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traps.c

/*
 * File:         arch/blackfin/kernel/traps.c
 * Based on:
 * Author:       Hamish Macdonald
 *
 * Created:
 * Description:  uses S/W interrupt 15 for the system calls
 *
 * Modified:
 *               Copyright 2004-2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.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, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/blackfin.h>
#include <asm/irq_handler.h>
#include <linux/irq.h>
#include <asm/trace.h>
#include <asm/fixed_code.h>
#include <asm/dma.h>

#ifdef CONFIG_KGDB
# include <linux/debugger.h>
# include <linux/kgdb.h>

# define CHK_DEBUGGER_TRAP() \
      do { \
            CHK_DEBUGGER(trapnr, sig, info.si_code, fp, ); \
      } while (0)
# define CHK_DEBUGGER_TRAP_MAYBE() \
      do { \
            if (kgdb_connected) \
                  CHK_DEBUGGER_TRAP(); \
      } while (0)
#else
# define CHK_DEBUGGER_TRAP() do { } while (0)
# define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
#endif

/* Initiate the event table handler */
void __init trap_init(void)
{
      CSYNC();
      bfin_write_EVT3(trap);
      CSYNC();
}

unsigned long saved_icplb_fault_addr, saved_dcplb_fault_addr;

static void decode_address(char *buf, unsigned long address)
{
      struct vm_list_struct *vml;
      struct task_struct *p;
      struct mm_struct *mm;
      unsigned long flags, offset;
      unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();

#ifdef CONFIG_KALLSYMS
      unsigned long symsize;
      const char *symname;
      char *modname;
      char *delim = ":";
      char namebuf[128];

      /* look up the address and see if we are in kernel space */
      symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);

      if (symname) {
            /* yeah! kernel space! */
            if (!modname)
                  modname = delim = "";
            sprintf(buf, "<0x%p> { %s%s%s%s + 0x%lx }",
                          (void *)address, delim, modname, delim, symname,
                          (unsigned long)offset);
            return;

      }
#endif

      /* Problem in fixed code section? */
      if (address >= FIXED_CODE_START && address < FIXED_CODE_END) {
            sprintf(buf, "<0x%p> /* Maybe fixed code section */", (void *)address);
            return;
      }

      /* Problem somewhere before the kernel start address */
      if (address < CONFIG_BOOT_LOAD) {
            sprintf(buf, "<0x%p> /* Maybe null pointer? */", (void *)address);
            return;
      }

      /* looks like we're off in user-land, so let's walk all the
       * mappings of all our processes and see if we can't be a whee
       * bit more specific
       */
      write_lock_irqsave(&tasklist_lock, flags);
      for_each_process(p) {
            mm = (in_atomic ? p->mm : get_task_mm(p));
            if (!mm)
                  continue;

            vml = mm->context.vmlist;
            while (vml) {
                  struct vm_area_struct *vma = vml->vma;

                  if (address >= vma->vm_start && address < vma->vm_end) {
                        char _tmpbuf[256];
                        char *name = p->comm;
                        struct file *file = vma->vm_file;

                        if (file)
                              name = d_path(&file->f_path, _tmpbuf,
                                          sizeof(_tmpbuf));

                        /* FLAT does not have its text aligned to the start of
                         * the map while FDPIC ELF does ...
                         */

                        /* before we can check flat/fdpic, we need to
                         * make sure current is valid
                         */
                        if ((unsigned long)current >= FIXED_CODE_START &&
                            !((unsigned long)current & 0x3)) {
                              if (current->mm &&
                                  (address > current->mm->start_code) &&
                                  (address < current->mm->end_code))
                                    offset = address - current->mm->start_code;
                              else
                                    offset = (address - vma->vm_start) +
                                           (vma->vm_pgoff << PAGE_SHIFT);

                              sprintf(buf, "<0x%p> [ %s + 0x%lx ]",
                                    (void *)address, name, offset);
                        } else
                              sprintf(buf, "<0x%p> [ %s vma:0x%lx-0x%lx]",
                                    (void *)address, name,
                                    vma->vm_start, vma->vm_end);

                        if (!in_atomic)
                              mmput(mm);

                        if (!strlen(buf))
                              sprintf(buf, "<0x%p> [ %s ] dynamic memory", (void *)address, name);

                        goto done;
                  }

                  vml = vml->next;
            }
            if (!in_atomic)
                  mmput(mm);
      }

      /* we were unable to find this address anywhere */
      sprintf(buf, "<0x%p> /* kernel dynamic memory */", (void *)address);

done:
      write_unlock_irqrestore(&tasklist_lock, flags);
}

asmlinkage void double_fault_c(struct pt_regs *fp)
{
      console_verbose();
      oops_in_progress = 1;
      printk(KERN_EMERG "\n" KERN_EMERG "Double Fault\n");
      dump_bfin_process(fp);
      dump_bfin_mem(fp);
      show_regs(fp);
      panic("Double Fault - unrecoverable event\n");

