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Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001/*
2 * linux/kernel/hrtimer.c
3 *
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08004 * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08005 * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08006 * Copyright(C) 2006-2007 Timesys Corp., Thomas Gleixner
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08007 *
8 * High-resolution kernel timers
9 *
10 * In contrast to the low-resolution timeout API implemented in
11 * kernel/timer.c, hrtimers provide finer resolution and accuracy
12 * depending on system configuration and capabilities.
13 *
14 * These timers are currently used for:
15 * - itimers
16 * - POSIX timers
17 * - nanosleep
18 * - precise in-kernel timing
19 *
20 * Started by: Thomas Gleixner and Ingo Molnar
21 *
22 * Credits:
23 * based on kernel/timer.c
24 *
Thomas Gleixner66188fa2006-02-01 03:05:13 -080025 * Help, testing, suggestions, bugfixes, improvements were
26 * provided by:
27 *
28 * George Anzinger, Andrew Morton, Steven Rostedt, Roman Zippel
29 * et. al.
30 *
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080031 * For licencing details see kernel-base/COPYING
32 */
33
34#include <linux/cpu.h>
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -080035#include <linux/irq.h>
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080036#include <linux/module.h>
37#include <linux/percpu.h>
38#include <linux/hrtimer.h>
39#include <linux/notifier.h>
40#include <linux/syscalls.h>
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -080041#include <linux/kallsyms.h>
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080042#include <linux/interrupt.h>
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -080043#include <linux/tick.h>
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -080044#include <linux/seq_file.h>
45#include <linux/err.h>
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080046
47#include <asm/uaccess.h>
48
49/**
50 * ktime_get - get the monotonic time in ktime_t format
51 *
52 * returns the time in ktime_t format
53 */
Thomas Gleixnerd316c572007-02-16 01:28:00 -080054ktime_t ktime_get(void)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080055{
56 struct timespec now;
57
58 ktime_get_ts(&now);
59
60 return timespec_to_ktime(now);
61}
Patrick McHardy641b9e02007-03-16 01:18:42 -070062EXPORT_SYMBOL_GPL(ktime_get);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080063
64/**
65 * ktime_get_real - get the real (wall-) time in ktime_t format
66 *
67 * returns the time in ktime_t format
68 */
Thomas Gleixnerd316c572007-02-16 01:28:00 -080069ktime_t ktime_get_real(void)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080070{
71 struct timespec now;
72
73 getnstimeofday(&now);
74
75 return timespec_to_ktime(now);
76}
77
78EXPORT_SYMBOL_GPL(ktime_get_real);
79
80/*
81 * The timer bases:
George Anzinger7978672c2006-02-01 03:05:11 -080082 *
83 * Note: If we want to add new timer bases, we have to skip the two
84 * clock ids captured by the cpu-timers. We do this by holding empty
85 * entries rather than doing math adjustment of the clock ids.
86 * This ensures that we capture erroneous accesses to these clock ids
87 * rather than moving them into the range of valid clock id's.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080088 */
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -080089DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080090{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -080091
92 .clock_base =
Thomas Gleixnerc0a31322006-01-09 20:52:32 -080093 {
Thomas Gleixner3c8aa392007-02-16 01:27:50 -080094 {
95 .index = CLOCK_REALTIME,
96 .get_time = &ktime_get_real,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -080097 .resolution = KTIME_LOW_RES,
Thomas Gleixner3c8aa392007-02-16 01:27:50 -080098 },
99 {
100 .index = CLOCK_MONOTONIC,
101 .get_time = &ktime_get,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800102 .resolution = KTIME_LOW_RES,
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800103 },
104 }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800105};
106
107/**
108 * ktime_get_ts - get the monotonic clock in timespec format
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800109 * @ts: pointer to timespec variable
110 *
111 * The function calculates the monotonic clock from the realtime
112 * clock and the wall_to_monotonic offset and stores the result
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800113 * in normalized timespec format in the variable pointed to by @ts.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800114 */
115void ktime_get_ts(struct timespec *ts)
116{
117 struct timespec tomono;
118 unsigned long seq;
119
120 do {
121 seq = read_seqbegin(&xtime_lock);
122 getnstimeofday(ts);
123 tomono = wall_to_monotonic;
124
125 } while (read_seqretry(&xtime_lock, seq));
126
127 set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
128 ts->tv_nsec + tomono.tv_nsec);
129}
Matt Helsley69778e32006-01-09 20:52:39 -0800130EXPORT_SYMBOL_GPL(ktime_get_ts);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800131
132/*
Thomas Gleixner92127c72006-03-26 01:38:05 -0800133 * Get the coarse grained time at the softirq based on xtime and
134 * wall_to_monotonic.
135 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800136static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
Thomas Gleixner92127c72006-03-26 01:38:05 -0800137{
138 ktime_t xtim, tomono;
Thomas Gleixnerad28d942007-03-16 13:38:21 -0800139 struct timespec xts, tom;
Thomas Gleixner92127c72006-03-26 01:38:05 -0800140 unsigned long seq;
141
142 do {
143 seq = read_seqbegin(&xtime_lock);
john stultz2c6b47d2007-07-24 17:47:43 -0700144 xts = current_kernel_time();
Thomas Gleixnerad28d942007-03-16 13:38:21 -0800145 tom = wall_to_monotonic;
Thomas Gleixner92127c72006-03-26 01:38:05 -0800146 } while (read_seqretry(&xtime_lock, seq));
147
john stultzf4304ab2007-02-16 01:27:26 -0800148 xtim = timespec_to_ktime(xts);
Thomas Gleixnerad28d942007-03-16 13:38:21 -0800149 tomono = timespec_to_ktime(tom);
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800150 base->clock_base[CLOCK_REALTIME].softirq_time = xtim;
151 base->clock_base[CLOCK_MONOTONIC].softirq_time =
152 ktime_add(xtim, tomono);
Thomas Gleixner92127c72006-03-26 01:38:05 -0800153}
154
155/*
Thomas Gleixner303e9672007-02-16 01:27:51 -0800156 * Helper function to check, whether the timer is running the callback
157 * function
158 */
159static inline int hrtimer_callback_running(struct hrtimer *timer)
160{
161 return timer->state & HRTIMER_STATE_CALLBACK;
162}
163
164/*
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800165 * Functions and macros which are different for UP/SMP systems are kept in a
166 * single place
167 */
168#ifdef CONFIG_SMP
169
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800170/*
171 * We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
172 * means that all timers which are tied to this base via timer->base are
173 * locked, and the base itself is locked too.
