1 /* 2 * drivers/base/power/wakeup.c - System wakeup events framework 3 * 4 * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 5 * 6 * This file is released under the GPLv2. 7 */ 8 9 #include <linux/device.h> 10 #include <linux/slab.h> 11 #include <linux/sched.h> 12 #include <linux/capability.h> 13 #include <linux/export.h> 14 #include <linux/suspend.h> 15 #include <linux/seq_file.h> 16 #include <linux/debugfs.h> 17 #include <linux/pm_wakeirq.h> 18 #include <trace/events/power.h> 19 20 #include "power.h" 21 22 /* 23 * If set, the suspend/hibernate code will abort transitions to a sleep state 24 * if wakeup events are registered during or immediately before the transition. 25 */ 26 bool events_check_enabled __read_mostly; 27 28 /* First wakeup IRQ seen by the kernel in the last cycle. */ 29 unsigned int pm_wakeup_irq __read_mostly; 30 31 /* If set and the system is suspending, terminate the suspend. */ 32 static bool pm_abort_suspend __read_mostly; 33 34 /* 35 * Combined counters of registered wakeup events and wakeup events in progress. 36 * They need to be modified together atomically, so it's better to use one 37 * atomic variable to hold them both. 38 */ 39 static atomic_t combined_event_count = ATOMIC_INIT(0); 40 41 #define IN_PROGRESS_BITS (sizeof(int) * 4) 42 #define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1) 43 44 static void split_counters(unsigned int *cnt, unsigned int *inpr) 45 { 46 unsigned int comb = atomic_read(&combined_event_count); 47 48 *cnt = (comb >> IN_PROGRESS_BITS); 49 *inpr = comb & MAX_IN_PROGRESS; 50 } 51 52 /* A preserved old value of the events counter. */ 53 static unsigned int saved_count; 54 55 static DEFINE_SPINLOCK(events_lock); 56 57 static void pm_wakeup_timer_fn(unsigned long data); 58 59 static LIST_HEAD(wakeup_sources); 60 61 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); 62 63 static struct wakeup_source deleted_ws = { 64 .name = "deleted", 65 .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock), 66 }; 67 68 /** 69 * wakeup_source_prepare - Prepare a new wakeup source for initialization. 70 * @ws: Wakeup source to prepare. 71 * @name: Pointer to the name of the new wakeup source. 72 * 73 * Callers must ensure that the @name string won't be freed when @ws is still in 74 * use. 75 */ 76 void wakeup_source_prepare(struct wakeup_source *ws, const char *name) 77 { 78 if (ws) { 79 memset(ws, 0, sizeof(*ws)); 80 ws->name = name; 81 } 82 } 83 EXPORT_SYMBOL_GPL(wakeup_source_prepare); 84 85 /** 86 * wakeup_source_create - Create a struct wakeup_source object. 87 * @name: Name of the new wakeup source. 88 */ 89 struct wakeup_source *wakeup_source_create(const char *name) 90 { 91 struct wakeup_source *ws; 92 93 ws = kmalloc(sizeof(*ws), GFP_KERNEL); 94 if (!ws) 95 return NULL; 96 97 wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL); 98 return ws; 99 } 100 EXPORT_SYMBOL_GPL(wakeup_source_create); 101 102 /** 103 * wakeup_source_drop - Prepare a struct wakeup_source object for destruction. 104 * @ws: Wakeup source to prepare for destruction. 105 * 106 * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never 107 * be run in parallel with this function for the same wakeup source object. 108 */ 109 void wakeup_source_drop(struct wakeup_source *ws) 110 { 111 if (!ws) 112 return; 113 114 del_timer_sync(&ws->timer); 115 __pm_relax(ws); 116 } 117 EXPORT_SYMBOL_GPL(wakeup_source_drop); 118 119 /* 120 * Record wakeup_source statistics being deleted into a dummy wakeup_source. 121 */ 122 static void wakeup_source_record(struct wakeup_source *ws) 123 { 124 unsigned long flags; 125 126 spin_lock_irqsave(&deleted_ws.lock, flags); 127 128 if (ws->event_count) { 129 deleted_ws.total_time = 130 ktime_add(deleted_ws.total_time, ws->total_time); 131 deleted_ws.prevent_sleep_time = 132 ktime_add(deleted_ws.prevent_sleep_time, 133 ws->prevent_sleep_time); 134 deleted_ws.max_time = 135 ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ? 