_phase;
      int   end_session;

      ahd_fetch_devinfo(ahd, &devinfo);
      end_session = FALSE;
      bus_phase = ahd_inb(ahd, LASTPHASE);

      if ((ahd_inb(ahd, LQISTAT2) & LQIPHASE_OUTPKT) != 0) {
            printf("LQIRETRY for LQIPHASE_OUTPKT\n");
            ahd_outb(ahd, LQCTL2, LQIRETRY);
      }
reswitch:
      switch (ahd->msg_type) {
      case MSG_TYPE_INITIATOR_MSGOUT:
      {
            int lastbyte;
            int phasemis;
            int msgdone;

            if (ahd->msgout_len == 0 && ahd->send_msg_perror == 0)
                  panic("HOST_MSG_LOOP interrupt with no active message");

#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                  ahd_print_devinfo(ahd, &devinfo);
                  printf("INITIATOR_MSG_OUT");
            }
#endif
            phasemis = bus_phase != P_MESGOUT;
            if (phasemis) {
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                        printf(" PHASEMIS %s\n",
                               ahd_lookup_phase_entry(bus_phase)
                                               ->phasemsg);
                  }
#endif
                  if (bus_phase == P_MESGIN) {
                        /*
                         * Change gears and see if
                         * this messages is of interest to
                         * us or should be passed back to
                         * the sequencer.
                         */
                        ahd_outb(ahd, CLRSINT1, CLRATNO);
                        ahd->send_msg_perror = 0;
                        ahd->msg_type = MSG_TYPE_INITIATOR_MSGIN;
                        ahd->msgin_index = 0;
                        goto reswitch;
                  }
                  end_session = TRUE;
                  break;
            }

            if (ahd->send_msg_perror) {
                  ahd_outb(ahd, CLRSINT1, CLRATNO);
                  ahd_outb(ahd, CLRSINT1, CLRREQINIT);
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                        printf(" byte 0x%x\n", ahd->send_msg_perror);
#endif
                  /*
                   * If we are notifying the target of a CRC error
                   * during packetized operations, the target is
                   * within its rights to acknowledge our message
                   * with a busfree.
                   */
                  if ((ahd->msg_flags & MSG_FLAG_PACKETIZED) != 0
                   && ahd->send_msg_perror == MSG_INITIATOR_DET_ERR)
                        ahd->msg_flags |= MSG_FLAG_EXPECT_IDE_BUSFREE;

                  ahd_outb(ahd, RETURN_2, ahd->send_msg_perror);
                  ahd_outb(ahd, RETURN_1, CONT_MSG_LOOP_WRITE);
                  break;
            }

            msgdone     = ahd->msgout_index == ahd->msgout_len;
            if (msgdone) {
                  /*
                   * The target has requested a retry.
                   * Re-assert ATN, reset our message index to
                   * 0, and try again.
                   */
                  ahd->msgout_index = 0;
                  ahd_assert_atn(ahd);
            }

            lastbyte = ahd->msgout_index == (ahd->msgout_len - 1);
            if (lastbyte) {
                  /* Last byte is signified by dropping ATN */
                  ahd_outb(ahd, CLRSINT1, CLRATNO);
            }

            /*
             * Clear our interrupt status and present
             * the next byte on the bus.
             */
            ahd_outb(ahd, CLRSINT1, CLRREQINIT);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                  printf(" byte 0x%x\n",
                         ahd->msgout_buf[ahd->msgout_index]);
#endif
            ahd_outb(ahd, RETURN_2, ahd->msgout_buf[ahd->msgout_index++]);
            ahd_outb(ahd, RETURN_1, CONT_MSG_LOOP_WRITE);
            break;
      }
      case MSG_TYPE_INITIATOR_MSGIN:
      {
            int phasemis;
            int message_done;

#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                  ahd_print_devinfo(ahd, &devinfo);
                  printf("INITIATOR_MSG_IN");
            }
#endif
            phasemis = bus_phase != P_MESGIN;
            if (phasemis) {
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                        printf(" PHASEMIS %s\n",
                               ahd_lookup_phase_entry(bus_phase)
                                               ->phasemsg);
                  }
#endif
                  ahd->msgin_index = 0;
                  if (bus_phase == P_MESGOUT
                   && (ahd->send_msg_perror != 0
                    || (ahd->msgout_len != 0
                     && ahd->msgout_index == 0))) {
                        ahd->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                        goto reswitch;
                  }
                  end_session = TRUE;
                  break;
            }

            /* Pull the byte in without acking it */
            ahd->msgin_buf[ahd->msgin_index] = ahd_inb(ahd, SCSIBUS);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                  printf(" byte 0x%x\n",
                         ahd->msgin_buf[ahd->msgin_index]);
#endif

            message_done = ahd_parse_msg(ahd, &devinfo);

            if (message_done) {
                  /*
                   * Clear our incoming message buffer in case there
                   * is another message following this one.
                   */
                  ahd->msgin_index = 0;

                  /*
                   * If this message illicited a response,
                   * assert ATN so the target takes us to the
                   * message out phase.
                   */
                  if (ahd->msgout_len != 0) {
#ifdef AHD_DEBUG
                        if ((ahd_debug & AHD_SHOW_MESSAGES) != 0) {
                              ahd_print_devinfo(ahd, &devinfo);
                              printf("Asserting ATN for response\n");
                        }
#endif
                        ahd_assert_atn(ahd);
                  }
            } else 
                  ahd->msgin_index++;

            if (message_done == MSGLOOP_TERMINATED) {
                  end_session = TRUE;
            } else {
                  /* Ack the byte */
                  ahd_outb(ahd, CLRSINT1, CLRREQINIT);
                  ahd_outb(ahd, RETURN_1, CONT_MSG_LOOP_READ);
            }
            break;
      }
      case MSG_TYPE_TARGET_MSGIN:
      {
            int msgdone;
            int msgout_request;

            /*
             * By default, the message loop will continue.
             */
            ahd_outb(ahd, RETURN_1, CONT_MSG_LOOP_TARG);

            if (ahd->msgout_len == 0)
                  panic("Target MSGIN with no active message");

            /*
             * If we interrupted a mesgout session, the initiator
             * will not know this until our first REQ.  So, we
             * only honor mesgout requests after we've sent our
             * first byte.
             */
            if ((ahd_inb(ahd, SCSISIGI) & ATNI) != 0
             && ahd->msgout_index > 0)
                  msgout_request = TRUE;
            else
                  msgout_request = FALSE;

            if (msgout_request) {

                  /*
                   * Change gears and see if
                   * this messages is of interest to
                   * us or should be passed back to
                   * the sequencer.
                   */
                  ahd->msg_type = MSG_TYPE_TARGET_MSGOUT;
                  ahd_outb(ahd, SCSISIGO, P_MESGOUT | BSYO);
                  ahd->msgin_index = 0;
                  /* Dummy read to REQ for first byte */
                  ahd_inb(ahd, SCSIDAT);
                  ahd_outb(ahd, SXFRCTL0,
                         ahd_inb(ahd, SXFRCTL0) | SPIOEN);
                  break;
            }

            msgdone = ahd->msgout_index == ahd->msgout_len;
            if (msgdone) {
                  ahd_outb(ahd, SXFRCTL0,
                         ahd_inb(ahd, SXFRCTL0) & ~SPIOEN);
                  end_session = TRUE;
                  break;
            }

            /*
             * Present the next byte on the bus.
             */
            ahd_outb(ahd, SXFRCTL0, ahd_inb(ahd, SXFRCTL0) | SPIOEN);
            ahd_outb(ahd, SCSIDAT, ahd->msgout_buf[ahd->msgout_index++]);
            break;
      }
      case MSG_TYPE_TARGET_MSGOUT:
      {
            int lastbyte;
            int msgdone;

            /*
             * By default, the message loop will continue.
             */
            ahd_outb(ahd, RETURN_1, CONT_MSG_LOOP_TARG);

            /*
             * The initiator signals that this is
             * the last byte by dropping ATN.
             */
            lastbyte = (ahd_inb(ahd, SCSISIGI) & ATNI) == 0;

            /*
             * Read the latched byte, but turn off SPIOEN first
             * so that we don't inadvertently cause a REQ for the
             * next byte.
             */
            ahd_outb(ahd, SXFRCTL0, ahd_inb(ahd, SXFRCTL0) & ~SPIOEN);
            ahd->msgin_buf[ahd->msgin_index] = ahd_inb(ahd, SCSIDAT);
            msgdone = ahd_parse_msg(ahd, &devinfo);
            if (msgdone == MSGLOOP_TERMINATED) {
                  /*
                   * The message is *really* done in that it caused
                   * us to go to bus free.  The sequencer has already
                   * been reset at this point, so pull the ejection
                   * handle.
                   */
                  return;
            }
            
            ahd->msgin_index++;

            /*
             * XXX Read spec about initiator dropping ATN too soon
             *     and use msgdone to detect it.
             */
            if (msgdone == MSGLOOP_MSGCOMPLETE) {
                  ahd->msgin_index = 0;

                  /*
                   * If this message illicited a response, transition
                   * to the Message in phase and send it.
                   */
                  if (ahd->msgout_len != 0) {
                        ahd_outb(ahd, SCSISIGO, P_MESGIN | BSYO);
                        ahd_outb(ahd, SXFRCTL0,
                               ahd_inb(ahd, SXFRCTL0) | SPIOEN);
                        ahd->msg_type = MSG_TYPE_TARGET_MSGIN;
                        ahd->msgin_index = 0;
                        break;
                  }
            }

            if (lastbyte)
                  end_session = TRUE;
            else {
                  /* Ask for the next byte. */
                  ahd_outb(ahd, SXFRCTL0,
                         ahd_inb(ahd, SXFRCTL0) | SPIOEN);
            }

            break;
      }
      default:
            panic("Unknown REQINIT message type");
      }

      if (end_session) {
            if ((ahd->msg_flags & MSG_FLAG_PACKETIZED) != 0) {
                  printf("%s: Returning to Idle Loop\n",
                         ahd_name(ahd));
                  ahd_clear_msg_state(ahd);

                  /*
                   * Perform the equivalent of a clear_target_state.
                   */
                  ahd_outb(ahd, LASTPHASE, P_BUSFREE);
                  ahd_outb(ahd, SEQ_FLAGS, NOT_IDENTIFIED|NO_CDB_SENT);
                  ahd_outb(ahd, SEQCTL0, FASTMODE|SEQRESET);
            } else {
                  ahd_clear_msg_state(ahd);
                  ahd_outb(ahd, RETURN_1, EXIT_MSG_LOOP);
            }
      }
}

/*
 * See if we sent a particular extended message to the target.
 * If "full" is true, return true only if the target saw the full
 * message.  If "full" is false, return true if the target saw at
 * least the first byte of the message.
 */
static int
ahd_sent_msg(struct ahd_softc *ahd, ahd_msgtype type, u_int msgval, int full)
{
      int found;
      u_int index;

      found = FALSE;
      index = 0;

      while (index < ahd->msgout_len) {
            if (ahd->msgout_buf[index] == MSG_EXTENDED) {
                  u_int end_index;

                  end_index = index + 1 + ahd->msgout_buf[index + 1];
                  if (ahd->msgout_buf[index+2] == msgval
                   && type == AHDMSG_EXT) {

                        if (full) {
                              if (ahd->msgout_index > end_index)
                                    found = TRUE;
                        } else if (ahd->msgout_index > index)
                              found = TRUE;
                  }
                  index = end_index;
            } else if (ahd->msgout_buf[index] >= MSG_SIMPLE_TASK
                  && ahd->msgout_buf[index] <= MSG_IGN_WIDE_RESIDUE) {

                  /* Skip tag type and tag id or residue param*/
                  index += 2;
            } else {
                  /* Single byte message */
                  if (type == AHDMSG_1B
                   && ahd->msgout_index > index
                   && (ahd->msgout_buf[index] == msgval
                    || ((ahd->msgout_buf[index] & MSG_IDENTIFYFLAG) != 0
                     && msgval == MSG_IDENTIFYFLAG)))
                        found = TRUE;
                  index++;
            }

            if (found)
                  break;
      }
      return (found);
}

/*
 * Wait for a complete incoming message, parse it, and respond accordingly.
 */
static int
ahd_parse_msg(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      struct      ahd_initiator_tinfo *tinfo;
      struct      ahd_tmode_tstate *tstate;
      int   reject;
      int   done;
      int   response;

      done = MSGLOOP_IN_PROG;
      response = FALSE;
      reject = FALSE;
      tinfo = ahd_fetch_transinfo(ahd, devinfo->channel, devinfo->our_scsiid,
                            devinfo->target, &tstate);

      /*
       * Parse as much of the message as is available,
       * rejecting it if we don't support it.  When
       * the entire message is available and has been
       * handled, return MSGLOOP_MSGCOMPLETE, indicating
       * that we have parsed an entire message.
       *
       * In the case of extended messages, we accept the length
       * byte outright and perform more checking once we know the
       * extended message type.
       */
      switch (ahd->msgin_buf[0]) {
      case MSG_DISCONNECT:
      case MSG_SAVEDATAPOINTER:
      case MSG_CMDCOMPLETE:
      case MSG_RESTOREPOINTERS:
      case MSG_IGN_WIDE_RESIDUE:
            /*
             * End our message loop as these are messages
             * the sequencer handles on its own.
             */
            done = MSGLOOP_TERMINATED;
            break;
      case MSG_MESSAGE_REJECT:
            response = ahd_handle_msg_reject(ahd, devinfo);
            /* FALLTHROUGH */
      case MSG_NOOP:
            done = MSGLOOP_MSGCOMPLETE;
            break;
      case MSG_EXTENDED:
      {
            /* Wait for enough of the message to begin validation */
            if (ahd->msgin_index < 2)
                  break;
            switch (ahd->msgin_buf[2]) {
            case MSG_EXT_SDTR:
            {
                  u_int  period;
                  u_int  ppr_options;
                  u_int  offset;
                  u_int  saved_offset;
                  
                  if (ahd->msgin_buf[1] != MSG_EXT_SDTR_LEN) {
                        reject = TRUE;
                        break;
                  }

                  /*
                   * Wait until we have both args before validating
                   * and acting on this message.
                   *
                   * Add one to MSG_EXT_SDTR_LEN to account for
                   * the extended message preamble.
                   */
                  if (ahd->msgin_index < (MSG_EXT_SDTR_LEN + 1))
                        break;

                  period = ahd->msgin_buf[3];
                  ppr_options = 0;
                  saved_offset = offset = ahd->msgin_buf[4];
                  ahd_devlimited_syncrate(ahd, tinfo, &period,
                                    &ppr_options, devinfo->role);
                  ahd_validate_offset(ahd, tinfo, period, &offset,
                                  tinfo->curr.width, devinfo->role);
                  if (bootverbose) {
                        printf("(%s:%c:%d:%d): Received "
                               "SDTR period %x, offset %x\n\t"
                               "Filtered to period %x, offset %x\n",
                               ahd_name(ahd), devinfo->channel,
                               devinfo->target, devinfo->lun,
                               ahd->msgin_buf[3], saved_offset,
                               period, offset);
                  }
                  ahd_set_syncrate(ahd, devinfo, period,
                               offset, ppr_options,
                               AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                               /*paused*/TRUE);

                  /*
                   * See if we initiated Sync Negotiation
                   * and didn't have to fall down to async
                   * transfers.
                   */
                  if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_SDTR, TRUE)) {
                        /* We started it */
                        if (saved_offset != offset) {
                              /* Went too low - force async */
                              reject = TRUE;
                        }
                  } else {
                        /*
                         * Send our own SDTR in reply
                         */
                        if (bootverbose
                         && devinfo->role == ROLE_INITIATOR) {
                              printf("(%s:%c:%d:%d): Target "
                                     "Initiated SDTR\n",
                                     ahd_name(ahd), devinfo->channel,
                                     devinfo->target, devinfo->lun);
                        }
                        ahd->msgout_index = 0;
                        ahd->msgout_len = 0;
                        ahd_construct_sdtr(ahd, devinfo,
                                       period, offset);
                        ahd->msgout_index = 0;
                        response = TRUE;
                  }
                  done = MSGLOOP_MSGCOMPLETE;
                  break;
            }
            case MSG_EXT_WDTR:
            {
                  u_int bus_width;
                  u_int saved_width;
                  u_int sending_reply;

                  sending_reply = FALSE;
                  if (ahd->msgin_buf[1] != MSG_EXT_WDTR_LEN) {
                        reject = TRUE;
                        break;
                  }

                  /*
                   * Wait until we have our arg before validating
                   * and acting on this message.
                   *
                   * Add one to MSG_EXT_WDTR_LEN to account for
                   * the extended message preamble.
                   */
                  if (ahd->msgin_index < (MSG_EXT_WDTR_LEN + 1))
                        break;

                  bus_width = ahd->msgin_buf[3];
                  saved_width = bus_width;
                  ahd_validate_width(ahd, tinfo, &bus_width,
                                 devinfo->role);
                  if (bootverbose) {
                        printf("(%s:%c:%d:%d): Received WDTR "
                               "%x filtered to %x\n",
                               ahd_name(ahd), devinfo->channel,
                               devinfo->target, devinfo->lun,
                               saved_width, bus_width);
                  }

                  if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_WDTR, TRUE)) {
                        /*
                         * Don't send a WDTR back to the
                         * target, since we asked first.
                         * If the width went higher than our
                         * request, reject it.
                         */
                        if (saved_width > bus_width) {
                              reject = TRUE;
                              printf("(%s:%c:%d:%d): requested %dBit "
                                     "transfers.  Rejecting...\n",
                                     ahd_name(ahd), devinfo->channel,
                                     devinfo->target, devinfo->lun,
                                     8 * (0x01 << bus_width));
                              bus_width = 0;
                        }
                  } else {
                        /*
                         * Send our own WDTR in reply
                         */
                        if (bootverbose
                         && devinfo->role == ROLE_INITIATOR) {
                              printf("(%s:%c:%d:%d): Target "
                                     "Initiated WDTR\n",
                                     ahd_name(ahd), devinfo->channel,
                                     devinfo->target, devinfo->lun);
                        }
                        ahd->msgout_index = 0;
                        ahd->msgout_len = 0;
                        ahd_construct_wdtr(ahd, devinfo, bus_width);
                        ahd->msgout_index = 0;
                        response = TRUE;
                        sending_reply = TRUE;
                  }
                  /*
                   * After a wide message, we are async, but
                   * some devices don't seem to honor this portion
                   * of the spec.  Force a renegotiation of the
                   * sync component of our transfer agreement even
                   * if our goal is async.  By updating our width
                   * after forcing the negotiation, we avoid
                   * renegotiating for width.
                   */
                  ahd_update_neg_request(ahd, devinfo, tstate,
                                     tinfo, AHD_NEG_ALWAYS);
                  ahd_set_width(ahd, devinfo, bus_width,
                              AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                              /*paused*/TRUE);
                  if (sending_reply == FALSE && reject == FALSE) {

                        /*
                         * We will always have an SDTR to send.
                         */
                        ahd->msgout_index = 0;
                        ahd->msgout_len = 0;
                        ahd_build_transfer_msg(ahd, devinfo);
                        ahd->msgout_index = 0;
                        response = TRUE;
                  }
                  done = MSGLOOP_MSGCOMPLETE;
                  break;
            }
            case MSG_EXT_PPR:
            {
                  u_int period;
                  u_int offset;
                  u_int bus_width;
                  u_int ppr_options;
                  u_int saved_width;
                  u_int saved_offset;
                  u_int saved_ppr_options;

                  if (ahd->msgin_buf[1] != MSG_EXT_PPR_LEN) {
                        reject = TRUE;
                        break;
                  }

                  /*
                   * Wait until we have all args before validating
                   * and acting on this message.
                   *
                   * Add one to MSG_EXT_PPR_LEN to account for
                   * the extended message preamble.
                   */
                  if (ahd->msgin_index < (MSG_EXT_PPR_LEN + 1))
                        break;

                  period = ahd->msgin_buf[3];
                  offset = ahd->msgin_buf[5];
                  bus_width = ahd->msgin_buf[6];
                  saved_width = bus_width;
                  ppr_options = ahd->msgin_buf[7];
                  /*
                   * According to the spec, a DT only
                   * period factor with no DT option
                   * set implies async.
                   */
                  if ((ppr_options & MSG_EXT_PPR_DT_REQ) == 0
                   && period <= 9)
                        offset = 0;
                  saved_ppr_options = ppr_options;
                  saved_offset = offset;

                  /*
                   * Transfer options are only available if we
                   * are negotiating wide.
                   */
                  if (bus_width == 0)
                        ppr_options &= MSG_EXT_PPR_QAS_REQ;

                  ahd_validate_width(ahd, tinfo, &bus_width,
                                 devinfo->role);
                  ahd_devlimited_syncrate(ahd, tinfo, &period,
                                    &ppr_options, devinfo->role);
                  ahd_validate_offset(ahd, tinfo, period, &offset,
                                  bus_width, devinfo->role);

                  if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_PPR, TRUE)) {
                        /*
                         * If we are unable to do any of the
                         * requested options (we went too low),
                         * then we'll have to reject the message.
                         */
                        if (saved_width > bus_width
                         || saved_offset != offset
                         || saved_ppr_options != ppr_options) {
                              reject = TRUE;
                              period = 0;
                              offset = 0;
                              bus_width = 0;
                              ppr_options = 0;
                        }
                  } else {
                        if (devinfo->role != ROLE_TARGET)
                              printf("(%s:%c:%d:%d): Target "
                                     "Initiated PPR\n",
                                     ahd_name(ahd), devinfo->channel,
                                     devinfo->target, devinfo->lun);
                        else
                              printf("(%s:%c:%d:%d): Initiator "
                                     "Initiated PPR\n",
                                     ahd_name(ahd), devinfo->channel,
                                     devinfo->target, devinfo->lun);
                        ahd->msgout_index = 0;
                        ahd->msgout_len = 0;
                        ahd_construct_ppr(ahd, devinfo, period, offset,
                                      bus_width, ppr_options);
                        ahd->msgout_index = 0;
                        response = TRUE;
                  }
                  if (bootverbose) {
                        printf("(%s:%c:%d:%d): Received PPR width %x, "
                               "period %x, offset %x,options %x\n"
                               "\tFiltered to width %x, period %x, "
                               "offset %x, options %x\n",
                               ahd_name(ahd), devinfo->channel,
                               devinfo->target, devinfo->lun,
                               saved_width, ahd->msgin_buf[3],
                               saved_offset, saved_ppr_options,
                               bus_width, period, offset, ppr_options);
                  }
                  ahd_set_width(ahd, devinfo, bus_width,
                              AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                              /*paused*/TRUE);
                  ahd_set_syncrate(ahd, devinfo, period,
                               offset, ppr_options,
                               AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                               /*paused*/TRUE);

                  done = MSGLOOP_MSGCOMPLETE;
                  break;
            }
            default:
                  /* Unknown extended message.  Reject it. */
                  reject = TRUE;
                  break;
            }
            break;
      }
#ifdef AHD_TARGET_MODE
      case MSG_BUS_DEV_RESET:
            ahd_handle_devreset(ahd, devinfo, CAM_LUN_WILDCARD,
                            CAM_BDR_SENT,
                            "Bus Device Reset Received",
                            /*verbose_level*/0);
            ahd_restart(ahd);
            done = MSGLOOP_TERMINATED;
            break;
      case MSG_ABORT_TAG:
      case MSG_ABORT:
      case MSG_CLEAR_QUEUE:
      {
            int tag;

            /* Target mode messages */
            if (devinfo->role != ROLE_TARGET) {
                  reject = TRUE;
                  break;
            }
            tag = SCB_LIST_NULL;
            if (ahd->msgin_buf[0] == MSG_ABORT_TAG)
                  tag = ahd_inb(ahd, INITIATOR_TAG);
            ahd_abort_scbs(ahd, devinfo->target, devinfo->channel,
                         devinfo->lun, tag, ROLE_TARGET,
                         CAM_REQ_ABORTED);

            tstate = ahd->enabled_targets[devinfo->our_scsiid];
            if (tstate != NULL) {
                  struct ahd_tmode_lstate* lstate;

                  lstate = tstate->enabled_luns[devinfo->lun];
                  if (lstate != NULL) {
                        ahd_queue_lstate_event(ahd, lstate,
                                           devinfo->our_scsiid,
                                           ahd->msgin_buf[0],
                                           /*arg*/tag);
                        ahd_send_lstate_events(ahd, lstate);
                  }
            }
            ahd_restart(ahd);
            done = MSGLOOP_TERMINATED;
            break;
      }
#endif
      case MSG_QAS_REQUEST:
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MESSAGES) != 0)
                  printf("%s: QAS request.  SCSISIGI == 0x%x\n",
                         ahd_name(ahd), ahd_inb(ahd, SCSISIGI));
#endif
            ahd->msg_flags |= MSG_FLAG_EXPECT_QASREJ_BUSFREE;
            /* FALLTHROUGH */
      case MSG_TERM_IO_PROC:
      default:
            reject = TRUE;
            break;
      }

      if (reject) {
            /*
             * Setup to reject the message.
             */
            ahd->msgout_index = 0;
            ahd->msgout_len = 1;
            ahd->msgout_buf[0] = MSG_MESSAGE_REJECT;
            done = MSGLOOP_MSGCOMPLETE;
            response = TRUE;
      }

      if (done != MSGLOOP_IN_PROG && !response)
            /* Clear the outgoing message buffer */
            ahd->msgout_len = 0;

      return (done);
}

/*
 * Process a message reject message.
 */
static int
ahd_handle_msg_reject(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      /*
       * What we care about here is if we had an
       * outstanding SDTR or WDTR message for this
       * target.  If we did, this is a signal that
       * the target is refusing negotiation.
       */
      struct scb *scb;
      struct ahd_initiator_tinfo *tinfo;
      struct ahd_tmode_tstate *tstate;
      u_int scb_index;
      u_int last_msg;
      int   response = 0;

      scb_index = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scb_index);
      tinfo = ahd_fetch_transinfo(ahd, devinfo->channel,
                            devinfo->our_scsiid,
                            devinfo->target, &tstate);
      /* Might be necessary */
      last_msg = ahd_inb(ahd, LAST_MSG);

      if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_PPR, /*full*/FALSE)) {
            if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_PPR, /*full*/TRUE)
             && tinfo->goal.period <= AHD_SYNCRATE_PACED) {
                  /*
                   * Target may not like our SPI-4 PPR Options.
                   * Attempt to negotiate 80MHz which will turn
                   * off these options.
                   */
                  if (bootverbose) {
                        printf("(%s:%c:%d:%d): PPR Rejected. "
                               "Trying simple U160 PPR\n",
                               ahd_name(ahd), devinfo->channel,
                               devinfo->target, devinfo->lun);
                  }
                  tinfo->goal.period = AHD_SYNCRATE_DT;
                  tinfo->goal.ppr_options &= MSG_EXT_PPR_IU_REQ
                                    |  MSG_EXT_PPR_QAS_REQ
                                    |  MSG_EXT_PPR_DT_REQ;
            } else {
                  /*
                   * Target does not support the PPR message.
                   * Attempt to negotiate SPI-2 style.
                   */
                  if (bootverbose) {
                        printf("(%s:%c:%d:%d): PPR Rejected. "
                               "Trying WDTR/SDTR\n",
                               ahd_name(ahd), devinfo->channel,
                               devinfo->target, devinfo->lun);
                  }
                  tinfo->goal.ppr_options = 0;
                  tinfo->curr.transport_version = 2;
                  tinfo->goal.transport_version = 2;
            }
            ahd->msgout_index = 0;
            ahd->msgout_len = 0;
            ahd_build_transfer_msg(ahd, devinfo);
            ahd->msgout_index = 0;
            response = 1;
      } else if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_WDTR, /*full*/FALSE)) {

