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  * 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 <asm/processor.h>
  21
  22 /* Returns 0 if exception not found and fixup otherwise.  */
  23 extern unsigned long search_exception_table(unsigned long);
  24
  25 /* THIS NEEDS CHANGING to use the board info structure.
  26 */
  27 #define END_OF_MEM      0x00400000
  28
  29 /*
  30  * Trap & Exception support
  31  */
  32
  33 static void print_backtrace(unsigned long *sp)
  34 {
  35         int cnt = 0;
  36         unsigned long i;
  37
  38         printf("Call backtrace: ");
  39         while (sp) {
  40                 if ((uint)sp > END_OF_MEM)
  41                         break;
  42
  43                 i = sp[1];
  44                 if (cnt++ % 7 == 0)
  45                         printf("\n");
  46                 printf("%08lX ", i);
  47                 if (cnt > 32) break;
  48                 sp = (unsigned long *)*sp;
  49         }
  50         printf("\n");
  51 }
  52
  53 void show_regs(struct pt_regs *regs)
  54 {
  55         int i;
  56
  57         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  58                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  59         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  60                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  61                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  62                regs->msr&MSR_IR ? 1 : 0,
  63                regs->msr&MSR_DR ? 1 : 0);
  64
  65         printf("\n");
  66         for (i = 0;  i < 32;  i++) {
  67                 if ((i % 8) == 0)
  68                 {
  69                         printf("GPR%02d: ", i);
  70                 }
  71
  72                 printf("%08lX ", regs->gpr[i]);
  73                 if ((i % 8) == 7)
  74                 {
  75                         printf("\n");
  76                 }
  77         }
  78 }
  79
  80
  81 static void _exception(int signr, struct pt_regs *regs)
  82 {
  83         show_regs(regs);
  84         print_backtrace((unsigned long *)regs->gpr[1]);
  85         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
  86 }
  87
  88 void MachineCheckException(struct pt_regs *regs)
  89 {
  90         unsigned long fixup;
  91
  92         /* Probing PCI using config cycles cause this exception
  93          * when a device is not present.  Catch it and return to
  94          * the PCI exception handler.
  95          */
  96         if ((fixup = search_exception_table(regs->nip)) != 0) {
  97                 regs->nip = fixup;
  98                 return;
  99         }
 100
 101         printf("Machine check in kernel mode.\n");
 102         printf("Caused by (from msr): ");
 103         printf("regs %p ",regs);
 104         switch( regs->msr & 0x000F0000) {
 105         case (0x80000000>>12):
 106                 printf("Machine check signal - probably due to mm fault\n"
 107                         "with mmu off\n");
 108                 break;
 109         case (0x80000000>>13):
 110                 printf("Transfer error ack signal\n");
 111                 break;
 112         case (0x80000000>>14):
 113                 printf("Data parity signal\n");
 114                 break;
 115         case (0x80000000>>15):
 116                 printf("Address parity signal\n");
 117                 break;
 118         default:
 119                 printf("Unknown values in msr\n");
 120         }
 121         show_regs(regs);
 122         print_backtrace((unsigned long *)regs->gpr[1]);
 123         panic("machine check");
 124 }
 125
 126 void AlignmentException(struct pt_regs *regs)
 127 {
 128         show_regs(regs);
 129         print_backtrace((unsigned long *)regs->gpr[1]);
 130         panic("Alignment Exception");
 131 }
 132
 133 void ProgramCheckException(struct pt_regs *regs)
 134 {
 135         show_regs(regs);
 136         print_backtrace((unsigned long *)regs->gpr[1]);
 137         panic("Program Check Exception");
 138 }
 139
 140 void SoftEmuException(struct pt_regs *regs)
 141 {
 142         show_regs(regs);
 143         print_backtrace((unsigned long *)regs->gpr[1]);
 144         panic("Software Emulation Exception");
 145 }
 146
 147
 148 void UnknownException(struct pt_regs *regs)
 149 {
 150         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 151                regs->nip, regs->msr, regs->trap);
 152         _exception(0, regs);
 153 }
 154
 155 #if defined(CONFIG_CMD_BEDBUG)
 156 extern void do_bedbug_breakpoint(struct pt_regs *);
 157 #endif
 158
 159 void DebugException(struct pt_regs *regs)
 160 {
 161
 162   printf("Debugger trap at @ %lx\n", regs->nip );
 163   show_regs(regs);
 164 #if defined(CONFIG_CMD_BEDBUG)
 165   do_bedbug_breakpoint( regs );
 166 #endif
 167 }
 168
 169 /* Probe an address by reading.  If not present, return -1, otherwise
 170  * return 0.
 171  */
 172 int addr_probe(uint *addr)
 173 {
 174 #if 0
 175         int     retval;
 176
 177         __asm__ __volatile__(                   \
 178                 "1:     lwz %0,0(%1)\n"         \
 179                 "       eieio\n"                \
 180                 "       li %0,0\n"              \
 181                 "2:\n"                          \
 182                 ".section .fixup,\"ax\"\n"      \
 183                 "3:     li %0,-1\n"             \
 184                 "       b 2b\n"                 \
 185                 ".section __ex_table,\"a\"\n"   \
 186                 "       .align 2\n"             \
 187                 "       .long 1b,3b\n"          \
 188                 ".text"                         \
 189                 : "=r" (retval) : "r"(addr));
 190
 191         return (retval);
 192 #endif
 193         return 0;
 194 }