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 #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 /**
  76  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  77  * @ws: Wakeup source to prepare.
  78  * @name: Pointer to the name of the new wakeup source.
  79  *
  80  * Callers must ensure that the @name string won't be freed when @ws is still in
  81  * use.
  82  */
  83 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  84 {
  85         if (ws) {
  86                 memset(ws, 0, sizeof(*ws));
  87                 ws->name = name;
  88         }
  89 }
  90 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  91
  92 /**
  93  * wakeup_source_create - Create a struct wakeup_source object.
  94  * @name: Name of the new wakeup source.
  95  */
  96 struct wakeup_source *wakeup_source_create(const char *name)
  97 {
  98         struct wakeup_source *ws;
  99
 100         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
 101         if (!ws)
 102                 return NULL;
 103
 104         wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
 105         return ws;
 106 }
 107 EXPORT_SYMBOL_GPL(wakeup_source_create);
 108
 109 /**
 110  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 111  * @ws: Wakeup source to prepare for destruction.
 112  *
 113  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 114  * be run in parallel with this function for the same wakeup source object.
 115  */
 116 void wakeup_source_drop(struct wakeup_source *ws)
 117 {
 118         if (!ws)
 119                 return;
 120
 121         __pm_relax(ws);
 122 }
 123 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 124
 125 /*
 126  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 127  */
 128 static void wakeup_source_record(struct wakeup_source *ws)
 129 {
 130         unsigned long flags;
 131
 132         spin_lock_irqsave(&deleted_ws.lock, flags);
 133
 134         if (ws->event_count) {
 135                 deleted_ws.total_time =
 136                         ktime_add(deleted_ws.total_time, ws->total_time);
 137                 deleted_ws.prevent_sleep_time =
 138                         ktime_add(deleted_ws.prevent_sleep_time,
 139                                   ws->prevent_sleep_time);
 140                 deleted_ws.max_time =
 141                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 142                                 deleted_ws.max_time : ws->max_time;
 143                 deleted_ws.event_count += ws->event_count;
 144                 deleted_ws.active_count += ws->active_count;
 145                 deleted_ws.relax_count += ws->relax_count;
 146                 deleted_ws.expire_count += ws->expire_count;
 147                 deleted_ws.wakeup_count += ws->wakeup_count;
 148         }
 149
 150         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 151 }
 152
 153 /**
 154  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 155  * @ws: Wakeup source to destroy.
 156  *
 157  * Use only for wakeup source objects created with wakeup_source_create().
 158  */
 159 void wakeup_source_destroy(struct wakeup_source *ws)
 160 {
 161         if (!ws)
 162                 return;
 163
 164         wakeup_source_drop(ws);
 165         wakeup_source_record(ws);
 166         kfree_const(ws->name);
 167         kfree(ws);
 168 }
 169 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 170
 171 /**
 172  * wakeup_source_add - Add given object to the list of wakeup sources.
 173  * @ws: Wakeup source object to add to the list.
 174  */
 175 void wakeup_source_add(struct wakeup_source *ws)
 176 {
 177         unsigned long flags;
 178
 179         if (WARN_ON(!ws))
 180                 return;
 181
 182         spin_lock_init(&ws->lock);
 183         timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
 184         ws->active = false;
 185
 186         raw_spin_lock_irqsave(&events_lock, flags);
 187         list_add_rcu(&ws->entry, &wakeup_sources);
 188         raw_spin_unlock_irqrestore(&events_lock, flags);
 189 }
 190 EXPORT_SYMBOL_GPL(wakeup_source_add);
 191
 192 /**
 193  * wakeup_source_remove - Remove given object from the wakeup sources list.
 194  * @ws: Wakeup source object to remove from the list.
 195  */
 196 void wakeup_source_remove(struct wakeup_source *ws)
 197 {
 198         unsigned long flags;
 199
 200         if (WARN_ON(!ws))
 201                 return;
 202
 203         raw_spin_lock_irqsave(&events_lock, flags);
 204         list_del_rcu(&ws->entry);
 205         raw_spin_unlock_irqrestore(&events_lock, flags);
 206         synchronize_srcu(&wakeup_srcu);
 207
 208         del_timer_sync(&ws->timer);
 209         /*
 210          * Clear timer.function to make wakeup_source_not_registered() treat
 211          * this wakeup source as not registered.
