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 */ |
c5e14e76 | 51 | static struct rtc_timer rtctimer; |
ff3ead96 | 52 | static struct rtc_device *rtcdev; |
c008ba58 | 53 | static DEFINE_SPINLOCK(rtcdev_lock); |
ff3ead96 | 54 | |
c008ba58 JS |
55 | /** |
56 | * alarmtimer_get_rtcdev - Return selected rtcdevice | |
57 | * | |
58 | * This function returns the rtc device to use for wakealarms. | |
59 | * If one has not already been chosen, it checks to see if a | |
60 | * functional rtc device is available. | |
61 | */ | |
57c498fa | 62 | struct rtc_device *alarmtimer_get_rtcdev(void) |
c008ba58 | 63 | { |
c008ba58 JS |
64 | unsigned long flags; |
65 | struct rtc_device *ret; | |
66 | ||
67 | spin_lock_irqsave(&rtcdev_lock, flags); | |
c008ba58 JS |
68 | ret = rtcdev; |
69 | spin_unlock_irqrestore(&rtcdev_lock, flags); | |
70 | ||
71 | return ret; | |
72 | } | |
8bc0dafb JS |
73 | |
74 | ||
75 | static int alarmtimer_rtc_add_device(struct device *dev, | |
76 | struct class_interface *class_intf) | |
77 | { | |
78 | unsigned long flags; | |
79 | struct rtc_device *rtc = to_rtc_device(dev); | |
80 | ||
81 | if (rtcdev) | |
82 | return -EBUSY; | |
83 | ||
84 | if (!rtc->ops->set_alarm) | |
85 | return -1; | |
86 | if (!device_may_wakeup(rtc->dev.parent)) | |
87 | return -1; | |
88 | ||
89 | spin_lock_irqsave(&rtcdev_lock, flags); | |
90 | if (!rtcdev) { | |
91 | rtcdev = rtc; | |
92 | /* hold a reference so it doesn't go away */ | |
93 | get_device(dev); | |
94 | } | |
95 | spin_unlock_irqrestore(&rtcdev_lock, flags); | |
96 | return 0; | |
97 | } | |
98 | ||
c5e14e76 TG |
99 | static inline void alarmtimer_rtc_timer_init(void) |
100 | { | |
101 | rtc_timer_init(&rtctimer, NULL, NULL); | |
102 | } | |
103 | ||
8bc0dafb JS |
104 | static struct class_interface alarmtimer_rtc_interface = { |
105 | .add_dev = &alarmtimer_rtc_add_device, | |
106 | }; | |
107 | ||
4523f6ad | 108 | static int alarmtimer_rtc_interface_setup(void) |
8bc0dafb JS |
109 | { |
110 | alarmtimer_rtc_interface.class = rtc_class; | |
4523f6ad TG |
111 | return class_interface_register(&alarmtimer_rtc_interface); |
112 | } | |
113 | static void alarmtimer_rtc_interface_remove(void) | |
114 | { | |
115 | class_interface_unregister(&alarmtimer_rtc_interface); | |
8bc0dafb | 116 | } |
1c6b39ad | 117 | #else |
57c498fa | 118 | struct rtc_device *alarmtimer_get_rtcdev(void) |
4523f6ad TG |
119 | { |
120 | return NULL; | |
121 | } | |
122 | #define rtcdev (NULL) | |
123 | static inline int alarmtimer_rtc_interface_setup(void) { return 0; } | |
124 | static inline void alarmtimer_rtc_interface_remove(void) { } | |
c5e14e76 | 125 | static inline void alarmtimer_rtc_timer_init(void) { } |
c008ba58 | 126 | #endif |
ff3ead96 | 127 | |
180bf812 | 128 | /** |
ff3ead96 JS |
129 | * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue |
130 | * @base: pointer to the base where the timer is being run | |
131 | * @alarm: pointer to alarm being enqueued. | |
132 | * | |
133 | * Adds alarm to a alarm_base timerqueue and if necessary sets | |
134 | * an hrtimer to run. | |
135 | * | |
136 | * Must hold base->lock when calling. | |
137 | */ | |
138 | static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) | |
139 | { | |
140 | timerqueue_add(&base->timerqueue, &alarm->node); | |
a28cde81 JS |
141 | alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
142 | ||
ff3ead96 JS |
143 | if (&alarm->node == timerqueue_getnext(&base->timerqueue)) { |
