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sbp2.c

/*
 * sbp2.c - SBP-2 protocol driver for IEEE-1394
 *
 * Copyright (C) 2000 James Goodwin, Filanet Corporation (www.filanet.com)
 * jamesg@filanet.com (JSG)
 *
 * Copyright (C) 2003 Ben Collins <bcollins@debian.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
 * Brief Description:
 *
 * This driver implements the Serial Bus Protocol 2 (SBP-2) over IEEE-1394
 * under Linux. The SBP-2 driver is implemented as an IEEE-1394 high-level
 * driver. It also registers as a SCSI lower-level driver in order to accept
 * SCSI commands for transport using SBP-2.
 *
 * You may access any attached SBP-2 storage devices as if they were SCSI
 * devices (e.g. mount /dev/sda1,  fdisk, mkfs, etc.).
 *
 * Current Issues:
 *
 *    - Error Handling: SCSI aborts and bus reset requests are handled somewhat
 *      but the code needs additional debugging.
 */

#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/stringify.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/blkdev.h>
#include <linux/smp_lock.h>
#include <linux/init.h>
#include <linux/pci.h>

#include <asm/current.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/byteorder.h>
#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/scatterlist.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>

#include "csr1212.h"
#include "ieee1394.h"
#include "ieee1394_types.h"
#include "ieee1394_core.h"
#include "nodemgr.h"
#include "hosts.h"
#include "highlevel.h"
#include "ieee1394_transactions.h"
#include "sbp2.h"

/*
 * Module load parameter definitions
 */

/*
 * Change max_speed on module load if you have a bad IEEE-1394
 * controller that has trouble running 2KB packets at 400mb.
 *
 * NOTE: On certain OHCI parts I have seen short packets on async transmit
 * (probably due to PCI latency/throughput issues with the part). You can
 * bump down the speed if you are running into problems.
 */
static int max_speed = IEEE1394_SPEED_MAX;
module_param(max_speed, int, 0644);
MODULE_PARM_DESC(max_speed, "Force max speed (3 = 800mb, 2 = 400mb, 1 = 200mb, 0 = 100mb)");

/*
 * Set serialize_io to 1 if you'd like only one scsi command sent
 * down to us at a time (debugging). This might be necessary for very
 * badly behaved sbp2 devices.
 *
 * TODO: Make this configurable per device.
 */
static int serialize_io = 1;
module_param(serialize_io, int, 0444);
MODULE_PARM_DESC(serialize_io, "Serialize I/O coming from scsi drivers (default = 1, faster = 0)");

/*
 * Bump up max_sectors if you'd like to support very large sized
 * transfers. Please note that some older sbp2 bridge chips are broken for
 * transfers greater or equal to 128KB.  Default is a value of 255
 * sectors, or just under 128KB (at 512 byte sector size). I can note that
 * the Oxsemi sbp2 chipsets have no problems supporting very large
 * transfer sizes.
 */
static int max_sectors = SBP2_MAX_SECTORS;
module_param(max_sectors, int, 0444);
MODULE_PARM_DESC(max_sectors, "Change max sectors per I/O supported (default = "
             __stringify(SBP2_MAX_SECTORS) ")");

/*
 * Exclusive login to sbp2 device? In most cases, the sbp2 driver should
 * do an exclusive login, as it's generally unsafe to have two hosts
 * talking to a single sbp2 device at the same time (filesystem coherency,
 * etc.). If you're running an sbp2 device that supports multiple logins,
 * and you're either running read-only filesystems or some sort of special
 * filesystem supporting multiple hosts, e.g. OpenGFS, Oracle Cluster
 * File System, or Lustre, then set exclusive_login to zero.
 *
 * So far only bridges from Oxford Semiconductor are known to support
 * concurrent logins. Depending on firmware, four or two concurrent logins
 * are possible on OXFW911 and newer Oxsemi bridges.
 */
static int exclusive_login = 1;
module_param(exclusive_login, int, 0644);
MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device (default = 1)");

/*
 * If any of the following workarounds is required for your device to work,
 * please submit the kernel messages logged by sbp2 to the linux1394-devel
 * mailing list.
 *
 * - 128kB max transfer
 *   Limit transfer size. Necessary for some old bridges.
 *
 * - 36 byte inquiry
 *   When scsi_mod probes the device, let the inquiry command look like that
 *   from MS Windows.
 *
 * - skip mode page 8
 *   Suppress sending of mode_sense for mode page 8 if the device pretends to
 *   support the SCSI Primary Block commands instead of Reduced Block Commands.
 *
 * - fix capacity
 *   Tell sd_mod to correct the last sector number reported by read_capacity.
 *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
 *   Don't use this with devices which don't have this bug.
 *
 * - override internal blacklist
 *   Instead of adding to the built-in blacklist, use only the workarounds
 *   specified in the module load parameter.
 *   Useful if a blacklist entry interfered with a non-broken device.
 */
static int sbp2_default_workarounds;
module_param_named(workarounds, sbp2_default_workarounds, int, 0644);
MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
      ", 128kB max transfer = " __stringify(SBP2_WORKAROUND_128K_MAX_TRANS)
      ", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
      ", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
      ", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
      ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
      ", or a combination)");

/* legacy parameter */
static int force_inquiry_hack;
module_param(force_inquiry_hack, int, 0644);
MODULE_PARM_DESC(force_inquiry_hack, "Deprecated, use 'workarounds'");

/*
 * Export information about protocols/devices supported by this driver.
 */
static struct ieee1394_device_id sbp2_id_table[] = {
      {
       .match_flags = IEEE1394_MATCH_SPECIFIER_ID | IEEE1394_MATCH_VERSION,
       .specifier_id = SBP2_UNIT_SPEC_ID_ENTRY & 0xffffff,
       .version = SBP2_SW_VERSION_ENTRY & 0xffffff},
      {}
};

MODULE_DEVICE_TABLE(ieee1394, sbp2_id_table);

/*
 * Debug levels, configured via kernel config, or enable here.
 */

#define CONFIG_IEEE1394_SBP2_DEBUG 0
/* #define CONFIG_IEEE1394_SBP2_DEBUG_ORBS */
/* #define CONFIG_IEEE1394_SBP2_DEBUG_DMA */
/* #define CONFIG_IEEE1394_SBP2_DEBUG 1 */
/* #define CONFIG_IEEE1394_SBP2_DEBUG 2 */
/* #define CONFIG_IEEE1394_SBP2_PACKET_DUMP */

#ifdef CONFIG_IEEE1394_SBP2_DEBUG_ORBS
#define SBP2_ORB_DEBUG(fmt, args...)      HPSB_ERR("sbp2(%s): "fmt, __FUNCTION__, ## args)
static u32 global_outstanding_command_orbs = 0;
#define outstanding_orb_incr global_outstanding_command_orbs++
#define outstanding_orb_decr global_outstanding_command_orbs--
#else
#define SBP2_ORB_DEBUG(fmt, args...)
#define outstanding_orb_incr
#define outstanding_orb_decr
#endif

#ifdef CONFIG_IEEE1394_SBP2_DEBUG_DMA
#define SBP2_DMA_ALLOC(fmt, args...) \
      HPSB_ERR("sbp2(%s)alloc(%d): "fmt, __FUNCTION__, \
             ++global_outstanding_dmas, ## args)
#define SBP2_DMA_FREE(fmt, args...) \
      HPSB_ERR("sbp2(%s)free(%d): "fmt, __FUNCTION__, \
             --global_outstanding_dmas, ## args)
static u32 global_outstanding_dmas = 0;
#else
#define SBP2_DMA_ALLOC(fmt, args...)
#define SBP2_DMA_FREE(fmt, args...)
#endif

#if CONFIG_IEEE1394_SBP2_DEBUG >= 2
#define SBP2_DEBUG(fmt, args...)    HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_INFO(fmt, args...)           HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)   HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)           HPSB_ERR("sbp2: "fmt, ## args)
#elif CONFIG_IEEE1394_SBP2_DEBUG == 1
#define SBP2_DEBUG(fmt, args...)    HPSB_DEBUG("sbp2: "fmt, ## args)
#define SBP2_INFO(fmt, args...)           HPSB_INFO("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)   HPSB_NOTICE("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)           HPSB_WARN("sbp2: "fmt, ## args)
#else
#define SBP2_DEBUG(fmt, args...)
#define SBP2_INFO(fmt, args...)           HPSB_INFO("sbp2: "fmt, ## args)
#define SBP2_NOTICE(fmt, args...)       HPSB_NOTICE("sbp2: "fmt, ## args)
#define SBP2_WARN(fmt, args...)         HPSB_WARN("sbp2: "fmt, ## args)
#endif

#define SBP2_ERR(fmt, args...)            HPSB_ERR("sbp2: "fmt, ## args)
#define SBP2_DEBUG_ENTER()          SBP2_DEBUG("%s", __FUNCTION__)

/*
 * Globals
 */

static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id,
                                 u32 status);

static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id,
                              u32 scsi_status, struct scsi_cmnd *SCpnt,
                              void (*done)(struct scsi_cmnd *));

static struct scsi_host_template scsi_driver_template;

static const u8 sbp2_speedto_max_payload[] = { 0x7, 0x8, 0x9, 0xA, 0xB, 0xC };

static void sbp2_host_reset(struct hpsb_host *host);

static int sbp2_probe(struct device *dev);
static int sbp2_remove(struct device *dev);
static int sbp2_update(struct unit_directory *ud);

static struct hpsb_highlevel sbp2_highlevel = {
      .name =           SBP2_DEVICE_NAME,
      .host_reset =     sbp2_host_reset,
};

static struct hpsb_address_ops sbp2_ops = {
      .write = sbp2_handle_status_write
};

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
static struct hpsb_address_ops sbp2_physdma_ops = {
      .read = sbp2_handle_physdma_read,
      .write = sbp2_handle_physdma_write,
};
#endif

static struct hpsb_protocol_driver sbp2_driver = {
      .name       = "SBP2 Driver",
      .id_table   = sbp2_id_table,
      .update           = sbp2_update,
      .driver           = {
            .name       = SBP2_DEVICE_NAME,
            .bus        = &ieee1394_bus_type,
            .probe            = sbp2_probe,
            .remove           = sbp2_remove,
      },
};

/*
 * List of devices with known bugs.
 *
 * The firmware_revision field, masked with 0xffff00, is the best indicator
 * for the type of bridge chip of a device.  It yields a few false positives
 * but this did not break correctly behaving devices so far.
 */
static const struct {
      u32 firmware_revision;
      u32 model_id;
      unsigned workarounds;
} sbp2_workarounds_table[] = {
      /* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
            .firmware_revision      = 0x002800,
            .model_id         = 0x001010,
            .workarounds            = SBP2_WORKAROUND_INQUIRY_36 |
                                SBP2_WORKAROUND_MODE_SENSE_8,
      },
      /* Initio bridges, actually only needed for some older ones */ {
            .firmware_revision      = 0x000200,
            .workarounds            = SBP2_WORKAROUND_INQUIRY_36,
      },
      /* Symbios bridge */ {
            .firmware_revision      = 0xa0b800,
            .workarounds            = SBP2_WORKAROUND_128K_MAX_TRANS,
      },
      /*
       * Note about the following Apple iPod blacklist entries:
       *
       * There are iPods (2nd gen, 3rd gen) with model_id==0.  Since our
       * matching logic treats 0 as a wildcard, we cannot match this ID
       * without rewriting the matching routine.  Fortunately these iPods
       * do not feature the read_capacity bug according to one report.
       * Read_capacity behaviour as well as model_id could change due to
       * Apple-supplied firmware updates though.
       */
      /* iPod 4th generation */ {
            .firmware_revision      = 0x0a2700,
            .model_id         = 0x000021,
            .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
      },
      /* iPod mini */ {
            .firmware_revision      = 0x0a2700,
            .model_id         = 0x000023,
            .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
      },
      /* iPod Photo */ {
            .firmware_revision      = 0x0a2700,
            .model_id         = 0x00007e,
            .workarounds            = SBP2_WORKAROUND_FIX_CAPACITY,
      }
};

