drivers/base/power/wakeup.c

   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 greater than 0 and the system is suspending, terminate the suspend. */
  32 static atomic_t 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(struct timer_list *t);
  58
  59 static LIST_HEAD(wakeup_sources);
  60
  61 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  62
  63 DEFINE_STATIC_SRCU(wakeup_srcu);
  64
  65 static struct wakeup_source deleted_ws = {
  66         .name = "deleted",
  67         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  68 };
  69
  70 /**
  71  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  72  * @ws: Wakeup source to prepare.
  73  * @name: Pointer to the name of the new wakeup source.
  74  *
  75  * Callers must ensure that the @name string won't be freed when @ws is still in
  76  * use.
  77  */
  78 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  79 {
  80         if (ws) {
  81                 memset(ws, 0, sizeof(*ws));
  82                 ws->name = name;
  83         }
  84 }
  85 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  86
  87 /**
  88  * wakeup_source_create - Create a struct wakeup_source object.
  89  * @name: Name of the new wakeup source.
  90  */
  91 struct wakeup_source *wakeup_source_create(const char *name)
  92 {
  93         struct wakeup_source *ws;
  94
  95         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  96         if (!ws)
  97                 return NULL;
  98
  99         wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
 100         return ws;
 101 }
 102 EXPORT_SYMBOL_GPL(wakeup_source_create);
 103
 104 /**
 105  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 106  * @ws: Wakeup source to prepare for destruction.
 107  *
 108  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 109  * be run in parallel with this function for the same wakeup source object.
 110  */
 111 void wakeup_source_drop(struct wakeup_source *ws)
 112 {
 113         if (!ws)
 114                 return;
 115
 116         del_timer_sync(&ws->timer);
 117         __pm_relax(ws);
 118 }
 119 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 120
 121 /*
 122  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 123  */
 124 static void wakeup_source_record(struct wakeup_source *ws)
 125 {
 126         unsigned long flags;
 127
 128         spin_lock_irqsave(&deleted_ws.lock, flags);
 129
 130         if (ws->event_count) {
 131                 deleted_ws.total_time =
 132                         ktime_add(deleted_ws.total_time, ws->total_time);
 133                 deleted_ws.prevent_sleep_time =
 134                         ktime_add(deleted_ws.prevent_sleep_time,
 135                                   ws->prevent_sleep_time);
 136                 deleted_ws.max_time =
 137                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 138                                 deleted_ws.max_time : ws->max_time;
 139                 deleted_ws.event_count += ws->event_count;
 140                 deleted_ws.active_count += ws->active_count;
 141                 deleted_ws.relax_count += ws->relax_count;
 142                 deleted_ws.expire_count += ws->expire_count;
 143                 deleted_ws.wakeup_count += ws->wakeup_count;
 144         }
 145
 146         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 147 }
 148
 149 /**
 150  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 151  * @ws: Wakeup source to destroy.
 152  *
 153  * Use only for wakeup source objects created with wakeup_source_create().
 154  */
 155 void wakeup_source_destroy(struct wakeup_source *ws)
 156 {
 157         if (!ws)
 158                 return;
 159
 160         wakeup_source_drop(ws);
 161         wakeup_source_record(ws);
 162         kfree_const(ws->name);
 163         kfree(ws);
 164 }
 165 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 166
 167 /**
 168  * wakeup_source_add - Add given object to the list of wakeup sources.
 169  * @ws: Wakeup source object to add to the list.
 170  */
 171 void wakeup_source_add(struct wakeup_source *ws)
 172 {
 173         unsigned long flags;
 174
 175         if (WARN_ON(!ws))
 176                 return;
 177
 178         spin_lock_init(&ws->lock);
 179         timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
 180         ws->active = false;
 181         ws->last_time = ktime_get();
 182
 183         spin_lock_irqsave(&events_lock, flags);
 184         list_add_rcu(&ws->entry, &wakeup_sources);
 185         spin_unlock_irqrestore(&events_lock, flags);
 186 }
 187 EXPORT_SYMBOL_GPL(wakeup_source_add);
 188
 189 /**
 190  * wakeup_source_remove - Remove given object from the wakeup sources list.
 191  * @ws: Wakeup source object to remove from the list.