            /* note 8bit xfers */
            printf("(%s:%c:%d:%d): refuses WIDE negotiation.  Using "
                   "8bit transfers\n", ahd_name(ahd),
                   devinfo->channel, devinfo->target, devinfo->lun);
            ahd_set_width(ahd, devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                        AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                        /*paused*/TRUE);
            /*
             * No need to clear the sync rate.  If the target
             * did not accept the command, our syncrate is
             * unaffected.  If the target started the negotiation,
             * but rejected our response, we already cleared the
             * sync rate before sending our WDTR.
             */
            if (tinfo->goal.offset != tinfo->curr.offset) {

                  /* Start the sync negotiation */
                  ahd->msgout_index = 0;
                  ahd->msgout_len = 0;
                  ahd_build_transfer_msg(ahd, devinfo);
                  ahd->msgout_index = 0;
                  response = 1;
            }
      } else if (ahd_sent_msg(ahd, AHDMSG_EXT, MSG_EXT_SDTR, /*full*/FALSE)) {
            /* note asynch xfers and clear flag */
            ahd_set_syncrate(ahd, devinfo, /*period*/0,
                         /*offset*/0, /*ppr_options*/0,
                         AHD_TRANS_ACTIVE|AHD_TRANS_GOAL,
                         /*paused*/TRUE);
            printf("(%s:%c:%d:%d): refuses synchronous negotiation. "
                   "Using asynchronous transfers\n",
                   ahd_name(ahd), devinfo->channel,
                   devinfo->target, devinfo->lun);
      } else if ((scb->hscb->control & MSG_SIMPLE_TASK) != 0) {
            int tag_type;
            int mask;

            tag_type = (scb->hscb->control & MSG_SIMPLE_TASK);

            if (tag_type == MSG_SIMPLE_TASK) {
                  printf("(%s:%c:%d:%d): refuses tagged commands.  "
                         "Performing non-tagged I/O\n", ahd_name(ahd),
                         devinfo->channel, devinfo->target, devinfo->lun);
                  ahd_set_tags(ahd, scb->io_ctx, devinfo, AHD_QUEUE_NONE);
                  mask = ~0x23;
            } else {
                  printf("(%s:%c:%d:%d): refuses %s tagged commands.  "
                         "Performing simple queue tagged I/O only\n",
                         ahd_name(ahd), devinfo->channel, devinfo->target,
                         devinfo->lun, tag_type == MSG_ORDERED_TASK
                         ? "ordered" : "head of queue");
                  ahd_set_tags(ahd, scb->io_ctx, devinfo, AHD_QUEUE_BASIC);
                  mask = ~0x03;
            }

            /*
             * Resend the identify for this CCB as the target
             * may believe that the selection is invalid otherwise.
             */
            ahd_outb(ahd, SCB_CONTROL,
                   ahd_inb_scbram(ahd, SCB_CONTROL) & mask);
            scb->hscb->control &= mask;
            ahd_set_transaction_tag(scb, /*enabled*/FALSE,
                              /*type*/MSG_SIMPLE_TASK);
            ahd_outb(ahd, MSG_OUT, MSG_IDENTIFYFLAG);
            ahd_assert_atn(ahd);
            ahd_busy_tcl(ahd, BUILD_TCL(scb->hscb->scsiid, devinfo->lun),
                       SCB_GET_TAG(scb));

            /*
             * Requeue all tagged commands for this target
             * currently in our posession so they can be
             * converted to untagged commands.
             */
            ahd_search_qinfifo(ahd, SCB_GET_TARGET(ahd, scb),
                           SCB_GET_CHANNEL(ahd, scb),
                           SCB_GET_LUN(scb), /*tag*/SCB_LIST_NULL,
                           ROLE_INITIATOR, CAM_REQUEUE_REQ,
                           SEARCH_COMPLETE);
      } else if (ahd_sent_msg(ahd, AHDMSG_1B, MSG_IDENTIFYFLAG, TRUE)) {
            /*
             * Most likely the device believes that we had
             * previously negotiated packetized.
             */
            ahd->msg_flags |= MSG_FLAG_EXPECT_PPR_BUSFREE
                         |  MSG_FLAG_IU_REQ_CHANGED;

            ahd_force_renegotiation(ahd, devinfo);
            ahd->msgout_index = 0;
            ahd->msgout_len = 0;
            ahd_build_transfer_msg(ahd, devinfo);
            ahd->msgout_index = 0;
            response = 1;
      } else {
            /*
             * Otherwise, we ignore it.
             */
            printf("%s:%c:%d: Message reject for %x -- ignored\n",
                   ahd_name(ahd), devinfo->channel, devinfo->target,
                   last_msg);
      }
      return (response);
}

/*
 * Process an ingnore wide residue message.
 */
static void
ahd_handle_ign_wide_residue(struct ahd_softc *ahd, struct ahd_devinfo *devinfo)
{
      u_int scb_index;
      struct scb *scb;

      scb_index = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scb_index);
      /*
       * XXX Actually check data direction in the sequencer?
       * Perhaps add datadir to some spare bits in the hscb?
       */
      if ((ahd_inb(ahd, SEQ_FLAGS) & DPHASE) == 0
       || ahd_get_transfer_dir(scb) != CAM_DIR_IN) {
            /*
             * Ignore the message if we haven't
             * seen an appropriate data phase yet.
             */
      } else {
            /*
             * If the residual occurred on the last
             * transfer and the transfer request was
             * expected to end on an odd count, do
             * nothing.  Otherwise, subtract a byte
             * and update the residual count accordingly.
             */
            uint32_t sgptr;

            sgptr = ahd_inb_scbram(ahd, SCB_RESIDUAL_SGPTR);
            if ((sgptr & SG_LIST_NULL) != 0
             && (ahd_inb_scbram(ahd, SCB_TASK_ATTRIBUTE)
                 & SCB_XFERLEN_ODD) != 0) {
                  /*
                   * If the residual occurred on the last
                   * transfer and the transfer request was
                   * expected to end on an odd count, do
                   * nothing.
                   */
            } else {
                  uint32_t data_cnt;
                  uint64_t data_addr;
                  uint32_t sglen;

                  /* Pull in the rest of the sgptr */
                  sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
                  data_cnt = ahd_inl_scbram(ahd, SCB_RESIDUAL_DATACNT);
                  if ((sgptr & SG_LIST_NULL) != 0) {
                        /*
                         * The residual data count is not updated
                         * for the command run to completion case.
                         * Explicitly zero the count.
                         */
                        data_cnt &= ~AHD_SG_LEN_MASK;
                  }
                  data_addr = ahd_inq(ahd, SHADDR);
                  data_cnt += 1;
                  data_addr -= 1;
                  sgptr &= SG_PTR_MASK;
                  if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
                        struct ahd_dma64_seg *sg;

                        sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);

                        /*
                         * The residual sg ptr points to the next S/G
                         * to load so we must go back one.
                         */
                        sg--;
                        sglen = ahd_le32toh(sg->len) & AHD_SG_LEN_MASK;
                        if (sg != scb->sg_list
                         && sglen < (data_cnt & AHD_SG_LEN_MASK)) {

                              sg--;
                              sglen = ahd_le32toh(sg->len);
                              /*
                               * Preserve High Address and SG_LIST
                               * bits while setting the count to 1.
                               */
                              data_cnt = 1|(sglen&(~AHD_SG_LEN_MASK));
                              data_addr = ahd_le64toh(sg->addr)
                                      + (sglen & AHD_SG_LEN_MASK)
                                      - 1;

                              /*
                               * Increment sg so it points to the
                               * "next" sg.
                               */
                              sg++;
                              sgptr = ahd_sg_virt_to_bus(ahd, scb,
                                                   sg);
                        }
                  } else {
                        struct ahd_dma_seg *sg;

                        sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);

                        /*
                         * The residual sg ptr points to the next S/G
                         * to load so we must go back one.
                         */
                        sg--;
                        sglen = ahd_le32toh(sg->len) & AHD_SG_LEN_MASK;
                        if (sg != scb->sg_list
                         && sglen < (data_cnt & AHD_SG_LEN_MASK)) {

                              sg--;
                              sglen = ahd_le32toh(sg->len);
                              /*
                               * Preserve High Address and SG_LIST
                               * bits while setting the count to 1.
                               */
                              data_cnt = 1|(sglen&(~AHD_SG_LEN_MASK));
                              data_addr = ahd_le32toh(sg->addr)
                                      + (sglen & AHD_SG_LEN_MASK)
                                      - 1;

                              /*
                               * Increment sg so it points to the
                               * "next" sg.
                               */
                              sg++;
                              sgptr = ahd_sg_virt_to_bus(ahd, scb,
                                                  sg);
                        }
                  }
                  /*
                   * Toggle the "oddness" of the transfer length
                   * to handle this mid-transfer ignore wide
                   * residue.  This ensures that the oddness is
                   * correct for subsequent data transfers.
                   */
                  ahd_outb(ahd, SCB_TASK_ATTRIBUTE,
                      ahd_inb_scbram(ahd, SCB_TASK_ATTRIBUTE)
                      ^ SCB_XFERLEN_ODD);

                  ahd_outl(ahd, SCB_RESIDUAL_SGPTR, sgptr);
                  ahd_outl(ahd, SCB_RESIDUAL_DATACNT, data_cnt);
                  /*
                   * The FIFO's pointers will be updated if/when the
                   * sequencer re-enters a data phase.
                   */
            }
      }
}


/*
 * Reinitialize the data pointers for the active transfer
 * based on its current residual.
 */
static void
ahd_reinitialize_dataptrs(struct ahd_softc *ahd)
{
      struct             scb *scb;
      ahd_mode_state     saved_modes;
      u_int        scb_index;
      u_int        wait;
      uint32_t     sgptr;
      uint32_t     resid;
      uint64_t     dataptr;

      AHD_ASSERT_MODES(ahd, AHD_MODE_DFF0_MSK|AHD_MODE_DFF1_MSK,
                   AHD_MODE_DFF0_MSK|AHD_MODE_DFF1_MSK);
                   
      scb_index = ahd_get_scbptr(ahd);
      scb = ahd_lookup_scb(ahd, scb_index);

      /*
       * Release and reacquire the FIFO so we
       * have a clean slate.
       */
      ahd_outb(ahd, DFFSXFRCTL, CLRCHN);
      wait = 1000;
      while (--wait && !(ahd_inb(ahd, MDFFSTAT) & FIFOFREE))
            ahd_delay(100);
      if (wait == 0) {
            ahd_print_path(ahd, scb);
            printf("ahd_reinitialize_dataptrs: Forcing FIFO free.\n");
            ahd_outb(ahd, DFFSXFRCTL, RSTCHN|CLRSHCNT);
      }
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      ahd_outb(ahd, DFFSTAT,
             ahd_inb(ahd, DFFSTAT)
            | (saved_modes == 0x11 ? CURRFIFO_1 : CURRFIFO_0));

      /*
       * Determine initial values for data_addr and data_cnt
       * for resuming the data phase.
       */
      sgptr = ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR);
      sgptr &= SG_PTR_MASK;

      resid = (ahd_inb_scbram(ahd, SCB_RESIDUAL_DATACNT + 2) << 16)
            | (ahd_inb_scbram(ahd, SCB_RESIDUAL_DATACNT + 1) << 8)
            | ahd_inb_scbram(ahd, SCB_RESIDUAL_DATACNT);

      if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0) {
            struct ahd_dma64_seg *sg;

            sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);

            /* The residual sg_ptr always points to the next sg */
            sg--;

            dataptr = ahd_le64toh(sg->addr)
                  + (ahd_le32toh(sg->len) & AHD_SG_LEN_MASK)
                  - resid;
            ahd_outl(ahd, HADDR + 4, dataptr >> 32);
      } else {
            struct       ahd_dma_seg *sg;

            sg = ahd_sg_bus_to_virt(ahd, scb, sgptr);

            /* The residual sg_ptr always points to the next sg */
            sg--;

            dataptr = ahd_le32toh(sg->addr)
                  + (ahd_le32toh(sg->len) & AHD_SG_LEN_MASK)
                  - resid;
            ahd_outb(ahd, HADDR + 4,
                   (ahd_le32toh(sg->len) & ~AHD_SG_LEN_MASK) >> 24);
      }
      ahd_outl(ahd, HADDR, dataptr);
      ahd_outb(ahd, HCNT + 2, resid >> 16);
      ahd_outb(ahd, HCNT + 1, resid >> 8);
      ahd_outb(ahd, HCNT, resid);
}

/*
 * Handle the effects of issuing a bus device reset message.
 */
static void
ahd_handle_devreset(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
                u_int lun, cam_status status, char *message,
                int verbose_level)
{
#ifdef AHD_TARGET_MODE
      struct ahd_tmode_tstate* tstate;
#endif
      int found;

      found = ahd_abort_scbs(ahd, devinfo->target, devinfo->channel,
                         lun, SCB_LIST_NULL, devinfo->role,
                         status);

#ifdef AHD_TARGET_MODE
      /*
       * Send an immediate notify ccb to all target mord peripheral
       * drivers affected by this action.
       */
      tstate = ahd->enabled_targets[devinfo->our_scsiid];
      if (tstate != NULL) {
            u_int cur_lun;
            u_int max_lun;

            if (lun != CAM_LUN_WILDCARD) {
                  cur_lun = 0;
                  max_lun = AHD_NUM_LUNS - 1;
            } else {
                  cur_lun = lun;
                  max_lun = lun;
            }
            for (cur_lun <= max_lun; cur_lun++) {
                  struct ahd_tmode_lstate* lstate;

                  lstate = tstate->enabled_luns[cur_lun];
                  if (lstate == NULL)
                        continue;

                  ahd_queue_lstate_event(ahd, lstate, devinfo->our_scsiid,
                                     MSG_BUS_DEV_RESET, /*arg*/0);
                  ahd_send_lstate_events(ahd, lstate);
            }
      }
#endif

      /*
       * Go back to async/narrow transfers and renegotiate.
       */
      ahd_set_width(ahd, devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                  AHD_TRANS_CUR, /*paused*/TRUE);
      ahd_set_syncrate(ahd, devinfo, /*period*/0, /*offset*/0,
                   /*ppr_options*/0, AHD_TRANS_CUR,
                   /*paused*/TRUE);
      
      if (status != CAM_SEL_TIMEOUT)
            ahd_send_async(ahd, devinfo->channel, devinfo->target,
                         CAM_LUN_WILDCARD, AC_SENT_BDR);

      if (message != NULL && bootverbose)
            printf("%s: %s on %c:%d. %d SCBs aborted\n", ahd_name(ahd),
                   message, devinfo->channel, devinfo->target, found);
}

#ifdef AHD_TARGET_MODE
static void
ahd_setup_target_msgin(struct ahd_softc *ahd, struct ahd_devinfo *devinfo,
                   struct scb *scb)
{

      /*              
       * To facilitate adding multiple messages together,
       * each routine should increment the index and len
       * variables instead of setting them explicitly.
       */             
      ahd->msgout_index = 0;
      ahd->msgout_len = 0;

      if (scb != NULL && (scb->flags & SCB_AUTO_NEGOTIATE) != 0)
            ahd_build_transfer_msg(ahd, devinfo);
      else
            panic("ahd_intr: AWAITING target message with no message");

      ahd->msgout_index = 0;
      ahd->msg_type = MSG_TYPE_TARGET_MSGIN;
}
#endif
/**************************** Initialization **********************************/
static u_int
ahd_sglist_size(struct ahd_softc *ahd)
{
      bus_size_t list_size;

      list_size = sizeof(struct ahd_dma_seg) * AHD_NSEG;
      if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0)
            list_size = sizeof(struct ahd_dma64_seg) * AHD_NSEG;
      return (list_size);
}

/*
 * Calculate the optimum S/G List allocation size.  S/G elements used
 * for a given transaction must be physically contiguous.  Assume the
 * OS will allocate full pages to us, so it doesn't make sense to request
 * less than a page.
 */
static u_int
ahd_sglist_allocsize(struct ahd_softc *ahd)
{
      bus_size_t sg_list_increment;
      bus_size_t sg_list_size;
      bus_size_t max_list_size;
      bus_size_t best_list_size;

      /* Start out with the minimum required for AHD_NSEG. */
      sg_list_increment = ahd_sglist_size(ahd);
      sg_list_size = sg_list_increment;

      /* Get us as close as possible to a page in size. */
      while ((sg_list_size + sg_list_increment) <= PAGE_SIZE)
            sg_list_size += sg_list_increment;

      /*
       * Try to reduce the amount of wastage by allocating
       * multiple pages.
       */
      best_list_size = sg_list_size;
      max_list_size = roundup(sg_list_increment, PAGE_SIZE);
      if (max_list_size < 4 * PAGE_SIZE)
            max_list_size = 4 * PAGE_SIZE;
      if (max_list_size > (AHD_SCB_MAX_ALLOC * sg_list_increment))
            max_list_size = (AHD_SCB_MAX_ALLOC * sg_list_increment);
      while ((sg_list_size + sg_list_increment) <= max_list_size
         &&  (sg_list_size % PAGE_SIZE) != 0) {
            bus_size_t new_mod;
            bus_size_t best_mod;

            sg_list_size += sg_list_increment;
            new_mod = sg_list_size % PAGE_SIZE;
            best_mod = best_list_size % PAGE_SIZE;
            if (new_mod > best_mod || new_mod == 0) {
                  best_list_size = sg_list_size;
            }
      }
      return (best_list_size);
}

/*
 * Allocate a controller structure for a new device
 * and perform initial initializion.
 */
struct ahd_softc *
ahd_alloc(void *platform_arg, char *name)
{
      struct  ahd_softc *ahd;

#ifndef     __FreeBSD__
      ahd = malloc(sizeof(*ahd), M_DEVBUF, M_NOWAIT);
      if (!ahd) {
            printf("aic7xxx: cannot malloc softc!\n");
            free(name, M_DEVBUF);
            return NULL;
      }
#else
      ahd = device_get_softc((device_t)platform_arg);
#endif
      memset(ahd, 0, sizeof(*ahd));
      ahd->seep_config = malloc(sizeof(*ahd->seep_config),
                          M_DEVBUF, M_NOWAIT);
      if (ahd->seep_config == NULL) {
#ifndef     __FreeBSD__
            free(ahd, M_DEVBUF);
#endif
            free(name, M_DEVBUF);
            return (NULL);
      }
      LIST_INIT(&ahd->pending_scbs);
      /* We don't know our unit number until the OSM sets it */
      ahd->name = name;
      ahd->unit = -1;
      ahd->description = NULL;
      ahd->bus_description = NULL;
      ahd->channel = 'A';
      ahd->chip = AHD_NONE;
      ahd->features = AHD_FENONE;
      ahd->bugs = AHD_BUGNONE;
      ahd->flags = AHD_SPCHK_ENB_A|AHD_RESET_BUS_A|AHD_TERM_ENB_A
               | AHD_EXTENDED_TRANS_A|AHD_STPWLEVEL_A;
      ahd_timer_init(&ahd->reset_timer);
      ahd_timer_init(&ahd->stat_timer);
      ahd->int_coalescing_timer = AHD_INT_COALESCING_TIMER_DEFAULT;
      ahd->int_coalescing_maxcmds = AHD_INT_COALESCING_MAXCMDS_DEFAULT;
      ahd->int_coalescing_mincmds = AHD_INT_COALESCING_MINCMDS_DEFAULT;
      ahd->int_coalescing_threshold = AHD_INT_COALESCING_THRESHOLD_DEFAULT;
      ahd->int_coalescing_stop_threshold =
          AHD_INT_COALESCING_STOP_THRESHOLD_DEFAULT;

      if (ahd_platform_alloc(ahd, platform_arg) != 0) {
            ahd_free(ahd);
            ahd = NULL;
      }
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MEMORY) != 0) {
            printf("%s: scb size = 0x%x, hscb size = 0x%x\n",
                   ahd_name(ahd), (u_int)sizeof(struct scb),
                   (u_int)sizeof(struct hardware_scb));
      }
#endif
      return (ahd);
}

int
ahd_softc_init(struct ahd_softc *ahd)
{

      ahd->unpause = 0;
      ahd->pause = PAUSE; 
      return (0);
}

void
ahd_set_unit(struct ahd_softc *ahd, int unit)
{
      ahd->unit = unit;
}

void
ahd_set_name(struct ahd_softc *ahd, char *name)
{
      if (ahd->name != NULL)
            free(ahd->name, M_DEVBUF);
      ahd->name = name;
}

void
ahd_free(struct ahd_softc *ahd)
{
      int i;

      switch (ahd->init_level) {
      default:
      case 5:
            ahd_shutdown(ahd);
            /* FALLTHROUGH */
      case 4:
            ahd_dmamap_unload(ahd, ahd->shared_data_dmat,
                          ahd->shared_data_map.dmamap);
            /* FALLTHROUGH */
      case 3:
            ahd_dmamem_free(ahd, ahd->shared_data_dmat, ahd->qoutfifo,
                        ahd->shared_data_map.dmamap);
            ahd_dmamap_destroy(ahd, ahd->shared_data_dmat,
                           ahd->shared_data_map.dmamap);
            /* FALLTHROUGH */
      case 2:
            ahd_dma_tag_destroy(ahd, ahd->shared_data_dmat);
      case 1:
#ifndef __linux__
            ahd_dma_tag_destroy(ahd, ahd->buffer_dmat);
#endif
            break;
      case 0:
            break;
      }

#ifndef __linux__
      ahd_dma_tag_destroy(ahd, ahd->parent_dmat);
#endif
      ahd_platform_free(ahd);
      ahd_fini_scbdata(ahd);
      for (i = 0; i < AHD_NUM_TARGETS; i++) {
            struct ahd_tmode_tstate *tstate;

            tstate = ahd->enabled_targets[i];
            if (tstate != NULL) {
#ifdef AHD_TARGET_MODE
                  int j;

                  for (j = 0; j < AHD_NUM_LUNS; j++) {
                        struct ahd_tmode_lstate *lstate;

                        lstate = tstate->enabled_luns[j];
                        if (lstate != NULL) {
                              xpt_free_path(lstate->path);
                              free(lstate, M_DEVBUF);
                        }
                  }
#endif
                  free(tstate, M_DEVBUF);
            }
      }
#ifdef AHD_TARGET_MODE
      if (ahd->black_hole != NULL) {
            xpt_free_path(ahd->black_hole->path);
            free(ahd->black_hole, M_DEVBUF);
      }
#endif
      if (ahd->name != NULL)
            free(ahd->name, M_DEVBUF);
      if (ahd->seep_config != NULL)
            free(ahd->seep_config, M_DEVBUF);
      if (ahd->saved_stack != NULL)
            free(ahd->saved_stack, M_DEVBUF);
#ifndef __FreeBSD__
      free(ahd, M_DEVBUF);
#endif
      return;
}

void
ahd_shutdown(void *arg)
{
      struct      ahd_softc *ahd;

      ahd = (struct ahd_softc *)arg;

      /*
       * Stop periodic timer callbacks.
       */
      ahd_timer_stop(&ahd->reset_timer);
      ahd_timer_stop(&ahd->stat_timer);

      /* This will reset most registers to 0, but not all */
      ahd_reset(ahd, /*reinit*/FALSE);
}

/*
 * Reset the controller and record some information about it
 * that is only available just after a reset.  If "reinit" is
 * non-zero, this reset occured after initial configuration
 * and the caller requests that the chip be fully reinitialized
 * to a runable state.  Chip interrupts are *not* enabled after
 * a reinitialization.  The caller must enable interrupts via
 * ahd_intr_enable().
 */
int
ahd_reset(struct ahd_softc *ahd, int reinit)
{
      u_int  sxfrctl1;
      int    wait;
      uint32_t cmd;
      
      /*
       * Preserve the value of the SXFRCTL1 register for all channels.
       * It contains settings that affect termination and we don't want
       * to disturb the integrity of the bus.
       */
      ahd_pause(ahd);
      ahd_update_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      sxfrctl1 = ahd_inb(ahd, SXFRCTL1);

      cmd = ahd_pci_read_config(ahd->dev_softc, PCIR_COMMAND, /*bytes*/2);
      if ((ahd->bugs & AHD_PCIX_CHIPRST_BUG) != 0) {
            uint32_t mod_cmd;

            /*
             * A4 Razor #632
             * During the assertion of CHIPRST, the chip
             * does not disable its parity logic prior to
             * the start of the reset.  This may cause a
             * parity error to be detected and thus a
             * spurious SERR or PERR assertion.  Disble
             * PERR and SERR responses during the CHIPRST.
             */
            mod_cmd = cmd & ~(PCIM_CMD_PERRESPEN|PCIM_CMD_SERRESPEN);
            ahd_pci_write_config(ahd->dev_softc, PCIR_COMMAND,
                             mod_cmd, /*bytes*/2);
      }
      ahd_outb(ahd, HCNTRL, CHIPRST | ahd->pause);

      /*
       * Ensure that the reset has finished.  We delay 1000us
       * prior to reading the register to make sure the chip
       * has sufficiently completed its reset to handle register
       * accesses.
       */
      wait = 1000;
      do {
            ahd_delay(1000);
      } while (--wait && !(ahd_inb(ahd, HCNTRL) & CHIPRSTACK));

      if (wait == 0) {
            printf("%s: WARNING - Failed chip reset!  "
                   "Trying to initialize anyway.\n", ahd_name(ahd));
      }
      ahd_outb(ahd, HCNTRL, ahd->pause);

      if ((ahd->bugs & AHD_PCIX_CHIPRST_BUG) != 0) {
            /*
             * Clear any latched PCI error status and restore
             * previous SERR and PERR response enables.
             */
            ahd_pci_write_config(ahd->dev_softc, PCIR_STATUS + 1,
                             0xFF, /*bytes*/1);
            ahd_pci_write_config(ahd->dev_softc, PCIR_COMMAND,
                             cmd, /*bytes*/2);
      }

      /*
       * Mode should be SCSI after a chip reset, but lets
       * set it just to be safe.  We touch the MODE_PTR
       * register directly so as to bypass the lazy update
       * code in ahd_set_modes().
       */
      ahd_known_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      ahd_outb(ahd, MODE_PTR,
             ahd_build_mode_state(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI));

      /*
       * Restore SXFRCTL1.
       *
       * We must always initialize STPWEN to 1 before we
       * restore the saved values.  STPWEN is initialized
       * to a tri-state condition which can only be cleared
       * by turning it on.
       */
      ahd_outb(ahd, SXFRCTL1, sxfrctl1|STPWEN);
      ahd_outb(ahd, SXFRCTL1, sxfrctl1);

      /* Determine chip configuration */
      ahd->features &= ~AHD_WIDE;
      if ((ahd_inb(ahd, SBLKCTL) & SELWIDE) != 0)
            ahd->features |= AHD_WIDE;

      /*
       * If a recovery action has forced a chip reset,
       * re-initialize the chip to our liking.
       */
      if (reinit != 0)
            ahd_chip_init(ahd);

      return (0);
}

/*
 * Determine the number of SCBs available on the controller
 */
int
ahd_probe_scbs(struct ahd_softc *ahd) {
      int i;

