drivers/base/power/domain.c

   1 /*
   2  * drivers/base/power/domain.c - Common code related to device power domains.
   3  *
   4  * Copyright (C) 2011 Rafael J. Wysocki <rjw@sisk.pl>, Renesas Electronics Corp.
   5  *
   6  * This file is released under the GPLv2.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/io.h>
  11 #include <linux/pm_runtime.h>
  12 #include <linux/pm_domain.h>
  13 #include <linux/pm_qos.h>
  14 #include <linux/slab.h>
  15 #include <linux/err.h>
  16 #include <linux/sched.h>
  17 #include <linux/suspend.h>
  18 #include <linux/export.h>
  19
  20 #define GENPD_DEV_CALLBACK(genpd, type, callback, dev)          \
  21 ({                                                              \
  22         type (*__routine)(struct device *__d);                  \
  23         type __ret = (type)0;                                   \
  24                                                                 \
  25         __routine = genpd->dev_ops.callback;                    \
  26         if (__routine) {                                        \
  27                 __ret = __routine(dev);                         \
  28         }                                                       \
  29         __ret;                                                  \
  30 })
  31
  32 #define GENPD_DEV_TIMED_CALLBACK(genpd, type, callback, dev, field, name)       \
  33 ({                                                                              \
  34         ktime_t __start = ktime_get();                                          \
  35         type __retval = GENPD_DEV_CALLBACK(genpd, type, callback, dev);         \
  36         s64 __elapsed = ktime_to_ns(ktime_sub(ktime_get(), __start));           \
  37         struct gpd_timing_data *__td = &dev_gpd_data(dev)->td;                  \
  38         if (!__retval && __elapsed > __td->field) {                             \
  39                 __td->field = __elapsed;                                        \
  40                 dev_dbg(dev, name " latency exceeded, new value %lld ns\n",     \
  41                         __elapsed);                                             \
  42                 genpd->max_off_time_changed = true;                             \
  43                 __td->constraint_changed = true;                                \
  44         }                                                                       \
  45         __retval;                                                               \
  46 })
  47
  48 static LIST_HEAD(gpd_list);
  49 static DEFINE_MUTEX(gpd_list_lock);
  50
  51 static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
  52 {
  53         struct generic_pm_domain *genpd = NULL, *gpd;
  54
  55         if (IS_ERR_OR_NULL(domain_name))
  56                 return NULL;
  57
  58         mutex_lock(&gpd_list_lock);
  59         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
  60                 if (!strcmp(gpd->name, domain_name)) {
  61                         genpd = gpd;
  62                         break;
  63                 }
  64         }
  65         mutex_unlock(&gpd_list_lock);
  66         return genpd;
  67 }
  68
  69 struct generic_pm_domain *dev_to_genpd(struct device *dev)
  70 {
  71         if (IS_ERR_OR_NULL(dev->pm_domain))
  72                 return ERR_PTR(-EINVAL);
  73
  74         return pd_to_genpd(dev->pm_domain);
  75 }
  76
  77 static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
  78 {
  79         return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
  80                                         stop_latency_ns, "stop");
  81 }
  82
  83 static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
  84 {
  85         return GENPD_DEV_TIMED_CALLBACK(genpd, int, start, dev,
  86                                         start_latency_ns, "start");
  87 }
  88
  89 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
  90 {
  91         bool ret = false;
  92
  93         if (!WARN_ON(atomic_read(&genpd->sd_count) == 0))
  94                 ret = !!atomic_dec_and_test(&genpd->sd_count);
  95
  96         return ret;
  97 }
  98
  99 static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 100 {
 101         atomic_inc(&genpd->sd_count);
 102         smp_mb__after_atomic();
 103 }
 104
 105 static void genpd_acquire_lock(struct generic_pm_domain *genpd)
 106 {
 107         DEFINE_WAIT(wait);
 108
 109         mutex_lock(&genpd->lock);
 110         /*
 111          * Wait for the domain to transition into either the active,
 112          * or the power off state.
 113          */
 114         for (;;) {
 115                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 116                                 TASK_UNINTERRUPTIBLE);
 117                 if (genpd->status == GPD_STATE_ACTIVE
 118                     || genpd->status == GPD_STATE_POWER_OFF)
 119                         break;
 120                 mutex_unlock(&genpd->lock);
 121
 122                 schedule();
 123
 124                 mutex_lock(&genpd->lock);
 125         }
 126         finish_wait(&genpd->status_wait_queue, &wait);
 127 }
 128
 129 static void genpd_release_lock(struct generic_pm_domain *genpd)
 130 {
 131         mutex_unlock(&genpd->lock);
 132 }
 133
 134 static void genpd_set_active(struct generic_pm_domain *genpd)
 135 {
 136         if (genpd->resume_count == 0)
 137                 genpd->status = GPD_STATE_ACTIVE;
 138 }
 139
 140 static void genpd_recalc_cpu_exit_latency(struct generic_pm_domain *genpd)
 141 {
 142         s64 usecs64;
 143
 144         if (!genpd->cpu_data)
 145                 return;
 146
 147         usecs64 = genpd->power_on_latency_ns;
 148         do_div(usecs64, NSEC_PER_USEC);
 149         usecs64 += genpd->cpu_data->saved_exit_latency;
 150         genpd->cpu_data->idle_state->exit_latency = usecs64;
 151 }
 152
 153 /**
 154  * __pm_genpd_poweron - Restore power to a given PM domain and its masters.
 155  * @genpd: PM domain to power up.
 156  *
 157  * Restore power to @genpd and all of its masters so that it is possible to
 158  * resume a device belonging to it.
 159  */
 160 static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
 161         __releases(&genpd->lock) __acquires(&genpd->lock)
 162 {
 163         struct gpd_link *link;
 164         DEFINE_WAIT(wait);
 165         int ret = 0;
 166
 167         /* If the domain's master is being waited for, we have to wait too. */
 168         for (;;) {
 169                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 170                                 TASK_UNINTERRUPTIBLE);
 171                 if (genpd->status != GPD_STATE_WAIT_MASTER)
 172                         break;
 173                 mutex_unlock(&genpd->lock);
 174
 175                 schedule();
 176
 177                 mutex_lock(&genpd->lock);
 178         }
 179         finish_wait(&genpd->status_wait_queue, &wait);
 180
 181         if (genpd->status == GPD_STATE_ACTIVE
 182             || (genpd->prepared_count > 0 && genpd->suspend_power_off))
 183                 return 0;
 184
 185         if (genpd->status != GPD_STATE_POWER_OFF) {
 186                 genpd_set_active(genpd);
 187                 return 0;
 188         }
 189
 190         if (genpd->cpu_data) {
 191                 cpuidle_pause_and_lock();
 192                 genpd->cpu_data->idle_state->disabled = true;
 193                 cpuidle_resume_and_unlock();
 194                 goto out;
 195         }
 196
 197         /*
 198          * The list is guaranteed not to change while the loop below is being
 199          * executed, unless one of the masters' .power_on() callbacks fiddles
 200          * with it.
 201          */
 202         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 203                 genpd_sd_counter_inc(link->master);
 204                 genpd->status = GPD_STATE_WAIT_MASTER;
 205
 206                 mutex_unlock(&genpd->lock);
 207
 208                 ret = pm_genpd_poweron(link->master);
 209
 210                 mutex_lock(&genpd->lock);
 211
 212                 /*
 213                  * The "wait for parent" status is guaranteed not to change
 214                  * while the master is powering on.
 215                  */
 216                 genpd->status = GPD_STATE_POWER_OFF;
 217                 wake_up_all(&genpd->status_wait_queue);
 218                 if (ret) {
 219                         genpd_sd_counter_dec(link->master);
 220                         goto err;
 221                 }
 222         }
 223
 224         if (genpd->power_on) {
 225                 ktime_t time_start = ktime_get();
 226                 s64 elapsed_ns;
 227
 228                 ret = genpd->power_on(genpd);
 229                 if (ret)
 230                         goto err;
 231
 232                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 233                 if (elapsed_ns > genpd->power_on_latency_ns) {
 234                         genpd->power_on_latency_ns = elapsed_ns;
 235                         genpd->max_off_time_changed = true;
 236                         genpd_recalc_cpu_exit_latency(genpd);
 237                         if (genpd->name)
 238                                 pr_warning("%s: Power-on latency exceeded, "
 239                                         "new value %lld ns\n", genpd->name,
 240                                         elapsed_ns);
 241                 }
 242         }
 243
 244  out:
 245         genpd_set_active(genpd);
 246
 247         return 0;
 248
 249  err:
 250         list_for_each_entry_continue_reverse(link, &genpd->slave_links, slave_node)
 251                 genpd_sd_counter_dec(link->master);
 252
 253         return ret;
 254 }
 255
 256 /**
 257  * pm_genpd_poweron - Restore power to a given PM domain and its masters.