 192  */
 193 void wakeup_source_remove(struct wakeup_source *ws)
 194 {
 195         unsigned long flags;
 196
 197         if (WARN_ON(!ws))
 198                 return;
 199
 200         spin_lock_irqsave(&events_lock, flags);
 201         list_del_rcu(&ws->entry);
 202         spin_unlock_irqrestore(&events_lock, flags);
 203         synchronize_srcu(&wakeup_srcu);
 204 }
 205 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 206
 207 /**
 208  * wakeup_source_register - Create wakeup source and add it to the list.
 209  * @name: Name of the wakeup source to register.
 210  */
 211 struct wakeup_source *wakeup_source_register(const char *name)
 212 {
 213         struct wakeup_source *ws;
 214
 215         ws = wakeup_source_create(name);
 216         if (ws)
 217                 wakeup_source_add(ws);
 218
 219         return ws;
 220 }
 221 EXPORT_SYMBOL_GPL(wakeup_source_register);
 222
 223 /**
 224  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 225  * @ws: Wakeup source object to unregister.
 226  */
 227 void wakeup_source_unregister(struct wakeup_source *ws)
 228 {
 229         if (ws) {
 230                 wakeup_source_remove(ws);
 231                 wakeup_source_destroy(ws);
 232         }
 233 }
 234 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 235
 236 /**
 237  * device_wakeup_attach - Attach a wakeup source object to a device object.
 238  * @dev: Device to handle.
 239  * @ws: Wakeup source object to attach to @dev.
 240  *
 241  * This causes @dev to be treated as a wakeup device.
 242  */
 243 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 244 {
 245         spin_lock_irq(&dev->power.lock);
 246         if (dev->power.wakeup) {
 247                 spin_unlock_irq(&dev->power.lock);
 248                 return -EEXIST;
 249         }
 250         dev->power.wakeup = ws;
 251         if (dev->power.wakeirq)
 252                 device_wakeup_attach_irq(dev, dev->power.wakeirq);
 253         spin_unlock_irq(&dev->power.lock);
 254         return 0;
 255 }
 256
 257 /**
 258  * device_wakeup_enable - Enable given device to be a wakeup source.
 259  * @dev: Device to handle.
 260  *
 261  * Create a wakeup source object, register it and attach it to @dev.
 262  */
 263 int device_wakeup_enable(struct device *dev)
 264 {
 265         struct wakeup_source *ws;
 266         int ret;
 267
 268         if (!dev || !dev->power.can_wakeup)
 269                 return -EINVAL;
 270
 271         ws = wakeup_source_register(dev_name(dev));
 272         if (!ws)
 273                 return -ENOMEM;
 274
 275         ret = device_wakeup_attach(dev, ws);
 276         if (ret)
 277                 wakeup_source_unregister(ws);
 278
 279         return ret;
 280 }
 281 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 282
 283 /**
 284  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 285  * @dev: Device to handle
 286  * @wakeirq: Device specific wakeirq entry
 287  *
 288  * Attach a device wakeirq to the wakeup source so the device
 289  * wake IRQ can be configured automatically for suspend and
 290  * resume.
 291  *
 292  * Call under the device's power.lock lock.
 293  */
 294 int device_wakeup_attach_irq(struct device *dev,
 295                              struct wake_irq *wakeirq)
 296 {
 297         struct wakeup_source *ws;
 298
 299         ws = dev->power.wakeup;
 300         if (!ws) {
 301                 dev_err(dev, "forgot to call call device_init_wakeup?\n");
 302                 return -EINVAL;
 303         }
 304
 305         if (ws->wakeirq)
 306                 return -EEXIST;
 307
 308         ws->wakeirq = wakeirq;
 309         return 0;
 310 }
 311
 312 /**
 313  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 314  * @dev: Device to handle
 315  *
 316  * Removes a device wakeirq from the wakeup source.
 317  *
 318  * Call under the device's power.lock lock.
 319  */
 320 void device_wakeup_detach_irq(struct device *dev)
 321 {
 322         struct wakeup_source *ws;
 323
 324         ws = dev->power.wakeup;
 325         if (ws)
 326                 ws->wakeirq = NULL;
 327 }
 328
 329 /**
 330  * device_wakeup_arm_wake_irqs(void)
 331  *
 332  * Itereates over the list of device wakeirqs to arm them.
