[linux-2.6-block.git] / include / linux / hrtimer.h

/*
 *  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>


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
 *
 * Special cases:
 * 0x03		callback function running and enqueued
 *		(was requeued on another CPU)
 * 0x09		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 bit in the above scenario.
 *
 * 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:	red black tree node for time ordered insertion
 * @_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_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
 * @start_pid: timer statistics field to store the pid of the task which
 *		started the timer
 *
 * The hrtimer structure must be initialized by hrtimer_init()
 */
struct hrtimer {
	struct rb_node			node;
	ktime_t				_expires;
	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.
 * @active:		red black tree root node for the active timers
 * @first:		pointer to the timer node which expires first
 * @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;
	clockid_t		index;
	struct rb_root		active;
	struct rb_node		*first;
	ktime_t			resolution;
	ktime_t			(*get_time)(void);
	ktime_t			softirq_time;
#ifdef CONFIG_HIGH_RES_TIMERS
	ktime_t			offset;
#endif
};

#define HRTIMER_MAX_CLOCK_BASES 2

/*
 * struct hrtimer_cpu_base - the per cpu clock bases
 * @lock:		lock protecting the base and associated clock bases
 *			and timers
 * @clock_base:		array of clock bases for this cpu
 * @curr_timer:		the timer which is executing a callback right now
 * @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
 */
struct hrtimer_cpu_base {
	raw_spinlock_t			lock;
	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
#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
};

static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
{
	timer->_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->_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->_expires = ktime_add_safe(time, ns_to_ktime(delta));
}

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

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

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

static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
{
	return timer->_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->_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->_expires);
}

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

#ifdef CONFIG_HIGH_RES_TIMERS
struct clock_event_device;

extern void clock_was_set(void);
extern void hres_timers_resume(void);
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

#else

# define MONOTONIC_RES_NSEC	LOW_RES_NSEC
# define KTIME_MONOTONIC_RES	KTIME_LOW_RES

/*
 * clock_was_set() is a NOP for non- high-resolution systems. The
 * time-sorted order guarantees that a timer does not expire early and
 * is expired in the next softirq when the clock was advanced.
 */
static inline void clock_was_set(void) { }
static inline void hrtimer_peek_ahead_timers(void) { }

static inline void hres_timers_resume(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;
}
#endif

extern ktime_t ktime_get(void);
extern ktime_t ktime_get_real(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.
 */
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(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);

#if BITS_PER_LONG < 64
extern u64 ktime_divns(const ktime_t kt, s64 div);
#else /* BITS_PER_LONG < 64 */
# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
#endif

