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 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 36 */ 37 static struct alarm_base { 38 spinlock_t lock; 39 struct timerqueue_head timerqueue; 40 ktime_t (*gettime)(void); 41 clockid_t base_clockid; 42 } alarm_bases[ALARM_NUMTYPE]; 43 44 /* freezer delta & lock used to handle clock_nanosleep triggered wakeups */ 45 static ktime_t freezer_delta; 46 static DEFINE_SPINLOCK(freezer_delta_lock); 47 48 static struct wakeup_source *ws; 49 50 #ifdef CONFIG_RTC_CLASS 51 /* rtc timer and device for setting alarm wakeups at suspend */ 52 static struct rtc_timer rtctimer; 53 static struct rtc_device *rtcdev; 54 static DEFINE_SPINLOCK(rtcdev_lock); 55 56 /** 57 * alarmtimer_get_rtcdev - Return selected rtcdevice 58 * 59 * This function returns the rtc device to use for wakealarms. 60 * If one has not already been chosen, it checks to see if a 61 * functional rtc device is available. 62 */ 63 struct rtc_device *alarmtimer_get_rtcdev(void) 64 { 65 unsigned long flags; 66 struct rtc_device *ret; 67 68 spin_lock_irqsave(&rtcdev_lock, flags); 69 ret = rtcdev; 70 spin_unlock_irqrestore(&rtcdev_lock, flags); 71 72 return ret; 73 } 74 EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); 75 76 static int alarmtimer_rtc_add_device(struct device *dev, 77 struct class_interface *class_intf) 78 { 79 unsigned long flags; 80 struct rtc_device *rtc = to_rtc_device(dev); 81 82 if (rtcdev) 83 return -EBUSY; 84 85 if (!rtc->ops->set_alarm) 86 return -1; 87 if (!device_may_wakeup(rtc->dev.parent)) 88 return -1; 89 90 spin_lock_irqsave(&rtcdev_lock, flags); 91 if (!rtcdev) { 92 rtcdev = rtc; 93 /* hold a reference so it doesn't go away */ 94 get_device(dev); 95 } 96 spin_unlock_irqrestore(&rtcdev_lock, flags); 97 return 0; 98 } 99 100 static inline void alarmtimer_rtc_timer_init(void) 101 { 102 rtc_timer_init(&rtctimer, NULL, NULL); 103 } 104 105 static struct class_interface alarmtimer_rtc_interface = { 106 .add_dev = &alarmtimer_rtc_add_device, 107 }; 108 109 static int alarmtimer_rtc_interface_setup(void) 110 { 111 alarmtimer_rtc_interface.class = rtc_class; 112 return class_interface_register(&alarmtimer_rtc_interface); 113 } 114 static void alarmtimer_rtc_interface_remove(void) 115 { 116 class_interface_unregister(&alarmtimer_rtc_interface); 117 } 118 #else 119 struct rtc_device *alarmtimer_get_rtcdev(void) 120 { 121 return NULL; 122 } 123 #define rtcdev (NULL) 124 static inline int alarmtimer_rtc_interface_setup(void) { return 0; } 125 static inline void alarmtimer_rtc_interface_remove(void) { } 126 static inline void alarmtimer_rtc_timer_init(void) { } 127 #endif 128 129 /** 130 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue 131 * @base: pointer to the base where the timer is being run 132 * @alarm: pointer to alarm being enqueued. 133 * 134 * Adds alarm to a alarm_base timerqueue 135 * 136 * Must hold base->lock when calling. 137 */ 138 static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) 139 { 140 if (alarm->state & ALARMTIMER_STATE_ENQUEUED) 141 timerqueue_del(&base->timerqueue, &alarm->node); 142 143 timerqueue_add(&base->timerqueue, &alarm->node); 144 alarm->state |= ALARMTIMER_STATE_ENQUEUED; 145 } 146 147 /** 148 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue 149 * @base: pointer to the base where the timer is running 150 * @alarm: pointer to alarm being removed 151 * 152 * Removes alarm to a alarm_base timerqueue 153 * 154 * Must hold base->lock when calling. 155 */ 156 static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm) 157 { 158 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) 159 return; 160 161 timerqueue_del(&base->timerqueue, &alarm->node); 162 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; 163 } 164 165 166 /** 167 * alarmtimer_fired - Handles alarm hrtimer being fired. 