arch/powerpc/cpu/mpc8220/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  * fixed Machine Check Reasons by Reinhard Meyer (r.meyer@emk-elektronik.de)
   9  *
  10  * (C) Copyright 2000-2003
  11  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  12  *
  13  * See file CREDITS for list of people who contributed to this
  14  * project.
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation; either version 2 of
  19  * the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  29  * MA 02111-1307 USA
  30  */
  31
  32 /*
  33  * This file handles the architecture-dependent parts of hardware exceptions
  34  */
  35
  36 #include <common.h>
  37 #include <command.h>
  38 #include <kgdb.h>
  39 #include <asm/processor.h>
  40
  41 /* Returns 0 if exception not found and fixup otherwise.  */
  42 extern unsigned long search_exception_table (unsigned long);
  43
  44 /* THIS NEEDS CHANGING to use the board info structure.
  45 */
  46 #define END_OF_MEM      0x02000000
  47
  48 /*
  49  * Trap & Exception support
  50  */
  51
  52 void print_backtrace (unsigned long *sp)
  53 {
  54         int cnt = 0;
  55         unsigned long i;
  56
  57         printf ("Call backtrace: ");
  58         while (sp) {
  59                 if ((uint) sp > END_OF_MEM)
  60                         break;
  61
  62                 i = sp[1];
  63                 if (cnt++ % 7 == 0)
  64                         printf ("\n");
  65                 printf ("%08lX ", i);
  66                 if (cnt > 32)
  67                         break;
  68                 sp = (unsigned long *) *sp;
  69         }
  70         printf ("\n");
  71 }
  72
  73 void show_regs (struct pt_regs *regs)
  74 {
  75         int i;
  76
  77         printf ("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  78                 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  79         printf ("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  80                 regs->msr,
  81                 regs->msr & MSR_EE ? 1 : 0, regs->msr & MSR_PR ? 1 : 0,
  82                 regs->msr & MSR_FP ? 1 : 0, regs->msr & MSR_ME ? 1 : 0,
  83                 regs->msr & MSR_IR ? 1 : 0, regs->msr & MSR_DR ? 1 : 0);
  84
  85         printf ("\n");
  86         for (i = 0; i < 32; i++) {
  87                 if ((i % 8) == 0) {
  88                         printf ("GPR%02d: ", i);
  89                 }
  90
  91                 printf ("%08lX ", regs->gpr[i]);
  92                 if ((i % 8) == 7) {
  93                         printf ("\n");
  94                 }
  95         }
  96 }
  97
  98
  99 void _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 MachineCheckException (struct pt_regs *regs)
 107 {
 108         unsigned long fixup;
 109
 110         /* Probing PCI using config cycles cause this exception
 111          * when a device is not present.  Catch it and return to
 112          * the PCI exception handler.
 113          */
 114         if ((fixup = search_exception_table (regs->nip)) != 0) {
 115                 regs->nip = fixup;
 116                 return;
 117         }
 118 #if defined(CONFIG_CMD_KGDB)
 119         if (debugger_exception_handler
 120             && (*debugger_exception_handler) (regs))
 121                 return;
 122 #endif
 123
 124         printf ("Machine check in kernel mode.\n");
 125         printf ("Caused by (from msr): ");
 126         printf ("regs %p ", regs);
 127         /* refer to 603e Manual (MPC603EUM/AD), chapter 4.5.2.1 */
 128         switch (regs->msr & 0x000F0000) {
 129         case (0x80000000 >> 12):
 130                 printf ("Machine check signal - probably due to mm fault\n"
 131                         "with mmu off\n");
 132                 break;
 133         case (0x80000000 >> 13):
 134                 printf ("Transfer error ack signal\n");
 135                 break;
 136         case (0x80000000 >> 14):
 137                 printf ("Data parity signal\n");
 138                 break;
 139         case (0x80000000 >> 15):
 140                 printf ("Address parity signal\n");
 141                 break;
 142         default:
 143                 printf ("Unknown values in msr\n");
 144         }
 145         show_regs (regs);
 146         print_backtrace ((unsigned long *) regs->gpr[1]);
 147         panic ("machine check");
 148 }
 149
 150 void AlignmentException (struct pt_regs *regs)
 151 {
 152 #if defined(CONFIG_CMD_KGDB)
 153         if (debugger_exception_handler
 154             && (*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 #if defined(CONFIG_CMD_KGDB)
 165         if (debugger_exception_handler
 166             && (*debugger_exception_handler) (regs))
 167                 return;
 168 #endif
 169         show_regs (regs);
 170         print_backtrace ((unsigned long *) regs->gpr[1]);
 171         panic ("Program Check Exception");
 172 }
 173
 174 void SoftEmuException (struct pt_regs *regs)
 175 {
 176 #if defined(CONFIG_CMD_KGDB)
 177         if (debugger_exception_handler
 178             && (*debugger_exception_handler) (regs))
 179                 return;
 180 #endif
 181         show_regs (regs);
 182         print_backtrace ((unsigned long *) regs->gpr[1]);
 183         panic ("Software Emulation Exception");
 184 }
 185
 186
 187 void UnknownException (struct pt_regs *regs)
 188 {
 189 #if defined(CONFIG_CMD_KGDB)
 190         if (debugger_exception_handler
 191             && (*debugger_exception_handler) (regs))
 192                 return;
 193 #endif
 194         printf ("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 195                 regs->nip, regs->msr, regs->trap);
 196         _exception (0, regs);
 197 }
 198
 199 #if defined(CONFIG_CMD_BEDBUG)
 200 extern void do_bedbug_breakpoint (struct pt_regs *);
 201 #endif
 202
 203 void DebugException (struct pt_regs *regs)
 204 {
 205
 206         printf ("Debugger trap at @ %lx\n", regs->nip);
 207         show_regs (regs);
 208 #if defined(CONFIG_CMD_BEDBUG)
 209         do_bedbug_breakpoint (regs);
 210 #endif
 211 }
 212
 213 /* Probe an address by reading.  If not present, return -1, otherwise
 214  * return 0.
 215  */
 216 int addr_probe (uint * addr)
 217 {
 218 #if 0
 219         int retval;
 220
 221         __asm__ __volatile__ ("1: lwz %0,0(%1)\n"
 222                               "   eieio\n"
 223                               "   li %0,0\n"
 224                               "2:\n"
 225                               ".section .fixup,\"ax\"\n"
 226                               "3: li %0,-1\n"
 227                               "   b 2b\n"
 228                               ".section __ex_table,\"a\"\n"
 229                               "   .align 2\n"
 230                               "   .long 1b,3b\n"
 231                               ".text":"=r" (retval):"r" (addr));
 232
 233         return (retval);
 234 #endif
 235         return 0;
 236 }