Commit b23d8e52 authored by Viresh Kumar's avatar Viresh Kumar Committed by Thomas Gleixner
Browse files

x86/apic: Migrate apic timer to new set_state interface 



Migrate apic driver to the new 'set-state' interface provided by
clockevents core, the earlier 'set-mode' interface is marked obsolete
now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

We weren't doing anything while switching to resume mode and so that
callback isn't implemented.

Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Bandan Das <bsd@redhat.com>
Link: http://lkml.kernel.org/r/1896ac5989d27f2ac37f4786af9bd537e1921b83.1437042675.git.viresh.kumar@linaro.org


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent c149e4cd

arch/x86/kernel/apic/apic.c

+51 −35
Original line number Diff line number Diff line
@@ -462,40 +462,53 @@ static int lapic_next_deadline(unsigned long delta, 
	return 0;

}



/*

 * Setup the lapic timer in periodic or oneshot mode

 */

static void lapic_timer_setup(enum clock_event_mode mode,

			      struct clock_event_device *evt)

static int lapic_timer_shutdown(struct clock_event_device *evt)

{

	unsigned long flags;

	unsigned int v;



	/* Lapic used as dummy for broadcast ? */

	if (evt->features & CLOCK_EVT_FEAT_DUMMY)

		return;

		return 0;



	local_irq_save(flags);



	switch (mode) {

	case CLOCK_EVT_MODE_PERIODIC:

	case CLOCK_EVT_MODE_ONESHOT:

		__setup_APIC_LVTT(lapic_timer_frequency,

				  mode != CLOCK_EVT_MODE_PERIODIC, 1);

		break;

	case CLOCK_EVT_MODE_UNUSED:

	case CLOCK_EVT_MODE_SHUTDOWN:

	v = apic_read(APIC_LVTT);

	v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);

	apic_write(APIC_LVTT, v);

	apic_write(APIC_TMICT, 0);

		break;

	case CLOCK_EVT_MODE_RESUME:

		/* Nothing to do here */

		break;



	local_irq_restore(flags);



	return 0;

}



static inline int

lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)

{

	unsigned long flags;



	/* Lapic used as dummy for broadcast ? */

	if (evt->features & CLOCK_EVT_FEAT_DUMMY)

		return 0;



	local_irq_save(flags);



	__setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);



	local_irq_restore(flags);



	return 0;

}



static int lapic_timer_set_periodic(struct clock_event_device *evt)

{

	return lapic_timer_set_periodic_oneshot(evt, false);

}



static int lapic_timer_set_oneshot(struct clock_event_device *evt)

{

	return lapic_timer_set_periodic_oneshot(evt, true);

}



/*
@@ -514,10 +527,13 @@ static void lapic_timer_broadcast(const struct cpumask *mask) 
 */

static struct clock_event_device lapic_clockevent = {

	.name			= "lapic",

	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT

			| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,

	.features		= CLOCK_EVT_FEAT_PERIODIC |

				  CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP

				  | CLOCK_EVT_FEAT_DUMMY,

	.shift			= 32,

	.set_mode	= lapic_timer_setup,

	.set_state_shutdown	= lapic_timer_shutdown,

	.set_state_periodic	= lapic_timer_set_periodic,

	.set_state_oneshot	= lapic_timer_set_oneshot,

	.set_next_event		= lapic_next_event,

	.broadcast		= lapic_timer_broadcast,

	.rating			= 100,
@@ -778,7 +794,7 @@ static int __init calibrate_APIC_clock(void) 
		 * Setup the apic timer manually

		 */

		levt->event_handler = lapic_cal_handler;

		lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);

		lapic_timer_set_periodic(levt);

		lapic_cal_loops = -1;



		/* Let the interrupts run */
@@ -788,7 +804,7 @@ static int __init calibrate_APIC_clock(void) 
			cpu_relax();



		/* Stop the lapic timer */

		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);

		lapic_timer_shutdown(levt);



		/* Jiffies delta */

		deltaj = lapic_cal_j2 - lapic_cal_j1;
@@ -878,7 +894,7 @@ static void local_apic_timer_interrupt(void) 
	if (!evt->event_handler) {

		pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);

		/* Switch it off */

		lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);

		lapic_timer_shutdown(evt);

		return;

	}

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