144 | hrtimer_try_to_cancel(&base->timer); | |
145 | hrtimer_start(&base->timer, alarm->node.expires, | |
146 | HRTIMER_MODE_ABS); | |
147 | } | |
148 | } | |
149 | ||
180bf812 | 150 | /** |
ff3ead96 JS |
151 | * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue |
152 | * @base: pointer to the base where the timer is running | |
153 | * @alarm: pointer to alarm being removed | |
154 | * | |
155 | * Removes alarm to a alarm_base timerqueue and if necessary sets | |
156 | * a new timer to run. | |
157 | * | |
158 | * Must hold base->lock when calling. | |
159 | */ | |
160 | static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm) | |
161 | { | |
162 | struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue); | |
163 | ||
a28cde81 JS |
164 | if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) |
165 | return; | |
166 | ||
ff3ead96 | 167 | timerqueue_del(&base->timerqueue, &alarm->node); |
a28cde81 JS |
168 | alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
169 | ||
ff3ead96 JS |
170 | if (next == &alarm->node) { |
171 | hrtimer_try_to_cancel(&base->timer); | |
172 | next = timerqueue_getnext(&base->timerqueue); | |
173 | if (!next) | |
174 | return; | |
175 | hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS); | |
176 | } | |
177 | } | |
178 | ||
7068b7a1 | 179 | |
180bf812 | 180 | /** |
7068b7a1 JS |
181 | * alarmtimer_fired - Handles alarm hrtimer being fired. |
182 | * @timer: pointer to hrtimer being run | |
ff3ead96 | 183 | * |
180bf812 JS |
184 | * When a alarm timer fires, this runs through the timerqueue to |
185 | * see which alarms expired, and runs those. If there are more alarm | |
186 | * timers queued for the future, we set the hrtimer to fire when | |
187 | * when the next future alarm timer expires. | |
ff3ead96 | 188 | */ |
7068b7a1 | 189 | static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
ff3ead96 | 190 | { |
7068b7a1 | 191 | struct alarm_base *base = container_of(timer, struct alarm_base, timer); |
ff3ead96 JS |
192 | struct timerqueue_node *next; |
193 | unsigned long flags; | |
194 | ktime_t now; | |
7068b7a1 | 195 | int ret = HRTIMER_NORESTART; |
54da23b7 | 196 | int restart = ALARMTIMER_NORESTART; |
ff3ead96 JS |
197 | |
198 | spin_lock_irqsave(&base->lock, flags); | |
199 | now = base->gettime(); | |
200 | while ((next = timerqueue_getnext(&base->timerqueue))) { | |
201 | struct alarm *alarm; | |
202 | ktime_t expired = next->expires; | |
203 | ||
c9c024b3 | 204 | if (expired.tv64 > now.tv64) |
ff3ead96 JS |
205 | break; |
206 | ||
207 | alarm = container_of(next, struct alarm, node); | |
208 | ||
209 | timerqueue_del(&base->timerqueue, &alarm->node); | |
a28cde81 | 210 | alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
54da23b7 | 211 | |
a28cde81 | 212 | alarm->state |= ALARMTIMER_STATE_CALLBACK; |
ff3ead96 JS |
213 | spin_unlock_irqrestore(&base->lock, flags); |
214 | if (alarm->function) | |
54da23b7 | 215 | restart = alarm->function(alarm, now); |
ff3ead96 | 216 | spin_lock_irqsave(&base->lock, flags); |
a28cde81 | 217 | alarm->state &= ~ALARMTIMER_STATE_CALLBACK; |
54da23b7 JS |
218 | |
219 | if (restart != ALARMTIMER_NORESTART) { | |
220 | timerqueue_add(&base->timerqueue, &alarm->node); | |
a28cde81 | 221 | alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
54da23b7 | 222 | } |
ff3ead96 JS |
223 | } |
224 | ||
225 | if (next) { | |
7068b7a1 JS |
226 | hrtimer_set_expires(&base->timer, next->expires); |
