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  * See file CREDITS for list of people who contributed to this
  13  * project.
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation; either version 2 of
  18  * the License, or (at your option) any later version.
  19  *
  20  * This program is distributed in the hope that it will be useful,
  21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23  * GNU General Public License for more details.
  24  *
  25  * You should have received a copy of the GNU General Public License
  26  * along with this program; if not, write to the Free Software
  27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  28  * MA 02111-1307 USA
  29  */
  30
  31 /*
  32  * This file handles the architecture-dependent parts of hardware exceptions
  33  */
  34
  35 #include <common.h>
  36 #include <command.h>
  37 #include <kgdb.h>
  38 #include <asm/processor.h>
  39
  40 /* Returns 0 if exception not found and fixup otherwise.  */
  41 extern unsigned long search_exception_table(unsigned long);
  42
  43 /* THIS NEEDS CHANGING to use the board info structure.
  44 */
  45 #define END_OF_MEM      0x02000000
  46
  47 /*
  48  * Trap & Exception support
  49  */
  50
  51 static void print_backtrace(unsigned long *sp)
  52 {
  53         int cnt = 0;
  54         unsigned long i;
  55
  56         printf("Call backtrace: ");
  57         while (sp) {
  58                 if ((uint)sp > END_OF_MEM)
  59                         break;
  60
  61                 i = sp[1];
  62                 if (cnt++ % 7 == 0)
  63                         printf("\n");
  64                 printf("%08lX ", i);
  65                 if (cnt > 32) break;
  66                 sp = (unsigned long *)*sp;
  67         }
  68         printf("\n");
  69 }
  70
  71 void show_regs(struct pt_regs *regs)
  72 {
  73         int i;
  74
  75         printf("NIP: %08lX XER: %08lX LR: %08lX REGS:"
  76                " %p TRAP: %04lx DAR: %08lX\n",
  77                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  78         printf("MSR: %08lx EE: %01x PR: %01x FP:"
  79                " %01x ME: %01x IR/DR: %01x%01x\n",
  80                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  81                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  82                regs->msr&MSR_IR ? 1 : 0,
  83                regs->msr&MSR_DR ? 1 : 0);
  84
  85         printf("\n");
  86         for (i = 0;  i < 32;  i++) {
  87                 if ((i % 8) == 0)
  88                 {
  89                         printf("GPR%02d: ", i);
  90                 }
  91
  92                 printf("%08lX ", regs->gpr[i]);
  93                 if ((i % 8) == 7)
  94                 {
  95                         printf("\n");
  96                 }
  97         }
  98 }
  99
 100
 101 static void _exception(int signr, struct pt_regs *regs)
 102 {
 103         show_regs(regs);
 104         print_backtrace((unsigned long *)regs->gpr[1]);
 105         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
 106 }
 107
 108 void MachineCheckException(struct pt_regs *regs)
 109 {
 110         unsigned long fixup;
 111
 112         /* Probing PCI using config cycles cause this exception
 113          * when a device is not present.  Catch it and return to
 114          * the PCI exception handler.
 115          */
 116         if ((fixup = search_exception_table(regs->nip)) != 0) {
 117                 regs->nip = fixup;
 118                 return;
 119         }
 120
 121 #if defined(CONFIG_CMD_KGDB)
 122         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 123                 return;
 124 #endif
 125
 126         printf("Machine check in kernel mode.\n");
 127         printf("Caused by (from msr): ");
 128         printf("regs %p ",regs);
 129         switch( regs->msr & 0x000F0000) {
 130         case (0x80000000>>12):
 131                 printf("Machine check signal - probably due to mm fault\n"
 132                         "with mmu off\n");
 133                 break;
 134         case (0x80000000>>13):
 135                 printf("Transfer error ack signal\n");
 136                 break;
 137         case (0x80000000>>14):
 138                 printf("Data parity signal\n");
 139                 break;
 140         case (0x80000000>>15):
 141                 printf("Address parity signal\n");
 142                 break;
 143         default:
 144                 printf("Unknown values in msr\n");
 145         }
 146         show_regs(regs);
 147         print_backtrace((unsigned long *)regs->gpr[1]);
 148         panic("machine check");
 149 }
 150
 151 void AlignmentException(struct pt_regs *regs)
 152 {
 153 #if defined(CONFIG_CMD_KGDB)
 154         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 155                 return;
 156 #endif
 157         show_regs(regs);
 158         print_backtrace((unsigned long *)regs->gpr[1]);
 159         panic("Alignment Exception");
 160 }
 161
 162 void ProgramCheckException(struct pt_regs *regs)
 163 {
 164         unsigned char *p = regs ? (unsigned char *)(regs->nip) : NULL;
 165         int i, j;
 166
 167 #if defined(CONFIG_CMD_KGDB)
 168         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 169                 return;
 170 #endif
 171         show_regs(regs);
 172
 173         p = (unsigned char *) ((unsigned long)p & 0xFFFFFFE0);
 174         p -= 32;
 175         for (i = 0; i < 256; i+=16) {
 176                 printf("%08x: ", (unsigned int)p+i);
 177                 for (j = 0; j < 16; j++) {
 178                         printf("%02x ", p[i+j]);
 179                 }
 180                 printf("\n");
 181         }
 182
 183         print_backtrace((unsigned long *)regs->gpr[1]);
 184         panic("Program Check Exception");
 185 }
 186
 187 void SoftEmuException(struct pt_regs *regs)
 188 {
 189 #if defined(CONFIG_CMD_KGDB)
 190         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 191                 return;
 192 #endif
 193         show_regs(regs);
 194         print_backtrace((unsigned long *)regs->gpr[1]);
 195         panic("Software Emulation Exception");
 196 }
 197
 198 void UnknownException(struct pt_regs *regs)
 199 {
 200 #if defined(CONFIG_CMD_KGDB)
 201         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 202                 return;
 203 #endif
 204         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 205                regs->nip, regs->msr, regs->trap);
 206         _exception(0, regs);
 207 }
 208
 209 /* Probe an address by reading.  If not present, return -1, otherwise
 210  * return 0.
 211  */
 212 int addr_probe(uint *addr)
 213 {
 214 #if 0
 215         int     retval;
 216
 217         __asm__ __volatile__(                   \
 218                 "1:     lwz %0,0(%1)\n"         \
 219                 "       eieio\n"                \
 220                 "       li %0,0\n"              \
 221                 "2:\n"                          \
 222                 ".section .fixup,\"ax\"\n"      \
 223                 "3:     li %0,-1\n"             \
 224                 "       b 2b\n"                 \
 225                 ".section __ex_table,\"a\"\n"   \
 226                 "       .align 2\n"             \
 227                 "       .long 1b,3b\n"          \
 228                 ".text"                         \
 229                 : "=r" (retval) : "r"(addr));
 230
 231         return (retval);
 232 #endif
 233         return 0;
 234 }