      AHD_ASSERT_MODES(ahd, ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK),
                   ~(AHD_MODE_UNKNOWN_MSK|AHD_MODE_CFG_MSK));
      for (i = 0; i < AHD_SCB_MAX; i++) {
            int j;

            ahd_set_scbptr(ahd, i);
            ahd_outw(ahd, SCB_BASE, i);
            for (j = 2; j < 64; j++)
                  ahd_outb(ahd, SCB_BASE+j, 0);
            /* Start out life as unallocated (needing an abort) */
            ahd_outb(ahd, SCB_CONTROL, MK_MESSAGE);
            if (ahd_inw_scbram(ahd, SCB_BASE) != i)
                  break;
            ahd_set_scbptr(ahd, 0);
            if (ahd_inw_scbram(ahd, SCB_BASE) != 0)
                  break;
      }
      return (i);
}

static void
ahd_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error) 
{
      dma_addr_t *baddr;

      baddr = (dma_addr_t *)arg;
      *baddr = segs->ds_addr;
}

static void
ahd_initialize_hscbs(struct ahd_softc *ahd)
{
      int i;

      for (i = 0; i < ahd->scb_data.maxhscbs; i++) {
            ahd_set_scbptr(ahd, i);

            /* Clear the control byte. */
            ahd_outb(ahd, SCB_CONTROL, 0);

            /* Set the next pointer */
            ahd_outw(ahd, SCB_NEXT, SCB_LIST_NULL);
      }
}

static int
ahd_init_scbdata(struct ahd_softc *ahd)
{
      struct      scb_data *scb_data;
      int   i;

      scb_data = &ahd->scb_data;
      TAILQ_INIT(&scb_data->free_scbs);
      for (i = 0; i < AHD_NUM_TARGETS * AHD_NUM_LUNS_NONPKT; i++)
            LIST_INIT(&scb_data->free_scb_lists[i]);
      LIST_INIT(&scb_data->any_dev_free_scb_list);
      SLIST_INIT(&scb_data->hscb_maps);
      SLIST_INIT(&scb_data->sg_maps);
      SLIST_INIT(&scb_data->sense_maps);

      /* Determine the number of hardware SCBs and initialize them */
      scb_data->maxhscbs = ahd_probe_scbs(ahd);
      if (scb_data->maxhscbs == 0) {
            printf("%s: No SCB space found\n", ahd_name(ahd));
            return (ENXIO);
      }

      ahd_initialize_hscbs(ahd);

      /*
       * Create our DMA tags.  These tags define the kinds of device
       * accessible memory allocations and memory mappings we will
       * need to perform during normal operation.
       *
       * Unless we need to further restrict the allocation, we rely
       * on the restrictions of the parent dmat, hence the common
       * use of MAXADDR and MAXSIZE.
       */

      /* DMA tag for our hardware scb structures */
      if (ahd_dma_tag_create(ahd, ahd->parent_dmat, /*alignment*/1,
                         /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                         /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                         /*highaddr*/BUS_SPACE_MAXADDR,
                         /*filter*/NULL, /*filterarg*/NULL,
                         PAGE_SIZE, /*nsegments*/1,
                         /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                         /*flags*/0, &scb_data->hscb_dmat) != 0) {
            goto error_exit;
      }

      scb_data->init_level++;

      /* DMA tag for our S/G structures. */
      if (ahd_dma_tag_create(ahd, ahd->parent_dmat, /*alignment*/8,
                         /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                         /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                         /*highaddr*/BUS_SPACE_MAXADDR,
                         /*filter*/NULL, /*filterarg*/NULL,
                         ahd_sglist_allocsize(ahd), /*nsegments*/1,
                         /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                         /*flags*/0, &scb_data->sg_dmat) != 0) {
            goto error_exit;
      }
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MEMORY) != 0)
            printf("%s: ahd_sglist_allocsize = 0x%x\n", ahd_name(ahd),
                   ahd_sglist_allocsize(ahd));
#endif

      scb_data->init_level++;

      /* DMA tag for our sense buffers.  We allocate in page sized chunks */
      if (ahd_dma_tag_create(ahd, ahd->parent_dmat, /*alignment*/1,
                         /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                         /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                         /*highaddr*/BUS_SPACE_MAXADDR,
                         /*filter*/NULL, /*filterarg*/NULL,
                         PAGE_SIZE, /*nsegments*/1,
                         /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                         /*flags*/0, &scb_data->sense_dmat) != 0) {
            goto error_exit;
      }

      scb_data->init_level++;

      /* Perform initial CCB allocation */
      ahd_alloc_scbs(ahd);

      if (scb_data->numscbs == 0) {
            printf("%s: ahd_init_scbdata - "
                   "Unable to allocate initial scbs\n",
                   ahd_name(ahd));
            goto error_exit;
      }

      /*
       * Note that we were successfull
       */
      return (0); 

error_exit:

      return (ENOMEM);
}

static struct scb *
ahd_find_scb_by_tag(struct ahd_softc *ahd, u_int tag)
{
      struct scb *scb;

      /*
       * Look on the pending list.
       */
      LIST_FOREACH(scb, &ahd->pending_scbs, pending_links) {
            if (SCB_GET_TAG(scb) == tag)
                  return (scb);
      }

      /*
       * Then on all of the collision free lists.
       */
      TAILQ_FOREACH(scb, &ahd->scb_data.free_scbs, links.tqe) {
            struct scb *list_scb;

            list_scb = scb;
            do {
                  if (SCB_GET_TAG(list_scb) == tag)
                        return (list_scb);
                  list_scb = LIST_NEXT(list_scb, collision_links);
            } while (list_scb);
      }

      /*
       * And finally on the generic free list.
       */
      LIST_FOREACH(scb, &ahd->scb_data.any_dev_free_scb_list, links.le) {
            if (SCB_GET_TAG(scb) == tag)
                  return (scb);
      }

      return (NULL);
}

static void
ahd_fini_scbdata(struct ahd_softc *ahd)
{
      struct scb_data *scb_data;

      scb_data = &ahd->scb_data;
      if (scb_data == NULL)
            return;

      switch (scb_data->init_level) {
      default:
      case 7:
      {
            struct map_node *sns_map;

            while ((sns_map = SLIST_FIRST(&scb_data->sense_maps)) != NULL) {
                  SLIST_REMOVE_HEAD(&scb_data->sense_maps, links);
                  ahd_dmamap_unload(ahd, scb_data->sense_dmat,
                                sns_map->dmamap);
                  ahd_dmamem_free(ahd, scb_data->sense_dmat,
                              sns_map->vaddr, sns_map->dmamap);
                  free(sns_map, M_DEVBUF);
            }
            ahd_dma_tag_destroy(ahd, scb_data->sense_dmat);
            /* FALLTHROUGH */
      }
      case 6:
      {
            struct map_node *sg_map;

            while ((sg_map = SLIST_FIRST(&scb_data->sg_maps)) != NULL) {
                  SLIST_REMOVE_HEAD(&scb_data->sg_maps, links);
                  ahd_dmamap_unload(ahd, scb_data->sg_dmat,
                                sg_map->dmamap);
                  ahd_dmamem_free(ahd, scb_data->sg_dmat,
                              sg_map->vaddr, sg_map->dmamap);
                  free(sg_map, M_DEVBUF);
            }
            ahd_dma_tag_destroy(ahd, scb_data->sg_dmat);
            /* FALLTHROUGH */
      }
      case 5:
      {
            struct map_node *hscb_map;

            while ((hscb_map = SLIST_FIRST(&scb_data->hscb_maps)) != NULL) {
                  SLIST_REMOVE_HEAD(&scb_data->hscb_maps, links);
                  ahd_dmamap_unload(ahd, scb_data->hscb_dmat,
                                hscb_map->dmamap);
                  ahd_dmamem_free(ahd, scb_data->hscb_dmat,
                              hscb_map->vaddr, hscb_map->dmamap);
                  free(hscb_map, M_DEVBUF);
            }
            ahd_dma_tag_destroy(ahd, scb_data->hscb_dmat);
            /* FALLTHROUGH */
      }
      case 4:
      case 3:
      case 2:
      case 1:
      case 0:
            break;
      }
}

/*
 * DSP filter Bypass must be enabled until the first selection
 * after a change in bus mode (Razor #491 and #493).
 */
static void
ahd_setup_iocell_workaround(struct ahd_softc *ahd)
{
      ahd_mode_state saved_modes;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
      ahd_outb(ahd, DSPDATACTL, ahd_inb(ahd, DSPDATACTL)
             | BYPASSENAB | RCVROFFSTDIS | XMITOFFSTDIS);
      ahd_outb(ahd, SIMODE0, ahd_inb(ahd, SIMODE0) | (ENSELDO|ENSELDI));
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MISC) != 0)
            printf("%s: Setting up iocell workaround\n", ahd_name(ahd));
#endif
      ahd_restore_modes(ahd, saved_modes);
      ahd->flags &= ~AHD_HAD_FIRST_SEL;
}

static void
ahd_iocell_first_selection(struct ahd_softc *ahd)
{
      ahd_mode_state    saved_modes;
      u_int       sblkctl;

      if ((ahd->flags & AHD_HAD_FIRST_SEL) != 0)
            return;
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      sblkctl = ahd_inb(ahd, SBLKCTL);
      ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MISC) != 0)
            printf("%s: iocell first selection\n", ahd_name(ahd));
#endif
      if ((sblkctl & ENAB40) != 0) {
            ahd_outb(ahd, DSPDATACTL,
                   ahd_inb(ahd, DSPDATACTL) & ~BYPASSENAB);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0)
                  printf("%s: BYPASS now disabled\n", ahd_name(ahd));
#endif
      }
      ahd_outb(ahd, SIMODE0, ahd_inb(ahd, SIMODE0) & ~(ENSELDO|ENSELDI));
      ahd_outb(ahd, CLRINT, CLRSCSIINT);
      ahd_restore_modes(ahd, saved_modes);
      ahd->flags |= AHD_HAD_FIRST_SEL;
}

/*************************** SCB Management ***********************************/
static void
ahd_add_col_list(struct ahd_softc *ahd, struct scb *scb, u_int col_idx)
{
      struct      scb_list *free_list;
      struct      scb_tailq *free_tailq;
      struct      scb *first_scb;

      scb->flags |= SCB_ON_COL_LIST;
      AHD_SET_SCB_COL_IDX(scb, col_idx);
      free_list = &ahd->scb_data.free_scb_lists[col_idx];
      free_tailq = &ahd->scb_data.free_scbs;
      first_scb = LIST_FIRST(free_list);
      if (first_scb != NULL) {
            LIST_INSERT_AFTER(first_scb, scb, collision_links);
      } else {
            LIST_INSERT_HEAD(free_list, scb, collision_links);
            TAILQ_INSERT_TAIL(free_tailq, scb, links.tqe);
      }
}

static void
ahd_rem_col_list(struct ahd_softc *ahd, struct scb *scb)
{
      struct      scb_list *free_list;
      struct      scb_tailq *free_tailq;
      struct      scb *first_scb;
      u_int col_idx;

      scb->flags &= ~SCB_ON_COL_LIST;
      col_idx = AHD_GET_SCB_COL_IDX(ahd, scb);
      free_list = &ahd->scb_data.free_scb_lists[col_idx];
      free_tailq = &ahd->scb_data.free_scbs;
      first_scb = LIST_FIRST(free_list);
      if (first_scb == scb) {
            struct scb *next_scb;

            /*
             * Maintain order in the collision free
             * lists for fairness if this device has
             * other colliding tags active.
             */
            next_scb = LIST_NEXT(scb, collision_links);
            if (next_scb != NULL) {
                  TAILQ_INSERT_AFTER(free_tailq, scb,
                                 next_scb, links.tqe);
            }
            TAILQ_REMOVE(free_tailq, scb, links.tqe);
      }
      LIST_REMOVE(scb, collision_links);
}

/*
 * Get a free scb. If there are none, see if we can allocate a new SCB.
 */
struct scb *
ahd_get_scb(struct ahd_softc *ahd, u_int col_idx)
{
      struct scb *scb;
      int tries;

      tries = 0;
look_again:
      TAILQ_FOREACH(scb, &ahd->scb_data.free_scbs, links.tqe) {
            if (AHD_GET_SCB_COL_IDX(ahd, scb) != col_idx) {
                  ahd_rem_col_list(ahd, scb);
                  goto found;
            }
      }
      if ((scb = LIST_FIRST(&ahd->scb_data.any_dev_free_scb_list)) == NULL) {

            if (tries++ != 0)
                  return (NULL);
            ahd_alloc_scbs(ahd);
            goto look_again;
      }
      LIST_REMOVE(scb, links.le);
      if (col_idx != AHD_NEVER_COL_IDX
       && (scb->col_scb != NULL)
       && (scb->col_scb->flags & SCB_ACTIVE) == 0) {
            LIST_REMOVE(scb->col_scb, links.le);
            ahd_add_col_list(ahd, scb->col_scb, col_idx);
      }
found:
      scb->flags |= SCB_ACTIVE;
      return (scb);
}

/*
 * Return an SCB resource to the free list.
 */
void
ahd_free_scb(struct ahd_softc *ahd, struct scb *scb)
{       

      /* Clean up for the next user */
      scb->flags = SCB_FLAG_NONE;
      scb->hscb->control = 0;
      ahd->scb_data.scbindex[SCB_GET_TAG(scb)] = NULL;

      if (scb->col_scb == NULL) {

            /*
             * No collision possible.  Just free normally.
             */
            LIST_INSERT_HEAD(&ahd->scb_data.any_dev_free_scb_list,
                         scb, links.le);
      } else if ((scb->col_scb->flags & SCB_ON_COL_LIST) != 0) {

            /*
             * The SCB we might have collided with is on
             * a free collision list.  Put both SCBs on
             * the generic list.
             */
            ahd_rem_col_list(ahd, scb->col_scb);
            LIST_INSERT_HEAD(&ahd->scb_data.any_dev_free_scb_list,
                         scb, links.le);
            LIST_INSERT_HEAD(&ahd->scb_data.any_dev_free_scb_list,
                         scb->col_scb, links.le);
      } else if ((scb->col_scb->flags
              & (SCB_PACKETIZED|SCB_ACTIVE)) == SCB_ACTIVE
            && (scb->col_scb->hscb->control & TAG_ENB) != 0) {

            /*
             * The SCB we might collide with on the next allocation
             * is still active in a non-packetized, tagged, context.
             * Put us on the SCB collision list.
             */
            ahd_add_col_list(ahd, scb,
                         AHD_GET_SCB_COL_IDX(ahd, scb->col_scb));
      } else {
            /*
             * The SCB we might collide with on the next allocation
             * is either active in a packetized context, or free.
             * Since we can't collide, put this SCB on the generic
             * free list.
             */
            LIST_INSERT_HEAD(&ahd->scb_data.any_dev_free_scb_list,
                         scb, links.le);
      }

      ahd_platform_scb_free(ahd, scb);
}

void
ahd_alloc_scbs(struct ahd_softc *ahd)
{
      struct scb_data *scb_data;
      struct scb  *next_scb;
      struct hardware_scb *hscb;
      struct map_node *hscb_map;
      struct map_node *sg_map;
      struct map_node *sense_map;
      uint8_t           *segs;
      uint8_t           *sense_data;
      dma_addr_t   hscb_busaddr;
      dma_addr_t   sg_busaddr;
      dma_addr_t   sense_busaddr;
      int          newcount;
      int          i;

      scb_data = &ahd->scb_data;
      if (scb_data->numscbs >= AHD_SCB_MAX_ALLOC)
            /* Can't allocate any more */
            return;

      if (scb_data->scbs_left != 0) {
            int offset;

            offset = (PAGE_SIZE / sizeof(*hscb)) - scb_data->scbs_left;
            hscb_map = SLIST_FIRST(&scb_data->hscb_maps);
            hscb = &((struct hardware_scb *)hscb_map->vaddr)[offset];
            hscb_busaddr = hscb_map->physaddr + (offset * sizeof(*hscb));
      } else {
            hscb_map = malloc(sizeof(*hscb_map), M_DEVBUF, M_NOWAIT);

            if (hscb_map == NULL)
                  return;

            /* Allocate the next batch of hardware SCBs */
            if (ahd_dmamem_alloc(ahd, scb_data->hscb_dmat,
                             (void **)&hscb_map->vaddr,
                             BUS_DMA_NOWAIT, &hscb_map->dmamap) != 0) {
                  free(hscb_map, M_DEVBUF);
                  return;
            }

            SLIST_INSERT_HEAD(&scb_data->hscb_maps, hscb_map, links);

            ahd_dmamap_load(ahd, scb_data->hscb_dmat, hscb_map->dmamap,
                        hscb_map->vaddr, PAGE_SIZE, ahd_dmamap_cb,
                        &hscb_map->physaddr, /*flags*/0);

            hscb = (struct hardware_scb *)hscb_map->vaddr;
            hscb_busaddr = hscb_map->physaddr;
            scb_data->scbs_left = PAGE_SIZE / sizeof(*hscb);
      }

      if (scb_data->sgs_left != 0) {
            int offset;

            offset = ((ahd_sglist_allocsize(ahd) / ahd_sglist_size(ahd))
                   - scb_data->sgs_left) * ahd_sglist_size(ahd);
            sg_map = SLIST_FIRST(&scb_data->sg_maps);
            segs = sg_map->vaddr + offset;
            sg_busaddr = sg_map->physaddr + offset;
      } else {
            sg_map = malloc(sizeof(*sg_map), M_DEVBUF, M_NOWAIT);

            if (sg_map == NULL)
                  return;

            /* Allocate the next batch of S/G lists */
            if (ahd_dmamem_alloc(ahd, scb_data->sg_dmat,
                             (void **)&sg_map->vaddr,
                             BUS_DMA_NOWAIT, &sg_map->dmamap) != 0) {
                  free(sg_map, M_DEVBUF);
                  return;
            }

            SLIST_INSERT_HEAD(&scb_data->sg_maps, sg_map, links);

            ahd_dmamap_load(ahd, scb_data->sg_dmat, sg_map->dmamap,
                        sg_map->vaddr, ahd_sglist_allocsize(ahd),
                        ahd_dmamap_cb, &sg_map->physaddr, /*flags*/0);

            segs = sg_map->vaddr;
            sg_busaddr = sg_map->physaddr;
            scb_data->sgs_left =
                ahd_sglist_allocsize(ahd) / ahd_sglist_size(ahd);
#ifdef AHD_DEBUG
            if (ahd_debug & AHD_SHOW_MEMORY)
                  printf("Mapped SG data\n");
#endif
      }

      if (scb_data->sense_left != 0) {
            int offset;

            offset = PAGE_SIZE - (AHD_SENSE_BUFSIZE * scb_data->sense_left);
            sense_map = SLIST_FIRST(&scb_data->sense_maps);
            sense_data = sense_map->vaddr + offset;
            sense_busaddr = sense_map->physaddr + offset;
      } else {
            sense_map = malloc(sizeof(*sense_map), M_DEVBUF, M_NOWAIT);

            if (sense_map == NULL)
                  return;

            /* Allocate the next batch of sense buffers */
            if (ahd_dmamem_alloc(ahd, scb_data->sense_dmat,
                             (void **)&sense_map->vaddr,
                             BUS_DMA_NOWAIT, &sense_map->dmamap) != 0) {
                  free(sense_map, M_DEVBUF);
                  return;
            }

            SLIST_INSERT_HEAD(&scb_data->sense_maps, sense_map, links);

            ahd_dmamap_load(ahd, scb_data->sense_dmat, sense_map->dmamap,
                        sense_map->vaddr, PAGE_SIZE, ahd_dmamap_cb,
                        &sense_map->physaddr, /*flags*/0);

            sense_data = sense_map->vaddr;
            sense_busaddr = sense_map->physaddr;
            scb_data->sense_left = PAGE_SIZE / AHD_SENSE_BUFSIZE;
#ifdef AHD_DEBUG
            if (ahd_debug & AHD_SHOW_MEMORY)
                  printf("Mapped sense data\n");
#endif
      }

      newcount = MIN(scb_data->sense_left, scb_data->scbs_left);
      newcount = MIN(newcount, scb_data->sgs_left);
      newcount = MIN(newcount, (AHD_SCB_MAX_ALLOC - scb_data->numscbs));
      for (i = 0; i < newcount; i++) {
            struct scb_platform_data *pdata;
            u_int col_tag;
#ifndef __linux__
            int error;
#endif

            next_scb = (struct scb *)malloc(sizeof(*next_scb),
                                    M_DEVBUF, M_NOWAIT);
            if (next_scb == NULL)
                  break;

            pdata = (struct scb_platform_data *)malloc(sizeof(*pdata),
                                             M_DEVBUF, M_NOWAIT);
            if (pdata == NULL) {
                  free(next_scb, M_DEVBUF);
                  break;
            }
            next_scb->platform_data = pdata;
            next_scb->hscb_map = hscb_map;
            next_scb->sg_map = sg_map;
            next_scb->sense_map = sense_map;
            next_scb->sg_list = segs;
            next_scb->sense_data = sense_data;
            next_scb->sense_busaddr = sense_busaddr;
            memset(hscb, 0, sizeof(*hscb));
            next_scb->hscb = hscb;
            hscb->hscb_busaddr = ahd_htole32(hscb_busaddr);

            /*
             * The sequencer always starts with the second entry.
             * The first entry is embedded in the scb.
             */
            next_scb->sg_list_busaddr = sg_busaddr;
            if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0)
                  next_scb->sg_list_busaddr
                      += sizeof(struct ahd_dma64_seg);
            else
                  next_scb->sg_list_busaddr += sizeof(struct ahd_dma_seg);
            next_scb->ahd_softc = ahd;
            next_scb->flags = SCB_FLAG_NONE;
#ifndef __linux__
            error = ahd_dmamap_create(ahd, ahd->buffer_dmat, /*flags*/0,
                                &next_scb->dmamap);
            if (error != 0) {
                  free(next_scb, M_DEVBUF);
                  free(pdata, M_DEVBUF);
                  break;
            }
#endif
            next_scb->hscb->tag = ahd_htole16(scb_data->numscbs);
            col_tag = scb_data->numscbs ^ 0x100;
            next_scb->col_scb = ahd_find_scb_by_tag(ahd, col_tag);
            if (next_scb->col_scb != NULL)
                  next_scb->col_scb->col_scb = next_scb;
            ahd_free_scb(ahd, next_scb);
            hscb++;
            hscb_busaddr += sizeof(*hscb);
            segs += ahd_sglist_size(ahd);
            sg_busaddr += ahd_sglist_size(ahd);
            sense_data += AHD_SENSE_BUFSIZE;
            sense_busaddr += AHD_SENSE_BUFSIZE;
            scb_data->numscbs++;
            scb_data->sense_left--;
            scb_data->scbs_left--;
            scb_data->sgs_left--;
      }
}

void
ahd_controller_info(struct ahd_softc *ahd, char *buf)
{
      const char *speed;
      const char *type;
      int len;

      len = sprintf(buf, "%s: ", ahd_chip_names[ahd->chip & AHD_CHIPID_MASK]);
      buf += len;

      speed = "Ultra320 ";
      if ((ahd->features & AHD_WIDE) != 0) {
            type = "Wide ";
      } else {
            type = "Single ";
      }
      len = sprintf(buf, "%s%sChannel %c, SCSI Id=%d, ",
                  speed, type, ahd->channel, ahd->our_id);
      buf += len;

      sprintf(buf, "%s, %d SCBs", ahd->bus_description,
            ahd->scb_data.maxhscbs);
}

static const char *channel_strings[] = {
      "Primary Low",
      "Primary High",
      "Secondary Low", 
      "Secondary High"
};

static const char *termstat_strings[] = {
      "Terminated Correctly",
      "Over Terminated",
      "Under Terminated",
      "Not Configured"
};

/*
 * Start the board, ready for normal operation
 */
int
ahd_init(struct ahd_softc *ahd)
{
      uint8_t           *next_vaddr;
      dma_addr_t   next_baddr;
      size_t             driver_data_size;
      int          i;
      int          error;
      u_int        warn_user;
      uint8_t            current_sensing;
      uint8_t            fstat;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);

      ahd->stack_size = ahd_probe_stack_size(ahd);
      ahd->saved_stack = malloc(ahd->stack_size * sizeof(uint16_t),
                          M_DEVBUF, M_NOWAIT);
      if (ahd->saved_stack == NULL)
            return (ENOMEM);

      /*
       * Verify that the compiler hasn't over-agressively
       * padded important structures.
       */
      if (sizeof(struct hardware_scb) != 64)
            panic("Hardware SCB size is incorrect");

#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_DEBUG_SEQUENCER) != 0)
            ahd->flags |= AHD_SEQUENCER_DEBUG;
#endif

      /*
       * Default to allowing initiator operations.
       */
      ahd->flags |= AHD_INITIATORROLE;

      /*
       * Only allow target mode features if this unit has them enabled.
       */
      if ((AHD_TMODE_ENABLE & (0x1 << ahd->unit)) == 0)
            ahd->features &= ~AHD_TARGETMODE;

#ifndef __linux__
      /* DMA tag for mapping buffers into device visible space. */
      if (ahd_dma_tag_create(ahd, ahd->parent_dmat, /*alignment*/1,
                         /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                         /*lowaddr*/ahd->flags & AHD_39BIT_ADDRESSING
                              ? (dma_addr_t)0x7FFFFFFFFFULL
                              : BUS_SPACE_MAXADDR_32BIT,
                         /*highaddr*/BUS_SPACE_MAXADDR,
                         /*filter*/NULL, /*filterarg*/NULL,
                         /*maxsize*/(AHD_NSEG - 1) * PAGE_SIZE,
                         /*nsegments*/AHD_NSEG,
                         /*maxsegsz*/AHD_MAXTRANSFER_SIZE,
                         /*flags*/BUS_DMA_ALLOCNOW,
                         &ahd->buffer_dmat) != 0) {
            return (ENOMEM);
      }
#endif

      ahd->init_level++;

      /*
       * DMA tag for our command fifos and other data in system memory
       * the card's sequencer must be able to access.  For initiator
       * roles, we need to allocate space for the qoutfifo.  When providing
       * for the target mode role, we must additionally provide space for
       * the incoming target command fifo.
       */
      driver_data_size = AHD_SCB_MAX * sizeof(*ahd->qoutfifo)
                   + sizeof(struct hardware_scb);
      if ((ahd->features & AHD_TARGETMODE) != 0)
            driver_data_size += AHD_TMODE_CMDS * sizeof(struct target_cmd);
      if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0)
            driver_data_size += PKT_OVERRUN_BUFSIZE;
      if (ahd_dma_tag_create(ahd, ahd->parent_dmat, /*alignment*/1,
                         /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                         /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                         /*highaddr*/BUS_SPACE_MAXADDR,
                         /*filter*/NULL, /*filterarg*/NULL,
                         driver_data_size,
                         /*nsegments*/1,
                         /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                         /*flags*/0, &ahd->shared_data_dmat) != 0) {
            return (ENOMEM);
      }

      ahd->init_level++;

      /* Allocation of driver data */
      if (ahd_dmamem_alloc(ahd, ahd->shared_data_dmat,
                       (void **)&ahd->shared_data_map.vaddr,
                       BUS_DMA_NOWAIT,
                       &ahd->shared_data_map.dmamap) != 0) {
            return (ENOMEM);
      }

      ahd->init_level++;

