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33
34#include <linux/cpu.h>
35#include <linux/export.h>
36#include <linux/percpu.h>
37#include <linux/hrtimer.h>
38#include <linux/notifier.h>
39#include <linux/syscalls.h>
40#include <linux/kallsyms.h>
41#include <linux/interrupt.h>
42#include <linux/tick.h>
43#include <linux/seq_file.h>
44#include <linux/err.h>
45#include <linux/debugobjects.h>
46#include <linux/sched.h>
47#include <linux/sched/sysctl.h>
48#include <linux/sched/rt.h>
49#include <linux/sched/deadline.h>
50#include <linux/timer.h>
51#include <linux/freezer.h>
52
53#include <asm/uaccess.h>
54
55#include <trace/events/timer.h>
56
57#include "timekeeping.h"
58
59
60
61
62
63
64
65
66
67DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
68{
69
70 .lock = __RAW_SPIN_LOCK_UNLOCKED(hrtimer_bases.lock),
71 .clock_base =
72 {
73 {
74 .index = HRTIMER_BASE_MONOTONIC,
75 .clockid = CLOCK_MONOTONIC,
76 .get_time = &ktime_get,
77 .resolution = KTIME_LOW_RES,
78 },
79 {
80 .index = HRTIMER_BASE_REALTIME,
81 .clockid = CLOCK_REALTIME,
82 .get_time = &ktime_get_real,
83 .resolution = KTIME_LOW_RES,
84 },
85 {
86 .index = HRTIMER_BASE_BOOTTIME,
87 .clockid = CLOCK_BOOTTIME,
88 .get_time = &ktime_get_boottime,
89 .resolution = KTIME_LOW_RES,
90 },
91 {
92 .index = HRTIMER_BASE_TAI,
93 .clockid = CLOCK_TAI,
94 .get_time = &ktime_get_clocktai,
95 .resolution = KTIME_LOW_RES,
96 },
97 }
98};
99
100static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
101 [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
102 [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
103 [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,
104 [CLOCK_TAI] = HRTIMER_BASE_TAI,
105};
106
107static inline int hrtimer_clockid_to_base(clockid_t clock_id)
108{
109 return hrtimer_clock_to_base_table[clock_id];
110}
111
112
113
114
115
116
117static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
118{
119 ktime_t xtim, mono, boot, tai;
120 ktime_t off_real, off_boot, off_tai;
121
122 mono = ktime_get_update_offsets_tick(&off_real, &off_boot, &off_tai);
123 boot = ktime_add(mono, off_boot);
124 xtim = ktime_add(mono, off_real);
125 tai = ktime_add(mono, off_tai);
126
127 base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim;
128 base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono;
129 base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot;
130 base->clock_base[HRTIMER_BASE_TAI].softirq_time = tai;
131}
132
133
134
135
136
137#ifdef CONFIG_SMP
138
139
140
141
142
143
144
145
146
147
148
149
150
151static
152struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
153 unsigned long *flags)
154{
155 struct hrtimer_clock_base *base;
156
157 for (;;) {
158 base = timer->base;
159 if (likely(base != NULL)) {
160 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
161 if (likely(base == timer->base))
162 return base;
163
164 raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
165 }
166 cpu_relax();
167 }
168}
169
170
171
172
173
174
175
176
177static int
178hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base)
179{
180#ifdef CONFIG_HIGH_RES_TIMERS
181 ktime_t expires;
182
183 if (!new_base->cpu_base->hres_active)
184 return 0;
185
186 expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
187 return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
188#else
189 return 0;
190#endif
191}
192
193
194
195
196static inline struct hrtimer_clock_base *
197switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
198 int pinned)
199{
200 struct hrtimer_clock_base *new_base;
201 struct hrtimer_cpu_base *new_cpu_base;
202 int this_cpu = smp_processor_id();
203 int cpu = get_nohz_timer_target(pinned);
204 int basenum = base->index;
205
206again:
207 new_cpu_base = &per_cpu(hrtimer_bases, cpu);
208 new_base = &new_cpu_base->clock_base[basenum];
209
210 if (base != new_base) {
211
212
213
214
215
216
217
218
219
220 if (unlikely(hrtimer_callback_running(timer)))
221 return base;
222
223
224 timer->base = NULL;
225 raw_spin_unlock(&base->cpu_base->lock);
226 raw_spin_lock(&new_base->cpu_base->lock);
227
228 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
229 cpu = this_cpu;
230 raw_spin_unlock(&new_base->cpu_base->lock);
231 raw_spin_lock(&base->cpu_base->lock);
232 timer->base = base;
233 goto again;
234 }
235 timer->base = new_base;
236 } else {
237 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
238 cpu = this_cpu;
