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33
34#include <linux/cpu.h>
35#include <linux/module.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/timer.h>
48
49#include <asm/uaccess.h>
50
51#include <trace/events/timer.h>
52
53
54
55
56
57
58
59
60
61
62DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
63{
64
65 .clock_base =
66 {
67 {
68 .index = CLOCK_REALTIME,
69 .get_time = &ktime_get_real,
70 .resolution = KTIME_LOW_RES,
71 },
72 {
73 .index = CLOCK_MONOTONIC,
74 .get_time = &ktime_get,
75 .resolution = KTIME_LOW_RES,
76 },
77 }
78};
79
80
81
82
83
84static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
85{
86 ktime_t xtim, tomono;
87 struct timespec xts, tom;
88 unsigned long seq;
89
90 do {
91 seq = read_seqbegin(&xtime_lock);
92 xts = current_kernel_time();
93 tom = wall_to_monotonic;
94 } while (read_seqretry(&xtime_lock, seq));
95
96 xtim = timespec_to_ktime(xts);
97 tomono = timespec_to_ktime(tom);
98 base->clock_base[CLOCK_REALTIME].softirq_time = xtim;
99 base->clock_base[CLOCK_MONOTONIC].softirq_time =
100 ktime_add(xtim, tomono);
101}
102
103
104
105
106
107#ifdef CONFIG_SMP
108
109
110
111
112
113
114
115
116
117
118
119
120
121static
122struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
123 unsigned long *flags)
124{
125 struct hrtimer_clock_base *base;
126
127 for (;;) {
128 base = timer->base;
129 if (likely(base != NULL)) {
130 spin_lock_irqsave(&base->cpu_base->lock, *flags);
131 if (likely(base == timer->base))
132 return base;
133
134 spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
135 }
136 cpu_relax();
137 }
138}
139
140
141
142
143
144static int hrtimer_get_target(int this_cpu, int pinned)
145{
146#ifdef CONFIG_NO_HZ
147 if (!pinned && get_sysctl_timer_migration() && idle_cpu(this_cpu)) {
148 int preferred_cpu = get_nohz_load_balancer();
149
150 if (preferred_cpu >= 0)
151 return preferred_cpu;
152 }
153#endif
154 return this_cpu;
155}
156
157
158
159
160
161
162
163
164static int
165hrtimer_check_target(struct hrtimer *timer, struct hrtimer_clock_base *new_base)
166{
167#ifdef CONFIG_HIGH_RES_TIMERS
168 ktime_t expires;
169
170 if (!new_base->cpu_base->hres_active)
171 return 0;
172
173 expires = ktime_sub(hrtimer_get_expires(timer), new_base->offset);
174 return expires.tv64 <= new_base->cpu_base->expires_next.tv64;
175#else
176 return 0;
177#endif
178}
179
180
181
182
183static inline struct hrtimer_clock_base *
184switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
185 int pinned)
186{
187 struct hrtimer_clock_base *new_base;
188 struct hrtimer_cpu_base *new_cpu_base;
189 int this_cpu = smp_processor_id();
190 int cpu = hrtimer_get_target(this_cpu, pinned);
191
192again:
193 new_cpu_base = &per_cpu(hrtimer_bases, cpu);
194 new_base = &new_cpu_base->clock_base[base->index];
195
196 if (base != new_base) {
197
198
199
200
201
202
203
204
205
206 if (unlikely(hrtimer_callback_running(timer)))
207 return base;
208
209
210 timer->base = NULL;
211 spin_unlock(&base->cpu_base->lock);
212 spin_lock(&new_base->cpu_base->lock);
213
214 if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
215 cpu = this_cpu;
216 spin_unlock(&new_base->cpu_base->lock);
217 spin_lock(&base->cpu_base->lock);
218 timer->base = base;
219 goto again;
220 }
221 timer->base = new_base;
222 }
223 return new_base;
224}
225
226#else
227
228static inline struct hrtimer_clock_base *
229lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
230{
231 struct hrtimer_clock_base *base = timer->base;
232
233 spin_lock_irqsave(&base->cpu_base->lock, *flags);
234
235 return base;
236}
237
238# define switch_hrtimer_base(t, b, p) (b)
239
240#endif
241
242
243
244
245
246#if BITS_PER_LONG < 64
247# ifndef CONFIG_KTIME_SCALAR
248
249
250
251
252
253
254
255ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
256{
257 ktime_t tmp;
258
259 if (likely(nsec < NSEC_PER_SEC)) {
260 tmp.tv64 = nsec;
261 } else {
262 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
263
264 tmp = ktime_set((long)nsec, rem);
265 }
266
267 return ktime_add(kt, tmp);
268}
269
270EXPORT_SYMBOL_GPL(ktime_add_ns);
271
272
273
274
275
276
277
278
279ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec)
