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/resume-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 #else /* !CONFIG_PP_SLEEP_DEBUG */ 276 static inline void pm_print_times_init(void) {} 277 #endif /* CONFIG_PM_SLEEP_DEBUG */ 278 279 struct kobject *power_kobj; 280 281 /** 282 * state - control system sleep states. 283 * 284 * show() returns available sleep state labels, which may be "mem", "standby", 285 * "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a 286 * description of what they mean. 287 * 288 * store() accepts one of those strings, translates it into the proper 289 * enumerated value, and initiates a suspend transition. 290 */ 291 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, 292 char *buf) 293 { 294 char *s = buf; 295 #ifdef CONFIG_SUSPEND 296 suspend_state_t i; 297 298 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) 299 if (pm_states[i].state) 300 s += sprintf(s,"%s ", pm_states[i].label); 301 302 #endif 303 if (hibernation_available()) 304 s += sprintf(s, "disk "); 305 if (s != buf) 306 /* convert the last space to a newline */ 307 *(s-1) = '\n'; 308 return (s - buf); 309 } 310 311 static suspend_state_t decode_state(const char *buf, size_t n) 312 { 313 #ifdef CONFIG_SUSPEND 314 suspend_state_t state = PM_SUSPEND_MIN; 315 struct pm_sleep_state *s; 316 #endif 317 char *p; 318 int len; 319 320 p = memchr(buf, '\n', n); 321 len = p ? p - buf : n; 322 323 /* Check hibernation first. */ 324 if (len == 4 && !strncmp(buf, "disk", len)) 325 return PM_SUSPEND_MAX; 326 327 #ifdef CONFIG_SUSPEND 328 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) 329 if (s->state && len == strlen(s->label) 330 && !strncmp(buf, s->label, len)) 331 return s->state; 332 #endif 333 334 return PM_SUSPEND_ON; 335 } 336 337 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, 338 const char *buf, size_t n) 339 { 340 suspend_state_t state; 341 int error; 342 343 error = pm_autosleep_lock(); 344 if (error) 345 return error; 346 347 if (pm_autosleep_state() > PM_SUSPEND_ON) { 348 error = -EBUSY; 349 goto out; 350 } 351 352 state = decode_state(buf, n); 353 if (state < PM_SUSPEND_MAX) 354 error = pm_suspend(state); 355 else if (state == PM_SUSPEND_MAX) 356 error = hibernate(); 357 else 358 error = -EINVAL; 359 360 out: 361 pm_autosleep_unlock(); 362 return error ? error : n; 363 } 364 365 power_attr(state); 366 367 #ifdef CONFIG_PM_SLEEP 368 /* 369 * The 'wakeup_count' attribute, along with the functions defined in 370 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be 371 * handled in a non-racy way. 372 * 373 * If a wakeup event occurs when the system is in a sleep state, it simply is 374 * woken up. In turn, if an event that would wake the system up from a sleep 375 * state occurs when it is undergoing a transition to that sleep state, the 376 * transition should be aborted. Moreover, if such an event occurs when the 377 * system is in the working state, an attempt to start a transition to the 378 * given sleep state should fail during certain period after the detection of 379 * the event. Using the 'state' attribute alone is not sufficient to satisfy 380 * these requirements, because a wakeup event may occur exactly when 'state' 381 * is being written to and may be delivered to user space right before it is 382 * frozen, so the event will remain only partially processed until the system is 383 * woken up by another event. In particular, it won't cause the transition to 384 * a sleep state to be aborted. 385 * 386 * This difficulty may be overcome if user space uses 'wakeup_count' before 387 * writing to 'state'. It first should read from 'wakeup_count' and store 388 * the read value. Then, after carrying out its own preparations for the system 389 * transition to a sleep state, it should write the stored value to 390 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since 391 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it 392 * is allowed to write to 'state', but the transition will be aborted if there 393 * are any wakeup events detected after 'wakeup_count' was written to. 394 */ 395 396 static ssize_t wakeup_count_show(struct kobject *kobj, 397 struct kobj_attribute *attr, 398 char *buf) 399 { 400 unsigned int val; 401 402 return pm_get_wakeup_count(&val, true) ? 403 sprintf(buf, "%u\n", val) : -EINTR; 404 } 405 406 static ssize_t wakeup_count_store(struct kobject *kobj, 407 struct kobj_attribute *attr, 408 const char *buf, size_t n) 409 { 410 unsigned int val; 411 int error; 412 413 error = pm_autosleep_lock(); 414 if (error) 415 return error; 416 417 if (pm_autosleep_state() > PM_SUSPEND_ON) { 418 error = -EBUSY; 419 goto out; 420 } 421 422 error = -EINVAL; 423 if (sscanf(buf, "%u", &val) == 1) { 424 if (pm_save_wakeup_count(val)) 425 error = n; 426 else 427 pm_print_active_wakeup_sources(); 428 } 429 430 out: 431 pm_autosleep_unlock(); 432 return error; 433 } 434 435 power_attr(wakeup_count); 436 437 #ifdef CONFIG_PM_AUTOSLEEP 438 static ssize_t autosleep_show(struct kobject *kobj, 439 struct kobj_attribute *attr, 440 char *buf) 441 { 442 suspend_state_t state = pm_autosleep_state(); 443 444 if (state == PM_SUSPEND_ON) 445 return sprintf(buf, "off\n"); 446 447 #ifdef CONFIG_SUSPEND 448 if (state < PM_SUSPEND_MAX) 449 return sprintf(buf, "%s\n", pm_states[state].state ? 