/**************************************
 * General utility functions
 **************************************/

#ifndef __BIG_ENDIAN
/*
 * Converts a buffer from be32 to cpu byte ordering. Length is in bytes.
 */
static __inline__ void sbp2util_be32_to_cpu_buffer(void *buffer, int length)
{
      u32 *temp = buffer;

      for (length = (length >> 2); length--; )
            temp[length] = be32_to_cpu(temp[length]);

      return;
}

/*
 * Converts a buffer from cpu to be32 byte ordering. Length is in bytes.
 */
static __inline__ void sbp2util_cpu_to_be32_buffer(void *buffer, int length)
{
      u32 *temp = buffer;

      for (length = (length >> 2); length--; )
            temp[length] = cpu_to_be32(temp[length]);

      return;
}
#else /* BIG_ENDIAN */
/* Why waste the cpu cycles? */
#define sbp2util_be32_to_cpu_buffer(x,y)
#define sbp2util_cpu_to_be32_buffer(x,y)
#endif

#ifdef CONFIG_IEEE1394_SBP2_PACKET_DUMP
/*
 * Debug packet dump routine. Length is in bytes.
 */
static void sbp2util_packet_dump(void *buffer, int length, char *dump_name,
                         u32 dump_phys_addr)
{
      int i;
      unsigned char *dump = buffer;

      if (!dump || !length || !dump_name)
            return;

      if (dump_phys_addr)
            printk("[%s, 0x%x]", dump_name, dump_phys_addr);
      else
            printk("[%s]", dump_name);
      for (i = 0; i < length; i++) {
            if (i > 0x3f) {
                  printk("\n   ...");
                  break;
            }
            if ((i & 0x3) == 0)
                  printk("  ");
            if ((i & 0xf) == 0)
                  printk("\n   ");
            printk("%02x ", (int)dump[i]);
      }
      printk("\n");

      return;
}
#else
#define sbp2util_packet_dump(w,x,y,z)
#endif

/*
 * Goofy routine that basically does a down_timeout function.
 */
static int sbp2util_down_timeout(atomic_t *done, int timeout)
{
      int i;

      for (i = timeout; (i > 0 && atomic_read(done) == 0); i-= HZ/10) {
            if (msleep_interruptible(100))      /* 100ms */
                  return 1;
      }
      return (i > 0) ? 0 : 1;
}

/* Free's an allocated packet */
static void sbp2_free_packet(struct hpsb_packet *packet)
{
      hpsb_free_tlabel(packet);
      hpsb_free_packet(packet);
}

/* This is much like hpsb_node_write(), except it ignores the response
 * subaction and returns immediately. Can be used from interrupts.
 */
static int sbp2util_node_write_no_wait(struct node_entry *ne, u64 addr,
                               quadlet_t *buffer, size_t length)
{
      struct hpsb_packet *packet;

      packet = hpsb_make_writepacket(ne->host, ne->nodeid,
                               addr, buffer, length);
      if (!packet)
            return -ENOMEM;

      hpsb_set_packet_complete_task(packet,
                              (void (*)(void *))sbp2_free_packet,
                              packet);

      hpsb_node_fill_packet(ne, packet);

      if (hpsb_send_packet(packet) < 0) {
            sbp2_free_packet(packet);
            return -EIO;
      }

      return 0;
}

/*
 * This function is called to create a pool of command orbs used for
 * command processing. It is called when a new sbp2 device is detected.
 */
static int sbp2util_create_command_orb_pool(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      int i;
      unsigned long flags, orbs;
      struct sbp2_command_info *command;

      orbs = serialize_io ? 2 : SBP2_MAX_CMDS;

      spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
      for (i = 0; i < orbs; i++) {
            command = kzalloc(sizeof(*command), GFP_ATOMIC);
            if (!command) {
                  spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock,
                                     flags);
                  return -ENOMEM;
            }
            command->command_orb_dma =
                pci_map_single(hi->host->pdev, &command->command_orb,
                           sizeof(struct sbp2_command_orb),
                           PCI_DMA_BIDIRECTIONAL);
            SBP2_DMA_ALLOC("single command orb DMA");
            command->sge_dma =
                pci_map_single(hi->host->pdev,
                           &command->scatter_gather_element,
                           sizeof(command->scatter_gather_element),
                           PCI_DMA_BIDIRECTIONAL);
            SBP2_DMA_ALLOC("scatter_gather_element");
            INIT_LIST_HEAD(&command->list);
            list_add_tail(&command->list, &scsi_id->sbp2_command_orb_completed);
      }
      spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
      return 0;
}

/*
 * This function is called to delete a pool of command orbs.
 */
static void sbp2util_remove_command_orb_pool(struct scsi_id_instance_data *scsi_id)
{
      struct hpsb_host *host = scsi_id->hi->host;
      struct list_head *lh, *next;
      struct sbp2_command_info *command;
      unsigned long flags;

      spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
      if (!list_empty(&scsi_id->sbp2_command_orb_completed)) {
            list_for_each_safe(lh, next, &scsi_id->sbp2_command_orb_completed) {
                  command = list_entry(lh, struct sbp2_command_info, list);

                  /* Release our generic DMA's */
                  pci_unmap_single(host->pdev, command->command_orb_dma,
                               sizeof(struct sbp2_command_orb),
                               PCI_DMA_BIDIRECTIONAL);
                  SBP2_DMA_FREE("single command orb DMA");
                  pci_unmap_single(host->pdev, command->sge_dma,
                               sizeof(command->scatter_gather_element),
                               PCI_DMA_BIDIRECTIONAL);
                  SBP2_DMA_FREE("scatter_gather_element");

                  kfree(command);
            }
      }
      spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
      return;
}

/*
 * This function finds the sbp2_command for a given outstanding command
 * orb.Only looks at the inuse list.
 */
static struct sbp2_command_info *sbp2util_find_command_for_orb(
            struct scsi_id_instance_data *scsi_id, dma_addr_t orb)
{
      struct sbp2_command_info *command;
      unsigned long flags;

      spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
      if (!list_empty(&scsi_id->sbp2_command_orb_inuse)) {
            list_for_each_entry(command, &scsi_id->sbp2_command_orb_inuse, list) {
                  if (command->command_orb_dma == orb) {
                        spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
                        return command;
                  }
            }
      }
      spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

      SBP2_ORB_DEBUG("could not match command orb %x", (unsigned int)orb);

      return NULL;
}

/*
 * This function finds the sbp2_command for a given outstanding SCpnt.
 * Only looks at the inuse list.
 * Must be called with scsi_id->sbp2_command_orb_lock held.
 */
static struct sbp2_command_info *sbp2util_find_command_for_SCpnt(
            struct scsi_id_instance_data *scsi_id, void *SCpnt)
{
      struct sbp2_command_info *command;

      if (!list_empty(&scsi_id->sbp2_command_orb_inuse))
            list_for_each_entry(command, &scsi_id->sbp2_command_orb_inuse, list)
                  if (command->Current_SCpnt == SCpnt)
                        return command;
      return NULL;
}

/*
 * This function allocates a command orb used to send a scsi command.
 */
static struct sbp2_command_info *sbp2util_allocate_command_orb(
            struct scsi_id_instance_data *scsi_id,
            struct scsi_cmnd *Current_SCpnt,
            void (*Current_done)(struct scsi_cmnd *))
{
      struct list_head *lh;
      struct sbp2_command_info *command = NULL;
      unsigned long flags;

      spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
      if (!list_empty(&scsi_id->sbp2_command_orb_completed)) {
            lh = scsi_id->sbp2_command_orb_completed.next;
            list_del(lh);
            command = list_entry(lh, struct sbp2_command_info, list);
            command->Current_done = Current_done;
            command->Current_SCpnt = Current_SCpnt;
            list_add_tail(&command->list, &scsi_id->sbp2_command_orb_inuse);
      } else {
            SBP2_ERR("%s: no orbs available", __FUNCTION__);
      }
      spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);
      return command;
}

/* Free our DMA's */
static void sbp2util_free_command_dma(struct sbp2_command_info *command)
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)command->Current_SCpnt->device->host->hostdata[0];
      struct hpsb_host *host;

      if (!scsi_id) {
            SBP2_ERR("%s: scsi_id == NULL", __FUNCTION__);
            return;
      }

      host = scsi_id->ud->ne->host;

      if (command->cmd_dma) {
            if (command->dma_type == CMD_DMA_SINGLE) {
                  pci_unmap_single(host->pdev, command->cmd_dma,
                               command->dma_size, command->dma_dir);
                  SBP2_DMA_FREE("single bulk");
            } else if (command->dma_type == CMD_DMA_PAGE) {
                  pci_unmap_page(host->pdev, command->cmd_dma,
                               command->dma_size, command->dma_dir);
                  SBP2_DMA_FREE("single page");
            } /* XXX: Check for CMD_DMA_NONE bug */
            command->dma_type = CMD_DMA_NONE;
            command->cmd_dma = 0;
      }

      if (command->sge_buffer) {
            pci_unmap_sg(host->pdev, command->sge_buffer,
                       command->dma_size, command->dma_dir);
            SBP2_DMA_FREE("scatter list");
            command->sge_buffer = NULL;
      }
}

/*
 * This function moves a command to the completed orb list.
 * Must be called with scsi_id->sbp2_command_orb_lock held.
 */
static void sbp2util_mark_command_completed(
            struct scsi_id_instance_data *scsi_id,
            struct sbp2_command_info *command)
{
      list_del(&command->list);
      sbp2util_free_command_dma(command);
      list_add_tail(&command->list, &scsi_id->sbp2_command_orb_completed);
}

/*
 * Is scsi_id valid? Is the 1394 node still present?
 */
static inline int sbp2util_node_is_available(struct scsi_id_instance_data *scsi_id)
{
      return scsi_id && scsi_id->ne && !scsi_id->ne->in_limbo;
}

/*********************************************
 * IEEE-1394 core driver stack related section
 *********************************************/
static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud);

static int sbp2_probe(struct device *dev)
{
      struct unit_directory *ud;
      struct scsi_id_instance_data *scsi_id;

      SBP2_DEBUG_ENTER();

      ud = container_of(dev, struct unit_directory, device);

      /* Don't probe UD's that have the LUN flag. We'll probe the LUN(s)
       * instead. */
      if (ud->flags & UNIT_DIRECTORY_HAS_LUN_DIRECTORY)
            return -ENODEV;

      scsi_id = sbp2_alloc_device(ud);

      if (!scsi_id)
            return -ENOMEM;

      sbp2_parse_unit_directory(scsi_id, ud);

      return sbp2_start_device(scsi_id);
}

static int sbp2_remove(struct device *dev)
{
      struct unit_directory *ud;
      struct scsi_id_instance_data *scsi_id;
      struct scsi_device *sdev;

