[deliverable/linux.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_PERCPU:	Callback must run in hardirq context
 *					Special mode for tick emulation and
 *					scheduler timer. Such timers are per
 *					cpu and not allowed to be migrated on
 *					cpu unplug.
 *	HRTIMER_CB_IRQSAFE_UNLOCKED:	Callback should run in hardirq context
 *					with timer->base lock unlocked
 *					used for timers which call wakeup to
 *					avoid lock order problems with rq->lock
 */
enum hrtimer_cb_mode {
	HRTIMER_CB_SOFTIRQ,
	HRTIMER_CB_IRQSAFE,
	HRTIMER_CB_IRQSAFE_NO_RESTART,
	HRTIMER_CB_IRQSAFE_PERCPU,
	HRTIMER_CB_IRQSAFE_UNLOCKED,
};

/*
 * 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 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_PENDING	0x04
#define HRTIMER_STATE_MIGRATE	0x08

/**
 * 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;
	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
};

#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_cancel(struct hrtimer *timer);
extern int hrtimer_try_to_cancel(struct hrtimer *timer);

static inline int hrtimer_restart(struct hrtimer *timer)
{
	return hrtimer_start(timer, timer->expires, 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);

/* 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
ccc7dadf TG	50	* HRTIMER_CB_IRQSAFE_PERCPU: Callback must run in hardirq context
	51	* Special mode for tick emulation and
	52	* scheduler timer. Such timers are per
	53	* cpu and not allowed to be migrated on
	54	* cpu unplug.
	55	* HRTIMER_CB_IRQSAFE_UNLOCKED: Callback should run in hardirq context
	56	* with timer->base lock unlocked
	57	* used for timers which call wakeup to
	58	* avoid lock order problems with rq->lock
54cdfdb4 TG	59	*/
	60	enum hrtimer_cb_mode {
	61	HRTIMER_CB_SOFTIRQ,
	62	HRTIMER_CB_IRQSAFE,
	63	HRTIMER_CB_IRQSAFE_NO_RESTART,
ccc7dadf TG	64	HRTIMER_CB_IRQSAFE_PERCPU,
ccc7dadf TG	65	HRTIMER_CB_IRQSAFE_UNLOCKED,
54cdfdb4 TG	66	};
	67
	68	/*
	69	* Values to track state of the timer
303e967f TG	70	*
	71	* Possible states:
	72	*
	73	* 0x00 inactive
	74	* 0x01 enqueued into rbtree
	75	* 0x02 callback function running
54cdfdb4 TG	76	* 0x04 callback pending (high resolution mode)
54cdfdb4 TG	77	*
b00c1a99	78	* Special cases:
303e967f TG	79	* 0x03 callback function running and enqueued
303e967f TG	80	* (was requeued on another CPU)
b00c1a99	81	* 0x09 timer was migrated on CPU hotunplug
303e967f TG	82	* The "callback function running and enqueued" status is only possible on
	83	* SMP. It happens for example when a posix timer expired and the callback
	84	* queued a signal. Between dropping the lock which protects the posix timer
	85	* and reacquiring the base lock of the hrtimer, another CPU can deliver the
	86	* signal and rearm the timer. We have to preserve the callback running state,
	87	* as otherwise the timer could be removed before the softirq code finishes the
	88	* the handling of the timer.
	89	*
3eb05676	90	* The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to
303e967f TG	91	* preserve the HRTIMER_STATE_CALLBACK bit in the above scenario.
	92	*
	93	* All state transitions are protected by cpu_base->lock.
	94	*/
	95	#define HRTIMER_STATE_INACTIVE 0x00
	96	#define HRTIMER_STATE_ENQUEUED 0x01
	97	#define HRTIMER_STATE_CALLBACK 0x02
54cdfdb4	98	#define HRTIMER_STATE_PENDING 0x04
b00c1a99	99	#define HRTIMER_STATE_MIGRATE 0x08
303e967f	100
c0a31329 TG	101	/**
c0a31329 TG	102	* struct hrtimer - the basic hrtimer structure
c0a31329	103	* @node: red black tree node for time ordered insertion
c0a31329 TG	104	* @expires: the absolute expiry time in the hrtimers internal
	105	* representation. The time is related to the clock on
	106	* which the timer is based.
