include/linux/hrtimer.h - kernel/common - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  hrtimers - High-resolution kernel timers
  *
  *   Copyright(C) 2005, Thomas Gleixner <[email protected]>
  *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
  *
  *  data type definitions, declarations, prototypes
  *
  *  Started by: Thomas Gleixner and Ingo Molnar
  */
 #ifndef _LINUX_HRTIMER_H
 #define _LINUX_HRTIMER_H

 #include <linux/hrtimer_defs.h>
 #include <linux/hrtimer_types.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/percpu-defs.h>
 #include <linux/rbtree.h>
 #include <linux/timer.h>

 /*
  * Mode arguments of xxx_hrtimer functions:
  *
  * HRTIMER_MODE_ABS		- Time value is absolute
  * HRTIMER_MODE_REL		- Time value is relative to now
  * HRTIMER_MODE_PINNED		- Timer is bound to CPU (is only considered
  *				  when starting the timer)
  * HRTIMER_MODE_SOFT		- Timer callback function will be executed in
  *				  soft irq context
  * HRTIMER_MODE_HARD		- Timer callback function will be executed in
  *				  hard irq context even on PREEMPT_RT.
  */
 enum hrtimer_mode {
 	HRTIMER_MODE_ABS	= 0x00,
 	HRTIMER_MODE_REL	= 0x01,
 	HRTIMER_MODE_PINNED	= 0x02,
 	HRTIMER_MODE_SOFT	= 0x04,
 	HRTIMER_MODE_HARD	= 0x08,

 	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
 	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,

 	HRTIMER_MODE_ABS_SOFT	= HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,
 	HRTIMER_MODE_REL_SOFT	= HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,

 	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
 	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,

 	HRTIMER_MODE_ABS_HARD	= HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
 	HRTIMER_MODE_REL_HARD	= HRTIMER_MODE_REL | HRTIMER_MODE_HARD,

 	HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD,
 	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
 };

 /*
  * Values to track state of the timer
  *
  * Possible states:
  *
  * 0x00		inactive
  * 0x01		enqueued into rbtree
  *
  * The callback state is not part of the timer->state because clearing it would
  * mean touching the timer after the callback, this makes it impossible to free
  * the timer from the callback function.
  *
  * Therefore we track the callback state in:
  *
  *	timer->base->cpu_base->running == timer
  *
  * On SMP it is possible to have a "callback function running and enqueued"
  * status. It happens for example when a posix timer expired and the callback
  * queued a signal. Between dropping the lock which protects the posix timer
  * and reacquiring the base lock of the hrtimer, another CPU can deliver the
  * signal and rearm the timer.
  *
  * All state transitions are protected by cpu_base->lock.
  */
 #define HRTIMER_STATE_INACTIVE	0x00
 #define HRTIMER_STATE_ENQUEUED	0x01

 /**
  * struct hrtimer_sleeper - simple sleeper structure
  * @timer:	embedded timer structure
  * @task:	task to wake up
  *
  * task is set to NULL, when the timer expires.
  */
 struct hrtimer_sleeper {
 	struct hrtimer timer;
 	struct task_struct *task;
 };

 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
 {
 	timer->node.expires = time;
 	timer->_softexpires = time;
 }

 static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
 {
 	timer->_softexpires = time;
 	timer->node.expires = ktime_add_safe(time, delta);
 }

 static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
 {
 	timer->_softexpires = time;
 	timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
 }

 static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
 {
 	timer->node.expires = tv64;
 	timer->_softexpires = tv64;
 }

 static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
 {
 	timer->node.expires = ktime_add_safe(timer->node.expires, time);
 	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
 }

 static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
 {
 	timer->node.expires = ktime_add_ns(timer->node.expires, ns);
 	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
 }

 static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
 {
 	return timer->node.expires;
 }

 static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
 {
 	return timer->_softexpires;
 }

 static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
 {
 	return timer->node.expires;
 }
 static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
 {
 	return timer->_softexpires;
 }

 static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
 {
 	return ktime_to_ns(timer->node.expires);
 }

 static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
 {
 	return ktime_sub(timer->node.expires, timer->base->get_time());
 }

 static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
 {
 	return timer->base->get_time();
 }

 static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 {
 	return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
 		timer->base->cpu_base->hres_active : 0;
 }

