1 // SPDX-License-Identifier: GPL-2.0
3  *  hrtimers - High-resolution kernel timers
19 #include <linux/percpu-defs.h>
21 #include <linux/timer.h>
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
59  * Values to track state of the timer
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.
72  *	timer->base->cpu_base->running == timer
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
78  * signal and rearm the timer.
80  * All state transitions are protected by cpu_base->lock.
86  * struct hrtimer_sleeper - simple sleeper structure
87  * @timer:	embedded timer structure
90  * task is set to NULL, when the timer expires.
93 	struct hrtimer timer;  member
97 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)  in hrtimer_set_expires()  argument
99 	timer->node.expires = time;  in hrtimer_set_expires()
100 	timer->_softexpires = time;  in hrtimer_set_expires()
103 static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)  in hrtimer_set_expires_range()  argument
105 	timer->_softexpires = time;  in hrtimer_set_expires_range()
106 	timer->node.expires = ktime_add_safe(time, delta);  in hrtimer_set_expires_range()
109 static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)  in hrtimer_set_expires_range_ns()  argument
111 	timer->_softexpires = time;  in hrtimer_set_expires_range_ns()
112 	timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));  in hrtimer_set_expires_range_ns()
115 static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)  in hrtimer_set_expires_tv64()  argument
117 	timer->node.expires = tv64;  in hrtimer_set_expires_tv64()
118 	timer->_softexpires = tv64;  in hrtimer_set_expires_tv64()
121 static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)  in hrtimer_add_expires()  argument
123 	timer->node.expires = ktime_add_safe(timer->node.expires, time);  in hrtimer_add_expires()
124 	timer->_softexpires = ktime_add_safe(timer->_softexpires, time);  in hrtimer_add_expires()
127 static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)  in hrtimer_add_expires_ns()  argument
129 	timer->node.expires = ktime_add_ns(timer->node.expires, ns);  in hrtimer_add_expires_ns()
130 	timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);  in hrtimer_add_expires_ns()
133 static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)  in hrtimer_get_expires()  argument
135 	return timer->node.expires;  in hrtimer_get_expires()
138 static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)  in hrtimer_get_softexpires()  argument
140 	return timer->_softexpires;  in hrtimer_get_softexpires()
143 static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)  in hrtimer_get_expires_tv64()  argument
145 	return timer->node.expires;  in hrtimer_get_expires_tv64()
147 static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)  in hrtimer_get_softexpires_tv64()  argument
149 	return timer->_softexpires;  in hrtimer_get_softexpires_tv64()
152 static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)  in hrtimer_get_expires_ns()  argument
154 	return ktime_to_ns(timer->node.expires);  in hrtimer_get_expires_ns()
157 static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)  in hrtimer_expires_remaining()  argument
159 	return ktime_sub(timer->node.expires, timer->base->get_time());  in hrtimer_expires_remaining()
162 static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)  in hrtimer_cb_get_time()  argument
164 	return timer->base->get_time();  in hrtimer_cb_get_time()
167 static inline int hrtimer_is_hres_active(struct hrtimer *timer)  in hrtimer_is_hres_active()  argument
170 		timer->base->cpu_base->hres_active : 0;  in hrtimer_is_hres_active()
187 __hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)  in __hrtimer_expires_remaining_adjusted()  argument
189 	ktime_t rem = ktime_sub(timer->node.expires, now);  in __hrtimer_expires_remaining_adjusted()
195 	if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)  in __hrtimer_expires_remaining_adjusted()
196 		rem -= hrtimer_resolution;  in __hrtimer_expires_remaining_adjusted()
201 hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)  in hrtimer_expires_remaining_adjusted()  argument
203 	return __hrtimer_expires_remaining_adjusted(timer,  in hrtimer_expires_remaining_adjusted()
204 						    timer->base->get_time());  in hrtimer_expires_remaining_adjusted()
218 void hrtimer_cancel_wait_running(const struct hrtimer *timer);
220 static inline void hrtimer_cancel_wait_running(struct hrtimer *timer)  in hrtimer_cancel_wait_running()  argument
226 /* Exported timer functions: */
229 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
231 extern void hrtimer_setup(struct hrtimer *timer, enum hrtimer_restart (*function)(struct hrtimer *),
233 extern void hrtimer_setup_on_stack(struct hrtimer *timer,
240 extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
242 static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }  in destroy_hrtimer_on_stack()  argument
245 /* Basic timer operations: */
246 extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
250  * hrtimer_start - (re)start an hrtimer
251  * @timer:	the timer to be added
253  * @mode:	timer mode: absolute (HRTIMER_MODE_ABS) or
257 static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,  in hrtimer_start()  argument
260 	hrtimer_start_range_ns(timer, tim, 0, mode);  in hrtimer_start()
263 extern int hrtimer_cancel(struct hrtimer *timer);
264 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
266 static inline void hrtimer_start_expires(struct hrtimer *timer,  in hrtimer_start_expires()  argument
271 	soft = hrtimer_get_softexpires(timer);  in hrtimer_start_expires()
272 	hard = hrtimer_get_expires(timer);  in hrtimer_start_expires()
274 	hrtimer_start_range_ns(timer, soft, delta, mode);  in hrtimer_start_expires()
280 static inline void hrtimer_restart(struct hrtimer *timer)  in hrtimer_restart()  argument
282 	hrtimer_start_expires(timer, HRTIMER_MODE_ABS);  in hrtimer_restart()
286 extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
289  * hrtimer_get_remaining - get remaining time for the timer
290  * @timer:	the timer to read
292 static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)  in hrtimer_get_remaining()  argument
294 	return __hrtimer_get_remaining(timer, false);  in hrtimer_get_remaining()
300 extern bool hrtimer_active(const struct hrtimer *timer);
303  * hrtimer_is_queued - check, whether the timer is on one of the queues
304  * @timer:	Timer to check
306  * Returns: True if the timer is queued, false otherwise
310 static inline bool hrtimer_is_queued(struct hrtimer *timer)  in hrtimer_is_queued()  argument
312 	/* The READ_ONCE pairs with the update functions of timer->state */  in hrtimer_is_queued()
313 	return !!(READ_ONCE(timer->state) & HRTIMER_STATE_ENQUEUED);  in hrtimer_is_queued()
317  * Helper function to check, whether the timer is running the callback
320 static inline int hrtimer_callback_running(struct hrtimer *timer)  in hrtimer_callback_running()  argument
322 	return timer->base->running == timer;  in hrtimer_callback_running()
326  * hrtimer_update_function - Update the timer's callback function
327  * @timer:	Timer to update
330  * Only safe to call if the timer is not enqueued. Can be called in the callback function if the
331  * timer is not enqueued at the same time (see the comments above HRTIMER_STATE_ENQUEUED).
333 static inline void hrtimer_update_function(struct hrtimer *timer,  in hrtimer_update_function()  argument
336 	guard(raw_spinlock_irqsave)(&timer->base->cpu_base->lock);  in hrtimer_update_function()
338 	if (WARN_ON_ONCE(hrtimer_is_queued(timer)))  in hrtimer_update_function()
344 	timer->function = function;  in hrtimer_update_function()
349 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
352  * hrtimer_forward_now() - forward the timer expiry so it expires after now
353  * @timer:	hrtimer to forward
356  * It is a variant of hrtimer_forward(). The timer will expire after the current
359 static inline u64 hrtimer_forward_now(struct hrtimer *timer,  in hrtimer_forward_now()  argument
362 	return hrtimer_forward(timer, timer->base->get_time(), interval);  in hrtimer_forward_now()