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Commit | Line | Data |
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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); | |
a28cde81 JS |
129 | alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
130 | ||
ff3ead96 JS |
131 | if (&alarm->node == timerqueue_getnext(&base->timerqueue)) { |
132 | hrtimer_try_to_cancel(&base->timer); | |
133 | hrtimer_start(&base->timer, alarm->node.expires, | |
134 | HRTIMER_MODE_ABS); | |
135 | } | |
136 | } | |
137 | ||
180bf812 | 138 | /** |
ff3ead96 JS |
139 | * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue |
140 | * @base: pointer to the base where the timer is running | |
141 | * @alarm: pointer to alarm being removed | |
142 | * | |
143 | * Removes alarm to a alarm_base timerqueue and if necessary sets | |
144 | * a new timer to run. | |
145 | * | |
146 | * Must hold base->lock when calling. | |
147 | */ | |
148 | static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm) | |
149 | { | |
150 | struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue); | |
151 | ||
a28cde81 JS |
152 | if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) |
153 | return; | |
154 | ||
ff3ead96 | 155 | timerqueue_del(&base->timerqueue, &alarm->node); |
a28cde81 JS |
156 | alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
157 | ||
ff3ead96 JS |
158 | if (next == &alarm->node) { |
159 | hrtimer_try_to_cancel(&base->timer); | |
160 | next = timerqueue_getnext(&base->timerqueue); | |
161 | if (!next) | |
162 | return; | |
163 | hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS); | |
164 | } | |
165 | } | |
166 | ||
7068b7a1 | 167 | |
180bf812 | 168 | /** |
7068b7a1 JS |
169 | * alarmtimer_fired - Handles alarm hrtimer being fired. |
170 | * @timer: pointer to hrtimer being run | |
ff3ead96 | 171 | * |
180bf812 JS |
172 | * When a alarm timer fires, this runs through the timerqueue to |
173 | * see which alarms expired, and runs those. If there are more alarm | |
174 | * timers queued for the future, we set the hrtimer to fire when | |
175 | * when the next future alarm timer expires. | |
ff3ead96 | 176 | */ |
7068b7a1 | 177 | static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
ff3ead96 | 178 | { |
7068b7a1 | 179 | struct alarm_base *base = container_of(timer, struct alarm_base, timer); |
ff3ead96 JS |
180 | struct timerqueue_node *next; |
181 | unsigned long flags; | |
182 | ktime_t now; | |
7068b7a1 | 183 | int ret = HRTIMER_NORESTART; |
54da23b7 | 184 | int restart = ALARMTIMER_NORESTART; |
ff3ead96 JS |
185 | |
186 | spin_lock_irqsave(&base->lock, flags); | |
187 | now = base->gettime(); | |
188 | while ((next = timerqueue_getnext(&base->timerqueue))) { | |
189 | struct alarm *alarm; | |
190 | ktime_t expired = next->expires; | |
191 | ||
192 | if (expired.tv64 >= now.tv64) | |
193 | break; | |
194 | ||
195 | alarm = container_of(next, struct alarm, node); | |
196 | ||
197 | timerqueue_del(&base->timerqueue, &alarm->node); | |
a28cde81 | 198 | alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
54da23b7 | 199 | |
a28cde81 | 200 | alarm->state |= ALARMTIMER_STATE_CALLBACK; |
ff3ead96 JS |
201 | spin_unlock_irqrestore(&base->lock, flags); |
202 | if (alarm->function) | |
54da23b7 | 203 | restart = alarm->function(alarm, now); |