280{
281 ktime_t tmp;
282
283 if (likely(nsec < NSEC_PER_SEC)) {
284 tmp.tv64 = nsec;
285 } else {
286 unsigned long rem = do_div(nsec, NSEC_PER_SEC);
287
288 tmp = ktime_set((long)nsec, rem);
289 }
290
291 return ktime_sub(kt, tmp);
292}
293
294EXPORT_SYMBOL_GPL(ktime_sub_ns);
295# endif
296
297
298
299
300u64 ktime_divns(const ktime_t kt, s64 div)
301{
302 u64 dclc;
303 int sft = 0;
304
305 dclc = ktime_to_ns(kt);
306
307 while (div >> 32) {
308 sft++;
309 div >>= 1;
310 }
311 dclc >>= sft;
312 do_div(dclc, (unsigned long) div);
313
314 return dclc;
315}
316#endif
317
318
319
320
321ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
322{
323 ktime_t res = ktime_add(lhs, rhs);
324
325
326
327
328
329 if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
330 res = ktime_set(KTIME_SEC_MAX, 0);
331
332 return res;
333}
334
335EXPORT_SYMBOL_GPL(ktime_add_safe);
336
337#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
338
339static struct debug_obj_descr hrtimer_debug_descr;
340
341
342
343
344
345static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
346{
347 struct hrtimer *timer = addr;
348
349 switch (state) {
350 case ODEBUG_STATE_ACTIVE:
351 hrtimer_cancel(timer);
352 debug_object_init(timer, &hrtimer_debug_descr);
353 return 1;
354 default:
355 return 0;
356 }
357}
358
359
360
361
362
363
364static int hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
365{
366 switch (state) {
367
368 case ODEBUG_STATE_NOTAVAILABLE:
369 WARN_ON_ONCE(1);
370 return 0;
371
372 case ODEBUG_STATE_ACTIVE:
373 WARN_ON(1);
374
375 default:
376 return 0;
377 }
378}
379
380
381
382
383
384static int hrtimer_fixup_free(void *addr, enum debug_obj_state state)
385{
386 struct hrtimer *timer = addr;
387
388 switch (state) {
389 case ODEBUG_STATE_ACTIVE:
390 hrtimer_cancel(timer);
391 debug_object_free(timer, &hrtimer_debug_descr);
392 return 1;
393 default:
394 return 0;
395 }
396}
397
398static struct debug_obj_descr hrtimer_debug_descr = {
399 .name = "hrtimer",
400 .fixup_init = hrtimer_fixup_init,
401 .fixup_activate = hrtimer_fixup_activate,
402 .fixup_free = hrtimer_fixup_free,
403};
404
405static inline void debug_hrtimer_init(struct hrtimer *timer)
406{
407 debug_object_init(timer, &hrtimer_debug_descr);
408}
409
410static inline void debug_hrtimer_activate(struct hrtimer *timer)
411{
412 debug_object_activate(timer, &hrtimer_debug_descr);
413}
414
415static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
416{
417 debug_object_deactivate(timer, &hrtimer_debug_descr);
418}
419
420static inline void debug_hrtimer_free(struct hrtimer *timer)
421{
422 debug_object_free(timer, &hrtimer_debug_descr);
423}
424
425static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
426 enum hrtimer_mode mode);
427
428void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
429 enum hrtimer_mode mode)
430{
431 debug_object_init_on_stack(timer, &hrtimer_debug_descr);
432 __hrtimer_init(timer, clock_id, mode);
433}
434EXPORT_SYMBOL_GPL(hrtimer_init_on_stack);
435
436void destroy_hrtimer_on_stack(struct hrtimer *timer)
437{
438 debug_object_free(timer, &hrtimer_debug_descr);
439}
440
441#else
442static inline void debug_hrtimer_init(struct hrtimer *timer) { }
443static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
444static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
445#endif
446
447static inline void
448debug_init(struct hrtimer *timer, clockid_t clockid,
449 enum hrtimer_mode mode)
450{
451 debug_hrtimer_init(timer);
452 trace_hrtimer_init(timer, clockid, mode);
453}
454
455static inline void debug_activate(struct hrtimer *timer)
456{
457 debug_hrtimer_activate(timer);
458 trace_hrtimer_start(timer);
459}
460
461static inline void debug_deactivate(struct hrtimer *timer)
462{
463 debug_hrtimer_deactivate(timer);
464 trace_hrtimer_cancel(timer);
465}
466
467
468#ifdef CONFIG_HIGH_RES_TIMERS
469
470
471
472
473static int hrtimer_hres_enabled __read_mostly = 1;
474
475
476
477
478static int __init setup_hrtimer_hres(char *str)
479{
480 if (!strcmp(str, "off"))
481 hrtimer_hres_enabled = 0;
482 else if (!strcmp(str, "on"))
483 hrtimer_hres_enabled = 1;
484 else
485 return 0;
486 return 1;
487}
488
