1 // SPDX-License-Identifier: GPL-2.0
3 * hrtimers - High-resolution kernel timers
5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
6 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
8 * data type definitions, declarations, prototypes
10 * Started by: Thomas Gleixner and Ingo Molnar
12 #ifndef _LINUX_HRTIMER_H
13 #define _LINUX_HRTIMER_H
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>
24 * Mode arguments of xxx_hrtimer functions:
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
32 * HRTIMER_MODE_HARD - Timer callback function will be executed in
33 * hard irq context even on PREEMPT_RT.
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,
42 HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
43 HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
45 HRTIMER_MODE_ABS_SOFT = HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,
46 HRTIMER_MODE_REL_SOFT = HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,
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,
51 HRTIMER_MODE_ABS_HARD = HRTIMER_MODE_ABS | HRTIMER_MODE_HARD,
52 HRTIMER_MODE_REL_HARD = HRTIMER_MODE_REL | HRTIMER_MODE_HARD,
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,
59 * Values to track state of the timer
64 * 0x01 enqueued into rbtree
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.
70 * Therefore we track the callback state in:
72 * timer->base->cpu_base->running == timer
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.
80 * All state transitions are protected by cpu_base->lock.
82 #define HRTIMER_STATE_INACTIVE 0x00
83 #define HRTIMER_STATE_ENQUEUED 0x01
86 * struct hrtimer_sleeper - simple sleeper structure
87 * @timer: embedded timer structure
88 * @task: task to wake up
90 * task is set to NULL, when the timer expires.
92 struct hrtimer_sleeper {
94 struct task_struct *task;
97 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
99 timer->node.expires = time;
100 timer->_softexpires = time;
103 static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
105 timer->_softexpires = time;
106 timer->node.expires = ktime_add_safe(time, delta);
109 static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
111 timer->_softexpires = time;
112 timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
115 static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
117 timer->node.expires = tv64;
118 timer->_softexpires = tv64;
121 static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
123 timer->node.expires = ktime_add_safe(timer->node.expires, time);
124 timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
127 static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
129 timer->node.expires = ktime_add_ns(timer->node.expires, ns);
130 timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
133 static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
135 return timer->node.expires;
138 static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
140 return timer->_softexpires;
143 static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
145 return timer->node.expires;
147 static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
149 return timer->_softexpires;
152 static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
154 return ktime_to_ns(timer->node.expires);
157 static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
159 return ktime_sub(timer->node.expires, timer->base->get_time());
162 static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
164 return timer->base->get_time();
167 static inline int hrtimer_is_hres_active(struct hrtimer *timer)
169 return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
170 timer->base->cpu_base->hres_active : 0;
173 #ifdef CONFIG_HIGH_RES_TIMERS
174 struct clock_event_device;
176 extern void hrtimer_interrupt(struct clock_event_device *dev);
178 extern unsigned int hrtimer_resolution;
182 #define hrtimer_resolution (unsigned int)LOW_RES_NSEC
186 static inline ktime_t
187 __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
189 ktime_t rem = ktime_sub(timer->node.expires, now);
192 * Adjust relative timers for the extra we added in
193 * hrtimer_start_range_ns() to prevent short timeouts.
195 if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
196 rem -= hrtimer_resolution;
200 static inline ktime_t
201 hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
203 return __hrtimer_expires_remaining_adjusted(timer,
204 timer->base->get_time());
207 #ifdef CONFIG_TIMERFD
208 extern void timerfd_clock_was_set(void);
209 extern void timerfd_resume(void);
211 static inline void timerfd_clock_was_set(void) { }
212 static inline void timerfd_resume(void) { }
215 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
217 #ifdef CONFIG_PREEMPT_RT
218 void hrtimer_cancel_wait_running(const struct hrtimer *timer);
220 static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)
226 /* Exported timer functions: */
228 /* Initialize timers: */
229 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
230 enum hrtimer_mode mode);
231 extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
232 enum hrtimer_mode mode);
234 #ifdef CONFIG_DEBUG_OBJECTS_TIMERS
235 extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
236 enum hrtimer_mode mode);
237 extern void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
239 enum hrtimer_mode mode);
241 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
243 static inline void hrtimer_init_on_stack(struct hrtimer *timer,
244 clockid_t which_clock,
245 enum hrtimer_mode mode)
247 hrtimer_init(timer, which_clock, mode);
250 static inline void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
252 enum hrtimer_mode mode)
254 hrtimer_init_sleeper(sl, clock_id, mode);
257 static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
260 /* Basic timer operations: */
261 extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
262 u64 range_ns, const enum hrtimer_mode mode);
265 * hrtimer_start - (re)start an hrtimer
266 * @timer: the timer to be added
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!
272 static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
273 const enum hrtimer_mode mode)
275 hrtimer_start_range_ns(timer, tim, 0, mode);
278 extern int hrtimer_cancel(struct hrtimer *timer);
279 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
281 static inline void hrtimer_start_expires(struct hrtimer *timer,
282 enum hrtimer_mode mode)
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);
292 void hrtimer_sleeper_start_expires(struct hrtimer_sleeper *sl,
293 enum hrtimer_mode mode);
295 static inline void hrtimer_restart(struct hrtimer *timer)
297 hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
301 extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
304 * hrtimer_get_remaining - get remaining time for the timer
305 * @timer: the timer to read
307 static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
309 return __hrtimer_get_remaining(timer, false);
312 extern u64 hrtimer_get_next_event(void);
313 extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);
315 extern bool hrtimer_active(const struct hrtimer *timer);
318 * hrtimer_is_queued - check, whether the timer is on one of the queues
319 * @timer: Timer to check
321 * Returns: True if the timer is queued, false otherwise
323 * The function can be used lockless, but it gives only a current snapshot.
325 static inline bool hrtimer_is_queued(struct hrtimer *timer)
327 /* The READ_ONCE pairs with the update functions of timer->state */
328 return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);
332 * Helper function to check, whether the timer is running the callback
335 static inline int hrtimer_callback_running(struct hrtimer *timer)
337 return timer->base->running == timer;
340 /* Forward a hrtimer so it expires after now: */
342 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
345 * hrtimer_forward_now() - forward the timer expiry so it expires after now
346 * @timer: hrtimer to forward
347 * @interval: the interval to forward
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.
352 static inline u64 hrtimer_forward_now(struct hrtimer *timer,
355 return hrtimer_forward(timer, timer->base->get_time(), interval);
360 extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
361 extern long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode,
362 const clockid_t clockid);
364 extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
365 const enum hrtimer_mode mode);
366 extern int schedule_hrtimeout_range_clock(ktime_t *expires,
368 const enum hrtimer_mode mode,
370 extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
372 /* Soft interrupt function to run the hrtimer queues: */
373 extern void hrtimer_run_queues(void);
375 /* Bootup initialization: */
376 extern void __init hrtimers_init(void);
378 /* Show pending timers: */
379 extern void sysrq_timer_list_show(void);
381 int hrtimers_prepare_cpu(unsigned int cpu);
382 #ifdef CONFIG_HOTPLUG_CPU
383 int hrtimers_cpu_dying(unsigned int cpu);
385 #define hrtimers_cpu_dying NULL