ff3ead96 | 204 | spin_lock_irqsave(&base->lock, flags); |
a28cde81 | 205 | alarm->state &= ~ALARMTIMER_STATE_CALLBACK; |
54da23b7 JS |
206 | |
207 | if (restart != ALARMTIMER_NORESTART) { | |
208 | timerqueue_add(&base->timerqueue, &alarm->node); | |
a28cde81 | 209 | alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
54da23b7 | 210 | } |
ff3ead96 JS |
211 | } |
212 | ||
213 | if (next) { | |
7068b7a1 JS |
214 | hrtimer_set_expires(&base->timer, next->expires); |
215 | ret = HRTIMER_RESTART; | |
ff3ead96 JS |
216 | } |
217 | spin_unlock_irqrestore(&base->lock, flags); | |
ff3ead96 | 218 | |
7068b7a1 | 219 | return ret; |
ff3ead96 | 220 | |
ff3ead96 JS |
221 | } |
222 | ||
472647dc | 223 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 224 | /** |
ff3ead96 JS |
225 | * alarmtimer_suspend - Suspend time callback |
226 | * @dev: unused | |
227 | * @state: unused | |
228 | * | |
229 | * When we are going into suspend, we look through the bases | |
230 | * to see which is the soonest timer to expire. We then | |
231 | * set an rtc timer to fire that far into the future, which | |
232 | * will wake us from suspend. | |
233 | */ | |
234 | static int alarmtimer_suspend(struct device *dev) | |
235 | { | |
236 | struct rtc_time tm; | |
237 | ktime_t min, now; | |
238 | unsigned long flags; | |
c008ba58 | 239 | struct rtc_device *rtc; |
ff3ead96 JS |
240 | int i; |
241 | ||
242 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
243 | min = freezer_delta; | |
244 | freezer_delta = ktime_set(0, 0); | |
245 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
246 | ||
1c6b39ad | 247 | rtc = rtcdev; |
ff3ead96 | 248 | /* If we have no rtcdev, just return */ |
c008ba58 | 249 | if (!rtc) |
ff3ead96 JS |
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.tv64 || (delta.tv64 < min.tv64)) | |
265 | min = delta; | |
266 | } | |
267 | if (min.tv64 == 0) | |
268 | return 0; | |
269 | ||
270 | /* XXX - Should we enforce a minimum sleep time? */ | |
271 | WARN_ON(min.tv64 < NSEC_PER_SEC); | |
272 | ||
273 | /* Setup an rtc timer to fire that far in the future */ | |
c008ba58 JS |
274 | rtc_timer_cancel(rtc, &rtctimer); |
275 | rtc_read_time(rtc, &tm); | |
ff3ead96 JS |
276 | now = rtc_tm_to_ktime(tm); |
277 | now = ktime_add(now, min); | |
278 | ||
c008ba58 | 279 | rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0)); |
ff3ead96 JS |
280 | |
281 | return 0; | |
282 | } | |
472647dc JS |
283 | #else |
284 | static int alarmtimer_suspend(struct device *dev) | |
285 | { | |
286 | return 0; | |
287 | } | |
288 | #endif | |
ff3ead96 | 289 | |
9a7adcf5 JS |
290 | static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
291 | { | |
292 | ktime_t delta; | |
293 | unsigned long flags; | |
294 | struct alarm_base *base = &alarm_bases[type]; | |
295 | ||
296 | delta = ktime_sub(absexp, base->gettime()); | |
297 | ||
298 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
299 | if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64)) | |
300 | freezer_delta = delta; | |
301 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
302 | } | |
303 | ||
304 | ||
180bf812 | 305 | /** |
ff3ead96 JS |
306 | * alarm_init - Initialize an alarm structure |
307 | * @alarm: ptr to alarm to be initialized | |
308 | * @type: the type of the alarm | |
309 | * @function: callback that is run when the alarm fires | |
