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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 | |
54cdfdb4 | 57 | * |
b00c1a99 | 58 | * Special cases: |
303e967f TG |
59 | * 0x03 callback function running and enqueued |
60 | * (was requeued on another CPU) | |
b00c1a99 | 61 | * 0x09 timer was migrated on CPU hotunplug |
303e967f TG |
62 | * The "callback function running and enqueued" status is only possible on |
63 | * SMP. It happens for example when a posix timer expired and the callback | |
64 | * queued a signal. Between dropping the lock which protects the posix timer | |
65 | * and reacquiring the base lock of the hrtimer, another CPU can deliver the | |
66 | * signal and rearm the timer. We have to preserve the callback running state, | |
67 | * as otherwise the timer could be removed before the softirq code finishes the | |
68 | * the handling of the timer. | |
69 | * | |
3eb05676 | 70 | * The HRTIMER_STATE_ENQUEUED bit is always or'ed to the current state to |
303e967f TG |
71 | * preserve the HRTIMER_STATE_CALLBACK bit in the above scenario. |
72 | * | |
73 | * All state transitions are protected by cpu_base->lock. | |
74 | */ | |
75 | #define HRTIMER_STATE_INACTIVE 0x00 | |
76 | #define HRTIMER_STATE_ENQUEUED 0x01 | |
77 | #define HRTIMER_STATE_CALLBACK 0x02 | |
ca109491 | 78 | #define HRTIMER_STATE_MIGRATE 0x04 |
303e967f | 79 | |
c0a31329 TG |
80 | /** |
81 | * struct hrtimer - the basic hrtimer structure | |
998adc3d JS |
82 | * @node: timerqueue node, which also manages node.expires, |
83 | * the absolute expiry time in the hrtimers internal | |
c0a31329 | 84 | * representation. The time is related to the clock on |
592aa999 TG |
85 | * which the timer is based. Is setup by adding |
86 | * slack to the _softexpires value. For non range timers | |
87 | * identical to _softexpires. | |
88 | * @_softexpires: the absolute earliest expiry time of the hrtimer. | |
89 | * The time which was given as expiry time when the timer | |
90 | * was armed. | |
c0a31329 | 91 | * @function: timer expiry callback function |
c0a31329 | 92 | * @base: pointer to the timer base (per cpu and per clock) |
303e967f | 93 | * @state: state information (See bit values above) |
54cdfdb4 TG |
94 | * @start_site: timer statistics field to store the site where the timer |
95 | * was started | |
96 | * @start_comm: timer statistics field to store the name of the process which | |
97 | * started the timer | |
98 | * @start_pid: timer statistics field to store the pid of the task which | |
99 | * started the timer | |
c0a31329 | 100 | * |
54cdfdb4 | 101 | * The hrtimer structure must be initialized by hrtimer_init() |
c0a31329 TG |
102 | */ |
103 | struct hrtimer { | |
998adc3d | 104 | struct timerqueue_node node; |
654c8e0b | 105 | ktime_t _softexpires; |
3c8aa39d TG |
106 | enum hrtimer_restart (*function)(struct hrtimer *); |
107 | struct hrtimer_clock_base *base; | |
303e967f | 108 | unsigned long state; |
82f67cd9 | 109 | #ifdef CONFIG_TIMER_STATS |
1b024690 | 110 | int start_pid; |
82f67cd9 IM |
111 | void *start_site; |
112 | char start_comm[16]; | |
82f67cd9 | 113 | #endif |
c0a31329 TG |
114 | }; |
115 | ||
00362e33 TG |
116 | /** |
117 | * struct hrtimer_sleeper - simple sleeper structure | |
00362e33 TG |
118 | * @timer: embedded timer structure |
119 | * @task: task to wake up | |
120 | * | |
121 | * task is set to NULL, when the timer expires. | |
122 | */ | |
123 | struct hrtimer_sleeper { | |
124 | struct hrtimer timer; | |
125 | struct task_struct *task; | |
126 | }; | |
127 | ||
c0a31329 | 128 | /** |
d1d67174 | 129 | * struct hrtimer_clock_base - the timer base for a specific clock |
05fb6bf0 | 130 | * @cpu_base: per cpu clock base |
3c8aa39d TG |
131 | * @index: clock type index for per_cpu support when moving a |
132 | * timer to a base on another cpu. | |
92127c7a | 133 | * @active: red black tree root node for the active timers |
92127c7a TG |
134 | * @resolution: the resolution of the clock, in nanoseconds |
135 | * @get_time: function to retrieve the current time of the clock | |
92127c7a | 136 | * @softirq_time: the time when running the hrtimer queue in the softirq |
