Logo Search packages:      
Sourcecode: linux-2.6 version File versions  Download package

xmon.c

/*
 * Routines providing a simple monitor for use on the PowerMac.
 *
 * Copyright (C) 1996-2005 Paul Mackerras.
 *
 *      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.
 */
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/sysrq.h>
#include <linux/interrupt.h>

#include <asm/ptrace.h>
#include <asm/string.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/xmon.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/cputable.h>
#include <asm/rtas.h>
#include <asm/sstep.h>
#include <asm/bug.h>

#ifdef CONFIG_PPC64
#include <asm/hvcall.h>
#include <asm/paca.h>
#endif

#include "nonstdio.h"

#define scanhex   xmon_scanhex
#define skipbl    xmon_skipbl

#ifdef CONFIG_SMP
cpumask_t cpus_in_xmon = CPU_MASK_NONE;
static unsigned long xmon_taken = 1;
static int xmon_owner;
static int xmon_gate;
#endif /* CONFIG_SMP */

static unsigned long in_xmon = 0;

static unsigned long adrs;
static int size = 1;
#define MAX_DUMP (128 * 1024)
static unsigned long ndump = 64;
static unsigned long nidump = 16;
static unsigned long ncsum = 4096;
static int termch;
static char tmpstr[128];

#define JMP_BUF_LEN     23
static long bus_error_jmp[JMP_BUF_LEN];
static int catch_memory_errors;
static long *xmon_fault_jmp[NR_CPUS];
#define setjmp xmon_setjmp
#define longjmp xmon_longjmp

/* Breakpoint stuff */
struct bpt {
      unsigned long     address;
      unsigned int      instr[2];
      atomic_t    ref_count;
      int         enabled;
      unsigned long     pad;
};

/* Bits in bpt.enabled */
#define BP_IABR_TE      1           /* IABR translation enabled */
#define BP_IABR         2
#define BP_TRAP         8
#define BP_DABR         0x10

#define NBPTS     256
static struct bpt bpts[NBPTS];
static struct bpt dabr;
static struct bpt *iabr;
static unsigned bpinstr = 0x7fe00008;     /* trap */

#define BP_NUM(bp)      ((bp) - bpts + 1)

/* Prototypes */
static int cmds(struct pt_regs *);
static int mread(unsigned long, void *, int);
static int mwrite(unsigned long, void *, int);
static int handle_fault(struct pt_regs *);
static void byterev(unsigned char *, int);
static void memex(void);
static int bsesc(void);
static void dump(void);
static void prdump(unsigned long, long);
static int ppc_inst_dump(unsigned long, long, int);
void print_address(unsigned long);
static void backtrace(struct pt_regs *);
static void excprint(struct pt_regs *);
static void prregs(struct pt_regs *);
static void memops(int);
static void memlocate(void);
static void memzcan(void);
static void memdiffs(unsigned char *, unsigned char *, unsigned, unsigned);
int skipbl(void);
int scanhex(unsigned long *valp);
static void scannl(void);
static int hexdigit(int);
void getstring(char *, int);
static void flush_input(void);
static int inchar(void);
static void take_input(char *);
static unsigned long read_spr(int);
static void write_spr(int, unsigned long);
static void super_regs(void);
static void remove_bpts(void);
static void insert_bpts(void);
static void remove_cpu_bpts(void);
static void insert_cpu_bpts(void);
static struct bpt *at_breakpoint(unsigned long pc);
static struct bpt *in_breakpoint_table(unsigned long pc, unsigned long *offp);
static int  do_step(struct pt_regs *);
static void bpt_cmds(void);
static void cacheflush(void);
static int  cpu_cmd(void);
static void csum(void);
static void bootcmds(void);
static void proccall(void);
void dump_segments(void);
static void symbol_lookup(void);
static void xmon_print_symbol(unsigned long address, const char *mid,
                        const char *after);
static const char *getvecname(unsigned long vec);

extern int print_insn_powerpc(unsigned long, unsigned long, int);

extern void xmon_enter(void);
extern void xmon_leave(void);

extern long setjmp(long *);
extern void longjmp(long *, long);
extern void xmon_save_regs(struct pt_regs *);

#ifdef CONFIG_PPC64
#define REG       "%.16lx"
#define REGS_PER_LINE   4
#define LAST_VOLATILE   13
#else
#define REG       "%.8lx"
#define REGS_PER_LINE   8
#define LAST_VOLATILE   12
#endif

#define GETWORD(v)      (((v)[0] << 24) + ((v)[1] << 16) + ((v)[2] << 8) + (v)[3])

#define isxdigit(c)     (('0' <= (c) && (c) <= '9') \
                   || ('a' <= (c) && (c) <= 'f') \
                   || ('A' <= (c) && (c) <= 'F'))
#define isalnum(c)      (('0' <= (c) && (c) <= '9') \
                   || ('a' <= (c) && (c) <= 'z') \
                   || ('A' <= (c) && (c) <= 'Z'))
#define isspace(c)      (c == ' ' || c == '\t' || c == 10 || c == 13 || c == 0)

static char *help_string = "\
Commands:\n\
  b   show breakpoints\n\
  bd  set data breakpoint\n\
  bi  set instruction breakpoint\n\
  bc  clear breakpoint\n"
#ifdef CONFIG_SMP
  "\
  c   print cpus stopped in xmon\n\
  c#  try to switch to cpu number h (in hex)\n"
#endif
  "\
  C   checksum\n\
  d   dump bytes\n\
  di  dump instructions\n\
  df  dump float values\n\
  dd  dump double values\n\
  dr  dump stream of raw bytes\n\
  e   print exception information\n\
  f   flush cache\n\
  la  lookup symbol+offset of specified address\n\
  ls  lookup address of specified symbol\n\
  m   examine/change memory\n\
  mm  move a block of memory\n\
  ms  set a block of memory\n\
  md  compare two blocks of memory\n\
  ml  locate a block of memory\n\
  mz  zero a block of memory\n\
  mi  show information about memory allocation\n\
  p   call a procedure\n\
  r   print registers\n\
  s   single step\n\
  S   print special registers\n\
  t   print backtrace\n\
  x   exit monitor and recover\n\
  X   exit monitor and dont recover\n"
#ifdef CONFIG_PPC64
"  u  dump segment table or SLB\n"
#endif
#ifdef CONFIG_PPC_STD_MMU_32
"  u  dump segment registers\n"
#endif
"  ?  help\n"
"  zr reboot\n\
  zh  halt\n"
;

static struct pt_regs *xmon_regs;

static inline void sync(void)
{
      asm volatile("sync; isync");
}

static inline void store_inst(void *p)
{
      asm volatile ("dcbst 0,%0; sync; icbi 0,%0; isync" : : "r" (p));
}

static inline void cflush(void *p)
{
      asm volatile ("dcbf 0,%0; icbi 0,%0" : : "r" (p));
}

static inline void cinval(void *p)
{
      asm volatile ("dcbi 0,%0; icbi 0,%0" : : "r" (p));
}

/*
 * Disable surveillance (the service processor watchdog function)
 * while we are in xmon.
 * XXX we should re-enable it when we leave. :)
 */
#define SURVEILLANCE_TOKEN    9000

static inline void disable_surveillance(void)
{
#ifdef CONFIG_PPC_PSERIES
      /* Since this can't be a module, args should end up below 4GB. */
      static struct rtas_args args;

      /*
       * At this point we have got all the cpus we can into
       * xmon, so there is hopefully no other cpu calling RTAS
       * at the moment, even though we don't take rtas.lock.
       * If we did try to take rtas.lock there would be a
       * real possibility of deadlock.
       */
      args.token = rtas_token("set-indicator");
      if (args.token == RTAS_UNKNOWN_SERVICE)
            return;
      args.nargs = 3;
      args.nret = 1;
      args.rets = &args.args[3];
      args.args[0] = SURVEILLANCE_TOKEN;
      args.args[1] = 0;
      args.args[2] = 0;
      enter_rtas(__pa(&args));
#endif /* CONFIG_PPC_PSERIES */
}

