kernel/power/main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * kernel/power/main.c - PM subsystem core functionality.
   4  *
   5  * Copyright (c) 2003 Patrick Mochel
   6  * Copyright (c) 2003 Open Source Development Lab
   7  */
   8
   9 #include <linux/export.h>
  10 #include <linux/kobject.h>
  11 #include <linux/string.h>
  12 #include <linux/pm-trace.h>
  13 #include <linux/workqueue.h>
  14 #include <linux/debugfs.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/suspend.h>
  17 #include <linux/syscalls.h>
  18
  19 #include "power.h"
  20
  21 #ifdef CONFIG_PM_SLEEP
  22
  23 void lock_system_sleep(void)
  24 {
  25         current->flags |= PF_FREEZER_SKIP;
  26         mutex_lock(&system_transition_mutex);
  27 }
  28 EXPORT_SYMBOL_GPL(lock_system_sleep);
  29
  30 void unlock_system_sleep(void)
  31 {
  32         /*
  33          * Don't use freezer_count() because we don't want the call to
  34          * try_to_freeze() here.
  35          *
  36          * Reason:
  37          * Fundamentally, we just don't need it, because freezing condition
  38          * doesn't come into effect until we release the
  39          * system_transition_mutex lock, since the freezer always works with
  40          * system_transition_mutex held.
  41          *
  42          * More importantly, in the case of hibernation,
  43          * unlock_system_sleep() gets called in snapshot_read() and
  44          * snapshot_write() when the freezing condition is still in effect.
  45          * Which means, if we use try_to_freeze() here, it would make them
  46          * enter the refrigerator, thus causing hibernation to lockup.
  47          */
  48         current->flags &= ~PF_FREEZER_SKIP;
  49         mutex_unlock(&system_transition_mutex);
  50 }
  51 EXPORT_SYMBOL_GPL(unlock_system_sleep);
  52
  53 void ksys_sync_helper(void)
  54 {
  55         ktime_t start;
  56         long elapsed_msecs;
  57
  58         start = ktime_get();
  59         ksys_sync();
  60         elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start));
  61         pr_info("Filesystems sync: %ld.%03ld seconds\n",
  62                 elapsed_msecs / MSEC_PER_SEC, elapsed_msecs % MSEC_PER_SEC);
  63 }
  64 EXPORT_SYMBOL_GPL(ksys_sync_helper);
  65
  66 /* Routines for PM-transition notifications */
  67
  68 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
  69
  70 int register_pm_notifier(struct notifier_block *nb)
  71 {
  72         return blocking_notifier_chain_register(&pm_chain_head, nb);
  73 }
  74 EXPORT_SYMBOL_GPL(register_pm_notifier);
  75
  76 int unregister_pm_notifier(struct notifier_block *nb)
  77 {
  78         return blocking_notifier_chain_unregister(&pm_chain_head, nb);
  79 }
  80 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
  81
  82 int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
  83 {
  84         int ret;
  85
  86         ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
  87                                                 nr_to_call, nr_calls);
  88
  89         return notifier_to_errno(ret);
  90 }
  91 int pm_notifier_call_chain(unsigned long val)
  92 {
  93         return __pm_notifier_call_chain(val, -1, NULL);
  94 }
  95
  96 /* If set, devices may be suspended and resumed asynchronously. */
  97 int pm_async_enabled = 1;
  98
  99 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
 100                              char *buf)
 101 {
 102         return sprintf(buf, "%d\n", pm_async_enabled);
 103 }
 104
 105 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
 106                               const char *buf, size_t n)
 107 {
 108         unsigned long val;
 109
 110         if (kstrtoul(buf, 10, &val))
 111                 return -EINVAL;
 112
 113         if (val > 1)
 114                 return -EINVAL;
 115
 116         pm_async_enabled = val;
 117         return n;
 118 }
 119
 120 power_attr(pm_async);
 121
 122 #ifdef CONFIG_SUSPEND
 123 static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
 124                               char *buf)
 125 {
 126         char *s = buf;
 127         suspend_state_t i;
 128
 129         for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
 130                 if (mem_sleep_states[i]) {
 131                         const char *label = mem_sleep_states[i];
 132
 133                         if (mem_sleep_current == i)
 134                                 s += sprintf(s, "[%s] ", label);
 135                         else
