[mirror_ubuntu-artful-kernel.git] / arch / avr32 / kernel / traps.c

/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bug.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/uaccess.h>

#include <asm/addrspace.h>
#include <asm/mmu_context.h>
#include <asm/ocd.h>
#include <asm/sysreg.h>
#include <asm/traps.h>

ATOMIC_NOTIFIER_HEAD(avr32_die_chain);

int register_die_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_register(&avr32_die_chain, nb);
}
EXPORT_SYMBOL(register_die_notifier);

int unregister_die_notifier(struct notifier_block *nb)
{
	return atomic_notifier_chain_unregister(&avr32_die_chain, nb);
}
EXPORT_SYMBOL(unregister_die_notifier);

static DEFINE_SPINLOCK(die_lock);

void NORET_TYPE die(const char *str, struct pt_regs *regs, long err)
{
	static int die_counter;

	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);

	printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n" KERN_EMERG,
	       str, err, ++die_counter);
#ifdef CONFIG_PREEMPT
	printk("PREEMPT ");
#endif
#ifdef CONFIG_FRAME_POINTER
	printk("FRAME_POINTER ");
#endif
	if (current_cpu_data.features & AVR32_FEATURE_OCD) {
		unsigned long did = __mfdr(DBGREG_DID);
		printk("chip: 0x%03lx:0x%04lx rev %lu\n",
		       (did >> 1) & 0x7ff,
		       (did >> 12) & 0x7fff,
		       (did >> 28) & 0xf);
	} else {
		printk("cpu: arch %u r%u / core %u r%u\n",
		       current_cpu_data.arch_type,
		       current_cpu_data.arch_revision,
		       current_cpu_data.cpu_type,
		       current_cpu_data.cpu_revision);
	}

	print_modules();
	show_regs_log_lvl(regs, KERN_EMERG);
	show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
	bust_spinlocks(0);
	spin_unlock_irq(&die_lock);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	do_exit(err);
}

void _exception(long signr, struct pt_regs *regs, int code,
		unsigned long addr)
{
	siginfo_t info;

	if (!user_mode(regs))
		die("Unhandled exception in kernel mode", regs, signr);

	memset(&info, 0, sizeof(info));
	info.si_signo = signr;
	info.si_code = code;
	info.si_addr = (void __user *)addr;
	force_sig_info(signr, &info, current);

	/*
	 * Init gets no signals that it doesn't have a handler for.
	 * That's all very well, but if it has caused a synchronous
	 * exception and we ignore the resulting signal, it will just
	 * generate the same exception over and over again and we get
	 * nowhere.  Better to kill it and let the kernel panic.
	 */
	if (is_init(current)) {
		__sighandler_t handler;

		spin_lock_irq(&current->sighand->siglock);
		handler = current->sighand->action[signr-1].sa.sa_handler;
		spin_unlock_irq(&current->sighand->siglock);
		if (handler == SIG_DFL) {
			/* init has generated a synchronous exception
			   and it doesn't have a handler for the signal */
			printk(KERN_CRIT "init has generated signal %ld "
			       "but has no handler for it\n", signr);
			do_exit(signr);
		}
	}
}

asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
{
	printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n");
	show_regs_log_lvl(regs, KERN_ALERT);
	show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT);
}

asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
{
	die("Critical exception", regs, SIGKILL);
}

asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
{
	_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
}

/* This way of handling undefined instructions is stolen from ARM */
static LIST_HEAD(undef_hook);
static spinlock_t undef_lock = SPIN_LOCK_UNLOCKED;

void register_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_add(&hook->node, &undef_hook);
	spin_unlock_irq(&undef_lock);
}

void unregister_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_del(&hook->node);
	spin_unlock_irq(&undef_lock);
}

static int do_cop_absent(u32 insn)
{
	int cop_nr;
	u32 cpucr;

	if ((insn & 0xfdf00000) == 0xf1900000)
		/* LDC0 */
		cop_nr = 0;
	else
		cop_nr = (insn >> 13) & 0x7;

