suspend.c 16 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * kernel/power/suspend.c - Suspend to RAM and standby functionality.
  4. *
  5. * Copyright (c) 2003 Patrick Mochel
  6. * Copyright (c) 2003 Open Source Development Lab
  7. * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
  8. */
  9. #define pr_fmt(fmt) "PM: " fmt
  10. #include <linux/string.h>
  11. #include <linux/delay.h>
  12. #include <linux/errno.h>
  13. #include <linux/init.h>
  14. #include <linux/console.h>
  15. #include <linux/cpu.h>
  16. #include <linux/cpuidle.h>
  17. #include <linux/gfp.h>
  18. #include <linux/io.h>
  19. #include <linux/kernel.h>
  20. #include <linux/list.h>
  21. #include <linux/mm.h>
  22. #include <linux/slab.h>
  23. #include <linux/export.h>
  24. #include <linux/suspend.h>
  25. #include <linux/syscore_ops.h>
  26. #include <linux/swait.h>
  27. #include <linux/ftrace.h>
  28. #include <trace/events/power.h>
  29. #include <linux/compiler.h>
  30. #include <linux/moduleparam.h>
  31. #include <linux/wakeup_reason.h>
  32. #include "power.h"
  33. const char * const pm_labels[] = {
  34. [PM_SUSPEND_TO_IDLE] = "freeze",
  35. [PM_SUSPEND_STANDBY] = "standby",
  36. [PM_SUSPEND_MEM] = "mem",
  37. };
  38. const char *pm_states[PM_SUSPEND_MAX];
  39. static const char * const mem_sleep_labels[] = {
  40. [PM_SUSPEND_TO_IDLE] = "s2idle",
  41. [PM_SUSPEND_STANDBY] = "shallow",
  42. [PM_SUSPEND_MEM] = "deep",
  43. };
  44. const char *mem_sleep_states[PM_SUSPEND_MAX];
  45. suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
  46. suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
  47. suspend_state_t pm_suspend_target_state;
  48. EXPORT_SYMBOL_GPL(pm_suspend_target_state);
  49. unsigned int pm_suspend_global_flags;
  50. EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
  51. static const struct platform_suspend_ops *suspend_ops;
  52. static const struct platform_s2idle_ops *s2idle_ops;
  53. static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
  54. enum s2idle_states __read_mostly s2idle_state;
  55. static DEFINE_RAW_SPINLOCK(s2idle_lock);
  56. /**
  57. * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
  58. *
  59. * Return 'true' if suspend-to-idle has been selected as the default system
  60. * suspend method.
  61. */
  62. bool pm_suspend_default_s2idle(void)
  63. {
  64. return mem_sleep_current == PM_SUSPEND_TO_IDLE;
  65. }
  66. EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
  67. void s2idle_set_ops(const struct platform_s2idle_ops *ops)
  68. {
  69. lock_system_sleep();
  70. s2idle_ops = ops;
  71. unlock_system_sleep();
  72. }
  73. static void s2idle_begin(void)
  74. {
  75. s2idle_state = S2IDLE_STATE_NONE;
  76. }
  77. static void s2idle_enter(void)
  78. {
  79. trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
  80. raw_spin_lock_irq(&s2idle_lock);
  81. if (pm_wakeup_pending())
  82. goto out;
  83. s2idle_state = S2IDLE_STATE_ENTER;
  84. raw_spin_unlock_irq(&s2idle_lock);
  85. get_online_cpus();
  86. cpuidle_resume();
  87. /* Push all the CPUs into the idle loop. */
  88. wake_up_all_idle_cpus();
  89. /* Make the current CPU wait so it can enter the idle loop too. */
  90. swait_event_exclusive(s2idle_wait_head,
  91. s2idle_state == S2IDLE_STATE_WAKE);
  92. cpuidle_pause();
  93. put_online_cpus();
  94. raw_spin_lock_irq(&s2idle_lock);
  95. out:
  96. s2idle_state = S2IDLE_STATE_NONE;
  97. raw_spin_unlock_irq(&s2idle_lock);
  98. trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
  99. }
  100. static void s2idle_loop(void)
  101. {
  102. pm_pr_dbg("suspend-to-idle\n");
  103. /*
  104. * Suspend-to-idle equals:
  105. * frozen processes + suspended devices + idle processors.
