1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 4 * 5 * Modified by Cort Dougan (cort@cs.nmt.edu) 6 * and Paul Mackerras (paulus@cs.anu.edu.au) 7 * 8 * (C) Copyright 2000 9 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 10 */ 11 12 /* 13 * This file handles the architecture-dependent parts of hardware exceptions 14 */ 15 16 #include <common.h> 17 #include <command.h> 18 #include <kgdb.h> 19 #include <asm/processor.h> 20 21 DECLARE_GLOBAL_DATA_PTR; 22 23 /* Returns 0 if exception not found and fixup otherwise. */ 24 extern unsigned long search_exception_table(unsigned long); 25 26 /* 27 * End of addressable memory. This may be less than the actual 28 * amount of memory on the system if we're unable to keep all 29 * the memory mapped in. 30 */ 31 #define END_OF_MEM (gd->bd->bi_memstart + get_effective_memsize()) 32 33 /* 34 * Trap & Exception support 35 */ 36 37 static void print_backtrace(unsigned long *sp) 38 { 39 int cnt = 0; 40 unsigned long i; 41 42 printf("Call backtrace: "); 43 while (sp) { 44 if ((uint) sp > END_OF_MEM) 45 break; 46 47 i = sp[1]; 48 if (cnt++ % 7 == 0) 49 printf("\n"); 50 printf("%08lX ", i); 51 if (cnt > 32) 52 break; 53 sp = (unsigned long *)*sp; 54 } 55 printf("\n"); 56 } 57 58 void show_regs(struct pt_regs *regs) 59 { 60 int i; 61 62 printf("NIP: %08lX XER: %08lX LR: %08lX REGS:" 63 " %p TRAP: %04lx DAR: %08lX\n", 64 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 65 printf("MSR: %08lx EE: %01x PR: %01x FP:" 66 " %01x ME: %01x IR/DR: %01x%01x\n", 67 regs->msr, regs->msr & MSR_EE ? 1 : 0, 68 regs->msr & MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0, 69 regs->msr & MSR_ME ? 1 : 0, regs->msr & MSR_IR ? 1 : 0, 70 regs->msr & MSR_DR ? 1 : 0); 71 72 printf("\n"); 73 for (i = 0; i < 32; i++) { 74 if ((i % 8) == 0) { 75 printf("GPR%02d: ", i); 76 } 77 78 printf("%08lX ", regs->gpr[i]); 79 if ((i % 8) == 7) { 80 printf("\n"); 81 } 82 } 83 } 84 85 86 static void _exception(int signr, struct pt_regs *regs) 87 { 88 show_regs(regs); 89 print_backtrace((unsigned long *)regs->gpr[1]); 90 panic("Exception in kernel pc %lx signal %d", regs->nip, signr); 91 } 92 93 void MachineCheckException(struct pt_regs *regs) 94 { 95 unsigned long fixup; 96 97 /* Probing PCI using config cycles cause this exception 98 * when a device is not present. Catch it and return to 99 * the PCI exception handler. 100 */ 101 if ((fixup = search_exception_table(regs->nip)) != 0) { 102 regs->nip = fixup; 103 return; 104 } 105 106 #if defined(CONFIG_CMD_KGDB) 107 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 108 return; 109 #endif 110 111 printf("Machine check in kernel mode.\n"); 112 printf("Caused by (from msr): "); 113 printf("regs %p ", regs); 114 switch ( regs->msr & 0x001F0000) { 115 case (0x80000000>>11): 116 printf("MSS error. MSSSR0: %08x\n", mfspr(SPRN_MSSSR0)); 117 break; 118 case (0x80000000>>12): 119 printf("Machine check signal - probably due to mm fault\n" 120 "with mmu off\n"); 121 break; 122 case (0x80000000 >> 13): 123 printf("Transfer error ack signal\n"); 124 break; 125 case (0x80000000 >> 14): 126 printf("Data parity signal\n"); 127 break; 128 case (0x80000000 >> 15): 129 printf("Address parity signal\n"); 130 break; 131 default: 132 printf("Unknown values in msr\n"); 133 } 134 show_regs(regs); 135 print_backtrace((unsigned long *)regs->gpr[1]); 136 panic("machine check"); 137 } 138 139 void AlignmentException(struct pt_regs *regs) 140 { 141 #if defined(CONFIG_CMD_KGDB) 142 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 143 return; 144 #endif 145 show_regs(regs); 146 print_backtrace((unsigned long *)regs->gpr[1]); 147 panic("Alignment Exception"); 148 } 149 150 void ProgramCheckException(struct pt_regs *regs) 151 { 152 unsigned char *p = regs ? (unsigned char *)(regs->nip) : NULL; 153 int i, j; 154 155 #if defined(CONFIG_CMD_KGDB) 156 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 157 return; 158 #endif 159 show_regs(regs); 160 161 p = (unsigned char *)((unsigned long)p & 0xFFFFFFE0); 162 p -= 32; 163 for (i = 0; i < 256; i += 16) { 164 printf("%08x: ", (unsigned int)p + i); 165 for (j = 0; j < 16; j++) { 166 printf("%02x ", p[i + j]); 167 } 168 printf("\n"); 169 } 170 171 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 void UnknownException(struct pt_regs *regs) 187 { 188 #if defined(CONFIG_CMD_KGDB) 189 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 190 return; 191 #endif 192 printf("UnknownException regs@%lx\n", (ulong)regs); 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