]>
Commit | Line | Data |
---|---|---|
c0a31329 TG |
1 | /* |
2 | * linux/kernel/hrtimer.c | |
3 | * | |
4 | * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de> | |
5 | * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar | |
6 | * | |
7 | * High-resolution kernel timers | |
8 | * | |
9 | * In contrast to the low-resolution timeout API implemented in | |
10 | * kernel/timer.c, hrtimers provide finer resolution and accuracy | |
11 | * depending on system configuration and capabilities. | |
12 | * | |
13 | * These timers are currently used for: | |
14 | * - itimers | |
15 | * - POSIX timers | |
16 | * - nanosleep | |
17 | * - precise in-kernel timing | |
18 | * | |
19 | * Started by: Thomas Gleixner and Ingo Molnar | |
20 | * | |
21 | * Credits: | |
22 | * based on kernel/timer.c | |
23 | * | |
24 | * For licencing details see kernel-base/COPYING | |
25 | */ | |
26 | ||
27 | #include <linux/cpu.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/percpu.h> | |
30 | #include <linux/hrtimer.h> | |
31 | #include <linux/notifier.h> | |
32 | #include <linux/syscalls.h> | |
33 | #include <linux/interrupt.h> | |
34 | ||
35 | #include <asm/uaccess.h> | |
36 | ||
37 | /** | |
38 | * ktime_get - get the monotonic time in ktime_t format | |
39 | * | |
40 | * returns the time in ktime_t format | |
41 | */ | |
42 | static ktime_t ktime_get(void) | |
43 | { | |
44 | struct timespec now; | |
45 | ||
46 | ktime_get_ts(&now); | |
47 | ||
48 | return timespec_to_ktime(now); | |
49 | } | |
50 | ||
51 | /** | |
52 | * ktime_get_real - get the real (wall-) time in ktime_t format | |
53 | * | |
54 | * returns the time in ktime_t format | |
55 | */ | |
56 | static ktime_t ktime_get_real(void) | |
57 | { | |
58 | struct timespec now; | |
59 | ||
60 | getnstimeofday(&now); | |
61 | ||
62 | return timespec_to_ktime(now); | |
63 | } | |
64 | ||
65 | EXPORT_SYMBOL_GPL(ktime_get_real); | |
66 | ||
67 | /* | |
68 | * The timer bases: | |
69 | */ | |
70 | ||
71 | #define MAX_HRTIMER_BASES 2 | |
72 | ||
73 | static DEFINE_PER_CPU(struct hrtimer_base, hrtimer_bases[MAX_HRTIMER_BASES]) = | |
74 | { | |
75 | { | |
76 | .index = CLOCK_REALTIME, | |
77 | .get_time = &ktime_get_real, | |
78 | .resolution = KTIME_REALTIME_RES, | |
79 | }, | |
80 | { | |
81 | .index = CLOCK_MONOTONIC, | |
82 | .get_time = &ktime_get, | |
83 | .resolution = KTIME_MONOTONIC_RES, | |
84 | }, | |
85 | }; | |
86 | ||
87 | /** | |
88 | * ktime_get_ts - get the monotonic clock in timespec format | |
89 | * | |
90 | * @ts: pointer to timespec variable | |
91 | * | |
92 | * The function calculates the monotonic clock from the realtime | |
93 | * clock and the wall_to_monotonic offset and stores the result | |
94 | * in normalized timespec format in the variable pointed to by ts. | |
95 | */ | |
96 | void ktime_get_ts(struct timespec *ts) | |
97 | { | |
98 | struct timespec tomono; | |
99 | unsigned long seq; | |
100 | ||
101 | do { | |
102 | seq = read_seqbegin(&xtime_lock); | |
103 | getnstimeofday(ts); | |
104 | tomono = wall_to_monotonic; | |
105 | ||
106 | } while (read_seqretry(&xtime_lock, seq)); | |
107 | ||
108 | set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec, | |
109 | ts->tv_nsec + tomono.tv_nsec); | |
110 | } | |
69778e32 | 111 | EXPORT_SYMBOL_GPL(ktime_get_ts); |
c0a31329 TG |
112 | |
113 | /* | |
114 | * Functions and macros which are different for UP/SMP systems are kept in a | |
115 | * single place | |
116 | */ | |
117 | #ifdef CONFIG_SMP | |
118 | ||
119 | #define set_curr_timer(b, t) do { (b)->curr_timer = (t); } while (0) | |
120 | ||
121 | /* | |
122 | * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock | |
