d7eb231c71
We want to rename dev->state, so provide proper get and set functions. Rename clockevents_set_state() to clockevents_switch_state() to avoid confusion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org>
132 lines
3.2 KiB
C
132 lines
3.2 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/interrupt.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/sched.h>
|
|
|
|
#include "tick-internal.h"
|
|
|
|
/**
|
|
* tick_program_event
|
|
*/
|
|
int tick_program_event(ktime_t expires, int force)
|
|
{
|
|
struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
|
|
|
|
if (unlikely(expires.tv64 == KTIME_MAX)) {
|
|
/*
|
|
* We don't need the clock event device any more, stop it.
|
|
*/
|
|
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED);
|
|
return 0;
|
|
}
|
|
|
|
if (unlikely(clockevent_state_oneshot_stopped(dev))) {
|
|
/*
|
|
* We need the clock event again, configure it in ONESHOT mode
|
|
* before using it.
|
|
*/
|
|
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
|
|
}
|
|
|
|
return clockevents_program_event(dev, expires, force);
|
|
}
|
|
|
|
/**
|
|
* tick_resume_onshot - resume oneshot mode
|
|
*/
|
|
void tick_resume_oneshot(void)
|
|
{
|
|
struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
|
|
|
|
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
|
|
clockevents_program_event(dev, ktime_get(), true);
|
|
}
|
|
|
|
/**
|
|
* 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_switch_state(newdev, CLOCK_EVT_STATE_ONESHOT);
|
|
clockevents_program_event(newdev, next_event, true);
|
|
}
|
|
|
|
/**
|
|
* tick_switch_to_oneshot - switch to oneshot mode
|
|
*/
|
|
int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
|
|
{
|
|
struct tick_device *td = this_cpu_ptr(&tick_cpu_device);
|
|
struct clock_event_device *dev = td->evtdev;
|
|
|
|
if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
|
|
!tick_device_is_functional(dev)) {
|
|
|
|
printk(KERN_INFO "Clockevents: "
|
|
"could not switch to one-shot mode:");
|
|
if (!dev) {
|
|
printk(" no tick device\n");
|
|
} else {
|
|
if (!tick_device_is_functional(dev))
|
|
printk(" %s is not functional.\n", dev->name);
|
|
else
|
|
printk(" %s does not support one-shot mode.\n",
|
|
dev->name);
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
td->mode = TICKDEV_MODE_ONESHOT;
|
|
dev->event_handler = handler;
|
|
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT);
|
|
tick_broadcast_switch_to_oneshot();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tick_check_oneshot_mode - check whether the system is in oneshot mode
|
|
*
|
|
* returns 1 when either nohz or highres are enabled. otherwise 0.
|
|
*/
|
|
int tick_oneshot_mode_active(void)
|
|
{
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
local_irq_save(flags);
|
|
ret = __this_cpu_read(tick_cpu_device.mode) == TICKDEV_MODE_ONESHOT;
|
|
local_irq_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
#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
|