Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Alarmtimer interface
4 : *
5 : * This interface provides a timer which is similarto hrtimers,
6 : * but triggers a RTC alarm if the box is suspend.
7 : *
8 : * This interface is influenced by the Android RTC Alarm timer
9 : * interface.
10 : *
11 : * Copyright (C) 2010 IBM Corperation
12 : *
13 : * Author: John Stultz <john.stultz@linaro.org>
14 : */
15 : #include <linux/time.h>
16 : #include <linux/hrtimer.h>
17 : #include <linux/timerqueue.h>
18 : #include <linux/rtc.h>
19 : #include <linux/sched/signal.h>
20 : #include <linux/sched/debug.h>
21 : #include <linux/alarmtimer.h>
22 : #include <linux/mutex.h>
23 : #include <linux/platform_device.h>
24 : #include <linux/posix-timers.h>
25 : #include <linux/workqueue.h>
26 : #include <linux/freezer.h>
27 : #include <linux/compat.h>
28 : #include <linux/module.h>
29 : #include <linux/time_namespace.h>
30 :
31 : #include "posix-timers.h"
32 :
33 : #define CREATE_TRACE_POINTS
34 : #include <trace/events/alarmtimer.h>
35 :
36 : /**
37 : * struct alarm_base - Alarm timer bases
38 : * @lock: Lock for syncrhonized access to the base
39 : * @timerqueue: Timerqueue head managing the list of events
40 : * @get_ktime: Function to read the time correlating to the base
41 : * @get_timespec: Function to read the namespace time correlating to the base
42 : * @base_clockid: clockid for the base
43 : */
44 : static struct alarm_base {
45 : spinlock_t lock;
46 : struct timerqueue_head timerqueue;
47 : ktime_t (*get_ktime)(void);
48 : void (*get_timespec)(struct timespec64 *tp);
49 : clockid_t base_clockid;
50 : } alarm_bases[ALARM_NUMTYPE];
51 :
52 : #if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS)
53 : /* freezer information to handle clock_nanosleep triggered wakeups */
54 : static enum alarmtimer_type freezer_alarmtype;
55 : static ktime_t freezer_expires;
56 : static ktime_t freezer_delta;
57 : static DEFINE_SPINLOCK(freezer_delta_lock);
58 : #endif
59 :
60 : #ifdef CONFIG_RTC_CLASS
61 : /* rtc timer and device for setting alarm wakeups at suspend */
62 : static struct rtc_timer rtctimer;
63 : static struct rtc_device *rtcdev;
64 : static DEFINE_SPINLOCK(rtcdev_lock);
65 :
66 : /**
67 : * alarmtimer_get_rtcdev - Return selected rtcdevice
68 : *
69 : * This function returns the rtc device to use for wakealarms.
70 : */
71 0 : struct rtc_device *alarmtimer_get_rtcdev(void)
72 : {
73 0 : unsigned long flags;
74 0 : struct rtc_device *ret;
75 :
76 0 : spin_lock_irqsave(&rtcdev_lock, flags);
77 0 : ret = rtcdev;
78 0 : spin_unlock_irqrestore(&rtcdev_lock, flags);
79 :
80 0 : return ret;
81 : }
82 : EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
83 :
84 0 : static int alarmtimer_rtc_add_device(struct device *dev,
85 : struct class_interface *class_intf)
86 : {
87 0 : unsigned long flags;
88 0 : struct rtc_device *rtc = to_rtc_device(dev);
89 0 : struct platform_device *pdev;
90 0 : int ret = 0;
91 :
92 0 : if (rtcdev)
93 : return -EBUSY;
94 :
95 0 : if (!rtc->ops->set_alarm)
96 : return -1;
97 0 : if (!device_may_wakeup(rtc->dev.parent))
98 : return -1;
99 :
100 0 : pdev = platform_device_register_data(dev, "alarmtimer",
101 : PLATFORM_DEVID_AUTO, NULL, 0);
102 0 : if (!IS_ERR(pdev))
103 0 : device_init_wakeup(&pdev->dev, true);
104 :
105 0 : spin_lock_irqsave(&rtcdev_lock, flags);
106 0 : if (!IS_ERR(pdev) && !rtcdev) {
107 0 : if (!try_module_get(rtc->owner)) {
108 : ret = -1;
109 : goto unlock;
110 : }
111 :
112 0 : rtcdev = rtc;
113 : /* hold a reference so it doesn't go away */
114 0 : get_device(dev);
115 0 : pdev = NULL;
116 : } else {
117 : ret = -1;
118 : }
119 0 : unlock:
120 0 : spin_unlock_irqrestore(&rtcdev_lock, flags);
121 :
122 0 : platform_device_unregister(pdev);
123 :
124 0 : return ret;
125 : }
126 :
127 1 : static inline void alarmtimer_rtc_timer_init(void)
128 : {
129 1 : rtc_timer_init(&rtctimer, NULL, NULL);
