1 /* 2 * kernel/power/suspend.c - Suspend to RAM and standby functionality. 3 * 4 * Copyright (c) 2003 Patrick Mochel 5 * Copyright (c) 2003 Open Source Development Lab 6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. 7 * 8 * This file is released under the GPLv2. 9 */ 10 11 #include <linux/string.h> 12 #include <linux/delay.h> 13 #include <linux/errno.h> 14 #include <linux/init.h> 15 #include <linux/console.h> 16 #include <linux/cpu.h> 17 #include <linux/cpuidle.h> 18 #include <linux/syscalls.h> 19 #include <linux/gfp.h> 20 #include <linux/io.h> 21 #include <linux/kernel.h> 22 #include <linux/list.h> 23 #include <linux/mm.h> 24 #include <linux/slab.h> 25 #include <linux/export.h> 26 #include <linux/suspend.h> 27 #include <linux/syscore_ops.h> 28 #include <linux/ftrace.h> 29 #include <trace/events/power.h> 30 #include <linux/compiler.h> 31 #include <linux/moduleparam.h> 32 33 #include "power.h" 34 35 const char * const pm_labels[] = { 36 [PM_SUSPEND_FREEZE] = "freeze", 37 [PM_SUSPEND_STANDBY] = "standby", 38 [PM_SUSPEND_MEM] = "mem", 39 }; 40 const char *pm_states[PM_SUSPEND_MAX]; 41 static const char * const mem_sleep_labels[] = { 42 [PM_SUSPEND_FREEZE] = "s2idle", 43 [PM_SUSPEND_STANDBY] = "shallow", 44 [PM_SUSPEND_MEM] = "deep", 45 }; 46 const char *mem_sleep_states[PM_SUSPEND_MAX]; 47 48 suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE; 49 static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM; 50 51 unsigned int pm_suspend_global_flags; 52 EXPORT_SYMBOL_GPL(pm_suspend_global_flags); 53 54 static const struct platform_suspend_ops *suspend_ops; 55 static const struct platform_freeze_ops *freeze_ops; 56 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head); 57 58 enum freeze_state __read_mostly suspend_freeze_state; 59 static DEFINE_SPINLOCK(suspend_freeze_lock); 60 61 void freeze_set_ops(const struct platform_freeze_ops *ops) 62 { 63 lock_system_sleep(); 64 freeze_ops = ops; 65 unlock_system_sleep(); 66 } 67 68 static void freeze_begin(void) 69 { 70 suspend_freeze_state = FREEZE_STATE_NONE; 71 } 72 73 static void freeze_enter(void) 74 { 75 spin_lock_irq(&suspend_freeze_lock); 76 if (pm_wakeup_pending()) 77 goto out; 78 79 suspend_freeze_state = FREEZE_STATE_ENTER; 80 spin_unlock_irq(&suspend_freeze_lock); 81 82 get_online_cpus(); 83 cpuidle_resume(); 84 85 /* Push all the CPUs into the idle loop. */ 86 wake_up_all_idle_cpus(); 87 pr_debug("PM: suspend-to-idle\n"); 88 /* Make the current CPU wait so it can enter the idle loop too. */ 89 wait_event(suspend_freeze_wait_head, 90 suspend_freeze_state == FREEZE_STATE_WAKE); 91 pr_debug("PM: resume from suspend-to-idle\n"); 92 93 cpuidle_pause(); 94 put_online_cpus(); 95 96 spin_lock_irq(&suspend_freeze_lock); 97 98 out: 99 suspend_freeze_state = FREEZE_STATE_NONE; 100 spin_unlock_irq(&suspend_freeze_lock); 101 } 102 103 void freeze_wake(void) 104 { 105 unsigned long flags; 106 107 spin_lock_irqsave(&suspend_freeze_lock, flags); 108 if (suspend_freeze_state > FREEZE_STATE_NONE) { 109 suspend_freeze_state = FREEZE_STATE_WAKE; 110 wake_up(&suspend_freeze_wait_head); 111 } 112 spin_unlock_irqrestore(&suspend_freeze_lock, flags); 113 } 114 EXPORT_SYMBOL_GPL(freeze_wake); 115 116 static bool valid_state(suspend_state_t state) 117 { 118 /* 119 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level 120 * support and need to be valid to the low level 121 * implementation, no valid callback implies that none are valid. 122 */ 123 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); 124 } 125 126 void __init pm_states_init(void) 127 { 128 /* "mem" and "freeze" are always present in /sys/power/state. */ 129 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM]; 130 pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE]; 131 /* 132 * Suspend-to-idle should be supported even without any suspend_ops, 133 * initialize mem_sleep_states[] accordingly here. 134 */ 135 mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE]; 136 } 137 138 static int __init mem_sleep_default_setup(char *str) 139 { 140 suspend_state_t state; 141 142 for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++) 143 if (mem_sleep_labels[state] && 144 !strcmp(str, mem_sleep_labels[state])) { 145 mem_sleep_default = state; 146 break; 147 } 148 149 return 1; 150 } 151 __setup("mem_sleep_default=", mem_sleep_default_setup); 152 153 /** 154 * suspend_set_ops - Set the global suspend method table. 