]>
Commit | Line | Data |
---|---|---|
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> | |
23 | #include <linux/percpu.h> | |
24 | #include <linux/timer.h> | |
25 | #include <linux/timerqueue.h> | |
26 | ||
27 | struct hrtimer_clock_base; | |
28 | struct hrtimer_cpu_base; | |
29 | ||
30 | /* | |
31 | * Mode arguments of xxx_hrtimer functions: | |
32 | */ | |
33 | enum hrtimer_mode { | |
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, | |
39 | }; | |
40 | ||
41 | /* | |
42 | * Return values for the callback function | |
43 | */ | |
44 | enum hrtimer_restart { | |
45 | HRTIMER_NORESTART, /* Timer is not restarted */ | |
46 | HRTIMER_RESTART, /* Timer must be restarted */ | |
47 | }; | |
48 | ||
49 | /* | |
50 | * Values to track state of the timer | |
51 | * | |
52 | * Possible states: | |
53 | * | |
54 | * 0x00 inactive | |
55 | * 0x01 enqueued into rbtree | |
56 | * 0x02 callback function running | |
57 | * 0x04 timer is migrated to another cpu | |
58 | * | |
59 | * Special cases: | |
60 | * 0x03 callback function running and enqueued | |
61 | * (was requeued on another CPU) | |
62 | * 0x05 timer was migrated on CPU hotunplug | |
63 | * | |
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 | * | |
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. | |
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 | |
83 | #define HRTIMER_STATE_MIGRATE 0x04 | |
84 | ||
85 | /** | |
86 | * struct hrtimer - the basic hrtimer structure | |
87 | * @node: timerqueue node, which also manages node.expires, | |
88 | * the absolute expiry time in the hrtimers internal | |
89 | * representation. The time is related to the clock on | |
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. | |
96 | * @function: timer expiry callback function | |
97 | * @base: pointer to the timer base (per cpu and per clock) | |
98 | * @state: state information (See bit values above) | |
99 | * @start_pid: timer statistics field to store the pid of the task which | |
100 | * started the timer | |
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 | |
105 | * | |
106 | * The hrtimer structure must be initialized by hrtimer_init() | |
107 | */ | |
108 | struct hrtimer { | |
109 | struct timerqueue_node node; | |
110 | ktime_t _softexpires; | |
111 | enum hrtimer_restart (*function)(struct hrtimer *); | |
112 | struct hrtimer_clock_base *base; | |
113 | unsigned long state; | |
114 | #ifdef CONFIG_TIMER_STATS | |
115 | int start_pid; | |
116 | void *start_site; | |
117 | char start_comm[16]; | |
118 | #endif | |
119 | }; | |
120 | ||
121 | /** | |
122 | * struct hrtimer_sleeper - simple sleeper structure | |
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 | ||
133 | /** | |
134 | * struct hrtimer_clock_base - the timer base for a specific clock | |
135 | * @cpu_base: per cpu clock base | |
136 | * @index: clock type index for per_cpu support when moving a | |
137 | * timer to a base on another cpu. | |
138 | * @clockid: clock id for per_cpu support | |
139 | * @active: red black tree root node for the active timers | |
140 | * @resolution: the resolution of the clock, in nanoseconds | |
141 | * @get_time: function to retrieve the current time of the clock | |
142 | * @softirq_time: the time when running the hrtimer queue in the softirq | |
143 | * @offset: offset of this clock to the monotonic base | |
144 | */ | |
145 | struct hrtimer_clock_base { | |
146 | struct hrtimer_cpu_base *cpu_base; | |
147 | int index; | |
148 | clockid_t clockid; | |
149 | struct timerqueue_head active; | |
150 | ktime_t resolution; | |
151 | ktime_t (*get_time)(void); | |
152 | ktime_t softirq_time; | |
153 | ktime_t offset; | |
154 | }; | |
155 | ||
156 | enum hrtimer_base_type { | |
157 | HRTIMER_BASE_MONOTONIC, | |
