1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * drivers/base/power/wakeup.c - System wakeup events framework 4 * 5 * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 6 */ 7 #define pr_fmt(fmt) "PM: " fmt 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 #ifndef CONFIG_SUSPEND 23 suspend_state_t pm_suspend_target_state; 24 #define pm_suspend_target_state (PM_SUSPEND_ON) 25 #endif 26 27 /* 28 * If set, the suspend/hibernate code will abort transitions to a sleep state 29 * if wakeup events are registered during or immediately before the transition. 30 */ 31 bool events_check_enabled __read_mostly; 32 33 /* First wakeup IRQ seen by the kernel in the last cycle. */ 34 unsigned int pm_wakeup_irq __read_mostly; 35 36 /* If greater than 0 and the system is suspending, terminate the suspend. */ 37 static atomic_t pm_abort_suspend __read_mostly; 38 39 /* 40 * Combined counters of registered wakeup events and wakeup events in progress. 41 * They need to be modified together atomically, so it's better to use one 42 * atomic variable to hold them both. 43 */ 44 static atomic_t combined_event_count = ATOMIC_INIT(0); 45 46 #define IN_PROGRESS_BITS (sizeof(int) * 4) 47 #define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1) 48 49 static void split_counters(unsigned int *cnt, unsigned int *inpr) 50 { 51 unsigned int comb = atomic_read(&combined_event_count); 52 53 *cnt = (comb >> IN_PROGRESS_BITS); 54 *inpr = comb & MAX_IN_PROGRESS; 55 } 56 57 /* A preserved old value of the events counter. */ 58 static unsigned int saved_count; 59 60 static DEFINE_RAW_SPINLOCK(events_lock); 61 62 static void pm_wakeup_timer_fn(struct timer_list *t); 63 64 static LIST_HEAD(wakeup_sources); 65 66 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue); 67 68 DEFINE_STATIC_SRCU(wakeup_srcu); 69 70 static struct wakeup_source deleted_ws = { 71 .name = "deleted", 72 .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock), 73 }; 74 75 static DEFINE_IDA(wakeup_ida); 76 77 /** 78 * wakeup_source_create - Create a struct wakeup_source object. 79 * @name: Name of the new wakeup source. 80 */ 81 struct wakeup_source *wakeup_source_create(const char *name) 82 { 83 struct wakeup_source *ws; 84 const char *ws_name; 85 int id; 86 87 ws = kzalloc(sizeof(*ws), GFP_KERNEL); 88 if (!ws) 89 goto err_ws; 90 91 ws_name = kstrdup_const(name, GFP_KERNEL); 92 if (!ws_name) 93 goto err_name; 94 ws->name = ws_name; 95 96 id = ida_alloc(&wakeup_ida, GFP_KERNEL); 97 if (id < 0) 98 goto err_id; 99 ws->id = id; 100 101 return ws; 102 103 err_id: 104 kfree_const(ws->name); 105 err_name: 106 kfree(ws); 107 err_ws: 108 return NULL; 109 } 110 EXPORT_SYMBOL_GPL(wakeup_source_create); 111 112 /* 113 * Record wakeup_source statistics being deleted into a dummy wakeup_source. 114 */ 115 static void wakeup_source_record(struct wakeup_source *ws) 116 { 117 unsigned long flags; 118 119 spin_lock_irqsave(&deleted_ws.lock, flags); 120 121 if (ws->event_count) { 122 deleted_ws.total_time = 123 ktime_add(deleted_ws.total_time, ws->total_time); 124 deleted_ws.prevent_sleep_time = 125 ktime_add(deleted_ws.prevent_sleep_time, 126 ws->prevent_sleep_time); 127 deleted_ws.max_time = 128 ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ? 129 deleted_ws.max_time : ws->max_time; 130 deleted_ws.event_count += ws->event_count; 131 deleted_ws.active_count += ws->active_count; 132 deleted_ws.relax_count += ws->relax_count; 133 deleted_ws.expire_count += ws->expire_count; 134 deleted_ws.wakeup_count += ws->wakeup_count; 135 } 136 137 spin_unlock_irqrestore(&deleted_ws.lock, flags); 138 } 139 140 static void wakeup_source_free(struct wakeup_source *ws) 141 { 142 ida_free(&wakeup_ida, ws->id); 143 kfree_const(ws->name); 144 kfree(ws); 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 __pm_relax(ws); 159 wakeup_source_record(ws); 160 wakeup_source_free(ws); 161 } 162 EXPORT_SYMBOL_GPL(wakeup_source_destroy); 163 164 /** 165 * wakeup_source_add - Add given object to the list of wakeup sources. 