489__setup("highres=", setup_hrtimer_hres);
490
491
492
493
494static inline int hrtimer_is_hres_enabled(void)
495{
496 return hrtimer_hres_enabled;
497}
498
499
500
501
502static inline int hrtimer_hres_active(void)
503{
504 return __get_cpu_var(hrtimer_bases).hres_active;
505}
506
507
508
509
510
511
512static void
513hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
514{
515 int i;
516 struct hrtimer_clock_base *base = cpu_base->clock_base;
517 ktime_t expires, expires_next;
518
519 expires_next.tv64 = KTIME_MAX;
520
521 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
522 struct hrtimer *timer;
523
524 if (!base->first)
525 continue;
526 timer = rb_entry(base->first, struct hrtimer, node);
527 expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
528
529
530
531
532
533 if (expires.tv64 < 0)
534 expires.tv64 = 0;
535 if (expires.tv64 < expires_next.tv64)
536 expires_next = expires;
537 }
538
539 if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
540 return;
541
542 cpu_base->expires_next.tv64 = expires_next.tv64;
543
544 if (cpu_base->expires_next.tv64 != KTIME_MAX)
545 tick_program_event(cpu_base->expires_next, 1);
546}
547
548
549
550
551
552
553
554
555
556
557static int hrtimer_reprogram(struct hrtimer *timer,
558 struct hrtimer_clock_base *base)
559{
560 ktime_t *expires_next = &__get_cpu_var(hrtimer_bases).expires_next;
561 ktime_t expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
562 int res;
563
564 WARN_ON_ONCE(hrtimer_get_expires_tv64(timer) < 0);
565
566
567
568
569
570
571
572
573 if (hrtimer_callback_running(timer))
574 return 0;
575
576
577
578
579
580
581
582 if (expires.tv64 < 0)
583 return -ETIME;
584
585 if (expires.tv64 >= expires_next->tv64)
586 return 0;
587
588
589
590
591 res = tick_program_event(expires, 0);
592 if (!IS_ERR_VALUE(res))
593 *expires_next = expires;
594 return res;
595}
596
597
598
599
600
601
602
603static void retrigger_next_event(void *arg)
604{
605 struct hrtimer_cpu_base *base;
606 struct timespec realtime_offset;
607 unsigned long seq;
608
609 if (!hrtimer_hres_active())
610 return;
611
612 do {
613 seq = read_seqbegin(&xtime_lock);
614 set_normalized_timespec(&realtime_offset,
615 -wall_to_monotonic.tv_sec,
616 -wall_to_monotonic.tv_nsec);
617 } while (read_seqretry(&xtime_lock, seq));
618
619 base = &__get_cpu_var(hrtimer_bases);
620
621
622 spin_lock(&base->lock);
623 base->clock_base[CLOCK_REALTIME].offset =
624 timespec_to_ktime(realtime_offset);
625
626 hrtimer_force_reprogram(base, 0);
627 spin_unlock(&base->lock);
628}
629
630
631
632
633
634
635
636
637
638
639
640
641void clock_was_set(void)
642{
643
644 on_each_cpu(retrigger_next_event, NULL, 1);
645}
646
647
648
649
650
651void hres_timers_resume(void)
652{
653 WARN_ONCE(!irqs_disabled(),
654 KERN_INFO "hres_timers_resume() called with IRQs enabled!");
655
656 retrigger_next_event(NULL);
657}
658
659
660
661
662static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base)
663{
664 base->expires_next.tv64 = KTIME_MAX;
665 base->hres_active = 0;
666}
667
668
669
670
671static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
672{
673}
674
675
676
677
678
679
680
681
682static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
683 struct hrtimer_clock_base *base,
684 int wakeup)
685{
686 if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
687 if (wakeup) {
688 spin_unlock(&base->cpu_base->lock);
689 raise_softirq_irqoff(HRTIMER_SOFTIRQ);
690 spin_lock(&base->cpu_base->lock);
691 } else
692 __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
693
694 return 1;
695 }
696
697 return 0;
698}
699
700
701
702
703static int hrtimer_switch_to_hres(void)
704{
705 int cpu = smp_processor_id();
706 struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
707 unsigned long flags;
708
709 if (base->hres_active)
710 return 1;
711
712 local_irq_save(flags);
713
714 if (tick_init_highres()) {
715 local_irq_restore(flags);
716 printk(KERN_WARNING "Could not switch to high resolution "
717 "mode on CPU %d\n", cpu);
718 return 0;
719 }
720 base->hres_active = 1;
721 base->clock_base[CLOCK_REALTIME].resolution = KTIME_HIGH_RES;
722 base->clock_base[CLOCK_MONOTONIC].resolution = KTIME_HIGH_RES;