239 goto again;
240 }
241 }
242 return new_base;
243}
244
245#else
246
247static inline struct hrtimer_clock_base *
248lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
249{
250 struct hrtimer_clock_base *base = timer->base;
251
252 raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
253
254 return base;
255}
256
257# define switch_hrtimer_base(t, b, p) (b)
258
259#endif
260
261
262
263
264
265#if BITS_PER_LONG < 64
266
267
268
269u64 __ktime_divns(const ktime_t kt, s64 div)
270{
271 u64 dclc;
272 int sft = 0;
273
274 dclc = ktime_to_ns(kt);
275
276 while (div >> 32) {
277 sft++;
278 div >>= 1;
279 }
280 dclc >>= sft;
281 do_div(dclc, (unsigned long) div);
282
283 return dclc;
284}
285EXPORT_SYMBOL_GPL(__ktime_divns);
286#endif
287
288
289
290
291ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
292{
293 ktime_t res = ktime_add(lhs, rhs);
294
295
296
297
298
299 if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
300 res = ktime_set(KTIME_SEC_MAX, 0);
301
302 return res;
303}
304
305EXPORT_SYMBOL_GPL(ktime_add_safe);
306
307#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
308
309static struct debug_obj_descr hrtimer_debug_descr;
310
311static void *hrtimer_debug_hint(void *addr)
312{
313 return ((struct hrtimer *) addr)->function;
314}
315
316
317
318
319
320static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
321{
322 struct hrtimer *timer = addr;
323
324 switch (state) {
325 case ODEBUG_STATE_ACTIVE:
326 hrtimer_cancel(timer);
327 debug_object_init(timer, &hrtimer_debug_descr);
328 return 1;
329 default:
330 return 0;
331 }
332}
333
334
335
336
337
338
339static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
340{
341 switch (state) {
342
343 case ODEBUG_STATE_NOTAVAILABLE:
344 WARN_ON_ONCE(1);
345 return 0;
346
347 case ODEBUG_STATE_ACTIVE:
348 WARN_ON(1);
349
350 default:
351 return 0;
352 }
353}
354
355
356
357
358
359static int hrtimer_fixup_free(void *addr, enum debug_obj_state state)
360{
361 struct hrtimer *timer = addr;
362
363 switch (state) {
364 case ODEBUG_STATE_ACTIVE:
365 hrtimer_cancel(timer);
366 debug_object_free(timer, &hrtimer_debug_descr);
367 return 1;
368 default:
369 return 0;
370 }
371}
372
373static struct debug_obj_descr hrtimer_debug_descr = {
374 .name = "hrtimer",
375 .debug_hint = hrtimer_debug_hint,
376 .fixup_init = hrtimer_fixup_init,
377 .fixup_activate = hrtimer_fixup_activate,
378 .fixup_free = hrtimer_fixup_free,
379};
380
381static inline void debug_hrtimer_init(struct hrtimer *timer)
382{
383 debug_object_init(timer, &hrtimer_debug_descr);
384}
385
386static inline void debug_hrtimer_activate(struct hrtimer *timer)
387{
388 debug_object_activate(timer, &hrtimer_debug_descr);
389}
390
391static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
392{
393 debug_object_deactivate(timer, &hrtimer_debug_descr);
394}
395
396static inline void debug_hrtimer_free(struct hrtimer *timer)
397{
398 debug_object_free(timer, &hrtimer_debug_descr);
399}
400
401static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
402 enum hrtimer_mode mode);
403
404void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
405 enum hrtimer_mode mode)
406{
407 debug_object_init_on_stack(timer, &hrtimer_debug_descr);
408 __hrtimer_init(timer, clock_id, mode);
409}
410EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
411
412void destroy_hrtimer_on_stack(struct hrtimer *timer)
413{
414 debug_object_free(timer, &hrtimer_debug_descr);
415}
416
417#else
418static inline void debug_hrtimer_init(struct hrtimer *timer) { }
419static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
420static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
421#endif
422
423static inline void
424debug_init(struct hrtimer *timer, clockid_t clockid,
425 enum hrtimer_mode mode)
426{
427 debug_hrtimer_init(timer);
428 trace_hrtimer_init(timer, clockid, mode);
429}
430
431static inline void debug_activate(struct hrtimer *timer)
432{
433 debug_hrtimer_activate(timer);
434 trace_hrtimer_start(timer);
435}
436
437static inline void debug_deactivate(struct hrtimer *timer)
438{
439 debug_hrtimer_deactivate(timer);
440 trace_hrtimer_cancel(timer);
441}
442
443#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
444static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base)
445{
446 struct hrtimer_clock_base *base = cpu_base->clock_base;
447 ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
448 int i;
449