 136                                 s += sprintf(s, "%s ", label);
 137                 }
 138
 139         /* Convert the last space to a newline if needed. */
 140         if (s != buf)
 141                 *(s-1) = '\n';
 142
 143         return (s - buf);
 144 }
 145
 146 static suspend_state_t decode_suspend_state(const char *buf, size_t n)
 147 {
 148         suspend_state_t state;
 149         char *p;
 150         int len;
 151
 152         p = memchr(buf, '\n', n);
 153         len = p ? p - buf : n;
 154
 155         for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
 156                 const char *label = mem_sleep_states[state];
 157
 158                 if (label && len == strlen(label) && !strncmp(buf, label, len))
 159                         return state;
 160         }
 161
 162         return PM_SUSPEND_ON;
 163 }
 164
 165 static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
 166                                const char *buf, size_t n)
 167 {
 168         suspend_state_t state;
 169         int error;
 170
 171         error = pm_autosleep_lock();
 172         if (error)
 173                 return error;
 174
 175         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 176                 error = -EBUSY;
 177                 goto out;
 178         }
 179
 180         state = decode_suspend_state(buf, n);
 181         if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
 182                 mem_sleep_current = state;
 183         else
 184                 error = -EINVAL;
 185
 186  out:
 187         pm_autosleep_unlock();
 188         return error ? error : n;
 189 }
 190
 191 power_attr(mem_sleep);
 192 #endif /* CONFIG_SUSPEND */
 193
 194 #ifdef CONFIG_PM_SLEEP_DEBUG
 195 int pm_test_level = TEST_NONE;
 196
 197 static const char * const pm_tests[__TEST_AFTER_LAST] = {
 198         [TEST_NONE] = "none",
 199         [TEST_CORE] = "core",
 200         [TEST_CPUS] = "processors",
 201         [TEST_PLATFORM] = "platform",
 202         [TEST_DEVICES] = "devices",
 203         [TEST_FREEZER] = "freezer",
 204 };
 205
 206 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
 207                                 char *buf)
 208 {
 209         char *s = buf;
 210         int level;
 211
 212         for (level = TEST_FIRST; level <= TEST_MAX; level++)
 213                 if (pm_tests[level]) {
 214                         if (level == pm_test_level)
 215                                 s += sprintf(s, "[%s] ", pm_tests[level]);
 216                         else
 217                                 s += sprintf(s, "%s ", pm_tests[level]);
 218                 }
 219
 220         if (s != buf)
 221                 /* convert the last space to a newline */
 222                 *(s-1) = '\n';
 223
 224         return (s - buf);
 225 }
 226
 227 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
 228                                 const char *buf, size_t n)
 229 {
 230         const char * const *s;
 231         int level;
 232         char *p;
 233         int len;
 234         int error = -EINVAL;
 235
 236         p = memchr(buf, '\n', n);
 237         len = p ? p - buf : n;
 238
 239         lock_system_sleep();
 240
 241         level = TEST_FIRST;
 242         for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
 243                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
 244                         pm_test_level = level;
 245                         error = 0;
 246                         break;
 247                 }
 248
 249         unlock_system_sleep();
 250
 251         return error ? error : n;
 252 }
 253
 254 power_attr(pm_test);
 255 #endif /* CONFIG_PM_SLEEP_DEBUG */
 256
 257 static char *suspend_step_name(enum suspend_stat_step step)
 258 {
 259         switch (step) {
 260         case SUSPEND_FREEZE:
 261                 return "freeze";
 262         case SUSPEND_PREPARE:
 263                 return "prepare";
 264         case SUSPEND_SUSPEND:
 265                 return "suspend";
 266         case SUSPEND_SUSPEND_NOIRQ:
 267                 return "suspend_noirq";
 268         case SUSPEND_RESUME_NOIRQ:
 269                 return "resume_noirq";
 270         case SUSPEND_RESUME:
 271                 return "resume";
 272         default:
 273                 return "";
 274         }
 275 }
 276
 277 #define suspend_attr(_name)                                     \
 278 static ssize_t _name##_show(struct kobject *kobj,               \
