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