}

asmlinkage void trap_c(struct pt_regs *fp)
{
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
      int j;
#endif
      int sig = 0;
      siginfo_t info;
      unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;

      trace_buffer_save(j);

      /* Important - be very careful dereferncing pointers - will lead to
       * double faults if the stack has become corrupt
       */

      /* If the fault was caused by a kernel thread, or interrupt handler
       * we will kernel panic, so the system reboots.
       * If KGDB is enabled, don't set this for kernel breakpoints
      */

      /* TODO: check to see if we are in some sort of deferred HWERR
       * that we should be able to recover from, not kernel panic
       */
      if ((bfin_read_IPEND() & 0xFFC0) && (trapnr != VEC_STEP)
#ifdef CONFIG_KGDB
            && (trapnr != VEC_EXCPT02)
#endif
      ){
            console_verbose();
            oops_in_progress = 1;
      } else if (current) {
            if (current->mm == NULL) {
                  console_verbose();
                  oops_in_progress = 1;
            }
      }

      /* trap_c() will be called for exceptions. During exceptions
       * processing, the pc value should be set with retx value.
       * With this change we can cleanup some code in signal.c- TODO
       */
      fp->orig_pc = fp->retx;
      /* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n",
            trapnr, fp->ipend, fp->pc, fp->retx); */

      /* send the appropriate signal to the user program */
      switch (trapnr) {

      /* This table works in conjuction with the one in ./mach-common/entry.S
       * Some exceptions are handled there (in assembly, in exception space)
       * Some are handled here, (in C, in interrupt space)
       * Some, like CPLB, are handled in both, where the normal path is
       * handled in assembly/exception space, and the error path is handled
       * here
       */