136 deleted_ws.max_time : ws->max_time; 137 deleted_ws.event_count += ws->event_count; 138 deleted_ws.active_count += ws->active_count; 139 deleted_ws.relax_count += ws->relax_count; 140 deleted_ws.expire_count += ws->expire_count; 141 deleted_ws.wakeup_count += ws->wakeup_count; 142 } 143 144 spin_unlock_irqrestore(&deleted_ws.lock, flags); 145 } 146 147 /** 148 * wakeup_source_destroy - Destroy a struct wakeup_source object. 149 * @ws: Wakeup source to destroy. 150 * 151 * Use only for wakeup source objects created with wakeup_source_create(). 152 */ 153 void wakeup_source_destroy(struct wakeup_source *ws) 154 { 155 if (!ws) 156 return; 157 158 wakeup_source_drop(ws); 159 wakeup_source_record(ws); 160 kfree_const(ws->name); 161 kfree(ws); 162 } 163 EXPORT_SYMBOL_GPL(wakeup_source_destroy); 164 165 /** 166 * wakeup_source_add - Add given object to the list of wakeup sources. 167 * @ws: Wakeup source object to add to the list. 168 */ 169 void wakeup_source_add(struct wakeup_source *ws) 170 { 171 unsigned long flags; 172 173 if (WARN_ON(!ws)) 174 return; 175 176 spin_lock_init(&ws->lock); 177 setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws); 178 ws->active = false; 179 ws->last_time = ktime_get(); 180 181 spin_lock_irqsave(&events_lock, flags); 182 list_add_rcu(&ws->entry, &wakeup_sources); 183 spin_unlock_irqrestore(&events_lock, flags); 184 } 185 EXPORT_SYMBOL_GPL(wakeup_source_add); 186 187 /** 188 * wakeup_source_remove - Remove given object from the wakeup sources list. 189 * @ws: Wakeup source object to remove from the list. 190 */ 191 void wakeup_source_remove(struct wakeup_source *ws) 192 { 193 unsigned long flags; 194 195 if (WARN_ON(!ws)) 196 return; 197 198 spin_lock_irqsave(&events_lock, flags); 199 list_del_rcu(&ws->entry); 200 spin_unlock_irqrestore(&events_lock, flags); 201 synchronize_rcu(); 202 } 203 EXPORT_SYMBOL_GPL(wakeup_source_remove); 204 205 /** 206 * wakeup_source_register - Create wakeup source and add it to the list. 207 * @name: Name of the wakeup source to register. 208 */ 209 struct wakeup_source *wakeup_source_register(const char *name) 210 { 211 struct wakeup_source *ws; 212 213 ws = wakeup_source_create(name); 214 if (ws) 215 wakeup_source_add(ws); 216 217 return ws; 218 } 219 EXPORT_SYMBOL_GPL(wakeup_source_register); 220 221 /** 222 * wakeup_source_unregister - Remove wakeup source from the list and remove it. 223 * @ws: Wakeup source object to unregister. 224 */ 225 void wakeup_source_unregister(struct wakeup_source *ws) 226 { 227 if (ws) { 228 wakeup_source_remove(ws); 229 wakeup_source_destroy(ws); 230 } 231 } 232 EXPORT_SYMBOL_GPL(wakeup_source_unregister); 233 234 /** 235 * device_wakeup_attach - Attach a wakeup source object to a device object. 236 * @dev: Device to handle. 237 * @ws: Wakeup source object to attach to @dev. 238 * 239 * This causes @dev to be treated as a wakeup device. 240 */ 241 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws) 242 { 243 spin_lock_irq(&dev->power.lock); 244 if (dev->power.wakeup) { 245 spin_unlock_irq(&dev->power.lock); 246 return -EEXIST; 247 } 248 dev->power.wakeup = ws; 249 if (dev->power.wakeirq) 250 device_wakeup_attach_irq(dev, dev->power.wakeirq); 251 spin_unlock_irq(&dev->power.lock); 252 return 0; 253 } 254 255 /** 256 * device_wakeup_enable - Enable given device to be a wakeup source. 257 * @dev: Device to handle. 258 * 259 * Create a wakeup source object, register it and attach it to @dev. 260 */ 261 int device_wakeup_enable(struct device *dev) 262 { 263 struct wakeup_source *ws; 264 int ret; 265 266 if (!dev || !dev->power.can_wakeup) 267 return -EINVAL; 268 269 ws = wakeup_source_register(dev_name(dev)); 270 if (!ws) 271 return -ENOMEM; 272 273 ret = device_wakeup_attach(dev, ws); 274 if (ret) 275 wakeup_source_unregister(ws); 276 277 return ret; 278 } 279 EXPORT_SYMBOL_GPL(device_wakeup_enable); 280 281 /** 282 * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source 283 * @dev: Device to handle 284 * @wakeirq: Device specific wakeirq entry 285 * 286 * Attach a device wakeirq to the wakeup source so the device 287 * wake IRQ can be configured automatically for suspend and 288 * resume. 