450 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
451 struct timerqueue_node *next;
452 struct hrtimer *timer;
453
454 next = timerqueue_getnext(&base->active);
455 if (!next)
456 continue;
457
458 timer = container_of(next, struct hrtimer, node);
459 expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
460 if (expires.tv64 < expires_next.tv64)
461 expires_next = expires;
462 }
463
464
465
466
467
468 if (expires_next.tv64 < 0)
469 expires_next.tv64 = 0;
470 return expires_next;
471}
472#endif
473
474
475#ifdef CONFIG_HIGH_RES_TIMERS
476
477
478
479
480static int hrtimer_hres_enabled __read_mostly = 1;
481
482
483
484
485static int __init setup_hrtimer_hres(char *str)
486{
487 if (!strcmp(str, "off"))
488 hrtimer_hres_enabled = 0;
489 else if (!strcmp(str, "on"))
490 hrtimer_hres_enabled = 1;
491 else
492 return 0;
493 return 1;
494}
495
496__setup("highres=", setup_hrtimer_hres);
497
498
499
500
501static inline int hrtimer_is_hres_enabled(void)
502{
503 return hrtimer_hres_enabled;
504}
505
506
507
508
509static inline int hrtimer_hres_active(void)
510{
511 return __this_cpu_read(hrtimer_bases.hres_active);
512}
513
514
515
516
517
518
519static void
520hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
521{
522 ktime_t expires_next = __hrtimer_get_next_event(cpu_base);
523
524 if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
525 return;
526
527 cpu_base->expires_next.tv64 = expires_next.tv64;
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543 if (cpu_base->hang_detected)
544 return;
545
546 if (cpu_base->expires_next.tv64 != KTIME_MAX)
547 tick_program_event(cpu_base->expires_next, 1);
548}
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564static int hrtimer_reprogram(struct hrtimer *timer,
565 struct hrtimer_clock_base *base)
566{
567 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
568 ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
569 int res;
570
571 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
572
573
574
575
576
577
578
579
580 if (hrtimer_callback_running(timer))
581 return 0;
582
583
584
585
586
587
588
589 if (expires.tv64 < 0)
590 return -ETIME;
591
592 if (expires.tv64 >= cpu_base->expires_next.tv64)
593 return 0;
594
595
596
597
598
599
600
601 if (cpu_base->in_hrtirq)
602 return 0;
603
604
605
606
607
608
609
610 if (cpu_base->hang_detected)
611 return 0;
612
613
614
615
616 res = tick_program_event(expires, 0);
617 if (!IS_ERR_VALUE(res))
618 cpu_base->expires_next = expires;
619 return res;
620}
621
622
623
624
625static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
626{
627 base->expires_next.tv64 = KTIME_MAX;
628 base->hres_active = 0;
629}
630
631static inline ktime_t hrtimer_update_base(struct hrtimer_cpu_base *base)
632{
633 ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
634 ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
635 ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset;
636
637 return ktime_get_update_offsets_now(offs_real, offs_boot, offs_tai);
638}
639
640
641
642
643
644
645static void retrigger_next_event(void *arg)
646{
647 struct hrtimer_cpu_base *base = this_cpu_ptr(&hrtimer_bases);
648
649 if (!hrtimer_hres_active())
650 return;
651
652 raw_spin_lock(&base->lock);
653 hrtimer_update_base(base);
654 hrtimer_force_reprogram(base, 0);
655 raw_spin_unlock(&base->lock);
656}
657
658
659
660
661static int hrtimer_switch_to_hres(void)
662{
663 int i, cpu = smp_processor_id();
664 struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
665 unsigned long flags;
666
667 if (base->hres_active)
668 return 1;
669
670 local_irq_save(flags);
671
672 if (tick_init_highres()) {
673 local_irq_restore(flags);
674 printk(KERN_WARNING "Could not switch to high resolution "
675 "mode on CPU %d\n", cpu);
676 return 0;
677 }
678 base->hres_active = 1;
679 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
680 base->clock_base[i].resolution = KTIME_HIGH_RES;
681
682 tick_setup_sched_timer();
683
684 retrigger_next_event(NULL);
685 local_irq_restore(flags);
686 return 1;
687}
688
689static void clock_was_set_work(struct work_struct *work)
690{
691 clock_was_set();
692}
693
694static DECLARE_WORK(hrtimer_work, clock_was_set_work);
695
696
697
698
699
700void clock_was_set_delayed(void)
701{
702 schedule_work(&hrtimer_work);
703}
704
705#else
706
707static inline int hrtimer_hres_active(void) { return 0; }
708static inline int hrtimer_is_hres_enabled(void) { return 0; }