ff3ead96 JS |
310 | */ |
311 | void alarm_init(struct alarm *alarm, enum alarmtimer_type type, | |
4b41308d | 312 | enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
ff3ead96 JS |
313 | { |
314 | timerqueue_init(&alarm->node); | |
ff3ead96 JS |
315 | alarm->function = function; |
316 | alarm->type = type; | |
a28cde81 | 317 | alarm->state = ALARMTIMER_STATE_INACTIVE; |
ff3ead96 JS |
318 | } |
319 | ||
180bf812 | 320 | /** |
ff3ead96 JS |
321 | * alarm_start - Sets an alarm to fire |
322 | * @alarm: ptr to alarm to set | |
323 | * @start: time to run the alarm | |
ff3ead96 | 324 | */ |
9e264762 | 325 | void alarm_start(struct alarm *alarm, ktime_t start) |
ff3ead96 JS |
326 | { |
327 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
328 | unsigned long flags; | |
329 | ||
330 | spin_lock_irqsave(&base->lock, flags); | |
a28cde81 | 331 | if (alarmtimer_active(alarm)) |
ff3ead96 JS |
332 | alarmtimer_remove(base, alarm); |
333 | alarm->node.expires = start; | |
ff3ead96 | 334 | alarmtimer_enqueue(base, alarm); |
ff3ead96 JS |
335 | spin_unlock_irqrestore(&base->lock, flags); |
336 | } | |
337 | ||
180bf812 | 338 | /** |
9082c465 | 339 | * alarm_try_to_cancel - Tries to cancel an alarm timer |
ff3ead96 | 340 | * @alarm: ptr to alarm to be canceled |
9082c465 JS |
341 | * |
342 | * Returns 1 if the timer was canceled, 0 if it was not running, | |
343 | * and -1 if the callback was running | |
ff3ead96 | 344 | */ |
9082c465 | 345 | int alarm_try_to_cancel(struct alarm *alarm) |
ff3ead96 JS |
346 | { |
347 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
348 | unsigned long flags; | |
9082c465 | 349 | int ret = -1; |
ff3ead96 | 350 | spin_lock_irqsave(&base->lock, flags); |
9082c465 JS |
351 | |
352 | if (alarmtimer_callback_running(alarm)) | |
353 | goto out; | |
354 | ||
355 | if (alarmtimer_is_queued(alarm)) { | |
ff3ead96 | 356 | alarmtimer_remove(base, alarm); |
9082c465 JS |
357 | ret = 1; |
358 | } else | |
359 | ret = 0; | |
360 | out: | |
ff3ead96 | 361 | spin_unlock_irqrestore(&base->lock, flags); |
9082c465 | 362 | return ret; |
ff3ead96 JS |
363 | } |
364 | ||
365 | ||
9082c465 JS |
366 | /** |
367 | * alarm_cancel - Spins trying to cancel an alarm timer until it is done | |
368 | * @alarm: ptr to alarm to be canceled | |
369 | * | |
370 | * Returns 1 if the timer was canceled, 0 if it was not active. | |
371 | */ | |
372 | int alarm_cancel(struct alarm *alarm) | |
373 | { | |
374 | for (;;) { | |
375 | int ret = alarm_try_to_cancel(alarm); | |
376 | if (ret >= 0) | |
377 | return ret; | |
378 | cpu_relax(); | |
379 | } | |
380 | } | |
381 | ||
dce75a8c JS |
382 | |
383 | u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) | |
384 | { | |
385 | u64 overrun = 1; | |
386 | ktime_t delta; | |
387 | ||
388 | delta = ktime_sub(now, alarm->node.expires); | |
389 | ||
390 | if (delta.tv64 < 0) | |
391 | return 0; | |
392 | ||
393 | if (unlikely(delta.tv64 >= interval.tv64)) { | |
394 | s64 incr = ktime_to_ns(interval); | |
395 | ||
396 | overrun = ktime_divns(delta, incr); | |
397 | ||
398 | alarm->node.expires = ktime_add_ns(alarm->node.expires, | |
399 | incr*overrun); | |
400 | ||
401 | if (alarm->node.expires.tv64 > now.tv64) | |
402 | return overrun; | |
403 | /* | |
404 | * This (and the ktime_add() below) is the | |
405 | * correction for exact: | |