289 * 290 * Call under the device's power.lock lock. 291 */ 292 int device_wakeup_attach_irq(struct device *dev, 293 struct wake_irq *wakeirq) 294 { 295 struct wakeup_source *ws; 296 297 ws = dev->power.wakeup; 298 if (!ws) { 299 dev_err(dev, "forgot to call call device_init_wakeup?\n"); 300 return -EINVAL; 301 } 302 303 if (ws->wakeirq) 304 return -EEXIST; 305 306 ws->wakeirq = wakeirq; 307 return 0; 308 } 309 310 /** 311 * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source 312 * @dev: Device to handle 313 * 314 * Removes a device wakeirq from the wakeup source. 315 * 316 * Call under the device's power.lock lock. 317 */ 318 void device_wakeup_detach_irq(struct device *dev) 319 { 320 struct wakeup_source *ws; 321 322 ws = dev->power.wakeup; 323 if (ws) 324 ws->wakeirq = NULL; 325 } 326 327 /** 328 * device_wakeup_arm_wake_irqs(void) 329 * 330 * Itereates over the list of device wakeirqs to arm them. 331 */ 332 void device_wakeup_arm_wake_irqs(void) 333 { 334 struct wakeup_source *ws; 335 336 rcu_read_lock(); 337 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 338 if (ws->wakeirq) 339 dev_pm_arm_wake_irq(ws->wakeirq); 340 } 341 rcu_read_unlock(); 342 } 343 344 /** 345 * device_wakeup_disarm_wake_irqs(void) 346 * 347 * Itereates over the list of device wakeirqs to disarm them. 348 */ 349 void device_wakeup_disarm_wake_irqs(void) 350 { 351 struct wakeup_source *ws; 352 353 rcu_read_lock(); 354 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 355 if (ws->wakeirq) 356 dev_pm_disarm_wake_irq(ws->wakeirq); 357 } 358 rcu_read_unlock(); 359 } 360 361 /** 362 * device_wakeup_detach - Detach a device's wakeup source object from it. 363 * @dev: Device to detach the wakeup source object from. 364 * 365 * After it returns, @dev will not be treated as a wakeup device any more. 366 */ 367 static struct wakeup_source *device_wakeup_detach(struct device *dev) 368 { 369 struct wakeup_source *ws; 370 371 spin_lock_irq(&dev->power.lock); 372 ws = dev->power.wakeup; 373 dev->power.wakeup = NULL; 374 spin_unlock_irq(&dev->power.lock); 375 return ws; 376 } 377 378 /** 379 * device_wakeup_disable - Do not regard a device as a wakeup source any more. 380 * @dev: Device to handle. 381 * 382 * Detach the @dev's wakeup source object from it, unregister this wakeup source 383 * object and destroy it. 384 */ 385 int device_wakeup_disable(struct device *dev) 386 { 387 struct wakeup_source *ws; 388 389 if (!dev || !dev->power.can_wakeup) 390 return -EINVAL; 391 392 ws = device_wakeup_detach(dev); 393 if (ws) 394 wakeup_source_unregister(ws); 395 396 return 0; 397 } 398 EXPORT_SYMBOL_GPL(device_wakeup_disable); 399 400 /** 401 * device_set_wakeup_capable - Set/reset device wakeup capability flag. 402 * @dev: Device to handle. 403 * @capable: Whether or not @dev is capable of waking up the system from sleep. 404 * 405 * If @capable is set, set the @dev's power.can_wakeup flag and add its 406 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's 407 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs. 408 * 409 * This function may sleep and it can't be called from any context where 410 * sleeping is not allowed. 411 */ 412 void device_set_wakeup_capable(struct device *dev, bool capable) 413 { 414 if (!!dev->power.can_wakeup == !!capable) 415 return; 416 417 if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { 418 if (capable) { 419 if (wakeup_sysfs_add(dev)) 420 return; 421 } else { 422 wakeup_sysfs_remove(dev); 423 } 424 } 425 dev->power.can_wakeup = capable; 426 } 427 EXPORT_SYMBOL_GPL(device_set_wakeup_capable); 428 429 /** 430 * device_init_wakeup - Device wakeup initialization. 431 * @dev: Device to handle. 