kernel/power/main.c

   1 /*
   2  * kernel/power/main.c - PM subsystem core functionality.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  */
  10
  11 #include <linux/export.h>
  12 #include <linux/kobject.h>
  13 #include <linux/string.h>
  14 #include <linux/pm-trace.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/debugfs.h>
  17 #include <linux/seq_file.h>
  18
  19 #include "power.h"
  20
  21 DEFINE_MUTEX(pm_mutex);
  22
  23 #ifdef CONFIG_PM_SLEEP
  24
  25 /* Routines for PM-transition notifications */
  26
  27 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
  28
  29 int register_pm_notifier(struct notifier_block *nb)
  30 {
  31         return blocking_notifier_chain_register(&pm_chain_head, nb);
  32 }
  33 EXPORT_SYMBOL_GPL(register_pm_notifier);
  34
  35 int unregister_pm_notifier(struct notifier_block *nb)
  36 {
  37         return blocking_notifier_chain_unregister(&pm_chain_head, nb);
  38 }
  39 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
  40
  41 int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
  42 {
  43         int ret;
  44
  45         ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
  46                                                 nr_to_call, nr_calls);
  47
  48         return notifier_to_errno(ret);
  49 }
  50 int pm_notifier_call_chain(unsigned long val)
  51 {
  52         return __pm_notifier_call_chain(val, -1, NULL);
  53 }
  54
  55 /* If set, devices may be suspended and resumed asynchronously. */
  56 int pm_async_enabled = 1;
  57
  58 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
  59                              char *buf)
  60 {
  61         return sprintf(buf, "%d\n", pm_async_enabled);
  62 }
  63
  64 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
  65                               const char *buf, size_t n)
  66 {
  67         unsigned long val;
  68
  69         if (kstrtoul(buf, 10, &val))
  70                 return -EINVAL;
  71
  72         if (val > 1)
  73                 return -EINVAL;
  74
  75         pm_async_enabled = val;
  76         return n;
  77 }
  78
  79 power_attr(pm_async);
  80
  81 #ifdef CONFIG_SUSPEND
  82 static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
  83                               char *buf)
  84 {
  85         char *s = buf;
  86         suspend_state_t i;
  87
  88         for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
  89                 if (mem_sleep_states[i]) {
  90                         const char *label = mem_sleep_states[i];
  91
  92                         if (mem_sleep_current == i)
  93                                 s += sprintf(s, "[%s] ", label);
  94                         else
  95                                 s += sprintf(s, "%s ", label);
  96                 }
  97
  98         /* Convert the last space to a newline if needed. */
  99         if (s != buf)
 100                 *(s-1) = '\n';
 101
 102         return (s - buf);
 103 }
 104
 105 static suspend_state_t decode_suspend_state(const char *buf, size_t n)
 106 {
 107         suspend_state_t state;
 108         char *p;
 109         int len;
 110
 111         p = memchr(buf, '\n', n);
 112         len = p ? p - buf : n;
 113
 114         for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
 115                 const char *label = mem_sleep_states[state];
 116
 117                 if (label && len == strlen(label) && !strncmp(buf, label, len))
 118                         return state;
 119         }
 120
 121         return PM_SUSPEND_ON;
 122 }
 123
 124 static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
 125                                const char *buf, size_t n)
 126 {
 127         suspend_state_t state;
 128         int error;
 129
 130         error = pm_autosleep_lock();
 131         if (error)
 132                 return error;
 133
 134         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 135                 error = -EBUSY;
 136                 goto out;
 137         }
 138
 139         state = decode_suspend_state(buf, n);
 140         if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
 141                 mem_sleep_current = state;
 142         else
 143                 error = -EINVAL;
 144