166 * @ws: Wakeup source object to add to the list. 167 */ 168 void wakeup_source_add(struct wakeup_source *ws) 169 { 170 unsigned long flags; 171 172 if (WARN_ON(!ws)) 173 return; 174 175 spin_lock_init(&ws->lock); 176 timer_setup(&ws->timer, pm_wakeup_timer_fn, 0); 177 ws->active = false; 178 179 raw_spin_lock_irqsave(&events_lock, flags); 180 list_add_rcu(&ws->entry, &wakeup_sources); 181 raw_spin_unlock_irqrestore(&events_lock, flags); 182 } 183 EXPORT_SYMBOL_GPL(wakeup_source_add); 184 185 /** 186 * wakeup_source_remove - Remove given object from the wakeup sources list. 187 * @ws: Wakeup source object to remove from the list. 188 */ 189 void wakeup_source_remove(struct wakeup_source *ws) 190 { 191 unsigned long flags; 192 193 if (WARN_ON(!ws)) 194 return; 195 196 raw_spin_lock_irqsave(&events_lock, flags); 197 list_del_rcu(&ws->entry); 198 raw_spin_unlock_irqrestore(&events_lock, flags); 199 synchronize_srcu(&wakeup_srcu); 200 201 del_timer_sync(&ws->timer); 202 /* 203 * Clear timer.function to make wakeup_source_not_registered() treat 204 * this wakeup source as not registered. 205 */ 206 ws->timer.function = NULL; 207 } 208 EXPORT_SYMBOL_GPL(wakeup_source_remove); 209 210 /** 211 * wakeup_source_register - Create wakeup source and add it to the list. 212 * @dev: Device this wakeup source is associated with (or NULL if virtual). 213 * @name: Name of the wakeup source to register. 214 */ 215 struct wakeup_source *wakeup_source_register(struct device *dev, 216 const char *name) 217 { 218 struct wakeup_source *ws; 219 int ret; 220 221 ws = wakeup_source_create(name); 222 if (ws) { 223 if (!dev || device_is_registered(dev)) { 224 ret = wakeup_source_sysfs_add(dev, ws); 225 if (ret) { 226 wakeup_source_free(ws); 227 return NULL; 228 } 229 } 230 wakeup_source_add(ws); 231 } 232 return ws; 233 } 234 EXPORT_SYMBOL_GPL(wakeup_source_register); 235 236 /** 237 * wakeup_source_unregister - Remove wakeup source from the list and remove it. 238 * @ws: Wakeup source object to unregister. 239 */ 240 void wakeup_source_unregister(struct wakeup_source *ws) 241 { 242 if (ws) { 243 wakeup_source_remove(ws); 244 wakeup_source_sysfs_remove(ws); 245 wakeup_source_destroy(ws); 246 } 247 } 248 EXPORT_SYMBOL_GPL(wakeup_source_unregister); 249 250 /** 251 * wakeup_sources_read_lock - Lock wakeup source list for read. 252 * 253 * Returns an index of srcu lock for struct wakeup_srcu. 254 * This index must be passed to the matching wakeup_sources_read_unlock(). 255 */ 256 int wakeup_sources_read_lock(void) 257 { 258 return srcu_read_lock(&wakeup_srcu); 259 } 260 EXPORT_SYMBOL_GPL(wakeup_sources_read_lock); 261 262 /** 263 * wakeup_sources_read_unlock - Unlock wakeup source list. 264 * @idx: return value from corresponding wakeup_sources_read_lock() 265 */ 266 void wakeup_sources_read_unlock(int idx) 267 { 268 srcu_read_unlock(&wakeup_srcu, idx); 269 } 270 EXPORT_SYMBOL_GPL(wakeup_sources_read_unlock); 271 272 /** 273 * wakeup_sources_walk_start - Begin a walk on wakeup source list 274 * 275 * Returns first object of the list of wakeup sources. 276 * 277 * Note that to be safe, wakeup sources list needs to be locked by calling 278 * wakeup_source_read_lock() for this. 279 */ 280 struct wakeup_source *wakeup_sources_walk_start(void) 281 { 282 struct list_head *ws_head = &wakeup_sources; 283 284 return list_entry_rcu(ws_head->next, struct wakeup_source, entry); 285 } 286 EXPORT_SYMBOL_GPL(wakeup_sources_walk_start); 287 288 /** 289 * wakeup_sources_walk_next - Get next wakeup source from the list 290 * @ws: Previous wakeup source object 291 * 292 * Note that to be safe, wakeup sources list needs to be locked by calling 293 * wakeup_source_read_lock() for this. 294 */ 295 struct wakeup_source *wakeup_sources_walk_next(struct wakeup_source *ws) 296 { 297 struct list_head *ws_head = &wakeup_sources; 298 299 return list_next_or_null_rcu(ws_head, &ws->entry, 300 struct wakeup_source, entry); 301 } 302 EXPORT_SYMBOL_GPL(wakeup_sources_walk_next); 303 304 /** 305 * device_wakeup_attach - Attach a wakeup source object to a device object. 306 * @dev: Device to handle. 307 * @ws: Wakeup source object to attach to @dev. 308 * 309 * This causes @dev to be treated as a wakeup device. 310 */ 311 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws) 312 { 313 spin_lock_irq(&dev->power.lock); 314 if (dev->power.wakeup) { 315 spin_unlock_irq(&dev->power.lock); 316 return -EEXIST; 317 } 318 dev->power.wakeup = ws; 319 if (dev->power.wakeirq) 320 device_wakeup_attach_irq(dev, dev->power.wakeirq); 321 spin_unlock_irq(&dev->power.lock); 322 return 0; 323 } 324 325 /** 326 * device_wakeup_enable - Enable given device to be a wakeup source. 