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