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 spin_unlock_irq(&dev->power.lock); 250 return 0; 251 } 252 253 /** 254 * device_wakeup_enable - Enable given device to be a wakeup source. 255 * @dev: Device to handle. 256 * 257 * Create a wakeup source object, register it and attach it to @dev. 258 */ 259 int device_wakeup_enable(struct device *dev) 260 { 261 struct wakeup_source *ws; 262 int ret; 263 264 if (!dev || !dev->power.can_wakeup) 265 return -EINVAL; 266 267 ws = wakeup_source_register(dev_name(dev)); 268 if (!ws) 269 return -ENOMEM; 270 271 ret = device_wakeup_attach(dev, ws); 272 if (ret) 273 wakeup_source_unregister(ws); 274 275 return ret; 276 } 277 EXPORT_SYMBOL_GPL(device_wakeup_enable); 278 279 /** 280 * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source 281 * @dev: Device to handle 282 * @wakeirq: Device specific wakeirq entry 283 * 284 * Attach a device wakeirq to the wakeup source so the device 285 * wake IRQ can be configured automatically for suspend and 286 * resume. 287 * 288 * Call under the device's power.lock lock. 289 */ 290 int device_wakeup_attach_irq(struct device *dev, 291 struct wake_irq *wakeirq) 292 { 293 struct wakeup_source *ws; 294 295 ws = dev->power.wakeup; 296 if (!ws) { 297 dev_err(dev, "forgot to call call device_init_wakeup?\n"); 298 return -EINVAL; 299 } 300 301 if (ws->wakeirq) 302 return -EEXIST; 303 304 ws->wakeirq = wakeirq; 305 return 0; 306 } 307 308 /** 309 * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source 310 * @dev: Device to handle 311 * 312 * Removes a device wakeirq from the wakeup source. 313 * 314 * Call under the device's power.lock lock. 315 */ 316 void device_wakeup_detach_irq(struct device *dev) 317 { 318 struct wakeup_source *ws; 319 320 ws = dev->power.wakeup; 321 if (ws) 322 ws->wakeirq = NULL; 323 } 324 325 /** 326 * device_wakeup_arm_wake_irqs(void) 327 * 328 * Itereates over the list of device wakeirqs to arm them. 329 */ 330 void device_wakeup_arm_wake_irqs(void) 331 { 332 struct wakeup_source *ws; 333 334 rcu_read_lock(); 335 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 336 if (ws->wakeirq) 337 dev_pm_arm_wake_irq(ws->wakeirq); 338 } 339 rcu_read_unlock(); 340 } 341 342 /** 343 * device_wakeup_disarm_wake_irqs(void) 344 * 345 * Itereates over the list of device wakeirqs to disarm them. 346 */ 347 void device_wakeup_disarm_wake_irqs(void) 348 { 349 struct wakeup_source *ws; 350 351 rcu_read_lock(); 352 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 353 if (ws->wakeirq) 354 dev_pm_disarm_wake_irq(ws->wakeirq); 355 } 356 rcu_read_unlock(); 357 } 358 359 /** 360 * device_wakeup_detach - Detach a device's wakeup source object from it. 361 * @dev: Device to detach the wakeup source object from. 362 * 363 * After it returns, @dev will not be treated as a wakeup device any more. 364 */ 365 static struct wakeup_source *device_wakeup_detach(struct device *dev) 366 { 367 struct wakeup_source *ws; 368 369 spin_lock_irq(&dev->power.lock); 370 ws = dev->power.wakeup; 371 dev->power.wakeup = NULL; 372 spin_unlock_irq(&dev->power.lock); 373 return ws; 374 } 375 376 /** 377 * device_wakeup_disable - Do not regard a device as a wakeup source any more. 378 * @dev: Device to handle. 379 * 380 * Detach the @dev's wakeup source object from it, unregister this wakeup source 381 * object and destroy it. 382 */ 383 int device_wakeup_disable(struct device *dev) 384 { 385 struct wakeup_source *ws; 386 387 if (!dev || !dev->power.can_wakeup) 388 return -EINVAL; 389 390 ws = device_wakeup_detach(dev); 391 if (ws) 392 wakeup_source_unregister(ws); 393 394 return 0; 395 } 396 EXPORT_SYMBOL_GPL(device_wakeup_disable); 397 398 /** 399 * device_set_wakeup_capable - Set/reset device wakeup capability flag. 400 * @dev: Device to handle. 401 * @capable: Whether or not @dev is capable of waking up the system from sleep. 402 * 403 * If @capable is set, set the @dev's power.can_wakeup flag and add its 404 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's 405 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs. 406 * 407 * This function may sleep and it can't be called from any context where 408 * sleeping is not allowed. 