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v5.9
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  hrtimers - High-resolution kernel timers
  4 *
  5 *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
  6 *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
  7 *
  8 *  data type definitions, declarations, prototypes
  9 *
 10 *  Started by: Thomas Gleixner and Ingo Molnar
 11 */
 12#ifndef _LINUX_HRTIMER_H
 13#define _LINUX_HRTIMER_H
 14
 15#include <linux/hrtimer_defs.h>
 16#include <linux/rbtree.h>
 17#include <linux/init.h>
 18#include <linux/list.h>
 19#include <linux/percpu.h>
 20#include <linux/seqlock.h>
 21#include <linux/timer.h>
 22#include <linux/timerqueue.h>
 23
 24struct hrtimer_clock_base;
 25struct hrtimer_cpu_base;
 26
 27/*
 28 * Mode arguments of xxx_hrtimer functions:
 29 *
 30 * HRTIMER_MODE_ABS		- Time value is absolute
 31 * HRTIMER_MODE_REL		- Time value is relative to now
 32 * HRTIMER_MODE_PINNED		- Timer is bound to CPU (is only considered
 33 *				  when starting the timer)
 34 * HRTIMER_MODE_SOFT		- Timer callback function will be executed in
 35 *				  soft irq context
 36 * HRTIMER_MODE_HARD		- Timer callback function will be executed in
 37 *				  hard irq context even on PREEMPT_RT.
 38 */
 39enum hrtimer_mode {
 40	HRTIMER_MODE_ABS	= 0x00,
 41	HRTIMER_MODE_REL	= 0x01,
 42	HRTIMER_MODE_PINNED	= 0x02,
 43	HRTIMER_MODE_SOFT	= 0x04,
 44	HRTIMER_MODE_HARD	= 0x08,
 45
 46	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
 47	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
 48
 49	HRTIMER_MODE_ABS_SOFT	= HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,
 50	HRTIMER_MODE_REL_SOFT	= HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,
 51
 52	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
 53	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,
 54
 55	HRTIMER_MODE_ABS_HARD	= HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
 56	HRTIMER_MODE_REL_HARD	= HRTIMER_MODE_REL | HRTIMER_MODE_HARD,
 57
 58	HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD,
 59	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
 60};
 61
 62/*
 63 * Return values for the callback function
 64 */
 65enum hrtimer_restart {
 66	HRTIMER_NORESTART,	/* Timer is not restarted */
 67	HRTIMER_RESTART,	/* Timer must be restarted */
 68};
 69
 70/*
 71 * Values to track state of the timer
 72 *
 73 * Possible states:
 74 *
 75 * 0x00		inactive
 76 * 0x01		enqueued into rbtree
 77 *
 78 * The callback state is not part of the timer->state because clearing it would
 79 * mean touching the timer after the callback, this makes it impossible to free
 80 * the timer from the callback function.
 81 *
 82 * Therefore we track the callback state in:
 83 *
 84 *	timer->base->cpu_base->running == timer
 85 *
 86 * On SMP it is possible to have a "callback function running and enqueued"
 87 * status. It happens for example when a posix timer expired and the callback
 88 * queued a signal. Between dropping the lock which protects the posix timer
 89 * and reacquiring the base lock of the hrtimer, another CPU can deliver the
 90 * signal and rearm the timer.
 91 *
 92 * All state transitions are protected by cpu_base->lock.
 93 */
 94#define HRTIMER_STATE_INACTIVE	0x00
 95#define HRTIMER_STATE_ENQUEUED	0x01
 96
 97/**
 98 * struct hrtimer - the basic hrtimer structure
 99 * @node:	timerqueue node, which also manages node.expires,
100 *		the absolute expiry time in the hrtimers internal
101 *		representation. The time is related to the clock on
102 *		which the timer is based. Is setup by adding
103 *		slack to the _softexpires value. For non range timers
104 *		identical to _softexpires.
105 * @_softexpires: the absolute earliest expiry time of the hrtimer.
106 *		The time which was given as expiry time when the timer
107 *		was armed.
108 * @function:	timer expiry callback function
