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 40 #if defined(CONFIG_CMD_BEDBUG) 41 extern void do_bedbug_breakpoint(struct pt_regs *); 42 #endif 43 44 /* Returns 0 if exception not found and fixup otherwise. */ 45 extern unsigned long search_exception_table(unsigned long); 46 47 /* THIS NEEDS CHANGING to use the board info structure. 48 */ 49 #define END_OF_MEM 0x02000000 50 51 /* 52 * Trap & Exception support 53 */ 54 55 void 56 print_backtrace(unsigned long *sp) 57 { 58 int cnt = 0; 59 unsigned long i; 60 61 printf("Call backtrace: "); 62 while (sp) { 63 if ((uint)sp > END_OF_MEM) 64 break; 65 66 i = sp[1]; 67 if (cnt++ % 7 == 0) 68 printf("\n"); 69 printf("%08lX ", i); 70 if (cnt > 32) break; 71 sp = (unsigned long *)*sp; 72 } 73 printf("\n"); 74 } 75 76 void show_regs(struct pt_regs * regs) 77 { 78 int i; 79 80 printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n", 81 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 82 printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n", 83 regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, 84 regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, 85 regs->msr&MSR_IR ? 1 : 0, 86 regs->msr&MSR_DR ? 1 : 0); 87 88 printf("\n"); 89 for (i = 0; i < 32; i++) { 90 if ((i % 8) == 0) 91 { 92 printf("GPR%02d: ", i); 93 } 94 95 printf("%08lX ", regs->gpr[i]); 96 if ((i % 8) == 7) 97 { 98 printf("\n"); 99 } 100 } 101 } 102 103 104 void 105 _exception(int signr, struct pt_regs *regs) 106 { 107 show_regs(regs); 108 print_backtrace((unsigned long *)regs->gpr[1]); 109 panic("Exception in kernel pc %lx signal %d",regs->nip,signr); 110 } 111 112 void 113 MachineCheckException(struct pt_regs *regs) 114 { 115 unsigned long fixup; 116 117 /* Probing PCI using config cycles cause this exception 118 * when a device is not present. Catch it and return to 119 * the PCI exception handler. 120 */ 121 if ((fixup = search_exception_table(regs->nip)) != 0) { 122 regs->nip = fixup; 123 return; 124 } 125 126 #if defined(CONFIG_CMD_KGDB) 127 if (debugger_exception_handler && (*debugger_exception_handler)(regs)) 128 return; 129 #endif 130 131 printf("Machine check in kernel mode.\n"); 132 printf("Caused by (from msr): "); 133 printf("regs %p ",regs); 134 switch( regs->msr & 0x000F0000) { 135 case (0x80000000>>12): 136 printf("Machine check signal - probably due to mm fault\n" 137 "with mmu off\n"); 138 break; 139 case (0x80000000>>13): 140 printf("Transfer error ack signal\n"); 141 break; 142 case (0x80000000>>14): 143 printf("Data parity signal\n"); 144 break; 145 case (0x80000000>>15): 146 printf("Address parity signal\n"); 147 break; 148 default: 149 printf("Unknown values in msr\n"); 150 } 151 show_regs(regs); 152 print_backtrace((unsigned long *)regs->gpr[1]); 153 panic("machine check"); 154 } 155 156 void 157 AlignmentException(struct pt_regs *regs) 158 { 159 #if defined(CONFIG_CMD_KGDB) 160 if (debugger_exception_handler && (*debugger_exception_handler)(regs)) 161 return; 162 #endif 163 show_regs(regs); 164 print_backtrace((unsigned long *)regs->gpr[1]); 165 panic("Alignment Exception"); 166 } 167 168 void 169 ProgramCheckException(struct pt_regs *regs) 170 { 171 #if defined(CONFIG_CMD_KGDB) 172 if (debugger_exception_handler && (*debugger_exception_handler)(regs)) 173 return; 174 #endif 175 show_regs(regs); 176 print_backtrace((unsigned long *)regs->gpr[1]); 177 panic("Program Check Exception"); 178 } 179 180 void 181 SoftEmuException(struct pt_regs *regs) 182 { 183 #if defined(CONFIG_CMD_KGDB) 184 if (debugger_exception_handler && (*debugger_exception_handler)(regs)) 185 return; 186 #endif 187 show_regs(regs); 188 print_backtrace((unsigned long *)regs->gpr[1]); 189 panic("Software Emulation Exception"); 190 } 191 192 193 void 194 UnknownException(struct pt_regs *regs) 195 { 196 #if defined(CONFIG_CMD_KGDB) 197 if (debugger_exception_handler && (*debugger_exception_handler)(regs)) 198 return; 199 #endif 200 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 201 regs->nip, regs->msr, regs->trap); 202 _exception(0, regs); 203 } 204 205 void 206 DebugException(struct pt_regs *regs) 207 { 208 printf("Debugger trap at @ %lx\n", regs->nip ); 209 show_regs(regs); 210 #if defined(CONFIG_CMD_BEDBUG) 211 do_bedbug_breakpoint( regs ); 212 #endif 213 } 214 215 /* Probe an address by reading. If not present, return -1, otherwise 216 * return 0. 217 */ 218 int 219 addr_probe(uint *addr) 220 { 221 #if 0 222 int retval; 223 224 __asm__ __volatile__( \ 225 "1: lwz %0,0(%1)\n" \ 226 " eieio\n" \ 227 " li %0,0\n" \ 228 "2:\n" \ 229 ".section .fixup,\"ax\"\n" \ 230 "3: li %0,-1\n" \ 231 " b 2b\n" \ 232 ".section __ex_table,\"a\"\n" \ 233 " .align 2\n" \ 234 " .long 1b,3b\n" \ 235 ".text" \ 236 : "=r" (retval) : "r"(addr)); 237 238 return (retval); 239 #endif 240 return 0; 241 } 242