 212          */
 213         ws->timer.function = NULL;
 214 }
 215 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 216
 217 /**
 218  * wakeup_source_register - Create wakeup source and add it to the list.
 219  * @name: Name of the wakeup source to register.
 220  */
 221 struct wakeup_source *wakeup_source_register(const char *name)
 222 {
 223         struct wakeup_source *ws;
 224
 225         ws = wakeup_source_create(name);
 226         if (ws)
 227                 wakeup_source_add(ws);
 228
 229         return ws;
 230 }
 231 EXPORT_SYMBOL_GPL(wakeup_source_register);
 232
 233 /**
 234  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 235  * @ws: Wakeup source object to unregister.
 236  */
 237 void wakeup_source_unregister(struct wakeup_source *ws)
 238 {
 239         if (ws) {
 240                 wakeup_source_remove(ws);
 241                 wakeup_source_destroy(ws);
 242         }
 243 }
 244 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 245
 246 /**
 247  * device_wakeup_attach - Attach a wakeup source object to a device object.
 248  * @dev: Device to handle.
 249  * @ws: Wakeup source object to attach to @dev.
 250  *
 251  * This causes @dev to be treated as a wakeup device.
 252  */
 253 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 254 {
 255         spin_lock_irq(&dev->power.lock);
 256         if (dev->power.wakeup) {
 257                 spin_unlock_irq(&dev->power.lock);
 258                 return -EEXIST;
 259         }
 260         dev->power.wakeup = ws;
 261         if (dev->power.wakeirq)
 262                 device_wakeup_attach_irq(dev, dev->power.wakeirq);
 263         spin_unlock_irq(&dev->power.lock);
 264         return 0;
 265 }
 266
 267 /**
 268  * device_wakeup_enable - Enable given device to be a wakeup source.
 269  * @dev: Device to handle.
 270  *
 271  * Create a wakeup source object, register it and attach it to @dev.
 272  */
 273 int device_wakeup_enable(struct device *dev)
 274 {
 275         struct wakeup_source *ws;
 276         int ret;
 277
 278         if (!dev || !dev->power.can_wakeup)
 279                 return -EINVAL;
 280
 281         if (pm_suspend_target_state != PM_SUSPEND_ON)
 282                 dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__);
 283
 284         ws = wakeup_source_register(dev_name(dev));
 285         if (!ws)
 286                 return -ENOMEM;
 287
 288         ret = device_wakeup_attach(dev, ws);
 289         if (ret)
 290                 wakeup_source_unregister(ws);
 291
 292         return ret;
 293 }
 294 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 295
 296 /**
 297  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 298  * @dev: Device to handle
 299  * @wakeirq: Device specific wakeirq entry
 300  *
 301  * Attach a device wakeirq to the wakeup source so the device
 302  * wake IRQ can be configured automatically for suspend and
 303  * resume.
 304  *
 305  * Call under the device's power.lock lock.
 306  */
 307 void device_wakeup_attach_irq(struct device *dev,
 308                              struct wake_irq *wakeirq)
 309 {
 310         struct wakeup_source *ws;
 311
 312         ws = dev->power.wakeup;
 313         if (!ws)
 314                 return;
 315
 316         if (ws->wakeirq)
 317                 dev_err(dev, "Leftover wakeup IRQ found, overriding\n");
 318
 319         ws->wakeirq = wakeirq;
 320 }
 321
 322 /**
 323  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 324  * @dev: Device to handle
 325  *
 326  * Removes a device wakeirq from the wakeup source.
 327  *
 328  * Call under the device's power.lock lock.
 329  */
 330 void device_wakeup_detach_irq(struct device *dev)
 331 {
 332         struct wakeup_source *ws;
 333
 334         ws = dev->power.wakeup;
 335         if (ws)
 336                 ws->wakeirq = NULL;
 337 }
 338
 339 /**
 340  * device_wakeup_arm_wake_irqs(void)
 341  *
 342  * Itereates over the list of device wakeirqs to arm them.