168 * @timer: pointer to hrtimer being run 169 * 170 * When a alarm timer fires, this runs through the timerqueue to 171 * see which alarms expired, and runs those. If there are more alarm 172 * timers queued for the future, we set the hrtimer to fire when 173 * when the next future alarm timer expires. 174 */ 175 static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) 176 { 177 struct alarm *alarm = container_of(timer, struct alarm, timer); 178 struct alarm_base *base = &alarm_bases[alarm->type]; 179 unsigned long flags; 180 int ret = HRTIMER_NORESTART; 181 int restart = ALARMTIMER_NORESTART; 182 183 spin_lock_irqsave(&base->lock, flags); 184 alarmtimer_dequeue(base, alarm); 185 spin_unlock_irqrestore(&base->lock, flags); 186 187 if (alarm->function) 188 restart = alarm->function(alarm, base->gettime()); 189 190 spin_lock_irqsave(&base->lock, flags); 191 if (restart != ALARMTIMER_NORESTART) { 192 hrtimer_set_expires(&alarm->timer, alarm->node.expires); 193 alarmtimer_enqueue(base, alarm); 194 ret = HRTIMER_RESTART; 195 } 196 spin_unlock_irqrestore(&base->lock, flags); 197 198 return ret; 199 200 } 201 202 ktime_t alarm_expires_remaining(const struct alarm *alarm) 203 { 204 struct alarm_base *base = &alarm_bases[alarm->type]; 205 return ktime_sub(alarm->node.expires, base->gettime()); 206 } 207 EXPORT_SYMBOL_GPL(alarm_expires_remaining); 208 209 #ifdef CONFIG_RTC_CLASS 210 /** 211 * alarmtimer_suspend - Suspend time callback 212 * @dev: unused 213 * @state: unused 214 * 215 * When we are going into suspend, we look through the bases 216 * to see which is the soonest timer to expire. We then 217 * set an rtc timer to fire that far into the future, which 218 * will wake us from suspend. 219 */ 220 static int alarmtimer_suspend(struct device *dev) 221 { 222 struct rtc_time tm; 223 ktime_t min, now; 224 unsigned long flags; 225 struct rtc_device *rtc; 226 int i; 227 int ret; 228 229 spin_lock_irqsave(&freezer_delta_lock, flags); 230 min = freezer_delta; 231 freezer_delta = ktime_set(0, 0); 232 spin_unlock_irqrestore(&freezer_delta_lock, flags); 233 234 rtc = alarmtimer_get_rtcdev(); 235 /* If we have no rtcdev, just return */ 236 if (!rtc) 237 return 0; 238 239 /* Find the soonest timer to expire*/ 240 for (i = 0; i < ALARM_NUMTYPE; i++) { 241 struct alarm_base *base = &alarm_bases[i]; 242 struct timerqueue_node *next; 243 ktime_t delta; 244 245 spin_lock_irqsave(&base->lock, flags); 246 next = timerqueue_getnext(&base->timerqueue); 247 spin_unlock_irqrestore(&base->lock, flags); 248 if (!next) 249 continue; 250 delta = ktime_sub(next->expires, base->gettime()); 251 if (!min.tv64 || (delta.tv64 < min.tv64)) 252 min = delta; 253 } 254 if (min.tv64 == 0) 255 return 0; 256 257 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) { 258 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC); 259 return -EBUSY; 260 } 261 262 /* Setup an rtc timer to fire that far in the future */ 263 rtc_timer_cancel(rtc, &rtctimer); 264 rtc_read_time(rtc, &tm); 265 now = rtc_tm_to_ktime(tm); 266 now = ktime_add(now, min); 267 268 /* Set alarm, if in the past reject suspend briefly to handle */ 269 ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0)); 270 if (ret < 0) 271 __pm_wakeup_event(ws, MSEC_PER_SEC); 272 return ret; 273 } 274 #else 275 static int alarmtimer_suspend(struct device *dev) 276 { 277 return 0; 278 } 279 #endif 280 281 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 } 294 295 296 /** 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 301 */ 302 void alarm_init(struct alarm *alarm, enum alarmtimer_type type, 303 enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) 