projects/linux·blob v4.13 · refs

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1/*
2 * Alarmtimer interface
3 *
4 * This interface provides a timer which is similarto hrtimers,
5 * but triggers a RTC alarm if the box is suspend.
6 *
7 * This interface is influenced by the Android RTC Alarm timer
8 * interface.
9 *
10 * Copyright (C) 2010 IBM Corperation
11 *
12 * Author: John Stultz <[email protected]>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
17 */
18#include <linux/time.h>
19#include <linux/hrtimer.h>
20#include <linux/timerqueue.h>
21#include <linux/rtc.h>
22#include <linux/sched/signal.h>
23#include <linux/sched/debug.h>
24#include <linux/alarmtimer.h>
25#include <linux/mutex.h>
26#include <linux/platform_device.h>
27#include <linux/posix-timers.h>
28#include <linux/workqueue.h>
29#include <linux/freezer.h>
30#include <linux/compat.h>
31
32#include "posix-timers.h"
33
34#define CREATE_TRACE_POINTS
35#include <trace/events/alarmtimer.h>
36
37/**
38 * struct alarm_base - Alarm timer bases
39 * @lock: Lock for syncrhonized access to the base
40 * @timerqueue: Timerqueue head managing the list of events
41 * @gettime: Function to read the time correlating to the base
42 * @base_clockid: clockid for the base
43 */
44static struct alarm_base {
45 spinlock_t lock;
46 struct timerqueue_head timerqueue;
47 ktime_t (*gettime)(void);
48 clockid_t base_clockid;
49} alarm_bases[ALARM_NUMTYPE];
50
51#if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS)
52/* freezer information to handle clock_nanosleep triggered wakeups */
53static enum alarmtimer_type freezer_alarmtype;
54static ktime_t freezer_expires;
55static ktime_t freezer_delta;
56static DEFINE_SPINLOCK(freezer_delta_lock);
57#endif
58
59static struct wakeup_source *ws;
60
61#ifdef CONFIG_RTC_CLASS
62/* rtc timer and device for setting alarm wakeups at suspend */
63static struct rtc_timer rtctimer;
64static struct rtc_device *rtcdev;
65static DEFINE_SPINLOCK(rtcdev_lock);
66
67/**
68 * alarmtimer_get_rtcdev - Return selected rtcdevice
69 *
70 * This function returns the rtc device to use for wakealarms.
71 * If one has not already been chosen, it checks to see if a
72 * functional rtc device is available.
73 */
74struct rtc_device *alarmtimer_get_rtcdev(void)
75{
76 unsigned long flags;
77 struct rtc_device *ret;
78
79 spin_lock_irqsave(&rtcdev_lock, flags);
80 ret = rtcdev;
81 spin_unlock_irqrestore(&rtcdev_lock, flags);
82
83 return ret;
84}
85EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
86
87static int alarmtimer_rtc_add_device(struct device *dev,
88 struct class_interface *class_intf)
89{
90 unsigned long flags;
91 struct rtc_device *rtc = to_rtc_device(dev);
92
93 if (rtcdev)
94 return -EBUSY;
95
96 if (!rtc->ops->set_alarm)
97 return -1;
98 if (!device_may_wakeup(rtc->dev.parent))
99 return -1;
100
101 spin_lock_irqsave(&rtcdev_lock, flags);
102 if (!rtcdev) {
103 rtcdev = rtc;
104 /* hold a reference so it doesn't go away */
105 get_device(dev);
106 }
107 spin_unlock_irqrestore(&rtcdev_lock, flags);
108 return 0;
109}
110
111static inline void alarmtimer_rtc_timer_init(void)
112{
113 rtc_timer_init(&rtctimer, NULL, NULL);
114}
115
116static struct class_interface alarmtimer_rtc_interface = {
117 .add_dev = &alarmtimer_rtc_add_device,
118};
119
120static int alarmtimer_rtc_interface_setup(void)
121{
122 alarmtimer_rtc_interface.class = rtc_class;
123 return class_interface_register(&alarmtimer_rtc_interface);
124}
125static void alarmtimer_rtc_interface_remove(void)
126{
127 class_interface_unregister(&alarmtimer_rtc_interface);
128}
129#else
130struct rtc_device *alarmtimer_get_rtcdev(void)
131{
132 return NULL;
133}
134#define rtcdev (NULL)
135static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
136static inline void alarmtimer_rtc_interface_remove(void) { }
137static inline void alarmtimer_rtc_timer_init(void) { }
138#endif
139
140/**
141 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
142 * @base: pointer to the base where the timer is being run
143 * @alarm: pointer to alarm being enqueued.