 343  */
 344 void device_wakeup_arm_wake_irqs(void)
 345 {
 346         struct wakeup_source *ws;
 347         int srcuidx;
 348
 349         srcuidx = srcu_read_lock(&wakeup_srcu);
 350         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 351                 dev_pm_arm_wake_irq(ws->wakeirq);
 352         srcu_read_unlock(&wakeup_srcu, srcuidx);
 353 }
 354
 355 /**
 356  * device_wakeup_disarm_wake_irqs(void)
 357  *
 358  * Itereates over the list of device wakeirqs to disarm them.
 359  */
 360 void device_wakeup_disarm_wake_irqs(void)
 361 {
 362         struct wakeup_source *ws;
 363         int srcuidx;
 364
 365         srcuidx = srcu_read_lock(&wakeup_srcu);
 366         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 367                 dev_pm_disarm_wake_irq(ws->wakeirq);
 368         srcu_read_unlock(&wakeup_srcu, srcuidx);
 369 }
 370
 371 /**
 372  * device_wakeup_detach - Detach a device's wakeup source object from it.
 373  * @dev: Device to detach the wakeup source object from.
 374  *
 375  * After it returns, @dev will not be treated as a wakeup device any more.
 376  */
 377 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 378 {
 379         struct wakeup_source *ws;
 380
 381         spin_lock_irq(&dev->power.lock);
 382         ws = dev->power.wakeup;
 383         dev->power.wakeup = NULL;
 384         spin_unlock_irq(&dev->power.lock);
 385         return ws;
 386 }
 387
 388 /**
 389  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 390  * @dev: Device to handle.
 391  *
 392  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 393  * object and destroy it.
 394  */
 395 int device_wakeup_disable(struct device *dev)
 396 {
 397         struct wakeup_source *ws;
 398
 399         if (!dev || !dev->power.can_wakeup)
 400                 return -EINVAL;
 401
 402         ws = device_wakeup_detach(dev);
 403         wakeup_source_unregister(ws);
 404         return 0;
 405 }
 406 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 407
 408 /**
 409  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 410  * @dev: Device to handle.
 411  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 412  *
 413  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 414  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 415  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 416  *
 417  * This function may sleep and it can't be called from any context where
 418  * sleeping is not allowed.
 419  */
 420 void device_set_wakeup_capable(struct device *dev, bool capable)
 421 {
 422         if (!!dev->power.can_wakeup == !!capable)
 423                 return;
 424
 425         dev->power.can_wakeup = capable;
 426         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 427                 if (capable) {
 428                         int ret = wakeup_sysfs_add(dev);
 429
 430                         if (ret)
 431                                 dev_info(dev, "Wakeup sysfs attributes not added\n");
 432                 } else {
 433                         wakeup_sysfs_remove(dev);
 434                 }
 435         }
 436 }
 437 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 438
 439 /**
 440  * device_init_wakeup - Device wakeup initialization.
 441  * @dev: Device to handle.
 442  * @enable: Whether or not to enable @dev as a wakeup device.
 443  *
 444  * By default, most devices should leave wakeup disabled.  The exceptions are
 445  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 446  * possibly network interfaces, etc.  Also, devices that don't generate their
 447  * own wakeup requests but merely forward requests from one bus to another
 448  * (like PCI bridges) should have wakeup enabled by default.
 449  */
 450 int device_init_wakeup(struct device *dev, bool enable)
 451 {
 452         int ret = 0;
 453
 454         if (!dev)
 455                 return -EINVAL;
 456
 457         if (enable) {
 458                 device_set_wakeup_capable(dev, true);
 459                 ret = device_wakeup_enable(dev);
 460         } else {
 461                 device_wakeup_disable(dev);
 462                 device_set_wakeup_capable(dev, false);
 463         }
 464
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(device_init_wakeup);
 468
 469 /**
 470  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 471  * @dev: Device to handle.
 472  */
 473 int device_set_wakeup_enable(struct device *dev, bool enable)
 474 {
 475         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 476 }
 477 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 478
 479 /**
 480  * wakeup_source_not_registered - validate the given wakeup source.
 481  * @ws: Wakeup source to be validated.