227 | ret = HRTIMER_RESTART; | |
ff3ead96 JS |
228 | } |
229 | spin_unlock_irqrestore(&base->lock, flags); | |
ff3ead96 | 230 | |
7068b7a1 | 231 | return ret; |
ff3ead96 | 232 | |
ff3ead96 JS |
233 | } |
234 | ||
472647dc | 235 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 236 | /** |
ff3ead96 JS |
237 | * alarmtimer_suspend - Suspend time callback |
238 | * @dev: unused | |
239 | * @state: unused | |
240 | * | |
241 | * When we are going into suspend, we look through the bases | |
242 | * to see which is the soonest timer to expire. We then | |
243 | * set an rtc timer to fire that far into the future, which | |
244 | * will wake us from suspend. | |
245 | */ | |
246 | static int alarmtimer_suspend(struct device *dev) | |
247 | { | |
248 | struct rtc_time tm; | |
249 | ktime_t min, now; | |
250 | unsigned long flags; | |
c008ba58 | 251 | struct rtc_device *rtc; |
ff3ead96 JS |
252 | int i; |
253 | ||
254 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
255 | min = freezer_delta; | |
256 | freezer_delta = ktime_set(0, 0); | |
257 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
258 | ||
8bc0dafb | 259 | rtc = alarmtimer_get_rtcdev(); |
ff3ead96 | 260 | /* If we have no rtcdev, just return */ |
c008ba58 | 261 | if (!rtc) |
ff3ead96 JS |
262 | return 0; |
263 | ||
264 | /* Find the soonest timer to expire*/ | |
265 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
266 | struct alarm_base *base = &alarm_bases[i]; | |
267 | struct timerqueue_node *next; | |
268 | ktime_t delta; | |
269 | ||
270 | spin_lock_irqsave(&base->lock, flags); | |
271 | next = timerqueue_getnext(&base->timerqueue); | |
272 | spin_unlock_irqrestore(&base->lock, flags); | |
273 | if (!next) | |
274 | continue; | |
275 | delta = ktime_sub(next->expires, base->gettime()); | |
276 | if (!min.tv64 || (delta.tv64 < min.tv64)) | |
277 | min = delta; | |
278 | } | |
279 | if (min.tv64 == 0) | |
280 | return 0; | |
281 | ||
282 | /* XXX - Should we enforce a minimum sleep time? */ | |
283 | WARN_ON(min.tv64 < NSEC_PER_SEC); | |
284 | ||
285 | /* Setup an rtc timer to fire that far in the future */ | |
c008ba58 JS |
286 | rtc_timer_cancel(rtc, &rtctimer); |
287 | rtc_read_time(rtc, &tm); | |
ff3ead96 JS |
288 | now = rtc_tm_to_ktime(tm); |
289 | now = ktime_add(now, min); | |
290 | ||
c008ba58 | 291 | rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0)); |
ff3ead96 JS |
292 | |
293 | return 0; | |
294 | } | |
472647dc JS |
295 | #else |
296 | static int alarmtimer_suspend(struct device *dev) | |
297 | { | |
298 | return 0; | |
299 | } | |
300 | #endif | |
ff3ead96 | 301 | |
9a7adcf5 JS |
302 | static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type) |
303 | { | |
304 | ktime_t delta; | |
305 | unsigned long flags; | |
306 | struct alarm_base *base = &alarm_bases[type]; | |
307 | ||
308 | delta = ktime_sub(absexp, base->gettime()); | |
309 | ||
310 | spin_lock_irqsave(&freezer_delta_lock, flags); | |
311 | if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64)) | |
312 | freezer_delta = delta; | |
313 | spin_unlock_irqrestore(&freezer_delta_lock, flags); | |
314 | } | |
315 | ||
316 | ||
180bf812 | 317 | /** |
ff3ead96 JS |
318 | * alarm_init - Initialize an alarm structure |
319 | * @alarm: ptr to alarm to be initialized | |
320 | * @type: the type of the alarm | |
321 | * @function: callback that is run when the alarm fires | |
ff3ead96 JS |
322 | */ |
