include/linux/hrtimer.h - kernel/msm-5.4 - Gitiles

 // SPDX-License-Identifier: GPL-2.0
 /*
  *  hrtimers - High-resolution kernel timers
  *
  *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
  *   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/rbtree.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/percpu.h>
 #include <linux/timer.h>
 #include <linux/timerqueue.h>

 struct hrtimer_clock_base;
 struct hrtimer_cpu_base;

 /*
  * 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
  */
 enum hrtimer_mode {
 	HRTIMER_MODE_ABS	= 0x00,
 	HRTIMER_MODE_REL	= 0x01,
 	HRTIMER_MODE_PINNED	= 0x02,
 	HRTIMER_MODE_SOFT	= 0x04,

 	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,

 };

 /*
  * Return values for the callback function
  */
 enum hrtimer_restart {
 	HRTIMER_NORESTART,	/* Timer is not restarted */
 	HRTIMER_RESTART,	/* Timer must be restarted */
 };

 /*
  * 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 - the basic hrtimer structure
  * @node:	timerqueue node, which also manages node.expires,
  *		the absolute expiry time in the hrtimers internal
  *		representation. The time is related to the clock on
  *		which the timer is based. Is setup by adding
  *		slack to the _softexpires value. For non range timers
  *		identical to _softexpires.
  * @_softexpires: the absolute earliest expiry time of the hrtimer.
  *		The time which was given as expiry time when the timer
  *		was armed.
  * @function:	timer expiry callback function
  * @base:	pointer to the timer base (per cpu and per clock)
  * @state:	state information (See bit values above)
  * @is_rel:	Set if the timer was armed relative
  * @is_soft:	Set if hrtimer will be expired in soft interrupt context.
  *
  * The hrtimer structure must be initialized by hrtimer_init()
  */
 struct hrtimer {
 	struct timerqueue_node		node;
 	ktime_t				_softexpires;
 	enum hrtimer_restart		(*function)(struct hrtimer *);
 	struct hrtimer_clock_base	*base;
 	u8				state;
 	u8				is_rel;
 	u8				is_soft;
 };

 /**
  * 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;
 };

 #ifdef CONFIG_64BIT
 # define __hrtimer_clock_base_align	____cacheline_aligned
 #else
 # define __hrtimer_clock_base_align
 #endif

 /**
  * struct hrtimer_clock_base - the timer base for a specific clock
  * @cpu_base:		per cpu clock base
  * @index:		clock type index for per_cpu support when moving a
  *			timer to a base on another cpu.
  * @clockid:		clock id for per_cpu support
  * @seq:		seqcount around __run_hrtimer
  * @running:		pointer to the currently running hrtimer
  * @active:		red black tree root node for the active timers
  * @get_time:		function to retrieve the current time of the clock
  * @offset:		offset of this clock to the monotonic base
  */
 struct hrtimer_clock_base {
 	struct hrtimer_cpu_base	*cpu_base;
 	unsigned int		index;
 	clockid_t		clockid;
 	seqcount_t		seq;
 	struct hrtimer		*running;
 	struct timerqueue_head	active;
 	ktime_t			(*get_time)(void);
 	ktime_t			offset;
 } __hrtimer_clock_base_align;

 enum  hrtimer_base_type {
 	HRTIMER_BASE_MONOTONIC,
 	HRTIMER_BASE_REALTIME,
 	HRTIMER_BASE_BOOTTIME,
 	HRTIMER_BASE_TAI,
 	HRTIMER_BASE_MONOTONIC_SOFT,
 	HRTIMER_BASE_REALTIME_SOFT,
 	HRTIMER_BASE_BOOTTIME_SOFT,
 	HRTIMER_BASE_TAI_SOFT,
 	HRTIMER_MAX_CLOCK_BASES,
 };

 /**
  * struct hrtimer_cpu_base - the per cpu clock bases
  * @lock:		lock protecting the base and associated clock bases
  *			and timers
  * @cpu:		cpu number
  * @active_bases:	Bitfield to mark bases with active timers
  * @clock_was_set_seq:	Sequence counter of clock was set events
  * @hres_active:	State of high resolution mode
  * @in_hrtirq:		hrtimer_interrupt() is currently executing
  * @hang_detected:	The last hrtimer interrupt detected a hang
  * @softirq_activated:	displays, if the softirq is raised - update of softirq
  *			related settings is not required then.
  * @nr_events:		Total number of hrtimer interrupt events
  * @nr_retries:		Total number of hrtimer interrupt retries
  * @nr_hangs:		Total number of hrtimer interrupt hangs
  * @max_hang_time:	Maximum time spent in hrtimer_interrupt
  * @expires_next:	absolute time of the next event, is required for remote
  *			hrtimer enqueue; it is the total first expiry time (hard
  *			and soft hrtimer are taken into account)
  * @next_timer:		Pointer to the first expiring timer
  * @softirq_expires_next: Time to check, if soft queues needs also to be expired
  * @softirq_next_timer: Pointer to the first expiring softirq based timer
  * @clock_base:		array of clock bases for this cpu
  *
  * Note: next_timer is just an optimization for __remove_hrtimer().
  *	 Do not dereference the pointer because it is not reliable on
  *	 cross cpu removals.
  */
 struct hrtimer_cpu_base {
 	raw_spinlock_t			lock;
 	unsigned int			cpu;
 	unsigned int			active_bases;
 	unsigned int			clock_was_set_seq;
 	unsigned int			hres_active		: 1,
 					in_hrtirq		: 1,
 					hang_detected		: 1,
 					softirq_activated       : 1;
 #ifdef CONFIG_HIGH_RES_TIMERS
 	unsigned int			nr_events;
 	unsigned short			nr_retries;
 	unsigned short			nr_hangs;
 	unsigned int			max_hang_time;
 #endif
 	ktime_t				expires_next;
 	struct hrtimer			*next_timer;
 	ktime_t				softirq_expires_next;
 	struct hrtimer			*softirq_next_timer;
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
 } ____cacheline_aligned;