144 *
145 * Adds alarm to a alarm_base timerqueue
146 *
147 * Must hold base->lock when calling.
148 */
149static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
150{
151 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
152 timerqueue_del(&base->timerqueue, &alarm->node);
153
154 timerqueue_add(&base->timerqueue, &alarm->node);
155 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
156}
157
158/**
159 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
160 * @base: pointer to the base where the timer is running
161 * @alarm: pointer to alarm being removed
162 *
163 * Removes alarm to a alarm_base timerqueue
164 *
165 * Must hold base->lock when calling.
166 */
167static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
168{
169 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
170 return;
171
172 timerqueue_del(&base->timerqueue, &alarm->node);
173 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
174}
175
176
177/**
178 * alarmtimer_fired - Handles alarm hrtimer being fired.
179 * @timer: pointer to hrtimer being run
180 *
181 * When a alarm timer fires, this runs through the timerqueue to
182 * see which alarms expired, and runs those. If there are more alarm
183 * timers queued for the future, we set the hrtimer to fire when
184 * when the next future alarm timer expires.
185 */
186static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
187{
188 struct alarm *alarm = container_of(timer, struct alarm, timer);
189 struct alarm_base *base = &alarm_bases[alarm->type];
190 unsigned long flags;
191 int ret = HRTIMER_NORESTART;
192 int restart = ALARMTIMER_NORESTART;
193
194 spin_lock_irqsave(&base->lock, flags);
195 alarmtimer_dequeue(base, alarm);
196 spin_unlock_irqrestore(&base->lock, flags);
197
198 if (alarm->function)
199 restart = alarm->function(alarm, base->gettime());
200
201 spin_lock_irqsave(&base->lock, flags);
202 if (restart != ALARMTIMER_NORESTART) {
203 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
204 alarmtimer_enqueue(base, alarm);
205 ret = HRTIMER_RESTART;
206 }
207 spin_unlock_irqrestore(&base->lock, flags);
208
209 trace_alarmtimer_fired(alarm, base->gettime());
210 return ret;
211
212}
213
214ktime_t alarm_expires_remaining(const struct alarm *alarm)
215{
216 struct alarm_base *base = &alarm_bases[alarm->type];
217 return ktime_sub(alarm->node.expires, base->gettime());
218}
219EXPORT_SYMBOL_GPL(alarm_expires_remaining);
220
221#ifdef CONFIG_RTC_CLASS
222/**
223 * alarmtimer_suspend - Suspend time callback
224 * @dev: unused
225 * @state: unused
226 *
227 * When we are going into suspend, we look through the bases
228 * to see which is the soonest timer to expire. We then
229 * set an rtc timer to fire that far into the future, which
230 * will wake us from suspend.
231 */
232static int alarmtimer_suspend(struct device *dev)
233{
234 ktime_t min, now, expires;
235 int i, ret, type;
236 struct rtc_device *rtc;
237 unsigned long flags;
238 struct rtc_time tm;
239
240 spin_lock_irqsave(&freezer_delta_lock, flags);
241 min = freezer_delta;
242 expires = freezer_expires;
243 type = freezer_alarmtype;
244 freezer_delta = 0;
245 spin_unlock_irqrestore(&freezer_delta_lock, flags);
246
247 rtc = alarmtimer_get_rtcdev();
248 /* If we have no rtcdev, just return */
249 if (!rtc)
250 return 0;
251
252 /* Find the soonest timer to expire*/
253 for (i = 0; i < ALARM_NUMTYPE; i++) {
254 struct alarm_base *base = &alarm_bases[i];
255 struct timerqueue_node *next;
256 ktime_t delta;
257
258 spin_lock_irqsave(&base->lock, flags);
259 next = timerqueue_getnext(&base->timerqueue);
260 spin_unlock_irqrestore(&base->lock, flags);
261 if (!next)
262 continue;
263 delta = ktime_sub(next->expires, base->gettime());
264 if (!min || (delta < min)) {
265 expires = next->expires;
266 min = delta;
267 type = i;
268 }
269 }
270 if (min == 0)
271 return 0;
272
273 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