130 : }
131 :
132 : static struct class_interface alarmtimer_rtc_interface = {
133 : .add_dev = &alarmtimer_rtc_add_device,
134 : };
135 :
136 1 : static int alarmtimer_rtc_interface_setup(void)
137 : {
138 1 : alarmtimer_rtc_interface.class = rtc_class;
139 1 : return class_interface_register(&alarmtimer_rtc_interface);
140 : }
141 0 : static void alarmtimer_rtc_interface_remove(void)
142 : {
143 0 : class_interface_unregister(&alarmtimer_rtc_interface);
144 : }
145 : #else
146 : static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
147 : static inline void alarmtimer_rtc_interface_remove(void) { }
148 : static inline void alarmtimer_rtc_timer_init(void) { }
149 : #endif
150 :
151 : /**
152 : * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
153 : * @base: pointer to the base where the timer is being run
154 : * @alarm: pointer to alarm being enqueued.
155 : *
156 : * Adds alarm to a alarm_base timerqueue
157 : *
158 : * Must hold base->lock when calling.
159 : */
160 0 : static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
161 : {
162 0 : if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
163 0 : timerqueue_del(&base->timerqueue, &alarm->node);
164 :
165 0 : timerqueue_add(&base->timerqueue, &alarm->node);
166 0 : alarm->state |= ALARMTIMER_STATE_ENQUEUED;
167 0 : }
168 :
169 : /**
170 : * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
171 : * @base: pointer to the base where the timer is running
172 : * @alarm: pointer to alarm being removed
173 : *
174 : * Removes alarm to a alarm_base timerqueue
175 : *
176 : * Must hold base->lock when calling.
177 : */
178 0 : static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
179 : {
180 0 : if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
181 : return;
182 :
183 0 : timerqueue_del(&base->timerqueue, &alarm->node);
184 0 : alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
185 : }
186 :
187 :
188 : /**
189 : * alarmtimer_fired - Handles alarm hrtimer being fired.
190 : * @timer: pointer to hrtimer being run
191 : *
192 : * When a alarm timer fires, this runs through the timerqueue to
193 : * see which alarms expired, and runs those. If there are more alarm
194 : * timers queued for the future, we set the hrtimer to fire when
195 : * the next future alarm timer expires.
196 : */
197 0 : static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
198 : {
199 0 : struct alarm *alarm = container_of(timer, struct alarm, timer);
200 0 : struct alarm_base *base = &alarm_bases[alarm->type];
201 0 : unsigned long flags;
202 0 : int ret = HRTIMER_NORESTART;
203 0 : int restart = ALARMTIMER_NORESTART;
204 :
205 0 : spin_lock_irqsave(&base->lock, flags);
206 0 : alarmtimer_dequeue(base, alarm);
207 0 : spin_unlock_irqrestore(&base->lock, flags);
208 :
209 0 : if (alarm->function)
210 0 : restart = alarm->function(alarm, base->get_ktime());
211 :
212 0 : spin_lock_irqsave(&base->lock, flags);
213 0 : if (restart != ALARMTIMER_NORESTART) {
214 0 : hrtimer_set_expires(&alarm->timer, alarm->node.expires);
215 0 : alarmtimer_enqueue(base, alarm);
216 0 : ret = HRTIMER_RESTART;
217 : }
218 0 : spin_unlock_irqrestore(&base->lock, flags);
219 :
220 0 : trace_alarmtimer_fired(alarm, base->get_ktime());
221 0 : return ret;
222 :
223 : }
224 :
225 0 : ktime_t alarm_expires_remaining(const struct alarm *alarm)
226 : {
227 0 : struct alarm_base *base = &alarm_bases[alarm->type];
228 0 : return ktime_sub(alarm->node.expires, base->get_ktime());
229 : }
230 : EXPORT_SYMBOL_GPL(alarm_expires_remaining);
231 :
232 : #ifdef CONFIG_RTC_CLASS
233 : /**
234 : * alarmtimer_suspend - Suspend time callback
235 : * @dev: unused
236 : *
237 : * When we are going into suspend, we look through the bases
238 : * to see which is the soonest timer to expire. We then
239 : * set an rtc timer to fire that far into the future, which
240 : * will wake us from suspend.
