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 #ifdef CONFIG_HIBERNATION 304 s += sprintf(s, "%s\n", "disk"); 305 #else 306 if (s != buf) 307 /* convert the last space to a newline */ 308 *(s-1) = '\n'; 309 #endif 310 return (s - buf); 311 } 312 313 static suspend_state_t decode_state(const char *buf, size_t n) 314 { 315 #ifdef CONFIG_SUSPEND 316 suspend_state_t state = PM_SUSPEND_MIN; 317 struct pm_sleep_state *s; 318 #endif 319 char *p; 320 int len; 321 322 p = memchr(buf, '\n', n); 323 len = p ? p - buf : n; 324 325 /* Check hibernation first. */ 326 if (len == 4 && !strncmp(buf, "disk", len)) 327 return PM_SUSPEND_MAX; 328 329 #ifdef CONFIG_SUSPEND 330 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) 331 if (s->state && len == strlen(s->label) 332 && !strncmp(buf, s->label, len)) 333 return s->state; 334 #endif 335 336 return PM_SUSPEND_ON; 337 } 338 339 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, 340 const char *buf, size_t n) 341 { 342 suspend_state_t state; 343 int error; 344 345 error = pm_autosleep_lock(); 346 if (error) 347 return error; 348 349 if (pm_autosleep_state() > PM_SUSPEND_ON) { 350 error = -EBUSY; 351 goto out; 352 } 353 354 state = decode_state(buf, n); 355 if (state < PM_SUSPEND_MAX) 356 error = pm_suspend(state); 357 else if (state == PM_SUSPEND_MAX) 358 error = hibernate(); 359 else 360 error = -EINVAL; 361 362 out: 363 pm_autosleep_unlock(); 364 return error ? error : n; 365 } 366 367 power_attr(state); 368 369 #ifdef CONFIG_PM_SLEEP 370 /* 371 * The 'wakeup_count' attribute, along with the functions defined in 372 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be 373 * handled in a non-racy way. 374 * 375 * If a wakeup event occurs when the system is in a sleep state, it simply is 376 * woken up. In turn, if an event that would wake the system up from a sleep 377 * state occurs when it is undergoing a transition to that sleep state, the 378 * transition should be aborted. Moreover, if such an event occurs when the 379 * system is in the working state, an attempt to start a transition to the 380 * given sleep state should fail during certain period after the detection of 381 * the event. Using the 'state' attribute alone is not sufficient to satisfy 382 * these requirements, because a wakeup event may occur exactly when 'state' 383 * is being written to and may be delivered to user space right before it is 384 * frozen, so the event will remain only partially processed until the system is 385 * woken up by another event. In particular, it won't cause the transition to 386 * a sleep state to be aborted. 387 * 388 * This difficulty may be overcome if user space uses 'wakeup_count' before 389 * writing to 'state'. It first should read from 'wakeup_count' and store 390 * the read value. Then, after carrying out its own preparations for the system 391 * transition to a sleep state, it should write the stored value to 392 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since 393 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it 394 * is allowed to write to 'state', but the transition will be aborted if there 395 * are any wakeup events detected after 'wakeup_count' was written to. 396 */ 397 398 static ssize_t wakeup_count_show(struct kobject *kobj, 399 struct kobj_attribute *attr, 400 char *buf) 401 { 402 unsigned int val; 403 404 return pm_get_wakeup_count(&val, true) ? 405 sprintf(buf, "%u\n", val) : -EINTR; 406 } 407 408 static ssize_t wakeup_count_store(struct kobject *kobj, 409 struct kobj_attribute *attr, 410 const char *buf, size_t n) 411 { 412 unsigned int val; 413 int error; 414 415 error = pm_autosleep_lock(); 416 if (error) 417 return error; 418 419 if (pm_autosleep_state() > PM_SUSPEND_ON) { 420 error = -EBUSY; 421 goto out; 422 } 423 424 error = -EINVAL; 425 if (sscanf(buf, "%u", &val) == 1) { 426 if (pm_save_wakeup_count(val)) 427 error = n; 428 else 429 pm_print_active_wakeup_sources(); 430 } 431 432 out: 433 pm_autosleep_unlock(); 434 return error; 435 } 436 437 power_attr(wakeup_count); 438 439 #ifdef CONFIG_PM_AUTOSLEEP 440 static ssize_t autosleep_show(struct kobject *kobj, 441 struct kobj_attribute *attr, 442 char *buf) 443 { 444 suspend_state_t state = pm_autosleep_state(); 445 446 if (state == PM_SUSPEND_ON) 447 return sprintf(buf, "off\n"); 448 449 #ifdef CONFIG_SUSPEND 450 if (state < PM_SUSPEND_MAX) 451 return sprintf(buf, "%s\n", pm_states[state].state ? 