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