241 : */
242 0 : static int alarmtimer_suspend(struct device *dev)
243 : {
244 0 : ktime_t min, now, expires;
245 0 : int i, ret, type;
246 0 : struct rtc_device *rtc;
247 0 : unsigned long flags;
248 0 : struct rtc_time tm;
249 :
250 0 : spin_lock_irqsave(&freezer_delta_lock, flags);
251 0 : min = freezer_delta;
252 0 : expires = freezer_expires;
253 0 : type = freezer_alarmtype;
254 0 : freezer_delta = 0;
255 0 : spin_unlock_irqrestore(&freezer_delta_lock, flags);
256 :
257 0 : rtc = alarmtimer_get_rtcdev();
258 : /* If we have no rtcdev, just return */
259 0 : if (!rtc)
260 : return 0;
261 :
262 : /* Find the soonest timer to expire*/
263 0 : for (i = 0; i < ALARM_NUMTYPE; i++) {
264 0 : struct alarm_base *base = &alarm_bases[i];
265 0 : struct timerqueue_node *next;
266 0 : ktime_t delta;
267 :
268 0 : spin_lock_irqsave(&base->lock, flags);
269 0 : next = timerqueue_getnext(&base->timerqueue);
270 0 : spin_unlock_irqrestore(&base->lock, flags);
271 0 : if (!next)
272 0 : continue;
273 0 : delta = ktime_sub(next->expires, base->get_ktime());
274 0 : if (!min || (delta < min)) {
275 0 : expires = next->expires;
276 0 : min = delta;
277 0 : type = i;
278 : }
279 : }
280 0 : if (min == 0)
281 : return 0;
282 :
283 0 : if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
284 0 : pm_wakeup_event(dev, 2 * MSEC_PER_SEC);
285 : return -EBUSY;
286 : }
287 :
288 0 : trace_alarmtimer_suspend(expires, type);
289 :
290 : /* Setup an rtc timer to fire that far in the future */
291 0 : rtc_timer_cancel(rtc, &rtctimer);
292 0 : rtc_read_time(rtc, &tm);
293 0 : now = rtc_tm_to_ktime(tm);
294 0 : now = ktime_add(now, min);
295 :
296 : /* Set alarm, if in the past reject suspend briefly to handle */
297 0 : ret = rtc_timer_start(rtc, &rtctimer, now, 0);
298 0 : if (ret < 0)
299 0 : pm_wakeup_event(dev, MSEC_PER_SEC);
300 0 : return ret;
301 : }
302 :
303 0 : static int alarmtimer_resume(struct device *dev)
304 : {
305 0 : struct rtc_device *rtc;
306 :
307 0 : rtc = alarmtimer_get_rtcdev();
308 0 : if (rtc)
309 0 : rtc_timer_cancel(rtc, &rtctimer);
310 0 : return 0;
311 : }
312 :
313 : #else
314 : static int alarmtimer_suspend(struct device *dev)
315 : {
316 : return 0;
317 : }
318 :
319 : static int alarmtimer_resume(struct device *dev)
320 : {
321 : return 0;
322 : }
323 : #endif
324 :
325 : static void
326 0 : __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
327 : enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
328 : {
329 0 : timerqueue_init(&alarm->node);
330 0 : alarm->timer.function = alarmtimer_fired;
331 0 : alarm->function = function;
332 0 : alarm->type = type;
333 0 : alarm->state = ALARMTIMER_STATE_INACTIVE;
334 : }
335 :
336 : /**
337 : * alarm_init - Initialize an alarm structure
338 : * @alarm: ptr to alarm to be initialized
339 : * @type: the type of the alarm
340 : * @function: callback that is run when the alarm fires
341 : */
