1 /* 2 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 3 * 4 * Modified by Cort Dougan (cort@cs.nmt.edu) 5 * and Paul Mackerras (paulus@cs.anu.edu.au) 6 * 7 * (C) Copyright 2000 8 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 9 * 10 * SPDX-License-Identifier: GPL-2.0+ 11 */ 12 13 /* 14 * This file handles the architecture-dependent parts of hardware exceptions 15 */ 16 17 #include <common.h> 18 #include <command.h> 19 #include <kgdb.h> 20 #include <asm/processor.h> 21 22 DECLARE_GLOBAL_DATA_PTR; 23 24 /* Returns 0 if exception not found and fixup otherwise. */ 25 extern unsigned long search_exception_table(unsigned long); 26 27 /* 28 * End of addressable memory. This may be less than the actual 29 * amount of memory on the system if we're unable to keep all 30 * the memory mapped in. 31 */ 32 #define END_OF_MEM (gd->bd->bi_memstart + get_effective_memsize()) 33 34 /* 35 * Trap & Exception support 36 */ 37 38 static void print_backtrace(unsigned long *sp) 39 { 40 int cnt = 0; 41 unsigned long i; 42 43 printf("Call backtrace: "); 44 while (sp) { 45 if ((uint) sp > END_OF_MEM) 46 break; 47 48 i = sp[1]; 49 if (cnt++ % 7 == 0) 50 printf("\n"); 51 printf("%08lX ", i); 52 if (cnt > 32) 53 break; 54 sp = (unsigned long *)*sp; 55 } 56 printf("\n"); 57 } 58 59 void show_regs(struct pt_regs *regs) 60 { 61 int i; 62 63 printf("NIP: %08lX XER: %08lX LR: %08lX REGS:" 64 " %p TRAP: %04lx DAR: %08lX\n", 65 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 66 printf("MSR: %08lx EE: %01x PR: %01x FP:" 67 " %01x ME: %01x IR/DR: %01x%01x\n", 68 regs->msr, regs->msr & MSR_EE ? 1 : 0, 69 regs->msr & MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0, 70 regs->msr & MSR_ME ? 1 : 0, regs->msr & MSR_IR ? 1 : 0, 71 regs->msr & MSR_DR ? 1 : 0); 72 73 printf("\n"); 74 for (i = 0; i < 32; i++) { 75 if ((i % 8) == 0) { 76 printf("GPR%02d: ", i); 77 } 78 79 printf("%08lX ", regs->gpr[i]); 80 if ((i % 8) == 7) { 81 printf("\n"); 82 } 83 } 84 } 85 86 87 static void _exception(int signr, struct pt_regs *regs) 88 { 89 show_regs(regs); 90 print_backtrace((unsigned long *)regs->gpr[1]); 91 panic("Exception in kernel pc %lx signal %d", regs->nip, signr); 92 } 93 94 void MachineCheckException(struct pt_regs *regs) 95 { 96 unsigned long fixup; 97 98 /* Probing PCI using config cycles cause this exception 99 * when a device is not present. Catch it and return to 100 * the PCI exception handler. 101 */ 102 if ((fixup = search_exception_table(regs->nip)) != 0) { 103 regs->nip = fixup; 104 return; 105 } 106 107 #if defined(CONFIG_CMD_KGDB) 108 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 109 return; 110 #endif 111 112 printf("Machine check in kernel mode.\n"); 113 printf("Caused by (from msr): "); 114 printf("regs %p ", regs); 115 switch ( regs->msr & 0x001F0000) { 116 case (0x80000000>>11): 117 printf("MSS error. MSSSR0: %08x\n", mfspr(SPRN_MSSSR0)); 118 break; 119 case (0x80000000>>12): 120 printf("Machine check signal - probably due to mm fault\n" 121 "with mmu off\n"); 122 break; 123 case (0x80000000 >> 13): 124 printf("Transfer error ack signal\n"); 125 break; 126 case (0x80000000 >> 14): 127 printf("Data parity signal\n"); 128 break; 129 case (0x80000000 >> 15): 130 printf("Address parity signal\n"); 131 break; 132 default: 133 printf("Unknown values in msr\n"); 134 } 135 show_regs(regs); 136 print_backtrace((unsigned long *)regs->gpr[1]); 137 panic("machine check"); 138 } 139 140 void AlignmentException(struct pt_regs *regs) 141 { 142 #if defined(CONFIG_CMD_KGDB) 143 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 144 return; 145 #endif 146 show_regs(regs); 147 print_backtrace((unsigned long *)regs->gpr[1]); 148 panic("Alignment Exception"); 149 } 150 151 void ProgramCheckException(struct pt_regs *regs) 152 { 153 unsigned char *p = regs ? (unsigned char *)(regs->nip) : NULL; 154 int i, j; 155 156 #if defined(CONFIG_CMD_KGDB) 157 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 158 return; 159 #endif 160 show_regs(regs); 161 162 p = (unsigned char *)((unsigned long)p & 0xFFFFFFE0); 163 p -= 32; 164 for (i = 0; i < 256; i += 16) { 165 printf("%08x: ", (unsigned int)p + i); 166 for (j = 0; j < 16; j++) { 167 printf("%02x ", p[i + j]); 168 } 169 printf("\n"); 170 } 171 172 print_backtrace((unsigned long *)regs->gpr[1]); 173 panic("Program Check Exception"); 174 } 175 176 void SoftEmuException(struct pt_regs *regs) 177 { 178 #if defined(CONFIG_CMD_KGDB) 179 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 180 return; 181 #endif 182 show_regs(regs); 183 print_backtrace((unsigned long *)regs->gpr[1]); 184 panic("Software Emulation Exception"); 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("UnknownException regs@%lx\n", (ulong)regs); 194 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 195 regs->nip, regs->msr, regs->trap); 196 _exception(0, regs); 197 } 198 199 /* 200 * Probe an address by reading. 201 * If not present, return -1, 202 * otherwise return 0. 203 */ 204 int addr_probe(uint *addr) 205 { 206 return 0; 207 } 208