]>
Commit | Line | Data |
---|---|---|
ff3ead96 JS |
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 <john.stultz@linaro.org> | |
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/alarmtimer.h> | |
23 | #include <linux/mutex.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/posix-timers.h> | |
26 | #include <linux/workqueue.h> | |
27 | #include <linux/freezer.h> | |
28 | ||
180bf812 JS |
29 | /** |
30 | * struct alarm_base - Alarm timer bases | |
31 | * @lock: Lock for syncrhonized access to the base | |
32 | * @timerqueue: Timerqueue head managing the list of events | |
33 | * @timer: hrtimer used to schedule events while running | |
34 | * @gettime: Function to read the time correlating to the base | |
35 | * @base_clockid: clockid for the base | |
180bf812 | 36 | */ |
ff3ead96 JS |
37 | static struct alarm_base { |
38 | spinlock_t lock; | |
39 | struct timerqueue_head timerqueue; | |
40 | struct hrtimer timer; | |
41 | ktime_t (*gettime)(void); | |
42 | clockid_t base_clockid; | |
ff3ead96 JS |
43 | } alarm_bases[ALARM_NUMTYPE]; |
44 | ||
c008ba58 JS |
45 | /* freezer delta & lock used to handle clock_nanosleep triggered wakeups */ |
46 | static ktime_t freezer_delta; | |
47 | static DEFINE_SPINLOCK(freezer_delta_lock); | |
48 | ||
472647dc | 49 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 50 | /* rtc timer and device for setting alarm wakeups at suspend */ |
ff3ead96 JS |
51 | static struct rtc_timer rtctimer; |
52 | static struct rtc_device *rtcdev; | |
c008ba58 | 53 | static DEFINE_SPINLOCK(rtcdev_lock); |
ff3ead96 | 54 | |
c008ba58 JS |
55 | /** |
56 | * has_wakealarm - check rtc device has wakealarm ability | |
57 | * @dev: current device | |
58 | * @name_ptr: name to be returned | |
59 | * | |
60 | * This helper function checks to see if the rtc device can wake | |
61 | * from suspend. | |
62 | */ | |
63 | static int has_wakealarm(struct device *dev, void *name_ptr) | |
64 | { | |
65 | struct rtc_device *candidate = to_rtc_device(dev); | |
66 | ||
67 | if (!candidate->ops->set_alarm) | |
68 | return 0; | |
69 | if (!device_may_wakeup(candidate->dev.parent)) | |
70 | return 0; | |
71 | ||
72 | *(const char **)name_ptr = dev_name(dev); | |
73 | return 1; | |
74 | } | |
75 | ||
76 | /** | |
77 | * alarmtimer_get_rtcdev - Return selected rtcdevice | |
78 | * | |
79 | * This function returns the rtc device to use for wakealarms. | |
80 | * If one has not already been chosen, it checks to see if a | |
81 | * functional rtc device is available. | |
82 | */ | |
83 | static struct rtc_device *alarmtimer_get_rtcdev(void) | |
84 | { | |
85 | struct device *dev; | |
86 | char *str; | |
87 | unsigned long flags; | |
88 | struct rtc_device *ret; | |
89 | ||
90 | spin_lock_irqsave(&rtcdev_lock, flags); | |
91 | if (!rtcdev) { | |
92 | /* Find an rtc device and init the rtc_timer */ | |
93 | dev = class_find_device(rtc_class, NULL, &str, has_wakealarm); | |
94 | /* If we have a device then str is valid. See has_wakealarm() */ | |
95 | if (dev) { | |
96 | rtcdev = rtc_class_open(str); | |
97 | /* | |
98 | * Drop the reference we got in class_find_device, | |
99 | * rtc_open takes its own. | |
100 | */ | |
101 | put_device(dev); | |
102 | rtc_timer_init(&rtctimer, NULL, NULL); | |
103 | } | |
104 | } | |
105 | ret = rtcdev; | |
106 | spin_unlock_irqrestore(&rtcdev_lock, flags); | |
107 | ||
108 | return ret; | |
109 | } | |
1c6b39ad JS |
110 | #else |
111 | #define alarmtimer_get_rtcdev() (0) | |
112 | #define rtcdev (0) | |
c008ba58 | 113 | #endif |
ff3ead96 JS |
114 | |
115 | ||
180bf812 | 116 | /** |
ff3ead96 JS |
117 | * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue |
118 | * @base: pointer to the base where the timer is being run | |