409 */ 410 void device_set_wakeup_capable(struct device *dev, bool capable) 411 { 412 if (!!dev->power.can_wakeup == !!capable) 413 return; 414 415 if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { 416 if (capable) { 417 if (wakeup_sysfs_add(dev)) 418 return; 419 } else { 420 wakeup_sysfs_remove(dev); 421 } 422 } 423 dev->power.can_wakeup = capable; 424 } 425 EXPORT_SYMBOL_GPL(device_set_wakeup_capable); 426 427 /** 428 * device_init_wakeup - Device wakeup initialization. 429 * @dev: Device to handle. 430 * @enable: Whether or not to enable @dev as a wakeup device. 431 * 432 * By default, most devices should leave wakeup disabled. The exceptions are 433 * devices that everyone expects to be wakeup sources: keyboards, power buttons, 434 * possibly network interfaces, etc. Also, devices that don't generate their 435 * own wakeup requests but merely forward requests from one bus to another 436 * (like PCI bridges) should have wakeup enabled by default. 437 */ 438 int device_init_wakeup(struct device *dev, bool enable) 439 { 440 int ret = 0; 441 442 if (!dev) 443 return -EINVAL; 444 445 if (enable) { 446 device_set_wakeup_capable(dev, true); 447 ret = device_wakeup_enable(dev); 448 } else { 449 if (dev->power.can_wakeup) 450 device_wakeup_disable(dev); 451 452 device_set_wakeup_capable(dev, false); 453 } 454 455 return ret; 456 } 457 EXPORT_SYMBOL_GPL(device_init_wakeup); 458 459 /** 460 * device_set_wakeup_enable - Enable or disable a device to wake up the system. 461 * @dev: Device to handle. 462 */ 463 int device_set_wakeup_enable(struct device *dev, bool enable) 464 { 465 if (!dev || !dev->power.can_wakeup) 466 return -EINVAL; 467 468 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev); 469 } 470 EXPORT_SYMBOL_GPL(device_set_wakeup_enable); 471 472 /** 473 * wakeup_source_not_registered - validate the given wakeup source. 474 * @ws: Wakeup source to be validated. 475 */ 476 static bool wakeup_source_not_registered(struct wakeup_source *ws) 477 { 478 /* 479 * Use timer struct to check if the given source is initialized 480 * by wakeup_source_add. 481 */ 482 return ws->timer.function != pm_wakeup_timer_fn || 483 ws->timer.data != (unsigned long)ws; 484 } 485 486 /* 487 * The functions below use the observation that each wakeup event starts a 488 * period in which the system should not be suspended. The moment this period 489 * will end depends on how the wakeup event is going to be processed after being 490 * detected and all of the possible cases can be divided into two distinct 491 * groups. 492 * 493 * First, a wakeup event may be detected by the same functional unit that will 494 * carry out the entire processing of it and possibly will pass it to user space 495 * for further processing. In that case the functional unit that has detected 496 * the event may later "close" the "no suspend" period associated with it 497 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and 498 * pm_relax(), balanced with each other, is supposed to be used in such 499 * situations. 500 * 501 * Second, a wakeup event may be detected by one functional unit and processed 502 * by another one. In that case the unit that has detected it cannot really 503 * "close" the "no suspend" period associated with it, unless it knows in 504 * advance what's going to happen to the event during processing. This 505 * knowledge, however, may not be available to it, so it can simply specify time 506 * to wait before the system can be suspended and pass it as the second 507 * argument of pm_wakeup_event(). 508 * 509 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the 510 * "no suspend" period will be ended either by the pm_relax(), or by the timer 511 * function executed when the timer expires, whichever comes first. 512 */ 513 514 /** 515 * wakup_source_activate - Mark given wakeup source as active. 516 * @ws: Wakeup source to handle. 