709static inline int hrtimer_switch_to_hres(void) { return 0; }
710static inline void
711hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
712static inline int hrtimer_reprogram(struct hrtimer *timer,
713 struct hrtimer_clock_base *base)
714{
715 return 0;
716}
717static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
718static inline void retrigger_next_event(void *arg) { }
719
720#endif
721
722
723
724
725
726
727
728
729
730
731
732
733void clock_was_set(void)
734{
735#ifdef CONFIG_HIGH_RES_TIMERS
736
737 on_each_cpu(retrigger_next_event, NULL, 1);
738#endif
739 timerfd_clock_was_set();
740}
741
742
743
744
745
746
747
748void hrtimers_resume(void)
749{
750 WARN_ONCE(!irqs_disabled(),
751 KERN_INFO "hrtimers_resume() called with IRQs enabled!");
752
753
754 retrigger_next_event(NULL);
755
756 clock_was_set_delayed();
757}
758
759static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
760{
761#ifdef CONFIG_TIMER_STATS
762 if (timer->start_site)
763 return;
764 timer->start_site = __builtin_return_address(0);
765 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
766 timer->start_pid = current->pid;
767#endif
768}
769
770static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
771{
772#ifdef CONFIG_TIMER_STATS
773 timer->start_site = NULL;
774#endif
775}
776
777static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
778{
779#ifdef CONFIG_TIMER_STATS
780 if (likely(!timer_stats_active))
781 return;
782 timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
783 timer->function, timer->start_comm, 0);
784#endif
785}
786
787
788
789
790static inline
791void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
792{
793 raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
794}
795
796
797
798
799
800
801
802
803
804
805u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
806{
807 u64 orun = 1;
808 ktime_t delta;
809
810 delta = ktime_sub(now, hrtimer_get_expires(timer));
811
812 if (delta.tv64 < 0)
813 return 0;
814
815 if (interval.tv64 < timer->base->resolution.tv64)
816 interval.tv64 = timer->base->resolution.tv64;
817
818 if (unlikely(delta.tv64 >= interval.tv64)) {
819 s64 incr = ktime_to_ns(interval);
820
821 orun = ktime_divns(delta, incr);
822 hrtimer_add_expires_ns(timer, incr * orun);
823 if (hrtimer_get_expires_tv64(timer) > now.tv64)
824 return orun;
825
826
827
828
829 orun++;
830 }
831 hrtimer_add_expires(timer, interval);
832
833 return orun;
834}
835EXPORT_SYMBOL_GPL(hrtimer_forward);
836
837
838
839
840
841
842
843
844
845static int enqueue_hrtimer(struct hrtimer *timer,
846 struct hrtimer_clock_base *base)
847{
848 debug_activate(timer);
849
850 timerqueue_add(&base->active, &timer->node);
851 base->cpu_base->active_bases |= 1 << base->index;
852
853
854
855
856
857 timer->state |= HRTIMER_STATE_ENQUEUED;
858
859 return (&timer->node == base->active.next);
860}
861
862
863
864
865
866
867
868
869
870
871
872static void __remove_hrtimer(struct hrtimer *timer,
873 struct hrtimer_clock_base *base,
874 unsigned long newstate, int reprogram)
875{
876 struct timerqueue_node *next_timer;
877 if (!(timer->state & HRTIMER_STATE_ENQUEUED))
878 goto out;
879
880 next_timer = timerqueue_getnext(&base->active);
881 timerqueue_del(&base->active, &timer->node);
882 if (&timer->node == next_timer) {
883#ifdef CONFIG_HIGH_RES_TIMERS
884
885 if (reprogram && hrtimer_hres_active()) {
886 ktime_t expires;
887
888 expires = ktime_sub(hrtimer_get_expires(timer),
889 base->offset);
890 if (base->cpu_base->expires_next.tv64 == expires.tv64)
891 hrtimer_force_reprogram(base->cpu_base, 1);
892 }
893#endif
894 }
895 if (!timerqueue_getnext(&base->active))
896 base->cpu_base->active_bases &= ~(1 << base->index);
897out:
898 timer->state = newstate;
899}
900
901
902
903
904static inline int
905remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
906{
907 if (hrtimer_is_queued(timer)) {
908 unsigned long state;
909 int reprogram;
910
911
912
913
914
915
916
917
918
919 debug_deactivate(timer);
920 timer_stats_hrtimer_clear_start_info(timer);
921 reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
922
923
924
925
926
927 state = timer->state & HRTIMER_STATE_CALLBACK;
928 __remove_hrtimer(timer, base, state, reprogram);
929 return 1;
930 }
931 return 0;
932}
933
934int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
935 unsigned long delta_ns, const enum hrtimer_mode mode,
936 int wakeup)
937{
