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/*
* linux/arch/powerpc/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.
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* This file handles the architecture-dependent parts of hardware exceptions
*/
#include <common.h>
#include <command.h>
#include <kgdb.h>
#include <asm/processor.h>
#if defined(CONFIG_CMD_BEDBUG)
extern void do_bedbug_breakpoint(struct pt_regs *);
#endif
/* 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 0x02000000
/*
* Trap & Exception support
*/
static 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");
}
}
}
static 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;
}
#if defined(CONFIG_CMD_KGDB)
if (debugger_exception_handler && (*debugger_exception_handler)(regs))
return;
#endif
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)
{
#if defined(CONFIG_CMD_KGDB)
if (debugger_exception_handler && (*debugger_exception_handler)(regs))
return;
#endif
show_regs(regs);
print_backtrace((unsigned long *)regs->gpr[1]);
panic("Alignment Exception");
}
void ProgramCheckException(struct pt_regs *regs)
{
#if defined(CONFIG_CMD_KGDB)
if (debugger_exception_handler && (*debugger_exception_handler)(regs))
return;
#endif
show_regs(regs);
print_backtrace((unsigned long *)regs->gpr[1]);
panic("Program Check Exception");
}
void SoftEmuException(struct pt_regs *regs)
{
#if defined(CONFIG_CMD_KGDB)
if (debugger_exception_handler && (*debugger_exception_handler)(regs))
return;
#endif
show_regs(regs);
print_backtrace((unsigned long *)regs->gpr[1]);
panic("Software Emulation Exception");
}
void UnknownException(struct pt_regs *regs)
{
#if defined(CONFIG_CMD_KGDB)
if (debugger_exception_handler && (*debugger_exception_handler)(regs))
return;
#endif
printf("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
regs->nip, regs->msr, regs->trap);
_exception(0, regs);
}
void DebugException(struct pt_regs *regs)
{
printf("Debugger trap at @ %lx\n", regs->nip );
show_regs(regs);
#if defined(CONFIG_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;
}
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