174 *
175 * So __run_timers/migrate_timers can safely modify all timers which could
176 * be found on the lists/queues.
177 *
178 * When the timer's base is locked, and the timer removed from list, it is
179 * possible to set timer->base = NULL and drop the lock: the timer remains
180 * locked.
181 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800182static
183struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
184 unsigned long *flags)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800185{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800186 struct hrtimer_clock_base *base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800187
188 for (;;) {
189 base = timer->base;
190 if (likely(base != NULL)) {
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800191 spin_lock_irqsave(&base->cpu_base->lock, *flags);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800192 if (likely(base == timer->base))
193 return base;
194 /* The timer has migrated to another CPU: */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800195 spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800196 }
197 cpu_relax();
198 }
199}
200
201/*
202 * Switch the timer base to the current CPU when possible.
203 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800204static inline struct hrtimer_clock_base *
205switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800206{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800207 struct hrtimer_clock_base *new_base;
208 struct hrtimer_cpu_base *new_cpu_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800209
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800210 new_cpu_base = &__get_cpu_var(hrtimer_bases);
211 new_base = &new_cpu_base->clock_base[base->index];
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800212
213 if (base != new_base) {
214 /*
215 * We are trying to schedule the timer on the local CPU.
216 * However we can't change timer's base while it is running,
217 * so we keep it on the same CPU. No hassle vs. reprogramming
218 * the event source in the high resolution case. The softirq
219 * code will take care of this when the timer function has
220 * completed. There is no conflict as we hold the lock until
221 * the timer is enqueued.
222 */
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800223 if (unlikely(hrtimer_callback_running(timer)))
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800224 return base;
225
226 /* See the comment in lock_timer_base() */
227 timer->base = NULL;
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800228 spin_unlock(&base->cpu_base->lock);
229 spin_lock(&new_base->cpu_base->lock);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800230 timer->base = new_base;
231 }
232 return new_base;
233}
234
235#else /* CONFIG_SMP */
236
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800237static inline struct hrtimer_clock_base *
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800238lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
239{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800240 struct hrtimer_clock_base *base = timer->base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800241
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800242 spin_lock_irqsave(&base->cpu_base->lock, *flags);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800243
244 return base;
245}
246
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800247# define switch_hrtimer_base(t, b) (b)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800248
249#endif /* !CONFIG_SMP */
250
251/*
252 * Functions for the union type storage format of ktime_t which are
253 * too large for inlining:
254 */
255#if BITS_PER_LONG < 64
256# ifndef CONFIG_KTIME_SCALAR
257/**
258 * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800259 * @kt: addend
260 * @nsec: the scalar nsec value to add
261 *
262 * Returns the sum of kt and nsec in ktime_t format
263 */
264ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
265{
266 ktime_t tmp;
267
268 if (likely(nsec < NSEC_PER_SEC)) {
269 tmp.tv64 = nsec;
270 } else {
271 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
272
273 tmp = ktime_set((long)nsec, rem);
274 }
275
276 return ktime_add(kt, tmp);
277}
David Howellsb8b8fd22007-04-27 15:31:24 -0700278
279EXPORT_SYMBOL_GPL(ktime_add_ns);
Arnaldo Carvalho de Meloa2723782007-08-19 17:16:05 -0700280
281/**
282 * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable
283 * @kt: minuend
284 * @nsec: the scalar nsec value to subtract
285 *
286 * Returns the subtraction of @nsec from @kt in ktime_t format
287 */
288ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec)
289{
290 ktime_t tmp;
291
292 if (likely(nsec < NSEC_PER_SEC)) {
293 tmp.tv64 = nsec;
294 } else {
295 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
296
297 tmp = ktime_set((long)nsec, rem);
298 }
299
300 return ktime_sub(kt, tmp);
301}
302
303EXPORT_SYMBOL_GPL(ktime_sub_ns);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800304# endif /* !CONFIG_KTIME_SCALAR */
305
306/*
307 * Divide a ktime value by a nanosecond value
308 */
Davide Libenzi4d672e7a2008-02-04 22:27:26 -0800309u64 ktime_divns(const ktime_t kt, s64 div)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800310{
311 u64 dclc, inc, dns;
312 int sft = 0;
313
314 dclc = dns = ktime_to_ns(kt);
315 inc = div;
316 /* Make sure the divisor is less than 2^32: */
317 while (div >> 32) {
318 sft++;
319 div >>= 1;
320 }
321 dclc >>= sft;
322 do_div(dclc, (unsigned long) div);
323
Davide Libenzi4d672e7a2008-02-04 22:27:26 -0800324 return dclc;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800325}
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800326#endif /* BITS_PER_LONG >= 64 */
327
Peter Zijlstrad3d74452008-01-25 21:08:31 +0100328/*
329 * Check, whether the timer is on the callback pending list
330 */
331static inline int hrtimer_cb_pending(const struct hrtimer *timer)
332{
333 return timer->state & HRTIMER_STATE_PENDING;
334}
335
336/*
337 * Remove a timer from the callback pending list
338 */
339static inline void hrtimer_remove_cb_pending(struct hrtimer *timer)
340{
341 list_del_init(&timer->cb_entry);
342}
343
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800344/* High resolution timer related functions */
345#ifdef CONFIG_HIGH_RES_TIMERS
346
347/*
348 * High resolution timer enabled ?
349 */
350static int hrtimer_hres_enabled __read_mostly = 1;
351
352/*
353 * Enable / Disable high resolution mode
354 */
355static int __init setup_hrtimer_hres(char *str)
356{
357 if (!strcmp(str, "off"))
358 hrtimer_hres_enabled = 0;
359 else if (!strcmp(str, "on"))
360 hrtimer_hres_enabled = 1;
361 else
362 return 0;
363 return 1;
364}
365
366__setup("highres=", setup_hrtimer_hres);
367
368/*
369 * hrtimer_high_res_enabled - query, if the highres mode is enabled
370 */
371static inline int hrtimer_is_hres_enabled(void)
372{
373 return hrtimer_hres_enabled;
374}
375
376/*
377 * Is the high resolution mode active ?