109 * @base:	pointer to the timer base (per cpu and per clock)
110 * @state:	state information (See bit values above)
111 * @is_rel:	Set if the timer was armed relative
112 * @is_soft:	Set if hrtimer will be expired in soft interrupt context.
113 * @is_hard:	Set if hrtimer will be expired in hard interrupt context
114 *		even on RT.
115 *
116 * The hrtimer structure must be initialized by hrtimer_init()
117 */
118struct hrtimer {
119	struct timerqueue_node		node;
120	ktime_t				_softexpires;
121	enum hrtimer_restart		(*function)(struct hrtimer *);
122	struct hrtimer_clock_base	*base;
123	u8				state;
124	u8				is_rel;
125	u8				is_soft;
126	u8				is_hard;
127};
128
129/**
130 * struct hrtimer_sleeper - simple sleeper structure
131 * @timer:	embedded timer structure
132 * @task:	task to wake up
133 *
134 * task is set to NULL, when the timer expires.
135 */
136struct hrtimer_sleeper {
137	struct hrtimer timer;
138	struct task_struct *task;
139};
140
141#ifdef CONFIG_64BIT
142# define __hrtimer_clock_base_align	____cacheline_aligned
143#else
144# define __hrtimer_clock_base_align
145#endif
146
147/**
148 * struct hrtimer_clock_base - the timer base for a specific clock
149 * @cpu_base:		per cpu clock base
150 * @index:		clock type index for per_cpu support when moving a
151 *			timer to a base on another cpu.
152 * @clockid:		clock id for per_cpu support
153 * @seq:		seqcount around __run_hrtimer
154 * @running:		pointer to the currently running hrtimer
155 * @active:		red black tree root node for the active timers
156 * @get_time:		function to retrieve the current time of the clock
157 * @offset:		offset of this clock to the monotonic base
158 */
159struct hrtimer_clock_base {
160	struct hrtimer_cpu_base	*cpu_base;
161	unsigned int		index;
162	clockid_t		clockid;
163	seqcount_raw_spinlock_t	seq;
164	struct hrtimer		*running;
165	struct timerqueue_head	active;
166	ktime_t			(*get_time)(void);
167	ktime_t			offset;
168} __hrtimer_clock_base_align;
169
170enum  hrtimer_base_type {
171	HRTIMER_BASE_MONOTONIC,
172	HRTIMER_BASE_REALTIME,
173	HRTIMER_BASE_BOOTTIME,
174	HRTIMER_BASE_TAI,
175	HRTIMER_BASE_MONOTONIC_SOFT,
176	HRTIMER_BASE_REALTIME_SOFT,
177	HRTIMER_BASE_BOOTTIME_SOFT,
178	HRTIMER_BASE_TAI_SOFT,
179	HRTIMER_MAX_CLOCK_BASES,
180};
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
186 * @cpu:		cpu number
187 * @active_bases:	Bitfield to mark bases with active timers
188 * @clock_was_set_seq:	Sequence counter of clock was set events
189 * @hres_active:	State of high resolution mode
190 * @in_hrtirq:		hrtimer_interrupt() is currently executing
191 * @hang_detected:	The last hrtimer interrupt detected a hang
192 * @softirq_activated:	displays, if the softirq is raised - update of softirq
193 *			related settings is not required then.
194 * @nr_events:		Total number of hrtimer interrupt events
195 * @nr_retries:		Total number of hrtimer interrupt retries
196 * @nr_hangs:		Total number of hrtimer interrupt hangs
197 * @max_hang_time:	Maximum time spent in hrtimer_interrupt
198 * @softirq_expiry_lock: Lock which is taken while softirq based hrtimer are
199 *			 expired
200 * @timer_waiters:	A hrtimer_cancel() invocation waits for the timer
201 *			callback to finish.
202 * @expires_next:	absolute time of the next event, is required for remote
203 *			hrtimer enqueue; it is the total first expiry time (hard
204 *			and soft hrtimer are taken into account)
205 * @next_timer:		Pointer to the first expiring timer
206 * @softirq_expires_next: Time to check, if soft queues needs also to be expired
207 * @softirq_next_timer: Pointer to the first expiring softirq based timer
208 * @clock_base:		array of clock bases for this cpu
209 *
210 * Note: next_timer is just an optimization for __remove_hrtimer().
211 *	 Do not dereference the pointer because it is not reliable on
212 *	 cross cpu removals.
213 */