406 | */ | |
407 | overrun++; | |
408 | } | |
409 | ||
410 | alarm->node.expires = ktime_add(alarm->node.expires, interval); | |
411 | return overrun; | |
412 | } | |
413 | ||
414 | ||
415 | ||
416 | ||
180bf812 | 417 | /** |
9a7adcf5 JS |
418 | * clock2alarm - helper that converts from clockid to alarmtypes |
419 | * @clockid: clockid. | |
9a7adcf5 JS |
420 | */ |
421 | static enum alarmtimer_type clock2alarm(clockid_t clockid) | |
422 | { | |
423 | if (clockid == CLOCK_REALTIME_ALARM) | |
424 | return ALARM_REALTIME; | |
425 | if (clockid == CLOCK_BOOTTIME_ALARM) | |
426 | return ALARM_BOOTTIME; | |
427 | return -1; | |
428 | } | |
429 | ||
180bf812 | 430 | /** |
9a7adcf5 JS |
431 | * alarm_handle_timer - Callback for posix timers |
432 | * @alarm: alarm that fired | |
433 | * | |
434 | * Posix timer callback for expired alarm timers. | |
435 | */ | |
4b41308d JS |
436 | static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
437 | ktime_t now) | |
9a7adcf5 JS |
438 | { |
439 | struct k_itimer *ptr = container_of(alarm, struct k_itimer, | |
9e264762 | 440 | it.alarm.alarmtimer); |
9a7adcf5 JS |
441 | if (posix_timer_event(ptr, 0) != 0) |
442 | ptr->it_overrun++; | |
4b41308d | 443 | |
54da23b7 | 444 | /* Re-add periodic timers */ |
9e264762 JS |
445 | if (ptr->it.alarm.interval.tv64) { |
446 | ptr->it_overrun += alarm_forward(alarm, now, | |
447 | ptr->it.alarm.interval); | |
54da23b7 JS |
448 | return ALARMTIMER_RESTART; |
449 | } | |
4b41308d | 450 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
451 | } |
452 | ||
180bf812 | 453 | /** |
9a7adcf5 JS |
454 | * alarm_clock_getres - posix getres interface |
455 | * @which_clock: clockid | |
456 | * @tp: timespec to fill | |
457 | * | |
458 | * Returns the granularity of underlying alarm base clock | |
459 | */ | |
460 | static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
461 | { | |
462 | clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; | |
463 | ||
1c6b39ad JS |
464 | if (!alarmtimer_get_rtcdev()) |
465 | return -ENOTSUPP; | |
466 | ||
9a7adcf5 JS |
467 | return hrtimer_get_res(baseid, tp); |
468 | } | |
469 | ||
470 | /** | |
471 | * alarm_clock_get - posix clock_get interface | |
472 | * @which_clock: clockid | |
473 | * @tp: timespec to fill. | |
474 | * | |
475 | * Provides the underlying alarm base time. | |
476 | */ | |
477 | static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) | |
478 | { | |
479 | struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; | |
480 | ||
1c6b39ad JS |
481 | if (!alarmtimer_get_rtcdev()) |
482 | return -ENOTSUPP; | |
483 | ||
9a7adcf5 JS |
484 | *tp = ktime_to_timespec(base->gettime()); |
485 | return 0; | |
486 | } | |
487 | ||
488 | /** | |
489 | * alarm_timer_create - posix timer_create interface | |
490 | * @new_timer: k_itimer pointer to manage | |
491 | * | |
492 | * Initializes the k_itimer structure. | |
493 | */ | |
494 | static int alarm_timer_create(struct k_itimer *new_timer) | |
495 | { | |
496 | enum alarmtimer_type type; | |
497 | struct alarm_base *base; | |
498 | ||
1c6b39ad JS |
499 | if (!alarmtimer_get_rtcdev()) |
500 | return -ENOTSUPP; | |
501 | ||
9a7adcf5 JS |
502 | if (!capable(CAP_WAKE_ALARM)) |
503 | return -EPERM; | |
504 | ||
505 | type = clock2alarm(new_timer->it_clock); | |
506 | base = &alarm_bases[type]; | |