378 */
379static inline int hrtimer_hres_active(void)
380{
381 return __get_cpu_var(hrtimer_bases).hres_active;
382}
383
384/*
385 * Reprogram the event source with checking both queues for the
386 * next event
387 * Called with interrupts disabled and base->lock held
388 */
389static void hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base)
390{
391 int i;
392 struct hrtimer_clock_base *base = cpu_base->clock_base;
393 ktime_t expires;
394
395 cpu_base->expires_next.tv64 = KTIME_MAX;
396
397 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
398 struct hrtimer *timer;
399
400 if (!base->first)
401 continue;
402 timer = rb_entry(base->first, struct hrtimer, node);
403 expires = ktime_sub(timer->expires, base->offset);
404 if (expires.tv64 < cpu_base->expires_next.tv64)
405 cpu_base->expires_next = expires;
406 }
407
408 if (cpu_base->expires_next.tv64 != KTIME_MAX)
409 tick_program_event(cpu_base->expires_next, 1);
410}
411
412/*
413 * Shared reprogramming for clock_realtime and clock_monotonic
414 *
415 * When a timer is enqueued and expires earlier than the already enqueued
416 * timers, we have to check, whether it expires earlier than the timer for
417 * which the clock event device was armed.
418 *
419 * Called with interrupts disabled and base->cpu_base.lock held
420 */
421static int hrtimer_reprogram(struct hrtimer *timer,
422 struct hrtimer_clock_base *base)
423{
424 ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
425 ktime_t expires = ktime_sub(timer->expires, base->offset);
426 int res;
427
428 /*
429 * When the callback is running, we do not reprogram the clock event
430 * device. The timer callback is either running on a different CPU or
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +0200431 * the callback is executed in the hrtimer_interrupt context. The
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800432 * reprogramming is handled either by the softirq, which called the
433 * callback or at the end of the hrtimer_interrupt.
434 */
435 if (hrtimer_callback_running(timer))
436 return 0;
437
438 if (expires.tv64 >= expires_next->tv64)
439 return 0;
440
441 /*
442 * Clockevents returns -ETIME, when the event was in the past.
443 */
444 res = tick_program_event(expires, 0);
445 if (!IS_ERR_VALUE(res))
446 *expires_next = expires;
447 return res;
448}
449
450
451/*
452 * Retrigger next event is called after clock was set
453 *
454 * Called with interrupts disabled via on_each_cpu()
455 */
456static void retrigger_next_event(void *arg)
457{
458 struct hrtimer_cpu_base *base;
459 struct timespec realtime_offset;
460 unsigned long seq;
461
462 if (!hrtimer_hres_active())
463 return;
464
465 do {
466 seq = read_seqbegin(&xtime_lock);
467 set_normalized_timespec(&realtime_offset,
468 -wall_to_monotonic.tv_sec,
469 -wall_to_monotonic.tv_nsec);
470 } while (read_seqretry(&xtime_lock, seq));
471
472 base = &__get_cpu_var(hrtimer_bases);
473
474 /* Adjust CLOCK_REALTIME offset */
475 spin_lock(&base->lock);
476 base->clock_base[CLOCK_REALTIME].offset =
477 timespec_to_ktime(realtime_offset);
478
479 hrtimer_force_reprogram(base);
480 spin_unlock(&base->lock);
481}
482
483/*
484 * Clock realtime was set
485 *
486 * Change the offset of the realtime clock vs. the monotonic
487 * clock.
488 *
489 * We might have to reprogram the high resolution timer interrupt. On
490 * SMP we call the architecture specific code to retrigger _all_ high
491 * resolution timer interrupts. On UP we just disable interrupts and
492 * call the high resolution interrupt code.
493 */
494void clock_was_set(void)
495{
496 /* Retrigger the CPU local events everywhere */
497 on_each_cpu(retrigger_next_event, NULL, 0, 1);
498}
499
500/*
Ingo Molnar995f0542007-04-07 12:05:00 +0200501 * During resume we might have to reprogram the high resolution timer
502 * interrupt (on the local CPU):
503 */
504void hres_timers_resume(void)
505{
506 WARN_ON_ONCE(num_online_cpus() > 1);
507
508 /* Retrigger the CPU local events: */
509 retrigger_next_event(NULL);
510}
511
512/*
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800513 * Initialize the high resolution related parts of cpu_base
514 */
515static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
516{
517 base->expires_next.tv64 = KTIME_MAX;
518 base->hres_active = 0;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800519}
520
521/*
522 * Initialize the high resolution related parts of a hrtimer
523 */
524static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
525{
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800526}
527
528/*
529 * When High resolution timers are active, try to reprogram. Note, that in case
530 * the state has HRTIMER_STATE_CALLBACK set, no reprogramming and no expiry
531 * check happens. The timer gets enqueued into the rbtree. The reprogramming
532 * and expiry check is done in the hrtimer_interrupt or in the softirq.
533 */
534static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
535 struct hrtimer_clock_base *base)
536{
537 if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
538
539 /* Timer is expired, act upon the callback mode */
540 switch(timer->cb_mode) {
541 case HRTIMER_CB_IRQSAFE_NO_RESTART:
542 /*
543 * We can call the callback from here. No restart
544 * happens, so no danger of recursion
545 */
546 BUG_ON(timer->function(timer) != HRTIMER_NORESTART);
547 return 1;
548 case HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:
549 /*
550 * This is solely for the sched tick emulation with
551 * dynamic tick support to ensure that we do not
552 * restart the tick right on the edge and end up with
553 * the tick timer in the softirq ! The calling site
554 * takes care of this.
555 */
556 return 1;
557 case HRTIMER_CB_IRQSAFE:
558 case HRTIMER_CB_SOFTIRQ:
559 /*
560 * Move everything else into the softirq pending list !
