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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 Anzinger79786722006-02-01 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 */
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -0800309unsigned long 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
324 return (unsigned long) dclc;
325}
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 */
659unsigned long
Roman Zippel44f21472006-03-26 01:38:06 -0800660hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800661{
662 unsigned long orun = 1;
Roman Zippel44f21472006-03-26 01:38:06 -0800663 ktime_t delta;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800664
665 delta = ktime_sub(now, timer->expires);
666
667 if (delta.tv64 < 0)
668 return 0;
669
Thomas Gleixnerc9db4fa2006-01-12 11:47:34 +0100670 if (interval.tv64 < timer->base->resolution.tv64)
671 interval.tv64 = timer->base->resolution.tv64;
672
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800673 if (unlikely(delta.tv64 >= interval.tv64)) {
Roman Zippeldf869b62006-03-26 01:38:11 -0800674 s64 incr = ktime_to_ns(interval);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800675
676 orun = ktime_divns(delta, incr);
677 timer->expires = ktime_add_ns(timer->expires, incr * orun);
678 if (timer->expires.tv64 > now.tv64)
679 return orun;
680 /*
681 * This (and the ktime_add() below) is the
682 * correction for exact:
683 */
684 orun++;
685 }
686 timer->expires = ktime_add(timer->expires, interval);
Thomas Gleixner13788cc2007-03-16 13:38:20 -0800687 /*
688 * Make sure, that the result did not wrap with a very large
689 * interval.
690 */
691 if (timer->expires.tv64 < 0)
692 timer->expires = ktime_set(KTIME_SEC_MAX, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800693
694 return orun;
695}
Stas Sergeev6bdb6b62007-05-08 00:31:58 -0700696EXPORT_SYMBOL_GPL(hrtimer_forward);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800697
698/*
699 * enqueue_hrtimer - internal function to (re)start a timer
700 *
701 * The timer is inserted in expiry order. Insertion into the
702 * red black tree is O(log(n)). Must hold the base lock.
703 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800704static void enqueue_hrtimer(struct hrtimer *timer,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800705 struct hrtimer_clock_base *base, int reprogram)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800706{
707 struct rb_node **link = &base->active.rb_node;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800708 struct rb_node *parent = NULL;
709 struct hrtimer *entry;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700710 int leftmost = 1;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800711
712 /*
713 * Find the right place in the rbtree:
714 */
715 while (*link) {
716 parent = *link;
717 entry = rb_entry(parent, struct hrtimer, node);
718 /*
719 * We dont care about collisions. Nodes with
720 * the same expiry time stay together.
721 */
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700722 if (timer->expires.tv64 < entry->expires.tv64) {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800723 link = &(*link)->rb_left;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700724 } else {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800725 link = &(*link)->rb_right;
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700726 leftmost = 0;
727 }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800728 }
729
730 /*
Thomas Gleixner288867e2006-01-12 11:25:54 +0100731 * Insert the timer to the rbtree and check whether it
732 * replaces the first pending timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800733 */
Ingo Molnar99bc2fc2007-07-21 04:37:36 -0700734 if (leftmost) {
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800735 /*
736 * Reprogram the clock event device. When the timer is already
737 * expired hrtimer_enqueue_reprogram has either called the
738 * callback or added it to the pending list and raised the
739 * softirq.
740 *
741 * This is a NOP for !HIGHRES
742 */
743 if (reprogram && hrtimer_enqueue_reprogram(timer, base))
744 return;
745
746 base->first = &timer->node;
747 }
748
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800749 rb_link_node(&timer->node, parent, link);
750 rb_insert_color(&timer->node, &base->active);
Thomas Gleixner303e9672007-02-16 01:27:51 -0800751 /*
752 * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
753 * state of a possibly running callback.
754 */
755 timer->state |= HRTIMER_STATE_ENQUEUED;
Thomas Gleixner288867e2006-01-12 11:25:54 +0100756}
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800757
758/*
759 * __remove_hrtimer - internal function to remove a timer
760 *
761 * Caller must hold the base lock.