723
724 tick_setup_sched_timer();
725
726
727 retrigger_next_event(NULL);
728 local_irq_restore(flags);
729 return 1;
730}
731
732#else
733
734static inline int hrtimer_hres_active(void) { return 0; }
735static inline int hrtimer_is_hres_enabled(void) { return 0; }
736static inline int hrtimer_switch_to_hres(void) { return 0; }
737static inline void
738hrtimer_force_reprogram(struct hrtimer_cpu_base *base, int skip_equal) { }
739static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
740 struct hrtimer_clock_base *base,
741 int wakeup)
742{
743 return 0;
744}
745static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
746static inline void hrtimer_init_timer_hres(struct hrtimer *timer) { }
747
748#endif
749
750#ifdef CONFIG_TIMER_STATS
751void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer, void *addr)
752{
753 if (timer->start_site)
754 return;
755
756 timer->start_site = addr;
757 memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
758 timer->start_pid = current->pid;
759}
760#endif
761
762
763
764
765static inline
766void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
767{
768 spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
769}
770
771
772
773
774
775
776
777
778
779
780u64 hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
781{
782 u64 orun = 1;
783 ktime_t delta;
784
785 delta = ktime_sub(now, hrtimer_get_expires(timer));
786
787 if (delta.tv64 < 0)
788 return 0;
789
790 if (interval.tv64 < timer->base->resolution.tv64)
791 interval.tv64 = timer->base->resolution.tv64;
792
793 if (unlikely(delta.tv64 >= interval.tv64)) {
794 s64 incr = ktime_to_ns(interval);
795
796 orun = ktime_divns(delta, incr);
797 hrtimer_add_expires_ns(timer, incr * orun);
798 if (hrtimer_get_expires_tv64(timer) > now.tv64)
799 return orun;
800
801
802
803
804 orun++;
805 }
806 hrtimer_add_expires(timer, interval);
807
808 return orun;
809}
810EXPORT_SYMBOL_GPL(hrtimer_forward);
811
812
813
814
815
816
817
818
819
820static int enqueue_hrtimer(struct hrtimer *timer,
821 struct hrtimer_clock_base *base)
822{
823 struct rb_node **link = &base->active.rb_node;
824 struct rb_node *parent = NULL;
825 struct hrtimer *entry;
826 int leftmost = 1;
827
828 debug_activate(timer);
829
830
831
832
833 while (*link) {
834 parent = *link;
835 entry = rb_entry(parent, struct hrtimer, node);
836
837
838
839
840 if (hrtimer_get_expires_tv64(timer) <
841 hrtimer_get_expires_tv64(entry)) {
842 link = &(*link)->rb_left;
843 } else {
844 link = &(*link)->rb_right;
845 leftmost = 0;
846 }
847 }
848
849
850
851
852
853 if (leftmost)
854 base->first = &timer->node;
855
856 rb_link_node(&timer->node, parent, link);
857 rb_insert_color(&timer->node, &base->active);
858
859
860
861
862 timer->state |= HRTIMER_STATE_ENQUEUED;
863
864 return leftmost;
865}
866
867
868
869
870
871
872
873
874
875
876
877static void __remove_hrtimer(struct hrtimer *timer,
878 struct hrtimer_clock_base *base,
879 unsigned long newstate, int reprogram)
880{
881 if (!(timer->state & HRTIMER_STATE_ENQUEUED))
882 goto out;
883
884
885
886
887
888 if (base->first == &timer->node) {
889 base->first = rb_next(&timer->node);
890#ifdef CONFIG_HIGH_RES_TIMERS
891
892 if (reprogram && hrtimer_hres_active()) {
893 ktime_t expires;
894
895 expires = ktime_sub(hrtimer_get_expires(timer),
896 base->offset);
897 if (base->cpu_base->expires_next.tv64 == expires.tv64)
898 hrtimer_force_reprogram(base->cpu_base, 1);
899 }
900#endif
901 }
902 rb_erase(&timer->node, &base->active);
903out:
904 timer->state = newstate;
905}
906
907
908
909
910static inline int
911remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
912{
913 if (hrtimer_is_queued(timer)) {
914 int reprogram;
915
916
917
918
919
920
921
922
923
924 debug_deactivate(timer);
925 timer_stats_hrtimer_clear_start_info(timer);
926 reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
927 __remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
928 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
948 new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
949
950 if (mode & HRTIMER_MODE_REL) {
951 tim = ktime_add_safe(tim, new_base->get_time());
952
953
954
955