342 0 : void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
343 : enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
344 : {
345 0 : hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
346 : HRTIMER_MODE_ABS);
347 0 : __alarm_init(alarm, type, function);
348 0 : }
349 : EXPORT_SYMBOL_GPL(alarm_init);
350 :
351 : /**
352 : * alarm_start - Sets an absolute alarm to fire
353 : * @alarm: ptr to alarm to set
354 : * @start: time to run the alarm
355 : */
356 0 : void alarm_start(struct alarm *alarm, ktime_t start)
357 : {
358 0 : struct alarm_base *base = &alarm_bases[alarm->type];
359 0 : unsigned long flags;
360 :
361 0 : spin_lock_irqsave(&base->lock, flags);
362 0 : alarm->node.expires = start;
363 0 : alarmtimer_enqueue(base, alarm);
364 0 : hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
365 0 : spin_unlock_irqrestore(&base->lock, flags);
366 :
367 0 : trace_alarmtimer_start(alarm, base->get_ktime());
368 0 : }
369 : EXPORT_SYMBOL_GPL(alarm_start);
370 :
371 : /**
372 : * alarm_start_relative - Sets a relative alarm to fire
373 : * @alarm: ptr to alarm to set
374 : * @start: time relative to now to run the alarm
375 : */
376 0 : void alarm_start_relative(struct alarm *alarm, ktime_t start)
377 : {
378 0 : struct alarm_base *base = &alarm_bases[alarm->type];
379 :
380 0 : start = ktime_add_safe(start, base->get_ktime());
381 0 : alarm_start(alarm, start);
382 0 : }
383 : EXPORT_SYMBOL_GPL(alarm_start_relative);
384 :
385 0 : void alarm_restart(struct alarm *alarm)
386 : {
387 0 : struct alarm_base *base = &alarm_bases[alarm->type];
388 0 : unsigned long flags;
389 :
390 0 : spin_lock_irqsave(&base->lock, flags);
391 0 : hrtimer_set_expires(&alarm->timer, alarm->node.expires);
392 0 : hrtimer_restart(&alarm->timer);
393 0 : alarmtimer_enqueue(base, alarm);
394 0 : spin_unlock_irqrestore(&base->lock, flags);
395 0 : }
396 : EXPORT_SYMBOL_GPL(alarm_restart);
397 :
398 : /**
399 : * alarm_try_to_cancel - Tries to cancel an alarm timer
400 : * @alarm: ptr to alarm to be canceled
401 : *
402 : * Returns 1 if the timer was canceled, 0 if it was not running,
403 : * and -1 if the callback was running
404 : */
405 0 : int alarm_try_to_cancel(struct alarm *alarm)
406 : {
407 0 : struct alarm_base *base = &alarm_bases[alarm->type];
408 0 : unsigned long flags;
409 0 : int ret;
410 :
411 0 : spin_lock_irqsave(&base->lock, flags);
412 0 : ret = hrtimer_try_to_cancel(&alarm->timer);
413 0 : if (ret >= 0)
414 0 : alarmtimer_dequeue(base, alarm);
415 0 : spin_unlock_irqrestore(&base->lock, flags);
416 :
417 0 : trace_alarmtimer_cancel(alarm, base->get_ktime());
418 0 : return ret;
419 : }
420 : EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
421 :
422 :
423 : /**
424 : * alarm_cancel - Spins trying to cancel an alarm timer until it is done
425 : * @alarm: ptr to alarm to be canceled
426 : *
427 : * Returns 1 if the timer was canceled, 0 if it was not active.