	/* Try enabling the coprocessor */
	cpucr = sysreg_read(CPUCR);
	cpucr |= (1 << (24 + cop_nr));
	sysreg_write(CPUCR, cpucr);

	cpucr = sysreg_read(CPUCR);
	if (!(cpucr & (1 << (24 + cop_nr))))
		return -ENODEV;

	return 0;
}

int is_valid_bugaddr(unsigned long pc)
{
	unsigned short opcode;

	if (pc < PAGE_OFFSET)
		return 0;
	if (probe_kernel_address((u16 *)pc, opcode))
		return 0;

	return opcode == AVR32_BUG_OPCODE;
}

asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
{
	u32 insn;
	struct undef_hook *hook;
	void __user *pc;
	long code;

	if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
		enum bug_trap_type type;

		type = report_bug(regs->pc);
		switch (type) {
		case BUG_TRAP_TYPE_NONE:
			break;
		case BUG_TRAP_TYPE_WARN:
			regs->pc += 2;
			return;
		case BUG_TRAP_TYPE_BUG:
			die("Kernel BUG", regs, SIGKILL);
		}
	}

	local_irq_enable();

	if (user_mode(regs)) {
		pc = (void __user *)instruction_pointer(regs);
		if (get_user(insn, (u32 __user *)pc))
			goto invalid_area;

		if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
			return;

		spin_lock_irq(&undef_lock);
		list_for_each_entry(hook, &undef_hook, node) {
			if ((insn & hook->insn_mask) == hook->insn_val) {
				if (hook->fn(regs, insn) == 0) {
					spin_unlock_irq(&undef_lock);
					return;
				}
			}
		}
		spin_unlock_irq(&undef_lock);
	}

	switch (ecr) {
	case ECR_PRIVILEGE_VIOLATION:
		code = ILL_PRVOPC;
		break;
	case ECR_COPROC_ABSENT:
		code = ILL_COPROC;
		break;
	default:
		code = ILL_ILLOPC;
		break;
	}

	_exception(SIGILL, regs, code, regs->pc);
	return;

invalid_area:
	_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
}

asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
{
	/* We have no FPU yet */
	_exception(SIGILL, regs, ILL_COPROC, regs->pc);
}