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

#endif
Commit	Line	Data
	1	/*
	2	* include/linux/hrtimer.h
	3	*
	4	* hrtimers - High-resolution kernel timers
	5	*
	6	* Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
	7	* Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
	8	*
	9	* data type definitions, declarations, prototypes
	10	*
	11	* Started by: Thomas Gleixner and Ingo Molnar
	12	*
	13	* For licencing details see kernel-base/COPYING
	14	*/
	15	#ifndef _LINUX_HRTIMER_H
	16	#define _LINUX_HRTIMER_H
	17
	18	#include <linux/rbtree.h>
	19	#include <linux/ktime.h>
	20	#include <linux/init.h>
	21	#include <linux/list.h>
	22	#include <linux/wait.h>
	23	#include <linux/percpu.h>
	24	#include <linux/timer.h>
	25
	26
	27	struct hrtimer_clock_base;
	28	struct hrtimer_cpu_base;
	29
	30	/*
	31	* Mode arguments of xxx_hrtimer functions:
	32	*/
	33	enum hrtimer_mode {
	34	HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */
	35	HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */
	36	HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */
	37	HRTIMER_MODE_ABS_PINNED = 0x02,
	38	HRTIMER_MODE_REL_PINNED = 0x03,
	39	};
	40
	41	/*
	42	* Return values for the callback function
	43	*/
	44	enum hrtimer_restart {
	45	HRTIMER_NORESTART, /* Timer is not restarted */
	46	HRTIMER_RESTART, /* Timer must be restarted */
	47	};
	48
	49	/*
	50	* Values to track state of the timer
	51	*
	52	* Possible states:
	53	*
	54	* 0x00 inactive
	55	* 0x01 enqueued into rbtree
	56	* 0x02 callback function running
	57	*
	58	* Special cases:
	59	* 0x03 callback function running and enqueued
	60	* (was requeued on another CPU)
	61	* 0x09 timer was migrated on CPU hotunplug
	62	* The "callback function running and enqueued" status is only possible on
	63	* SMP. It happens for example when a posix timer expired and the callback
	64	* queued a signal. Between dropping the lock which protects the posix timer
	65	* and reacquiring the base lock of the hrtimer, another CPU can deliver the
	66	* signal and rearm the timer. We have to preserve the callback running state,
	67	* as otherwise the timer could be removed before the softirq code finishes the
	68	* the handling of the timer.
	69	*
	70	* The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to
	71	* preserve the HRTIMER_STATE_CALLBACK bit in the above scenario.
	72	*
	73	* All state transitions are protected by cpu_base->lock.
	74	*/
	75	#define HRTIMER_STATE_INACTIVE 0x00
	76	#define HRTIMER_STATE_ENQUEUED 0x01
	77	#define HRTIMER_STATE_CALLBACK 0x02
	78	#define HRTIMER_STATE_MIGRATE 0x04
	79
	80	/**
	81	* struct hrtimer - the basic hrtimer structure
	82	* @node: red black tree node for time ordered insertion
	83	* @_expires: the absolute expiry time in the hrtimers internal
	84	* representation. The time is related to the clock on
	85	* which the timer is based. Is setup by adding
	86	* slack to the _softexpires value. For non range timers
	87	* identical to _softexpires.
	88	* @_softexpires: the absolute earliest expiry time of the hrtimer.
	89	* The time which was given as expiry time when the timer
	90	* was armed.
	91	* @function: timer expiry callback function
	92	* @base: pointer to the timer base (per cpu and per clock)
	93	* @state: state information (See bit values above)
	94	* @start_site: timer statistics field to store the site where the timer
	95	* was started
	96	* @start_comm: timer statistics field to store the name of the process which
	97	* started the timer
	98	* @start_pid: timer statistics field to store the pid of the task which
	99	* started the timer
	100	*
	101	* The hrtimer structure must be initialized by hrtimer_init()
	102	*/
	103	struct hrtimer {
	104	struct rb_node node;
	105	ktime_t _expires;
	106	ktime_t _softexpires;
	107	enum hrtimer_restart (function)(struct hrtimer );
	108	struct hrtimer_clock_base *base;
	109	unsigned long state;
	110	#ifdef CONFIG_TIMER_STATS
	111	int start_pid;
	112	void *start_site;
	113	char start_comm[16];
	114	#endif
	115	};
	116
	117	/**
	118	* struct hrtimer_sleeper - simple sleeper structure
	119	* @timer: embedded timer structure
	120	* @task: task to wake up
	121	*
	122	* task is set to NULL, when the timer expires.
	123	*/
	124	struct hrtimer_sleeper {
	125	struct hrtimer timer;
	126	struct task_struct *task;
	127	};
	128
	129	/**
	130	* struct hrtimer_clock_base - the timer base for a specific clock
	131	* @cpu_base: per cpu clock base
	132	* @index: clock type index for per_cpu support when moving a
	133	* timer to a base on another cpu.
	134	* @active: red black tree root node for the active timers
	135	* @first: pointer to the timer node which expires first
	136	* @resolution: the resolution of the clock, in nanoseconds
	137	* @get_time: function to retrieve the current time of the clock
