Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a8f22264 authored by David S. Miller's avatar David S. Miller
Browse files

sparc64: Manage NMI watchdog enabling like x86. 



Use a per-cpu 'wd_enabled' boolean and a global atomic_t count
of watchdog NMI enabled cpus which is set to '-1' if something
is wrong with the watchdog and it can't be used.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 825c9fb4

arch/sparc/include/asm/nmi.h

+1 −1
Original line number Diff line number Diff line
@@ -5,6 +5,6 @@ extern int __init nmi_init(void); 
extern void perfctr_irq(int irq, struct pt_regs *regs);

extern void nmi_adjust_hz(unsigned int new_hz);



extern int nmi_usable;

extern atomic_t nmi_active;



#endif /* __NMI_H */

arch/sparc/kernel/nmi.c

+43 −17
Original line number Diff line number Diff line
@@ -34,10 +34,17 @@ 
static int nmi_watchdog_active;

static int panic_on_timeout;



int nmi_usable;

EXPORT_SYMBOL_GPL(nmi_usable);

/* nmi_active:

 * >0: the NMI watchdog is active, but can be disabled

 * <0: the NMI watchdog has not been set up, and cannot be enabled

 *  0: the NMI watchdog is disabled, but can be enabled

 */

atomic_t nmi_active = ATOMIC_INIT(0);		/* oprofile uses this */

EXPORT_SYMBOL(nmi_active);



static unsigned int nmi_hz = HZ;

static DEFINE_PER_CPU(short, wd_enabled);

static int endflag __initdata;



static DEFINE_PER_CPU(unsigned int, last_irq_sum);

static DEFINE_PER_CPU(local_t, alert_counter);
@@ -110,7 +117,7 @@ notrace __kprobes void perfctr_irq(int irq, struct pt_regs *regs) 
		__get_cpu_var(last_irq_sum) = sum;

		local_set(&__get_cpu_var(alert_counter), 0);

	}

	if (nmi_usable) {

	if (__get_cpu_var(wd_enabled)) {

		write_pic(picl_value(nmi_hz));

		pcr_ops->write(pcr_enable);

	}
@@ -121,8 +128,6 @@ static inline unsigned int get_nmi_count(int cpu) 
	return cpu_data(cpu).__nmi_count;

}



static int endflag __initdata;



static __init void nmi_cpu_busy(void *data)

{

	local_irq_enable_in_hardirq();
@@ -143,12 +148,15 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count) 
	printk(KERN_WARNING

		"and attach the output of the 'dmesg' command.\n");



	nmi_usable = 0;

	per_cpu(wd_enabled, cpu) = 0;

	atomic_dec(&nmi_active);

}



static void stop_watchdog(void *unused)

static void stop_nmi_watchdog(void *unused)

{

	pcr_ops->write(PCR_PIC_PRIV);

	__get_cpu_var(wd_enabled) = 0;

	atomic_dec(&nmi_active);

}



static int __init check_nmi_watchdog(void)
@@ -156,6 +164,9 @@ static int __init check_nmi_watchdog(void) 
	unsigned int *prev_nmi_count;

	int cpu, err;



	if (!atomic_read(&nmi_active))

		return 0;



	prev_nmi_count = kmalloc(nr_cpu_ids * sizeof(unsigned int), GFP_KERNEL);

	if (!prev_nmi_count) {

		err = -ENOMEM;
@@ -172,12 +183,15 @@ static int __init check_nmi_watchdog(void) 
	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 (!nmi_usable) {

	if (!atomic_read(&nmi_active)) {

		kfree(prev_nmi_count);

		atomic_set(&nmi_active, -1);

		err = -ENODEV;

		goto error;

	}
@@ -188,12 +202,26 @@ static int __init check_nmi_watchdog(void) 
	kfree(prev_nmi_count);

	return 0;

error:

	on_each_cpu(stop_watchdog, NULL, 1);

	on_each_cpu(stop_nmi_watchdog, NULL, 1);

	return err;

}



static void start_watchdog(void *unused)

static void start_nmi_watchdog(void *unused)

{

	__get_cpu_var(wd_enabled) = 1;

	atomic_inc(&nmi_active);



	pcr_ops->write(PCR_PIC_PRIV);

	write_pic(picl_value(nmi_hz));



	pcr_ops->write(pcr_enable);

}



static void nmi_adjust_hz_one(void *unused)

{

	if (!__get_cpu_var(wd_enabled))

		return;



	pcr_ops->write(PCR_PIC_PRIV);

	write_pic(picl_value(nmi_hz));
@@ -203,13 +231,13 @@ static void start_watchdog(void *unused) 
void nmi_adjust_hz(unsigned int new_hz)

{

	nmi_hz = new_hz;

	on_each_cpu(start_watchdog, NULL, 1);

	on_each_cpu(nmi_adjust_hz_one, NULL, 1);

}

EXPORT_SYMBOL_GPL(nmi_adjust_hz);



static int nmi_shutdown(struct notifier_block *nb, unsigned long cmd, void *p)

{

	on_each_cpu(stop_watchdog, NULL, 1);

	on_each_cpu(stop_nmi_watchdog, NULL, 1);

	return 0;

}
@@ -221,16 +249,14 @@ int __init nmi_init(void) 
{

	int err;



	nmi_usable = 1;



	on_each_cpu(start_watchdog, NULL, 1);

	on_each_cpu(start_nmi_watchdog, NULL, 1);



	err = check_nmi_watchdog();

	if (!err) {

		err = register_reboot_notifier(&nmi_reboot_notifier);

		if (err) {

			nmi_usable = 0;

			on_each_cpu(stop_watchdog, NULL, 1);

			on_each_cpu(stop_nmi_watchdog, NULL, 1);

			atomic_set(&nmi_active, -1);

		}

	}

	return err;

arch/sparc/oprofile/init.c

+1 −1
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static void timer_stop(void) 


static int op_nmi_timer_init(struct oprofile_operations *ops)

{

	if (!nmi_usable)

	if (atomic_read(&nmi_active) <= 0)

		return -ENODEV;



	ops->start = timer_start;