      /* 0x00 - Linux Syscall, getting here is an error */
      /* 0x01 - userspace gdb breakpoint, handled here */
      case VEC_EXCPT01:
            info.si_code = TRAP_ILLTRAP;
            sig = SIGTRAP;
            CHK_DEBUGGER_TRAP_MAYBE();
            /* Check if this is a breakpoint in kernel space */
            if (fp->ipend & 0xffc0)
                  return;
            else
                  break;
#ifdef CONFIG_KGDB
      case VEC_EXCPT02 :             /* gdb connection */
            info.si_code = TRAP_ILLTRAP;
            sig = SIGTRAP;
            CHK_DEBUGGER_TRAP();
            return;
#else
      /* 0x02 - User Defined, Caught by default */
#endif
      /* 0x03 - User Defined, userspace stack overflow */
      case VEC_EXCPT03:
            info.si_code = SEGV_STACKFLOW;
            sig = SIGSEGV;
            printk(KERN_NOTICE EXC_0x03(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x04 - User Defined, Caught by default */
      /* 0x05 - User Defined, Caught by default */
      /* 0x06 - User Defined, Caught by default */
      /* 0x07 - User Defined, Caught by default */
      /* 0x08 - User Defined, Caught by default */
      /* 0x09 - User Defined, Caught by default */
      /* 0x0A - User Defined, Caught by default */
      /* 0x0B - User Defined, Caught by default */
      /* 0x0C - User Defined, Caught by default */
      /* 0x0D - User Defined, Caught by default */
      /* 0x0E - User Defined, Caught by default */
      /* 0x0F - User Defined, Caught by default */
      /* 0x10 HW Single step, handled here */
      case VEC_STEP:
            info.si_code = TRAP_STEP;
            sig = SIGTRAP;
            CHK_DEBUGGER_TRAP_MAYBE();
            /* Check if this is a single step in kernel space */
            if (fp->ipend & 0xffc0)
                  return;
            else
                  break;
      /* 0x11 - Trace Buffer Full, handled here */
      case VEC_OVFLOW:
            info.si_code = TRAP_TRACEFLOW;
            sig = SIGTRAP;
            printk(KERN_NOTICE EXC_0x11(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x12 - Reserved, Caught by default */
      /* 0x13 - Reserved, Caught by default */
      /* 0x14 - Reserved, Caught by default */
      /* 0x15 - Reserved, Caught by default */
      /* 0x16 - Reserved, Caught by default */
      /* 0x17 - Reserved, Caught by default */
      /* 0x18 - Reserved, Caught by default */
      /* 0x19 - Reserved, Caught by default */
      /* 0x1A - Reserved, Caught by default */
      /* 0x1B - Reserved, Caught by default */
      /* 0x1C - Reserved, Caught by default */
      /* 0x1D - Reserved, Caught by default */
      /* 0x1E - Reserved, Caught by default */
      /* 0x1F - Reserved, Caught by default */
      /* 0x20 - Reserved, Caught by default */
      /* 0x21 - Undefined Instruction, handled here */
      case VEC_UNDEF_I:
            info.si_code = ILL_ILLOPC;
            sig = SIGILL;
            printk(KERN_NOTICE EXC_0x21(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x22 - Illegal Instruction Combination, handled here */
      case VEC_ILGAL_I:
            info.si_code = ILL_ILLPARAOP;
            sig = SIGILL;
            printk(KERN_NOTICE EXC_0x22(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x23 - Data CPLB protection violation, handled here */
      case VEC_CPLB_VL:
            info.si_code = ILL_CPLB_VI;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x23(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x24 - Data access misaligned, handled here */
      case VEC_MISALI_D:
            info.si_code = BUS_ADRALN;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x24(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x25 - Unrecoverable Event, handled here */
      case VEC_UNCOV:
            info.si_code = ILL_ILLEXCPT;
            sig = SIGILL;
            printk(KERN_NOTICE EXC_0x25(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
            error case is handled here */
      case VEC_CPLB_M:
            info.si_code = BUS_ADRALN;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x26(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
      case VEC_CPLB_MHIT:
            info.si_code = ILL_CPLB_MULHIT;
            sig = SIGSEGV;
#ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
            if (saved_dcplb_fault_addr < FIXED_CODE_START)
                  printk(KERN_NOTICE "NULL pointer access\n");
            else
#endif
                  printk(KERN_NOTICE EXC_0x27(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x28 - Emulation Watchpoint, handled here */
      case VEC_WATCH:
            info.si_code = TRAP_WATCHPT;
            sig = SIGTRAP;
            pr_debug(EXC_0x28(KERN_DEBUG));
            CHK_DEBUGGER_TRAP_MAYBE();
            /* Check if this is a watchpoint in kernel space */
            if (fp->ipend & 0xffc0)
                  return;
            else
                  break;
#ifdef CONFIG_BF535
      /* 0x29 - Instruction fetch access error (535 only) */
      case VEC_ISTRU_VL:      /* ADSP-BF535 only (MH) */
            info.si_code = BUS_OPFETCH;
            sig = SIGBUS;
            printk(KERN_NOTICE "BF535: VEC_ISTRU_VL\n");
            CHK_DEBUGGER_TRAP();
            break;
#else
      /* 0x29 - Reserved, Caught by default */
#endif
      /* 0x2A - Instruction fetch misaligned, handled here */
      case VEC_MISALI_I:
            info.si_code = BUS_ADRALN;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x2A(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x2B - Instruction CPLB protection violation, handled here */
      case VEC_CPLB_I_VL:
            info.si_code = ILL_CPLB_VI;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x2B(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
      case VEC_CPLB_I_M:
            info.si_code = ILL_CPLB_MISS;
            sig = SIGBUS;
            printk(KERN_NOTICE EXC_0x2C(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x2D - Instruction CPLB Multiple Hits, handled here */
      case VEC_CPLB_I_MHIT:
            info.si_code = ILL_CPLB_MULHIT;
            sig = SIGSEGV;
#ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
            if (saved_icplb_fault_addr < FIXED_CODE_START)
                  printk(KERN_NOTICE "Jump to NULL address\n");
            else
#endif
                  printk(KERN_NOTICE EXC_0x2D(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x2E - Illegal use of Supervisor Resource, handled here */
      case VEC_ILL_RES:
            info.si_code = ILL_PRVOPC;
            sig = SIGILL;
            printk(KERN_NOTICE EXC_0x2E(KERN_NOTICE));
            CHK_DEBUGGER_TRAP();
            break;
      /* 0x2F - Reserved, Caught by default */
      /* 0x30 - Reserved, Caught by default */
      /* 0x31 - Reserved, Caught by default */
      /* 0x32 - Reserved, Caught by default */
      /* 0x33 - Reserved, Caught by default */
      /* 0x34 - Reserved, Caught by default */
      /* 0x35 - Reserved, Caught by default */
      /* 0x36 - Reserved, Caught by default */
      /* 0x37 - Reserved, Caught by default */
      /* 0x38 - Reserved, Caught by default */
      /* 0x39 - Reserved, Caught by default */
      /* 0x3A - Reserved, Caught by default */
      /* 0x3B - Reserved, Caught by default */
      /* 0x3C - Reserved, Caught by default */
      /* 0x3D - Reserved, Caught by default */
      /* 0x3E - Reserved, Caught by default */
      /* 0x3F - Reserved, Caught by default */
      case VEC_HWERR:
            info.si_code = BUS_ADRALN;
            sig = SIGBUS;
            switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {
            /* System MMR Error */
            case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):
                  info.si_code = BUS_ADRALN;
                  sig = SIGBUS;
                  printk(KERN_NOTICE HWC_x2(KERN_NOTICE));
                  break;
            /* External Memory Addressing Error */
            case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):
                  info.si_code = BUS_ADRERR;
                  sig = SIGBUS;
                  printk(KERN_NOTICE HWC_x3(KERN_NOTICE));
                  break;
            /* Performance Monitor Overflow */
            case (SEQSTAT_HWERRCAUSE_PERF_FLOW):
                  printk(KERN_NOTICE HWC_x12(KERN_NOTICE));
                  break;
            /* RAISE 5 instruction */
            case (SEQSTAT_HWERRCAUSE_RAISE_5):
                  printk(KERN_NOTICE HWC_x18(KERN_NOTICE));
                  break;
            default:        /* Reserved */
                  printk(KERN_NOTICE HWC_default(KERN_NOTICE));
                  break;
            }
            CHK_DEBUGGER_TRAP();
            break;
      default:
            info.si_code = TRAP_ILLTRAP;
            sig = SIGTRAP;
            printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n",
                  (fp->seqstat & SEQSTAT_EXCAUSE));
            CHK_DEBUGGER_TRAP();
            break;
      }