  106. * Thus s2idle_enter() should be called right after all devices have
  107. * been suspended.
  108. *
  109. * Wakeups during the noirq suspend of devices may be spurious, so try
  110. * to avoid them upfront.
  111. */
  112. for (;;) {
  113. if (s2idle_ops && s2idle_ops->wake) {
  114. if (s2idle_ops->wake())
  115. break;
  116. } else if (pm_wakeup_pending()) {
  117. break;
  118. }
  119. clear_wakeup_reasons();
  120. s2idle_enter();
  121. }
  122. pm_pr_dbg("resume from suspend-to-idle\n");
  123. }
  124. void s2idle_wake(void)
  125. {
  126. unsigned long flags;
  127. raw_spin_lock_irqsave(&s2idle_lock, flags);
  128. if (s2idle_state > S2IDLE_STATE_NONE) {
  129. s2idle_state = S2IDLE_STATE_WAKE;
  130. swake_up_one(&s2idle_wait_head);
  131. }
  132. raw_spin_unlock_irqrestore(&s2idle_lock, flags);
  133. }
  134. EXPORT_SYMBOL_GPL(s2idle_wake);
  135. static bool valid_state(suspend_state_t state)
  136. {
  137. /*
  138. * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
  139. * support and need to be valid to the low level
  140. * implementation, no valid callback implies that none are valid.
  141. */
  142. return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
  143. }
  144. void __init pm_states_init(void)
  145. {
  146. /* "mem" and "freeze" are always present in /sys/power/state. */
  147. pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
  148. pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
  149. /*
  150. * Suspend-to-idle should be supported even without any suspend_ops,
  151. * initialize mem_sleep_states[] accordingly here.
  152. */
  153. mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
  154. }
  155. static int __init mem_sleep_default_setup(char *str)
  156. {
  157. suspend_state_t state;
  158. for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
  159. if (mem_sleep_labels[state] &&
  160. !strcmp(str, mem_sleep_labels[state])) {
  161. mem_sleep_default = state;
  162. break;
  163. }
  164. return 1;
  165. }
  166. __setup("mem_sleep_default=", mem_sleep_default_setup);
  167. /**
  168. * suspend_set_ops - Set the global suspend method table.
  169. * @ops: Suspend operations to use.
  170. */
  171. void suspend_set_ops(const struct platform_suspend_ops *ops)
  172. {
  173. lock_system_sleep();
  174. suspend_ops = ops;
  175. if (valid_state(PM_SUSPEND_STANDBY)) {
  176. mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
  177. pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
  178. if (mem_sleep_default == PM_SUSPEND_STANDBY)
  179. mem_sleep_current = PM_SUSPEND_STANDBY;
  180. }
  181. if (valid_state(PM_SUSPEND_MEM)) {
  182. mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
  183. if (mem_sleep_default >= PM_SUSPEND_MEM)
  184. mem_sleep_current = PM_SUSPEND_MEM;
  185. }
  186. unlock_system_sleep();
  187. }
  188. EXPORT_SYMBOL_GPL(suspend_set_ops);
  189. /**
  190. * suspend_valid_only_mem - Generic memory-only valid callback.
  191. *
  192. * Platform drivers that implement mem suspend only and only need to check for
  193. * that in their .valid() callback can use this instead of rolling their own
  194. * .valid() callback.
  195. */
  196. int suspend_valid_only_mem(suspend_state_t state)
  197. {
  198. return state == PM_SUSPEND_MEM;
  199. }
  200. EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
  201. static bool sleep_state_supported(suspend_state_t state)
  202. {
  203. return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
  204. }
  205. static int platform_suspend_prepare(suspend_state_t state)
  206. {
  207. return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
  208. suspend_ops->prepare() : 0;
  209. }
  210. static int platform_suspend_prepare_late(suspend_state_t state)
  211. {
  212. return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
  213. s2idle_ops->prepare() : 0;
  214. }
  215. static int platform_suspend_prepare_noirq(suspend_state_t state)
  216. {
  217. if (state == PM_SUSPEND_TO_IDLE)
  218. return s2idle_ops && s2idle_ops->prepare_late ?
