Beispiel #1
0
/*
 * proc handler for /proc/sys/kernel/nmi
 */
int proc_nmi_enabled(struct ctl_table *table, int write,
			void __user *buffer, size_t *length, loff_t *ppos)
{
	int old_state;

	nmi_watchdog_enabled = (atomic_read(&nmi_active) > 0) ? 1 : 0;
	old_state = nmi_watchdog_enabled;
	proc_dointvec(table, write, buffer, length, ppos);
	if (!!old_state == !!nmi_watchdog_enabled)
		return 0;

	if (atomic_read(&nmi_active) < 0 || !nmi_watchdog_active()) {
		printk(KERN_WARNING
			"NMI watchdog is permanently disabled\n");
		return -EIO;
	}

	if (nmi_watchdog == NMI_LOCAL_APIC) {
		if (nmi_watchdog_enabled)
			enable_lapic_nmi_watchdog();
		else
			disable_lapic_nmi_watchdog();
	} else if (nmi_watchdog == NMI_IO_APIC) {
		if (nmi_watchdog_enabled)
			enable_ioapic_nmi_watchdog();
		else
			disable_ioapic_nmi_watchdog();
	} else {
		printk(KERN_WARNING
			"NMI watchdog doesn't know what hardware to touch\n");
		return -EIO;
	}
	return 0;
}
Beispiel #2
0
int __init check_nmi_watchdog(void)
{
	unsigned int *prev_nmi_count;
	int cpu;

	if (!nmi_watchdog_active() || !atomic_read(&nmi_active))
		return 0;

	prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(int), GFP_KERNEL);
	if (!prev_nmi_count)
		goto error;

	printk(KERN_INFO "Testing NMI watchdog ... ");

#ifdef CONFIG_SMP
	if (nmi_watchdog == NMI_LOCAL_APIC)
		smp_call_function(nmi_cpu_busy, (void *)&endflag, 0);
#endif

	for_each_possible_cpu(cpu)
		prev_nmi_count[cpu] = get_nmi_count(cpu);
	local_irq_enable();
	mdelay((20 * 1000) / nmi_hz); /* wait 20 ticks */

	for_each_online_cpu(cpu) {
		if (!per_cpu(wd_enabled, cpu))
			continue;
		if (get_nmi_count(cpu) - prev_nmi_count[cpu] <= 5)
			report_broken_nmi(cpu, prev_nmi_count);
	}
	endflag = 1;
	if (!atomic_read(&nmi_active)) {
		kfree(prev_nmi_count);
		atomic_set(&nmi_active, -1);
		goto error;
	}
	printk("OK.\n");

	/*
	 * now that we know it works we can reduce NMI frequency to
	 * something more reasonable; makes a difference in some configs
	 */
	if (nmi_watchdog == NMI_LOCAL_APIC)
		nmi_hz = lapic_adjust_nmi_hz(1);

	kfree(prev_nmi_count);
	return 0;
error:
	if (nmi_watchdog == NMI_IO_APIC) {
		if (!timer_through_8259)
			legacy_pic->chip->mask(0);
		on_each_cpu(__acpi_nmi_disable, NULL, 1);
	}

#ifdef CONFIG_X86_32
	timer_ack = 0;
#endif
	return -1;
}
Beispiel #3
0
void stop_apic_nmi_watchdog(void *unused)
{
	/* only support LOCAL and IO APICs for now */
	if (!nmi_watchdog_active())
		return;
	if (__get_cpu_var(wd_enabled) == 0)
		return;
	if (nmi_watchdog == NMI_LOCAL_APIC)
		lapic_watchdog_stop();
	else
		__acpi_nmi_disable(NULL);
	__get_cpu_var(wd_enabled) = 0;
	atomic_dec(&nmi_active);
}
void stop_apic_nmi_watchdog(void *unused)
{
    struct hrtimer *hrtimer = &__get_cpu_var(nmi_watchdog_hrtimer);

    /* only support LOCAL and IO APICs for now */
    if (!nmi_watchdog_active())
        return;
    if (__get_cpu_var(wd_enabled) == 0)
        return;

    /* disable the hrtimer */
    hrtimer_cancel(hrtimer);

    if (nmi_watchdog == NMI_LOCAL_APIC)
        lapic_watchdog_stop();
    else
        __acpi_nmi_disable(NULL);
    __get_cpu_var(wd_enabled) = 0;
    atomic_dec(&nmi_active);
}