 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 void clock_was_set_delayed(void);

 extern unsigned int hrtimer_resolution;

 #else

 #define hrtimer_resolution	(unsigned int)LOW_RES_NSEC

 static inline void clock_was_set_delayed(void) { }

 #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());
 }

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

 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);


 /* Exported timer functions: */

 /* Initialize timers: */
 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 			 enum hrtimer_mode mode);

 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
 extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
 				  enum hrtimer_mode mode);

 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
 #else
 static inline void hrtimer_init_on_stack(struct hrtimer *timer,
 					 clockid_t which_clock,
 					 enum hrtimer_mode mode)
 {
 	hrtimer_init(timer, which_clock, mode);
 }
 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);
 }

 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);

 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);

 /*
  * Helper function to check, whether the timer is on one of the queues
  */
 static inline int hrtimer_is_queued(struct hrtimer *timer)
 {
 	return 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;
 }

 /* 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
  *
  * Forward the timer expiry so it will expire after the current time
  * of the hrtimer clock base. Returns the number of overruns.
  *
  * Can be safely called from the callback function of @timer. If
  * called from other contexts @timer must neither be enqueued nor
  * running the callback and the caller needs to take care of
  * serialization.
  *
  * Note: This only updates the timer expiry value and does not requeue
  * the timer.
  */
 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(const struct timespec64 *rqtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);

 extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 				 struct task_struct *tsk);

 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);
 #ifdef CONFIG_HOTPLUG_CPU
 int hrtimers_dead_cpu(unsigned int cpu);
 #else
 #define hrtimers_dead_cpu	NULL
 #endif

 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* hrtimers - High-resolution kernel timers
	*
	* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
	* 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/rbtree.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/percpu.h>
	#include <linux/timer.h>
	#include <linux/timerqueue.h>

	struct hrtimer_clock_base;
	struct hrtimer_cpu_base;

	/*
	* 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
	*/
	enum hrtimer_mode {
	HRTIMER_MODE_ABS = 0x00,
	HRTIMER_MODE_REL = 0x01,
	HRTIMER_MODE_PINNED = 0x02,
	HRTIMER_MODE_SOFT = 0x04,

	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,

	};

	/*
	* Return values for the callback function
	*/
	enum hrtimer_restart {
	HRTIMER_NORESTART, /* Timer is not restarted */
	HRTIMER_RESTART, /* Timer must be restarted */
	};

	/*
	* 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 - the basic hrtimer structure
	* @node: timerqueue node, which also manages node.expires,
	* the absolute expiry time in the hrtimers internal
	* representation. The time is related to the clock on
	* which the timer is based. Is setup by adding
	* slack to the _softexpires value. For non range timers
	* identical to _softexpires.
	* @_softexpires: the absolute earliest expiry time of the hrtimer.
	* The time which was given as expiry time when the timer
	* was armed.
	* @function: timer expiry callback function
	* @base: pointer to the timer base (per cpu and per clock)
	* @state: state information (See bit values above)
	* @is_rel: Set if the timer was armed relative
	* @is_soft: Set if hrtimer will be expired in soft interrupt context.
	*
	* The hrtimer structure must be initialized by hrtimer_init()
	*/
	struct hrtimer {
	struct timerqueue_node node;
	ktime_t _softexpires;
	enum hrtimer_restart (function)(struct hrtimer );
	struct hrtimer_clock_base *base;
	u8 state;
	u8 is_rel;
	u8 is_soft;
	};

	/**
	* 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;
	};

	#ifdef CONFIG_64BIT
	# define __hrtimer_clock_base_align ____cacheline_aligned
	#else
	# define __hrtimer_clock_base_align
	#endif