 279                 struct kobj_attribute *attr, char *buf)         \
 280 {                                                               \
 281         return sprintf(buf, "%d\n", suspend_stats._name);       \
 282 }                                                               \
 283 static struct kobj_attribute _name = __ATTR_RO(_name)
 284
 285 suspend_attr(success);
 286 suspend_attr(fail);
 287 suspend_attr(failed_freeze);
 288 suspend_attr(failed_prepare);
 289 suspend_attr(failed_suspend);
 290 suspend_attr(failed_suspend_late);
 291 suspend_attr(failed_suspend_noirq);
 292 suspend_attr(failed_resume);
 293 suspend_attr(failed_resume_early);
 294 suspend_attr(failed_resume_noirq);
 295
 296 static ssize_t last_failed_dev_show(struct kobject *kobj,
 297                 struct kobj_attribute *attr, char *buf)
 298 {
 299         int index;
 300         char *last_failed_dev = NULL;
 301
 302         index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 303         index %= REC_FAILED_NUM;
 304         last_failed_dev = suspend_stats.failed_devs[index];
 305
 306         return sprintf(buf, "%s\n", last_failed_dev);
 307 }
 308 static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
 309
 310 static ssize_t last_failed_errno_show(struct kobject *kobj,
 311                 struct kobj_attribute *attr, char *buf)
 312 {
 313         int index;
 314         int last_failed_errno;
 315
 316         index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
 317         index %= REC_FAILED_NUM;
 318         last_failed_errno = suspend_stats.errno[index];
 319
 320         return sprintf(buf, "%d\n", last_failed_errno);
 321 }
 322 static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
 323
 324 static ssize_t last_failed_step_show(struct kobject *kobj,
 325                 struct kobj_attribute *attr, char *buf)
 326 {
 327         int index;
 328         enum suspend_stat_step step;
 329         char *last_failed_step = NULL;
 330
 331         index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
 332         index %= REC_FAILED_NUM;
 333         step = suspend_stats.failed_steps[index];
 334         last_failed_step = suspend_step_name(step);
 335
 336         return sprintf(buf, "%s\n", last_failed_step);
 337 }
 338 static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
 339
 340 static struct attribute *suspend_attrs[] = {
 341         &success.attr,
 342         &fail.attr,
 343         &failed_freeze.attr,
 344         &failed_prepare.attr,
 345         &failed_suspend.attr,
 346         &failed_suspend_late.attr,
 347         &failed_suspend_noirq.attr,
 348         &failed_resume.attr,
 349         &failed_resume_early.attr,
 350         &failed_resume_noirq.attr,
 351         &last_failed_dev.attr,
 352         &last_failed_errno.attr,
 353         &last_failed_step.attr,
 354         NULL,
 355 };
 356
 357 static struct attribute_group suspend_attr_group = {
 358         .name = "suspend_stats",
 359         .attrs = suspend_attrs,
 360 };
 361
 362 #ifdef CONFIG_DEBUG_FS
 363 static int suspend_stats_show(struct seq_file *s, void *unused)
 364 {
 365         int i, index, last_dev, last_errno, last_step;
 366
 367         last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
 368         last_dev %= REC_FAILED_NUM;
 369         last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
 370         last_errno %= REC_FAILED_NUM;
 371         last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
 372         last_step %= REC_FAILED_NUM;
 373         seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
 374                         "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
 375                         "success", suspend_stats.success,
 376                         "fail", suspend_stats.fail,
 377                         "failed_freeze", suspend_stats.failed_freeze,
 378                         "failed_prepare", suspend_stats.failed_prepare,
 379                         "failed_suspend", suspend_stats.failed_suspend,
 380                         "failed_suspend_late",
 381                                 suspend_stats.failed_suspend_late,
 382                         "failed_suspend_noirq",
 383                                 suspend_stats.failed_suspend_noirq,
 384                         "failed_resume", suspend_stats.failed_resume,
 385                         "failed_resume_early",
 386                                 suspend_stats.failed_resume_early,
 387                         "failed_resume_noirq",