 #ifdef CONFIG_HIGH_RES_TIMERS
 struct clock_event_device;

 extern void hrtimer_interrupt(struct clock_event_device *dev);

 extern unsigned int hrtimer_resolution;

 #else

 #define hrtimer_resolution	(unsigned int)LOW_RES_NSEC

 #endif

 static inline ktime_t
 __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
 {
 	ktime_t rem = ktime_sub(timer->node.expires, now);

 	/*
 	 * Adjust relative timers for the extra we added in
 	 * hrtimer_start_range_ns() to prevent short timeouts.
 	 */
 	if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
 		rem -= hrtimer_resolution;
 	return rem;
 }

 static inline ktime_t
 hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
 {
 	return __hrtimer_expires_remaining_adjusted(timer,
 						    timer->base->get_time());
 }

 #ifdef CONFIG_TIMERFD
 extern void timerfd_clock_was_set(void);
 extern void timerfd_resume(void);
 #else
 static inline void timerfd_clock_was_set(void) { }
 static inline void timerfd_resume(void) { }
 #endif

 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);

 #ifdef CONFIG_PREEMPT_RT
 void hrtimer_cancel_wait_running(const struct hrtimer *timer);
 #else
 static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
 {
 	cpu_relax();
 }
 #endif

 /* Exported timer functions: */

 /* Initialize timers: */
 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 			 enum hrtimer_mode mode);
 extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *),
 			  clockid_t clock_id, enum hrtimer_mode mode);
 extern void hrtimer_setup_on_stack(struct hrtimer *timer,
 				   enum hrtimer_restart (*function)(struct hrtimer *),
 				   clockid_t clock_id, enum hrtimer_mode mode);
 extern void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id,
 					   enum hrtimer_mode mode);

 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
 #else
 static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
 #endif

 /* Basic timer operations: */
 extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 				   u64 range_ns, const enum hrtimer_mode mode);

 /**
  * hrtimer_start - (re)start an hrtimer
  * @timer:	the timer to be added
  * @tim:	expiry time
  * @mode:	timer mode: absolute (HRTIMER_MODE_ABS) or
  *		relative (HRTIMER_MODE_REL), and pinned (HRTIMER_MODE_PINNED);
  *		softirq based mode is considered for debug purpose only!
  */
 static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
 				 const enum hrtimer_mode mode)
 {
 	hrtimer_start_range_ns(timer, tim, 0, mode);
 }

 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);

 static inline void hrtimer_start_expires(struct hrtimer *timer,
 					 enum hrtimer_mode mode)
 {
 	u64 delta;
 	ktime_t soft, hard;
 	soft = hrtimer_get_softexpires(timer);
 	hard = hrtimer_get_expires(timer);
 	delta = ktime_to_ns(ktime_sub(hard, soft));
 	hrtimer_start_range_ns(timer, soft, delta, mode);
 }

 void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
 				   enum hrtimer_mode mode);

 static inline void hrtimer_restart(struct hrtimer *timer)
 {
 	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
 }

 /* Query timers: */
 extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);

 /**
  * hrtimer_get_remaining - get remaining time for the timer
  * @timer:	the timer to read
  */
 static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
 {
 	return __hrtimer_get_remaining(timer, false);
 }

 extern u64 hrtimer_get_next_event(void);
 extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);

 extern bool hrtimer_active(const struct hrtimer *timer);

 /**
  * hrtimer_is_queued - check, whether the timer is on one of the queues
  * @timer:	Timer to check
  *
  * Returns: True if the timer is queued, false otherwise
  *
  * The function can be used lockless, but it gives only a current snapshot.
  */
 static inline bool hrtimer_is_queued(struct hrtimer *timer)
 {
 	/* The READ_ONCE pairs with the update functions of timer->state */
 	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
 }

 /*
  * Helper function to check, whether the timer is running the callback
  * function
  */
 static inline int hrtimer_callback_running(struct hrtimer *timer)
 {
 	return timer->base->running == timer;
 }

