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_SLEEP_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_SLEEP_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 bool pm_debug_messages_on __read_mostly;
 365
 366 static ssize_t pm_debug_messages_show(struct kobject *kobj,
 367                                       struct kobj_attribute *attr, char *buf)
 368 {
 369         return sprintf(buf, "%d\n", pm_debug_messages_on);
 370 }
 371
 372 static ssize_t pm_debug_messages_store(struct kobject *kobj,
 373                                        struct kobj_attribute *attr,
 374                                        const char *buf, size_t n)
 375 {
 376         unsigned long val;
 377
 378         if (kstrtoul(buf, 10, &val))
 379                 return -EINVAL;
 380
 381         if (val > 1)
 382                 return -EINVAL;
 383
 384         pm_debug_messages_on = !!val;
 385         return n;
 386 }
 387
 388 power_attr(pm_debug_messages);
 389
 390 /**
 391  * __pm_pr_dbg - Print a suspend debug message to the kernel log.
 392  * @defer: Whether or not to use printk_deferred() to print the message.
 393  * @fmt: Message format.
 394  *
 395  * The message will be emitted if enabled through the pm_debug_messages
 396  * sysfs attribute.
 397  */
 398 void __pm_pr_dbg(bool defer, const char *fmt, ...)
 399 {
 400         struct va_format vaf;
 401         va_list args;
 402
 403         if (!pm_debug_messages_on)
 404                 return;
 405
 406         va_start(args, fmt);
 407
 408         vaf.fmt = fmt;
 409         vaf.va = &args;
 410
 411         if (defer)
 412                 printk_deferred(KERN_DEBUG "PM: %pV", &vaf);
 413         else
 414                 printk(KERN_DEBUG "PM: %pV", &vaf);
 415
 416         va_end(args);
 417 }
 418
 419 #else /* !CONFIG_PM_SLEEP_DEBUG */
 420 static inline void pm_print_times_init(void) {}
 421 #endif /* CONFIG_PM_SLEEP_DEBUG */
 422
 423 struct kobject *power_kobj;
 424
 425 /**
 426  * state - control system sleep states.
 427  *
 428  * show() returns available sleep state labels, which may be "mem", "standby",
 429  * "freeze" and "disk" (hibernation).  See Documentation/power/states.txt for a
 430  * description of what they mean.
 431  *
 432  * store() accepts one of those strings, translates it into the proper
 433  * enumerated value, and initiates a suspend transition.
 434  */
 435 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 436                           char *buf)
 437 {
 438         char *s = buf;
 439 #ifdef CONFIG_SUSPEND
 440         suspend_state_t i;
 441
 442         for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
 443                 if (pm_states[i])
 444                         s += sprintf(s,"%s ", pm_states[i]);
 445
 446 #endif
 447         if (hibernation_available())
 448                 s += sprintf(s, "disk ");
 449         if (s != buf)
 450                 /* convert the last space to a newline */
 451                 *(s-1) = '\n';
 452         return (s - buf);
 453 }
 454
 455 static suspend_state_t decode_state(const char *buf, size_t n)
 456 {
 457 #ifdef CONFIG_SUSPEND
 458         suspend_state_t state;
 459 #endif
 460         char *p;
 461         int len;
 462
 463         p = memchr(buf, '\n', n);
 464         len = p ? p - buf : n;
 465
 466         /* Check hibernation first. */
 467         if (len == 4 && !strncmp(buf, "disk", len))
 468                 return PM_SUSPEND_MAX;
 469
 470 #ifdef CONFIG_SUSPEND
 471         for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
 472                 const char *label = pm_states[state];
 473
 474                 if (label && len == strlen(label) && !strncmp(buf, label, len))
 475                         return state;
 476         }
 477 #endif
 478
 479         return PM_SUSPEND_ON;
 480 }
 481
 482 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
 483                            const char *buf, size_t n)
 484 {
 485         suspend_state_t state;
 486         int error;
 487
 488         error = pm_autosleep_lock();
 489         if (error)
 490                 return error;
 491
 492         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 493                 error = -EBUSY;
 494                 goto out;
 495         }
 496
 497         state = decode_state(buf, n);
 498         if (state < PM_SUSPEND_MAX) {
 499                 if (state == PM_SUSPEND_MEM)
 500                         state = mem_sleep_current;
 501
 502                 error = pm_suspend(state);
 503         } else if (state == PM_SUSPEND_MAX) {
 504                 error = hibernate();
 505         } else {
 506                 error = -EINVAL;
 507         }
 508
 509  out:
 510         pm_autosleep_unlock();
 511         return error ? error : n;
 512 }
 513
 514 power_attr(state);
 515
 516 #ifdef CONFIG_PM_SLEEP
 517 /*
 518  * The 'wakeup_count' attribute, along with the functions defined in
 519  * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
 520  * handled in a non-racy way.