 258  * @genpd: PM domain to power up.
 259  */
 260 int pm_genpd_poweron(struct generic_pm_domain *genpd)
 261 {
 262         int ret;
 263
 264         mutex_lock(&genpd->lock);
 265         ret = __pm_genpd_poweron(genpd);
 266         mutex_unlock(&genpd->lock);
 267         return ret;
 268 }
 269
 270 /**
 271  * pm_genpd_name_poweron - Restore power to a given PM domain and its masters.
 272  * @domain_name: Name of the PM domain to power up.
 273  */
 274 int pm_genpd_name_poweron(const char *domain_name)
 275 {
 276         struct generic_pm_domain *genpd;
 277
 278         genpd = pm_genpd_lookup_name(domain_name);
 279         return genpd ? pm_genpd_poweron(genpd) : -EINVAL;
 280 }
 281
 282 #ifdef CONFIG_PM_RUNTIME
 283
 284 static int genpd_start_dev_no_timing(struct generic_pm_domain *genpd,
 285                                      struct device *dev)
 286 {
 287         return GENPD_DEV_CALLBACK(genpd, int, start, dev);
 288 }
 289
 290 static int genpd_save_dev(struct generic_pm_domain *genpd, struct device *dev)
 291 {
 292         return GENPD_DEV_TIMED_CALLBACK(genpd, int, save_state, dev,
 293                                         save_state_latency_ns, "state save");
 294 }
 295
 296 static int genpd_restore_dev(struct generic_pm_domain *genpd, struct device *dev)
 297 {
 298         return GENPD_DEV_TIMED_CALLBACK(genpd, int, restore_state, dev,
 299                                         restore_state_latency_ns,
 300                                         "state restore");
 301 }
 302
 303 static int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 304                                      unsigned long val, void *ptr)
 305 {
 306         struct generic_pm_domain_data *gpd_data;
 307         struct device *dev;
 308
 309         gpd_data = container_of(nb, struct generic_pm_domain_data, nb);
 310
 311         mutex_lock(&gpd_data->lock);
 312         dev = gpd_data->base.dev;
 313         if (!dev) {
 314                 mutex_unlock(&gpd_data->lock);
 315                 return NOTIFY_DONE;
 316         }
 317         mutex_unlock(&gpd_data->lock);
 318
 319         for (;;) {
 320                 struct generic_pm_domain *genpd;
 321                 struct pm_domain_data *pdd;
 322
 323                 spin_lock_irq(&dev->power.lock);
 324
 325                 pdd = dev->power.subsys_data ?
 326                                 dev->power.subsys_data->domain_data : NULL;
 327                 if (pdd && pdd->dev) {
 328                         to_gpd_data(pdd)->td.constraint_changed = true;
 329                         genpd = dev_to_genpd(dev);
 330                 } else {
 331                         genpd = ERR_PTR(-ENODATA);
 332                 }
 333
 334                 spin_unlock_irq(&dev->power.lock);
 335
 336                 if (!IS_ERR(genpd)) {
 337                         mutex_lock(&genpd->lock);
 338                         genpd->max_off_time_changed = true;
 339                         mutex_unlock(&genpd->lock);
 340                 }
 341
 342                 dev = dev->parent;
 343                 if (!dev || dev->power.ignore_children)
 344                         break;
 345         }
 346
 347         return NOTIFY_DONE;
 348 }
 349
 350 /**
 351  * __pm_genpd_save_device - Save the pre-suspend state of a device.
 352  * @pdd: Domain data of the device to save the state of.
 353  * @genpd: PM domain the device belongs to.
 354  */
 355 static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 356                                   struct generic_pm_domain *genpd)
 357         __releases(&genpd->lock) __acquires(&genpd->lock)
 358 {
 359         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 360         struct device *dev = pdd->dev;
 361         int ret = 0;
 362
 363         if (gpd_data->need_restore)
 364                 return 0;
 365
 366         mutex_unlock(&genpd->lock);
 367
 368         genpd_start_dev(genpd, dev);
 369         ret = genpd_save_dev(genpd, dev);
 370         genpd_stop_dev(genpd, dev);
 371
 372         mutex_lock(&genpd->lock);
 373
 374         if (!ret)
 375                 gpd_data->need_restore = true;
 376
 377         return ret;
 378 }
 379
 380 /**
 381  * __pm_genpd_restore_device - Restore the pre-suspend state of a device.
 382  * @pdd: Domain data of the device to restore the state of.
 383  * @genpd: PM domain the device belongs to.
 384  */
 385 static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 386                                       struct generic_pm_domain *genpd)
 387         __releases(&genpd->lock) __acquires(&genpd->lock)
 388 {
 389         struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
 390         struct device *dev = pdd->dev;
 391         bool need_restore = gpd_data->need_restore;
 392
 393         gpd_data->need_restore = false;
 394         mutex_unlock(&genpd->lock);
 395
 396         genpd_start_dev(genpd, dev);
 397         if (need_restore)
 398                 genpd_restore_dev(genpd, dev);
 399
 400         mutex_lock(&genpd->lock);
 401 }
 402
 403 /**
 404  * genpd_abort_poweroff - Check if a PM domain power off should be aborted.
 405  * @genpd: PM domain to check.
 406  *
 407  * Return true if a PM domain's status changed to GPD_STATE_ACTIVE during
 408  * a "power off" operation, which means that a "power on" has occured in the
 409  * meantime, or if its resume_count field is different from zero, which means
 410  * that one of its devices has been resumed in the meantime.
 411  */
 412 static bool genpd_abort_poweroff(struct generic_pm_domain *genpd)
 413 {
 414         return genpd->status == GPD_STATE_WAIT_MASTER
 415                 || genpd->status == GPD_STATE_ACTIVE || genpd->resume_count > 0;
 416 }
 417
 418 /**
 419  * genpd_queue_power_off_work - Queue up the execution of pm_genpd_poweroff().
 420  * @genpd: PM domait to power off.
 421  *
 422  * Queue up the execution of pm_genpd_poweroff() unless it's already been done
 423  * before.
 424  */
 425 static void genpd_queue_power_off_work(struct generic_pm_domain *genpd)
 426 {
 427         queue_work(pm_wq, &genpd->power_off_work);
 428 }
 429
 430 /**
 431  * pm_genpd_poweroff - Remove power from a given PM domain.
 432  * @genpd: PM domain to power down.
 433  *
 434  * If all of the @genpd's devices have been suspended and all of its subdomains
 435  * have been powered down, run the runtime suspend callbacks provided by all of
 436  * the @genpd's devices' drivers and remove power from @genpd.
 437  */
 438 static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
 439         __releases(&genpd->lock) __acquires(&genpd->lock)
 440 {
 441         struct pm_domain_data *pdd;
 442         struct gpd_link *link;
 443         unsigned int not_suspended;
 444         int ret = 0;
 445
 446  start:
 447         /*
 448          * Do not try to power off the domain in the following situations:
 449          * (1) The domain is already in the "power off" state.
 450          * (2) The domain is waiting for its master to power up.
 451          * (3) One of the domain's devices is being resumed right now.
 452          * (4) System suspend is in progress.
 453          */
 454         if (genpd->status == GPD_STATE_POWER_OFF
 455             || genpd->status == GPD_STATE_WAIT_MASTER
 456             || genpd->resume_count > 0 || genpd->prepared_count > 0)
 457                 return 0;
 458
 459         if (atomic_read(&genpd->sd_count) > 0)
 460                 return -EBUSY;
 461
 462         not_suspended = 0;
 463         list_for_each_entry(pdd, &genpd->dev_list, list_node) {
 464                 enum pm_qos_flags_status stat;
 465
 466                 stat = dev_pm_qos_flags(pdd->dev,
 467                                         PM_QOS_FLAG_NO_POWER_OFF
 468                                                 | PM_QOS_FLAG_REMOTE_WAKEUP);
 469                 if (stat > PM_QOS_FLAGS_NONE)
 470                         return -EBUSY;
 471
 472                 if (pdd->dev->driver && (!pm_runtime_suspended(pdd->dev)
 473                     || pdd->dev->power.irq_safe))
 474                         not_suspended++;
 475         }
 476
 477         if (not_suspended > genpd->in_progress)
 478                 return -EBUSY;
 479
 480         if (genpd->poweroff_task) {
 481                 /*
 482                  * Another instance of pm_genpd_poweroff() is executing
 483                  * callbacks, so tell it to start over and return.