517 * 518 * Update the @ws' statistics and, if @ws has just been activated, notify the PM 519 * core of the event by incrementing the counter of of wakeup events being 520 * processed. 521 */ 522 static void wakeup_source_activate(struct wakeup_source *ws) 523 { 524 unsigned int cec; 525 526 if (WARN_ONCE(wakeup_source_not_registered(ws), 527 "unregistered wakeup source\n")) 528 return; 529 530 /* 531 * active wakeup source should bring the system 532 * out of PM_SUSPEND_FREEZE state 533 */ 534 freeze_wake(); 535 536 ws->active = true; 537 ws->active_count++; 538 ws->last_time = ktime_get(); 539 if (ws->autosleep_enabled) 540 ws->start_prevent_time = ws->last_time; 541 542 /* Increment the counter of events in progress. */ 543 cec = atomic_inc_return(&combined_event_count); 544 545 trace_wakeup_source_activate(ws->name, cec); 546 } 547 548 /** 549 * wakeup_source_report_event - Report wakeup event using the given source. 550 * @ws: Wakeup source to report the event for. 551 */ 552 static void wakeup_source_report_event(struct wakeup_source *ws) 553 { 554 ws->event_count++; 555 /* This is racy, but the counter is approximate anyway. */ 556 if (events_check_enabled) 557 ws->wakeup_count++; 558 559 if (!ws->active) 560 wakeup_source_activate(ws); 561 } 562 563 /** 564 * __pm_stay_awake - Notify the PM core of a wakeup event. 565 * @ws: Wakeup source object associated with the source of the event. 566 * 567 * It is safe to call this function from interrupt context. 568 */ 569 void __pm_stay_awake(struct wakeup_source *ws) 570 { 571 unsigned long flags; 572 573 if (!ws) 574 return; 575 576 spin_lock_irqsave(&ws->lock, flags); 577 578 wakeup_source_report_event(ws); 579 del_timer(&ws->timer); 580 ws->timer_expires = 0; 581 582 spin_unlock_irqrestore(&ws->lock, flags); 583 } 584 EXPORT_SYMBOL_GPL(__pm_stay_awake); 585 586 /** 587 * pm_stay_awake - Notify the PM core that a wakeup event is being processed. 588 * @dev: Device the wakeup event is related to. 589 * 590 * Notify the PM core of a wakeup event (signaled by @dev) by calling 591 * __pm_stay_awake for the @dev's wakeup source object. 592 * 593 * Call this function after detecting of a wakeup event if pm_relax() is going 594 * to be called directly after processing the event (and possibly passing it to 595 * user space for further processing). 596 */ 597 void pm_stay_awake(struct device *dev) 598 { 599 unsigned long flags; 600 601 if (!dev) 602 return; 603 604 spin_lock_irqsave(&dev->power.lock, flags); 605 __pm_stay_awake(dev->power.wakeup); 606 spin_unlock_irqrestore(&dev->power.lock, flags); 607 } 608 EXPORT_SYMBOL_GPL(pm_stay_awake); 609 610 #ifdef CONFIG_PM_AUTOSLEEP 611 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now) 612 { 613 ktime_t delta = ktime_sub(now, ws->start_prevent_time); 614 ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta); 615 } 616 #else 617 static inline void update_prevent_sleep_time(struct wakeup_source *ws, 618 ktime_t now) {} 619 #endif 620 621 /** 622 * wakup_source_deactivate - Mark given wakeup source as inactive. 623 * @ws: Wakeup source to handle. 624 * 625 * Update the @ws' statistics and notify the PM core that the wakeup source has 626 * become inactive by decrementing the counter of wakeup events being processed 627 * and incrementing the counter of registered wakeup events. 628 */ 629 static void wakeup_source_deactivate(struct wakeup_source *ws) 630 { 631 unsigned int cnt, inpr, cec; 632 ktime_t duration; 633 ktime_t now; 634 635 ws->relax_count++; 636 /* 637 * __pm_relax() may be called directly or from a timer function. 638 * If it is called directly right after the timer function has been 639 * started, but before the timer function calls __pm_relax(), it is 640 * possible that __pm_stay_awake() will be called in the meantime and 641 * will set ws->active. Then, ws->active may be cleared immediately 642 * by the __pm_relax() called from the timer function, but in such a 643 * case ws->relax_count will be different from ws->active_count. 