arch/powerpc/cpu/74xx_7xx/traps.c

   1 /*
   2  * linux/arch/powerpc/kernel/traps.c
   3  *
   4  * Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
   5  *
   6  * Modified by Cort Dougan (cort@cs.nmt.edu)
   7  * and Paul Mackerras (paulus@cs.anu.edu.au)
   8  *
   9  * (C) Copyright 2000
  10  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  11  *
  12  * SPDX-License-Identifier:     GPL-2.0+
  13  */
  14
  15 /*
  16  * This file handles the architecture-dependent parts of hardware exceptions
  17  */
  18
  19 #include <common.h>
  20 #include <command.h>
  21 #include <kgdb.h>
  22 #include <asm/processor.h>
  23
  24 /* Returns 0 if exception not found and fixup otherwise.  */
  25 extern unsigned long search_exception_table(unsigned long);
  26
  27 /* THIS NEEDS CHANGING to use the board info structure.
  28 */
  29 #define END_OF_MEM      0x02000000
  30
  31 /*
  32  * Trap & Exception support
  33  */
  34
  35 static void print_backtrace(unsigned long *sp)
  36 {
  37         int cnt = 0;
  38         unsigned long i;
  39
  40         printf("Call backtrace: ");
  41         while (sp) {
  42                 if ((uint)sp > END_OF_MEM)
  43                         break;
  44
  45                 i = sp[1];
  46                 if (cnt++ % 7 == 0)
  47                         printf("\n");
  48                 printf("%08lX ", i);
  49                 if (cnt > 32) break;
  50                 sp = (unsigned long *)*sp;
  51         }
  52         printf("\n");
  53 }
  54
  55 void show_regs(struct pt_regs *regs)
  56 {
  57         int i;
  58
  59         printf("NIP: %08lX XER: %08lX LR: %08lX REGS:"
  60                " %p TRAP: %04lx DAR: %08lX\n",
  61                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  62         printf("MSR: %08lx EE: %01x PR: %01x FP:"
  63                " %01x ME: %01x IR/DR: %01x%01x\n",
  64                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  65                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  66                regs->msr&MSR_IR ? 1 : 0,
  67                regs->msr&MSR_DR ? 1 : 0);
  68
  69         printf("\n");
  70         for (i = 0;  i < 32;  i++) {
  71                 if ((i % 8) == 0)
  72                 {
  73                         printf("GPR%02d: ", i);
  74                 }
  75
  76                 printf("%08lX ", regs->gpr[i]);
  77                 if ((i % 8) == 7)
  78                 {
  79                         printf("\n");
  80                 }
  81         }
  82 }
  83
  84
  85 static void _exception(int signr, struct pt_regs *regs)
  86 {
  87         show_regs(regs);
  88         print_backtrace((unsigned long *)regs->gpr[1]);
  89         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
  90 }
  91
  92 void MachineCheckException(struct pt_regs *regs)
  93 {
  94         unsigned long fixup;
  95
  96         /* Probing PCI using config cycles cause this exception
  97          * when a device is not present.  Catch it and return to
  98          * the PCI exception handler.
  99          */
 100         if ((fixup = search_exception_table(regs->nip)) != 0) {
 101                 regs->nip = fixup;
 102                 return;
 103         }
 104
 105 #if defined(CONFIG_CMD_KGDB)
 106         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 107                 return;
 108 #endif
 109
 110         printf("Machine check in kernel mode.\n");
 111         printf("Caused by (from msr): ");
 112         printf("regs %p ",regs);
 113         switch( regs->msr & 0x000F0000) {
 114         case (0x80000000>>12):
 115                 printf("Machine check signal - probably due to mm fault\n"
 116                         "with mmu off\n");
 117                 break;
 118         case (0x80000000>>13):
 119                 printf("Transfer error ack signal\n");
 120                 break;
 121         case (0x80000000>>14):
 122                 printf("Data parity signal\n");
 123                 break;
 124         case (0x80000000>>15):
 125                 printf("Address parity signal\n");
 126                 break;
 127         default:
 128                 printf("Unknown values in msr\n");
 129         }
 130         show_regs(regs);
 131         print_backtrace((unsigned long *)regs->gpr[1]);
 132         panic("machine check");
 133 }
 134
 135 void AlignmentException(struct pt_regs *regs)
 136 {
 137 #if defined(CONFIG_CMD_KGDB)
 138         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 139                 return;
 140 #endif
 141         show_regs(regs);
 142         print_backtrace((unsigned long *)regs->gpr[1]);
 143         panic("Alignment Exception");
 144 }
 145
 146 void ProgramCheckException(struct pt_regs *regs)
 147 {
 148         unsigned char *p = regs ? (unsigned char *)(regs->nip) : NULL;
 149         int i, j;
 150
 151 #if defined(CONFIG_CMD_KGDB)
 152         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 153                 return;
 154 #endif
 155         show_regs(regs);
 156
 157         p = (unsigned char *) ((unsigned long)p & 0xFFFFFFE0);
 158         p -= 32;
 159         for (i = 0; i < 256; i+=16) {
 160                 printf("%08x: ", (unsigned int)p+i);
 161                 for (j = 0; j < 16; j++) {
 162                         printf("%02x ", p[i+j]);
 163                 }
 164                 printf("\n");
 165         }
 166
 167         print_backtrace((unsigned long *)regs->gpr[1]);
 168         panic("Program Check Exception");
 169 }
 170
 171 void SoftEmuException(struct pt_regs *regs)
 172 {
 173 #if defined(CONFIG_CMD_KGDB)
 174         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 175                 return;
 176 #endif
 177         show_regs(regs);
 178         print_backtrace((unsigned long *)regs->gpr[1]);
 179         panic("Software Emulation Exception");
 180 }
 181
 182 void UnknownException(struct pt_regs *regs)
 183 {
 184 #if defined(CONFIG_CMD_KGDB)
 185         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 186                 return;
 187 #endif
 188         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 189                regs->nip, regs->msr, regs->trap);
 190         _exception(0, regs);
 191 }
 192
 193 /* Probe an address by reading.  If not present, return -1, otherwise
 194  * return 0.
 195  */
 196 int addr_probe(uint *addr)
 197 {
 198 #if 0
 199         int     retval;
 200
 201         __asm__ __volatile__(                   \
 202                 "1:     lwz %0,0(%1)\n"         \
 203                 "       eieio\n"                \
 204                 "       li %0,0\n"              \
 205                 "2:\n"                          \
 206                 ".section .fixup,\"ax\"\n"      \
 207                 "3:     li %0,-1\n"             \
 208                 "       b 2b\n"                 \
 209                 ".section __ex_table,\"a\"\n"   \
 210                 "       .align 2\n"             \
 211                 "       .long 1b,3b\n"          \
 212                 ".text"                         \
 213                 : "=r" (retval) : "r"(addr));
 214
 215         return (retval);
 216 #endif
 217         return 0;
 218 }