432 * @enable: Whether or not to enable @dev as a wakeup device. 433 * 434 * By default, most devices should leave wakeup disabled. The exceptions are 435 * devices that everyone expects to be wakeup sources: keyboards, power buttons, 436 * possibly network interfaces, etc. Also, devices that don't generate their 437 * own wakeup requests but merely forward requests from one bus to another 438 * (like PCI bridges) should have wakeup enabled by default. 439 */ 440 int device_init_wakeup(struct device *dev, bool enable) 441 { 442 int ret = 0; 443 444 if (!dev) 445 return -EINVAL; 446 447 if (enable) { 448 device_set_wakeup_capable(dev, true); 449 ret = device_wakeup_enable(dev); 450 } else { 451 if (dev->power.can_wakeup) 452 device_wakeup_disable(dev); 453 454 device_set_wakeup_capable(dev, false); 455 } 456 457 return ret; 458 } 459 EXPORT_SYMBOL_GPL(device_init_wakeup); 460 461 /** 462 * device_set_wakeup_enable - Enable or disable a device to wake up the system. 463 * @dev: Device to handle. 464 */ 465 int device_set_wakeup_enable(struct device *dev, bool enable) 466 { 467 if (!dev || !dev->power.can_wakeup) 468 return -EINVAL; 469 470 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev); 471 } 472 EXPORT_SYMBOL_GPL(device_set_wakeup_enable); 473 474 /** 475 * wakeup_source_not_registered - validate the given wakeup source. 476 * @ws: Wakeup source to be validated. 477 */ 478 static bool wakeup_source_not_registered(struct wakeup_source *ws) 479 { 480 /* 481 * Use timer struct to check if the given source is initialized 482 * by wakeup_source_add. 483 */ 484 return ws->timer.function != pm_wakeup_timer_fn || 485 ws->timer.data != (unsigned long)ws; 486 } 487 488 /* 489 * The functions below use the observation that each wakeup event starts a 490 * period in which the system should not be suspended. The moment this period 491 * will end depends on how the wakeup event is going to be processed after being 492 * detected and all of the possible cases can be divided into two distinct 493 * groups. 494 * 495 * First, a wakeup event may be detected by the same functional unit that will 496 * carry out the entire processing of it and possibly will pass it to user space 497 * for further processing. In that case the functional unit that has detected 498 * the event may later "close" the "no suspend" period associated with it 499 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and 500 * pm_relax(), balanced with each other, is supposed to be used in such 501 * situations. 502 * 503 * Second, a wakeup event may be detected by one functional unit and processed 504 * by another one. In that case the unit that has detected it cannot really 505 * "close" the "no suspend" period associated with it, unless it knows in 506 * advance what's going to happen to the event during processing. This 507 * knowledge, however, may not be available to it, so it can simply specify time 508 * to wait before the system can be suspended and pass it as the second 509 * argument of pm_wakeup_event(). 510 * 511 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the 512 * "no suspend" period will be ended either by the pm_relax(), or by the timer 513 * function executed when the timer expires, whichever comes first. 514 */ 515 516 /** 517 * wakup_source_activate - Mark given wakeup source as active. 518 * @ws: Wakeup source to handle. 519 * 520 * Update the @ws' statistics and, if @ws has just been activated, notify the PM 521 * core of the event by incrementing the counter of of wakeup events being 522 * processed. 