561 */
562 list_add_tail(&timer->cb_entry,
563 &base->cpu_base->cb_pending);
564 timer->state = HRTIMER_STATE_PENDING;
565 raise_softirq(HRTIMER_SOFTIRQ);
566 return 1;
567 default:
568 BUG();
569 }
570 }
571 return 0;
572}
573
574/*
575 * Switch to high resolution mode
576 */
Thomas Gleixnerf8953852007-03-06 01:42:08 -0800577static int hrtimer_switch_to_hres(void)
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800578{
Ingo Molnar820de5c2007-07-21 04:37:36 -0700579 int cpu = smp_processor_id();
580 struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800581 unsigned long flags;
582
583 if (base->hres_active)
Thomas Gleixnerf8953852007-03-06 01:42:08 -0800584 return 1;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800585
586 local_irq_save(flags);
587
588 if (tick_init_highres()) {
589 local_irq_restore(flags);
Ingo Molnar820de5c2007-07-21 04:37:36 -0700590 printk(KERN_WARNING "Could not switch to high resolution "
591 "mode on CPU %d\n", cpu);
Thomas Gleixnerf8953852007-03-06 01:42:08 -0800592 return 0;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800593 }
594 base->hres_active = 1;
595 base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
596 base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
597
598 tick_setup_sched_timer();
599
600 /* "Retrigger" the interrupt to get things going */
601 retrigger_next_event(NULL);
602 local_irq_restore(flags);
Michael Ellermanedfed662007-10-29 16:35:29 +1100603 printk(KERN_DEBUG "Switched to high resolution mode on CPU %d\n",
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800604 smp_processor_id());
Thomas Gleixnerf8953852007-03-06 01:42:08 -0800605 return 1;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800606}
607
608#else
609
610static inline int hrtimer_hres_active(void) { return 0; }
611static inline int hrtimer_is_hres_enabled(void) { return 0; }
Thomas Gleixnerf8953852007-03-06 01:42:08 -0800612static inline int hrtimer_switch_to_hres(void) { return 0; }
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800613static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
614static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
615 struct hrtimer_clock_base *base)
616{
617 return 0;
618}
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800619static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
620static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
Peter Zijlstrad3d74452008-01-25 21:08:31 +0100621static inline int hrtimer_reprogram(struct hrtimer *timer,
622 struct hrtimer_clock_base *base)
623{
624 return 0;
625}
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800626
627#endif /* CONFIG_HIGH_RES_TIMERS */
628
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800629#ifdef CONFIG_TIMER_STATS
630void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr)
631{
632 if (timer->start_site)
633 return;
634
635 timer->start_site = addr;
636 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
637 timer->start_pid = current->pid;
638}
639#endif
640
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800641/*
Uwe Kleine-König6506f2a2007-10-20 01:56:53 +0200642 * Counterpart to lock_hrtimer_base above:
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800643 */
644static inline
645void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
646{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800647 spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800648}
649
650/**
651 * hrtimer_forward - forward the timer expiry
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800652 * @timer: hrtimer to forward
Roman Zippel44f21472006-03-26 01:38:06 -0800653 * @now: forward past this time
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800654 * @interval: the interval to forward
655 *
656 * Forward the timer expiry so it will expire in the future.
Jonathan Corbet8dca6f32006-01-16 15:58:55 -0700657 * Returns the number of overruns.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800658 */
Davide Libenzi4d672e7a2008-02-04 22:27:26 -0800659u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800660{
Davide Libenzi4d672e7a2008-02-04 22:27:26 -0800661 u64 orun = 1;
Roman Zippel44f21472006-03-26 01:38:06 -0800662 ktime_t delta;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800663
664 delta = ktime_sub(now, timer->expires);
665
666 if (delta.tv64 < 0)
667 return 0;
668
Thomas Gleixnerc9db4fa2006-01-12 11:47:34 +0100669 if (interval.tv64 < timer->base->resolution.tv64)
670 interval.tv64 = timer->base->resolution.tv64;
671
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800672 if (unlikely(delta.tv64 >= interval.tv64)) {
Roman Zippeldf869b62006-03-26 01:38:11 -0800673 s64 incr = ktime_to_ns(interval);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800674
675 orun = ktime_divns(delta, incr);
676 timer->expires = ktime_add_ns(timer->expires, incr * orun);
677 if (timer->expires.tv64 > now.tv64)
678 return orun;
679 /*
680 * This (and the ktime_add() below) is the
681 * correction for exact:
682 */
683 orun++;
684 }
685 timer->expires = ktime_add(timer->expires, interval);
Thomas Gleixner13788cc2007-03-16 13:38:20 -0800686 /*
687 * Make sure, that the result did not wrap with a very large
688 * interval.
689 */
690 if (timer->expires.tv64 < 0)
691 timer->expires = ktime_set(KTIME_SEC_MAX, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800692
693 return orun;
694}
Stas Sergeev6bdb6b62007-05-08 00:31:58 -0700695EXPORT_SYMBOL_GPL(hrtimer_forward);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800696
697/*
698 * enqueue_hrtimer - internal function to (re)start a timer
699 *
700 * The timer is inserted in expiry order. Insertion into the
701 * red black tree is O(log(n)). Must hold the base lock.
702 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800703static void enqueue_hrtimer(struct hrtimer *timer,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800704 struct hrtimer_clock_base *base, int reprogram)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800705{
706 struct rb_node **link = &base->active.rb_node;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800707 struct rb_node *parent = NULL;
708 struct hrtimer *entry;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700709 int leftmost = 1;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800710
711 /*
712 * Find the right place in the rbtree:
713 */
714 while (*link) {
715 parent = *link;
716 entry = rb_entry(parent, struct hrtimer, node);
717 /*
718 * We dont care about collisions. Nodes with
719 * the same expiry time stay together.
720 */
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700721 if (timer->expires.tv64 < entry->expires.tv64) {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800722 link = &(*link)->rb_left;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700723 } else {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800724 link = &(*link)->rb_right;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700725 leftmost = 0;
726 }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800727 }
728
729 /*
Thomas Gleixner288867e2006-01-12 11:25:54 +0100730 * Insert the timer to the rbtree and check whether it
731 * replaces the first pending timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800732 */
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700733 if (leftmost) {
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800734 /*
735 * Reprogram the clock event device. When the timer is already
736 * expired hrtimer_enqueue_reprogram has either called the
737 * callback or added it to the pending list and raised the
738 * softirq.
739 *
740 * This is a NOP for !HIGHRES
741 */
742 if (reprogram && hrtimer_enqueue_reprogram(timer, base))
743 return;
744
745 base->first = &timer->node;
746 }
747
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800748 rb_link_node(&timer->node, parent, link);
749 rb_insert_color(&timer->node, &base->active);
Thomas Gleixner303e9672007-02-16 01:27:51 -0800750 /*
751 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
752 * state of a possibly running callback.
753 */
754 timer->state |= HRTIMER_STATE_ENQUEUED;
Thomas Gleixner288867e2006-01-12 11:25:54 +0100755}
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800756
757/*
758 * __remove_hrtimer - internal function to remove a timer
759 *
760 * Caller must hold the base lock.
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800761 *
762 * High resolution timer mode reprograms the clock event device when the
763 * timer is the one which expires next. The caller can disable this by setting
764 * reprogram to zero. This is useful, when the context does a reprogramming
765 * anyway (e.g. timer interrupt)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800766 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800767static void __remove_hrtimer(struct hrtimer *timer,
Thomas Gleixner303e9672007-02-16 01:27:51 -0800768 struct hrtimer_clock_base *base,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800769 unsigned long newstate, int reprogram)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800770{
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800771 /* High res. callback list. NOP for !HIGHRES */
772 if (hrtimer_cb_pending(timer))
773 hrtimer_remove_cb_pending(timer);
774 else {
775 /*
776 * Remove the timer from the rbtree and replace the
777 * first entry pointer if necessary.
