cpu/mpc8xx/traps.c

   1 /*
   2  * linux/arch/ppc/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 #if defined(CONFIG_CMD_BEDBUG)
  41 extern void do_bedbug_breakpoint(struct pt_regs *);
  42 #endif
  43
  44 /* Returns 0 if exception not found and fixup otherwise.  */
  45 extern unsigned long search_exception_table(unsigned long);
  46
  47 /* THIS NEEDS CHANGING to use the board info structure.
  48 */
  49 #define END_OF_MEM      0x02000000
  50
  51 /*
  52  * Trap & Exception support
  53  */
  54
  55 void
  56 print_backtrace(unsigned long *sp)
  57 {
  58         int cnt = 0;
  59         unsigned long i;
  60
  61         printf("Call backtrace: ");
  62         while (sp) {
  63                 if ((uint)sp > END_OF_MEM)
  64                         break;
  65
  66                 i = sp[1];
  67                 if (cnt++ % 7 == 0)
  68                         printf("\n");
  69                 printf("%08lX ", i);
  70                 if (cnt > 32) break;
  71                 sp = (unsigned long *)*sp;
  72         }
  73         printf("\n");
  74 }
  75
  76 void show_regs(struct pt_regs * regs)
  77 {
  78         int i;
  79
  80         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  81                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  82         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  83                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  84                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  85                regs->msr&MSR_IR ? 1 : 0,
  86                regs->msr&MSR_DR ? 1 : 0);
  87
  88         printf("\n");
  89         for (i = 0;  i < 32;  i++) {
  90                 if ((i % 8) == 0)
  91                 {
  92                         printf("GPR%02d: ", i);
  93                 }
  94
  95                 printf("%08lX ", regs->gpr[i]);
  96                 if ((i % 8) == 7)
  97                 {
  98                         printf("\n");
  99                 }
 100         }
 101 }
 102
 103
 104 void
 105 _exception(int signr, struct pt_regs *regs)
 106 {
 107         show_regs(regs);
 108         print_backtrace((unsigned long *)regs->gpr[1]);
 109         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
 110 }
 111
 112 void
 113 MachineCheckException(struct pt_regs *regs)
 114 {
 115         unsigned long fixup;
 116
 117         /* Probing PCI using config cycles cause this exception
 118          * when a device is not present.  Catch it and return to
 119          * the PCI exception handler.
 120          */
 121         if ((fixup = search_exception_table(regs->nip)) != 0) {
 122                 regs->nip = fixup;
 123                 return;
 124         }
 125
 126 #if defined(CONFIG_CMD_KGDB)
 127         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 128                 return;
 129 #endif
 130
 131         printf("Machine check in kernel mode.\n");
 132         printf("Caused by (from msr): ");
 133         printf("regs %p ",regs);
 134         switch( regs->msr & 0x000F0000) {
 135         case (0x80000000>>12):
 136                 printf("Machine check signal - probably due to mm fault\n"
 137                         "with mmu off\n");
 138                 break;
 139         case (0x80000000>>13):
 140                 printf("Transfer error ack signal\n");
 141                 break;
 142         case (0x80000000>>14):
 143                 printf("Data parity signal\n");
 144                 break;
 145         case (0x80000000>>15):
 146                 printf("Address parity signal\n");
 147                 break;
 148         default:
 149                 printf("Unknown values in msr\n");
 150         }
 151         show_regs(regs);
 152         print_backtrace((unsigned long *)regs->gpr[1]);
 153         panic("machine check");
 154 }
 155
 156 void
 157 AlignmentException(struct pt_regs *regs)
 158 {
 159 #if defined(CONFIG_CMD_KGDB)
 160         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 161                 return;
 162 #endif
 163         show_regs(regs);
 164         print_backtrace((unsigned long *)regs->gpr[1]);
 165         panic("Alignment Exception");
 166 }
 167
 168 void
 169 ProgramCheckException(struct pt_regs *regs)
 170 {
 171 #if defined(CONFIG_CMD_KGDB)
 172         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 173                 return;
 174 #endif
 175         show_regs(regs);
 176         print_backtrace((unsigned long *)regs->gpr[1]);
 177         panic("Program Check Exception");
 178 }
 179
 180 void
 181 SoftEmuException(struct pt_regs *regs)
 182 {
 183 #if defined(CONFIG_CMD_KGDB)
 184         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 185                 return;
 186 #endif
 187         show_regs(regs);
 188         print_backtrace((unsigned long *)regs->gpr[1]);
 189         panic("Software Emulation Exception");
 190 }
 191
 192
 193 void
 194 UnknownException(struct pt_regs *regs)
 195 {
 196 #if defined(CONFIG_CMD_KGDB)
 197         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 198                 return;
 199 #endif
 200         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 201                regs->nip, regs->msr, regs->trap);
 202         _exception(0, regs);
 203 }
 204
 205 void
 206 DebugException(struct pt_regs *regs)
 207 {
 208   printf("Debugger trap at @ %lx\n", regs->nip );
 209   show_regs(regs);
 210 #if defined(CONFIG_CMD_BEDBUG)
 211   do_bedbug_breakpoint( regs );
 212 #endif
 213 }
 214
 215 /* Probe an address by reading.  If not present, return -1, otherwise
 216  * return 0.
 217  */
 218 int
 219 addr_probe(uint *addr)
 220 {
 221 #if 0
 222         int     retval;
 223
 224         __asm__ __volatile__(                   \
 225                 "1:     lwz %0,0(%1)\n"         \
 226                 "       eieio\n"                \
 227                 "       li %0,0\n"              \
 228                 "2:\n"                          \
 229                 ".section .fixup,\"ax\"\n"      \
 230                 "3:     li %0,-1\n"             \
 231                 "       b 2b\n"                 \
 232                 ".section __ex_table,\"a\"\n"   \
 233                 "       .align 2\n"             \
 234                 "       .long 1b,3b\n"          \
 235                 ".text"                         \
 236                 : "=r" (retval) : "r"(addr));
 237
 238         return (retval);
 239 #endif
 240         return 0;
 241 }