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); 741