119 | * @alarm: pointer to alarm being enqueued. | |
120 | * | |
121 | * Adds alarm to a alarm_base timerqueue and if necessary sets | |
122 | * an hrtimer to run. | |
123 | * | |
124 | * Must hold base->lock when calling. | |
125 | */ | |
126 | static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) | |
127 | { | |
128 | timerqueue_add(&base->timerqueue, &alarm->node); | |
129 | if (&alarm->node == timerqueue_getnext(&base->timerqueue)) { | |
130 | hrtimer_try_to_cancel(&base->timer); | |
131 | hrtimer_start(&base->timer, alarm->node.expires, | |
132 | HRTIMER_MODE_ABS); | |
133 | } | |
134 | } | |
135 | ||
180bf812 | 136 | /** |
ff3ead96 JS |
137 | * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue |
138 | * @base: pointer to the base where the timer is running | |
139 | * @alarm: pointer to alarm being removed | |
140 | * | |
141 | * Removes alarm to a alarm_base timerqueue and if necessary sets | |
142 | * a new timer to run. | |
143 | * | |
144 | * Must hold base->lock when calling. | |
145 | */ | |
146 | static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm) | |
147 | { | |
148 | struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue); | |
149 | ||
150 | timerqueue_del(&base->timerqueue, &alarm->node); | |
151 | if (next == &alarm->node) { | |
152 | hrtimer_try_to_cancel(&base->timer); | |
153 | next = timerqueue_getnext(&base->timerqueue); | |
154 | if (!next) | |
155 | return; | |
156 | hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS); | |
157 | } | |
158 | } | |
159 | ||
7068b7a1 | 160 | |
180bf812 | 161 | /** |
7068b7a1 JS |
162 | * alarmtimer_fired - Handles alarm hrtimer being fired. |
163 | * @timer: pointer to hrtimer being run | |
ff3ead96 | 164 | * |
180bf812 JS |
165 | * When a alarm timer fires, this runs through the timerqueue to |
166 | * see which alarms expired, and runs those. If there are more alarm | |
167 | * timers queued for the future, we set the hrtimer to fire when | |
168 | * when the next future alarm timer expires. | |
ff3ead96 | 169 | */ |
7068b7a1 | 170 | static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
ff3ead96 | 171 | { |
7068b7a1 | 172 | struct alarm_base *base = container_of(timer, struct alarm_base, timer); |
ff3ead96 JS |
173 | struct timerqueue_node *next; |
174 | unsigned long flags; | |
175 | ktime_t now; | |
7068b7a1 | 176 | int ret = HRTIMER_NORESTART; |
54da23b7 | 177 | int restart = ALARMTIMER_NORESTART; |
ff3ead96 JS |
178 | |
179 | spin_lock_irqsave(&base->lock, flags); | |
180 | now = base->gettime(); | |
181 | while ((next = timerqueue_getnext(&base->timerqueue))) { | |
182 | struct alarm *alarm; | |
183 | ktime_t expired = next->expires; | |
184 | ||
185 | if (expired.tv64 >= now.tv64) | |
186 | break; | |
187 | ||
188 | alarm = container_of(next, struct alarm, node); | |
189 | ||
190 | timerqueue_del(&base->timerqueue, &alarm->node); | |
191 | alarm->enabled = 0; | |
54da23b7 | 192 | |
ff3ead96 JS |
193 | spin_unlock_irqrestore(&base->lock, flags); |
194 | if (alarm->function) | |
54da23b7 | 195 | restart = alarm->function(alarm, now); |
ff3ead96 | 196 | spin_lock_irqsave(&base->lock, flags); |
54da23b7 JS |
197 | |
198 | if (restart != ALARMTIMER_NORESTART) { | |
199 | timerqueue_add(&base->timerqueue, &alarm->node); | |
200 | alarm->enabled = 1; | |
201 | } | |
ff3ead96 JS |
202 | } |
203 | ||
204 | if (next) { | |
7068b7a1 JS |
205 | hrtimer_set_expires(&base->timer, next->expires); |
206 | ret = HRTIMER_RESTART; | |
ff3ead96 JS |
207 | } |
208 | spin_unlock_irqrestore(&base->lock, flags); | |
ff3ead96 | 209 | |
7068b7a1 | 210 | return ret; |
ff3ead96 | 211 | |
ff3ead96 JS |
212 | } |
213 | ||
472647dc | 214 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 215 | /** |
