include/linux/hrtimer.h - kernel/msm-4.9 - Gitiles

 /*
  *  include/linux/hrtimer.h
  *
  *  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
  *
  *  For licencing details see kernel-base/COPYING
  */
 #ifndef _LINUX_HRTIMER_H
 #define _LINUX_HRTIMER_H

 #include <linux/rbtree.h>
 #include <linux/ktime.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/wait.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:
  */
 enum hrtimer_mode {
 	HRTIMER_MODE_ABS = 0x0,		/* Time value is absolute */
 	HRTIMER_MODE_REL = 0x1,		/* Time value is relative to now */
 	HRTIMER_MODE_PINNED = 0x02,	/* Timer is bound to CPU */
 	HRTIMER_MODE_ABS_PINNED = 0x02,
 	HRTIMER_MODE_REL_PINNED = 0x03,
 };

 /*
  * 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
  * 0x02		callback function running
  * 0x04		timer is migrated to another cpu
  *
  * Special cases:
  * 0x03		callback function running and enqueued
  *		(was requeued on another CPU)
  * 0x05		timer was migrated on CPU hotunplug
  *
  * The "callback function running and enqueued" status is only possible on
  * SMP. 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. We have to preserve the callback running state,
  * as otherwise the timer could be removed before the softirq code finishes the
  * the handling of the timer.
  *
  * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state
  * to preserve the HRTIMER_STATE_CALLBACK in the above scenario. This
  * also affects HRTIMER_STATE_MIGRATE where the preservation is not
  * necessary. HRTIMER_STATE_MIGRATE is cleared after the timer is
  * enqueued on the new cpu.
  *
  * All state transitions are protected by cpu_base->lock.
  */
 #define HRTIMER_STATE_INACTIVE	0x00
 #define HRTIMER_STATE_ENQUEUED	0x01
 #define HRTIMER_STATE_CALLBACK	0x02
 #define HRTIMER_STATE_MIGRATE	0x04

 /**
  * 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)
  * @start_pid: timer statistics field to store the pid of the task which
  *		started the timer
  * @start_site:	timer statistics field to store the site where the timer
  *		was started
  * @start_comm: timer statistics field to store the name of the process which
  *		started the timer
  *
  * 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;
 	unsigned long			state;
 #ifdef CONFIG_TIMER_STATS
 	int				start_pid;
 	void				*start_site;
 	char				start_comm[16];
 #endif
 };

 /**
  * 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;
 };

 /**
  * 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
  * @active:		red black tree root node for the active timers
  * @resolution:		the resolution of the clock, in nanoseconds
  * @get_time:		function to retrieve the current time of the clock
  * @softirq_time:	the time when running the hrtimer queue in the softirq
  * @offset:		offset of this clock to the monotonic base
  */
 struct hrtimer_clock_base {
 	struct hrtimer_cpu_base	*cpu_base;
 	int			index;
 	clockid_t		clockid;
 	struct timerqueue_head	active;
 	ktime_t			resolution;
 	ktime_t			(*get_time)(void);
 	ktime_t			softirq_time;
 	ktime_t			offset;
 };

 enum  hrtimer_base_type {
 	HRTIMER_BASE_MONOTONIC,
 	HRTIMER_BASE_REALTIME,
 	HRTIMER_BASE_BOOTTIME,
 	HRTIMER_BASE_TAI,
 	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:	Indicates that clock was set from irq context.
  * @expires_next:	absolute time of the next event which was scheduled
  *			via clock_set_next_event()
  * @hres_active:	State of high resolution mode
  * @hang_detected:	The last hrtimer interrupt detected a hang
  * @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
  * @clock_base:		array of clock bases for this cpu
  */
 struct hrtimer_cpu_base {
 	raw_spinlock_t			lock;
 	unsigned int			cpu;
 	unsigned int			active_bases;
 	unsigned int			clock_was_set;
 #ifdef CONFIG_HIGH_RES_TIMERS
 	ktime_t				expires_next;
 	int				hres_active;
 	int				hang_detected;
 	unsigned long			nr_events;
 	unsigned long			nr_retries;
 	unsigned long			nr_hangs;
 	ktime_t				max_hang_time;
 #endif
 	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
 };

 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, unsigned long 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 = tv64;
 	timer->_softexpires.tv64 = 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.tv64;
 }
 static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
 {
 	return timer->_softexpires.tv64;
 }

 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());
 }

 #ifdef CONFIG_HIGH_RES_TIMERS
 struct clock_event_device;

 extern void hrtimer_interrupt(struct clock_event_device *dev);

 /*
  * In high resolution mode the time reference must be read accurate
  */
 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 timer->base->cpu_base->hres_active;
 }

 extern void hrtimer_peek_ahead_timers(void);