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800762 *
763 * High resolution timer mode reprograms the clock event device when the
764 * timer is the one which expires next. The caller can disable this by setting
765 * reprogram to zero. This is useful, when the context does a reprogramming
766 * anyway (e.g. timer interrupt)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800767 */
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800768static void __remove_hrtimer(struct hrtimer *timer,
Thomas Gleixner303e9672007-02-16 01:27:51 -0800769 struct hrtimer_clock_base *base,
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800770 unsigned long newstate, int reprogram)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800771{
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800772 /* High res. callback list. NOP for !HIGHRES */
773 if (hrtimer_cb_pending(timer))
774 hrtimer_remove_cb_pending(timer);
775 else {
776 /*
777 * Remove the timer from the rbtree and replace the
778 * first entry pointer if necessary.
779 */
780 if (base->first == &timer->node) {
781 base->first = rb_next(&timer->node);
782 /* Reprogram the clock event device. if enabled */
783 if (reprogram && hrtimer_hres_active())
784 hrtimer_force_reprogram(base->cpu_base);
785 }
786 rb_erase(&timer->node, &base->active);
787 }
Thomas Gleixner303e9672007-02-16 01:27:51 -0800788 timer->state = newstate;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800789}
790
791/*
792 * remove hrtimer, called with base lock held
793 */
794static inline int
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800795remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800796{
Thomas Gleixner303e9672007-02-16 01:27:51 -0800797 if (hrtimer_is_queued(timer)) {
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800798 int reprogram;
799
800 /*
801 * Remove the timer and force reprogramming when high
802 * resolution mode is active and the timer is on the current
803 * CPU. If we remove a timer on another CPU, reprogramming is
804 * skipped. The interrupt event on this CPU is fired and
805 * reprogramming happens in the interrupt handler. This is a
806 * rare case and less expensive than a smp call.
807 */
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800808 timer_stats_hrtimer_clear_start_info(timer);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800809 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
810 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
811 reprogram);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800812 return 1;
813 }
814 return 0;
815}
816
817/**
818 * hrtimer_start - (re)start an relative timer on the current CPU
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800819 * @timer: the timer to be added
820 * @tim: expiry time
821 * @mode: expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
822 *
823 * Returns:
824 * 0 on success
825 * 1 when the timer was active
826 */
827int
828hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
829{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800830 struct hrtimer_clock_base *base, *new_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800831 unsigned long flags;
832 int ret;
833
834 base = lock_hrtimer_base(timer, &flags);
835
836 /* Remove an active timer from the queue: */
837 ret = remove_hrtimer(timer, base);
838
839 /* Switch the timer base, if necessary: */
840 new_base = switch_hrtimer_base(timer, base);
841
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -0800842 if (mode == HRTIMER_MODE_REL) {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800843 tim = ktime_add(tim, new_base->get_time());
Ingo Molnar06027bd2006-02-14 13:53:15 -0800844 /*
845 * CONFIG_TIME_LOW_RES is a temporary way for architectures
846 * to signal that they simply return xtime in
847 * do_gettimeoffset(). In this case we want to round up by
848 * resolution when starting a relative timer, to avoid short
849 * timeouts. This will go away with the GTOD framework.
850 */
851#ifdef CONFIG_TIME_LOW_RES
852 tim = ktime_add(tim, base->resolution);
853#endif
Thomas Gleixner62f0f612007-12-07 19:16:17 +0100854 /*
855 * Careful here: User space might have asked for a
856 * very long sleep, so the add above might result in a
857 * negative number, which enqueues the timer in front
858 * of the queue.
859 */
860 if (tim.tv64 < 0)
861 tim.tv64 = KTIME_MAX;
Ingo Molnar06027bd2006-02-14 13:53:15 -0800862 }
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800863 timer->expires = tim;
864
Ingo Molnar82f67cd2007-02-16 01:28:13 -0800865 timer_stats_hrtimer_set_start_info(timer);
866
Ingo Molnar935c6312007-03-28 13:17:18 +0200867 /*
868 * Only allow reprogramming if the new base is on this CPU.