428 : */
429 0 : int alarm_cancel(struct alarm *alarm)
430 : {
431 0 : for (;;) {
432 0 : int ret = alarm_try_to_cancel(alarm);
433 0 : if (ret >= 0)
434 0 : return ret;
435 0 : hrtimer_cancel_wait_running(&alarm->timer);
436 : }
437 : }
438 : EXPORT_SYMBOL_GPL(alarm_cancel);
439 :
440 :
441 0 : u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
442 : {
443 0 : u64 overrun = 1;
444 0 : ktime_t delta;
445 :
446 0 : delta = ktime_sub(now, alarm->node.expires);
447 :
448 0 : if (delta < 0)
449 : return 0;
450 :
451 0 : if (unlikely(delta >= interval)) {
452 0 : s64 incr = ktime_to_ns(interval);
453 :
454 0 : overrun = ktime_divns(delta, incr);
455 :
456 0 : alarm->node.expires = ktime_add_ns(alarm->node.expires,
457 : incr*overrun);
458 :
459 0 : if (alarm->node.expires > now)
460 : return overrun;
461 : /*
462 : * This (and the ktime_add() below) is the
463 : * correction for exact:
464 : */
465 0 : overrun++;
466 : }
467 :
468 0 : alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
469 0 : return overrun;
470 : }
471 : EXPORT_SYMBOL_GPL(alarm_forward);
472 :
473 0 : u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
474 : {
475 0 : struct alarm_base *base = &alarm_bases[alarm->type];
476 :
477 0 : return alarm_forward(alarm, base->get_ktime(), interval);
478 : }
479 : EXPORT_SYMBOL_GPL(alarm_forward_now);
480 :
481 : #ifdef CONFIG_POSIX_TIMERS
482 :
483 : static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
484 : {
485 : struct alarm_base *base;
486 : unsigned long flags;
487 : ktime_t delta;
488 :
489 : switch(type) {
490 : case ALARM_REALTIME:
491 : base = &alarm_bases[ALARM_REALTIME];
492 : type = ALARM_REALTIME_FREEZER;
493 : break;
494 : case ALARM_BOOTTIME:
495 : base = &alarm_bases[ALARM_BOOTTIME];
496 : type = ALARM_BOOTTIME_FREEZER;
497 : break;
498 : default:
499 : WARN_ONCE(1, "Invalid alarm type: %d\n", type);
500 : return;
501 : }
502 :
503 : delta = ktime_sub(absexp, base->get_ktime());
504 :
505 : spin_lock_irqsave(&freezer_delta_lock, flags);
506 : if (!freezer_delta || (delta < freezer_delta)) {
507 : freezer_delta = delta;
508 : freezer_expires = absexp;
509 : freezer_alarmtype = type;
510 : }
511 : spin_unlock_irqrestore(&freezer_delta_lock, flags);
512 : }
513 :
514 : /**
515 : * clock2alarm - helper that converts from clockid to alarmtypes
516 : * @clockid: clockid.
517 : */
518 0 : static enum alarmtimer_type clock2alarm(clockid_t clockid)
519 : {
520 0 : if (clockid == CLOCK_REALTIME_ALARM)
521 : return ALARM_REALTIME;
522 0 : if (clockid == CLOCK_BOOTTIME_ALARM)
523 0 : return ALARM_BOOTTIME;
524 : return -1;
525 : }
526 :
527 : /**
528 : * alarm_handle_timer - Callback for posix timers
529 : * @alarm: alarm that fired
530 : * @now: time at the timer expiration
531 : *
532 : * Posix timer callback for expired alarm timers.
533 : *
534 : * Return: whether the timer is to be restarted
535 : */
536 0 : static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
537 : ktime_t now)
538 : {
539 0 : struct k_itimer *ptr = container_of(alarm, struct k_itimer,
540 : it.alarm.alarmtimer);
541 0 : enum alarmtimer_restart result = ALARMTIMER_NORESTART;
542 0 : unsigned long flags;
543 0 : int si_private = 0;
544 :
545 0 : spin_lock_irqsave(&ptr->it_lock, flags);
546 :
547 0 : ptr->it_active = 0;
548 0 : if (ptr->it_interval)
549 0 : si_private = ++ptr->it_requeue_pending;
550 :
551 0 : if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
552 : /*
553 : * Handle ignored signals and rearm the timer. This will go
554 : * away once we handle ignored signals proper.
