[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>

struct hrtimer_clock_base;
struct hrtimer_cpu_base;

/*
 * Mode arguments of xxx_hrtimer functions:
 */
enum hrtimer_mode {
	HRTIMER_MODE_ABS,	/* Time value is absolute */
	HRTIMER_MODE_REL,	/* Time value is relative to now */
};

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

/*
 * hrtimer callback modes:
 *
 *	HRTIMER_CB_SOFTIRQ:		Callback must run in softirq context
 *	HRTIMER_CB_IRQSAFE:		Callback may run in hardirq context
 *	HRTIMER_CB_IRQSAFE_NO_RESTART:	Callback may run in hardirq context and
 *					does not restart the timer
 *	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:	Callback must run in hardirq context
 *					Special mode for tick emultation
 */
enum hrtimer_cb_mode {
	HRTIMER_CB_SOFTIRQ,
	HRTIMER_CB_IRQSAFE,
	HRTIMER_CB_IRQSAFE_NO_RESTART,
	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,
};

/*
 * Values to track state of the timer
 *
 * Possible states:
 *
 * 0x00		inactive
 * 0x01		enqueued into rbtree
 * 0x02		callback function running
 * 0x04		callback pending (high resolution mode)
 *
 * Special case:
 * 0x03		callback function running and enqueued
 *		(was requeued on another CPU)
 * 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_PENDING	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.
 * @function:	timer expiry callback function
 * @base:	pointer to the timer base (per cpu and per clock)
 * @state:	state information (See bit values above)
 * @cb_mode:	high resolution timer feature to select the callback execution
 *		 mode
 * @cb_entry:	list head to enqueue an expired timer into the callback list
 * @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;
	enum hrtimer_cb_mode		cb_mode;
	struct list_head		cb_entry;
#ifdef CONFIG_TIMER_STATS
	void				*start_site;
	char				start_comm[16];
	int				start_pid;
#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
 * @get_softirq_time:	function to retrieve the current time from the softirq
 * @softirq_time:	the time when running the hrtimer queue in the softirq
 * @offset:		offset of this clock to the monotonic base
 * @reprogram:		function to reprogram the timer event
 */
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			(*get_softirq_time)(void);
	ktime_t			softirq_time;
#ifdef CONFIG_HIGH_RES_TIMERS
	ktime_t			offset;
	int			(*reprogram)(struct hrtimer *t,
					     struct hrtimer_clock_base *b,
					     ktime_t n);
#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
 * @check_clocks:	Indictator, when set evaluate time source and clock
 *			event devices whether high resolution mode can be
 *			activated.
 * @cb_pending:		Expired timers are moved from the rbtree to this
 *			list in the timer interrupt. The list is processed
 *			in the softirq.
 * @nr_events:		Total number of timer interrupt events
 */
struct hrtimer_cpu_base {
	spinlock_t			lock;
	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
	struct list_head		cb_pending;
#ifdef CONFIG_HIGH_RES_TIMERS
	ktime_t				expires_next;
	int				hres_active;
	unsigned long			nr_events;
#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, unsigned long 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;
}

/*
 * 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 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);

/* 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_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, hrtimer_get_expires(timer), 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 | HRTIMER_STATE_PENDING);
}

/*
 * 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);

/*
 * Timer-statistics info:
 */
#ifdef CONFIG_TIMER_STATS

extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
				     void *timerf, char *comm,
				     unsigned int timer_flag);

static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
{
	timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
				 timer->function, timer->start_comm, 0);
}

extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,
						 void *addr);

static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
{
	__timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
}

static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
{
	timer->start_site = NULL;
}
#else
static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
{
}