523 */ 524 static void wakeup_source_activate(struct wakeup_source *ws) 525 { 526 unsigned int cec; 527 528 if (WARN_ONCE(wakeup_source_not_registered(ws), 529 "unregistered wakeup source\n")) 530 return; 531 532 /* 533 * active wakeup source should bring the system 534 * out of PM_SUSPEND_FREEZE state 535 */ 536 freeze_wake(); 537 538 ws->active = true; 539 ws->active_count++; 540 ws->last_time = ktime_get(); 541 if (ws->autosleep_enabled) 542 ws->start_prevent_time = ws->last_time; 543 544 /* Increment the counter of events in progress. */ 545 cec = atomic_inc_return(&combined_event_count); 546 547 trace_wakeup_source_activate(ws->name, cec); 548 } 549 550 /** 551 * wakeup_source_report_event - Report wakeup event using the given source. 552 * @ws: Wakeup source to report the event for. 553 */ 554 static void wakeup_source_report_event(struct wakeup_source *ws) 555 { 556 ws->event_count++; 557 /* This is racy, but the counter is approximate anyway. */ 558 if (events_check_enabled) 559 ws->wakeup_count++; 560 561 if (!ws->active) 562 wakeup_source_activate(ws); 563 } 564 565 /** 566 * __pm_stay_awake - Notify the PM core of a wakeup event. 567 * @ws: Wakeup source object associated with the source of the event. 568 * 569 * It is safe to call this function from interrupt context. 570 */ 571 void __pm_stay_awake(struct wakeup_source *ws) 572 { 573 unsigned long flags; 574 575 if (!ws) 576 return; 577 578 spin_lock_irqsave(&ws->lock, flags); 579 580 wakeup_source_report_event(ws); 581 del_timer(&ws->timer); 582 ws->timer_expires = 0; 583 584 spin_unlock_irqrestore(&ws->lock, flags); 585 } 586 EXPORT_SYMBOL_GPL(__pm_stay_awake); 587 588 /** 589 * pm_stay_awake - Notify the PM core that a wakeup event is being processed. 590 * @dev: Device the wakeup event is related to. 591 * 592 * Notify the PM core of a wakeup event (signaled by @dev) by calling 593 * __pm_stay_awake for the @dev's wakeup source object. 594 * 595 * Call this function after detecting of a wakeup event if pm_relax() is going 596 * to be called directly after processing the event (and possibly passing it to 597 * user space for further processing). 598 */ 599 void pm_stay_awake(struct device *dev) 600 { 601 unsigned long flags; 602 603 if (!dev) 604 return; 605 606 spin_lock_irqsave(&dev->power.lock, flags); 607 __pm_stay_awake(dev->power.wakeup); 608 spin_unlock_irqrestore(&dev->power.lock, flags); 609 } 610 EXPORT_SYMBOL_GPL(pm_stay_awake); 611 612 #ifdef CONFIG_PM_AUTOSLEEP 613 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now) 614 { 615 ktime_t delta = ktime_sub(now, ws->start_prevent_time); 616 ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta); 617 } 618 #else 619 static inline void update_prevent_sleep_time(struct wakeup_source *ws, 620 ktime_t now) {} 621 #endif 622 623 /** 624 * wakup_source_deactivate - Mark given wakeup source as inactive. 625 * @ws: Wakeup source to handle. 626 * 627 * Update the @ws' statistics and notify the PM core that the wakeup source has 628 * become inactive by decrementing the counter of wakeup events being processed 629 * and incrementing the counter of registered wakeup events. 630 */ 631 static void wakeup_source_deactivate(struct wakeup_source *ws) 632 { 633 unsigned int cnt, inpr, cec; 634 ktime_t duration; 635 ktime_t now; 636 637 ws->relax_count++; 638 /* 639 * __pm_relax() may be called directly or from a timer function. 640 * If it is called directly right after the timer function has been 641 * started, but before the timer function calls __pm_relax(), it is 642 * possible that __pm_stay_awake() will be called in the meantime and 643 * will set ws->active. Then, ws->active may be cleared immediately 644 * by the __pm_relax() called from the timer function, but in such a 645 * case ws->relax_count will be different from ws->active_count. 646 */ 647 if (ws->relax_count != ws->active_count) { 648 ws->relax_count--; 649 return; 650 } 651 652 ws->active = false; 653 654 now = ktime_get(); 655 duration = ktime_sub(now, ws->last_time); 656 ws->total_time = ktime_add(ws->total_time, duration); 657 if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time)) 658 ws->max_time = duration; 659 660 ws->last_time = now; 661 del_timer(&ws->timer); 662 ws->timer_expires = 0; 663 664 if (ws->autosleep_enabled) 665 update_prevent_sleep_time(ws, now); 666 667 /* 668 * Increment the counter of registered wakeup events and decrement the 669 * couter of wakeup events in progress simultaneously. 