54cdfdb4 | 137 | * @offset: offset of this clock to the monotonic base |
c0a31329 | 138 | */ |
3c8aa39d TG |
139 | struct hrtimer_clock_base { |
140 | struct hrtimer_cpu_base *cpu_base; | |
c0a31329 | 141 | clockid_t index; |
998adc3d | 142 | struct timerqueue_head active; |
e2787630 | 143 | ktime_t resolution; |
c0a31329 | 144 | ktime_t (*get_time)(void); |
92127c7a | 145 | ktime_t softirq_time; |
54cdfdb4 TG |
146 | #ifdef CONFIG_HIGH_RES_TIMERS |
147 | ktime_t offset; | |
54cdfdb4 | 148 | #endif |
3c8aa39d TG |
149 | }; |
150 | ||
151 | #define HRTIMER_MAX_CLOCK_BASES 2 | |
152 | ||
153 | /* | |
154 | * struct hrtimer_cpu_base - the per cpu clock bases | |
155 | * @lock: lock protecting the base and associated clock bases | |
156 | * and timers | |
3c8aa39d | 157 | * @clock_base: array of clock bases for this cpu |
54cdfdb4 TG |
158 | * @expires_next: absolute time of the next event which was scheduled |
159 | * via clock_set_next_event() | |
160 | * @hres_active: State of high resolution mode | |
41d2e494 TG |
161 | * @hang_detected: The last hrtimer interrupt detected a hang |
162 | * @nr_events: Total number of hrtimer interrupt events | |
163 | * @nr_retries: Total number of hrtimer interrupt retries | |
164 | * @nr_hangs: Total number of hrtimer interrupt hangs | |
165 | * @max_hang_time: Maximum time spent in hrtimer_interrupt | |
3c8aa39d TG |
166 | */ |
167 | struct hrtimer_cpu_base { | |
ecb49d1a | 168 | raw_spinlock_t lock; |
3c8aa39d | 169 | struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; |
54cdfdb4 TG |
170 | #ifdef CONFIG_HIGH_RES_TIMERS |
171 | ktime_t expires_next; | |
172 | int hres_active; | |
41d2e494 | 173 | int hang_detected; |
54cdfdb4 | 174 | unsigned long nr_events; |
41d2e494 TG |
175 | unsigned long nr_retries; |
176 | unsigned long nr_hangs; | |
177 | ktime_t max_hang_time; | |
54cdfdb4 | 178 | #endif |
c0a31329 TG |
179 | }; |
180 | ||
63ca243b AV |
181 | static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) |
182 | { | |
998adc3d | 183 | timer->node.expires = time; |
654c8e0b | 184 | timer->_softexpires = time; |
63ca243b | 185 | } |
654c8e0b AV |
186 | |
187 | static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) | |
188 | { | |
189 | timer->_softexpires = time; | |
998adc3d | 190 | timer->node.expires = ktime_add_safe(time, delta); |
654c8e0b AV |
191 | } |
192 | ||
193 | static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) | |
194 | { | |
195 | timer->_softexpires = time; | |
998adc3d | 196 | timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); |
654c8e0b AV |
197 | } |
198 | ||
63ca243b AV |
199 | static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) |
200 | { | |
998adc3d | 201 | timer->node.expires.tv64 = tv64; |
654c8e0b | 202 | timer->_softexpires.tv64 = tv64; |
63ca243b AV |
203 | } |
204 | ||
205 | static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) | |
206 | { | |
998adc3d | 207 | timer->node.expires = ktime_add_safe(timer->node.expires, time); |
654c8e0b | 208 | timer->_softexpires = ktime_add_safe(timer->_softexpires, time); |
63ca243b AV |
209 | } |
210 | ||
7597bc94 | 211 | static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) |
63ca243b | 212 | { |
998adc3d | 213 | timer->node.expires = ktime_add_ns(timer->node.expires, ns); |
654c8e0b | 214 | timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); |
63ca243b AV |
215 | } |
216 | ||
217 | static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) | |
218 | { | |
998adc3d | 219 | return timer->node.expires; |
63ca243b AV |
220 | } |
221 | ||
654c8e0b AV |
222 | static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) |
223 | { | |
224 | return timer->_softexpires; | |
225 | } | |
226 | ||
63ca243b AV |
227 | static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) |
228 | { | |
998adc3d | 229 | return timer->node.expires.tv64; |
63ca243b | 230 | } |
654c8e0b AV |
231 | static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) |
232 | { | |
233 | return timer->_softexpires.tv64; | |
234 | } | |
63ca243b AV |
235 | |
236 | static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) | |
237 | { | |