 333  */
 334 void device_wakeup_arm_wake_irqs(void)
 335 {
 336         struct wakeup_source *ws;
 337         int srcuidx;
 338
 339         srcuidx = srcu_read_lock(&wakeup_srcu);
 340         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 341                 dev_pm_arm_wake_irq(ws->wakeirq);
 342         srcu_read_unlock(&wakeup_srcu, srcuidx);
 343 }
 344
 345 /**
 346  * device_wakeup_disarm_wake_irqs(void)
 347  *
 348  * Itereates over the list of device wakeirqs to disarm them.
 349  */
 350 void device_wakeup_disarm_wake_irqs(void)
 351 {
 352         struct wakeup_source *ws;
 353         int srcuidx;
 354
 355         srcuidx = srcu_read_lock(&wakeup_srcu);
 356         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 357                 dev_pm_disarm_wake_irq(ws->wakeirq);
 358         srcu_read_unlock(&wakeup_srcu, srcuidx);
 359 }
 360
 361 /**
 362  * device_wakeup_detach - Detach a device's wakeup source object from it.
 363  * @dev: Device to detach the wakeup source object from.
 364  *
 365  * After it returns, @dev will not be treated as a wakeup device any more.
 366  */
 367 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 368 {
 369         struct wakeup_source *ws;
 370
 371         spin_lock_irq(&dev->power.lock);
 372         ws = dev->power.wakeup;
 373         dev->power.wakeup = NULL;
 374         spin_unlock_irq(&dev->power.lock);
 375         return ws;
 376 }
 377
 378 /**
 379  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 380  * @dev: Device to handle.
 381  *
 382  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 383  * object and destroy it.
 384  */
 385 int device_wakeup_disable(struct device *dev)
 386 {
 387         struct wakeup_source *ws;
 388
 389         if (!dev || !dev->power.can_wakeup)
 390                 return -EINVAL;
 391
 392         ws = device_wakeup_detach(dev);
 393         wakeup_source_unregister(ws);
 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         dev->power.can_wakeup = capable;
 416         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 417                 if (capable) {
 418                         int ret = wakeup_sysfs_add(dev);
 419
 420                         if (ret)
 421                                 dev_info(dev, "Wakeup sysfs attributes not added\n");
 422                 } else {
 423                         wakeup_sysfs_remove(dev);
 424                 }
 425         }
 426 }
 427 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 428
 429 /**
 430  * device_init_wakeup - Device wakeup initialization.
 431  * @dev: Device to handle.
 432  * @enable: Whether or not to enable @dev as a wakeup device.
 433  *
 434  * By default, most devices should leave wakeup disabled.  The exceptions are
 435  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 436  * possibly network interfaces, etc.  Also, devices that don't generate their
 437  * own wakeup requests but merely forward requests from one bus to another
 438  * (like PCI bridges) should have wakeup enabled by default.
 439  */
 440 int device_init_wakeup(struct device *dev, bool enable)
 441 {
 442         int ret = 0;
 443
 444         if (!dev)
 445                 return -EINVAL;
 446
 447         if (enable) {
 448                 device_set_wakeup_capable(dev, true);
 449                 ret = device_wakeup_enable(dev);
 450         } else {
 451                 if (dev->power.can_wakeup)
 452                         device_wakeup_disable(dev);
 453
 454                 device_set_wakeup_capable(dev, false);
 455         }
 456
 457         return ret;
 458 }
 459 EXPORT_SYMBOL_GPL(device_init_wakeup);
 460
 461 /**
 462  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 463  * @dev: Device to handle.
 464  */
 465 int device_set_wakeup_enable(struct device *dev, bool enable)
 466 {
 467         if (!dev || !dev->power.can_wakeup)
 468                 return -EINVAL;
 469
 470         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 471 }
 472 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 473
 474 /**
 475  * wakeup_source_not_registered - validate the given wakeup source.
 476  * @ws: Wakeup source to be validated.
 477  */
 478 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 479 {
 480         /*
 481          * Use timer struct to check if the given source is initialized
 482          * by wakeup_source_add.