956
957
958
959#ifdef CONFIG_TIME_LOW_RES
960 tim = ktime_add_safe(tim, base->resolution);
961#endif
962 }
963
964 hrtimer_set_expires_range_ns(timer, tim, delta_ns);
965
966 timer_stats_hrtimer_set_start_info(timer);
967
968 leftmost = enqueue_hrtimer(timer, new_base);
969
970
971
972
973
974
975
976 if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
977 hrtimer_enqueue_reprogram(timer, new_base, wakeup);
978
979 unlock_hrtimer_base(timer, &flags);
980
981 return ret;
982}
983
984
985
986
987
988
989
990
991
992
993
994
995int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
996 unsigned long delta_ns, const enum hrtimer_mode mode)
997{
998 return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1);
999}
1000EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012int
1013hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
1014{
1015 return __hrtimer_start_range_ns(timer, tim, 0, mode, 1);
1016}
1017EXPORT_SYMBOL_GPL(hrtimer_start);
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030int hrtimer_try_to_cancel(struct hrtimer *timer)
1031{
1032 struct hrtimer_clock_base *base;
1033 unsigned long flags;
1034 int ret = -1;
1035
1036 base = lock_hrtimer_base(timer, &flags);
1037
1038 if (!hrtimer_callback_running(timer))
1039 ret = remove_hrtimer(timer, base);
1040
1041 unlock_hrtimer_base(timer, &flags);
1042
1043 return ret;
1044
1045}
1046EXPORT_SYMBOL_GPL(hrtimer_try_to_cancel);
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056int hrtimer_cancel(struct hrtimer *timer)
1057{
1058 for (;;) {
1059 int ret = hrtimer_try_to_cancel(timer);
1060
1061 if (ret >= 0)
1062 return ret;
1063 cpu_relax();
1064 }
1065}
1066EXPORT_SYMBOL_GPL(hrtimer_cancel);
1067
1068
1069
1070
1071
1072ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
1073{
1074 struct hrtimer_clock_base *base;
1075 unsigned long flags;
1076 ktime_t rem;
1077
1078 base = lock_hrtimer_base(timer, &flags);
1079 rem = hrtimer_expires_remaining(timer);
1080 unlock_hrtimer_base(timer, &flags);
1081
1082 return rem;
1083}
1084EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
1085
1086#ifdef CONFIG_NO_HZ
1087
1088
1089
1090
1091
1092
1093ktime_t hrtimer_get_next_event(void)
1094{
1095 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1096 struct hrtimer_clock_base *base = cpu_base->clock_base;
1097 ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
1098 unsigned long flags;
1099 int i;
1100
1101 spin_lock_irqsave(&cpu_base->lock, flags);
1102
1103 if (!hrtimer_hres_active()) {
1104 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
1105 struct hrtimer *timer;
1106
1107 if (!base->first)
1108 continue;
1109
1110 timer = rb_entry(base->first, struct hrtimer, node);
1111 delta.tv64 = hrtimer_get_expires_tv64(timer);
1112 delta = ktime_sub(delta, base->get_time());
1113 if (delta.tv64 < mindelta.tv64)
1114 mindelta.tv64 = delta.tv64;
1115 }
1116 }
1117
1118 spin_unlock_irqrestore(&cpu_base->lock, flags);
1119
1120 if (mindelta.tv64 < 0)
1121 mindelta.tv64 = 0;
1122 return mindelta;
1123}
1124#endif
1125
1126static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1127 enum hrtimer_mode mode)
1128{
1129 struct hrtimer_cpu_base *cpu_base;
1130
1131 memset(timer, 0, sizeof(struct hrtimer));
1132
1133 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1134
1135 if (clock_id == CLOCK_REALTIME && mode != HRTIMER_MODE_ABS)
1136 clock_id = CLOCK_MONOTONIC;
1137
1138 timer->base = &cpu_base->clock_base[clock_id];
1139 hrtimer_init_timer_hres(timer);
1140
1141#ifdef CONFIG_TIMER_STATS
1142 timer->start_site = NULL;
1143 timer->start_pid = -1;
1144 memset(timer->start_comm, 0, TASK_COMM_LEN);
1145#endif
1146}
1147
1148
1149
1150
1151
1152
1153
1154void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
1155 enum hrtimer_mode mode)
1156{
1157 debug_init(timer, clock_id, mode);
1158 __hrtimer_init(timer, clock_id, mode);
1159}
1160EXPORT_SYMBOL_GPL(hrtimer_init);
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
1171{
1172 struct hrtimer_cpu_base *cpu_base;
1173
1174 cpu_base = &__raw_get_cpu_var(hrtimer_bases);
1175 *tp = ktime_to_timespec(cpu_base->clock_base[which_clock].resolution);
1176
1177 return 0;
1178}
