Commit | Line | Data |
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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> | |
40b86062 | 23 | #include <linux/percpu.h> |
507e1231 | 24 | #include <linux/timer.h> |
998adc3d | 25 | #include <linux/timerqueue.h> |
c0a31329 | 26 | |
3c8aa39d TG |
27 | struct hrtimer_clock_base; |
28 | struct hrtimer_cpu_base; | |
29 | ||
c0a31329 TG |
30 | /* |
31 | * Mode arguments of xxx_hrtimer functions: | |
32 | */ | |
33 | enum hrtimer_mode { | |
597d0275 AB |
34 | HRTIMER_MODE_ABS = 0x0, /* Time value is absolute */ |
35 | HRTIMER_MODE_REL = 0x1, /* Time value is relative to now */ | |
36 | HRTIMER_MODE_PINNED = 0x02, /* Timer is bound to CPU */ | |
37 | HRTIMER_MODE_ABS_PINNED = 0x02, | |
38 | HRTIMER_MODE_REL_PINNED = 0x03, | |
c0a31329 TG |
39 | }; |
40 | ||
c9cb2e3d TG |
41 | /* |
42 | * Return values for the callback function | |
43 | */ | |
c0a31329 | 44 | enum hrtimer_restart { |
c9cb2e3d TG |
45 | HRTIMER_NORESTART, /* Timer is not restarted */ |
46 | HRTIMER_RESTART, /* Timer must be restarted */ | |
c0a31329 TG |
47 | }; |
48 | ||
54cdfdb4 TG |
49 | /* |
50 | * Values to track state of the timer | |
303e967f TG |
51 | * |
52 | * Possible states: | |
53 | * | |
54 | * 0x00 inactive | |
55 | * 0x01 enqueued into rbtree | |
56 | * 0x02 callback function running | |
53370d2e | 57 | * 0x04 timer is migrated to another cpu |
54cdfdb4 | 58 | * |
b00c1a99 | 59 | * Special cases: |
303e967f TG |
60 | * 0x03 callback function running and enqueued |
61 | * (was requeued on another CPU) | |
53370d2e TG |
62 | * 0x05 timer was migrated on CPU hotunplug |
63 | * | |
303e967f TG |
64 | * The "callback function running and enqueued" status is only possible on |
65 | * SMP. It happens for example when a posix timer expired and the callback | |
66 | * queued a signal. Between dropping the lock which protects the posix timer | |
67 | * and reacquiring the base lock of the hrtimer, another CPU can deliver the | |
68 | * signal and rearm the timer. We have to preserve the callback running state, | |
69 | * as otherwise the timer could be removed before the softirq code finishes the | |
70 | * the handling of the timer. | |
71 | * | |
53370d2e TG |
72 | * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state |
73 | * to preserve the HRTIMER_STATE_CALLBACK in the above scenario. This | |
74 | * also affects HRTIMER_STATE_MIGRATE where the preservation is not | |
75 | * necessary. HRTIMER_STATE_MIGRATE is cleared after the timer is | |
76 | * enqueued on the new cpu. | |
303e967f TG |
77 | * |
78 | * All state transitions are protected by cpu_base->lock. | |
79 | */ | |
80 | #define HRTIMER_STATE_INACTIVE 0x00 | |
81 | #define HRTIMER_STATE_ENQUEUED 0x01 | |
82 | #define HRTIMER_STATE_CALLBACK 0x02 | |
ca109491 | 83 | #define HRTIMER_STATE_MIGRATE 0x04 |
303e967f | 84 | |
c0a31329 TG |
85 | /** |
86 | * struct hrtimer - the basic hrtimer structure | |
998adc3d JS |
87 | * @node: timerqueue node, which also manages node.expires, |
88 | * the absolute expiry time in the hrtimers internal | |
c0a31329 | 89 | * representation. The time is related to the clock on |
592aa999 TG |
90 | * which the timer is based. Is setup by adding |
91 | * slack to the _softexpires value. For non range timers | |
92 | * identical to _softexpires. | |
93 | * @_softexpires: the absolute earliest expiry time of the hrtimer. | |
94 | * The time which was given as expiry time when the timer | |
95 | * was armed. | |
c0a31329 | 96 | * @function: timer expiry callback function |
c0a31329 | 97 | * @base: pointer to the timer base (per cpu and per clock) |
303e967f | 98 | * @state: state information (See bit values above) |
