/* * linux/arch/ppc/kernel/traps.c * * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modified by Cort Dougan (cort@cs.nmt.edu) * and Paul Mackerras (paulus@cs.anu.edu.au) * * (C) Copyright 2000 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. * * See file CREDITS for list of people who contributed to this * project. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, * MA 02111-1307 USA */ /* * This file handles the architecture-dependent parts of hardware exceptions */ #include #include /* Returns 0 if exception not found and fixup otherwise. */ extern unsigned long search_exception_table(unsigned long); /* THIS NEEDS CHANGING to use the board info structure. */ #define END_OF_MEM 0x00400000 /* * Trap & Exception support */ void print_backtrace(unsigned long *sp) { int cnt = 0; unsigned long i; printf("Call backtrace: "); while (sp) { if ((uint)sp > END_OF_MEM) break; i = sp[1]; if (cnt++ % 7 == 0) printf("\n"); printf("%08lX ", i); if (cnt > 32) break; sp = (unsigned long *)*sp; } printf("\n"); } void show_regs(struct pt_regs * regs) { int i; printf("NIP: %08lX XER: %08lX LR: %08lX REGS: %p TRAP: %04lx DAR: %08lX\n", regs->nip, regs->xer, regs->link, regs, regs->trap, regs->dar); printf("MSR: %08lx EE: %01x PR: %01x FP: %01x ME: %01x IR/DR: %01x%01x\n", regs->msr, regs->msr&MSR_EE ? 1 : 0, regs->msr&MSR_PR ? 1 : 0, regs->msr & MSR_FP ? 1 : 0,regs->msr&MSR_ME ? 1 : 0, regs->msr&MSR_IR ? 1 : 0, regs->msr&MSR_DR ? 1 : 0); printf("\n"); for (i = 0; i < 32; i++) { if ((i % 8) == 0) { printf("GPR%02d: ", i); } printf("%08lX ", regs->gpr[i]); if ((i % 8) == 7) { printf("\n"); } } } void _exception(int signr, struct pt_regs *regs) { show_regs(regs); print_backtrace((unsigned long *)regs->gpr[1]); panic("Exception in kernel pc %lx signal %d",regs->nip,signr); } void MachineCheckException(struct pt_regs *regs) { unsigned long fixup; /* Probing PCI using config cycles cause this exception * when a device is not present. Catch it and return to * the PCI exception handler. */ if ((fixup = search_exception_table(regs->nip)) != 0) { regs->nip = fixup; return; } printf("Machine check in kernel mode.\n"); printf("Caused by (from msr): "); printf("regs %p ",regs); switch( regs->msr & 0x000F0000) { case (0x80000000>>12): printf("Machine check signal - probably due to mm fault\n" "with mmu off\n"); break; case (0x80000000>>13): printf("Transfer error ack signal\n"); break; case (0x80000000>>14): printf("Data parity signal\n"); break; case (0x80000000>>15): printf("Address parity signal\n"); break; default: printf("Unknown values in msr\n"); } show_regs(regs); print_backtrace((unsigned long *)regs->gpr[1]); panic("machine check"); } void AlignmentException(struct pt_regs *regs) { show_regs(regs); print_backtrace((unsigned long *)regs->gpr[1]); panic("Alignment Exception"); } void ProgramCheckException(struct pt_regs *regs) { show_regs(regs); print_backtrace((unsigned long *)regs->gpr[1]); panic("Program Check Exception"); } void SoftEmuException(struct pt_regs *regs) { show_regs(regs); print_backtrace((unsigned long *)regs->gpr[1]); panic("Software Emulation Exception"); } void UnknownException(struct pt_regs *regs) { printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n", regs->nip, regs->msr, regs->trap); _exception(0, regs); } #if (CONFIG_COMMANDS & CFG_CMD_BEDBUG) extern void do_bedbug_breakpoint(struct pt_regs *); #endif void DebugException(struct pt_regs *regs) { printf("Debugger trap at @ %lx\n", regs->nip ); show_regs(regs); #if (CONFIG_COMMANDS & CFG_CMD_BEDBUG) do_bedbug_breakpoint( regs ); #endif } /* Probe an address by reading. If not present, return -1, otherwise * return 0. */ int addr_probe(uint *addr) { #if 0 int retval; __asm__ __volatile__( \ "1: lwz %0,0(%1)\n" \ " eieio\n" \ " li %0,0\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: li %0,-1\n" \ " b 2b\n" \ ".section __ex_table,\"a\"\n" \ " .align 2\n" \ " .long 1b,3b\n" \ ".text" \ : "=r" (retval) : "r"(addr)); return (retval); #endif return 0; }