 483          */
 484         return ws->timer.function != (TIMER_FUNC_TYPE)pm_wakeup_timer_fn;
 485 }
 486
 487 /*
 488  * The functions below use the observation that each wakeup event starts a
 489  * period in which the system should not be suspended.  The moment this period
 490  * will end depends on how the wakeup event is going to be processed after being
 491  * detected and all of the possible cases can be divided into two distinct
 492  * groups.
 493  *
 494  * First, a wakeup event may be detected by the same functional unit that will
 495  * carry out the entire processing of it and possibly will pass it to user space
 496  * for further processing.  In that case the functional unit that has detected
 497  * the event may later "close" the "no suspend" period associated with it
 498  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 499  * pm_relax(), balanced with each other, is supposed to be used in such
 500  * situations.
 501  *
 502  * Second, a wakeup event may be detected by one functional unit and processed
 503  * by another one.  In that case the unit that has detected it cannot really
 504  * "close" the "no suspend" period associated with it, unless it knows in
 505  * advance what's going to happen to the event during processing.  This
 506  * knowledge, however, may not be available to it, so it can simply specify time
 507  * to wait before the system can be suspended and pass it as the second
 508  * argument of pm_wakeup_event().
 509  *
 510  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 511  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 512  * function executed when the timer expires, whichever comes first.
 513  */
 514
 515 /**
 516  * wakup_source_activate - Mark given wakeup source as active.
 517  * @ws: Wakeup source to handle.
 518  *
 519  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 520  * core of the event by incrementing the counter of of wakeup events being
 521  * processed.
 522  */
 523 static void wakeup_source_activate(struct wakeup_source *ws)
 524 {
 525         unsigned int cec;
 526
 527         if (WARN_ONCE(wakeup_source_not_registered(ws),
 528                         "unregistered wakeup source\n"))
 529                 return;
 530
 531         ws->active = true;
 532         ws->active_count++;
 533         ws->last_time = ktime_get();
 534         if (ws->autosleep_enabled)
 535                 ws->start_prevent_time = ws->last_time;
 536
 537         /* Increment the counter of events in progress. */
 538         cec = atomic_inc_return(&combined_event_count);
 539
 540         trace_wakeup_source_activate(ws->name, cec);
 541 }
 542
 543 /**
 544  * wakeup_source_report_event - Report wakeup event using the given source.
 545  * @ws: Wakeup source to report the event for.
 546  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 547  */
 548 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
 549 {
 550         ws->event_count++;
 551         /* This is racy, but the counter is approximate anyway. */
 552         if (events_check_enabled)
 553                 ws->wakeup_count++;
 554
 555         if (!ws->active)
 556                 wakeup_source_activate(ws);
 557
 558         if (hard)
 559                 pm_system_wakeup();
 560 }
 561
 562 /**
 563  * __pm_stay_awake - Notify the PM core of a wakeup event.
 564  * @ws: Wakeup source object associated with the source of the event.
 565  *
 566  * It is safe to call this function from interrupt context.
 567  */
 568 void __pm_stay_awake(struct wakeup_source *ws)
 569 {
 570         unsigned long flags;
 571
 572         if (!ws)
 573                 return;
 574
 575         spin_lock_irqsave(&ws->lock, flags);
 576
 577         wakeup_source_report_event(ws, false);
 578         del_timer(&ws->timer);
 579         ws->timer_expires = 0;
 580
 581         spin_unlock_irqrestore(&ws->lock, flags);
 582 }
 583 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 584
 585 /**
 586  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 587  * @dev: Device the wakeup event is related to.
 588  *
 589  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 590  * __pm_stay_awake for the @dev's wakeup source object.
 591  *
 592  * Call this function after detecting of a wakeup event if pm_relax() is going
 593  * to be called directly after processing the event (and possibly passing it to
 594  * user space for further processing).
 595  */
 596 void pm_stay_awake(struct device *dev)
 597 {
 598         unsigned long flags;
 599
 600         if (!dev)
 601                 return;
 602
 603         spin_lock_irqsave(&dev->power.lock, flags);
 604         __pm_stay_awake(dev->power.wakeup);
 605         spin_unlock_irqrestore(&dev->power.lock, flags);
 606 }
 607 EXPORT_SYMBOL_GPL(pm_stay_awake);
 608
 609 #ifdef CONFIG_PM_AUTOSLEEP
 610 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 611 {
 612         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 613         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 614 }
 615 #else
 616 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 617                                              ktime_t now) {}
 618 #endif
 619
 620 /**
 621  * wakup_source_deactivate - Mark given wakeup source as inactive.