      BUG_ON(sig == 0);

      if (sig != SIGTRAP) {
            unsigned long *stack;
            dump_bfin_process(fp);
            dump_bfin_mem(fp);
            show_regs(fp);

            /* Print out the trace buffer if it makes sense */
#ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
            if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M)
                  printk(KERN_NOTICE "No trace since you do not have "
                        "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n"
                        KERN_NOTICE "\n");
            else
#endif
                  dump_bfin_trace_buffer();

            if (oops_in_progress) {
                  /* Dump the current kernel stack */
                  printk(KERN_NOTICE "\n" KERN_NOTICE "Kernel Stack\n");
                  show_stack(current, NULL);

                  print_modules();
#ifndef CONFIG_ACCESS_CHECK
                  printk(KERN_EMERG "Please turn on "
                         "CONFIG_ACCESS_CHECK\n");
#endif
                  panic("Kernel exception");
            } else {
                  /* Dump the user space stack */
                  stack = (unsigned long *)rdusp();
                  printk(KERN_NOTICE "Userspace Stack\n");
                  show_stack(NULL, stack);
            }
      }

      info.si_signo = sig;
      info.si_errno = 0;
      info.si_addr = (void __user *)fp->pc;
      force_sig_info(sig, &info, current);

      trace_buffer_restore(j);
      return;
}

/* Typical exception handling routines    */

#define EXPAND_LEN ((1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 256 - 1)

/*
 * Similar to get_user, do some address checking, then dereference
 * Return true on sucess, false on bad address
 */
bool get_instruction(unsigned short *val, unsigned short *address)
{

      unsigned long addr;

      addr = (unsigned long)address;

      /* Check for odd addresses */
      if (addr & 0x1)
            return false;

      /* Check that things do not wrap around */
      if (addr > (addr + 2))
            return false;

      /*
       * Since we are in exception context, we need to do a little address checking
       * We need to make sure we are only accessing valid memory, and
       * we don't read something in the async space that can hang forever
       */
      if ((addr >= FIXED_CODE_START && (addr + 2) <= physical_mem_end) ||
#if L2_LENGTH != 0
          (addr >= L2_START && (addr + 2) <= (L2_START + L2_LENGTH)) ||
#endif
          (addr >= BOOT_ROM_START && (addr + 2) <= (BOOT_ROM_START + BOOT_ROM_LENGTH)) ||
#if L1_DATA_A_LENGTH != 0
          (addr >= L1_DATA_A_START && (addr + 2) <= (L1_DATA_A_START + L1_DATA_A_LENGTH)) ||
#endif
#if L1_DATA_B_LENGTH != 0
          (addr >= L1_DATA_B_START && (addr + 2) <= (L1_DATA_B_START + L1_DATA_B_LENGTH)) ||
#endif
          (addr >= L1_SCRATCH_START && (addr + 2) <= (L1_SCRATCH_START + L1_SCRATCH_LENGTH)) ||
          (!(bfin_read_EBIU_AMBCTL0() & B0RDYEN) &&
             addr >= ASYNC_BANK0_BASE && (addr + 2) <= (ASYNC_BANK0_BASE + ASYNC_BANK0_SIZE)) ||
          (!(bfin_read_EBIU_AMBCTL0() & B1RDYEN) &&
             addr >= ASYNC_BANK1_BASE && (addr + 2) <= (ASYNC_BANK1_BASE + ASYNC_BANK1_SIZE)) ||
          (!(bfin_read_EBIU_AMBCTL1() & B2RDYEN) &&
             addr >= ASYNC_BANK2_BASE && (addr + 2) <= (ASYNC_BANK2_BASE + ASYNC_BANK1_SIZE)) ||
          (!(bfin_read_EBIU_AMBCTL1() & B3RDYEN) &&
            addr >= ASYNC_BANK3_BASE && (addr + 2) <= (ASYNC_BANK3_BASE + ASYNC_BANK1_SIZE))) {
            *val = *address;
            return true;
      }