 521  *
 522  * If a wakeup event occurs when the system is in a sleep state, it simply is
 523  * woken up.  In turn, if an event that would wake the system up from a sleep
 524  * state occurs when it is undergoing a transition to that sleep state, the
 525  * transition should be aborted.  Moreover, if such an event occurs when the
 526  * system is in the working state, an attempt to start a transition to the
 527  * given sleep state should fail during certain period after the detection of
 528  * the event.  Using the 'state' attribute alone is not sufficient to satisfy
 529  * these requirements, because a wakeup event may occur exactly when 'state'
 530  * is being written to and may be delivered to user space right before it is
 531  * frozen, so the event will remain only partially processed until the system is
 532  * woken up by another event.  In particular, it won't cause the transition to
 533  * a sleep state to be aborted.
 534  *
 535  * This difficulty may be overcome if user space uses 'wakeup_count' before
 536  * writing to 'state'.  It first should read from 'wakeup_count' and store
 537  * the read value.  Then, after carrying out its own preparations for the system
 538  * transition to a sleep state, it should write the stored value to
 539  * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
 540  * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
 541  * is allowed to write to 'state', but the transition will be aborted if there
 542  * are any wakeup events detected after 'wakeup_count' was written to.
 543  */
 544
 545 static ssize_t wakeup_count_show(struct kobject *kobj,
 546                                 struct kobj_attribute *attr,
 547                                 char *buf)
 548 {
 549         unsigned int val;
 550
 551         return pm_get_wakeup_count(&val, true) ?
 552                 sprintf(buf, "%u\n", val) : -EINTR;
 553 }
 554
 555 static ssize_t wakeup_count_store(struct kobject *kobj,
 556                                 struct kobj_attribute *attr,
 557                                 const char *buf, size_t n)
 558 {
 559         unsigned int val;
 560         int error;
 561
 562         error = pm_autosleep_lock();
 563         if (error)
 564                 return error;
 565
 566         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 567                 error = -EBUSY;
 568                 goto out;
 569         }
 570
 571         error = -EINVAL;
 572         if (sscanf(buf, "%u", &val) == 1) {
 573                 if (pm_save_wakeup_count(val))
 574                         error = n;
 575                 else
 576                         pm_print_active_wakeup_sources();
 577         }
 578
 579  out:
 580         pm_autosleep_unlock();
 581         return error;
 582 }
 583
 584 power_attr(wakeup_count);
 585
 586 #ifdef CONFIG_PM_AUTOSLEEP
 587 static ssize_t autosleep_show(struct kobject *kobj,
 588                               struct kobj_attribute *attr,
 589                               char *buf)
 590 {
 591         suspend_state_t state = pm_autosleep_state();
 592
 593         if (state == PM_SUSPEND_ON)
 594                 return sprintf(buf, "off\n");
 595
 596 #ifdef CONFIG_SUSPEND
 597         if (state < PM_SUSPEND_MAX)
 598                 return sprintf(buf, "%s\n", pm_states[state] ?
 599                                         pm_states[state] : "error");
 600 #endif
 601 #ifdef CONFIG_HIBERNATION
 602         return sprintf(buf, "disk\n");
 603 #else
 604         return sprintf(buf, "error");
 605 #endif
 606 }
 607
 608 static ssize_t autosleep_store(struct kobject *kobj,
 609                                struct kobj_attribute *attr,
 610                                const char *buf, size_t n)
 611 {
 612         suspend_state_t state = decode_state(buf, n);
 613         int error;
 614
 615         if (state == PM_SUSPEND_ON
 616             && strcmp(buf, "off") && strcmp(buf, "off\n"))
 617                 return -EINVAL;
 618
 619         if (state == PM_SUSPEND_MEM)
 620                 state = mem_sleep_current;
 621
 622         error = pm_autosleep_set_state(state);
 623         return error ? error : n;
 624 }
 625
 626 power_attr(autosleep);
 627 #endif /* CONFIG_PM_AUTOSLEEP */
 628
 629 #ifdef CONFIG_PM_WAKELOCKS
 630 static ssize_t wake_lock_show(struct kobject *kobj,
 631                               struct kobj_attribute *attr,
 632                               char *buf)
 633 {
 634         return pm_show_wakelocks(buf, true);
 635 }
 636
 637 static ssize_t wake_lock_store(struct kobject *kobj,
 638                                struct kobj_attribute *attr,