869 * (it might still be on another CPU if the timer was pending)
870 */
871 enqueue_hrtimer(timer, new_base,
872 new_base->cpu_base == &__get_cpu_var(hrtimer_bases));
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800873
874 unlock_hrtimer_base(timer, &flags);
875
876 return ret;
877}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700878EXPORT_SYMBOL_GPL(hrtimer_start);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800879
880/**
881 * hrtimer_try_to_cancel - try to deactivate a timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800882 * @timer: hrtimer to stop
883 *
884 * Returns:
885 * 0 when the timer was not active
886 * 1 when the timer was active
887 * -1 when the timer is currently excuting the callback function and
Randy Dunlapfa9799e2006-06-25 05:49:15 -0700888 * cannot be stopped
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800889 */
890int hrtimer_try_to_cancel(struct hrtimer *timer)
891{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800892 struct hrtimer_clock_base *base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800893 unsigned long flags;
894 int ret = -1;
895
896 base = lock_hrtimer_base(timer, &flags);
897
Thomas Gleixner303e9672007-02-16 01:27:51 -0800898 if (!hrtimer_callback_running(timer))
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800899 ret = remove_hrtimer(timer, base);
900
901 unlock_hrtimer_base(timer, &flags);
902
903 return ret;
904
905}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700906EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800907
908/**
909 * hrtimer_cancel - cancel a timer and wait for the handler to finish.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800910 * @timer: the timer to be cancelled
911 *
912 * Returns:
913 * 0 when the timer was not active
914 * 1 when the timer was active
915 */
916int hrtimer_cancel(struct hrtimer *timer)
917{
918 for (;;) {
919 int ret = hrtimer_try_to_cancel(timer);
920
921 if (ret >= 0)
922 return ret;
Joe Korty5ef37b12006-04-10 22:54:13 -0700923 cpu_relax();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800924 }
925}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700926EXPORT_SYMBOL_GPL(hrtimer_cancel);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800927
928/**
929 * hrtimer_get_remaining - get remaining time for the timer
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800930 * @timer: the timer to read
931 */
932ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
933{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800934 struct hrtimer_clock_base *base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800935 unsigned long flags;
936 ktime_t rem;
937
938 base = lock_hrtimer_base(timer, &flags);
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800939 rem = ktime_sub(timer->expires, base->get_time());
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800940 unlock_hrtimer_base(timer, &flags);
941
942 return rem;
943}
Stephen Hemminger8d16b762006-05-30 21:26:09 -0700944EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800945
Thomas Gleixnerfd064b92007-02-16 01:27:47 -0800946#if defined(CONFIG_NO_IDLE_HZ) || defined(CONFIG_NO_HZ)
Tony Lindgren69239742006-03-06 15:42:45 -0800947/**
948 * hrtimer_get_next_event - get the time until next expiry event
949 *
950 * Returns the delta to the next expiry event or KTIME_MAX if no timer
951 * is pending.
952 */
953ktime_t hrtimer_get_next_event(void)
954{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800955 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
956 struct hrtimer_clock_base *base = cpu_base->clock_base;
Tony Lindgren69239742006-03-06 15:42:45 -0800957 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
958 unsigned long flags;
959 int i;
960
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800961 spin_lock_irqsave(&cpu_base->lock, flags);
962
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800963 if (!hrtimer_hres_active()) {
964 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
965 struct hrtimer *timer;
Tony Lindgren69239742006-03-06 15:42:45 -0800966
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800967 if (!base->first)
968 continue;
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800969
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -0800970 timer = rb_entry(base->first, struct hrtimer, node);
971 delta.tv64 = timer->expires.tv64;
972 delta = ktime_sub(delta, base->get_time());
973 if (delta.tv64 < mindelta.tv64)
974 mindelta.tv64 = delta.tv64;
975 }
Tony Lindgren69239742006-03-06 15:42:45 -0800976 }
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800977
978 spin_unlock_irqrestore(&cpu_base->lock, flags);
979
Tony Lindgren69239742006-03-06 15:42:45 -0800980 if (mindelta.tv64 < 0)
981 mindelta.tv64 = 0;
982 return mindelta;
983}
984#endif
985
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800986/**
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800987 * hrtimer_init - initialize a timer to the given clock
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800988 * @timer: the timer to be initialized
