/*
* HW exception handling
*
* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2008 PetaLogix
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of this
* archive for more details.
*/
/*
* This file handles the architecture-dependent parts of hardware exceptions
*/
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include <asm/exceptions.h>
#include <asm/entry.h> /* For KM CPU var */
#include <linux/uaccess.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <asm/current.h>
#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
#define MICROBLAZE_IBUS_EXCEPTION 0x03
#define MICROBLAZE_DBUS_EXCEPTION 0x04
#define MICROBLAZE_DIV_ZERO_EXCEPTION 0x05
#define MICROBLAZE_FPU_EXCEPTION 0x06
#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
static DEFINE_SPINLOCK(die_lock);
void die(const char *str, struct pt_regs *fp, long err)
{
console_verbose();
spin_lock_irq(&die_lock);
printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
show_regs(fp);
spin_unlock_irq(&die_lock);
/* do_exit() should take care of panic'ing from an interrupt
* context so we don't handle it here
*/
do_exit(err);
}
void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
{
siginfo_t info;
if (kernel_mode(regs)) {
debugger(regs);
die("Exception in kernel mode", regs, signr);
}
info.si_signo = signr;
info.si_errno = 0;
info.si_code = code;
info.si_addr = (void __user *) addr;
force_sig_info(signr, &info, current);
}
asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
int fsr, int addr)
{
#ifdef CONFIG_MMU
int code;
addr = regs->pc;
#endif
#if 0
printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
type, user_mode(regs) ? "user" : "kernel", fsr,
(unsigned int) regs->pc, (unsigned int) regs->esr);
#endif
switch (type & 0x1F) {
case MICROBLAZE_ILL_OPCODE_EXCEPTION:
if (user_mode(regs)) {
printk(KERN_WARNING "Illegal opcode exception in user mode.\n");
_exception(SIGILL, regs, ILL_ILLOPC, addr);
return;
}
printk(KERN_WARNING "Illegal opcode exception in kernel mode.\n");
die("opcode exception", regs, SIGBUS);
break;
case MICROBLAZE_IBUS_EXCEPTION:
if (user_mode(regs)) {
printk(KERN_WARNING "Instruction bus error exception in user mode.\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Instruction bus error exception in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DBUS_EXCEPTION:
if (user_mode(regs)) {
printk(KERN_WARNING "Data bus error exception in user mode.\n");
_exception(SIGBUS, regs, BUS_ADRERR, addr);
return;
}
printk(KERN_WARNING "Data bus error exception in kernel mode.\n");
die("bus exception", regs, SIGBUS);
break;
case MICROBLAZE_DIV_ZERO_EXCEPTION:
if (user_mode(regs)) {
printk(KERN_WARNING "Divide by zero exception in user mode\n");
_exception(SIGILL, regs, ILL_ILLOPC, addr);
return;
}
printk(KERN_WARNING "Divide by zero exception in kernel mode.\n");
die("Divide by exception", regs, SIGBUS);
break;
case MICROBLAZE_FPU_EXCEPTION:
printk(KERN_WARNING "FPU exception\n");
/* IEEE FP exception */
/* I removed fsr variable and use code var for storing fsr */
if (fsr & FSR_IO)
fsr = FPE_FLTINV;
else if (fsr & FSR_OF)
fsr = FPE_FLTOVF;
else if (fsr & FSR_UF)
fsr = FPE_FLTUND;
else if (fsr & FSR_DZ)
fsr = FPE_FLTDIV;
else if (fsr & FSR_DO)
fsr = FPE_FLTRES;
_exception(SIGFPE, regs, fsr, addr);
break;
#ifdef CONFIG_MMU
case MICROBLAZE_PRIVILEGED_EXCEPTION:
printk(KERN_WARNING "Privileged exception\n");
/* "brk r0,r0" - used as debug breakpoint */
if (get_user(code, (unsigned long *)regs->pc) == 0
&& code == 0x980c0000) {
_exception(SIGTRAP, regs, TRAP_BRKPT, addr);
} else {
_exception(SIGILL, regs, ILL_PRVOPC, addr);
}
break;
#endif
default:
/* FIXME what to do in unexpected exception */
printk(KERN_WARNING "Unexpected exception %02x "
"PC=%08x in %s mode\n", type, (unsigned int) addr,
kernel_mode(regs) ? "kernel" : "user");
}
return;
}