      /* And permanently map it in */
      ahd_dmamap_load(ahd, ahd->shared_data_dmat, ahd->shared_data_map.dmamap,
                  ahd->shared_data_map.vaddr, driver_data_size,
                  ahd_dmamap_cb, &ahd->shared_data_map.physaddr,
                  /*flags*/0);
      ahd->qoutfifo = (struct ahd_completion *)ahd->shared_data_map.vaddr;
      next_vaddr = (uint8_t *)&ahd->qoutfifo[AHD_QOUT_SIZE];
      next_baddr = ahd->shared_data_map.physaddr
               + AHD_QOUT_SIZE*sizeof(struct ahd_completion);
      if ((ahd->features & AHD_TARGETMODE) != 0) {
            ahd->targetcmds = (struct target_cmd *)next_vaddr;
            next_vaddr += AHD_TMODE_CMDS * sizeof(struct target_cmd);
            next_baddr += AHD_TMODE_CMDS * sizeof(struct target_cmd);
      }

      if ((ahd->bugs & AHD_PKT_BITBUCKET_BUG) != 0) {
            ahd->overrun_buf = next_vaddr;
            next_vaddr += PKT_OVERRUN_BUFSIZE;
            next_baddr += PKT_OVERRUN_BUFSIZE;
      }

      /*
       * We need one SCB to serve as the "next SCB".  Since the
       * tag identifier in this SCB will never be used, there is
       * no point in using a valid HSCB tag from an SCB pulled from
       * the standard free pool.  So, we allocate this "sentinel"
       * specially from the DMA safe memory chunk used for the QOUTFIFO.
       */
      ahd->next_queued_hscb = (struct hardware_scb *)next_vaddr;
      ahd->next_queued_hscb_map = &ahd->shared_data_map;
      ahd->next_queued_hscb->hscb_busaddr = ahd_htole32(next_baddr);

      ahd->init_level++;

      /* Allocate SCB data now that buffer_dmat is initialized */
      if (ahd_init_scbdata(ahd) != 0)
            return (ENOMEM);

      if ((ahd->flags & AHD_INITIATORROLE) == 0)
            ahd->flags &= ~AHD_RESET_BUS_A;

      /*
       * Before committing these settings to the chip, give
       * the OSM one last chance to modify our configuration.
       */
      ahd_platform_init(ahd);

      /* Bring up the chip. */
      ahd_chip_init(ahd);

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);

      if ((ahd->flags & AHD_CURRENT_SENSING) == 0)
            goto init_done;

      /*
       * Verify termination based on current draw and
       * warn user if the bus is over/under terminated.
       */
      error = ahd_write_flexport(ahd, FLXADDR_ROMSTAT_CURSENSECTL,
                           CURSENSE_ENB);
      if (error != 0) {
            printf("%s: current sensing timeout 1\n", ahd_name(ahd));
            goto init_done;
      }
      for (i = 20, fstat = FLX_FSTAT_BUSY;
           (fstat & FLX_FSTAT_BUSY) != 0 && i; i--) {
            error = ahd_read_flexport(ahd, FLXADDR_FLEXSTAT, &fstat);
            if (error != 0) {
                  printf("%s: current sensing timeout 2\n",
                         ahd_name(ahd));
                  goto init_done;
            }
      }
      if (i == 0) {
            printf("%s: Timedout during current-sensing test\n",
                   ahd_name(ahd));
            goto init_done;
      }

      /* Latch Current Sensing status. */
      error = ahd_read_flexport(ahd, FLXADDR_CURRENT_STAT, &current_sensing);
      if (error != 0) {
            printf("%s: current sensing timeout 3\n", ahd_name(ahd));
            goto init_done;
      }

      /* Diable current sensing. */
      ahd_write_flexport(ahd, FLXADDR_ROMSTAT_CURSENSECTL, 0);

#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_TERMCTL) != 0) {
            printf("%s: current_sensing == 0x%x\n",
                   ahd_name(ahd), current_sensing);
      }
#endif
      warn_user = 0;
      for (i = 0; i < 4; i++, current_sensing >>= FLX_CSTAT_SHIFT) {
            u_int term_stat;

            term_stat = (current_sensing & FLX_CSTAT_MASK);
            switch (term_stat) {
            case FLX_CSTAT_OVER:
            case FLX_CSTAT_UNDER:
                  warn_user++;
            case FLX_CSTAT_INVALID:
            case FLX_CSTAT_OKAY:
                  if (warn_user == 0 && bootverbose == 0)
                        break;
                  printf("%s: %s Channel %s\n", ahd_name(ahd),
                         channel_strings[i], termstat_strings[term_stat]);
                  break;
            }
      }
      if (warn_user) {
            printf("%s: WARNING. Termination is not configured correctly.\n"
                   "%s: WARNING. SCSI bus operations may FAIL.\n",
                   ahd_name(ahd), ahd_name(ahd));
      }
init_done:
      ahd_restart(ahd);
      ahd_timer_reset(&ahd->stat_timer, AHD_STAT_UPDATE_US,
                  ahd_stat_timer, ahd);
      return (0);
}

/*
 * (Re)initialize chip state after a chip reset.
 */
static void
ahd_chip_init(struct ahd_softc *ahd)
{
      uint32_t busaddr;
      u_int  sxfrctl1;
      u_int  scsiseq_template;
      u_int  wait;
      u_int  i;
      u_int  target;

      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      /*
       * Take the LED out of diagnostic mode
       */
      ahd_outb(ahd, SBLKCTL, ahd_inb(ahd, SBLKCTL) & ~(DIAGLEDEN|DIAGLEDON));

      /*
       * Return HS_MAILBOX to its default value.
       */
      ahd->hs_mailbox = 0;
      ahd_outb(ahd, HS_MAILBOX, 0);

      /* Set the SCSI Id, SXFRCTL0, SXFRCTL1, and SIMODE1. */
      ahd_outb(ahd, IOWNID, ahd->our_id);
      ahd_outb(ahd, TOWNID, ahd->our_id);
      sxfrctl1 = (ahd->flags & AHD_TERM_ENB_A) != 0 ? STPWEN : 0;
      sxfrctl1 |= (ahd->flags & AHD_SPCHK_ENB_A) != 0 ? ENSPCHK : 0;
      if ((ahd->bugs & AHD_LONG_SETIMO_BUG)
       && (ahd->seltime != STIMESEL_MIN)) {
            /*
             * The selection timer duration is twice as long
             * as it should be.  Halve it by adding "1" to
             * the user specified setting.
             */
            sxfrctl1 |= ahd->seltime + STIMESEL_BUG_ADJ;
      } else {
            sxfrctl1 |= ahd->seltime;
      }
            
      ahd_outb(ahd, SXFRCTL0, DFON);
      ahd_outb(ahd, SXFRCTL1, sxfrctl1|ahd->seltime|ENSTIMER|ACTNEGEN);
      ahd_outb(ahd, SIMODE1, ENSELTIMO|ENSCSIRST|ENSCSIPERR);

      /*
       * Now that termination is set, wait for up
       * to 500ms for our transceivers to settle.  If
       * the adapter does not have a cable attached,
       * the transceivers may never settle, so don't
       * complain if we fail here.
       */
      for (wait = 10000;
           (ahd_inb(ahd, SBLKCTL) & (ENAB40|ENAB20)) == 0 && wait;
           wait--)
            ahd_delay(100);

      /* Clear any false bus resets due to the transceivers settling */
      ahd_outb(ahd, CLRSINT1, CLRSCSIRSTI);
      ahd_outb(ahd, CLRINT, CLRSCSIINT);

      /* Initialize mode specific S/G state. */
      for (i = 0; i < 2; i++) {
            ahd_set_modes(ahd, AHD_MODE_DFF0 + i, AHD_MODE_DFF0 + i);
            ahd_outb(ahd, LONGJMP_ADDR + 1, INVALID_ADDR);
            ahd_outb(ahd, SG_STATE, 0);
            ahd_outb(ahd, CLRSEQINTSRC, 0xFF);
            ahd_outb(ahd, SEQIMODE,
                   ENSAVEPTRS|ENCFG4DATA|ENCFG4ISTAT
                  |ENCFG4TSTAT|ENCFG4ICMD|ENCFG4TCMD);
      }

      ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
      ahd_outb(ahd, DSCOMMAND0, ahd_inb(ahd, DSCOMMAND0)|MPARCKEN|CACHETHEN);
      ahd_outb(ahd, DFF_THRSH, RD_DFTHRSH_75|WR_DFTHRSH_75);
      ahd_outb(ahd, SIMODE0, ENIOERR|ENOVERRUN);
      ahd_outb(ahd, SIMODE3, ENNTRAMPERR|ENOSRAMPERR);
      if ((ahd->bugs & AHD_BUSFREEREV_BUG) != 0) {
            ahd_outb(ahd, OPTIONMODE, AUTOACKEN|AUTO_MSGOUT_DE);
      } else {
            ahd_outb(ahd, OPTIONMODE, AUTOACKEN|BUSFREEREV|AUTO_MSGOUT_DE);
      }
      ahd_outb(ahd, SCSCHKN, CURRFIFODEF|WIDERESEN|SHVALIDSTDIS);
      if ((ahd->chip & AHD_BUS_MASK) == AHD_PCIX)
            /*
             * Do not issue a target abort when a split completion
             * error occurs.  Let our PCIX interrupt handler deal
             * with it instead. H2A4 Razor #625
             */
            ahd_outb(ahd, PCIXCTL, ahd_inb(ahd, PCIXCTL) | SPLTSTADIS);

      if ((ahd->bugs & AHD_LQOOVERRUN_BUG) != 0)
            ahd_outb(ahd, LQOSCSCTL, LQONOCHKOVER);

      /*
       * Tweak IOCELL settings.
       */
      if ((ahd->flags & AHD_HP_BOARD) != 0) {
            for (i = 0; i < NUMDSPS; i++) {
                  ahd_outb(ahd, DSPSELECT, i);
                  ahd_outb(ahd, WRTBIASCTL, WRTBIASCTL_HP_DEFAULT);
            }
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0)
                  printf("%s: WRTBIASCTL now 0x%x\n", ahd_name(ahd),
                         WRTBIASCTL_HP_DEFAULT);
#endif
      }
      ahd_setup_iocell_workaround(ahd);

      /*
       * Enable LQI Manager interrupts.
       */
      ahd_outb(ahd, LQIMODE1, ENLQIPHASE_LQ|ENLQIPHASE_NLQ|ENLIQABORT
                        | ENLQICRCI_LQ|ENLQICRCI_NLQ|ENLQIBADLQI
                        | ENLQIOVERI_LQ|ENLQIOVERI_NLQ);
      ahd_outb(ahd, LQOMODE0, ENLQOATNLQ|ENLQOATNPKT|ENLQOTCRC);
      /*
       * We choose to have the sequencer catch LQOPHCHGINPKT errors
       * manually for the command phase at the start of a packetized
       * selection case.  ENLQOBUSFREE should be made redundant by
       * the BUSFREE interrupt, but it seems that some LQOBUSFREE
       * events fail to assert the BUSFREE interrupt so we must
       * also enable LQOBUSFREE interrupts.
       */
      ahd_outb(ahd, LQOMODE1, ENLQOBUSFREE);

      /*
       * Setup sequencer interrupt handlers.
       */
      ahd_outw(ahd, INTVEC1_ADDR, ahd_resolve_seqaddr(ahd, LABEL_seq_isr));
      ahd_outw(ahd, INTVEC2_ADDR, ahd_resolve_seqaddr(ahd, LABEL_timer_isr));

      /*
       * Setup SCB Offset registers.
       */
      if ((ahd->bugs & AHD_PKT_LUN_BUG) != 0) {
            ahd_outb(ahd, LUNPTR, offsetof(struct hardware_scb,
                   pkt_long_lun));
      } else {
            ahd_outb(ahd, LUNPTR, offsetof(struct hardware_scb, lun));
      }
      ahd_outb(ahd, CMDLENPTR, offsetof(struct hardware_scb, cdb_len));
      ahd_outb(ahd, ATTRPTR, offsetof(struct hardware_scb, task_attribute));
      ahd_outb(ahd, FLAGPTR, offsetof(struct hardware_scb, task_management));
      ahd_outb(ahd, CMDPTR, offsetof(struct hardware_scb,
                               shared_data.idata.cdb));
      ahd_outb(ahd, QNEXTPTR,
             offsetof(struct hardware_scb, next_hscb_busaddr));
      ahd_outb(ahd, ABRTBITPTR, MK_MESSAGE_BIT_OFFSET);
      ahd_outb(ahd, ABRTBYTEPTR, offsetof(struct hardware_scb, control));
      if ((ahd->bugs & AHD_PKT_LUN_BUG) != 0) {
            ahd_outb(ahd, LUNLEN,
                   sizeof(ahd->next_queued_hscb->pkt_long_lun) - 1);
      } else {
            ahd_outb(ahd, LUNLEN, LUNLEN_SINGLE_LEVEL_LUN);
      }
      ahd_outb(ahd, CDBLIMIT, SCB_CDB_LEN_PTR - 1);
      ahd_outb(ahd, MAXCMD, 0xFF);
      ahd_outb(ahd, SCBAUTOPTR,
             AUSCBPTR_EN | offsetof(struct hardware_scb, tag));

      /* We haven't been enabled for target mode yet. */
      ahd_outb(ahd, MULTARGID, 0);
      ahd_outb(ahd, MULTARGID + 1, 0);

      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      /* Initialize the negotiation table. */
      if ((ahd->features & AHD_NEW_IOCELL_OPTS) == 0) {
            /*
             * Clear the spare bytes in the neg table to avoid
             * spurious parity errors.
             */
            for (target = 0; target < AHD_NUM_TARGETS; target++) {
                  ahd_outb(ahd, NEGOADDR, target);
                  ahd_outb(ahd, ANNEXCOL, AHD_ANNEXCOL_PER_DEV0);
                  for (i = 0; i < AHD_NUM_PER_DEV_ANNEXCOLS; i++)
                        ahd_outb(ahd, ANNEXDAT, 0);
            }
      }
      for (target = 0; target < AHD_NUM_TARGETS; target++) {
            struct       ahd_devinfo devinfo;
            struct       ahd_initiator_tinfo *tinfo;
            struct       ahd_tmode_tstate *tstate;

            tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                                  target, &tstate);
            ahd_compile_devinfo(&devinfo, ahd->our_id,
                            target, CAM_LUN_WILDCARD,
                            'A', ROLE_INITIATOR);
            ahd_update_neg_table(ahd, &devinfo, &tinfo->curr);
      }

      ahd_outb(ahd, CLRSINT3, NTRAMPERR|OSRAMPERR);
      ahd_outb(ahd, CLRINT, CLRSCSIINT);

#ifdef NEEDS_MORE_TESTING
      /*
       * Always enable abort on incoming L_Qs if this feature is
       * supported.  We use this to catch invalid SCB references.
       */
      if ((ahd->bugs & AHD_ABORT_LQI_BUG) == 0)
            ahd_outb(ahd, LQCTL1, ABORTPENDING);
      else
#endif
            ahd_outb(ahd, LQCTL1, 0);

      /* All of our queues are empty */
      ahd->qoutfifonext = 0;
      ahd->qoutfifonext_valid_tag = QOUTFIFO_ENTRY_VALID;
      ahd_outb(ahd, QOUTFIFO_ENTRY_VALID_TAG, QOUTFIFO_ENTRY_VALID);
      for (i = 0; i < AHD_QOUT_SIZE; i++)
            ahd->qoutfifo[i].valid_tag = 0;
      ahd_sync_qoutfifo(ahd, BUS_DMASYNC_PREREAD);

      ahd->qinfifonext = 0;
      for (i = 0; i < AHD_QIN_SIZE; i++)
            ahd->qinfifo[i] = SCB_LIST_NULL;

      if ((ahd->features & AHD_TARGETMODE) != 0) {
            /* All target command blocks start out invalid. */
            for (i = 0; i < AHD_TMODE_CMDS; i++)
                  ahd->targetcmds[i].cmd_valid = 0;
            ahd_sync_tqinfifo(ahd, BUS_DMASYNC_PREREAD);
            ahd->tqinfifonext = 1;
            ahd_outb(ahd, KERNEL_TQINPOS, ahd->tqinfifonext - 1);
            ahd_outb(ahd, TQINPOS, ahd->tqinfifonext);
      }

      /* Initialize Scratch Ram. */
      ahd_outb(ahd, SEQ_FLAGS, 0);
      ahd_outb(ahd, SEQ_FLAGS2, 0);

      /* We don't have any waiting selections */
      ahd_outw(ahd, WAITING_TID_HEAD, SCB_LIST_NULL);
      ahd_outw(ahd, WAITING_TID_TAIL, SCB_LIST_NULL);
      ahd_outw(ahd, MK_MESSAGE_SCB, SCB_LIST_NULL);
      ahd_outw(ahd, MK_MESSAGE_SCSIID, 0xFF);
      for (i = 0; i < AHD_NUM_TARGETS; i++)
            ahd_outw(ahd, WAITING_SCB_TAILS + (2 * i), SCB_LIST_NULL);

      /*
       * Nobody is waiting to be DMAed into the QOUTFIFO.
       */
      ahd_outw(ahd, COMPLETE_SCB_HEAD, SCB_LIST_NULL);
      ahd_outw(ahd, COMPLETE_SCB_DMAINPROG_HEAD, SCB_LIST_NULL);
      ahd_outw(ahd, COMPLETE_DMA_SCB_HEAD, SCB_LIST_NULL);
      ahd_outw(ahd, COMPLETE_DMA_SCB_TAIL, SCB_LIST_NULL);
      ahd_outw(ahd, COMPLETE_ON_QFREEZE_HEAD, SCB_LIST_NULL);

      /*
       * The Freeze Count is 0.
       */
      ahd->qfreeze_cnt = 0;
      ahd_outw(ahd, QFREEZE_COUNT, 0);
      ahd_outw(ahd, KERNEL_QFREEZE_COUNT, 0);

      /*
       * Tell the sequencer where it can find our arrays in memory.
       */
      busaddr = ahd->shared_data_map.physaddr;
      ahd_outl(ahd, SHARED_DATA_ADDR, busaddr);
      ahd_outl(ahd, QOUTFIFO_NEXT_ADDR, busaddr);

      /*
       * Setup the allowed SCSI Sequences based on operational mode.
       * If we are a target, we'll enable select in operations once
       * we've had a lun enabled.
       */
      scsiseq_template = ENAUTOATNP;
      if ((ahd->flags & AHD_INITIATORROLE) != 0)
            scsiseq_template |= ENRSELI;
      ahd_outb(ahd, SCSISEQ_TEMPLATE, scsiseq_template);

      /* There are no busy SCBs yet. */
      for (target = 0; target < AHD_NUM_TARGETS; target++) {
            int lun;

            for (lun = 0; lun < AHD_NUM_LUNS_NONPKT; lun++)
                  ahd_unbusy_tcl(ahd, BUILD_TCL_RAW(target, 'A', lun));
      }

      /*
       * Initialize the group code to command length table.
       * Vendor Unique codes are set to 0 so we only capture
       * the first byte of the cdb.  These can be overridden
       * when target mode is enabled.
       */
      ahd_outb(ahd, CMDSIZE_TABLE, 5);
      ahd_outb(ahd, CMDSIZE_TABLE + 1, 9);
      ahd_outb(ahd, CMDSIZE_TABLE + 2, 9);
      ahd_outb(ahd, CMDSIZE_TABLE + 3, 0);
      ahd_outb(ahd, CMDSIZE_TABLE + 4, 15);
      ahd_outb(ahd, CMDSIZE_TABLE + 5, 11);
      ahd_outb(ahd, CMDSIZE_TABLE + 6, 0);
      ahd_outb(ahd, CMDSIZE_TABLE + 7, 0);
            
      /* Tell the sequencer of our initial queue positions */
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);
      ahd_outb(ahd, QOFF_CTLSTA, SCB_QSIZE_512);
      ahd->qinfifonext = 0;
      ahd_set_hnscb_qoff(ahd, ahd->qinfifonext);
      ahd_set_hescb_qoff(ahd, 0);
      ahd_set_snscb_qoff(ahd, 0);
      ahd_set_sescb_qoff(ahd, 0);
      ahd_set_sdscb_qoff(ahd, 0);

      /*
       * Tell the sequencer which SCB will be the next one it receives.
       */
      busaddr = ahd_le32toh(ahd->next_queued_hscb->hscb_busaddr);
      ahd_outl(ahd, NEXT_QUEUED_SCB_ADDR, busaddr);

      /*
       * Default to coalescing disabled.
       */
      ahd_outw(ahd, INT_COALESCING_CMDCOUNT, 0);
      ahd_outw(ahd, CMDS_PENDING, 0);
      ahd_update_coalescing_values(ahd, ahd->int_coalescing_timer,
                             ahd->int_coalescing_maxcmds,
                             ahd->int_coalescing_mincmds);
      ahd_enable_coalescing(ahd, FALSE);

      ahd_loadseq(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      if (ahd->features & AHD_AIC79XXB_SLOWCRC) {
            u_int negodat3 = ahd_inb(ahd, NEGCONOPTS);

            negodat3 |= ENSLOWCRC;
            ahd_outb(ahd, NEGCONOPTS, negodat3);
            negodat3 = ahd_inb(ahd, NEGCONOPTS);
            if (!(negodat3 & ENSLOWCRC))
                  printf("aic79xx: failed to set the SLOWCRC bit\n");
            else
                  printf("aic79xx: SLOWCRC bit set\n");
      }
}

/*
 * Setup default device and controller settings.
 * This should only be called if our probe has
 * determined that no configuration data is available.
 */
int
ahd_default_config(struct ahd_softc *ahd)
{
      int   targ;

      ahd->our_id = 7;

      /*
       * Allocate a tstate to house information for our
       * initiator presence on the bus as well as the user
       * data for any target mode initiator.
       */
      if (ahd_alloc_tstate(ahd, ahd->our_id, 'A') == NULL) {
            printf("%s: unable to allocate ahd_tmode_tstate.  "
                   "Failing attach\n", ahd_name(ahd));
            return (ENOMEM);
      }

      for (targ = 0; targ < AHD_NUM_TARGETS; targ++) {
            struct       ahd_devinfo devinfo;
            struct       ahd_initiator_tinfo *tinfo;
            struct       ahd_tmode_tstate *tstate;
            uint16_t target_mask;

            tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                                  targ, &tstate);
            /*
             * We support SPC2 and SPI4.
             */
            tinfo->user.protocol_version = 4;
            tinfo->user.transport_version = 4;

            target_mask = 0x01 << targ;
            ahd->user_discenable |= target_mask;
            tstate->discenable |= target_mask;
            ahd->user_tagenable |= target_mask;
#ifdef AHD_FORCE_160
            tinfo->user.period = AHD_SYNCRATE_DT;
#else
            tinfo->user.period = AHD_SYNCRATE_160;
#endif
            tinfo->user.offset = MAX_OFFSET;
            tinfo->user.ppr_options = MSG_EXT_PPR_RD_STRM
                              | MSG_EXT_PPR_WR_FLOW
                              | MSG_EXT_PPR_HOLD_MCS
                              | MSG_EXT_PPR_IU_REQ
                              | MSG_EXT_PPR_QAS_REQ
                              | MSG_EXT_PPR_DT_REQ;
            if ((ahd->features & AHD_RTI) != 0)
                  tinfo->user.ppr_options |= MSG_EXT_PPR_RTI;

            tinfo->user.width = MSG_EXT_WDTR_BUS_16_BIT;

            /*
             * Start out Async/Narrow/Untagged and with
             * conservative protocol support.
             */
            tinfo->goal.protocol_version = 2;
            tinfo->goal.transport_version = 2;
            tinfo->curr.protocol_version = 2;
            tinfo->curr.transport_version = 2;
            ahd_compile_devinfo(&devinfo, ahd->our_id,
                            targ, CAM_LUN_WILDCARD,
                            'A', ROLE_INITIATOR);
            tstate->tagenable &= ~target_mask;
            ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                        AHD_TRANS_CUR|AHD_TRANS_GOAL, /*paused*/TRUE);
            ahd_set_syncrate(ahd, &devinfo, /*period*/0, /*offset*/0,
                         /*ppr_options*/0, AHD_TRANS_CUR|AHD_TRANS_GOAL,
                         /*paused*/TRUE);
      }
      return (0);
}

/*
 * Parse device configuration information.
 */
int
ahd_parse_cfgdata(struct ahd_softc *ahd, struct seeprom_config *sc)
{
      int targ;
      int max_targ;

      max_targ = sc->max_targets & CFMAXTARG;
      ahd->our_id = sc->brtime_id & CFSCSIID;

      /*
       * Allocate a tstate to house information for our
       * initiator presence on the bus as well as the user
       * data for any target mode initiator.
       */
      if (ahd_alloc_tstate(ahd, ahd->our_id, 'A') == NULL) {
            printf("%s: unable to allocate ahd_tmode_tstate.  "
                   "Failing attach\n", ahd_name(ahd));
            return (ENOMEM);
      }

      for (targ = 0; targ < max_targ; targ++) {
            struct       ahd_devinfo devinfo;
            struct       ahd_initiator_tinfo *tinfo;
            struct       ahd_transinfo *user_tinfo;
            struct       ahd_tmode_tstate *tstate;
            uint16_t target_mask;

            tinfo = ahd_fetch_transinfo(ahd, 'A', ahd->our_id,
                                  targ, &tstate);
            user_tinfo = &tinfo->user;