155 * @ops: Suspend operations to use. 156 */ 157 void suspend_set_ops(const struct platform_suspend_ops *ops) 158 { 159 lock_system_sleep(); 160 161 suspend_ops = ops; 162 163 if (valid_state(PM_SUSPEND_STANDBY)) { 164 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY]; 165 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY]; 166 if (mem_sleep_default == PM_SUSPEND_STANDBY) 167 mem_sleep_current = PM_SUSPEND_STANDBY; 168 } 169 if (valid_state(PM_SUSPEND_MEM)) { 170 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM]; 171 if (mem_sleep_default == PM_SUSPEND_MEM) 172 mem_sleep_current = PM_SUSPEND_MEM; 173 } 174 175 unlock_system_sleep(); 176 } 177 EXPORT_SYMBOL_GPL(suspend_set_ops); 178 179 /** 180 * suspend_valid_only_mem - Generic memory-only valid callback. 181 * 182 * Platform drivers that implement mem suspend only and only need to check for 183 * that in their .valid() callback can use this instead of rolling their own 184 * .valid() callback. 185 */ 186 int suspend_valid_only_mem(suspend_state_t state) 187 { 188 return state == PM_SUSPEND_MEM; 189 } 190 EXPORT_SYMBOL_GPL(suspend_valid_only_mem); 191 192 static bool sleep_state_supported(suspend_state_t state) 193 { 194 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter); 195 } 196 197 static int platform_suspend_prepare(suspend_state_t state) 198 { 199 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ? 200 suspend_ops->prepare() : 0; 201 } 202 203 static int platform_suspend_prepare_late(suspend_state_t state) 204 { 205 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ? 206 freeze_ops->prepare() : 0; 207 } 208 209 static int platform_suspend_prepare_noirq(suspend_state_t state) 210 { 211 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ? 212 suspend_ops->prepare_late() : 0; 213 } 214 215 static void platform_resume_noirq(suspend_state_t state) 216 { 217 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake) 218 suspend_ops->wake(); 219 } 220 221 static void platform_resume_early(suspend_state_t state) 222 { 223 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore) 224 freeze_ops->restore(); 225 } 226 227 static void platform_resume_finish(suspend_state_t state) 228 { 229 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish) 230 suspend_ops->finish(); 231 } 232 233 static int platform_suspend_begin(suspend_state_t state) 234 { 235 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin) 236 return freeze_ops->begin(); 237 else if (suspend_ops && suspend_ops->begin) 238 return suspend_ops->begin(state); 239 else 240 return 0; 241 } 242 243 static void platform_resume_end(suspend_state_t state) 244 { 245 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end) 246 freeze_ops->end(); 247 else if (suspend_ops && suspend_ops->end) 248 suspend_ops->end(); 249 } 250 251 static void platform_recover(suspend_state_t state) 252 { 253 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover) 254 suspend_ops->recover(); 255 } 256 257 static bool platform_suspend_again(suspend_state_t state) 258 { 259 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ? 260 suspend_ops->suspend_again() : false; 261 } 262 263 #ifdef CONFIG_PM_DEBUG 264 static unsigned int pm_test_delay = 5; 265 module_param(pm_test_delay, uint, 0644); 266 MODULE_PARM_DESC(pm_test_delay, 267 "Number of seconds to wait before resuming from suspend test"); 268 #endif 269 270 static int suspend_test(int level) 271 { 272 #ifdef CONFIG_PM_DEBUG 273 if (pm_test_level == level) { 274 pr_info("suspend debug: Waiting for %d second(s).