123 | * means that all timers which are tied to this base via timer->base are | |
124 | * locked, and the base itself is locked too. | |
125 | * | |
126 | * So __run_timers/migrate_timers can safely modify all timers which could | |
127 | * be found on the lists/queues. | |
128 | * | |
129 | * When the timer's base is locked, and the timer removed from list, it is | |
130 | * possible to set timer->base = NULL and drop the lock: the timer remains | |
131 | * locked. | |
132 | */ | |
133 | static struct hrtimer_base *lock_hrtimer_base(const struct hrtimer *timer, | |
134 | unsigned long *flags) | |
135 | { | |
136 | struct hrtimer_base *base; | |
137 | ||
138 | for (;;) { | |
139 | base = timer->base; | |
140 | if (likely(base != NULL)) { | |
141 | spin_lock_irqsave(&base->lock, *flags); | |
142 | if (likely(base == timer->base)) | |
143 | return base; | |
144 | /* The timer has migrated to another CPU: */ | |
145 | spin_unlock_irqrestore(&base->lock, *flags); | |
146 | } | |
147 | cpu_relax(); | |
148 | } | |
149 | } | |
150 | ||
151 | /* | |
152 | * Switch the timer base to the current CPU when possible. | |
153 | */ | |
154 | static inline struct hrtimer_base * | |
155 | switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_base *base) | |
156 | { | |
157 | struct hrtimer_base *new_base; | |
158 | ||
159 | new_base = &__get_cpu_var(hrtimer_bases[base->index]); | |
160 | ||
161 | if (base != new_base) { | |
162 | /* | |
163 | * We are trying to schedule the timer on the local CPU. | |
164 | * However we can't change timer's base while it is running, | |
165 | * so we keep it on the same CPU. No hassle vs. reprogramming | |
166 | * the event source in the high resolution case. The softirq | |
167 | * code will take care of this when the timer function has | |
168 | * completed. There is no conflict as we hold the lock until | |
169 | * the timer is enqueued. | |
170 | */ | |
171 | if (unlikely(base->curr_timer == timer)) | |
172 | return base; | |
173 | ||
174 | /* See the comment in lock_timer_base() */ | |
175 | timer->base = NULL; | |
176 | spin_unlock(&base->lock); | |
177 | spin_lock(&new_base->lock); | |
178 | timer->base = new_base; | |
179 | } | |
180 | return new_base; | |
181 | } | |
182 | ||
183 | #else /* CONFIG_SMP */ | |
184 | ||
185 | #define set_curr_timer(b, t) do { } while (0) | |
186 | ||
187 | static inline struct hrtimer_base * | |
188 | lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
189 | { | |
190 | struct hrtimer_base *base = timer->base; | |
191 | ||
192 | spin_lock_irqsave(&base->lock, *flags); | |
193 | ||
194 | return base; | |
195 | } | |
196 | ||
197 | #define switch_hrtimer_base(t, b) (b) | |
198 | ||
199 | #endif /* !CONFIG_SMP */ | |
200 | ||
201 | /* | |
202 | * Functions for the union type storage format of ktime_t which are | |
203 | * too large for inlining: | |
204 | */ | |
205 | #if BITS_PER_LONG < 64 | |
206 | # ifndef CONFIG_KTIME_SCALAR | |
207 | /** | |
208 | * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable | |
209 | * | |
210 | * @kt: addend | |
211 | * @nsec: the scalar nsec value to add | |
212 | * | |
213 | * Returns the sum of kt and nsec in ktime_t format | |
214 | */ | |
215 | ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) | |
216 | { | |
217 | ktime_t tmp; | |
218 | ||
219 | if (likely(nsec < NSEC_PER_SEC)) { | |
220 | tmp.tv64 = nsec; | |
221 | } else { | |
222 | unsigned long rem = do_div(nsec, NSEC_PER_SEC); | |
223 | ||
224 | tmp = ktime_set((long)nsec, rem); | |
225 | } | |
226 | ||
227 | return ktime_add(kt, tmp); | |
228 | } | |
229 | ||