e2e680fb VK |
99 | * @start_pid: timer statistics field to store the pid of the task which |
100 | * started the timer | |
54cdfdb4 TG |
101 | * @start_site: timer statistics field to store the site where the timer |
102 | * was started | |
103 | * @start_comm: timer statistics field to store the name of the process which | |
104 | * started the timer | |
c0a31329 | 105 | * |
54cdfdb4 | 106 | * The hrtimer structure must be initialized by hrtimer_init() |
c0a31329 TG |
107 | */ |
108 | struct hrtimer { | |
998adc3d | 109 | struct timerqueue_node node; |
654c8e0b | 110 | ktime_t _softexpires; |
3c8aa39d TG |
111 | enum hrtimer_restart (*function)(struct hrtimer *); |
112 | struct hrtimer_clock_base *base; | |
303e967f | 113 | unsigned long state; |
82f67cd9 | 114 | #ifdef CONFIG_TIMER_STATS |
1b024690 | 115 | int start_pid; |
82f67cd9 IM |
116 | void *start_site; |
117 | char start_comm[16]; | |
82f67cd9 | 118 | #endif |
c0a31329 TG |
119 | }; |
120 | ||
00362e33 TG |
121 | /** |
122 | * struct hrtimer_sleeper - simple sleeper structure | |
00362e33 TG |
123 | * @timer: embedded timer structure |
124 | * @task: task to wake up | |
125 | * | |
126 | * task is set to NULL, when the timer expires. | |
127 | */ | |
128 | struct hrtimer_sleeper { | |
129 | struct hrtimer timer; | |
130 | struct task_struct *task; | |
131 | }; | |
132 | ||
c0a31329 | 133 | /** |
d1d67174 | 134 | * struct hrtimer_clock_base - the timer base for a specific clock |
05fb6bf0 | 135 | * @cpu_base: per cpu clock base |
3c8aa39d TG |
136 | * @index: clock type index for per_cpu support when moving a |
137 | * timer to a base on another cpu. | |
4d258b25 | 138 | * @clockid: clock id for per_cpu support |
92127c7a | 139 | * @active: red black tree root node for the active timers |
92127c7a TG |
140 | * @resolution: the resolution of the clock, in nanoseconds |
141 | * @get_time: function to retrieve the current time of the clock | |
92127c7a | 142 | * @softirq_time: the time when running the hrtimer queue in the softirq |
54cdfdb4 | 143 | * @offset: offset of this clock to the monotonic base |
c0a31329 | 144 | */ |
3c8aa39d TG |
145 | struct hrtimer_clock_base { |
146 | struct hrtimer_cpu_base *cpu_base; | |
ab8177bc TG |
147 | int index; |
148 | clockid_t clockid; | |
998adc3d | 149 | struct timerqueue_head active; |
e2787630 | 150 | ktime_t resolution; |
c0a31329 | 151 | ktime_t (*get_time)(void); |
92127c7a | 152 | ktime_t softirq_time; |
54cdfdb4 | 153 | ktime_t offset; |
3c8aa39d TG |
154 | }; |
155 | ||
e06383db | 156 | enum hrtimer_base_type { |
e06383db | 157 | HRTIMER_BASE_MONOTONIC, |
68fa61c0 | 158 | HRTIMER_BASE_REALTIME, |
70a08cca | 159 | HRTIMER_BASE_BOOTTIME, |
90adda98 | 160 | HRTIMER_BASE_TAI, |
e06383db JS |
161 | HRTIMER_MAX_CLOCK_BASES, |
162 | }; | |
3c8aa39d TG |
163 | |
164 | /* | |
165 | * struct hrtimer_cpu_base - the per cpu clock bases | |
166 | * @lock: lock protecting the base and associated clock bases | |
167 | * and timers | |
cddd0248 | 168 | * @cpu: cpu number |
ab8177bc | 169 | * @active_bases: Bitfield to mark bases with active timers |
f55a6faa | 170 | * @clock_was_set: Indicates that clock was set from irq context. |
54cdfdb4 TG |
171 | * @expires_next: absolute time of the next event which was scheduled |
172 | * via clock_set_next_event() | |
9bc74919 | 173 | * @in_hrtirq: hrtimer_interrupt() is currently executing |
54cdfdb4 | 174 | * @hres_active: State of high resolution mode |
41d2e494 TG |
175 | * @hang_detected: The last hrtimer interrupt detected a hang |
176 | * @nr_events: Total number of hrtimer interrupt events | |
177 | * @nr_retries: Total number of hrtimer interrupt retries | |
178 | * @nr_hangs: Total number of hrtimer interrupt hangs | |