214struct hrtimer_cpu_base {
215	raw_spinlock_t			lock;
216	unsigned int			cpu;
217	unsigned int			active_bases;
218	unsigned int			clock_was_set_seq;
219	unsigned int			hres_active		: 1,
220					in_hrtirq		: 1,
221					hang_detected		: 1,
222					softirq_activated       : 1;
223#ifdef CONFIG_HIGH_RES_TIMERS
224	unsigned int			nr_events;
225	unsigned short			nr_retries;
226	unsigned short			nr_hangs;
227	unsigned int			max_hang_time;
228#endif
229#ifdef CONFIG_PREEMPT_RT
230	spinlock_t			softirq_expiry_lock;
231	atomic_t			timer_waiters;
232#endif
233	ktime_t				expires_next;
234	struct hrtimer			*next_timer;
235	ktime_t				softirq_expires_next;
236	struct hrtimer			*softirq_next_timer;
237	struct hrtimer_clock_base	clock_base[HRTIMER_MAX_CLOCK_BASES];
238} ____cacheline_aligned;
239
240static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
241{
242	timer->node.expires = time;
243	timer->_softexpires = time;
244}
245
246static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
247{
248	timer->_softexpires = time;
249	timer->node.expires = ktime_add_safe(time, delta);
250}
251
252static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
253{
254	timer->_softexpires = time;
255	timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
256}
257
258static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
259{
260	timer->node.expires = tv64;
261	timer->_softexpires = tv64;
262}
263
264static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
265{
266	timer->node.expires = ktime_add_safe(timer->node.expires, time);
267	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
268}
269
270static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
271{
272	timer->node.expires = ktime_add_ns(timer->node.expires, ns);
273	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
274}
275
276static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
277{
278	return timer->node.expires;
279}
280
281static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
282{
283	return timer->_softexpires;
284}
285
286static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
287{
288	return timer->node.expires;
289}
290static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
291{
292	return timer->_softexpires;
293}
294
295static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
296{
297	return ktime_to_ns(timer->node.expires);
298}
299
300static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
301{
302	return ktime_sub(timer->node.expires, timer->base->get_time());
303}
304
305static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
306{
307	return timer->base->get_time();
308}
309
310static inline int hrtimer_is_hres_active(struct hrtimer *timer)
311{
312	return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
313		timer->base->cpu_base->hres_active : 0;
314}
315
316#ifdef CONFIG_HIGH_RES_TIMERS
317struct clock_event_device;
318
319extern void hrtimer_interrupt(struct clock_event_device *dev);
320
321extern void clock_was_set_delayed(void);
322
323extern unsigned int hrtimer_resolution;
324
325#else
326
327#define hrtimer_resolution	(unsigned int)LOW_RES_NSEC
328
329static inline void clock_was_set_delayed(void) { }
330
331#endif
332
333static inline ktime_t
334__hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
335{
336	ktime_t rem = ktime_sub(timer->node.expires, now);
337
338	/*
339	 * Adjust relative timers for the extra we added in
340	 * hrtimer_start_range_ns() to prevent short timeouts.
341	 */
342	if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
343		rem -= hrtimer_resolution;
344	return rem;
345}
346
347static inline ktime_t
348hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
349{
350	return __hrtimer_expires_remaining_adjusted(timer,
351						    timer->base->get_time());
352}
353
354extern void clock_was_set(void);
355#ifdef CONFIG_TIMERFD
356extern void timerfd_clock_was_set(void);
 
