1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * linux/arch/powerpc/kernel/traps.c 4 * 5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 6 * 7 * Modified by Cort Dougan (cort@cs.nmt.edu) 8 * and Paul Mackerras (paulus@cs.anu.edu.au) 9 * 10 * (C) Copyright 2000 11 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 12 */ 13 14 /* 15 * This file handles the architecture-dependent parts of hardware exceptions 16 */ 17 18 #include <common.h> 19 #include <command.h> 20 #include <asm/processor.h> 21 22 /* Returns 0 if exception not found and fixup otherwise. */ 23 extern unsigned long search_exception_table(unsigned long); 24 25 /* THIS NEEDS CHANGING to use the board info structure. 26 */ 27 #define END_OF_MEM 0x02000000 28 29 /* 30 * Trap & Exception support 31 */ 32 33 static void print_backtrace(unsigned long *sp) 34 { 35 int cnt = 0; 36 unsigned long i; 37 38 printf("Call backtrace: "); 39 while (sp) { 40 if ((uint)sp > END_OF_MEM) 41 break; 42 43 i = sp[1]; 44 if (cnt++ % 7 == 0) 45 printf("\n"); 46 printf("%08lX ", i); 47 if (cnt > 32) 48 break; 49 sp = (unsigned long *)*sp; 50 } 51 printf("\n"); 52 } 53 54 static 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, 62 regs->msr & MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0, 63 regs->msr & MSR_ME ? 1 : 0, 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 printf("GPR%02d: ", i); 70 71 printf("%08lX ", regs->gpr[i]); 72 if ((i % 8) == 7) 73 printf("\n"); 74 } 75 } 76 77 78 static void _exception(int signr, struct pt_regs *regs) 79 { 80 show_regs(regs); 81 print_backtrace((unsigned long *)regs->gpr[1]); 82 panic("Exception in kernel pc %lx signal %d", regs->nip, signr); 83 } 84 85 void MachineCheckException(struct pt_regs *regs) 86 { 87 unsigned long fixup = search_exception_table(regs->nip); 88 89 /* Probing PCI using config cycles cause this exception 90 * when a device is not present. Catch it and return to 91 * the PCI exception handler. 92 */ 93 if (fixup != 0) { 94 regs->nip = fixup; 95 return; 96 } 97 98 printf("Machine check in kernel mode.\n"); 99 printf("Caused by (from msr): "); 100 printf("regs %p ", regs); 101 switch (regs->msr & 0x000F0000) { 102 case (0x80000000 >> 12): 103 printf("Machine check signal - probably due to mm fault\n" 104 "with mmu off\n"); 105 break; 106 case (0x80000000 >> 13): 107 printf("Transfer error ack signal\n"); 108 break; 109 case (0x80000000 >> 14): 110 printf("Data parity signal\n"); 111 break; 112 case (0x80000000 >> 15): 113 printf("Address parity signal\n"); 114 break; 115 default: 116 printf("Unknown values in msr\n"); 117 } 118 show_regs(regs); 119 print_backtrace((unsigned long *)regs->gpr[1]); 120 panic("machine check"); 121 } 122 123 void AlignmentException(struct pt_regs *regs) 124 { 125 show_regs(regs); 126 print_backtrace((unsigned long *)regs->gpr[1]); 127 panic("Alignment Exception"); 128 } 129 130 void ProgramCheckException(struct pt_regs *regs) 131 { 132 show_regs(regs); 133 print_backtrace((unsigned long *)regs->gpr[1]); 134 panic("Program Check Exception"); 135 } 136 137 void SoftEmuException(struct pt_regs *regs) 138 { 139 show_regs(regs); 140 print_backtrace((unsigned long *)regs->gpr[1]); 141 panic("Software Emulation Exception"); 142 } 143 144 145 void UnknownException(struct pt_regs *regs) 146 { 147 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 148 regs->nip, regs->msr, regs->trap); 149 _exception(0, regs); 150 } 151 152 void DebugException(struct pt_regs *regs) 153 { 154 printf("Debugger trap at @ %lx\n", regs->nip); 155 show_regs(regs); 156 } 157