static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
{
}

static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
{
}
#endif

#endif
Commit	Line	Data
c0a31329 TG	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
3c8aa39d TG	24	struct hrtimer_clock_base;
	25	struct hrtimer_cpu_base;
	26
c0a31329 TG	27	/*
	28	* Mode arguments of xxx_hrtimer functions:
	29	*/
	30	enum hrtimer_mode {
c9cb2e3d TG	31	HRTIMER_MODE_ABS, /* Time value is absolute */
c9cb2e3d TG	32	HRTIMER_MODE_REL, /* Time value is relative to now */
c0a31329 TG	33	};
c0a31329 TG	34
c9cb2e3d TG	35	/*
	36	* Return values for the callback function
	37	*/
c0a31329	38	enum hrtimer_restart {
c9cb2e3d TG	39	HRTIMER_NORESTART, /* Timer is not restarted */
c9cb2e3d TG	40	HRTIMER_RESTART, /* Timer must be restarted */
c0a31329 TG	41	};
c0a31329 TG	42
303e967f	43	/*
54cdfdb4 TG	44	* hrtimer callback modes:
	45	*
	46	* HRTIMER_CB_SOFTIRQ: Callback must run in softirq context
	47	* HRTIMER_CB_IRQSAFE: Callback may run in hardirq context
	48	* HRTIMER_CB_IRQSAFE_NO_RESTART: Callback may run in hardirq context and
	49	* does not restart the timer
8437fdc7	50	* HRTIMER_CB_IRQSAFE_NO_SOFTIRQ: Callback must run in hardirq context
54cdfdb4 TG	51	* Special mode for tick emultation
	52	*/
	53	enum hrtimer_cb_mode {
	54	HRTIMER_CB_SOFTIRQ,
	55	HRTIMER_CB_IRQSAFE,
	56	HRTIMER_CB_IRQSAFE_NO_RESTART,
	57	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,
	58	};
	59
	60	/*
	61	* Values to track state of the timer
303e967f TG	62	*
	63	* Possible states:
	64	*
	65	* 0x00 inactive
	66	* 0x01 enqueued into rbtree
	67	* 0x02 callback function running
54cdfdb4 TG	68	* 0x04 callback pending (high resolution mode)
	69	*
	70	* Special case:
303e967f TG	71	* 0x03 callback function running and enqueued
303e967f TG	72	* (was requeued on another CPU)
303e967f TG	73	* The "callback function running and enqueued" status is only possible on
	74	* SMP. It happens for example when a posix timer expired and the callback
	75	* queued a signal. Between dropping the lock which protects the posix timer
	76	* and reacquiring the base lock of the hrtimer, another CPU can deliver the
	77	* signal and rearm the timer. We have to preserve the callback running state,
	78	* as otherwise the timer could be removed before the softirq code finishes the
	79	* the handling of the timer.
	80	*
3eb05676	81	* The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to
303e967f TG	82	* preserve the HRTIMER_STATE_CALLBACK bit in the above scenario.
	83	*
	84	* All state transitions are protected by cpu_base->lock.
	85	*/
	86	#define HRTIMER_STATE_INACTIVE 0x00
	87	#define HRTIMER_STATE_ENQUEUED 0x01
	88	#define HRTIMER_STATE_CALLBACK 0x02
54cdfdb4	89	#define HRTIMER_STATE_PENDING 0x04
303e967f	90
c0a31329 TG	91	/**
c0a31329 TG	92	* struct hrtimer - the basic hrtimer structure
c0a31329	93	* @node: red black tree node for time ordered insertion
c0a31329 TG	94	* @expires: the absolute expiry time in the hrtimers internal
	95	* representation. The time is related to the clock on
	96	* which the timer is based.
c0a31329	97	* @function: timer expiry callback function
c0a31329	98	* @base: pointer to the timer base (per cpu and per clock)
303e967f	99	* @state: state information (See bit values above)
54cdfdb4 TG	100	* @cb_mode: high resolution timer feature to select the callback execution
	101	* mode
	102	* @cb_entry: list head to enqueue an expired timer into the callback list
	103	* @start_site: timer statistics field to store the site where the timer
	104	* was started
	105	* @start_comm: timer statistics field to store the name of the process which
	106	* started the timer
	107	* @start_pid: timer statistics field to store the pid of the task which
	108	* started the timer
c0a31329	109	*
54cdfdb4	110	* The hrtimer structure must be initialized by hrtimer_init()
c0a31329 TG	111	*/
c0a31329 TG	112	struct hrtimer {
3c8aa39d	113	struct rb_node node;
799b64de	114	ktime_t _expires;
654c8e0b	115	ktime_t _softexpires;
3c8aa39d TG	116	enum hrtimer_restart (function)(struct hrtimer );
3c8aa39d TG	117	struct hrtimer_clock_base *base;
303e967f	118	unsigned long state;
54cdfdb4 TG	119	enum hrtimer_cb_mode cb_mode;
54cdfdb4 TG	120	struct list_head cb_entry;
82f67cd9 IM	121	#ifdef CONFIG_TIMER_STATS
	122	void *start_site;
	123	char start_comm[16];