#if L1_CODE_LENGTH != 0
      if (addr >= L1_CODE_START && (addr + 2) <= (L1_CODE_START + L1_CODE_LENGTH)) {
            dma_memcpy(val, address, 2);
            return true;
      }
#endif


      return false;
}

/* 
 * decode the instruction if we are printing out the trace, as it
 * makes things easier to follow, without running it through objdump
 * These are the normal instructions which cause change of flow, which
 * would be at the source of the trace buffer
 */
void decode_instruction(unsigned short *address)
{
      unsigned short opcode;

      if (get_instruction(&opcode, address)) {
            if (opcode == 0x0010)
                  printk("RTS");
            else if (opcode == 0x0011)
                  printk("RTI");
            else if (opcode == 0x0012)
                  printk("RTX");
            else if (opcode >= 0x0050 && opcode <= 0x0057)
                  printk("JUMP (P%i)", opcode & 7);
            else if (opcode >= 0x0060 && opcode <= 0x0067)
                  printk("CALL (P%i)", opcode & 7);
            else if (opcode >= 0x0070 && opcode <= 0x0077)
                  printk("CALL (PC+P%i)", opcode & 7);
            else if (opcode >= 0x0080 && opcode <= 0x0087)
                  printk("JUMP (PC+P%i)", opcode & 7);
            else if ((opcode >= 0x1000 && opcode <= 0x13FF) || (opcode >= 0x1800 && opcode <= 0x1BFF))
                  printk("IF !CC JUMP");
            else if ((opcode >= 0x1400 && opcode <= 0x17ff) || (opcode >= 0x1c00 && opcode <= 0x1fff))
                  printk("IF CC JUMP");
            else if (opcode >= 0x2000 && opcode <= 0x2fff)
                  printk("JUMP.S");
            else if (opcode >= 0xe080 && opcode <= 0xe0ff)
                  printk("LSETUP");
            else if (opcode >= 0xe200 && opcode <= 0xe2ff)
                  printk("JUMP.L");
            else if (opcode >= 0xe300 && opcode <= 0xe3ff)
                  printk("CALL pcrel");
            else
                  printk("0x%04x", opcode);
      }

}

void dump_bfin_trace_buffer(void)
{
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
      int tflags, i = 0;
      char buf[150];
      unsigned short *addr;
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
      int j, index;
#endif

      trace_buffer_save(tflags);

      printk(KERN_NOTICE "Hardware Trace:\n");

#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
      printk(KERN_NOTICE "WARNING: Expanded trace turned on - can not trace exceptions\n");
#endif

      if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
            for (; bfin_read_TBUFSTAT() & TBUFCNT; i++) {
                  decode_address(buf, (unsigned long)bfin_read_TBUF());
                  printk(KERN_NOTICE "%4i Target : %s\n", i, buf);
                  addr = (unsigned short *)bfin_read_TBUF();
                  decode_address(buf, (unsigned long)addr);
                  printk(KERN_NOTICE "     Source : %s ", buf);
                  decode_instruction(addr);
                  printk("\n");
            }
      }

#ifdef CONFIG_DEBUG_BFIN_HWTRACE_EXPAND
      if (trace_buff_offset)
            index = trace_buff_offset / 4;
      else
            index = EXPAND_LEN;

      j = (1 << CONFIG_DEBUG_BFIN_HWTRACE_EXPAND_LEN) * 128;
      while (j) {
            decode_address(buf, software_trace_buff[index]);
            printk(KERN_NOTICE "%4i Target : %s\n", i, buf);
            index -= 1;
            if (index < 0 )
                  index = EXPAND_LEN;
            decode_address(buf, software_trace_buff[index]);
            printk(KERN_NOTICE "     Source : %s ", buf);
            decode_instruction((unsigned short *)software_trace_buff[index]);
            printk("\n");
            index -= 1;
            if (index < 0)
                  index = EXPAND_LEN;
            j--;
            i++;
      }
#endif

      trace_buffer_restore(tflags);
#endif
}
EXPORT_SYMBOL(dump_bfin_trace_buffer);

/*
 * Checks to see if the address pointed to is either a
 * 16-bit CALL instruction, or a 32-bit CALL instruction
 */
bool is_bfin_call(unsigned short *addr)
{
      unsigned short opcode = 0, *ins_addr;
      ins_addr = (unsigned short *)addr;

      if (!get_instruction(&opcode, ins_addr))
            return false;

      if ((opcode >= 0x0060 && opcode <= 0x0067) ||
          (opcode >= 0x0070 && opcode <= 0x0077))
            return true;

      ins_addr--;
      if (!get_instruction(&opcode, ins_addr))
            return false;

      if (opcode >= 0xE300 && opcode <= 0xE3FF)
            return true;

      return false;

}
void show_stack(struct task_struct *task, unsigned long *stack)
{
      unsigned int *addr, *endstack, *fp = 0, *frame;
      unsigned short *ins_addr;
      char buf[150];
      unsigned int i, j, ret_addr, frame_no = 0;

      /*
       * If we have been passed a specific stack, use that one otherwise
       *    if we have been passed a task structure, use that, otherwise
       *    use the stack of where the variable "stack" exists
       */

      if (stack == NULL) {
            if (task) {
                  /* We know this is a kernel stack, so this is the start/end */
                  stack = (unsigned long *)task->thread.ksp;
                  endstack = (unsigned int *)(((unsigned int)(stack) & ~(THREAD_SIZE - 1)) + THREAD_SIZE);
            } else {
                  /* print out the existing stack info */
                  stack = (unsigned long *)&stack;
                  endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack);
            }
      } else
            endstack = (unsigned int *)PAGE_ALIGN((unsigned int)stack);

      decode_address(buf, (unsigned int)stack);
      printk(KERN_NOTICE "Stack info:\n" KERN_NOTICE " SP: [0x%p] %s\n", stack, buf);
      addr = (unsigned int *)((unsigned int)stack & ~0x3F);