230 | #else /* CONFIG_KTIME_SCALAR */ | |
231 | ||
232 | # endif /* !CONFIG_KTIME_SCALAR */ | |
233 | ||
234 | /* | |
235 | * Divide a ktime value by a nanosecond value | |
236 | */ | |
237 | static unsigned long ktime_divns(const ktime_t kt, nsec_t div) | |
238 | { | |
239 | u64 dclc, inc, dns; | |
240 | int sft = 0; | |
241 | ||
242 | dclc = dns = ktime_to_ns(kt); | |
243 | inc = div; | |
244 | /* Make sure the divisor is less than 2^32: */ | |
245 | while (div >> 32) { | |
246 | sft++; | |
247 | div >>= 1; | |
248 | } | |
249 | dclc >>= sft; | |
250 | do_div(dclc, (unsigned long) div); | |
251 | ||
252 | return (unsigned long) dclc; | |
253 | } | |
254 | ||
255 | #else /* BITS_PER_LONG < 64 */ | |
256 | # define ktime_divns(kt, div) (unsigned long)((kt).tv64 / (div)) | |
257 | #endif /* BITS_PER_LONG >= 64 */ | |
258 | ||
259 | /* | |
260 | * Counterpart to lock_timer_base above: | |
261 | */ | |
262 | static inline | |
263 | void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags) | |
264 | { | |
265 | spin_unlock_irqrestore(&timer->base->lock, *flags); | |
266 | } | |
267 | ||
268 | /** | |
269 | * hrtimer_forward - forward the timer expiry | |
270 | * | |
271 | * @timer: hrtimer to forward | |
272 | * @interval: the interval to forward | |
273 | * | |
274 | * Forward the timer expiry so it will expire in the future. | |
275 | * The number of overruns is added to the overrun field. | |
276 | */ | |
277 | unsigned long | |
278 | hrtimer_forward(struct hrtimer *timer, const ktime_t interval) | |
279 | { | |
280 | unsigned long orun = 1; | |
281 | ktime_t delta, now; | |
282 | ||
283 | now = timer->base->get_time(); | |
284 | ||
285 | delta = ktime_sub(now, timer->expires); | |
286 | ||
287 | if (delta.tv64 < 0) | |
288 | return 0; | |
289 | ||
290 | if (unlikely(delta.tv64 >= interval.tv64)) { | |
291 | nsec_t incr = ktime_to_ns(interval); | |
292 | ||
293 | orun = ktime_divns(delta, incr); | |
294 | timer->expires = ktime_add_ns(timer->expires, incr * orun); | |
295 | if (timer->expires.tv64 > now.tv64) | |
296 | return orun; | |
297 | /* | |
298 | * This (and the ktime_add() below) is the | |
299 | * correction for exact: | |
300 | */ | |
301 | orun++; | |
302 | } | |
303 | timer->expires = ktime_add(timer->expires, interval); | |
304 | ||
305 | return orun; | |
306 | } | |
307 | ||
308 | /* | |
309 | * enqueue_hrtimer - internal function to (re)start a timer | |
310 | * | |
311 | * The timer is inserted in expiry order. Insertion into the | |
312 | * red black tree is O(log(n)). Must hold the base lock. | |
313 | */ | |
314 | static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) | |
315 | { | |
316 | struct rb_node **link = &base->active.rb_node; | |
317 | struct list_head *prev = &base->pending; | |
318 | struct rb_node *parent = NULL; | |
319 | struct hrtimer *entry; | |
320 | ||
321 | /* | |
322 | * Find the right place in the rbtree: | |
323 | */ | |
324 | while (*link) { | |
325 | parent = *link; | |
326 | entry = rb_entry(parent, struct hrtimer, node); | |
327 | /* | |
328 | * We dont care about collisions. Nodes with | |
329 | * the same expiry time stay together. | |
330 | */ | |
331 | if (timer->expires.tv64 < entry->expires.tv64) | |
332 | link = &(*link)->rb_left; | |
333 | else { | |
334 | link = &(*link)->rb_right; | |
335 | prev = &entry->list; | |
336 | } | |
337 | } | |
338 | ||
339 | /* | |
340 | * Insert the timer to the rbtree and to the sorted list: | |
341 | */ | |
342 | rb_link_node(&timer->node, parent, link); | |
343 | rb_insert_color(&timer->node, &base->active); | |
344 | list_add(&timer->list, prev); | |
345 | ||
346 | timer->state = HRTIMER_PENDING; | |