1179EXPORT_SYMBOL_GPL(hrtimer_get_res);
1180
1181static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
1182{
1183 struct hrtimer_clock_base *base = timer->base;
1184 struct hrtimer_cpu_base *cpu_base = base->cpu_base;
1185 enum hrtimer_restart (*fn)(struct hrtimer *);
1186 int restart;
1187
1188 WARN_ON(!irqs_disabled());
1189
1190 debug_deactivate(timer);
1191 __remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
1192 timer_stats_account_hrtimer(timer);
1193 fn = timer->function;
1194
1195
1196
1197
1198
1199
1200 spin_unlock(&cpu_base->lock);
1201 trace_hrtimer_expire_entry(timer, now);
1202 restart = fn(timer);
1203 trace_hrtimer_expire_exit(timer);
1204 spin_lock(&cpu_base->lock);
1205
1206
1207
1208
1209
1210
1211 if (restart != HRTIMER_NORESTART) {
1212 BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
1213 enqueue_hrtimer(timer, base);
1214 }
1215 timer->state &= ~HRTIMER_STATE_CALLBACK;
1216}
1217
1218#ifdef CONFIG_HIGH_RES_TIMERS
1219
1220static int force_clock_reprogram;
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234static inline void
1235hrtimer_interrupt_hanging(struct clock_event_device *dev,
1236 ktime_t try_time)
1237{
1238 force_clock_reprogram = 1;
1239 dev->min_delta_ns = (unsigned long)try_time.tv64 * 3;
1240 printk(KERN_WARNING "hrtimer: interrupt too slow, "
1241 "forcing clock min delta to %lu ns\n", dev->min_delta_ns);
1242}
1243
1244
1245
1246
1247void hrtimer_interrupt(struct clock_event_device *dev)
1248{
1249 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1250 struct hrtimer_clock_base *base;
1251 ktime_t expires_next, now;
1252 int nr_retries = 0;
1253 int i;
1254
1255 BUG_ON(!cpu_base->hres_active);
1256 cpu_base->nr_events++;
1257 dev->next_event.tv64 = KTIME_MAX;
1258
1259 retry:
1260
1261 if (!(++nr_retries % 5))
1262 hrtimer_interrupt_hanging(dev, ktime_sub(ktime_get(), now));
1263
1264 now = ktime_get();
1265
1266 expires_next.tv64 = KTIME_MAX;
1267
1268 spin_lock(&cpu_base->lock);
1269
1270
1271
1272
1273
1274
1275
1276 cpu_base->expires_next.tv64 = KTIME_MAX;
1277
1278 base = cpu_base->clock_base;
1279
1280 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1281 ktime_t basenow;
1282 struct rb_node *node;
1283
1284 basenow = ktime_add(now, base->offset);
1285
1286 while ((node = base->first)) {
1287 struct hrtimer *timer;
1288
1289 timer = rb_entry(node, struct hrtimer, node);
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304 if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
1305 ktime_t expires;
1306
1307 expires = ktime_sub(hrtimer_get_expires(timer),
1308 base->offset);
1309 if (expires.tv64 < expires_next.tv64)
1310 expires_next = expires;
1311 break;
1312 }
1313
1314 __run_hrtimer(timer, &basenow);
1315 }
1316 base++;
1317 }
1318
1319
1320
1321
1322
1323 cpu_base->expires_next = expires_next;
1324 spin_unlock(&cpu_base->lock);
1325
1326
1327 if (expires_next.tv64 != KTIME_MAX) {
1328 if (tick_program_event(expires_next, force_clock_reprogram))
1329 goto retry;
1330 }
1331}
1332
1333
1334
1335
1336
1337static void __hrtimer_peek_ahead_timers(void)
1338{
1339 struct tick_device *td;
1340
1341 if (!hrtimer_hres_active())
1342 return;
1343
1344 td = &__get_cpu_var(tick_cpu_device);
1345 if (td && td->evtdev)
1346 hrtimer_interrupt(td->evtdev);
1347}
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358void hrtimer_peek_ahead_timers(void)
1359{
1360 unsigned long flags;
1361
1362 local_irq_save(flags);
1363 __hrtimer_peek_ahead_timers();
1364 local_irq_restore(flags);
1365}
1366
1367static void run_hrtimer_softirq(struct softirq_action *h)
1368{
1369 hrtimer_peek_ahead_timers();
1370}
1371
1372#else
1373
1374static inline void __hrtimer_peek_ahead_timers(void) { }
1375
1376#endif
1377
1378
1379
1380
1381
1382
1383
1384
1385void hrtimer_run_pending(void)
1386{
1387 if (hrtimer_hres_active())
1388 return;
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398 if (tick_check_oneshot_change(!hrtimer_is_hres_enabled()))
1399 hrtimer_switch_to_hres();
1400}
1401
1402
1403
1404
1405void hrtimer_run_queues(void)
1406{
1407 struct rb_node *node;
1408 struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
1409 struct hrtimer_clock_base *base;