#ifdef CONFIG_SMP
static int xmon_speaker;

static void get_output_lock(void)
{
      int me = smp_processor_id() + 0x100;
      int last_speaker = 0, prev;
      long timeout;

      if (xmon_speaker == me)
            return;
      for (;;) {
            if (xmon_speaker == 0) {
                  last_speaker = cmpxchg(&xmon_speaker, 0, me);
                  if (last_speaker == 0)
                        return;
            }
            timeout = 10000000;
            while (xmon_speaker == last_speaker) {
                  if (--timeout > 0)
                        continue;
                  /* hostile takeover */
                  prev = cmpxchg(&xmon_speaker, last_speaker, me);
                  if (prev == last_speaker)
                        return;
                  break;
            }
      }
}

static void release_output_lock(void)
{
      xmon_speaker = 0;
}
#endif

static int xmon_core(struct pt_regs *regs, int fromipi)
{
      int cmd = 0;
      unsigned long msr;
      struct bpt *bp;
      long recurse_jmp[JMP_BUF_LEN];
      unsigned long offset;
#ifdef CONFIG_SMP
      int cpu;
      int secondary;
      unsigned long timeout;
#endif

      msr = mfmsr();
      mtmsr(msr & ~MSR_EE);   /* disable interrupts */

      bp = in_breakpoint_table(regs->nip, &offset);
      if (bp != NULL) {
            regs->nip = bp->address + offset;
            atomic_dec(&bp->ref_count);
      }

      remove_cpu_bpts();

#ifdef CONFIG_SMP
      cpu = smp_processor_id();
      if (cpu_isset(cpu, cpus_in_xmon)) {
            get_output_lock();
            excprint(regs);
            printf("cpu 0x%x: Exception %lx %s in xmon, "
                   "returning to main loop\n",
                   cpu, regs->trap, getvecname(TRAP(regs)));
            release_output_lock();
            longjmp(xmon_fault_jmp[cpu], 1);
      }

      if (setjmp(recurse_jmp) != 0) {
            if (!in_xmon || !xmon_gate) {
                  get_output_lock();
                  printf("xmon: WARNING: bad recursive fault "
                         "on cpu 0x%x\n", cpu);
                  release_output_lock();
                  goto waiting;
            }
            secondary = !(xmon_taken && cpu == xmon_owner);
            goto cmdloop;
      }

      xmon_fault_jmp[cpu] = recurse_jmp;
      cpu_set(cpu, cpus_in_xmon);

      bp = NULL;
      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF))
            bp = at_breakpoint(regs->nip);
      if (bp || (regs->msr & MSR_RI) == 0)
            fromipi = 0;

      if (!fromipi) {
            get_output_lock();
            excprint(regs);
            if (bp) {
                  printf("cpu 0x%x stopped at breakpoint 0x%x (",
                         cpu, BP_NUM(bp));
                  xmon_print_symbol(regs->nip, " ", ")\n");
            }
            if ((regs->msr & MSR_RI) == 0)
                  printf("WARNING: exception is not recoverable, "
                         "can't continue\n");
            release_output_lock();
      }

 waiting:
      secondary = 1;
      while (secondary && !xmon_gate) {
            if (in_xmon == 0) {
                  if (fromipi)
                        goto leave;
                  secondary = test_and_set_bit(0, &in_xmon);
            }
            barrier();
      }

      if (!secondary && !xmon_gate) {
            /* we are the first cpu to come in */
            /* interrupt other cpu(s) */
            int ncpus = num_online_cpus();

            xmon_owner = cpu;
            mb();
            if (ncpus > 1) {
                  smp_send_debugger_break(MSG_ALL_BUT_SELF);
                  /* wait for other cpus to come in */
                  for (timeout = 100000000; timeout != 0; --timeout) {
                        if (cpus_weight(cpus_in_xmon) >= ncpus)
                              break;
                        barrier();
                  }
            }
            remove_bpts();
            disable_surveillance();
            /* for breakpoint or single step, print the current instr. */
            if (bp || TRAP(regs) == 0xd00)
                  ppc_inst_dump(regs->nip, 1, 0);
            printf("enter ? for help\n");
            mb();
            xmon_gate = 1;
            barrier();
      }

 cmdloop:
      while (in_xmon) {
            if (secondary) {
                  if (cpu == xmon_owner) {
                        if (!test_and_set_bit(0, &xmon_taken)) {
                              secondary = 0;
                              continue;
                        }
                        /* missed it */
                        while (cpu == xmon_owner)
                              barrier();
                  }
                  barrier();
            } else {
                  cmd = cmds(regs);
                  if (cmd != 0) {
                        /* exiting xmon */
                        insert_bpts();
                        xmon_gate = 0;
                        wmb();
                        in_xmon = 0;
                        break;
                  }
                  /* have switched to some other cpu */
                  secondary = 1;
            }
      }
 leave:
      cpu_clear(cpu, cpus_in_xmon);
      xmon_fault_jmp[cpu] = NULL;
#else
      /* UP is simple... */
      if (in_xmon) {
            printf("Exception %lx %s in xmon, returning to main loop\n",
                   regs->trap, getvecname(TRAP(regs)));
            longjmp(xmon_fault_jmp[0], 1);
      }
      if (setjmp(recurse_jmp) == 0) {
            xmon_fault_jmp[0] = recurse_jmp;
            in_xmon = 1;

            excprint(regs);
            bp = at_breakpoint(regs->nip);
            if (bp) {
                  printf("Stopped at breakpoint %x (", BP_NUM(bp));
                  xmon_print_symbol(regs->nip, " ", ")\n");
            }
            if ((regs->msr & MSR_RI) == 0)
                  printf("WARNING: exception is not recoverable, "
                         "can't continue\n");
            remove_bpts();
            disable_surveillance();
            /* for breakpoint or single step, print the current instr. */
            if (bp || TRAP(regs) == 0xd00)
                  ppc_inst_dump(regs->nip, 1, 0);
            printf("enter ? for help\n");
      }

      cmd = cmds(regs);

      insert_bpts();
      in_xmon = 0;
#endif

      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF)) {
            bp = at_breakpoint(regs->nip);
            if (bp != NULL) {
                  int stepped = emulate_step(regs, bp->instr[0]);
                  if (stepped == 0) {
                        regs->nip = (unsigned long) &bp->instr[0];
                        atomic_inc(&bp->ref_count);
                  } else if (stepped < 0) {
                        printf("Couldn't single-step %s instruction\n",
                            (IS_RFID(bp->instr[0])? "rfid": "mtmsrd"));
                  }
            }
      }

      insert_cpu_bpts();

      mtmsr(msr);       /* restore interrupt enable */

      return cmd != 'X';
}

int xmon(struct pt_regs *excp)
{
      struct pt_regs regs;

      if (excp == NULL) {
            xmon_save_regs(&regs);
            excp = &regs;
      }
      return xmon_core(excp, 0);
}
EXPORT_SYMBOL(xmon);

irqreturn_t
xmon_irq(int irq, void *d, struct pt_regs *regs)
{
      unsigned long flags;
      local_irq_save(flags);
      printf("Keyboard interrupt\n");
      xmon(regs);
      local_irq_restore(flags);
      return IRQ_HANDLED;
}

static int xmon_bpt(struct pt_regs *regs)
{
      struct bpt *bp;
      unsigned long offset;

      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
            return 0;

      /* Are we at the trap at bp->instr[1] for some bp? */
      bp = in_breakpoint_table(regs->nip, &offset);
      if (bp != NULL && offset == 4) {
            regs->nip = bp->address + 4;
            atomic_dec(&bp->ref_count);
            return 1;
      }

      /* Are we at a breakpoint? */
      bp = at_breakpoint(regs->nip);
      if (!bp)
            return 0;

      xmon_core(regs, 0);

      return 1;
}

static int xmon_sstep(struct pt_regs *regs)
{
      if (user_mode(regs))
            return 0;
      xmon_core(regs, 0);
      return 1;
}

static int xmon_dabr_match(struct pt_regs *regs)
{
      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
            return 0;
      if (dabr.enabled == 0)
            return 0;
      xmon_core(regs, 0);
      return 1;
}

static int xmon_iabr_match(struct pt_regs *regs)
{
      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) != (MSR_IR|MSR_SF))
            return 0;
      if (iabr == 0)
            return 0;
      xmon_core(regs, 0);
      return 1;
}

static int xmon_ipi(struct pt_regs *regs)
{
#ifdef CONFIG_SMP
      if (in_xmon && !cpu_isset(smp_processor_id(), cpus_in_xmon))
            xmon_core(regs, 1);
#endif
      return 0;
}

static int xmon_fault_handler(struct pt_regs *regs)
{
      struct bpt *bp;
      unsigned long offset;

      if (in_xmon && catch_memory_errors)
            handle_fault(regs);     /* doesn't return */

      if ((regs->msr & (MSR_IR|MSR_PR|MSR_SF)) == (MSR_IR|MSR_SF)) {
            bp = in_breakpoint_table(regs->nip, &offset);
            if (bp != NULL) {
                  regs->nip = bp->address + offset;
                  atomic_dec(&bp->ref_count);
            }
      }

      return 0;
}

static struct bpt *at_breakpoint(unsigned long pc)
{
      int i;
      struct bpt *bp;