 482  */
 483 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 484 {
 485         /*
 486          * Use timer struct to check if the given source is initialized
 487          * by wakeup_source_add.
 488          */
 489         return ws->timer.function != pm_wakeup_timer_fn;
 490 }
 491
 492 /*
 493  * The functions below use the observation that each wakeup event starts a
 494  * period in which the system should not be suspended.  The moment this period
 495  * will end depends on how the wakeup event is going to be processed after being
 496  * detected and all of the possible cases can be divided into two distinct
 497  * groups.
 498  *
 499  * First, a wakeup event may be detected by the same functional unit that will
 500  * carry out the entire processing of it and possibly will pass it to user space
 501  * for further processing.  In that case the functional unit that has detected
 502  * the event may later "close" the "no suspend" period associated with it
 503  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 504  * pm_relax(), balanced with each other, is supposed to be used in such
 505  * situations.
 506  *
 507  * Second, a wakeup event may be detected by one functional unit and processed
 508  * by another one.  In that case the unit that has detected it cannot really
 509  * "close" the "no suspend" period associated with it, unless it knows in
 510  * advance what's going to happen to the event during processing.  This
 511  * knowledge, however, may not be available to it, so it can simply specify time
 512  * to wait before the system can be suspended and pass it as the second
 513  * argument of pm_wakeup_event().
 514  *
 515  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 516  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 517  * function executed when the timer expires, whichever comes first.
 518  */
 519
 520 /**
 521  * wakup_source_activate - Mark given wakeup source as active.
 522  * @ws: Wakeup source to handle.
 523  *
 524  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 525  * core of the event by incrementing the counter of of wakeup events being
 526  * processed.
 527  */
 528 static void wakeup_source_activate(struct wakeup_source *ws)
 529 {
 530         unsigned int cec;
 531
 532         if (WARN_ONCE(wakeup_source_not_registered(ws),
 533                         "unregistered wakeup source\n"))
 534                 return;
 535
 536         ws->active = true;
 537         ws->active_count++;
 538         ws->last_time = ktime_get();
 539         if (ws->autosleep_enabled)
 540                 ws->start_prevent_time = ws->last_time;
 541
 542         /* Increment the counter of events in progress. */
 543         cec = atomic_inc_return(&combined_event_count);
 544
 545         trace_wakeup_source_activate(ws->name, cec);
 546 }
 547
 548 /**
 549  * wakeup_source_report_event - Report wakeup event using the given source.
 550  * @ws: Wakeup source to report the event for.
 551  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 552  */
 553 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
 554 {
 555         ws->event_count++;
 556         /* This is racy, but the counter is approximate anyway. */
 557         if (events_check_enabled)
 558                 ws->wakeup_count++;
 559
 560         if (!ws->active)
 561                 wakeup_source_activate(ws);
 562
 563         if (hard)
 564                 pm_system_wakeup();
 565 }
 566
 567 /**
 568  * __pm_stay_awake - Notify the PM core of a wakeup event.
 569  * @ws: Wakeup source object associated with the source of the event.
 570  *
 571  * It is safe to call this function from interrupt context.
 572  */
 573 void __pm_stay_awake(struct wakeup_source *ws)
 574 {
 575         unsigned long flags;
 576
 577         if (!ws)
 578                 return;
 579
 580         spin_lock_irqsave(&ws->lock, flags);
 581
 582         wakeup_source_report_event(ws, false);
 583         del_timer(&ws->timer);
 584         ws->timer_expires = 0;
 585
 586         spin_unlock_irqrestore(&ws->lock, flags);
 587 }
 588 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 589
 590 /**
 591  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 592  * @dev: Device the wakeup event is related to.
 593  *
 594  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 595  * __pm_stay_awake for the @dev's wakeup source object.
 596  *
 597  * Call this function after detecting of a wakeup event if pm_relax() is going
 598  * to be called directly after processing the event (and possibly passing it to
 599  * user space for further processing).