274 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
275 return -EBUSY;
276 }
277
278 trace_alarmtimer_suspend(expires, type);
279
280 /* Setup an rtc timer to fire that far in the future */
281 rtc_timer_cancel(rtc, &rtctimer);
282 rtc_read_time(rtc, &tm);
283 now = rtc_tm_to_ktime(tm);
284 now = ktime_add(now, min);
285
286 /* Set alarm, if in the past reject suspend briefly to handle */
287 ret = rtc_timer_start(rtc, &rtctimer, now, 0);
288 if (ret < 0)
289 __pm_wakeup_event(ws, MSEC_PER_SEC);
290 return ret;
291}
292
293static int alarmtimer_resume(struct device *dev)
294{
295 struct rtc_device *rtc;
296
297 rtc = alarmtimer_get_rtcdev();
298 if (rtc)
299 rtc_timer_cancel(rtc, &rtctimer);
300 return 0;
301}
302
303#else
304static int alarmtimer_suspend(struct device *dev)
305{
306 return 0;
307}
308
309static int alarmtimer_resume(struct device *dev)
310{
311 return 0;
312}
313#endif
314
315/**
316 * alarm_init - Initialize an alarm structure
317 * @alarm: ptr to alarm to be initialized
318 * @type: the type of the alarm
319 * @function: callback that is run when the alarm fires
320 */
321void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
322 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
323{
324 timerqueue_init(&alarm->node);
325 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
326 HRTIMER_MODE_ABS);
327 alarm->timer.function = alarmtimer_fired;
328 alarm->function = function;
329 alarm->type = type;
330 alarm->state = ALARMTIMER_STATE_INACTIVE;
331}
332EXPORT_SYMBOL_GPL(alarm_init);
333
334/**
335 * alarm_start - Sets an absolute alarm to fire
336 * @alarm: ptr to alarm to set
337 * @start: time to run the alarm
338 */
339void alarm_start(struct alarm *alarm, ktime_t start)
340{
341 struct alarm_base *base = &alarm_bases[alarm->type];
342 unsigned long flags;
343
344 spin_lock_irqsave(&base->lock, flags);
345 alarm->node.expires = start;
346 alarmtimer_enqueue(base, alarm);
347 hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
348 spin_unlock_irqrestore(&base->lock, flags);
349
350 trace_alarmtimer_start(alarm, base->gettime());
351}
352EXPORT_SYMBOL_GPL(alarm_start);
353
354/**
355 * alarm_start_relative - Sets a relative alarm to fire
356 * @alarm: ptr to alarm to set
357 * @start: time relative to now to run the alarm
358 */
359void alarm_start_relative(struct alarm *alarm, ktime_t start)
360{
361 struct alarm_base *base = &alarm_bases[alarm->type];
362
363 start = ktime_add_safe(start, base->gettime());
364 alarm_start(alarm, start);
365}
366EXPORT_SYMBOL_GPL(alarm_start_relative);
367
368void alarm_restart(struct alarm *alarm)
369{
370 struct alarm_base *base = &alarm_bases[alarm->type];
371 unsigned long flags;
372
373 spin_lock_irqsave(&base->lock, flags);
374 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
375 hrtimer_restart(&alarm->timer);
376 alarmtimer_enqueue(base, alarm);
377 spin_unlock_irqrestore(&base->lock, flags);
378}
379EXPORT_SYMBOL_GPL(alarm_restart);
380
381/**
382 * alarm_try_to_cancel - Tries to cancel an alarm timer
383 * @alarm: ptr to alarm to be canceled
384 *
385 * Returns 1 if the timer was canceled, 0 if it was not running,
386 * and -1 if the callback was running
387 */
388int alarm_try_to_cancel(struct alarm *alarm)
389{
390 struct alarm_base *base = &alarm_bases[alarm->type];
391 unsigned long flags;
392 int ret;
393
394 spin_lock_irqsave(&base->lock, flags);
395 ret = hrtimer_try_to_cancel(&alarm->timer);
396 if (ret >= 0)
397 alarmtimer_dequeue(base, alarm);
398 spin_unlock_irqrestore(&base->lock, flags);
399
400 trace_alarmtimer_cancel(alarm, base->gettime());
401 return ret;
402}
403EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
404
405
406/**
407 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
408 * @alarm: ptr to alarm to be canceled
409 *
410 * Returns 1 if the timer was canceled, 0 if it was not active.
