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 (strict_strtoul(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 struct kobject *power_kobj; 239 240 /** 241 * state - control system power state. 242 * 243 * show() returns what states are supported, which is hard-coded to 244 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and 245 * 'disk' (Suspend-to-Disk). 246 * 247 * store() accepts one of those strings, translates it into the 248 * proper enumerated value, and initiates a suspend transition. 249 */ 250 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, 251 char *buf) 252 { 253 char *s = buf; 254 #ifdef CONFIG_SUSPEND 255 int i; 256 257 for (i = 0; i < PM_SUSPEND_MAX; i++) { 258 if (pm_states[i] && valid_state(i)) 259 s += sprintf(s,"%s ", pm_states[i]); 260 } 261 #endif 262 #ifdef CONFIG_HIBERNATION 263 s += sprintf(s, "%s\n", "disk"); 264 #else 265 if (s != buf) 266 /* convert the last space to a newline */ 267 *(s-1) = '\n'; 268 #endif 269 return (s - buf); 270 } 271 272 static suspend_state_t decode_state(const char *buf, size_t n) 273 { 274 #ifdef CONFIG_SUSPEND 275 suspend_state_t state = PM_SUSPEND_STANDBY; 276 const char * const *s; 277 #endif 278 char *p; 279 int len; 280 281 p = memchr(buf, '\n', n); 282 len = p ? p - buf : n; 283 284 /* Check hibernation first. */ 285 if (len == 4 && !strncmp(buf, "disk", len)) 286 return PM_SUSPEND_MAX; 287 288 #ifdef CONFIG_SUSPEND 289 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) 290 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) 291 return state; 292 #endif 293 294 return PM_SUSPEND_ON; 295 } 296 297 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr, 298 const char *buf, size_t n) 299 { 300 suspend_state_t state; 301 int error; 302 303 error = pm_autosleep_lock(); 304 if (error) 305 return error; 306 307 if (pm_autosleep_state() > PM_SUSPEND_ON) { 308 error = -EBUSY; 309 goto out; 310 } 311 312 state = decode_state(buf, n); 313 if (state < PM_SUSPEND_MAX) 314 error = pm_suspend(state); 315 else if (state == PM_SUSPEND_MAX) 316 error = hibernate(); 317 else 318 error = -EINVAL; 319 320 out: 321 pm_autosleep_unlock(); 322 return error ? error : n; 323 } 324 325 power_attr(state); 326 327 #ifdef CONFIG_PM_SLEEP 328 /* 329 * The 'wakeup_count' attribute, along with the functions defined in 330 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be 331 * handled in a non-racy way. 332 * 333 * If a wakeup event occurs when the system is in a sleep state, it simply is 334 * woken up. In turn, if an event that would wake the system up from a sleep 335 * state occurs when it is undergoing a transition to that sleep state, the 336 * transition should be aborted. Moreover, if such an event occurs when the 337 * system is in the working state, an attempt to start a transition to the 338 * given sleep state should fail during certain period after the detection of 339 * the event. Using the 'state' attribute alone is not sufficient to satisfy 340 * these requirements, because a wakeup event may occur exactly when 'state' 341 * is being written to and may be delivered to user space right before it is 342 * frozen, so the event will remain only partially processed until the system is 343 * woken up by another event. In particular, it won't cause the transition to 344 * a sleep state to be aborted. 345 * 346 * This difficulty may be overcome if user space uses 'wakeup_count' before 347 * writing to 'state'. It first should read from 'wakeup_count' and store 348 * the read value. Then, after carrying out its own preparations for the system 349 * transition to a sleep state, it should write the stored value to 350 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since 351 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it 352 * is allowed to write to 'state', but the transition will be aborted if there 353 * are any wakeup events detected after 'wakeup_count' was written to. 354 */ 355 356 static ssize_t wakeup_count_show(struct kobject *kobj, 357 struct kobj_attribute *attr, 358 char *buf) 359 { 360 unsigned int val; 361 362 return pm_get_wakeup_count(&val, true) ? 