ff3ead96 JS |
216 | * alarmtimer_suspend - Suspend time callback |
217 | * @dev: unused | |
218 | * @state: unused | |
219 | * | |
220 | * When we are going into suspend, we look through the bases | |
221 | * to see which is the soonest timer to expire. We then | |
222 | * set an rtc timer to fire that far into the future, which | |
223 | * will wake us from suspend. | |
224 | */ | |
225 | static int alarmtimer_suspend(struct device *dev) | |
226 | { | |
227 | struct rtc_time tm; | |
228 | ktime_t min, now; | |
229 | unsigned long flags; | |
c008ba58 | 230 | struct rtc_device *rtc; |
ff3ead96 JS |
231 | int i; |
232 | ||
233 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
234 | min = freezer_delta; | |
235 | freezer_delta = ktime_set(0, 0); | |
236 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
237 | ||
1c6b39ad | 238 | rtc = rtcdev; |
ff3ead96 | 239 | /* If we have no rtcdev, just return */ |
c008ba58 | 240 | if (!rtc) |
ff3ead96 JS |
241 | return 0; |
242 | ||
243 | /* Find the soonest timer to expire*/ | |
244 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
245 | struct alarm_base *base = &alarm_bases[i]; | |
246 | struct timerqueue_node *next; | |
247 | ktime_t delta; | |
248 | ||
249 | spin_lock_irqsave(&base->lock, flags); | |
250 | next = timerqueue_getnext(&base->timerqueue); | |
251 | spin_unlock_irqrestore(&base->lock, flags); | |
252 | if (!next) | |
253 | continue; | |
254 | delta = ktime_sub(next->expires, base->gettime()); | |
255 | if (!min.tv64 || (delta.tv64 < min.tv64)) | |
256 | min = delta; | |
257 | } | |
258 | if (min.tv64 == 0) | |
259 | return 0; | |
260 | ||
261 | /* XXX - Should we enforce a minimum sleep time? */ | |
262 | WARN_ON(min.tv64 < NSEC_PER_SEC); | |
263 | ||
264 | /* Setup an rtc timer to fire that far in the future */ | |
c008ba58 JS |
265 | rtc_timer_cancel(rtc, &rtctimer); |
266 | rtc_read_time(rtc, &tm); | |
ff3ead96 JS |
267 | now = rtc_tm_to_ktime(tm); |
268 | now = ktime_add(now, min); | |
269 | ||
c008ba58 | 270 | rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0)); |
ff3ead96 JS |
271 | |
272 | return 0; | |
273 | } | |
472647dc JS |
274 | #else |
275 | static int alarmtimer_suspend(struct device *dev) | |
276 | { | |
277 | return 0; | |
278 | } | |
279 | #endif | |
ff3ead96 | 280 | |
9a7adcf5 JS |
281 | static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
282 | { | |
283 | ktime_t delta; | |
284 | unsigned long flags; | |
285 | struct alarm_base *base = &alarm_bases[type]; | |
286 | ||
287 | delta = ktime_sub(absexp, base->gettime()); | |
288 | ||
289 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
290 | if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64)) | |
291 | freezer_delta = delta; | |
292 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
293 | } | |
294 | ||
295 | ||
180bf812 | 296 | /** |
ff3ead96 JS |
297 | * alarm_init - Initialize an alarm structure |
298 | * @alarm: ptr to alarm to be initialized | |
299 | * @type: the type of the alarm | |
300 | * @function: callback that is run when the alarm fires | |
ff3ead96 JS |
301 | */ |
302 | void alarm_init(struct alarm *alarm, enum alarmtimer_type type, | |
4b41308d | 303 | enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
ff3ead96 JS |
304 | { |
305 | timerqueue_init(&alarm->node); | |
306 | alarm->period = ktime_set(0, 0); | |
307 | alarm->function = function; | |
308 | alarm->type = type; | |
309 | alarm->enabled = 0; | |
310 | } | |
311 | ||
180bf812 | 312 | /** |
ff3ead96 JS |
313 | * alarm_start - Sets an alarm to fire |
314 | * @alarm: ptr to alarm to set | |
315 | * @start: time to run the alarm | |
316 | * @period: period at which the alarm will recur | |
