arch/powerpc/cpu/mpc824x/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 <asm/processor.h>
  37
  38 /* Returns 0 if exception not found and fixup otherwise.  */
  39 extern unsigned long search_exception_table(unsigned long);
  40
  41 /* THIS NEEDS CHANGING to use the board info structure.
  42 */
  43 #define END_OF_MEM      0x00400000
  44
  45 /*
  46  * Trap & Exception support
  47  */
  48
  49 static void print_backtrace(unsigned long *sp)
  50 {
  51         int cnt = 0;
  52         unsigned long i;
  53
  54         printf("Call backtrace: ");
  55         while (sp) {
  56                 if ((uint)sp > END_OF_MEM)
  57                         break;
  58
  59                 i = sp[1];
  60                 if (cnt++ % 7 == 0)
  61                         printf("\n");
  62                 printf("%08lX ", i);
  63                 if (cnt > 32) break;
  64                 sp = (unsigned long *)*sp;
  65         }
  66         printf("\n");
  67 }
  68
  69 void show_regs(struct pt_regs *regs)
  70 {
  71         int i;
  72
  73         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  74                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  75         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  76                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  77                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  78                regs->msr&MSR_IR ? 1 : 0,
  79                regs->msr&MSR_DR ? 1 : 0);
  80
  81         printf("\n");
  82         for (i = 0;  i < 32;  i++) {
  83                 if ((i % 8) == 0)
  84                 {
  85                         printf("GPR%02d: ", i);
  86                 }
  87
  88                 printf("%08lX ", regs->gpr[i]);
  89                 if ((i % 8) == 7)
  90                 {
  91                         printf("\n");
  92                 }
  93         }
  94 }
  95
  96
  97 static void _exception(int signr, struct pt_regs *regs)
  98 {
  99         show_regs(regs);
 100         print_backtrace((unsigned long *)regs->gpr[1]);
 101         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
 102 }
 103
 104 void MachineCheckException(struct pt_regs *regs)
 105 {
 106         unsigned long fixup;
 107
 108         /* Probing PCI using config cycles cause this exception
 109          * when a device is not present.  Catch it and return to
 110          * the PCI exception handler.
 111          */
 112         if ((fixup = search_exception_table(regs->nip)) != 0) {
 113                 regs->nip = fixup;
 114                 return;
 115         }
 116
 117         printf("Machine check in kernel mode.\n");
 118         printf("Caused by (from msr): ");
 119         printf("regs %p ",regs);
 120         switch( regs->msr & 0x000F0000) {
 121         case (0x80000000>>12):
 122                 printf("Machine check signal - probably due to mm fault\n"
 123                         "with mmu off\n");
 124                 break;
 125         case (0x80000000>>13):
 126                 printf("Transfer error ack signal\n");
 127                 break;
 128         case (0x80000000>>14):
 129                 printf("Data parity signal\n");
 130                 break;
 131         case (0x80000000>>15):
 132                 printf("Address parity signal\n");
 133                 break;
 134         default:
 135                 printf("Unknown values in msr\n");
 136         }
 137         show_regs(regs);
 138         print_backtrace((unsigned long *)regs->gpr[1]);
 139         panic("machine check");
 140 }
 141
 142 void AlignmentException(struct pt_regs *regs)
 143 {
 144         show_regs(regs);
 145         print_backtrace((unsigned long *)regs->gpr[1]);
 146         panic("Alignment Exception");
 147 }
 148
 149 void ProgramCheckException(struct pt_regs *regs)
 150 {
 151         show_regs(regs);
 152         print_backtrace((unsigned long *)regs->gpr[1]);
 153         panic("Program Check Exception");
 154 }
 155
 156 void SoftEmuException(struct pt_regs *regs)
 157 {
 158         show_regs(regs);
 159         print_backtrace((unsigned long *)regs->gpr[1]);
 160         panic("Software Emulation Exception");
 161 }
 162
 163
 164 void UnknownException(struct pt_regs *regs)
 165 {
 166         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 167                regs->nip, regs->msr, regs->trap);
 168         _exception(0, regs);
 169 }
 170
 171 #if defined(CONFIG_CMD_BEDBUG)
 172 extern void do_bedbug_breakpoint(struct pt_regs *);
 173 #endif
 174
 175 void DebugException(struct pt_regs *regs)
 176 {
 177
 178   printf("Debugger trap at @ %lx\n", regs->nip );
 179   show_regs(regs);
 180 #if defined(CONFIG_CMD_BEDBUG)
 181   do_bedbug_breakpoint( regs );
 182 #endif
 183 }
 184
 185 /* Probe an address by reading.  If not present, return -1, otherwise
 186  * return 0.
 187  */
 188 int addr_probe(uint *addr)
 189 {
 190 #if 0
 191         int     retval;
 192
 193         __asm__ __volatile__(                   \
 194                 "1:     lwz %0,0(%1)\n"         \
 195                 "       eieio\n"                \
 196                 "       li %0,0\n"              \
 197                 "2:\n"                          \
 198                 ".section .fixup,\"ax\"\n"      \
 199                 "3:     li %0,-1\n"             \
 200                 "       b 2b\n"                 \
 201                 ".section __ex_table,\"a\"\n"   \
 202                 "       .align 2\n"             \
 203                 "       .long 1b,3b\n"          \
 204                 ".text"                         \
 205                 : "=r" (retval) : "r"(addr));
 206
 207         return (retval);
 208 #endif
 209         return 0;
 210 }