c0a31329	107	* @function: timer expiry callback function
c0a31329	108	* @base: pointer to the timer base (per cpu and per clock)
303e967f	109	* @state: state information (See bit values above)
54cdfdb4 TG	110	* @cb_mode: high resolution timer feature to select the callback execution
	111	* mode
	112	* @cb_entry: list head to enqueue an expired timer into the callback list
	113	* @start_site: timer statistics field to store the site where the timer
	114	* was started
	115	* @start_comm: timer statistics field to store the name of the process which
	116	* started the timer
	117	* @start_pid: timer statistics field to store the pid of the task which
	118	* started the timer
c0a31329	119	*
54cdfdb4	120	* The hrtimer structure must be initialized by hrtimer_init()
c0a31329 TG	121	*/
c0a31329 TG	122	struct hrtimer {
3c8aa39d TG	123	struct rb_node node;
	124	ktime_t expires;
	125	enum hrtimer_restart (function)(struct hrtimer );
	126	struct hrtimer_clock_base *base;
303e967f	127	unsigned long state;
54cdfdb4 TG	128	enum hrtimer_cb_mode cb_mode;
54cdfdb4 TG	129	struct list_head cb_entry;
82f67cd9 IM	130	#ifdef CONFIG_TIMER_STATS
	131	void *start_site;
	132	char start_comm[16];
	133	int start_pid;
	134	#endif
c0a31329 TG	135	};
c0a31329 TG	136
00362e33 TG	137	/**
00362e33 TG	138	* struct hrtimer_sleeper - simple sleeper structure
00362e33 TG	139	* @timer: embedded timer structure
	140	* @task: task to wake up
	141	*
	142	* task is set to NULL, when the timer expires.
	143	*/
	144	struct hrtimer_sleeper {
	145	struct hrtimer timer;
	146	struct task_struct *task;
	147	};
	148
c0a31329	149	/**
d1d67174	150	* struct hrtimer_clock_base - the timer base for a specific clock
05fb6bf0	151	* @cpu_base: per cpu clock base
3c8aa39d TG	152	* @index: clock type index for per_cpu support when moving a
3c8aa39d TG	153	* timer to a base on another cpu.
92127c7a TG	154	* @active: red black tree root node for the active timers
	155	* @first: pointer to the timer node which expires first
	156	* @resolution: the resolution of the clock, in nanoseconds
	157	* @get_time: function to retrieve the current time of the clock
a580290c	158	* @get_softirq_time: function to retrieve the current time from the softirq
92127c7a	159	* @softirq_time: the time when running the hrtimer queue in the softirq
54cdfdb4 TG	160	* @offset: offset of this clock to the monotonic base
54cdfdb4 TG	161	* @reprogram: function to reprogram the timer event
c0a31329	162	*/
3c8aa39d TG	163	struct hrtimer_clock_base {
3c8aa39d TG	164	struct hrtimer_cpu_base *cpu_base;
c0a31329	165	clockid_t index;
c0a31329	166	struct rb_root active;
288867ec	167	struct rb_node *first;
e2787630	168	ktime_t resolution;
c0a31329	169	ktime_t (*get_time)(void);
92127c7a	170	ktime_t (*get_softirq_time)(void);
92127c7a	171	ktime_t softirq_time;
54cdfdb4 TG	172	#ifdef CONFIG_HIGH_RES_TIMERS
	173	ktime_t offset;
	174	int (reprogram)(struct hrtimer t,
	175	struct hrtimer_clock_base *b,
	176	ktime_t n);
	177	#endif
3c8aa39d TG	178	};
	179
	180	#define HRTIMER_MAX_CLOCK_BASES 2
	181
	182	/*
	183	* struct hrtimer_cpu_base - the per cpu clock bases
	184	* @lock: lock protecting the base and associated clock bases
	185	* and timers
3c8aa39d TG	186	* @clock_base: array of clock bases for this cpu
3c8aa39d TG	187	* @curr_timer: the timer which is executing a callback right now
54cdfdb4 TG	188	* @expires_next: absolute time of the next event which was scheduled
	189	* via clock_set_next_event()
	190	* @hres_active: State of high resolution mode
	191	* @check_clocks: Indictator, when set evaluate time source and clock
	192	* event devices whether high resolution mode can be
	193	* activated.