  219. s2idle_ops->prepare_late() : 0;
  220. return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
  221. }
  222. static void platform_resume_noirq(suspend_state_t state)
  223. {
  224. if (state == PM_SUSPEND_TO_IDLE) {
  225. if (s2idle_ops && s2idle_ops->restore_early)
  226. s2idle_ops->restore_early();
  227. } else if (suspend_ops->wake) {
  228. suspend_ops->wake();
  229. }
  230. }
  231. static void platform_resume_early(suspend_state_t state)
  232. {
  233. if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
  234. s2idle_ops->restore();
  235. }
  236. static void platform_resume_finish(suspend_state_t state)
  237. {
  238. if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
  239. suspend_ops->finish();
  240. }
  241. static int platform_suspend_begin(suspend_state_t state)
  242. {
  243. if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
  244. return s2idle_ops->begin();
  245. else if (suspend_ops && suspend_ops->begin)
  246. return suspend_ops->begin(state);
  247. else
  248. return 0;
  249. }
  250. static void platform_resume_end(suspend_state_t state)
  251. {
  252. if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
  253. s2idle_ops->end();
  254. else if (suspend_ops && suspend_ops->end)
  255. suspend_ops->end();
  256. }
  257. static void platform_recover(suspend_state_t state)
  258. {
  259. if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
  260. suspend_ops->recover();
  261. }
  262. static bool platform_suspend_again(suspend_state_t state)
  263. {
  264. return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
  265. suspend_ops->suspend_again() : false;
  266. }
  267. #ifdef CONFIG_PM_DEBUG
  268. static unsigned int pm_test_delay = 5;
  269. module_param(pm_test_delay, uint, 0644);
  270. MODULE_PARM_DESC(pm_test_delay,
  271. "Number of seconds to wait before resuming from suspend test");
  272. #endif
  273. static int suspend_test(int level)
  274. {
  275. #ifdef CONFIG_PM_DEBUG
  276. if (pm_test_level == level) {
  277. pr_info("suspend debug: Waiting for %d second(s).\n",
  278. pm_test_delay);
  279. mdelay(pm_test_delay * 1000);
  280. return 1;
  281. }
  282. #endif /* !CONFIG_PM_DEBUG */
  283. return 0;
  284. }
  285. /**
  286. * suspend_prepare - Prepare for entering system sleep state.
  287. *
  288. * Common code run for every system sleep state that can be entered (except for
  289. * hibernation). Run suspend notifiers, allocate the "suspend" console and
  290. * freeze processes.
  291. */
  292. static int suspend_prepare(suspend_state_t state)
  293. {
  294. int error;
  295. if (!sleep_state_supported(state))
  296. return -EPERM;
  297. pm_prepare_console();
  298. error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
  299. if (error)
  300. goto Restore;
  301. trace_suspend_resume(TPS("freeze_processes"), 0, true);
  302. error = suspend_freeze_processes();
  303. trace_suspend_resume(TPS("freeze_processes"), 0, false);
  304. if (!error)
  305. return 0;
  306. log_suspend_abort_reason("One or more tasks refusing to freeze");
  307. suspend_stats.failed_freeze++;
  308. dpm_save_failed_step(SUSPEND_FREEZE);
  309. pm_notifier_call_chain(PM_POST_SUSPEND);
  310. Restore:
  311. pm_restore_console();
  312. return error;
  313. }
  314. /* default implementation */
  315. void __weak arch_suspend_disable_irqs(void)
  316. {
  317. local_irq_disable();
  318. }
  319. /* default implementation */
  320. void __weak arch_suspend_enable_irqs(void)
  321. {
  322. local_irq_enable();
  323. }
  324. /**
  325. * suspend_enter - Make the system enter the given sleep state.