      bp = bpts;
      for (i = 0; i < NBPTS; ++i, ++bp)
            if (bp->enabled && pc == bp->address)
                  return bp;
      return NULL;
}

static struct bpt *in_breakpoint_table(unsigned long nip, unsigned long *offp)
{
      unsigned long off;

      off = nip - (unsigned long) bpts;
      if (off >= sizeof(bpts))
            return NULL;
      off %= sizeof(struct bpt);
      if (off != offsetof(struct bpt, instr[0])
          && off != offsetof(struct bpt, instr[1]))
            return NULL;
      *offp = off - offsetof(struct bpt, instr[0]);
      return (struct bpt *) (nip - off);
}

static struct bpt *new_breakpoint(unsigned long a)
{
      struct bpt *bp;

      a &= ~3UL;
      bp = at_breakpoint(a);
      if (bp)
            return bp;

      for (bp = bpts; bp < &bpts[NBPTS]; ++bp) {
            if (!bp->enabled && atomic_read(&bp->ref_count) == 0) {
                  bp->address = a;
                  bp->instr[1] = bpinstr;
                  store_inst(&bp->instr[1]);
                  return bp;
            }
      }

      printf("Sorry, no free breakpoints.  Please clear one first.\n");
      return NULL;
}

static void insert_bpts(void)
{
      int i;
      struct bpt *bp;

      bp = bpts;
      for (i = 0; i < NBPTS; ++i, ++bp) {
            if ((bp->enabled & (BP_TRAP|BP_IABR)) == 0)
                  continue;
            if (mread(bp->address, &bp->instr[0], 4) != 4) {
                  printf("Couldn't read instruction at %lx, "
                         "disabling breakpoint there\n", bp->address);
                  bp->enabled = 0;
                  continue;
            }
            if (IS_MTMSRD(bp->instr[0]) || IS_RFID(bp->instr[0])) {
                  printf("Breakpoint at %lx is on an mtmsrd or rfid "
                         "instruction, disabling it\n", bp->address);
                  bp->enabled = 0;
                  continue;
            }
            store_inst(&bp->instr[0]);
            if (bp->enabled & BP_IABR)
                  continue;
            if (mwrite(bp->address, &bpinstr, 4) != 4) {
                  printf("Couldn't write instruction at %lx, "
                         "disabling breakpoint there\n", bp->address);
                  bp->enabled &= ~BP_TRAP;
                  continue;
            }
            store_inst((void *)bp->address);
      }
}

static void insert_cpu_bpts(void)
{
      if (dabr.enabled)
            set_dabr(dabr.address | (dabr.enabled & 7));
      if (iabr && cpu_has_feature(CPU_FTR_IABR))
            mtspr(SPRN_IABR, iabr->address
                   | (iabr->enabled & (BP_IABR|BP_IABR_TE)));
}

static void remove_bpts(void)
{
      int i;
      struct bpt *bp;
      unsigned instr;

      bp = bpts;
      for (i = 0; i < NBPTS; ++i, ++bp) {
            if ((bp->enabled & (BP_TRAP|BP_IABR)) != BP_TRAP)
                  continue;
            if (mread(bp->address, &instr, 4) == 4
                && instr == bpinstr
                && mwrite(bp->address, &bp->instr, 4) != 4)
                  printf("Couldn't remove breakpoint at %lx\n",
                         bp->address);
            else
                  store_inst((void *)bp->address);
      }
}

static void remove_cpu_bpts(void)
{
      set_dabr(0);
      if (cpu_has_feature(CPU_FTR_IABR))
            mtspr(SPRN_IABR, 0);
}

/* Command interpreting routine */
static char *last_cmd;

static int
cmds(struct pt_regs *excp)
{
      int cmd = 0;

      last_cmd = NULL;
      xmon_regs = excp;
      for(;;) {
#ifdef CONFIG_SMP
            printf("%x:", smp_processor_id());
#endif /* CONFIG_SMP */
            printf("mon> ");
            flush_input();
            termch = 0;
            cmd = skipbl();
            if( cmd == '\n' ) {
                  if (last_cmd == NULL)
                        continue;
                  take_input(last_cmd);
                  last_cmd = NULL;
                  cmd = inchar();
            }
            switch (cmd) {
            case 'm':
                  cmd = inchar();
                  switch (cmd) {
                  case 'm':
                  case 's':
                  case 'd':
                        memops(cmd);
                        break;
                  case 'l':
                        memlocate();
                        break;
                  case 'z':
                        memzcan();
                        break;
                  case 'i':
                        show_mem();
                        break;
                  default:
                        termch = cmd;
                        memex();
                  }
                  break;
            case 'd':
                  dump();
                  break;
            case 'l':
                  symbol_lookup();
                  break;
            case 'r':
                  prregs(excp);     /* print regs */
                  break;
            case 'e':
                  excprint(excp);
                  break;
            case 'S':
                  super_regs();
                  break;
            case 't':
                  backtrace(excp);
                  break;
            case 'f':
                  cacheflush();
                  break;
            case 's':
                  if (do_step(excp))
                        return cmd;
                  break;
            case 'x':
            case 'X':
                  return cmd;
            case EOF:
                  printf(" <no input ...>\n");
                  mdelay(2000);
                  return cmd;
            case '?':
                  printf(help_string);
                  break;
            case 'b':
                  bpt_cmds();
                  break;
            case 'C':
                  csum();
                  break;
            case 'c':
                  if (cpu_cmd())
                        return 0;
                  break;
            case 'z':
                  bootcmds();
                  break;
            case 'p':
                  proccall();
                  break;
#ifdef CONFIG_PPC_STD_MMU
            case 'u':
                  dump_segments();
                  break;
#endif
            default:
                  printf("Unrecognized command: ");
                    do {
                        if (' ' < cmd && cmd <= '~')
                              putchar(cmd);
                        else
                              printf("\\x%x", cmd);
                        cmd = inchar();
                    } while (cmd != '\n'); 
                  printf(" (type ? for help)\n");
                  break;
            }
      }
}

/*
 * Step a single instruction.
 * Some instructions we emulate, others we execute with MSR_SE set.
 */
static int do_step(struct pt_regs *regs)
{
      unsigned int instr;
      int stepped;

      /* check we are in 64-bit kernel mode, translation enabled */
      if ((regs->msr & (MSR_SF|MSR_PR|MSR_IR)) == (MSR_SF|MSR_IR)) {
            if (mread(regs->nip, &instr, 4) == 4) {
                  stepped = emulate_step(regs, instr);
                  if (stepped < 0) {
                        printf("Couldn't single-step %s instruction\n",
                               (IS_RFID(instr)? "rfid": "mtmsrd"));
                        return 0;
                  }
                  if (stepped > 0) {
                        regs->trap = 0xd00 | (regs->trap & 1);
                        printf("stepped to ");
                        xmon_print_symbol(regs->nip, " ", "\n");
                        ppc_inst_dump(regs->nip, 1, 0);
                        return 0;
                  }
            }
      }
      regs->msr |= MSR_SE;
      return 1;
}

static void bootcmds(void)
{
      int cmd;

      cmd = inchar();
      if (cmd == 'r')
            ppc_md.restart(NULL);
      else if (cmd == 'h')
            ppc_md.halt();
      else if (cmd == 'p')
            ppc_md.power_off();
}

static int cpu_cmd(void)
{
#ifdef CONFIG_SMP
      unsigned long cpu;
      int timeout;
      int count;

      if (!scanhex(&cpu)) {
            /* print cpus waiting or in xmon */
            printf("cpus stopped:");
            count = 0;
            for (cpu = 0; cpu < NR_CPUS; ++cpu) {
                  if (cpu_isset(cpu, cpus_in_xmon)) {
                        if (count == 0)
                              printf(" %x", cpu);
                        ++count;
                  } else {
                        if (count > 1)
                              printf("-%x", cpu - 1);
                        count = 0;
                  }
            }
            if (count > 1)
                  printf("-%x", NR_CPUS - 1);
            printf("\n");
            return 0;
      }
      /* try to switch to cpu specified */
      if (!cpu_isset(cpu, cpus_in_xmon)) {
            printf("cpu 0x%x isn't in xmon\n", cpu);
            return 0;
      }
      xmon_taken = 0;
      mb();
      xmon_owner = cpu;
      timeout = 10000000;
      while (!xmon_taken) {
            if (--timeout == 0) {
                  if (test_and_set_bit(0, &xmon_taken))
                        break;
                  /* take control back */
                  mb();
                  xmon_owner = smp_processor_id();
                  printf("cpu %u didn't take control\n", cpu);
                  return 0;
            }
            barrier();
      }
      return 1;
#else
      return 0;
#endif /* CONFIG_SMP */
}

static unsigned short fcstab[256] = {
      0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
      0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
      0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
      0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
      0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
      0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
      0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
      0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
      0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
      0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
      0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
      0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
      0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
      0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
      0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
      0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
      0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
      0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
      0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
      0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
      0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
      0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
      0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
      0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
      0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
      0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
      0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
      0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
      0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
      0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
      0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
      0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