 622  * @ws: Wakeup source to handle.
 623  *
 624  * Update the @ws' statistics and notify the PM core that the wakeup source has
 625  * become inactive by decrementing the counter of wakeup events being processed
 626  * and incrementing the counter of registered wakeup events.
 627  */
 628 static void wakeup_source_deactivate(struct wakeup_source *ws)
 629 {
 630         unsigned int cnt, inpr, cec;
 631         ktime_t duration;
 632         ktime_t now;
 633
 634         ws->relax_count++;
 635         /*
 636          * __pm_relax() may be called directly or from a timer function.
 637          * If it is called directly right after the timer function has been
 638          * started, but before the timer function calls __pm_relax(), it is
 639          * possible that __pm_stay_awake() will be called in the meantime and
 640          * will set ws->active.  Then, ws->active may be cleared immediately
 641          * by the __pm_relax() called from the timer function, but in such a
 642          * case ws->relax_count will be different from ws->active_count.
 643          */
 644         if (ws->relax_count != ws->active_count) {
 645                 ws->relax_count--;
 646                 return;
 647         }
 648
 649         ws->active = false;
 650
 651         now = ktime_get();
 652         duration = ktime_sub(now, ws->last_time);
 653         ws->total_time = ktime_add(ws->total_time, duration);
 654         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 655                 ws->max_time = duration;
 656
 657         ws->last_time = now;
 658         del_timer(&ws->timer);
 659         ws->timer_expires = 0;
 660
 661         if (ws->autosleep_enabled)
 662                 update_prevent_sleep_time(ws, now);
 663
 664         /*
 665          * Increment the counter of registered wakeup events and decrement the
 666          * couter of wakeup events in progress simultaneously.
 667          */
 668         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 669         trace_wakeup_source_deactivate(ws->name, cec);
 670
 671         split_counters(&cnt, &inpr);
 672         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 673                 wake_up(&wakeup_count_wait_queue);
 674 }
 675
 676 /**
 677  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 678  * @ws: Wakeup source object associated with the source of the event.
 679  *
 680  * Call this function for wakeup events whose processing started with calling
 681  * __pm_stay_awake().
 682  *
 683  * It is safe to call it from interrupt context.
 684  */
 685 void __pm_relax(struct wakeup_source *ws)
 686 {
 687         unsigned long flags;
 688
 689         if (!ws)
 690                 return;
 691
 692         spin_lock_irqsave(&ws->lock, flags);
 693         if (ws->active)
 694                 wakeup_source_deactivate(ws);
 695         spin_unlock_irqrestore(&ws->lock, flags);
 696 }
 697 EXPORT_SYMBOL_GPL(__pm_relax);
 698
 699 /**
 700  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 701  * @dev: Device that signaled the event.
 702  *
 703  * Execute __pm_relax() for the @dev's wakeup source object.
 704  */
 705 void pm_relax(struct device *dev)
 706 {
 707         unsigned long flags;
 708
 709         if (!dev)
 710                 return;
 711
 712         spin_lock_irqsave(&dev->power.lock, flags);
 713         __pm_relax(dev->power.wakeup);
 714         spin_unlock_irqrestore(&dev->power.lock, flags);
 715 }
 716 EXPORT_SYMBOL_GPL(pm_relax);
 717
 718 /**
 719  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 720  * @data: Address of the wakeup source object associated with the event source.
 721  *
 722  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 723  * in @data if it is currently active and its timer has not been canceled and
 724  * the expiration time of the timer is not in future.
 725  */
 726 static void pm_wakeup_timer_fn(struct timer_list *t)
 727 {
 728         struct wakeup_source *ws = from_timer(ws, t, timer);
 729         unsigned long flags;
 730
 731         spin_lock_irqsave(&ws->lock, flags);
 732
 733         if (ws->active && ws->timer_expires
 734             && time_after_eq(jiffies, ws->timer_expires)) {
 735                 wakeup_source_deactivate(ws);
 736                 ws->expire_count++;
 737         }
 738
 739         spin_unlock_irqrestore(&ws->lock, flags);
 740 }
 741
 742 /**
 743  * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
 744  * @ws: Wakeup source object associated with the event source.