327 * @dev: Device to handle. 328 * 329 * Create a wakeup source object, register it and attach it to @dev. 330 */ 331 int device_wakeup_enable(struct device *dev) 332 { 333 struct wakeup_source *ws; 334 int ret; 335 336 if (!dev || !dev->power.can_wakeup) 337 return -EINVAL; 338 339 if (pm_suspend_target_state != PM_SUSPEND_ON) 340 dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__); 341 342 ws = wakeup_source_register(dev, dev_name(dev)); 343 if (!ws) 344 return -ENOMEM; 345 346 ret = device_wakeup_attach(dev, ws); 347 if (ret) 348 wakeup_source_unregister(ws); 349 350 return ret; 351 } 352 EXPORT_SYMBOL_GPL(device_wakeup_enable); 353 354 /** 355 * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source 356 * @dev: Device to handle 357 * @wakeirq: Device specific wakeirq entry 358 * 359 * Attach a device wakeirq to the wakeup source so the device 360 * wake IRQ can be configured automatically for suspend and 361 * resume. 362 * 363 * Call under the device's power.lock lock. 364 */ 365 void device_wakeup_attach_irq(struct device *dev, 366 struct wake_irq *wakeirq) 367 { 368 struct wakeup_source *ws; 369 370 ws = dev->power.wakeup; 371 if (!ws) 372 return; 373 374 if (ws->wakeirq) 375 dev_err(dev, "Leftover wakeup IRQ found, overriding\n"); 376 377 ws->wakeirq = wakeirq; 378 } 379 380 /** 381 * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source 382 * @dev: Device to handle 383 * 384 * Removes a device wakeirq from the wakeup source. 385 * 386 * Call under the device's power.lock lock. 387 */ 388 void device_wakeup_detach_irq(struct device *dev) 389 { 390 struct wakeup_source *ws; 391 392 ws = dev->power.wakeup; 393 if (ws) 394 ws->wakeirq = NULL; 395 } 396 397 /** 398 * device_wakeup_arm_wake_irqs(void) 399 * 400 * Itereates over the list of device wakeirqs to arm them. 401 */ 402 void device_wakeup_arm_wake_irqs(void) 403 { 404 struct wakeup_source *ws; 405 int srcuidx; 406 407 srcuidx = srcu_read_lock(&wakeup_srcu); 408 list_for_each_entry_rcu(ws, &wakeup_sources, entry) 409 dev_pm_arm_wake_irq(ws->wakeirq); 410 srcu_read_unlock(&wakeup_srcu, srcuidx); 411 } 412 413 /** 414 * device_wakeup_disarm_wake_irqs(void) 415 * 416 * Itereates over the list of device wakeirqs to disarm them. 417 */ 418 void device_wakeup_disarm_wake_irqs(void) 419 { 420 struct wakeup_source *ws; 421 int srcuidx; 422 423 srcuidx = srcu_read_lock(&wakeup_srcu); 424 list_for_each_entry_rcu(ws, &wakeup_sources, entry) 425 dev_pm_disarm_wake_irq(ws->wakeirq); 426 srcu_read_unlock(&wakeup_srcu, srcuidx); 427 } 428 429 /** 430 * device_wakeup_detach - Detach a device's wakeup source object from it. 431 * @dev: Device to detach the wakeup source object from. 432 * 433 * After it returns, @dev will not be treated as a wakeup device any more. 434 */ 435 static struct wakeup_source *device_wakeup_detach(struct device *dev) 436 { 437 struct wakeup_source *ws; 438 439 spin_lock_irq(&dev->power.lock); 440 ws = dev->power.wakeup; 441 dev->power.wakeup = NULL; 442 spin_unlock_irq(&dev->power.lock); 443 return ws; 444 } 445 446 /** 447 * device_wakeup_disable - Do not regard a device as a wakeup source any more. 448 * @dev: Device to handle. 449 * 450 * Detach the @dev's wakeup source object from it, unregister this wakeup source 451 * object and destroy it. 452 */ 453 int device_wakeup_disable(struct device *dev) 454 { 455 struct wakeup_source *ws; 456 457 if (!dev || !dev->power.can_wakeup) 458 return -EINVAL; 459 460 ws = device_wakeup_detach(dev); 461 wakeup_source_unregister(ws); 462 return 0; 463 } 464 EXPORT_SYMBOL_GPL(device_wakeup_disable); 465 466 /** 467 * device_set_wakeup_capable - Set/reset device wakeup capability flag. 468 * @dev: Device to handle. 469 * @capable: Whether or not @dev is capable of waking up the system from sleep. 470 * 471 * If @capable is set, set the @dev's power.can_wakeup flag and add its 472 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's 473 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs. 474 * 475 * This function may sleep and it can't be called from any context where 476 * sleeping is not allowed. 