path: root/arch/powerpc/kernel/traps.c

/*
 *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
 *
 *  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.
 *
 *  Modified by Cort Dougan (cort@cs.nmt.edu)
 *  and Paul Mackerras (paulus@samba.org)
 */

/*
 * This file handles the architecture-dependent parts of hardware exceptions
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/prctl.h>
#include <linux/delay.h>
#include <linux/kprobes.h>
#include <linux/kexec.h>
#include <linux/backlight.h>
#include <linux/bug.h>
#include <linux/kdebug.h>

#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/pmc.h>
#ifdef CONFIG_PPC32
#include <asm/reg.h>
#endif
#ifdef CONFIG_PMAC_BACKLIGHT
#include <asm/backlight.h>
#endif
#ifdef CONFIG_PPC64
#include <asm/firmware.h>
#include <asm/processor.h>
#endif
#include <asm/kexec.h>

#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
int (*__debugger)(struct pt_regs *regs);
int (*__debugger_ipi)(struct pt_regs *regs);
int (*__debugger_bpt)(struct pt_regs *regs);
int (*__debugger_sstep)(struct pt_regs *regs);
int (*__debugger_iabr_match)(struct pt_regs *regs);
int (*__debugger_dabr_match)(struct pt_regs *regs);
int (*__debugger_fault_handler)(struct pt_regs *regs);

EXPORT_SYMBOL(__debugger);
EXPORT_SYMBOL(__debugger_ipi);
EXPORT_SYMBOL(__debugger_bpt);
EXPORT_SYMBOL(__debugger_sstep);
EXPORT_SYMBOL(__debugger_iabr_match);
EXPORT_SYMBOL(__debugger_dabr_match);
EXPORT_SYMBOL(__debugger_fault_handler);
#endif

/*
 * Trap & Exception support
 */

#ifdef CONFIG_PMAC_BACKLIGHT
static void pmac_backlight_unblank(void)
{
	mutex_lock(&pmac_backlight_mutex);
	if (pmac_backlight) {
		struct backlight_properties *props;

		props = &pmac_backlight->props;
		props->brightness = props->max_brightness;
		props->power = FB_BLANK_UNBLANK;
		backlight_update_status(pmac_backlight);
	}
	mutex_unlock(&pmac_backlight_mutex);
}
#else
static inline void pmac_backlight_unblank(void) { }
#endif

int die(const char *str, struct pt_regs *regs, long err)
{
	static struct {
		spinlock_t lock;
		u32 lock_owner;
		int lock_owner_depth;
	} die = {
		.lock =			__SPIN_LOCK_UNLOCKED(die.lock),
		.lock_owner =		-1,
		.lock_owner_depth =	0
	};
	static int die_counter;
	unsigned long flags;

	if (debugger(regs))
		return 1;

	oops_enter();

	if (die.lock_owner != raw_smp_processor_id()) {
		console_verbose();
		spin_lock_irqsave(&die.lock, flags);
		die.lock_owner = smp_processor_id();
		die.lock_owner_depth = 0;
		bust_spinlocks(1);
		if (machine_is(powermac))
			pmac_backlight_unblank();
	} else {
		local_save_flags(flags);
	}

	if (++die.lock_owner_depth < 3) {
		printk("Oops: %s, sig: %ld [#%d]\n", st