450 pm_states[state].label : "error"); 451 #endif 452 #ifdef CONFIG_HIBERNATION 453 return sprintf(buf, "disk\n"); 454 #else 455 return sprintf(buf, "error"); 456 #endif 457 } 458 459 static ssize_t autosleep_store(struct kobject *kobj, 460 struct kobj_attribute *attr, 461 const char *buf, size_t n) 462 { 463 suspend_state_t state = decode_state(buf, n); 464 int error; 465 466 if (state == PM_SUSPEND_ON 467 && strcmp(buf, "off") && strcmp(buf, "off\n")) 468 return -EINVAL; 469 470 error = pm_autosleep_set_state(state); 471 return error ? error : n; 472 } 473 474 power_attr(autosleep); 475 #endif /* CONFIG_PM_AUTOSLEEP */ 476 477 #ifdef CONFIG_PM_WAKELOCKS 478 static ssize_t wake_lock_show(struct kobject *kobj, 479 struct kobj_attribute *attr, 480 char *buf) 481 { 482 return pm_show_wakelocks(buf, true); 483 } 484 485 static ssize_t wake_lock_store(struct kobject *kobj, 486 struct kobj_attribute *attr, 487 const char *buf, size_t n) 488 { 489 int error = pm_wake_lock(buf); 490 return error ? error : n; 491 } 492 493 power_attr(wake_lock); 494 495 static ssize_t wake_unlock_show(struct kobject *kobj, 496 struct kobj_attribute *attr, 497 char *buf) 498 { 499 return pm_show_wakelocks(buf, false); 500 } 501 502 static ssize_t wake_unlock_store(struct kobject *kobj, 503 struct kobj_attribute *attr, 504 const char *buf, size_t n) 505 { 506 int error = pm_wake_unlock(buf); 507 return error ? error : n; 508 } 509 510 power_attr(wake_unlock); 511 512 #endif /* CONFIG_PM_WAKELOCKS */ 513 #endif /* CONFIG_PM_SLEEP */ 514 515 #ifdef CONFIG_PM_TRACE 516 int pm_trace_enabled; 517 518 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, 519 char *buf) 520 { 521 return sprintf(buf, "%d\n", pm_trace_enabled); 522 } 523 524 static ssize_t 525 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, 526 const char *buf, size_t n) 527 { 528 int val; 529 530 if (sscanf(buf, "%d", &val) == 1) { 531 pm_trace_enabled = !!val; 532 if (pm_trace_enabled) { 533 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n" 534 "PM: Correct system time has to be restored manually after resume.\n"); 535 } 536 return n; 537 } 538 return -EINVAL; 539 } 540 541 power_attr(pm_trace); 542 543 static ssize_t pm_trace_dev_match_show(struct kobject *kobj, 544 struct kobj_attribute *attr, 545 char *buf) 546 { 547 return show_trace_dev_match(buf, PAGE_SIZE); 548 } 549 550 static ssize_t 551 pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr, 552 const char *buf, size_t n) 553 { 554 return -EINVAL; 555 } 556 557 power_attr(pm_trace_dev_match); 558 559 #endif /* CONFIG_PM_TRACE */ 560 561 #ifdef CONFIG_FREEZER 562 static ssize_t pm_freeze_timeout_show(struct kobject *kobj, 563 struct kobj_attribute *attr, char *buf) 564 { 565 return sprintf(buf, "%u\n", freeze_timeout_msecs); 566 } 567 568 static ssize_t pm_freeze_timeout_store(struct kobject *kobj, 569 struct kobj_attribute *attr, 570 const char *buf, size_t n) 571 { 572 unsigned long val; 573 574 if (kstrtoul(buf, 10, &val)) 575 return -EINVAL; 576 577 freeze_timeout_msecs = val; 578 return n; 579 } 580 581 power_attr(pm_freeze_timeout); 582 583 #endif /* CONFIG_FREEZER*/ 584 585 static struct attribute * g[] = { 586 &state_attr.attr, 587 #ifdef CONFIG_PM_TRACE 588 &pm_trace_attr.attr, 589 &pm_trace_dev_match_attr.attr, 590 #endif 591 #ifdef CONFIG_PM_SLEEP 592 &pm_async_attr.attr, 593 &wakeup_count_attr.attr, 594 #ifdef CONFIG_PM_AUTOSLEEP 595 &autosleep_attr.attr, 596 #endif 597 #ifdef CONFIG_PM_WAKELOCKS 598 &wake_lock_attr.attr, 599 &wake_unlock_attr.attr, 600 #endif 601 #ifdef CONFIG_PM_DEBUG 602 &pm_test_attr.attr, 603 #endif 604 #ifdef CONFIG_PM_SLEEP_DEBUG 605 &pm_print_times_attr.attr, 606 #endif 607 #endif 608 #ifdef CONFIG_FREEZER 609 &pm_freeze_timeout_attr.attr, 610 #endif 611 NULL, 612 }; 613 614 static struct attribute_group attr_group = { 615 .attrs = g, 616 }; 617 618 #ifdef CONFIG_PM_RUNTIME 619 struct workqueue_struct *pm_wq; 620 EXPORT_SYMBOL_GPL(pm_wq); 621 622 static int __init pm_start_workqueue(void) 623 { 624 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0); 625 626 return pm_wq ? 0 : -ENOMEM; 627 } 628 #else 629 static inline int pm_start_workqueue(void) { return 0; } 630 #endif 631 632 static int __init pm_init(void) 633 { 634 int error = pm_start_workqueue(); 635 if (error) 636 return error; 637 hibernate_image_size_init(); 638 hibernate_reserved_size_init(); 639 power_kobj = kobject_create_and_add("power", NULL); 640 if (!power_kobj) 641 return -ENOMEM; 642 error = sysfs_create_group(power_kobj, &attr_group); 643 if (error) 644 return error; 645 pm_print_times_init(); 646 return pm_autosleep_init(); 647 } 648 649 core_initcall(pm_init); 650