357#else
358static inline void timerfd_clock_was_set(void) { }
 
359#endif
360extern void hrtimers_resume(void);
361
362DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
363
364#ifdef CONFIG_PREEMPT_RT
365void hrtimer_cancel_wait_running(const struct hrtimer *timer);
366#else
367static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
368{
369	cpu_relax();
370}
371#endif
372
373/* Exported timer functions: */
374
375/* Initialize timers: */
376extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
377			 enum hrtimer_mode mode);
378extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
379				 enum hrtimer_mode mode);
380
381#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
382extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
383				  enum hrtimer_mode mode);
384extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
385					  clockid_t clock_id,
386					  enum hrtimer_mode mode);
387
388extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
389#else
390static inline void hrtimer_init_on_stack(struct hrtimer *timer,
391					 clockid_t which_clock,
392					 enum hrtimer_mode mode)
393{
394	hrtimer_init(timer, which_clock, mode);
395}
396
397static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
398						 clockid_t clock_id,
399						 enum hrtimer_mode mode)
400{
401	hrtimer_init_sleeper(sl, clock_id, mode);
402}
403
404static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
405#endif
406
407/* Basic timer operations: */
408extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
409				   u64 range_ns, const enum hrtimer_mode mode);
410
411/**
412 * hrtimer_start - (re)start an hrtimer
413 * @timer:	the timer to be added
414 * @tim:	expiry time
415 * @mode:	timer mode: absolute (HRTIMER_MODE_ABS) or
416 *		relative (HRTIMER_MODE_REL), and pinned (HRTIMER_MODE_PINNED);
417 *		softirq based mode is considered for debug purpose only!
418 */
419static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
420				 const enum hrtimer_mode mode)
421{
422	hrtimer_start_range_ns(timer, tim, 0, mode);
423}
424
425extern int hrtimer_cancel(struct hrtimer *timer);
426extern int hrtimer_try_to_cancel(struct hrtimer *timer);
427
428static inline void hrtimer_start_expires(struct hrtimer *timer,
429					 enum hrtimer_mode mode)
430{
431	u64 delta;
432	ktime_t soft, hard;
433	soft = hrtimer_get_softexpires(timer);
434	hard = hrtimer_get_expires(timer);
435	delta = ktime_to_ns(ktime_sub(hard, soft));
436	hrtimer_start_range_ns(timer, soft, delta, mode);
437}
438
439void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
440				   enum hrtimer_mode mode);
441
442static inline void hrtimer_restart(struct hrtimer *timer)
443{
444	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
445}
446
447/* Query timers: */
448extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
449
 
 
 
 
450static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
451{
452	return __hrtimer_get_remaining(timer, false);
453}
454
455extern u64 hrtimer_get_next_event(void);
456extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);
457
458extern bool hrtimer_active(const struct hrtimer *timer);
459
460/**
461 * hrtimer_is_queued = check, whether the timer is on one of the queues
462 * @timer:	Timer to check
463 *
464 * Returns: True if the timer is queued, false otherwise
465 *
466 * The function can be used lockless, but it gives only a current snapshot.
467 */
468static inline bool hrtimer_is_queued(struct hrtimer *timer)
469{
470	/* The READ_ONCE pairs with the update functions of timer->state */
471	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
472}
473
474/*
475 * Helper function to check, whether the timer is running the callback
476 * function
477 */
478static inline int hrtimer_callback_running(struct hrtimer *timer)
479{
480	return timer->base->running == timer;
481}
482
483/* Forward a hrtimer so it expires after now: */
484extern u64
485hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
486
487/**
488 * hrtimer_forward_now - forward the timer expiry so it expires after now
489 * @timer:	hrtimer to forward
490 * @interval:	the interval to forward
491 *
492 * Forward the timer expiry so it will expire after the current time
493 * of the hrtimer clock base. Returns the number of overruns.
494 *
495 * Can be safely called from the callback function of @timer. If
496 * called from other contexts @timer must neither be enqueued nor
497 * running the callback and the caller needs to take care of
498 * serialization.
499 *
500 * Note: This only updates the timer expiry value and does not requeue
501 * the timer.
502 */
503static inline u64 hrtimer_forward_now(struct hrtimer *timer,
504				      ktime_t interval)
505{
506	return hrtimer_forward(timer, timer->base->get_time(), interval);
507}
508
509/* Precise sleep: */
510
511extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
512extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
513			      const clockid_t clockid);
514
515extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
516				    const enum hrtimer_mode mode);
517extern int schedule_hrtimeout_range_clock(ktime_t *expires,
518					  u64 delta,
519					  const enum hrtimer_mode mode,
520					  clockid_t clock_id);
521extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
522
523/* Soft interrupt function to run the hrtimer queues: */
524extern void hrtimer_run_queues(void);
525
526/* Bootup initialization: */
527extern void __init hrtimers_init(void);
528
529/* Show pending timers: */
530extern void sysrq_timer_list_show(void);
531
532int hrtimers_prepare_cpu(unsigned int cpu);
533#ifdef CONFIG_HOTPLUG_CPU
534int hrtimers_dead_cpu(unsigned int cpu);
535#else
536#define hrtimers_dead_cpu	NULL
537#endif
538
539#endif
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  hrtimers - High-resolution kernel timers
  4 *
  5 *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
  6 *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
  7 *
  8 *  data type definitions, declarations, prototypes
  9 *
 10 *  Started by: Thomas Gleixner and Ingo Molnar
 11 */
 12#ifndef _LINUX_HRTIMER_H
 13#define _LINUX_HRTIMER_H
 14
 15#include <linux/hrtimer_defs.h>
 16#include <linux/hrtimer_types.h>
 17#include <linux/init.h>
 18#include <linux/list.h>
 19#include <linux/percpu-defs.h>
 20#include <linux/rbtree.h>
 21#include <linux/timer.h>
 