1410 int index, gettime = 1;
1411
1412 if (hrtimer_hres_active())
1413 return;
1414
1415 for (index = 0; index < HRTIMER_MAX_CLOCK_BASES; index++) {
1416 base = &cpu_base->clock_base[index];
1417
1418 if (!base->first)
1419 continue;
1420
1421 if (gettime) {
1422 hrtimer_get_softirq_time(cpu_base);
1423 gettime = 0;
1424 }
1425
1426 spin_lock(&cpu_base->lock);
1427
1428 while ((node = base->first)) {
1429 struct hrtimer *timer;
1430
1431 timer = rb_entry(node, struct hrtimer, node);
1432 if (base->softirq_time.tv64 <=
1433 hrtimer_get_expires_tv64(timer))
1434 break;
1435
1436 __run_hrtimer(timer, &base->softirq_time);
1437 }
1438 spin_unlock(&cpu_base->lock);
1439 }
1440}
1441
1442
1443
1444
1445static enum hrtimer_restart hrtimer_wakeup(struct hrtimer *timer)
1446{
1447 struct hrtimer_sleeper *t =
1448 container_of(timer, struct hrtimer_sleeper, timer);
1449 struct task_struct *task = t->task;
1450
1451 t->task = NULL;
1452 if (task)
1453 wake_up_process(task);
1454
1455 return HRTIMER_NORESTART;
1456}
1457
1458void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
1459{
1460 sl->timer.function = hrtimer_wakeup;
1461 sl->task = task;
1462}
1463EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
1464
1465static int __sched do_nanosleep(struct hrtimer_sleeper *t, enum hrtimer_mode mode)
1466{
1467 hrtimer_init_sleeper(t, current);
1468
1469 do {
1470 set_current_state(TASK_INTERRUPTIBLE);
1471 hrtimer_start_expires(&t->timer, mode);
1472 if (!hrtimer_active(&t->timer))
1473 t->task = NULL;
1474
1475 if (likely(t->task))
1476 schedule();
1477
1478 hrtimer_cancel(&t->timer);
1479 mode = HRTIMER_MODE_ABS;
1480
1481 } while (t->task && !signal_pending(current));
1482
1483 __set_current_state(TASK_RUNNING);
1484
1485 return t->task == NULL;
1486}
1487
1488static int update_rmtp(struct hrtimer *timer, struct timespec __user *rmtp)
1489{
1490 struct timespec rmt;
1491 ktime_t rem;
1492
1493 rem = hrtimer_expires_remaining(timer);
1494 if (rem.tv64 <= 0)
1495 return 0;
1496 rmt = ktime_to_timespec(rem);
1497
1498 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
1499 return -EFAULT;
1500
1501 return 1;
1502}
1503
1504long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
1505{
1506 struct hrtimer_sleeper t;
1507 struct timespec __user *rmtp;
1508 int ret = 0;
1509
1510 hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
1511 HRTIMER_MODE_ABS);
1512 hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
1513
1514 if (do_nanosleep(&t, HRTIMER_MODE_ABS))
1515 goto out;
1516
1517 rmtp = restart->nanosleep.rmtp;
1518 if (rmtp) {
1519 ret = update_rmtp(&t.timer, rmtp);
1520 if (ret <= 0)
1521 goto out;
1522 }
1523
1524
1525 ret = -ERESTART_RESTARTBLOCK;
1526out:
1527 destroy_hrtimer_on_stack(&t.timer);
1528 return ret;
1529}
1530
1531long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
1532 const enum hrtimer_mode mode, const clockid_t clockid)
1533{
1534 struct restart_block *restart;
1535 struct hrtimer_sleeper t;
1536 int ret = 0;
1537 unsigned long slack;
1538
1539 slack = current->timer_slack_ns;
1540 if (rt_task(current))
1541 slack = 0;
1542
1543 hrtimer_init_on_stack(&t.timer, clockid, mode);
1544 hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1545 if (do_nanosleep(&t, mode))
1546 goto out;
1547
1548
1549 if (mode == HRTIMER_MODE_ABS) {
1550 ret = -ERESTARTNOHAND;
1551 goto out;
1552 }
1553
1554 if (rmtp) {
1555 ret = update_rmtp(&t.timer, rmtp);
1556 if (ret <= 0)
1557 goto out;
1558 }
1559
1560 restart = ¤t_thread_info()->restart_block;
1561 restart->fn = hrtimer_nanosleep_restart;
1562 restart->nanosleep.index = t.timer.base->index;
1563 restart->nanosleep.rmtp = rmtp;
1564 restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
1565
1566 ret = -ERESTART_RESTARTBLOCK;
1567out:
1568 destroy_hrtimer_on_stack(&t.timer);
1569 return ret;
1570}
1571
1572SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
1573 struct timespec __user *, rmtp)
1574{
1575 struct timespec tu;
1576
1577 if (copy_from_user(&tu, rqtp, sizeof(tu)))
1578 return -EFAULT;
1579
1580 if (!timespec_valid(&tu))
1581 return -EINVAL;
1582
1583 return hrtimer_nanosleep(&tu, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