304 { 305 timerqueue_init(&alarm->node); 306 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid, 307 HRTIMER_MODE_ABS); 308 alarm->timer.function = alarmtimer_fired; 309 alarm->function = function; 310 alarm->type = type; 311 alarm->state = ALARMTIMER_STATE_INACTIVE; 312 } 313 EXPORT_SYMBOL_GPL(alarm_init); 314 315 /** 316 * alarm_start - Sets an absolute alarm to fire 317 * @alarm: ptr to alarm to set 318 * @start: time to run the alarm 319 */ 320 void alarm_start(struct alarm *alarm, ktime_t start) 321 { 322 struct alarm_base *base = &alarm_bases[alarm->type]; 323 unsigned long flags; 324 325 spin_lock_irqsave(&base->lock, flags); 326 alarm->node.expires = start; 327 alarmtimer_enqueue(base, alarm); 328 hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS); 329 spin_unlock_irqrestore(&base->lock, flags); 330 } 331 EXPORT_SYMBOL_GPL(alarm_start); 332 333 /** 334 * alarm_start_relative - Sets a relative alarm to fire 335 * @alarm: ptr to alarm to set 336 * @start: time relative to now to run the alarm 337 */ 338 void alarm_start_relative(struct alarm *alarm, ktime_t start) 339 { 340 struct alarm_base *base = &alarm_bases[alarm->type]; 341 342 start = ktime_add(start, base->gettime()); 343 alarm_start(alarm, start); 344 } 345 EXPORT_SYMBOL_GPL(alarm_start_relative); 346 347 void alarm_restart(struct alarm *alarm) 348 { 349 struct alarm_base *base = &alarm_bases[alarm->type]; 350 unsigned long flags; 351 352 spin_lock_irqsave(&base->lock, flags); 353 hrtimer_set_expires(&alarm->timer, alarm->node.expires); 354 hrtimer_restart(&alarm->timer); 355 alarmtimer_enqueue(base, alarm); 356 spin_unlock_irqrestore(&base->lock, flags); 357 } 358 EXPORT_SYMBOL_GPL(alarm_restart); 359 360 /** 361 * alarm_try_to_cancel - Tries to cancel an alarm timer 362 * @alarm: ptr to alarm to be canceled 363 * 364 * Returns 1 if the timer was canceled, 0 if it was not running, 365 * and -1 if the callback was running 366 */ 367 int alarm_try_to_cancel(struct alarm *alarm) 368 { 369 struct alarm_base *base = &alarm_bases[alarm->type]; 370 unsigned long flags; 371 int ret; 372 373 spin_lock_irqsave(&base->lock, flags); 374 ret = hrtimer_try_to_cancel(&alarm->timer); 375 if (ret >= 0) 376 alarmtimer_dequeue(base, alarm); 377 spin_unlock_irqrestore(&base->lock, flags); 378 return ret; 379 } 380 EXPORT_SYMBOL_GPL(alarm_try_to_cancel); 381 382 383 /** 384 * alarm_cancel - Spins trying to cancel an alarm timer until it is done 385 * @alarm: ptr to alarm to be canceled 386 * 387 * Returns 1 if the timer was canceled, 0 if it was not active. 388 */ 389 int alarm_cancel(struct alarm *alarm) 390 { 391 for (;;) { 392 int ret = alarm_try_to_cancel(alarm); 393 if (ret >= 0) 394 return ret; 395 cpu_relax(); 396 } 397 } 398 EXPORT_SYMBOL_GPL(alarm_cancel); 399 400 401 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval) 402 { 403 u64 overrun = 1; 404 ktime_t delta; 405 406 delta = ktime_sub(now, alarm->node.expires); 407 408 if (delta.tv64 < 0) 409 return 0; 410 411 if (unlikely(delta.tv64 >= interval.tv64)) { 412 s64 incr = ktime_to_ns(interval); 413 414 overrun = ktime_divns(delta, incr); 415 416 alarm->node.expires = ktime_add_ns(alarm->node.expires, 417 incr*overrun); 418 419 if (alarm->node.expires.tv64 > now.tv64) 420 return overrun; 421 /* 422 * This (and the ktime_add() below) is the 423 * correction for exact: 424 */ 425 overrun++; 426 } 427 428 alarm->node.expires = ktime_add(alarm->node.expires, interval); 429 return overrun; 430 } 431 EXPORT_SYMBOL_GPL(alarm_forward); 432 433 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval) 434 { 435 struct alarm_base *base = &alarm_bases[alarm->type]; 436 437 return alarm_forward(alarm, base->gettime(), interval); 438 } 439 EXPORT_SYMBOL_GPL(alarm_forward_now); 440 441 442 /** 443 * clock2alarm - helper that converts from clockid to alarmtypes 444 * @clockid: clockid. 