	138	* @softirq_time: the time when running the hrtimer queue in the softirq
	139	* @offset: offset of this clock to the monotonic base
	140	*/
	141	struct hrtimer_clock_base {
	142	struct hrtimer_cpu_base *cpu_base;
	143	clockid_t index;
	144	struct rb_root active;
	145	struct rb_node *first;
	146	ktime_t resolution;
	147	ktime_t (*get_time)(void);
	148	ktime_t softirq_time;
	149	#ifdef CONFIG_HIGH_RES_TIMERS
	150	ktime_t offset;
	151	#endif
	152	};
	153
	154	#define HRTIMER_MAX_CLOCK_BASES 2
	155
	156	/*
	157	* struct hrtimer_cpu_base - the per cpu clock bases
	158	* @lock: lock protecting the base and associated clock bases
	159	* and timers
	160	* @clock_base: array of clock bases for this cpu
	161	* @curr_timer: the timer which is executing a callback right now
	162	* @expires_next: absolute time of the next event which was scheduled
	163	* via clock_set_next_event()
	164	* @hres_active: State of high resolution mode
	165	* @hang_detected: The last hrtimer interrupt detected a hang
	166	* @nr_events: Total number of hrtimer interrupt events
	167	* @nr_retries: Total number of hrtimer interrupt retries
	168	* @nr_hangs: Total number of hrtimer interrupt hangs
	169	* @max_hang_time: Maximum time spent in hrtimer_interrupt
	170	*/
	171	struct hrtimer_cpu_base {
	172	raw_spinlock_t lock;
	173	struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
	174	#ifdef CONFIG_HIGH_RES_TIMERS
	175	ktime_t expires_next;
	176	int hres_active;
	177	int hang_detected;
	178	unsigned long nr_events;
	179	unsigned long nr_retries;
	180	unsigned long nr_hangs;
	181	ktime_t max_hang_time;
	182	#endif
	183	};
	184
	185	static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
	186	{
	187	timer->_expires = time;
	188	timer->_softexpires = time;
	189	}
	190
	191	static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
	192	{
	193	timer->_softexpires = time;
	194	timer->_expires = ktime_add_safe(time, delta);
	195	}
	196
	197	static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta)
	198	{
	199	timer->_softexpires = time;
	200	timer->_expires = ktime_add_safe(time, ns_to_ktime(delta));
	201	}
	202
	203	static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
	204	{
	205	timer->_expires.tv64 = tv64;
	206	timer->_softexpires.tv64 = tv64;
	207	}
	208
	209	static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
	210	{
	211	timer->_expires = ktime_add_safe(timer->_expires, time);
	212	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
	213	}
	214
	215	static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
	216	{
	217	timer->_expires = ktime_add_ns(timer->_expires, ns);
	218	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
	219	}
	220
	221	static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
	222	{
	223	return timer->_expires;
	224	}
	225
	226	static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
	227	{
	228	return timer->_softexpires;
	229	}
	230
	231	static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
	232	{
	233	return timer->_expires.tv64;
	234	}
	235	static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
	236	{
	237	return timer->_softexpires.tv64;
	238	}
	239
	240	static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
	241	{
	242	return ktime_to_ns(timer->_expires);
	243	}
	244
	245	static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
	246	{
	247	return ktime_sub(timer->_expires, timer->base->get_time());
	248	}
	249
	250	#ifdef CONFIG_HIGH_RES_TIMERS
	251	struct clock_event_device;
	252
	253	extern void clock_was_set(void);
	254	extern void hres_timers_resume(void);
	255	extern void hrtimer_interrupt(struct clock_event_device *dev);
	256
	257	/*
	258	* In high resolution mode the time reference must be read accurate
	259	*/
	260	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	261	{
	262	return timer->base->get_time();
	263	}
	264
	265	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	266	{
	267	return timer->base->cpu_base->hres_active;
	268	}
	269
	270	extern void hrtimer_peek_ahead_timers(void);
	271
	272	/*
	273	* The resolution of the clocks. The resolution value is returned in
	274	* the clock_getres() system call to give application programmers an
	275	* idea of the (in)accuracy of timers. Timer values are rounded up to
	276	* this resolution values.
	277	*/
	278	# define HIGH_RES_NSEC 1
	279	# define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC }
	280	# define MONOTONIC_RES_NSEC HIGH_RES_NSEC
	281	# define KTIME_MONOTONIC_RES KTIME_HIGH_RES
	282
	283	#else
	284
	285	# define MONOTONIC_RES_NSEC LOW_RES_NSEC
	286	# define KTIME_MONOTONIC_RES KTIME_LOW_RES
	287
	288	/*
	289	* clock_was_set() is a NOP for non- high-resolution systems. The
	290	* time-sorted order guarantees that a timer does not expire early and
	291	* is expired in the next softirq when the clock was advanced.