 484                  */
 485                 genpd->status = GPD_STATE_REPEAT;
 486                 return 0;
 487         }
 488
 489         if (genpd->gov && genpd->gov->power_down_ok) {
 490                 if (!genpd->gov->power_down_ok(&genpd->domain))
 491                         return -EAGAIN;
 492         }
 493
 494         genpd->status = GPD_STATE_BUSY;
 495         genpd->poweroff_task = current;
 496
 497         list_for_each_entry_reverse(pdd, &genpd->dev_list, list_node) {
 498                 ret = atomic_read(&genpd->sd_count) == 0 ?
 499                         __pm_genpd_save_device(pdd, genpd) : -EBUSY;
 500
 501                 if (genpd_abort_poweroff(genpd))
 502                         goto out;
 503
 504                 if (ret) {
 505                         genpd_set_active(genpd);
 506                         goto out;
 507                 }
 508
 509                 if (genpd->status == GPD_STATE_REPEAT) {
 510                         genpd->poweroff_task = NULL;
 511                         goto start;
 512                 }
 513         }
 514
 515         if (genpd->cpu_data) {
 516                 /*
 517                  * If cpu_data is set, cpuidle should turn the domain off when
 518                  * the CPU in it is idle.  In that case we don't decrement the
 519                  * subdomain counts of the master domains, so that power is not
 520                  * removed from the current domain prematurely as a result of
 521                  * cutting off the masters' power.
 522                  */
 523                 genpd->status = GPD_STATE_POWER_OFF;
 524                 cpuidle_pause_and_lock();
 525                 genpd->cpu_data->idle_state->disabled = false;
 526                 cpuidle_resume_and_unlock();
 527                 goto out;
 528         }
 529
 530         if (genpd->power_off) {
 531                 ktime_t time_start;
 532                 s64 elapsed_ns;
 533
 534                 if (atomic_read(&genpd->sd_count) > 0) {
 535                         ret = -EBUSY;
 536                         goto out;
 537                 }
 538
 539                 time_start = ktime_get();
 540
 541                 /*
 542                  * If sd_count > 0 at this point, one of the subdomains hasn't
 543                  * managed to call pm_genpd_poweron() for the master yet after
 544                  * incrementing it.  In that case pm_genpd_poweron() will wait
 545                  * for us to drop the lock, so we can call .power_off() and let
 546                  * the pm_genpd_poweron() restore power for us (this shouldn't
 547                  * happen very often).
 548                  */
 549                 ret = genpd->power_off(genpd);
 550                 if (ret == -EBUSY) {
 551                         genpd_set_active(genpd);
 552                         goto out;
 553                 }
 554
 555                 elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
 556                 if (elapsed_ns > genpd->power_off_latency_ns) {
 557                         genpd->power_off_latency_ns = elapsed_ns;
 558                         genpd->max_off_time_changed = true;
 559                         if (genpd->name)
 560                                 pr_warning("%s: Power-off latency exceeded, "
 561                                         "new value %lld ns\n", genpd->name,
 562                                         elapsed_ns);
 563                 }
 564         }
 565
 566         genpd->status = GPD_STATE_POWER_OFF;
 567
 568         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 569                 genpd_sd_counter_dec(link->master);
 570                 genpd_queue_power_off_work(link->master);
 571         }
 572
 573  out:
 574         genpd->poweroff_task = NULL;
 575         wake_up_all(&genpd->status_wait_queue);
 576         return ret;
 577 }
 578
 579 /**
 580  * genpd_power_off_work_fn - Power off PM domain whose subdomain count is 0.
 581  * @work: Work structure used for scheduling the execution of this function.
 582  */
 583 static void genpd_power_off_work_fn(struct work_struct *work)
 584 {
 585         struct generic_pm_domain *genpd;
 586
 587         genpd = container_of(work, struct generic_pm_domain, power_off_work);
 588
 589         genpd_acquire_lock(genpd);
 590         pm_genpd_poweroff(genpd);
 591         genpd_release_lock(genpd);
 592 }
 593
 594 /**
 595  * pm_genpd_runtime_suspend - Suspend a device belonging to I/O PM domain.
 596  * @dev: Device to suspend.
 597  *
 598  * Carry out a runtime suspend of a device under the assumption that its
 599  * pm_domain field points to the domain member of an object of type
 600  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 601  */
 602 static int pm_genpd_runtime_suspend(struct device *dev)
 603 {
 604         struct generic_pm_domain *genpd;
 605         bool (*stop_ok)(struct device *__dev);
 606         int ret;
 607
 608         dev_dbg(dev, "%s()\n", __func__);
 609
 610         genpd = dev_to_genpd(dev);
 611         if (IS_ERR(genpd))
 612                 return -EINVAL;
 613
 614         stop_ok = genpd->gov ? genpd->gov->stop_ok : NULL;
 615         if (stop_ok && !stop_ok(dev))
 616                 return -EBUSY;
 617
 618         ret = genpd_stop_dev(genpd, dev);
 619         if (ret)
 620                 return ret;
 621
 622         /*
 623          * If power.irq_safe is set, this routine will be run with interrupts
 624          * off, so it can't use mutexes.
 625          */
 626         if (dev->power.irq_safe)
 627                 return 0;
 628
 629         mutex_lock(&genpd->lock);
 630         genpd->in_progress++;
 631         pm_genpd_poweroff(genpd);
 632         genpd->in_progress--;
 633         mutex_unlock(&genpd->lock);
 634
 635         return 0;
 636 }
 637
 638 /**
 639  * pm_genpd_runtime_resume - Resume a device belonging to I/O PM domain.
 640  * @dev: Device to resume.
 641  *
 642  * Carry out a runtime resume of a device under the assumption that its
 643  * pm_domain field points to the domain member of an object of type
 644  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 645  */
 646 static int pm_genpd_runtime_resume(struct device *dev)
 647 {
 648         struct generic_pm_domain *genpd;
 649         DEFINE_WAIT(wait);
 650         int ret;
 651
 652         dev_dbg(dev, "%s()\n", __func__);
 653
 654         genpd = dev_to_genpd(dev);
 655         if (IS_ERR(genpd))
 656                 return -EINVAL;
 657
 658         /* If power.irq_safe, the PM domain is never powered off. */
 659         if (dev->power.irq_safe)
 660                 return genpd_start_dev_no_timing(genpd, dev);
 661
 662         mutex_lock(&genpd->lock);
 663         ret = __pm_genpd_poweron(genpd);
 664         if (ret) {
 665                 mutex_unlock(&genpd->lock);
 666                 return ret;
 667         }
 668         genpd->status = GPD_STATE_BUSY;
 669         genpd->resume_count++;
 670         for (;;) {
 671                 prepare_to_wait(&genpd->status_wait_queue, &wait,
 672                                 TASK_UNINTERRUPTIBLE);
 673                 /*
 674                  * If current is the powering off task, we have been called
 675                  * reentrantly from one of the device callbacks, so we should
 676                  * not wait.
 677                  */
 678                 if (!genpd->poweroff_task || genpd->poweroff_task == current)
 679                         break;
 680                 mutex_unlock(&genpd->lock);
 681
 682                 schedule();
 683
 684                 mutex_lock(&genpd->lock);
 685         }
 686         finish_wait(&genpd->status_wait_queue, &wait);
 687         __pm_genpd_restore_device(dev->power.subsys_data->domain_data, genpd);
 688         genpd->resume_count--;
 689         genpd_set_active(genpd);
 690         wake_up_all(&genpd->status_wait_queue);
 691         mutex_unlock(&genpd->lock);
 692
 693         return 0;
 694 }
 695
 696 static bool pd_ignore_unused;
 697 static int __init pd_ignore_unused_setup(char *__unused)
 698 {
 699         pd_ignore_unused = true;
 700         return 1;
 701 }
 702 __setup("pd_ignore_unused", pd_ignore_unused_setup);
 703
 704 /**
 705  * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
 706  */
 707 void pm_genpd_poweroff_unused(void)
 708 {
 709         struct generic_pm_domain *genpd;
 710
 711         if (pd_ignore_unused) {
 712                 pr_warn("genpd: Not disabling unused power domains\n");
 713                 return;
 714         }
 715
 716         mutex_lock(&gpd_list_lock);
 717
 718         list_for_each_entry(genpd, &gpd_list, gpd_list_node)
 719                 genpd_queue_power_off_work(genpd);
 720
 721         mutex_unlock(&gpd_list_lock);
 722 }
 723
 724 static int __init genpd_poweroff_unused(void)
 725 {
 726         pm_genpd_poweroff_unused();
 727         return 0;
 728 }
 729 late_initcall(genpd_poweroff_unused);
 730
 731 #else
 732
 733 static inline int genpd_dev_pm_qos_notifier(struct notifier_block *nb,
 734                                             unsigned long val, void *ptr)
 735 {
 736         return NOTIFY_DONE;
 737 }
 738
 739 static inline void
 740 genpd_queue_power_off_work(struct generic_pm_domain *genpd) {}
 741
 742 static inline void genpd_power_off_work_fn(struct work_struct *work) {}
 743
 744 #define pm_genpd_runtime_suspend        NULL
 745 #define pm_genpd_runtime_resume         NULL
 746
 747 #endif /* CONFIG_PM_RUNTIME */
 748
 749 #ifdef CONFIG_PM_SLEEP
 750
 751 /**
 752  * pm_genpd_present - Check if the given PM domain has been initialized.
