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 extern ulong get_effective_memsize(void); 33 #define END_OF_MEM (gd->bd->bi_memstart + get_effective_memsize()) 34 35 /* 36 * Trap & Exception support 37 */ 38 39 static void print_backtrace(unsigned long *sp) 40 { 41 int cnt = 0; 42 unsigned long i; 43 44 printf("Call backtrace: "); 45 while (sp) { 46 if ((uint) sp > END_OF_MEM) 47 break; 48 49 i = sp[1]; 50 if (cnt++ % 7 == 0) 51 printf("\n"); 52 printf("%08lX ", i); 53 if (cnt > 32) 54 break; 55 sp = (unsigned long *)*sp; 56 } 57 printf("\n"); 58 } 59 60 void show_regs(struct pt_regs *regs) 61 { 62 int i; 63 64 printf("NIP: %08lX XER: %08lX LR: %08lX REGS:" 65 " %p TRAP: %04lx DAR: %08lX\n", 66 regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); 67 printf("MSR: %08lx EE: %01x PR: %01x FP:" 68 " %01x ME: %01x IR/DR: %01x%01x\n", 69 regs->msr, regs->msr & MSR_EE ? 1 : 0, 70 regs->msr & MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0, 71 regs->msr & MSR_ME ? 1 : 0, regs->msr & MSR_IR ? 1 : 0, 72 regs->msr & MSR_DR ? 1 : 0); 73 74 printf("\n"); 75 for (i = 0; i < 32; i++) { 76 if ((i % 8) == 0) { 77 printf("GPR%02d: ", i); 78 } 79 80 printf("%08lX ", regs->gpr[i]); 81 if ((i % 8) == 7) { 82 printf("\n"); 83 } 84 } 85 } 86 87 88 static void _exception(int signr, struct pt_regs *regs) 89 { 90 show_regs(regs); 91 print_backtrace((unsigned long *)regs->gpr[1]); 92 panic("Exception in kernel pc %lx signal %d", regs->nip, signr); 93 } 94 95 void MachineCheckException(struct pt_regs *regs) 96 { 97 unsigned long fixup; 98 99 /* Probing PCI using config cycles cause this exception 100 * when a device is not present. Catch it and return to 101 * the PCI exception handler. 102 */ 103 if ((fixup = search_exception_table(regs->nip)) != 0) { 104 regs->nip = fixup; 105 return; 106 } 107 108 #if defined(CONFIG_CMD_KGDB) 109 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 110 return; 111 #endif 112 113 printf("Machine check in kernel mode.\n"); 114 printf("Caused by (from msr): "); 115 printf("regs %p ", regs); 116 switch ( regs->msr & 0x001F0000) { 117 case (0x80000000>>11): 118 printf("MSS error. MSSSR0: %08x\n", mfspr(SPRN_MSSSR0)); 119 break; 120 case (0x80000000>>12): 121 printf("Machine check signal - probably due to mm fault\n" 122 "with mmu off\n"); 123 break; 124 case (0x80000000 >> 13): 125 printf("Transfer error ack signal\n"); 126 break; 127 case (0x80000000 >> 14): 128 printf("Data parity signal\n"); 129 break; 130 case (0x80000000 >> 15): 131 printf("Address parity signal\n"); 132 break; 133 default: 134 printf("Unknown values in msr\n"); 135 } 136 show_regs(regs); 137 print_backtrace((unsigned long *)regs->gpr[1]); 138 panic("machine check"); 139 } 140 141 void AlignmentException(struct pt_regs *regs) 142 { 143 #if defined(CONFIG_CMD_KGDB) 144 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 145 return; 146 #endif 147 show_regs(regs); 148 print_backtrace((unsigned long *)regs->gpr[1]); 149 panic("Alignment Exception"); 150 } 151 152 void ProgramCheckException(struct pt_regs *regs) 153 { 154 unsigned char *p = regs ? (unsigned char *)(regs->nip) : NULL; 155 int i, j; 156 157 #if defined(CONFIG_CMD_KGDB) 158 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 159 return; 160 #endif 161 show_regs(regs); 162 163 p = (unsigned char *)((unsigned long)p & 0xFFFFFFE0); 164 p -= 32; 165 for (i = 0; i < 256; i += 16) { 166 printf("%08x: ", (unsigned int)p + i); 167 for (j = 0; j < 16; j++) { 168 printf("%02x ", p[i + j]); 169 } 170 printf("\n"); 171 } 172 173 print_backtrace((unsigned long *)regs->gpr[1]); 174 panic("Program Check Exception"); 175 } 176 177 void SoftEmuException(struct pt_regs *regs) 178 { 179 #if defined(CONFIG_CMD_KGDB) 180 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 181 return; 182 #endif 183 show_regs(regs); 184 print_backtrace((unsigned long *)regs->gpr[1]); 185 panic("Software Emulation Exception"); 186 } 187 188 void UnknownException(struct pt_regs *regs) 189 { 190 #if defined(CONFIG_CMD_KGDB) 191 if (debugger_exception_handler && (*debugger_exception_handler) (regs)) 192 return; 193 #endif 194 printf("UnknownException regs@%lx\n", (ulong)regs); 195 printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", 196 regs->nip, regs->msr, regs->trap); 197 _exception(0, regs); 198 } 199 200 /* 201 * Probe an address by reading. 202 * If not present, return -1, 203 * otherwise return 0. 204 */ 205 int addr_probe(uint *addr) 206 { 207 return 0; 208 } 209