	292	*/
	293	static inline void clock_was_set(void) { }
	294	static inline void hrtimer_peek_ahead_timers(void) { }
	295
	296	static inline void hres_timers_resume(void) { }
	297
	298	/*
	299	* In non high resolution mode the time reference is taken from
	300	* the base softirq time variable.
	301	*/
	302	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	303	{
	304	return timer->base->softirq_time;
	305	}
	306
	307	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	308	{
	309	return 0;
	310	}
	311	#endif
	312
	313	extern ktime_t ktime_get(void);
	314	extern ktime_t ktime_get_real(void);
	315
	316
	317	DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
	318
	319
	320	/* Exported timer functions: */
	321
	322	/* Initialize timers: */
	323	extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
	324	enum hrtimer_mode mode);
	325
	326	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
	327	extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
	328	enum hrtimer_mode mode);
	329
	330	extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
	331	#else
	332	static inline void hrtimer_init_on_stack(struct hrtimer *timer,
	333	clockid_t which_clock,
	334	enum hrtimer_mode mode)
	335	{
	336	hrtimer_init(timer, which_clock, mode);
	337	}
	338	static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
	339	#endif
	340
	341	/* Basic timer operations: */
	342	extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
	343	const enum hrtimer_mode mode);
	344	extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
	345	unsigned long range_ns, const enum hrtimer_mode mode);
	346	extern int
	347	__hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
	348	unsigned long delta_ns,
	349	const enum hrtimer_mode mode, int wakeup);
	350
	351	extern int hrtimer_cancel(struct hrtimer *timer);
	352	extern int hrtimer_try_to_cancel(struct hrtimer *timer);
	353
	354	static inline int hrtimer_start_expires(struct hrtimer *timer,
	355	enum hrtimer_mode mode)
	356	{
	357	unsigned long delta;
	358	ktime_t soft, hard;
	359	soft = hrtimer_get_softexpires(timer);
	360	hard = hrtimer_get_expires(timer);
	361	delta = ktime_to_ns(ktime_sub(hard, soft));
	362	return hrtimer_start_range_ns(timer, soft, delta, mode);
	363	}
	364
	365	static inline int hrtimer_restart(struct hrtimer *timer)
	366	{
	367	return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
	368	}
	369
	370	/* Query timers: */
	371	extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
	372	extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
	373
	374	extern ktime_t hrtimer_get_next_event(void);
	375
	376	/*
	377	* A timer is active, when it is enqueued into the rbtree or the callback
	378	* function is running.
	379	*/
	380	static inline int hrtimer_active(const struct hrtimer *timer)
	381	{
	382	return timer->state != HRTIMER_STATE_INACTIVE;
	383	}
	384
	385	/*
	386	* Helper function to check, whether the timer is on one of the queues
	387	*/
	388	static inline int hrtimer_is_queued(struct hrtimer *timer)
	389	{
	390	return timer->state & HRTIMER_STATE_ENQUEUED;
	391	}
	392
	393	/*
	394	* Helper function to check, whether the timer is running the callback
	395	* function
	396	*/
	397	static inline int hrtimer_callback_running(struct hrtimer *timer)
	398	{
	399	return timer->state & HRTIMER_STATE_CALLBACK;
	400	}
	401
	402	/* Forward a hrtimer so it expires after now: */
	403	extern u64
	404	hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
	405
	406	/* Forward a hrtimer so it expires after the hrtimer's current now */
	407	static inline u64 hrtimer_forward_now(struct hrtimer *timer,
	408	ktime_t interval)
	409	{
	410	return hrtimer_forward(timer, timer->base->get_time(), interval);
	411	}
	412
	413	/* Precise sleep: */
	414	extern long hrtimer_nanosleep(struct timespec *rqtp,
	415	struct timespec __user *rmtp,
	416	const enum hrtimer_mode mode,
	417	const clockid_t clockid);
	418	extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
	419
	420	extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
	421	struct task_struct *tsk);
	422
	423	extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
	424	const enum hrtimer_mode mode);
	425	extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
	426
	427	/* Soft interrupt function to run the hrtimer queues: */
	428	extern void hrtimer_run_queues(void);
	429	extern void hrtimer_run_pending(void);
	430
	431	/* Bootup initialization: */
	432	extern void __init hrtimers_init(void);
	433
	434	#if BITS_PER_LONG < 64
	435	extern u64 ktime_divns(const ktime_t kt, s64 div);
	436	#else /* BITS_PER_LONG < 64 */
	437	# define ktime_divns(kt, div) (u64)((kt).tv64 / (div))
	438	#endif
	439
	440	/* Show pending timers: */
	441	extern void sysrq_timer_list_show(void);
	442
	443	#endif