      SBP2_DEBUG_ENTER();

      ud = container_of(dev, struct unit_directory, device);
      scsi_id = ud->device.driver_data;
      if (!scsi_id)
            return 0;

      if (scsi_id->scsi_host) {
            /* Get rid of enqueued commands if there is no chance to
             * send them. */
            if (!sbp2util_node_is_available(scsi_id))
                  sbp2scsi_complete_all_commands(scsi_id, DID_NO_CONNECT);
            /* scsi_remove_device() will trigger shutdown functions of SCSI
             * highlevel drivers which would deadlock if blocked. */
            scsi_unblock_requests(scsi_id->scsi_host);
      }
      sdev = scsi_id->sdev;
      if (sdev) {
            scsi_id->sdev = NULL;
            scsi_remove_device(sdev);
      }

      sbp2_logout_device(scsi_id);
      sbp2_remove_device(scsi_id);

      return 0;
}

static int sbp2_update(struct unit_directory *ud)
{
      struct scsi_id_instance_data *scsi_id = ud->device.driver_data;

      SBP2_DEBUG_ENTER();

      if (sbp2_reconnect_device(scsi_id)) {

            /*
             * Ok, reconnect has failed. Perhaps we didn't
             * reconnect fast enough. Try doing a regular login, but
             * first do a logout just in case of any weirdness.
             */
            sbp2_logout_device(scsi_id);

            if (sbp2_login_device(scsi_id)) {
                  /* Login failed too, just fail, and the backend
                   * will call our sbp2_remove for us */
                  SBP2_ERR("Failed to reconnect to sbp2 device!");
                  return -EBUSY;
            }
      }

      /* Set max retries to something large on the device. */
      sbp2_set_busy_timeout(scsi_id);

      /* Do a SBP-2 fetch agent reset. */
      sbp2_agent_reset(scsi_id, 1);

      /* Get the max speed and packet size that we can use. */
      sbp2_max_speed_and_size(scsi_id);

      /* Complete any pending commands with busy (so they get
       * retried) and remove them from our queue
       */
      sbp2scsi_complete_all_commands(scsi_id, DID_BUS_BUSY);

      /* Make sure we unblock requests (since this is likely after a bus
       * reset). */
      scsi_unblock_requests(scsi_id->scsi_host);

      return 0;
}

/* This functions is called by the sbp2_probe, for each new device. We now
 * allocate one scsi host for each scsi_id (unit directory). */
static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud)
{
      struct sbp2scsi_host_info *hi;
      struct Scsi_Host *scsi_host = NULL;
      struct scsi_id_instance_data *scsi_id = NULL;

      SBP2_DEBUG_ENTER();

      scsi_id = kzalloc(sizeof(*scsi_id), GFP_KERNEL);
      if (!scsi_id) {
            SBP2_ERR("failed to create scsi_id");
            goto failed_alloc;
      }

      scsi_id->ne = ud->ne;
      scsi_id->ud = ud;
      scsi_id->speed_code = IEEE1394_SPEED_100;
      scsi_id->max_payload_size = sbp2_speedto_max_payload[IEEE1394_SPEED_100];
      scsi_id->status_fifo_addr = CSR1212_INVALID_ADDR_SPACE;
      atomic_set(&scsi_id->sbp2_login_complete, 0);
      INIT_LIST_HEAD(&scsi_id->sbp2_command_orb_inuse);
      INIT_LIST_HEAD(&scsi_id->sbp2_command_orb_completed);
      INIT_LIST_HEAD(&scsi_id->scsi_list);
      spin_lock_init(&scsi_id->sbp2_command_orb_lock);

      ud->device.driver_data = scsi_id;

      hi = hpsb_get_hostinfo(&sbp2_highlevel, ud->ne->host);
      if (!hi) {
            hi = hpsb_create_hostinfo(&sbp2_highlevel, ud->ne->host, sizeof(*hi));
            if (!hi) {
                  SBP2_ERR("failed to allocate hostinfo");
                  goto failed_alloc;
            }
            SBP2_DEBUG("sbp2_alloc_device: allocated hostinfo");
            hi->host = ud->ne->host;
            INIT_LIST_HEAD(&hi->scsi_ids);

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
            /* Handle data movement if physical dma is not
             * enabled or not supported on host controller */
            if (!hpsb_register_addrspace(&sbp2_highlevel, ud->ne->host,
                                   &sbp2_physdma_ops,
                                   0x0ULL, 0xfffffffcULL)) {
                  SBP2_ERR("failed to register lower 4GB address range");
                  goto failed_alloc;
            }
#endif
      }

      /* Prevent unloading of the 1394 host */
      if (!try_module_get(hi->host->driver->owner)) {
            SBP2_ERR("failed to get a reference on 1394 host driver");
            goto failed_alloc;
      }

      scsi_id->hi = hi;

      list_add_tail(&scsi_id->scsi_list, &hi->scsi_ids);

      /* Register the status FIFO address range. We could use the same FIFO
       * for targets at different nodes. However we need different FIFOs per
       * target in order to support multi-unit devices.
       * The FIFO is located out of the local host controller's physical range
       * but, if possible, within the posted write area. Status writes will
       * then be performed as unified transactions. This slightly reduces
       * bandwidth usage, and some Prolific based devices seem to require it.
       */
      scsi_id->status_fifo_addr = hpsb_allocate_and_register_addrspace(
                  &sbp2_highlevel, ud->ne->host, &sbp2_ops,
                  sizeof(struct sbp2_status_block), sizeof(quadlet_t),
                  ud->ne->host->low_addr_space, CSR1212_ALL_SPACE_END);
      if (scsi_id->status_fifo_addr == CSR1212_INVALID_ADDR_SPACE) {
            SBP2_ERR("failed to allocate status FIFO address range");
            goto failed_alloc;
      }

      /* Register our host with the SCSI stack. */
      scsi_host = scsi_host_alloc(&scsi_driver_template,
                            sizeof(unsigned long));
      if (!scsi_host) {
            SBP2_ERR("failed to register scsi host");
            goto failed_alloc;
      }

      scsi_host->hostdata[0] = (unsigned long)scsi_id;

      if (!scsi_add_host(scsi_host, &ud->device)) {
            scsi_id->scsi_host = scsi_host;
            return scsi_id;
      }

      SBP2_ERR("failed to add scsi host");
      scsi_host_put(scsi_host);

failed_alloc:
      sbp2_remove_device(scsi_id);
      return NULL;
}

static void sbp2_host_reset(struct hpsb_host *host)
{
      struct sbp2scsi_host_info *hi;
      struct scsi_id_instance_data *scsi_id;

      hi = hpsb_get_hostinfo(&sbp2_highlevel, host);

      if (hi) {
            list_for_each_entry(scsi_id, &hi->scsi_ids, scsi_list)
                  scsi_block_requests(scsi_id->scsi_host);
      }
}

/*
 * This function is where we first pull the node unique ids, and then
 * allocate memory and register a SBP-2 device.
 */
static int sbp2_start_device(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      int error;

      SBP2_DEBUG_ENTER();

      /* Login FIFO DMA */
      scsi_id->login_response =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_login_response),
                             &scsi_id->login_response_dma);
      if (!scsi_id->login_response)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for login FIFO");

      /* Query logins ORB DMA */
      scsi_id->query_logins_orb =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_query_logins_orb),
                             &scsi_id->query_logins_orb_dma);
      if (!scsi_id->query_logins_orb)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for query logins ORB");

      /* Query logins response DMA */
      scsi_id->query_logins_response =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_query_logins_response),
                             &scsi_id->query_logins_response_dma);
      if (!scsi_id->query_logins_response)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for query logins response");

      /* Reconnect ORB DMA */
      scsi_id->reconnect_orb =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_reconnect_orb),
                             &scsi_id->reconnect_orb_dma);
      if (!scsi_id->reconnect_orb)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for reconnect ORB");

      /* Logout ORB DMA */
      scsi_id->logout_orb =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_logout_orb),
                             &scsi_id->logout_orb_dma);
      if (!scsi_id->logout_orb)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for logout ORB");

      /* Login ORB DMA */
      scsi_id->login_orb =
            pci_alloc_consistent(hi->host->pdev,
                             sizeof(struct sbp2_login_orb),
                             &scsi_id->login_orb_dma);
      if (!scsi_id->login_orb)
            goto alloc_fail;
      SBP2_DMA_ALLOC("consistent DMA region for login ORB");

      SBP2_DEBUG("New SBP-2 device inserted, SCSI ID = %x", scsi_id->ud->id);

      /*
       * Create our command orb pool
       */
      if (sbp2util_create_command_orb_pool(scsi_id)) {
            SBP2_ERR("sbp2util_create_command_orb_pool failed!");
            sbp2_remove_device(scsi_id);
            return -ENOMEM;
      }

      /* Schedule a timeout here. The reason is that we may be so close
       * to a bus reset, that the device is not available for logins.
       * This can happen when the bus reset is caused by the host
       * connected to the sbp2 device being removed. That host would
       * have a certain amount of time to relogin before the sbp2 device
       * allows someone else to login instead. One second makes sense. */
      msleep_interruptible(1000);
      if (signal_pending(current)) {
            sbp2_remove_device(scsi_id);
            return -EINTR;
      }

      /*
       * Login to the sbp-2 device
       */
      if (sbp2_login_device(scsi_id)) {
            /* Login failed, just remove the device. */
            sbp2_remove_device(scsi_id);
            return -EBUSY;
      }

      /*
       * Set max retries to something large on the device
       */
      sbp2_set_busy_timeout(scsi_id);

      /*
       * Do a SBP-2 fetch agent reset
       */
      sbp2_agent_reset(scsi_id, 1);

      /*
       * Get the max speed and packet size that we can use
       */
      sbp2_max_speed_and_size(scsi_id);

      /* Add this device to the scsi layer now */
      error = scsi_add_device(scsi_id->scsi_host, 0, scsi_id->ud->id, 0);
      if (error) {
            SBP2_ERR("scsi_add_device failed");
            sbp2_logout_device(scsi_id);
            sbp2_remove_device(scsi_id);
            return error;
      }

      return 0;

alloc_fail:
      SBP2_ERR("Could not allocate memory for scsi_id");
      sbp2_remove_device(scsi_id);
      return -ENOMEM;
}

/*
 * This function removes an sbp2 device from the sbp2scsi_host_info struct.
 */
static void sbp2_remove_device(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi;

      SBP2_DEBUG_ENTER();

      if (!scsi_id)
            return;

      hi = scsi_id->hi;

      /* This will remove our scsi device aswell */
      if (scsi_id->scsi_host) {
            scsi_remove_host(scsi_id->scsi_host);
            scsi_host_put(scsi_id->scsi_host);
      }

      sbp2util_remove_command_orb_pool(scsi_id);

      list_del(&scsi_id->scsi_list);

      if (scsi_id->login_response) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_login_response),
                            scsi_id->login_response,
                            scsi_id->login_response_dma);
            SBP2_DMA_FREE("single login FIFO");
      }

      if (scsi_id->login_orb) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_login_orb),
                            scsi_id->login_orb,
                            scsi_id->login_orb_dma);
            SBP2_DMA_FREE("single login ORB");
      }

      if (scsi_id->reconnect_orb) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_reconnect_orb),
                            scsi_id->reconnect_orb,
                            scsi_id->reconnect_orb_dma);
            SBP2_DMA_FREE("single reconnect orb");
      }

      if (scsi_id->logout_orb) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_logout_orb),
                            scsi_id->logout_orb,
                            scsi_id->logout_orb_dma);
            SBP2_DMA_FREE("single logout orb");
      }

      if (scsi_id->query_logins_orb) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_query_logins_orb),
                            scsi_id->query_logins_orb,
                            scsi_id->query_logins_orb_dma);
            SBP2_DMA_FREE("single query logins orb");
      }

      if (scsi_id->query_logins_response) {
            pci_free_consistent(hi->host->pdev,
                            sizeof(struct sbp2_query_logins_response),
                            scsi_id->query_logins_response,
                            scsi_id->query_logins_response_dma);
            SBP2_DMA_FREE("single query logins data");
      }

      if (scsi_id->status_fifo_addr != CSR1212_INVALID_ADDR_SPACE)
            hpsb_unregister_addrspace(&sbp2_highlevel, hi->host,
                                scsi_id->status_fifo_addr);

      scsi_id->ud->device.driver_data = NULL;

      if (hi)
            module_put(hi->host->driver->owner);