477 */ 478 void device_set_wakeup_capable(struct device *dev, bool capable) 479 { 480 if (!!dev->power.can_wakeup == !!capable) 481 return; 482 483 dev->power.can_wakeup = capable; 484 if (device_is_registered(dev) && !list_empty(&dev->power.entry)) { 485 if (capable) { 486 int ret = wakeup_sysfs_add(dev); 487 488 if (ret) 489 dev_info(dev, "Wakeup sysfs attributes not added\n"); 490 } else { 491 wakeup_sysfs_remove(dev); 492 } 493 } 494 } 495 EXPORT_SYMBOL_GPL(device_set_wakeup_capable); 496 497 /** 498 * device_init_wakeup - Device wakeup initialization. 499 * @dev: Device to handle. 500 * @enable: Whether or not to enable @dev as a wakeup device. 501 * 502 * By default, most devices should leave wakeup disabled. The exceptions are 503 * devices that everyone expects to be wakeup sources: keyboards, power buttons, 504 * possibly network interfaces, etc. Also, devices that don't generate their 505 * own wakeup requests but merely forward requests from one bus to another 506 * (like PCI bridges) should have wakeup enabled by default. 507 */ 508 int device_init_wakeup(struct device *dev, bool enable) 509 { 510 int ret = 0; 511 512 if (!dev) 513 return -EINVAL; 514 515 if (enable) { 516 device_set_wakeup_capable(dev, true); 517 ret = device_wakeup_enable(dev); 518 } else { 519 device_wakeup_disable(dev); 520 device_set_wakeup_capable(dev, false); 521 } 522 523 return ret; 524 } 525 EXPORT_SYMBOL_GPL(device_init_wakeup); 526 527 /** 528 * device_set_wakeup_enable - Enable or disable a device to wake up the system. 529 * @dev: Device to handle. 530 */ 531 int device_set_wakeup_enable(struct device *dev, bool enable) 532 { 533 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev); 534 } 535 EXPORT_SYMBOL_GPL(device_set_wakeup_enable); 536 537 /** 538 * wakeup_source_not_registered - validate the given wakeup source. 539 * @ws: Wakeup source to be validated. 540 */ 541 static bool wakeup_source_not_registered(struct wakeup_source *ws) 542 { 543 /* 544 * Use timer struct to check if the given source is initialized 545 * by wakeup_source_add. 546 */ 547 return ws->timer.function != pm_wakeup_timer_fn; 548 } 549 550 /* 551 * The functions below use the observation that each wakeup event starts a 552 * period in which the system should not be suspended. The moment this period 553 * will end depends on how the wakeup event is going to be processed after being 554 * detected and all of the possible cases can be divided into two distinct 555 * groups. 556 * 557 * First, a wakeup event may be detected by the same functional unit that will 558 * carry out the entire processing of it and possibly will pass it to user space 559 * for further processing. In that case the functional unit that has detected 560 * the event may later "close" the "no suspend" period associated with it 561 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and 562 * pm_relax(), balanced with each other, is supposed to be used in such 563 * situations. 564 * 565 * Second, a wakeup event may be detected by one functional unit and processed 566 * by another one. In that case the unit that has detected it cannot really 567 * "close" the "no suspend" period associated with it, unless it knows in 568 * advance what's going to happen to the event during processing. This 569 * knowledge, however, may not be available to it, so it can simply specify time 570 * to wait before the system can be suspended and pass it as the second 571 * argument of pm_wakeup_event(). 572 * 573 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the 574 * "no suspend" period will be ended either by the pm_relax(), or by the timer 575 * function executed when the timer expires, whichever comes first. 576 */ 577 578 /** 579 * wakup_source_activate - Mark given wakeup source as active. 580 * @ws: Wakeup source to handle. 581 * 582 * Update the @ws' statistics and, if @ws has just been activated, notify the PM 583 * core of the event by incrementing the counter of of wakeup events being 584 * processed. 585 */ 586 static void wakeup_source_activate(struct wakeup_source *ws) 587 { 588 unsigned int cec; 589 590 if (WARN_ONCE(wakeup_source_not_registered(ws), 591 "unregistered wakeup source\n")) 592 return; 593 594 ws->active = true; 595 ws->active_count++; 596 ws->last_time = ktime_get(); 597 if (ws->autosleep_enabled) 598 ws->start_prevent_time = ws->last_time; 599 600 /* Increment the counter of events in progress. */ 601 cec = atomic_inc_return(&combined_event_count); 602 603 trace_wakeup_source_activate(ws->name, cec); 604 } 605 606 /** 607 * wakeup_source_report_event - Report wakeup event using the given source. 