778 */
779 if (base->first == &timer->node) {
780 base->first = rb_next(&timer->node);
781 /* Reprogram the clock event device. if enabled */
782 if (reprogram && hrtimer_hres_active())
783 hrtimer_force_reprogram(base->cpu_base);
784 }
785 rb_erase(&timer->node, &base->active);
786 }
Thomas Gleixner303e9672007-02-16 01:27:51 -0800787 timer->state = newstate;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800788}
789
790/*
791 * remove hrtimer, called with base lock held
792 */
793static inline int
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800794remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800795{
Thomas Gleixner303e9672007-02-16 01:27:51 -0800796 if (hrtimer_is_queued(timer)) {
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800797 int reprogram;
798
799 /*
800 * Remove the timer and force reprogramming when high
801 * resolution mode is active and the timer is on the current
802 * CPU. If we remove a timer on another CPU, reprogramming is
803 * skipped. The interrupt event on this CPU is fired and
804 * reprogramming happens in the interrupt handler. This is a
805 * rare case and less expensive than a smp call.
806 */
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800807 timer_stats_hrtimer_clear_start_info(timer);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800808 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
809 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
810 reprogram);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800811 return 1;
812 }
813 return 0;
814}
815
816/**
817 * hrtimer_start - (re)start an relative timer on the current CPU
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800818 * @timer: the timer to be added
819 * @tim: expiry time
820 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
821 *
822 * Returns:
823 * 0 on success
824 * 1 when the timer was active
825 */
826int
827hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
828{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800829 struct hrtimer_clock_base *base, *new_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800830 unsigned long flags;
831 int ret;
832
833 base = lock_hrtimer_base(timer, &flags);
834
835 /* Remove an active timer from the queue: */
836 ret = remove_hrtimer(timer, base);
837
838 /* Switch the timer base, if necessary: */
839 new_base = switch_hrtimer_base(timer, base);
840
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -0800841 if (mode == HRTIMER_MODE_REL) {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800842 tim = ktime_add(tim, new_base->get_time());
Ingo Molnar06027bd2006-02-14 13:53:15 -0800843 /*
844 * CONFIG_TIME_LOW_RES is a temporary way for architectures
845 * to signal that they simply return xtime in
846 * do_gettimeoffset(). In this case we want to round up by
847 * resolution when starting a relative timer, to avoid short
848 * timeouts. This will go away with the GTOD framework.
849 */
850#ifdef CONFIG_TIME_LOW_RES
851 tim = ktime_add(tim, base->resolution);
852#endif
Thomas Gleixner62f0f612007-12-07 19:16:17 +0100853 /*
854 * Careful here: User space might have asked for a
855 * very long sleep, so the add above might result in a
856 * negative number, which enqueues the timer in front
857 * of the queue.
858 */
859 if (tim.tv64 < 0)
860 tim.tv64 = KTIME_MAX;
Ingo Molnar06027bd2006-02-14 13:53:15 -0800861 }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800862 timer->expires = tim;
863
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800864 timer_stats_hrtimer_set_start_info(timer);
865
Ingo Molnar935c6312007-03-28 13:17:18 +0200866 /*
867 * Only allow reprogramming if the new base is on this CPU.
868 * (it might still be on another CPU if the timer was pending)
869 */
870 enqueue_hrtimer(timer, new_base,
871 new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800872
873 unlock_hrtimer_base(timer, &flags);
874
875 return ret;
876}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700877EXPORT_SYMBOL_GPL(hrtimer_start);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800878
879/**
880 * hrtimer_try_to_cancel - try to deactivate a timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800881 * @timer: hrtimer to stop
882 *
883 * Returns:
884 * 0 when the timer was not active
885 * 1 when the timer was active
886 * -1 when the timer is currently excuting the callback function and
Randy Dunlapfa9799e2006-06-25 05:49:15 -0700887 * cannot be stopped
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800888 */
889int hrtimer_try_to_cancel(struct hrtimer *timer)
890{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800891 struct hrtimer_clock_base *base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800892 unsigned long flags;
893 int ret = -1;
894
895 base = lock_hrtimer_base(timer, &flags);
896
Thomas Gleixner303e9672007-02-16 01:27:51 -0800897 if (!hrtimer_callback_running(timer))
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800898 ret = remove_hrtimer(timer, base);
899
900 unlock_hrtimer_base(timer, &flags);
901
902 return ret;
903
904}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700905EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800906
907/**
908 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800909 * @timer: the timer to be cancelled
910 *
911 * Returns:
912 * 0 when the timer was not active
913 * 1 when the timer was active
914 */
915int hrtimer_cancel(struct hrtimer *timer)
916{
917 for (;;) {
918 int ret = hrtimer_try_to_cancel(timer);
919
920 if (ret >= 0)
921 return ret;
Joe Korty5ef37b12006-04-10 22:54:13 -0700922 cpu_relax();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800923 }
924}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700925EXPORT_SYMBOL_GPL(hrtimer_cancel);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800926
927/**
928 * hrtimer_get_remaining - get remaining time for the timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800929 * @timer: the timer to read
930 */
931ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
932{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800933 struct hrtimer_clock_base *base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800934 unsigned long flags;
935 ktime_t rem;
936
937 base = lock_hrtimer_base(timer, &flags);
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800938 rem = ktime_sub(timer->expires, base->get_time());
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800939 unlock_hrtimer_base(timer, &flags);
940
941 return rem;
942}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700943EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800944
Thomas Gleixnerfd064b92007-02-16 01:27:47 -0800945#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ)
Tony Lindgren69239742006-03-06 15:42:45 -0800946/**
947 * hrtimer_get_next_event - get the time until next expiry event
948 *
949 * Returns the delta to the next expiry event or KTIME_MAX if no timer
950 * is pending.