            /*
             * We support SPC2 and SPI4.
             */
            tinfo->user.protocol_version = 4;
            tinfo->user.transport_version = 4;

            target_mask = 0x01 << targ;
            ahd->user_discenable &= ~target_mask;
            tstate->discenable &= ~target_mask;
            ahd->user_tagenable &= ~target_mask;
            if (sc->device_flags[targ] & CFDISC) {
                  tstate->discenable |= target_mask;
                  ahd->user_discenable |= target_mask;
                  ahd->user_tagenable |= target_mask;
            } else {
                  /*
                   * Cannot be packetized without disconnection.
                   */
                  sc->device_flags[targ] &= ~CFPACKETIZED;
            }

            user_tinfo->ppr_options = 0;
            user_tinfo->period = (sc->device_flags[targ] & CFXFER);
            if (user_tinfo->period < CFXFER_ASYNC) {
                  if (user_tinfo->period <= AHD_PERIOD_10MHz)
                        user_tinfo->ppr_options |= MSG_EXT_PPR_DT_REQ;
                  user_tinfo->offset = MAX_OFFSET;
            } else  {
                  user_tinfo->offset = 0;
                  user_tinfo->period = AHD_ASYNC_XFER_PERIOD;
            }
#ifdef AHD_FORCE_160
            if (user_tinfo->period <= AHD_SYNCRATE_160)
                  user_tinfo->period = AHD_SYNCRATE_DT;
#endif

            if ((sc->device_flags[targ] & CFPACKETIZED) != 0) {
                  user_tinfo->ppr_options |= MSG_EXT_PPR_RD_STRM
                                    |  MSG_EXT_PPR_WR_FLOW
                                    |  MSG_EXT_PPR_HOLD_MCS
                                    |  MSG_EXT_PPR_IU_REQ;
                  if ((ahd->features & AHD_RTI) != 0)
                        user_tinfo->ppr_options |= MSG_EXT_PPR_RTI;
            }

            if ((sc->device_flags[targ] & CFQAS) != 0)
                  user_tinfo->ppr_options |= MSG_EXT_PPR_QAS_REQ;

            if ((sc->device_flags[targ] & CFWIDEB) != 0)
                  user_tinfo->width = MSG_EXT_WDTR_BUS_16_BIT;
            else
                  user_tinfo->width = MSG_EXT_WDTR_BUS_8_BIT;
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_MISC) != 0)
                  printf("(%d): %x:%x:%x:%x\n", targ, user_tinfo->width,
                         user_tinfo->period, user_tinfo->offset,
                         user_tinfo->ppr_options);
#endif
            /*
             * Start out Async/Narrow/Untagged and with
             * conservative protocol support.
             */
            tstate->tagenable &= ~target_mask;
            tinfo->goal.protocol_version = 2;
            tinfo->goal.transport_version = 2;
            tinfo->curr.protocol_version = 2;
            tinfo->curr.transport_version = 2;
            ahd_compile_devinfo(&devinfo, ahd->our_id,
                            targ, CAM_LUN_WILDCARD,
                            'A', ROLE_INITIATOR);
            ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                        AHD_TRANS_CUR|AHD_TRANS_GOAL, /*paused*/TRUE);
            ahd_set_syncrate(ahd, &devinfo, /*period*/0, /*offset*/0,
                         /*ppr_options*/0, AHD_TRANS_CUR|AHD_TRANS_GOAL,
                         /*paused*/TRUE);
      }

      ahd->flags &= ~AHD_SPCHK_ENB_A;
      if (sc->bios_control & CFSPARITY)
            ahd->flags |= AHD_SPCHK_ENB_A;

      ahd->flags &= ~AHD_RESET_BUS_A;
      if (sc->bios_control & CFRESETB)
            ahd->flags |= AHD_RESET_BUS_A;

      ahd->flags &= ~AHD_EXTENDED_TRANS_A;
      if (sc->bios_control & CFEXTEND)
            ahd->flags |= AHD_EXTENDED_TRANS_A;

      ahd->flags &= ~AHD_BIOS_ENABLED;
      if ((sc->bios_control & CFBIOSSTATE) == CFBS_ENABLED)
            ahd->flags |= AHD_BIOS_ENABLED;

      ahd->flags &= ~AHD_STPWLEVEL_A;
      if ((sc->adapter_control & CFSTPWLEVEL) != 0)
            ahd->flags |= AHD_STPWLEVEL_A;

      return (0);
}

/*
 * Parse device configuration information.
 */
int
ahd_parse_vpddata(struct ahd_softc *ahd, struct vpd_config *vpd)
{
      int error;

      error = ahd_verify_vpd_cksum(vpd);
      if (error == 0)
            return (EINVAL);
      if ((vpd->bios_flags & VPDBOOTHOST) != 0)
            ahd->flags |= AHD_BOOT_CHANNEL;
      return (0);
}

void
ahd_intr_enable(struct ahd_softc *ahd, int enable)
{
      u_int hcntrl;

      hcntrl = ahd_inb(ahd, HCNTRL);
      hcntrl &= ~INTEN;
      ahd->pause &= ~INTEN;
      ahd->unpause &= ~INTEN;
      if (enable) {
            hcntrl |= INTEN;
            ahd->pause |= INTEN;
            ahd->unpause |= INTEN;
      }
      ahd_outb(ahd, HCNTRL, hcntrl);
}

void
ahd_update_coalescing_values(struct ahd_softc *ahd, u_int timer, u_int maxcmds,
                       u_int mincmds)
{
      if (timer > AHD_TIMER_MAX_US)
            timer = AHD_TIMER_MAX_US;
      ahd->int_coalescing_timer = timer;

      if (maxcmds > AHD_INT_COALESCING_MAXCMDS_MAX)
            maxcmds = AHD_INT_COALESCING_MAXCMDS_MAX;
      if (mincmds > AHD_INT_COALESCING_MINCMDS_MAX)
            mincmds = AHD_INT_COALESCING_MINCMDS_MAX;
      ahd->int_coalescing_maxcmds = maxcmds;
      ahd_outw(ahd, INT_COALESCING_TIMER, timer / AHD_TIMER_US_PER_TICK);
      ahd_outb(ahd, INT_COALESCING_MAXCMDS, -maxcmds);
      ahd_outb(ahd, INT_COALESCING_MINCMDS, -mincmds);
}

void
ahd_enable_coalescing(struct ahd_softc *ahd, int enable)
{

      ahd->hs_mailbox &= ~ENINT_COALESCE;
      if (enable)
            ahd->hs_mailbox |= ENINT_COALESCE;
      ahd_outb(ahd, HS_MAILBOX, ahd->hs_mailbox);
      ahd_flush_device_writes(ahd);
      ahd_run_qoutfifo(ahd);
}

/*
 * Ensure that the card is paused in a location
 * outside of all critical sections and that all
 * pending work is completed prior to returning.
 * This routine should only be called from outside
 * an interrupt context.
 */
void
ahd_pause_and_flushwork(struct ahd_softc *ahd)
{
      u_int intstat;
      u_int maxloops;

      maxloops = 1000;
      ahd->flags |= AHD_ALL_INTERRUPTS;
      ahd_pause(ahd);
      /*
       * Freeze the outgoing selections.  We do this only
       * until we are safely paused without further selections
       * pending.
       */
      ahd->qfreeze_cnt--;
      ahd_outw(ahd, KERNEL_QFREEZE_COUNT, ahd->qfreeze_cnt);
      ahd_outb(ahd, SEQ_FLAGS2, ahd_inb(ahd, SEQ_FLAGS2) | SELECTOUT_QFROZEN);
      do {

            ahd_unpause(ahd);
            /*
             * Give the sequencer some time to service
             * any active selections.
             */
            ahd_delay(500);

            ahd_intr(ahd);
            ahd_pause(ahd);
            intstat = ahd_inb(ahd, INTSTAT);
            if ((intstat & INT_PEND) == 0) {
                  ahd_clear_critical_section(ahd);
                  intstat = ahd_inb(ahd, INTSTAT);
            }
      } while (--maxloops
            && (intstat != 0xFF || (ahd->features & AHD_REMOVABLE) == 0)
            && ((intstat & INT_PEND) != 0
             || (ahd_inb(ahd, SCSISEQ0) & ENSELO) != 0
             || (ahd_inb(ahd, SSTAT0) & (SELDO|SELINGO)) != 0));

      if (maxloops == 0) {
            printf("Infinite interrupt loop, INTSTAT = %x",
                  ahd_inb(ahd, INTSTAT));
      }
      ahd->qfreeze_cnt++;
      ahd_outw(ahd, KERNEL_QFREEZE_COUNT, ahd->qfreeze_cnt);

      ahd_flush_qoutfifo(ahd);

      ahd->flags &= ~AHD_ALL_INTERRUPTS;
}

int
ahd_suspend(struct ahd_softc *ahd)
{

      ahd_pause_and_flushwork(ahd);

      if (LIST_FIRST(&ahd->pending_scbs) != NULL) {
            ahd_unpause(ahd);
            return (EBUSY);
      }
      ahd_shutdown(ahd);
      return (0);
}

int
ahd_resume(struct ahd_softc *ahd)
{

      ahd_reset(ahd, /*reinit*/TRUE);
      ahd_intr_enable(ahd, TRUE); 
      ahd_restart(ahd);
      return (0);
}

/************************** Busy Target Table *********************************/
/*
 * Set SCBPTR to the SCB that contains the busy
 * table entry for TCL.  Return the offset into
 * the SCB that contains the entry for TCL.
 * saved_scbid is dereferenced and set to the
 * scbid that should be restored once manipualtion
 * of the TCL entry is complete.
 */
static __inline u_int
ahd_index_busy_tcl(struct ahd_softc *ahd, u_int *saved_scbid, u_int tcl)
{
      /*
       * Index to the SCB that contains the busy entry.
       */
      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      *saved_scbid = ahd_get_scbptr(ahd);
      ahd_set_scbptr(ahd, TCL_LUN(tcl)
                 | ((TCL_TARGET_OFFSET(tcl) & 0xC) << 4));

      /*
       * And now calculate the SCB offset to the entry.
       * Each entry is 2 bytes wide, hence the
       * multiplication by 2.
       */
      return (((TCL_TARGET_OFFSET(tcl) & 0x3) << 1) + SCB_DISCONNECTED_LISTS);
}

/*
 * Return the untagged transaction id for a given target/channel lun.
 */
u_int
ahd_find_busy_tcl(struct ahd_softc *ahd, u_int tcl)
{
      u_int scbid;
      u_int scb_offset;
      u_int saved_scbptr;
            
      scb_offset = ahd_index_busy_tcl(ahd, &saved_scbptr, tcl);
      scbid = ahd_inw_scbram(ahd, scb_offset);
      ahd_set_scbptr(ahd, saved_scbptr);
      return (scbid);
}

void
ahd_busy_tcl(struct ahd_softc *ahd, u_int tcl, u_int scbid)
{
      u_int scb_offset;
      u_int saved_scbptr;
            
      scb_offset = ahd_index_busy_tcl(ahd, &saved_scbptr, tcl);
      ahd_outw(ahd, scb_offset, scbid);
      ahd_set_scbptr(ahd, saved_scbptr);
}

/************************** SCB and SCB queue management **********************/
int
ahd_match_scb(struct ahd_softc *ahd, struct scb *scb, int target,
            char channel, int lun, u_int tag, role_t role)
{
      int targ = SCB_GET_TARGET(ahd, scb);
      char chan = SCB_GET_CHANNEL(ahd, scb);
      int slun = SCB_GET_LUN(scb);
      int match;

      match = ((chan == channel) || (channel == ALL_CHANNELS));
      if (match != 0)
            match = ((targ == target) || (target == CAM_TARGET_WILDCARD));
      if (match != 0)
            match = ((lun == slun) || (lun == CAM_LUN_WILDCARD));
      if (match != 0) {
#ifdef AHD_TARGET_MODE
            int group;

            group = XPT_FC_GROUP(scb->io_ctx->ccb_h.func_code);
            if (role == ROLE_INITIATOR) {
                  match = (group != XPT_FC_GROUP_TMODE)
                        && ((tag == SCB_GET_TAG(scb))
                         || (tag == SCB_LIST_NULL));
            } else if (role == ROLE_TARGET) {
                  match = (group == XPT_FC_GROUP_TMODE)
                        && ((tag == scb->io_ctx->csio.tag_id)
                         || (tag == SCB_LIST_NULL));
            }
#else /* !AHD_TARGET_MODE */
            match = ((tag == SCB_GET_TAG(scb)) || (tag == SCB_LIST_NULL));
#endif /* AHD_TARGET_MODE */
      }

      return match;
}

void
ahd_freeze_devq(struct ahd_softc *ahd, struct scb *scb)
{
      int   target;
      char  channel;
      int   lun;

      target = SCB_GET_TARGET(ahd, scb);
      lun = SCB_GET_LUN(scb);
      channel = SCB_GET_CHANNEL(ahd, scb);
      
      ahd_search_qinfifo(ahd, target, channel, lun,
                     /*tag*/SCB_LIST_NULL, ROLE_UNKNOWN,
                     CAM_REQUEUE_REQ, SEARCH_COMPLETE);

      ahd_platform_freeze_devq(ahd, scb);
}

void
ahd_qinfifo_requeue_tail(struct ahd_softc *ahd, struct scb *scb)
{
      struct scb  *prev_scb;
      ahd_mode_state     saved_modes;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);
      prev_scb = NULL;
      if (ahd_qinfifo_count(ahd) != 0) {
            u_int prev_tag;
            u_int prev_pos;

            prev_pos = AHD_QIN_WRAP(ahd->qinfifonext - 1);
            prev_tag = ahd->qinfifo[prev_pos];
            prev_scb = ahd_lookup_scb(ahd, prev_tag);
      }
      ahd_qinfifo_requeue(ahd, prev_scb, scb);
      ahd_set_hnscb_qoff(ahd, ahd->qinfifonext);
      ahd_restore_modes(ahd, saved_modes);
}

static void
ahd_qinfifo_requeue(struct ahd_softc *ahd, struct scb *prev_scb,
                struct scb *scb)
{
      if (prev_scb == NULL) {
            uint32_t busaddr;

            busaddr = ahd_le32toh(scb->hscb->hscb_busaddr);
            ahd_outl(ahd, NEXT_QUEUED_SCB_ADDR, busaddr);
      } else {
            prev_scb->hscb->next_hscb_busaddr = scb->hscb->hscb_busaddr;
            ahd_sync_scb(ahd, prev_scb, 
                       BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
      }
      ahd->qinfifo[AHD_QIN_WRAP(ahd->qinfifonext)] = SCB_GET_TAG(scb);
      ahd->qinfifonext++;
      scb->hscb->next_hscb_busaddr = ahd->next_queued_hscb->hscb_busaddr;
      ahd_sync_scb(ahd, scb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
}

static int
ahd_qinfifo_count(struct ahd_softc *ahd)
{
      u_int qinpos;
      u_int wrap_qinpos;
      u_int wrap_qinfifonext;

      AHD_ASSERT_MODES(ahd, AHD_MODE_CCHAN_MSK, AHD_MODE_CCHAN_MSK);
      qinpos = ahd_get_snscb_qoff(ahd);
      wrap_qinpos = AHD_QIN_WRAP(qinpos);
      wrap_qinfifonext = AHD_QIN_WRAP(ahd->qinfifonext);
      if (wrap_qinfifonext >= wrap_qinpos)
            return (wrap_qinfifonext - wrap_qinpos);
      else
            return (wrap_qinfifonext
                  + ARRAY_SIZE(ahd->qinfifo) - wrap_qinpos);
}

void
ahd_reset_cmds_pending(struct ahd_softc *ahd)
{
      struct            scb *scb;
      ahd_mode_state    saved_modes;
      u_int       pending_cmds;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

      /*
       * Don't count any commands as outstanding that the
       * sequencer has already marked for completion.
       */
      ahd_flush_qoutfifo(ahd);

      pending_cmds = 0;
      LIST_FOREACH(scb, &ahd->pending_scbs, pending_links) {
            pending_cmds++;
      }
      ahd_outw(ahd, CMDS_PENDING, pending_cmds - ahd_qinfifo_count(ahd));
      ahd_restore_modes(ahd, saved_modes);
      ahd->flags &= ~AHD_UPDATE_PEND_CMDS;
}

static void
ahd_done_with_status(struct ahd_softc *ahd, struct scb *scb, uint32_t status)
{
      cam_status ostat;
      cam_status cstat;

      ostat = ahd_get_transaction_status(scb);
      if (ostat == CAM_REQ_INPROG)
            ahd_set_transaction_status(scb, status);
      cstat = ahd_get_transaction_status(scb);
      if (cstat != CAM_REQ_CMP)
            ahd_freeze_scb(scb);
      ahd_done(ahd, scb);
}

int
ahd_search_qinfifo(struct ahd_softc *ahd, int target, char channel,
               int lun, u_int tag, role_t role, uint32_t status,
               ahd_search_action action)
{
      struct scb  *scb;
      struct scb  *mk_msg_scb;
      struct scb  *prev_scb;
      ahd_mode_state     saved_modes;
      u_int        qinstart;
      u_int        qinpos;
      u_int        qintail;
      u_int        tid_next;
      u_int        tid_prev;
      u_int        scbid;
      u_int        seq_flags2;
      u_int        savedscbptr;
      uint32_t     busaddr;
      int          found;
      int          targets;

      /* Must be in CCHAN mode */
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);

      /*
       * Halt any pending SCB DMA.  The sequencer will reinitiate
       * this dma if the qinfifo is not empty once we unpause.
       */
      if ((ahd_inb(ahd, CCSCBCTL) & (CCARREN|CCSCBEN|CCSCBDIR))
       == (CCARREN|CCSCBEN|CCSCBDIR)) {
            ahd_outb(ahd, CCSCBCTL,
                   ahd_inb(ahd, CCSCBCTL) & ~(CCARREN|CCSCBEN));
            while ((ahd_inb(ahd, CCSCBCTL) & (CCARREN|CCSCBEN)) != 0)
                  ;
      }
      /* Determine sequencer's position in the qinfifo. */
      qintail = AHD_QIN_WRAP(ahd->qinfifonext);
      qinstart = ahd_get_snscb_qoff(ahd);
      qinpos = AHD_QIN_WRAP(qinstart);
      found = 0;
      prev_scb = NULL;

      if (action == SEARCH_PRINT) {
            printf("qinstart = %d qinfifonext = %d\nQINFIFO:",
                   qinstart, ahd->qinfifonext);
      }

      /*
       * Start with an empty queue.  Entries that are not chosen
       * for removal will be re-added to the queue as we go.
       */
      ahd->qinfifonext = qinstart;
      busaddr = ahd_le32toh(ahd->next_queued_hscb->hscb_busaddr);
      ahd_outl(ahd, NEXT_QUEUED_SCB_ADDR, busaddr);

      while (qinpos != qintail) {
            scb = ahd_lookup_scb(ahd, ahd->qinfifo[qinpos]);
            if (scb == NULL) {
                  printf("qinpos = %d, SCB index = %d\n",
                        qinpos, ahd->qinfifo[qinpos]);
                  panic("Loop 1\n");
            }

            if (ahd_match_scb(ahd, scb, target, channel, lun, tag, role)) {
                  /*
                   * We found an scb that needs to be acted on.
                   */
                  found++;
                  switch (action) {
                  case SEARCH_COMPLETE:
                        if ((scb->flags & SCB_ACTIVE) == 0)
                              printf("Inactive SCB in qinfifo\n");
                        ahd_done_with_status(ahd, scb, status);
                        /* FALLTHROUGH */
                  case SEARCH_REMOVE:
                        break;
                  case SEARCH_PRINT:
                        printf(" 0x%x", ahd->qinfifo[qinpos]);
                        /* FALLTHROUGH */
                  case SEARCH_COUNT:
                        ahd_qinfifo_requeue(ahd, prev_scb, scb);
                        prev_scb = scb;
                        break;
                  }
            } else {
                  ahd_qinfifo_requeue(ahd, prev_scb, scb);
                  prev_scb = scb;
            }
            qinpos = AHD_QIN_WRAP(qinpos+1);
      }

      ahd_set_hnscb_qoff(ahd, ahd->qinfifonext);

      if (action == SEARCH_PRINT)
            printf("\nWAITING_TID_QUEUES:\n");

      /*
       * Search waiting for selection lists.  We traverse the
       * list of "their ids" waiting for selection and, if
       * appropriate, traverse the SCBs of each "their id"
       * looking for matches.
       */
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      seq_flags2 = ahd_inb(ahd, SEQ_FLAGS2);
      if ((seq_flags2 & PENDING_MK_MESSAGE) != 0) {
            scbid = ahd_inw(ahd, MK_MESSAGE_SCB);
            mk_msg_scb = ahd_lookup_scb(ahd, scbid);
      } else
            mk_msg_scb = NULL;
      savedscbptr = ahd_get_scbptr(ahd);
      tid_next = ahd_inw(ahd, WAITING_TID_HEAD);
      tid_prev = SCB_LIST_NULL;
      targets = 0;
      for (scbid = tid_next; !SCBID_IS_NULL(scbid); scbid = tid_next) {
            u_int tid_head;
            u_int tid_tail;

            targets++;
            if (targets > AHD_NUM_TARGETS)
                  panic("TID LIST LOOP");

            if (scbid >= ahd->scb_data.numscbs) {
                  printf("%s: Waiting TID List inconsistency. "
                         "SCB index == 0x%x, yet numscbs == 0x%x.",
                         ahd_name(ahd), scbid, ahd->scb_data.numscbs);
                  ahd_dump_card_state(ahd);
                  panic("for safety");
            }
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: SCB = 0x%x Not Active!\n",
                         ahd_name(ahd), scbid);
                  panic("Waiting TID List traversal\n");
            }
            ahd_set_scbptr(ahd, scbid);
            tid_next = ahd_inw_scbram(ahd, SCB_NEXT2);
            if (ahd_match_scb(ahd, scb, target, channel, CAM_LUN_WILDCARD,
                          SCB_LIST_NULL, ROLE_UNKNOWN) == 0) {
                  tid_prev = scbid;
                  continue;
            }

            /*
             * We found a list of scbs that needs to be searched.
             */
            if (action == SEARCH_PRINT)
                  printf("       %d ( ", SCB_GET_TARGET(ahd, scb));
            tid_head = scbid;
            found += ahd_search_scb_list(ahd, target, channel,
                                   lun, tag, role, status,
                                   action, &tid_head, &tid_tail,
                                   SCB_GET_TARGET(ahd, scb));
            /*
             * Check any MK_MESSAGE SCB that is still waiting to
             * enter this target's waiting for selection queue.
             */
            if (mk_msg_scb != NULL
             && ahd_match_scb(ahd, mk_msg_scb, target, channel,
                          lun, tag, role)) {

                  /*
                   * We found an scb that needs to be acted on.
                   */
                  found++;
                  switch (action) {
                  case SEARCH_COMPLETE:
                        if ((mk_msg_scb->flags & SCB_ACTIVE) == 0)
                              printf("Inactive SCB pending MK_MSG\n");
                        ahd_done_with_status(ahd, mk_msg_scb, status);
                        /* FALLTHROUGH */
                  case SEARCH_REMOVE:
                  {
                        u_int tail_offset;

                        printf("Removing MK_MSG scb\n");

                        /*
                         * Reset our tail to the tail of the
                         * main per-target list.
                         */
                        tail_offset = WAITING_SCB_TAILS
                            + (2 * SCB_GET_TARGET(ahd, mk_msg_scb));
                        ahd_outw(ahd, tail_offset, tid_tail);

                        seq_flags2 &= ~PENDING_MK_MESSAGE;
                        ahd_outb(ahd, SEQ_FLAGS2, seq_flags2);
                        ahd_outw(ahd, CMDS_PENDING,
                               ahd_inw(ahd, CMDS_PENDING)-1);
                        mk_msg_scb = NULL;
                        break;
                  }
                  case SEARCH_PRINT:
                        printf(" 0x%x", SCB_GET_TAG(scb));
                        /* FALLTHROUGH */
                  case SEARCH_COUNT:
                        break;
                  }
            }

            if (mk_msg_scb != NULL
             && SCBID_IS_NULL(tid_head)
             && ahd_match_scb(ahd, scb, target, channel, CAM_LUN_WILDCARD,
                          SCB_LIST_NULL, ROLE_UNKNOWN)) {

                  /*
                   * When removing the last SCB for a target
                   * queue with a pending MK_MESSAGE scb, we
                   * must queue the MK_MESSAGE scb.
                   */
                  printf("Queueing mk_msg_scb\n");
                  tid_head = ahd_inw(ahd, MK_MESSAGE_SCB);
                  seq_flags2 &= ~PENDING_MK_MESSAGE;
                  ahd_outb(ahd, SEQ_FLAGS2, seq_flags2);
                  mk_msg_scb = NULL;
            }
            if (tid_head != scbid)
                  ahd_stitch_tid_list(ahd, tid_prev, tid_head, tid_next);
            if (!SCBID_IS_NULL(tid_head))
                  tid_prev = tid_head;
            if (action == SEARCH_PRINT)
                  printf(")\n");
      }

      /* Restore saved state. */
      ahd_set_scbptr(ahd, savedscbptr);
      ahd_restore_modes(ahd, saved_modes);
      return (found);
}

static int
ahd_search_scb_list(struct ahd_softc *ahd, int target, char channel,
                int lun, u_int tag, role_t role, uint32_t status,
                ahd_search_action action, u_int *list_head, 
                u_int *list_tail, u_int tid)
{
      struct      scb *scb;
      u_int scbid;
      u_int next;
      u_int prev;
      int   found;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      found = 0;
      prev = SCB_LIST_NULL;
      next = *list_head;
      *list_tail = SCB_LIST_NULL;
      for (scbid = next; !SCBID_IS_NULL(scbid); scbid = next) {
            if (scbid >= ahd->scb_data.numscbs) {
                  printf("%s:SCB List inconsistency. "
                         "SCB == 0x%x, yet numscbs == 0x%x.",
                         ahd_name(ahd), scbid, ahd->scb_data.numscbs);
                  ahd_dump_card_state(ahd);
                  panic("for safety");
            }
            scb = ahd_lookup_scb(ahd, scbid);
            if (scb == NULL) {
                  printf("%s: SCB = %d Not Active!\n",
                         ahd_name(ahd), scbid);
                  panic("Waiting List traversal\n");
            }
            ahd_set_scbptr(ahd, scbid);
            *list_tail = scbid;
            next = ahd_inw_scbram(ahd, SCB_NEXT);
            if (ahd_match_scb(ahd, scb, target, channel,
                          lun, SCB_LIST_NULL, role) == 0) {
                  prev = scbid;
                  continue;
            }
            found++;
            switch (action) {
            case SEARCH_COMPLETE:
                  if ((scb->flags & SCB_ACTIVE) == 0)
                        printf("Inactive SCB in Waiting List\n");
                  ahd_done_with_status(ahd, scb, status);
                  /* FALLTHROUGH */
            case SEARCH_REMOVE:
                  ahd_rem_wscb(ahd, scbid, prev, next, tid);
                  *list_tail = prev;
                  if (SCBID_IS_NULL(prev))
                        *list_head = next;
                  break;
            case SEARCH_PRINT:
                  printf("0x%x ", scbid);
            case SEARCH_COUNT:
                  prev = scbid;
                  break;
            }
            if (found > AHD_SCB_MAX)
                  panic("SCB LIST LOOP");
      }
      if (action == SEARCH_COMPLETE
       || action == SEARCH_REMOVE)
            ahd_outw(ahd, CMDS_PENDING, ahd_inw(ahd, CMDS_PENDING) - found);
      return (found);
}

static void
ahd_stitch_tid_list(struct ahd_softc *ahd, u_int tid_prev,
                u_int tid_cur, u_int tid_next)
{
      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);

      if (SCBID_IS_NULL(tid_cur)) {

            /* Bypass current TID list */
            if (SCBID_IS_NULL(tid_prev)) {
                  ahd_outw(ahd, WAITING_TID_HEAD, tid_next);
            } else {
                  ahd_set_scbptr(ahd, tid_prev);
                  ahd_outw(ahd, SCB_NEXT2, tid_next);
            }
            if (SCBID_IS_NULL(tid_next))
                  ahd_outw(ahd, WAITING_TID_TAIL, tid_prev);
      } else {

            /* Stitch through tid_cur */
            if (SCBID_IS_NULL(tid_prev)) {
                  ahd_outw(ahd, WAITING_TID_HEAD, tid_cur);
            } else {
                  ahd_set_scbptr(ahd, tid_prev);
                  ahd_outw(ahd, SCB_NEXT2, tid_cur);
            }
            ahd_set_scbptr(ahd, tid_cur);
            ahd_outw(ahd, SCB_NEXT2, tid_next);

            if (SCBID_IS_NULL(tid_next))
                  ahd_outw(ahd, WAITING_TID_TAIL, tid_cur);
      }
}

/*
 * Manipulate the waiting for selection list and return the
 * scb that follows the one that we remove.
 */
static u_int
ahd_rem_wscb(struct ahd_softc *ahd, u_int scbid,
           u_int prev, u_int next, u_int tid)
{
      u_int tail_offset;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      if (!SCBID_IS_NULL(prev)) {
            ahd_set_scbptr(ahd, prev);
            ahd_outw(ahd, SCB_NEXT, next);
      }