347 | } | |
348 | ||
349 | ||
350 | /* | |
351 | * __remove_hrtimer - internal function to remove a timer | |
352 | * | |
353 | * Caller must hold the base lock. | |
354 | */ | |
355 | static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) | |
356 | { | |
357 | /* | |
358 | * Remove the timer from the sorted list and from the rbtree: | |
359 | */ | |
360 | list_del(&timer->list); | |
361 | rb_erase(&timer->node, &base->active); | |
362 | } | |
363 | ||
364 | /* | |
365 | * remove hrtimer, called with base lock held | |
366 | */ | |
367 | static inline int | |
368 | remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base) | |
369 | { | |
370 | if (hrtimer_active(timer)) { | |
371 | __remove_hrtimer(timer, base); | |
372 | timer->state = HRTIMER_INACTIVE; | |
373 | return 1; | |
374 | } | |
375 | return 0; | |
376 | } | |
377 | ||
378 | /** | |
379 | * hrtimer_start - (re)start an relative timer on the current CPU | |
380 | * | |
381 | * @timer: the timer to be added | |
382 | * @tim: expiry time | |
383 | * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL) | |
384 | * | |
385 | * Returns: | |
386 | * 0 on success | |
387 | * 1 when the timer was active | |
388 | */ | |
389 | int | |
390 | hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode) | |
391 | { | |
392 | struct hrtimer_base *base, *new_base; | |
393 | unsigned long flags; | |
394 | int ret; | |
395 | ||
396 | base = lock_hrtimer_base(timer, &flags); | |
397 | ||
398 | /* Remove an active timer from the queue: */ | |
399 | ret = remove_hrtimer(timer, base); | |
400 | ||
401 | /* Switch the timer base, if necessary: */ | |
402 | new_base = switch_hrtimer_base(timer, base); | |
403 | ||
404 | if (mode == HRTIMER_REL) | |
405 | tim = ktime_add(tim, new_base->get_time()); | |
406 | timer->expires = tim; | |
407 | ||
408 | enqueue_hrtimer(timer, new_base); | |
409 | ||
410 | unlock_hrtimer_base(timer, &flags); | |
411 | ||
412 | return ret; | |
413 | } | |
414 | ||
415 | /** | |
416 | * hrtimer_try_to_cancel - try to deactivate a timer | |
417 | * | |
418 | * @timer: hrtimer to stop | |
419 | * | |
420 | * Returns: | |
421 | * 0 when the timer was not active | |
422 | * 1 when the timer was active | |
423 | * -1 when the timer is currently excuting the callback function and | |
424 | * can not be stopped | |
425 | */ | |
426 | int hrtimer_try_to_cancel(struct hrtimer *timer) | |
427 | { | |
428 | struct hrtimer_base *base; | |
429 | unsigned long flags; | |
430 | int ret = -1; | |
431 | ||
432 | base = lock_hrtimer_base(timer, &flags); | |
433 | ||
434 | if (base->curr_timer != timer) | |
435 | ret = remove_hrtimer(timer, base); | |
436 | ||
437 | unlock_hrtimer_base(timer, &flags); | |
438 | ||
439 | return ret; | |
440 | ||
441 | } | |
442 | ||
443 | /** | |
444 | * hrtimer_cancel - cancel a timer and wait for the handler to finish. | |
445 | * | |
446 | * @timer: the timer to be cancelled | |
447 | * | |
448 | * Returns: | |
449 | * 0 when the timer was not active | |
450 | * 1 when the timer was active | |
451 | */ | |
452 | int hrtimer_cancel(struct hrtimer *timer) | |
453 | { | |
454 | for (;;) { | |
455 | int ret = hrtimer_try_to_cancel(timer); | |
456 | ||
457 | if (ret >= 0) | |
458 | return ret; | |
459 | } | |
460 | } | |
461 | ||
462 | /** | |
463 | * hrtimer_get_remaining - get remaining time for the timer | |
464 | * | |
465 | * @timer: the timer to read | |
466 | */ | |
467 | ktime_t hrtimer_get_remaining(const struct hrtimer *timer) | |
468 | { | |
469 | struct hrtimer_base *base; | |
470 | unsigned long flags; | |
471 | ktime_t rem; | |
472 | ||