 
 
 
 22
 23/*
 24 * Mode arguments of xxx_hrtimer functions:
 25 *
 26 * HRTIMER_MODE_ABS		- Time value is absolute
 27 * HRTIMER_MODE_REL		- Time value is relative to now
 28 * HRTIMER_MODE_PINNED		- Timer is bound to CPU (is only considered
 29 *				  when starting the timer)
 30 * HRTIMER_MODE_SOFT		- Timer callback function will be executed in
 31 *				  soft irq context
 32 * HRTIMER_MODE_HARD		- Timer callback function will be executed in
 33 *				  hard irq context even on PREEMPT_RT.
 34 */
 35enum hrtimer_mode {
 36	HRTIMER_MODE_ABS	= 0x00,
 37	HRTIMER_MODE_REL	= 0x01,
 38	HRTIMER_MODE_PINNED	= 0x02,
 39	HRTIMER_MODE_SOFT	= 0x04,
 40	HRTIMER_MODE_HARD	= 0x08,
 41
 42	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
 43	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
 44
 45	HRTIMER_MODE_ABS_SOFT	= HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,
 46	HRTIMER_MODE_REL_SOFT	= HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,
 47
 48	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
 49	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,
 50
 51	HRTIMER_MODE_ABS_HARD	= HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
 52	HRTIMER_MODE_REL_HARD	= HRTIMER_MODE_REL | HRTIMER_MODE_HARD,
 53
 54	HRTIMER_MODE_ABS_PINNED_HARD = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_HARD,
 55	HRTIMER_MODE_REL_PINNED_HARD = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_HARD,
 56};
 57
 58/*
 
 
 
 
 
 
 