	/**
	* struct hrtimer_clock_base - the timer base for a specific clock
	* @cpu_base: per cpu clock base
	* @index: clock type index for per_cpu support when moving a
	* timer to a base on another cpu.
	* @clockid: clock id for per_cpu support
	* @seq: seqcount around __run_hrtimer
	* @running: pointer to the currently running hrtimer
	* @active: red black tree root node for the active timers
	* @get_time: function to retrieve the current time of the clock
	* @offset: offset of this clock to the monotonic base
	*/
	struct hrtimer_clock_base {
	struct hrtimer_cpu_base *cpu_base;
	unsigned int index;
	clockid_t clockid;
	seqcount_t seq;
	struct hrtimer *running;
	struct timerqueue_head active;
	ktime_t (*get_time)(void);
	ktime_t offset;
	} __hrtimer_clock_base_align;

	enum hrtimer_base_type {
	HRTIMER_BASE_MONOTONIC,
	HRTIMER_BASE_REALTIME,
	HRTIMER_BASE_BOOTTIME,
	HRTIMER_BASE_TAI,
	HRTIMER_BASE_MONOTONIC_SOFT,
	HRTIMER_BASE_REALTIME_SOFT,
	HRTIMER_BASE_BOOTTIME_SOFT,
	HRTIMER_BASE_TAI_SOFT,
	HRTIMER_MAX_CLOCK_BASES,
	};

	/**
	* struct hrtimer_cpu_base - the per cpu clock bases
	* @lock: lock protecting the base and associated clock bases
	* and timers
	* @cpu: cpu number
	* @active_bases: Bitfield to mark bases with active timers
	* @clock_was_set_seq: Sequence counter of clock was set events
	* @hres_active: State of high resolution mode
	* @in_hrtirq: hrtimer_interrupt() is currently executing
	* @hang_detected: The last hrtimer interrupt detected a hang
	* @softirq_activated: displays, if the softirq is raised - update of softirq
	* related settings is not required then.
	* @nr_events: Total number of hrtimer interrupt events
	* @nr_retries: Total number of hrtimer interrupt retries
	* @nr_hangs: Total number of hrtimer interrupt hangs
	* @max_hang_time: Maximum time spent in hrtimer_interrupt
	* @expires_next: absolute time of the next event, is required for remote
	* hrtimer enqueue; it is the total first expiry time (hard
	* and soft hrtimer are taken into account)
	* @next_timer: Pointer to the first expiring timer
	* @softirq_expires_next: Time to check, if soft queues needs also to be expired
	* @softirq_next_timer: Pointer to the first expiring softirq based timer
	* @clock_base: array of clock bases for this cpu
	*
	* Note: next_timer is just an optimization for __remove_hrtimer().
	* Do not dereference the pointer because it is not reliable on
	* cross cpu removals.
	*/
	struct hrtimer_cpu_base {
	raw_spinlock_t lock;
	unsigned int cpu;
	unsigned int active_bases;
	unsigned int clock_was_set_seq;
	unsigned int hres_active : 1,
	in_hrtirq : 1,
	hang_detected : 1,
	softirq_activated : 1;
	#ifdef CONFIG_HIGH_RES_TIMERS
	unsigned int nr_events;
	unsigned short nr_retries;
	unsigned short nr_hangs;
	unsigned int max_hang_time;
	#endif
	ktime_t expires_next;
	struct hrtimer *next_timer;
	ktime_t softirq_expires_next;
	struct hrtimer *softirq_next_timer;
	struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
	} ____cacheline_aligned;

	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 void clock_was_set_delayed(void);

	extern unsigned int hrtimer_resolution;

	#else

	#define hrtimer_resolution (unsigned int)LOW_RES_NSEC

	static inline void clock_was_set_delayed(void) { }

	#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());
	}

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

	DECLARE_PER_CPU(struct tick_device, tick_cpu_device);


	/* Exported timer functions: */

	/* Initialize timers: */
	extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
	enum hrtimer_mode mode);

	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
	extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
	enum hrtimer_mode mode);

	extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
	#else
	static inline void hrtimer_init_on_stack(struct hrtimer *timer,
	clockid_t which_clock,
	enum hrtimer_mode mode)
	{
	hrtimer_init(timer, which_clock, mode);
	}
	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);
	}

	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);

	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);

	/*
	* Helper function to check, whether the timer is on one of the queues
	*/
	static inline int hrtimer_is_queued(struct hrtimer *timer)
	{
	return 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;
	}

	/* 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
	*
	* Forward the timer expiry so it will expire after the current time
	* of the hrtimer clock base. Returns the number of overruns.
	*
	* Can be safely called from the callback function of @timer. If
	* called from other contexts @timer must neither be enqueued nor
	* running the callback and the caller needs to take care of
	* serialization.
	*
	* Note: This only updates the timer expiry value and does not requeue
	* the timer.
	*/
	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(const struct timespec64 *rqtp,
	const enum hrtimer_mode mode,
	const clockid_t clockid);

	extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
	struct task_struct *tsk);

	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);
	#ifdef CONFIG_HOTPLUG_CPU
	int hrtimers_dead_cpu(unsigned int cpu);
	#else
	#define hrtimers_dead_cpu NULL
	#endif

	#endif