      /* First thing is to look for a frame pointer */
      for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0;
            addr < endstack; addr++, i++) {
            if (*addr & 0x1)
                  continue;
            ins_addr = (unsigned short *)*addr;
            ins_addr--;
            if (is_bfin_call(ins_addr))
                  fp = addr - 1;

            if (fp) {
                  /* Let's check to see if it is a frame pointer */
                  while (fp >= (addr - 1) && fp < endstack && fp)
                        fp = (unsigned int *)*fp;
                  if (fp == 0 || fp == endstack) {
                        fp = addr - 1;
                        break;
                  }
                  fp = 0;
            }
      }
      if (fp) {
            frame = fp;
            printk(" FP: (0x%p)\n", fp);
      } else
            frame = 0;

      /*
       * Now that we think we know where things are, we
       * walk the stack again, this time printing things out
       * incase there is no frame pointer, we still look for
       * valid return addresses
       */

      /* First time print out data, next time, print out symbols */
      for (j = 0; j <= 1; j++) {
            if (j)
                  printk(KERN_NOTICE "Return addresses in stack:\n");
            else
                  printk(KERN_NOTICE " Memory from 0x%08lx to %p", ((long unsigned int)stack & ~0xF), endstack);

            fp = frame;
            frame_no = 0;

            for (addr = (unsigned int *)((unsigned int)stack & ~0xF), i = 0;
                 addr <= endstack; addr++, i++) {

                  ret_addr = 0;
                  if (!j && i % 8 == 0)
                        printk("\n" KERN_NOTICE "%p:",addr);

                  /* if it is an odd address, or zero, just skip it */
                  if (*addr & 0x1 || !*addr)
                        goto print;

                  ins_addr = (unsigned short *)*addr;

                  /* Go back one instruction, and see if it is a CALL */
                  ins_addr--;
                  ret_addr = is_bfin_call(ins_addr);
 print:
                  if (!j && stack == (unsigned long *)addr)
                        printk("[%08x]", *addr);
                  else if (ret_addr)
                        if (j) {
                              decode_address(buf, (unsigned int)*addr);
                              if (frame == addr) {
                                    printk(KERN_NOTICE "   frame %2i : %s\n", frame_no, buf);
                                    continue;
                              }
                              printk(KERN_NOTICE "    address : %s\n", buf);
                        } else
                              printk("<%08x>", *addr);
                  else if (fp == addr) {
                        if (j)
                              frame = addr+1;
                        else
                              printk("(%08x)", *addr);

                        fp = (unsigned int *)*addr;
                        frame_no++;

                  } else if (!j)
                        printk(" %08x ", *addr);
            }
            if (!j)
                  printk("\n");
      }

}

void dump_stack(void)
{
      unsigned long stack;
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
      int tflags;
#endif
      trace_buffer_save(tflags);
      dump_bfin_trace_buffer();
      show_stack(current, &stack);
      trace_buffer_restore(tflags);
}
EXPORT_SYMBOL(dump_stack);

void dump_bfin_process(struct pt_regs *fp)
{
      /* We should be able to look at fp->ipend, but we don't push it on the
       * stack all the time, so do this until we fix that */
      unsigned int context = bfin_read_IPEND();

      if (oops_in_progress)
            printk(KERN_EMERG "Kernel OOPS in progress\n");

      if (context & 0x0020 && (fp->seqstat & SEQSTAT_EXCAUSE) == VEC_HWERR)
            printk(KERN_NOTICE "HW Error context\n");
      else if (context & 0x0020)
            printk(KERN_NOTICE "Deferred Exception context\n");
      else if (context & 0x3FC0)
            printk(KERN_NOTICE "Interrupt context\n");
      else if (context & 0x4000)
            printk(KERN_NOTICE "Deferred Interrupt context\n");
      else if (context & 0x8000)
            printk(KERN_NOTICE "Kernel process context\n");

      /* Because we are crashing, and pointers could be bad, we check things
       * pretty closely before we use them
       */
      if ((unsigned long)current >= FIXED_CODE_START &&
          !((unsigned long)current & 0x3) && current->pid) {
            printk(KERN_NOTICE "CURRENT PROCESS:\n");
            if (current->comm >= (char *)FIXED_CODE_START)
                  printk(KERN_NOTICE "COMM=%s PID=%d\n",
                        current->comm, current->pid);
            else
                  printk(KERN_NOTICE "COMM= invalid\n");

            if (!((unsigned long)current->mm & 0x3) && (unsigned long)current->mm >= FIXED_CODE_START)
                  printk(KERN_NOTICE  "TEXT = 0x%p-0x%p        DATA = 0x%p-0x%p\n"
                        KERN_NOTICE " BSS = 0x%p-0x%p  USER-STACK = 0x%p\n"
                        KERN_NOTICE "\n",
                        (void *)current->mm->start_code,
                        (void *)current->mm->end_code,
                        (void *)current->mm->start_data,
                        (void *)current->mm->end_data,
                        (void *)current->mm->end_data,
                        (void *)current->mm->brk,
                        (void *)current->mm->start_stack);
            else
                  printk(KERN_NOTICE "invalid mm\n");
      } else
            printk(KERN_NOTICE "\n" KERN_NOTICE
                 "No Valid process in current context\n");
}