	194	* @cb_pending: Expired timers are moved from the rbtree to this
	195	* list in the timer interrupt. The list is processed
	196	* in the softirq.
	197	* @nr_events: Total number of timer interrupt events
3c8aa39d TG	198	*/
	199	struct hrtimer_cpu_base {
	200	spinlock_t lock;
3c8aa39d	201	struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
d3d74453	202	struct list_head cb_pending;
54cdfdb4 TG	203	#ifdef CONFIG_HIGH_RES_TIMERS
	204	ktime_t expires_next;
	205	int hres_active;
54cdfdb4 TG	206	unsigned long nr_events;
54cdfdb4 TG	207	#endif
c0a31329 TG	208	};
c0a31329 TG	209
54cdfdb4 TG	210	#ifdef CONFIG_HIGH_RES_TIMERS
	211	struct clock_event_device;
	212
	213	extern void clock_was_set(void);
995f054f	214	extern void hres_timers_resume(void);
54cdfdb4 TG	215	extern void hrtimer_interrupt(struct clock_event_device *dev);
	216
	217	/*
	218	* In high resolution mode the time reference must be read accurate
	219	*/
	220	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	221	{
	222	return timer->base->get_time();
	223	}
	224
8f4d37ec PZ	225	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	226	{
	227	return timer->base->cpu_base->hres_active;
	228	}
	229
54cdfdb4 TG	230	/*
	231	* The resolution of the clocks. The resolution value is returned in
	232	* the clock_getres() system call to give application programmers an
	233	* idea of the (in)accuracy of timers. Timer values are rounded up to
	234	* this resolution values.
	235	*/
151db1fc TB	236	# define HIGH_RES_NSEC 1
	237	# define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC }
	238	# define MONOTONIC_RES_NSEC HIGH_RES_NSEC
54cdfdb4 TG	239	# define KTIME_MONOTONIC_RES KTIME_HIGH_RES
	240
	241	#else
	242
151db1fc	243	# define MONOTONIC_RES_NSEC LOW_RES_NSEC
54cdfdb4 TG	244	# define KTIME_MONOTONIC_RES KTIME_LOW_RES
54cdfdb4 TG	245
becf8b5d TG	246	/*
	247	* clock_was_set() is a NOP for non- high-resolution systems. The
	248	* time-sorted order guarantees that a timer does not expire early and
	249	* is expired in the next softirq when the clock was advanced.
	250	*/
54cdfdb4 TG	251	static inline void clock_was_set(void) { }
54cdfdb4 TG	252
995f054f IM	253	static inline void hres_timers_resume(void) { }
995f054f IM	254
54cdfdb4 TG	255	/*
	256	* In non high resolution mode the time reference is taken from
	257	* the base softirq time variable.
	258	*/
	259	static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
	260	{
	261	return timer->base->softirq_time;
	262	}
	263
8f4d37ec PZ	264	static inline int hrtimer_is_hres_active(struct hrtimer *timer)
	265	{
	266	return 0;
	267	}
54cdfdb4 TG	268	#endif
54cdfdb4 TG	269
d316c57f TG	270	extern ktime_t ktime_get(void);
d316c57f TG	271	extern ktime_t ktime_get_real(void);
becf8b5d	272
c0a31329 TG	273	/* Exported timer functions: */
	274
	275	/* Initialize timers: */
7978672c GA	276	extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
7978672c GA	277	enum hrtimer_mode mode);
c0a31329	278
237fc6e7 TG	279	#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
	280	extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
	281	enum hrtimer_mode mode);
	282
	283	extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
	284	#else
	285	static inline void hrtimer_init_on_stack(struct hrtimer *timer,
	286	clockid_t which_clock,
	287	enum hrtimer_mode mode)
	288	{
	289	hrtimer_init(timer, which_clock, mode);
	290	}
	291	static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
	292	#endif
	293
c0a31329 TG	294	/* Basic timer operations: */
	295	extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
	296	const enum hrtimer_mode mode);
	297	extern int hrtimer_cancel(struct hrtimer *timer);
	298	extern int hrtimer_try_to_cancel(struct hrtimer *timer);
	299
c9cb2e3d TG	300	static inline int hrtimer_restart(struct hrtimer *timer)
	301	{
	302	return hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
	303	}
c0a31329 TG	304
	305	/* Query timers: */
	306	extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
	307	extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
	308
69239749	309	extern ktime_t hrtimer_get_next_event(void);
69239749	310
303e967f TG	311	/*
	312	* A timer is active, when it is enqueued into the rbtree or the callback
	313	* function is running.
