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Commit 6321dd60 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Linus Torvalds
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[PATCH] Save/restore periodic tick information over suspend/resume 



The programming of periodic tick devices needs to be saved/restored
across suspend/resume - otherwise we might end up with a system coming
up that relies on getting a PIT (or HPET) interrupt, while those devices
default to 'no interrupts' after powerup. (To confuse things it worked
to a certain degree on some systems because the lapic gets initialized
as a side-effect of SMP bootup.)

This suspend / resume thing was dropped unintentionally during the
last-minute -mm code reshuffling.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c3442e29

kernel/time/tick-broadcast.c

+36 −0
Original line number Diff line number Diff line
@@ -284,6 +284,42 @@ void tick_shutdown_broadcast(unsigned int *cpup) 
	spin_unlock_irqrestore(&tick_broadcast_lock, flags);

}



void tick_suspend_broadcast(void)

{

	struct clock_event_device *bc;

	unsigned long flags;



	spin_lock_irqsave(&tick_broadcast_lock, flags);



	bc = tick_broadcast_device.evtdev;

	if (bc && tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)

		clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);



	spin_unlock_irqrestore(&tick_broadcast_lock, flags);

}



int tick_resume_broadcast(void)

{

	struct clock_event_device *bc;

	unsigned long flags;

	int broadcast = 0;



	spin_lock_irqsave(&tick_broadcast_lock, flags);



	bc = tick_broadcast_device.evtdev;

	if (bc) {

		if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC &&

		    !cpus_empty(tick_broadcast_mask))

			tick_broadcast_start_periodic(bc);



		broadcast = cpu_isset(smp_processor_id(), tick_broadcast_mask);

	}

	spin_unlock_irqrestore(&tick_broadcast_lock, flags);



	return broadcast;

}





#ifdef CONFIG_TICK_ONESHOT



static cpumask_t tick_broadcast_oneshot_mask;

kernel/time/tick-common.c

+32 −0
Original line number Diff line number Diff line
@@ -298,6 +298,28 @@ static void tick_shutdown(unsigned int *cpup) 
	spin_unlock_irqrestore(&tick_device_lock, flags);

}



static void tick_suspend_periodic(void)

{

	struct tick_device *td = &__get_cpu_var(tick_cpu_device);

	unsigned long flags;



	spin_lock_irqsave(&tick_device_lock, flags);

	if (td->mode == TICKDEV_MODE_PERIODIC)

		clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);

	spin_unlock_irqrestore(&tick_device_lock, flags);

}



static void tick_resume_periodic(void)

{

	struct tick_device *td = &__get_cpu_var(tick_cpu_device);

	unsigned long flags;



	spin_lock_irqsave(&tick_device_lock, flags);

	if (td->mode == TICKDEV_MODE_PERIODIC)

		tick_setup_periodic(td->evtdev, 0);

	spin_unlock_irqrestore(&tick_device_lock, flags);

}



/*

 * Notification about clock event devices

 */
@@ -325,6 +347,16 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason, 
		tick_shutdown(dev);

		break;



	case CLOCK_EVT_NOTIFY_SUSPEND:

		tick_suspend_periodic();

		tick_suspend_broadcast();

		break;



	case CLOCK_EVT_NOTIFY_RESUME:

		if (!tick_resume_broadcast())

			tick_resume_periodic();

		break;



	default:

		break;

	}

kernel/time/tick-internal.h

+4 −0
Original line number Diff line number Diff line
@@ -67,6 +67,8 @@ extern int tick_check_broadcast_device(struct clock_event_device *dev); 
extern int tick_is_broadcast_device(struct clock_event_device *dev);

extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);

extern void tick_shutdown_broadcast(unsigned int *cpup);

extern void tick_suspend_broadcast(void);

extern int tick_resume_broadcast(void);



extern void

tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
@@ -90,6 +92,8 @@ static inline int tick_device_uses_broadcast(struct clock_event_device *dev, 
static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }

static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }

static inline void tick_shutdown_broadcast(unsigned int *cpup) { }

static inline void tick_suspend_broadcast(void) { }

static inline int tick_resume_broadcast(void) { return 0; }



/*

 * Set the periodic handler in non broadcast mode

kernel/timer.c

+6 −0
Original line number Diff line number Diff line
@@ -997,6 +997,9 @@ static int timekeeping_resume(struct sys_device *dev) 
	write_sequnlock_irqrestore(&xtime_lock, flags);



	touch_softlockup_watchdog();



	clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);



	/* Resume hrtimers */

	clock_was_set();
@@ -1011,6 +1014,9 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state) 
	timekeeping_suspended = 1;

	timekeeping_suspend_time = read_persistent_clock();

	write_sequnlock_irqrestore(&xtime_lock, flags);



	clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);



	return 0;

}