938 struct hrtimer_clock_base *base, *new_base;
939 unsigned long flags;
940 int ret, leftmost;
941
942 base = lock_hrtimer_base(timer, &flags);
943
944
945 ret = remove_hrtimer(timer, base);
946
947 if (mode & HRTIMER_MODE_REL) {
948 tim = ktime_add_safe(tim, base->get_time());
949
950
951
952
953
954
955
956#ifdef CONFIG_TIME_LOW_RES
957 tim = ktime_add_safe(tim, base->resolution);
958#endif
959 }
960
961 hrtimer_set_expires_range_ns(timer, tim, delta_ns);
962
963
964 new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
965
966 timer_stats_hrtimer_set_start_info(timer);
967
968 leftmost = enqueue_hrtimer(timer, new_base);
969
970 if (!leftmost) {
971 unlock_hrtimer_base(timer, &flags);
972 return ret;
973 }
974
975 if (!hrtimer_is_hres_active(timer)) {
976
977
978
979
980 wake_up_nohz_cpu(new_base->cpu_base->cpu);
981 } else if (new_base->cpu_base == this_cpu_ptr(&hrtimer_bases) &&
982 hrtimer_reprogram(timer, new_base)) {
983
984
985
986
987
988
989 if (wakeup) {
990
991
992
993
994 raw_spin_unlock(&new_base->cpu_base->lock);
995 raise_softirq_irqoff(HRTIMER_SOFTIRQ);
996 local_irq_restore(flags);
997 return ret;
998 } else {
999 __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
1000 }
1001 }
1002
1003 unlock_hrtimer_base(timer, &flags);
1004
1005 return ret;
1006}
1007EXPORT_SYMBOL_GPL(__hrtimer_start_range_ns);
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
1022 unsigned long delta_ns, const enum hrtimer_mode mode)
1023{
1024 return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1);
1025}
1026EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039int
1040hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
1041{
1042 return __hrtimer_start_range_ns(timer, tim, 0, mode, 1);
1043}
1044EXPORT_SYMBOL_GPL(hrtimer_start);
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057int hrtimer_try_to_cancel(struct hrtimer *timer)
1058{
1059 struct hrtimer_clock_base *base;
1060 unsigned long flags;
1061 int ret = -1;
1062
1063 base = lock_hrtimer_base(timer, &flags);
1064
1065 if (!hrtimer_callback_running(timer))
1066 ret = remove_hrtimer(timer, base);
1067
1068 unlock_hrtimer_base(timer, &flags);
1069
1070 return ret;
1071
1072}
1073EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083int hrtimer_cancel(struct hrtimer *timer)
1084{
1085 for (;;) {
1086 int ret = hrtimer_try_to_cancel(timer);
1087
1088 if (ret >= 0)
1089 return ret;
1090 cpu_relax();
1091 }
1092}
1093EXPORT_SYMBOL_GPL(hrtimer_cancel);
1094
1095
1096
1097
1098
1099ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
1100{
1101 unsigned long flags;
1102 ktime_t rem;
1103
1104 lock_hrtimer_base(timer, &flags);
1105 rem = hrtimer_expires_remaining(timer);
1106 unlock_hrtimer_base(timer, &flags);
1107
1108 return rem;
1109}
1110EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
1111
1112#ifdef CONFIG_NO_HZ_COMMON
1113
1114
1115
1116
1117
1118
1119ktime_t hrtimer_get_next_event(void)
1120{
1121 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1122 ktime_t mindelta = { .tv64 = KTIME_MAX };
1123 unsigned long flags;
1124
1125 raw_spin_lock_irqsave(&cpu_base->lock, flags);
1126
1127 if (!hrtimer_hres_active())
1128 mindelta = ktime_sub(__hrtimer_get_next_event(cpu_base),
1129 ktime_get());
1130
1131 raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
1132
1133 if (mindelta.tv64 < 0)
1134 mindelta.tv64 = 0;
1135 return mindelta;
1136}
1137#endif
1138
1139static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1140 enum hrtimer_mode mode)
1141{
1142 struct hrtimer_cpu_base *cpu_base;
1143 int base;
1144
1145 memset(timer, 0, sizeof(struct hrtimer));
1146
1147 cpu_base = raw_cpu_ptr(&hrtimer_bases);
1148
1149 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
1150 clock_id = CLOCK_MONOTONIC;
1151
1152 base = hrtimer_clockid_to_base(clock_id);
1153 timer->base = &cpu_base->clock_base[base];
1154 timerqueue_init(&timer->node);
1155
1156#ifdef CONFIG_TIMER_STATS
1157 timer->start_site = NULL;
1158 timer->start_pid = -1;
1159 memset(timer->start_comm, 0, TASK_COMM_LEN);
1160#endif
1161}
1162
1163
1164
1165
1166
1167
1168
1169void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1170 enum hrtimer_mode mode)
1171{
1172 debug_init(timer, clock_id, mode);
1173 __hrtimer_init(timer, clock_id, mode);
1174}
1175EXPORT_SYMBOL_GPL(hrtimer_init);
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1186{
1187 struct hrtimer_cpu_base *cpu_base;