#define FCS(fcs, c)     (((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])

static void
csum(void)
{
      unsigned int i;
      unsigned short fcs;
      unsigned char v;

      if (!scanhex(&adrs))
            return;
      if (!scanhex(&ncsum))
            return;
      fcs = 0xffff;
      for (i = 0; i < ncsum; ++i) {
            if (mread(adrs+i, &v, 1) == 0) {
                  printf("csum stopped at %x\n", adrs+i);
                  break;
            }
            fcs = FCS(fcs, v);
      }
      printf("%x\n", fcs);
}

/*
 * Check if this is a suitable place to put a breakpoint.
 */
static long check_bp_loc(unsigned long addr)
{
      unsigned int instr;

      addr &= ~3;
      if (!is_kernel_addr(addr)) {
            printf("Breakpoints may only be placed at kernel addresses\n");
            return 0;
      }
      if (!mread(addr, &instr, sizeof(instr))) {
            printf("Can't read instruction at address %lx\n", addr);
            return 0;
      }
      if (IS_MTMSRD(instr) || IS_RFID(instr)) {
            printf("Breakpoints may not be placed on mtmsrd or rfid "
                   "instructions\n");
            return 0;
      }
      return 1;
}

static char *breakpoint_help_string = 
    "Breakpoint command usage:\n"
    "b                show breakpoints\n"
    "b <addr> [cnt]   set breakpoint at given instr addr\n"
    "bc               clear all breakpoints\n"
    "bc <n/addr>      clear breakpoint number n or at addr\n"
    "bi <addr> [cnt]  set hardware instr breakpoint (POWER3/RS64 only)\n"
    "bd <addr> [cnt]  set hardware data breakpoint\n"
    "";

static void
bpt_cmds(void)
{
      int cmd;
      unsigned long a;
      int mode, i;
      struct bpt *bp;
      const char badaddr[] = "Only kernel addresses are permitted "
            "for breakpoints\n";

      cmd = inchar();
      switch (cmd) {
#ifndef CONFIG_8xx
      case 'd':   /* bd - hardware data breakpoint */
            mode = 7;
            cmd = inchar();
            if (cmd == 'r')
                  mode = 5;
            else if (cmd == 'w')
                  mode = 6;
            else
                  termch = cmd;
            dabr.address = 0;
            dabr.enabled = 0;
            if (scanhex(&dabr.address)) {
                  if (!is_kernel_addr(dabr.address)) {
                        printf(badaddr);
                        break;
                  }
                  dabr.address &= ~7;
                  dabr.enabled = mode | BP_DABR;
            }
            break;

      case 'i':   /* bi - hardware instr breakpoint */
            if (!cpu_has_feature(CPU_FTR_IABR)) {
                  printf("Hardware instruction breakpoint "
                         "not supported on this cpu\n");
                  break;
            }
            if (iabr) {
                  iabr->enabled &= ~(BP_IABR | BP_IABR_TE);
                  iabr = NULL;
            }
            if (!scanhex(&a))
                  break;
            if (!check_bp_loc(a))
                  break;
            bp = new_breakpoint(a);
            if (bp != NULL) {
                  bp->enabled |= BP_IABR | BP_IABR_TE;
                  iabr = bp;
            }
            break;
#endif

      case 'c':
            if (!scanhex(&a)) {
                  /* clear all breakpoints */
                  for (i = 0; i < NBPTS; ++i)
                        bpts[i].enabled = 0;
                  iabr = NULL;
                  dabr.enabled = 0;
                  printf("All breakpoints cleared\n");
                  break;
            }

            if (a <= NBPTS && a >= 1) {
                  /* assume a breakpoint number */
                  bp = &bpts[a-1];  /* bp nums are 1 based */
            } else {
                  /* assume a breakpoint address */
                  bp = at_breakpoint(a);
                  if (bp == 0) {
                        printf("No breakpoint at %x\n", a);
                        break;
                  }
            }

            printf("Cleared breakpoint %x (", BP_NUM(bp));
            xmon_print_symbol(bp->address, " ", ")\n");
            bp->enabled = 0;
            break;

      default:
            termch = cmd;
              cmd = skipbl();
            if (cmd == '?') {
                  printf(breakpoint_help_string);
                  break;
            }
            termch = cmd;
            if (!scanhex(&a)) {
                  /* print all breakpoints */
                  printf("   type            address\n");
                  if (dabr.enabled) {
                        printf("   data   "REG"  [", dabr.address);
                        if (dabr.enabled & 1)
                              printf("r");
                        if (dabr.enabled & 2)
                              printf("w");
                        printf("]\n");
                  }
                  for (bp = bpts; bp < &bpts[NBPTS]; ++bp) {
                        if (!bp->enabled)
                              continue;
                        printf("%2x %s   ", BP_NUM(bp),
                            (bp->enabled & BP_IABR)? "inst": "trap");
                        xmon_print_symbol(bp->address, "  ", "\n");
                  }
                  break;
            }

            if (!check_bp_loc(a))
                  break;
            bp = new_breakpoint(a);
            if (bp != NULL)
                  bp->enabled |= BP_TRAP;
            break;
      }
}

/* Very cheap human name for vector lookup. */
static
const char *getvecname(unsigned long vec)
{
      char *ret;

      switch (vec) {
      case 0x100: ret = "(System Reset)"; break;
      case 0x200: ret = "(Machine Check)"; break;
      case 0x300: ret = "(Data Access)"; break;
      case 0x380: ret = "(Data SLB Access)"; break;
      case 0x400: ret = "(Instruction Access)"; break;
      case 0x480: ret = "(Instruction SLB Access)"; break;
      case 0x500: ret = "(Hardware Interrupt)"; break;
      case 0x600: ret = "(Alignment)"; break;
      case 0x700: ret = "(Program Check)"; break;
      case 0x800: ret = "(FPU Unavailable)"; break;
      case 0x900: ret = "(Decrementer)"; break;
      case 0xc00: ret = "(System Call)"; break;
      case 0xd00: ret = "(Single Step)"; break;
      case 0xf00: ret = "(Performance Monitor)"; break;
      case 0xf20: ret = "(Altivec Unavailable)"; break;
      case 0x1300:      ret = "(Instruction Breakpoint)"; break;
      default: ret = "";
      }
      return ret;
}

static void get_function_bounds(unsigned long pc, unsigned long *startp,
                        unsigned long *endp)
{
      unsigned long size, offset;
      const char *name;
      char *modname;

      *startp = *endp = 0;
      if (pc == 0)
            return;
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();
            name = kallsyms_lookup(pc, &size, &offset, &modname, tmpstr);
            if (name != NULL) {
                  *startp = pc - offset;
                  *endp = pc - offset + size;
            }
            sync();
      }
      catch_memory_errors = 0;
}

static int xmon_depth_to_print = 64;

#ifdef CONFIG_PPC64
#define LRSAVE_OFFSET         0x10
#define REG_FRAME_MARKER      0x7265677368657265ul    /* "regshere" */
#define MARKER_OFFSET         0x60
#define REGS_OFFSET           0x70
#else
#define LRSAVE_OFFSET         4
#define REG_FRAME_MARKER      0x72656773
#define MARKER_OFFSET         8
#define REGS_OFFSET           16
#endif

static void xmon_show_stack(unsigned long sp, unsigned long lr,
                      unsigned long pc)
{
      unsigned long ip;
      unsigned long newsp;
      unsigned long marker;
      int count = 0;
      struct pt_regs regs;

      do {
            if (sp < PAGE_OFFSET) {
                  if (sp != 0)
                        printf("SP (%lx) is in userspace\n", sp);
                  break;
            }

            if (!mread(sp + LRSAVE_OFFSET, &ip, sizeof(unsigned long))
                || !mread(sp, &newsp, sizeof(unsigned long))) {
                  printf("Couldn't read stack frame at %lx\n", sp);
                  break;
            }