158 | HRTIMER_BASE_REALTIME, | |
159 | HRTIMER_BASE_BOOTTIME, | |
160 | HRTIMER_BASE_TAI, | |
161 | HRTIMER_MAX_CLOCK_BASES, | |
162 | }; | |
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 | |
168 | * @active_bases: Bitfield to mark bases with active timers | |
169 | * @clock_was_set: Indicates that clock was set from irq context. | |
170 | * @expires_next: absolute time of the next event which was scheduled | |
171 | * via clock_set_next_event() | |
172 | * @hres_active: State of high resolution mode | |
173 | * @hang_detected: The last hrtimer interrupt detected a hang | |
174 | * @nr_events: Total number of hrtimer interrupt events | |
175 | * @nr_retries: Total number of hrtimer interrupt retries | |
176 | * @nr_hangs: Total number of hrtimer interrupt hangs | |
177 | * @max_hang_time: Maximum time spent in hrtimer_interrupt | |
178 | * @clock_base: array of clock bases for this cpu | |
179 | */ | |
180 | struct hrtimer_cpu_base { | |
181 | raw_spinlock_t lock; | |
182 | unsigned int active_bases; | |
183 | unsigned int clock_was_set; | |
184 | #ifdef CONFIG_HIGH_RES_TIMERS | |
185 | ktime_t expires_next; | |
186 | int hres_active; | |
187 | int hang_detected; | |
188 | unsigned long nr_events; | |
189 | unsigned long nr_retries; | |
190 | unsigned long nr_hangs; | |
191 | ktime_t max_hang_time; | |
192 | #endif | |
193 | struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES]; | |
194 | }; | |
195 | ||
196 | static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time) | |
197 | { | |
198 | timer->node.expires = time; | |
199 | timer->_softexpires = time; | |
200 | } | |
201 | ||
202 | static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta) | |
203 | { | |
204 | timer->_softexpires = time; | |
205 | timer->node.expires = ktime_add_safe(time, delta); | |
206 | } | |
207 | ||
208 | static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, unsigned long delta) | |
209 | { | |
210 | timer->_softexpires = time; | |
211 | timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta)); | |
212 | } | |
213 | ||
214 | static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64) | |
215 | { | |
216 | timer->node.expires.tv64 = tv64; | |
217 | timer->_softexpires.tv64 = tv64; | |
218 | } | |
219 | ||
220 | static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time) | |
221 | { | |
222 | timer->node.expires = ktime_add_safe(timer->node.expires, time); | |
223 | timer->_softexpires = ktime_add_safe(timer->_softexpires, time); | |
224 | } | |
225 | ||
226 | static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns) | |
227 | { | |
228 | timer->node.expires = ktime_add_ns(timer->node.expires, ns); | |
229 | timer->_softexpires = ktime_add_ns(timer->_softexpires, ns); | |
230 | } | |
231 | ||
232 | static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer) | |
233 | { | |
234 | return timer->node.expires; | |
235 | } | |
236 | ||
237 | static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer) | |
238 | { | |
239 | return timer->_softexpires; | |
240 | } | |
241 | ||
242 | static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer) | |
243 | { | |
244 | return timer->node.expires.tv64; | |
245 | } | |
246 | static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer) | |
247 | { | |
248 | return timer->_softexpires.tv64; | |
249 | } | |
250 | ||
251 | static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer) | |
252 | { | |
253 | return ktime_to_ns(timer->node.expires); | |
254 | } | |
255 | ||
256 | static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer) | |
257 | { | |
258 | return ktime_sub(timer->node.expires, timer->base->get_time()); | |
259 | } | |
260 | ||
261 | #ifdef CONFIG_HIGH_RES_TIMERS | |
262 | struct clock_event_device; | |