ff3ead96 JS |
317 | */ |
318 | void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period) | |
319 | { | |
320 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
321 | unsigned long flags; | |
322 | ||
323 | spin_lock_irqsave(&base->lock, flags); | |
324 | if (alarm->enabled) | |
325 | alarmtimer_remove(base, alarm); | |
326 | alarm->node.expires = start; | |
327 | alarm->period = period; | |
328 | alarmtimer_enqueue(base, alarm); | |
329 | alarm->enabled = 1; | |
330 | spin_unlock_irqrestore(&base->lock, flags); | |
331 | } | |
332 | ||
180bf812 | 333 | /** |
ff3ead96 JS |
334 | * alarm_cancel - Tries to cancel an alarm timer |
335 | * @alarm: ptr to alarm to be canceled | |
ff3ead96 JS |
336 | */ |
337 | void alarm_cancel(struct alarm *alarm) | |
338 | { | |
339 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
340 | unsigned long flags; | |
341 | ||
342 | spin_lock_irqsave(&base->lock, flags); | |
343 | if (alarm->enabled) | |
344 | alarmtimer_remove(base, alarm); | |
345 | alarm->enabled = 0; | |
346 | spin_unlock_irqrestore(&base->lock, flags); | |
347 | } | |
348 | ||
349 | ||
dce75a8c JS |
350 | |
351 | u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) | |
352 | { | |
353 | u64 overrun = 1; | |
354 | ktime_t delta; | |
355 | ||
356 | delta = ktime_sub(now, alarm->node.expires); | |
357 | ||
358 | if (delta.tv64 < 0) | |
359 | return 0; | |
360 | ||
361 | if (unlikely(delta.tv64 >= interval.tv64)) { | |
362 | s64 incr = ktime_to_ns(interval); | |
363 | ||
364 | overrun = ktime_divns(delta, incr); | |
365 | ||
366 | alarm->node.expires = ktime_add_ns(alarm->node.expires, | |
367 | incr*overrun); | |
368 | ||
369 | if (alarm->node.expires.tv64 > now.tv64) | |
370 | return overrun; | |
371 | /* | |
372 | * This (and the ktime_add() below) is the | |
373 | * correction for exact: | |
374 | */ | |
375 | overrun++; | |
376 | } | |
377 | ||
378 | alarm->node.expires = ktime_add(alarm->node.expires, interval); | |
379 | return overrun; | |
380 | } | |
381 | ||
382 | ||
383 | ||
384 | ||
180bf812 | 385 | /** |
9a7adcf5 JS |
386 | * clock2alarm - helper that converts from clockid to alarmtypes |
387 | * @clockid: clockid. | |
9a7adcf5 JS |
388 | */ |
389 | static enum alarmtimer_type clock2alarm(clockid_t clockid) | |
390 | { | |
391 | if (clockid == CLOCK_REALTIME_ALARM) | |
392 | return ALARM_REALTIME; | |
393 | if (clockid == CLOCK_BOOTTIME_ALARM) | |
394 | return ALARM_BOOTTIME; | |
395 | return -1; | |
396 | } | |
397 | ||
180bf812 | 398 | /** |
9a7adcf5 JS |
399 | * alarm_handle_timer - Callback for posix timers |
400 | * @alarm: alarm that fired | |
401 | * | |
402 | * Posix timer callback for expired alarm timers. | |
403 | */ | |
4b41308d JS |
404 | static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
405 | ktime_t now) | |
9a7adcf5 JS |
406 | { |
407 | struct k_itimer *ptr = container_of(alarm, struct k_itimer, | |
408 | it.alarmtimer); | |
409 | if (posix_timer_event(ptr, 0) != 0) | |
410 | ptr->it_overrun++; | |
4b41308d | 411 | |
54da23b7 JS |
412 | /* Re-add periodic timers */ |
413 | if (alarm->period.tv64) { | |
dce75a8c | 414 | ptr->it_overrun += alarm_forward(alarm, now, alarm->period); |
54da23b7 JS |
415 | return ALARMTIMER_RESTART; |
416 | } | |
4b41308d | 417 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
418 | } |
419 | ||
180bf812 | 420 | /** |
9a7adcf5 JS |
421 | * alarm_clock_getres - posix getres interface |
422 | * @which_clock: clockid | |
423 | * @tp: timespec to fill | |
424 | * | |
425 | * Returns the granularity of underlying alarm base clock | |
426 | */ | |
427 | static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
428 | { | |
429 | clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; | |