      /*
       * SCBs that have MK_MESSAGE set in them may
       * cause the tail pointer to be updated without
       * setting the next pointer of the previous tail.
       * Only clear the tail if the removed SCB was
       * the tail.
       */
      tail_offset = WAITING_SCB_TAILS + (2 * tid);
      if (SCBID_IS_NULL(next)
       && ahd_inw(ahd, tail_offset) == scbid)
            ahd_outw(ahd, tail_offset, prev);

      ahd_add_scb_to_free_list(ahd, scbid);
      return (next);
}

/*
 * Add the SCB as selected by SCBPTR onto the on chip list of
 * free hardware SCBs.  This list is empty/unused if we are not
 * performing SCB paging.
 */
static void
ahd_add_scb_to_free_list(struct ahd_softc *ahd, u_int scbid)
{
/* XXX Need some other mechanism to designate "free". */
      /*
       * Invalidate the tag so that our abort
       * routines don't think it's active.
      ahd_outb(ahd, SCB_TAG, SCB_LIST_NULL);
       */
}

/******************************** Error Handling ******************************/
/*
 * Abort all SCBs that match the given description (target/channel/lun/tag),
 * setting their status to the passed in status if the status has not already
 * been modified from CAM_REQ_INPROG.  This routine assumes that the sequencer
 * is paused before it is called.
 */
int
ahd_abort_scbs(struct ahd_softc *ahd, int target, char channel,
             int lun, u_int tag, role_t role, uint32_t status)
{
      struct            scb *scbp;
      struct            scb *scbp_next;
      u_int       i, j;
      u_int       maxtarget;
      u_int       minlun;
      u_int       maxlun;
      int         found;
      ahd_mode_state    saved_modes;

      /* restore this when we're done */
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      found = ahd_search_qinfifo(ahd, target, channel, lun, SCB_LIST_NULL,
                           role, CAM_REQUEUE_REQ, SEARCH_COMPLETE);

      /*
       * Clean out the busy target table for any untagged commands.
       */
      i = 0;
      maxtarget = 16;
      if (target != CAM_TARGET_WILDCARD) {
            i = target;
            if (channel == 'B')
                  i += 8;
            maxtarget = i + 1;
      }

      if (lun == CAM_LUN_WILDCARD) {
            minlun = 0;
            maxlun = AHD_NUM_LUNS_NONPKT;
      } else if (lun >= AHD_NUM_LUNS_NONPKT) {
            minlun = maxlun = 0;
      } else {
            minlun = lun;
            maxlun = lun + 1;
      }

      if (role != ROLE_TARGET) {
            for (;i < maxtarget; i++) {
                  for (j = minlun;j < maxlun; j++) {
                        u_int scbid;
                        u_int tcl;

                        tcl = BUILD_TCL_RAW(i, 'A', j);
                        scbid = ahd_find_busy_tcl(ahd, tcl);
                        scbp = ahd_lookup_scb(ahd, scbid);
                        if (scbp == NULL
                         || ahd_match_scb(ahd, scbp, target, channel,
                                      lun, tag, role) == 0)
                              continue;
                        ahd_unbusy_tcl(ahd, BUILD_TCL_RAW(i, 'A', j));
                  }
            }
      }

      /*
       * Don't abort commands that have already completed,
       * but haven't quite made it up to the host yet.
       */
      ahd_flush_qoutfifo(ahd);

      /*
       * Go through the pending CCB list and look for
       * commands for this target that are still active.
       * These are other tagged commands that were
       * disconnected when the reset occurred.
       */
      scbp_next = LIST_FIRST(&ahd->pending_scbs);
      while (scbp_next != NULL) {
            scbp = scbp_next;
            scbp_next = LIST_NEXT(scbp, pending_links);
            if (ahd_match_scb(ahd, scbp, target, channel, lun, tag, role)) {
                  cam_status ostat;

                  ostat = ahd_get_transaction_status(scbp);
                  if (ostat == CAM_REQ_INPROG)
                        ahd_set_transaction_status(scbp, status);
                  if (ahd_get_transaction_status(scbp) != CAM_REQ_CMP)
                        ahd_freeze_scb(scbp);
                  if ((scbp->flags & SCB_ACTIVE) == 0)
                        printf("Inactive SCB on pending list\n");
                  ahd_done(ahd, scbp);
                  found++;
            }
      }
      ahd_restore_modes(ahd, saved_modes);
      ahd_platform_abort_scbs(ahd, target, channel, lun, tag, role, status);
      ahd->flags |= AHD_UPDATE_PEND_CMDS;
      return found;
}

static void
ahd_reset_current_bus(struct ahd_softc *ahd)
{
      uint8_t scsiseq;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      ahd_outb(ahd, SIMODE1, ahd_inb(ahd, SIMODE1) & ~ENSCSIRST);
      scsiseq = ahd_inb(ahd, SCSISEQ0) & ~(ENSELO|ENARBO|SCSIRSTO);
      ahd_outb(ahd, SCSISEQ0, scsiseq | SCSIRSTO);
      ahd_flush_device_writes(ahd);
      ahd_delay(AHD_BUSRESET_DELAY);
      /* Turn off the bus reset */
      ahd_outb(ahd, SCSISEQ0, scsiseq);
      ahd_flush_device_writes(ahd);
      ahd_delay(AHD_BUSRESET_DELAY);
      if ((ahd->bugs & AHD_SCSIRST_BUG) != 0) {
            /*
             * 2A Razor #474
             * Certain chip state is not cleared for
             * SCSI bus resets that we initiate, so
             * we must reset the chip.
             */
            ahd_reset(ahd, /*reinit*/TRUE);
            ahd_intr_enable(ahd, /*enable*/TRUE);
            AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      }

      ahd_clear_intstat(ahd);
}

int
ahd_reset_channel(struct ahd_softc *ahd, char channel, int initiate_reset)
{
      struct      ahd_devinfo devinfo;
      u_int initiator;
      u_int target;
      u_int max_scsiid;
      int   found;
      u_int fifo;
      u_int next_fifo;
      uint8_t scsiseq;

      /*
       * Check if the last bus reset is cleared
       */
      if (ahd->flags & AHD_BUS_RESET_ACTIVE) {
            printf("%s: bus reset still active\n",
                   ahd_name(ahd));
            return 0;
      }
      ahd->flags |= AHD_BUS_RESET_ACTIVE;

      ahd->pending_device = NULL;

      ahd_compile_devinfo(&devinfo,
                      CAM_TARGET_WILDCARD,
                      CAM_TARGET_WILDCARD,
                      CAM_LUN_WILDCARD,
                      channel, ROLE_UNKNOWN);
      ahd_pause(ahd);

      /* Make sure the sequencer is in a safe location. */
      ahd_clear_critical_section(ahd);

      /*
       * Run our command complete fifos to ensure that we perform
       * completion processing on any commands that 'completed'
       * before the reset occurred.
       */
      ahd_run_qoutfifo(ahd);
#ifdef AHD_TARGET_MODE
      if ((ahd->flags & AHD_TARGETROLE) != 0) {
            ahd_run_tqinfifo(ahd, /*paused*/TRUE);
      }
#endif
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

      /*
       * Disable selections so no automatic hardware
       * functions will modify chip state.
       */
      ahd_outb(ahd, SCSISEQ0, 0);
      ahd_outb(ahd, SCSISEQ1, 0);

      /*
       * Safely shut down our DMA engines.  Always start with
       * the FIFO that is not currently active (if any are
       * actively connected).
       */
      next_fifo = fifo = ahd_inb(ahd, DFFSTAT) & CURRFIFO;
      if (next_fifo > CURRFIFO_1)
            /* If disconneced, arbitrarily start with FIFO1. */
            next_fifo = fifo = 0;
      do {
            next_fifo ^= CURRFIFO_1;
            ahd_set_modes(ahd, next_fifo, next_fifo);
            ahd_outb(ahd, DFCNTRL,
                   ahd_inb(ahd, DFCNTRL) & ~(SCSIEN|HDMAEN));
            while ((ahd_inb(ahd, DFCNTRL) & HDMAENACK) != 0)
                  ahd_delay(10);
            /*
             * Set CURRFIFO to the now inactive channel.
             */
            ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
            ahd_outb(ahd, DFFSTAT, next_fifo);
      } while (next_fifo != fifo);

      /*
       * Reset the bus if we are initiating this reset
       */
      ahd_clear_msg_state(ahd);
      ahd_outb(ahd, SIMODE1,
             ahd_inb(ahd, SIMODE1) & ~(ENBUSFREE|ENSCSIRST));

      if (initiate_reset)
            ahd_reset_current_bus(ahd);

      ahd_clear_intstat(ahd);

      /*
       * Clean up all the state information for the
       * pending transactions on this bus.
       */
      found = ahd_abort_scbs(ahd, CAM_TARGET_WILDCARD, channel,
                         CAM_LUN_WILDCARD, SCB_LIST_NULL,
                         ROLE_UNKNOWN, CAM_SCSI_BUS_RESET);

      /*
       * Cleanup anything left in the FIFOs.
       */
      ahd_clear_fifo(ahd, 0);
      ahd_clear_fifo(ahd, 1);

      /*
       * Reenable selections
       */
      ahd_outb(ahd, SIMODE1, ahd_inb(ahd, SIMODE1) | ENSCSIRST);
      scsiseq = ahd_inb(ahd, SCSISEQ_TEMPLATE);
      ahd_outb(ahd, SCSISEQ1, scsiseq & (ENSELI|ENRSELI|ENAUTOATNP));

      max_scsiid = (ahd->features & AHD_WIDE) ? 15 : 7;
#ifdef AHD_TARGET_MODE
      /*
       * Send an immediate notify ccb to all target more peripheral
       * drivers affected by this action.
       */
      for (target = 0; target <= max_scsiid; target++) {
            struct ahd_tmode_tstate* tstate;
            u_int lun;

            tstate = ahd->enabled_targets[target];
            if (tstate == NULL)
                  continue;
            for (lun = 0; lun < AHD_NUM_LUNS; lun++) {
                  struct ahd_tmode_lstate* lstate;

                  lstate = tstate->enabled_luns[lun];
                  if (lstate == NULL)
                        continue;

                  ahd_queue_lstate_event(ahd, lstate, CAM_TARGET_WILDCARD,
                                     EVENT_TYPE_BUS_RESET, /*arg*/0);
                  ahd_send_lstate_events(ahd, lstate);
            }
      }
#endif
      /* Notify the XPT that a bus reset occurred */
      ahd_send_async(ahd, devinfo.channel, CAM_TARGET_WILDCARD,
                   CAM_LUN_WILDCARD, AC_BUS_RESET);

      /*
       * Revert to async/narrow transfers until we renegotiate.
       */
      for (target = 0; target <= max_scsiid; target++) {

            if (ahd->enabled_targets[target] == NULL)
                  continue;
            for (initiator = 0; initiator <= max_scsiid; initiator++) {
                  struct ahd_devinfo devinfo;

                  ahd_compile_devinfo(&devinfo, target, initiator,
                                  CAM_LUN_WILDCARD,
                                  'A', ROLE_UNKNOWN);
                  ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                              AHD_TRANS_CUR, /*paused*/TRUE);
                  ahd_set_syncrate(ahd, &devinfo, /*period*/0,
                               /*offset*/0, /*ppr_options*/0,
                               AHD_TRANS_CUR, /*paused*/TRUE);
            }
      }

      ahd_restart(ahd);

      return (found);
}

/**************************** Statistics Processing ***************************/
static void
ahd_stat_timer(void *arg)
{
      struct      ahd_softc *ahd = arg;
      u_long      s;
      int   enint_coal;
      
      ahd_lock(ahd, &s);

      enint_coal = ahd->hs_mailbox & ENINT_COALESCE;
      if (ahd->cmdcmplt_total > ahd->int_coalescing_threshold)
            enint_coal |= ENINT_COALESCE;
      else if (ahd->cmdcmplt_total < ahd->int_coalescing_stop_threshold)
            enint_coal &= ~ENINT_COALESCE;

      if (enint_coal != (ahd->hs_mailbox & ENINT_COALESCE)) {
            ahd_enable_coalescing(ahd, enint_coal);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_INT_COALESCING) != 0)
                  printf("%s: Interrupt coalescing "
                         "now %sabled. Cmds %d\n",
                         ahd_name(ahd),
                         (enint_coal & ENINT_COALESCE) ? "en" : "dis",
                         ahd->cmdcmplt_total);
#endif
      }

      ahd->cmdcmplt_bucket = (ahd->cmdcmplt_bucket+1) & (AHD_STAT_BUCKETS-1);
      ahd->cmdcmplt_total -= ahd->cmdcmplt_counts[ahd->cmdcmplt_bucket];
      ahd->cmdcmplt_counts[ahd->cmdcmplt_bucket] = 0;
      ahd_timer_reset(&ahd->stat_timer, AHD_STAT_UPDATE_US,
                  ahd_stat_timer, ahd);
      ahd_unlock(ahd, &s);
}

/****************************** Status Processing *****************************/
void
ahd_handle_scb_status(struct ahd_softc *ahd, struct scb *scb)
{
      if (scb->hscb->shared_data.istatus.scsi_status != 0) {
            ahd_handle_scsi_status(ahd, scb);
      } else {
            ahd_calc_residual(ahd, scb);
            ahd_done(ahd, scb);
      }
}

void
ahd_handle_scsi_status(struct ahd_softc *ahd, struct scb *scb)
{
      struct      hardware_scb *hscb;
      int   paused;

      /*
       * The sequencer freezes its select-out queue
       * anytime a SCSI status error occurs.  We must
       * handle the error and increment our qfreeze count
       * to allow the sequencer to continue.  We don't
       * bother clearing critical sections here since all
       * operations are on data structures that the sequencer
       * is not touching once the queue is frozen.
       */
      hscb = scb->hscb; 

      if (ahd_is_paused(ahd)) {
            paused = 1;
      } else {
            paused = 0;
            ahd_pause(ahd);
      }

      /* Freeze the queue until the client sees the error. */
      ahd_freeze_devq(ahd, scb);
      ahd_freeze_scb(scb);
      ahd->qfreeze_cnt++;
      ahd_outw(ahd, KERNEL_QFREEZE_COUNT, ahd->qfreeze_cnt);

      if (paused == 0)
            ahd_unpause(ahd);

      /* Don't want to clobber the original sense code */
      if ((scb->flags & SCB_SENSE) != 0) {
            /*
             * Clear the SCB_SENSE Flag and perform
             * a normal command completion.
             */
            scb->flags &= ~SCB_SENSE;
            ahd_set_transaction_status(scb, CAM_AUTOSENSE_FAIL);
            ahd_done(ahd, scb);
            return;
      }
      ahd_set_transaction_status(scb, CAM_SCSI_STATUS_ERROR);
      ahd_set_scsi_status(scb, hscb->shared_data.istatus.scsi_status);
      switch (hscb->shared_data.istatus.scsi_status) {
      case STATUS_PKT_SENSE:
      {
            struct scsi_status_iu_header *siu;

            ahd_sync_sense(ahd, scb, BUS_DMASYNC_POSTREAD);
            siu = (struct scsi_status_iu_header *)scb->sense_data;
            ahd_set_scsi_status(scb, siu->status);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_SENSE) != 0) {
                  ahd_print_path(ahd, scb);
                  printf("SCB 0x%x Received PKT Status of 0x%x\n",
                         SCB_GET_TAG(scb), siu->status);
                  printf("\tflags = 0x%x, sense len = 0x%x, "
                         "pktfail = 0x%x\n",
                         siu->flags, scsi_4btoul(siu->sense_length),
                         scsi_4btoul(siu->pkt_failures_length));
            }
#endif
            if ((siu->flags & SIU_RSPVALID) != 0) {
                  ahd_print_path(ahd, scb);
                  if (scsi_4btoul(siu->pkt_failures_length) < 4) {
                        printf("Unable to parse pkt_failures\n");
                  } else {

                        switch (SIU_PKTFAIL_CODE(siu)) {
                        case SIU_PFC_NONE:
                              printf("No packet failure found\n");
                              break;
                        case SIU_PFC_CIU_FIELDS_INVALID:
                              printf("Invalid Command IU Field\n");
                              break;
                        case SIU_PFC_TMF_NOT_SUPPORTED:
                              printf("TMF not supportd\n");
                              break;
                        case SIU_PFC_TMF_FAILED:
                              printf("TMF failed\n");
                              break;
                        case SIU_PFC_INVALID_TYPE_CODE:
                              printf("Invalid L_Q Type code\n");
                              break;
                        case SIU_PFC_ILLEGAL_REQUEST:
                              printf("Illegal request\n");
                        default:
                              break;
                        }
                  }
                  if (siu->status == SCSI_STATUS_OK)
                        ahd_set_transaction_status(scb,
                                             CAM_REQ_CMP_ERR);
            }
            if ((siu->flags & SIU_SNSVALID) != 0) {
                  scb->flags |= SCB_PKT_SENSE;
#ifdef AHD_DEBUG
                  if ((ahd_debug & AHD_SHOW_SENSE) != 0)
                        printf("Sense data available\n");
#endif
            }
            ahd_done(ahd, scb);
            break;
      }
      case SCSI_STATUS_CMD_TERMINATED:
      case SCSI_STATUS_CHECK_COND:
      {
            struct ahd_devinfo devinfo;
            struct ahd_dma_seg *sg;
            struct scsi_sense *sc;
            struct ahd_initiator_tinfo *targ_info;
            struct ahd_tmode_tstate *tstate;
            struct ahd_transinfo *tinfo;
#ifdef AHD_DEBUG
            if (ahd_debug & AHD_SHOW_SENSE) {
                  ahd_print_path(ahd, scb);
                  printf("SCB %d: requests Check Status\n",
                         SCB_GET_TAG(scb));
            }
#endif

            if (ahd_perform_autosense(scb) == 0)
                  break;

            ahd_compile_devinfo(&devinfo, SCB_GET_OUR_ID(scb),
                            SCB_GET_TARGET(ahd, scb),
                            SCB_GET_LUN(scb),
                            SCB_GET_CHANNEL(ahd, scb),
                            ROLE_INITIATOR);
            targ_info = ahd_fetch_transinfo(ahd,
                                    devinfo.channel,
                                    devinfo.our_scsiid,
                                    devinfo.target,
                                    &tstate);
            tinfo = &targ_info->curr;
            sg = scb->sg_list;
            sc = (struct scsi_sense *)hscb->shared_data.idata.cdb;
            /*
             * Save off the residual if there is one.
             */
            ahd_update_residual(ahd, scb);
#ifdef AHD_DEBUG
            if (ahd_debug & AHD_SHOW_SENSE) {
                  ahd_print_path(ahd, scb);
                  printf("Sending Sense\n");
            }
#endif
            scb->sg_count = 0;
            sg = ahd_sg_setup(ahd, scb, sg, ahd_get_sense_bufaddr(ahd, scb),
                          ahd_get_sense_bufsize(ahd, scb),
                          /*last*/TRUE);
            sc->opcode = REQUEST_SENSE;
            sc->byte2 = 0;
            if (tinfo->protocol_version <= SCSI_REV_2
             && SCB_GET_LUN(scb) < 8)
                  sc->byte2 = SCB_GET_LUN(scb) << 5;
            sc->unused[0] = 0;
            sc->unused[1] = 0;
            sc->length = ahd_get_sense_bufsize(ahd, scb);
            sc->control = 0;

            /*
             * We can't allow the target to disconnect.
             * This will be an untagged transaction and
             * having the target disconnect will make this
             * transaction indestinguishable from outstanding
             * tagged transactions.
             */
            hscb->control = 0;

            /*
             * This request sense could be because the
             * the device lost power or in some other
             * way has lost our transfer negotiations.
             * Renegotiate if appropriate.  Unit attention
             * errors will be reported before any data
             * phases occur.
             */
            if (ahd_get_residual(scb) == ahd_get_transfer_length(scb)) {
                  ahd_update_neg_request(ahd, &devinfo,
                                     tstate, targ_info,
                                     AHD_NEG_IF_NON_ASYNC);
            }
            if (tstate->auto_negotiate & devinfo.target_mask) {
                  hscb->control |= MK_MESSAGE;
                  scb->flags &=
                      ~(SCB_NEGOTIATE|SCB_ABORT|SCB_DEVICE_RESET);
                  scb->flags |= SCB_AUTO_NEGOTIATE;
            }
            hscb->cdb_len = sizeof(*sc);
            ahd_setup_data_scb(ahd, scb);
            scb->flags |= SCB_SENSE;
            ahd_queue_scb(ahd, scb);
            break;
      }
      case SCSI_STATUS_OK:
            printf("%s: Interrupted for staus of 0???\n",
                   ahd_name(ahd));
            /* FALLTHROUGH */
      default:
            ahd_done(ahd, scb);
            break;
      }
}

/*
 * Calculate the residual for a just completed SCB.
 */
void
ahd_calc_residual(struct ahd_softc *ahd, struct scb *scb)
{
      struct hardware_scb *hscb;
      struct initiator_status *spkt;
      uint32_t sgptr;
      uint32_t resid_sgptr;
      uint32_t resid;

      /*
       * 5 cases.
       * 1) No residual.
       *    SG_STATUS_VALID clear in sgptr.
       * 2) Transferless command
       * 3) Never performed any transfers.
       *    sgptr has SG_FULL_RESID set.
       * 4) No residual but target did not
       *    save data pointers after the
       *    last transfer, so sgptr was
       *    never updated.
       * 5) We have a partial residual.
       *    Use residual_sgptr to determine
       *    where we are.
       */

      hscb = scb->hscb;
      sgptr = ahd_le32toh(hscb->sgptr);
      if ((sgptr & SG_STATUS_VALID) == 0)
            /* Case 1 */
            return;
      sgptr &= ~SG_STATUS_VALID;

      if ((sgptr & SG_LIST_NULL) != 0)
            /* Case 2 */
            return;

      /*
       * Residual fields are the same in both
       * target and initiator status packets,
       * so we can always use the initiator fields
       * regardless of the role for this SCB.
       */
      spkt = &hscb->shared_data.istatus;
      resid_sgptr = ahd_le32toh(spkt->residual_sgptr);
      if ((sgptr & SG_FULL_RESID) != 0) {
            /* Case 3 */
            resid = ahd_get_transfer_length(scb);
      } else if ((resid_sgptr & SG_LIST_NULL) != 0) {
            /* Case 4 */
            return;
      } else if ((resid_sgptr & SG_OVERRUN_RESID) != 0) {
            ahd_print_path(ahd, scb);
            printf("data overrun detected Tag == 0x%x.\n",
                   SCB_GET_TAG(scb));
            ahd_freeze_devq(ahd, scb);
            ahd_set_transaction_status(scb, CAM_DATA_RUN_ERR);
            ahd_freeze_scb(scb);
            return;
      } else if ((resid_sgptr & ~SG_PTR_MASK) != 0) {
            panic("Bogus resid sgptr value 0x%x\n", resid_sgptr);
            /* NOTREACHED */
      } else {
            struct ahd_dma_seg *sg;

            /*
             * Remainder of the SG where the transfer
             * stopped.  
             */
            resid = ahd_le32toh(spkt->residual_datacnt) & AHD_SG_LEN_MASK;
            sg = ahd_sg_bus_to_virt(ahd, scb, resid_sgptr & SG_PTR_MASK);

            /* The residual sg_ptr always points to the next sg */
            sg--;

            /*
             * Add up the contents of all residual
             * SG segments that are after the SG where
             * the transfer stopped.
             */
            while ((ahd_le32toh(sg->len) & AHD_DMA_LAST_SEG) == 0) {
                  sg++;
                  resid += ahd_le32toh(sg->len) & AHD_SG_LEN_MASK;
            }
      }
      if ((scb->flags & SCB_SENSE) == 0)
            ahd_set_residual(scb, resid);
      else
            ahd_set_sense_residual(scb, resid);

#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_MISC) != 0) {
            ahd_print_path(ahd, scb);
            printf("Handled %sResidual of %d bytes\n",
                   (scb->flags & SCB_SENSE) ? "Sense " : "", resid);
      }
#endif
}

/******************************* Target Mode **********************************/
#ifdef AHD_TARGET_MODE
/*
 * Add a target mode event to this lun's queue
 */
static void
ahd_queue_lstate_event(struct ahd_softc *ahd, struct ahd_tmode_lstate *lstate,
                   u_int initiator_id, u_int event_type, u_int event_arg)
{
      struct ahd_tmode_event *event;
      int pending;

      xpt_freeze_devq(lstate->path, /*count*/1);
      if (lstate->event_w_idx >= lstate->event_r_idx)
            pending = lstate->event_w_idx - lstate->event_r_idx;
      else
            pending = AHD_TMODE_EVENT_BUFFER_SIZE + 1
                  - (lstate->event_r_idx - lstate->event_w_idx);

      if (event_type == EVENT_TYPE_BUS_RESET
       || event_type == MSG_BUS_DEV_RESET) {
            /*
             * Any earlier events are irrelevant, so reset our buffer.
             * This has the effect of allowing us to deal with reset
             * floods (an external device holding down the reset line)
             * without losing the event that is really interesting.
             */
            lstate->event_r_idx = 0;
            lstate->event_w_idx = 0;
            xpt_release_devq(lstate->path, pending, /*runqueue*/FALSE);
      }

      if (pending == AHD_TMODE_EVENT_BUFFER_SIZE) {
            xpt_print_path(lstate->path);
            printf("immediate event %x:%x lost\n",
                   lstate->event_buffer[lstate->event_r_idx].event_type,
                   lstate->event_buffer[lstate->event_r_idx].event_arg);
            lstate->event_r_idx++;
            if (lstate->event_r_idx == AHD_TMODE_EVENT_BUFFER_SIZE)
                  lstate->event_r_idx = 0;
            xpt_release_devq(lstate->path, /*count*/1, /*runqueue*/FALSE);
      }

      event = &lstate->event_buffer[lstate->event_w_idx];
      event->initiator_id = initiator_id;
      event->event_type = event_type;
      event->event_arg = event_arg;
      lstate->event_w_idx++;
      if (lstate->event_w_idx == AHD_TMODE_EVENT_BUFFER_SIZE)
            lstate->event_w_idx = 0;
}

/*
 * Send any target mode events queued up waiting
 * for immediate notify resources.
 */
void
ahd_send_lstate_events(struct ahd_softc *ahd, struct ahd_tmode_lstate *lstate)
{
      struct ccb_hdr *ccbh;
      struct ccb_immed_notify *inot;

      while (lstate->event_r_idx != lstate->event_w_idx
          && (ccbh = SLIST_FIRST(&lstate->immed_notifies)) != NULL) {
            struct ahd_tmode_event *event;

            event = &lstate->event_buffer[lstate->event_r_idx];
            SLIST_REMOVE_HEAD(&lstate->immed_notifies, sim_links.sle);
            inot = (struct ccb_immed_notify *)ccbh;
            switch (event->event_type) {
            case EVENT_TYPE_BUS_RESET:
                  ccbh->status = CAM_SCSI_BUS_RESET|CAM_DEV_QFRZN;
                  break;
            default:
                  ccbh->status = CAM_MESSAGE_RECV|CAM_DEV_QFRZN;
                  inot->message_args[0] = event->event_type;
                  inot->message_args[1] = event->event_arg;
                  break;
            }
            inot->initiator_id = event->initiator_id;
            inot->sense_len = 0;
            xpt_done((union ccb *)inot);
            lstate->event_r_idx++;
            if (lstate->event_r_idx == AHD_TMODE_EVENT_BUFFER_SIZE)
                  lstate->event_r_idx = 0;
      }
}
#endif