263 | ||
264 | extern void hrtimer_interrupt(struct clock_event_device *dev); | |
265 | ||
266 | /* | |
267 | * In high resolution mode the time reference must be read accurate | |
268 | */ | |
269 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
270 | { | |
271 | return timer->base->get_time(); | |
272 | } | |
273 | ||
274 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) | |
275 | { | |
276 | return timer->base->cpu_base->hres_active; | |
277 | } | |
278 | ||
279 | extern void hrtimer_peek_ahead_timers(void); | |
280 | ||
281 | /* | |
282 | * The resolution of the clocks. The resolution value is returned in | |
283 | * the clock_getres() system call to give application programmers an | |
284 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
285 | * this resolution values. | |
286 | */ | |
287 | # define HIGH_RES_NSEC 1 | |
288 | # define KTIME_HIGH_RES (ktime_t) { .tv64 = HIGH_RES_NSEC } | |
289 | # define MONOTONIC_RES_NSEC HIGH_RES_NSEC | |
290 | # define KTIME_MONOTONIC_RES KTIME_HIGH_RES | |
291 | ||
292 | extern void clock_was_set_delayed(void); | |
293 | ||
294 | #else | |
295 | ||
296 | # define MONOTONIC_RES_NSEC LOW_RES_NSEC | |
297 | # define KTIME_MONOTONIC_RES KTIME_LOW_RES | |
298 | ||
299 | static inline void hrtimer_peek_ahead_timers(void) { } | |
300 | ||
301 | /* | |
302 | * In non high resolution mode the time reference is taken from | |
303 | * the base softirq time variable. | |
304 | */ | |
305 | static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer) | |
306 | { | |
307 | return timer->base->softirq_time; | |
308 | } | |
309 | ||
310 | static inline int hrtimer_is_hres_active(struct hrtimer *timer) | |
311 | { | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static inline void clock_was_set_delayed(void) { } | |
316 | ||
317 | #endif | |
318 | ||
319 | extern void clock_was_set(void); | |
320 | #ifdef CONFIG_TIMERFD | |
321 | extern void timerfd_clock_was_set(void); | |
322 | #else | |
323 | static inline void timerfd_clock_was_set(void) { } | |
324 | #endif | |
325 | extern void hrtimers_resume(void); | |
326 | ||
327 | extern ktime_t ktime_get(void); | |
328 | extern ktime_t ktime_get_real(void); | |
329 | extern ktime_t ktime_get_boottime(void); | |
330 | extern ktime_t ktime_get_monotonic_offset(void); | |
331 | extern ktime_t ktime_get_clocktai(void); | |
332 | extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot, | |
333 | ktime_t *offs_tai); | |
334 | ||
335 | DECLARE_PER_CPU(struct tick_device, tick_cpu_device); | |
336 | ||
337 | ||
338 | /* Exported timer functions: */ | |
339 | ||
340 | /* Initialize timers: */ | |
341 | extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock, | |
342 | enum hrtimer_mode mode); | |
343 | ||
344 | #ifdef CONFIG_DEBUG_OBJECTS_TIMERS | |
345 | extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock, | |
346 | enum hrtimer_mode mode); | |
347 | ||
348 | extern void destroy_hrtimer_on_stack(struct hrtimer *timer); | |
349 | #else | |
350 | static inline void hrtimer_init_on_stack(struct hrtimer *timer, | |
351 | clockid_t which_clock, | |
352 | enum hrtimer_mode mode) | |
353 | { | |
354 | hrtimer_init(timer, which_clock, mode); | |
355 | } | |
356 | static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { } | |
357 | #endif | |
358 | ||
359 | /* Basic timer operations: */ | |
360 | extern int hrtimer_start(struct hrtimer *timer, ktime_t tim, | |
361 | const enum hrtimer_mode mode); | |
362 | extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
363 | unsigned long range_ns, const enum hrtimer_mode mode); | |
364 | extern int | |
365 | __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, | |
366 | unsigned long delta_ns, | |
367 | const enum hrtimer_mode mode, int wakeup); | |