998adc3d | 238 | return ktime_to_ns(timer->node.expires); |
63ca243b AV |
239 | } |
240 | ||
241 | static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) | |
242 | { | |
998adc3d | 243 | return ktime_sub(timer->node.expires, timer->base->get_time()); |
63ca243b AV |
244 | } |
245 | ||
54cdfdb4 TG |
246 | #ifdef CONFIG_HIGH_RES_TIMERS |
247 | struct clock_event_device; | |
248 | ||
249 | extern void clock_was_set(void); | |
995f054f | 250 | extern void hres_timers_resume(void); |
54cdfdb4 TG |
251 | extern void hrtimer_interrupt(struct clock_event_device *dev); |
252 | ||
253 | /* | |
254 | * In high resolution mode the time reference must be read accurate | |
255 | */ | |
256 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
257 | { | |
258 | return timer->base->get_time(); | |
259 | } | |
260 | ||
8f4d37ec PZ |
261 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
262 | { | |
263 | return timer->base->cpu_base->hres_active; | |
264 | } | |
265 | ||
2075eb8d AV |
266 | extern void hrtimer_peek_ahead_timers(void); |
267 | ||
54cdfdb4 TG |
268 | /* |
269 | * The resolution of the clocks. The resolution value is returned in | |
270 | * the clock_getres() system call to give application programmers an | |
271 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
272 | * this resolution values. | |
273 | */ | |
151db1fc TB |
274 | # define HIGH_RES_NSEC 1 |
275 | # define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC } | |
276 | # define MONOTONIC_RES_NSEC HIGH_RES_NSEC | |
54cdfdb4 TG |
277 | # define KTIME_MONOTONIC_RES KTIME_HIGH_RES |
278 | ||
279 | #else | |
280 | ||
151db1fc | 281 | # define MONOTONIC_RES_NSEC LOW_RES_NSEC |
54cdfdb4 TG |
282 | # define KTIME_MONOTONIC_RES KTIME_LOW_RES |
283 | ||
becf8b5d TG |
284 | /* |
285 | * clock_was_set() is a NOP for non- high-resolution systems. The | |
286 | * time-sorted order guarantees that a timer does not expire early and | |
287 | * is expired in the next softirq when the clock was advanced. | |
288 | */ | |
54cdfdb4 | 289 | static inline void clock_was_set(void) { } |
2075eb8d | 290 | static inline void hrtimer_peek_ahead_timers(void) { } |
54cdfdb4 | 291 | |
995f054f IM |
292 | static inline void hres_timers_resume(void) { } |
293 | ||
54cdfdb4 TG |
294 | /* |
295 | * In non high resolution mode the time reference is taken from | |
296 | * the base softirq time variable. | |
297 | */ | |
298 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
299 | { | |
300 | return timer->base->softirq_time; | |
301 | } | |
302 | ||
8f4d37ec PZ |
303 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) |
304 | { | |
305 | return 0; | |
306 | } | |
54cdfdb4 TG |
307 | #endif |
308 | ||
d316c57f TG |
309 | extern ktime_t ktime_get(void); |
310 | extern ktime_t ktime_get_real(void); | |
becf8b5d | 311 | |
2e94d1f7 AV |
312 | |
313 | DECLARE_PER_CPU(struct tick_device, tick_cpu_device); | |
2e94d1f7 AV |
314 | |
315 | ||
c0a31329 TG |
316 | /* Exported timer functions: */ |
317 | ||
318 | /* Initialize timers: */ | |
7978672c GA |
319 | extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, |
320 | enum hrtimer_mode mode); | |
c0a31329 | 321 | |
237fc6e7 TG |
322 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS |
323 | extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, | |
324 | enum hrtimer_mode mode); | |
325 | ||
326 | extern void destroy_hrtimer_on_stack(struct hrtimer *timer); | |
327 | #else | |
328 | static inline void hrtimer_init_on_stack(struct hrtimer *timer, | |
329 | clockid_t which_clock, | |
330 | enum hrtimer_mode mode) | |
331 | { | |
332 | hrtimer_init(timer, which_clock, mode); | |
333 | } | |
334 | static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } | |
335 | #endif | |
336 | ||
c0a31329 TG |
337 | /* Basic timer operations: */ |
338 | extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, | |
339 | const enum hrtimer_mode mode); | |
da8f2e17 AV |
340 | extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, |
341 | unsigned long range_ns, const enum hrtimer_mode mode); | |
7f1e2ca9 PZ |
342 | extern int |
343 | __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
344 | unsigned long delta_ns, | |