      SBP2_DEBUG("SBP-2 device removed, SCSI ID = %d", scsi_id->ud->id);

      kfree(scsi_id);
}

#ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
/*
 * This function deals with physical dma write requests (for adapters that do not support
 * physical dma in hardware). Mostly just here for debugging...
 */
static int sbp2_handle_physdma_write(struct hpsb_host *host, int nodeid,
                             int destid, quadlet_t *data, u64 addr,
                             size_t length, u16 flags)
{

      /*
       * Manually put the data in the right place.
       */
      memcpy(bus_to_virt((u32) addr), data, length);
      sbp2util_packet_dump(data, length, "sbp2 phys dma write by device",
                       (u32) addr);
      return RCODE_COMPLETE;
}

/*
 * This function deals with physical dma read requests (for adapters that do not support
 * physical dma in hardware). Mostly just here for debugging...
 */
static int sbp2_handle_physdma_read(struct hpsb_host *host, int nodeid,
                            quadlet_t *data, u64 addr, size_t length,
                            u16 flags)
{

      /*
       * Grab data from memory and send a read response.
       */
      memcpy(data, bus_to_virt((u32) addr), length);
      sbp2util_packet_dump(data, length, "sbp2 phys dma read by device",
                       (u32) addr);
      return RCODE_COMPLETE;
}
#endif

/**************************************
 * SBP-2 protocol related section
 **************************************/

/*
 * This function queries the device for the maximum concurrent logins it
 * supports.
 */
static int sbp2_query_logins(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      quadlet_t data[2];
      int max_logins;
      int active_logins;

      SBP2_DEBUG_ENTER();

      scsi_id->query_logins_orb->reserved1 = 0x0;
      scsi_id->query_logins_orb->reserved2 = 0x0;

      scsi_id->query_logins_orb->query_response_lo = scsi_id->query_logins_response_dma;
      scsi_id->query_logins_orb->query_response_hi = ORB_SET_NODE_ID(hi->host->node_id);

      scsi_id->query_logins_orb->lun_misc = ORB_SET_FUNCTION(SBP2_QUERY_LOGINS_REQUEST);
      scsi_id->query_logins_orb->lun_misc |= ORB_SET_NOTIFY(1);
      scsi_id->query_logins_orb->lun_misc |= ORB_SET_LUN(scsi_id->sbp2_lun);

      scsi_id->query_logins_orb->reserved_resp_length =
            ORB_SET_QUERY_LOGINS_RESP_LENGTH(sizeof(struct sbp2_query_logins_response));

      scsi_id->query_logins_orb->status_fifo_hi =
            ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
      scsi_id->query_logins_orb->status_fifo_lo =
            ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

      sbp2util_cpu_to_be32_buffer(scsi_id->query_logins_orb, sizeof(struct sbp2_query_logins_orb));

      sbp2util_packet_dump(scsi_id->query_logins_orb, sizeof(struct sbp2_query_logins_orb),
                       "sbp2 query logins orb", scsi_id->query_logins_orb_dma);

      memset(scsi_id->query_logins_response, 0, sizeof(struct sbp2_query_logins_response));
      memset(&scsi_id->status_block, 0, sizeof(struct sbp2_status_block));

      data[0] = ORB_SET_NODE_ID(hi->host->node_id);
      data[1] = scsi_id->query_logins_orb_dma;
      sbp2util_cpu_to_be32_buffer(data, 8);

      atomic_set(&scsi_id->sbp2_login_complete, 0);

      hpsb_node_write(scsi_id->ne, scsi_id->sbp2_management_agent_addr, data, 8);

      if (sbp2util_down_timeout(&scsi_id->sbp2_login_complete, 2*HZ)) {
            SBP2_INFO("Error querying logins to SBP-2 device - timed out");
            return -EIO;
      }

      if (scsi_id->status_block.ORB_offset_lo != scsi_id->query_logins_orb_dma) {
            SBP2_INFO("Error querying logins to SBP-2 device - timed out");
            return -EIO;
      }

      if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {

            SBP2_INFO("Error querying logins to SBP-2 device - timed out");
            return -EIO;
      }

      sbp2util_cpu_to_be32_buffer(scsi_id->query_logins_response, sizeof(struct sbp2_query_logins_response));

      SBP2_DEBUG("length_max_logins = %x",
               (unsigned int)scsi_id->query_logins_response->length_max_logins);

      max_logins = RESPONSE_GET_MAX_LOGINS(scsi_id->query_logins_response->length_max_logins);
      SBP2_INFO("Maximum concurrent logins supported: %d", max_logins);

      active_logins = RESPONSE_GET_ACTIVE_LOGINS(scsi_id->query_logins_response->length_max_logins);
      SBP2_INFO("Number of active logins: %d", active_logins);

      if (active_logins >= max_logins) {
            return -EIO;
      }

      return 0;
}

/*
 * This function is called in order to login to a particular SBP-2 device,
 * after a bus reset.
 */
static int sbp2_login_device(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      quadlet_t data[2];

      SBP2_DEBUG_ENTER();

      if (!scsi_id->login_orb) {
            SBP2_DEBUG("%s: login_orb not alloc'd!", __FUNCTION__);
            return -EIO;
      }

      if (!exclusive_login) {
            if (sbp2_query_logins(scsi_id)) {
                  SBP2_INFO("Device does not support any more concurrent logins");
                  return -EIO;
            }
      }

      /* Set-up login ORB, assume no password */
      scsi_id->login_orb->password_hi = 0;
      scsi_id->login_orb->password_lo = 0;

      scsi_id->login_orb->login_response_lo = scsi_id->login_response_dma;
      scsi_id->login_orb->login_response_hi = ORB_SET_NODE_ID(hi->host->node_id);

      scsi_id->login_orb->lun_misc = ORB_SET_FUNCTION(SBP2_LOGIN_REQUEST);
      scsi_id->login_orb->lun_misc |= ORB_SET_RECONNECT(0); /* One second reconnect time */
      scsi_id->login_orb->lun_misc |= ORB_SET_EXCLUSIVE(exclusive_login);     /* Exclusive access to device */
      scsi_id->login_orb->lun_misc |= ORB_SET_NOTIFY(1);    /* Notify us of login complete */
      scsi_id->login_orb->lun_misc |= ORB_SET_LUN(scsi_id->sbp2_lun);

      scsi_id->login_orb->passwd_resp_lengths =
            ORB_SET_LOGIN_RESP_LENGTH(sizeof(struct sbp2_login_response));

      scsi_id->login_orb->status_fifo_hi =
            ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
      scsi_id->login_orb->status_fifo_lo =
            ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

      sbp2util_cpu_to_be32_buffer(scsi_id->login_orb, sizeof(struct sbp2_login_orb));

      sbp2util_packet_dump(scsi_id->login_orb, sizeof(struct sbp2_login_orb),
                       "sbp2 login orb", scsi_id->login_orb_dma);

      memset(scsi_id->login_response, 0, sizeof(struct sbp2_login_response));
      memset(&scsi_id->status_block, 0, sizeof(struct sbp2_status_block));

      data[0] = ORB_SET_NODE_ID(hi->host->node_id);
      data[1] = scsi_id->login_orb_dma;
      sbp2util_cpu_to_be32_buffer(data, 8);

      atomic_set(&scsi_id->sbp2_login_complete, 0);

      hpsb_node_write(scsi_id->ne, scsi_id->sbp2_management_agent_addr, data, 8);

      /*
       * Wait for login status (up to 20 seconds)...
       */
      if (sbp2util_down_timeout(&scsi_id->sbp2_login_complete, 20*HZ)) {
            SBP2_ERR("Error logging into SBP-2 device - login timed-out");
            return -EIO;
      }

      /*
       * Sanity. Make sure status returned matches login orb.
       */
      if (scsi_id->status_block.ORB_offset_lo != scsi_id->login_orb_dma) {
            SBP2_ERR("Error logging into SBP-2 device - login timed-out");
            return -EIO;
      }

      /*
       * Check status
       */
      if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {

            SBP2_ERR("Error logging into SBP-2 device - login failed");
            return -EIO;
      }

      /*
       * Byte swap the login response, for use when reconnecting or
       * logging out.
       */
      sbp2util_cpu_to_be32_buffer(scsi_id->login_response, sizeof(struct sbp2_login_response));

      /*
       * Grab our command block agent address from the login response.
       */
      SBP2_DEBUG("command_block_agent_hi = %x",
               (unsigned int)scsi_id->login_response->command_block_agent_hi);
      SBP2_DEBUG("command_block_agent_lo = %x",
               (unsigned int)scsi_id->login_response->command_block_agent_lo);

      scsi_id->sbp2_command_block_agent_addr =
            ((u64)scsi_id->login_response->command_block_agent_hi) << 32;
      scsi_id->sbp2_command_block_agent_addr |= ((u64)scsi_id->login_response->command_block_agent_lo);
      scsi_id->sbp2_command_block_agent_addr &= 0x0000ffffffffffffULL;

      SBP2_INFO("Logged into SBP-2 device");

      return 0;

}

/*
 * This function is called in order to logout from a particular SBP-2
 * device, usually called during driver unload.
 */
static int sbp2_logout_device(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      quadlet_t data[2];
      int error;

      SBP2_DEBUG_ENTER();

      /*
       * Set-up logout ORB
       */
      scsi_id->logout_orb->reserved1 = 0x0;
      scsi_id->logout_orb->reserved2 = 0x0;
      scsi_id->logout_orb->reserved3 = 0x0;
      scsi_id->logout_orb->reserved4 = 0x0;

      scsi_id->logout_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_LOGOUT_REQUEST);
      scsi_id->logout_orb->login_ID_misc |= ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID);

      /* Notify us when complete */
      scsi_id->logout_orb->login_ID_misc |= ORB_SET_NOTIFY(1);

      scsi_id->logout_orb->reserved5 = 0x0;
      scsi_id->logout_orb->status_fifo_hi =
            ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
      scsi_id->logout_orb->status_fifo_lo =
            ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

      /*
       * Byte swap ORB if necessary
       */
      sbp2util_cpu_to_be32_buffer(scsi_id->logout_orb, sizeof(struct sbp2_logout_orb));

      sbp2util_packet_dump(scsi_id->logout_orb, sizeof(struct sbp2_logout_orb),
                       "sbp2 logout orb", scsi_id->logout_orb_dma);

      /*
       * Ok, let's write to the target's management agent register
       */
      data[0] = ORB_SET_NODE_ID(hi->host->node_id);
      data[1] = scsi_id->logout_orb_dma;
      sbp2util_cpu_to_be32_buffer(data, 8);

      atomic_set(&scsi_id->sbp2_login_complete, 0);

      error = hpsb_node_write(scsi_id->ne,
                        scsi_id->sbp2_management_agent_addr, data, 8);
      if (error)
            return error;

      /* Wait for device to logout...1 second. */
      if (sbp2util_down_timeout(&scsi_id->sbp2_login_complete, HZ))
            return -EIO;