 600  */
 601 void pm_stay_awake(struct device *dev)
 602 {
 603         unsigned long flags;
 604
 605         if (!dev)
 606                 return;
 607
 608         spin_lock_irqsave(&dev->power.lock, flags);
 609         __pm_stay_awake(dev->power.wakeup);
 610         spin_unlock_irqrestore(&dev->power.lock, flags);
 611 }
 612 EXPORT_SYMBOL_GPL(pm_stay_awake);
 613
 614 #ifdef CONFIG_PM_AUTOSLEEP
 615 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 616 {
 617         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 618         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 619 }
 620 #else
 621 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 622                                              ktime_t now) {}
 623 #endif
 624
 625 /**
 626  * wakup_source_deactivate - Mark given wakeup source as inactive.
 627  * @ws: Wakeup source to handle.
 628  *
 629  * Update the @ws' statistics and notify the PM core that the wakeup source has
 630  * become inactive by decrementing the counter of wakeup events being processed
 631  * and incrementing the counter of registered wakeup events.
 632  */
 633 static void wakeup_source_deactivate(struct wakeup_source *ws)
 634 {
 635         unsigned int cnt, inpr, cec;
 636         ktime_t duration;
 637         ktime_t now;
 638
 639         ws->relax_count++;
 640         /*
 641          * __pm_relax() may be called directly or from a timer function.
 642          * If it is called directly right after the timer function has been
 643          * started, but before the timer function calls __pm_relax(), it is
 644          * possible that __pm_stay_awake() will be called in the meantime and
 645          * will set ws->active.  Then, ws->active may be cleared immediately
 646          * by the __pm_relax() called from the timer function, but in such a
 647          * case ws->relax_count will be different from ws->active_count.
 648          */
 649         if (ws->relax_count != ws->active_count) {
 650                 ws->relax_count--;
 651                 return;
 652         }
 653
 654         ws->active = false;
 655
 656         now = ktime_get();
 657         duration = ktime_sub(now, ws->last_time);
 658         ws->total_time = ktime_add(ws->total_time, duration);
 659         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 660                 ws->max_time = duration;
 661
 662         ws->last_time = now;
 663         del_timer(&ws->timer);
 664         ws->timer_expires = 0;
 665
 666         if (ws->autosleep_enabled)
 667                 update_prevent_sleep_time(ws, now);
 668
 669         /*
 670          * Increment the counter of registered wakeup events and decrement the
 671          * couter of wakeup events in progress simultaneously.
 672          */
 673         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 674         trace_wakeup_source_deactivate(ws->name, cec);
 675
 676         split_counters(&cnt, &inpr);
 677         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 678                 wake_up(&wakeup_count_wait_queue);
 679 }
 680
 681 /**
 682  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 683  * @ws: Wakeup source object associated with the source of the event.
 684  *
 685  * Call this function for wakeup events whose processing started with calling
 686  * __pm_stay_awake().
 687  *
 688  * It is safe to call it from interrupt context.
 689  */
 690 void __pm_relax(struct wakeup_source *ws)
 691 {
 692         unsigned long flags;
 693
 694         if (!ws)
 695                 return;
 696
 697         spin_lock_irqsave(&ws->lock, flags);
 698         if (ws->active)
 699                 wakeup_source_deactivate(ws);
 700         spin_unlock_irqrestore(&ws->lock, flags);
 701 }
 702 EXPORT_SYMBOL_GPL(__pm_relax);
 703
 704 /**
 705  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 706  * @dev: Device that signaled the event.
 707  *
 708  * Execute __pm_relax() for the @dev's wakeup source object.
 709  */
 710 void pm_relax(struct device *dev)
 711 {
 712         unsigned long flags;
 713
 714         if (!dev)
 715                 return;
 716
 717         spin_lock_irqsave(&dev->power.lock, flags);
 718         __pm_relax(dev->power.wakeup);
 719         spin_unlock_irqrestore(&dev->power.lock, flags);
 720 }
 721 EXPORT_SYMBOL_GPL(pm_relax);
 722
 723 /**
 724  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 725  * @data: Address of the wakeup source object associated with the event source.
 726  *
 727  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 728  * in @data if it is currently active and its timer has not been canceled and
 729  * the expiration time of the timer is not in future.