 388                                 suspend_stats.failed_resume_noirq);
 389         seq_printf(s,   "failures:\n  last_failed_dev:\t%-s\n",
 390                         suspend_stats.failed_devs[last_dev]);
 391         for (i = 1; i < REC_FAILED_NUM; i++) {
 392                 index = last_dev + REC_FAILED_NUM - i;
 393                 index %= REC_FAILED_NUM;
 394                 seq_printf(s, "\t\t\t%-s\n",
 395                         suspend_stats.failed_devs[index]);
 396         }
 397         seq_printf(s,   "  last_failed_errno:\t%-d\n",
 398                         suspend_stats.errno[last_errno]);
 399         for (i = 1; i < REC_FAILED_NUM; i++) {
 400                 index = last_errno + REC_FAILED_NUM - i;
 401                 index %= REC_FAILED_NUM;
 402                 seq_printf(s, "\t\t\t%-d\n",
 403                         suspend_stats.errno[index]);
 404         }
 405         seq_printf(s,   "  last_failed_step:\t%-s\n",
 406                         suspend_step_name(
 407                                 suspend_stats.failed_steps[last_step]));
 408         for (i = 1; i < REC_FAILED_NUM; i++) {
 409                 index = last_step + REC_FAILED_NUM - i;
 410                 index %= REC_FAILED_NUM;
 411                 seq_printf(s, "\t\t\t%-s\n",
 412                         suspend_step_name(
 413                                 suspend_stats.failed_steps[index]));
 414         }
 415
 416         return 0;
 417 }
 418 DEFINE_SHOW_ATTRIBUTE(suspend_stats);
 419
 420 static int __init pm_debugfs_init(void)
 421 {
 422         debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
 423                         NULL, NULL, &suspend_stats_fops);
 424         return 0;
 425 }
 426
 427 late_initcall(pm_debugfs_init);
 428 #endif /* CONFIG_DEBUG_FS */
 429
 430 #endif /* CONFIG_PM_SLEEP */
 431
 432 #ifdef CONFIG_PM_SLEEP_DEBUG
 433 /*
 434  * pm_print_times: print time taken by devices to suspend and resume.
 435  *
 436  * show() returns whether printing of suspend and resume times is enabled.
 437  * store() accepts 0 or 1.  0 disables printing and 1 enables it.
 438  */
 439 bool pm_print_times_enabled;
 440
 441 static ssize_t pm_print_times_show(struct kobject *kobj,
 442                                    struct kobj_attribute *attr, char *buf)
 443 {
 444         return sprintf(buf, "%d\n", pm_print_times_enabled);
 445 }
 446
 447 static ssize_t pm_print_times_store(struct kobject *kobj,
 448                                     struct kobj_attribute *attr,
 449                                     const char *buf, size_t n)
 450 {
 451         unsigned long val;
 452
 453         if (kstrtoul(buf, 10, &val))
 454                 return -EINVAL;
 455
 456         if (val > 1)
 457                 return -EINVAL;
 458
 459         pm_print_times_enabled = !!val;
 460         return n;
 461 }
 462
 463 power_attr(pm_print_times);
 464
 465 static inline void pm_print_times_init(void)
 466 {
 467         pm_print_times_enabled = !!initcall_debug;
 468 }
 469
 470 static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
 471                                         struct kobj_attribute *attr,
 472                                         char *buf)
 473 {
 474         return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
 475 }
 476
 477 power_attr_ro(pm_wakeup_irq);
 478
 479 bool pm_debug_messages_on __read_mostly;
 480
 481 static ssize_t pm_debug_messages_show(struct kobject *kobj,
 482                                       struct kobj_attribute *attr, char *buf)
 483 {
 484         return sprintf(buf, "%d\n", pm_debug_messages_on);
 485 }
 486
 487 static ssize_t pm_debug_messages_store(struct kobject *kobj,
 488                                        struct kobj_attribute *attr,
 489                                        const char *buf, size_t n)
 490 {
 491         unsigned long val;
 492
 493         if (kstrtoul(buf, 10, &val))
 494                 return -EINVAL;
 495
 496         if (val > 1)
 497                 return -EINVAL;
 498
 499         pm_debug_messages_on = !!val;
 500         return n;
 501 }
 502
 503 power_attr(pm_debug_messages);
 504
 505 /**
 506  * __pm_pr_dbg - Print a suspend debug message to the kernel log.
 507  * @defer: Whether or not to use printk_deferred() to print the message.
 508  * @fmt: Message format.
 509  *
 510  * The message will be emitted if enabled through the pm_debug_messages
 511  * sysfs attribute.
 512  */
 513 void __pm_pr_dbg(bool defer, const char *fmt, ...)