 /**
  * hrtimer_update_function - Update the timer's callback function
  * @timer:	Timer to update
  * @function:	New callback function
  *
  * Only safe to call if the timer is not enqueued. Can be called in the callback function if the
  * timer is not enqueued at the same time (see the comments above HRTIMER_STATE_ENQUEUED).
  */
 static inline void hrtimer_update_function(struct hrtimer *timer,
 					   enum hrtimer_restart (*function)(struct hrtimer *))
 {
 	guard(raw_spinlock_irqsave)(&timer->base->cpu_base->lock);

 	if (WARN_ON_ONCE(hrtimer_is_queued(timer)))
 		return;

 	if (WARN_ON_ONCE(!function))
 		return;

 	timer->function = function;
 }

 /* Forward a hrtimer so it expires after now: */
 extern u64
 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);

 /**
  * hrtimer_forward_now() - forward the timer expiry so it expires after now
  * @timer:	hrtimer to forward
  * @interval:	the interval to forward
  *
  * It is a variant of hrtimer_forward(). The timer will expire after the current
  * time of the hrtimer clock base. See hrtimer_forward() for details.
  */
 static inline u64 hrtimer_forward_now(struct hrtimer *timer,
 				      ktime_t interval)
 {
 	return hrtimer_forward(timer, timer->base->get_time(), interval);
 }

 /* Precise sleep: */

 extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
 extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
 			      const clockid_t clockid);

 extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
 				    const enum hrtimer_mode mode);
 extern int schedule_hrtimeout_range_clock(ktime_t *expires,
 					  u64 delta,
 					  const enum hrtimer_mode mode,
 					  clockid_t clock_id);
 extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);

 /* Soft interrupt function to run the hrtimer queues: */
 extern void hrtimer_run_queues(void);

 /* Bootup initialization: */
 extern void __init hrtimers_init(void);

 /* Show pending timers: */
 extern void sysrq_timer_list_show(void);

 int hrtimers_prepare_cpu(unsigned int cpu);
 int hrtimers_cpu_starting(unsigned int cpu);
 #ifdef CONFIG_HOTPLUG_CPU
 int hrtimers_cpu_dying(unsigned int cpu);
 #else
 #define hrtimers_cpu_dying	NULL
 #endif

 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* hrtimers - High-resolution kernel timers
	*
	* Copyright(C) 2005, Thomas Gleixner <[email protected]>
	* Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
	*
	* data type definitions, declarations, prototypes
	*
	* Started by: Thomas Gleixner and Ingo Molnar
	*/
	#ifndef _LINUX_HRTIMER_H
	#define _LINUX_HRTIMER_H

	#include <linux/hrtimer_defs.h>
	#include <linux/hrtimer_types.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/percpu-defs.h>
	#include <linux/rbtree.h>
	#include <linux/timer.h>

	/*
	* Mode arguments of xxx_hrtimer functions:
	*
	* HRTIMER_MODE_ABS - Time value is absolute
	* HRTIMER_MODE_REL - Time value is relative to now
	* HRTIMER_MODE_PINNED - Timer is bound to CPU (is only considered
	* when starting the timer)
	* HRTIMER_MODE_SOFT - Timer callback function will be executed in
	* soft irq context
	* HRTIMER_MODE_HARD - Timer callback function will be executed in
	* hard irq context even on PREEMPT_RT.
	*/
	enum hrtimer_mode {
	HRTIMER_MODE_ABS = 0x00,
	HRTIMER_MODE_REL = 0x01,
	HRTIMER_MODE_PINNED = 0x02,
	HRTIMER_MODE_SOFT = 0x04,
	HRTIMER_MODE_HARD = 0x08,

	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS \| HRTIMER_MODE_PINNED,
	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL \| HRTIMER_MODE_PINNED,

	HRTIMER_MODE_ABS_SOFT = HRTIMER_MODE_ABS \| HRTIMER_MODE_SOFT,
	HRTIMER_MODE_REL_SOFT = HRTIMER_MODE_REL \| HRTIMER_MODE_SOFT,

	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED \| HRTIMER_MODE_SOFT,
	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED \| HRTIMER_MODE_SOFT,

	HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS \| HRTIMER_MODE_HARD,
	HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL \| HRTIMER_MODE_HARD,

	HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED \| HRTIMER_MODE_HARD,
	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED \| HRTIMER_MODE_HARD,
	};