411 */
412int alarm_cancel(struct alarm *alarm)
413{
414 for (;;) {
415 int ret = alarm_try_to_cancel(alarm);
416 if (ret >= 0)
417 return ret;
418 cpu_relax();
419 }
420}
421EXPORT_SYMBOL_GPL(alarm_cancel);
422
423
424u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
425{
426 u64 overrun = 1;
427 ktime_t delta;
428
429 delta = ktime_sub(now, alarm->node.expires);
430
431 if (delta < 0)
432 return 0;
433
434 if (unlikely(delta >= interval)) {
435 s64 incr = ktime_to_ns(interval);
436
437 overrun = ktime_divns(delta, incr);
438
439 alarm->node.expires = ktime_add_ns(alarm->node.expires,
440 incr*overrun);
441
442 if (alarm->node.expires > now)
443 return overrun;
444 /*
445 * This (and the ktime_add() below) is the
446 * correction for exact:
447 */
448 overrun++;
449 }
450
451 alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
452 return overrun;
453}
454EXPORT_SYMBOL_GPL(alarm_forward);
455
456u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
457{
458 struct alarm_base *base = &alarm_bases[alarm->type];
459
460 return alarm_forward(alarm, base->gettime(), interval);
461}
462EXPORT_SYMBOL_GPL(alarm_forward_now);
463
464#ifdef CONFIG_POSIX_TIMERS
465
466static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
467{
468 struct alarm_base *base;
469 unsigned long flags;
470 ktime_t delta;
471
472 switch(type) {
473 case ALARM_REALTIME:
474 base = &alarm_bases[ALARM_REALTIME];
475 type = ALARM_REALTIME_FREEZER;
476 break;
477 case ALARM_BOOTTIME:
478 base = &alarm_bases[ALARM_BOOTTIME];
479 type = ALARM_BOOTTIME_FREEZER;
480 break;
481 default:
482 WARN_ONCE(1, "Invalid alarm type: %d\n", type);
483 return;
484 }
485
486 delta = ktime_sub(absexp, base->gettime());
487
488 spin_lock_irqsave(&freezer_delta_lock, flags);
489 if (!freezer_delta || (delta < freezer_delta)) {
490 freezer_delta = delta;
491 freezer_expires = absexp;
492 freezer_alarmtype = type;
493 }
494 spin_unlock_irqrestore(&freezer_delta_lock, flags);
495}
496
497/**
498 * clock2alarm - helper that converts from clockid to alarmtypes
499 * @clockid: clockid.
500 */
501static enum alarmtimer_type clock2alarm(clockid_t clockid)
502{
503 if (clockid == CLOCK_REALTIME_ALARM)
504 return ALARM_REALTIME;
505 if (clockid == CLOCK_BOOTTIME_ALARM)
506 return ALARM_BOOTTIME;
507 return -1;
508}
509
510/**
511 * alarm_handle_timer - Callback for posix timers
512 * @alarm: alarm that fired
513 *
514 * Posix timer callback for expired alarm timers.
515 */
516static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
517 ktime_t now)
518{
519 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
520 it.alarm.alarmtimer);
521 enum alarmtimer_restart result = ALARMTIMER_NORESTART;
522 unsigned long flags;
523 int si_private = 0;
524
525 spin_lock_irqsave(&ptr->it_lock, flags);
526
527 ptr->it_active = 0;
528 if (ptr->it_interval)
529 si_private = ++ptr->it_requeue_pending;
530
531 if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
532 /*
533 * Handle ignored signals and rearm the timer. This will go
534 * away once we handle ignored signals proper.