9e264762 | 507 | alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer); |
9a7adcf5 JS |
508 | return 0; |
509 | } | |
510 | ||
511 | /** | |
512 | * alarm_timer_get - posix timer_get interface | |
513 | * @new_timer: k_itimer pointer | |
514 | * @cur_setting: itimerspec data to fill | |
515 | * | |
516 | * Copies the itimerspec data out from the k_itimer | |
517 | */ | |
518 | static void alarm_timer_get(struct k_itimer *timr, | |
519 | struct itimerspec *cur_setting) | |
520 | { | |
ea7802f6 JS |
521 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
522 | ||
9a7adcf5 | 523 | cur_setting->it_interval = |
9e264762 | 524 | ktime_to_timespec(timr->it.alarm.interval); |
9a7adcf5 | 525 | cur_setting->it_value = |
9e264762 | 526 | ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires); |
9a7adcf5 JS |
527 | return; |
528 | } | |
529 | ||
530 | /** | |
531 | * alarm_timer_del - posix timer_del interface | |
532 | * @timr: k_itimer pointer to be deleted | |
533 | * | |
534 | * Cancels any programmed alarms for the given timer. | |
535 | */ | |
536 | static int alarm_timer_del(struct k_itimer *timr) | |
537 | { | |
1c6b39ad JS |
538 | if (!rtcdev) |
539 | return -ENOTSUPP; | |
540 | ||
9082c465 JS |
541 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
542 | return TIMER_RETRY; | |
543 | ||
9a7adcf5 JS |
544 | return 0; |
545 | } | |
546 | ||
547 | /** | |
548 | * alarm_timer_set - posix timer_set interface | |
549 | * @timr: k_itimer pointer to be deleted | |
550 | * @flags: timer flags | |
551 | * @new_setting: itimerspec to be used | |
552 | * @old_setting: itimerspec being replaced | |
553 | * | |
554 | * Sets the timer to new_setting, and starts the timer. | |
555 | */ | |
556 | static int alarm_timer_set(struct k_itimer *timr, int flags, | |
557 | struct itimerspec *new_setting, | |
558 | struct itimerspec *old_setting) | |
559 | { | |
1c6b39ad JS |
560 | if (!rtcdev) |
561 | return -ENOTSUPP; | |
562 | ||
971c90bf JS |
563 | if (old_setting) |
564 | alarm_timer_get(timr, old_setting); | |
9a7adcf5 JS |
565 | |
566 | /* If the timer was already set, cancel it */ | |
9082c465 JS |
567 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
568 | return TIMER_RETRY; | |
9a7adcf5 JS |
569 | |
570 | /* start the timer */ | |
9e264762 JS |
571 | timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval); |
572 | alarm_start(&timr->it.alarm.alarmtimer, | |
573 | timespec_to_ktime(new_setting->it_value)); | |
9a7adcf5 JS |
574 | return 0; |
575 | } | |
576 | ||
577 | /** | |
578 | * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep | |
579 | * @alarm: ptr to alarm that fired | |
580 | * | |
581 | * Wakes up the task that set the alarmtimer | |
582 | */ | |
4b41308d JS |
583 | static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
584 | ktime_t now) | |
9a7adcf5 JS |
585 | { |
586 | struct task_struct *task = (struct task_struct *)alarm->data; | |
587 | ||
588 | alarm->data = NULL; | |
589 | if (task) | |
590 | wake_up_process(task); | |
4b41308d | 591 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
592 | } |
593 | ||
594 | /** | |
595 | * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation | |
596 | * @alarm: ptr to alarmtimer | |
597 | * @absexp: absolute expiration time | |
598 | * | |
599 | * Sets the alarm timer and sleeps until it is fired or interrupted. | |
