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