179 | * @max_hang_time: Maximum time spent in hrtimer_interrupt | |
ab8177bc | 180 | * @clock_base: array of clock bases for this cpu |
3c8aa39d TG |
181 | */ |
182 | struct hrtimer_cpu_base { | |
ecb49d1a | 183 | raw_spinlock_t lock; |
cddd0248 | 184 | unsigned int cpu; |
f55a6faa JS |
185 | unsigned int active_bases; |
186 | unsigned int clock_was_set; | |
54cdfdb4 TG |
187 | #ifdef CONFIG_HIGH_RES_TIMERS |
188 | ktime_t expires_next; | |
9bc74919 | 189 | int in_hrtirq; |
54cdfdb4 | 190 | int hres_active; |
41d2e494 | 191 | int hang_detected; |
54cdfdb4 | 192 | unsigned long nr_events; |
41d2e494 TG |
193 | unsigned long nr_retries; |
194 | unsigned long nr_hangs; | |
195 | ktime_t max_hang_time; | |
54cdfdb4 | 196 | #endif |
f24444b0 | 197 | struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; |
c0a31329 TG |
198 | }; |
199 | ||
63ca243b AV |
200 | static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) |
201 | { | |
998adc3d | 202 | timer->node.expires = time; |
654c8e0b | 203 | timer->_softexpires = time; |
63ca243b | 204 | } |
654c8e0b AV |
205 | |
206 | static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) | |
207 | { | |
208 | timer->_softexpires = time; | |
998adc3d | 209 | timer->node.expires = ktime_add_safe(time, delta); |
654c8e0b AV |
210 | } |
211 | ||
212 | static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) | |
213 | { | |
214 | timer->_softexpires = time; | |
998adc3d | 215 | timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); |
654c8e0b AV |
216 | } |
217 | ||
63ca243b AV |
218 | static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) |
219 | { | |
998adc3d | 220 | timer->node.expires.tv64 = tv64; |
654c8e0b | 221 | timer->_softexpires.tv64 = tv64; |
63ca243b AV |
222 | } |
223 | ||
224 | static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) | |
225 | { | |
998adc3d | 226 | timer->node.expires = ktime_add_safe(timer->node.expires, time); |
654c8e0b | 227 | timer->_softexpires = ktime_add_safe(timer->_softexpires, time); |
63ca243b AV |
228 | } |
229 | ||
7597bc94 | 230 | static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) |
63ca243b | 231 | { |
998adc3d | 232 | timer->node.expires = ktime_add_ns(timer->node.expires, ns); |
654c8e0b | 233 | timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); |
63ca243b AV |
234 | } |
235 | ||
236 | static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) | |
237 | { | |
998adc3d | 238 | return timer->node.expires; |
63ca243b AV |
239 | } |
240 | ||
654c8e0b AV |
241 | static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) |
242 | { | |
243 | return timer->_softexpires; | |
244 | } | |
245 | ||
63ca243b AV |
246 | static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) |
247 | { | |
998adc3d | 248 | return timer->node.expires.tv64; |
63ca243b | 249 | } |
654c8e0b AV |
250 | static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) |
251 | { | |
252 | return timer->_softexpires.tv64; | |
253 | } | |
63ca243b AV |
254 | |
255 | static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) | |
256 | { | |
998adc3d | 257 | return ktime_to_ns(timer->node.expires); |
63ca243b AV |
258 | } |
259 | ||
260 | static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) | |
261 | { | |
998adc3d | 262 | return ktime_sub(timer->node.expires, timer->base->get_time()); |
63ca243b AV |
263 | } |
264 | ||
54cdfdb4 TG |
265 | #ifdef CONFIG_HIGH_RES_TIMERS |
266 | struct clock_event_device; | |
267 | ||
54cdfdb4 TG |
268 | extern void hrtimer_interrupt(struct clock_event_device *dev); |
269 | ||
270 | /* | |
271 | * In high resolution mode the time reference must be read accurate | |
272 | */ | |