void dump_bfin_mem(struct pt_regs *fp)
{
      unsigned short *addr, *erraddr, val = 0, err = 0;
      char sti = 0, buf[6];

      erraddr = (void *)fp->pc;

      printk(KERN_NOTICE "return address: [0x%p]; contents of:", erraddr);

      for (addr = (unsigned short *)((unsigned long)erraddr & ~0xF) - 0x10;
           addr < (unsigned short *)((unsigned long)erraddr & ~0xF) + 0x10;
           addr++) {
            if (!((unsigned long)addr & 0xF))
                  printk("\n" KERN_NOTICE "0x%p: ", addr);

            if (get_instruction(&val, addr)) {
                        val = 0;
                        sprintf(buf, "????");
            } else
                  sprintf(buf, "%04x", val);

            if (addr == erraddr) {
                  printk("[%s]", buf);
                  err = val;
            } else
                  printk(" %s ", buf);

            /* Do any previous instructions turn on interrupts? */
            if (addr <= erraddr &&                    /* in the past */
                ((val >= 0x0040 && val <= 0x0047) ||  /* STI instruction */
                  val == 0x017b))                     /* [SP++] = RETI */
                  sti = 1;
      }

      printk("\n");

      /* Hardware error interrupts can be deferred */
      if (unlikely(sti && (fp->seqstat & SEQSTAT_EXCAUSE) == VEC_HWERR &&
          oops_in_progress)){
            printk(KERN_NOTICE "Looks like this was a deferred error - sorry\n");
#ifndef CONFIG_DEBUG_HWERR
            printk(KERN_NOTICE "The remaining message may be meaningless\n"
                  KERN_NOTICE "You should enable CONFIG_DEBUG_HWERR to get a"
                   " better idea where it came from\n");
#else
            /* If we are handling only one peripheral interrupt
             * and current mm and pid are valid, and the last error
             * was in that user space process's text area
             * print it out - because that is where the problem exists
             */
            if ((!(((fp)->ipend & ~0x30) & (((fp)->ipend & ~0x30) - 1))) &&
                 (current->pid && current->mm)) {
                  /* And the last RETI points to the current userspace context */
                  if ((fp + 1)->pc >= current->mm->start_code &&
                      (fp + 1)->pc <= current->mm->end_code) {
                        printk(KERN_NOTICE "It might be better to look around here : \n");
                        printk(KERN_NOTICE "-------------------------------------------\n");
                        show_regs(fp + 1);
                        printk(KERN_NOTICE "-------------------------------------------\n");
                  }
            }
#endif
      }
}

void show_regs(struct pt_regs *fp)
{
      char buf [150];
      struct irqaction *action;
      unsigned int i;
      unsigned long flags;

      printk(KERN_NOTICE "\n" KERN_NOTICE "SEQUENCER STATUS:\t\t%s\n", print_tainted());
      printk(KERN_NOTICE " SEQSTAT: %08lx  IPEND: %04lx  SYSCFG: %04lx\n",
            (long)fp->seqstat, fp->ipend, fp->syscfg);
      printk(KERN_NOTICE "  HWERRCAUSE: 0x%lx\n",
            (fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14);
      printk(KERN_NOTICE "  EXCAUSE   : 0x%lx\n",
            fp->seqstat & SEQSTAT_EXCAUSE);
      for (i = 6; i <= 15 ; i++) {
            if (fp->ipend & (1 << i)) {
                  decode_address(buf, bfin_read32(EVT0 + 4*i));
                  printk(KERN_NOTICE "  physical IVG%i asserted : %s\n", i, buf);
            }
      }

      /* if no interrupts are going off, don't print this out */
      if (fp->ipend & ~0x3F) {
            for (i = 0; i < (NR_IRQS - 1); i++) {
                  spin_lock_irqsave(&irq_desc[i].lock, flags);
                  action = irq_desc[i].action;
                  if (!action)
                        goto unlock;

                  decode_address(buf, (unsigned int)action->handler);
                  printk(KERN_NOTICE "  logical irq %3d mapped  : %s", i, buf);
                  for (action = action->next; action; action = action->next) {
                        decode_address(buf, (unsigned int)action->handler);
                        printk(", %s", buf);
                  }
                  printk("\n");
unlock:
                  spin_unlock_irqrestore(&irq_desc[i].lock, flags);
            }
      }

      decode_address(buf, fp->rete);
      printk(KERN_NOTICE " RETE: %s\n", buf);
      decode_address(buf, fp->retn);
      printk(KERN_NOTICE " RETN: %s\n", buf);
      decode_address(buf, fp->retx);
      printk(KERN_NOTICE " RETX: %s\n", buf);
      decode_address(buf, fp->rets);
      printk(KERN_NOTICE " RETS: %s\n", buf);
      decode_address(buf, fp->pc);
      printk(KERN_NOTICE " PC  : %s\n", buf);