 
 59 * Values to track state of the timer
 60 *
 61 * Possible states:
 62 *
 63 * 0x00		inactive
 64 * 0x01		enqueued into rbtree
 65 *
 66 * The callback state is not part of the timer->state because clearing it would
 67 * mean touching the timer after the callback, this makes it impossible to free
 68 * the timer from the callback function.
 69 *
 70 * Therefore we track the callback state in:
 71 *
 72 *	timer->base->cpu_base->running == timer
 73 *
 74 * On SMP it is possible to have a "callback function running and enqueued"
 75 * status. It happens for example when a posix timer expired and the callback
 76 * queued a signal. Between dropping the lock which protects the posix timer
 77 * and reacquiring the base lock of the hrtimer, another CPU can deliver the
 78 * signal and rearm the timer.
 79 *
 80 * All state transitions are protected by cpu_base->lock.
 81 */
 82#define HRTIMER_STATE_INACTIVE	0x00
 83#define HRTIMER_STATE_ENQUEUED	0x01
 84
 85/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 86 * struct hrtimer_sleeper - simple sleeper structure
 87 * @timer:	embedded timer structure
 88 * @task:	task to wake up
 89 *
 90 * task is set to NULL, when the timer expires.
 91 */
 92struct hrtimer_sleeper {
 93	struct hrtimer timer;
 94	struct task_struct *task;
 95};
 96
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 97static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
 98{
 99	timer->node.expires = time;
100	timer->_softexpires = time;
101}
102
103static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
104{
105	timer->_softexpires = time;
106	timer->node.expires = ktime_add_safe(time, delta);
107}
108
109static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
110{
111	timer->_softexpires = time;
112	timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
113}
114
115static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
116{
117	timer->node.expires = tv64;
118	timer->_softexpires = tv64;
119}
120
121static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
122{
123	timer->node.expires = ktime_add_safe(timer->node.expires, time);
124	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
125}
126
127static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
128{
129	timer->node.expires = ktime_add_ns(timer->node.expires, ns);
130	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
131}
132
133static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
134{
135	return timer->node.expires;
136}
137
138static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
139{
140	return timer->_softexpires;
141}
142
143static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
144{
145	return timer->node.expires;
146}
147static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
148{
149	return timer->_softexpires;
150}
151
152static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
153{
154	return ktime_to_ns(timer->node.expires);
155}
156
157static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
158{
159	return ktime_sub(timer->node.expires, timer->base->get_time());
160}
161
162static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
163{
164	return timer->base->get_time();
165}
166
167static inline int hrtimer_is_hres_active(struct hrtimer *timer)
168{
169	return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
170		timer->base->cpu_base->hres_active : 0;
171}
172
173#ifdef CONFIG_HIGH_RES_TIMERS
174struct clock_event_device;
175
176extern void hrtimer_interrupt(struct clock_event_device *dev);
177
 
 
178extern unsigned int hrtimer_resolution;
179
180#else
181
182#define hrtimer_resolution	(unsigned int)LOW_RES_NSEC
183
 
 
184#endif
185
186static inline ktime_t
187__hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
188{
189	ktime_t rem = ktime_sub(timer->node.expires, now);
190
191	/*
192	 * Adjust relative timers for the extra we added in
193	 * hrtimer_start_range_ns() to prevent short timeouts.
194	 */
195	if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
196		rem -= hrtimer_resolution;
197	return rem;
198}
199
200static inline ktime_t
201hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
202{
203	return __hrtimer_expires_remaining_adjusted(timer,
204						    timer->base->get_time());
205}
206
 
207#ifdef CONFIG_TIMERFD
208extern void timerfd_clock_was_set(void);
209extern void timerfd_resume(void);
210#else
211static inline void timerfd_clock_was_set(void) { }
212static inline void timerfd_resume(void) { }
213#endif
 
