[net-next-2.6.git] / arch / x86 / kernel / apic / hw_nmi.c

/*
 *  HW NMI watchdog support
 *
 *  started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
 *
 *  Arch specific calls to support NMI watchdog
 *
 *  Bits copied from original nmi.c file
 *
 */
#include <asm/apic.h>

#include <linux/cpumask.h>
#include <linux/kdebug.h>
#include <linux/notifier.h>
#include <linux/kprobes.h>
#include <linux/nmi.h>
#include <linux/module.h>

/* For reliability, we're prepared to waste bits here. */
static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;

u64 hw_nmi_get_sample_period(void)
{
	return (u64)(cpu_khz) * 1000 * 60;
}

#ifdef ARCH_HAS_NMI_WATCHDOG
void arch_trigger_all_cpu_backtrace(void)
{
	int i;

	cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);

	printk(KERN_INFO "sending NMI to all CPUs:\n");
	apic->send_IPI_all(NMI_VECTOR);

	/* Wait for up to 10 seconds for all CPUs to do the backtrace */
	for (i = 0; i < 10 * 1000; i++) {
		if (cpumask_empty(to_cpumask(backtrace_mask)))
			break;
		mdelay(1);
	}
}

static int __kprobes
arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
			 unsigned long cmd, void *__args)
{
	struct die_args *args = __args;
	struct pt_regs *regs;
	int cpu = smp_processor_id();

	switch (cmd) {
	case DIE_NMI:
	case DIE_NMI_IPI:
		break;

	default:
		return NOTIFY_DONE;
	}

	regs = args->regs;

	if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
		static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;

		arch_spin_lock(&lock);
		printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
		show_regs(regs);
		dump_stack();
		arch_spin_unlock(&lock);
		cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
		return NOTIFY_STOP;
	}

	return NOTIFY_DONE;
}

static __read_mostly struct notifier_block backtrace_notifier = {
	.notifier_call          = arch_trigger_all_cpu_backtrace_handler,
	.next                   = NULL,
	.priority               = 1
};

static int __init register_trigger_all_cpu_backtrace(void)
{
	register_die_notifier(&backtrace_notifier);
	return 0;
}
early_initcall(register_trigger_all_cpu_backtrace);
#endif

/* STUB calls to mimic old nmi_watchdog behaviour */
#if defined(CONFIG_X86_LOCAL_APIC)
unsigned int nmi_watchdog = NMI_NONE;
EXPORT_SYMBOL(nmi_watchdog);
void acpi_nmi_enable(void) { return; }
void acpi_nmi_disable(void) { return; }
#endif
atomic_t nmi_active = ATOMIC_INIT(0);           /* oprofile uses this */
EXPORT_SYMBOL(nmi_active);
int unknown_nmi_panic;
void cpu_nmi_set_wd_enabled(void) { return; }
void stop_apic_nmi_watchdog(void *unused) { return; }
void setup_apic_nmi_watchdog(void *unused) { return; }
int __init check_nmi_watchdog(void) { return 0; }
Commit	Line	Data
1fb9d6ad DZ	1	/*
	2	* HW NMI watchdog support
	3	*
	4	* started by Don Zickus, Copyright (C) 2010 Red Hat, Inc.
	5	*
	6	* Arch specific calls to support NMI watchdog
	7	*
	8	* Bits copied from original nmi.c file
	9	*
	10	*/
5e85391b	11	#include <asm/apic.h>
1fb9d6ad	12
1fb9d6ad	13	#include <linux/cpumask.h>
7cbb7e7f DZ	14	#include <linux/kdebug.h>
	15	#include <linux/notifier.h>
	16	#include <linux/kprobes.h>
1fb9d6ad DZ	17	#include <linux/nmi.h>
	18	#include <linux/module.h>
	19
	20	/* For reliability, we're prepared to waste bits here. */
	21	static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
	22
504d7cf1 DZ	23	u64 hw_nmi_get_sample_period(void)
504d7cf1 DZ	24	{
58687acb	25	return (u64)(cpu_khz) * 1000 * 60;
504d7cf1 DZ	26	}
504d7cf1 DZ	27
2cc4452b	28	#ifdef ARCH_HAS_NMI_WATCHDOG
1fb9d6ad DZ	29	void arch_trigger_all_cpu_backtrace(void)
	30	{
	31	int i;
	32
	33	cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
	34
	35	printk(KERN_INFO "sending NMI to all CPUs:\n");
	36	apic->send_IPI_all(NMI_VECTOR);
	37
	38	/* Wait for up to 10 seconds for all CPUs to do the backtrace */
	39	for (i = 0; i < 10 * 1000; i++) {
	40	if (cpumask_empty(to_cpumask(backtrace_mask)))
	41	break;
	42	mdelay(1);
	43	}
	44	}
7cbb7e7f DZ	45
	46	static int __kprobes
	47	arch_trigger_all_cpu_backtrace_handler(struct notifier_block *self,
	48	unsigned long cmd, void *__args)
	49	{
	50	struct die_args *args = __args;
	51	struct pt_regs *regs;
	52	int cpu = smp_processor_id();
	53
	54	switch (cmd) {
	55	case DIE_NMI:
	56	case DIE_NMI_IPI:
	57	break;
	58
	59	default:
	60	return NOTIFY_DONE;
	61	}
	62
	63	regs = args->regs;
	64
	65	if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
	66	static arch_spinlock_t lock = __ARCH_SPIN_LOCK_UNLOCKED;
	67
	68	arch_spin_lock(&lock);
	69	printk(KERN_WARNING "NMI backtrace for cpu %d\n", cpu);
	70	show_regs(regs);
	71	dump_stack();
	72	arch_spin_unlock(&lock);
	73	cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
	74	return NOTIFY_STOP;
	75	}
	76
	77	return NOTIFY_DONE;
	78	}
	79
	80	static __read_mostly struct notifier_block backtrace_notifier = {
	81	.notifier_call = arch_trigger_all_cpu_backtrace_handler,
	82	.next = NULL,
	83	.priority = 1
	84	};
	85
	86	static int __init register_trigger_all_cpu_backtrace(void)
	87	{
	88	register_die_notifier(&backtrace_notifier);
	89	return 0;
	90	}
	91	early_initcall(register_trigger_all_cpu_backtrace);
2cc4452b	92	#endif
1fb9d6ad DZ	93
1fb9d6ad DZ	94	/* STUB calls to mimic old nmi_watchdog behaviour */
504d7cf1	95	#if defined(CONFIG_X86_LOCAL_APIC)
1fb9d6ad DZ	96	unsigned int nmi_watchdog = NMI_NONE;
1fb9d6ad DZ	97	EXPORT_SYMBOL(nmi_watchdog);
504d7cf1 DZ	98	void acpi_nmi_enable(void) { return; }
	99	void acpi_nmi_disable(void) { return; }
	100	#endif
1fb9d6ad DZ	101	atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
1fb9d6ad DZ	102	EXPORT_SYMBOL(nmi_active);
1fb9d6ad DZ	103	int unknown_nmi_panic;
1fb9d6ad DZ	104	void cpu_nmi_set_wd_enabled(void) { return; }
1fb9d6ad DZ	105	void stop_apic_nmi_watchdog(void *unused) { return; }
	106	void setup_apic_nmi_watchdog(void *unused) { return; }
	107	int __init check_nmi_watchdog(void) { return 0; }