arch/powerpc/cpu/mpc8xx/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  * SPDX-License-Identifier:     GPL-2.0+
  13  */
  14
  15 /*
  16  * This file handles the architecture-dependent parts of hardware exceptions
  17  */
  18
  19 #include <common.h>
  20 #include <command.h>
  21 #include <kgdb.h>
  22 #include <asm/processor.h>
  23
  24 #if defined(CONFIG_CMD_BEDBUG)
  25 extern void do_bedbug_breakpoint(struct pt_regs *);
  26 #endif
  27
  28 /* Returns 0 if exception not found and fixup otherwise.  */
  29 extern unsigned long search_exception_table(unsigned long);
  30
  31 /* THIS NEEDS CHANGING to use the board info structure.
  32 */
  33 #define END_OF_MEM      0x02000000
  34
  35 /*
  36  * Trap & Exception support
  37  */
  38
  39 static void print_backtrace(unsigned long *sp)
  40 {
  41         int cnt = 0;
  42         unsigned long i;
  43
  44         printf("Call backtrace: ");
  45         while (sp) {
  46                 if ((uint)sp > END_OF_MEM)
  47                         break;
  48
  49                 i = sp[1];
  50                 if (cnt++ % 7 == 0)
  51                         printf("\n");
  52                 printf("%08lX ", i);
  53                 if (cnt > 32) break;
  54                 sp = (unsigned long *)*sp;
  55         }
  56         printf("\n");
  57 }
  58
  59 void show_regs(struct pt_regs *regs)
  60 {
  61         int i;
  62
  63         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  64                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  65         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  66                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  67                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  68                regs->msr&MSR_IR ? 1 : 0,
  69                regs->msr&MSR_DR ? 1 : 0);
  70
  71         printf("\n");
  72         for (i = 0;  i < 32;  i++) {
  73                 if ((i % 8) == 0)
  74                 {
  75                         printf("GPR%02d: ", i);
  76                 }
  77
  78                 printf("%08lX ", regs->gpr[i]);
  79                 if ((i % 8) == 7)
  80                 {
  81                         printf("\n");
  82                 }
  83         }
  84 }
  85
  86
  87 static void _exception(int signr, struct pt_regs *regs)
  88 {
  89         show_regs(regs);
  90         print_backtrace((unsigned long *)regs->gpr[1]);
  91         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
  92 }
  93
  94 void MachineCheckException(struct pt_regs *regs)
  95 {
  96         unsigned long fixup;
  97
  98         /* Probing PCI using config cycles cause this exception
  99          * when a device is not present.  Catch it and return to
 100          * the PCI exception handler.
 101          */
 102         if ((fixup = search_exception_table(regs->nip)) != 0) {
 103                 regs->nip = fixup;
 104                 return;
 105         }
 106
 107 #if defined(CONFIG_CMD_KGDB)
 108         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 109                 return;
 110 #endif
 111
 112         printf("Machine check in kernel mode.\n");
 113         printf("Caused by (from msr): ");
 114         printf("regs %p ",regs);
 115         switch( regs->msr & 0x000F0000) {
 116         case (0x80000000>>12):
 117                 printf("Machine check signal - probably due to mm fault\n"
 118                         "with mmu off\n");
 119                 break;
 120         case (0x80000000>>13):
 121                 printf("Transfer error ack signal\n");
 122                 break;
 123         case (0x80000000>>14):
 124                 printf("Data parity signal\n");
 125                 break;
 126         case (0x80000000>>15):
 127                 printf("Address parity signal\n");
 128                 break;
 129         default:
 130                 printf("Unknown values in msr\n");
 131         }
 132         show_regs(regs);
 133         print_backtrace((unsigned long *)regs->gpr[1]);
 134         panic("machine check");
 135 }
 136
 137 void AlignmentException(struct pt_regs *regs)
 138 {
 139 #if defined(CONFIG_CMD_KGDB)
 140         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 141                 return;
 142 #endif
 143         show_regs(regs);
 144         print_backtrace((unsigned long *)regs->gpr[1]);
 145         panic("Alignment Exception");
 146 }
 147
 148 void ProgramCheckException(struct pt_regs *regs)
 149 {
 150 #if defined(CONFIG_CMD_KGDB)
 151         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 152                 return;
 153 #endif
 154         show_regs(regs);
 155         print_backtrace((unsigned long *)regs->gpr[1]);
 156         panic("Program Check Exception");
 157 }
 158
 159 void SoftEmuException(struct pt_regs *regs)
 160 {
 161 #if defined(CONFIG_CMD_KGDB)
 162         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 163                 return;
 164 #endif
 165         show_regs(regs);
 166         print_backtrace((unsigned long *)regs->gpr[1]);
 167         panic("Software Emulation Exception");
 168 }
 169
 170
 171 void UnknownException(struct pt_regs *regs)
 172 {
 173 #if defined(CONFIG_CMD_KGDB)
 174         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 175                 return;
 176 #endif
 177         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 178                regs->nip, regs->msr, regs->trap);
 179         _exception(0, regs);
 180 }
 181
 182 void DebugException(struct pt_regs *regs)
 183 {
 184   printf("Debugger trap at @ %lx\n", regs->nip );
 185   show_regs(regs);
 186 #if defined(CONFIG_CMD_BEDBUG)
 187   do_bedbug_breakpoint( regs );
 188 #endif
 189 }
 190
 191 /* Probe an address by reading.  If not present, return -1, otherwise
 192  * return 0.
 193  */
 194 int addr_probe(uint *addr)
 195 {
 196 #if 0
 197         int     retval;
 198
 199         __asm__ __volatile__(                   \
 200                 "1:     lwz %0,0(%1)\n"         \
 201                 "       eieio\n"                \
 202                 "       li %0,0\n"              \
 203                 "2:\n"                          \
 204                 ".section .fixup,\"ax\"\n"      \
 205                 "3:     li %0,-1\n"             \
 206                 "       b 2b\n"                 \
 207                 ".section __ex_table,\"a\"\n"   \
 208                 "       .align 2\n"             \
 209                 "       .long 1b,3b\n"          \
 210                 ".text"                         \
 211                 : "=r" (retval) : "r"(addr));
 212
 213         return (retval);
 214 #endif
 215         return 0;
 216 }