      SBP2_INFO("Logged out of SBP-2 device");

      return 0;

}

/*
 * This function is called in order to reconnect to a particular SBP-2
 * device, after a bus reset.
 */
static int sbp2_reconnect_device(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      quadlet_t data[2];
      int error;

      SBP2_DEBUG_ENTER();

      /*
       * Set-up reconnect ORB
       */
      scsi_id->reconnect_orb->reserved1 = 0x0;
      scsi_id->reconnect_orb->reserved2 = 0x0;
      scsi_id->reconnect_orb->reserved3 = 0x0;
      scsi_id->reconnect_orb->reserved4 = 0x0;

      scsi_id->reconnect_orb->login_ID_misc = ORB_SET_FUNCTION(SBP2_RECONNECT_REQUEST);
      scsi_id->reconnect_orb->login_ID_misc |=
            ORB_SET_LOGIN_ID(scsi_id->login_response->length_login_ID);

      /* Notify us when complete */
      scsi_id->reconnect_orb->login_ID_misc |= ORB_SET_NOTIFY(1);

      scsi_id->reconnect_orb->reserved5 = 0x0;
      scsi_id->reconnect_orb->status_fifo_hi =
            ORB_SET_STATUS_FIFO_HI(scsi_id->status_fifo_addr, hi->host->node_id);
      scsi_id->reconnect_orb->status_fifo_lo =
            ORB_SET_STATUS_FIFO_LO(scsi_id->status_fifo_addr);

      /*
       * Byte swap ORB if necessary
       */
      sbp2util_cpu_to_be32_buffer(scsi_id->reconnect_orb, sizeof(struct sbp2_reconnect_orb));

      sbp2util_packet_dump(scsi_id->reconnect_orb, sizeof(struct sbp2_reconnect_orb),
                       "sbp2 reconnect orb", scsi_id->reconnect_orb_dma);

      /*
       * Initialize status fifo
       */
      memset(&scsi_id->status_block, 0, sizeof(struct sbp2_status_block));

      /*
       * Ok, let's write to the target's management agent register
       */
      data[0] = ORB_SET_NODE_ID(hi->host->node_id);
      data[1] = scsi_id->reconnect_orb_dma;
      sbp2util_cpu_to_be32_buffer(data, 8);

      atomic_set(&scsi_id->sbp2_login_complete, 0);

      error = hpsb_node_write(scsi_id->ne,
                        scsi_id->sbp2_management_agent_addr, data, 8);
      if (error)
            return error;

      /*
       * Wait for reconnect status (up to 1 second)...
       */
      if (sbp2util_down_timeout(&scsi_id->sbp2_login_complete, HZ)) {
            SBP2_ERR("Error reconnecting to SBP-2 device - reconnect timed-out");
            return -EIO;
      }

      /*
       * Sanity. Make sure status returned matches reconnect orb.
       */
      if (scsi_id->status_block.ORB_offset_lo != scsi_id->reconnect_orb_dma) {
            SBP2_ERR("Error reconnecting to SBP-2 device - reconnect timed-out");
            return -EIO;
      }

      /*
       * Check status
       */
      if (STATUS_GET_RESP(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc) ||
          STATUS_GET_SBP_STATUS(scsi_id->status_block.ORB_offset_hi_misc)) {

            SBP2_ERR("Error reconnecting to SBP-2 device - reconnect failed");
            return -EIO;
      }

      HPSB_DEBUG("Reconnected to SBP-2 device");

      return 0;

}

/*
 * This function is called in order to set the busy timeout (number of
 * retries to attempt) on the sbp2 device.
 */
static int sbp2_set_busy_timeout(struct scsi_id_instance_data *scsi_id)
{
      quadlet_t data;

      SBP2_DEBUG_ENTER();

      data = cpu_to_be32(SBP2_BUSY_TIMEOUT_VALUE);
      if (hpsb_node_write(scsi_id->ne, SBP2_BUSY_TIMEOUT_ADDRESS, &data, 4))
            SBP2_ERR("%s error", __FUNCTION__);
      return 0;
}

/*
 * This function is called to parse sbp2 device's config rom unit
 * directory. Used to determine things like sbp2 management agent offset,
 * and command set used (SCSI or RBC).
 */
static void sbp2_parse_unit_directory(struct scsi_id_instance_data *scsi_id,
                              struct unit_directory *ud)
{
      struct csr1212_keyval *kv;
      struct csr1212_dentry *dentry;
      u64 management_agent_addr;
      u32 command_set_spec_id, command_set, unit_characteristics,
          firmware_revision;
      unsigned workarounds;
      int i;

      SBP2_DEBUG_ENTER();

      management_agent_addr = 0x0;
      command_set_spec_id = 0x0;
      command_set = 0x0;
      unit_characteristics = 0x0;
      firmware_revision = 0x0;

      /* Handle different fields in the unit directory, based on keys */
      csr1212_for_each_dir_entry(ud->ne->csr, kv, ud->ud_kv, dentry) {
            switch (kv->key.id) {
            case CSR1212_KV_ID_DEPENDENT_INFO:
                  if (kv->key.type == CSR1212_KV_TYPE_CSR_OFFSET) {
                        /* Save off the management agent address */
                        management_agent_addr =
                            CSR1212_REGISTER_SPACE_BASE +
                            (kv->value.csr_offset << 2);

                        SBP2_DEBUG("sbp2_management_agent_addr = %x",
                                 (unsigned int)management_agent_addr);
                  } else if (kv->key.type == CSR1212_KV_TYPE_IMMEDIATE) {
                        scsi_id->sbp2_lun =
                            ORB_SET_LUN(kv->value.immediate);
                  }
                  break;

            case SBP2_COMMAND_SET_SPEC_ID_KEY:
                  /* Command spec organization */
                  command_set_spec_id = kv->value.immediate;
                  SBP2_DEBUG("sbp2_command_set_spec_id = %x",
                           (unsigned int)command_set_spec_id);
                  break;

            case SBP2_COMMAND_SET_KEY:
                  /* Command set used by sbp2 device */
                  command_set = kv->value.immediate;
                  SBP2_DEBUG("sbp2_command_set = %x",
                           (unsigned int)command_set);
                  break;

            case SBP2_UNIT_CHARACTERISTICS_KEY:
                  /*
                   * Unit characterisitcs (orb related stuff
                   * that I'm not yet paying attention to)
                   */
                  unit_characteristics = kv->value.immediate;
                  SBP2_DEBUG("sbp2_unit_characteristics = %x",
                           (unsigned int)unit_characteristics);
                  break;

            case SBP2_FIRMWARE_REVISION_KEY:
                  /* Firmware revision */
                  firmware_revision = kv->value.immediate;
                  SBP2_DEBUG("sbp2_firmware_revision = %x",
                           (unsigned int)firmware_revision);
                  break;

            default:
                  break;
            }
      }

      workarounds = sbp2_default_workarounds;
      if (force_inquiry_hack) {
            SBP2_WARN("force_inquiry_hack is deprecated. "
                    "Use parameter 'workarounds' instead.");
            workarounds |= SBP2_WORKAROUND_INQUIRY_36;
      }

      if (!(workarounds & SBP2_WORKAROUND_OVERRIDE))
            for (i = 0; i < ARRAY_SIZE(sbp2_workarounds_table); i++) {
                  if (sbp2_workarounds_table[i].firmware_revision &&
                      sbp2_workarounds_table[i].firmware_revision !=
                      (firmware_revision & 0xffff00))
                        continue;
                  if (sbp2_workarounds_table[i].model_id &&
                      sbp2_workarounds_table[i].model_id != ud->model_id)
                        continue;
                  workarounds |= sbp2_workarounds_table[i].workarounds;
                  break;
            }

      if (workarounds)
            SBP2_INFO("Workarounds for node " NODE_BUS_FMT ": 0x%x "
                    "(firmware_revision 0x%06x, vendor_id 0x%06x,"
                    " model_id 0x%06x)",
                    NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
                    workarounds, firmware_revision,
                    ud->vendor_id ? ud->vendor_id : ud->ne->vendor_id,
                    ud->model_id);

      /* We would need one SCSI host template for each target to adjust
       * max_sectors on the fly, therefore warn only. */
      if (workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
          (max_sectors * 512) > (128 * 1024))
            SBP2_WARN("Node " NODE_BUS_FMT ": Bridge only supports 128KB "
                    "max transfer size. WARNING: Current max_sectors "
                    "setting is larger than 128KB (%d sectors)",
                    NODE_BUS_ARGS(ud->ne->host, ud->ne->nodeid),
                    max_sectors);

      /* If this is a logical unit directory entry, process the parent
       * to get the values. */
      if (ud->flags & UNIT_DIRECTORY_LUN_DIRECTORY) {
            struct unit_directory *parent_ud =
                  container_of(ud->device.parent, struct unit_directory, device);
            sbp2_parse_unit_directory(scsi_id, parent_ud);
      } else {
            scsi_id->sbp2_management_agent_addr = management_agent_addr;
            scsi_id->sbp2_command_set_spec_id = command_set_spec_id;
            scsi_id->sbp2_command_set = command_set;
            scsi_id->sbp2_unit_characteristics = unit_characteristics;
            scsi_id->sbp2_firmware_revision = firmware_revision;
            scsi_id->workarounds = workarounds;
            if (ud->flags & UNIT_DIRECTORY_HAS_LUN)
                  scsi_id->sbp2_lun = ORB_SET_LUN(ud->lun);
      }
}

#define SBP2_PAYLOAD_TO_BYTES(p) (1 << ((p) + 2))

/*
 * This function is called in order to determine the max speed and packet
 * size we can use in our ORBs. Note, that we (the driver and host) only
 * initiate the transaction. The SBP-2 device actually transfers the data
 * (by reading from the DMA area we tell it). This means that the SBP-2
 * device decides the actual maximum data it can transfer. We just tell it
 * the speed that it needs to use, and the max_rec the host supports, and
 * it takes care of the rest.
 */
static int sbp2_max_speed_and_size(struct scsi_id_instance_data *scsi_id)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      u8 payload;

      SBP2_DEBUG_ENTER();

      scsi_id->speed_code =
          hi->host->speed[NODEID_TO_NODE(scsi_id->ne->nodeid)];

      /* Bump down our speed if the user requested it */
      if (scsi_id->speed_code > max_speed) {
            scsi_id->speed_code = max_speed;
            SBP2_ERR("Forcing SBP-2 max speed down to %s",
                   hpsb_speedto_str[scsi_id->speed_code]);
      }

      /* Payload size is the lesser of what our speed supports and what
       * our host supports.  */
      payload = min(sbp2_speedto_max_payload[scsi_id->speed_code],
                  (u8) (hi->host->csr.max_rec - 1));

      /* If physical DMA is off, work around limitation in ohci1394:
       * packet size must not exceed PAGE_SIZE */
      if (scsi_id->ne->host->low_addr_space < (1ULL << 32))
            while (SBP2_PAYLOAD_TO_BYTES(payload) + 24 > PAGE_SIZE &&
                   payload)
                  payload--;

      HPSB_DEBUG("Node " NODE_BUS_FMT ": Max speed [%s] - Max payload [%u]",
               NODE_BUS_ARGS(hi->host, scsi_id->ne->nodeid),
               hpsb_speedto_str[scsi_id->speed_code],
               SBP2_PAYLOAD_TO_BYTES(payload));

      scsi_id->max_payload_size = payload;
      return 0;
}

/*
 * This function is called in order to perform a SBP-2 agent reset.
 */
static int sbp2_agent_reset(struct scsi_id_instance_data *scsi_id, int wait)
{
      quadlet_t data;
      u64 addr;
      int retval;