	314	*/
c0a31329 TG	315	static inline int hrtimer_active(const struct hrtimer *timer)
c0a31329 TG	316	{
303e967f	317	return timer->state != HRTIMER_STATE_INACTIVE;
c0a31329 TG	318	}
c0a31329 TG	319
54cdfdb4 TG	320	/*
	321	* Helper function to check, whether the timer is on one of the queues
	322	*/
	323	static inline int hrtimer_is_queued(struct hrtimer *timer)
	324	{
	325	return timer->state &
	326	(HRTIMER_STATE_ENQUEUED \| HRTIMER_STATE_PENDING);
	327	}
	328
4346f654 OH	329	/*
	330	* Helper function to check, whether the timer is running the callback
	331	* function
	332	*/
	333	static inline int hrtimer_callback_running(struct hrtimer *timer)
	334	{
	335	return timer->state & HRTIMER_STATE_CALLBACK;
	336	}
	337
c0a31329	338	/* Forward a hrtimer so it expires after now: */
4d672e7a	339	extern u64
44f21475	340	hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
c0a31329	341
5e05ad7d	342	/* Forward a hrtimer so it expires after the hrtimer's current now */
4d672e7a DL	343	static inline u64 hrtimer_forward_now(struct hrtimer *timer,
4d672e7a DL	344	ktime_t interval)
5e05ad7d DL	345	{
	346	return hrtimer_forward(timer, timer->base->get_time(), interval);
	347	}
	348
10c94ec1 TG	349	/* Precise sleep: */
10c94ec1 TG	350	extern long hrtimer_nanosleep(struct timespec *rqtp,
080344b9	351	struct timespec __user *rmtp,
10c94ec1 TG	352	const enum hrtimer_mode mode,
10c94ec1 TG	353	const clockid_t clockid);
1711ef38	354	extern long hrtimer_nanosleep_restart(struct restart_block *restart_block);
10c94ec1	355
00362e33 TG	356	extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
	357	struct task_struct *tsk);
	358
c0a31329 TG	359	/* Soft interrupt function to run the hrtimer queues: */
c0a31329 TG	360	extern void hrtimer_run_queues(void);
d3d74453	361	extern void hrtimer_run_pending(void);
c0a31329 TG	362
	363	/* Bootup initialization: */
	364	extern void __init hrtimers_init(void);
	365
79bf2bb3	366	#if BITS_PER_LONG < 64
4d672e7a	367	extern u64 ktime_divns(const ktime_t kt, s64 div);
79bf2bb3	368	#else /* BITS_PER_LONG < 64 */
4d672e7a	369	# define ktime_divns(kt, div) (u64)((kt).tv64 / (div))
79bf2bb3 TG	370	#endif
79bf2bb3 TG	371
88ad0bf6 IM	372	/* Show pending timers: */
	373	extern void sysrq_timer_list_show(void);
	374
82f67cd9 IM	375	/*
	376	* Timer-statistics info:
	377	*/
	378	#ifdef CONFIG_TIMER_STATS
	379
	380	extern void timer_stats_update_stats(void timer, pid_t pid, void startf,
c5c061b8 VP	381	void timerf, char comm,
c5c061b8 VP	382	unsigned int timer_flag);
82f67cd9 IM	383
	384	static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
	385	{
	386	timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
c5c061b8	387	timer->function, timer->start_comm, 0);
82f67cd9 IM	388	}
	389
	390	extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,
	391	void *addr);
	392
	393	static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
	394	{
	395	__timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
	396	}
	397
	398	static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
	399	{
	400	timer->start_site = NULL;
	401	}
	402	#else
	403	static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
	404	{
	405	}
	406
	407	static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
	408	{
	409	}
	410
	411	static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
	412	{
	413	}
	414	#endif
	415
c0a31329	416	#endif