670 */ 671 cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count); 672 trace_wakeup_source_deactivate(ws->name, cec); 673 674 split_counters(&cnt, &inpr); 675 if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) 676 wake_up(&wakeup_count_wait_queue); 677 } 678 679 /** 680 * __pm_relax - Notify the PM core that processing of a wakeup event has ended. 681 * @ws: Wakeup source object associated with the source of the event. 682 * 683 * Call this function for wakeup events whose processing started with calling 684 * __pm_stay_awake(). 685 * 686 * It is safe to call it from interrupt context. 687 */ 688 void __pm_relax(struct wakeup_source *ws) 689 { 690 unsigned long flags; 691 692 if (!ws) 693 return; 694 695 spin_lock_irqsave(&ws->lock, flags); 696 if (ws->active) 697 wakeup_source_deactivate(ws); 698 spin_unlock_irqrestore(&ws->lock, flags); 699 } 700 EXPORT_SYMBOL_GPL(__pm_relax); 701 702 /** 703 * pm_relax - Notify the PM core that processing of a wakeup event has ended. 704 * @dev: Device that signaled the event. 705 * 706 * Execute __pm_relax() for the @dev's wakeup source object. 707 */ 708 void pm_relax(struct device *dev) 709 { 710 unsigned long flags; 711 712 if (!dev) 713 return; 714 715 spin_lock_irqsave(&dev->power.lock, flags); 716 __pm_relax(dev->power.wakeup); 717 spin_unlock_irqrestore(&dev->power.lock, flags); 718 } 719 EXPORT_SYMBOL_GPL(pm_relax); 720 721 /** 722 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event. 723 * @data: Address of the wakeup source object associated with the event source. 724 * 725 * Call wakeup_source_deactivate() for the wakeup source whose address is stored 726 * in @data if it is currently active and its timer has not been canceled and 727 * the expiration time of the timer is not in future. 728 */ 729 static void pm_wakeup_timer_fn(unsigned long data) 730 { 731 struct wakeup_source *ws = (struct wakeup_source *)data; 732 unsigned long flags; 733 734 spin_lock_irqsave(&ws->lock, flags); 735 736 if (ws->active && ws->timer_expires 737 && time_after_eq(jiffies, ws->timer_expires)) { 738 wakeup_source_deactivate(ws); 739 ws->expire_count++; 740 } 741 742 spin_unlock_irqrestore(&ws->lock, flags); 743 } 744 745 /** 746 * __pm_wakeup_event - Notify the PM core of a wakeup event. 747 * @ws: Wakeup source object associated with the event source. 748 * @msec: Anticipated event processing time (in milliseconds). 749 * 750 * Notify the PM core of a wakeup event whose source is @ws that will take 751 * approximately @msec milliseconds to be processed by the kernel. If @ws is 752 * not active, activate it. If @msec is nonzero, set up the @ws' timer to 753 * execute pm_wakeup_timer_fn() in future. 754 * 755 * It is safe to call this function from interrupt context. 756 */ 757 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec) 758 { 759 unsigned long flags; 760 unsigned long expires; 761 762 if (!ws) 763 return; 764 765 spin_lock_irqsave(&ws->lock, flags); 766 767 wakeup_source_report_event(ws); 768 769 if (!msec) { 770 wakeup_source_deactivate(ws); 771 goto unlock; 772 } 773 774 expires = jiffies + msecs_to_jiffies(msec); 775 if (!expires) 776 expires = 1; 777 778 if (!ws->timer_expires || time_after(expires, ws->timer_expires)) { 779 mod_timer(&ws->timer, expires); 780 ws->timer_expires = expires; 781 } 782 783 unlock: 784 spin_unlock_irqrestore(&ws->lock, flags); 785 } 786 EXPORT_SYMBOL_GPL(__pm_wakeup_event); 787 788 789 /** 790 * pm_wakeup_event - Notify the PM core of a wakeup event. 791 * @dev: Device the wakeup event is related to. 792 * @msec: Anticipated event processing time (in milliseconds). 793 * 794 * Call __pm_wakeup_event() for the @dev's wakeup source object. 