 /*
  * The resolution of the clocks. The resolution value is returned in
  * the clock_getres() system call to give application programmers an
  * idea of the (in)accuracy of timers. Timer values are rounded up to
  * this resolution values.
  */
 # define HIGH_RES_NSEC		1
 # define KTIME_HIGH_RES		(ktime_t) { .tv64 = HIGH_RES_NSEC }
 # define MONOTONIC_RES_NSEC	HIGH_RES_NSEC
 # define KTIME_MONOTONIC_RES	KTIME_HIGH_RES

 extern void clock_was_set_delayed(void);

 #else

 # define MONOTONIC_RES_NSEC	LOW_RES_NSEC
 # define KTIME_MONOTONIC_RES	KTIME_LOW_RES

 static inline void hrtimer_peek_ahead_timers(void) { }

 /*
  * In non high resolution mode the time reference is taken from
  * the base softirq time variable.
  */
 static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
 {
 	return timer->base->softirq_time;
 }

 static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 {
 	return 0;
 }

 static inline void clock_was_set_delayed(void) { }

 #endif

 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 int hrtimer_start(struct hrtimer *timer, ktime_t tim,
 			 const enum hrtimer_mode mode);
 extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 			unsigned long range_ns, const enum hrtimer_mode mode);
 extern int
 __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
 			 unsigned long delta_ns,
 			 const enum hrtimer_mode mode, int wakeup);

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

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

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

 /* Query timers: */
 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
 extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);

 extern ktime_t hrtimer_get_next_event(void);

 /*
  * A timer is active, when it is enqueued into the rbtree or the
  * callback function is running or it's in the state of being migrated
  * to another cpu.
  */
 static inline int hrtimer_active(const struct hrtimer *timer)
 {
 	return timer->state != HRTIMER_STATE_INACTIVE;
 }

 /*
  * 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->state & HRTIMER_STATE_CALLBACK;
 }

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

 /* Forward a hrtimer so it expires after the hrtimer's current now */
 static inline u64 hrtimer_forward_now(struct hrtimer *timer,
 				      ktime_t interval)
 {
 	return hrtimer_forward(timer, timer->base->get_time(), interval);
 }

 /* Precise sleep: */
 extern long hrtimer_nanosleep(struct timespec *rqtp,
 			      struct timespec __user *rmtp,
 			      const enum hrtimer_mode mode,
 			      const clockid_t clockid);
 extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);

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

 extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
 						const enum hrtimer_mode mode);
 extern int schedule_hrtimeout_range_clock(ktime_t *expires,
 		unsigned long delta, const enum hrtimer_mode mode, int clock);
 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);
 extern void hrtimer_run_pending(void);

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

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

 #endif
	/*
	* include/linux/hrtimer.h
	*
	* 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
	*
	* For licencing details see kernel-base/COPYING
	*/
	#ifndef _LINUX_HRTIMER_H
	#define _LINUX_HRTIMER_H

	#include <linux/rbtree.h>
	#include <linux/ktime.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/wait.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:
	*/
	enum hrtimer_mode {
	HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */
	HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */
	HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */
	HRTIMER_MODE_ABS_PINNED = 0x02,
	HRTIMER_MODE_REL_PINNED = 0x03,
	};

	/*
	* 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
	* 0x02 callback function running
	* 0x04 timer is migrated to another cpu
	*
	* Special cases:
	* 0x03 callback function running and enqueued
	* (was requeued on another CPU)
	* 0x05 timer was migrated on CPU hotunplug
	*
	* The "callback function running and enqueued" status is only possible on
	* SMP. 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. We have to preserve the callback running state,
	* as otherwise the timer could be removed before the softirq code finishes the
	* the handling of the timer.
	*
	* The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state
	* to preserve the HRTIMER_STATE_CALLBACK in the above scenario. This
	* also affects HRTIMER_STATE_MIGRATE where the preservation is not
	* necessary. HRTIMER_STATE_MIGRATE is cleared after the timer is
	* enqueued on the new cpu.
	*
	* All state transitions are protected by cpu_base->lock.
	*/
	#define HRTIMER_STATE_INACTIVE 0x00
	#define HRTIMER_STATE_ENQUEUED 0x01
	#define HRTIMER_STATE_CALLBACK 0x02
	#define HRTIMER_STATE_MIGRATE 0x04

	/**
	* 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)
	* @start_pid: timer statistics field to store the pid of the task which
	* started the timer
	* @start_site: timer statistics field to store the site where the timer
	* was started
	* @start_comm: timer statistics field to store the name of the process which
	* started the timer
	*
	* 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;
	unsigned long state;
	#ifdef CONFIG_TIMER_STATS
	int start_pid;
	void *start_site;
	char start_comm[16];
	#endif
	};

