Contributors: 16
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Thomas Gleixner |
242 |
62.86% |
9 |
29.03% |
| Ingo Molnar |
40 |
10.39% |
2 |
6.45% |
| Viresh Kumar |
38 |
9.87% |
3 |
9.68% |
| John Stultz |
12 |
3.12% |
1 |
3.23% |
| Martin Schwidefsky |
8 |
2.08% |
1 |
3.23% |
| Christoph Lameter |
7 |
1.82% |
2 |
6.45% |
| Rusty Russell |
7 |
1.82% |
3 |
9.68% |
| Prasad Sodagudi |
6 |
1.56% |
1 |
3.23% |
| Geert Uytterhoeven |
5 |
1.30% |
1 |
3.23% |
| Sunday Adelodun |
5 |
1.30% |
1 |
3.23% |
| Linus Torvalds |
4 |
1.04% |
1 |
3.23% |
| John Levon |
3 |
0.78% |
1 |
3.23% |
| Len Brown |
3 |
0.78% |
2 |
6.45% |
| Paul Jackson |
2 |
0.52% |
1 |
3.23% |
| Dipankar Sarma |
2 |
0.52% |
1 |
3.23% |
| Russell King |
1 |
0.26% |
1 |
3.23% |
| Total |
385 |
|
31 |
|
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains functions which manage high resolution tick
* related events.
*
* Copyright(C) 2005-2006, Linutronix GmbH, Thomas Gleixner <tglx@kernel.org>
* Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
* Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
*/
#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 - program the CPU local timer device for the next event
* @expires: the time at which the next timer event should occur
* @force: flag to force reprograming even if the event time hasn't changed
*
* Return: 0 on success, negative error code on failure
*/
int tick_program_event(ktime_t expires, int force)
{
struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
if (unlikely(expires == KTIME_MAX)) {
/*
* We don't need the clock event device any more, stop it.
*/
clockevents_switch_state(dev, CLOCK_EVT_STATE_ONESHOT_STOPPED);
dev->next_event = KTIME_MAX;
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_oneshot - 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)
* @newdev: Pointer to the clock event device to configure
* @handler: Function to be called when the event device triggers an interrupt
* @next_event: Initial expiry time for the next event (in ktime)
*
* Configures the specified clock event device for onshot mode,
* assigns the given handler as its event callback, and programs
* the device to trigger at the specified next event time.
*/
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
* @handler: function to call when an event occurs on the tick device
*
* Return: 0 on success, -EINVAL if the tick device is not present,
* not functional, or does not support 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)) {
pr_info("Clockevents: could not switch to one-shot mode:");
if (!dev) {
pr_cont(" no tick device\n");
} else {
if (!tick_device_is_functional(dev))
pr_cont(" %s is not functional.\n", dev->name);
else
pr_cont(" %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_oneshot_mode_active - check whether the system is in oneshot mode
*
* Return: 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.
*
* Return: 0 on success, -EINVAL if the tick device cannot switch
* to oneshot/high-resolution mode.
*/
int tick_init_highres(void)
{
return tick_switch_to_oneshot(hrtimer_interrupt);
}
#endif