323 | void alarm_init(struct alarm *alarm, enum alarmtimer_type type, | |
4b41308d | 324 | enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
ff3ead96 JS |
325 | { |
326 | timerqueue_init(&alarm->node); | |
ff3ead96 JS |
327 | alarm->function = function; |
328 | alarm->type = type; | |
a28cde81 | 329 | alarm->state = ALARMTIMER_STATE_INACTIVE; |
ff3ead96 JS |
330 | } |
331 | ||
180bf812 | 332 | /** |
ff3ead96 JS |
333 | * alarm_start - Sets an alarm to fire |
334 | * @alarm: ptr to alarm to set | |
335 | * @start: time to run the alarm | |
ff3ead96 | 336 | */ |
9e264762 | 337 | void alarm_start(struct alarm *alarm, ktime_t start) |
ff3ead96 JS |
338 | { |
339 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
340 | unsigned long flags; | |
341 | ||
342 | spin_lock_irqsave(&base->lock, flags); | |
a28cde81 | 343 | if (alarmtimer_active(alarm)) |
ff3ead96 JS |
344 | alarmtimer_remove(base, alarm); |
345 | alarm->node.expires = start; | |
ff3ead96 | 346 | alarmtimer_enqueue(base, alarm); |
ff3ead96 JS |
347 | spin_unlock_irqrestore(&base->lock, flags); |
348 | } | |
349 | ||
180bf812 | 350 | /** |
9082c465 | 351 | * alarm_try_to_cancel - Tries to cancel an alarm timer |
ff3ead96 | 352 | * @alarm: ptr to alarm to be canceled |
9082c465 JS |
353 | * |
354 | * Returns 1 if the timer was canceled, 0 if it was not running, | |
355 | * and -1 if the callback was running | |
ff3ead96 | 356 | */ |
9082c465 | 357 | int alarm_try_to_cancel(struct alarm *alarm) |
ff3ead96 JS |
358 | { |
359 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
360 | unsigned long flags; | |
9082c465 | 361 | int ret = -1; |
ff3ead96 | 362 | spin_lock_irqsave(&base->lock, flags); |
9082c465 JS |
363 | |
364 | if (alarmtimer_callback_running(alarm)) | |
365 | goto out; | |
366 | ||
367 | if (alarmtimer_is_queued(alarm)) { | |
ff3ead96 | 368 | alarmtimer_remove(base, alarm); |
9082c465 JS |
369 | ret = 1; |
370 | } else | |
371 | ret = 0; | |
372 | out: | |
ff3ead96 | 373 | spin_unlock_irqrestore(&base->lock, flags); |
9082c465 | 374 | return ret; |
ff3ead96 JS |
375 | } |
376 | ||
377 | ||
9082c465 JS |
378 | /** |
379 | * alarm_cancel - Spins trying to cancel an alarm timer until it is done | |
380 | * @alarm: ptr to alarm to be canceled | |
381 | * | |
382 | * Returns 1 if the timer was canceled, 0 if it was not active. | |
383 | */ | |
384 | int alarm_cancel(struct alarm *alarm) | |
385 | { | |
386 | for (;;) { | |
387 | int ret = alarm_try_to_cancel(alarm); | |
388 | if (ret >= 0) | |
389 | return ret; | |
390 | cpu_relax(); | |
391 | } | |
392 | } | |
393 | ||
dce75a8c JS |
394 | |
395 | u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) | |
396 | { | |
397 | u64 overrun = 1; | |
398 | ktime_t delta; | |
399 | ||
400 | delta = ktime_sub(now, alarm->node.expires); | |
401 | ||
402 | if (delta.tv64 < 0) | |
403 | return 0; | |
404 | ||
405 | if (unlikely(delta.tv64 >= interval.tv64)) { | |
406 | s64 incr = ktime_to_ns(interval); | |
407 | ||
408 | overrun = ktime_divns(delta, incr); | |
409 | ||
410 | alarm->node.expires = ktime_add_ns(alarm->node.expires, | |
411 | incr*overrun); | |
412 | ||
413 | if (alarm->node.expires.tv64 > now.tv64) | |
414 | return overrun; | |
415 | /* | |
416 | * This (and the ktime_add() below) is the | |
417 | * correction for exact: | |
418 | */ | |
419 | overrun++; | |
420 | } | |
421 | ||
422 | alarm->node.expires = ktime_add(alarm->node.expires, interval); | |
423 | return overrun; | |
424 | } | |