608 * @ws: Wakeup source to report the event for. 609 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle. 610 */ 611 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard) 612 { 613 ws->event_count++; 614 /* This is racy, but the counter is approximate anyway. */ 615 if (events_check_enabled) 616 ws->wakeup_count++; 617 618 if (!ws->active) 619 wakeup_source_activate(ws); 620 621 if (hard) 622 pm_system_wakeup(); 623 } 624 625 /** 626 * __pm_stay_awake - Notify the PM core of a wakeup event. 627 * @ws: Wakeup source object associated with the source of the event. 628 * 629 * It is safe to call this function from interrupt context. 630 */ 631 void __pm_stay_awake(struct wakeup_source *ws) 632 { 633 unsigned long flags; 634 635 if (!ws) 636 return; 637 638 spin_lock_irqsave(&ws->lock, flags); 639 640 wakeup_source_report_event(ws, false); 641 del_timer(&ws->timer); 642 ws->timer_expires = 0; 643 644 spin_unlock_irqrestore(&ws->lock, flags); 645 } 646 EXPORT_SYMBOL_GPL(__pm_stay_awake); 647 648 /** 649 * pm_stay_awake - Notify the PM core that a wakeup event is being processed. 650 * @dev: Device the wakeup event is related to. 651 * 652 * Notify the PM core of a wakeup event (signaled by @dev) by calling 653 * __pm_stay_awake for the @dev's wakeup source object. 654 * 655 * Call this function after detecting of a wakeup event if pm_relax() is going 656 * to be called directly after processing the event (and possibly passing it to 657 * user space for further processing). 658 */ 659 void pm_stay_awake(struct device *dev) 660 { 661 unsigned long flags; 662 663 if (!dev) 664 return; 665 666 spin_lock_irqsave(&dev->power.lock, flags); 667 __pm_stay_awake(dev->power.wakeup); 668 spin_unlock_irqrestore(&dev->power.lock, flags); 669 } 670 EXPORT_SYMBOL_GPL(pm_stay_awake); 671 672 #ifdef CONFIG_PM_AUTOSLEEP 673 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now) 674 { 675 ktime_t delta = ktime_sub(now, ws->start_prevent_time); 676 ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta); 677 } 678 #else 679 static inline void update_prevent_sleep_time(struct wakeup_source *ws, 680 ktime_t now) {} 681 #endif 682 683 /** 684 * wakup_source_deactivate - Mark given wakeup source as inactive. 685 * @ws: Wakeup source to handle. 686 * 687 * Update the @ws' statistics and notify the PM core that the wakeup source has 688 * become inactive by decrementing the counter of wakeup events being processed 689 * and incrementing the counter of registered wakeup events. 690 */ 691 static void wakeup_source_deactivate(struct wakeup_source *ws) 692 { 693 unsigned int cnt, inpr, cec; 694 ktime_t duration; 695 ktime_t now; 696 697 ws->relax_count++; 698 /* 699 * __pm_relax() may be called directly or from a timer function. 700 * If it is called directly right after the timer function has been 701 * started, but before the timer function calls __pm_relax(), it is 702 * possible that __pm_stay_awake() will be called in the meantime and 703 * will set ws->active. Then, ws->active may be cleared immediately 704 * by the __pm_relax() called from the timer function, but in such a 705 * case ws->relax_count will be different from ws->active_count. 706 */ 707 if (ws->relax_count != ws->active_count) { 708 ws->relax_count--; 709 return; 710 } 711 712 ws->active = false; 713 714 now = ktime_get(); 715 duration = ktime_sub(now, ws->last_time); 716 ws->total_time = ktime_add(ws->total_time, duration); 717 if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time)) 718 ws->max_time = duration; 719 720 ws->last_time = now; 721 del_timer(&ws->timer); 722 ws->timer_expires = 0; 723 724 if (ws->autosleep_enabled) 725 update_prevent_sleep_time(ws, now); 726 727 /* 728 * Increment the counter of registered wakeup events and decrement the 729 * couter of wakeup events in progress simultaneously. 730 */ 731 cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count); 732 trace_wakeup_source_deactivate(ws->name, cec); 733 734 split_counters(&cnt, &inpr); 735 if (!inpr && waitqueue_active(&wakeup_count_wait_queue)) 736 wake_up(&wakeup_count_wait_queue); 737 } 738 739 /** 740 * __pm_relax - Notify the PM core that processing of a wakeup event has ended. 