368 | ||
369 | extern int hrtimer_cancel(struct hrtimer *timer); | |
370 | extern int hrtimer_try_to_cancel(struct hrtimer *timer); | |
371 | ||
372 | static inline int hrtimer_start_expires(struct hrtimer *timer, | |
373 | enum hrtimer_mode mode) | |
374 | { | |
375 | unsigned long delta; | |
376 | ktime_t soft, hard; | |
377 | soft = hrtimer_get_softexpires(timer); | |
378 | hard = hrtimer_get_expires(timer); | |
379 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
380 | return hrtimer_start_range_ns(timer, soft, delta, mode); | |
381 | } | |
382 | ||
383 | static inline int hrtimer_restart(struct hrtimer *timer) | |
384 | { | |
385 | return hrtimer_start_expires(timer, HRTIMER_MODE_ABS); | |
386 | } | |
387 | ||
388 | /* Query timers: */ | |
389 | extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer); | |
390 | extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp); | |
391 | ||
392 | extern ktime_t hrtimer_get_next_event(void); | |
393 | ||
394 | /* | |
395 | * A timer is active, when it is enqueued into the rbtree or the | |
396 | * callback function is running or it's in the state of being migrated | |
397 | * to another cpu. | |
398 | */ | |
399 | static inline int hrtimer_active(const struct hrtimer *timer) | |
400 | { | |
401 | return timer->state != HRTIMER_STATE_INACTIVE; | |
402 | } | |
403 | ||
404 | /* | |
405 | * Helper function to check, whether the timer is on one of the queues | |
406 | */ | |
407 | static inline int hrtimer_is_queued(struct hrtimer *timer) | |
408 | { | |
409 | return timer->state & HRTIMER_STATE_ENQUEUED; | |
410 | } | |
411 | ||
412 | /* | |
413 | * Helper function to check, whether the timer is running the callback | |
414 | * function | |
415 | */ | |
416 | static inline int hrtimer_callback_running(struct hrtimer *timer) | |
417 | { | |
418 | return timer->state & HRTIMER_STATE_CALLBACK; | |
419 | } | |
420 | ||
421 | /* Forward a hrtimer so it expires after now: */ | |
422 | extern u64 | |
423 | hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval); | |
424 | ||
425 | /* Forward a hrtimer so it expires after the hrtimer's current now */ | |
426 | static inline u64 hrtimer_forward_now(struct hrtimer *timer, | |
427 | ktime_t interval) | |
428 | { | |
429 | return hrtimer_forward(timer, timer->base->get_time(), interval); | |
430 | } | |
431 | ||
432 | /* Precise sleep: */ | |
433 | extern long hrtimer_nanosleep(struct timespec *rqtp, | |
434 | struct timespec __user *rmtp, | |
435 | const enum hrtimer_mode mode, | |
436 | const clockid_t clockid); | |
437 | extern long hrtimer_nanosleep_restart(struct restart_block *restart_block); | |
438 | ||
439 | extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, | |
440 | struct task_struct *tsk); | |
441 | ||
442 | extern int schedule_hrtimeout_range(ktime_t *expires, unsigned long delta, | |
443 | const enum hrtimer_mode mode); | |
444 | extern int schedule_hrtimeout_range_clock(ktime_t *expires, | |
445 | unsigned long delta, const enum hrtimer_mode mode, int clock); | |
446 | extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode); | |
447 | ||
448 | /* Soft interrupt function to run the hrtimer queues: */ | |
449 | extern void hrtimer_run_queues(void); | |
450 | extern void hrtimer_run_pending(void); | |
451 | ||
452 | /* Bootup initialization: */ | |
453 | extern void __init hrtimers_init(void); | |
454 | ||
455 | #if BITS_PER_LONG < 64 | |
456 | extern u64 ktime_divns(const ktime_t kt, s64 div); | |
457 | #else /* BITS_PER_LONG < 64 */ | |
458 | # define ktime_divns(kt, div) (u64)((kt).tv64 / (div)) | |
459 | #endif | |
460 | ||
461 | /* Show pending timers: */ | |
462 | extern void sysrq_timer_list_show(void); | |
463 | ||
464 | #endif |