 730  */
 731 static void pm_wakeup_timer_fn(struct timer_list *t)
 732 {
 733         struct wakeup_source *ws = from_timer(ws, t, timer);
 734         unsigned long flags;
 735
 736         spin_lock_irqsave(&ws->lock, flags);
 737
 738         if (ws->active && ws->timer_expires
 739             && time_after_eq(jiffies, ws->timer_expires)) {
 740                 wakeup_source_deactivate(ws);
 741                 ws->expire_count++;
 742         }
 743
 744         spin_unlock_irqrestore(&ws->lock, flags);
 745 }
 746
 747 /**
 748  * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
 749  * @ws: Wakeup source object associated with the event source.
 750  * @msec: Anticipated event processing time (in milliseconds).
 751  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 752  *
 753  * Notify the PM core of a wakeup event whose source is @ws that will take
 754  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 755  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 756  * execute pm_wakeup_timer_fn() in future.
 757  *
 758  * It is safe to call this function from interrupt context.
 759  */
 760 void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
 761 {
 762         unsigned long flags;
 763         unsigned long expires;
 764
 765         if (!ws)
 766                 return;
 767
 768         spin_lock_irqsave(&ws->lock, flags);
 769
 770         wakeup_source_report_event(ws, hard);
 771
 772         if (!msec) {
 773                 wakeup_source_deactivate(ws);
 774                 goto unlock;
 775         }
 776
 777         expires = jiffies + msecs_to_jiffies(msec);
 778         if (!expires)
 779                 expires = 1;
 780
 781         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 782                 mod_timer(&ws->timer, expires);
 783                 ws->timer_expires = expires;
 784         }
 785
 786  unlock:
 787         spin_unlock_irqrestore(&ws->lock, flags);
 788 }
 789 EXPORT_SYMBOL_GPL(pm_wakeup_ws_event);
 790
 791 /**
 792  * pm_wakeup_dev_event - Notify the PM core of a wakeup event.
 793  * @dev: Device the wakeup event is related to.
 794  * @msec: Anticipated event processing time (in milliseconds).
 795  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 796  *
 797  * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
 798  */
 799 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
 800 {
 801         unsigned long flags;
 802
 803         if (!dev)
 804                 return;
 805
 806         spin_lock_irqsave(&dev->power.lock, flags);
 807         pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
 808         spin_unlock_irqrestore(&dev->power.lock, flags);
 809 }
 810 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
 811
 812 void pm_print_active_wakeup_sources(void)
 813 {
 814         struct wakeup_source *ws;
 815         int srcuidx, active = 0;
 816         struct wakeup_source *last_activity_ws = NULL;
 817
 818         srcuidx = srcu_read_lock(&wakeup_srcu);
 819         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 820                 if (ws->active) {
 821                         pr_debug("active wakeup source: %s\n", ws->name);
 822                         active = 1;
 823                 } else if (!active &&
 824                            (!last_activity_ws ||
 825                             ktime_to_ns(ws->last_time) >
 826                             ktime_to_ns(last_activity_ws->last_time))) {
 827                         last_activity_ws = ws;
 828                 }
 829         }
 830
 831         if (!active && last_activity_ws)
 832                 pr_debug("last active wakeup source: %s\n",
 833                         last_activity_ws->name);
 834         srcu_read_unlock(&wakeup_srcu, srcuidx);
 835 }
 836 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 837
 838 /**
 839  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 840  *
 841  * Compare the current number of registered wakeup events with its preserved
 842  * value from the past and return true if new wakeup events have been registered
 843  * since the old value was stored.  Also return true if the current number of
 844  * wakeup events being processed is different from zero.