1188 int base = hrtimer_clockid_to_base(which_clock);
1189
1190 cpu_base = raw_cpu_ptr(&hrtimer_bases);
1191 *tp = ktime_to_timespec(cpu_base->clock_base[base].resolution);
1192
1193 return 0;
1194}
1195EXPORT_SYMBOL_GPL(hrtimer_get_res);
1196
1197static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
1198{
1199 struct hrtimer_clock_base *base = timer->base;
1200 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1201 enum hrtimer_restart (*fn)(struct hrtimer *);
1202 int restart;
1203
1204 WARN_ON(!irqs_disabled());
1205
1206 debug_deactivate(timer);
1207 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1208 timer_stats_account_hrtimer(timer);
1209 fn = timer->function;
1210
1211
1212
1213
1214
1215
1216 raw_spin_unlock(&cpu_base->lock);
1217 trace_hrtimer_expire_entry(timer, now);
1218 restart = fn(timer);
1219 trace_hrtimer_expire_exit(timer);
1220 raw_spin_lock(&cpu_base->lock);
1221
1222
1223
1224
1225
1226
1227 if (restart != HRTIMER_NORESTART) {
1228 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1229 enqueue_hrtimer(timer, base);
1230 }
1231
1232 WARN_ON_ONCE(!(timer->state & HRTIMER_STATE_CALLBACK));
1233
1234 timer->state &= ~HRTIMER_STATE_CALLBACK;
1235}
1236
1237#ifdef CONFIG_HIGH_RES_TIMERS
1238
1239
1240
1241
1242
1243void hrtimer_interrupt(struct clock_event_device *dev)
1244{
1245 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1246 ktime_t expires_next, now, entry_time, delta;
1247 int i, retries = 0;
1248
1249 BUG_ON(!cpu_base->hres_active);
1250 cpu_base->nr_events++;
1251 dev->next_event.tv64 = KTIME_MAX;
1252
1253 raw_spin_lock(&cpu_base->lock);
1254 entry_time = now = hrtimer_update_base(cpu_base);
1255retry:
1256 cpu_base->in_hrtirq = 1;
1257
1258
1259
1260
1261
1262
1263
1264 cpu_base->expires_next.tv64 = KTIME_MAX;
1265
1266 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1267 struct hrtimer_clock_base *base;
1268 struct timerqueue_node *node;
1269 ktime_t basenow;
1270
1271 if (!(cpu_base->active_bases & (1 << i)))
1272 continue;
1273
1274 base = cpu_base->clock_base + i;
1275 basenow = ktime_add(now, base->offset);
1276
1277 while ((node = timerqueue_getnext(&base->active))) {
1278 struct hrtimer *timer;
1279
1280 timer = container_of(node, struct hrtimer, node);
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294 if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer))
1295 break;
1296
1297 __run_hrtimer(timer, &basenow);
1298 }
1299 }
1300
1301 expires_next = __hrtimer_get_next_event(cpu_base);
1302
1303
1304
1305
1306 cpu_base->expires_next = expires_next;
1307 cpu_base->in_hrtirq = 0;
1308 raw_spin_unlock(&cpu_base->lock);
1309
1310
1311 if (expires_next.tv64 == KTIME_MAX ||
1312 !tick_program_event(expires_next, 0)) {
1313 cpu_base->hang_detected = 0;
1314 return;
1315 }
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330 raw_spin_lock(&cpu_base->lock);
1331 now = hrtimer_update_base(cpu_base);
1332 cpu_base->nr_retries++;
1333 if (++retries < 3)
1334 goto retry;
1335
1336
1337
1338
1339
1340
1341 cpu_base->nr_hangs++;
1342 cpu_base->hang_detected = 1;
1343 raw_spin_unlock(&cpu_base->lock);
1344 delta = ktime_sub(now, entry_time);
1345 if (delta.tv64 > cpu_base->max_hang_time.tv64)
1346 cpu_base->max_hang_time = delta;
1347
1348
1349
1350
1351 if (delta.tv64 > 100 * NSEC_PER_MSEC)
1352 expires_next = ktime_add_ns(now, 100 * NSEC_PER_MSEC);
1353 else
1354 expires_next = ktime_add(now, delta);
1355 tick_program_event(expires_next, 1);
1356 printk_once(KERN_WARNING "hrtimer: interrupt took %llu ns\n",
1357 ktime_to_ns(delta));
1358}
1359
1360
1361
1362
1363
1364static void __hrtimer_peek_ahead_timers(void)
1365{
1366 struct tick_device *td;
1367
1368 if (!hrtimer_hres_active())
1369 return;
1370
1371 td = this_cpu_ptr(&tick_cpu_device);
1372 if (td && td->evtdev)
1373 hrtimer_interrupt(td->evtdev);
1374}
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385void hrtimer_peek_ahead_timers(void)
1386{
1387 unsigned long flags;
1388
1389 local_irq_save(flags);
1390 __hrtimer_peek_ahead_timers();
1391 local_irq_restore(flags);
1392}
1393
1394static void run_hrtimer_softirq(struct softirq_action *h)
1395{
1396 hrtimer_peek_ahead_timers();
1397}
1398
1399#else
1400
1401static inline void __hrtimer_peek_ahead_timers(void) { }
1402
1403#endif
1404
1405
1406
1407
1408
1409
1410
1411
1412void hrtimer_run_pending(void)
1413{
1414 if (hrtimer_hres_active())
1415 return;