273 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
274 | { | |
275 | return timer->base->get_time(); | |
276 | } | |
277 | ||
8f4d37ec PZ |
278 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
279 | { | |
280 | return timer->base->cpu_base->hres_active; | |
281 | } | |
282 | ||
2075eb8d AV |
283 | extern void hrtimer_peek_ahead_timers(void); |
284 | ||
54cdfdb4 TG |
285 | /* |
286 | * The resolution of the clocks. The resolution value is returned in | |
287 | * the clock_getres() system call to give application programmers an | |
288 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
289 | * this resolution values. | |
290 | */ | |
151db1fc TB |
291 | # define HIGH_RES_NSEC 1 |
292 | # define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC } | |
293 | # define MONOTONIC_RES_NSEC HIGH_RES_NSEC | |
54cdfdb4 TG |
294 | # define KTIME_MONOTONIC_RES KTIME_HIGH_RES |
295 | ||
f55a6faa JS |
296 | extern void clock_was_set_delayed(void); |
297 | ||
54cdfdb4 TG |
298 | #else |
299 | ||
151db1fc | 300 | # define MONOTONIC_RES_NSEC LOW_RES_NSEC |
54cdfdb4 TG |
301 | # define KTIME_MONOTONIC_RES KTIME_LOW_RES |
302 | ||
2075eb8d | 303 | static inline void hrtimer_peek_ahead_timers(void) { } |
54cdfdb4 TG |
304 | |
305 | /* | |
306 | * In non high resolution mode the time reference is taken from | |
307 | * the base softirq time variable. | |
308 | */ | |
309 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
310 | { | |
311 | return timer->base->softirq_time; | |
312 | } | |
313 | ||
8f4d37ec PZ |
314 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
315 | { | |
316 | return 0; | |
317 | } | |
f55a6faa JS |
318 | |
319 | static inline void clock_was_set_delayed(void) { } | |
320 | ||
54cdfdb4 TG |
321 | #endif |
322 | ||
b12a03ce | 323 | extern void clock_was_set(void); |
9ec26907 TG |
324 | #ifdef CONFIG_TIMERFD |
325 | extern void timerfd_clock_was_set(void); | |
326 | #else | |
327 | static inline void timerfd_clock_was_set(void) { } | |
328 | #endif | |
b12a03ce TG |
329 | extern void hrtimers_resume(void); |
330 | ||
2e94d1f7 | 331 | DECLARE_PER_CPU(struct tick_device, tick_cpu_device); |
2e94d1f7 AV |
332 | |
333 | ||
c0a31329 TG |
334 | /* Exported timer functions: */ |
335 | ||
336 | /* Initialize timers: */ | |
7978672c GA |
337 | extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, |
338 | enum hrtimer_mode mode); | |
c0a31329 | 339 | |
237fc6e7 TG |
340 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
341 | extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, | |
342 | enum hrtimer_mode mode); | |
343 | ||
344 | extern void destroy_hrtimer_on_stack(struct hrtimer *timer); | |
345 | #else | |
346 | static inline void hrtimer_init_on_stack(struct hrtimer *timer, | |
347 | clockid_t which_clock, | |
348 | enum hrtimer_mode mode) | |
349 | { | |
350 | hrtimer_init(timer, which_clock, mode); | |
351 | } | |
352 | static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } | |
353 | #endif | |
354 | ||
c0a31329 TG |
355 | /* Basic timer operations: */ |
356 | extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, | |
357 | const enum hrtimer_mode mode); | |
da8f2e17 AV |
358 | extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
359 | unsigned long range_ns, const enum hrtimer_mode mode); | |
7f1e2ca9 PZ |
360 | extern int |
361 | __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
362 | unsigned long delta_ns, | |
363 | const enum hrtimer_mode mode, int wakeup); | |
364 | ||
c0a31329 TG |
365 | extern int hrtimer_cancel(struct hrtimer *timer); |
366 | extern int hrtimer_try_to_cancel(struct hrtimer *timer); | |
367 | ||
63ca243b AV |
368 | static inline int hrtimer_start_expires(struct hrtimer *timer, |