989 * @clock_id: the clock to be used
George Anzinger79786722006-02-01 03:05:11 -0800990 * @mode: timer mode abs/rel
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800991 */
George Anzinger79786722006-02-01 03:05:11 -0800992void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
993 enum hrtimer_mode mode)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800994{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800995 struct hrtimer_cpu_base *cpu_base;
George Anzinger79786722006-02-01 03:05:11 -0800996
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800997 memset(timer, 0, sizeof(struct hrtimer));
George Anzinger79786722006-02-01 03:05:11 -0800998
Thomas Gleixner3c8aa392007-02-16 01:27:50 -0800999 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
George Anzinger79786722006-02-01 03:05:11 -08001000
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001001 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
George Anzinger79786722006-02-01 03:05:11 -08001002 clock_id = CLOCK_MONOTONIC;
1003
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001004 timer->base = &cpu_base->clock_base[clock_id];
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001005 INIT_LIST_HEAD(&timer->cb_entry);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001006 hrtimer_init_timer_hres(timer);
Ingo Molnar82f67cd2007-02-16 01:28:13 -08001007
1008#ifdef CONFIG_TIMER_STATS
1009 timer->start_site = NULL;
1010 timer->start_pid = -1;
1011 memset(timer->start_comm, 0, TASK_COMM_LEN);
1012#endif
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001013}
Stephen Hemminger8d16b762006-05-30 21:26:09 -07001014EXPORT_SYMBOL_GPL(hrtimer_init);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001015
1016/**
1017 * hrtimer_get_res - get the timer resolution for a clock
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001018 * @which_clock: which clock to query
1019 * @tp: pointer to timespec variable to store the resolution
1020 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001021 * Store the resolution of the clock selected by @which_clock in the
1022 * variable pointed to by @tp.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001023 */
1024int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1025{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001026 struct hrtimer_cpu_base *cpu_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001027
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001028 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1029 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001030
1031 return 0;
1032}
Stephen Hemminger8d16b762006-05-30 21:26:09 -07001033EXPORT_SYMBOL_GPL(hrtimer_get_res);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001034
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001035static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001036{
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001037 spin_lock_irq(&cpu_base->lock);
1038
1039 while (!list_empty(&cpu_base->cb_pending)) {
1040 enum hrtimer_restart (*fn)(struct hrtimer *);
1041 struct hrtimer *timer;
1042 int restart;
1043
1044 timer = list_entry(cpu_base->cb_pending.next,
1045 struct hrtimer, cb_entry);
1046
Ingo Molnar82f67cd2007-02-16 01:28:13 -08001047 timer_stats_account_hrtimer(timer);
1048
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001049 fn = timer->function;
1050 __remove_hrtimer(timer, timer->base, HRTIMER_STATE_CALLBACK, 0);
1051 spin_unlock_irq(&cpu_base->lock);
1052
1053 restart = fn(timer);
1054
1055 spin_lock_irq(&cpu_base->lock);
1056
1057 timer->state &= ~HRTIMER_STATE_CALLBACK;
1058 if (restart == HRTIMER_RESTART) {
1059 BUG_ON(hrtimer_active(timer));
1060 /*
1061 * Enqueue the timer, allow reprogramming of the event
1062 * device
1063 */
1064 enqueue_hrtimer(timer, timer->base, 1);
1065 } else if (hrtimer_active(timer)) {
1066 /*
1067 * If the timer was rearmed on another CPU, reprogram
1068 * the event device.
1069 */
1070 if (timer->base->first == &timer->node)
1071 hrtimer_reprogram(timer, timer->base);
1072 }
1073 }
1074 spin_unlock_irq(&cpu_base->lock);
1075}
1076
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001077static void __run_hrtimer(struct hrtimer *timer)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001078{
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001079 struct hrtimer_clock_base *base = timer->base;
1080 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1081 enum hrtimer_restart (*fn)(struct hrtimer *);
1082 int restart;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001083
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001084 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1085 timer_stats_account_hrtimer(timer);
Dimitri Sivanich3055add2006-03-31 02:31:20 -08001086
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001087 fn = timer->function;
1088 if (timer->cb_mode == HRTIMER_CB_IRQSAFE_NO_SOFTIRQ) {
1089 /*
1090 * Used for scheduler timers, avoid lock inversion with
1091 * rq->lock and tasklist_lock.