 514 {
 515         struct va_format vaf;
 516         va_list args;
 517
 518         if (!pm_debug_messages_on)
 519                 return;
 520
 521         va_start(args, fmt);
 522
 523         vaf.fmt = fmt;
 524         vaf.va = &args;
 525
 526         if (defer)
 527                 printk_deferred(KERN_DEBUG "PM: %pV", &vaf);
 528         else
 529                 printk(KERN_DEBUG "PM: %pV", &vaf);
 530
 531         va_end(args);
 532 }
 533
 534 #else /* !CONFIG_PM_SLEEP_DEBUG */
 535 static inline void pm_print_times_init(void) {}
 536 #endif /* CONFIG_PM_SLEEP_DEBUG */
 537
 538 struct kobject *power_kobj;
 539
 540 /**
 541  * state - control system sleep states.
 542  *
 543  * show() returns available sleep state labels, which may be "mem", "standby",
 544  * "freeze" and "disk" (hibernation).
 545  * See Documentation/admin-guide/pm/sleep-states.rst for a description of
 546  * what they mean.
 547  *
 548  * store() accepts one of those strings, translates it into the proper
 549  * enumerated value, and initiates a suspend transition.
 550  */
 551 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 552                           char *buf)
 553 {
 554         char *s = buf;
 555 #ifdef CONFIG_SUSPEND
 556         suspend_state_t i;
 557
 558         for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
 559                 if (pm_states[i])
 560                         s += sprintf(s,"%s ", pm_states[i]);
 561
 562 #endif
 563         if (hibernation_available())
 564                 s += sprintf(s, "disk ");
 565         if (s != buf)
 566                 /* convert the last space to a newline */
 567                 *(s-1) = '\n';
 568         return (s - buf);
 569 }
 570
 571 static suspend_state_t decode_state(const char *buf, size_t n)
 572 {
 573 #ifdef CONFIG_SUSPEND
 574         suspend_state_t state;
 575 #endif
 576         char *p;
 577         int len;
 578
 579         p = memchr(buf, '\n', n);
 580         len = p ? p - buf : n;
 581
 582         /* Check hibernation first. */
 583         if (len == 4 && str_has_prefix(buf, "disk"))
 584                 return PM_SUSPEND_MAX;
 585
 586 #ifdef CONFIG_SUSPEND
 587         for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
 588                 const char *label = pm_states[state];
 589
 590                 if (label && len == strlen(label) && !strncmp(buf, label, len))
 591                         return state;
 592         }
 593 #endif
 594
 595         return PM_SUSPEND_ON;
 596 }
 597
 598 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
 599                            const char *buf, size_t n)
 600 {
 601         suspend_state_t state;
 602         int error;
 603
 604         error = pm_autosleep_lock();
 605         if (error)
 606                 return error;
 607
 608         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 609                 error = -EBUSY;
 610                 goto out;
 611         }
 612
 613         state = decode_state(buf, n);
 614         if (state < PM_SUSPEND_MAX) {
 615                 if (state == PM_SUSPEND_MEM)
 616                         state = mem_sleep_current;
 617
 618                 error = pm_suspend(state);
 619         } else if (state == PM_SUSPEND_MAX) {
 620                 error = hibernate();
 621         } else {
 622                 error = -EINVAL;
 623         }
 624
 625  out:
 626         pm_autosleep_unlock();
 627         return error ? error : n;
 628 }
 629
 630 power_attr(state);
 631
 632 #ifdef CONFIG_PM_SLEEP
 633 /*
 634  * The 'wakeup_count' attribute, along with the functions defined in
 635  * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
 636  * handled in a non-racy way.
 637  *
 638  * If a wakeup event occurs when the system is in a sleep state, it simply is
 639  * woken up.  In turn, if an event that would wake the system up from a sleep
 640  * state occurs when it is undergoing a transition to that sleep state, the
 641  * transition should be aborted.  Moreover, if such an event occurs when the
 642  * system is in the working state, an attempt to start a transition to the
 643  * given sleep state should fail during certain period after the detection of
 644  * the event.  Using the 'state' attribute alone is not sufficient to satisfy
 645  * these requirements, because a wakeup event may occur exactly when 'state'
 646  * is being written to and may be delivered to user space right before it is
 647  * frozen, so the event will remain only partially processed until the system is
 648  * woken up by another event.  In particular, it won't cause the transition to
 649  * a sleep state to be aborted.