425 | ||
426 | ||
427 | ||
428 | ||
180bf812 | 429 | /** |
9a7adcf5 JS |
430 | * clock2alarm - helper that converts from clockid to alarmtypes |
431 | * @clockid: clockid. | |
9a7adcf5 JS |
432 | */ |
433 | static enum alarmtimer_type clock2alarm(clockid_t clockid) | |
434 | { | |
435 | if (clockid == CLOCK_REALTIME_ALARM) | |
436 | return ALARM_REALTIME; | |
437 | if (clockid == CLOCK_BOOTTIME_ALARM) | |
438 | return ALARM_BOOTTIME; | |
439 | return -1; | |
440 | } | |
441 | ||
180bf812 | 442 | /** |
9a7adcf5 JS |
443 | * alarm_handle_timer - Callback for posix timers |
444 | * @alarm: alarm that fired | |
445 | * | |
446 | * Posix timer callback for expired alarm timers. | |
447 | */ | |
4b41308d JS |
448 | static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
449 | ktime_t now) | |
9a7adcf5 JS |
450 | { |
451 | struct k_itimer *ptr = container_of(alarm, struct k_itimer, | |
9e264762 | 452 | it.alarm.alarmtimer); |
9a7adcf5 JS |
453 | if (posix_timer_event(ptr, 0) != 0) |
454 | ptr->it_overrun++; | |
4b41308d | 455 | |
54da23b7 | 456 | /* Re-add periodic timers */ |
9e264762 JS |
457 | if (ptr->it.alarm.interval.tv64) { |
458 | ptr->it_overrun += alarm_forward(alarm, now, | |
459 | ptr->it.alarm.interval); | |
54da23b7 JS |
460 | return ALARMTIMER_RESTART; |
461 | } | |
4b41308d | 462 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
463 | } |
464 | ||
180bf812 | 465 | /** |
9a7adcf5 JS |
466 | * alarm_clock_getres - posix getres interface |
467 | * @which_clock: clockid | |
468 | * @tp: timespec to fill | |
469 | * | |
470 | * Returns the granularity of underlying alarm base clock | |
471 | */ | |
472 | static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
473 | { | |
474 | clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; | |
475 | ||
1c6b39ad JS |
476 | if (!alarmtimer_get_rtcdev()) |
477 | return -ENOTSUPP; | |
478 | ||
9a7adcf5 JS |
479 | return hrtimer_get_res(baseid, tp); |
480 | } | |
481 | ||
482 | /** | |
483 | * alarm_clock_get - posix clock_get interface | |
484 | * @which_clock: clockid | |
485 | * @tp: timespec to fill. | |
486 | * | |
487 | * Provides the underlying alarm base time. | |
488 | */ | |
489 | static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) | |
490 | { | |
491 | struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; | |
492 | ||
1c6b39ad JS |
493 | if (!alarmtimer_get_rtcdev()) |
494 | return -ENOTSUPP; | |
495 | ||
9a7adcf5 JS |
496 | *tp = ktime_to_timespec(base->gettime()); |
497 | return 0; | |
498 | } | |
499 | ||
500 | /** | |
501 | * alarm_timer_create - posix timer_create interface | |
502 | * @new_timer: k_itimer pointer to manage | |
503 | * | |
504 | * Initializes the k_itimer structure. | |
505 | */ | |
506 | static int alarm_timer_create(struct k_itimer *new_timer) | |
507 | { | |
508 | enum alarmtimer_type type; | |
509 | struct alarm_base *base; | |
510 | ||
1c6b39ad JS |
511 | if (!alarmtimer_get_rtcdev()) |
512 | return -ENOTSUPP; | |
513 | ||
9a7adcf5 JS |
514 | if (!capable(CAP_WAKE_ALARM)) |
515 | return -EPERM; | |
516 | ||
517 | type = clock2alarm(new_timer->it_clock); | |
518 | base = &alarm_bases[type]; | |
9e264762 | 519 | alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer); |
9a7adcf5 JS |
520 | return 0; |
521 | } | |
522 | ||
523 | /** | |
524 | * alarm_timer_get - posix timer_get interface | |
525 | * @new_timer: k_itimer pointer | |
526 | * @cur_setting: itimerspec data to fill | |