345 | const enum hrtimer_mode mode, int wakeup); | |
346 | ||
c0a31329 TG |
347 | extern int hrtimer_cancel(struct hrtimer *timer); |
348 | extern int hrtimer_try_to_cancel(struct hrtimer *timer); | |
349 | ||
63ca243b AV |
350 | static inline int hrtimer_start_expires(struct hrtimer *timer, |
351 | enum hrtimer_mode mode) | |
352 | { | |
da8f2e17 AV |
353 | unsigned long delta; |
354 | ktime_t soft, hard; | |
355 | soft = hrtimer_get_softexpires(timer); | |
356 | hard = hrtimer_get_expires(timer); | |
357 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
4ce105d3 | 358 | return hrtimer_start_range_ns(timer, soft, delta, mode); |
63ca243b AV |
359 | } |
360 | ||
c9cb2e3d TG |
361 | static inline int hrtimer_restart(struct hrtimer *timer) |
362 | { | |
654c8e0b | 363 | return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); |
c9cb2e3d | 364 | } |
c0a31329 TG |
365 | |
366 | /* Query timers: */ | |
367 | extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); | |
368 | extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); | |
369 | ||
69239749 | 370 | extern ktime_t hrtimer_get_next_event(void); |
69239749 | 371 | |
303e967f TG |
372 | /* |
373 | * A timer is active, when it is enqueued into the rbtree or the callback | |
374 | * function is running. | |
375 | */ | |
c0a31329 TG |
376 | static inline int hrtimer_active(const struct hrtimer *timer) |
377 | { | |
303e967f | 378 | return timer->state != HRTIMER_STATE_INACTIVE; |
c0a31329 TG |
379 | } |
380 | ||
54cdfdb4 TG |
381 | /* |
382 | * Helper function to check, whether the timer is on one of the queues | |
383 | */ | |
384 | static inline int hrtimer_is_queued(struct hrtimer *timer) | |
385 | { | |
ca109491 | 386 | return timer->state & HRTIMER_STATE_ENQUEUED; |
54cdfdb4 TG |
387 | } |
388 | ||
4346f654 OH |
389 | /* |
390 | * Helper function to check, whether the timer is running the callback | |
391 | * function | |
392 | */ | |
393 | static inline int hrtimer_callback_running(struct hrtimer *timer) | |
394 | { | |
395 | return timer->state & HRTIMER_STATE_CALLBACK; | |
396 | } | |
397 | ||
c0a31329 | 398 | /* Forward a hrtimer so it expires after now: */ |
4d672e7a | 399 | extern u64 |
44f21475 | 400 | hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); |
c0a31329 | 401 | |
5e05ad7d | 402 | /* Forward a hrtimer so it expires after the hrtimer's current now */ |
4d672e7a DL |
403 | static inline u64 hrtimer_forward_now(struct hrtimer *timer, |
404 | ktime_t interval) | |
5e05ad7d DL |
405 | { |
406 | return hrtimer_forward(timer, timer->base->get_time(), interval); | |
407 | } | |
408 | ||
10c94ec1 TG |
409 | /* Precise sleep: */ |
410 | extern long hrtimer_nanosleep(struct timespec *rqtp, | |
080344b9 | 411 | struct timespec __user *rmtp, |
10c94ec1 TG |
412 | const enum hrtimer_mode mode, |
413 | const clockid_t clockid); | |
1711ef38 | 414 | extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); |
10c94ec1 | 415 | |
00362e33 TG |
416 | extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, |
417 | struct task_struct *tsk); | |
418 | ||
654c8e0b AV |
419 | extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, |
420 | const enum hrtimer_mode mode); | |
351b3f7a CE |
421 | extern int schedule_hrtimeout_range_clock(ktime_t *expires, |
422 | unsigned long delta, const enum hrtimer_mode mode, int clock); | |
7bb67439 AV |
423 | extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); |
424 | ||
c0a31329 TG |
425 | /* Soft interrupt function to run the hrtimer queues: */ |
426 | extern void hrtimer_run_queues(void); | |
d3d74453 | 427 | extern void hrtimer_run_pending(void); |
c0a31329 TG |
428 | |
429 | /* Bootup initialization: */ | |
430 | extern void __init hrtimers_init(void); | |
431 | ||
79bf2bb3 | 432 | #if BITS_PER_LONG < 64 |
4d672e7a | 433 | extern u64 ktime_divns(const ktime_t kt, s64 div); |
79bf2bb3 | 434 | #else /* BITS_PER_LONG < 64 */ |
4d672e7a | 435 | # define ktime_divns(kt, div) (u64)((kt).tv64 / (div)) |
79bf2bb3 TG |
436 | #endif |
437 | ||
88ad0bf6 IM |
438 | /* Show pending timers: */ |
439 | extern void sysrq_timer_list_show(void); | |
440 | ||
c0a31329 | 441 | #endif |