 650  *
 651  * This difficulty may be overcome if user space uses 'wakeup_count' before
 652  * writing to 'state'.  It first should read from 'wakeup_count' and store
 653  * the read value.  Then, after carrying out its own preparations for the system
 654  * transition to a sleep state, it should write the stored value to
 655  * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
 656  * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
 657  * is allowed to write to 'state', but the transition will be aborted if there
 658  * are any wakeup events detected after 'wakeup_count' was written to.
 659  */
 660
 661 static ssize_t wakeup_count_show(struct kobject *kobj,
 662                                 struct kobj_attribute *attr,
 663                                 char *buf)
 664 {
 665         unsigned int val;
 666
 667         return pm_get_wakeup_count(&val, true) ?
 668                 sprintf(buf, "%u\n", val) : -EINTR;
 669 }
 670
 671 static ssize_t wakeup_count_store(struct kobject *kobj,
 672                                 struct kobj_attribute *attr,
 673                                 const char *buf, size_t n)
 674 {
 675         unsigned int val;
 676         int error;
 677
 678         error = pm_autosleep_lock();
 679         if (error)
 680                 return error;
 681
 682         if (pm_autosleep_state() > PM_SUSPEND_ON) {
 683                 error = -EBUSY;
 684                 goto out;
 685         }
 686
 687         error = -EINVAL;
 688         if (sscanf(buf, "%u", &val) == 1) {
 689                 if (pm_save_wakeup_count(val))
 690                         error = n;
 691                 else
 692                         pm_print_active_wakeup_sources();
 693         }
 694
 695  out:
 696         pm_autosleep_unlock();
 697         return error;
 698 }
 699
 700 power_attr(wakeup_count);
 701
 702 #ifdef CONFIG_PM_AUTOSLEEP
 703 static ssize_t autosleep_show(struct kobject *kobj,
 704                               struct kobj_attribute *attr,
 705                               char *buf)
 706 {
 707         suspend_state_t state = pm_autosleep_state();
 708
 709         if (state == PM_SUSPEND_ON)
 710                 return sprintf(buf, "off\n");
 711
 712 #ifdef CONFIG_SUSPEND
 713         if (state < PM_SUSPEND_MAX)
 714                 return sprintf(buf, "%s\n", pm_states[state] ?
 715                                         pm_states[state] : "error");
 716 #endif
 717 #ifdef CONFIG_HIBERNATION
 718         return sprintf(buf, "disk\n");
 719 #else
 720         return sprintf(buf, "error");
 721 #endif
 722 }
 723
 724 static ssize_t autosleep_store(struct kobject *kobj,
 725                                struct kobj_attribute *attr,
 726                                const char *buf, size_t n)
 727 {
 728         suspend_state_t state = decode_state(buf, n);
 729         int error;
 730
 731         if (state == PM_SUSPEND_ON
 732             && strcmp(buf, "off") && strcmp(buf, "off\n"))
 733                 return -EINVAL;
 734
 735         if (state == PM_SUSPEND_MEM)
 736                 state = mem_sleep_current;
 737
 738         error = pm_autosleep_set_state(state);
 739         return error ? error : n;
 740 }
 741
 742 power_attr(autosleep);
 743 #endif /* CONFIG_PM_AUTOSLEEP */
 744
 745 #ifdef CONFIG_PM_WAKELOCKS
 746 static ssize_t wake_lock_show(struct kobject *kobj,
 747                               struct kobj_attribute *attr,
 748                               char *buf)
 749 {
 750         return pm_show_wakelocks(buf, true);
 751 }
 752
 753 static ssize_t wake_lock_store(struct kobject *kobj,
 754                                struct kobj_attribute *attr,
 755                                const char *buf, size_t n)
 756 {
 757         int error = pm_wake_lock(buf);
 758         return error ? error : n;
 759 }
 760
 761 power_attr(wake_lock);
 762
 763 static ssize_t wake_unlock_show(struct kobject *kobj,
 764                                 struct kobj_attribute *attr,
 765                                 char *buf)
 766 {
 767         return pm_show_wakelocks(buf, false);
 768 }
 769
 770 static ssize_t wake_unlock_store(struct kobject *kobj,
 771                                  struct kobj_attribute *attr,