 145  out:
 146         pm_autosleep_unlock();
 147         return error ? error : n;
 148 }
 149
 150 power_attr(mem_sleep);
 151 #endif /* CONFIG_SUSPEND */
 152
 153 #ifdef CONFIG_PM_DEBUG
 154 int pm_test_level = TEST_NONE;
 155
 156 static const char * const pm_tests[__TEST_AFTER_LAST] = {
 157         [TEST_NONE] = "none",
 158         [TEST_CORE] = "core",
 159         [TEST_CPUS] = "processors",
 160         [TEST_PLATFORM] = "platform",
 161         [TEST_DEVICES] = "devices",
 162         [TEST_FREEZER] = "freezer",
 163 };
 164
 165 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
 166                                 char *buf)
 167 {
 168         char *s = buf;
 169         int level;
 170
 171         for (level = TEST_FIRST; level <= TEST_MAX; level++)
 172                 if (pm_tests[level]) {
 173                         if (level == pm_test_level)
 174                                 s += sprintf(s, "[%s] ", pm_tests[level]);
 175                         else
 176                                 s += sprintf(s, "%s ", pm_tests[level]);
 177                 }
 178
 179         if (s != buf)
 180                 /* convert the last space to a newline */
 181                 *(s-1) = '\n';
 182
 183         return (s - buf);
 184 }
 185
 186 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
 187                                 const char *buf, size_t n)
 188 {
 189         const char * const *s;
 190         int level;
 191         char *p;
 192         int len;
 193         int error = -EINVAL;
 194
 195         p = memchr(buf, '\n', n);
 196         len = p ? p - buf : n;
 197
 198         lock_system_sleep();
 199
 200         level = TEST_FIRST;
 201         for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
 202                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
 203                         pm_test_level = level;
 204                         error = 0;
 205                         break;
 206                 }
 207
 208         unlock_system_sleep();
 209
 210         return error ? error : n;
 211 }
 212
 213 power_attr(pm_test);
 214 #endif /* CONFIG_PM_DEBUG */
 215
 216 #ifdef CONFIG_DEBUG_FS
 217 static char *suspend_step_name(enum suspend_stat_step step)
 218 {
 219         switch (step) {
 220         case SUSPEND_FREEZE:
 221                 return "freeze";
 222         case SUSPEND_PREPARE:
 223                 return "prepare";
 224         case SUSPEND_SUSPEND:
 225                 return "suspend";
 226         case SUSPEND_SUSPEND_NOIRQ:
 227                 return "suspend_noirq";
 228         case SUSPEND_RESUME_NOIRQ:
 229                 return "resume_noirq";
 230         case SUSPEND_RESUME:
 231                 return "resume";
 232         default:
 233                 return "";
 234         }
 235 }
 236
 237 static int suspend_stats_show(struct seq_file *s, void *unused)
 238 {
 239         int i, index, last_dev, last_errno, last_step;
 240
 241         last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 242         last_dev %= REC_FAILED_NUM;
 243         last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
 244         last_errno %= REC_FAILED_NUM;
 245         last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
 246         last_step %= REC_FAILED_NUM;
 247         seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
 248                         "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
 249                         "success", suspend_stats.success,
 250                         "fail", suspend_stats.fail,
 251                         "failed_freeze", suspend_stats.failed_freeze,
 252                         "failed_prepare", suspend_stats.failed_prepare,
 253                         "failed_suspend", suspend_stats.failed_suspend,
 254                         "failed_suspend_late",
 255                                 suspend_stats.failed_suspend_late,
 256                         "failed_suspend_noirq",
 257                                 suspend_stats.failed_suspend_noirq,
 258                         "failed_resume", suspend_stats.failed_resume,
 259                         "failed_resume_early",
 260                                 suspend_stats.failed_resume_early,