555 : */
556 0 : ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval);
557 0 : ++ptr->it_requeue_pending;
558 0 : ptr->it_active = 1;
559 0 : result = ALARMTIMER_RESTART;
560 : }
561 0 : spin_unlock_irqrestore(&ptr->it_lock, flags);
562 :
563 0 : return result;
564 : }
565 :
566 : /**
567 : * alarm_timer_rearm - Posix timer callback for rearming timer
568 : * @timr: Pointer to the posixtimer data struct
569 : */
570 0 : static void alarm_timer_rearm(struct k_itimer *timr)
571 : {
572 0 : struct alarm *alarm = &timr->it.alarm.alarmtimer;
573 :
574 0 : timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);
575 0 : alarm_start(alarm, alarm->node.expires);
576 0 : }
577 :
578 : /**
579 : * alarm_timer_forward - Posix timer callback for forwarding timer
580 : * @timr: Pointer to the posixtimer data struct
581 : * @now: Current time to forward the timer against
582 : */
583 0 : static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now)
584 : {
585 0 : struct alarm *alarm = &timr->it.alarm.alarmtimer;
586 :
587 0 : return alarm_forward(alarm, timr->it_interval, now);
588 : }
589 :
590 : /**
591 : * alarm_timer_remaining - Posix timer callback to retrieve remaining time
592 : * @timr: Pointer to the posixtimer data struct
593 : * @now: Current time to calculate against
594 : */
595 0 : static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now)
596 : {
597 0 : struct alarm *alarm = &timr->it.alarm.alarmtimer;
598 :
599 0 : return ktime_sub(alarm->node.expires, now);
600 : }
601 :
602 : /**
603 : * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer
604 : * @timr: Pointer to the posixtimer data struct
605 : */
606 0 : static int alarm_timer_try_to_cancel(struct k_itimer *timr)
607 : {
608 0 : return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
609 : }
610 :
611 : /**
612 : * alarm_timer_wait_running - Posix timer callback to wait for a timer
613 : * @timr: Pointer to the posixtimer data struct
614 : *
615 : * Called from the core code when timer cancel detected that the callback
616 : * is running. @timr is unlocked and rcu read lock is held to prevent it
617 : * from being freed.
618 : */
619 0 : static void alarm_timer_wait_running(struct k_itimer *timr)
620 : {
621 0 : hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer);
622 0 : }
623 :
624 : /**
625 : * alarm_timer_arm - Posix timer callback to arm a timer
626 : * @timr: Pointer to the posixtimer data struct
627 : * @expires: The new expiry time
628 : * @absolute: Expiry value is absolute time
629 : * @sigev_none: Posix timer does not deliver signals
630 : */
631 0 : static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires,
632 : bool absolute, bool sigev_none)
633 : {
634 0 : struct alarm *alarm = &timr->it.alarm.alarmtimer;
635 0 : struct alarm_base *base = &alarm_bases[alarm->type];
636 :
637 0 : if (!absolute)
638 0 : expires = ktime_add_safe(expires, base->get_ktime());
639 0 : if (sigev_none)
640 0 : alarm->node.expires = expires;
641 : else
642 0 : alarm_start(&timr->it.alarm.alarmtimer, expires);
643 0 : }
644 :
645 : /**
646 : * alarm_clock_getres - posix getres interface
647 : * @which_clock: clockid
648 : * @tp: timespec to fill
649 : *
650 : * Returns the granularity of underlying alarm base clock
651 : */
652 0 : static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
653 : {
654 0 : if (!alarmtimer_get_rtcdev())
655 : return -EINVAL;
656 :
657 0 : tp->tv_sec = 0;
658 0 : tp->tv_nsec = hrtimer_resolution;
659 0 : return 0;
660 : }
661 :
662 : /**
663 : * alarm_clock_get_timespec - posix clock_get_timespec interface
664 : * @which_clock: clockid
665 : * @tp: timespec to fill.
666 : *
667 : * Provides the underlying alarm base time in a tasks time namespace.
668 : */
669 0 : static int alarm_clock_get_timespec(clockid_t which_clock, struct timespec64 *tp)
670 : {
671 0 : struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
672 :
673 0 : if (!alarmtimer_get_rtcdev())
674 : return -EINVAL;
675 :
676 0 : base->get_timespec(tp);
677 :
678 0 : return 0;
679 : }
680 :
681 : /**
682 : * alarm_clock_get_ktime - posix clock_get_ktime interface
683 : * @which_clock: clockid
684 : *
685 : * Provides the underlying alarm base time in the root namespace.
686 : */
687 0 : static ktime_t alarm_clock_get_ktime(clockid_t which_clock)
688 : {
689 0 : struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
690 :
691 0 : if (!alarmtimer_get_rtcdev())
692 : return -EINVAL;
693 :
694 0 : return base->get_ktime();
695 : }
696 :
697 : /**
698 : * alarm_timer_create - posix timer_create interface
699 : * @new_timer: k_itimer pointer to manage
700 : *
701 : * Initializes the k_itimer structure.