      SBP2_DEBUG_ENTER();

      data = ntohl(SBP2_AGENT_RESET_DATA);
      addr = scsi_id->sbp2_command_block_agent_addr + SBP2_AGENT_RESET_OFFSET;

      if (wait)
            retval = hpsb_node_write(scsi_id->ne, addr, &data, 4);
      else
            retval = sbp2util_node_write_no_wait(scsi_id->ne, addr, &data, 4);

      if (retval < 0) {
            SBP2_ERR("hpsb_node_write failed.\n");
            return -EIO;
      }

      /*
       * Need to make sure orb pointer is written on next command
       */
      scsi_id->last_orb = NULL;

      return 0;
}

static void sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
                             struct sbp2scsi_host_info *hi,
                             struct sbp2_command_info *command,
                             unsigned int scsi_use_sg,
                             struct scatterlist *sgpnt,
                             u32 orb_direction,
                             enum dma_data_direction dma_dir)
{
      command->dma_dir = dma_dir;
      orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
      orb->misc |= ORB_SET_DIRECTION(orb_direction);

      /* Special case if only one element (and less than 64KB in size) */
      if ((scsi_use_sg == 1) &&
          (sgpnt[0].length <= SBP2_MAX_SG_ELEMENT_LENGTH)) {

            SBP2_DEBUG("Only one s/g element");
            command->dma_size = sgpnt[0].length;
            command->dma_type = CMD_DMA_PAGE;
            command->cmd_dma = pci_map_page(hi->host->pdev,
                                    sgpnt[0].page,
                                    sgpnt[0].offset,
                                    command->dma_size,
                                    command->dma_dir);
            SBP2_DMA_ALLOC("single page scatter element");

            orb->data_descriptor_lo = command->cmd_dma;
            orb->misc |= ORB_SET_DATA_SIZE(command->dma_size);

      } else {
            struct sbp2_unrestricted_page_table *sg_element =
                              &command->scatter_gather_element[0];
            u32 sg_count, sg_len;
            dma_addr_t sg_addr;
            int i, count = pci_map_sg(hi->host->pdev, sgpnt, scsi_use_sg,
                                dma_dir);

            SBP2_DMA_ALLOC("scatter list");

            command->dma_size = scsi_use_sg;
            command->sge_buffer = sgpnt;

            /* use page tables (s/g) */
            orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
            orb->data_descriptor_lo = command->sge_dma;

            /*
             * Loop through and fill out our sbp-2 page tables
             * (and split up anything too large)
             */
            for (i = 0, sg_count = 0 ; i < count; i++, sgpnt++) {
                  sg_len = sg_dma_len(sgpnt);
                  sg_addr = sg_dma_address(sgpnt);
                  while (sg_len) {
                        sg_element[sg_count].segment_base_lo = sg_addr;
                        if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
                              sg_element[sg_count].length_segment_base_hi =
                                    PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
                              sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
                              sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
                        } else {
                              sg_element[sg_count].length_segment_base_hi =
                                    PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
                              sg_len = 0;
                        }
                        sg_count++;
                  }
            }

            /* Number of page table (s/g) elements */
            orb->misc |= ORB_SET_DATA_SIZE(sg_count);

            sbp2util_packet_dump(sg_element,
                             (sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
                             "sbp2 s/g list", command->sge_dma);

            /* Byte swap page tables if necessary */
            sbp2util_cpu_to_be32_buffer(sg_element,
                                  (sizeof(struct sbp2_unrestricted_page_table)) *
                                  sg_count);
      }
}

static void sbp2_prep_command_orb_no_sg(struct sbp2_command_orb *orb,
                              struct sbp2scsi_host_info *hi,
                              struct sbp2_command_info *command,
                              struct scatterlist *sgpnt,
                              u32 orb_direction,
                              unsigned int scsi_request_bufflen,
                              void *scsi_request_buffer,
                              enum dma_data_direction dma_dir)
{
      command->dma_dir = dma_dir;
      command->dma_size = scsi_request_bufflen;
      command->dma_type = CMD_DMA_SINGLE;
      command->cmd_dma = pci_map_single(hi->host->pdev, scsi_request_buffer,
                                command->dma_size, command->dma_dir);
      orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
      orb->misc |= ORB_SET_DIRECTION(orb_direction);

      SBP2_DMA_ALLOC("single bulk");

      /*
       * Handle case where we get a command w/o s/g enabled (but
       * check for transfers larger than 64K)
       */
      if (scsi_request_bufflen <= SBP2_MAX_SG_ELEMENT_LENGTH) {

            orb->data_descriptor_lo = command->cmd_dma;
            orb->misc |= ORB_SET_DATA_SIZE(scsi_request_bufflen);

      } else {
            struct sbp2_unrestricted_page_table *sg_element =
                  &command->scatter_gather_element[0];
            u32 sg_count, sg_len;
            dma_addr_t sg_addr;

            /*
             * Need to turn this into page tables, since the
             * buffer is too large.
             */
            orb->data_descriptor_lo = command->sge_dma;

            /* Use page tables (s/g) */
            orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);

            /*
             * fill out our sbp-2 page tables (and split up
             * the large buffer)
             */
            sg_count = 0;
            sg_len = scsi_request_bufflen;
            sg_addr = command->cmd_dma;
            while (sg_len) {
                  sg_element[sg_count].segment_base_lo = sg_addr;
                  if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
                        sg_element[sg_count].length_segment_base_hi =
                              PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
                        sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
                        sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
                  } else {
                        sg_element[sg_count].length_segment_base_hi =
                              PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
                        sg_len = 0;
                  }
                  sg_count++;
            }

            /* Number of page table (s/g) elements */
            orb->misc |= ORB_SET_DATA_SIZE(sg_count);

            sbp2util_packet_dump(sg_element,
                             (sizeof(struct sbp2_unrestricted_page_table)) * sg_count,
                             "sbp2 s/g list", command->sge_dma);

            /* Byte swap page tables if necessary */
            sbp2util_cpu_to_be32_buffer(sg_element,
                                  (sizeof(struct sbp2_unrestricted_page_table)) *
                                   sg_count);
      }
}

/*
 * This function is called to create the actual command orb and s/g list
 * out of the scsi command itself.
 */
static void sbp2_create_command_orb(struct scsi_id_instance_data *scsi_id,
                            struct sbp2_command_info *command,
                            unchar *scsi_cmd,
                            unsigned int scsi_use_sg,
                            unsigned int scsi_request_bufflen,
                            void *scsi_request_buffer,
                            enum dma_data_direction dma_dir)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      struct scatterlist *sgpnt = (struct scatterlist *)scsi_request_buffer;
      struct sbp2_command_orb *command_orb = &command->command_orb;
      u32 orb_direction;

      /*
       * Set-up our command ORB..
       *
       * NOTE: We're doing unrestricted page tables (s/g), as this is
       * best performance (at least with the devices I have). This means
       * that data_size becomes the number of s/g elements, and
       * page_size should be zero (for unrestricted).
       */
      command_orb->next_ORB_hi = ORB_SET_NULL_PTR(1);
      command_orb->next_ORB_lo = 0x0;
      command_orb->misc = ORB_SET_MAX_PAYLOAD(scsi_id->max_payload_size);
      command_orb->misc |= ORB_SET_SPEED(scsi_id->speed_code);
      command_orb->misc |= ORB_SET_NOTIFY(1);   /* Notify us when complete */

      if (dma_dir == DMA_NONE)
            orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
      else if (dma_dir == DMA_TO_DEVICE && scsi_request_bufflen)
            orb_direction = ORB_DIRECTION_WRITE_TO_MEDIA;
      else if (dma_dir == DMA_FROM_DEVICE && scsi_request_bufflen)
            orb_direction = ORB_DIRECTION_READ_FROM_MEDIA;
      else {
            SBP2_WARN("Falling back to DMA_NONE");
            orb_direction = ORB_DIRECTION_NO_DATA_TRANSFER;
      }

      /* Set-up our pagetable stuff */
      if (orb_direction == ORB_DIRECTION_NO_DATA_TRANSFER) {
            SBP2_DEBUG("No data transfer");
            command_orb->data_descriptor_hi = 0x0;
            command_orb->data_descriptor_lo = 0x0;
            command_orb->misc |= ORB_SET_DIRECTION(1);
      } else if (scsi_use_sg) {
            SBP2_DEBUG("Use scatter/gather");
            sbp2_prep_command_orb_sg(command_orb, hi, command, scsi_use_sg,
                               sgpnt, orb_direction, dma_dir);
      } else {
            SBP2_DEBUG("No scatter/gather");
            sbp2_prep_command_orb_no_sg(command_orb, hi, command, sgpnt,
                                  orb_direction, scsi_request_bufflen,
                                  scsi_request_buffer, dma_dir);
      }

      /* Byte swap command ORB if necessary */
      sbp2util_cpu_to_be32_buffer(command_orb, sizeof(struct sbp2_command_orb));

      /* Put our scsi command in the command ORB */
      memset(command_orb->cdb, 0, 12);
      memcpy(command_orb->cdb, scsi_cmd, COMMAND_SIZE(*scsi_cmd));
}

/*
 * This function is called in order to begin a regular SBP-2 command.
 */
static int sbp2_link_orb_command(struct scsi_id_instance_data *scsi_id,
                         struct sbp2_command_info *command)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      struct sbp2_command_orb *command_orb = &command->command_orb;
      struct node_entry *ne = scsi_id->ne;
      u64 addr;

      outstanding_orb_incr;
      SBP2_ORB_DEBUG("sending command orb %p, total orbs = %x",
                   command_orb, global_outstanding_command_orbs);

      pci_dma_sync_single_for_device(hi->host->pdev, command->command_orb_dma,
                               sizeof(struct sbp2_command_orb),
                               PCI_DMA_BIDIRECTIONAL);
      pci_dma_sync_single_for_device(hi->host->pdev, command->sge_dma,
                               sizeof(command->scatter_gather_element),
                               PCI_DMA_BIDIRECTIONAL);
      /*
       * Check to see if there are any previous orbs to use
       */
      if (scsi_id->last_orb == NULL) {
            quadlet_t data[2];

            /*
             * Ok, let's write to the target's management agent register
             */
            addr = scsi_id->sbp2_command_block_agent_addr + SBP2_ORB_POINTER_OFFSET;
            data[0] = ORB_SET_NODE_ID(hi->host->node_id);
            data[1] = command->command_orb_dma;
            sbp2util_cpu_to_be32_buffer(data, 8);

            SBP2_ORB_DEBUG("write command agent, command orb %p", command_orb);

            if (sbp2util_node_write_no_wait(ne, addr, data, 8) < 0) {
                  SBP2_ERR("sbp2util_node_write_no_wait failed.\n");
                  return -EIO;
            }

            SBP2_ORB_DEBUG("write command agent complete");

            scsi_id->last_orb = command_orb;
            scsi_id->last_orb_dma = command->command_orb_dma;

      } else {
            quadlet_t data;

            /*
             * We have an orb already sent (maybe or maybe not
             * processed) that we can append this orb to. So do so,
             * and ring the doorbell. Have to be very careful
             * modifying these next orb pointers, as they are accessed
             * both by the sbp2 device and us.
             */
            scsi_id->last_orb->next_ORB_lo =
                cpu_to_be32(command->command_orb_dma);
            /* Tells hardware that this pointer is valid */
            scsi_id->last_orb->next_ORB_hi = 0x0;
            pci_dma_sync_single_for_device(hi->host->pdev,
                                     scsi_id->last_orb_dma,
                                     sizeof(struct sbp2_command_orb),
                                     PCI_DMA_BIDIRECTIONAL);