 753  * @genpd: PM domain to check.
 754  */
 755 static bool pm_genpd_present(struct generic_pm_domain *genpd)
 756 {
 757         struct generic_pm_domain *gpd;
 758
 759         if (IS_ERR_OR_NULL(genpd))
 760                 return false;
 761
 762         list_for_each_entry(gpd, &gpd_list, gpd_list_node)
 763                 if (gpd == genpd)
 764                         return true;
 765
 766         return false;
 767 }
 768
 769 static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
 770                                     struct device *dev)
 771 {
 772         return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
 773 }
 774
 775 /**
 776  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
 777  * @genpd: PM domain to power off, if possible.
 778  *
 779  * Check if the given PM domain can be powered off (during system suspend or
 780  * hibernation) and do that if so.  Also, in that case propagate to its masters.
 781  *
 782  * This function is only called in "noirq" and "syscore" stages of system power
 783  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 784  * executed sequentially, so it is guaranteed that it will never run twice in
 785  * parallel).
 786  */
 787 static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
 788 {
 789         struct gpd_link *link;
 790
 791         if (genpd->status == GPD_STATE_POWER_OFF)
 792                 return;
 793
 794         if (genpd->suspended_count != genpd->device_count
 795             || atomic_read(&genpd->sd_count) > 0)
 796                 return;
 797
 798         if (genpd->power_off)
 799                 genpd->power_off(genpd);
 800
 801         genpd->status = GPD_STATE_POWER_OFF;
 802
 803         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 804                 genpd_sd_counter_dec(link->master);
 805                 pm_genpd_sync_poweroff(link->master);
 806         }
 807 }
 808
 809 /**
 810  * pm_genpd_sync_poweron - Synchronously power on a PM domain and its masters.
 811  * @genpd: PM domain to power on.
 812  *
 813  * This function is only called in "noirq" and "syscore" stages of system power
 814  * transitions, so it need not acquire locks (all of the "noirq" callbacks are
 815  * executed sequentially, so it is guaranteed that it will never run twice in
 816  * parallel).
 817  */
 818 static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
 819 {
 820         struct gpd_link *link;
 821
 822         if (genpd->status != GPD_STATE_POWER_OFF)
 823                 return;
 824
 825         list_for_each_entry(link, &genpd->slave_links, slave_node) {
 826                 pm_genpd_sync_poweron(link->master);
 827                 genpd_sd_counter_inc(link->master);
 828         }
 829
 830         if (genpd->power_on)
 831                 genpd->power_on(genpd);
 832
 833         genpd->status = GPD_STATE_ACTIVE;
 834 }
 835
 836 /**
 837  * resume_needed - Check whether to resume a device before system suspend.
 838  * @dev: Device to check.
 839  * @genpd: PM domain the device belongs to.
 840  *
 841  * There are two cases in which a device that can wake up the system from sleep
 842  * states should be resumed by pm_genpd_prepare(): (1) if the device is enabled
 843  * to wake up the system and it has to remain active for this purpose while the
 844  * system is in the sleep state and (2) if the device is not enabled to wake up
 845  * the system from sleep states and it generally doesn't generate wakeup signals
 846  * by itself (those signals are generated on its behalf by other parts of the
 847  * system).  In the latter case it may be necessary to reconfigure the device's
 848  * wakeup settings during system suspend, because it may have been set up to
 849  * signal remote wakeup from the system's working state as needed by runtime PM.
 850  * Return 'true' in either of the above cases.
 851  */
 852 static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 853 {
 854         bool active_wakeup;
 855
 856         if (!device_can_wakeup(dev))
 857                 return false;
 858
 859         active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 860         return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 861 }
 862
 863 /**
 864  * pm_genpd_prepare - Start power transition of a device in a PM domain.
 865  * @dev: Device to start the transition of.
 866  *
 867  * Start a power transition of a device (during a system-wide power transition)
 868  * under the assumption that its pm_domain field points to the domain member of
 869  * an object of type struct generic_pm_domain representing a PM domain
 870  * consisting of I/O devices.
 871  */
 872 static int pm_genpd_prepare(struct device *dev)
 873 {
 874         struct generic_pm_domain *genpd;
 875         int ret;
 876
 877         dev_dbg(dev, "%s()\n", __func__);
 878
 879         genpd = dev_to_genpd(dev);
 880         if (IS_ERR(genpd))
 881                 return -EINVAL;
 882
 883         /*
 884          * If a wakeup request is pending for the device, it should be woken up
 885          * at this point and a system wakeup event should be reported if it's
 886          * set up to wake up the system from sleep states.
 887          */
 888         pm_runtime_get_noresume(dev);
 889         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 890                 pm_wakeup_event(dev, 0);
 891
 892         if (pm_wakeup_pending()) {
 893                 pm_runtime_put(dev);
 894                 return -EBUSY;
 895         }
 896
 897         if (resume_needed(dev, genpd))
 898                 pm_runtime_resume(dev);
 899
 900         genpd_acquire_lock(genpd);
 901
 902         if (genpd->prepared_count++ == 0) {
 903                 genpd->suspended_count = 0;
 904                 genpd->suspend_power_off = genpd->status == GPD_STATE_POWER_OFF;
 905         }
 906
 907         genpd_release_lock(genpd);
 908
 909         if (genpd->suspend_power_off) {
 910                 pm_runtime_put_noidle(dev);
 911                 return 0;
 912         }
 913
 914         /*
 915          * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 916          * so pm_genpd_poweron() will return immediately, but if the device
 917          * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 918          * to make it operational.
 919          */
 920         pm_runtime_resume(dev);
 921         __pm_runtime_disable(dev, false);
 922
 923         ret = pm_generic_prepare(dev);
 924         if (ret) {
 925                 mutex_lock(&genpd->lock);
 926
 927                 if (--genpd->prepared_count == 0)
 928                         genpd->suspend_power_off = false;
 929
 930                 mutex_unlock(&genpd->lock);
 931                 pm_runtime_enable(dev);
 932         }
 933
 934         pm_runtime_put(dev);
 935         return ret;
 936 }
 937
 938 /**
 939  * pm_genpd_suspend - Suspend a device belonging to an I/O PM domain.
 940  * @dev: Device to suspend.
 941  *
 942  * Suspend a device under the assumption that its pm_domain field points to the
 943  * domain member of an object of type struct generic_pm_domain representing
 944  * a PM domain consisting of I/O devices.
 945  */
 946 static int pm_genpd_suspend(struct device *dev)
 947 {
 948         struct generic_pm_domain *genpd;
 949
 950         dev_dbg(dev, "%s()\n", __func__);
 951
 952         genpd = dev_to_genpd(dev);
 953         if (IS_ERR(genpd))
 954                 return -EINVAL;
 955
 956         return genpd->suspend_power_off ? 0 : pm_generic_suspend(dev);
 957 }
 958
 959 /**
 960  * pm_genpd_suspend_late - Late suspend of a device from an I/O PM domain.
 961  * @dev: Device to suspend.
 962  *
 963  * Carry out a late suspend of a device under the assumption that its
 964  * pm_domain field points to the domain member of an object of type
 965  * struct generic_pm_domain representing a PM domain consisting of I/O devices.
 966  */
 967 static int pm_genpd_suspend_late(struct device *dev)
 968 {
 969         struct generic_pm_domain *genpd;
 970
 971         dev_dbg(dev, "%s()\n", __func__);
 972
 973         genpd = dev_to_genpd(dev);
 974         if (IS_ERR(genpd))
 975                 return -EINVAL;
 976
 977         return genpd->suspend_power_off ? 0 : pm_generic_suspend_late(dev);
 978 }
 979
 980 /**
 981  * pm_genpd_suspend_noirq - Completion of suspend of device in an I/O PM domain.
 982  * @dev: Device to suspend.
 983  *
 984  * Stop the device and remove power from the domain if all devices in it have
 985  * been stopped.