            /*
             * For the first stack frame, try to work out if
             * LR and/or the saved LR value in the bottommost
             * stack frame are valid.
             */
            if ((pc | lr) != 0) {
                  unsigned long fnstart, fnend;
                  unsigned long nextip;
                  int printip = 1;

                  get_function_bounds(pc, &fnstart, &fnend);
                  nextip = 0;
                  if (newsp > sp)
                        mread(newsp + LRSAVE_OFFSET, &nextip,
                              sizeof(unsigned long));
                  if (lr == ip) {
                        if (lr < PAGE_OFFSET
                            || (fnstart <= lr && lr < fnend))
                              printip = 0;
                  } else if (lr == nextip) {
                        printip = 0;
                  } else if (lr >= PAGE_OFFSET
                           && !(fnstart <= lr && lr < fnend)) {
                        printf("[link register   ] ");
                        xmon_print_symbol(lr, " ", "\n");
                  }
                  if (printip) {
                        printf("["REG"] ", sp);
                        xmon_print_symbol(ip, " ", " (unreliable)\n");
                  }
                  pc = lr = 0;

            } else {
                  printf("["REG"] ", sp);
                  xmon_print_symbol(ip, " ", "\n");
            }

            /* Look for "regshere" marker to see if this is
               an exception frame. */
            if (mread(sp + MARKER_OFFSET, &marker, sizeof(unsigned long))
                && marker == REG_FRAME_MARKER) {
                  if (mread(sp + REGS_OFFSET, &regs, sizeof(regs))
                      != sizeof(regs)) {
                        printf("Couldn't read registers at %lx\n",
                               sp + REGS_OFFSET);
                        break;
                  }
                        printf("--- Exception: %lx %s at ", regs.trap,
                         getvecname(TRAP(&regs)));
                  pc = regs.nip;
                  lr = regs.link;
                  xmon_print_symbol(pc, " ", "\n");
            }

            if (newsp == 0)
                  break;

            sp = newsp;
      } while (count++ < xmon_depth_to_print);
}

static void backtrace(struct pt_regs *excp)
{
      unsigned long sp;

      if (scanhex(&sp))
            xmon_show_stack(sp, 0, 0);
      else
            xmon_show_stack(excp->gpr[1], excp->link, excp->nip);
      scannl();
}

static void print_bug_trap(struct pt_regs *regs)
{
      struct bug_entry *bug;
      unsigned long addr;

      if (regs->msr & MSR_PR)
            return;           /* not in kernel */
      addr = regs->nip; /* address of trap instruction */
      if (addr < PAGE_OFFSET)
            return;
      bug = find_bug(regs->nip);
      if (bug == NULL)
            return;
      if (bug->line & BUG_WARNING_TRAP)
            return;

      printf("kernel BUG in %s at %s:%d!\n",
             bug->function, bug->file, (unsigned int)bug->line);
}

void excprint(struct pt_regs *fp)
{
      unsigned long trap;

#ifdef CONFIG_SMP
      printf("cpu 0x%x: ", smp_processor_id());
#endif /* CONFIG_SMP */

      trap = TRAP(fp);
      printf("Vector: %lx %s at [%lx]\n", fp->trap, getvecname(trap), fp);
      printf("    pc: ");
      xmon_print_symbol(fp->nip, ": ", "\n");

      printf("    lr: ", fp->link);
      xmon_print_symbol(fp->link, ": ", "\n");

      printf("    sp: %lx\n", fp->gpr[1]);
      printf("   msr: %lx\n", fp->msr);

      if (trap == 0x300 || trap == 0x380 || trap == 0x600) {
            printf("   dar: %lx\n", fp->dar);
            if (trap != 0x380)
                  printf(" dsisr: %lx\n", fp->dsisr);
      }

      printf("  current = 0x%lx\n", current);
#ifdef CONFIG_PPC64
      printf("  paca    = 0x%lx\n", get_paca());
#endif
      if (current) {
            printf("    pid   = %ld, comm = %s\n",
                   current->pid, current->comm);
      }

      if (trap == 0x700)
            print_bug_trap(fp);
}

void prregs(struct pt_regs *fp)
{
      int n, trap;
      unsigned long base;
      struct pt_regs regs;

      if (scanhex(&base)) {
            if (setjmp(bus_error_jmp) == 0) {
                  catch_memory_errors = 1;
                  sync();
                  regs = *(struct pt_regs *)base;
                  sync();
                  __delay(200);
            } else {
                  catch_memory_errors = 0;
                  printf("*** Error reading registers from "REG"\n",
                         base);
                  return;
            }
            catch_memory_errors = 0;
            fp = &regs;
      }

#ifdef CONFIG_PPC64
      if (FULL_REGS(fp)) {
            for (n = 0; n < 16; ++n)
                  printf("R%.2ld = "REG"   R%.2ld = "REG"\n",
                         n, fp->gpr[n], n+16, fp->gpr[n+16]);
      } else {
            for (n = 0; n < 7; ++n)
                  printf("R%.2ld = "REG"   R%.2ld = "REG"\n",
                         n, fp->gpr[n], n+7, fp->gpr[n+7]);
      }
#else
      for (n = 0; n < 32; ++n) {
            printf("R%.2d = %.8x%s", n, fp->gpr[n],
                   (n & 3) == 3? "\n": "   ");
            if (n == 12 && !FULL_REGS(fp)) {
                  printf("\n");
                  break;
            }
      }
#endif
      printf("pc  = ");
      xmon_print_symbol(fp->nip, " ", "\n");
      printf("lr  = ");
      xmon_print_symbol(fp->link, " ", "\n");
      printf("msr = "REG"   cr  = %.8lx\n", fp->msr, fp->ccr);
      printf("ctr = "REG"   xer = "REG"   trap = %4lx\n",
             fp->ctr, fp->xer, fp->trap);
      trap = TRAP(fp);
      if (trap == 0x300 || trap == 0x380 || trap == 0x600)
            printf("dar = "REG"   dsisr = %.8lx\n", fp->dar, fp->dsisr);
}

void cacheflush(void)
{
      int cmd;
      unsigned long nflush;

      cmd = inchar();
      if (cmd != 'i')
            termch = cmd;
      scanhex((void *)&adrs);
      if (termch != '\n')
            termch = 0;
      nflush = 1;
      scanhex(&nflush);
      nflush = (nflush + L1_CACHE_BYTES - 1) / L1_CACHE_BYTES;
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();

            if (cmd != 'i') {
                  for (; nflush > 0; --nflush, adrs += L1_CACHE_BYTES)
                        cflush((void *) adrs);
            } else {
                  for (; nflush > 0; --nflush, adrs += L1_CACHE_BYTES)
                        cinval((void *) adrs);
            }
            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
      }
      catch_memory_errors = 0;
}

unsigned long
read_spr(int n)
{
      unsigned int instrs[2];
      unsigned long (*code)(void);
      unsigned long ret = -1UL;
#ifdef CONFIG_PPC64
      unsigned long opd[3];

      opd[0] = (unsigned long)instrs;
      opd[1] = 0;
      opd[2] = 0;
      code = (unsigned long (*)(void)) opd;
#else
      code = (unsigned long (*)(void)) instrs;
#endif

      /* mfspr r3,n; blr */
      instrs[0] = 0x7c6002a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
      instrs[1] = 0x4e800020;
      store_inst(instrs);
      store_inst(instrs+1);

      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();

            ret = code();

            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
            n = size;
      }

      return ret;
}

void
write_spr(int n, unsigned long val)
{
      unsigned int instrs[2];
      unsigned long (*code)(unsigned long);
#ifdef CONFIG_PPC64
      unsigned long opd[3];

      opd[0] = (unsigned long)instrs;
      opd[1] = 0;
      opd[2] = 0;
      code = (unsigned long (*)(unsigned long)) opd;
#else
      code = (unsigned long (*)(unsigned long)) instrs;
#endif

      instrs[0] = 0x7c6003a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
      instrs[1] = 0x4e800020;
      store_inst(instrs);
      store_inst(instrs+1);

      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();

            code(val);