527 | * | |
528 | * Copies the itimerspec data out from the k_itimer | |
529 | */ | |
530 | static void alarm_timer_get(struct k_itimer *timr, | |
531 | struct itimerspec *cur_setting) | |
532 | { | |
ea7802f6 JS |
533 | memset(cur_setting, 0, sizeof(struct itimerspec)); |
534 | ||
9a7adcf5 | 535 | cur_setting->it_interval = |
9e264762 | 536 | ktime_to_timespec(timr->it.alarm.interval); |
9a7adcf5 | 537 | cur_setting->it_value = |
9e264762 | 538 | ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires); |
9a7adcf5 JS |
539 | return; |
540 | } | |
541 | ||
542 | /** | |
543 | * alarm_timer_del - posix timer_del interface | |
544 | * @timr: k_itimer pointer to be deleted | |
545 | * | |
546 | * Cancels any programmed alarms for the given timer. | |
547 | */ | |
548 | static int alarm_timer_del(struct k_itimer *timr) | |
549 | { | |
1c6b39ad JS |
550 | if (!rtcdev) |
551 | return -ENOTSUPP; | |
552 | ||
9082c465 JS |
553 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
554 | return TIMER_RETRY; | |
555 | ||
9a7adcf5 JS |
556 | return 0; |
557 | } | |
558 | ||
559 | /** | |
560 | * alarm_timer_set - posix timer_set interface | |
561 | * @timr: k_itimer pointer to be deleted | |
562 | * @flags: timer flags | |
563 | * @new_setting: itimerspec to be used | |
564 | * @old_setting: itimerspec being replaced | |
565 | * | |
566 | * Sets the timer to new_setting, and starts the timer. | |
567 | */ | |
568 | static int alarm_timer_set(struct k_itimer *timr, int flags, | |
569 | struct itimerspec *new_setting, | |
570 | struct itimerspec *old_setting) | |
571 | { | |
1c6b39ad JS |
572 | if (!rtcdev) |
573 | return -ENOTSUPP; | |
574 | ||
971c90bf JS |
575 | if (old_setting) |
576 | alarm_timer_get(timr, old_setting); | |
9a7adcf5 JS |
577 | |
578 | /* If the timer was already set, cancel it */ | |
9082c465 JS |
579 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
580 | return TIMER_RETRY; | |
9a7adcf5 JS |
581 | |
582 | /* start the timer */ | |
9e264762 JS |
583 | timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval); |
584 | alarm_start(&timr->it.alarm.alarmtimer, | |
585 | timespec_to_ktime(new_setting->it_value)); | |
9a7adcf5 JS |
586 | return 0; |
587 | } | |
588 | ||
589 | /** | |
590 | * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep | |
591 | * @alarm: ptr to alarm that fired | |
592 | * | |
593 | * Wakes up the task that set the alarmtimer | |
594 | */ | |
4b41308d JS |
595 | static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
596 | ktime_t now) | |
9a7adcf5 JS |
597 | { |
598 | struct task_struct *task = (struct task_struct *)alarm->data; | |
599 | ||
600 | alarm->data = NULL; | |
601 | if (task) | |
602 | wake_up_process(task); | |
4b41308d | 603 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
604 | } |
605 | ||
606 | /** | |
607 | * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation | |
608 | * @alarm: ptr to alarmtimer | |
609 | * @absexp: absolute expiration time | |
610 | * | |
611 | * Sets the alarm timer and sleeps until it is fired or interrupted. | |
612 | */ | |
613 | static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) | |
614 | { | |
615 | alarm->data = (void *)current; | |
616 | do { | |
617 | set_current_state(TASK_INTERRUPTIBLE); | |
9e264762 | 618 | alarm_start(alarm, absexp); |
9a7adcf5 JS |
619 | if (likely(alarm->data)) |
620 | schedule(); | |
621 | ||
622 | alarm_cancel(alarm); | |