 986  */
 987 static int pm_genpd_suspend_noirq(struct device *dev)
 988 {
 989         struct generic_pm_domain *genpd;
 990
 991         dev_dbg(dev, "%s()\n", __func__);
 992
 993         genpd = dev_to_genpd(dev);
 994         if (IS_ERR(genpd))
 995                 return -EINVAL;
 996
 997         if (genpd->suspend_power_off
 998             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
 999                 return 0;
1000
1001         genpd_stop_dev(genpd, dev);
1002
1003         /*
1004          * Since all of the "noirq" callbacks are executed sequentially, it is
1005          * guaranteed that this function will never run twice in parallel for
1006          * the same PM domain, so it is not necessary to use locking here.
1007          */
1008         genpd->suspended_count++;
1009         pm_genpd_sync_poweroff(genpd);
1010
1011         return 0;
1012 }
1013
1014 /**
1015  * pm_genpd_resume_noirq - Start of resume of device in an I/O PM domain.
1016  * @dev: Device to resume.
1017  *
1018  * Restore power to the device's PM domain, if necessary, and start the device.
1019  */
1020 static int pm_genpd_resume_noirq(struct device *dev)
1021 {
1022         struct generic_pm_domain *genpd;
1023
1024         dev_dbg(dev, "%s()\n", __func__);
1025
1026         genpd = dev_to_genpd(dev);
1027         if (IS_ERR(genpd))
1028                 return -EINVAL;
1029
1030         if (genpd->suspend_power_off
1031             || (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev)))
1032                 return 0;
1033
1034         /*
1035          * Since all of the "noirq" callbacks are executed sequentially, it is
1036          * guaranteed that this function will never run twice in parallel for
1037          * the same PM domain, so it is not necessary to use locking here.
1038          */
1039         pm_genpd_sync_poweron(genpd);
1040         genpd->suspended_count--;
1041
1042         return genpd_start_dev(genpd, dev);
1043 }
1044
1045 /**
1046  * pm_genpd_resume_early - Early resume of a device in an I/O PM domain.
1047  * @dev: Device to resume.
1048  *
1049  * Carry out an early resume of a device under the assumption that its
1050  * pm_domain field points to the domain member of an object of type
1051  * struct generic_pm_domain representing a power domain consisting of I/O
1052  * devices.
1053  */
1054 static int pm_genpd_resume_early(struct device *dev)
1055 {
1056         struct generic_pm_domain *genpd;
1057
1058         dev_dbg(dev, "%s()\n", __func__);
1059
1060         genpd = dev_to_genpd(dev);
1061         if (IS_ERR(genpd))
1062                 return -EINVAL;
1063
1064         return genpd->suspend_power_off ? 0 : pm_generic_resume_early(dev);
1065 }
1066
1067 /**
1068  * pm_genpd_resume - Resume of device in an I/O PM domain.
1069  * @dev: Device to resume.
1070  *
1071  * Resume a device under the assumption that its pm_domain field points to the
1072  * domain member of an object of type struct generic_pm_domain representing
1073  * a power domain consisting of I/O devices.
1074  */
1075 static int pm_genpd_resume(struct device *dev)
1076 {
1077         struct generic_pm_domain *genpd;
1078
1079         dev_dbg(dev, "%s()\n", __func__);
1080
1081         genpd = dev_to_genpd(dev);
1082         if (IS_ERR(genpd))
1083                 return -EINVAL;
1084
1085         return genpd->suspend_power_off ? 0 : pm_generic_resume(dev);
1086 }
1087
1088 /**
1089  * pm_genpd_freeze - Freezing a device in an I/O PM domain.
1090  * @dev: Device to freeze.
1091  *
1092  * Freeze a device under the assumption that its pm_domain field points to the
1093  * domain member of an object of type struct generic_pm_domain representing
1094  * a power domain consisting of I/O devices.
1095  */
1096 static int pm_genpd_freeze(struct device *dev)
1097 {
1098         struct generic_pm_domain *genpd;
1099
1100         dev_dbg(dev, "%s()\n", __func__);
1101
1102         genpd = dev_to_genpd(dev);
1103         if (IS_ERR(genpd))
1104                 return -EINVAL;
1105
1106         return genpd->suspend_power_off ? 0 : pm_generic_freeze(dev);
1107 }
1108
1109 /**
1110  * pm_genpd_freeze_late - Late freeze of a device in an I/O PM domain.
1111  * @dev: Device to freeze.
1112  *
1113  * Carry out a late freeze of a device under the assumption that its
1114  * pm_domain field points to the domain member of an object of type
1115  * struct generic_pm_domain representing a power domain consisting of I/O
1116  * devices.
1117  */
1118 static int pm_genpd_freeze_late(struct device *dev)
1119 {
1120         struct generic_pm_domain *genpd;
1121
1122         dev_dbg(dev, "%s()\n", __func__);
1123
1124         genpd = dev_to_genpd(dev);
1125         if (IS_ERR(genpd))
1126                 return -EINVAL;
1127
1128         return genpd->suspend_power_off ? 0 : pm_generic_freeze_late(dev);
1129 }
1130
1131 /**
1132  * pm_genpd_freeze_noirq - Completion of freezing a device in an I/O PM domain.
1133  * @dev: Device to freeze.
1134  *
1135  * Carry out a late freeze of a device under the assumption that its
1136  * pm_domain field points to the domain member of an object of type
1137  * struct generic_pm_domain representing a power domain consisting of I/O
1138  * devices.
1139  */
1140 static int pm_genpd_freeze_noirq(struct device *dev)
1141 {
1142         struct generic_pm_domain *genpd;
1143
1144         dev_dbg(dev, "%s()\n", __func__);
1145
1146         genpd = dev_to_genpd(dev);
1147         if (IS_ERR(genpd))
1148                 return -EINVAL;
1149
1150         return genpd->suspend_power_off ? 0 : genpd_stop_dev(genpd, dev);
1151 }
1152
1153 /**
1154  * pm_genpd_thaw_noirq - Early thaw of device in an I/O PM domain.
1155  * @dev: Device to thaw.
1156  *
1157  * Start the device, unless power has been removed from the domain already
1158  * before the system transition.
1159  */
1160 static int pm_genpd_thaw_noirq(struct device *dev)
1161 {
1162         struct generic_pm_domain *genpd;
1163
1164         dev_dbg(dev, "%s()\n", __func__);
1165
1166         genpd = dev_to_genpd(dev);
1167         if (IS_ERR(genpd))
1168                 return -EINVAL;
1169
1170         return genpd->suspend_power_off ? 0 : genpd_start_dev(genpd, dev);
1171 }
1172
1173 /**
1174  * pm_genpd_thaw_early - Early thaw of device in an I/O PM domain.
1175  * @dev: Device to thaw.
1176  *
1177  * Carry out an early thaw of a device under the assumption that its
1178  * pm_domain field points to the domain member of an object of type
1179  * struct generic_pm_domain representing a power domain consisting of I/O
1180  * devices.
1181  */
1182 static int pm_genpd_thaw_early(struct device *dev)
1183 {
1184         struct generic_pm_domain *genpd;
1185
1186         dev_dbg(dev, "%s()\n", __func__);
1187
1188         genpd = dev_to_genpd(dev);
1189         if (IS_ERR(genpd))
1190                 return -EINVAL;
1191
1192         return genpd->suspend_power_off ? 0 : pm_generic_thaw_early(dev);
1193 }
1194
1195 /**
1196  * pm_genpd_thaw - Thaw a device belonging to an I/O power domain.
1197  * @dev: Device to thaw.
1198  *
1199  * Thaw a device under the assumption that its pm_domain field points to the
1200  * domain member of an object of type struct generic_pm_domain representing
1201  * a power domain consisting of I/O devices.
1202  */
1203 static int pm_genpd_thaw(struct device *dev)
1204 {
1205         struct generic_pm_domain *genpd;
1206
1207         dev_dbg(dev, "%s()\n", __func__);
1208
1209         genpd = dev_to_genpd(dev);
1210         if (IS_ERR(genpd))
1211                 return -EINVAL;
1212
1213         return genpd->suspend_power_off ? 0 : pm_generic_thaw(dev);
1214 }
1215
1216 /**
1217  * pm_genpd_restore_noirq - Start of restore of device in an I/O PM domain.
1218  * @dev: Device to resume.
1219  *
1220  * Make sure the domain will be in the same power state as before the
1221  * hibernation the system is resuming from and start the device if necessary.
1222  */
1223 static int pm_genpd_restore_noirq(struct device *dev)
1224 {
1225         struct generic_pm_domain *genpd;
1226
1227         dev_dbg(dev, "%s()\n", __func__);
1228
1229         genpd = dev_to_genpd(dev);
1230         if (IS_ERR(genpd))
1231                 return -EINVAL;
1232
1233         /*
1234          * Since all of the "noirq" callbacks are executed sequentially, it is
1235          * guaranteed that this function will never run twice in parallel for
1236          * the same PM domain, so it is not necessary to use locking here.