445 */ 446 static enum alarmtimer_type clock2alarm(clockid_t clockid) 447 { 448 if (clockid == CLOCK_REALTIME_ALARM) 449 return ALARM_REALTIME; 450 if (clockid == CLOCK_BOOTTIME_ALARM) 451 return ALARM_BOOTTIME; 452 return -1; 453 } 454 455 /** 456 * alarm_handle_timer - Callback for posix timers 457 * @alarm: alarm that fired 458 * 459 * Posix timer callback for expired alarm timers. 460 */ 461 static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, 462 ktime_t now) 463 { 464 unsigned long flags; 465 struct k_itimer *ptr = container_of(alarm, struct k_itimer, 466 it.alarm.alarmtimer); 467 enum alarmtimer_restart result = ALARMTIMER_NORESTART; 468 469 spin_lock_irqsave(&ptr->it_lock, flags); 470 if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) { 471 if (posix_timer_event(ptr, 0) != 0) 472 ptr->it_overrun++; 473 } 474 475 /* Re-add periodic timers */ 476 if (ptr->it.alarm.interval.tv64) { 477 ptr->it_overrun += alarm_forward(alarm, now, 478 ptr->it.alarm.interval); 479 result = ALARMTIMER_RESTART; 480 } 481 spin_unlock_irqrestore(&ptr->it_lock, flags); 482 483 return result; 484 } 485 486 /** 487 * alarm_clock_getres - posix getres interface 488 * @which_clock: clockid 489 * @tp: timespec to fill 490 * 491 * Returns the granularity of underlying alarm base clock 492 */ 493 static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) 494 { 495 if (!alarmtimer_get_rtcdev()) 496 return -EINVAL; 497 498 tp->tv_sec = 0; 499 tp->tv_nsec = hrtimer_resolution; 500 return 0; 501 } 502 503 /** 504 * alarm_clock_get - posix clock_get interface 505 * @which_clock: clockid 506 * @tp: timespec to fill. 507 * 508 * Provides the underlying alarm base time. 509 */ 510 static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) 511 { 512 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; 513 514 if (!alarmtimer_get_rtcdev()) 515 return -EINVAL; 516 517 *tp = ktime_to_timespec(base->gettime()); 518 return 0; 519 } 520 521 /** 522 * alarm_timer_create - posix timer_create interface 523 * @new_timer: k_itimer pointer to manage 524 * 525 * Initializes the k_itimer structure. 526 */ 527 static int alarm_timer_create(struct k_itimer *new_timer) 528 { 529 enum alarmtimer_type type; 530 struct alarm_base *base; 531 532 if (!alarmtimer_get_rtcdev()) 533 return -ENOTSUPP; 534 535 if (!capable(CAP_WAKE_ALARM)) 536 return -EPERM; 537 538 type = clock2alarm(new_timer->it_clock); 539 base = &alarm_bases[type]; 540 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer); 541 return 0; 542 } 543 544 /** 545 * alarm_timer_get - posix timer_get interface 546 * @new_timer: k_itimer pointer 547 * @cur_setting: itimerspec data to fill 548 * 549 * Copies out the current itimerspec data 550 */ 551 static void alarm_timer_get(struct k_itimer *timr, 552 struct itimerspec *cur_setting) 553 { 554 ktime_t relative_expiry_time = 555 alarm_expires_remaining(&(timr->it.alarm.alarmtimer)); 556 557 if (ktime_to_ns(relative_expiry_time) > 0) { 558 cur_setting->it_value = ktime_to_timespec(relative_expiry_time); 559 } else { 560 cur_setting->it_value.tv_sec = 0; 561 cur_setting->it_value.tv_nsec = 0; 562 } 563 564 cur_setting->it_interval = ktime_to_timespec(timr->it.alarm.interval); 565 } 566 567 /** 568 * alarm_timer_del - posix timer_del interface 569 * @timr: k_itimer pointer to be deleted 570 * 571 * Cancels any programmed alarms for the given timer. 