741 * @ws: Wakeup source object associated with the source of the event. 742 * 743 * Call this function for wakeup events whose processing started with calling 744 * __pm_stay_awake(). 745 * 746 * It is safe to call it from interrupt context. 747 */ 748 void __pm_relax(struct wakeup_source *ws) 749 { 750 unsigned long flags; 751 752 if (!ws) 753 return; 754 755 spin_lock_irqsave(&ws->lock, flags); 756 if (ws->active) 757 wakeup_source_deactivate(ws); 758 spin_unlock_irqrestore(&ws->lock, flags); 759 } 760 EXPORT_SYMBOL_GPL(__pm_relax); 761 762 /** 763 * pm_relax - Notify the PM core that processing of a wakeup event has ended. 764 * @dev: Device that signaled the event. 765 * 766 * Execute __pm_relax() for the @dev's wakeup source object. 767 */ 768 void pm_relax(struct device *dev) 769 { 770 unsigned long flags; 771 772 if (!dev) 773 return; 774 775 spin_lock_irqsave(&dev->power.lock, flags); 776 __pm_relax(dev->power.wakeup); 777 spin_unlock_irqrestore(&dev->power.lock, flags); 778 } 779 EXPORT_SYMBOL_GPL(pm_relax); 780 781 /** 782 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event. 783 * @data: Address of the wakeup source object associated with the event source. 784 * 785 * Call wakeup_source_deactivate() for the wakeup source whose address is stored 786 * in @data if it is currently active and its timer has not been canceled and 787 * the expiration time of the timer is not in future. 788 */ 789 static void pm_wakeup_timer_fn(struct timer_list *t) 790 { 791 struct wakeup_source *ws = from_timer(ws, t, timer); 792 unsigned long flags; 793 794 spin_lock_irqsave(&ws->lock, flags); 795 796 if (ws->active && ws->timer_expires 797 && time_after_eq(jiffies, ws->timer_expires)) { 798 wakeup_source_deactivate(ws); 799 ws->expire_count++; 800 } 801 802 spin_unlock_irqrestore(&ws->lock, flags); 803 } 804 805 /** 806 * pm_wakeup_ws_event - Notify the PM core of a wakeup event. 807 * @ws: Wakeup source object associated with the event source. 808 * @msec: Anticipated event processing time (in milliseconds). 809 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle. 810 * 811 * Notify the PM core of a wakeup event whose source is @ws that will take 812 * approximately @msec milliseconds to be processed by the kernel. If @ws is 813 * not active, activate it. If @msec is nonzero, set up the @ws' timer to 814 * execute pm_wakeup_timer_fn() in future. 815 * 816 * It is safe to call this function from interrupt context. 817 */ 818 void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard) 819 { 820 unsigned long flags; 821 unsigned long expires; 822 823 if (!ws) 824 return; 825 826 spin_lock_irqsave(&ws->lock, flags); 827 828 wakeup_source_report_event(ws, hard); 829 830 if (!msec) { 831 wakeup_source_deactivate(ws); 832 goto unlock; 833 } 834 835 expires = jiffies + msecs_to_jiffies(msec); 836 if (!expires) 837 expires = 1; 838 839 if (!ws->timer_expires || time_after(expires, ws->timer_expires)) { 840 mod_timer(&ws->timer, expires); 841 ws->timer_expires = expires; 842 } 843 844 unlock: 845 spin_unlock_irqrestore(&ws->lock, flags); 846 } 847 EXPORT_SYMBOL_GPL(pm_wakeup_ws_event); 848 849 /** 850 * pm_wakeup_dev_event - Notify the PM core of a wakeup event. 851 * @dev: Device the wakeup event is related to. 852 * @msec: Anticipated event processing time (in milliseconds). 853 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle. 854 * 855 * Call pm_wakeup_ws_event() for the @dev's wakeup source object. 856 */ 857 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard) 858 { 859 unsigned long flags; 860 861 if (!dev) 862 return; 863 864 spin_lock_irqsave(&dev->power.lock, flags); 865 pm_wakeup_ws_event(dev->power.wakeup, msec, hard); 866 spin_unlock_irqrestore(&dev->power.lock, flags); 867 } 868 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event); 869 870 void pm_print_active_wakeup_sources(void) 871 { 872 struct wakeup_source *ws; 873 int srcuidx, active = 0; 874 struct wakeup_source *last_activity_ws = NULL; 875 876 srcuidx = srcu_read_lock(&wakeup_srcu); 877 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 878 if (ws->active) { 879 pm_pr_dbg("active wakeup source: %s\n", ws->name); 880 active = 1; 881 } else if (!active && 882 (!last_activity_ws || 883 ktime_to_ns(ws->last_time) > 884 ktime_to_ns(last_activity_ws->last_time))) { 885 last_activity_ws = ws; 886 } 887 } 888 889 if (!active && last_activity_ws) 890 pm_pr_dbg("last active wakeup source: %s\n", 891 last_activity_ws->name); 892 srcu_read_unlock(&wakeup_srcu, srcuidx); 893 } 894 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources); 895 896 /** 897 * pm_wakeup_pending - Check if power transition in progress should be aborted. 