1584}
1585
1586
1587
1588
1589static void __cpuinit init_hrtimers_cpu(int cpu)
1590{
1591 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
1592 int i;
1593
1594 spin_lock_init(&cpu_base->lock);
1595
1596 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
1597 cpu_base->clock_base[i].cpu_base = cpu_base;
1598
1599 hrtimer_init_hres(cpu_base);
1600}
1601
1602#ifdef CONFIG_HOTPLUG_CPU
1603
1604static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
1605 struct hrtimer_clock_base *new_base)
1606{
1607 struct hrtimer *timer;
1608 struct rb_node *node;
1609
1610 while ((node = rb_first(&old_base->active))) {
1611 timer = rb_entry(node, struct hrtimer, node);
1612 BUG_ON(hrtimer_callback_running(timer));
1613 debug_deactivate(timer);
1614
1615
1616
1617
1618
1619
1620 __remove_hrtimer(timer, old_base, HRTIMER_STATE_MIGRATE, 0);
1621 timer->base = new_base;
1622
1623
1624
1625
1626
1627
1628
1629
1630 enqueue_hrtimer(timer, new_base);
1631
1632
1633 timer->state &= ~HRTIMER_STATE_MIGRATE;
1634 }
1635}
1636
1637static void migrate_hrtimers(int scpu)
1638{
1639 struct hrtimer_cpu_base *old_base, *new_base;
1640 int i;
1641
1642 BUG_ON(cpu_online(scpu));
1643 tick_cancel_sched_timer(scpu);
1644
1645 local_irq_disable();
1646 old_base = &per_cpu(hrtimer_bases, scpu);
1647 new_base = &__get_cpu_var(hrtimer_bases);
1648
1649
1650
1651
1652 spin_lock(&new_base->lock);
1653 spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
1654
1655 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
1656 migrate_hrtimer_list(&old_base->clock_base[i],
1657 &new_base->clock_base[i]);
1658 }
1659
1660 spin_unlock(&old_base->lock);
1661 spin_unlock(&new_base->lock);
1662
1663
1664 __hrtimer_peek_ahead_timers();
1665 local_irq_enable();
1666}
1667
1668#endif
1669
1670static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
1671 unsigned long action, void *hcpu)
1672{
1673 int scpu = (long)hcpu;
1674
1675 switch (action) {
1676
1677 case CPU_UP_PREPARE:
1678 case CPU_UP_PREPARE_FROZEN:
1679 init_hrtimers_cpu(scpu);
1680 break;
1681
1682#ifdef CONFIG_HOTPLUG_CPU
1683 case CPU_DYING:
1684 case CPU_DYING_FROZEN:
1685 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DYING, &scpu);
1686 break;
1687 case CPU_DEAD:
1688 case CPU_DEAD_FROZEN:
1689 {
1690 clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &scpu);
1691 migrate_hrtimers(scpu);
1692 break;
1693 }
1694#endif
1695
1696 default:
1697 break;
1698 }
1699
1700 return NOTIFY_OK;
1701}
1702
1703static struct notifier_block __cpuinitdata hrtimers_nb = {
1704 .notifier_call = hrtimer_cpu_notify,
1705};
1706
1707void __init hrtimers_init(void)
1708{
1709 hrtimer_cpu_notify(&hrtimers_nb, (unsigned long)CPU_UP_PREPARE,
1710 (void *)(long)smp_processor_id());
1711 register_cpu_notifier(&hrtimers_nb);
1712#ifdef CONFIG_HIGH_RES_TIMERS
1713 open_softirq(HRTIMER_SOFTIRQ, run_hrtimer_softirq);
1714#endif
1715}
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745int __sched schedule_hrtimeout_range(ktime_t *expires, unsigned long delta,
1746 const enum hrtimer_mode mode)
1747{
1748 struct hrtimer_sleeper t;
1749
1750
1751
1752
1753
1754 if (expires && !expires->tv64) {
1755 __set_current_state(TASK_RUNNING);
1756 return 0;
1757 }
1758
1759
1760
1761
1762 if (!expires) {
1763 schedule();
1764 __set_current_state(TASK_RUNNING);
1765 return -EINTR;
1766 }
1767
1768 hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC, mode);
1769 hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
1770
1771 hrtimer_init_sleeper(&t, current);
1772
1773 hrtimer_start_expires(&t.timer, mode);
1774 if (!hrtimer_active(&t.timer))
1775 t.task = NULL;
1776
1777 if (likely(t.task))
1778 schedule();
1779
1780 hrtimer_cancel(&t.timer);
1781 destroy_hrtimer_on_stack(&t.timer);
1782
1783 __set_current_state(TASK_RUNNING);
1784
1785 return !t.task ? 0 : -EINTR;
1786}
1787EXPORT_SYMBOL_GPL(schedule_hrtimeout_range);
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811int __sched schedule_hrtimeout(ktime_t *expires,
1812 const enum hrtimer_mode mode)
1813{
1814 return schedule_hrtimeout_range(expires, 0, mode);
1815}
1816EXPORT_SYMBOL_GPL(schedule_hrtimeout);
1817