 745  * @msec: Anticipated event processing time (in milliseconds).
 746  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 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_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
 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, hard);
 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_ws_event);
 785
 786 /**
 787  * pm_wakeup_event - Notify the PM core of a wakeup event.
 788  * @dev: Device the wakeup event is related to.
 789  * @msec: Anticipated event processing time (in milliseconds).
 790  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 791  *
 792  * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
 793  */
 794 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
 795 {
 796         unsigned long flags;
 797
 798         if (!dev)
 799                 return;
 800
 801         spin_lock_irqsave(&dev->power.lock, flags);
 802         pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
 803         spin_unlock_irqrestore(&dev->power.lock, flags);
 804 }
 805 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
 806
 807 void pm_print_active_wakeup_sources(void)
 808 {
 809         struct wakeup_source *ws;
 810         int srcuidx, active = 0;
 811         struct wakeup_source *last_activity_ws = NULL;
 812
 813         srcuidx = srcu_read_lock(&wakeup_srcu);
 814         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 815                 if (ws->active) {
 816                         pr_debug("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_debug("last active wakeup source: %s\n",
 828                         last_activity_ws->name);
 829         srcu_read_unlock(&wakeup_srcu, srcuidx);
 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 || atomic_read(&pm_abort_suspend) > 0;
 862 }
 863
 864 void pm_system_wakeup(void)
 865 {
 866         atomic_inc(&pm_abort_suspend);
 867         s2idle_wake();
 868 }
 869 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 870
 871 void pm_system_cancel_wakeup(void)
 872 {
 873         atomic_dec(&pm_abort_suspend);
 874 }
 875
 876 void pm_wakeup_clear(bool reset)
 877 {
 878         pm_wakeup_irq = 0;
 879         if (reset)
 880                 atomic_set(&pm_abort_suspend, 0);
 881 }
 882
 883 void pm_system_irq_wakeup(unsigned int irq_number)
 884 {
 885         if (pm_wakeup_irq == 0) {
 886                 pm_wakeup_irq = irq_number;
 887                 pm_system_wakeup();
 888         }
 889 }
 890
 891 /**
 892  * pm_get_wakeup_count - Read the number of registered wakeup events.
 893  * @count: Address to store the value at.
 894  * @block: Whether or not to block.
 895  *
 896  * Store the number of registered wakeup events at the address in @count.  If
 897  * @block is set, block until the current number of wakeup events being
 898  * processed is zero.
 899  *
 900  * Return 'false' if the current number of wakeup events being processed is
 901  * nonzero.  Otherwise return 'true'.
 902  */
 903 bool pm_get_wakeup_count(unsigned int *count, bool block)
 904 {
 905         unsigned int cnt, inpr;
 906
 907         if (block) {
 908                 DEFINE_WAIT(wait);
 909
 910                 for (;;) {
 911                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 912                                         TASK_INTERRUPTIBLE);
 913                         split_counters(&cnt, &inpr);
 914                         if (inpr == 0 || signal_pending(current))
 915                                 break;
 916                         pm_print_active_wakeup_sources();
 917                         schedule();
 918                 }
 919                 finish_wait(&wakeup_count_wait_queue, &wait);
 920         }
 921
 922         split_counters(&cnt, &inpr);
 923         *count = cnt;
 924         return !inpr;
 925 }
 926
 927 /**
 928  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 929  * @count: Value to compare with the current number of registered wakeup events.
 930  *
 931  * If @count is equal to the current number of registered wakeup events and the
 932  * current number of wakeup events being processed is zero, store @count as the
 933  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 934  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 935  * detection and return 'false'.