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1426 hrtimer_switch_to_hres();
1427}
1428
1429
1430
1431
1432void hrtimer_run_queues(void)
1433{
1434 struct timerqueue_node *node;
1435 struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
1436 struct hrtimer_clock_base *base;
1437 int index, gettime = 1;
1438
1439 if (hrtimer_hres_active())
1440 return;
1441
1442 for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
1443 base = &cpu_base->clock_base[index];
1444 if (!timerqueue_getnext(&base->active))
1445 continue;
1446
1447 if (gettime) {
1448 hrtimer_get_softirq_time(cpu_base);
1449 gettime = 0;
1450 }
1451
1452 raw_spin_lock(&cpu_base->lock);
1453
1454 while ((node = timerqueue_getnext(&base->active))) {
1455 struct hrtimer *timer;
1456
1457 timer = container_of(node, struct hrtimer, node);
1458 if (base->softirq_time.tv64 <=
1459 hrtimer_get_expires_tv64(timer))
1460 break;
1461
1462 __run_hrtimer(timer, &base->softirq_time);
1463 }
1464 raw_spin_unlock(&cpu_base->lock);
1465 }
1466}
1467
1468
1469
1470
1471static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
1472{
1473 struct hrtimer_sleeper *t =
1474 container_of(timer, struct hrtimer_sleeper, timer);
1475 struct task_struct *task = t->task;
1476
1477 t->task = NULL;
1478 if (task)
1479 wake_up_process(task);
1480
1481 return HRTIMER_NORESTART;
1482}
1483
1484void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
1485{
1486 sl->timer.function = hrtimer_wakeup;
1487 sl->task = task;
1488}
1489EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
1490
1491static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
1492{
1493 hrtimer_init_sleeper(t, current);
1494
1495 do {
1496 set_current_state(TASK_INTERRUPTIBLE);
1497 hrtimer_start_expires(&t->timer, mode);
1498 if (!hrtimer_active(&t->timer))
1499 t->task = NULL;
1500
1501 if (likely(t->task))
1502 freezable_schedule();
1503
1504 hrtimer_cancel(&t->timer);
1505 mode = HRTIMER_MODE_ABS;
1506
1507 } while (t->task && !signal_pending(current));
1508
1509 __set_current_state(TASK_RUNNING);
1510
1511 return t->task == NULL;
1512}
1513
1514static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
1515{
1516 struct timespec rmt;
1517 ktime_t rem;
1518
1519 rem = hrtimer_expires_remaining(timer);
1520 if (rem.tv64 <= 0)
1521 return 0;
1522 rmt = ktime_to_timespec(rem);
1523
1524 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1525 return -EFAULT;
1526
1527 return 1;
1528}
1529
1530long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1531{
1532 struct hrtimer_sleeper t;
1533 struct timespec __user *rmtp;
1534 int ret = 0;
1535
1536 hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
1537 HRTIMER_MODE_ABS);
1538 hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
1539
1540 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1541 goto out;
1542
1543 rmtp = restart->nanosleep.rmtp;
1544 if (rmtp) {
1545 ret = update_rmtp(&t.timer, rmtp);
1546 if (ret <= 0)
1547 goto out;
1548 }
1549
1550
1551 ret = -ERESTART_RESTARTBLOCK;
1552out:
1553 destroy_hrtimer_on_stack(&t.timer);
1554 return ret;
1555}
1556
1557long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1558 const enum hrtimer_mode mode, const clockid_t clockid)
1559{
1560 struct restart_block *restart;
1561 struct hrtimer_sleeper t;
1562 int ret = 0;
1563 unsigned long slack;
1564
1565 slack = current->timer_slack_ns;
1566 if (dl_task(current) || rt_task(current))
1567 slack = 0;
1568
1569 hrtimer_init_on_stack(&t.timer, clockid, mode);
1570 hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1571 if (do_nanosleep(&t, mode))
1572 goto out;
1573
1574
1575 if (mode == HRTIMER_MODE_ABS) {
1576 ret = -ERESTARTNOHAND;
1577 goto out;
1578 }
1579
1580 if (rmtp) {
1581 ret = update_rmtp(&t.timer, rmtp);
1582 if (ret <= 0)
1583 goto out;
1584 }
1585
1586 restart = ¤t->restart_block;
1587 restart->fn = hrtimer_nanosleep_restart;
1588 restart->nanosleep.clockid = t.timer.base->clockid;
1589 restart->nanosleep.rmtp = rmtp;
1590 restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
1591
1592 ret = -ERESTART_RESTARTBLOCK;
1593out:
1594 destroy_hrtimer_on_stack(&t.timer);
1595 return ret;
1596}
1597
1598SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
1599 struct timespec __user *, rmtp)
1600{
1601 struct timespec tu;
1602
1603 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1604 return -EFAULT;
1605
1606 if (!timespec_valid(&tu))
1607 return -EINVAL;
1608