            /*
             * Ring the doorbell
             */
            data = cpu_to_be32(command->command_orb_dma);
            addr = scsi_id->sbp2_command_block_agent_addr + SBP2_DOORBELL_OFFSET;

            SBP2_ORB_DEBUG("ring doorbell, command orb %p", command_orb);

            if (sbp2util_node_write_no_wait(ne, addr, &data, 4) < 0) {
                  SBP2_ERR("sbp2util_node_write_no_wait failed");
                  return -EIO;
            }

            scsi_id->last_orb = command_orb;
            scsi_id->last_orb_dma = command->command_orb_dma;

      }
      return 0;
}

/*
 * This function is called in order to begin a regular SBP-2 command.
 */
static int sbp2_send_command(struct scsi_id_instance_data *scsi_id,
                       struct scsi_cmnd *SCpnt,
                       void (*done)(struct scsi_cmnd *))
{
      unchar *cmd = (unchar *) SCpnt->cmnd;
      unsigned int request_bufflen = SCpnt->request_bufflen;
      struct sbp2_command_info *command;

      SBP2_DEBUG_ENTER();
      SBP2_DEBUG("SCSI transfer size = %x", request_bufflen);
      SBP2_DEBUG("SCSI s/g elements = %x", (unsigned int)SCpnt->use_sg);

      /*
       * Allocate a command orb and s/g structure
       */
      command = sbp2util_allocate_command_orb(scsi_id, SCpnt, done);
      if (!command) {
            return -EIO;
      }

      /*
       * Now actually fill in the comamnd orb and sbp2 s/g list
       */
      sbp2_create_command_orb(scsi_id, command, cmd, SCpnt->use_sg,
                        request_bufflen, SCpnt->request_buffer,
                        SCpnt->sc_data_direction);

      sbp2util_packet_dump(&command->command_orb, sizeof(struct sbp2_command_orb),
                       "sbp2 command orb", command->command_orb_dma);

      /*
       * Initialize status fifo
       */
      memset(&scsi_id->status_block, 0, sizeof(struct sbp2_status_block));

      /*
       * Link up the orb, and ring the doorbell if needed
       */
      sbp2_link_orb_command(scsi_id, command);

      return 0;
}

/*
 * Translates SBP-2 status into SCSI sense data for check conditions
 */
static unsigned int sbp2_status_to_sense_data(unchar *sbp2_status, unchar *sense_data)
{
      SBP2_DEBUG_ENTER();

      /*
       * Ok, it's pretty ugly...   ;-)
       */
      sense_data[0] = 0x70;
      sense_data[1] = 0x0;
      sense_data[2] = sbp2_status[9];
      sense_data[3] = sbp2_status[12];
      sense_data[4] = sbp2_status[13];
      sense_data[5] = sbp2_status[14];
      sense_data[6] = sbp2_status[15];
      sense_data[7] = 10;
      sense_data[8] = sbp2_status[16];
      sense_data[9] = sbp2_status[17];
      sense_data[10] = sbp2_status[18];
      sense_data[11] = sbp2_status[19];
      sense_data[12] = sbp2_status[10];
      sense_data[13] = sbp2_status[11];
      sense_data[14] = sbp2_status[20];
      sense_data[15] = sbp2_status[21];

      return sbp2_status[8] & 0x3f; /* return scsi status */
}

/*
 * This function deals with status writes from the SBP-2 device
 */
static int sbp2_handle_status_write(struct hpsb_host *host, int nodeid, int destid,
                            quadlet_t *data, u64 addr, size_t length, u16 fl)
{
      struct sbp2scsi_host_info *hi;
      struct scsi_id_instance_data *scsi_id = NULL, *scsi_id_tmp;
      struct scsi_cmnd *SCpnt = NULL;
      u32 scsi_status = SBP2_SCSI_STATUS_GOOD;
      struct sbp2_command_info *command;
      unsigned long flags;

      SBP2_DEBUG_ENTER();

      sbp2util_packet_dump(data, length, "sbp2 status write by device", (u32)addr);

      if (!host) {
            SBP2_ERR("host is NULL - this is bad!");
            return RCODE_ADDRESS_ERROR;
      }

      hi = hpsb_get_hostinfo(&sbp2_highlevel, host);

      if (!hi) {
            SBP2_ERR("host info is NULL - this is bad!");
            return RCODE_ADDRESS_ERROR;
      }

      /*
       * Find our scsi_id structure by looking at the status fifo address
       * written to by the sbp2 device.
       */
      list_for_each_entry(scsi_id_tmp, &hi->scsi_ids, scsi_list) {
            if (scsi_id_tmp->ne->nodeid == nodeid &&
                scsi_id_tmp->status_fifo_addr == addr) {
                  scsi_id = scsi_id_tmp;
                  break;
            }
      }

      if (!scsi_id) {
            SBP2_ERR("scsi_id is NULL - device is gone?");
            return RCODE_ADDRESS_ERROR;
      }

      /*
       * Put response into scsi_id status fifo...
       */
      memcpy(&scsi_id->status_block, data, length);

      /*
       * Byte swap first two quadlets (8 bytes) of status for processing
       */
      sbp2util_be32_to_cpu_buffer(&scsi_id->status_block, 8);

      /*
       * Handle command ORB status here if necessary. First, need to match status with command.
       */
      command = sbp2util_find_command_for_orb(scsi_id, scsi_id->status_block.ORB_offset_lo);
      if (command) {

            SBP2_DEBUG("Found status for command ORB");
            pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                  sizeof(struct sbp2_command_orb),
                                  PCI_DMA_BIDIRECTIONAL);
            pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                  sizeof(command->scatter_gather_element),
                                  PCI_DMA_BIDIRECTIONAL);

            SBP2_ORB_DEBUG("matched command orb %p", &command->command_orb);
            outstanding_orb_decr;

            /*
             * Matched status with command, now grab scsi command pointers and check status
             */
            SCpnt = command->Current_SCpnt;
            spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
            sbp2util_mark_command_completed(scsi_id, command);
            spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

            if (SCpnt) {

                  /*
                   * See if the target stored any scsi status information
                   */
                  if (STATUS_GET_LENGTH(scsi_id->status_block.ORB_offset_hi_misc) > 1) {
                        /*
                         * Translate SBP-2 status to SCSI sense data
                         */
                        SBP2_DEBUG("CHECK CONDITION");
                        scsi_status = sbp2_status_to_sense_data((unchar *)&scsi_id->status_block, SCpnt->sense_buffer);
                  }

                  /*
                   * Check to see if the dead bit is set. If so, we'll have to initiate
                   * a fetch agent reset.
                   */
                  if (STATUS_GET_DEAD_BIT(scsi_id->status_block.ORB_offset_hi_misc)) {

                        /*
                         * Initiate a fetch agent reset.
                         */
                        SBP2_DEBUG("Dead bit set - initiating fetch agent reset");
                                sbp2_agent_reset(scsi_id, 0);
                  }

                  SBP2_ORB_DEBUG("completing command orb %p", &command->command_orb);
            }

            /*
             * Check here to see if there are no commands in-use. If there are none, we can
             * null out last orb so that next time around we write directly to the orb pointer...
             * Quick start saves one 1394 bus transaction.
             */
            spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
            if (list_empty(&scsi_id->sbp2_command_orb_inuse)) {
                  scsi_id->last_orb = NULL;
            }
            spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

      } else {

            /*
             * It's probably a login/logout/reconnect status.
             */
            if ((scsi_id->login_orb_dma == scsi_id->status_block.ORB_offset_lo) ||
                (scsi_id->query_logins_orb_dma == scsi_id->status_block.ORB_offset_lo) ||
                (scsi_id->reconnect_orb_dma == scsi_id->status_block.ORB_offset_lo) ||
                (scsi_id->logout_orb_dma == scsi_id->status_block.ORB_offset_lo)) {
                  atomic_set(&scsi_id->sbp2_login_complete, 1);
            }
      }

      if (SCpnt) {

            /* Complete the SCSI command. */
            SBP2_DEBUG("Completing SCSI command");
            sbp2scsi_complete_command(scsi_id, scsi_status, SCpnt,
                                command->Current_done);
            SBP2_ORB_DEBUG("command orb completed");
      }

      return RCODE_COMPLETE;
}

/**************************************
 * SCSI interface related section
 **************************************/

/*
 * This routine is the main request entry routine for doing I/O. It is
 * called from the scsi stack directly.
 */
static int sbp2scsi_queuecommand(struct scsi_cmnd *SCpnt,
                         void (*done)(struct scsi_cmnd *))
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
      struct sbp2scsi_host_info *hi;
      int result = DID_NO_CONNECT << 16;

      SBP2_DEBUG_ENTER();
#if (CONFIG_IEEE1394_SBP2_DEBUG >= 2) || defined(CONFIG_IEEE1394_SBP2_PACKET_DUMP)
      scsi_print_command(SCpnt);
#endif

      if (!sbp2util_node_is_available(scsi_id))
            goto done;

      hi = scsi_id->hi;

      if (!hi) {
            SBP2_ERR("sbp2scsi_host_info is NULL - this is bad!");
            goto done;
      }

      /*
       * Until we handle multiple luns, just return selection time-out
       * to any IO directed at non-zero LUNs
       */
      if (SCpnt->device->lun)
            goto done;

      /*
       * Check for request sense command, and handle it here
       * (autorequest sense)
       */
      if (SCpnt->cmnd[0] == REQUEST_SENSE) {
            SBP2_DEBUG("REQUEST_SENSE");
            memcpy(SCpnt->request_buffer, SCpnt->sense_buffer, SCpnt->request_bufflen);
            memset(SCpnt->sense_buffer, 0, sizeof(SCpnt->sense_buffer));
            sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_GOOD, SCpnt, done);
            return 0;
      }

      /*
       * Check to see if we are in the middle of a bus reset.
       */
      if (!hpsb_node_entry_valid(scsi_id->ne)) {
            SBP2_ERR("Bus reset in progress - rejecting command");
            result = DID_BUS_BUSY << 16;
            goto done;
      }

      /*
       * Bidirectional commands are not yet implemented,
       * and unknown transfer direction not handled.
       */
      if (SCpnt->sc_data_direction == DMA_BIDIRECTIONAL) {
            SBP2_ERR("Cannot handle DMA_BIDIRECTIONAL - rejecting command");
            result = DID_ERROR << 16;
            goto done;
      }

      /*
       * Try and send our SCSI command
       */
      if (sbp2_send_command(scsi_id, SCpnt, done)) {
            SBP2_ERR("Error sending SCSI command");
            sbp2scsi_complete_command(scsi_id, SBP2_SCSI_STATUS_SELECTION_TIMEOUT,
                                SCpnt, done);
      }
      return 0;

done:
      SCpnt->result = result;
      done(SCpnt);
      return 0;
}

/*
 * This function is called in order to complete all outstanding SBP-2
 * commands (in case of resets, etc.).
 */
static void sbp2scsi_complete_all_commands(struct scsi_id_instance_data *scsi_id,
                                 u32 status)
{
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      struct list_head *lh;
      struct sbp2_command_info *command;
      unsigned long flags;