951 */
952ktime_t hrtimer_get_next_event(void)
953{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800954 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
955 struct hrtimer_clock_base *base = cpu_base->clock_base;
Tony Lindgren69239742006-03-06 15:42:45 -0800956 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
957 unsigned long flags;
958 int i;
959
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800960 spin_lock_irqsave(&cpu_base->lock, flags);
961
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800962 if (!hrtimer_hres_active()) {
963 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
964 struct hrtimer *timer;
Tony Lindgren69239742006-03-06 15:42:45 -0800965
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800966 if (!base->first)
967 continue;
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800968
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800969 timer = rb_entry(base->first, struct hrtimer, node);
970 delta.tv64 = timer->expires.tv64;
971 delta = ktime_sub(delta, base->get_time());
972 if (delta.tv64 < mindelta.tv64)
973 mindelta.tv64 = delta.tv64;
974 }
Tony Lindgren69239742006-03-06 15:42:45 -0800975 }
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800976
977 spin_unlock_irqrestore(&cpu_base->lock, flags);
978
Tony Lindgren69239742006-03-06 15:42:45 -0800979 if (mindelta.tv64 < 0)
980 mindelta.tv64 = 0;
981 return mindelta;
982}
983#endif
984
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800985/**
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800986 * hrtimer_init - initialize a timer to the given clock
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800987 * @timer: the timer to be initialized
988 * @clock_id: the clock to be used
George Anzinger7978672c2006-02-01 03:05:11 -0800989 * @mode: timer mode abs/rel
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800990 */
George Anzinger7978672c2006-02-01 03:05:11 -0800991void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
992 enum hrtimer_mode mode)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800993{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800994 struct hrtimer_cpu_base *cpu_base;
George Anzinger7978672c2006-02-01 03:05:11 -0800995
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800996 memset(timer, 0, sizeof(struct hrtimer));
George Anzinger7978672c2006-02-01 03:05:11 -0800997
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800998 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
George Anzinger7978672c2006-02-01 03:05:11 -0800999
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001000 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
George Anzinger7978672c2006-02-01 03:05:11 -08001001 clock_id = CLOCK_MONOTONIC;
1002
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001003 timer->base = &cpu_base->clock_base[clock_id];
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001004 INIT_LIST_HEAD(&timer->cb_entry);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001005 hrtimer_init_timer_hres(timer);
Ingo Molnar82f67cd2007-02-16 01:28:13 -08001006
1007#ifdef CONFIG_TIMER_STATS
1008 timer->start_site = NULL;
1009 timer->start_pid = -1;
1010 memset(timer->start_comm, 0, TASK_COMM_LEN);
1011#endif
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001012}
Stephen Hemminger8d16b762006-05-30 21:26:09 -07001013EXPORT_SYMBOL_GPL(hrtimer_init);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001014
1015/**
1016 * hrtimer_get_res - get the timer resolution for a clock
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001017 * @which_clock: which clock to query
1018 * @tp: pointer to timespec variable to store the resolution
1019 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001020 * Store the resolution of the clock selected by @which_clock in the
1021 * variable pointed to by @tp.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001022 */
1023int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1024{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001025 struct hrtimer_cpu_base *cpu_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001026
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001027 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1028 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001029
1030 return 0;
1031}
Stephen Hemminger8d16b762006-05-30 21:26:09 -07001032EXPORT_SYMBOL_GPL(hrtimer_get_res);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001033
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001034static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001035{
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001036 spin_lock_irq(&cpu_base->lock);
1037
1038 while (!list_empty(&cpu_base->cb_pending)) {
1039 enum hrtimer_restart (*fn)(struct hrtimer *);
1040 struct hrtimer *timer;
1041 int restart;
1042
1043 timer = list_entry(cpu_base->cb_pending.next,
1044 struct hrtimer, cb_entry);
1045
Ingo Molnar82f67cd2007-02-16 01:28:13 -08001046 timer_stats_account_hrtimer(timer);
1047
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001048 fn = timer->function;
1049 __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
1050 spin_unlock_irq(&cpu_base->lock);
1051
1052 restart = fn(timer);
1053
1054 spin_lock_irq(&cpu_base->lock);
1055
1056 timer->state &= ~HRTIMER_STATE_CALLBACK;
1057 if (restart == HRTIMER_RESTART) {
1058 BUG_ON(hrtimer_active(timer));
1059 /*
1060 * Enqueue the timer, allow reprogramming of the event
1061 * device
1062 */
1063 enqueue_hrtimer(timer, timer->base, 1);
1064 } else if (hrtimer_active(timer)) {
1065 /*
1066 * If the timer was rearmed on another CPU, reprogram
1067 * the event device.
1068 */
1069 if (timer->base->first == &timer->node)
1070 hrtimer_reprogram(timer, timer->base);
1071 }
1072 }
1073 spin_unlock_irq(&cpu_base->lock);
1074}
1075
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001076static void __run_hrtimer(struct hrtimer *timer)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001077{
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001078 struct hrtimer_clock_base *base = timer->base;
1079 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1080 enum hrtimer_restart (*fn)(struct hrtimer *);
1081 int restart;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001082
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001083 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1084 timer_stats_account_hrtimer(timer);
Dimitri Sivanich3055add2006-03-31 02:31:20 -08001085
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001086 fn = timer->function;
1087 if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) {
1088 /*
1089 * Used for scheduler timers, avoid lock inversion with
1090 * rq->lock and tasklist_lock.
1091 *
1092 * These timers are required to deal with enqueue expiry
1093 * themselves and are not allowed to migrate.
1094 */
1095 spin_unlock(&cpu_base->lock);
1096 restart = fn(timer);
1097 spin_lock(&cpu_base->lock);
1098 } else
Roman Zippel05cfb612006-03-26 01:38:12 -08001099 restart = fn(timer);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001100
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001101 /*
1102 * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid
1103 * reprogramming of the event hardware. This happens at the end of this
1104 * function anyway.