430 | ||
1c6b39ad JS |
431 | if (!alarmtimer_get_rtcdev()) |
432 | return -ENOTSUPP; | |
433 | ||
9a7adcf5 JS |
434 | return hrtimer_get_res(baseid, tp); |
435 | } | |
436 | ||
437 | /** | |
438 | * alarm_clock_get - posix clock_get interface | |
439 | * @which_clock: clockid | |
440 | * @tp: timespec to fill. | |
441 | * | |
442 | * Provides the underlying alarm base time. | |
443 | */ | |
444 | static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) | |
445 | { | |
446 | struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; | |
447 | ||
1c6b39ad JS |
448 | if (!alarmtimer_get_rtcdev()) |
449 | return -ENOTSUPP; | |
450 | ||
9a7adcf5 JS |
451 | *tp = ktime_to_timespec(base->gettime()); |
452 | return 0; | |
453 | } | |
454 | ||
455 | /** | |
456 | * alarm_timer_create - posix timer_create interface | |
457 | * @new_timer: k_itimer pointer to manage | |
458 | * | |
459 | * Initializes the k_itimer structure. | |
460 | */ | |
461 | static int alarm_timer_create(struct k_itimer *new_timer) | |
462 | { | |
463 | enum alarmtimer_type type; | |
464 | struct alarm_base *base; | |
465 | ||
1c6b39ad JS |
466 | if (!alarmtimer_get_rtcdev()) |
467 | return -ENOTSUPP; | |
468 | ||
9a7adcf5 JS |
469 | if (!capable(CAP_WAKE_ALARM)) |
470 | return -EPERM; | |
471 | ||
472 | type = clock2alarm(new_timer->it_clock); | |
473 | base = &alarm_bases[type]; | |
474 | alarm_init(&new_timer->it.alarmtimer, type, alarm_handle_timer); | |
475 | return 0; | |
476 | } | |
477 | ||
478 | /** | |
479 | * alarm_timer_get - posix timer_get interface | |
480 | * @new_timer: k_itimer pointer | |
481 | * @cur_setting: itimerspec data to fill | |
482 | * | |
483 | * Copies the itimerspec data out from the k_itimer | |
484 | */ | |
485 | static void alarm_timer_get(struct k_itimer *timr, | |
486 | struct itimerspec *cur_setting) | |
487 | { | |
ea7802f6 JS |
488 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
489 | ||
9a7adcf5 JS |
490 | cur_setting->it_interval = |
491 | ktime_to_timespec(timr->it.alarmtimer.period); | |
492 | cur_setting->it_value = | |
493 | ktime_to_timespec(timr->it.alarmtimer.node.expires); | |
494 | return; | |
495 | } | |
496 | ||
497 | /** | |
498 | * alarm_timer_del - posix timer_del interface | |
499 | * @timr: k_itimer pointer to be deleted | |
500 | * | |
501 | * Cancels any programmed alarms for the given timer. | |
502 | */ | |
503 | static int alarm_timer_del(struct k_itimer *timr) | |
504 | { | |
1c6b39ad JS |
505 | if (!rtcdev) |
506 | return -ENOTSUPP; | |
507 | ||
9a7adcf5 JS |
508 | alarm_cancel(&timr->it.alarmtimer); |
509 | return 0; | |
510 | } | |
511 | ||
512 | /** | |
513 | * alarm_timer_set - posix timer_set interface | |
514 | * @timr: k_itimer pointer to be deleted | |
515 | * @flags: timer flags | |
516 | * @new_setting: itimerspec to be used | |
517 | * @old_setting: itimerspec being replaced | |
518 | * | |
519 | * Sets the timer to new_setting, and starts the timer. | |
520 | */ | |
521 | static int alarm_timer_set(struct k_itimer *timr, int flags, | |
522 | struct itimerspec *new_setting, | |
523 | struct itimerspec *old_setting) | |
524 | { | |
1c6b39ad JS |
525 | if (!rtcdev) |
526 | return -ENOTSUPP; | |
527 | ||
971c90bf JS |
528 | if (old_setting) |
529 | alarm_timer_get(timr, old_setting); | |
9a7adcf5 JS |
530 | |
531 | /* If the timer was already set, cancel it */ | |
532 | alarm_cancel(&timr->it.alarmtimer); | |
533 | ||
534 | /* start the timer */ | |
535 | alarm_start(&timr->it.alarmtimer, | |
536 | timespec_to_ktime(new_setting->it_value), | |
537 | timespec_to_ktime(new_setting->it_interval)); | |
538 | return 0; | |
539 | } | |
540 | ||
541 | /** | |
542 | * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep | |
