linux/kernel/time/tick-oneshot.c
Randy Dunlap f3cb80804b time: Fix various kernel-doc problems
Clean up kernel-doc complaints about function names and non-kernel-doc
comments in kernel/time/. Fixes these warnings:

  kernel/time/time.c:479: warning: expecting prototype for set_normalized_timespec(). Prototype was for set_normalized_timespec64() instead
  kernel/time/time.c:553: warning: expecting prototype for msecs_to_jiffies(). Prototype was for __msecs_to_jiffies() instead

  kernel/time/timekeeping.c:1595: warning: contents before sections
  kernel/time/timekeeping.c:1705: warning: This comment starts with '/**', but isn't a kernel-doc comment.
   * We have three kinds of time sources to use for sleep time
  kernel/time/timekeeping.c:1726: warning: This comment starts with '/**', but isn't a kernel-doc comment.
   * 1) can be determined whether to use or not only when doing

  kernel/time/tick-oneshot.c:21: warning: missing initial short description on line:
   * tick_program_event
  kernel/time/tick-oneshot.c:107: warning: expecting prototype for tick_check_oneshot_mode(). Prototype was for tick_oneshot_mode_active() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230103032849.12723-1-rdunlap@infradead.org
2023-01-03 11:07:58 +01:00

129 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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
*/
#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
*/
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)
*/
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)) {
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
*
* 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