702 : */
703 0 : static int alarm_timer_create(struct k_itimer *new_timer)
704 : {
705 0 : enum alarmtimer_type type;
706 :
707 0 : if (!alarmtimer_get_rtcdev())
708 : return -EOPNOTSUPP;
709 :
710 0 : if (!capable(CAP_WAKE_ALARM))
711 : return -EPERM;
712 :
713 0 : type = clock2alarm(new_timer->it_clock);
714 0 : alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
715 0 : return 0;
716 : }
717 :
718 : /**
719 : * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
720 : * @alarm: ptr to alarm that fired
721 : * @now: time at the timer expiration
722 : *
723 : * Wakes up the task that set the alarmtimer
724 : *
725 : * Return: ALARMTIMER_NORESTART
726 : */
727 0 : static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
728 : ktime_t now)
729 : {
730 0 : struct task_struct *task = (struct task_struct *)alarm->data;
731 :
732 0 : alarm->data = NULL;
733 0 : if (task)
734 0 : wake_up_process(task);
735 0 : return ALARMTIMER_NORESTART;
736 : }
737 :
738 : /**
739 : * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
740 : * @alarm: ptr to alarmtimer
741 : * @absexp: absolute expiration time
742 : * @type: alarm type (BOOTTIME/REALTIME).
743 : *
744 : * Sets the alarm timer and sleeps until it is fired or interrupted.
745 : */
746 0 : static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
747 : enum alarmtimer_type type)
748 : {
749 0 : struct restart_block *restart;
750 0 : alarm->data = (void *)current;
751 0 : do {
752 0 : set_current_state(TASK_INTERRUPTIBLE);
753 0 : alarm_start(alarm, absexp);
754 0 : if (likely(alarm->data))
755 0 : schedule();
756 :
757 0 : alarm_cancel(alarm);
758 0 : } while (alarm->data && !signal_pending(current));
759 :
760 0 : __set_current_state(TASK_RUNNING);
761 :
762 0 : destroy_hrtimer_on_stack(&alarm->timer);
763 :
764 0 : if (!alarm->data)
765 : return 0;
766 :
767 0 : if (freezing(current))
768 : alarmtimer_freezerset(absexp, type);
769 0 : restart = ¤t->restart_block;
770 0 : if (restart->nanosleep.type != TT_NONE) {
771 0 : struct timespec64 rmt;
772 0 : ktime_t rem;
773 :
774 0 : rem = ktime_sub(absexp, alarm_bases[type].get_ktime());
775 :
776 0 : if (rem <= 0)
777 : return 0;
778 0 : rmt = ktime_to_timespec64(rem);
779 :
780 0 : return nanosleep_copyout(restart, &rmt);
781 : }
782 : return -ERESTART_RESTARTBLOCK;
783 : }
784 :
785 : static void
786 0 : alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type,
787 : enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
788 : {
789 0 : hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,
790 : HRTIMER_MODE_ABS);
791 0 : __alarm_init(alarm, type, function);
792 0 : }
793 :
794 : /**
795 : * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
796 : * @restart: ptr to restart block
797 : *
798 : * Handles restarted clock_nanosleep calls
799 : */
800 0 : static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
801 : {
802 0 : enum alarmtimer_type type = restart->nanosleep.clockid;
803 0 : ktime_t exp = restart->nanosleep.expires;
804 0 : struct alarm alarm;
805 :
806 0 : alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
807 :
808 0 : return alarmtimer_do_nsleep(&alarm, exp, type);
809 : }
810 :
811 : /**
812 : * alarm_timer_nsleep - alarmtimer nanosleep
813 : * @which_clock: clockid
814 : * @flags: determins abstime or relative
815 : * @tsreq: requested sleep time (abs or rel)
816 : *
817 : * Handles clock_nanosleep calls against _ALARM clockids
818 : */
819 0 : static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
820 : const struct timespec64 *tsreq)
821 : {
822 0 : enum alarmtimer_type type = clock2alarm(which_clock);
823 0 : struct restart_block *restart = ¤t->restart_block;