543 | * @alarm: ptr to alarm that fired | |
544 | * | |
545 | * Wakes up the task that set the alarmtimer | |
546 | */ | |
4b41308d JS |
547 | static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
548 | ktime_t now) | |
9a7adcf5 JS |
549 | { |
550 | struct task_struct *task = (struct task_struct *)alarm->data; | |
551 | ||
552 | alarm->data = NULL; | |
553 | if (task) | |
554 | wake_up_process(task); | |
4b41308d | 555 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
556 | } |
557 | ||
558 | /** | |
559 | * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation | |
560 | * @alarm: ptr to alarmtimer | |
561 | * @absexp: absolute expiration time | |
562 | * | |
563 | * Sets the alarm timer and sleeps until it is fired or interrupted. | |
564 | */ | |
565 | static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) | |
566 | { | |
567 | alarm->data = (void *)current; | |
568 | do { | |
569 | set_current_state(TASK_INTERRUPTIBLE); | |
570 | alarm_start(alarm, absexp, ktime_set(0, 0)); | |
571 | if (likely(alarm->data)) | |
572 | schedule(); | |
573 | ||
574 | alarm_cancel(alarm); | |
575 | } while (alarm->data && !signal_pending(current)); | |
576 | ||
577 | __set_current_state(TASK_RUNNING); | |
578 | ||
579 | return (alarm->data == NULL); | |
580 | } | |
581 | ||
582 | ||
583 | /** | |
584 | * update_rmtp - Update remaining timespec value | |
585 | * @exp: expiration time | |
586 | * @type: timer type | |
587 | * @rmtp: user pointer to remaining timepsec value | |
588 | * | |
589 | * Helper function that fills in rmtp value with time between | |
590 | * now and the exp value | |
591 | */ | |
592 | static int update_rmtp(ktime_t exp, enum alarmtimer_type type, | |
593 | struct timespec __user *rmtp) | |
594 | { | |
595 | struct timespec rmt; | |
596 | ktime_t rem; | |
597 | ||
598 | rem = ktime_sub(exp, alarm_bases[type].gettime()); | |
599 | ||
600 | if (rem.tv64 <= 0) | |
601 | return 0; | |
602 | rmt = ktime_to_timespec(rem); | |
603 | ||
604 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
605 | return -EFAULT; | |
606 | ||
607 | return 1; | |
608 | ||
609 | } | |
610 | ||
611 | /** | |
612 | * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep | |
613 | * @restart: ptr to restart block | |
614 | * | |
615 | * Handles restarted clock_nanosleep calls | |
616 | */ | |
617 | static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) | |
618 | { | |
ab8177bc | 619 | enum alarmtimer_type type = restart->nanosleep.clockid; |
9a7adcf5 JS |
620 | ktime_t exp; |
621 | struct timespec __user *rmtp; | |
622 | struct alarm alarm; | |
623 | int ret = 0; | |
624 | ||
625 | exp.tv64 = restart->nanosleep.expires; | |
626 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
627 | ||
628 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
629 | goto out; | |
630 | ||
631 | if (freezing(current)) | |
632 | alarmtimer_freezerset(exp, type); | |
633 | ||
634 | rmtp = restart->nanosleep.rmtp; | |
635 | if (rmtp) { | |
636 | ret = update_rmtp(exp, type, rmtp); | |
637 | if (ret <= 0) | |
638 | goto out; | |
639 | } | |
640 | ||
641 | ||
642 | /* The other values in restart are already filled in */ | |
643 | ret = -ERESTART_RESTARTBLOCK; | |
644 | out: | |
645 | return ret; | |
646 | } | |
647 | ||
648 | /** | |
649 | * alarm_timer_nsleep - alarmtimer nanosleep | |
650 | * @which_clock: clockid | |
651 | * @flags: determins abstime or relative | |
652 | * @tsreq: requested sleep time (abs or rel) | |
653 | * @rmtp: remaining sleep time saved | |
654 | * | |
655 | * Handles clock_nanosleep calls against _ALARM clockids | |
656 | */ | |
657 | static int alarm_timer_nsleep(const clockid_t which_clock, int flags, | |
