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) break; 49 sp = (unsigned long *)*sp; 50 } 51 printf("\n"); 52 } 53 54 void show_regs(struct pt_regs *regs) 55 { 56 int i; 57 58 printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n", 59 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 60 printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n", 61 regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, 62 regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, 63 regs->msr&MSR_IR ? 1 : 0, 64 regs->msr&MSR_DR ? 1 : 0); 65 66 printf("\n"); 67 for (i = 0; i < 32; i++) { 68 if ((i % 8) == 0) 69 { 70 printf("GPR%02d: ", i); 71 } 72 73 printf("%08lX ", regs->gpr[i]); 74 if ((i % 8) == 7) 75 { 76 printf("\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 void MachineCheckException(struct pt_regs *regs) 90 { 91 unsigned long fixup; 92 93 /* Probing PCI using config cycles cause this exception 94 * when a device is not present. Catch it and return to 95 * the PCI exception handler. 96 */ 97 if ((fixup = search_exception_table(regs->nip)) != 0) { 98 regs->nip = fixup; 99 return; 100 } 101 102 printf("Machine check in kernel mode.\n"); 103 printf("Caused by (from msr): "); 104 printf("regs %p ",regs); 105 switch( regs->msr & 0x000F0000) { 106 case (0x80000000>>12): 107 printf("Machine check signal - probably due to mm fault\n" 108 "with mmu off\n"); 109 break; 110 case (0x80000000>>13): 111 printf("Transfer error ack signal\n"); 112 break; 113 case (0x80000000>>14): 114 printf("Data parity signal\n"); 115 break; 116 case (0x80000000>>15): 117 printf("Address parity signal\n"); 118 break; 119 default: 120 printf("Unknown values in msr\n"); 121 } 122 show_regs(regs); 123 print_backtrace((unsigned long *)regs->gpr[1]); 124 panic("machine check"); 125 } 126 127 void AlignmentException(struct pt_regs *regs) 128 { 129 show_regs(regs); 130 print_backtrace((unsigned long *)regs->gpr[1]); 131 panic("Alignment Exception"); 132 } 133 134 void ProgramCheckException(struct pt_regs *regs) 135 { 136 show_regs(regs); 137 print_backtrace((unsigned long *)regs->gpr[1]); 138 panic("Program Check Exception"); 139 } 140 141 void SoftEmuException(struct pt_regs *regs) 142 { 143 show_regs(regs); 144 print_backtrace((unsigned long *)regs->gpr[1]); 145 panic("Software Emulation Exception"); 146 } 147 148 149 void UnknownException(struct pt_regs *regs) 150 { 151 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 152 regs->nip, regs->msr, regs->trap); 153 _exception(0, regs); 154 } 155 156 void DebugException(struct pt_regs *regs) 157 { 158 printf("Debugger trap at @ %lx\n", regs->nip ); 159 show_regs(regs); 160 } 161 162 /* Probe an address by reading. If not present, return -1, otherwise 163 * return 0. 164 */ 165 int addr_probe(uint *addr) 166 { 167 return 0; 168 } 169