824 0 : struct alarm alarm;
825 0 : ktime_t exp;
826 0 : int ret = 0;
827 :
828 0 : if (!alarmtimer_get_rtcdev())
829 : return -EOPNOTSUPP;
830 :
831 0 : if (flags & ~TIMER_ABSTIME)
832 : return -EINVAL;
833 :
834 0 : if (!capable(CAP_WAKE_ALARM))
835 : return -EPERM;
836 :
837 0 : alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
838 :
839 0 : exp = timespec64_to_ktime(*tsreq);
840 : /* Convert (if necessary) to absolute time */
841 0 : if (flags != TIMER_ABSTIME) {
842 0 : ktime_t now = alarm_bases[type].get_ktime();
843 :
844 0 : exp = ktime_add_safe(now, exp);
845 : } else {
846 0 : exp = timens_ktime_to_host(which_clock, exp);
847 : }
848 :
849 0 : ret = alarmtimer_do_nsleep(&alarm, exp, type);
850 0 : if (ret != -ERESTART_RESTARTBLOCK)
851 : return ret;
852 :
853 : /* abs timers don't set remaining time or restart */
854 0 : if (flags == TIMER_ABSTIME)
855 : return -ERESTARTNOHAND;
856 :
857 0 : restart->fn = alarm_timer_nsleep_restart;
858 0 : restart->nanosleep.clockid = type;
859 0 : restart->nanosleep.expires = exp;
860 0 : return ret;
861 : }
862 :
863 : const struct k_clock alarm_clock = {
864 : .clock_getres = alarm_clock_getres,
865 : .clock_get_ktime = alarm_clock_get_ktime,
866 : .clock_get_timespec = alarm_clock_get_timespec,
867 : .timer_create = alarm_timer_create,
868 : .timer_set = common_timer_set,
869 : .timer_del = common_timer_del,
870 : .timer_get = common_timer_get,
871 : .timer_arm = alarm_timer_arm,
872 : .timer_rearm = alarm_timer_rearm,
873 : .timer_forward = alarm_timer_forward,
874 : .timer_remaining = alarm_timer_remaining,
875 : .timer_try_to_cancel = alarm_timer_try_to_cancel,
876 : .timer_wait_running = alarm_timer_wait_running,
877 : .nsleep = alarm_timer_nsleep,
878 : };
879 : #endif /* CONFIG_POSIX_TIMERS */
880 :
881 :
882 : /* Suspend hook structures */
883 : static const struct dev_pm_ops alarmtimer_pm_ops = {
884 : .suspend = alarmtimer_suspend,
885 : .resume = alarmtimer_resume,
886 : };
887 :
888 : static struct platform_driver alarmtimer_driver = {
889 : .driver = {
890 : .name = "alarmtimer",
891 : .pm = &alarmtimer_pm_ops,
892 : }
893 : };
894 :
895 0 : static void get_boottime_timespec(struct timespec64 *tp)
896 : {
897 0 : ktime_get_boottime_ts64(tp);
898 0 : timens_add_boottime(tp);
899 0 : }
900 :
901 : /**
902 : * alarmtimer_init - Initialize alarm timer code
903 : *
904 : * This function initializes the alarm bases and registers
905 : * the posix clock ids.
906 : */
907 1 : static int __init alarmtimer_init(void)
908 : {
909 1 : int error;
910 1 : int i;
911 :
912 1 : alarmtimer_rtc_timer_init();
913 :
914 : /* Initialize alarm bases */
915 1 : alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
916 1 : alarm_bases[ALARM_REALTIME].get_ktime = &ktime_get_real;
917 1 : alarm_bases[ALARM_REALTIME].get_timespec = ktime_get_real_ts64;
918 1 : alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
919 1 : alarm_bases[ALARM_BOOTTIME].get_ktime = &ktime_get_boottime;
920 1 : alarm_bases[ALARM_BOOTTIME].get_timespec = get_boottime_timespec;
921 3 : for (i = 0; i < ALARM_NUMTYPE; i++) {
922 2 : timerqueue_init_head(&alarm_bases[i].timerqueue);
923 2 : spin_lock_init(&alarm_bases[i].lock);
924 : }
925 :
926 1 : error = alarmtimer_rtc_interface_setup();
927 1 : if (error)
928 : return error;
929 :
930 1 : error = platform_driver_register(&alarmtimer_driver);
931 1 : if (error)
932 0 : goto out_if;
933 :
934 : return 0;
935 0 : out_if:
936 0 : alarmtimer_rtc_interface_remove();
937 0 : return error;
938 : }
939 : device_initcall(alarmtimer_init);
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