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
print_backtrace(unsigned long * sp)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
show_regs(struct pt_regs * regs)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
_exception(int signr,struct pt_regs * regs)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
MachineCheckException(struct pt_regs * regs)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
AlignmentException(struct pt_regs * regs)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
ProgramCheckException(struct pt_regs * regs)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
SoftEmuException(struct pt_regs * regs)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
UnknownException(struct pt_regs * regs)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
DebugException(struct pt_regs * regs)152 void DebugException(struct pt_regs *regs)
153 {
154 printf("Debugger trap at @ %lx\n", regs->nip);
155 show_regs(regs);
156 }
157