898 * 899 * Compare the current number of registered wakeup events with its preserved 900 * value from the past and return true if new wakeup events have been registered 901 * since the old value was stored. Also return true if the current number of 902 * wakeup events being processed is different from zero. 903 */ 904 bool pm_wakeup_pending(void) 905 { 906 unsigned long flags; 907 bool ret = false; 908 909 raw_spin_lock_irqsave(&events_lock, flags); 910 if (events_check_enabled) { 911 unsigned int cnt, inpr; 912 913 split_counters(&cnt, &inpr); 914 ret = (cnt != saved_count || inpr > 0); 915 events_check_enabled = !ret; 916 } 917 raw_spin_unlock_irqrestore(&events_lock, flags); 918 919 if (ret) { 920 pm_pr_dbg("Wakeup pending, aborting suspend\n"); 921 pm_print_active_wakeup_sources(); 922 } 923 924 return ret || atomic_read(&pm_abort_suspend) > 0; 925 } 926 927 void pm_system_wakeup(void) 928 { 929 atomic_inc(&pm_abort_suspend); 930 s2idle_wake(); 931 } 932 EXPORT_SYMBOL_GPL(pm_system_wakeup); 933 934 void pm_system_cancel_wakeup(void) 935 { 936 atomic_dec_if_positive(&pm_abort_suspend); 937 } 938 939 void pm_wakeup_clear(bool reset) 940 { 941 pm_wakeup_irq = 0; 942 if (reset) 943 atomic_set(&pm_abort_suspend, 0); 944 } 945 946 void pm_system_irq_wakeup(unsigned int irq_number) 947 { 948 if (pm_wakeup_irq == 0) { 949 pm_wakeup_irq = irq_number; 950 pm_system_wakeup(); 951 } 952 } 953 954 /** 955 * pm_get_wakeup_count - Read the number of registered wakeup events. 956 * @count: Address to store the value at. 957 * @block: Whether or not to block. 958 * 959 * Store the number of registered wakeup events at the address in @count. If 960 * @block is set, block until the current number of wakeup events being 961 * processed is zero. 962 * 963 * Return 'false' if the current number of wakeup events being processed is 964 * nonzero. Otherwise return 'true'. 965 */ 966 bool pm_get_wakeup_count(unsigned int *count, bool block) 967 { 968 unsigned int cnt, inpr; 969 970 if (block) { 971 DEFINE_WAIT(wait); 972 973 for (;;) { 974 prepare_to_wait(&wakeup_count_wait_queue, &wait, 975 TASK_INTERRUPTIBLE); 976 split_counters(&cnt, &inpr); 977 if (inpr == 0 || signal_pending(current)) 978 break; 979 pm_print_active_wakeup_sources(); 980 schedule(); 981 } 982 finish_wait(&wakeup_count_wait_queue, &wait); 983 } 984 985 split_counters(&cnt, &inpr); 986 *count = cnt; 987 return !inpr; 988 } 989 990 /** 991 * pm_save_wakeup_count - Save the current number of registered wakeup events. 992 * @count: Value to compare with the current number of registered wakeup events. 993 * 994 * If @count is equal to the current number of registered wakeup events and the 995 * current number of wakeup events being processed is zero, store @count as the 996 * old number of registered wakeup events for pm_check_wakeup_events(), enable 997 * wakeup events detection and return 'true'. Otherwise disable wakeup events 998 * detection and return 'false'. 999 */ 1000 bool pm_save_wakeup_count(unsigned int count) 1001 { 1002 unsigned int cnt, inpr; 1003 unsigned long flags; 1004 1005 events_check_enabled = false; 1006 raw_spin_lock_irqsave(&events_lock, flags); 1007 split_counters(&cnt, &inpr); 1008 if (cnt == count && inpr == 0) { 1009 saved_count = count; 1010 events_check_enabled = true; 1011 } 1012 raw_spin_unlock_irqrestore(&events_lock, flags); 1013 return events_check_enabled; 1014 } 1015 1016 #ifdef CONFIG_PM_AUTOSLEEP 1017 /** 1018 * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources. 1019 * @enabled: Whether to set or to clear the autosleep_enabled flags. 