1237          *
1238          * At this point suspended_count == 0 means we are being run for the
1239          * first time for the given domain in the present cycle.
1240          */
1241         if (genpd->suspended_count++ == 0) {
1242                 /*
1243                  * The boot kernel might put the domain into arbitrary state,
1244                  * so make it appear as powered off to pm_genpd_sync_poweron(),
1245                  * so that it tries to power it on in case it was really off.
1246                  */
1247                 genpd->status = GPD_STATE_POWER_OFF;
1248                 if (genpd->suspend_power_off) {
1249                         /*
1250                          * If the domain was off before the hibernation, make
1251                          * sure it will be off going forward.
1252                          */
1253                         if (genpd->power_off)
1254                                 genpd->power_off(genpd);
1255
1256                         return 0;
1257                 }
1258         }
1259
1260         if (genpd->suspend_power_off)
1261                 return 0;
1262
1263         pm_genpd_sync_poweron(genpd);
1264
1265         return genpd_start_dev(genpd, dev);
1266 }
1267
1268 /**
1269  * pm_genpd_complete - Complete power transition of a device in a power domain.
1270  * @dev: Device to complete the transition of.
1271  *
1272  * Complete a power transition of a device (during a system-wide power
1273  * transition) under the assumption that its pm_domain field points to the
1274  * domain member of an object of type struct generic_pm_domain representing
1275  * a power domain consisting of I/O devices.
1276  */
1277 static void pm_genpd_complete(struct device *dev)
1278 {
1279         struct generic_pm_domain *genpd;
1280         bool run_complete;
1281
1282         dev_dbg(dev, "%s()\n", __func__);
1283
1284         genpd = dev_to_genpd(dev);
1285         if (IS_ERR(genpd))
1286                 return;
1287
1288         mutex_lock(&genpd->lock);
1289
1290         run_complete = !genpd->suspend_power_off;
1291         if (--genpd->prepared_count == 0)
1292                 genpd->suspend_power_off = false;
1293
1294         mutex_unlock(&genpd->lock);
1295
1296         if (run_complete) {
1297                 pm_generic_complete(dev);
1298                 pm_runtime_set_active(dev);
1299                 pm_runtime_enable(dev);
1300                 pm_request_idle(dev);
1301         }
1302 }
1303
1304 /**
1305  * genpd_syscore_switch - Switch power during system core suspend or resume.
1306  * @dev: Device that normally is marked as "always on" to switch power for.
1307  *
1308  * This routine may only be called during the system core (syscore) suspend or
1309  * resume phase for devices whose "always on" flags are set.
1310  */
1311 static void genpd_syscore_switch(struct device *dev, bool suspend)
1312 {
1313         struct generic_pm_domain *genpd;
1314
1315         genpd = dev_to_genpd(dev);
1316         if (!pm_genpd_present(genpd))
1317                 return;
1318
1319         if (suspend) {
1320                 genpd->suspended_count++;
1321                 pm_genpd_sync_poweroff(genpd);
1322         } else {
1323                 pm_genpd_sync_poweron(genpd);
1324                 genpd->suspended_count--;
1325         }
1326 }
1327
1328 void pm_genpd_syscore_poweroff(struct device *dev)
1329 {
1330         genpd_syscore_switch(dev, true);
1331 }
1332 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweroff);
1333
1334 void pm_genpd_syscore_poweron(struct device *dev)
1335 {
1336         genpd_syscore_switch(dev, false);
1337 }
1338 EXPORT_SYMBOL_GPL(pm_genpd_syscore_poweron);
1339
1340 #else
1341
1342 #define pm_genpd_prepare                NULL
1343 #define pm_genpd_suspend                NULL
1344 #define pm_genpd_suspend_late           NULL
1345 #define pm_genpd_suspend_noirq          NULL
1346 #define pm_genpd_resume_early           NULL
1347 #define pm_genpd_resume_noirq           NULL
1348 #define pm_genpd_resume                 NULL
1349 #define pm_genpd_freeze                 NULL
1350 #define pm_genpd_freeze_late            NULL
1351 #define pm_genpd_freeze_noirq           NULL
1352 #define pm_genpd_thaw_early             NULL
1353 #define pm_genpd_thaw_noirq             NULL
1354 #define pm_genpd_thaw                   NULL
1355 #define pm_genpd_restore_noirq          NULL
1356 #define pm_genpd_complete               NULL
1357
1358 #endif /* CONFIG_PM_SLEEP */
1359
1360 static struct generic_pm_domain_data *__pm_genpd_alloc_dev_data(struct device *dev)
1361 {
1362         struct generic_pm_domain_data *gpd_data;
1363
1364         gpd_data = kzalloc(sizeof(*gpd_data), GFP_KERNEL);
1365         if (!gpd_data)
1366                 return NULL;
1367
1368         mutex_init(&gpd_data->lock);
1369         gpd_data->nb.notifier_call = genpd_dev_pm_qos_notifier;
1370         dev_pm_qos_add_notifier(dev, &gpd_data->nb);
1371         return gpd_data;
1372 }
1373
1374 static void __pm_genpd_free_dev_data(struct device *dev,
1375                                      struct generic_pm_domain_data *gpd_data)
1376 {
1377         dev_pm_qos_remove_notifier(dev, &gpd_data->nb);
1378         kfree(gpd_data);
1379 }
1380
1381 /**
1382  * __pm_genpd_add_device - Add a device to an I/O PM domain.
1383  * @genpd: PM domain to add the device to.
1384  * @dev: Device to be added.
1385  * @td: Set of PM QoS timing parameters to attach to the device.
1386  */
1387 int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
1388                           struct gpd_timing_data *td)
1389 {
1390         struct generic_pm_domain_data *gpd_data_new, *gpd_data = NULL;
1391         struct pm_domain_data *pdd;
1392         int ret = 0;
1393
1394         dev_dbg(dev, "%s()\n", __func__);
1395
1396         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev))
1397                 return -EINVAL;
1398
1399         gpd_data_new = __pm_genpd_alloc_dev_data(dev);
1400         if (!gpd_data_new)
1401                 return -ENOMEM;
1402
1403         genpd_acquire_lock(genpd);
1404
1405         if (genpd->prepared_count > 0) {
1406                 ret = -EAGAIN;
1407                 goto out;
1408         }
1409
1410         list_for_each_entry(pdd, &genpd->dev_list, list_node)
1411                 if (pdd->dev == dev) {
1412                         ret = -EINVAL;
1413                         goto out;
1414                 }
1415
1416         ret = dev_pm_get_subsys_data(dev);
1417         if (ret)
1418                 goto out;
1419
1420         genpd->device_count++;
1421         genpd->max_off_time_changed = true;
1422
1423         spin_lock_irq(&dev->power.lock);
1424
1425         dev->pm_domain = &genpd->domain;
1426         if (dev->power.subsys_data->domain_data) {
1427                 gpd_data = to_gpd_data(dev->power.subsys_data->domain_data);
1428         } else {
1429                 gpd_data = gpd_data_new;
1430                 dev->power.subsys_data->domain_data = &gpd_data->base;
1431         }
1432         gpd_data->refcount++;
1433         if (td)
1434                 gpd_data->td = *td;
1435
1436         spin_unlock_irq(&dev->power.lock);
1437
1438         mutex_lock(&gpd_data->lock);
1439         gpd_data->base.dev = dev;
1440         list_add_tail(&gpd_data->base.list_node, &genpd->dev_list);
1441         gpd_data->need_restore = genpd->status == GPD_STATE_POWER_OFF;
1442         gpd_data->td.constraint_changed = true;
1443         gpd_data->td.effective_constraint_ns = -1;
1444         mutex_unlock(&gpd_data->lock);
1445
1446  out:
1447         genpd_release_lock(genpd);
1448
1449         if (gpd_data != gpd_data_new)
1450                 __pm_genpd_free_dev_data(dev, gpd_data_new);
1451
1452         return ret;
1453 }
1454
1455 /**
1456  * __pm_genpd_of_add_device - Add a device to an I/O PM domain.
1457  * @genpd_node: Device tree node pointer representing a PM domain to which the
1458  *   the device is added to.
1459  * @dev: Device to be added.
1460  * @td: Set of PM QoS timing parameters to attach to the device.
