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 <asm/processor.h> 22 23 /* Returns 0 if exception not found and fixup otherwise. */ 24 extern unsigned long search_exception_table(unsigned long); 25 26 /* THIS NEEDS CHANGING to use the board info structure. 27 */ 28 #define END_OF_MEM 0x02000000 29 30 /* 31 * Trap & Exception support 32 */ 33 34 static void print_backtrace(unsigned long *sp) 35 { 36 int cnt = 0; 37 unsigned long i; 38 39 printf("Call backtrace: "); 40 while (sp) { 41 if ((uint)sp > END_OF_MEM) 42 break; 43 44 i = sp[1]; 45 if (cnt++ % 7 == 0) 46 printf("\n"); 47 printf("%08lX ", i); 48 if (cnt > 32) 49 break; 50 sp = (unsigned long *)*sp; 51 } 52 printf("\n"); 53 } 54 55 void show_regs(struct pt_regs *regs) 56 { 57 int i; 58 59 printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n", 60 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 61 printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n", 62 regs->msr, regs->msr & MSR_EE ? 1 : 0, 63 regs->msr & MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0, 64 regs->msr & MSR_ME ? 1 : 0, regs->msr & MSR_IR ? 1 : 0, 65 regs->msr & MSR_DR ? 1 : 0); 66 67 printf("\n"); 68 for (i = 0; i < 32; i++) { 69 if ((i % 8) == 0) 70 printf("GPR%02d: ", i); 71 72 printf("%08lX ", regs->gpr[i]); 73 if ((i % 8) == 7) 74 printf("\n"); 75 } 76 } 77 78 79 static void _exception(int signr, struct pt_regs *regs) 80 { 81 show_regs(regs); 82 print_backtrace((unsigned long *)regs->gpr[1]); 83 panic("Exception in kernel pc %lx signal %d", regs->nip, signr); 84 } 85 86 void MachineCheckException(struct pt_regs *regs) 87 { 88 unsigned long fixup = search_exception_table(regs->nip); 89 90 /* Probing PCI using config cycles cause this exception 91 * when a device is not present. Catch it and return to 92 * the PCI exception handler. 93 */ 94 if (fixup != 0) { 95 regs->nip = fixup; 96 return; 97 } 98 99 printf("Machine check in kernel mode.\n"); 100 printf("Caused by (from msr): "); 101 printf("regs %p ", regs); 102 switch (regs->msr & 0x000F0000) { 103 case (0x80000000 >> 12): 104 printf("Machine check signal - probably due to mm fault\n" 105 "with mmu off\n"); 106 break; 107 case (0x80000000 >> 13): 108 printf("Transfer error ack signal\n"); 109 break; 110 case (0x80000000 >> 14): 111 printf("Data parity signal\n"); 112 break; 113 case (0x80000000 >> 15): 114 printf("Address parity signal\n"); 115 break; 116 default: 117 printf("Unknown values in msr\n"); 118 } 119 show_regs(regs); 120 print_backtrace((unsigned long *)regs->gpr[1]); 121 panic("machine check"); 122 } 123 124 void AlignmentException(struct pt_regs *regs) 125 { 126 show_regs(regs); 127 print_backtrace((unsigned long *)regs->gpr[1]); 128 panic("Alignment Exception"); 129 } 130 131 void ProgramCheckException(struct pt_regs *regs) 132 { 133 show_regs(regs); 134 print_backtrace((unsigned long *)regs->gpr[1]); 135 panic("Program Check Exception"); 136 } 137 138 void SoftEmuException(struct pt_regs *regs) 139 { 140 show_regs(regs); 141 print_backtrace((unsigned long *)regs->gpr[1]); 142 panic("Software Emulation Exception"); 143 } 144 145 146 void UnknownException(struct pt_regs *regs) 147 { 148 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 149 regs->nip, regs->msr, regs->trap); 150 _exception(0, regs); 151 } 152 153 void DebugException(struct pt_regs *regs) 154 { 155 printf("Debugger trap at @ %lx\n", regs->nip); 156 show_regs(regs); 157 } 158 159 /* Probe an address by reading. If not present, return -1, otherwise 160 * return 0. 161 */ 162 int addr_probe(uint *addr) 163 { 164 return 0; 165 } 166