452 pm_states[state].label : "error"); 453 #endif 454 #ifdef CONFIG_HIBERNATION 455 return sprintf(buf, "disk\n"); 456 #else 457 return sprintf(buf, "error"); 458 #endif 459 } 460 461 static ssize_t autosleep_store(struct kobject *kobj, 462 struct kobj_attribute *attr, 463 const char *buf, size_t n) 464 { 465 suspend_state_t state = decode_state(buf, n); 466 int error; 467 468 if (state == PM_SUSPEND_ON 469 && strcmp(buf, "off") && strcmp(buf, "off\n")) 470 return -EINVAL; 471 472 error = pm_autosleep_set_state(state); 473 return error ? error : n; 474 } 475 476 power_attr(autosleep); 477 #endif /* CONFIG_PM_AUTOSLEEP */ 478 479 #ifdef CONFIG_PM_WAKELOCKS 480 static ssize_t wake_lock_show(struct kobject *kobj, 481 struct kobj_attribute *attr, 482 char *buf) 483 { 484 return pm_show_wakelocks(buf, true); 485 } 486 487 static ssize_t wake_lock_store(struct kobject *kobj, 488 struct kobj_attribute *attr, 489 const char *buf, size_t n) 490 { 491 int error = pm_wake_lock(buf); 492 return error ? error : n; 493 } 494 495 power_attr(wake_lock); 496 497 static ssize_t wake_unlock_show(struct kobject *kobj, 498 struct kobj_attribute *attr, 499 char *buf) 500 { 501 return pm_show_wakelocks(buf, false); 502 } 503 504 static ssize_t wake_unlock_store(struct kobject *kobj, 505 struct kobj_attribute *attr, 506 const char *buf, size_t n) 507 { 508 int error = pm_wake_unlock(buf); 509 return error ? error : n; 510 } 511 512 power_attr(wake_unlock); 513 514 #endif /* CONFIG_PM_WAKELOCKS */ 515 #endif /* CONFIG_PM_SLEEP */ 516 517 #ifdef CONFIG_PM_TRACE 518 int pm_trace_enabled; 519 520 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, 521 char *buf) 522 { 523 return sprintf(buf, "%d\n", pm_trace_enabled); 524 } 525 526 static ssize_t 527 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, 528 const char *buf, size_t n) 529 { 530 int val; 531 532 if (sscanf(buf, "%d", &val) == 1) { 533 pm_trace_enabled = !!val; 534 if (pm_trace_enabled) { 535 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n" 536 "PM: Correct system time has to be restored manually after resume.\n"); 537 } 538 return n; 539 } 540 return -EINVAL; 541 } 542 543 power_attr(pm_trace); 544 545 static ssize_t pm_trace_dev_match_show(struct kobject *kobj, 546 struct kobj_attribute *attr, 547 char *buf) 548 { 549 return show_trace_dev_match(buf, PAGE_SIZE); 550 } 551 552 static ssize_t 553 pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr, 554 const char *buf, size_t n) 555 { 556 return -EINVAL; 557 } 558 559 power_attr(pm_trace_dev_match); 560 561 #endif /* CONFIG_PM_TRACE */ 562 563 #ifdef CONFIG_FREEZER 564 static ssize_t pm_freeze_timeout_show(struct kobject *kobj, 565 struct kobj_attribute *attr, char *buf) 566 { 567 return sprintf(buf, "%u\n", freeze_timeout_msecs); 568 } 569 570 static ssize_t pm_freeze_timeout_store(struct kobject *kobj, 571 struct kobj_attribute *attr, 572 const char *buf, size_t n) 573 { 574 unsigned long val; 575 576 if (kstrtoul(buf, 10, &val)) 577 return -EINVAL; 578 579 freeze_timeout_msecs = val; 580 return n; 581 } 582 583 power_attr(pm_freeze_timeout); 584 585 #endif /* CONFIG_FREEZER*/ 586 587 static struct attribute * g[] = { 588 &state_attr.attr, 589 #ifdef CONFIG_PM_TRACE 590 &pm_trace_attr.attr, 591 &pm_trace_dev_match_attr.attr, 592 #endif 593 #ifdef CONFIG_PM_SLEEP 594 &pm_async_attr.attr, 595 &wakeup_count_attr.attr, 596 #ifdef CONFIG_PM_AUTOSLEEP 597 &autosleep_attr.attr, 598 #endif 599 #ifdef CONFIG_PM_WAKELOCKS 600 &wake_lock_attr.attr, 601 &wake_unlock_attr.attr, 602 #endif 603 #ifdef CONFIG_PM_DEBUG 604 &pm_test_attr.attr, 605 #endif 606 #ifdef CONFIG_PM_SLEEP_DEBUG 607 &pm_print_times_attr.attr, 608 #endif 609 #endif 610 #ifdef CONFIG_FREEZER 611 &pm_freeze_timeout_attr.attr, 612 #endif 613 NULL, 614 }; 615 616 static struct attribute_group attr_group = { 617 .attrs = g, 618 }; 619 620 #ifdef CONFIG_PM_RUNTIME 621 struct workqueue_struct *pm_wq; 622 EXPORT_SYMBOL_GPL(pm_wq); 623 624 static int __init pm_start_workqueue(void) 625 { 626 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0); 627 628 return pm_wq ? 0 : -ENOMEM; 629 } 630 #else 631 static inline int pm_start_workqueue(void) { return 0; } 632 #endif 633 634 static int __init pm_init(void) 635 { 636 int error = pm_start_workqueue(); 637 if (error) 638 return error; 639 hibernate_image_size_init(); 640 hibernate_reserved_size_init(); 641 power_kobj = kobject_create_and_add("power", NULL); 642 if (!power_kobj) 643 return -ENOMEM; 644 error = sysfs_create_group(power_kobj, &attr_group); 645 if (error) 646 return error; 647 pm_print_times_init(); 648 return pm_autosleep_init(); 649 } 650 651 core_initcall(pm_init); 652