      if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) &&
          (((long)fp->seqstat & SEQSTAT_EXCAUSE) != VEC_HWERR)) {
            decode_address(buf, saved_dcplb_fault_addr);
            printk(KERN_NOTICE "DCPLB_FAULT_ADDR: %s\n", buf);
            decode_address(buf, saved_icplb_fault_addr);
            printk(KERN_NOTICE "ICPLB_FAULT_ADDR: %s\n", buf);
      }

      printk(KERN_NOTICE "\n" KERN_NOTICE "PROCESSOR STATE:\n");
      printk(KERN_NOTICE " R0 : %08lx    R1 : %08lx    R2 : %08lx    R3 : %08lx\n",
            fp->r0, fp->r1, fp->r2, fp->r3);
      printk(KERN_NOTICE " R4 : %08lx    R5 : %08lx    R6 : %08lx    R7 : %08lx\n",
            fp->r4, fp->r5, fp->r6, fp->r7);
      printk(KERN_NOTICE " P0 : %08lx    P1 : %08lx    P2 : %08lx    P3 : %08lx\n",
            fp->p0, fp->p1, fp->p2, fp->p3);
      printk(KERN_NOTICE " P4 : %08lx    P5 : %08lx    FP : %08lx    SP : %08lx\n",
            fp->p4, fp->p5, fp->fp, (long)fp);
      printk(KERN_NOTICE " LB0: %08lx    LT0: %08lx    LC0: %08lx\n",
            fp->lb0, fp->lt0, fp->lc0);
      printk(KERN_NOTICE " LB1: %08lx    LT1: %08lx    LC1: %08lx\n",
            fp->lb1, fp->lt1, fp->lc1);
      printk(KERN_NOTICE " B0 : %08lx    L0 : %08lx    M0 : %08lx    I0 : %08lx\n",
            fp->b0, fp->l0, fp->m0, fp->i0);
      printk(KERN_NOTICE " B1 : %08lx    L1 : %08lx    M1 : %08lx    I1 : %08lx\n",
            fp->b1, fp->l1, fp->m1, fp->i1);
      printk(KERN_NOTICE " B2 : %08lx    L2 : %08lx    M2 : %08lx    I2 : %08lx\n",
            fp->b2, fp->l2, fp->m2, fp->i2);
      printk(KERN_NOTICE " B3 : %08lx    L3 : %08lx    M3 : %08lx    I3 : %08lx\n",
            fp->b3, fp->l3, fp->m3, fp->i3);
      printk(KERN_NOTICE "A0.w: %08lx   A0.x: %08lx   A1.w: %08lx   A1.x: %08lx\n",
            fp->a0w, fp->a0x, fp->a1w, fp->a1x);

      printk(KERN_NOTICE "USP : %08lx  ASTAT: %08lx\n",
            rdusp(), fp->astat);

      printk(KERN_NOTICE "\n");
}

#ifdef CONFIG_SYS_BFIN_SPINLOCK_L1
asmlinkage int sys_bfin_spinlock(int *spinlock)__attribute__((l1_text));
#endif

asmlinkage int sys_bfin_spinlock(int *spinlock)
{
      int ret = 0;
      int tmp = 0;

      local_irq_disable();
      ret = get_user(tmp, spinlock);
      if (ret == 0) {
            if (tmp)
                  ret = 1;
            tmp = 1;
            put_user(tmp, spinlock);
      }
      local_irq_enable();
      return ret;
}

int bfin_request_exception(unsigned int exception, void (*handler)(void))
{
      void (*curr_handler)(void);

      if (exception > 0x3F)
            return -EINVAL;

      curr_handler = ex_table[exception];

      if (curr_handler != ex_replaceable)
            return -EBUSY;

      ex_table[exception] = handler;

      return 0;
}
EXPORT_SYMBOL(bfin_request_exception);

int bfin_free_exception(unsigned int exception, void (*handler)(void))
{
      void (*curr_handler)(void);

      if (exception > 0x3F)
            return -EINVAL;

      curr_handler = ex_table[exception];

      if (curr_handler != handler)
            return -EBUSY;

      ex_table[exception] = ex_replaceable;

      return 0;
}
EXPORT_SYMBOL(bfin_free_exception);

void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
{
      switch (cplb_panic) {
      case CPLB_NO_UNLOCKED:
            printk(KERN_EMERG "All CPLBs are locked\n");
            break;
      case CPLB_PROT_VIOL:
            return;
      case CPLB_NO_ADDR_MATCH:
            return;
      case CPLB_UNKNOWN_ERR:
            printk(KERN_EMERG "Unknown CPLB Exception\n");
            break;
      }

      oops_in_progress = 1;

      dump_bfin_process(fp);
      dump_bfin_mem(fp);
      show_regs(fp);
      dump_stack();
      panic("Unrecoverable event\n");
}

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