 772                                  const char *buf, size_t n)
 773 {
 774         int error = pm_wake_unlock(buf);
 775         return error ? error : n;
 776 }
 777
 778 power_attr(wake_unlock);
 779
 780 #endif /* CONFIG_PM_WAKELOCKS */
 781 #endif /* CONFIG_PM_SLEEP */
 782
 783 #ifdef CONFIG_PM_TRACE
 784 int pm_trace_enabled;
 785
 786 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
 787                              char *buf)
 788 {
 789         return sprintf(buf, "%d\n", pm_trace_enabled);
 790 }
 791
 792 static ssize_t
 793 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
 794                const char *buf, size_t n)
 795 {
 796         int val;
 797
 798         if (sscanf(buf, "%d", &val) == 1) {
 799                 pm_trace_enabled = !!val;
 800                 if (pm_trace_enabled) {
 801                         pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
 802                                 "PM: Correct system time has to be restored manually after resume.\n");
 803                 }
 804                 return n;
 805         }
 806         return -EINVAL;
 807 }
 808
 809 power_attr(pm_trace);
 810
 811 static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
 812                                        struct kobj_attribute *attr,
 813                                        char *buf)
 814 {
 815         return show_trace_dev_match(buf, PAGE_SIZE);
 816 }
 817
 818 power_attr_ro(pm_trace_dev_match);
 819
 820 #endif /* CONFIG_PM_TRACE */
 821
 822 #ifdef CONFIG_FREEZER
 823 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
 824                                       struct kobj_attribute *attr, char *buf)
 825 {
 826         return sprintf(buf, "%u\n", freeze_timeout_msecs);
 827 }
 828
 829 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
 830                                        struct kobj_attribute *attr,
 831                                        const char *buf, size_t n)
 832 {
 833         unsigned long val;
 834
 835         if (kstrtoul(buf, 10, &val))
 836                 return -EINVAL;
 837
 838         freeze_timeout_msecs = val;
 839         return n;
 840 }
 841
 842 power_attr(pm_freeze_timeout);
 843
 844 #endif  /* CONFIG_FREEZER*/
 845
 846 static struct attribute * g[] = {
 847         &state_attr.attr,
 848 #ifdef CONFIG_PM_TRACE
 849         &pm_trace_attr.attr,
 850         &pm_trace_dev_match_attr.attr,
 851 #endif
 852 #ifdef CONFIG_PM_SLEEP
 853         &pm_async_attr.attr,
 854         &wakeup_count_attr.attr,
 855 #ifdef CONFIG_SUSPEND
 856         &mem_sleep_attr.attr,
 857 #endif
 858 #ifdef CONFIG_PM_AUTOSLEEP
 859         &autosleep_attr.attr,
 860 #endif
 861 #ifdef CONFIG_PM_WAKELOCKS
 862         &wake_lock_attr.attr,
 863         &wake_unlock_attr.attr,
 864 #endif
 865 #ifdef CONFIG_PM_SLEEP_DEBUG
 866         &pm_test_attr.attr,
 867         &pm_print_times_attr.attr,
 868         &pm_wakeup_irq_attr.attr,
 869         &pm_debug_messages_attr.attr,
 870 #endif
 871 #endif
 872 #ifdef CONFIG_FREEZER
 873         &pm_freeze_timeout_attr.attr,
 874 #endif
 875         NULL,
 876 };
 877
 878 static const struct attribute_group attr_group = {
 879         .attrs = g,
 880 };
 881
 882 static const struct attribute_group *attr_groups[] = {
 883         &attr_group,
 884 #ifdef CONFIG_PM_SLEEP
 885         &suspend_attr_group,
 886 #endif
 887         NULL,
 888 };
 889
 890 struct workqueue_struct *pm_wq;
 891 EXPORT_SYMBOL_GPL(pm_wq);
 892
 893 static int __init pm_start_workqueue(void)
 894 {
 895         pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
 896
 897         return pm_wq ? 0 : -ENOMEM;
 898 }
 899
 900 static int __init pm_init(void)
 901 {
 902         int error = pm_start_workqueue();
 903         if (error)
 904                 return error;
 905         hibernate_image_size_init();
 906         hibernate_reserved_size_init();
 907         pm_states_init();
 908         power_kobj = kobject_create_and_add("power", NULL);
 909         if (!power_kobj)
 910                 return -ENOMEM;
 911         error = sysfs_create_groups(power_kobj, attr_groups);
 912         if (error)
 913                 return error;
 914         pm_print_times_init();
 915         return pm_autosleep_init();
 916 }
 917
 918 core_initcall(pm_init);