            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
            n = size;
      }
}

static unsigned long regno;
extern char exc_prolog;
extern char dec_exc;

void super_regs(void)
{
      int cmd;
      unsigned long val;
#ifdef CONFIG_PPC_ISERIES
      struct paca_struct *ptrPaca = NULL;
      struct lppaca *ptrLpPaca = NULL;
      struct ItLpRegSave *ptrLpRegSave = NULL;
#endif

      cmd = skipbl();
      if (cmd == '\n') {
              unsigned long sp, toc;
            asm("mr %0,1" : "=r" (sp) :);
            asm("mr %0,2" : "=r" (toc) :);

            printf("msr  = "REG"  sprg0= "REG"\n",
                   mfmsr(), mfspr(SPRN_SPRG0));
            printf("pvr  = "REG"  sprg1= "REG"\n",
                   mfspr(SPRN_PVR), mfspr(SPRN_SPRG1)); 
            printf("dec  = "REG"  sprg2= "REG"\n",
                   mfspr(SPRN_DEC), mfspr(SPRN_SPRG2));
            printf("sp   = "REG"  sprg3= "REG"\n", sp, mfspr(SPRN_SPRG3));
            printf("toc  = "REG"  dar  = "REG"\n", toc, mfspr(SPRN_DAR));
#ifdef CONFIG_PPC_ISERIES
            // Dump out relevant Paca data areas.
            printf("Paca: \n");
            ptrPaca = get_paca();
    
            printf("  Local Processor Control Area (LpPaca): \n");
            ptrLpPaca = ptrPaca->lppaca_ptr;
            printf("    Saved Srr0=%.16lx  Saved Srr1=%.16lx \n",
                   ptrLpPaca->saved_srr0, ptrLpPaca->saved_srr1);
            printf("    Saved Gpr3=%.16lx  Saved Gpr4=%.16lx \n",
                   ptrLpPaca->saved_gpr3, ptrLpPaca->saved_gpr4);
            printf("    Saved Gpr5=%.16lx \n", ptrLpPaca->saved_gpr5);
    
            printf("  Local Processor Register Save Area (LpRegSave): \n");
            ptrLpRegSave = ptrPaca->reg_save_ptr;
            printf("    Saved Sprg0=%.16lx  Saved Sprg1=%.16lx \n",
                   ptrLpRegSave->xSPRG0, ptrLpRegSave->xSPRG0);
            printf("    Saved Sprg2=%.16lx  Saved Sprg3=%.16lx \n",
                   ptrLpRegSave->xSPRG2, ptrLpRegSave->xSPRG3);
            printf("    Saved Msr  =%.16lx  Saved Nia  =%.16lx \n",
                   ptrLpRegSave->xMSR, ptrLpRegSave->xNIA);
#endif

            return;
      }

      scanhex(&regno);
      switch (cmd) {
      case 'w':
            val = read_spr(regno);
            scanhex(&val);
            write_spr(regno, val);
            /* fall through */
      case 'r':
            printf("spr %lx = %lx\n", regno, read_spr(regno));
            break;
      }
      scannl();
}

/*
 * Stuff for reading and writing memory safely
 */
int
mread(unsigned long adrs, void *buf, int size)
{
      volatile int n;
      char *p, *q;

      n = 0;
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();
            p = (char *)adrs;
            q = (char *)buf;
            switch (size) {
            case 2:
                  *(u16 *)q = *(u16 *)p;
                  break;
            case 4:
                  *(u32 *)q = *(u32 *)p;
                  break;
            case 8:
                  *(u64 *)q = *(u64 *)p;
                  break;
            default:
                  for( ; n < size; ++n) {
                        *q++ = *p++;
                        sync();
                  }
            }
            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
            n = size;
      }
      catch_memory_errors = 0;
      return n;
}

int
mwrite(unsigned long adrs, void *buf, int size)
{
      volatile int n;
      char *p, *q;

      n = 0;
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();
            p = (char *) adrs;
            q = (char *) buf;
            switch (size) {
            case 2:
                  *(u16 *)p = *(u16 *)q;
                  break;
            case 4:
                  *(u32 *)p = *(u32 *)q;
                  break;
            case 8:
                  *(u64 *)p = *(u64 *)q;
                  break;
            default:
                  for ( ; n < size; ++n) {
                        *p++ = *q++;
                        sync();
                  }
            }
            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
            n = size;
      } else {
            printf("*** Error writing address %x\n", adrs + n);
      }
      catch_memory_errors = 0;
      return n;
}

static int fault_type;
static int fault_except;
static char *fault_chars[] = { "--", "**", "##" };

static int handle_fault(struct pt_regs *regs)
{
      fault_except = TRAP(regs);
      switch (TRAP(regs)) {
      case 0x200:
            fault_type = 0;
            break;
      case 0x300:
      case 0x380:
            fault_type = 1;
            break;
      default:
            fault_type = 2;
      }

      longjmp(bus_error_jmp, 1);

      return 0;
}

#define SWAP(a, b, t)   ((t) = (a), (a) = (b), (b) = (t))

void
byterev(unsigned char *val, int size)
{
      int t;
      
      switch (size) {
      case 2:
            SWAP(val[0], val[1], t);
            break;
      case 4:
            SWAP(val[0], val[3], t);
            SWAP(val[1], val[2], t);
            break;
      case 8: /* is there really any use for this? */
            SWAP(val[0], val[7], t);
            SWAP(val[1], val[6], t);
            SWAP(val[2], val[5], t);
            SWAP(val[3], val[4], t);
            break;
      }
}

static int brev;
static int mnoread;

static char *memex_help_string = 
    "Memory examine command usage:\n"
    "m [addr] [flags] examine/change memory\n"
    "  addr is optional.  will start where left off.\n"
    "  flags may include chars from this set:\n"
    "    b   modify by bytes (default)\n"
    "    w   modify by words (2 byte)\n"
    "    l   modify by longs (4 byte)\n"
    "    d   modify by doubleword (8 byte)\n"
    "    r   toggle reverse byte order mode\n"
    "    n   do not read memory (for i/o spaces)\n"
    "    .   ok to read (default)\n"
    "NOTE: flags are saved as defaults\n"
    "";

static char *memex_subcmd_help_string = 
    "Memory examine subcommands:\n"
    "  hexval   write this val to current location\n"
    "  'string' write chars from string to this location\n"
    "  '        increment address\n"
    "  ^        decrement address\n"
    "  /        increment addr by 0x10.  //=0x100, ///=0x1000, etc\n"
    "  \\        decrement addr by 0x10.  \\\\=0x100, \\\\\\=0x1000, etc\n"
    "  `        clear no-read flag\n"
    "  ;        stay at this addr\n"
    "  v        change to byte mode\n"
    "  w        change to word (2 byte) mode\n"
    "  l        change to long (4 byte) mode\n"
    "  u        change to doubleword (8 byte) mode\n"
    "  m addr   change current addr\n"
    "  n        toggle no-read flag\n"
    "  r        toggle byte reverse flag\n"
    "  < count  back up count bytes\n"
    "  > count  skip forward count bytes\n"
    "  x        exit this mode\n"
    "";

void
memex(void)
{
      int cmd, inc, i, nslash;
      unsigned long n;
      unsigned char val[16];

      scanhex((void *)&adrs);
      cmd = skipbl();
      if (cmd == '?') {
            printf(memex_help_string);
            return;
      } else {
            termch = cmd;
      }
      last_cmd = "m\n";
      while ((cmd = skipbl()) != '\n') {
            switch( cmd ){
            case 'b':   size = 1;   break;
            case 'w':   size = 2;   break;
            case 'l':   size = 4;   break;
            case 'd':   size = 8;   break;
            case 'r':   brev = !brev;     break;
            case 'n':   mnoread = 1;      break;
            case '.':   mnoread = 0;      break;
            }
      }
      if( size <= 0 )
            size = 1;
      else if( size > 8 )
            size = 8;
      for(;;){
            if (!mnoread)
                  n = mread(adrs, val, size);
            printf(REG"%c", adrs, brev? 'r': ' ');
            if (!mnoread) {
                  if (brev)
                        byterev(val, size);
                  putchar(' ');
                  for (i = 0; i < n; ++i)
                        printf("%.2x", val[i]);
                  for (; i < size; ++i)
                        printf("%s", fault_chars[fault_type]);
            }
            putchar(' ');
            inc = size;
            nslash = 0;
            for(;;){
                  if( scanhex(&n) ){
                        for (i = 0; i < size; ++i)
                              val[i] = n >> (i * 8);
                        if (!brev)
                              byterev(val, size);
                        mwrite(adrs, val, size);
                        inc = size;
                  }
                  cmd = skipbl();
                  if (cmd == '\n')
                        break;
                  inc = 0;
                  switch (cmd) {
                  case '\'':
                        for(;;){
                              n = inchar();
                              if( n == '\\' )
                                    n = bsesc();
                              else if( n == '\'' )
                                    break;
                              for (i = 0; i < size; ++i)
                                    val[i] = n >> (i * 8);
                              if (!brev)
                                    byterev(val, size);
                              mwrite(adrs, val, size);
                              adrs += size;
                        }
                        adrs -= size;
                        inc = size;
                        break;
                  case ',':
                        adrs += size;
                        break;
                  case '.':
                        mnoread = 0;
                        break;
                  case ';':
                        break;
                  case 'x':
                  case EOF:
                        scannl();
                        return;
                  case 'b':
                  case 'v':
                        size = 1;
                        break;
                  case 'w':
                        size = 2;
                        break;
                  case 'l':
                        size = 4;
                        break;
                  case 'u':
                        size = 8;
                        break;
                  case '^':
                        adrs -= size;
                        break;
                        break;
                  case '/':
                        if (nslash > 0)
                              adrs -= 1 << nslash;
                        else
                              nslash = 0;
                        nslash += 4;
                        adrs += 1 << nslash;
                        break;
                  case '\\':
                        if (nslash < 0)
                              adrs += 1 << -nslash;
                        else
                              nslash = 0;
                        nslash -= 4;
                        adrs -= 1 << -nslash;
                        break;
                  case 'm':
                        scanhex((void *)&adrs);
                        break;
                  case 'n':
                        mnoread = 1;
                        break;
                  case 'r':
                        brev = !brev;
                        break;
                  case '<':
                        n = size;
                        scanhex(&n);
                        adrs -= n;
                        break;
                  case '>':
                        n = size;
                        scanhex(&n);
                        adrs += n;
                        break;
                  case '?':
                        printf(memex_subcmd_help_string);
                        break;
                  }
            }
            adrs += inc;
      }
}

