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