1105 */
1106 if (restart != HRTIMER_NORESTART) {
1107 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1108 enqueue_hrtimer(timer, base, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001109 }
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001110 timer->state &= ~HRTIMER_STATE_CALLBACK;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001111}
1112
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001113#ifdef CONFIG_HIGH_RES_TIMERS
1114
1115/*
1116 * High resolution timer interrupt
1117 * Called with interrupts disabled
1118 */
1119void hrtimer_interrupt(struct clock_event_device *dev)
1120{
1121 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1122 struct hrtimer_clock_base *base;
1123 ktime_t expires_next, now;
1124 int i, raise = 0;
1125
1126 BUG_ON(!cpu_base->hres_active);
1127 cpu_base->nr_events++;
1128 dev->next_event.tv64 = KTIME_MAX;
1129
1130 retry:
1131 now = ktime_get();
1132
1133 expires_next.tv64 = KTIME_MAX;
1134
1135 base = cpu_base->clock_base;
1136
1137 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1138 ktime_t basenow;
1139 struct rb_node *node;
1140
1141 spin_lock(&cpu_base->lock);
1142
1143 basenow = ktime_add(now, base->offset);
1144
1145 while ((node = base->first)) {
1146 struct hrtimer *timer;
1147
1148 timer = rb_entry(node, struct hrtimer, node);
1149
1150 if (basenow.tv64 < timer->expires.tv64) {
1151 ktime_t expires;
1152
1153 expires = ktime_sub(timer->expires,
1154 base->offset);
1155 if (expires.tv64 < expires_next.tv64)
1156 expires_next = expires;
1157 break;
1158 }
1159
1160 /* Move softirq callbacks to the pending list */
1161 if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
1162 __remove_hrtimer(timer, base,
1163 HRTIMER_STATE_PENDING, 0);
1164 list_add_tail(&timer->cb_entry,
1165 &base->cpu_base->cb_pending);
1166 raise = 1;
1167 continue;
1168 }
1169
1170 __run_hrtimer(timer);
1171 }
1172 spin_unlock(&cpu_base->lock);
1173 base++;
1174 }
1175
1176 cpu_base->expires_next = expires_next;
1177
1178 /* Reprogramming necessary ? */
1179 if (expires_next.tv64 != KTIME_MAX) {
1180 if (tick_program_event(expires_next, 0))
1181 goto retry;
1182 }
1183
1184 /* Raise softirq ? */
1185 if (raise)
1186 raise_softirq(HRTIMER_SOFTIRQ);
1187}
1188
1189static void run_hrtimer_softirq(struct softirq_action *h)
1190{
1191 run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));
1192}
1193
1194#endif /* CONFIG_HIGH_RES_TIMERS */
1195
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001196/*
1197 * Called from timer softirq every jiffy, expire hrtimers:
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001198 *
1199 * For HRT its the fall back code to run the softirq in the timer
1200 * softirq context in case the hrtimer initialization failed or has
1201 * not been done yet.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001202 */
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001203void hrtimer_run_pending(void)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001204{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001205 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001206
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001207 if (hrtimer_hres_active())
1208 return;
1209
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001210 /*
1211 * This _is_ ugly: We have to check in the softirq context,
1212 * whether we can switch to highres and / or nohz mode. The
1213 * clocksource switch happens in the timer interrupt with
1214 * xtime_lock held. Notification from there only sets the
1215 * check bit in the tick_oneshot code, otherwise we might
1216 * deadlock vs. xtime_lock.
1217 */
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001218 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001219 hrtimer_switch_to_hres();
1220
1221 run_hrtimer_pending(cpu_base);
1222}
1223
1224/*
1225 * Called from hardirq context every jiffy
1226 */
1227static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
1228 int index)
1229{
1230 struct rb_node *node;
1231 struct hrtimer_clock_base *base = &cpu_base->clock_base[index];
1232
1233 if (!base->first)
1234 return;
1235
1236 if (base->get_softirq_time)
1237 base->softirq_time = base->get_softirq_time();
1238
1239 spin_lock(&cpu_base->lock);
1240
1241 while ((node = base->first)) {
1242 struct hrtimer *timer;
1243
1244 timer = rb_entry(node, struct hrtimer, node);
1245 if (base->softirq_time.tv64 <= timer->expires.tv64)
1246 break;
1247
1248 if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
1249 __remove_hrtimer(timer, base, HRTIMER_STATE_PENDING, 0);
1250 list_add_tail(&timer->cb_entry,
1251 &base->cpu_base->cb_pending);
1252 continue;
1253 }
1254
1255 __run_hrtimer(timer);
1256 }
1257 spin_unlock(&cpu_base->lock);
1258}
1259
1260void hrtimer_run_queues(void)
1261{
1262 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1263 int i;
1264
1265 if (hrtimer_hres_active())
1266 return;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001267
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001268 hrtimer_get_softirq_time(cpu_base);
Thomas Gleixner92127c72006-03-26 01:38:05 -08001269
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001270 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1271 run_hrtimer_queue(cpu_base, i);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001272}
1273
1274/*
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001275 * Sleep related functions:
1276 */
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001277static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
Thomas Gleixner00362e32006-03-31 02:31:17 -08001278{
1279 struct hrtimer_sleeper *t =
1280 container_of(timer, struct hrtimer_sleeper, timer);
1281 struct task_struct *task = t->task;
1282
1283 t->task = NULL;
1284 if (task)
1285 wake_up_process(task);
1286
1287 return HRTIMER_NORESTART;
1288}
1289
Ingo Molnar36c8b582006-07-03 00:25:41 -07001290void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
Thomas Gleixner00362e32006-03-31 02:31:17 -08001291{
1292 sl->timer.function = hrtimer_wakeup;
1293 sl->task = task;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001294#ifdef CONFIG_HIGH_RES_TIMERS
Peter Zijlstra37bb6cb2008-01-25 21:08:32 +01001295 sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001296#endif
Thomas Gleixner00362e32006-03-31 02:31:17 -08001297}
1298
Thomas Gleixner669d7862006-03-31 02:31:19 -08001299static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001300{
Thomas Gleixner669d7862006-03-31 02:31:19 -08001301 hrtimer_init_sleeper(t, current);
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001302
Roman Zippel432569b2006-03-26 01:38:08 -08001303 do {
1304 set_current_state(TASK_INTERRUPTIBLE);
1305 hrtimer_start(&t->timer, t->timer.expires, mode);
Peter Zijlstra37bb6cb2008-01-25 21:08:32 +01001306 if (!hrtimer_active(&t->timer))
1307 t->task = NULL;
Roman Zippel432569b2006-03-26 01:38:08 -08001308
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001309 if (likely(t->task))
1310 schedule();
Roman Zippel432569b2006-03-26 01:38:08 -08001311
Thomas Gleixner669d7862006-03-31 02:31:19 -08001312 hrtimer_cancel(&t->timer);
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001313 mode = HRTIMER_MODE_ABS;
Roman Zippel432569b2006-03-26 01:38:08 -08001314
Thomas Gleixner669d7862006-03-31 02:31:19 -08001315 } while (t->task && !signal_pending(current));
1316
Peter Zijlstra3588a082008-02-01 17:45:13 +01001317 __set_current_state(TASK_RUNNING);
1318
Thomas Gleixner669d7862006-03-31 02:31:19 -08001319 return t->task == NULL;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001320}
1321
Toyo Abe1711ef382006-09-29 02:00:28 -07001322long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001323{
Thomas Gleixner669d7862006-03-31 02:31:19 -08001324 struct hrtimer_sleeper t;
Anton Blanchard04c22712007-10-15 16:06:04 -05001325 struct timespec *rmtp;
Roman Zippel432569b2006-03-26 01:38:08 -08001326 ktime_t time;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001327
1328 restart->fn = do_no_restart_syscall;
1329
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001330 hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS);