      SBP2_DEBUG_ENTER();

      spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
      while (!list_empty(&scsi_id->sbp2_command_orb_inuse)) {
            SBP2_DEBUG("Found pending command to complete");
            lh = scsi_id->sbp2_command_orb_inuse.next;
            command = list_entry(lh, struct sbp2_command_info, list);
            pci_dma_sync_single_for_cpu(hi->host->pdev, command->command_orb_dma,
                                  sizeof(struct sbp2_command_orb),
                                  PCI_DMA_BIDIRECTIONAL);
            pci_dma_sync_single_for_cpu(hi->host->pdev, command->sge_dma,
                                  sizeof(command->scatter_gather_element),
                                  PCI_DMA_BIDIRECTIONAL);
            sbp2util_mark_command_completed(scsi_id, command);
            if (command->Current_SCpnt) {
                  command->Current_SCpnt->result = status << 16;
                  command->Current_done(command->Current_SCpnt);
            }
      }
      spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

      return;
}

/*
 * This function is called in order to complete a regular SBP-2 command.
 *
 * This can be called in interrupt context.
 */
static void sbp2scsi_complete_command(struct scsi_id_instance_data *scsi_id,
                              u32 scsi_status, struct scsi_cmnd *SCpnt,
                              void (*done)(struct scsi_cmnd *))
{
      SBP2_DEBUG_ENTER();

      /*
       * Sanity
       */
      if (!SCpnt) {
            SBP2_ERR("SCpnt is NULL");
            return;
      }

      /*
       * If a bus reset is in progress and there was an error, don't
       * complete the command, just let it get retried at the end of the
       * bus reset.
       */
      if (!hpsb_node_entry_valid(scsi_id->ne)
          && (scsi_status != SBP2_SCSI_STATUS_GOOD)) {
            SBP2_ERR("Bus reset in progress - retry command later");
            return;
      }

      /*
       * Switch on scsi status
       */
      switch (scsi_status) {
      case SBP2_SCSI_STATUS_GOOD:
            SCpnt->result = DID_OK << 16;
            break;

      case SBP2_SCSI_STATUS_BUSY:
            SBP2_ERR("SBP2_SCSI_STATUS_BUSY");
            SCpnt->result = DID_BUS_BUSY << 16;
            break;

      case SBP2_SCSI_STATUS_CHECK_CONDITION:
            SBP2_DEBUG("SBP2_SCSI_STATUS_CHECK_CONDITION");
            SCpnt->result = CHECK_CONDITION << 1 | DID_OK << 16;
#if CONFIG_IEEE1394_SBP2_DEBUG >= 1
            scsi_print_command(SCpnt);
            scsi_print_sense(SBP2_DEVICE_NAME, SCpnt);
#endif
            break;

      case SBP2_SCSI_STATUS_SELECTION_TIMEOUT:
            SBP2_ERR("SBP2_SCSI_STATUS_SELECTION_TIMEOUT");
            SCpnt->result = DID_NO_CONNECT << 16;
            scsi_print_command(SCpnt);
            break;

      case SBP2_SCSI_STATUS_CONDITION_MET:
      case SBP2_SCSI_STATUS_RESERVATION_CONFLICT:
      case SBP2_SCSI_STATUS_COMMAND_TERMINATED:
            SBP2_ERR("Bad SCSI status = %x", scsi_status);
            SCpnt->result = DID_ERROR << 16;
            scsi_print_command(SCpnt);
            break;

      default:
            SBP2_ERR("Unsupported SCSI status = %x", scsi_status);
            SCpnt->result = DID_ERROR << 16;
      }

      /*
       * If a bus reset is in progress and there was an error, complete
       * the command as busy so that it will get retried.
       */
      if (!hpsb_node_entry_valid(scsi_id->ne)
          && (scsi_status != SBP2_SCSI_STATUS_GOOD)) {
            SBP2_ERR("Completing command with busy (bus reset)");
            SCpnt->result = DID_BUS_BUSY << 16;
      }

      /*
       * If a unit attention occurs, return busy status so it gets
       * retried... it could have happened because of a 1394 bus reset
       * or hot-plug...
       * XXX  DID_BUS_BUSY is actually a bad idea because it will defy
       * the scsi layer's retry logic.
       */
#if 0
      if ((scsi_status == SBP2_SCSI_STATUS_CHECK_CONDITION) &&
          (SCpnt->sense_buffer[2] == UNIT_ATTENTION)) {
            SBP2_DEBUG("UNIT ATTENTION - return busy");
            SCpnt->result = DID_BUS_BUSY << 16;
      }
#endif

      /*
       * Tell scsi stack that we're done with this command
       */
      done(SCpnt);
}

static int sbp2scsi_slave_alloc(struct scsi_device *sdev)
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)sdev->host->hostdata[0];

      scsi_id->sdev = sdev;

      if (scsi_id->workarounds & SBP2_WORKAROUND_INQUIRY_36)
            sdev->inquiry_len = 36;
      return 0;
}

static int sbp2scsi_slave_configure(struct scsi_device *sdev)
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)sdev->host->hostdata[0];

      blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
      sdev->use_10_for_rw = 1;
      sdev->use_10_for_ms = 1;

      if (sdev->type == TYPE_DISK &&
          scsi_id->workarounds & SBP2_WORKAROUND_MODE_SENSE_8)
            sdev->skip_ms_page_8 = 1;
      if (scsi_id->workarounds & SBP2_WORKAROUND_FIX_CAPACITY)
            sdev->fix_capacity = 1;
      if (scsi_id->ne->guid_vendor_id == 0x0010b9 && /* Maxtor's OUI */
          (sdev->type == TYPE_DISK || sdev->type == TYPE_RBC))
            sdev->allow_restart = 1;
      return 0;
}

static void sbp2scsi_slave_destroy(struct scsi_device *sdev)
{
      ((struct scsi_id_instance_data *)sdev->host->hostdata[0])->sdev = NULL;
      return;
}

/*
 * Called by scsi stack when something has really gone wrong.  Usually
 * called when a command has timed-out for some reason.
 */
static int sbp2scsi_abort(struct scsi_cmnd *SCpnt)
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];
      struct sbp2scsi_host_info *hi = scsi_id->hi;
      struct sbp2_command_info *command;
      unsigned long flags;

      SBP2_ERR("aborting sbp2 command");
      scsi_print_command(SCpnt);

      if (sbp2util_node_is_available(scsi_id)) {

            /*
             * Right now, just return any matching command structures
             * to the free pool.
             */
            spin_lock_irqsave(&scsi_id->sbp2_command_orb_lock, flags);
            command = sbp2util_find_command_for_SCpnt(scsi_id, SCpnt);
            if (command) {
                  SBP2_DEBUG("Found command to abort");
                  pci_dma_sync_single_for_cpu(hi->host->pdev,
                                        command->command_orb_dma,
                                        sizeof(struct sbp2_command_orb),
                                        PCI_DMA_BIDIRECTIONAL);
                  pci_dma_sync_single_for_cpu(hi->host->pdev,
                                        command->sge_dma,
                                        sizeof(command->scatter_gather_element),
                                        PCI_DMA_BIDIRECTIONAL);
                  sbp2util_mark_command_completed(scsi_id, command);
                  if (command->Current_SCpnt) {
                        command->Current_SCpnt->result = DID_ABORT << 16;
                        command->Current_done(command->Current_SCpnt);
                  }
            }
            spin_unlock_irqrestore(&scsi_id->sbp2_command_orb_lock, flags);

            /*
             * Initiate a fetch agent reset.
             */
            sbp2_agent_reset(scsi_id, 0);
            sbp2scsi_complete_all_commands(scsi_id, DID_BUS_BUSY);
      }

      return SUCCESS;
}

/*
 * Called by scsi stack when something has really gone wrong.
 */
static int sbp2scsi_reset(struct scsi_cmnd *SCpnt)
{
      struct scsi_id_instance_data *scsi_id =
            (struct scsi_id_instance_data *)SCpnt->device->host->hostdata[0];

      SBP2_ERR("reset requested");

      if (sbp2util_node_is_available(scsi_id)) {
            SBP2_ERR("Generating sbp2 fetch agent reset");
            sbp2_agent_reset(scsi_id, 0);
      }

      return SUCCESS;
}

static ssize_t sbp2_sysfs_ieee1394_id_show(struct device *dev,
                                 struct device_attribute *attr,
                                 char *buf)
{
      struct scsi_device *sdev;
      struct scsi_id_instance_data *scsi_id;
      int lun;

      if (!(sdev = to_scsi_device(dev)))
            return 0;

      if (!(scsi_id = (struct scsi_id_instance_data *)sdev->host->hostdata[0]))
            return 0;

      lun = ORB_SET_LUN(scsi_id->sbp2_lun);

      return sprintf(buf, "%016Lx:%d:%d\n", (unsigned long long)scsi_id->ne->guid,
                   scsi_id->ud->id, lun);
}
static DEVICE_ATTR(ieee1394_id, S_IRUGO, sbp2_sysfs_ieee1394_id_show, NULL);

static struct device_attribute *sbp2_sysfs_sdev_attrs[] = {
      &dev_attr_ieee1394_id,
      NULL
};

MODULE_AUTHOR("Ben Collins <bcollins@debian.org>");
MODULE_DESCRIPTION("IEEE-1394 SBP-2 protocol driver");
MODULE_SUPPORTED_DEVICE(SBP2_DEVICE_NAME);
MODULE_LICENSE("GPL");

/* SCSI host template */
static struct scsi_host_template scsi_driver_template = {
      .module =               THIS_MODULE,
      .name =                       "SBP-2 IEEE-1394",
      .proc_name =                  SBP2_DEVICE_NAME,
      .queuecommand =               sbp2scsi_queuecommand,
      .eh_abort_handler =           sbp2scsi_abort,
      .eh_device_reset_handler =    sbp2scsi_reset,
      .slave_alloc =                sbp2scsi_slave_alloc,
      .slave_configure =            sbp2scsi_slave_configure,
      .slave_destroy =        sbp2scsi_slave_destroy,
      .this_id =              -1,
      .sg_tablesize =               SG_ALL,
      .use_clustering =       ENABLE_CLUSTERING,
      .cmd_per_lun =                SBP2_MAX_CMDS,
      .can_queue =                  SBP2_MAX_CMDS,
      .emulated =             1,
      .sdev_attrs =                 sbp2_sysfs_sdev_attrs,
};

static int sbp2_module_init(void)
{
      int ret;

      SBP2_DEBUG_ENTER();

      /* Module load debug option to force one command at a time (serializing I/O) */
      if (serialize_io) {
            SBP2_INFO("Driver forced to serialize I/O (serialize_io=1)");
            SBP2_INFO("Try serialize_io=0 for better performance");
            scsi_driver_template.can_queue = 1;
            scsi_driver_template.cmd_per_lun = 1;
      }

      if (sbp2_default_workarounds & SBP2_WORKAROUND_128K_MAX_TRANS &&
          (max_sectors * 512) > (128 * 1024))
            max_sectors = 128 * 1024 / 512;
      scsi_driver_template.max_sectors = max_sectors;

      /* Register our high level driver with 1394 stack */
      hpsb_register_highlevel(&sbp2_highlevel);

      ret = hpsb_register_protocol(&sbp2_driver);
      if (ret) {
            SBP2_ERR("Failed to register protocol");
            hpsb_unregister_highlevel(&sbp2_highlevel);
            return ret;
      }

      return 0;
}

static void __exit sbp2_module_exit(void)
{
      SBP2_DEBUG_ENTER();

      hpsb_unregister_protocol(&sbp2_driver);

      hpsb_unregister_highlevel(&sbp2_highlevel);
}

module_init(sbp2_module_init);
module_exit(sbp2_module_exit);

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