1092 *
1093 * These timers are required to deal with enqueue expiry
1094 * themselves and are not allowed to migrate.
1095 */
1096 spin_unlock(&cpu_base->lock);
1097 restart = fn(timer);
1098 spin_lock(&cpu_base->lock);
1099 } else
Roman Zippel05cfb612006-03-26 01:38:12 -08001100 restart = fn(timer);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001101
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001102 /*
1103 * Note: We clear the CALLBACK bit after enqueue_hrtimer to avoid
1104 * reprogramming of the event hardware. This happens at the end of this
1105 * function anyway.
1106 */
1107 if (restart != HRTIMER_NORESTART) {
1108 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1109 enqueue_hrtimer(timer, base, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001110 }
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001111 timer->state &= ~HRTIMER_STATE_CALLBACK;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001112}
1113
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001114#ifdef CONFIG_HIGH_RES_TIMERS
1115
1116/*
1117 * High resolution timer interrupt
1118 * Called with interrupts disabled
1119 */
1120void hrtimer_interrupt(struct clock_event_device *dev)
1121{
1122 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1123 struct hrtimer_clock_base *base;
1124 ktime_t expires_next, now;
1125 int i, raise = 0;
1126
1127 BUG_ON(!cpu_base->hres_active);
1128 cpu_base->nr_events++;
1129 dev->next_event.tv64 = KTIME_MAX;
1130
1131 retry:
1132 now = ktime_get();
1133
1134 expires_next.tv64 = KTIME_MAX;
1135
1136 base = cpu_base->clock_base;
1137
1138 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1139 ktime_t basenow;
1140 struct rb_node *node;
1141
1142 spin_lock(&cpu_base->lock);
1143
1144 basenow = ktime_add(now, base->offset);
1145
1146 while ((node = base->first)) {
1147 struct hrtimer *timer;
1148
1149 timer = rb_entry(node, struct hrtimer, node);
1150
1151 if (basenow.tv64 < timer->expires.tv64) {
1152 ktime_t expires;
1153
1154 expires = ktime_sub(timer->expires,
1155 base->offset);
1156 if (expires.tv64 < expires_next.tv64)
1157 expires_next = expires;
1158 break;
1159 }
1160
1161 /* Move softirq callbacks to the pending list */
1162 if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
1163 __remove_hrtimer(timer, base,
1164 HRTIMER_STATE_PENDING, 0);
1165 list_add_tail(&timer->cb_entry,
1166 &base->cpu_base->cb_pending);
1167 raise = 1;
1168 continue;
1169 }
1170
1171 __run_hrtimer(timer);
1172 }
1173 spin_unlock(&cpu_base->lock);
1174 base++;
1175 }
1176
1177 cpu_base->expires_next = expires_next;
1178
1179 /* Reprogramming necessary ? */
1180 if (expires_next.tv64 != KTIME_MAX) {
1181 if (tick_program_event(expires_next, 0))
1182 goto retry;
1183 }
1184
1185 /* Raise softirq ? */
1186 if (raise)
1187 raise_softirq(HRTIMER_SOFTIRQ);
1188}
1189
1190static void run_hrtimer_softirq(struct softirq_action *h)
1191{
1192 run_hrtimer_pending(&__get_cpu_var(hrtimer_bases));
1193}
1194
1195#endif /* CONFIG_HIGH_RES_TIMERS */
1196
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001197/*
1198 * Called from timer softirq every jiffy, expire hrtimers:
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001199 *
1200 * For HRT its the fall back code to run the softirq in the timer
1201 * softirq context in case the hrtimer initialization failed or has
1202 * not been done yet.
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001203 */
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001204void hrtimer_run_pending(void)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001205{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001206 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001207
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001208 if (hrtimer_hres_active())
1209 return;
1210
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001211 /*
1212 * This _is_ ugly: We have to check in the softirq context,
1213 * whether we can switch to highres and / or nohz mode. The
1214 * clocksource switch happens in the timer interrupt with
1215 * xtime_lock held. Notification from there only sets the
1216 * check bit in the tick_oneshot code, otherwise we might
1217 * deadlock vs. xtime_lock.