 845  */
 846 bool pm_wakeup_pending(void)
 847 {
 848         unsigned long flags;
 849         bool ret = false;
 850
 851         raw_spin_lock_irqsave(&events_lock, flags);
 852         if (events_check_enabled) {
 853                 unsigned int cnt, inpr;
 854
 855                 split_counters(&cnt, &inpr);
 856                 ret = (cnt != saved_count || inpr > 0);
 857                 events_check_enabled = !ret;
 858         }
 859         raw_spin_unlock_irqrestore(&events_lock, flags);
 860
 861         if (ret) {
 862                 pr_debug("PM: Wakeup pending, aborting suspend\n");
 863                 pm_print_active_wakeup_sources();
 864         }
 865
 866         return ret || atomic_read(&pm_abort_suspend) > 0;
 867 }
 868
 869 void pm_system_wakeup(void)
 870 {
 871         atomic_inc(&pm_abort_suspend);
 872         s2idle_wake();
 873 }
 874 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 875
 876 void pm_system_cancel_wakeup(void)
 877 {
 878         atomic_dec(&pm_abort_suspend);
 879 }
 880
 881 void pm_wakeup_clear(bool reset)
 882 {
 883         pm_wakeup_irq = 0;
 884         if (reset)
 885                 atomic_set(&pm_abort_suspend, 0);
 886 }
 887
 888 void pm_system_irq_wakeup(unsigned int irq_number)
 889 {
 890         if (pm_wakeup_irq == 0) {
 891                 pm_wakeup_irq = irq_number;
 892                 pm_system_wakeup();
 893         }
 894 }
 895
 896 /**
 897  * pm_get_wakeup_count - Read the number of registered wakeup events.
 898  * @count: Address to store the value at.
 899  * @block: Whether or not to block.
 900  *
 901  * Store the number of registered wakeup events at the address in @count.  If
 902  * @block is set, block until the current number of wakeup events being
 903  * processed is zero.
 904  *
 905  * Return 'false' if the current number of wakeup events being processed is
 906  * nonzero.  Otherwise return 'true'.
 907  */
 908 bool pm_get_wakeup_count(unsigned int *count, bool block)
 909 {
 910         unsigned int cnt, inpr;
 911
 912         if (block) {
 913                 DEFINE_WAIT(wait);
 914
 915                 for (;;) {
 916                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 917                                         TASK_INTERRUPTIBLE);
 918                         split_counters(&cnt, &inpr);
 919                         if (inpr == 0 || signal_pending(current))
 920                                 break;
 921                         pm_print_active_wakeup_sources();
 922                         schedule();
 923                 }
 924                 finish_wait(&wakeup_count_wait_queue, &wait);
 925         }
 926
 927         split_counters(&cnt, &inpr);
 928         *count = cnt;
 929         return !inpr;
 930 }
 931
 932 /**
 933  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 934  * @count: Value to compare with the current number of registered wakeup events.
 935  *
 936  * If @count is equal to the current number of registered wakeup events and the
 937  * current number of wakeup events being processed is zero, store @count as the
 938  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 939  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 940  * detection and return 'false'.
 941  */
 942 bool pm_save_wakeup_count(unsigned int count)
 943 {
 944         unsigned int cnt, inpr;
 945         unsigned long flags;
 946
 947         events_check_enabled = false;
 948         raw_spin_lock_irqsave(&events_lock, flags);
 949         split_counters(&cnt, &inpr);
 950         if (cnt == count && inpr == 0) {
 951                 saved_count = count;
 952                 events_check_enabled = true;
 953         }
 954         raw_spin_unlock_irqrestore(&events_lock, flags);
 955         return events_check_enabled;
 956 }
 957
 958 #ifdef CONFIG_PM_AUTOSLEEP
 959 /**
 960  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 961  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 962  */
 963 void pm_wakep_autosleep_enabled(bool set)
 964 {
 965         struct wakeup_source *ws;
 966         ktime_t now = ktime_get();
 967         int srcuidx;
 968
 969         srcuidx = srcu_read_lock(&wakeup_srcu);
 970         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 971                 spin_lock_irq(&ws->lock);
 972                 if (ws->autosleep_enabled != set) {
 973                         ws->autosleep_enabled = set;
 974                         if (ws->active) {
 975                                 if (set)
 976                                         ws->start_prevent_time = now;
 977                                 else
 978                                         update_prevent_sleep_time(ws, now);
 979                         }
 980                 }
 981                 spin_unlock_irq(&ws->lock);
 982         }
 983         srcu_read_unlock(&wakeup_srcu, srcuidx);
 984 }
 985 #endif /* CONFIG_PM_AUTOSLEEP */
 986
 987 static struct dentry *wakeup_sources_stats_dentry;
 988
 989 /**
 990  * print_wakeup_source_stats - Print wakeup source statistics information.