795 */ 796 void pm_wakeup_event(struct device *dev, unsigned int msec) 797 { 798 unsigned long flags; 799 800 if (!dev) 801 return; 802 803 spin_lock_irqsave(&dev->power.lock, flags); 804 __pm_wakeup_event(dev->power.wakeup, msec); 805 spin_unlock_irqrestore(&dev->power.lock, flags); 806 } 807 EXPORT_SYMBOL_GPL(pm_wakeup_event); 808 809 void pm_print_active_wakeup_sources(void) 810 { 811 struct wakeup_source *ws; 812 int active = 0; 813 struct wakeup_source *last_activity_ws = NULL; 814 815 rcu_read_lock(); 816 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 817 if (ws->active) { 818 pr_info("active wakeup source: %s\n", ws->name); 819 active = 1; 820 } else if (!active && 821 (!last_activity_ws || 822 ktime_to_ns(ws->last_time) > 823 ktime_to_ns(last_activity_ws->last_time))) { 824 last_activity_ws = ws; 825 } 826 } 827 828 if (!active && last_activity_ws) 829 pr_info("last active wakeup source: %s\n", 830 last_activity_ws->name); 831 rcu_read_unlock(); 832 } 833 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); 834 835 /** 836 * pm_wakeup_pending - Check if power transition in progress should be aborted. 837 * 838 * Compare the current number of registered wakeup events with its preserved 839 * value from the past and return true if new wakeup events have been registered 840 * since the old value was stored. Also return true if the current number of 841 * wakeup events being processed is different from zero. 842 */ 843 bool pm_wakeup_pending(void) 844 { 845 unsigned long flags; 846 bool ret = false; 847 848 spin_lock_irqsave(&events_lock, flags); 849 if (events_check_enabled) { 850 unsigned int cnt, inpr; 851 852 split_counters(&cnt, &inpr); 853 ret = (cnt != saved_count || inpr > 0); 854 events_check_enabled = !ret; 855 } 856 spin_unlock_irqrestore(&events_lock, flags); 857 858 if (ret) { 859 pr_info("PM: Wakeup pending, aborting suspend\n"); 860 pm_print_active_wakeup_sources(); 861 } 862 863 return ret || pm_abort_suspend; 864 } 865 866 void pm_system_wakeup(void) 867 { 868 pm_abort_suspend = true; 869 freeze_wake(); 870 } 871 EXPORT_SYMBOL_GPL(pm_system_wakeup); 872 873 void pm_wakeup_clear(void) 874 { 875 pm_abort_suspend = false; 876 pm_wakeup_irq = 0; 877 } 878 879 void pm_system_irq_wakeup(unsigned int irq_number) 880 { 881 if (pm_wakeup_irq == 0) { 882 pm_wakeup_irq = irq_number; 883 pm_system_wakeup(); 884 } 885 } 886 887 /** 888 * pm_get_wakeup_count - Read the number of registered wakeup events. 889 * @count: Address to store the value at. 890 * @block: Whether or not to block. 891 * 892 * Store the number of registered wakeup events at the address in @count. If 893 * @block is set, block until the current number of wakeup events being 894 * processed is zero. 895 * 896 * Return 'false' if the current number of wakeup events being processed is 897 * nonzero. Otherwise return 'true'. 898 */ 899 bool pm_get_wakeup_count(unsigned int *count, bool block) 900 { 901 unsigned int cnt, inpr; 902 903 if (block) { 904 DEFINE_WAIT(wait); 905 906 for (;;) { 907 prepare_to_wait(&wakeup_count_wait_queue, &wait, 908 TASK_INTERRUPTIBLE); 909 split_counters(&cnt, &inpr); 910 if (inpr == 0 || signal_pending(current)) 911 break; 912 913 schedule(); 914 } 915 finish_wait(&wakeup_count_wait_queue, &wait); 916 } 917 918 split_counters(&cnt, &inpr); 919 *count = cnt; 920 return !inpr; 921 } 922 923 /** 924 * pm_save_wakeup_count - Save the current number of registered wakeup events. 925 * @count: Value to compare with the current number of registered wakeup events. 926 * 927 * If @count is equal to the current number of registered wakeup events and the 928 * current number of wakeup events being processed is zero, store @count as the 929 * old number of registered wakeup events for pm_check_wakeup_events(), enable 930 * wakeup events detection and return 'true'. Otherwise disable wakeup events 931 * detection and return 'false'. 