/******************** Sequencer Program Patching/Download *********************/

#ifdef AHD_DUMP_SEQ
void
ahd_dumpseq(struct ahd_softc* ahd)
{
      int i;
      int max_prog;

      max_prog = 2048;

      ahd_outb(ahd, SEQCTL0, PERRORDIS|FAILDIS|FASTMODE|LOADRAM);
      ahd_outw(ahd, PRGMCNT, 0);
      for (i = 0; i < max_prog; i++) {
            uint8_t ins_bytes[4];

            ahd_insb(ahd, SEQRAM, ins_bytes, 4);
            printf("0x%08x\n", ins_bytes[0] << 24
                         | ins_bytes[1] << 16
                         | ins_bytes[2] << 8
                         | ins_bytes[3]);
      }
}
#endif

static void
ahd_loadseq(struct ahd_softc *ahd)
{
      struct      cs cs_table[num_critical_sections];
      u_int begin_set[num_critical_sections];
      u_int end_set[num_critical_sections];
      struct      patch *cur_patch;
      u_int cs_count;
      u_int cur_cs;
      u_int i;
      int   downloaded;
      u_int skip_addr;
      u_int sg_prefetch_cnt;
      u_int sg_prefetch_cnt_limit;
      u_int sg_prefetch_align;
      u_int sg_size;
      u_int cacheline_mask;
      uint8_t     download_consts[DOWNLOAD_CONST_COUNT];

      if (bootverbose)
            printf("%s: Downloading Sequencer Program...",
                   ahd_name(ahd));

#if DOWNLOAD_CONST_COUNT != 8
#error "Download Const Mismatch"
#endif
      /*
       * Start out with 0 critical sections
       * that apply to this firmware load.
       */
      cs_count = 0;
      cur_cs = 0;
      memset(begin_set, 0, sizeof(begin_set));
      memset(end_set, 0, sizeof(end_set));

      /*
       * Setup downloadable constant table.
       * 
       * The computation for the S/G prefetch variables is
       * a bit complicated.  We would like to always fetch
       * in terms of cachelined sized increments.  However,
       * if the cacheline is not an even multiple of the
       * SG element size or is larger than our SG RAM, using
       * just the cache size might leave us with only a portion
       * of an SG element at the tail of a prefetch.  If the
       * cacheline is larger than our S/G prefetch buffer less
       * the size of an SG element, we may round down to a cacheline
       * that doesn't contain any or all of the S/G of interest
       * within the bounds of our S/G ram.  Provide variables to
       * the sequencer that will allow it to handle these edge
       * cases.
       */
      /* Start by aligning to the nearest cacheline. */
      sg_prefetch_align = ahd->pci_cachesize;
      if (sg_prefetch_align == 0)
            sg_prefetch_align = 8;
      /* Round down to the nearest power of 2. */
      while (powerof2(sg_prefetch_align) == 0)
            sg_prefetch_align--;

      cacheline_mask = sg_prefetch_align - 1;

      /*
       * If the cacheline boundary is greater than half our prefetch RAM
       * we risk not being able to fetch even a single complete S/G
       * segment if we align to that boundary.
       */
      if (sg_prefetch_align > CCSGADDR_MAX/2)
            sg_prefetch_align = CCSGADDR_MAX/2;
      /* Start by fetching a single cacheline. */
      sg_prefetch_cnt = sg_prefetch_align;
      /*
       * Increment the prefetch count by cachelines until
       * at least one S/G element will fit.
       */
      sg_size = sizeof(struct ahd_dma_seg);
      if ((ahd->flags & AHD_64BIT_ADDRESSING) != 0)
            sg_size = sizeof(struct ahd_dma64_seg);
      while (sg_prefetch_cnt < sg_size)
            sg_prefetch_cnt += sg_prefetch_align;
      /*
       * If the cacheline is not an even multiple of
       * the S/G size, we may only get a partial S/G when
       * we align. Add a cacheline if this is the case.
       */
      if ((sg_prefetch_align % sg_size) != 0
       && (sg_prefetch_cnt < CCSGADDR_MAX))
            sg_prefetch_cnt += sg_prefetch_align;
      /*
       * Lastly, compute a value that the sequencer can use
       * to determine if the remainder of the CCSGRAM buffer
       * has a full S/G element in it.
       */
      sg_prefetch_cnt_limit = -(sg_prefetch_cnt - sg_size + 1);
      download_consts[SG_PREFETCH_CNT] = sg_prefetch_cnt;
      download_consts[SG_PREFETCH_CNT_LIMIT] = sg_prefetch_cnt_limit;
      download_consts[SG_PREFETCH_ALIGN_MASK] = ~(sg_prefetch_align - 1);
      download_consts[SG_PREFETCH_ADDR_MASK] = (sg_prefetch_align - 1);
      download_consts[SG_SIZEOF] = sg_size;
      download_consts[PKT_OVERRUN_BUFOFFSET] =
            (ahd->overrun_buf - (uint8_t *)ahd->qoutfifo) / 256;
      download_consts[SCB_TRANSFER_SIZE] = SCB_TRANSFER_SIZE_1BYTE_LUN;
      download_consts[CACHELINE_MASK] = cacheline_mask;
      cur_patch = patches;
      downloaded = 0;
      skip_addr = 0;
      ahd_outb(ahd, SEQCTL0, PERRORDIS|FAILDIS|FASTMODE|LOADRAM);
      ahd_outw(ahd, PRGMCNT, 0);

      for (i = 0; i < sizeof(seqprog)/4; i++) {
            if (ahd_check_patch(ahd, &cur_patch, i, &skip_addr) == 0) {
                  /*
                   * Don't download this instruction as it
                   * is in a patch that was removed.
                   */
                  continue;
            }
            /*
             * Move through the CS table until we find a CS
             * that might apply to this instruction.
             */
            for (; cur_cs < num_critical_sections; cur_cs++) {
                  if (critical_sections[cur_cs].end <= i) {
                        if (begin_set[cs_count] == TRUE
                         && end_set[cs_count] == FALSE) {
                              cs_table[cs_count].end = downloaded;
                              end_set[cs_count] = TRUE;
                              cs_count++;
                        }
                        continue;
                  }
                  if (critical_sections[cur_cs].begin <= i
                   && begin_set[cs_count] == FALSE) {
                        cs_table[cs_count].begin = downloaded;
                        begin_set[cs_count] = TRUE;
                  }
                  break;
            }
            ahd_download_instr(ahd, i, download_consts);
            downloaded++;
      }

      ahd->num_critical_sections = cs_count;
      if (cs_count != 0) {

            cs_count *= sizeof(struct cs);
            ahd->critical_sections = malloc(cs_count, M_DEVBUF, M_NOWAIT);
            if (ahd->critical_sections == NULL)
                  panic("ahd_loadseq: Could not malloc");
            memcpy(ahd->critical_sections, cs_table, cs_count);
      }
      ahd_outb(ahd, SEQCTL0, PERRORDIS|FAILDIS|FASTMODE);

      if (bootverbose) {
            printf(" %d instructions downloaded\n", downloaded);
            printf("%s: Features 0x%x, Bugs 0x%x, Flags 0x%x\n",
                   ahd_name(ahd), ahd->features, ahd->bugs, ahd->flags);
      }
}

static int
ahd_check_patch(struct ahd_softc *ahd, struct patch **start_patch,
            u_int start_instr, u_int *skip_addr)
{
      struct      patch *cur_patch;
      struct      patch *last_patch;
      u_int num_patches;

      num_patches = ARRAY_SIZE(patches);
      last_patch = &patches[num_patches];
      cur_patch = *start_patch;

      while (cur_patch < last_patch && start_instr == cur_patch->begin) {

            if (cur_patch->patch_func(ahd) == 0) {

                  /* Start rejecting code */
                  *skip_addr = start_instr + cur_patch->skip_instr;
                  cur_patch += cur_patch->skip_patch;
            } else {
                  /* Accepted this patch.  Advance to the next
                   * one and wait for our intruction pointer to
                   * hit this point.
                   */
                  cur_patch++;
            }
      }

      *start_patch = cur_patch;
      if (start_instr < *skip_addr)
            /* Still skipping */
            return (0);

      return (1);
}

static u_int
ahd_resolve_seqaddr(struct ahd_softc *ahd, u_int address)
{
      struct patch *cur_patch;
      int address_offset;
      u_int skip_addr;
      u_int i;

      address_offset = 0;
      cur_patch = patches;
      skip_addr = 0;

      for (i = 0; i < address;) {

            ahd_check_patch(ahd, &cur_patch, i, &skip_addr);

            if (skip_addr > i) {
                  int end_addr;

                  end_addr = MIN(address, skip_addr);
                  address_offset += end_addr - i;
                  i = skip_addr;
            } else {
                  i++;
            }
      }
      return (address - address_offset);
}

static void
ahd_download_instr(struct ahd_softc *ahd, u_int instrptr, uint8_t *dconsts)
{
      union ins_formats instr;
      struct      ins_format1 *fmt1_ins;
      struct      ins_format3 *fmt3_ins;
      u_int opcode;

      /*
       * The firmware is always compiled into a little endian format.
       */
      instr.integer = ahd_le32toh(*(uint32_t*)&seqprog[instrptr * 4]);

      fmt1_ins = &instr.format1;
      fmt3_ins = NULL;

      /* Pull the opcode */
      opcode = instr.format1.opcode;
      switch (opcode) {
      case AIC_OP_JMP:
      case AIC_OP_JC:
      case AIC_OP_JNC:
      case AIC_OP_CALL:
      case AIC_OP_JNE:
      case AIC_OP_JNZ:
      case AIC_OP_JE:
      case AIC_OP_JZ:
      {
            fmt3_ins = &instr.format3;
            fmt3_ins->address = ahd_resolve_seqaddr(ahd, fmt3_ins->address);
            /* FALLTHROUGH */
      }
      case AIC_OP_OR:
      case AIC_OP_AND:
      case AIC_OP_XOR:
      case AIC_OP_ADD:
      case AIC_OP_ADC:
      case AIC_OP_BMOV:
            if (fmt1_ins->parity != 0) {
                  fmt1_ins->immediate = dconsts[fmt1_ins->immediate];
            }
            fmt1_ins->parity = 0;
            /* FALLTHROUGH */
      case AIC_OP_ROL:
      {
            int i, count;

            /* Calculate odd parity for the instruction */
            for (i = 0, count = 0; i < 31; i++) {
                  uint32_t mask;

                  mask = 0x01 << i;
                  if ((instr.integer & mask) != 0)
                        count++;
            }
            if ((count & 0x01) == 0)
                  instr.format1.parity = 1;

            /* The sequencer is a little endian cpu */
            instr.integer = ahd_htole32(instr.integer);
            ahd_outsb(ahd, SEQRAM, instr.bytes, 4);
            break;
      }
      default:
            panic("Unknown opcode encountered in seq program");
            break;
      }
}

static int
ahd_probe_stack_size(struct ahd_softc *ahd)
{
      int last_probe;

      last_probe = 0;
      while (1) {
            int i;

            /*
             * We avoid using 0 as a pattern to avoid
             * confusion if the stack implementation
             * "back-fills" with zeros when "poping'
             * entries.
             */
            for (i = 1; i <= last_probe+1; i++) {
                   ahd_outb(ahd, STACK, i & 0xFF);
                   ahd_outb(ahd, STACK, (i >> 8) & 0xFF);
            }

            /* Verify */
            for (i = last_probe+1; i > 0; i--) {
                  u_int stack_entry;

                  stack_entry = ahd_inb(ahd, STACK)
                            |(ahd_inb(ahd, STACK) << 8);
                  if (stack_entry != i)
                        goto sized;
            }
            last_probe++;
      }
sized:
      return (last_probe);
}

int
ahd_print_register(ahd_reg_parse_entry_t *table, u_int num_entries,
               const char *name, u_int address, u_int value,
               u_int *cur_column, u_int wrap_point)
{
      int   printed;
      u_int printed_mask;

      if (cur_column != NULL && *cur_column >= wrap_point) {
            printf("\n");
            *cur_column = 0;
      }
      printed = printf("%s[0x%x]", name, value);
      if (table == NULL) {
            printed += printf(" ");
            *cur_column += printed;
            return (printed);
      }
      printed_mask = 0;
      while (printed_mask != 0xFF) {
            int entry;

            for (entry = 0; entry < num_entries; entry++) {
                  if (((value & table[entry].mask)
                    != table[entry].value)
                   || ((printed_mask & table[entry].mask)
                    == table[entry].mask))
                        continue;

                  printed += printf("%s%s",
                                printed_mask == 0 ? ":(" : "|",
                                table[entry].name);
                  printed_mask |= table[entry].mask;
                  
                  break;
            }
            if (entry >= num_entries)
                  break;
      }
      if (printed_mask != 0)
            printed += printf(") ");
      else
            printed += printf(" ");
      if (cur_column != NULL)
            *cur_column += printed;
      return (printed);
}

void
ahd_dump_card_state(struct ahd_softc *ahd)
{
      struct scb  *scb;
      ahd_mode_state     saved_modes;
      u_int        dffstat;
      int          paused;
      u_int        scb_index;
      u_int        saved_scb_index;
      u_int        cur_col;
      int          i;

      if (ahd_is_paused(ahd)) {
            paused = 1;
      } else {
            paused = 0;
            ahd_pause(ahd);
      }
      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      printf(">>>>>>>>>>>>>>>>>> Dump Card State Begins <<<<<<<<<<<<<<<<<\n"
             "%s: Dumping Card State at program address 0x%x Mode 0x%x\n",
             ahd_name(ahd), 
             ahd_inw(ahd, CURADDR),
             ahd_build_mode_state(ahd, ahd->saved_src_mode,
                            ahd->saved_dst_mode));
      if (paused)
            printf("Card was paused\n");

      if (ahd_check_cmdcmpltqueues(ahd))
            printf("Completions are pending\n");

      /*
       * Mode independent registers.
       */
      cur_col = 0;
      ahd_intstat_print(ahd_inb(ahd, INTSTAT), &cur_col, 50);
      ahd_seloid_print(ahd_inb(ahd, SELOID), &cur_col, 50);
      ahd_selid_print(ahd_inb(ahd, SELID), &cur_col, 50);
      ahd_hs_mailbox_print(ahd_inb(ahd, LOCAL_HS_MAILBOX), &cur_col, 50);
      ahd_intctl_print(ahd_inb(ahd, INTCTL), &cur_col, 50);
      ahd_seqintstat_print(ahd_inb(ahd, SEQINTSTAT), &cur_col, 50);
      ahd_saved_mode_print(ahd_inb(ahd, SAVED_MODE), &cur_col, 50);
      ahd_dffstat_print(ahd_inb(ahd, DFFSTAT), &cur_col, 50);
      ahd_scsisigi_print(ahd_inb(ahd, SCSISIGI), &cur_col, 50);
      ahd_scsiphase_print(ahd_inb(ahd, SCSIPHASE), &cur_col, 50);
      ahd_scsibus_print(ahd_inb(ahd, SCSIBUS), &cur_col, 50);
      ahd_lastphase_print(ahd_inb(ahd, LASTPHASE), &cur_col, 50);
      ahd_scsiseq0_print(ahd_inb(ahd, SCSISEQ0), &cur_col, 50);
      ahd_scsiseq1_print(ahd_inb(ahd, SCSISEQ1), &cur_col, 50);
      ahd_seqctl0_print(ahd_inb(ahd, SEQCTL0), &cur_col, 50);
      ahd_seqintctl_print(ahd_inb(ahd, SEQINTCTL), &cur_col, 50);
      ahd_seq_flags_print(ahd_inb(ahd, SEQ_FLAGS), &cur_col, 50);
      ahd_seq_flags2_print(ahd_inb(ahd, SEQ_FLAGS2), &cur_col, 50);
      ahd_qfreeze_count_print(ahd_inw(ahd, QFREEZE_COUNT), &cur_col, 50);
      ahd_kernel_qfreeze_count_print(ahd_inw(ahd, KERNEL_QFREEZE_COUNT),
                               &cur_col, 50);
      ahd_mk_message_scb_print(ahd_inw(ahd, MK_MESSAGE_SCB), &cur_col, 50);
      ahd_mk_message_scsiid_print(ahd_inb(ahd, MK_MESSAGE_SCSIID),
                            &cur_col, 50);
      ahd_sstat0_print(ahd_inb(ahd, SSTAT0), &cur_col, 50);
      ahd_sstat1_print(ahd_inb(ahd, SSTAT1), &cur_col, 50);
      ahd_sstat2_print(ahd_inb(ahd, SSTAT2), &cur_col, 50);
      ahd_sstat3_print(ahd_inb(ahd, SSTAT3), &cur_col, 50);
      ahd_perrdiag_print(ahd_inb(ahd, PERRDIAG), &cur_col, 50);
      ahd_simode1_print(ahd_inb(ahd, SIMODE1), &cur_col, 50);
      ahd_lqistat0_print(ahd_inb(ahd, LQISTAT0), &cur_col, 50);
      ahd_lqistat1_print(ahd_inb(ahd, LQISTAT1), &cur_col, 50);
      ahd_lqistat2_print(ahd_inb(ahd, LQISTAT2), &cur_col, 50);
      ahd_lqostat0_print(ahd_inb(ahd, LQOSTAT0), &cur_col, 50);
      ahd_lqostat1_print(ahd_inb(ahd, LQOSTAT1), &cur_col, 50);
      ahd_lqostat2_print(ahd_inb(ahd, LQOSTAT2), &cur_col, 50);
      printf("\n");
      printf("\nSCB Count = %d CMDS_PENDING = %d LASTSCB 0x%x "
             "CURRSCB 0x%x NEXTSCB 0x%x\n",
             ahd->scb_data.numscbs, ahd_inw(ahd, CMDS_PENDING),
             ahd_inw(ahd, LASTSCB), ahd_inw(ahd, CURRSCB),
             ahd_inw(ahd, NEXTSCB));
      cur_col = 0;
      /* QINFIFO */
      ahd_search_qinfifo(ahd, CAM_TARGET_WILDCARD, ALL_CHANNELS,
                     CAM_LUN_WILDCARD, SCB_LIST_NULL,
                     ROLE_UNKNOWN, /*status*/0, SEARCH_PRINT);
      saved_scb_index = ahd_get_scbptr(ahd);
      printf("Pending list:");
      i = 0;
      LIST_FOREACH(scb, &ahd->pending_scbs, pending_links) {
            if (i++ > AHD_SCB_MAX)
                  break;
            cur_col = printf("\n%3d FIFO_USE[0x%x] ", SCB_GET_TAG(scb),
                         ahd_inb_scbram(ahd, SCB_FIFO_USE_COUNT));
            ahd_set_scbptr(ahd, SCB_GET_TAG(scb));
            ahd_scb_control_print(ahd_inb_scbram(ahd, SCB_CONTROL),
                              &cur_col, 60);
            ahd_scb_scsiid_print(ahd_inb_scbram(ahd, SCB_SCSIID),
                             &cur_col, 60);
      }
      printf("\nTotal %d\n", i);

      printf("Kernel Free SCB list: ");
      i = 0;
      TAILQ_FOREACH(scb, &ahd->scb_data.free_scbs, links.tqe) {
            struct scb *list_scb;

            list_scb = scb;
            do {
                  printf("%d ", SCB_GET_TAG(list_scb));
                  list_scb = LIST_NEXT(list_scb, collision_links);
            } while (list_scb && i++ < AHD_SCB_MAX);
      }

      LIST_FOREACH(scb, &ahd->scb_data.any_dev_free_scb_list, links.le) {
            if (i++ > AHD_SCB_MAX)
                  break;
            printf("%d ", SCB_GET_TAG(scb));
      }
      printf("\n");

      printf("Sequencer Complete DMA-inprog list: ");
      scb_index = ahd_inw(ahd, COMPLETE_SCB_DMAINPROG_HEAD);
      i = 0;
      while (!SCBID_IS_NULL(scb_index) && i++ < AHD_SCB_MAX) {
            ahd_set_scbptr(ahd, scb_index);
            printf("%d ", scb_index);
            scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
      }
      printf("\n");

      printf("Sequencer Complete list: ");
      scb_index = ahd_inw(ahd, COMPLETE_SCB_HEAD);
      i = 0;
      while (!SCBID_IS_NULL(scb_index) && i++ < AHD_SCB_MAX) {
            ahd_set_scbptr(ahd, scb_index);
            printf("%d ", scb_index);
            scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
      }
      printf("\n");

      
      printf("Sequencer DMA-Up and Complete list: ");
      scb_index = ahd_inw(ahd, COMPLETE_DMA_SCB_HEAD);
      i = 0;
      while (!SCBID_IS_NULL(scb_index) && i++ < AHD_SCB_MAX) {
            ahd_set_scbptr(ahd, scb_index);
            printf("%d ", scb_index);
            scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
      }
      printf("\n");
      printf("Sequencer On QFreeze and Complete list: ");
      scb_index = ahd_inw(ahd, COMPLETE_ON_QFREEZE_HEAD);
      i = 0;
      while (!SCBID_IS_NULL(scb_index) && i++ < AHD_SCB_MAX) {
            ahd_set_scbptr(ahd, scb_index);
            printf("%d ", scb_index);
            scb_index = ahd_inw_scbram(ahd, SCB_NEXT_COMPLETE);
      }
      printf("\n");
      ahd_set_scbptr(ahd, saved_scb_index);
      dffstat = ahd_inb(ahd, DFFSTAT);
      for (i = 0; i < 2; i++) {
#ifdef AHD_DEBUG
            struct scb *fifo_scb;
#endif
            u_int     fifo_scbptr;

            ahd_set_modes(ahd, AHD_MODE_DFF0 + i, AHD_MODE_DFF0 + i);
            fifo_scbptr = ahd_get_scbptr(ahd);
            printf("\n\n%s: FIFO%d %s, LONGJMP == 0x%x, SCB 0x%x\n",
                   ahd_name(ahd), i,
                   (dffstat & (FIFO0FREE << i)) ? "Free" : "Active",
                   ahd_inw(ahd, LONGJMP_ADDR), fifo_scbptr);
            cur_col = 0;
            ahd_seqimode_print(ahd_inb(ahd, SEQIMODE), &cur_col, 50);
            ahd_seqintsrc_print(ahd_inb(ahd, SEQINTSRC), &cur_col, 50);
            ahd_dfcntrl_print(ahd_inb(ahd, DFCNTRL), &cur_col, 50);
            ahd_dfstatus_print(ahd_inb(ahd, DFSTATUS), &cur_col, 50);
            ahd_sg_cache_shadow_print(ahd_inb(ahd, SG_CACHE_SHADOW),
                                &cur_col, 50);
            ahd_sg_state_print(ahd_inb(ahd, SG_STATE), &cur_col, 50);
            ahd_dffsxfrctl_print(ahd_inb(ahd, DFFSXFRCTL), &cur_col, 50);
            ahd_soffcnt_print(ahd_inb(ahd, SOFFCNT), &cur_col, 50);
            ahd_mdffstat_print(ahd_inb(ahd, MDFFSTAT), &cur_col, 50);
            if (cur_col > 50) {
                  printf("\n");
                  cur_col = 0;
            }
            cur_col += printf("SHADDR = 0x%x%x, SHCNT = 0x%x ",
                          ahd_inl(ahd, SHADDR+4),
                          ahd_inl(ahd, SHADDR),
                          (ahd_inb(ahd, SHCNT)
                        | (ahd_inb(ahd, SHCNT + 1) << 8)
                        | (ahd_inb(ahd, SHCNT + 2) << 16)));
            if (cur_col > 50) {
                  printf("\n");
                  cur_col = 0;
            }
            cur_col += printf("HADDR = 0x%x%x, HCNT = 0x%x ",
                          ahd_inl(ahd, HADDR+4),
                          ahd_inl(ahd, HADDR),
                          (ahd_inb(ahd, HCNT)
                        | (ahd_inb(ahd, HCNT + 1) << 8)
                        | (ahd_inb(ahd, HCNT + 2) << 16)));
            ahd_ccsgctl_print(ahd_inb(ahd, CCSGCTL), &cur_col, 50);
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_SG) != 0) {
                  fifo_scb = ahd_lookup_scb(ahd, fifo_scbptr);
                  if (fifo_scb != NULL)
                        ahd_dump_sglist(fifo_scb);
            }
#endif
      }
      printf("\nLQIN: ");
      for (i = 0; i < 20; i++)
            printf("0x%x ", ahd_inb(ahd, LQIN + i));
      printf("\n");
      ahd_set_modes(ahd, AHD_MODE_CFG, AHD_MODE_CFG);
      printf("%s: LQISTATE = 0x%x, LQOSTATE = 0x%x, OPTIONMODE = 0x%x\n",
             ahd_name(ahd), ahd_inb(ahd, LQISTATE), ahd_inb(ahd, LQOSTATE),
             ahd_inb(ahd, OPTIONMODE));
      printf("%s: OS_SPACE_CNT = 0x%x MAXCMDCNT = 0x%x\n",
             ahd_name(ahd), ahd_inb(ahd, OS_SPACE_CNT),
             ahd_inb(ahd, MAXCMDCNT));
      printf("%s: SAVED_SCSIID = 0x%x SAVED_LUN = 0x%x\n",
             ahd_name(ahd), ahd_inb(ahd, SAVED_SCSIID),
             ahd_inb(ahd, SAVED_LUN));
      ahd_simode0_print(ahd_inb(ahd, SIMODE0), &cur_col, 50);
      printf("\n");
      ahd_set_modes(ahd, AHD_MODE_CCHAN, AHD_MODE_CCHAN);
      cur_col = 0;
      ahd_ccscbctl_print(ahd_inb(ahd, CCSCBCTL), &cur_col, 50);
      printf("\n");
      ahd_set_modes(ahd, ahd->saved_src_mode, ahd->saved_dst_mode);
      printf("%s: REG0 == 0x%x, SINDEX = 0x%x, DINDEX = 0x%x\n",
             ahd_name(ahd), ahd_inw(ahd, REG0), ahd_inw(ahd, SINDEX),
             ahd_inw(ahd, DINDEX));
      printf("%s: SCBPTR == 0x%x, SCB_NEXT == 0x%x, SCB_NEXT2 == 0x%x\n",
             ahd_name(ahd), ahd_get_scbptr(ahd),
             ahd_inw_scbram(ahd, SCB_NEXT),
             ahd_inw_scbram(ahd, SCB_NEXT2));
      printf("CDB %x %x %x %x %x %x\n",
             ahd_inb_scbram(ahd, SCB_CDB_STORE),
             ahd_inb_scbram(ahd, SCB_CDB_STORE+1),
             ahd_inb_scbram(ahd, SCB_CDB_STORE+2),
             ahd_inb_scbram(ahd, SCB_CDB_STORE+3),
             ahd_inb_scbram(ahd, SCB_CDB_STORE+4),
             ahd_inb_scbram(ahd, SCB_CDB_STORE+5));
      printf("STACK:");
      for (i = 0; i < ahd->stack_size; i++) {
            ahd->saved_stack[i] =
                ahd_inb(ahd, STACK)|(ahd_inb(ahd, STACK) << 8);
            printf(" 0x%x", ahd->saved_stack[i]);
      }
      for (i = ahd->stack_size-1; i >= 0; i--) {
            ahd_outb(ahd, STACK, ahd->saved_stack[i] & 0xFF);
            ahd_outb(ahd, STACK, (ahd->saved_stack[i] >> 8) & 0xFF);
      }
      printf("\n<<<<<<<<<<<<<<<<< Dump Card State Ends >>>>>>>>>>>>>>>>>>\n");
      ahd_restore_modes(ahd, saved_modes);
      if (paused == 0)
            ahd_unpause(ahd);
}

void
ahd_dump_scbs(struct ahd_softc *ahd)
{
      ahd_mode_state saved_modes;
      u_int        saved_scb_index;
      int          i;

      saved_modes = ahd_save_modes(ahd);
      ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);
      saved_scb_index = ahd_get_scbptr(ahd);
      for (i = 0; i < AHD_SCB_MAX; i++) {
            ahd_set_scbptr(ahd, i);
            printf("%3d", i);
            printf("(CTRL 0x%x ID 0x%x N 0x%x N2 0x%x SG 0x%x, RSG 0x%x)\n",
                   ahd_inb_scbram(ahd, SCB_CONTROL),
                   ahd_inb_scbram(ahd, SCB_SCSIID),
                   ahd_inw_scbram(ahd, SCB_NEXT),
                   ahd_inw_scbram(ahd, SCB_NEXT2),
                   ahd_inl_scbram(ahd, SCB_SGPTR),
                   ahd_inl_scbram(ahd, SCB_RESIDUAL_SGPTR));
      }
      printf("\n");
      ahd_set_scbptr(ahd, saved_scb_index);
      ahd_restore_modes(ahd, saved_modes);
}