	/**
	* 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;
	};

	/**
	* 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
	* @active: red black tree root node for the active timers
	* @resolution: the resolution of the clock, in nanoseconds
	* @get_time: function to retrieve the current time of the clock
	* @softirq_time: the time when running the hrtimer queue in the softirq
	* @offset: offset of this clock to the monotonic base
	*/
	struct hrtimer_clock_base {
	struct hrtimer_cpu_base *cpu_base;
	int index;
	clockid_t clockid;
	struct timerqueue_head active;
	ktime_t resolution;
	ktime_t (*get_time)(void);
	ktime_t softirq_time;
	ktime_t offset;
	};

	enum hrtimer_base_type {
	HRTIMER_BASE_MONOTONIC,
	HRTIMER_BASE_REALTIME,
	HRTIMER_BASE_BOOTTIME,
	HRTIMER_BASE_TAI,
	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: Indicates that clock was set from irq context.
	* @expires_next: absolute time of the next event which was scheduled
	* via clock_set_next_event()
	* @hres_active: State of high resolution mode
	* @hang_detected: The last hrtimer interrupt detected a hang
	* @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
	* @clock_base: array of clock bases for this cpu
	*/
	struct hrtimer_cpu_base {
	raw_spinlock_t lock;
	unsigned int cpu;
	unsigned int active_bases;
	unsigned int clock_was_set;
	#ifdef CONFIG_HIGH_RES_TIMERS
	ktime_t expires_next;
	int hres_active;
	int hang_detected;
	unsigned long nr_events;
	unsigned long nr_retries;
	unsigned long nr_hangs;
	ktime_t max_hang_time;
	#endif
	struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
	};

	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, unsigned long 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 = tv64;
	timer->_softexpires.tv64 = 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.tv64;
	}
	static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
	{
	return timer->_softexpires.tv64;
	}

	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());
	}

	#ifdef CONFIG_HIGH_RES_TIMERS
	struct clock_event_device;

	extern void hrtimer_interrupt(struct clock_event_device *dev);

	/*
	* In high resolution mode the time reference must be read accurate
	*/
	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 timer->base->cpu_base->hres_active;
	}

	extern void hrtimer_peek_ahead_timers(void);

	/*
	* The resolution of the clocks. The resolution value is returned in
	* the clock_getres() system call to give application programmers an
	* idea of the (in)accuracy of timers. Timer values are rounded up to
	* this resolution values.
	*/
	# define HIGH_RES_NSEC 1
	# define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC }
	# define MONOTONIC_RES_NSEC HIGH_RES_NSEC
	# define KTIME_MONOTONIC_RES KTIME_HIGH_RES

	extern void clock_was_set_delayed(void);

	#else

	# define MONOTONIC_RES_NSEC LOW_RES_NSEC
	# define KTIME_MONOTONIC_RES KTIME_LOW_RES

	static inline void hrtimer_peek_ahead_timers(void) { }

	/*
	* In non high resolution mode the time reference is taken from
	* the base softirq time variable.
	*/
	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	{
	return timer->base->softirq_time;
	}

	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	{
	return 0;
	}

	static inline void clock_was_set_delayed(void) { }

	#endif

	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 int hrtimer_start(struct hrtimer *timer, ktime_t tim,
	const enum hrtimer_mode mode);
	extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
	unsigned long range_ns, const enum hrtimer_mode mode);
	extern int
	__hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
	unsigned long delta_ns,
	const enum hrtimer_mode mode, int wakeup);

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

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

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

	/* Query timers: */
	extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
	extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);

	extern ktime_t hrtimer_get_next_event(void);

	/*
	* A timer is active, when it is enqueued into the rbtree or the
	* callback function is running or it's in the state of being migrated
	* to another cpu.
	*/
	static inline int hrtimer_active(const struct hrtimer *timer)
	{
	return timer->state != HRTIMER_STATE_INACTIVE;
	}

	/*
	* 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->state & HRTIMER_STATE_CALLBACK;
	}

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

	/* Forward a hrtimer so it expires after the hrtimer's current now */
	static inline u64 hrtimer_forward_now(struct hrtimer *timer,
	ktime_t interval)
	{
	return hrtimer_forward(timer, timer->base->get_time(), interval);
	}

	/* Precise sleep: */
	extern long hrtimer_nanosleep(struct timespec *rqtp,
	struct timespec __user *rmtp,
	const enum hrtimer_mode mode,
	const clockid_t clockid);
	extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);

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

	extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
	const enum hrtimer_mode mode);
	extern int schedule_hrtimeout_range_clock(ktime_t *expires,
	unsigned long delta, const enum hrtimer_mode mode, int clock);
	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);
	extern void hrtimer_run_pending(void);

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

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

	#endif