932 */ 933 bool pm_save_wakeup_count(unsigned int count) 934 { 935 unsigned int cnt, inpr; 936 unsigned long flags; 937 938 events_check_enabled = false; 939 spin_lock_irqsave(&events_lock, flags); 940 split_counters(&cnt, &inpr); 941 if (cnt == count && inpr == 0) { 942 saved_count = count; 943 events_check_enabled = true; 944 } 945 spin_unlock_irqrestore(&events_lock, flags); 946 return events_check_enabled; 947 } 948 949 #ifdef CONFIG_PM_AUTOSLEEP 950 /** 951 * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources. 952 * @enabled: Whether to set or to clear the autosleep_enabled flags. 953 */ 954 void pm_wakep_autosleep_enabled(bool set) 955 { 956 struct wakeup_source *ws; 957 ktime_t now = ktime_get(); 958 959 rcu_read_lock(); 960 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 961 spin_lock_irq(&ws->lock); 962 if (ws->autosleep_enabled != set) { 963 ws->autosleep_enabled = set; 964 if (ws->active) { 965 if (set) 966 ws->start_prevent_time = now; 967 else 968 update_prevent_sleep_time(ws, now); 969 } 970 } 971 spin_unlock_irq(&ws->lock); 972 } 973 rcu_read_unlock(); 974 } 975 #endif /* CONFIG_PM_AUTOSLEEP */ 976 977 static struct dentry *wakeup_sources_stats_dentry; 978 979 /** 980 * print_wakeup_source_stats - Print wakeup source statistics information. 981 * @m: seq_file to print the statistics into. 982 * @ws: Wakeup source object to print the statistics for. 983 */ 984 static int print_wakeup_source_stats(struct seq_file *m, 985 struct wakeup_source *ws) 986 { 987 unsigned long flags; 988 ktime_t total_time; 989 ktime_t max_time; 990 unsigned long active_count; 991 ktime_t active_time; 992 ktime_t prevent_sleep_time; 993 994 spin_lock_irqsave(&ws->lock, flags); 995 996 total_time = ws->total_time; 997 max_time = ws->max_time; 998 prevent_sleep_time = ws->prevent_sleep_time; 999 active_count = ws->active_count; 1000 if (ws->active) { 1001 ktime_t now = ktime_get(); 1002 1003 active_time = ktime_sub(now, ws->last_time); 1004 total_time = ktime_add(total_time, active_time); 1005 if (active_time.tv64 > max_time.tv64) 1006 max_time = active_time; 1007 1008 if (ws->autosleep_enabled) 1009 prevent_sleep_time = ktime_add(prevent_sleep_time, 1010 ktime_sub(now, ws->start_prevent_time)); 1011 } else { 1012 active_time = ktime_set(0, 0); 1013 } 1014 1015 seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n", 1016 ws->name, active_count, ws->event_count, 1017 ws->wakeup_count, ws->expire_count, 1018 ktime_to_ms(active_time), ktime_to_ms(total_time), 1019 ktime_to_ms(max_time), ktime_to_ms(ws->last_time), 1020 ktime_to_ms(prevent_sleep_time)); 1021 1022 spin_unlock_irqrestore(&ws->lock, flags); 1023 1024 return 0; 1025 } 1026 1027 /** 1028 * wakeup_sources_stats_show - Print wakeup sources statistics information. 1029 * @m: seq_file to print the statistics into. 1030 */ 1031 static int wakeup_sources_stats_show(struct seq_file *m, void *unused) 1032 { 1033 struct wakeup_source *ws; 1034 1035 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" 1036 "expire_count\tactive_since\ttotal_time\tmax_time\t" 1037 "last_change\tprevent_suspend_time\n"); 1038 1039 rcu_read_lock(); 1040 list_for_each_entry_rcu(ws, &wakeup_sources, entry) 1041 print_wakeup_source_stats(m, ws); 1042 rcu_read_unlock(); 1043 1044 print_wakeup_source_stats(m, &deleted_ws); 1045 1046 return 0; 1047 } 1048 1049 static int wakeup_sources_stats_open(struct inode *inode, struct file *file) 1050 { 1051 return single_open(file, wakeup_sources_stats_show, NULL); 1052 } 1053 1054 static const struct file_operations wakeup_sources_stats_fops = { 1055 .owner = THIS_MODULE, 1056 .open = wakeup_sources_stats_open, 1057 .read = seq_read, 1058 .llseek = seq_lseek, 1059 .release = single_release, 1060 }; 1061 1062 static int __init wakeup_sources_debugfs_init(void) 1063 { 1064 wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources", 1065 S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops); 1066 return 0; 1067 } 1068 1069 postcore_initcall(wakeup_sources_debugfs_init); 1070