1020 */ 1021 void pm_wakep_autosleep_enabled(bool set) 1022 { 1023 struct wakeup_source *ws; 1024 ktime_t now = ktime_get(); 1025 int srcuidx; 1026 1027 srcuidx = srcu_read_lock(&wakeup_srcu); 1028 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 1029 spin_lock_irq(&ws->lock); 1030 if (ws->autosleep_enabled != set) { 1031 ws->autosleep_enabled = set; 1032 if (ws->active) { 1033 if (set) 1034 ws->start_prevent_time = now; 1035 else 1036 update_prevent_sleep_time(ws, now); 1037 } 1038 } 1039 spin_unlock_irq(&ws->lock); 1040 } 1041 srcu_read_unlock(&wakeup_srcu, srcuidx); 1042 } 1043 #endif /* CONFIG_PM_AUTOSLEEP */ 1044 1045 /** 1046 * print_wakeup_source_stats - Print wakeup source statistics information. 1047 * @m: seq_file to print the statistics into. 1048 * @ws: Wakeup source object to print the statistics for. 1049 */ 1050 static int print_wakeup_source_stats(struct seq_file *m, 1051 struct wakeup_source *ws) 1052 { 1053 unsigned long flags; 1054 ktime_t total_time; 1055 ktime_t max_time; 1056 unsigned long active_count; 1057 ktime_t active_time; 1058 ktime_t prevent_sleep_time; 1059 1060 spin_lock_irqsave(&ws->lock, flags); 1061 1062 total_time = ws->total_time; 1063 max_time = ws->max_time; 1064 prevent_sleep_time = ws->prevent_sleep_time; 1065 active_count = ws->active_count; 1066 if (ws->active) { 1067 ktime_t now = ktime_get(); 1068 1069 active_time = ktime_sub(now, ws->last_time); 1070 total_time = ktime_add(total_time, active_time); 1071 if (active_time > max_time) 1072 max_time = active_time; 1073 1074 if (ws->autosleep_enabled) 1075 prevent_sleep_time = ktime_add(prevent_sleep_time, 1076 ktime_sub(now, ws->start_prevent_time)); 1077 } else { 1078 active_time = 0; 1079 } 1080 1081 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", 1082 ws->name, active_count, ws->event_count, 1083 ws->wakeup_count, ws->expire_count, 1084 ktime_to_ms(active_time), ktime_to_ms(total_time), 1085 ktime_to_ms(max_time), ktime_to_ms(ws->last_time), 1086 ktime_to_ms(prevent_sleep_time)); 1087 1088 spin_unlock_irqrestore(&ws->lock, flags); 1089 1090 return 0; 1091 } 1092 1093 static void *wakeup_sources_stats_seq_start(struct seq_file *m, 1094 loff_t *pos) 1095 { 1096 struct wakeup_source *ws; 1097 loff_t n = *pos; 1098 int *srcuidx = m->private; 1099 1100 if (n == 0) { 1101 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t" 1102 "expire_count\tactive_since\ttotal_time\tmax_time\t" 1103 "last_change\tprevent_suspend_time\n"); 1104 } 1105 1106 *srcuidx = srcu_read_lock(&wakeup_srcu); 1107 list_for_each_entry_rcu(ws, &wakeup_sources, entry) { 1108 if (n-- <= 0) 1109 return ws; 1110 } 1111 1112 return NULL; 1113 } 1114 1115 static void *wakeup_sources_stats_seq_next(struct seq_file *m, 1116 void *v, loff_t *pos) 1117 { 1118 struct wakeup_source *ws = v; 1119 struct wakeup_source *next_ws = NULL; 1120 1121 ++(*pos); 1122 1123 list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) { 1124 next_ws = ws; 1125 break; 1126 } 1127 1128 return next_ws; 1129 } 1130 1131 static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v) 1132 { 1133 int *srcuidx = m->private; 1134 1135 srcu_read_unlock(&wakeup_srcu, *srcuidx); 1136 } 1137 1138 /** 1139 * wakeup_sources_stats_seq_show - Print wakeup sources statistics information. 1140 * @m: seq_file to print the statistics into. 1141 * @v: wakeup_source of each iteration 1142 */ 1143 static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v) 1144 { 1145 struct wakeup_source *ws = v; 1146 1147 print_wakeup_source_stats(m, ws); 1148 1149 return 0; 1150 } 1151 1152 static const struct seq_operations wakeup_sources_stats_seq_ops = { 1153 .start = wakeup_sources_stats_seq_start, 1154 .next = wakeup_sources_stats_seq_next, 1155 .stop = wakeup_sources_stats_seq_stop, 1156 .show = wakeup_sources_stats_seq_show, 1157 }; 1158 1159 static int wakeup_sources_stats_open(struct inode *inode, struct file *file) 1160 { 1161 return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int)); 1162 } 1163 1164 static const struct file_operations wakeup_sources_stats_fops = { 1165 .owner = THIS_MODULE, 1166 .open = wakeup_sources_stats_open, 1167 .read = seq_read, 1168 .llseek = seq_lseek, 1169 .release = seq_release_private, 1170 }; 1171 1172 static int __init wakeup_sources_debugfs_init(void) 1173 { 1174 debugfs_create_file("wakeup_sources", S_IRUGO, NULL, NULL, 1175 &wakeup_sources_stats_fops); 1176 return 0; 1177 } 1178 1179 postcore_initcall(wakeup_sources_debugfs_init); 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