	/*
	* Values to track state of the timer
	*
	* Possible states:
	*
	* 0x00 inactive
	* 0x01 enqueued into rbtree
	*
	* The callback state is not part of the timer->state because clearing it would
	* mean touching the timer after the callback, this makes it impossible to free
	* the timer from the callback function.
	*
	* Therefore we track the callback state in:
	*
	* timer->base->cpu_base->running == timer
	*
	* On SMP it is possible to have a "callback function running and enqueued"
	* status. It happens for example when a posix timer expired and the callback
	* queued a signal. Between dropping the lock which protects the posix timer
	* and reacquiring the base lock of the hrtimer, another CPU can deliver the
	* signal and rearm the timer.
	*
	* All state transitions are protected by cpu_base->lock.
	*/
	#define HRTIMER_STATE_INACTIVE 0x00
	#define HRTIMER_STATE_ENQUEUED 0x01

	/**
	* struct hrtimer_sleeper - simple sleeper structure
	* @timer: embedded timer structure
	* @task: task to wake up
	*
	* task is set to NULL, when the timer expires.
	*/
	struct hrtimer_sleeper {
	struct hrtimer timer;
	struct task_struct *task;
	};

	static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
	{
	timer->node.expires = time;
	timer->_softexpires = time;
	}

	static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
	{
	timer->_softexpires = time;
	timer->node.expires = ktime_add_safe(time, delta);
	}

	static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
	{
	timer->_softexpires = time;
	timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
	}

	static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
	{
	timer->node.expires = tv64;
	timer->_softexpires = tv64;
	}

	static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
	{
	timer->node.expires = ktime_add_safe(timer->node.expires, time);
	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
	}

	static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
	{
	timer->node.expires = ktime_add_ns(timer->node.expires, ns);
	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
	}

	static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
	{
	return timer->node.expires;
	}

	static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
	{
	return timer->_softexpires;
	}

	static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
	{
	return timer->node.expires;
	}
	static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
	{
	return timer->_softexpires;
	}

	static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
	{
	return ktime_to_ns(timer->node.expires);
	}

	static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
	{
	return ktime_sub(timer->node.expires, timer->base->get_time());
	}

	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	{
	return timer->base->get_time();
	}

	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	{
	return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
	timer->base->cpu_base->hres_active : 0;
	}

	#ifdef CONFIG_HIGH_RES_TIMERS
	struct clock_event_device;

	extern void hrtimer_interrupt(struct clock_event_device *dev);

	extern unsigned int hrtimer_resolution;

	#else

	#define hrtimer_resolution (unsigned int)LOW_RES_NSEC

	#endif

	static inline ktime_t
	__hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
	{
	ktime_t rem = ktime_sub(timer->node.expires, now);

	/*
	* Adjust relative timers for the extra we added in
	* hrtimer_start_range_ns() to prevent short timeouts.
	*/
	if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
	rem -= hrtimer_resolution;
	return rem;
	}

	static inline ktime_t
	hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
	{
	return __hrtimer_expires_remaining_adjusted(timer,
	timer->base->get_time());
	}

	#ifdef CONFIG_TIMERFD
	extern void timerfd_clock_was_set(void);
	extern void timerfd_resume(void);
	#else
	static inline void timerfd_clock_was_set(void) { }
	static inline void timerfd_resume(void) { }
	#endif

	DECLARE_PER_CPU(struct tick_device, tick_cpu_device);

	#ifdef CONFIG_PREEMPT_RT
	void hrtimer_cancel_wait_running(const struct hrtimer *timer);
	#else
	static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
	{
	cpu_relax();
	}
	#endif

	/* Exported timer functions: */

	/* Initialize timers: */
	extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
	enum hrtimer_mode mode);
	extern void hrtimer_setup(struct hrtimer timer, enum hrtimer_restart (function)(struct hrtimer *),
	clockid_t clock_id, enum hrtimer_mode mode);
	extern void hrtimer_setup_on_stack(struct hrtimer *timer,
	enum hrtimer_restart (function)(struct hrtimer ),
	clockid_t clock_id, enum hrtimer_mode mode);
	extern void hrtimer_setup_sleeper_on_stack(struct hrtimer_sleeper *sl, clockid_t clock_id,
	enum hrtimer_mode mode);

	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
	extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
	#else
	static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
	#endif

	/* Basic timer operations: */
	extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
	u64 range_ns, const enum hrtimer_mode mode);