int
bsesc(void)
{
      int c;

      c = inchar();
      switch( c ){
      case 'n':   c = '\n';   break;
      case 'r':   c = '\r';   break;
      case 'b':   c = '\b';   break;
      case 't':   c = '\t';   break;
      }
      return c;
}

static void xmon_rawdump (unsigned long adrs, long ndump)
{
      long n, m, r, nr;
      unsigned char temp[16];

      for (n = ndump; n > 0;) {
            r = n < 16? n: 16;
            nr = mread(adrs, temp, r);
            adrs += nr;
            for (m = 0; m < r; ++m) {
                  if (m < nr)
                        printf("%.2x", temp[m]);
                  else
                        printf("%s", fault_chars[fault_type]);
            }
            n -= r;
            if (nr < r)
                  break;
      }
      printf("\n");
}

#define isxdigit(c)     (('0' <= (c) && (c) <= '9') \
                   || ('a' <= (c) && (c) <= 'f') \
                   || ('A' <= (c) && (c) <= 'F'))
void
dump(void)
{
      int c;

      c = inchar();
      if ((isxdigit(c) && c != 'f' && c != 'd') || c == '\n')
            termch = c;
      scanhex((void *)&adrs);
      if (termch != '\n')
            termch = 0;
      if (c == 'i') {
            scanhex(&nidump);
            if (nidump == 0)
                  nidump = 16;
            else if (nidump > MAX_DUMP)
                  nidump = MAX_DUMP;
            adrs += ppc_inst_dump(adrs, nidump, 1);
            last_cmd = "di\n";
      } else if (c == 'r') {
            scanhex(&ndump);
            if (ndump == 0)
                  ndump = 64;
            xmon_rawdump(adrs, ndump);
            adrs += ndump;
            last_cmd = "dr\n";
      } else {
            scanhex(&ndump);
            if (ndump == 0)
                  ndump = 64;
            else if (ndump > MAX_DUMP)
                  ndump = MAX_DUMP;
            prdump(adrs, ndump);
            adrs += ndump;
            last_cmd = "d\n";
      }
}

void
prdump(unsigned long adrs, long ndump)
{
      long n, m, c, r, nr;
      unsigned char temp[16];

      for (n = ndump; n > 0;) {
            printf(REG, adrs);
            putchar(' ');
            r = n < 16? n: 16;
            nr = mread(adrs, temp, r);
            adrs += nr;
            for (m = 0; m < r; ++m) {
                    if ((m & (sizeof(long) - 1)) == 0 && m > 0)
                        putchar(' ');
                  if (m < nr)
                        printf("%.2x", temp[m]);
                  else
                        printf("%s", fault_chars[fault_type]);
            }
            for (; m < 16; ++m) {
                    if ((m & (sizeof(long) - 1)) == 0)
                        putchar(' ');
                  printf("  ");
            }
            printf("  |");
            for (m = 0; m < r; ++m) {
                  if (m < nr) {
                        c = temp[m];
                        putchar(' ' <= c && c <= '~'? c: '.');
                  } else
                        putchar(' ');
            }
            n -= r;
            for (; m < 16; ++m)
                  putchar(' ');
            printf("|\n");
            if (nr < r)
                  break;
      }
}

int
ppc_inst_dump(unsigned long adr, long count, int praddr)
{
      int nr, dotted;
      unsigned long first_adr;
      unsigned long inst, last_inst = 0;
      unsigned char val[4];

      dotted = 0;
      for (first_adr = adr; count > 0; --count, adr += 4) {
            nr = mread(adr, val, 4);
            if (nr == 0) {
                  if (praddr) {
                        const char *x = fault_chars[fault_type];
                        printf(REG"  %s%s%s%s\n", adr, x, x, x, x);
                  }
                  break;
            }
            inst = GETWORD(val);
            if (adr > first_adr && inst == last_inst) {
                  if (!dotted) {
                        printf(" ...\n");
                        dotted = 1;
                  }
                  continue;
            }
            dotted = 0;
            last_inst = inst;
            if (praddr)
                  printf(REG"  %.8x", adr, inst);
            printf("\t");
            print_insn_powerpc(inst, adr, 0);   /* always returns 4 */
            printf("\n");
      }
      return adr - first_adr;
}

void
print_address(unsigned long addr)
{
      xmon_print_symbol(addr, "\t# ", "");
}


/*
 * Memory operations - move, set, print differences
 */
static unsigned long mdest;         /* destination address */
static unsigned long msrc;          /* source address */
static unsigned long mval;          /* byte value to set memory to */
static unsigned long mcount;        /* # bytes to affect */
static unsigned long mdiffs;        /* max # differences to print */

void
memops(int cmd)
{
      scanhex((void *)&mdest);
      if( termch != '\n' )
            termch = 0;
      scanhex((void *)(cmd == 's'? &mval: &msrc));
      if( termch != '\n' )
            termch = 0;
      scanhex((void *)&mcount);
      switch( cmd ){
      case 'm':
            memmove((void *)mdest, (void *)msrc, mcount);
            break;
      case 's':
            memset((void *)mdest, mval, mcount);
            break;
      case 'd':
            if( termch != '\n' )
                  termch = 0;
            scanhex((void *)&mdiffs);
            memdiffs((unsigned char *)mdest, (unsigned char *)msrc, mcount, mdiffs);
            break;
      }
}

void
memdiffs(unsigned char *p1, unsigned char *p2, unsigned nb, unsigned maxpr)
{
      unsigned n, prt;

      prt = 0;
      for( n = nb; n > 0; --n )
            if( *p1++ != *p2++ )
                  if( ++prt <= maxpr )
                        printf("%.16x %.2x # %.16x %.2x\n", p1 - 1,
                              p1[-1], p2 - 1, p2[-1]);
      if( prt > maxpr )
            printf("Total of %d differences\n", prt);
}

static unsigned mend;
static unsigned mask;

void
memlocate(void)
{
      unsigned a, n;
      unsigned char val[4];

      last_cmd = "ml";
      scanhex((void *)&mdest);
      if (termch != '\n') {
            termch = 0;
            scanhex((void *)&mend);
            if (termch != '\n') {
                  termch = 0;
                  scanhex((void *)&mval);
                  mask = ~0;
                  if (termch != '\n') termch = 0;
                  scanhex((void *)&mask);
            }
      }
      n = 0;
      for (a = mdest; a < mend; a += 4) {
            if (mread(a, val, 4) == 4
                  && ((GETWORD(val) ^ mval) & mask) == 0) {
                  printf("%.16x:  %.16x\n", a, GETWORD(val));
                  if (++n >= 10)
                        break;
            }
      }
}

static unsigned long mskip = 0x1000;
static unsigned long mlim = 0xffffffff;

void
memzcan(void)
{
      unsigned char v;
      unsigned a;
      int ok, ook;

      scanhex(&mdest);
      if (termch != '\n') termch = 0;
      scanhex(&mskip);
      if (termch != '\n') termch = 0;
      scanhex(&mlim);
      ook = 0;
      for (a = mdest; a < mlim; a += mskip) {
            ok = mread(a, &v, 1);
            if (ok && !ook) {
                  printf("%.8x .. ", a);
            } else if (!ok && ook)
                  printf("%.8x\n", a - mskip);
            ook = ok;
            if (a + mskip < a)
                  break;
      }
      if (ook)
            printf("%.8x\n", a - mskip);
}

void proccall(void)
{
      unsigned long args[8];
      unsigned long ret;
      int i;
      typedef unsigned long (*callfunc_t)(unsigned long, unsigned long,
                  unsigned long, unsigned long, unsigned long,
                  unsigned long, unsigned long, unsigned long);
      callfunc_t func;

      if (!scanhex(&adrs))
            return;
      if (termch != '\n')
            termch = 0;
      for (i = 0; i < 8; ++i)
            args[i] = 0;
      for (i = 0; i < 8; ++i) {
            if (!scanhex(&args[i]) || termch == '\n')
                  break;
            termch = 0;
      }
      func = (callfunc_t) adrs;
      ret = 0;
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();
            ret = func(args[0], args[1], args[2], args[3],
                     args[4], args[5], args[6], args[7]);
            sync();
            printf("return value is %x\n", ret);
      } else {
            printf("*** %x exception occurred\n", fault_except);
      }
      catch_memory_errors = 0;
}