369 | enum hrtimer_mode mode) | |
370 | { | |
da8f2e17 AV |
371 | unsigned long delta; |
372 | ktime_t soft, hard; | |
373 | soft = hrtimer_get_softexpires(timer); | |
374 | hard = hrtimer_get_expires(timer); | |
375 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
4ce105d3 | 376 | return hrtimer_start_range_ns(timer, soft, delta, mode); |
63ca243b AV |
377 | } |
378 | ||
c9cb2e3d TG |
379 | static inline int hrtimer_restart(struct hrtimer *timer) |
380 | { | |
654c8e0b | 381 | return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); |
c9cb2e3d | 382 | } |
c0a31329 TG |
383 | |
384 | /* Query timers: */ | |
385 | extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); | |
386 | extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); | |
387 | ||
69239749 | 388 | extern ktime_t hrtimer_get_next_event(void); |
69239749 | 389 | |
303e967f | 390 | /* |
53370d2e TG |
391 | * A timer is active, when it is enqueued into the rbtree or the |
392 | * callback function is running or it's in the state of being migrated | |
393 | * to another cpu. | |
303e967f | 394 | */ |
c0a31329 TG |
395 | static inline int hrtimer_active(const struct hrtimer *timer) |
396 | { | |
303e967f | 397 | return timer->state != HRTIMER_STATE_INACTIVE; |
c0a31329 TG |
398 | } |
399 | ||
54cdfdb4 TG |
400 | /* |
401 | * Helper function to check, whether the timer is on one of the queues | |
402 | */ | |
403 | static inline int hrtimer_is_queued(struct hrtimer *timer) | |
404 | { | |
ca109491 | 405 | return timer->state & HRTIMER_STATE_ENQUEUED; |
54cdfdb4 TG |
406 | } |
407 | ||
4346f654 OH |
408 | /* |
409 | * Helper function to check, whether the timer is running the callback | |
410 | * function | |
411 | */ | |
412 | static inline int hrtimer_callback_running(struct hrtimer *timer) | |
413 | { | |
414 | return timer->state & HRTIMER_STATE_CALLBACK; | |
415 | } | |
416 | ||
c0a31329 | 417 | /* Forward a hrtimer so it expires after now: */ |
4d672e7a | 418 | extern u64 |
44f21475 | 419 | hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); |
c0a31329 | 420 | |
5e05ad7d | 421 | /* Forward a hrtimer so it expires after the hrtimer's current now */ |
4d672e7a DL |
422 | static inline u64 hrtimer_forward_now(struct hrtimer *timer, |
423 | ktime_t interval) | |
5e05ad7d DL |
424 | { |
425 | return hrtimer_forward(timer, timer->base->get_time(), interval); | |
426 | } | |
427 | ||
10c94ec1 TG |
428 | /* Precise sleep: */ |
429 | extern long hrtimer_nanosleep(struct timespec *rqtp, | |
080344b9 | 430 | struct timespec __user *rmtp, |
10c94ec1 TG |
431 | const enum hrtimer_mode mode, |
432 | const clockid_t clockid); | |
1711ef38 | 433 | extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); |
10c94ec1 | 434 | |
00362e33 TG |
435 | extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, |
436 | struct task_struct *tsk); | |
437 | ||
654c8e0b AV |
438 | extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, |
439 | const enum hrtimer_mode mode); | |
351b3f7a CE |
440 | extern int schedule_hrtimeout_range_clock(ktime_t *expires, |
441 | unsigned long delta, const enum hrtimer_mode mode, int clock); | |
7bb67439 AV |
442 | extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); |
443 | ||
c0a31329 TG |
444 | /* Soft interrupt function to run the hrtimer queues: */ |
445 | extern void hrtimer_run_queues(void); | |
d3d74453 | 446 | extern void hrtimer_run_pending(void); |
c0a31329 TG |
447 | |
448 | /* Bootup initialization: */ | |
449 | extern void __init hrtimers_init(void); | |
450 | ||
88ad0bf6 IM |
451 | /* Show pending timers: */ |
452 | extern void sysrq_timer_list_show(void); | |
453 | ||
c0a31329 | 454 | #endif |