 991  * @m: seq_file to print the statistics into.
 992  * @ws: Wakeup source object to print the statistics for.
 993  */
 994 static int print_wakeup_source_stats(struct seq_file *m,
 995                                      struct wakeup_source *ws)
 996 {
 997         unsigned long flags;
 998         ktime_t total_time;
 999         ktime_t max_time;
1000         unsigned long active_count;
1001         ktime_t active_time;
1002         ktime_t prevent_sleep_time;
1003
1004         spin_lock_irqsave(&ws->lock, flags);
1005
1006         total_time = ws->total_time;
1007         max_time = ws->max_time;
1008         prevent_sleep_time = ws->prevent_sleep_time;
1009         active_count = ws->active_count;
1010         if (ws->active) {
1011                 ktime_t now = ktime_get();
1012
1013                 active_time = ktime_sub(now, ws->last_time);
1014                 total_time = ktime_add(total_time, active_time);
1015                 if (active_time > max_time)
1016                         max_time = active_time;
1017
1018                 if (ws->autosleep_enabled)
1019                         prevent_sleep_time = ktime_add(prevent_sleep_time,
1020                                 ktime_sub(now, ws->start_prevent_time));
1021         } else {
1022                 active_time = 0;
1023         }
1024
1025         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",
1026                    ws->name, active_count, ws->event_count,
1027                    ws->wakeup_count, ws->expire_count,
1028                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1029                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1030                    ktime_to_ms(prevent_sleep_time));
1031
1032         spin_unlock_irqrestore(&ws->lock, flags);
1033
1034         return 0;
1035 }
1036
1037 static void *wakeup_sources_stats_seq_start(struct seq_file *m,
1038                                         loff_t *pos)
1039 {
1040         struct wakeup_source *ws;
1041         loff_t n = *pos;
1042         int *srcuidx = m->private;
1043
1044         if (n == 0) {
1045                 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1046                         "expire_count\tactive_since\ttotal_time\tmax_time\t"
1047                         "last_change\tprevent_suspend_time\n");
1048         }
1049
1050         *srcuidx = srcu_read_lock(&wakeup_srcu);
1051         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
1052                 if (n-- <= 0)
1053                         return ws;
1054         }
1055
1056         return NULL;
1057 }
1058
1059 static void *wakeup_sources_stats_seq_next(struct seq_file *m,
1060                                         void *v, loff_t *pos)
1061 {
1062         struct wakeup_source *ws = v;
1063         struct wakeup_source *next_ws = NULL;
1064
1065         ++(*pos);
1066
1067         list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) {
1068                 next_ws = ws;
1069                 break;
1070         }
1071
1072         return next_ws;
1073 }
1074
1075 static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v)
1076 {
1077         int *srcuidx = m->private;
1078
1079         srcu_read_unlock(&wakeup_srcu, *srcuidx);
1080 }
1081
1082 /**
1083  * wakeup_sources_stats_seq_show - Print wakeup sources statistics information.
1084  * @m: seq_file to print the statistics into.
1085  * @v: wakeup_source of each iteration
1086  */
1087 static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v)
1088 {
1089         struct wakeup_source *ws = v;
1090
1091         print_wakeup_source_stats(m, ws);
1092
1093         return 0;
1094 }
1095
1096 static const struct seq_operations wakeup_sources_stats_seq_ops = {
1097         .start = wakeup_sources_stats_seq_start,
1098         .next  = wakeup_sources_stats_seq_next,
1099         .stop  = wakeup_sources_stats_seq_stop,
1100         .show  = wakeup_sources_stats_seq_show,
1101 };
1102
1103 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1104 {
1105         return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int));
1106 }
1107
1108 static const struct file_operations wakeup_sources_stats_fops = {
1109         .owner = THIS_MODULE,
1110         .open = wakeup_sources_stats_open,
1111         .read = seq_read,
1112         .llseek = seq_lseek,
1113         .release = seq_release_private,
1114 };
1115
1116 static int __init wakeup_sources_debugfs_init(void)
1117 {
1118         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1119                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1120         return 0;
1121 }
1122
1123 postcore_initcall(wakeup_sources_debugfs_init);