mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-23 12:43:55 +08:00
85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
|
/*
|
||
|
* linux/kernel/time/tick-oneshot.c
|
||
|
*
|
||
|
* This file contains functions which manage high resolution tick
|
||
|
* related events.
|
||
|
*
|
||
|
* Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
|
||
|
* Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
|
||
|
* Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
|
||
|
*
|
||
|
* This code is licenced under the GPL version 2. For details see
|
||
|
* kernel-base/COPYING.
|
||
|
*/
|
||
|
#include <linux/cpu.h>
|
||
|
#include <linux/err.h>
|
||
|
#include <linux/hrtimer.h>
|
||
|
#include <linux/irq.h>
|
||
|
#include <linux/percpu.h>
|
||
|
#include <linux/profile.h>
|
||
|
#include <linux/sched.h>
|
||
|
#include <linux/tick.h>
|
||
|
|
||
|
#include "tick-internal.h"
|
||
|
|
||
|
/**
|
||
|
* tick_program_event
|
||
|
*/
|
||
|
int tick_program_event(ktime_t expires, int force)
|
||
|
{
|
||
|
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
|
||
|
ktime_t now = ktime_get();
|
||
|
|
||
|
while (1) {
|
||
|
int ret = clockevents_program_event(dev, expires, now);
|
||
|
|
||
|
if (!ret || !force)
|
||
|
return ret;
|
||
|
now = ktime_get();
|
||
|
expires = ktime_add(now, ktime_set(0, dev->min_delta_ns));
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* tick_setup_oneshot - setup the event device for oneshot mode (hres or nohz)
|
||
|
*/
|
||
|
void tick_setup_oneshot(struct clock_event_device *newdev,
|
||
|
void (*handler)(struct clock_event_device *),
|
||
|
ktime_t next_event)
|
||
|
{
|
||
|
newdev->event_handler = handler;
|
||
|
clockevents_set_mode(newdev, CLOCK_EVT_MODE_ONESHOT);
|
||
|
clockevents_program_event(newdev, next_event, ktime_get());
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* tick_switch_to_oneshot - switch to oneshot mode
|
||
|
*/
|
||
|
int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
|
||
|
{
|
||
|
struct tick_device *td = &__get_cpu_var(tick_cpu_device);
|
||
|
struct clock_event_device *dev = td->evtdev;
|
||
|
|
||
|
if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
|
||
|
!tick_device_is_functional(dev))
|
||
|
return -EINVAL;
|
||
|
|
||
|
td->mode = TICKDEV_MODE_ONESHOT;
|
||
|
dev->event_handler = handler;
|
||
|
clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT);
|
||
|
tick_broadcast_switch_to_oneshot();
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
#ifdef CONFIG_HIGH_RES_TIMERS
|
||
|
/**
|
||
|
* tick_init_highres - switch to high resolution mode
|
||
|
*
|
||
|
* Called with interrupts disabled.
|
||
|
*/
|
||
|
int tick_init_highres(void)
|
||
|
{
|
||
|
return tick_switch_to_oneshot(hrtimer_interrupt);
|
||
|
}
|
||
|
#endif
|