Toyo Abe1711ef382006-09-29 02:00:28 -07001331 t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001332
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001333 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001334 return 0;
1335
Anton Blanchard04c22712007-10-15 16:06:04 -05001336 rmtp = (struct timespec *)restart->arg1;
Roman Zippel432569b2006-03-26 01:38:08 -08001337 if (rmtp) {
1338 time = ktime_sub(t.timer.expires, t.timer.base->get_time());
1339 if (time.tv64 <= 0)
1340 return 0;
Anton Blanchard04c22712007-10-15 16:06:04 -05001341 *rmtp = ktime_to_timespec(time);
Roman Zippel432569b2006-03-26 01:38:08 -08001342 }
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001343
Toyo Abe1711ef382006-09-29 02:00:28 -07001344 restart->fn = hrtimer_nanosleep_restart;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001345
1346 /* The other values in restart are already filled in */
1347 return -ERESTART_RESTARTBLOCK;
1348}
1349
Anton Blanchard04c22712007-10-15 16:06:04 -05001350long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp,
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001351 const enum hrtimer_mode mode, const clockid_t clockid)
1352{
1353 struct restart_block *restart;
Thomas Gleixner669d7862006-03-31 02:31:19 -08001354 struct hrtimer_sleeper t;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001355 ktime_t rem;
1356
Roman Zippel432569b2006-03-26 01:38:08 -08001357 hrtimer_init(&t.timer, clockid, mode);
1358 t.timer.expires = timespec_to_ktime(*rqtp);
1359 if (do_nanosleep(&t, mode))
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001360 return 0;
1361
George Anzinger7978672c2006-02-01 03:05:11 -08001362 /* Absolute timers do not update the rmtp value and restart: */
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001363 if (mode == HRTIMER_MODE_ABS)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001364 return -ERESTARTNOHAND;
1365
Roman Zippel432569b2006-03-26 01:38:08 -08001366 if (rmtp) {
1367 rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
1368 if (rem.tv64 <= 0)
1369 return 0;
Anton Blanchard04c22712007-10-15 16:06:04 -05001370 *rmtp = ktime_to_timespec(rem);
Roman Zippel432569b2006-03-26 01:38:08 -08001371 }
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001372
1373 restart = &current_thread_info()->restart_block;
Toyo Abe1711ef382006-09-29 02:00:28 -07001374 restart->fn = hrtimer_nanosleep_restart;
1375 restart->arg0 = (unsigned long) t.timer.base->index;
1376 restart->arg1 = (unsigned long) rmtp;
1377 restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF;
1378 restart->arg3 = t.timer.expires.tv64 >> 32;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001379
1380 return -ERESTART_RESTARTBLOCK;
1381}
1382
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001383asmlinkage long
1384sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
1385{
Anton Blanchard04c22712007-10-15 16:06:04 -05001386 struct timespec tu, rmt;
1387 int ret;
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001388
1389 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1390 return -EFAULT;
1391
1392 if (!timespec_valid(&tu))
1393 return -EINVAL;
1394
Anton Blanchard04c22712007-10-15 16:06:04 -05001395 ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL,
1396 CLOCK_MONOTONIC);
1397
1398 if (ret && rmtp) {
1399 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1400 return -EFAULT;
1401 }
1402
1403 return ret;
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001404}
1405
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001406/*
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001407 * Functions related to boot-time initialization:
1408 */
Randy Dunlap0ec160d2008-01-21 17:18:24 -08001409static void __cpuinit init_hrtimers_cpu(int cpu)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001410{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001411 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001412 int i;
1413
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001414 spin_lock_init(&cpu_base->lock);
1415 lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
1416
1417 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1418 cpu_base->clock_base[i].cpu_base = cpu_base;
1419
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001420 INIT_LIST_HEAD(&cpu_base->cb_pending);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001421 hrtimer_init_hres(cpu_base);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001422}
1423
1424#ifdef CONFIG_HOTPLUG_CPU
1425
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001426static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1427 struct hrtimer_clock_base *new_base)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001428{
1429 struct hrtimer *timer;
1430 struct rb_node *node;
1431
1432 while ((node = rb_first(&old_base->active))) {
1433 timer = rb_entry(node, struct hrtimer, node);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001434 BUG_ON(hrtimer_callback_running(timer));
1435 __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001436 timer->base = new_base;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001437 /*
1438 * Enqueue the timer. Allow reprogramming of the event device
1439 */
1440 enqueue_hrtimer(timer, new_base, 1);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001441 }
1442}
1443
1444static void migrate_hrtimers(int cpu)
1445{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001446 struct hrtimer_cpu_base *old_base, *new_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001447 int i;
1448
1449 BUG_ON(cpu_online(cpu));
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001450 old_base = &per_cpu(hrtimer_bases, cpu);
1451 new_base = &get_cpu_var(hrtimer_bases);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001452
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001453 tick_cancel_sched_timer(cpu);
1454
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001455 local_irq_disable();
Heiko Carstense81ce1f2007-03-05 00:30:51 -08001456 double_spin_lock(&new_base->lock, &old_base->lock,
1457 smp_processor_id() < cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001458
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001459 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001460 migrate_hrtimer_list(&old_base->clock_base[i],
1461 &new_base->clock_base[i]);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001462 }
1463
Heiko Carstense81ce1f2007-03-05 00:30:51 -08001464 double_spin_unlock(&new_base->lock, &old_base->lock,
1465 smp_processor_id() < cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001466 local_irq_enable();
1467 put_cpu_var(hrtimer_bases);
1468}
1469#endif /* CONFIG_HOTPLUG_CPU */
1470
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001471static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001472 unsigned long action, void *hcpu)
1473{
David Miller7713a7d2007-07-16 17:17:44 -07001474 unsigned int cpu = (long)hcpu;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001475
1476 switch (action) {
1477
1478 case CPU_UP_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001479 case CPU_UP_PREPARE_FROZEN:
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001480 init_hrtimers_cpu(cpu);
1481 break;
1482
1483#ifdef CONFIG_HOTPLUG_CPU
1484 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001485 case CPU_DEAD_FROZEN:
Thomas Gleixnerd316c572007-02-16 01:28:00 -08001486 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001487 migrate_hrtimers(cpu);
1488 break;
1489#endif
1490
1491 default:
1492 break;
1493 }
1494
1495 return NOTIFY_OK;
1496}
1497
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001498static struct notifier_block __cpuinitdata hrtimers_nb = {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001499 .notifier_call = hrtimer_cpu_notify,
1500};
1501
1502void __init hrtimers_init(void)
1503{
1504 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1505 (void *)(long)smp_processor_id());
1506 register_cpu_notifier(&hrtimers_nb);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001507#ifdef CONFIG_HIGH_RES_TIMERS
1508 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
1509#endif
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001510}
1511