1218 */
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001219 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001220 hrtimer_switch_to_hres();
1221
1222 run_hrtimer_pending(cpu_base);
1223}
1224
1225/*
1226 * Called from hardirq context every jiffy
1227 */
1228static inline void run_hrtimer_queue(struct hrtimer_cpu_base *cpu_base,
1229 int index)
1230{
1231 struct rb_node *node;
1232 struct hrtimer_clock_base *base = &cpu_base->clock_base[index];
1233
1234 if (!base->first)
1235 return;
1236
1237 if (base->get_softirq_time)
1238 base->softirq_time = base->get_softirq_time();
1239
1240 spin_lock(&cpu_base->lock);
1241
1242 while ((node = base->first)) {
1243 struct hrtimer *timer;
1244
1245 timer = rb_entry(node, struct hrtimer, node);
1246 if (base->softirq_time.tv64 <= timer->expires.tv64)
1247 break;
1248
1249 if (timer->cb_mode == HRTIMER_CB_SOFTIRQ) {
1250 __remove_hrtimer(timer, base, HRTIMER_STATE_PENDING, 0);
1251 list_add_tail(&timer->cb_entry,
1252 &base->cpu_base->cb_pending);
1253 continue;
1254 }
1255
1256 __run_hrtimer(timer);
1257 }
1258 spin_unlock(&cpu_base->lock);
1259}
1260
1261void hrtimer_run_queues(void)
1262{
1263 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1264 int i;
1265
1266 if (hrtimer_hres_active())
1267 return;
Thomas Gleixner79bf2bb2007-02-16 01:28:03 -08001268
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001269 hrtimer_get_softirq_time(cpu_base);
Thomas Gleixner92127c72006-03-26 01:38:05 -08001270
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001271 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1272 run_hrtimer_queue(cpu_base, i);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001273}
1274
1275/*
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001276 * Sleep related functions:
1277 */
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001278static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
Thomas Gleixner00362e32006-03-31 02:31:17 -08001279{
1280 struct hrtimer_sleeper *t =
1281 container_of(timer, struct hrtimer_sleeper, timer);
1282 struct task_struct *task = t->task;
1283
1284 t->task = NULL;
1285 if (task)
1286 wake_up_process(task);
1287
1288 return HRTIMER_NORESTART;
1289}
1290
Ingo Molnar36c8b582006-07-03 00:25:41 -07001291void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
Thomas Gleixner00362e32006-03-31 02:31:17 -08001292{
1293 sl->timer.function = hrtimer_wakeup;
1294 sl->task = task;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001295#ifdef CONFIG_HIGH_RES_TIMERS
Peter Zijlstra37bb6cb2008-01-25 21:08:32 +01001296 sl->timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001297#endif
Thomas Gleixner00362e32006-03-31 02:31:17 -08001298}
1299
Thomas Gleixner669d7862006-03-31 02:31:19 -08001300static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001301{
Thomas Gleixner669d7862006-03-31 02:31:19 -08001302 hrtimer_init_sleeper(t, current);
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001303
Roman Zippel432569b2006-03-26 01:38:08 -08001304 do {
1305 set_current_state(TASK_INTERRUPTIBLE);
1306 hrtimer_start(&t->timer, t->timer.expires, mode);
Peter Zijlstra37bb6cb2008-01-25 21:08:32 +01001307 if (!hrtimer_active(&t->timer))
1308 t->task = NULL;
Roman Zippel432569b2006-03-26 01:38:08 -08001309
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001310 if (likely(t->task))
1311 schedule();
Roman Zippel432569b2006-03-26 01:38:08 -08001312
Thomas Gleixner669d7862006-03-31 02:31:19 -08001313 hrtimer_cancel(&t->timer);
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001314 mode = HRTIMER_MODE_ABS;
Roman Zippel432569b2006-03-26 01:38:08 -08001315
Thomas Gleixner669d7862006-03-31 02:31:19 -08001316 } while (t->task && !signal_pending(current));
1317
1318 return t->task == NULL;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001319}
1320
Toyo Abe1711ef32006-09-29 02:00:28 -07001321long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001322{
Thomas Gleixner669d7862006-03-31 02:31:19 -08001323 struct hrtimer_sleeper t;
Anton Blanchard04c22712007-10-15 16:06:04 -05001324 struct timespec *rmtp;
Roman Zippel432569b2006-03-26 01:38:08 -08001325 ktime_t time;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001326