	/**
	* hrtimer_start - (re)start an hrtimer
	* @timer: the timer to be added
	* @tim: expiry time
	* @mode: timer mode: absolute (HRTIMER_MODE_ABS) or
	* relative (HRTIMER_MODE_REL), and pinned (HRTIMER_MODE_PINNED);
	* softirq based mode is considered for debug purpose only!
	*/
	static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
	const enum hrtimer_mode mode)
	{
	hrtimer_start_range_ns(timer, tim, 0, mode);
	}

	extern int hrtimer_cancel(struct hrtimer *timer);
	extern int hrtimer_try_to_cancel(struct hrtimer *timer);

	static inline void hrtimer_start_expires(struct hrtimer *timer,
	enum hrtimer_mode mode)
	{
	u64 delta;
	ktime_t soft, hard;
	soft = hrtimer_get_softexpires(timer);
	hard = hrtimer_get_expires(timer);
	delta = ktime_to_ns(ktime_sub(hard, soft));
	hrtimer_start_range_ns(timer, soft, delta, mode);
	}

	void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
	enum hrtimer_mode mode);

	static inline void hrtimer_restart(struct hrtimer *timer)
	{
	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
	}

	/* Query timers: */
	extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);

	/**
	* hrtimer_get_remaining - get remaining time for the timer
	* @timer: the timer to read
	*/
	static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
	{
	return __hrtimer_get_remaining(timer, false);
	}

	extern u64 hrtimer_get_next_event(void);
	extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);

	extern bool hrtimer_active(const struct hrtimer *timer);

	/**
	* hrtimer_is_queued - check, whether the timer is on one of the queues
	* @timer: Timer to check
	*
	* Returns: True if the timer is queued, false otherwise
	*
	* The function can be used lockless, but it gives only a current snapshot.
	*/
	static inline bool hrtimer_is_queued(struct hrtimer *timer)
	{
	/* The READ_ONCE pairs with the update functions of timer->state */
	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
	}

	/*
	* Helper function to check, whether the timer is running the callback
	* function
	*/
	static inline int hrtimer_callback_running(struct hrtimer *timer)
	{
	return timer->base->running == timer;
	}

	/**
	* hrtimer_update_function - Update the timer's callback function
	* @timer: Timer to update
	* @function: New callback function
	*
	* Only safe to call if the timer is not enqueued. Can be called in the callback function if the
	* timer is not enqueued at the same time (see the comments above HRTIMER_STATE_ENQUEUED).
	*/
	static inline void hrtimer_update_function(struct hrtimer *timer,
	enum hrtimer_restart (function)(struct hrtimer ))
	{
	guard(raw_spinlock_irqsave)(&timer->base->cpu_base->lock);

	if (WARN_ON_ONCE(hrtimer_is_queued(timer)))
	return;

	if (WARN_ON_ONCE(!function))
	return;

	timer->function = function;
	}

	/* Forward a hrtimer so it expires after now: */
	extern u64
	hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);

	/**
	* hrtimer_forward_now() - forward the timer expiry so it expires after now
	* @timer: hrtimer to forward
	* @interval: the interval to forward
	*
	* It is a variant of hrtimer_forward(). The timer will expire after the current
	* time of the hrtimer clock base. See hrtimer_forward() for details.
	*/
	static inline u64 hrtimer_forward_now(struct hrtimer *timer,
	ktime_t interval)
	{
	return hrtimer_forward(timer, timer->base->get_time(), interval);
	}

	/* Precise sleep: */

	extern int nanosleep_copyout(struct restart_block , struct timespec64 );
	extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
	const clockid_t clockid);

	extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
	const enum hrtimer_mode mode);
	extern int schedule_hrtimeout_range_clock(ktime_t *expires,
	u64 delta,
	const enum hrtimer_mode mode,
	clockid_t clock_id);
	extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);

	/* Soft interrupt function to run the hrtimer queues: */
	extern void hrtimer_run_queues(void);

	/* Bootup initialization: */
	extern void __init hrtimers_init(void);

	/* Show pending timers: */
	extern void sysrq_timer_list_show(void);

	int hrtimers_prepare_cpu(unsigned int cpu);
	int hrtimers_cpu_starting(unsigned int cpu);
	#ifdef CONFIG_HOTPLUG_CPU
	int hrtimers_cpu_dying(unsigned int cpu);
	#else
	#define hrtimers_cpu_dying NULL
	#endif

	#endif