572 */ 573 static int alarm_timer_del(struct k_itimer *timr) 574 { 575 if (!rtcdev) 576 return -ENOTSUPP; 577 578 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) 579 return TIMER_RETRY; 580 581 return 0; 582 } 583 584 /** 585 * alarm_timer_set - posix timer_set interface 586 * @timr: k_itimer pointer to be deleted 587 * @flags: timer flags 588 * @new_setting: itimerspec to be used 589 * @old_setting: itimerspec being replaced 590 * 591 * Sets the timer to new_setting, and starts the timer. 592 */ 593 static int alarm_timer_set(struct k_itimer *timr, int flags, 594 struct itimerspec *new_setting, 595 struct itimerspec *old_setting) 596 { 597 ktime_t exp; 598 599 if (!rtcdev) 600 return -ENOTSUPP; 601 602 if (flags & ~TIMER_ABSTIME) 603 return -EINVAL; 604 605 if (old_setting) 606 alarm_timer_get(timr, old_setting); 607 608 /* If the timer was already set, cancel it */ 609 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) 610 return TIMER_RETRY; 611 612 /* start the timer */ 613 timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval); 614 exp = timespec_to_ktime(new_setting->it_value); 615 /* Convert (if necessary) to absolute time */ 616 if (flags != TIMER_ABSTIME) { 617 ktime_t now; 618 619 now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime(); 620 exp = ktime_add(now, exp); 621 } 622 623 alarm_start(&timr->it.alarm.alarmtimer, exp); 624 return 0; 625 } 626 627 /** 628 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep 629 * @alarm: ptr to alarm that fired 630 * 631 * Wakes up the task that set the alarmtimer 632 */ 633 static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, 634 ktime_t now) 635 { 636 struct task_struct *task = (struct task_struct *)alarm->data; 637 638 alarm->data = NULL; 639 if (task) 640 wake_up_process(task); 641 return ALARMTIMER_NORESTART; 642 } 643 644 /** 645 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation 646 * @alarm: ptr to alarmtimer 647 * @absexp: absolute expiration time 648 * 649 * Sets the alarm timer and sleeps until it is fired or interrupted. 650 */ 651 static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) 652 { 653 alarm->data = (void *)current; 654 do { 655 set_current_state(TASK_INTERRUPTIBLE); 656 alarm_start(alarm, absexp); 657 if (likely(alarm->data)) 658 schedule(); 659 660 alarm_cancel(alarm); 661 } while (alarm->data && !signal_pending(current)); 662 663 __set_current_state(TASK_RUNNING); 664 665 return (alarm->data == NULL); 666 } 667 668 669 /** 670 * update_rmtp - Update remaining timespec value 671 * @exp: expiration time 672 * @type: timer type 673 * @rmtp: user pointer to remaining timepsec value 674 * 675 * Helper function that fills in rmtp value with time between 676 * now and the exp value 677 */ 678 static int update_rmtp(ktime_t exp, enum alarmtimer_type type, 679 struct timespec __user *rmtp) 680 { 681 struct timespec rmt; 682 ktime_t rem; 683 684 rem = ktime_sub(exp, alarm_bases[type].gettime()); 685 686 if (rem.tv64 <= 0) 687 return 0; 688 rmt = ktime_to_timespec(rem); 689 690 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) 691 return -EFAULT; 692 693 return 1; 694 695 } 696 697 /** 698 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep 699 * @restart: ptr to restart block 700 * 701 * Handles restarted clock_nanosleep calls 702 */ 703 static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) 704 { 705 enum alarmtimer_type type = restart->nanosleep.clockid; 706 ktime_t exp; 707 struct timespec __user *rmtp; 708 struct alarm alarm; 709 int ret = 0; 710 711 exp.tv64 = restart->nanosleep.expires; 712 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); 713 714 if (alarmtimer_do_nsleep(&alarm, exp)) 715 goto out; 716 717 if (freezing(current)) 718 alarmtimer_freezerset(exp, type); 719 720 rmtp = restart->nanosleep.rmtp; 721 if (rmtp) { 722 ret = update_rmtp(exp, type, rmtp); 723 if (ret <= 0) 724 goto out; 725 } 726 727 728 /* The other values in restart are already filled