623 | } while (alarm->data && !signal_pending(current)); | |
624 | ||
625 | __set_current_state(TASK_RUNNING); | |
626 | ||
627 | return (alarm->data == NULL); | |
628 | } | |
629 | ||
630 | ||
631 | /** | |
632 | * update_rmtp - Update remaining timespec value | |
633 | * @exp: expiration time | |
634 | * @type: timer type | |
635 | * @rmtp: user pointer to remaining timepsec value | |
636 | * | |
637 | * Helper function that fills in rmtp value with time between | |
638 | * now and the exp value | |
639 | */ | |
640 | static int update_rmtp(ktime_t exp, enum alarmtimer_type type, | |
641 | struct timespec __user *rmtp) | |
642 | { | |
643 | struct timespec rmt; | |
644 | ktime_t rem; | |
645 | ||
646 | rem = ktime_sub(exp, alarm_bases[type].gettime()); | |
647 | ||
648 | if (rem.tv64 <= 0) | |
649 | return 0; | |
650 | rmt = ktime_to_timespec(rem); | |
651 | ||
652 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
653 | return -EFAULT; | |
654 | ||
655 | return 1; | |
656 | ||
657 | } | |
658 | ||
659 | /** | |
660 | * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep | |
661 | * @restart: ptr to restart block | |
662 | * | |
663 | * Handles restarted clock_nanosleep calls | |
664 | */ | |
665 | static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) | |
666 | { | |
ab8177bc | 667 | enum alarmtimer_type type = restart->nanosleep.clockid; |
9a7adcf5 JS |
668 | ktime_t exp; |
669 | struct timespec __user *rmtp; | |
670 | struct alarm alarm; | |
671 | int ret = 0; | |
672 | ||
673 | exp.tv64 = restart->nanosleep.expires; | |
674 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
675 | ||
676 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
677 | goto out; | |
678 | ||
679 | if (freezing(current)) | |
680 | alarmtimer_freezerset(exp, type); | |
681 | ||
682 | rmtp = restart->nanosleep.rmtp; | |
683 | if (rmtp) { | |
684 | ret = update_rmtp(exp, type, rmtp); | |
685 | if (ret <= 0) | |
686 | goto out; | |
687 | } | |
688 | ||
689 | ||
690 | /* The other values in restart are already filled in */ | |
691 | ret = -ERESTART_RESTARTBLOCK; | |
692 | out: | |
693 | return ret; | |
694 | } | |
695 | ||
696 | /** | |
697 | * alarm_timer_nsleep - alarmtimer nanosleep | |
698 | * @which_clock: clockid | |
699 | * @flags: determins abstime or relative | |
700 | * @tsreq: requested sleep time (abs or rel) | |
701 | * @rmtp: remaining sleep time saved | |
702 | * | |
703 | * Handles clock_nanosleep calls against _ALARM clockids | |
704 | */ | |
705 | static int alarm_timer_nsleep(const clockid_t which_clock, int flags, | |
706 | struct timespec *tsreq, struct timespec __user *rmtp) | |
707 | { | |
708 | enum alarmtimer_type type = clock2alarm(which_clock); | |
709 | struct alarm alarm; | |
710 | ktime_t exp; | |
711 | int ret = 0; | |
712 | struct restart_block *restart; | |
713 | ||
1c6b39ad JS |
714 | if (!alarmtimer_get_rtcdev()) |
715 | return -ENOTSUPP; | |
716 | ||
9a7adcf5 JS |
717 | if (!capable(CAP_WAKE_ALARM)) |
718 | return -EPERM; | |
719 | ||
720 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
721 | ||
722 | exp = timespec_to_ktime(*tsreq); | |
723 | /* Convert (if necessary) to absolute time */ | |
724 | if (flags != TIMER_ABSTIME) { | |
725 | ktime_t now = alarm_bases[type].gettime(); | |
726 | exp = ktime_add(now, exp); | |
727 | } | |
728 | ||
729 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
730 | goto out; | |
731 | ||
732 | if (freezing(current)) | |
733 | alarmtimer_freezerset(exp, type); | |