600 | */ | |
601 | static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) | |
602 | { | |
603 | alarm->data = (void *)current; | |
604 | do { | |
605 | set_current_state(TASK_INTERRUPTIBLE); | |
9e264762 | 606 | alarm_start(alarm, absexp); |
9a7adcf5 JS |
607 | if (likely(alarm->data)) |
608 | schedule(); | |
609 | ||
610 | alarm_cancel(alarm); | |
611 | } while (alarm->data && !signal_pending(current)); | |
612 | ||
613 | __set_current_state(TASK_RUNNING); | |
614 | ||
615 | return (alarm->data == NULL); | |
616 | } | |
617 | ||
618 | ||
619 | /** | |
620 | * update_rmtp - Update remaining timespec value | |
621 | * @exp: expiration time | |
622 | * @type: timer type | |
623 | * @rmtp: user pointer to remaining timepsec value | |
624 | * | |
625 | * Helper function that fills in rmtp value with time between | |
626 | * now and the exp value | |
627 | */ | |
628 | static int update_rmtp(ktime_t exp, enum alarmtimer_type type, | |
629 | struct timespec __user *rmtp) | |
630 | { | |
631 | struct timespec rmt; | |
632 | ktime_t rem; | |
633 | ||
634 | rem = ktime_sub(exp, alarm_bases[type].gettime()); | |
635 | ||
636 | if (rem.tv64 <= 0) | |
637 | return 0; | |
638 | rmt = ktime_to_timespec(rem); | |
639 | ||
640 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
641 | return -EFAULT; | |
642 | ||
643 | return 1; | |
644 | ||
645 | } | |
646 | ||
647 | /** | |
648 | * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep | |
649 | * @restart: ptr to restart block | |
650 | * | |
651 | * Handles restarted clock_nanosleep calls | |
652 | */ | |
653 | static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) | |
654 | { | |
ab8177bc | 655 | enum alarmtimer_type type = restart->nanosleep.clockid; |
9a7adcf5 JS |
656 | ktime_t exp; |
657 | struct timespec __user *rmtp; | |
658 | struct alarm alarm; | |
659 | int ret = 0; | |
660 | ||
661 | exp.tv64 = restart->nanosleep.expires; | |
662 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
663 | ||
664 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
665 | goto out; | |
666 | ||
667 | if (freezing(current)) | |
668 | alarmtimer_freezerset(exp, type); | |
669 | ||
670 | rmtp = restart->nanosleep.rmtp; | |
671 | if (rmtp) { | |
672 | ret = update_rmtp(exp, type, rmtp); | |
673 | if (ret <= 0) | |
674 | goto out; | |
675 | } | |
676 | ||
677 | ||
678 | /* The other values in restart are already filled in */ | |
679 | ret = -ERESTART_RESTARTBLOCK; | |
680 | out: | |
681 | return ret; | |
682 | } | |
683 | ||
684 | /** | |
685 | * alarm_timer_nsleep - alarmtimer nanosleep | |
686 | * @which_clock: clockid | |
687 | * @flags: determins abstime or relative | |
688 | * @tsreq: requested sleep time (abs or rel) | |
689 | * @rmtp: remaining sleep time saved | |
690 | * | |
691 | * Handles clock_nanosleep calls against _ALARM clockids | |
692 | */ | |
693 | static int alarm_timer_nsleep(const clockid_t which_clock, int flags, | |
694 | struct timespec *tsreq, struct timespec __user *rmtp) | |
695 | { | |
696 | enum alarmtimer_type type = clock2alarm(which_clock); | |
697 | struct alarm alarm; | |
698 | ktime_t exp; | |
699 | int ret = 0; | |
700 | struct restart_block *restart; | |
701 | ||
1c6b39ad JS |
702 | if (!alarmtimer_get_rtcdev()) |
703 | return -ENOTSUPP; | |
704 | ||
9a7adcf5 JS |
705 | if (!capable(CAP_WAKE_ALARM)) |