in */ 729 ret = -ERESTART_RESTARTBLOCK; 730 out: 731 return ret; 732 } 733 734 /** 735 * alarm_timer_nsleep - alarmtimer nanosleep 736 * @which_clock: clockid 737 * @flags: determins abstime or relative 738 * @tsreq: requested sleep time (abs or rel) 739 * @rmtp: remaining sleep time saved 740 * 741 * Handles clock_nanosleep calls against _ALARM clockids 742 */ 743 static int alarm_timer_nsleep(const clockid_t which_clock, int flags, 744 struct timespec *tsreq, struct timespec __user *rmtp) 745 { 746 enum alarmtimer_type type = clock2alarm(which_clock); 747 struct alarm alarm; 748 ktime_t exp; 749 int ret = 0; 750 struct restart_block *restart; 751 752 if (!alarmtimer_get_rtcdev()) 753 return -ENOTSUPP; 754 755 if (flags & ~TIMER_ABSTIME) 756 return -EINVAL; 757 758 if (!capable(CAP_WAKE_ALARM)) 759 return -EPERM; 760 761 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); 762 763 exp = timespec_to_ktime(*tsreq); 764 /* Convert (if necessary) to absolute time */ 765 if (flags != TIMER_ABSTIME) { 766 ktime_t now = alarm_bases[type].gettime(); 767 exp = ktime_add(now, exp); 768 } 769 770 if (alarmtimer_do_nsleep(&alarm, exp)) 771 goto out; 772 773 if (freezing(current)) 774 alarmtimer_freezerset(exp, type); 775 776 /* abs timers don't set remaining time or restart */ 777 if (flags == TIMER_ABSTIME) { 778 ret = -ERESTARTNOHAND; 779 goto out; 780 } 781 782 if (rmtp) { 783 ret = update_rmtp(exp, type, rmtp); 784 if (ret <= 0) 785 goto out; 786 } 787 788 restart = ¤t->restart_block; 789 restart->fn = alarm_timer_nsleep_restart; 790 restart->nanosleep.clockid = type; 791 restart->nanosleep.expires = exp.tv64; 792 restart->nanosleep.rmtp = rmtp; 793 ret = -ERESTART_RESTARTBLOCK; 794 795 out: 796 return ret; 797 } 798 799 800 /* Suspend hook structures */ 801 static const struct dev_pm_ops alarmtimer_pm_ops = { 802 .suspend = alarmtimer_suspend, 803 }; 804 805 static struct platform_driver alarmtimer_driver = { 806 .driver = { 807 .name = "alarmtimer", 808 .pm = &alarmtimer_pm_ops, 809 } 810 }; 811 812 /** 813 * alarmtimer_init - Initialize alarm timer code 814 * 815 * This function initializes the alarm bases and registers 816 * the posix clock ids. 817 */ 818 static int __init alarmtimer_init(void) 819 { 820 struct platform_device *pdev; 821 int error = 0; 822 int i; 823 struct k_clock alarm_clock = { 824 .clock_getres = alarm_clock_getres, 825 .clock_get = alarm_clock_get, 826 .timer_create = alarm_timer_create, 827 .timer_set = alarm_timer_set, 828 .timer_del = alarm_timer_del, 829 .timer_get = alarm_timer_get, 830 .nsleep = alarm_timer_nsleep, 831 }; 832 833 alarmtimer_rtc_timer_init(); 834 835 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); 836 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); 837 838 /* Initialize alarm bases */ 839 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; 840 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; 841 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; 842 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; 843 for (i = 0; i < ALARM_NUMTYPE; i++) { 844 timerqueue_init_head(&alarm_bases[i].timerqueue); 845 spin_lock_init(&alarm_bases[i].lock); 846 } 847 848 error = alarmtimer_rtc_interface_setup(); 849 if (error) 850 return error; 851 852 error = platform_driver_register(&alarmtimer_driver); 853 if (error) 854 goto out_if; 855 856 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0); 857 if (IS_ERR(pdev)) { 858 error = PTR_ERR(pdev); 859 goto out_drv; 860 } 861 ws = wakeup_source_register("alarmtimer"); 862 return 0; 863 864 out_drv: 865 platform_driver_unregister(&alarmtimer_driver); 866 out_if: 867 alarmtimer_rtc_interface_remove(); 868 return error; 869 } 870 device_initcall(alarmtimer_init); 871