644 */ 645 if (ws->relax_count != ws->active_count) { 646 ws->relax_count--; 647 return; 648 } 649 650 ws->active = false; 651 652 now = ktime_get(); 653 duration = ktime_sub(now, ws->last_time); 654 ws->total_time = ktime_add(ws->total_time, duration); 655 if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time)) 656 ws->max_time = duration; 657 658 ws->last_time = now; 659 del_timer(&ws->timer); 660 ws->timer_expires = 0; 661 662 if (ws->autosleep_enabled) 663 update_prevent_sleep_time(ws, now); 664 665 /* 666 * Increment the counter of registered wakeup events and decrement the 667 * couter of wakeup events in progress simultaneously. 668 */ 669 cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count); 670 trace_wakeup_source_deactivate(ws->name, cec); 671 672 split_counters(&cnt, &inpr); 673 if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) 674 wake_up(&wakeup_count_wait_queue); 675 } 676 677 /** 678 * __pm_relax - Notify the PM core that processing of a wakeup event has ended. 679 * @ws: Wakeup source object associated with the source of the event. 680 * 681 * Call this function for wakeup events whose processing started with calling 682 * __pm_stay_awake(). 683 * 684 * It is safe to call it from interrupt context. 685 */ 686 void __pm_relax(struct wakeup_source *ws) 687 { 688 unsigned long flags; 689 690 if (!ws) 691 return; 692 693 spin_lock_irqsave(&ws->lock, flags); 694 if (ws->active) 695 wakeup_source_deactivate(ws); 696 spin_unlock_irqrestore(&ws->lock, flags); 697 } 698 EXPORT_SYMBOL_GPL(__pm_relax); 699 700 /** 701 * pm_relax - Notify the PM core that processing of a wakeup event has ended. 702 * @dev: Device that signaled the event. 703 * 704 * Execute __pm_relax() for the @dev's wakeup source object. 705 */ 706 void pm_relax(struct device *dev) 707 { 708 unsigned long flags; 709 710 if (!dev) 711 return; 712 713 spin_lock_irqsave(&dev->power.lock, flags); 714 __pm_relax(dev->power.wakeup); 715 spin_unlock_irqrestore(&dev->power.lock, flags); 716 } 717 EXPORT_SYMBOL_GPL(pm_relax); 718 719 /** 720 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event. 721 * @data: Address of the wakeup source object associated with the event source. 722 * 723 * Call wakeup_source_deactivate() for the wakeup source whose address is stored 724 * in @data if it is currently active and its timer has not been canceled and 725 * the expiration time of the timer is not in future. 726 */ 727 static void pm_wakeup_timer_fn(unsigned long data) 728 { 729 struct wakeup_source *ws = (struct wakeup_source *)data; 730 unsigned long flags; 731 732 spin_lock_irqsave(&ws->lock, flags); 733 734 if (ws->active && ws->timer_expires 735 && time_after_eq(jiffies, ws->timer_expires)) { 736 wakeup_source_deactivate(ws); 737 ws->expire_count++; 738 } 739 740 spin_unlock_irqrestore(&ws->lock, flags); 741 } 742 743 /** 744 * __pm_wakeup_event - Notify the PM core of a wakeup event. 745 * @ws: Wakeup source object associated with the event source. 746 * @msec: Anticipated event processing time (in milliseconds). 747 * 748 * Notify the PM core of a wakeup event whose source is @ws that will take 749 * approximately @msec milliseconds to be processed by the kernel. If @ws is 750 * not active, activate it. If @msec is nonzero, set up the @ws' timer to 751 * execute pm_wakeup_timer_fn() in future. 752 * 753 * It is safe to call this function from interrupt context. 754 */ 755 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec) 756 { 757 unsigned long flags; 758 unsigned long expires; 759 760 if (!ws) 761 return; 762 763 spin_lock_irqsave(&ws->lock, flags); 764 765 wakeup_source_report_event(ws); 766 767 if (!msec) { 768 wakeup_source_deactivate(ws); 769 goto unlock; 770 } 771 772 expires = jiffies + msecs_to_jiffies(msec); 773 if (!expires) 774 expires = 1; 775 776 if (!ws->timer_expires || time_after(expires, ws->timer_expires)) { 777 mod_timer(&ws->timer, expires); 778 ws->timer_expires = expires; 779 } 780 781 unlock: 782 spin_unlock_irqrestore(&ws->lock, flags); 783 } 784 EXPORT_SYMBOL_GPL(__pm_wakeup_event); 785 786 787 /** 788 * pm_wakeup_event - Notify the PM core of a wakeup event. 