734 | ||
735 | /* abs timers don't set remaining time or restart */ | |
736 | if (flags == TIMER_ABSTIME) { | |
737 | ret = -ERESTARTNOHAND; | |
738 | goto out; | |
739 | } | |
740 | ||
741 | if (rmtp) { | |
742 | ret = update_rmtp(exp, type, rmtp); | |
743 | if (ret <= 0) | |
744 | goto out; | |
745 | } | |
746 | ||
747 | restart = ¤t_thread_info()->restart_block; | |
748 | restart->fn = alarm_timer_nsleep_restart; | |
ab8177bc | 749 | restart->nanosleep.clockid = type; |
9a7adcf5 JS |
750 | restart->nanosleep.expires = exp.tv64; |
751 | restart->nanosleep.rmtp = rmtp; | |
752 | ret = -ERESTART_RESTARTBLOCK; | |
753 | ||
754 | out: | |
755 | return ret; | |
756 | } | |
ff3ead96 | 757 | |
ff3ead96 JS |
758 | |
759 | /* Suspend hook structures */ | |
760 | static const struct dev_pm_ops alarmtimer_pm_ops = { | |
761 | .suspend = alarmtimer_suspend, | |
762 | }; | |
763 | ||
764 | static struct platform_driver alarmtimer_driver = { | |
765 | .driver = { | |
766 | .name = "alarmtimer", | |
767 | .pm = &alarmtimer_pm_ops, | |
768 | } | |
769 | }; | |
770 | ||
771 | /** | |
772 | * alarmtimer_init - Initialize alarm timer code | |
773 | * | |
774 | * This function initializes the alarm bases and registers | |
775 | * the posix clock ids. | |
776 | */ | |
777 | static int __init alarmtimer_init(void) | |
778 | { | |
4523f6ad | 779 | struct platform_device *pdev; |
ff3ead96 JS |
780 | int error = 0; |
781 | int i; | |
9a7adcf5 JS |
782 | struct k_clock alarm_clock = { |
783 | .clock_getres = alarm_clock_getres, | |
784 | .clock_get = alarm_clock_get, | |
785 | .timer_create = alarm_timer_create, | |
786 | .timer_set = alarm_timer_set, | |
787 | .timer_del = alarm_timer_del, | |
788 | .timer_get = alarm_timer_get, | |
789 | .nsleep = alarm_timer_nsleep, | |
790 | }; | |
791 | ||
c5e14e76 | 792 | alarmtimer_rtc_timer_init(); |
ad30dfa9 | 793 | |
9a7adcf5 JS |
794 | posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); |
795 | posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); | |
ff3ead96 JS |
796 | |
797 | /* Initialize alarm bases */ | |
798 | alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; | |
799 | alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; | |
800 | alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; | |
801 | alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; | |
802 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
803 | timerqueue_init_head(&alarm_bases[i].timerqueue); | |
804 | spin_lock_init(&alarm_bases[i].lock); | |
805 | hrtimer_init(&alarm_bases[i].timer, | |
806 | alarm_bases[i].base_clockid, | |
807 | HRTIMER_MODE_ABS); | |
808 | alarm_bases[i].timer.function = alarmtimer_fired; | |
ff3ead96 | 809 | } |
8bc0dafb | 810 | |
4523f6ad TG |
811 | error = alarmtimer_rtc_interface_setup(); |
812 | if (error) | |
813 | return error; | |
814 | ||
ff3ead96 | 815 | error = platform_driver_register(&alarmtimer_driver); |
4523f6ad TG |
816 | if (error) |
817 | goto out_if; | |
ff3ead96 | 818 | |
4523f6ad TG |
819 | pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0); |
820 | if (IS_ERR(pdev)) { | |
821 | error = PTR_ERR(pdev); | |
822 | goto out_drv; | |
823 | } | |
824 | return 0; | |
825 | ||
826 | out_drv: | |
827 | platform_driver_unregister(&alarmtimer_driver); | |
828 | out_if: | |
829 | alarmtimer_rtc_interface_remove(); | |
ff3ead96 JS |
830 | return error; |
831 | } | |
832 | device_initcall(alarmtimer_init); |