\n", 275 pm_test_delay); 276 mdelay(pm_test_delay * 1000); 277 return 1; 278 } 279 #endif /* !CONFIG_PM_DEBUG */ 280 return 0; 281 } 282 283 /** 284 * suspend_prepare - Prepare for entering system sleep state. 285 * 286 * Common code run for every system sleep state that can be entered (except for 287 * hibernation). Run suspend notifiers, allocate the "suspend" console and 288 * freeze processes. 289 */ 290 static int suspend_prepare(suspend_state_t state) 291 { 292 int error, nr_calls = 0; 293 294 if (!sleep_state_supported(state)) 295 return -EPERM; 296 297 pm_prepare_console(); 298 299 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls); 300 if (error) { 301 nr_calls--; 302 goto Finish; 303 } 304 305 trace_suspend_resume(TPS("freeze_processes"), 0, true); 306 error = suspend_freeze_processes(); 307 trace_suspend_resume(TPS("freeze_processes"), 0, false); 308 if (!error) 309 return 0; 310 311 suspend_stats.failed_freeze++; 312 dpm_save_failed_step(SUSPEND_FREEZE); 313 Finish: 314 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL); 315 pm_restore_console(); 316 return error; 317 } 318 319 /* default implementation */ 320 void __weak arch_suspend_disable_irqs(void) 321 { 322 local_irq_disable(); 323 } 324 325 /* default implementation */ 326 void __weak arch_suspend_enable_irqs(void) 327 { 328 local_irq_enable(); 329 } 330 331 /** 332 * suspend_enter - Make the system enter the given sleep state. 333 * @state: System sleep state to enter. 334 * @wakeup: Returns information that the sleep state should not be re-entered. 335 * 336 * This function should be called after devices have been suspended. 337 */ 338 static int suspend_enter(suspend_state_t state, bool *wakeup) 339 { 340 int error; 341 342 error = platform_suspend_prepare(state); 343 if (error) 344 goto Platform_finish; 345 346 error = dpm_suspend_late(PMSG_SUSPEND); 347 if (error) { 348 pr_err("PM: late suspend of devices failed\n"); 349 goto Platform_finish; 350 } 351 error = platform_suspend_prepare_late(state); 352 if (error) 353 goto Devices_early_resume; 354 355 error = dpm_suspend_noirq(PMSG_SUSPEND); 356 if (error) { 357 pr_err("PM: noirq suspend of devices failed\n"); 358 goto Platform_early_resume; 359 } 360 error = platform_suspend_prepare_noirq(state); 361 if (error) 362 goto Platform_wake; 363 364 if (suspend_test(TEST_PLATFORM)) 365 goto Platform_wake; 366 367 /* 368 * PM_SUSPEND_FREEZE equals 369 * frozen processes + suspended devices + idle processors. 370 * Thus we should invoke freeze_enter() soon after 371 * all the devices are suspended. 372 */ 373 if (state == PM_SUSPEND_FREEZE) { 374 trace_suspend_resume(TPS("machine_suspend"), state, true); 375 freeze_enter(); 376 trace_suspend_resume(TPS("machine_suspend"), state, false); 377 goto Platform_wake; 378 } 379 380 error = disable_nonboot_cpus(); 381 if (error || suspend_test(TEST_CPUS)) 382 goto Enable_cpus; 383 384 arch_suspend_disable_irqs(); 385 BUG_ON(!irqs_disabled()); 386 387 error = syscore_suspend(); 388 if (!error) { 389 *wakeup = pm_wakeup_pending(); 390 if (!(suspend_test(TEST_CORE) || *wakeup)) { 391 trace_suspend_resume(TPS("machine_suspend"), 392 state, true); 393 error = suspend_ops->enter(state); 394 trace_suspend_resume(TPS("machine_suspend"), 395 state, false); 396 events_check_enabled = false; 397 } else if (*wakeup) { 398 error = -EBUSY; 399 } 400 syscore_resume(); 401 } 402 403 arch_suspend_enable_irqs(); 404 BUG_ON(irqs_disabled()); 405 406 Enable_cpus: 407 enable_nonboot_cpus(); 408 409 Platform_wake: 410 platform_resume_noirq(state); 411 dpm_resume_noirq(PMSG_RESUME); 412 413 Platform_early_resume: 414 platform_resume_early(state); 415 416 Devices_early_resume: 417 dpm_resume_early(PMSG_RESUME); 418 419 Platform_finish: 420 platform_resume_finish(state); 421 return error; 422 } 423 424 /** 425 * suspend_devices_and_enter - Suspend devices and enter system sleep state. 426 * @state: System sleep state to enter. 