void __init trap_init(void)
{

}
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* Copyright (C) 2004-2006 Atmel Corporation
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
623b0355 HS	8
623b0355 HS	9	#include <linux/bug.h>
5f97f7f9	10	#include <linux/init.h>
5f97f7f9	11	#include <linux/kallsyms.h>
623b0355	12	#include <linux/module.h>
5f97f7f9	13	#include <linux/notifier.h>
623b0355 HS	14	#include <linux/sched.h>
623b0355 HS	15	#include <linux/uaccess.h>
5f97f7f9	16
5f97f7f9	17	#include <asm/addrspace.h>
5f97f7f9	18	#include <asm/mmu_context.h>
623b0355 HS	19	#include <asm/ocd.h>
	20	#include <asm/sysreg.h>
	21	#include <asm/traps.h>
5f97f7f9 HS	22
	23	ATOMIC_NOTIFIER_HEAD(avr32_die_chain);
	24
	25	int register_die_notifier(struct notifier_block *nb)
	26	{
5f97f7f9 HS	27	return atomic_notifier_chain_register(&avr32_die_chain, nb);
	28	}
	29	EXPORT_SYMBOL(register_die_notifier);
	30
	31	int unregister_die_notifier(struct notifier_block *nb)
	32	{
	33	return atomic_notifier_chain_unregister(&avr32_die_chain, nb);
	34	}
	35	EXPORT_SYMBOL(unregister_die_notifier);
	36
	37	static DEFINE_SPINLOCK(die_lock);
	38
623b0355	39	void NORET_TYPE die(const char str, struct pt_regs regs, long err)
5f97f7f9	40	{
5f97f7f9 HS	41	static int die_counter;
	42
	43	console_verbose();
	44	spin_lock_irq(&die_lock);
	45	bust_spinlocks(1);
	46
623b0355 HS	47	printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n" KERN_EMERG,
	48	str, err, ++die_counter);
	49	#ifdef CONFIG_PREEMPT
	50	printk("PREEMPT ");
	51	#endif
	52	#ifdef CONFIG_FRAME_POINTER
	53	printk("FRAME_POINTER ");
	54	#endif
	55	if (current_cpu_data.features & AVR32_FEATURE_OCD) {
	56	unsigned long did = __mfdr(DBGREG_DID);
	57	printk("chip: 0x%03lx:0x%04lx rev %lu\n",
	58	(did >> 1) & 0x7ff,
	59	(did >> 12) & 0x7fff,
	60	(did >> 28) & 0xf);
	61	} else {
	62	printk("cpu: arch %u r%u / core %u r%u\n",
	63	current_cpu_data.arch_type,
	64	current_cpu_data.arch_revision,
	65	current_cpu_data.cpu_type,
	66	current_cpu_data.cpu_revision);
5f97f7f9 HS	67	}
5f97f7f9 HS	68
623b0355 HS	69	print_modules();
	70	show_regs_log_lvl(regs, KERN_EMERG);
	71	show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
5f97f7f9 HS	72	bust_spinlocks(0);
5f97f7f9 HS	73	spin_unlock_irq(&die_lock);
623b0355 HS	74
	75	if (in_interrupt())
	76	panic("Fatal exception in interrupt");
	77
	78	if (panic_on_oops)
	79	panic("Fatal exception");
	80
	81	do_exit(err);
5f97f7f9 HS	82	}
5f97f7f9 HS	83
623b0355 HS	84	void _exception(long signr, struct pt_regs *regs, int code,
623b0355 HS	85	unsigned long addr)
5f97f7f9	86	{
623b0355 HS	87	siginfo_t info;
623b0355 HS	88
5f97f7f9	89	if (!user_mode(regs))
623b0355 HS	90	die("Unhandled exception in kernel mode", regs, signr);
	91
	92	memset(&info, 0, sizeof(info));
	93	info.si_signo = signr;
	94	info.si_code = code;
	95	info.si_addr = (void __user *)addr;
	96	force_sig_info(signr, &info, current);
5f97f7f9	97
5f97f7f9	98	/*
623b0355 HS	99	* Init gets no signals that it doesn't have a handler for.
	100	* That's all very well, but if it has caused a synchronous
	101	* exception and we ignore the resulting signal, it will just
	102	* generate the same exception over and over again and we get
	103	* nowhere. Better to kill it and let the kernel panic.
5f97f7f9	104	*/
623b0355 HS	105	if (is_init(current)) {
	106	__sighandler_t handler;
	107
	108	spin_lock_irq(&current->sighand->siglock);
	109	handler = current->sighand->action[signr-1].sa.sa_handler;
	110	spin_unlock_irq(&current->sighand->siglock);
	111	if (handler == SIG_DFL) {
	112	/* init has generated a synchronous exception
	113	and it doesn't have a handler for the signal */
	114	printk(KERN_CRIT "init has generated signal %ld "
	115	"but has no handler for it\n", signr);
	116	do_exit(signr);
	117	}
	118	}
	119	}
5f97f7f9	120
623b0355 HS	121	asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
	122	{