214
215DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
216
217#ifdef CONFIG_PREEMPT_RT
218void hrtimer_cancel_wait_running(const struct hrtimer *timer);
219#else
220static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
221{
222	cpu_relax();
223}
224#endif
225
226/* Exported timer functions: */
227
228/* Initialize timers: */
229extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
230			 enum hrtimer_mode mode);
231extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
232				 enum hrtimer_mode mode);
233
234#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
235extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
236				  enum hrtimer_mode mode);
237extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
238					  clockid_t clock_id,
239					  enum hrtimer_mode mode);
240
241extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
242#else
243static inline void hrtimer_init_on_stack(struct hrtimer *timer,
244					 clockid_t which_clock,
245					 enum hrtimer_mode mode)
246{
247	hrtimer_init(timer, which_clock, mode);
248}
249
250static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
251						 clockid_t clock_id,
252						 enum hrtimer_mode mode)
253{
254	hrtimer_init_sleeper(sl, clock_id, mode);
255}
256
257static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
258#endif
259
260/* Basic timer operations: */
261extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
262				   u64 range_ns, const enum hrtimer_mode mode);
263
264/**
265 * hrtimer_start - (re)start an hrtimer
266 * @timer:	the timer to be added
267 * @tim:	expiry time
268 * @mode:	timer mode: absolute (HRTIMER_MODE_ABS) or
269 *		relative (HRTIMER_MODE_REL), and pinned (HRTIMER_MODE_PINNED);
270 *		softirq based mode is considered for debug purpose only!
271 */
272static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
273				 const enum hrtimer_mode mode)
274{
275	hrtimer_start_range_ns(timer, tim, 0, mode);
276}
277
278extern int hrtimer_cancel(struct hrtimer *timer);
279extern int hrtimer_try_to_cancel(struct hrtimer *timer);
280
281static inline void hrtimer_start_expires(struct hrtimer *timer,
282					 enum hrtimer_mode mode)
283{
284	u64 delta;
285	ktime_t soft, hard;
286	soft = hrtimer_get_softexpires(timer);
287	hard = hrtimer_get_expires(timer);
288	delta = ktime_to_ns(ktime_sub(hard, soft));
289	hrtimer_start_range_ns(timer, soft, delta, mode);
290}
291
292void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
293				   enum hrtimer_mode mode);
294
295static inline void hrtimer_restart(struct hrtimer *timer)
296{
297	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
298}
299
300/* Query timers: */
301extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
302
303/**
304 * hrtimer_get_remaining - get remaining time for the timer
305 * @timer:	the timer to read
306 */
307static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
308{
309	return __hrtimer_get_remaining(timer, false);
310}
311
312extern u64 hrtimer_get_next_event(void);
313extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);
314
315extern bool hrtimer_active(const struct hrtimer *timer);
316
317/**
318 * hrtimer_is_queued - check, whether the timer is on one of the queues
319 * @timer:	Timer to check
320 *
321 * Returns: True if the timer is queued, false otherwise
322 *
323 * The function can be used lockless, but it gives only a current snapshot.
324 */
325static inline bool hrtimer_is_queued(struct hrtimer *timer)
326{
327	/* The READ_ONCE pairs with the update functions of timer->state */
328	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
329}
330
331/*
332 * Helper function to check, whether the timer is running the callback
333 * function
334 */
335static inline int hrtimer_callback_running(struct hrtimer *timer)
336{
337	return timer->base->running == timer;
338}
339
340/* Forward a hrtimer so it expires after now: */
341extern u64
342hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
343
344/**
345 * hrtimer_forward_now() - forward the timer expiry so it expires after now
346 * @timer:	hrtimer to forward
347 * @interval:	the interval to forward
348 *
349 * It is a variant of hrtimer_forward(). The timer will expire after the current
350 * time of the hrtimer clock base. See hrtimer_forward() for details.
 
 
 
 
 
 
 
 
351 */
352static inline u64 hrtimer_forward_now(struct hrtimer *timer,
353				      ktime_t interval)
354{
355	return hrtimer_forward(timer, timer->base->get_time(), interval);
356}
357
358/* Precise sleep: */
359
360extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
361extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
362			      const clockid_t clockid);
363
364extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
365				    const enum hrtimer_mode mode);
366extern int schedule_hrtimeout_range_clock(ktime_t *expires,
367					  u64 delta,
368					  const enum hrtimer_mode mode,
369					  clockid_t clock_id);
370extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
371
372/* Soft interrupt function to run the hrtimer queues: */
373extern void hrtimer_run_queues(void);
374
375/* Bootup initialization: */
376extern void __init hrtimers_init(void);
377
378/* Show pending timers: */
379extern void sysrq_timer_list_show(void);
380
381int hrtimers_prepare_cpu(unsigned int cpu);
382#ifdef CONFIG_HOTPLUG_CPU
383int hrtimers_cpu_dying(unsigned int cpu);
384#else
385#define hrtimers_cpu_dying	NULL
386#endif
387
388#endif