 261                         "failed_resume_noirq",
 262                                 suspend_stats.failed_resume_noirq);
 263         seq_printf(s,   "failures:\n  last_failed_dev:\t%-s\n",
 264                         suspend_stats.failed_devs[last_dev]);
 265         for (i = 1; i < REC_FAILED_NUM; i++) {
 266                 index = last_dev + REC_FAILED_NUM - i;
 267                 index %= REC_FAILED_NUM;
 268                 seq_printf(s, "\t\t\t%-s\n",
 269                         suspend_stats.failed_devs[index]);
 270         }
 271         seq_printf(s,   "  last_failed_errno:\t%-d\n",
 272                         suspend_stats.errno[last_errno]);
 273         for (i = 1; i < REC_FAILED_NUM; i++) {
 274                 index = last_errno + REC_FAILED_NUM - i;
 275                 index %= REC_FAILED_NUM;
 276                 seq_printf(s, "\t\t\t%-d\n",
 277                         suspend_stats.errno[index]);
 278         }
 279         seq_printf(s,   "  last_failed_step:\t%-s\n",
 280                         suspend_step_name(
 281                                 suspend_stats.failed_steps[last_step]));
 282         for (i = 1; i < REC_FAILED_NUM; i++) {
 283                 index = last_step + REC_FAILED_NUM - i;
 284                 index %= REC_FAILED_NUM;
 285                 seq_printf(s, "\t\t\t%-s\n",
 286                         suspend_step_name(
 287                                 suspend_stats.failed_steps[index]));
 288         }
 289
 290         return 0;
 291 }
 292
 293 static int suspend_stats_open(struct inode *inode, struct file *file)
 294 {
 295         return single_open(file, suspend_stats_show, NULL);
 296 }
 297
 298 static const struct file_operations suspend_stats_operations = {
 299         .open           = suspend_stats_open,
 300         .read           = seq_read,
 301         .llseek         = seq_lseek,
 302         .release        = single_release,
 303 };
 304
 305 static int __init pm_debugfs_init(void)
 306 {
 307         debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
 308                         NULL, NULL, &suspend_stats_operations);
 309         return 0;
 310 }
 311
 312 late_initcall(pm_debugfs_init);
 313 #endif /* CONFIG_DEBUG_FS */
 314
 315 #endif /* CONFIG_PM_SLEEP */
 316
 317 #ifdef CONFIG_PM_SLEEP_DEBUG
 318 /*
 319  * pm_print_times: print time taken by devices to suspend and resume.
 320  *
 321  * show() returns whether printing of suspend and resume times is enabled.
 322  * store() accepts 0 or 1.  0 disables printing and 1 enables it.
 323  */
 324 bool pm_print_times_enabled;
 325
 326 static ssize_t pm_print_times_show(struct kobject *kobj,
 327                                    struct kobj_attribute *attr, char *buf)
 328 {
 329         return sprintf(buf, "%d\n", pm_print_times_enabled);
 330 }
 331
 332 static ssize_t pm_print_times_store(struct kobject *kobj,
 333                                     struct kobj_attribute *attr,
 334                                     const char *buf, size_t n)
 335 {
 336         unsigned long val;
 337
 338         if (kstrtoul(buf, 10, &val))
 339                 return -EINVAL;
 340
 341         if (val > 1)
 342                 return -EINVAL;
 343
 344         pm_print_times_enabled = !!val;
 345         return n;
 346 }
 347
 348 power_attr(pm_print_times);
 349
 350 static inline void pm_print_times_init(void)
 351 {
 352         pm_print_times_enabled = !!initcall_debug;
 353 }
 354
 355 static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
 356                                         struct kobj_attribute *attr,
 357                                         char *buf)
 358 {
 359         return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
 360 }
 361
 362 power_attr_ro(pm_wakeup_irq);
 363
 364 #else /* !CONFIG_PM_SLEEP_DEBUG */
 365 static inline void pm_print_times_init(void) {}
 366 #endif /* CONFIG_PM_SLEEP_DEBUG */
 367
 368 struct kobject *power_kobj;
 369
 370 /**
 371  * state - control system sleep states.
 372  *
 373  * show() returns available sleep state labels, which may be "mem", "standby",
 374  * "freeze" and "disk" (hibernation).  See Documentation/power/states.txt for a
 375  * description of what they mean.