/**************************** Flexport Logic **********************************/
/*
 * Read count 16bit words from 16bit word address start_addr from the
 * SEEPROM attached to the controller, into buf, using the controller's
 * SEEPROM reading state machine.  Optionally treat the data as a byte
 * stream in terms of byte order.
 */
int
ahd_read_seeprom(struct ahd_softc *ahd, uint16_t *buf,
             u_int start_addr, u_int count, int bytestream)
{
      u_int cur_addr;
      u_int end_addr;
      int   error;

      /*
       * If we never make it through the loop even once,
       * we were passed invalid arguments.
       */
      error = EINVAL;
      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      end_addr = start_addr + count;
      for (cur_addr = start_addr; cur_addr < end_addr; cur_addr++) {

            ahd_outb(ahd, SEEADR, cur_addr);
            ahd_outb(ahd, SEECTL, SEEOP_READ | SEESTART);
            
            error = ahd_wait_seeprom(ahd);
            if (error)
                  break;
            if (bytestream != 0) {
                  uint8_t *bytestream_ptr;

                  bytestream_ptr = (uint8_t *)buf;
                  *bytestream_ptr++ = ahd_inb(ahd, SEEDAT);
                  *bytestream_ptr = ahd_inb(ahd, SEEDAT+1);
            } else {
                  /*
                   * ahd_inw() already handles machine byte order.
                   */
                  *buf = ahd_inw(ahd, SEEDAT);
            }
            buf++;
      }
      return (error);
}

/*
 * Write count 16bit words from buf, into SEEPROM attache to the
 * controller starting at 16bit word address start_addr, using the
 * controller's SEEPROM writing state machine.
 */
int
ahd_write_seeprom(struct ahd_softc *ahd, uint16_t *buf,
              u_int start_addr, u_int count)
{
      u_int cur_addr;
      u_int end_addr;
      int   error;
      int   retval;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      error = ENOENT;

      /* Place the chip into write-enable mode */
      ahd_outb(ahd, SEEADR, SEEOP_EWEN_ADDR);
      ahd_outb(ahd, SEECTL, SEEOP_EWEN | SEESTART);
      error = ahd_wait_seeprom(ahd);
      if (error)
            return (error);

      /*
       * Write the data.  If we don't get throught the loop at
       * least once, the arguments were invalid.
       */
      retval = EINVAL;
      end_addr = start_addr + count;
      for (cur_addr = start_addr; cur_addr < end_addr; cur_addr++) {
            ahd_outw(ahd, SEEDAT, *buf++);
            ahd_outb(ahd, SEEADR, cur_addr);
            ahd_outb(ahd, SEECTL, SEEOP_WRITE | SEESTART);
            
            retval = ahd_wait_seeprom(ahd);
            if (retval)
                  break;
      }

      /*
       * Disable writes.
       */
      ahd_outb(ahd, SEEADR, SEEOP_EWDS_ADDR);
      ahd_outb(ahd, SEECTL, SEEOP_EWDS | SEESTART);
      error = ahd_wait_seeprom(ahd);
      if (error)
            return (error);
      return (retval);
}

/*
 * Wait ~100us for the serial eeprom to satisfy our request.
 */
int
ahd_wait_seeprom(struct ahd_softc *ahd)
{
      int cnt;

      cnt = 5000;
      while ((ahd_inb(ahd, SEESTAT) & (SEEARBACK|SEEBUSY)) != 0 && --cnt)
            ahd_delay(5);

      if (cnt == 0)
            return (ETIMEDOUT);
      return (0);
}

/*
 * Validate the two checksums in the per_channel
 * vital product data struct.
 */
int
ahd_verify_vpd_cksum(struct vpd_config *vpd)
{
      int i;
      int maxaddr;
      uint32_t checksum;
      uint8_t *vpdarray;

      vpdarray = (uint8_t *)vpd;
      maxaddr = offsetof(struct vpd_config, vpd_checksum);
      checksum = 0;
      for (i = offsetof(struct vpd_config, resource_type); i < maxaddr; i++)
            checksum = checksum + vpdarray[i];
      if (checksum == 0
       || (-checksum & 0xFF) != vpd->vpd_checksum)
            return (0);

      checksum = 0;
      maxaddr = offsetof(struct vpd_config, checksum);
      for (i = offsetof(struct vpd_config, default_target_flags);
           i < maxaddr; i++)
            checksum = checksum + vpdarray[i];
      if (checksum == 0
       || (-checksum & 0xFF) != vpd->checksum)
            return (0);
      return (1);
}

int
ahd_verify_cksum(struct seeprom_config *sc)
{
      int i;
      int maxaddr;
      uint32_t checksum;
      uint16_t *scarray;

      maxaddr = (sizeof(*sc)/2) - 1;
      checksum = 0;
      scarray = (uint16_t *)sc;

      for (i = 0; i < maxaddr; i++)
            checksum = checksum + scarray[i];
      if (checksum == 0
       || (checksum & 0xFFFF) != sc->checksum) {
            return (0);
      } else {
            return (1);
      }
}

int
ahd_acquire_seeprom(struct ahd_softc *ahd)
{
      /*
       * We should be able to determine the SEEPROM type
       * from the flexport logic, but unfortunately not
       * all implementations have this logic and there is
       * no programatic method for determining if the logic
       * is present.
       */
      return (1);
#if 0
      uint8_t     seetype;
      int   error;

      error = ahd_read_flexport(ahd, FLXADDR_ROMSTAT_CURSENSECTL, &seetype);
      if (error != 0
         || ((seetype & FLX_ROMSTAT_SEECFG) == FLX_ROMSTAT_SEE_NONE))
            return (0);
      return (1);
#endif
}

void
ahd_release_seeprom(struct ahd_softc *ahd)
{
      /* Currently a no-op */
}

int
ahd_write_flexport(struct ahd_softc *ahd, u_int addr, u_int value)
{
      int error;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      if (addr > 7)
            panic("ahd_write_flexport: address out of range");
      ahd_outb(ahd, BRDCTL, BRDEN|(addr << 3));
      error = ahd_wait_flexport(ahd);
      if (error != 0)
            return (error);
      ahd_outb(ahd, BRDDAT, value);
      ahd_flush_device_writes(ahd);
      ahd_outb(ahd, BRDCTL, BRDSTB|BRDEN|(addr << 3));
      ahd_flush_device_writes(ahd);
      ahd_outb(ahd, BRDCTL, BRDEN|(addr << 3));
      ahd_flush_device_writes(ahd);
      ahd_outb(ahd, BRDCTL, 0);
      ahd_flush_device_writes(ahd);
      return (0);
}

int
ahd_read_flexport(struct ahd_softc *ahd, u_int addr, uint8_t *value)
{
      int   error;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      if (addr > 7)
            panic("ahd_read_flexport: address out of range");
      ahd_outb(ahd, BRDCTL, BRDRW|BRDEN|(addr << 3));
      error = ahd_wait_flexport(ahd);
      if (error != 0)
            return (error);
      *value = ahd_inb(ahd, BRDDAT);
      ahd_outb(ahd, BRDCTL, 0);
      ahd_flush_device_writes(ahd);
      return (0);
}

/*
 * Wait at most 2 seconds for flexport arbitration to succeed.
 */
int
ahd_wait_flexport(struct ahd_softc *ahd)
{
      int cnt;

      AHD_ASSERT_MODES(ahd, AHD_MODE_SCSI_MSK, AHD_MODE_SCSI_MSK);
      cnt = 1000000 * 2 / 5;
      while ((ahd_inb(ahd, BRDCTL) & FLXARBACK) == 0 && --cnt)
            ahd_delay(5);

      if (cnt == 0)
            return (ETIMEDOUT);
      return (0);
}

/************************* Target Mode ****************************************/
#ifdef AHD_TARGET_MODE
cam_status
ahd_find_tmode_devs(struct ahd_softc *ahd, struct cam_sim *sim, union ccb *ccb,
                struct ahd_tmode_tstate **tstate,
                struct ahd_tmode_lstate **lstate,
                int notfound_failure)
{

      if ((ahd->features & AHD_TARGETMODE) == 0)
            return (CAM_REQ_INVALID);

      /*
       * Handle the 'black hole' device that sucks up
       * requests to unattached luns on enabled targets.
       */
      if (ccb->ccb_h.target_id == CAM_TARGET_WILDCARD
       && ccb->ccb_h.target_lun == CAM_LUN_WILDCARD) {
            *tstate = NULL;
            *lstate = ahd->black_hole;
      } else {
            u_int max_id;

            max_id = (ahd->features & AHD_WIDE) ? 16 : 8;
            if (ccb->ccb_h.target_id >= max_id)
                  return (CAM_TID_INVALID);

            if (ccb->ccb_h.target_lun >= AHD_NUM_LUNS)
                  return (CAM_LUN_INVALID);

            *tstate = ahd->enabled_targets[ccb->ccb_h.target_id];
            *lstate = NULL;
            if (*tstate != NULL)
                  *lstate =
                      (*tstate)->enabled_luns[ccb->ccb_h.target_lun];
      }

      if (notfound_failure != 0 && *lstate == NULL)
            return (CAM_PATH_INVALID);

      return (CAM_REQ_CMP);
}

void
ahd_handle_en_lun(struct ahd_softc *ahd, struct cam_sim *sim, union ccb *ccb)
{
#if NOT_YET
      struct         ahd_tmode_tstate *tstate;
      struct         ahd_tmode_lstate *lstate;
      struct         ccb_en_lun *cel;
      cam_status status;
      u_int    target;
      u_int    lun;
      u_int    target_mask;
      u_long         s;
      char     channel;

      status = ahd_find_tmode_devs(ahd, sim, ccb, &tstate, &lstate,
                             /*notfound_failure*/FALSE);

      if (status != CAM_REQ_CMP) {
            ccb->ccb_h.status = status;
            return;
      }

      if ((ahd->features & AHD_MULTIROLE) != 0) {
            u_int    our_id;

            our_id = ahd->our_id;
            if (ccb->ccb_h.target_id != our_id) {
                  if ((ahd->features & AHD_MULTI_TID) != 0
                   && (ahd->flags & AHD_INITIATORROLE) != 0) {
                        /*
                         * Only allow additional targets if
                         * the initiator role is disabled.
                         * The hardware cannot handle a re-select-in
                         * on the initiator id during a re-select-out
                         * on a different target id.
                         */
                        status = CAM_TID_INVALID;
                  } else if ((ahd->flags & AHD_INITIATORROLE) != 0
                        || ahd->enabled_luns > 0) {
                        /*
                         * Only allow our target id to change
                         * if the initiator role is not configured
                         * and there are no enabled luns which
                         * are attached to the currently registered
                         * scsi id.
                         */
                        status = CAM_TID_INVALID;
                  }
            }
      }

      if (status != CAM_REQ_CMP) {
            ccb->ccb_h.status = status;
            return;
      }

      /*
       * We now have an id that is valid.
       * If we aren't in target mode, switch modes.
       */
      if ((ahd->flags & AHD_TARGETROLE) == 0
       && ccb->ccb_h.target_id != CAM_TARGET_WILDCARD) {
            u_long      s;

            printf("Configuring Target Mode\n");
            ahd_lock(ahd, &s);
            if (LIST_FIRST(&ahd->pending_scbs) != NULL) {
                  ccb->ccb_h.status = CAM_BUSY;
                  ahd_unlock(ahd, &s);
                  return;
            }
            ahd->flags |= AHD_TARGETROLE;
            if ((ahd->features & AHD_MULTIROLE) == 0)
                  ahd->flags &= ~AHD_INITIATORROLE;
            ahd_pause(ahd);
            ahd_loadseq(ahd);
            ahd_restart(ahd);
            ahd_unlock(ahd, &s);
      }
      cel = &ccb->cel;
      target = ccb->ccb_h.target_id;
      lun = ccb->ccb_h.target_lun;
      channel = SIM_CHANNEL(ahd, sim);
      target_mask = 0x01 << target;
      if (channel == 'B')
            target_mask <<= 8;

      if (cel->enable != 0) {
            u_int scsiseq1;

            /* Are we already enabled?? */
            if (lstate != NULL) {
                  xpt_print_path(ccb->ccb_h.path);
                  printf("Lun already enabled\n");
                  ccb->ccb_h.status = CAM_LUN_ALRDY_ENA;
                  return;
            }

            if (cel->grp6_len != 0
             || cel->grp7_len != 0) {
                  /*
                   * Don't (yet?) support vendor
                   * specific commands.
                   */
                  ccb->ccb_h.status = CAM_REQ_INVALID;
                  printf("Non-zero Group Codes\n");
                  return;
            }

            /*
             * Seems to be okay.
             * Setup our data structures.
             */
            if (target != CAM_TARGET_WILDCARD && tstate == NULL) {
                  tstate = ahd_alloc_tstate(ahd, target, channel);
                  if (tstate == NULL) {
                        xpt_print_path(ccb->ccb_h.path);
                        printf("Couldn't allocate tstate\n");
                        ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        return;
                  }
            }
            lstate = malloc(sizeof(*lstate), M_DEVBUF, M_NOWAIT);
            if (lstate == NULL) {
                  xpt_print_path(ccb->ccb_h.path);
                  printf("Couldn't allocate lstate\n");
                  ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                  return;
            }
            memset(lstate, 0, sizeof(*lstate));
            status = xpt_create_path(&lstate->path, /*periph*/NULL,
                               xpt_path_path_id(ccb->ccb_h.path),
                               xpt_path_target_id(ccb->ccb_h.path),
                               xpt_path_lun_id(ccb->ccb_h.path));
            if (status != CAM_REQ_CMP) {
                  free(lstate, M_DEVBUF);
                  xpt_print_path(ccb->ccb_h.path);
                  printf("Couldn't allocate path\n");
                  ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                  return;
            }
            SLIST_INIT(&lstate->accept_tios);
            SLIST_INIT(&lstate->immed_notifies);
            ahd_lock(ahd, &s);
            ahd_pause(ahd);
            if (target != CAM_TARGET_WILDCARD) {
                  tstate->enabled_luns[lun] = lstate;
                  ahd->enabled_luns++;

                  if ((ahd->features & AHD_MULTI_TID) != 0) {
                        u_int targid_mask;

                        targid_mask = ahd_inw(ahd, TARGID);
                        targid_mask |= target_mask;
                        ahd_outw(ahd, TARGID, targid_mask);
                        ahd_update_scsiid(ahd, targid_mask);
                  } else {
                        u_int our_id;
                        char  channel;

                        channel = SIM_CHANNEL(ahd, sim);
                        our_id = SIM_SCSI_ID(ahd, sim);

                        /*
                         * This can only happen if selections
                         * are not enabled
                         */
                        if (target != our_id) {
                              u_int sblkctl;
                              char  cur_channel;
                              int   swap;

                              sblkctl = ahd_inb(ahd, SBLKCTL);
                              cur_channel = (sblkctl & SELBUSB)
                                        ? 'B' : 'A';
                              if ((ahd->features & AHD_TWIN) == 0)
                                    cur_channel = 'A';
                              swap = cur_channel != channel;
                              ahd->our_id = target;

                              if (swap)
                                    ahd_outb(ahd, SBLKCTL,
                                           sblkctl ^ SELBUSB);

                              ahd_outb(ahd, SCSIID, target);

                              if (swap)
                                    ahd_outb(ahd, SBLKCTL, sblkctl);
                        }
                  }
            } else
                  ahd->black_hole = lstate;
            /* Allow select-in operations */
            if (ahd->black_hole != NULL && ahd->enabled_luns > 0) {
                  scsiseq1 = ahd_inb(ahd, SCSISEQ_TEMPLATE);
                  scsiseq1 |= ENSELI;
                  ahd_outb(ahd, SCSISEQ_TEMPLATE, scsiseq1);
                  scsiseq1 = ahd_inb(ahd, SCSISEQ1);
                  scsiseq1 |= ENSELI;
                  ahd_outb(ahd, SCSISEQ1, scsiseq1);
            }
            ahd_unpause(ahd);
            ahd_unlock(ahd, &s);
            ccb->ccb_h.status = CAM_REQ_CMP;
            xpt_print_path(ccb->ccb_h.path);
            printf("Lun now enabled for target mode\n");
      } else {
            struct scb *scb;
            int i, empty;

            if (lstate == NULL) {
                  ccb->ccb_h.status = CAM_LUN_INVALID;
                  return;
            }

            ahd_lock(ahd, &s);
            
            ccb->ccb_h.status = CAM_REQ_CMP;
            LIST_FOREACH(scb, &ahd->pending_scbs, pending_links) {
                  struct ccb_hdr *ccbh;

                  ccbh = &scb->io_ctx->ccb_h;
                  if (ccbh->func_code == XPT_CONT_TARGET_IO
                   && !xpt_path_comp(ccbh->path, ccb->ccb_h.path)){
                        printf("CTIO pending\n");
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                        ahd_unlock(ahd, &s);
                        return;
                  }
            }

            if (SLIST_FIRST(&lstate->accept_tios) != NULL) {
                  printf("ATIOs pending\n");
                  ccb->ccb_h.status = CAM_REQ_INVALID;
            }

            if (SLIST_FIRST(&lstate->immed_notifies) != NULL) {
                  printf("INOTs pending\n");
                  ccb->ccb_h.status = CAM_REQ_INVALID;
            }

            if (ccb->ccb_h.status != CAM_REQ_CMP) {
                  ahd_unlock(ahd, &s);
                  return;
            }

            xpt_print_path(ccb->ccb_h.path);
            printf("Target mode disabled\n");
            xpt_free_path(lstate->path);
            free(lstate, M_DEVBUF);

            ahd_pause(ahd);
            /* Can we clean up the target too? */
            if (target != CAM_TARGET_WILDCARD) {
                  tstate->enabled_luns[lun] = NULL;
                  ahd->enabled_luns--;
                  for (empty = 1, i = 0; i < 8; i++)
                        if (tstate->enabled_luns[i] != NULL) {
                              empty = 0;
                              break;
                        }

                  if (empty) {
                        ahd_free_tstate(ahd, target, channel,
                                    /*force*/FALSE);
                        if (ahd->features & AHD_MULTI_TID) {
                              u_int targid_mask;

                              targid_mask = ahd_inw(ahd, TARGID);
                              targid_mask &= ~target_mask;
                              ahd_outw(ahd, TARGID, targid_mask);
                              ahd_update_scsiid(ahd, targid_mask);
                        }
                  }
            } else {

                  ahd->black_hole = NULL;

                  /*
                   * We can't allow selections without
                   * our black hole device.
                   */
                  empty = TRUE;
            }
            if (ahd->enabled_luns == 0) {
                  /* Disallow select-in */
                  u_int scsiseq1;

                  scsiseq1 = ahd_inb(ahd, SCSISEQ_TEMPLATE);
                  scsiseq1 &= ~ENSELI;
                  ahd_outb(ahd, SCSISEQ_TEMPLATE, scsiseq1);
                  scsiseq1 = ahd_inb(ahd, SCSISEQ1);
                  scsiseq1 &= ~ENSELI;
                  ahd_outb(ahd, SCSISEQ1, scsiseq1);

                  if ((ahd->features & AHD_MULTIROLE) == 0) {
                        printf("Configuring Initiator Mode\n");
                        ahd->flags &= ~AHD_TARGETROLE;
                        ahd->flags |= AHD_INITIATORROLE;
                        ahd_pause(ahd);
                        ahd_loadseq(ahd);
                        ahd_restart(ahd);
                        /*
                         * Unpaused.  The extra unpause
                         * that follows is harmless.
                         */
                  }
            }
            ahd_unpause(ahd);
            ahd_unlock(ahd, &s);
      }
#endif
}

static void
ahd_update_scsiid(struct ahd_softc *ahd, u_int targid_mask)
{
#if NOT_YET
      u_int scsiid_mask;
      u_int scsiid;

      if ((ahd->features & AHD_MULTI_TID) == 0)
            panic("ahd_update_scsiid called on non-multitid unit\n");

      /*
       * Since we will rely on the TARGID mask
       * for selection enables, ensure that OID
       * in SCSIID is not set to some other ID
       * that we don't want to allow selections on.
       */
      if ((ahd->features & AHD_ULTRA2) != 0)
            scsiid = ahd_inb(ahd, SCSIID_ULTRA2);
      else
            scsiid = ahd_inb(ahd, SCSIID);
      scsiid_mask = 0x1 << (scsiid & OID);
      if ((targid_mask & scsiid_mask) == 0) {
            u_int our_id;

            /* ffs counts from 1 */
            our_id = ffs(targid_mask);
            if (our_id == 0)
                  our_id = ahd->our_id;
            else
                  our_id--;
            scsiid &= TID;
            scsiid |= our_id;
      }
      if ((ahd->features & AHD_ULTRA2) != 0)
            ahd_outb(ahd, SCSIID_ULTRA2, scsiid);
      else
            ahd_outb(ahd, SCSIID, scsiid);
#endif
}

void
ahd_run_tqinfifo(struct ahd_softc *ahd, int paused)
{
      struct target_cmd *cmd;

      ahd_sync_tqinfifo(ahd, BUS_DMASYNC_POSTREAD);
      while ((cmd = &ahd->targetcmds[ahd->tqinfifonext])->cmd_valid != 0) {

            /*
             * Only advance through the queue if we
             * have the resources to process the command.
             */
            if (ahd_handle_target_cmd(ahd, cmd) != 0)
                  break;

            cmd->cmd_valid = 0;
            ahd_dmamap_sync(ahd, ahd->shared_data_dmat,
                        ahd->shared_data_map.dmamap,
                        ahd_targetcmd_offset(ahd, ahd->tqinfifonext),
                        sizeof(struct target_cmd),
                        BUS_DMASYNC_PREREAD);
            ahd->tqinfifonext++;

            /*
             * Lazily update our position in the target mode incoming
             * command queue as seen by the sequencer.
             */
            if ((ahd->tqinfifonext & (HOST_TQINPOS - 1)) == 1) {
                  u_int hs_mailbox;

                  hs_mailbox = ahd_inb(ahd, HS_MAILBOX);
                  hs_mailbox &= ~HOST_TQINPOS;
                  hs_mailbox |= ahd->tqinfifonext & HOST_TQINPOS;
                  ahd_outb(ahd, HS_MAILBOX, hs_mailbox);
            }
      }
}

static int
ahd_handle_target_cmd(struct ahd_softc *ahd, struct target_cmd *cmd)
{
      struct        ahd_tmode_tstate *tstate;
      struct        ahd_tmode_lstate *lstate;
      struct        ccb_accept_tio *atio;
      uint8_t *byte;
      int     initiator;
      int     target;
      int     lun;

      initiator = SCSIID_TARGET(ahd, cmd->scsiid);
      target = SCSIID_OUR_ID(cmd->scsiid);
      lun    = (cmd->identify & MSG_IDENTIFY_LUNMASK);

      byte = cmd->bytes;
      tstate = ahd->enabled_targets[target];
      lstate = NULL;
      if (tstate != NULL)
            lstate = tstate->enabled_luns[lun];

      /*
       * Commands for disabled luns go to the black hole driver.
       */
      if (lstate == NULL)
            lstate = ahd->black_hole;

      atio = (struct ccb_accept_tio*)SLIST_FIRST(&lstate->accept_tios);
      if (atio == NULL) {
            ahd->flags |= AHD_TQINFIFO_BLOCKED;
            /*
             * Wait for more ATIOs from the peripheral driver for this lun.
             */
            return (1);
      } else
            ahd->flags &= ~AHD_TQINFIFO_BLOCKED;
#ifdef AHD_DEBUG
      if ((ahd_debug & AHD_SHOW_TQIN) != 0)
            printf("Incoming command from %d for %d:%d%s\n",
                   initiator, target, lun,
                   lstate == ahd->black_hole ? "(Black Holed)" : "");
#endif
      SLIST_REMOVE_HEAD(&lstate->accept_tios, sim_links.sle);

      if (lstate == ahd->black_hole) {
            /* Fill in the wildcards */
            atio->ccb_h.target_id = target;
            atio->ccb_h.target_lun = lun;
      }

      /*
       * Package it up and send it off to
       * whomever has this lun enabled.
       */
      atio->sense_len = 0;
      atio->init_id = initiator;
      if (byte[0] != 0xFF) {
            /* Tag was included */
            atio->tag_action = *byte++;
            atio->tag_id = *byte++;
            atio->ccb_h.flags = CAM_TAG_ACTION_VALID;
      } else {
            atio->ccb_h.flags = 0;
      }
      byte++;

      /* Okay.  Now determine the cdb size based on the command code */
      switch (*byte >> CMD_GROUP_CODE_SHIFT) {
      case 0:
            atio->cdb_len = 6;
            break;
      case 1:
      case 2:
            atio->cdb_len = 10;
            break;
      case 4:
            atio->cdb_len = 16;
            break;
      case 5:
            atio->cdb_len = 12;
            break;
      case 3:
      default:
            /* Only copy the opcode. */
            atio->cdb_len = 1;
            printf("Reserved or VU command code type encountered\n");
            break;
      }
      
      memcpy(atio->cdb_io.cdb_bytes, byte, atio->cdb_len);

      atio->ccb_h.status |= CAM_CDB_RECVD;

      if ((cmd->identify & MSG_IDENTIFY_DISCFLAG) == 0) {
            /*
             * We weren't allowed to disconnect.
             * We're hanging on the bus until a
             * continue target I/O comes in response
             * to this accept tio.
             */
#ifdef AHD_DEBUG
            if ((ahd_debug & AHD_SHOW_TQIN) != 0)
                  printf("Received Immediate Command %d:%d:%d - %p\n",
                         initiator, target, lun, ahd->pending_device);
#endif
            ahd->pending_device = lstate;
            ahd_freeze_ccb((union ccb *)atio);
            atio->ccb_h.flags |= CAM_DIS_DISCONNECT;
      }
      xpt_done((union ccb*)atio);
      return (0);
}

#endif

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