arch/powerpc/cpu/mpc8260/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 #include <asm/m8260_pci.h>
  24
  25 /* Returns 0 if exception not found and fixup otherwise.  */
  26 extern unsigned long search_exception_table(unsigned long);
  27
  28 /* THIS NEEDS CHANGING to use the board info structure.
  29 */
  30 #define END_OF_MEM      0x02000000
  31
  32 /*
  33  * Trap & Exception support
  34  */
  35
  36 static void print_backtrace(unsigned long *sp)
  37 {
  38         int cnt = 0;
  39         unsigned long i;
  40
  41         puts ("Call backtrace: ");
  42         while (sp) {
  43                 if ((uint)sp > END_OF_MEM)
  44                         break;
  45
  46                 i = sp[1];
  47                 if (cnt++ % 7 == 0)
  48                         putc ('\n');
  49                 printf("%08lX ", i);
  50                 if (cnt > 32) break;
  51                 sp = (unsigned long *)*sp;
  52         }
  53         putc ('\n');
  54 }
  55
  56 void show_regs(struct pt_regs *regs)
  57 {
  58         int i;
  59
  60         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  61                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  62         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  63                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  64                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  65                regs->msr&MSR_IR ? 1 : 0,
  66                regs->msr&MSR_DR ? 1 : 0);
  67
  68         putc ('\n');
  69         for (i = 0;  i < 32;  i++) {
  70                 if ((i % 8) == 0) {
  71                         printf("GPR%02d: ", i);
  72                 }
  73
  74                 printf("%08lX ", regs->gpr[i]);
  75                 if ((i % 8) == 7) {
  76                         putc ('\n');
  77                 }
  78         }
  79 }
  80
  81
  82 static void _exception(int signr, struct pt_regs *regs)
  83 {
  84         show_regs(regs);
  85         print_backtrace((unsigned long *)regs->gpr[1]);
  86         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
  87 }
  88
  89 #ifdef CONFIG_PCI
  90 void dump_pci (void)
  91 {
  92
  93         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  94
  95         printf ("PCI: err status %x err mask %x err ctrl %x\n",
  96                 le32_to_cpu (immap->im_pci.pci_esr),
  97                 le32_to_cpu (immap->im_pci.pci_emr),
  98                 le32_to_cpu (immap->im_pci.pci_ecr));
  99         printf ("     error address %x error data %x ctrl %x\n",
 100                 le32_to_cpu (immap->im_pci.pci_eacr),
 101                 le32_to_cpu (immap->im_pci.pci_edcr),
 102                 le32_to_cpu (immap->im_pci.pci_eccr));
 103
 104 }
 105 #endif
 106
 107 void 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 #ifdef CONFIG_PCI
 116         volatile immap_t *immap  = (immap_t *)CONFIG_SYS_IMMR;
 117 #ifdef DEBUG
 118         dump_pci();
 119 #endif
 120         /* clear the error in the error status register */
 121         if(immap->im_pci.pci_esr & cpu_to_le32(PCI_ERROR_PCI_NO_RSP)) {
 122                 immap->im_pci.pci_esr = cpu_to_le32(PCI_ERROR_PCI_NO_RSP);
 123                 return;
 124         }
 125 #endif
 126         if ((fixup = search_exception_table(regs->nip)) != 0) {
 127                 regs->nip = fixup;
 128                 return;
 129         }
 130
 131 #if defined(CONFIG_CMD_KGDB)
 132         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 133                 return;
 134 #endif
 135
 136         puts ("Machine check in kernel mode.\n"
 137                 "Caused by (from msr): ");
 138         printf("regs %p ",regs);
 139         switch( regs->msr & 0x000F0000) {
 140         case (0x80000000>>12):
 141                 puts ("Machine check signal - probably due to mm fault\n"
 142                         "with mmu off\n");
 143                 break;
 144         case (0x80000000>>13):
 145                 puts ("Transfer error ack signal\n");
 146                 break;
 147         case (0x80000000>>14):
 148                 puts ("Data parity signal\n");
 149                 break;
 150         case (0x80000000>>15):
 151                 puts ("Address parity signal\n");
 152                 break;
 153         default:
 154                 puts ("Unknown values in msr\n");
 155         }
 156         show_regs(regs);
 157         print_backtrace((unsigned long *)regs->gpr[1]);
 158 #ifdef CONFIG_PCI
 159         dump_pci();
 160 #endif
 161         panic("machine check");
 162 }
 163
 164 void AlignmentException(struct pt_regs *regs)
 165 {
 166 #if defined(CONFIG_CMD_KGDB)
 167         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 168                 return;
 169 #endif
 170         show_regs(regs);
 171         print_backtrace((unsigned long *)regs->gpr[1]);
 172         panic("Alignment Exception");
 173 }
 174
 175 void ProgramCheckException(struct pt_regs *regs)
 176 {
 177 #if defined(CONFIG_CMD_KGDB)
 178         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 179                 return;
 180 #endif
 181         show_regs(regs);
 182         print_backtrace((unsigned long *)regs->gpr[1]);
 183         panic("Program Check Exception");
 184 }
 185
 186 void SoftEmuException(struct pt_regs *regs)
 187 {
 188 #if defined(CONFIG_CMD_KGDB)
 189         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 190                 return;
 191 #endif
 192         show_regs(regs);
 193         print_backtrace((unsigned long *)regs->gpr[1]);
 194         panic("Software Emulation Exception");
 195 }
 196
 197
 198 void UnknownException(struct pt_regs *regs)
 199 {
 200 #if defined(CONFIG_CMD_KGDB)
 201         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 202                 return;
 203 #endif
 204         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 205                regs->nip, regs->msr, regs->trap);
 206         _exception(0, regs);
 207 }
 208
 209 #if defined(CONFIG_CMD_BEDBUG)
 210 extern void do_bedbug_breakpoint(struct pt_regs *);
 211 #endif
 212
 213 void DebugException(struct pt_regs *regs)
 214 {
 215
 216   printf("Debugger trap at @ %lx\n", regs->nip );
 217   show_regs(regs);
 218 #if defined(CONFIG_CMD_BEDBUG)
 219   do_bedbug_breakpoint( regs );
 220 #endif
 221 }
 222
 223 /* Probe an address by reading.  If not present, return -1, otherwise
 224  * return 0.
 225  */
 226 int addr_probe(uint *addr)
 227 {
 228 #if 0
 229         int     retval;
 230
 231         __asm__ __volatile__(                   \
 232                 "1:     lwz %0,0(%1)\n"         \
 233                 "       eieio\n"                \
 234                 "       li %0,0\n"              \
 235                 "2:\n"                          \
 236                 ".section .fixup,\"ax\"\n"      \
 237                 "3:     li %0,-1\n"             \
 238                 "       b 2b\n"                 \
 239                 ".section __ex_table,\"a\"\n"   \
 240                 "       .align 2\n"             \
 241                 "       .long 1b,3b\n"          \
 242                 ".text"                         \
 243                 : "=r" (retval) : "r"(addr));
 244
 245         return (retval);
 246 #endif
 247         return 0;
 248 }