	124	int start_pid;
	125	#endif
c0a31329 TG	126	};
c0a31329 TG	127
00362e33 TG	128	/**
00362e33 TG	129	* struct hrtimer_sleeper - simple sleeper structure
00362e33 TG	130	* @timer: embedded timer structure
	131	* @task: task to wake up
	132	*
	133	* task is set to NULL, when the timer expires.
	134	*/
	135	struct hrtimer_sleeper {
	136	struct hrtimer timer;
	137	struct task_struct *task;
	138	};
	139
c0a31329	140	/**
d1d67174	141	* struct hrtimer_clock_base - the timer base for a specific clock
05fb6bf0	142	* @cpu_base: per cpu clock base
3c8aa39d TG	143	* @index: clock type index for per_cpu support when moving a
3c8aa39d TG	144	* timer to a base on another cpu.
92127c7a TG	145	* @active: red black tree root node for the active timers
	146	* @first: pointer to the timer node which expires first
	147	* @resolution: the resolution of the clock, in nanoseconds
	148	* @get_time: function to retrieve the current time of the clock
a580290c	149	* @get_softirq_time: function to retrieve the current time from the softirq
92127c7a	150	* @softirq_time: the time when running the hrtimer queue in the softirq
54cdfdb4 TG	151	* @offset: offset of this clock to the monotonic base
54cdfdb4 TG	152	* @reprogram: function to reprogram the timer event
c0a31329	153	*/
3c8aa39d TG	154	struct hrtimer_clock_base {
3c8aa39d TG	155	struct hrtimer_cpu_base *cpu_base;
c0a31329	156	clockid_t index;
c0a31329	157	struct rb_root active;
288867ec	158	struct rb_node *first;
e2787630	159	ktime_t resolution;
c0a31329	160	ktime_t (*get_time)(void);
92127c7a	161	ktime_t (*get_softirq_time)(void);
92127c7a	162	ktime_t softirq_time;
54cdfdb4 TG	163	#ifdef CONFIG_HIGH_RES_TIMERS
	164	ktime_t offset;
	165	int (reprogram)(struct hrtimer t,
	166	struct hrtimer_clock_base *b,
	167	ktime_t n);
	168	#endif
3c8aa39d TG	169	};
	170
	171	#define HRTIMER_MAX_CLOCK_BASES 2
	172
	173	/*
	174	* struct hrtimer_cpu_base - the per cpu clock bases
	175	* @lock: lock protecting the base and associated clock bases
	176	* and timers
3c8aa39d TG	177	* @clock_base: array of clock bases for this cpu
3c8aa39d TG	178	* @curr_timer: the timer which is executing a callback right now
54cdfdb4 TG	179	* @expires_next: absolute time of the next event which was scheduled
	180	* via clock_set_next_event()
	181	* @hres_active: State of high resolution mode
	182	* @check_clocks: Indictator, when set evaluate time source and clock
	183	* event devices whether high resolution mode can be
	184	* activated.
	185	* @cb_pending: Expired timers are moved from the rbtree to this
	186	* list in the timer interrupt. The list is processed
	187	* in the softirq.
	188	* @nr_events: Total number of timer interrupt events
3c8aa39d TG	189	*/
	190	struct hrtimer_cpu_base {
	191	spinlock_t lock;
3c8aa39d	192	struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
d3d74453	193	struct list_head cb_pending;
54cdfdb4 TG	194	#ifdef CONFIG_HIGH_RES_TIMERS
	195	ktime_t expires_next;
	196	int hres_active;
54cdfdb4 TG	197	unsigned long nr_events;
54cdfdb4 TG	198	#endif
c0a31329 TG	199	};
c0a31329 TG	200
63ca243b AV	201	static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
63ca243b AV	202	{
799b64de	203	timer->_expires = time;
654c8e0b	204	timer->_softexpires = time;
63ca243b	205	}
654c8e0b AV	206
	207	static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
	208	{
	209	timer->_softexpires = time;
	210	timer->_expires = ktime_add_safe(time, delta);
	211	}
	212
	213	static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta)
	214	{
	215	timer->_softexpires = time;
	216	timer->_expires = ktime_add_safe(time, ns_to_ktime(delta));
	217	}
	218
63ca243b AV	219	static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
63ca243b AV	220	{
799b64de	221	timer->_expires.tv64 = tv64;
654c8e0b	222	timer->_softexpires.tv64 = tv64;
63ca243b AV	223	}
	224
	225	static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
	226	{
799b64de	227	timer->_expires = ktime_add_safe(timer->_expires, time);
654c8e0b	228	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
63ca243b AV	229	}
	230
	231	static inline void hrtimer_add_expires_ns(struct hrtimer *timer, unsigned long ns)
	232	{
799b64de	233	timer->_expires = ktime_add_ns(timer->_expires, ns);
654c8e0b	234	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
63ca243b AV	235	}
	236