1609 return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
1610}
1611
1612
1613
1614
1615static void init_hrtimers_cpu(int cpu)
1616{
1617 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
1618 int i;
1619
1620 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1621 cpu_base->clock_base[i].cpu_base = cpu_base;
1622 timerqueue_init_head(&cpu_base->clock_base[i].active);
1623 }
1624
1625 cpu_base->cpu = cpu;
1626 hrtimer_init_hres(cpu_base);
1627}
1628
1629#ifdef CONFIG_HOTPLUG_CPU
1630
1631static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1632 struct hrtimer_clock_base *new_base)
1633{
1634 struct hrtimer *timer;
1635 struct timerqueue_node *node;
1636
1637 while ((node = timerqueue_getnext(&old_base->active))) {
1638 timer = container_of(node, struct hrtimer, node);
1639 BUG_ON(hrtimer_callback_running(timer));
1640 debug_deactivate(timer);
1641
1642
1643
1644
1645
1646
1647 __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
1648 timer->base = new_base;
1649
1650
1651
1652
1653
1654
1655
1656
1657 enqueue_hrtimer(timer, new_base);
1658
1659
1660 timer->state &= ~HRTIMER_STATE_MIGRATE;
1661 }
1662}
1663
1664static void migrate_hrtimers(int scpu)
1665{
1666 struct hrtimer_cpu_base *old_base, *new_base;
1667 int i;
1668
1669 BUG_ON(cpu_online(scpu));
1670 tick_cancel_sched_timer(scpu);
1671
1672 local_irq_disable();
1673 old_base = &per_cpu(hrtimer_bases, scpu);
1674 new_base = this_cpu_ptr(&hrtimer_bases);
1675
1676
1677
1678
1679 raw_spin_lock(&new_base->lock);
1680 raw_spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1681
1682 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1683 migrate_hrtimer_list(&old_base->clock_base[i],
1684 &new_base->clock_base[i]);
1685 }
1686
1687 raw_spin_unlock(&old_base->lock);
1688 raw_spin_unlock(&new_base->lock);
1689
1690
1691 __hrtimer_peek_ahead_timers();
1692 local_irq_enable();
1693}
1694
1695#endif
1696
1697static int hrtimer_cpu_notify(struct notifier_block *self,
1698 unsigned long action, void *hcpu)
1699{
1700 int scpu = (long)hcpu;
1701
1702 switch (action) {
1703
1704 case CPU_UP_PREPARE:
1705 case CPU_UP_PREPARE_FROZEN:
1706 init_hrtimers_cpu(scpu);
1707 break;
1708
1709#ifdef CONFIG_HOTPLUG_CPU
1710 case CPU_DYING:
1711 case CPU_DYING_FROZEN:
1712 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu);
1713 break;
1714 case CPU_DEAD:
1715 case CPU_DEAD_FROZEN:
1716 {
1717 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu);
1718 migrate_hrtimers(scpu);
1719 break;
1720 }
1721#endif
1722
1723 default:
1724 break;
1725 }
1726
1727 return NOTIFY_OK;
1728}
1729
1730static struct notifier_block hrtimers_nb = {
1731 .notifier_call = hrtimer_cpu_notify,
1732};
1733
1734void __init hrtimers_init(void)
1735{
1736 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1737 (void *)(long)smp_processor_id());
1738 register_cpu_notifier(&hrtimers_nb);
1739#ifdef CONFIG_HIGH_RES_TIMERS
1740 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
1741#endif
1742}
1743
1744
1745
1746
1747
1748
1749
1750
1751int __sched
1752schedule_hrtimeout_range_clock(ktime_t *expires, unsigned long delta,
1753 const enum hrtimer_mode mode, int clock)
1754{
1755 struct hrtimer_sleeper t;
1756
1757
1758
1759
1760
1761 if (expires && !expires->tv64) {
1762 __set_current_state(TASK_RUNNING);
1763 return 0;
1764 }
1765
1766
1767
1768
1769 if (!expires) {
1770 schedule();
1771 return -EINTR;
1772 }
1773
1774 hrtimer_init_on_stack(&t.timer, clock, mode);
1775 hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
1776
1777 hrtimer_init_sleeper(&t, current);
1778
1779 hrtimer_start_expires(&t.timer, mode);
1780 if (!hrtimer_active(&t.timer))
1781 t.task = NULL;
1782
1783 if (likely(t.task))
1784 schedule();
1785
1786 hrtimer_cancel(&t.timer);
1787 destroy_hrtimer_on_stack(&t.timer);
1788
1789 __set_current_state(TASK_RUNNING);
1790
1791 return !t.task ? 0 : -EINTR;
1792}
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1822int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
1823 const enum hrtimer_mode mode)
1824{
1825 return schedule_hrtimeout_range_clock(expires, delta, mode,
1826 CLOCK_MONOTONIC);
1827}
1828EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
1829
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1852int __sched schedule_hrtimeout(ktime_t *expires,
1853 const enum hrtimer_mode mode)
1854{
1855 return schedule_hrtimeout_range(expires, 0, mode);
1856}
1857EXPORT_SYMBOL_GPL(schedule_hrtimeout);
1858