1327 restart->fn = do_no_restart_syscall;
1328
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001329 hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS);
Toyo Abe1711ef32006-09-29 02:00:28 -07001330 t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001331
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001332 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001333 return 0;
1334
Anton Blanchard04c22712007-10-15 16:06:04 -05001335 rmtp = (struct timespec *)restart->arg1;
Roman Zippel432569b2006-03-26 01:38:08 -08001336 if (rmtp) {
1337 time = ktime_sub(t.timer.expires, t.timer.base->get_time());
1338 if (time.tv64 <= 0)
1339 return 0;
Anton Blanchard04c22712007-10-15 16:06:04 -05001340 *rmtp = ktime_to_timespec(time);
Roman Zippel432569b2006-03-26 01:38:08 -08001341 }
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001342
Toyo Abe1711ef32006-09-29 02:00:28 -07001343 restart->fn = hrtimer_nanosleep_restart;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001344
1345 /* The other values in restart are already filled in */
1346 return -ERESTART_RESTARTBLOCK;
1347}
1348
Anton Blanchard04c22712007-10-15 16:06:04 -05001349long hrtimer_nanosleep(struct timespec *rqtp, struct timespec *rmtp,
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001350 const enum hrtimer_mode mode, const clockid_t clockid)
1351{
1352 struct restart_block *restart;
Thomas Gleixner669d7862006-03-31 02:31:19 -08001353 struct hrtimer_sleeper t;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001354 ktime_t rem;
1355
Roman Zippel432569b2006-03-26 01:38:08 -08001356 hrtimer_init(&t.timer, clockid, mode);
1357 t.timer.expires = timespec_to_ktime(*rqtp);
1358 if (do_nanosleep(&t, mode))
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001359 return 0;
1360
George Anzinger79786722006-02-01 03:05:11 -08001361 /* Absolute timers do not update the rmtp value and restart: */
Thomas Gleixnerc9cb2e32007-02-16 01:27:49 -08001362 if (mode == HRTIMER_MODE_ABS)
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001363 return -ERESTARTNOHAND;
1364
Roman Zippel432569b2006-03-26 01:38:08 -08001365 if (rmtp) {
1366 rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
1367 if (rem.tv64 <= 0)
1368 return 0;
Anton Blanchard04c22712007-10-15 16:06:04 -05001369 *rmtp = ktime_to_timespec(rem);
Roman Zippel432569b2006-03-26 01:38:08 -08001370 }
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001371
1372 restart = &current_thread_info()->restart_block;
Toyo Abe1711ef32006-09-29 02:00:28 -07001373 restart->fn = hrtimer_nanosleep_restart;
1374 restart->arg0 = (unsigned long) t.timer.base->index;
1375 restart->arg1 = (unsigned long) rmtp;
1376 restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF;
1377 restart->arg3 = t.timer.expires.tv64 >> 32;
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001378
1379 return -ERESTART_RESTARTBLOCK;
1380}
1381
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001382asmlinkage long
1383sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
1384{
Anton Blanchard04c22712007-10-15 16:06:04 -05001385 struct timespec tu, rmt;
1386 int ret;
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001387
1388 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1389 return -EFAULT;
1390
1391 if (!timespec_valid(&tu))
1392 return -EINVAL;
1393
Anton Blanchard04c22712007-10-15 16:06:04 -05001394 ret = hrtimer_nanosleep(&tu, rmtp ? &rmt : NULL, HRTIMER_MODE_REL,
1395 CLOCK_MONOTONIC);
1396
1397 if (ret && rmtp) {
1398 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1399 return -EFAULT;
1400 }
1401
1402 return ret;
Thomas Gleixner6ba1b912006-01-09 20:52:36 -08001403}
1404
Thomas Gleixner10c94ec2006-01-09 20:52:35 -08001405/*
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001406 * Functions related to boot-time initialization:
1407 */
Randy Dunlap0ec160d2008-01-21 17:18:24 -08001408static void __cpuinit init_hrtimers_cpu(int cpu)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001409{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001410 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001411 int i;
1412
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001413 spin_lock_init(&cpu_base->lock);