473 | base = lock_hrtimer_base(timer, &flags); | |
474 | rem = ktime_sub(timer->expires, timer->base->get_time()); | |
475 | unlock_hrtimer_base(timer, &flags); | |
476 | ||
477 | return rem; | |
478 | } | |
479 | ||
480 | /** | |
481 | * hrtimer_rebase - rebase an initialized hrtimer to a different base | |
482 | * | |
483 | * @timer: the timer to be rebased | |
484 | * @clock_id: the clock to be used | |
485 | */ | |
486 | void hrtimer_rebase(struct hrtimer *timer, const clockid_t clock_id) | |
487 | { | |
488 | struct hrtimer_base *bases; | |
489 | ||
490 | bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); | |
491 | timer->base = &bases[clock_id]; | |
492 | } | |
493 | ||
494 | /** | |
495 | * hrtimer_init - initialize a timer to the given clock | |
496 | * | |
497 | * @timer: the timer to be initialized | |
498 | * @clock_id: the clock to be used | |
499 | */ | |
500 | void hrtimer_init(struct hrtimer *timer, const clockid_t clock_id) | |
501 | { | |
502 | memset(timer, 0, sizeof(struct hrtimer)); | |
503 | hrtimer_rebase(timer, clock_id); | |
504 | } | |
505 | ||
506 | /** | |
507 | * hrtimer_get_res - get the timer resolution for a clock | |
508 | * | |
509 | * @which_clock: which clock to query | |
510 | * @tp: pointer to timespec variable to store the resolution | |
511 | * | |
512 | * Store the resolution of the clock selected by which_clock in the | |
513 | * variable pointed to by tp. | |
514 | */ | |
515 | int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp) | |
516 | { | |
517 | struct hrtimer_base *bases; | |
518 | ||
519 | tp->tv_sec = 0; | |
520 | bases = per_cpu(hrtimer_bases, raw_smp_processor_id()); | |
521 | tp->tv_nsec = bases[which_clock].resolution; | |
522 | ||
523 | return 0; | |
524 | } | |
525 | ||
526 | /* | |
527 | * Expire the per base hrtimer-queue: | |
528 | */ | |
529 | static inline void run_hrtimer_queue(struct hrtimer_base *base) | |
530 | { | |
531 | ktime_t now = base->get_time(); | |
532 | ||
533 | spin_lock_irq(&base->lock); | |
534 | ||
535 | while (!list_empty(&base->pending)) { | |
536 | struct hrtimer *timer; | |
537 | int (*fn)(void *); | |
538 | int restart; | |
539 | void *data; | |
540 | ||
541 | timer = list_entry(base->pending.next, struct hrtimer, list); | |
542 | if (now.tv64 <= timer->expires.tv64) | |
543 | break; | |
544 | ||
545 | fn = timer->function; | |
546 | data = timer->data; | |
547 | set_curr_timer(base, timer); | |
548 | __remove_hrtimer(timer, base); | |
549 | spin_unlock_irq(&base->lock); | |
550 | ||
551 | /* | |
552 | * fn == NULL is special case for the simplest timer | |
553 | * variant - wake up process and do not restart: | |
554 | */ | |
555 | if (!fn) { | |
556 | wake_up_process(data); | |
557 | restart = HRTIMER_NORESTART; | |
558 | } else | |
559 | restart = fn(data); | |
560 | ||
561 | spin_lock_irq(&base->lock); | |
562 | ||
563 | if (restart == HRTIMER_RESTART) | |
564 | enqueue_hrtimer(timer, base); | |
565 | else | |
566 | timer->state = HRTIMER_EXPIRED; | |
567 | } | |
568 | set_curr_timer(base, NULL); | |
569 | spin_unlock_irq(&base->lock); | |
570 | } | |
571 | ||
572 | /* | |
573 | * Called from timer softirq every jiffy, expire hrtimers: | |
574 | */ | |
575 | void hrtimer_run_queues(void) | |
576 | { | |
577 | struct hrtimer_base *base = __get_cpu_var(hrtimer_bases); | |
578 | int i; | |
579 | ||
580 | for (i = 0; i < MAX_HRTIMER_BASES; i++) | |
581 | run_hrtimer_queue(&base[i]); | |
582 | } | |
583 | ||
10c94ec1 TG |
584 | /* |
585 | * Sleep related functions: | |
586 | */ | |
587 | ||
588 | /** | |
589 | * schedule_hrtimer - sleep until timeout | |
590 | * | |