535 */
536 ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval);
537 ++ptr->it_requeue_pending;
538 ptr->it_active = 1;
539 result = ALARMTIMER_RESTART;
540 }
541 spin_unlock_irqrestore(&ptr->it_lock, flags);
542
543 return result;
544}
545
546/**
547 * alarm_timer_rearm - Posix timer callback for rearming timer
548 * @timr: Pointer to the posixtimer data struct
549 */
550static void alarm_timer_rearm(struct k_itimer *timr)
551{
552 struct alarm *alarm = &timr->it.alarm.alarmtimer;
553
554 timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);
555 alarm_start(alarm, alarm->node.expires);
556}
557
558/**
559 * alarm_timer_forward - Posix timer callback for forwarding timer
560 * @timr: Pointer to the posixtimer data struct
561 * @now: Current time to forward the timer against
562 */
563static int alarm_timer_forward(struct k_itimer *timr, ktime_t now)
564{
565 struct alarm *alarm = &timr->it.alarm.alarmtimer;
566
567 return (int) alarm_forward(alarm, timr->it_interval, now);
568}
569
570/**
571 * alarm_timer_remaining - Posix timer callback to retrieve remaining time
572 * @timr: Pointer to the posixtimer data struct
573 * @now: Current time to calculate against
574 */
575static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now)
576{
577 struct alarm *alarm = &timr->it.alarm.alarmtimer;
578
579 return ktime_sub(now, alarm->node.expires);
580}
581
582/**
583 * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer
584 * @timr: Pointer to the posixtimer data struct
585 */
586static int alarm_timer_try_to_cancel(struct k_itimer *timr)
587{
588 return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
589}
590
591/**
592 * alarm_timer_arm - Posix timer callback to arm a timer
593 * @timr: Pointer to the posixtimer data struct
594 * @expires: The new expiry time
595 * @absolute: Expiry value is absolute time
596 * @sigev_none: Posix timer does not deliver signals
597 */
598static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires,
599 bool absolute, bool sigev_none)
600{
601 struct alarm *alarm = &timr->it.alarm.alarmtimer;
602 struct alarm_base *base = &alarm_bases[alarm->type];
603
604 if (!absolute)
605 expires = ktime_add_safe(expires, base->gettime());
606 if (sigev_none)
607 alarm->node.expires = expires;
608 else
609 alarm_start(&timr->it.alarm.alarmtimer, expires);
610}
611
612/**
613 * alarm_clock_getres - posix getres interface
614 * @which_clock: clockid
615 * @tp: timespec to fill
616 *
617 * Returns the granularity of underlying alarm base clock
618 */
619static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
620{
621 if (!alarmtimer_get_rtcdev())
622 return -EINVAL;
623
624 tp->tv_sec = 0;
625 tp->tv_nsec = hrtimer_resolution;
626 return 0;
627}
628
629/**
630 * alarm_clock_get - posix clock_get interface
631 * @which_clock: clockid
632 * @tp: timespec to fill.
633 *
634 * Provides the underlying alarm base time.
635 */
636static int alarm_clock_get(clockid_t which_clock, struct timespec64 *tp)
637{
638 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
639
640 if (!alarmtimer_get_rtcdev())
641 return -EINVAL;
642
643 *tp = ktime_to_timespec64(base->gettime());
644 return 0;
645}
646
647/**
648 * alarm_timer_create - posix timer_create interface
649 * @new_timer: k_itimer pointer to manage
650 *
651 * Initializes the k_itimer structure.
652 */
653static int alarm_timer_create(struct k_itimer *new_timer)
654{
655 enum alarmtimer_type type;
656
657 if (!alarmtimer_get_rtcdev())
658 return -ENOTSUPP;
659
660 if (!capable(CAP_WAKE_ALARM))
661 return -EPERM;
662
663 type = clock2alarm(new_timer->it_clock);
664 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
665 return 0;
666}
667
668/**
669 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
670 * @alarm: ptr to alarm that fired
671 *
672 * Wakes up the task that set the alarmtimer
673 */
674static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
675 ktime_t now)
676{
677 struct task_struct *task = (struct task_struct *)alarm->data;
678
679 alarm->data = NULL;
680 if (task)
681 wake_up_process(task);
682 return ALARMTIMER_NORESTART;
683}
684
685/**
686 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
687 * @alarm: ptr to alarmtimer
688 * @absexp: absolute expiration time
689 *
690 * Sets the alarm timer and sleeps until it is fired or interrupted.