 639                                const char *buf, size_t n)
 640 {
 641         int error = pm_wake_lock(buf);
 642         return error ? error : n;
 643 }
 644
 645 power_attr(wake_lock);
 646
 647 static ssize_t wake_unlock_show(struct kobject *kobj,
 648                                 struct kobj_attribute *attr,
 649                                 char *buf)
 650 {
 651         return pm_show_wakelocks(buf, false);
 652 }
 653
 654 static ssize_t wake_unlock_store(struct kobject *kobj,
 655                                  struct kobj_attribute *attr,
 656                                  const char *buf, size_t n)
 657 {
 658         int error = pm_wake_unlock(buf);
 659         return error ? error : n;
 660 }
 661
 662 power_attr(wake_unlock);
 663
 664 #endif /* CONFIG_PM_WAKELOCKS */
 665 #endif /* CONFIG_PM_SLEEP */
 666
 667 #ifdef CONFIG_PM_TRACE
 668 int pm_trace_enabled;
 669
 670 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
 671                              char *buf)
 672 {
 673         return sprintf(buf, "%d\n", pm_trace_enabled);
 674 }
 675
 676 static ssize_t
 677 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
 678                const char *buf, size_t n)
 679 {
 680         int val;
 681
 682         if (sscanf(buf, "%d", &val) == 1) {
 683                 pm_trace_enabled = !!val;
 684                 if (pm_trace_enabled) {
 685                         pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
 686                                 "PM: Correct system time has to be restored manually after resume.\n");
 687                 }
 688                 return n;
 689         }
 690         return -EINVAL;
 691 }
 692
 693 power_attr(pm_trace);
 694
 695 static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
 696                                        struct kobj_attribute *attr,
 697                                        char *buf)
 698 {
 699         return show_trace_dev_match(buf, PAGE_SIZE);
 700 }
 701
 702 power_attr_ro(pm_trace_dev_match);
 703
 704 #endif /* CONFIG_PM_TRACE */
 705
 706 #ifdef CONFIG_FREEZER
 707 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
 708                                       struct kobj_attribute *attr, char *buf)
 709 {
 710         return sprintf(buf, "%u\n", freeze_timeout_msecs);
 711 }
 712
 713 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
 714                                        struct kobj_attribute *attr,
 715                                        const char *buf, size_t n)
 716 {
 717         unsigned long val;
 718
 719         if (kstrtoul(buf, 10, &val))
 720                 return -EINVAL;
 721
 722         freeze_timeout_msecs = val;
 723         return n;
 724 }
 725
 726 power_attr(pm_freeze_timeout);
 727
 728 #endif  /* CONFIG_FREEZER*/
 729
 730 static struct attribute * g[] = {
 731         &state_attr.attr,
 732 #ifdef CONFIG_PM_TRACE
 733         &pm_trace_attr.attr,
 734         &pm_trace_dev_match_attr.attr,
 735 #endif
 736 #ifdef CONFIG_PM_SLEEP
 737         &pm_async_attr.attr,
 738         &wakeup_count_attr.attr,
 739 #ifdef CONFIG_SUSPEND
 740         &mem_sleep_attr.attr,
 741 #endif
 742 #ifdef CONFIG_PM_AUTOSLEEP
 743         &autosleep_attr.attr,
 744 #endif
 745 #ifdef CONFIG_PM_WAKELOCKS
 746         &wake_lock_attr.attr,
 747         &wake_unlock_attr.attr,
 748 #endif
 749 #ifdef CONFIG_PM_SLEEP_DEBUG
 750         &pm_test_attr.attr,
 751         &pm_print_times_attr.attr,
 752         &pm_wakeup_irq_attr.attr,
 753         &pm_debug_messages_attr.attr,
 754 #endif
 755 #endif
 756 #ifdef CONFIG_FREEZER
 757         &pm_freeze_timeout_attr.attr,
 758 #endif
 759         NULL,
 760 };
 761
 762 static const struct attribute_group attr_group = {
 763         .attrs = g,
 764 };
 765
 766 struct workqueue_struct *pm_wq;
 767 EXPORT_SYMBOL_GPL(pm_wq);
 768
 769 static int __init pm_start_workqueue(void)
 770 {
 771         pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
 772
 773         return pm_wq ? 0 : -ENOMEM;
 774 }
 775
 776 static int __init pm_init(void)
 777 {
 778         int error = pm_start_workqueue();
 779         if (error)
 780                 return error;
 781         hibernate_image_size_init();
 782         hibernate_reserved_size_init();
 783         pm_states_init();
 784         power_kobj = kobject_create_and_add("power", NULL);
 785         if (!power_kobj)
 786                 return -ENOMEM;
 787         error = sysfs_create_group(power_kobj, &attr_group);
 788         if (error)
 789                 return error;
 790         pm_print_times_init();
 791         return pm_autosleep_init();
 792 }
 793
 794 core_initcall(pm_init);