 376  *
 377  * store() accepts one of those strings, translates it into the proper
 378  * enumerated value, and initiates a suspend transition.
 379  */
 380 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 381                           char *buf)
 382 {
 383         char *s = buf;
 384 #ifdef CONFIG_SUSPEND
 385         suspend_state_t i;
 386
 387         for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
 388                 if (pm_states[i])
 389                         s += sprintf(s,"%s ", pm_states[i]);
 390
 391 #endif
 392         if (hibernation_available())
 393                 s += sprintf(s, "disk ");
 394         if (s != buf)
 395                 /* convert the last space to a newline */
 396                 *(s-1) = '\n';
 397         return (s - buf);
 398 }
 399
 400 static suspend_state_t decode_state(const char *buf, size_t n)
 401 {
 402 #ifdef CONFIG_SUSPEND
 403         suspend_state_t state;
 404 #endif
 405         char *p;
 406         int len;
 407
 408         p = memchr(buf, '\n', n);
 409         len = p ? p - buf : n;
 410
 411         /* Check hibernation first. */
 412         if (len == 4 && !strncmp(buf, "disk", len))
 413                 return PM_SUSPEND_MAX;
 414
 415 #ifdef CONFIG_SUSPEND
 416         for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
 417                 const char *label = pm_states[state];
 418
 419                 if (label && len == strlen(label) && !strncmp(buf, label, len))
 420                         return state;
 421         }
 422 #endif
 423
 424         return PM_SUSPEND_ON;
 425 }
 426
 427 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
 428                            const char *buf, size_t n)
 429 {
 430         suspend_state_t state;
 431         int error;
 432
 433         error = pm_autosleep_lock();
 434         if (error)
 435                 return error;
 436
 437         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 438                 error = -EBUSY;
 439                 goto out;
 440         }
 441
 442         state = decode_state(buf, n);
 443         if (state < PM_SUSPEND_MAX) {
 444                 if (state == PM_SUSPEND_MEM)
 445                         state = mem_sleep_current;
 446
 447                 error = pm_suspend(state);
 448         } else if (state == PM_SUSPEND_MAX) {
 449                 error = hibernate();
 450         } else {
 451                 error = -EINVAL;
 452         }
 453
 454  out:
 455         pm_autosleep_unlock();
 456         return error ? error : n;
 457 }
 458
 459 power_attr(state);
 460
 461 #ifdef CONFIG_PM_SLEEP
 462 /*
 463  * The 'wakeup_count' attribute, along with the functions defined in
 464  * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
 465  * handled in a non-racy way.
 466  *
 467  * If a wakeup event occurs when the system is in a sleep state, it simply is
 468  * woken up.  In turn, if an event that would wake the system up from a sleep
 469  * state occurs when it is undergoing a transition to that sleep state, the
 470  * transition should be aborted.  Moreover, if such an event occurs when the
 471  * system is in the working state, an attempt to start a transition to the
 472  * given sleep state should fail during certain period after the detection of
 473  * the event.  Using the 'state' attribute alone is not sufficient to satisfy
 474  * these requirements, because a wakeup event may occur exactly when 'state'
 475  * is being written to and may be delivered to user space right before it is
 476  * frozen, so the event will remain only partially processed until the system is
 477  * woken up by another event.  In particular, it won't cause the transition to
 478  * a sleep state to be aborted.
 479  *
 480  * This difficulty may be overcome if user space uses 'wakeup_count' before
 481  * writing to 'state'.  It first should read from 'wakeup_count' and store
 482  * the read value.  Then, after carrying out its own preparations for the system
 483  * transition to a sleep state, it should write the stored value to
 484  * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
 485  * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
 486  * is allowed to write to 'state', but the transition will be aborted if there
 487  * are any wakeup events detected after 'wakeup_count' was written to.
 488  */
 489
 490 static ssize_t wakeup_count_show(struct kobject *kobj,
 491                                 struct kobj_attribute *attr,
 492                                 char *buf)
 493 {
 494         unsigned int val;
 495
 496         return pm_get_wakeup_count(&val, true) ?