591 | * @timer: hrtimer variable initialized with the correct clock base | |
592 | * @mode: timeout value is abs/rel | |
593 | * | |
594 | * Make the current task sleep until @timeout is | |
595 | * elapsed. | |
596 | * | |
597 | * You can set the task state as follows - | |
598 | * | |
599 | * %TASK_UNINTERRUPTIBLE - at least @timeout is guaranteed to | |
600 | * pass before the routine returns. The routine will return 0 | |
601 | * | |
602 | * %TASK_INTERRUPTIBLE - the routine may return early if a signal is | |
603 | * delivered to the current task. In this case the remaining time | |
604 | * will be returned | |
605 | * | |
606 | * The current task state is guaranteed to be TASK_RUNNING when this | |
607 | * routine returns. | |
608 | */ | |
609 | static ktime_t __sched | |
610 | schedule_hrtimer(struct hrtimer *timer, const enum hrtimer_mode mode) | |
611 | { | |
612 | /* fn stays NULL, meaning single-shot wakeup: */ | |
613 | timer->data = current; | |
614 | ||
615 | hrtimer_start(timer, timer->expires, mode); | |
616 | ||
617 | schedule(); | |
618 | hrtimer_cancel(timer); | |
619 | ||
620 | /* Return the remaining time: */ | |
621 | if (timer->state != HRTIMER_EXPIRED) | |
622 | return ktime_sub(timer->expires, timer->base->get_time()); | |
623 | else | |
624 | return (ktime_t) {.tv64 = 0 }; | |
625 | } | |
626 | ||
627 | static inline ktime_t __sched | |
628 | schedule_hrtimer_interruptible(struct hrtimer *timer, | |
629 | const enum hrtimer_mode mode) | |
630 | { | |
631 | set_current_state(TASK_INTERRUPTIBLE); | |
632 | ||
633 | return schedule_hrtimer(timer, mode); | |
634 | } | |
635 | ||
636 | static long __sched | |
637 | nanosleep_restart(struct restart_block *restart, clockid_t clockid) | |
638 | { | |
639 | struct timespec __user *rmtp, tu; | |
640 | void *rfn_save = restart->fn; | |
641 | struct hrtimer timer; | |
642 | ktime_t rem; | |
643 | ||
644 | restart->fn = do_no_restart_syscall; | |
645 | ||
646 | hrtimer_init(&timer, clockid); | |
647 | ||
648 | timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0; | |
649 | ||
650 | rem = schedule_hrtimer_interruptible(&timer, HRTIMER_ABS); | |
651 | ||
652 | if (rem.tv64 <= 0) | |
653 | return 0; | |
654 | ||
655 | rmtp = (struct timespec __user *) restart->arg2; | |
656 | tu = ktime_to_timespec(rem); | |
657 | if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu))) | |
658 | return -EFAULT; | |
659 | ||
660 | restart->fn = rfn_save; | |
661 | ||
662 | /* The other values in restart are already filled in */ | |
663 | return -ERESTART_RESTARTBLOCK; | |
664 | } | |
665 | ||
666 | static long __sched nanosleep_restart_mono(struct restart_block *restart) | |
667 | { | |
668 | return nanosleep_restart(restart, CLOCK_MONOTONIC); | |
669 | } | |
670 | ||
671 | static long __sched nanosleep_restart_real(struct restart_block *restart) | |
672 | { | |
673 | return nanosleep_restart(restart, CLOCK_REALTIME); | |
674 | } | |
675 | ||
676 | long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp, | |
677 | const enum hrtimer_mode mode, const clockid_t clockid) | |
678 | { | |
679 | struct restart_block *restart; | |
680 | struct hrtimer timer; | |
681 | struct timespec tu; | |
682 | ktime_t rem; | |
683 | ||
684 | hrtimer_init(&timer, clockid); | |
685 | ||
686 | timer.expires = timespec_to_ktime(*rqtp); | |
687 | ||
688 | rem = schedule_hrtimer_interruptible(&timer, mode); | |
689 | if (rem.tv64 <= 0) | |
690 | return 0; | |
691 | ||
692 | /* Absolute timers do not update the rmtp value: */ | |
693 | if (mode == HRTIMER_ABS) | |
694 | return -ERESTARTNOHAND; | |
695 | ||
696 | tu = ktime_to_timespec(rem); | |
697 | ||