706 | return -EPERM; | |
707 | ||
708 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
709 | ||
710 | exp = timespec_to_ktime(*tsreq); | |
711 | /* Convert (if necessary) to absolute time */ | |
712 | if (flags != TIMER_ABSTIME) { | |
713 | ktime_t now = alarm_bases[type].gettime(); | |
714 | exp = ktime_add(now, exp); | |
715 | } | |
716 | ||
717 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
718 | goto out; | |
719 | ||
720 | if (freezing(current)) | |
721 | alarmtimer_freezerset(exp, type); | |
722 | ||
723 | /* abs timers don't set remaining time or restart */ | |
724 | if (flags == TIMER_ABSTIME) { | |
725 | ret = -ERESTARTNOHAND; | |
726 | goto out; | |
727 | } | |
728 | ||
729 | if (rmtp) { | |
730 | ret = update_rmtp(exp, type, rmtp); | |
731 | if (ret <= 0) | |
732 | goto out; | |
733 | } | |
734 | ||
735 | restart = ¤t_thread_info()->restart_block; | |
736 | restart->fn = alarm_timer_nsleep_restart; | |
ab8177bc | 737 | restart->nanosleep.clockid = type; |
9a7adcf5 JS |
738 | restart->nanosleep.expires = exp.tv64; |
739 | restart->nanosleep.rmtp = rmtp; | |
740 | ret = -ERESTART_RESTARTBLOCK; | |
741 | ||
742 | out: | |
743 | return ret; | |
744 | } | |
ff3ead96 | 745 | |
ff3ead96 JS |
746 | |
747 | /* Suspend hook structures */ | |
748 | static const struct dev_pm_ops alarmtimer_pm_ops = { | |
749 | .suspend = alarmtimer_suspend, | |
750 | }; | |
751 | ||
752 | static struct platform_driver alarmtimer_driver = { | |
753 | .driver = { | |
754 | .name = "alarmtimer", | |
755 | .pm = &alarmtimer_pm_ops, | |
756 | } | |
757 | }; | |
758 | ||
759 | /** | |
760 | * alarmtimer_init - Initialize alarm timer code | |
761 | * | |
762 | * This function initializes the alarm bases and registers | |
763 | * the posix clock ids. | |
764 | */ | |
765 | static int __init alarmtimer_init(void) | |
766 | { | |
767 | int error = 0; | |
768 | int i; | |
9a7adcf5 JS |
769 | struct k_clock alarm_clock = { |
770 | .clock_getres = alarm_clock_getres, | |
771 | .clock_get = alarm_clock_get, | |
772 | .timer_create = alarm_timer_create, | |
773 | .timer_set = alarm_timer_set, | |
774 | .timer_del = alarm_timer_del, | |
775 | .timer_get = alarm_timer_get, | |
776 | .nsleep = alarm_timer_nsleep, | |
777 | }; | |
778 | ||
779 | posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); | |
780 | posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); | |
ff3ead96 JS |
781 | |
782 | /* Initialize alarm bases */ | |
783 | alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; | |
784 | alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; | |
785 | alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; | |
786 | alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; | |
787 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
788 | timerqueue_init_head(&alarm_bases[i].timerqueue); | |
789 | spin_lock_init(&alarm_bases[i].lock); | |
790 | hrtimer_init(&alarm_bases[i].timer, | |
791 | alarm_bases[i].base_clockid, | |
792 | HRTIMER_MODE_ABS); | |
793 | alarm_bases[i].timer.function = alarmtimer_fired; | |
ff3ead96 JS |
794 | } |
795 | error = platform_driver_register(&alarmtimer_driver); | |
796 | platform_device_register_simple("alarmtimer", -1, NULL, 0); | |
797 | ||
798 | return error; | |
799 | } | |
800 | device_initcall(alarmtimer_init); | |
801 |