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  * 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 <command.h>
  37 #include <kgdb.h>
  38 #include <asm/processor.h>
  39 #include <asm/m8260_pci.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 static void print_backtrace(unsigned long *sp)
  53 {
  54         int cnt = 0;
  55         unsigned long i;
  56
  57         puts ("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                         putc ('\n');
  65                 printf("%08lX ", i);
  66                 if (cnt > 32) break;
  67                 sp = (unsigned long *)*sp;
  68         }
  69         putc ('\n');
  70 }
  71
  72 void show_regs(struct pt_regs *regs)
  73 {
  74         int i;
  75
  76         printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n",
  77                regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar);
  78         printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n",
  79                regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0,
  80                regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0,
  81                regs->msr&MSR_IR ? 1 : 0,
  82                regs->msr&MSR_DR ? 1 : 0);
  83
  84         putc ('\n');
  85         for (i = 0;  i < 32;  i++) {
  86                 if ((i % 8) == 0) {
  87                         printf("GPR%02d: ", i);
  88                 }
  89
  90                 printf("%08lX ", regs->gpr[i]);
  91                 if ((i % 8) == 7) {
  92                         putc ('\n');
  93                 }
  94         }
  95 }
  96
  97
  98 static void _exception(int signr, struct pt_regs *regs)
  99 {
 100         show_regs(regs);
 101         print_backtrace((unsigned long *)regs->gpr[1]);
 102         panic("Exception in kernel pc %lx signal %d",regs->nip,signr);
 103 }
 104
 105 #ifdef CONFIG_PCI
 106 void dump_pci (void)
 107 {
 108
 109         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
 110
 111         printf ("PCI: err status %x err mask %x err ctrl %x\n",
 112                 le32_to_cpu (immap->im_pci.pci_esr),
 113                 le32_to_cpu (immap->im_pci.pci_emr),
 114                 le32_to_cpu (immap->im_pci.pci_ecr));
 115         printf ("     error address %x error data %x ctrl %x\n",
 116                 le32_to_cpu (immap->im_pci.pci_eacr),
 117                 le32_to_cpu (immap->im_pci.pci_edcr),
 118                 le32_to_cpu (immap->im_pci.pci_eccr));
 119
 120 }
 121 #endif
 122
 123 void MachineCheckException(struct pt_regs *regs)
 124 {
 125         unsigned long fixup;
 126
 127         /* Probing PCI using config cycles cause this exception
 128          * when a device is not present.  Catch it and return to
 129          * the PCI exception handler.
 130          */
 131 #ifdef CONFIG_PCI
 132         volatile immap_t *immap  = (immap_t *)CONFIG_SYS_IMMR;
 133 #ifdef DEBUG
 134         dump_pci();
 135 #endif
 136         /* clear the error in the error status register */
 137         if(immap->im_pci.pci_esr & cpu_to_le32(PCI_ERROR_PCI_NO_RSP)) {
 138                 immap->im_pci.pci_esr = cpu_to_le32(PCI_ERROR_PCI_NO_RSP);
 139                 return;
 140         }
 141 #endif
 142         if ((fixup = search_exception_table(regs->nip)) != 0) {
 143                 regs->nip = fixup;
 144                 return;
 145         }
 146
 147 #if defined(CONFIG_CMD_KGDB)
 148         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 149                 return;
 150 #endif
 151
 152         puts ("Machine check in kernel mode.\n"
 153                 "Caused by (from msr): ");
 154         printf("regs %p ",regs);
 155         switch( regs->msr & 0x000F0000) {
 156         case (0x80000000>>12):
 157                 puts ("Machine check signal - probably due to mm fault\n"
 158                         "with mmu off\n");
 159                 break;
 160         case (0x80000000>>13):
 161                 puts ("Transfer error ack signal\n");
 162                 break;
 163         case (0x80000000>>14):
 164                 puts ("Data parity signal\n");
 165                 break;
 166         case (0x80000000>>15):
 167                 puts ("Address parity signal\n");
 168                 break;
 169         default:
 170                 puts ("Unknown values in msr\n");
 171         }
 172         show_regs(regs);
 173         print_backtrace((unsigned long *)regs->gpr[1]);
 174 #ifdef CONFIG_PCI
 175         dump_pci();
 176 #endif
 177         panic("machine check");
 178 }
 179
 180 void AlignmentException(struct pt_regs *regs)
 181 {
 182 #if defined(CONFIG_CMD_KGDB)
 183         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 184                 return;
 185 #endif
 186         show_regs(regs);
 187         print_backtrace((unsigned long *)regs->gpr[1]);
 188         panic("Alignment Exception");
 189 }
 190
 191 void ProgramCheckException(struct pt_regs *regs)
 192 {
 193 #if defined(CONFIG_CMD_KGDB)
 194         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 195                 return;
 196 #endif
 197         show_regs(regs);
 198         print_backtrace((unsigned long *)regs->gpr[1]);
 199         panic("Program Check Exception");
 200 }
 201
 202 void SoftEmuException(struct pt_regs *regs)
 203 {
 204 #if defined(CONFIG_CMD_KGDB)
 205         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 206                 return;
 207 #endif
 208         show_regs(regs);
 209         print_backtrace((unsigned long *)regs->gpr[1]);
 210         panic("Software Emulation Exception");
 211 }
 212
 213
 214 void UnknownException(struct pt_regs *regs)
 215 {
 216 #if defined(CONFIG_CMD_KGDB)
 217         if (debugger_exception_handler && (*debugger_exception_handler)(regs))
 218                 return;
 219 #endif
 220         printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
 221                regs->nip, regs->msr, regs->trap);
 222         _exception(0, regs);
 223 }
 224
 225 #if defined(CONFIG_CMD_BEDBUG)
 226 extern void do_bedbug_breakpoint(struct pt_regs *);
 227 #endif
 228
 229 void DebugException(struct pt_regs *regs)
 230 {
 231
 232   printf("Debugger trap at @ %lx\n", regs->nip );
 233   show_regs(regs);
 234 #if defined(CONFIG_CMD_BEDBUG)
 235   do_bedbug_breakpoint( regs );
 236 #endif
 237 }
 238
 239 /* Probe an address by reading.  If not present, return -1, otherwise
 240  * return 0.
 241  */
 242 int addr_probe(uint *addr)
 243 {
 244 #if 0
 245         int     retval;
 246
 247         __asm__ __volatile__(                   \
 248                 "1:     lwz %0,0(%1)\n"         \
 249                 "       eieio\n"                \
 250                 "       li %0,0\n"              \
 251                 "2:\n"                          \
 252                 ".section .fixup,\"ax\"\n"      \
 253                 "3:     li %0,-1\n"             \
 254                 "       b 2b\n"                 \
 255                 ".section __ex_table,\"a\"\n"   \
 256                 "       .align 2\n"             \
 257                 "       .long 1b,3b\n"          \
 258                 ".text"                         \
 259                 : "=r" (retval) : "r"(addr));
 260
 261         return (retval);
 262 #endif
 263         return 0;
 264 }