	237	static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
	238	{
799b64de	239	return timer->_expires;
63ca243b AV	240	}
63ca243b AV	241
654c8e0b AV	242	static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
	243	{
	244	return timer->_softexpires;
	245	}
	246
63ca243b AV	247	static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
63ca243b AV	248	{
799b64de	249	return timer->_expires.tv64;
63ca243b	250	}
654c8e0b AV	251	static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
	252	{
	253	return timer->_softexpires.tv64;
	254	}
63ca243b AV	255
	256	static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
	257	{
799b64de	258	return ktime_to_ns(timer->_expires);
63ca243b AV	259	}
	260
	261	static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
	262	{
799b64de	263	return ktime_sub(timer->_expires, timer->base->get_time());
63ca243b AV	264	}
63ca243b AV	265
584fb4a7 AV	266	#ifdef CONFIG_HIGH_RES_TIMERS
	267	struct clock_event_device;
	268
	269	extern void clock_was_set(void);
	270	extern void hres_timers_resume(void);
	271	extern void hrtimer_interrupt(struct clock_event_device *dev);
	272
2ec02270 AV	273	/*
	274	* In high resolution mode the time reference must be read accurate
	275	*/
	276	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	277	{
	278	return timer->base->get_time();
	279	}
	280
	281	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	282	{
	283	return timer->base->cpu_base->hres_active;
	284	}
	285
54cdfdb4 TG	286	/*
	287	* The resolution of the clocks. The resolution value is returned in
	288	* the clock_getres() system call to give application programmers an
	289	* idea of the (in)accuracy of timers. Timer values are rounded up to
	290	* this resolution values.
	291	*/
151db1fc TB	292	# define HIGH_RES_NSEC 1
	293	# define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC }
	294	# define MONOTONIC_RES_NSEC HIGH_RES_NSEC
54cdfdb4 TG	295	# define KTIME_MONOTONIC_RES KTIME_HIGH_RES
	296
	297	#else
	298
151db1fc	299	# define MONOTONIC_RES_NSEC LOW_RES_NSEC
54cdfdb4 TG	300	# define KTIME_MONOTONIC_RES KTIME_LOW_RES
54cdfdb4 TG	301
becf8b5d TG	302	/*
	303	* clock_was_set() is a NOP for non- high-resolution systems. The
	304	* time-sorted order guarantees that a timer does not expire early and
	305	* is expired in the next softirq when the clock was advanced.
	306	*/
54cdfdb4 TG	307	static inline void clock_was_set(void) { }
54cdfdb4 TG	308
995f054f IM	309	static inline void hres_timers_resume(void) { }
995f054f IM	310
54cdfdb4 TG	311	/*
	312	* In non high resolution mode the time reference is taken from
	313	* the base softirq time variable.
	314	*/
	315	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	316	{
	317	return timer->base->softirq_time;
	318	}
	319
8f4d37ec PZ	320	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	321	{
	322	return 0;
	323	}
54cdfdb4 TG	324	#endif
54cdfdb4 TG	325
d316c57f TG	326	extern ktime_t ktime_get(void);
d316c57f TG	327	extern ktime_t ktime_get_real(void);
becf8b5d	328
c0a31329 TG	329	/* Exported timer functions: */
	330
	331	/* Initialize timers: */
7978672c GA	332	extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
7978672c GA	333	enum hrtimer_mode mode);
c0a31329	334
237fc6e7 TG	335	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
	336	extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
	337	enum hrtimer_mode mode);
	338
	339	extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
	340	#else
	341	static inline void hrtimer_init_on_stack(struct hrtimer *timer,
	342	clockid_t which_clock,
	343	enum hrtimer_mode mode)
	344	{
	345	hrtimer_init(timer, which_clock, mode);
	346	}
	347	static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
	348	#endif
	349
c0a31329 TG	350	/* Basic timer operations: */
	351	extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
	352	const enum hrtimer_mode mode);
da8f2e17 AV	353	extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
da8f2e17 AV	354	unsigned long range_ns, const enum hrtimer_mode mode);
c0a31329 TG	355	extern int hrtimer_cancel(struct hrtimer *timer);
	356	extern int hrtimer_try_to_cancel(struct hrtimer *timer);
	357
63ca243b AV	358	static inline int hrtimer_start_expires(struct hrtimer *timer,
	359	enum hrtimer_mode mode)
	360	{
da8f2e17 AV	361	unsigned long delta;
	362	ktime_t soft, hard;
	363	soft = hrtimer_get_softexpires(timer);
