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