 497                 sprintf(buf, "%u\n", val) : -EINTR;
 498 }
 499
 500 static ssize_t wakeup_count_store(struct kobject *kobj,
 501                                 struct kobj_attribute *attr,
 502                                 const char *buf, size_t n)
 503 {
 504         unsigned int val;
 505         int error;
 506
 507         error = pm_autosleep_lock();
 508         if (error)
 509                 return error;
 510
 511         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 512                 error = -EBUSY;
 513                 goto out;
 514         }
 515
 516         error = -EINVAL;
 517         if (sscanf(buf, "%u", &val) == 1) {
 518                 if (pm_save_wakeup_count(val))
 519                         error = n;
 520                 else
 521                         pm_print_active_wakeup_sources();
 522         }
 523
 524  out:
 525         pm_autosleep_unlock();
 526         return error;
 527 }
 528
 529 power_attr(wakeup_count);
 530
 531 #ifdef CONFIG_PM_AUTOSLEEP
 532 static ssize_t autosleep_show(struct kobject *kobj,
 533                               struct kobj_attribute *attr,
 534                               char *buf)
 535 {
 536         suspend_state_t state = pm_autosleep_state();
 537
 538         if (state == PM_SUSPEND_ON)
 539                 return sprintf(buf, "off\n");
 540
 541 #ifdef CONFIG_SUSPEND
 542         if (state < PM_SUSPEND_MAX)
 543                 return sprintf(buf, "%s\n", pm_states[state] ?
 544                                         pm_states[state] : "error");
 545 #endif
 546 #ifdef CONFIG_HIBERNATION
 547         return sprintf(buf, "disk\n");
 548 #else
 549         return sprintf(buf, "error");
 550 #endif
 551 }
 552
 553 static ssize_t autosleep_store(struct kobject *kobj,
 554                                struct kobj_attribute *attr,
 555                                const char *buf, size_t n)
 556 {
 557         suspend_state_t state = decode_state(buf, n);
 558         int error;
 559
 560         if (state == PM_SUSPEND_ON
 561             && strcmp(buf, "off") && strcmp(buf, "off\n"))
 562                 return -EINVAL;
 563
 564         if (state == PM_SUSPEND_MEM)
 565                 state = mem_sleep_current;
 566
 567         error = pm_autosleep_set_state(state);
 568         return error ? error : n;
 569 }
 570
 571 power_attr(autosleep);
 572 #endif /* CONFIG_PM_AUTOSLEEP */
 573
 574 #ifdef CONFIG_PM_WAKELOCKS
 575 static ssize_t wake_lock_show(struct kobject *kobj,
 576                               struct kobj_attribute *attr,
 577                               char *buf)
 578 {
 579         return pm_show_wakelocks(buf, true);
 580 }
 581
 582 static ssize_t wake_lock_store(struct kobject *kobj,
 583                                struct kobj_attribute *attr,
 584                                const char *buf, size_t n)
 585 {
 586         int error = pm_wake_lock(buf);
 587         return error ? error : n;
 588 }
 589
 590 power_attr(wake_lock);
 591
 592 static ssize_t wake_unlock_show(struct kobject *kobj,
 593                                 struct kobj_attribute *attr,
 594                                 char *buf)
 595 {
 596         return pm_show_wakelocks(buf, false);
 597 }
 598
 599 static ssize_t wake_unlock_store(struct kobject *kobj,
 600                                  struct kobj_attribute *attr,
 601                                  const char *buf, size_t n)
 602 {
 603         int error = pm_wake_unlock(buf);
 604         return error ? error : n;
 605 }
 606
 607 power_attr(wake_unlock);
 608
 609 #endif /* CONFIG_PM_WAKELOCKS */
 610 #endif /* CONFIG_PM_SLEEP */
 611
 612 #ifdef CONFIG_PM_TRACE
 613 int pm_trace_enabled;
 614