427 */ 428 int suspend_devices_and_enter(suspend_state_t state) 429 { 430 int error; 431 bool wakeup = false; 432 433 if (!sleep_state_supported(state)) 434 return -ENOSYS; 435 436 error = platform_suspend_begin(state); 437 if (error) 438 goto Close; 439 440 suspend_console(); 441 suspend_test_start(); 442 error = dpm_suspend_start(PMSG_SUSPEND); 443 if (error) { 444 pr_err("PM: Some devices failed to suspend, or early wake event detected\n"); 445 goto Recover_platform; 446 } 447 suspend_test_finish("suspend devices"); 448 if (suspend_test(TEST_DEVICES)) 449 goto Recover_platform; 450 451 do { 452 error = suspend_enter(state, &wakeup); 453 } while (!error && !wakeup && platform_suspend_again(state)); 454 455 Resume_devices: 456 suspend_test_start(); 457 dpm_resume_end(PMSG_RESUME); 458 suspend_test_finish("resume devices"); 459 trace_suspend_resume(TPS("resume_console"), state, true); 460 resume_console(); 461 trace_suspend_resume(TPS("resume_console"), state, false); 462 463 Close: 464 platform_resume_end(state); 465 return error; 466 467 Recover_platform: 468 platform_recover(state); 469 goto Resume_devices; 470 } 471 472 /** 473 * suspend_finish - Clean up before finishing the suspend sequence. 474 * 475 * Call platform code to clean up, restart processes, and free the console that 476 * we've allocated. This routine is not called for hibernation. 477 */ 478 static void suspend_finish(void) 479 { 480 suspend_thaw_processes(); 481 pm_notifier_call_chain(PM_POST_SUSPEND); 482 pm_restore_console(); 483 } 484 485 /** 486 * enter_state - Do common work needed to enter system sleep state. 487 * @state: System sleep state to enter. 488 * 489 * Make sure that no one else is trying to put the system into a sleep state. 490 * Fail if that's not the case. Otherwise, prepare for system suspend, make the 491 * system enter the given sleep state and clean up after wakeup. 492 */ 493 static int enter_state(suspend_state_t state) 494 { 495 int error; 496 497 trace_suspend_resume(TPS("suspend_enter"), state, true); 498 if (state == PM_SUSPEND_FREEZE) { 499 #ifdef CONFIG_PM_DEBUG 500 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { 501 pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n"); 502 return -EAGAIN; 503 } 504 #endif 505 } else if (!valid_state(state)) { 506 return -EINVAL; 507 } 508 if (!mutex_trylock(&pm_mutex)) 509 return -EBUSY; 510 511 if (state == PM_SUSPEND_FREEZE) 512 freeze_begin(); 513 514 #ifndef CONFIG_SUSPEND_SKIP_SYNC 515 trace_suspend_resume(TPS("sync_filesystems"), 0, true); 516 pr_info("PM: Syncing filesystems ... "); 517 sys_sync(); 518 pr_cont("done.\n"); 519 trace_suspend_resume(TPS("sync_filesystems"), 0, false); 520 #endif 521 522 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]); 523 pm_suspend_clear_flags(); 524 error = suspend_prepare(state); 525 if (error) 526 goto Unlock; 527 528 if (suspend_test(TEST_FREEZER)) 529 goto Finish; 530 531 trace_suspend_resume(TPS("suspend_enter"), state, false); 532 pr_debug("PM: Suspending system (%s)\n", pm_states[state]); 533 pm_restrict_gfp_mask(); 534 error = suspend_devices_and_enter(state); 535 pm_restore_gfp_mask(); 536 537 Finish: 538 pr_debug("PM: Finishing wakeup.\n"); 539 suspend_finish(); 540 Unlock: 541 mutex_unlock(&pm_mutex); 542 return error; 543 } 544 545 /** 546 * pm_suspend - Externally visible function for suspending the system. 547 * @state: System sleep state to enter. 548 * 549 * Check if the value of @state represents one of the supported states, 550 * execute enter_state() and update system suspend statistics. 551 */ 552 int pm_suspend(suspend_state_t state) 553 { 554 int error; 555 556 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX) 557 return -EINVAL; 558 559 error = enter_state(state); 560 if (error) { 561 suspend_stats.fail++; 562 dpm_save_failed_errno(error); 563 } else { 564 suspend_stats.success++; 565 } 566 return error; 567 } 568 EXPORT_SYMBOL(pm_suspend); 569