	364	hard = hrtimer_get_expires(timer);
	365	delta = ktime_to_ns(ktime_sub(hard, soft));
	366	return hrtimer_start_range_ns(timer, hrtimer_get_expires(timer), delta, mode);
63ca243b AV	367	}
63ca243b AV	368
c9cb2e3d TG	369	static inline int hrtimer_restart(struct hrtimer *timer)
c9cb2e3d TG	370	{
654c8e0b	371	return hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
c9cb2e3d	372	}
c0a31329 TG	373
	374	/* Query timers: */
	375	extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
	376	extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
	377
69239749	378	extern ktime_t hrtimer_get_next_event(void);
69239749	379
303e967f TG	380	/*
	381	* A timer is active, when it is enqueued into the rbtree or the callback
	382	* function is running.
	383	*/
c0a31329 TG	384	static inline int hrtimer_active(const struct hrtimer *timer)
c0a31329 TG	385	{
303e967f	386	return timer->state != HRTIMER_STATE_INACTIVE;
c0a31329 TG	387	}
c0a31329 TG	388
54cdfdb4 TG	389	/*
	390	* Helper function to check, whether the timer is on one of the queues
	391	*/
	392	static inline int hrtimer_is_queued(struct hrtimer *timer)
	393	{
	394	return timer->state &
	395	(HRTIMER_STATE_ENQUEUED \| HRTIMER_STATE_PENDING);
	396	}
	397
4346f654 OH	398	/*
	399	* Helper function to check, whether the timer is running the callback
	400	* function
	401	*/
	402	static inline int hrtimer_callback_running(struct hrtimer *timer)
	403	{
	404	return timer->state & HRTIMER_STATE_CALLBACK;
	405	}
	406
c0a31329	407	/* Forward a hrtimer so it expires after now: */
4d672e7a	408	extern u64
44f21475	409	hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
c0a31329	410
5e05ad7d	411	/* Forward a hrtimer so it expires after the hrtimer's current now */
4d672e7a DL	412	static inline u64 hrtimer_forward_now(struct hrtimer *timer,
4d672e7a DL	413	ktime_t interval)
5e05ad7d DL	414	{
	415	return hrtimer_forward(timer, timer->base->get_time(), interval);
	416	}
	417
10c94ec1 TG	418	/* Precise sleep: */
10c94ec1 TG	419	extern long hrtimer_nanosleep(struct timespec *rqtp,
080344b9	420	struct timespec __user *rmtp,
10c94ec1 TG	421	const enum hrtimer_mode mode,
10c94ec1 TG	422	const clockid_t clockid);
1711ef38	423	extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
10c94ec1	424
00362e33 TG	425	extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
	426	struct task_struct *tsk);
	427
654c8e0b AV	428	extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
654c8e0b AV	429	const enum hrtimer_mode mode);
7bb67439 AV	430	extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
7bb67439 AV	431
c0a31329 TG	432	/* Soft interrupt function to run the hrtimer queues: */
c0a31329 TG	433	extern void hrtimer_run_queues(void);
d3d74453	434	extern void hrtimer_run_pending(void);
c0a31329 TG	435
	436	/* Bootup initialization: */
	437	extern void __init hrtimers_init(void);
	438
79bf2bb3	439	#if BITS_PER_LONG < 64
4d672e7a	440	extern u64 ktime_divns(const ktime_t kt, s64 div);
79bf2bb3	441	#else /* BITS_PER_LONG < 64 */
4d672e7a	442	# define ktime_divns(kt, div) (u64)((kt).tv64 / (div))
79bf2bb3 TG	443	#endif
79bf2bb3 TG	444
88ad0bf6 IM	445	/* Show pending timers: */
	446	extern void sysrq_timer_list_show(void);
	447
82f67cd9 IM	448	/*
	449	* Timer-statistics info:
	450	*/
	451	#ifdef CONFIG_TIMER_STATS
	452
	453	extern void timer_stats_update_stats(void timer, pid_t pid, void startf,
c5c061b8 VP	454	void timerf, char comm,
c5c061b8 VP	455	unsigned int timer_flag);
82f67cd9 IM	456
	457	static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
	458	{
	459	timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
c5c061b8	460	timer->function, timer->start_comm, 0);
82f67cd9 IM	461	}
	462
	463	extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,
	464	void *addr);
	465
	466	static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
	467	{
	468	__timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
	469	}
	470
	471	static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
	472	{
	473	timer->start_site = NULL;
	474	}
	475	#else
	476	static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
	477	{
	478	}
	479
	480	static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
	481	{
	482	}
	483
	484	static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
	485	{
	486	}
	487	#endif
	488
c0a31329	489	#endif