1461  */
1462 int __pm_genpd_of_add_device(struct device_node *genpd_node, struct device *dev,
1463                              struct gpd_timing_data *td)
1464 {
1465         struct generic_pm_domain *genpd = NULL, *gpd;
1466
1467         dev_dbg(dev, "%s()\n", __func__);
1468
1469         if (IS_ERR_OR_NULL(genpd_node) || IS_ERR_OR_NULL(dev))
1470                 return -EINVAL;
1471
1472         mutex_lock(&gpd_list_lock);
1473         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1474                 if (gpd->of_node == genpd_node) {
1475                         genpd = gpd;
1476                         break;
1477                 }
1478         }
1479         mutex_unlock(&gpd_list_lock);
1480
1481         if (!genpd)
1482                 return -EINVAL;
1483
1484         return __pm_genpd_add_device(genpd, dev, td);
1485 }
1486
1487
1488 /**
1489  * __pm_genpd_name_add_device - Find I/O PM domain and add a device to it.
1490  * @domain_name: Name of the PM domain to add the device to.
1491  * @dev: Device to be added.
1492  * @td: Set of PM QoS timing parameters to attach to the device.
1493  */
1494 int __pm_genpd_name_add_device(const char *domain_name, struct device *dev,
1495                                struct gpd_timing_data *td)
1496 {
1497         return __pm_genpd_add_device(pm_genpd_lookup_name(domain_name), dev, td);
1498 }
1499
1500 /**
1501  * pm_genpd_remove_device - Remove a device from an I/O PM domain.
1502  * @genpd: PM domain to remove the device from.
1503  * @dev: Device to be removed.
1504  */
1505 int pm_genpd_remove_device(struct generic_pm_domain *genpd,
1506                            struct device *dev)
1507 {
1508         struct generic_pm_domain_data *gpd_data;
1509         struct pm_domain_data *pdd;
1510         bool remove = false;
1511         int ret = 0;
1512
1513         dev_dbg(dev, "%s()\n", __func__);
1514
1515         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(dev)
1516             ||  IS_ERR_OR_NULL(dev->pm_domain)
1517             ||  pd_to_genpd(dev->pm_domain) != genpd)
1518                 return -EINVAL;
1519
1520         genpd_acquire_lock(genpd);
1521
1522         if (genpd->prepared_count > 0) {
1523                 ret = -EAGAIN;
1524                 goto out;
1525         }
1526
1527         genpd->device_count--;
1528         genpd->max_off_time_changed = true;
1529
1530         spin_lock_irq(&dev->power.lock);
1531
1532         dev->pm_domain = NULL;
1533         pdd = dev->power.subsys_data->domain_data;
1534         list_del_init(&pdd->list_node);
1535         gpd_data = to_gpd_data(pdd);
1536         if (--gpd_data->refcount == 0) {
1537                 dev->power.subsys_data->domain_data = NULL;
1538                 remove = true;
1539         }
1540
1541         spin_unlock_irq(&dev->power.lock);
1542
1543         mutex_lock(&gpd_data->lock);
1544         pdd->dev = NULL;
1545         mutex_unlock(&gpd_data->lock);
1546
1547         genpd_release_lock(genpd);
1548
1549         dev_pm_put_subsys_data(dev);
1550         if (remove)
1551                 __pm_genpd_free_dev_data(dev, gpd_data);
1552
1553         return 0;
1554
1555  out:
1556         genpd_release_lock(genpd);
1557
1558         return ret;
1559 }
1560
1561 /**
1562  * pm_genpd_dev_need_restore - Set/unset the device's "need restore" flag.
1563  * @dev: Device to set/unset the flag for.
1564  * @val: The new value of the device's "need restore" flag.
1565  */
1566 void pm_genpd_dev_need_restore(struct device *dev, bool val)
1567 {
1568         struct pm_subsys_data *psd;
1569         unsigned long flags;
1570
1571         spin_lock_irqsave(&dev->power.lock, flags);
1572
1573         psd = dev_to_psd(dev);
1574         if (psd && psd->domain_data)
1575                 to_gpd_data(psd->domain_data)->need_restore = val;
1576
1577         spin_unlock_irqrestore(&dev->power.lock, flags);
1578 }
1579 EXPORT_SYMBOL_GPL(pm_genpd_dev_need_restore);
1580
1581 /**
1582  * pm_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
1583  * @genpd: Master PM domain to add the subdomain to.
1584  * @subdomain: Subdomain to be added.
1585  */
1586 int pm_genpd_add_subdomain(struct generic_pm_domain *genpd,
1587                            struct generic_pm_domain *subdomain)
1588 {
1589         struct gpd_link *link;
1590         int ret = 0;
1591
1592         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain)
1593             || genpd == subdomain)
1594                 return -EINVAL;
1595
1596  start:
1597         genpd_acquire_lock(genpd);
1598         mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1599
1600         if (subdomain->status != GPD_STATE_POWER_OFF
1601             && subdomain->status != GPD_STATE_ACTIVE) {
1602                 mutex_unlock(&subdomain->lock);
1603                 genpd_release_lock(genpd);
1604                 goto start;
1605         }
1606
1607         if (genpd->status == GPD_STATE_POWER_OFF
1608             &&  subdomain->status != GPD_STATE_POWER_OFF) {
1609                 ret = -EINVAL;
1610                 goto out;
1611         }
1612
1613         list_for_each_entry(link, &genpd->master_links, master_node) {
1614                 if (link->slave == subdomain && link->master == genpd) {
1615                         ret = -EINVAL;
1616                         goto out;
1617                 }
1618         }
1619
1620         link = kzalloc(sizeof(*link), GFP_KERNEL);
1621         if (!link) {
1622                 ret = -ENOMEM;
1623                 goto out;
1624         }
1625         link->master = genpd;
1626         list_add_tail(&link->master_node, &genpd->master_links);
1627         link->slave = subdomain;
1628         list_add_tail(&link->slave_node, &subdomain->slave_links);
1629         if (subdomain->status != GPD_STATE_POWER_OFF)
1630                 genpd_sd_counter_inc(genpd);
1631
1632  out:
1633         mutex_unlock(&subdomain->lock);
1634         genpd_release_lock(genpd);
1635
1636         return ret;
1637 }
1638
1639 /**
1640  * pm_genpd_add_subdomain_names - Add a subdomain to an I/O PM domain.
1641  * @master_name: Name of the master PM domain to add the subdomain to.
1642  * @subdomain_name: Name of the subdomain to be added.
1643  */
1644 int pm_genpd_add_subdomain_names(const char *master_name,
1645                                  const char *subdomain_name)
1646 {
1647         struct generic_pm_domain *master = NULL, *subdomain = NULL, *gpd;
1648
1649         if (IS_ERR_OR_NULL(master_name) || IS_ERR_OR_NULL(subdomain_name))
1650                 return -EINVAL;
1651
1652         mutex_lock(&gpd_list_lock);
1653         list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
1654                 if (!master && !strcmp(gpd->name, master_name))
1655                         master = gpd;
1656
1657                 if (!subdomain && !strcmp(gpd->name, subdomain_name))
1658                         subdomain = gpd;
1659
1660                 if (master && subdomain)
1661                         break;
1662         }
1663         mutex_unlock(&gpd_list_lock);
1664
1665         return pm_genpd_add_subdomain(master, subdomain);
1666 }
1667
1668 /**
1669  * pm_genpd_remove_subdomain - Remove a subdomain from an I/O PM domain.
1670  * @genpd: Master PM domain to remove the subdomain from.
1671  * @subdomain: Subdomain to be removed.
1672  */
1673 int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
1674                               struct generic_pm_domain *subdomain)
1675 {
1676         struct gpd_link *link;
1677         int ret = -EINVAL;
1678
1679         if (IS_ERR_OR_NULL(genpd) || IS_ERR_OR_NULL(subdomain))
1680                 return -EINVAL;
1681
1682  start:
1683         genpd_acquire_lock(genpd);
1684
1685         list_for_each_entry(link, &genpd->master_links, master_node) {
1686                 if (link->slave != subdomain)
1687                         continue;
1688
1689                 mutex_lock_nested(&subdomain->lock, SINGLE_DEPTH_NESTING);
1690
1691                 if (subdomain->status != GPD_STATE_POWER_OFF
1692                     && subdomain->status != GPD_STATE_ACTIVE) {
1693                         mutex_unlock(&subdomain->lock);
1694                         genpd_release_lock(genpd);
1695                         goto start;
1696                 }
1697
1698                 list_del(&link->master_node);
1699                 list_del(&link->slave_node);
1700                 kfree(link);
1701                 if (subdomain->status != GPD_STATE_POWER_OFF)
1702                         genpd_sd_counter_dec(genpd);
1703
1704                 mutex_unlock(&subdomain->lock);
1705
1706                 ret = 0;
1707                 break;
1708         }
1709
1710         genpd_release_lock(genpd);
1711
1712         return ret;
1713 }
1714
1715 /**
1716  * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
1717  * @genpd: PM domain to be connected with cpuidle.
1718  * @state: cpuidle state this domain can disable/enable.