	123	printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n");
	124	show_regs_log_lvl(regs, KERN_ALERT);
	125	show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT);
5f97f7f9 HS	126	}
	127
	128	asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
	129	{
623b0355	130	die("Critical exception", regs, SIGKILL);
5f97f7f9 HS	131	}
	132
	133	asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
	134	{
623b0355	135	_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
5f97f7f9 HS	136	}
	137
	138	/* This way of handling undefined instructions is stolen from ARM */
	139	static LIST_HEAD(undef_hook);
	140	static spinlock_t undef_lock = SPIN_LOCK_UNLOCKED;
	141
	142	void register_undef_hook(struct undef_hook *hook)
	143	{
	144	spin_lock_irq(&undef_lock);
	145	list_add(&hook->node, &undef_hook);
	146	spin_unlock_irq(&undef_lock);
	147	}
	148
	149	void unregister_undef_hook(struct undef_hook *hook)
	150	{
	151	spin_lock_irq(&undef_lock);
	152	list_del(&hook->node);
	153	spin_unlock_irq(&undef_lock);
	154	}
	155
	156	static int do_cop_absent(u32 insn)
	157	{
	158	int cop_nr;
	159	u32 cpucr;
623b0355 HS	160
623b0355 HS	161	if ((insn & 0xfdf00000) == 0xf1900000)
5f97f7f9 HS	162	/* LDC0 */
	163	cop_nr = 0;
	164	else
	165	cop_nr = (insn >> 13) & 0x7;
	166
	167	/* Try enabling the coprocessor */
	168	cpucr = sysreg_read(CPUCR);
	169	cpucr \|= (1 << (24 + cop_nr));
	170	sysreg_write(CPUCR, cpucr);
	171
	172	cpucr = sysreg_read(CPUCR);
623b0355 HS	173	if (!(cpucr & (1 << (24 + cop_nr))))
623b0355 HS	174	return -ENODEV;
5f97f7f9 HS	175
	176	return 0;
	177	}
	178
623b0355	179	int is_valid_bugaddr(unsigned long pc)
5f97f7f9	180	{
623b0355 HS	181	unsigned short opcode;
	182
	183	if (pc < PAGE_OFFSET)
	184	return 0;
	185	if (probe_kernel_address((u16 *)pc, opcode))
	186	return 0;
5f97f7f9	187
623b0355	188	return opcode == AVR32_BUG_OPCODE;
5f97f7f9	189	}
5f97f7f9 HS	190
	191	asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
	192	{
	193	u32 insn;
	194	struct undef_hook *hook;
5f97f7f9	195	void __user *pc;
623b0355	196	long code;
5f97f7f9	197
623b0355 HS	198	if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
	199	enum bug_trap_type type;
	200
	201	type = report_bug(regs->pc);
	202	switch (type) {
	203	case BUG_TRAP_TYPE_NONE:
	204	break;
	205	case BUG_TRAP_TYPE_WARN:
	206	regs->pc += 2;
	207	return;
	208	case BUG_TRAP_TYPE_BUG:
	209	die("Kernel BUG", regs, SIGKILL);
	210	}
	211	}
5f97f7f9 HS	212
	213	local_irq_enable();
	214
623b0355 HS	215	if (user_mode(regs)) {
	216	pc = (void __user *)instruction_pointer(regs);
	217	if (get_user(insn, (u32 __user *)pc))
	218	goto invalid_area;
5f97f7f9	219
623b0355	220	if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
5f97f7f9	221	return;
5f97f7f9	222
623b0355 HS	223	spin_lock_irq(&undef_lock);
	224	list_for_each_entry(hook, &undef_hook, node) {
	225	if ((insn & hook->insn_mask) == hook->insn_val) {
	226	if (hook->fn(regs, insn) == 0) {
	227	spin_unlock_irq(&undef_lock);
	228	return;
	229	}
5f97f7f9 HS	230	}
5f97f7f9 HS	231	}
623b0355	232	spin_unlock_irq(&undef_lock);
5f97f7f9	233	}
5f97f7f9	234
5f97f7f9	235	switch (ecr) {
5f97f7f9	236	case ECR_PRIVILEGE_VIOLATION:
623b0355	237	code = ILL_PRVOPC;
5f97f7f9 HS	238	break;
5f97f7f9 HS	239	case ECR_COPROC_ABSENT:
623b0355	240	code = ILL_COPROC;
5f97f7f9 HS	241	break;
5f97f7f9 HS	242	default:
623b0355 HS	243	code = ILL_ILLOPC;
623b0355 HS	244	break;
5f97f7f9 HS	245	}
5f97f7f9 HS	246
623b0355	247	_exception(SIGILL, regs, code, regs->pc);
5f97f7f9 HS	248	return;
5f97f7f9 HS	249
623b0355 HS	250	invalid_area:
623b0355 HS	251	_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
5f97f7f9 HS	252	}
	253
	254	asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
	255	{
623b0355 HS	256	/* We have no FPU yet */
623b0355 HS	257	_exception(SIGILL, regs, ILL_COPROC, regs->pc);
5f97f7f9 HS	258	}
	259
	260
	261	void __init trap_init(void)
	262	{
	263
	264	}