789 * @dev: Device the wakeup event is related to. 790 * @msec: Anticipated event processing time (in milliseconds). 791 * 792 * Call __pm_wakeup_event() for the @dev's wakeup source object. 793 */ 794 void pm_wakeup_event(struct device *dev, unsigned int msec) 795 { 796 unsigned long flags; 797 798 if (!dev) 799 return; 800 801 spin_lock_irqsave(&dev->power.lock, flags); 802 __pm_wakeup_event(dev->power.wakeup, msec); 803 spin_unlock_irqrestore(&dev->power.lock, flags); 804 } 805 EXPORT_SYMBOL_GPL(pm_wakeup_event); 806 807 void pm_print_active_wakeup_sources(void) 808 { 809 struct wakeup_source *ws; 810 int active = 0; 811 struct wakeup_source *last_activity_ws = NULL; 812 813 rcu_read_lock(); 814 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 815 if (ws->active) { 816 pr_info("active wakeup source: %s\n", ws->name); 817 active = 1; 818 } else if (!active && 819 (!last_activity_ws || 820 ktime_to_ns(ws->last_time) > 821 ktime_to_ns(last_activity_ws->last_time))) { 822 last_activity_ws = ws; 823 } 824 } 825 826 if (!active && last_activity_ws) 827 pr_info("last active wakeup source: %s\n", 828 last_activity_ws->name); 829 rcu_read_unlock(); 830 } 831 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); 832 833 /** 834 * pm_wakeup_pending - Check if power transition in progress should be aborted. 835 * 836 * Compare the current number of registered wakeup events with its preserved 837 * value from the past and return true if new wakeup events have been registered 838 * since the old value was stored. Also return true if the current number of 839 * wakeup events being processed is different from zero. 840 */ 841 bool pm_wakeup_pending(void) 842 { 843 unsigned long flags; 844 bool ret = false; 845 846 spin_lock_irqsave(&events_lock, flags); 847 if (events_check_enabled) { 848 unsigned int cnt, inpr; 849 850 split_counters(&cnt, &inpr); 851 ret = (cnt != saved_count || inpr > 0); 852 events_check_enabled = !ret; 853 } 854 spin_unlock_irqrestore(&events_lock, flags); 855 856 if (ret) { 857 pr_info("PM: Wakeup pending, aborting suspend\n"); 858 pm_print_active_wakeup_sources(); 859 } 860 861 return ret || pm_abort_suspend; 862 } 863 864 void pm_system_wakeup(void) 865 { 866 pm_abort_suspend = true; 867 freeze_wake(); 868 } 869 EXPORT_SYMBOL_GPL(pm_system_wakeup); 870 871 void pm_wakeup_clear(void) 872 { 873 pm_abort_suspend = false; 874 pm_wakeup_irq = 0; 875 } 876 877 void pm_system_irq_wakeup(unsigned int irq_number) 878 { 879 if (pm_wakeup_irq == 0) { 880 pm_wakeup_irq = irq_number; 881 pm_system_wakeup(); 882 } 883 } 884 885 /** 886 * pm_get_wakeup_count - Read the number of registered wakeup events. 887 * @count: Address to store the value at. 888 * @block: Whether or not to block. 889 * 890 * Store the number of registered wakeup events at the address in @count. If 891 * @block is set, block until the current number of wakeup events being 892 * processed is zero. 893 * 894 * Return 'false' if the current number of wakeup events being processed is 895 * nonzero. Otherwise return 'true'. 896 */ 897 bool pm_get_wakeup_count(unsigned int *count, bool block) 898 { 899 unsigned int cnt, inpr; 900 901 if (block) { 902 DEFINE_WAIT(wait); 903 904 for (;;) { 905 prepare_to_wait(&wakeup_count_wait_queue, &wait, 906 TASK_INTERRUPTIBLE); 907 split_counters(&cnt, &inpr); 908 if (inpr == 0 || signal_pending(current)) 909 break; 910 911 schedule(); 912 } 913 finish_wait(&wakeup_count_wait_queue, &wait); 914 } 915 916 split_counters(&cnt, &inpr); 917 *count = cnt; 918 return !inpr; 919 } 920 921 /** 922 * pm_save_wakeup_count - Save the current number of registered wakeup events. 923 * @count: Value to compare with the current number of registered wakeup events. 924 * 925 * If @count is equal to the current number of registered wakeup events and the 926 * current number of wakeup events being processed is zero, store @count as the 927 * old number of registered wakeup events for pm_check_wakeup_events(), enable 928 * wakeup events detection and return 'true'. Otherwise disable wakeup events 929 * detection and return 'false'. 