Commit ba7eda4c authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Thomas Gleixner
Browse files

x86_64: Add (not yet used) clock event functions 



Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarChris Wright <chrisw@sous-sol.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
parent 02290683

arch/x86/kernel/apic_64.c

+79 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/sysdev.h>

#include <linux/module.h>

#include <linux/ioport.h>

#include <linux/clockchips.h>



#include <asm/atomic.h>

#include <asm/smp.h>
@@ -57,6 +58,77 @@ static struct resource lapic_resource = { 


static unsigned int calibration_result;



static int lapic_next_event(unsigned long delta,

			    struct clock_event_device *evt);

static void lapic_timer_setup(enum clock_event_mode mode,

			      struct clock_event_device *evt);



static void lapic_timer_broadcast(cpumask_t mask);



static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen);



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,

	.shift		= 32,

	.set_mode	= lapic_timer_setup,

	.set_next_event	= lapic_next_event,

	.broadcast	= lapic_timer_broadcast,

	.rating		= 100,

	.irq		= -1,

};

static DEFINE_PER_CPU(struct clock_event_device, lapic_events);



static int lapic_next_event(unsigned long delta,

			    struct clock_event_device *evt)

{

	apic_write(APIC_TMICT, delta);

	return 0;

}



static void lapic_timer_setup(enum clock_event_mode mode,

			      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;



	local_irq_save(flags);



	switch (mode) {

	case CLOCK_EVT_MODE_PERIODIC:

	case CLOCK_EVT_MODE_ONESHOT:

		__setup_APIC_LVTT(calibration_result,

				  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);

		break;

	case CLOCK_EVT_MODE_RESUME:

		/* Nothing to do here */

		break;

	}



	local_irq_restore(flags);

}



/*

 * Local APIC timer broadcast function

 */

static void lapic_timer_broadcast(cpumask_t mask)

{

#ifdef CONFIG_SMP

	send_IPI_mask(mask, LOCAL_TIMER_VECTOR);

#endif

}



/*

 * cpu_mask that denotes the CPUs that needs timer interrupt coming in as

 * IPIs in place of local APIC timers
@@ -866,6 +938,13 @@ static void __init calibrate_APIC_clock(void) 
	printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",

		result / 1000 / 1000, result / 1000 % 1000);



	/* Calculate the scaled math multiplication factor */

	lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC, 32);

	lapic_clockevent.max_delta_ns =

		clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);

	lapic_clockevent.min_delta_ns =

		clockevent_delta2ns(0xF, &lapic_clockevent);



	calibration_result = result / HZ;

}

arch/x86_64/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -40,6 +40,10 @@ config CLOCKSOURCE_WATCHDOG 
	bool

	default y



config GENERIC_CLOCKEVENTS_MIGR

	bool

	default y



config ZONE_DMA32

	bool

	default y
@@ -134,6 +138,8 @@ source "init/Kconfig" 


menu "Processor type and features"



source "kernel/time/Kconfig"



choice

	prompt "Subarchitecture Type"

	default X86_PC