363 sprintf(buf, "%u\n", val) : -EINTR; 364 } 365 366 static ssize_t wakeup_count_store(struct kobject *kobj, 367 struct kobj_attribute *attr, 368 const char *buf, size_t n) 369 { 370 unsigned int val; 371 int error; 372 373 error = pm_autosleep_lock(); 374 if (error) 375 return error; 376 377 if (pm_autosleep_state() > PM_SUSPEND_ON) { 378 error = -EBUSY; 379 goto out; 380 } 381 382 error = -EINVAL; 383 if (sscanf(buf, "%u", &val) == 1) { 384 if (pm_save_wakeup_count(val)) 385 error = n; 386 } 387 388 out: 389 pm_autosleep_unlock(); 390 return error; 391 } 392 393 power_attr(wakeup_count); 394 395 #ifdef CONFIG_PM_AUTOSLEEP 396 static ssize_t autosleep_show(struct kobject *kobj, 397 struct kobj_attribute *attr, 398 char *buf) 399 { 400 suspend_state_t state = pm_autosleep_state(); 401 402 if (state == PM_SUSPEND_ON) 403 return sprintf(buf, "off\n"); 404 405 #ifdef CONFIG_SUSPEND 406 if (state < PM_SUSPEND_MAX) 407 return sprintf(buf, "%s\n", valid_state(state) ? 408 pm_states[state] : "error"); 409 #endif 410 #ifdef CONFIG_HIBERNATION 411 return sprintf(buf, "disk\n"); 412 #else 413 return sprintf(buf, "error"); 414 #endif 415 } 416 417 static ssize_t autosleep_store(struct kobject *kobj, 418 struct kobj_attribute *attr, 419 const char *buf, size_t n) 420 { 421 suspend_state_t state = decode_state(buf, n); 422 int error; 423 424 if (state == PM_SUSPEND_ON 425 && strcmp(buf, "off") && strcmp(buf, "off\n")) 426 return -EINVAL; 427 428 error = pm_autosleep_set_state(state); 429 return error ? error : n; 430 } 431 432 power_attr(autosleep); 433 #endif /* CONFIG_PM_AUTOSLEEP */ 434 435 #ifdef CONFIG_PM_WAKELOCKS 436 static ssize_t wake_lock_show(struct kobject *kobj, 437 struct kobj_attribute *attr, 438 char *buf) 439 { 440 return pm_show_wakelocks(buf, true); 441 } 442 443 static ssize_t wake_lock_store(struct kobject *kobj, 444 struct kobj_attribute *attr, 445 const char *buf, size_t n) 446 { 447 int error = pm_wake_lock(buf); 448 return error ? error : n; 449 } 450 451 power_attr(wake_lock); 452 453 static ssize_t wake_unlock_show(struct kobject *kobj, 454 struct kobj_attribute *attr, 455 char *buf) 456 { 457 return pm_show_wakelocks(buf, false); 458 } 459 460 static ssize_t wake_unlock_store(struct kobject *kobj, 461 struct kobj_attribute *attr, 462 const char *buf, size_t n) 463 { 464 int error = pm_wake_unlock(buf); 465 return error ? error : n; 466 } 467 468 power_attr(wake_unlock); 469 470 #endif /* CONFIG_PM_WAKELOCKS */ 471 #endif /* CONFIG_PM_SLEEP */ 472 473 #ifdef CONFIG_PM_TRACE 474 int pm_trace_enabled; 475 476 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr, 477 char *buf) 478 { 479 return sprintf(buf, "%d\n", pm_trace_enabled); 480 } 481 482 static ssize_t 483 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr, 484 const char *buf, size_t n) 485 { 486 int val; 487 488 if (sscanf(buf, "%d", &val) == 1) { 489 pm_trace_enabled = !!val; 490 return n; 491 } 492 return -EINVAL; 493 } 494 495 power_attr(pm_trace); 496 497 static ssize_t pm_trace_dev_match_show(struct kobject *kobj, 498 struct kobj_attribute *attr, 499 char *buf) 500 { 501 return show_trace_dev_match(buf, PAGE_SIZE); 502 } 503 504 static ssize_t 505 pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr, 506 const char *buf, size_t n) 507 { 508 return -EINVAL; 509 } 510 511 power_attr(pm_trace_dev_match); 512 513 #endif /* CONFIG_PM_TRACE */ 514 515 static struct attribute * g[] = { 516 &state_attr.attr, 517 #ifdef CONFIG_PM_TRACE 518 &pm_trace_attr.attr, 519 &pm_trace_dev_match_attr.attr, 520 #endif 521 #ifdef CONFIG_PM_SLEEP 522 &pm_async_attr.attr, 523 &wakeup_count_attr.attr, 524 #ifdef CONFIG_PM_AUTOSLEEP 525 &autosleep_attr.attr, 526 #endif 527 #ifdef CONFIG_PM_WAKELOCKS 528 &wake_lock_attr.attr, 529 &wake_unlock_attr.attr, 530 #endif 531 #ifdef CONFIG_PM_DEBUG 532 &pm_test_attr.attr, 533 #endif 534 #endif 535 NULL, 536 }; 537 538 static struct attribute_group attr_group = { 539 .attrs = g, 540 }; 541 542 #ifdef CONFIG_PM_RUNTIME 543 struct workqueue_struct *pm_wq; 544 EXPORT_SYMBOL_GPL(pm_wq); 545 546 static int __init pm_start_workqueue(void) 547 { 548 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0); 549 550 return pm_wq ? 0 : -ENOMEM; 551 } 552 #else 553 static inline int pm_start_workqueue(void) { return 0; } 554 #endif 555 556 static int __init pm_init(void) 557 { 558 int error = pm_start_workqueue(); 559 if (error) 560 return error; 561 hibernate_image_size_init(); 562 hibernate_reserved_size_init(); 563 power_kobj = kobject_create_and_add("power", NULL); 564 if (!power_kobj) 565 return -ENOMEM; 566 error = sysfs_create_group(power_kobj, &attr_group); 567 if (error) 568 return error; 569 return pm_autosleep_init(); 570 } 571 572 core_initcall(pm_init); 573