1414 lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
1415
1416 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1417 cpu_base->clock_base[i].cpu_base = cpu_base;
1418
Peter Zijlstrad3d74452008-01-25 21:08:31 +01001419 INIT_LIST_HEAD(&cpu_base->cb_pending);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001420 hrtimer_init_hres(cpu_base);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001421}
1422
1423#ifdef CONFIG_HOTPLUG_CPU
1424
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001425static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1426 struct hrtimer_clock_base *new_base)
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001427{
1428 struct hrtimer *timer;
1429 struct rb_node *node;
1430
1431 while ((node = rb_first(&old_base->active))) {
1432 timer = rb_entry(node, struct hrtimer, node);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001433 BUG_ON(hrtimer_callback_running(timer));
1434 __remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001435 timer->base = new_base;
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001436 /*
1437 * Enqueue the timer. Allow reprogramming of the event device
1438 */
1439 enqueue_hrtimer(timer, new_base, 1);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001440 }
1441}
1442
1443static void migrate_hrtimers(int cpu)
1444{
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001445 struct hrtimer_cpu_base *old_base, *new_base;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001446 int i;
1447
1448 BUG_ON(cpu_online(cpu));
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001449 old_base = &per_cpu(hrtimer_bases, cpu);
1450 new_base = &get_cpu_var(hrtimer_bases);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001451
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001452 tick_cancel_sched_timer(cpu);
1453
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001454 local_irq_disable();
Heiko Carstense81ce1f2007-03-05 00:30:51 -08001455 double_spin_lock(&new_base->lock, &old_base->lock,
1456 smp_processor_id() < cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001457
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001458 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
Thomas Gleixner3c8aa392007-02-16 01:27:50 -08001459 migrate_hrtimer_list(&old_base->clock_base[i],
1460 &new_base->clock_base[i]);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001461 }
1462
Heiko Carstense81ce1f2007-03-05 00:30:51 -08001463 double_spin_unlock(&new_base->lock, &old_base->lock,
1464 smp_processor_id() < cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001465 local_irq_enable();
1466 put_cpu_var(hrtimer_bases);
1467}
1468#endif /* CONFIG_HOTPLUG_CPU */
1469
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001470static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001471 unsigned long action, void *hcpu)
1472{
David Miller7713a7d2007-07-16 17:17:44 -07001473 unsigned int cpu = (long)hcpu;
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001474
1475 switch (action) {
1476
1477 case CPU_UP_PREPARE:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001478 case CPU_UP_PREPARE_FROZEN:
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001479 init_hrtimers_cpu(cpu);
1480 break;
1481
1482#ifdef CONFIG_HOTPLUG_CPU
1483 case CPU_DEAD:
Rafael J. Wysocki8bb78442007-05-09 02:35:10 -07001484 case CPU_DEAD_FROZEN:
Thomas Gleixnerd316c572007-02-16 01:28:00 -08001485 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001486 migrate_hrtimers(cpu);
1487 break;
1488#endif
1489
1490 default:
1491 break;
1492 }
1493
1494 return NOTIFY_OK;
1495}
1496
Chandra Seetharaman8c78f302006-07-30 03:03:35 -07001497static struct notifier_block __cpuinitdata hrtimers_nb = {
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001498 .notifier_call = hrtimer_cpu_notify,
1499};
1500
1501void __init hrtimers_init(void)
1502{
1503 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1504 (void *)(long)smp_processor_id());
1505 register_cpu_notifier(&hrtimers_nb);
Thomas Gleixner54cdfdb2007-02-16 01:28:11 -08001506#ifdef CONFIG_HIGH_RES_TIMERS
1507 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq, NULL);
1508#endif
Thomas Gleixnerc0a31322006-01-09 20:52:32 -08001509}
1510