1719  *
1720  * Make a PM domain behave as though it contained a CPU core, that is, instead
1721  * of calling its power down routine it will enable the given cpuidle state so
1722  * that the cpuidle subsystem can power it down (if possible and desirable).
1723  */
1724 int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
1725 {
1726         struct cpuidle_driver *cpuidle_drv;
1727         struct gpd_cpu_data *cpu_data;
1728         struct cpuidle_state *idle_state;
1729         int ret = 0;
1730
1731         if (IS_ERR_OR_NULL(genpd) || state < 0)
1732                 return -EINVAL;
1733
1734         genpd_acquire_lock(genpd);
1735
1736         if (genpd->cpu_data) {
1737                 ret = -EEXIST;
1738                 goto out;
1739         }
1740         cpu_data = kzalloc(sizeof(*cpu_data), GFP_KERNEL);
1741         if (!cpu_data) {
1742                 ret = -ENOMEM;
1743                 goto out;
1744         }
1745         cpuidle_drv = cpuidle_driver_ref();
1746         if (!cpuidle_drv) {
1747                 ret = -ENODEV;
1748                 goto err_drv;
1749         }
1750         if (cpuidle_drv->state_count <= state) {
1751                 ret = -EINVAL;
1752                 goto err;
1753         }
1754         idle_state = &cpuidle_drv->states[state];
1755         if (!idle_state->disabled) {
1756                 ret = -EAGAIN;
1757                 goto err;
1758         }
1759         cpu_data->idle_state = idle_state;
1760         cpu_data->saved_exit_latency = idle_state->exit_latency;
1761         genpd->cpu_data = cpu_data;
1762         genpd_recalc_cpu_exit_latency(genpd);
1763
1764  out:
1765         genpd_release_lock(genpd);
1766         return ret;
1767
1768  err:
1769         cpuidle_driver_unref();
1770
1771  err_drv:
1772         kfree(cpu_data);
1773         goto out;
1774 }
1775
1776 /**
1777  * pm_genpd_name_attach_cpuidle - Find PM domain and connect cpuidle to it.
1778  * @name: Name of the domain to connect to cpuidle.
1779  * @state: cpuidle state this domain can manipulate.
1780  */
1781 int pm_genpd_name_attach_cpuidle(const char *name, int state)
1782 {
1783         return pm_genpd_attach_cpuidle(pm_genpd_lookup_name(name), state);
1784 }
1785
1786 /**
1787  * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
1788  * @genpd: PM domain to remove the cpuidle connection from.
1789  *
1790  * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
1791  * given PM domain.
1792  */
1793 int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
1794 {
1795         struct gpd_cpu_data *cpu_data;
1796         struct cpuidle_state *idle_state;
1797         int ret = 0;
1798
1799         if (IS_ERR_OR_NULL(genpd))
1800                 return -EINVAL;
1801
1802         genpd_acquire_lock(genpd);
1803
1804         cpu_data = genpd->cpu_data;
1805         if (!cpu_data) {
1806                 ret = -ENODEV;
1807                 goto out;
1808         }
1809         idle_state = cpu_data->idle_state;
1810         if (!idle_state->disabled) {
1811                 ret = -EAGAIN;
1812                 goto out;
1813         }
1814         idle_state->exit_latency = cpu_data->saved_exit_latency;
1815         cpuidle_driver_unref();
1816         genpd->cpu_data = NULL;
1817         kfree(cpu_data);
1818
1819  out:
1820         genpd_release_lock(genpd);
1821         return ret;
1822 }
1823
1824 /**
1825  * pm_genpd_name_detach_cpuidle - Find PM domain and disconnect cpuidle from it.
1826  * @name: Name of the domain to disconnect cpuidle from.
1827  */
1828 int pm_genpd_name_detach_cpuidle(const char *name)
1829 {
1830         return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
1831 }
1832
1833 /* Default device callbacks for generic PM domains. */
1834
1835 /**
1836  * pm_genpd_default_save_state - Default "save device state" for PM domains.
1837  * @dev: Device to handle.
1838  */
1839 static int pm_genpd_default_save_state(struct device *dev)
1840 {
1841         int (*cb)(struct device *__dev);
1842
1843         if (dev->type && dev->type->pm)
1844                 cb = dev->type->pm->runtime_suspend;
1845         else if (dev->class && dev->class->pm)
1846                 cb = dev->class->pm->runtime_suspend;
1847         else if (dev->bus && dev->bus->pm)
1848                 cb = dev->bus->pm->runtime_suspend;
1849         else
1850                 cb = NULL;
1851
1852         if (!cb && dev->driver && dev->driver->pm)
1853                 cb = dev->driver->pm->runtime_suspend;
1854
1855         return cb ? cb(dev) : 0;
1856 }
1857
1858 /**
1859  * pm_genpd_default_restore_state - Default PM domains "restore device state".
1860  * @dev: Device to handle.
1861  */
1862 static int pm_genpd_default_restore_state(struct device *dev)
1863 {
1864         int (*cb)(struct device *__dev);
1865
1866         if (dev->type && dev->type->pm)
1867                 cb = dev->type->pm->runtime_resume;
1868         else if (dev->class && dev->class->pm)
1869                 cb = dev->class->pm->runtime_resume;
1870         else if (dev->bus && dev->bus->pm)
1871                 cb = dev->bus->pm->runtime_resume;
1872         else
1873                 cb = NULL;
1874
1875         if (!cb && dev->driver && dev->driver->pm)
1876                 cb = dev->driver->pm->runtime_resume;
1877
1878         return cb ? cb(dev) : 0;
1879 }
1880
1881 /**
1882  * pm_genpd_init - Initialize a generic I/O PM domain object.
1883  * @genpd: PM domain object to initialize.
1884  * @gov: PM domain governor to associate with the domain (may be NULL).
1885  * @is_off: Initial value of the domain's power_is_off field.
1886  */
1887 void pm_genpd_init(struct generic_pm_domain *genpd,
1888                    struct dev_power_governor *gov, bool is_off)
1889 {
1890         if (IS_ERR_OR_NULL(genpd))
1891                 return;
1892
1893         INIT_LIST_HEAD(&genpd->master_links);
1894         INIT_LIST_HEAD(&genpd->slave_links);
1895         INIT_LIST_HEAD(&genpd->dev_list);
1896         mutex_init(&genpd->lock);
1897         genpd->gov = gov;
1898         INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
1899         genpd->in_progress = 0;
1900         atomic_set(&genpd->sd_count, 0);
1901         genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
1902         init_waitqueue_head(&genpd->status_wait_queue);
1903         genpd->poweroff_task = NULL;
1904         genpd->resume_count = 0;
1905         genpd->device_count = 0;
1906         genpd->max_off_time_ns = -1;
1907         genpd->max_off_time_changed = true;
1908         genpd->domain.ops.runtime_suspend = pm_genpd_runtime_suspend;
1909         genpd->domain.ops.runtime_resume = pm_genpd_runtime_resume;
1910         genpd->domain.ops.prepare = pm_genpd_prepare;
1911         genpd->domain.ops.suspend = pm_genpd_suspend;
1912         genpd->domain.ops.suspend_late = pm_genpd_suspend_late;
1913         genpd->domain.ops.suspend_noirq = pm_genpd_suspend_noirq;
1914         genpd->domain.ops.resume_noirq = pm_genpd_resume_noirq;
1915         genpd->domain.ops.resume_early = pm_genpd_resume_early;
1916         genpd->domain.ops.resume = pm_genpd_resume;
1917         genpd->domain.ops.freeze = pm_genpd_freeze;
1918         genpd->domain.ops.freeze_late = pm_genpd_freeze_late;
1919         genpd->domain.ops.freeze_noirq = pm_genpd_freeze_noirq;
1920         genpd->domain.ops.thaw_noirq = pm_genpd_thaw_noirq;
1921         genpd->domain.ops.thaw_early = pm_genpd_thaw_early;
1922         genpd->domain.ops.thaw = pm_genpd_thaw;
1923         genpd->domain.ops.poweroff = pm_genpd_suspend;
1924         genpd->domain.ops.poweroff_late = pm_genpd_suspend_late;
1925         genpd->domain.ops.poweroff_noirq = pm_genpd_suspend_noirq;
1926         genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
1927         genpd->domain.ops.restore_early = pm_genpd_resume_early;
1928         genpd->domain.ops.restore = pm_genpd_resume;
1929         genpd->domain.ops.complete = pm_genpd_complete;
1930         genpd->dev_ops.save_state = pm_genpd_default_save_state;
1931         genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
1932         mutex_lock(&gpd_list_lock);
1933         list_add(&genpd->gpd_list_node, &gpd_list);
1934         mutex_unlock(&gpd_list_lock);
1935 }