658 | struct timespec *tsreq, struct timespec __user *rmtp) | |
659 | { | |
660 | enum alarmtimer_type type = clock2alarm(which_clock); | |
661 | struct alarm alarm; | |
662 | ktime_t exp; | |
663 | int ret = 0; | |
664 | struct restart_block *restart; | |
665 | ||
1c6b39ad JS |
666 | if (!alarmtimer_get_rtcdev()) |
667 | return -ENOTSUPP; | |
668 | ||
9a7adcf5 JS |
669 | if (!capable(CAP_WAKE_ALARM)) |
670 | return -EPERM; | |
671 | ||
672 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
673 | ||
674 | exp = timespec_to_ktime(*tsreq); | |
675 | /* Convert (if necessary) to absolute time */ | |
676 | if (flags != TIMER_ABSTIME) { | |
677 | ktime_t now = alarm_bases[type].gettime(); | |
678 | exp = ktime_add(now, exp); | |
679 | } | |
680 | ||
681 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
682 | goto out; | |
683 | ||
684 | if (freezing(current)) | |
685 | alarmtimer_freezerset(exp, type); | |
686 | ||
687 | /* abs timers don't set remaining time or restart */ | |
688 | if (flags == TIMER_ABSTIME) { | |
689 | ret = -ERESTARTNOHAND; | |
690 | goto out; | |
691 | } | |
692 | ||
693 | if (rmtp) { | |
694 | ret = update_rmtp(exp, type, rmtp); | |
695 | if (ret <= 0) | |
696 | goto out; | |
697 | } | |
698 | ||
699 | restart = ¤t_thread_info()->restart_block; | |
700 | restart->fn = alarm_timer_nsleep_restart; | |
ab8177bc | 701 | restart->nanosleep.clockid = type; |
9a7adcf5 JS |
702 | restart->nanosleep.expires = exp.tv64; |
703 | restart->nanosleep.rmtp = rmtp; | |
704 | ret = -ERESTART_RESTARTBLOCK; | |
705 | ||
706 | out: | |
707 | return ret; | |
708 | } | |
ff3ead96 | 709 | |
ff3ead96 JS |
710 | |
711 | /* Suspend hook structures */ | |
712 | static const struct dev_pm_ops alarmtimer_pm_ops = { | |
713 | .suspend = alarmtimer_suspend, | |
714 | }; | |
715 | ||
716 | static struct platform_driver alarmtimer_driver = { | |
717 | .driver = { | |
718 | .name = "alarmtimer", | |
719 | .pm = &alarmtimer_pm_ops, | |
720 | } | |
721 | }; | |
722 | ||
723 | /** | |
724 | * alarmtimer_init - Initialize alarm timer code | |
725 | * | |
726 | * This function initializes the alarm bases and registers | |
727 | * the posix clock ids. | |
728 | */ | |
729 | static int __init alarmtimer_init(void) | |
730 | { | |
731 | int error = 0; | |
732 | int i; | |
9a7adcf5 JS |
733 | struct k_clock alarm_clock = { |
734 | .clock_getres = alarm_clock_getres, | |
735 | .clock_get = alarm_clock_get, | |
736 | .timer_create = alarm_timer_create, | |
737 | .timer_set = alarm_timer_set, | |
738 | .timer_del = alarm_timer_del, | |
739 | .timer_get = alarm_timer_get, | |
740 | .nsleep = alarm_timer_nsleep, | |
741 | }; | |
742 | ||
743 | posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); | |
744 | posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); | |
ff3ead96 JS |
745 | |
746 | /* Initialize alarm bases */ | |
747 | alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; | |
748 | alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; | |
749 | alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; | |
750 | alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; | |
751 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
752 | timerqueue_init_head(&alarm_bases[i].timerqueue); | |
753 | spin_lock_init(&alarm_bases[i].lock); | |
754 | hrtimer_init(&alarm_bases[i].timer, | |
755 | alarm_bases[i].base_clockid, | |
756 | HRTIMER_MODE_ABS); | |
757 | alarm_bases[i].timer.function = alarmtimer_fired; | |
ff3ead96 JS |
758 | } |
759 | error = platform_driver_register(&alarmtimer_driver); | |
760 | platform_device_register_simple("alarmtimer", -1, NULL, 0); | |
761 | ||
762 | return error; | |
763 | } | |
764 | device_initcall(alarmtimer_init); | |
765 |