 936  */
 937 bool pm_save_wakeup_count(unsigned int count)
 938 {
 939         unsigned int cnt, inpr;
 940         unsigned long flags;
 941
 942         events_check_enabled = false;
 943         spin_lock_irqsave(&events_lock, flags);
 944         split_counters(&cnt, &inpr);
 945         if (cnt == count && inpr == 0) {
 946                 saved_count = count;
 947                 events_check_enabled = true;
 948         }
 949         spin_unlock_irqrestore(&events_lock, flags);
 950         return events_check_enabled;
 951 }
 952
 953 #ifdef CONFIG_PM_AUTOSLEEP
 954 /**
 955  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 956  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 957  */
 958 void pm_wakep_autosleep_enabled(bool set)
 959 {
 960         struct wakeup_source *ws;
 961         ktime_t now = ktime_get();
 962         int srcuidx;
 963
 964         srcuidx = srcu_read_lock(&wakeup_srcu);
 965         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 966                 spin_lock_irq(&ws->lock);
 967                 if (ws->autosleep_enabled != set) {
 968                         ws->autosleep_enabled = set;
 969                         if (ws->active) {
 970                                 if (set)
 971                                         ws->start_prevent_time = now;
 972                                 else
 973                                         update_prevent_sleep_time(ws, now);
 974                         }
 975                 }
 976                 spin_unlock_irq(&ws->lock);
 977         }
 978         srcu_read_unlock(&wakeup_srcu, srcuidx);
 979 }
 980 #endif /* CONFIG_PM_AUTOSLEEP */
 981
 982 static struct dentry *wakeup_sources_stats_dentry;
 983
 984 /**
 985  * print_wakeup_source_stats - Print wakeup source statistics information.
 986  * @m: seq_file to print the statistics into.
 987  * @ws: Wakeup source object to print the statistics for.
 988  */
 989 static int print_wakeup_source_stats(struct seq_file *m,
 990                                      struct wakeup_source *ws)
 991 {
 992         unsigned long flags;
 993         ktime_t total_time;
 994         ktime_t max_time;
 995         unsigned long active_count;
 996         ktime_t active_time;
 997         ktime_t prevent_sleep_time;
 998
 999         spin_lock_irqsave(&ws->lock, flags);
1000
1001         total_time = ws->total_time;
1002         max_time = ws->max_time;
1003         prevent_sleep_time = ws->prevent_sleep_time;
1004         active_count = ws->active_count;
1005         if (ws->active) {
1006                 ktime_t now = ktime_get();
1007
1008                 active_time = ktime_sub(now, ws->last_time);
1009                 total_time = ktime_add(total_time, active_time);
1010                 if (active_time > max_time)
1011                         max_time = active_time;
1012
1013                 if (ws->autosleep_enabled)
1014                         prevent_sleep_time = ktime_add(prevent_sleep_time,
1015                                 ktime_sub(now, ws->start_prevent_time));
1016         } else {
1017                 active_time = 0;
1018         }
1019
1020         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",
1021                    ws->name, active_count, ws->event_count,
1022                    ws->wakeup_count, ws->expire_count,
1023                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1024                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1025                    ktime_to_ms(prevent_sleep_time));
1026
1027         spin_unlock_irqrestore(&ws->lock, flags);
1028
1029         return 0;
1030 }
1031
1032 /**
1033  * wakeup_sources_stats_show - Print wakeup sources statistics information.
1034  * @m: seq_file to print the statistics into.
1035  */
1036 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
1037 {
1038         struct wakeup_source *ws;
1039         int srcuidx;
1040
1041         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1042                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
1043                 "last_change\tprevent_suspend_time\n");
1044
1045         srcuidx = srcu_read_lock(&wakeup_srcu);
1046         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
1047                 print_wakeup_source_stats(m, ws);
1048         srcu_read_unlock(&wakeup_srcu, srcuidx);
1049
1050         print_wakeup_source_stats(m, &deleted_ws);
1051
1052         return 0;
1053 }
1054
1055 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1056 {
1057         return single_open(file, wakeup_sources_stats_show, NULL);
1058 }
1059
1060 static const struct file_operations wakeup_sources_stats_fops = {
1061         .owner = THIS_MODULE,
1062         .open = wakeup_sources_stats_open,
1063         .read = seq_read,
1064         .llseek = seq_lseek,
1065         .release = single_release,
1066 };
1067
1068 static int __init wakeup_sources_debugfs_init(void)
1069 {
1070         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1071                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1072         return 0;
1073 }
1074
1075 postcore_initcall(wakeup_sources_debugfs_init);