 615 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
 616                              char *buf)
 617 {
 618         return sprintf(buf, "%d\n", pm_trace_enabled);
 619 }
 620
 621 static ssize_t
 622 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
 623                const char *buf, size_t n)
 624 {
 625         int val;
 626
 627         if (sscanf(buf, "%d", &val) == 1) {
 628                 pm_trace_enabled = !!val;
 629                 if (pm_trace_enabled) {
 630                         pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
 631                                 "PM: Correct system time has to be restored manually after resume.\n");
 632                 }
 633                 return n;
 634         }
 635         return -EINVAL;
 636 }
 637
 638 power_attr(pm_trace);
 639
 640 static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
 641                                        struct kobj_attribute *attr,
 642                                        char *buf)
 643 {
 644         return show_trace_dev_match(buf, PAGE_SIZE);
 645 }
 646
 647 power_attr_ro(pm_trace_dev_match);
 648
 649 #endif /* CONFIG_PM_TRACE */
 650
 651 #ifdef CONFIG_FREEZER
 652 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
 653                                       struct kobj_attribute *attr, char *buf)
 654 {
 655         return sprintf(buf, "%u\n", freeze_timeout_msecs);
 656 }
 657
 658 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
 659                                        struct kobj_attribute *attr,
 660                                        const char *buf, size_t n)
 661 {
 662         unsigned long val;
 663
 664         if (kstrtoul(buf, 10, &val))
 665                 return -EINVAL;
 666
 667         freeze_timeout_msecs = val;
 668         return n;
 669 }
 670
 671 power_attr(pm_freeze_timeout);
 672
 673 #endif  /* CONFIG_FREEZER*/
 674
 675 static struct attribute * g[] = {
 676         &state_attr.attr,
 677 #ifdef CONFIG_PM_TRACE
 678         &pm_trace_attr.attr,
 679         &pm_trace_dev_match_attr.attr,
 680 #endif
 681 #ifdef CONFIG_PM_SLEEP
 682         &pm_async_attr.attr,
 683         &wakeup_count_attr.attr,
 684 #ifdef CONFIG_SUSPEND
 685         &mem_sleep_attr.attr,
 686 #endif
 687 #ifdef CONFIG_PM_AUTOSLEEP
 688         &autosleep_attr.attr,
 689 #endif
 690 #ifdef CONFIG_PM_WAKELOCKS
 691         &wake_lock_attr.attr,
 692         &wake_unlock_attr.attr,
 693 #endif
 694 #ifdef CONFIG_PM_DEBUG
 695         &pm_test_attr.attr,
 696 #endif
 697 #ifdef CONFIG_PM_SLEEP_DEBUG
 698         &pm_print_times_attr.attr,
 699         &pm_wakeup_irq_attr.attr,
 700 #endif
 701 #endif
 702 #ifdef CONFIG_FREEZER
 703         &pm_freeze_timeout_attr.attr,
 704 #endif
 705         NULL,
 706 };
 707
 708 static const struct attribute_group attr_group = {
 709         .attrs = g,
 710 };
 711
 712 struct workqueue_struct *pm_wq;
 713 EXPORT_SYMBOL_GPL(pm_wq);
 714
 715 static int __init pm_start_workqueue(void)
 716 {
 717         pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
 718
 719         return pm_wq ? 0 : -ENOMEM;
 720 }
 721
 722 static int __init pm_init(void)
 723 {
 724         int error = pm_start_workqueue();
 725         if (error)
 726                 return error;
 727         hibernate_image_size_init();
 728         hibernate_reserved_size_init();
 729         pm_states_init();
 730         power_kobj = kobject_create_and_add("power", NULL);
 731         if (!power_kobj)
 732                 return -ENOMEM;
 733         error = sysfs_create_group(power_kobj, &attr_group);
 734         if (error)
 735                 return error;
 736         pm_print_times_init();
 737         return pm_autosleep_init();
 738 }
 739
 740 core_initcall(pm_init);