698 | if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu))) | |
699 | return -EFAULT; | |
700 | ||
701 | restart = ¤t_thread_info()->restart_block; | |
702 | restart->fn = (clockid == CLOCK_MONOTONIC) ? | |
703 | nanosleep_restart_mono : nanosleep_restart_real; | |
704 | restart->arg0 = timer.expires.tv64 & 0xFFFFFFFF; | |
705 | restart->arg1 = timer.expires.tv64 >> 32; | |
706 | restart->arg2 = (unsigned long) rmtp; | |
707 | ||
708 | return -ERESTART_RESTARTBLOCK; | |
709 | } | |
710 | ||
6ba1b912 TG |
711 | asmlinkage long |
712 | sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp) | |
713 | { | |
714 | struct timespec tu; | |
715 | ||
716 | if (copy_from_user(&tu, rqtp, sizeof(tu))) | |
717 | return -EFAULT; | |
718 | ||
719 | if (!timespec_valid(&tu)) | |
720 | return -EINVAL; | |
721 | ||
722 | return hrtimer_nanosleep(&tu, rmtp, HRTIMER_REL, CLOCK_MONOTONIC); | |
723 | } | |
724 | ||
c0a31329 TG |
725 | /* |
726 | * Functions related to boot-time initialization: | |
727 | */ | |
728 | static void __devinit init_hrtimers_cpu(int cpu) | |
729 | { | |
730 | struct hrtimer_base *base = per_cpu(hrtimer_bases, cpu); | |
731 | int i; | |
732 | ||
733 | for (i = 0; i < MAX_HRTIMER_BASES; i++) { | |
734 | spin_lock_init(&base->lock); | |
735 | INIT_LIST_HEAD(&base->pending); | |
736 | base++; | |
737 | } | |
738 | } | |
739 | ||
740 | #ifdef CONFIG_HOTPLUG_CPU | |
741 | ||
742 | static void migrate_hrtimer_list(struct hrtimer_base *old_base, | |
743 | struct hrtimer_base *new_base) | |
744 | { | |
745 | struct hrtimer *timer; | |
746 | struct rb_node *node; | |
747 | ||
748 | while ((node = rb_first(&old_base->active))) { | |
749 | timer = rb_entry(node, struct hrtimer, node); | |
750 | __remove_hrtimer(timer, old_base); | |
751 | timer->base = new_base; | |
752 | enqueue_hrtimer(timer, new_base); | |
753 | } | |
754 | } | |
755 | ||
756 | static void migrate_hrtimers(int cpu) | |
757 | { | |
758 | struct hrtimer_base *old_base, *new_base; | |
759 | int i; | |
760 | ||
761 | BUG_ON(cpu_online(cpu)); | |
762 | old_base = per_cpu(hrtimer_bases, cpu); | |
763 | new_base = get_cpu_var(hrtimer_bases); | |
764 | ||
765 | local_irq_disable(); | |
766 | ||
767 | for (i = 0; i < MAX_HRTIMER_BASES; i++) { | |
768 | ||
769 | spin_lock(&new_base->lock); | |
770 | spin_lock(&old_base->lock); | |
771 | ||
772 | BUG_ON(old_base->curr_timer); | |
773 | ||
774 | migrate_hrtimer_list(old_base, new_base); | |
775 | ||
776 | spin_unlock(&old_base->lock); | |
777 | spin_unlock(&new_base->lock); | |
778 | old_base++; | |
779 | new_base++; | |
780 | } | |
781 | ||
782 | local_irq_enable(); | |
783 | put_cpu_var(hrtimer_bases); | |
784 | } | |
785 | #endif /* CONFIG_HOTPLUG_CPU */ | |
786 | ||
787 | static int __devinit hrtimer_cpu_notify(struct notifier_block *self, | |
788 | unsigned long action, void *hcpu) | |
789 | { | |
790 | long cpu = (long)hcpu; | |
791 | ||
792 | switch (action) { | |
793 | ||
794 | case CPU_UP_PREPARE: | |
795 | init_hrtimers_cpu(cpu); | |
796 | break; | |
797 | ||
798 | #ifdef CONFIG_HOTPLUG_CPU | |
799 | case CPU_DEAD: | |
800 | migrate_hrtimers(cpu); | |
801 | break; | |
802 | #endif | |
803 | ||
804 | default: | |
805 | break; | |
806 | } | |
807 | ||
808 | return NOTIFY_OK; | |
809 | } | |
810 | ||
811 | static struct notifier_block __devinitdata hrtimers_nb = { | |
812 | .notifier_call = hrtimer_cpu_notify, | |
813 | }; | |
814 | ||
815 | void __init hrtimers_init(void) | |
816 | { | |
817 | hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE, | |
818 | (void *)(long)smp_processor_id()); | |
819 | register_cpu_notifier(&hrtimers_nb); | |
820 | } | |
821 |