/* Input scanning routines */
int
skipbl(void)
{
      int c;

      if( termch != 0 ){
            c = termch;
            termch = 0;
      } else
            c = inchar();
      while( c == ' ' || c == '\t' )
            c = inchar();
      return c;
}

#define N_PTREGS  44
static char *regnames[N_PTREGS] = {
      "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
      "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
      "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
      "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
      "pc", "msr", "or3", "ctr", "lr", "xer", "ccr",
#ifdef CONFIG_PPC64
      "softe",
#else
      "mq",
#endif
      "trap", "dar", "dsisr", "res"
};

int
scanhex(unsigned long *vp)
{
      int c, d;
      unsigned long v;

      c = skipbl();
      if (c == '%') {
            /* parse register name */
            char regname[8];
            int i;

            for (i = 0; i < sizeof(regname) - 1; ++i) {
                  c = inchar();
                  if (!isalnum(c)) {
                        termch = c;
                        break;
                  }
                  regname[i] = c;
            }
            regname[i] = 0;
            for (i = 0; i < N_PTREGS; ++i) {
                  if (strcmp(regnames[i], regname) == 0) {
                        if (xmon_regs == NULL) {
                              printf("regs not available\n");
                              return 0;
                        }
                        *vp = ((unsigned long *)xmon_regs)[i];
                        return 1;
                  }
            }
            printf("invalid register name '%%%s'\n", regname);
            return 0;
      }

      /* skip leading "0x" if any */

      if (c == '0') {
            c = inchar();
            if (c == 'x') {
                  c = inchar();
            } else {
                  d = hexdigit(c);
                  if (d == EOF) {
                        termch = c;
                        *vp = 0;
                        return 1;
                  }
            }
      } else if (c == '$') {
            int i;
            for (i=0; i<63; i++) {
                  c = inchar();
                  if (isspace(c)) {
                        termch = c;
                        break;
                  }
                  tmpstr[i] = c;
            }
            tmpstr[i++] = 0;
            *vp = 0;
            if (setjmp(bus_error_jmp) == 0) {
                  catch_memory_errors = 1;
                  sync();
                  *vp = kallsyms_lookup_name(tmpstr);
                  sync();
            }
            catch_memory_errors = 0;
            if (!(*vp)) {
                  printf("unknown symbol '%s'\n", tmpstr);
                  return 0;
            }
            return 1;
      }

      d = hexdigit(c);
      if (d == EOF) {
            termch = c;
            return 0;
      }
      v = 0;
      do {
            v = (v << 4) + d;
            c = inchar();
            d = hexdigit(c);
      } while (d != EOF);
      termch = c;
      *vp = v;
      return 1;
}

void
scannl(void)
{
      int c;

      c = termch;
      termch = 0;
      while( c != '\n' )
            c = inchar();
}

int hexdigit(int c)
{
      if( '0' <= c && c <= '9' )
            return c - '0';
      if( 'A' <= c && c <= 'F' )
            return c - ('A' - 10);
      if( 'a' <= c && c <= 'f' )
            return c - ('a' - 10);
      return EOF;
}

void
getstring(char *s, int size)
{
      int c;

      c = skipbl();
      do {
            if( size > 1 ){
                  *s++ = c;
                  --size;
            }
            c = inchar();
      } while( c != ' ' && c != '\t' && c != '\n' );
      termch = c;
      *s = 0;
}

static char line[256];
static char *lineptr;

void
flush_input(void)
{
      lineptr = NULL;
}

int
inchar(void)
{
      if (lineptr == NULL || *lineptr == 0) {
            if (xmon_gets(line, sizeof(line)) == NULL) {
                  lineptr = NULL;
                  return EOF;
            }
            lineptr = line;
      }
      return *lineptr++;
}

void
take_input(char *str)
{
      lineptr = str;
}


static void
symbol_lookup(void)
{
      int type = inchar();
      unsigned long addr;
      static char tmp[64];

      switch (type) {
      case 'a':
            if (scanhex(&addr))
                  xmon_print_symbol(addr, ": ", "\n");
            termch = 0;
            break;
      case 's':
            getstring(tmp, 64);
            if (setjmp(bus_error_jmp) == 0) {
                  catch_memory_errors = 1;
                  sync();
                  addr = kallsyms_lookup_name(tmp);
                  if (addr)
                        printf("%s: %lx\n", tmp, addr);
                  else
                        printf("Symbol '%s' not found.\n", tmp);
                  sync();
            }
            catch_memory_errors = 0;
            termch = 0;
            break;
      }
}


/* Print an address in numeric and symbolic form (if possible) */
static void xmon_print_symbol(unsigned long address, const char *mid,
                        const char *after)
{
      char *modname;
      const char *name = NULL;
      unsigned long offset, size;

      printf(REG, address);
      if (setjmp(bus_error_jmp) == 0) {
            catch_memory_errors = 1;
            sync();
            name = kallsyms_lookup(address, &size, &offset, &modname,
                               tmpstr);
            sync();
            /* wait a little while to see if we get a machine check */
            __delay(200);
      }

      catch_memory_errors = 0;

      if (name) {
            printf("%s%s+%#lx/%#lx", mid, name, offset, size);
            if (modname)
                  printf(" [%s]", modname);
      }
      printf("%s", after);
}

#ifdef CONFIG_PPC64
static void dump_slb(void)
{
      int i;
      unsigned long tmp;

      printf("SLB contents of cpu %x\n", smp_processor_id());

      for (i = 0; i < SLB_NUM_ENTRIES; i++) {
            asm volatile("slbmfee  %0,%1" : "=r" (tmp) : "r" (i));
            printf("%02d %016lx ", i, tmp);

            asm volatile("slbmfev  %0,%1" : "=r" (tmp) : "r" (i));
            printf("%016lx\n", tmp);
      }
}

static void dump_stab(void)
{
      int i;
      unsigned long *tmp = (unsigned long *)get_paca()->stab_addr;

      printf("Segment table contents of cpu %x\n", smp_processor_id());

      for (i = 0; i < PAGE_SIZE/16; i++) {
            unsigned long a, b;

            a = *tmp++;
            b = *tmp++;

            if (a || b) {
                  printf("%03d %016lx ", i, a);
                  printf("%016lx\n", b);
            }
      }
}

void dump_segments(void)
{
      if (cpu_has_feature(CPU_FTR_SLB))
            dump_slb();
      else
            dump_stab();
}
#endif

#ifdef CONFIG_PPC_STD_MMU_32
void dump_segments(void)
{
      int i;

      printf("sr0-15 =");
      for (i = 0; i < 16; ++i)
            printf(" %x", mfsrin(i));
      printf("\n");
}
#endif

void xmon_init(int enable)
{
      if (enable) {
            __debugger = xmon;
            __debugger_ipi = xmon_ipi;
            __debugger_bpt = xmon_bpt;
            __debugger_sstep = xmon_sstep;
            __debugger_iabr_match = xmon_iabr_match;
            __debugger_dabr_match = xmon_dabr_match;
            __debugger_fault_handler = xmon_fault_handler;
      } else {
            __debugger = NULL;
            __debugger_ipi = NULL;
            __debugger_bpt = NULL;
            __debugger_sstep = NULL;
            __debugger_iabr_match = NULL;
            __debugger_dabr_match = NULL;
            __debugger_fault_handler = NULL;
      }
      xmon_map_scc();
}

#ifdef CONFIG_MAGIC_SYSRQ
static void sysrq_handle_xmon(int key, struct pt_regs *pt_regs,
                        struct tty_struct *tty) 
{
      /* ensure xmon is enabled */
      xmon_init(1);
      debugger(pt_regs);
}

static struct sysrq_key_op sysrq_xmon_op = 
{
      .handler =  sysrq_handle_xmon,
      .help_msg = "Xmon",
      .action_msg =     "Entering xmon",
};

static int __init setup_xmon_sysrq(void)
{
      register_sysrq_key('x', &sysrq_xmon_op);
      return 0;
}
__initcall(setup_xmon_sysrq);
#endif /* CONFIG_MAGIC_SYSRQ */

Generated by  Doxygen 1.6.0   Back to index