930 */ 931 bool pm_save_wakeup_count(unsigned int count) 932 { 933 unsigned int cnt, inpr; 934 unsigned long flags; 935 936 events_check_enabled = false; 937 spin_lock_irqsave(&events_lock, flags); 938 split_counters(&cnt, &inpr); 939 if (cnt == count && inpr == 0) { 940 saved_count = count; 941 events_check_enabled = true; 942 } 943 spin_unlock_irqrestore(&events_lock, flags); 944 return events_check_enabled; 945 } 946 947 #ifdef CONFIG_PM_AUTOSLEEP 948 /** 949 * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources. 950 * @enabled: Whether to set or to clear the autosleep_enabled flags. 951 */ 952 void pm_wakep_autosleep_enabled(bool set) 953 { 954 struct wakeup_source *ws; 955 ktime_t now = ktime_get(); 956 957 rcu_read_lock(); 958 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 959 spin_lock_irq(&ws->lock); 960 if (ws->autosleep_enabled != set) { 961 ws->autosleep_enabled = set; 962 if (ws->active) { 963 if (set) 964 ws->start_prevent_time = now; 965 else 966 update_prevent_sleep_time(ws, now); 967 } 968 } 969 spin_unlock_irq(&ws->lock); 970 } 971 rcu_read_unlock(); 972 } 973 #endif /* CONFIG_PM_AUTOSLEEP */ 974 975 static struct dentry *wakeup_sources_stats_dentry; 976 977 /** 978 * print_wakeup_source_stats - Print wakeup source statistics information. 979 * @m: seq_file to print the statistics into. 980 * @ws: Wakeup source object to print the statistics for. 981 */ 982 static int print_wakeup_source_stats(struct seq_file *m, 983 struct wakeup_source *ws) 984 { 985 unsigned long flags; 986 ktime_t total_time; 987 ktime_t max_time; 988 unsigned long active_count; 989 ktime_t active_time; 990 ktime_t prevent_sleep_time; 991 992 spin_lock_irqsave(&ws->lock, flags); 993 994 total_time = ws->total_time; 995 max_time = ws->max_time; 996 prevent_sleep_time = ws->prevent_sleep_time; 997 active_count = ws->active_count; 998 if (ws->active) { 999 ktime_t now = ktime_get(); 1000 1001 active_time = ktime_sub(now, ws->last_time); 1002 total_time = ktime_add(total_time, active_time); 1003 if (active_time.tv64 > max_time.tv64) 1004 max_time = active_time; 1005 1006 if (ws->autosleep_enabled) 1007 prevent_sleep_time = ktime_add(prevent_sleep_time, 1008 ktime_sub(now, ws->start_prevent_time)); 1009 } else { 1010 active_time = ktime_set(0, 0); 1011 } 1012 1013 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", 1014 ws->name, active_count, ws->event_count, 1015 ws->wakeup_count, ws->expire_count, 1016 ktime_to_ms(active_time), ktime_to_ms(total_time), 1017 ktime_to_ms(max_time), ktime_to_ms(ws->last_time), 1018 ktime_to_ms(prevent_sleep_time)); 1019 1020 spin_unlock_irqrestore(&ws->lock, flags); 1021 1022 return 0; 1023 } 1024 1025 /** 1026 * wakeup_sources_stats_show - Print wakeup sources statistics information. 1027 * @m: seq_file to print the statistics into. 1028 */ 1029 static int wakeup_sources_stats_show(struct seq_file *m, void *unused) 1030 { 1031 struct wakeup_source *ws; 1032 1033 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" 1034 "expire_count\tactive_since\ttotal_time\tmax_time\t" 1035 "last_change\tprevent_suspend_time\n"); 1036 1037 rcu_read_lock(); 1038 list_for_each_entry_rcu(ws, &wakeup_sources, entry) 1039 print_wakeup_source_stats(m, ws); 1040 rcu_read_unlock(); 1041 1042 print_wakeup_source_stats(m, &deleted_ws); 1043 1044 return 0; 1045 } 1046 1047 static int wakeup_sources_stats_open(struct inode *inode, struct file *file) 1048 { 1049 return single_open(file, wakeup_sources_stats_show, NULL); 1050 } 1051 1052 static const struct file_operations wakeup_sources_stats_fops = { 1053 .owner = THIS_MODULE, 1054 .open = wakeup_sources_stats_open, 1055 .read = seq_read, 1056 .llseek = seq_lseek, 1057 .release = single_release, 1058 }; 1059 1060 static int __init wakeup_sources_debugfs_init(void) 1061 { 1062 wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources", 1063 S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops); 1064 return 0; 1065 } 1066 1067 postcore_initcall(wakeup_sources_debugfs_init); 1068