691 */
692static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
693 enum alarmtimer_type type)
694{
695 struct restart_block *restart;
696 alarm->data = (void *)current;
697 do {
698 set_current_state(TASK_INTERRUPTIBLE);
699 alarm_start(alarm, absexp);
700 if (likely(alarm->data))
701 schedule();
702
703 alarm_cancel(alarm);
704 } while (alarm->data && !signal_pending(current));
705
706 __set_current_state(TASK_RUNNING);
707
708 if (!alarm->data)
709 return 0;
710
711 if (freezing(current))
712 alarmtimer_freezerset(absexp, type);
713 restart = &current->restart_block;
714 if (restart->nanosleep.type != TT_NONE) {
715 struct timespec64 rmt;
716 ktime_t rem;
717
718 rem = ktime_sub(absexp, alarm_bases[type].gettime());
719
720 if (rem <= 0)
721 return 0;
722 rmt = ktime_to_timespec64(rem);
723
724 return nanosleep_copyout(restart, &rmt);
725 }
726 return -ERESTART_RESTARTBLOCK;
727}
728
729/**
730 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
731 * @restart: ptr to restart block
732 *
733 * Handles restarted clock_nanosleep calls
734 */
735static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
736{
737 enum alarmtimer_type type = restart->nanosleep.clockid;
738 ktime_t exp = restart->nanosleep.expires;
739 struct alarm alarm;
740
741 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
742
743 return alarmtimer_do_nsleep(&alarm, exp, type);
744}
745
746/**
747 * alarm_timer_nsleep - alarmtimer nanosleep
748 * @which_clock: clockid
749 * @flags: determins abstime or relative
750 * @tsreq: requested sleep time (abs or rel)
751 * @rmtp: remaining sleep time saved
752 *
753 * Handles clock_nanosleep calls against _ALARM clockids
754 */
755static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
756 const struct timespec64 *tsreq)
757{
758 enum alarmtimer_type type = clock2alarm(which_clock);
759 struct restart_block *restart = &current->restart_block;
760 struct alarm alarm;
761 ktime_t exp;
762 int ret = 0;
763
764 if (!alarmtimer_get_rtcdev())
765 return -ENOTSUPP;
766
767 if (flags & ~TIMER_ABSTIME)
768 return -EINVAL;
769
770 if (!capable(CAP_WAKE_ALARM))
771 return -EPERM;
772
773 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
774
775 exp = timespec64_to_ktime(*tsreq);
776 /* Convert (if necessary) to absolute time */
777 if (flags != TIMER_ABSTIME) {
778 ktime_t now = alarm_bases[type].gettime();
779 exp = ktime_add(now, exp);
780 }
781
782 ret = alarmtimer_do_nsleep(&alarm, exp, type);
783 if (ret != -ERESTART_RESTARTBLOCK)
784 return ret;
785
786 /* abs timers don't set remaining time or restart */
787 if (flags == TIMER_ABSTIME)
788 return -ERESTARTNOHAND;
789
790 restart->fn = alarm_timer_nsleep_restart;
791 restart->nanosleep.clockid = type;
792 restart->nanosleep.expires = exp;
793 return ret;
794}
795
796const struct k_clock alarm_clock = {
797 .clock_getres = alarm_clock_getres,
798 .clock_get = alarm_clock_get,
799 .timer_create = alarm_timer_create,
800 .timer_set = common_timer_set,
801 .timer_del = common_timer_del,
802 .timer_get = common_timer_get,
803 .timer_arm = alarm_timer_arm,
804 .timer_rearm = alarm_timer_rearm,
805 .timer_forward = alarm_timer_forward,
806 .timer_remaining = alarm_timer_remaining,
807 .timer_try_to_cancel = alarm_timer_try_to_cancel,
808 .nsleep = alarm_timer_nsleep,
809};
810#endif /* CONFIG_POSIX_TIMERS */
811
812
813/* Suspend hook structures */
814static const struct dev_pm_ops alarmtimer_pm_ops = {
815 .suspend = alarmtimer_suspend,
816 .resume = alarmtimer_resume,
817};
818
819static struct platform_driver alarmtimer_driver = {
820 .driver = {
821 .name = "alarmtimer",
822 .pm = &alarmtimer_pm_ops,
823 }
824};
825
826/**
827 * alarmtimer_init - Initialize alarm timer code
828 *
829 * This function initializes the alarm bases and registers
830 * the posix clock ids.
831 */
832static int __init alarmtimer_init(void)
833{
834 struct platform_device *pdev;
835 int error = 0;
836 int i;
837
838 alarmtimer_rtc_timer_init();
839
840 /* Initialize alarm bases */
841 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
842 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
843 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
844 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
845 for (i = 0; i < ALARM_NUMTYPE; i++) {
846 timerqueue_init_head(&alarm_bases[i].timerqueue);
847 spin_lock_init(&alarm_bases[i].lock);
848 }
849
850 error = alarmtimer_rtc_interface_setup();
851 if (error)
852 return error;
853
854 error = platform_driver_register(&alarmtimer_driver);
855 if (error)
856 goto out_if;
857
858 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
859 if (IS_ERR(pdev)) {
860 error = PTR_ERR(pdev);
861 goto out_drv;
862 }
863 ws = wakeup_source_register("alarmtimer");
864 return 0;
865
866out_drv:
867 platform_driver_unregister(&alarmtimer_driver);
868out_if:
869 alarmtimer_rtc_interface_remove();
870 return error;
871}
872device_initcall(alarmtimer_init);