  326. * @state: System sleep state to enter.
  327. * @wakeup: Returns information that the sleep state should not be re-entered.
  328. *
  329. * This function should be called after devices have been suspended.
  330. */
  331. static int suspend_enter(suspend_state_t state, bool *wakeup)
  332. {
  333. int error, last_dev;
  334. error = platform_suspend_prepare(state);
  335. if (error)
  336. goto Platform_finish;
  337. error = dpm_suspend_late(PMSG_SUSPEND);
  338. if (error) {
  339. last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
  340. last_dev %= REC_FAILED_NUM;
  341. pr_err("late suspend of devices failed\n");
  342. log_suspend_abort_reason("late suspend of %s device failed",
  343. suspend_stats.failed_devs[last_dev]);
  344. goto Platform_finish;
  345. }
  346. error = platform_suspend_prepare_late(state);
  347. if (error)
  348. goto Devices_early_resume;
  349. error = dpm_suspend_noirq(PMSG_SUSPEND);
  350. if (error) {
  351. last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
  352. last_dev %= REC_FAILED_NUM;
  353. pr_err("noirq suspend of devices failed\n");
  354. log_suspend_abort_reason("noirq suspend of %s device failed",
  355. suspend_stats.failed_devs[last_dev]);
  356. goto Platform_early_resume;
  357. }
  358. error = platform_suspend_prepare_noirq(state);
  359. if (error)
  360. goto Platform_wake;
  361. if (suspend_test(TEST_PLATFORM))
  362. goto Platform_wake;
  363. if (state == PM_SUSPEND_TO_IDLE) {
  364. s2idle_loop();
  365. goto Platform_wake;
  366. }
  367. error = suspend_disable_secondary_cpus();
  368. if (error || suspend_test(TEST_CPUS)) {
  369. log_suspend_abort_reason("Disabling non-boot cpus failed");
  370. goto Enable_cpus;
  371. }
  372. arch_suspend_disable_irqs();
  373. BUG_ON(!irqs_disabled());
  374. system_state = SYSTEM_SUSPEND;
  375. error = syscore_suspend();
  376. if (!error) {
  377. *wakeup = pm_wakeup_pending();
  378. if (!(suspend_test(TEST_CORE) || *wakeup)) {
  379. trace_suspend_resume(TPS("machine_suspend"),
  380. state, true);
  381. error = suspend_ops->enter(state);
  382. trace_suspend_resume(TPS("machine_suspend"),
  383. state, false);
  384. } else if (*wakeup) {
  385. error = -EBUSY;
  386. }
  387. syscore_resume();
  388. }
  389. system_state = SYSTEM_RUNNING;
  390. arch_suspend_enable_irqs();
  391. BUG_ON(irqs_disabled());
  392. Enable_cpus:
  393. suspend_enable_secondary_cpus();
  394. Platform_wake:
  395. platform_resume_noirq(state);
  396. dpm_resume_noirq(PMSG_RESUME);
  397. Platform_early_resume:
  398. platform_resume_early(state);
  399. Devices_early_resume:
  400. dpm_resume_early(PMSG_RESUME);
  401. Platform_finish:
  402. platform_resume_finish(state);
  403. return error;
  404. }
  405. /**
  406. * suspend_devices_and_enter - Suspend devices and enter system sleep state.
  407. * @state: System sleep state to enter.
  408. */
  409. int suspend_devices_and_enter(suspend_state_t state)
  410. {
  411. int error;
  412. bool wakeup = false;
  413. if (!sleep_state_supported(state))
  414. return -ENOSYS;
  415. pm_suspend_target_state = state;
  416. if (state == PM_SUSPEND_TO_IDLE)
  417. pm_set_suspend_no_platform();
  418. error = platform_suspend_begin(state);
  419. if (error)
  420. goto Close;
  421. suspend_console();
  422. suspend_test_start();
  423. error = dpm_suspend_start(PMSG_SUSPEND);
  424. if (error) {
  425. pr_err("Some devices failed to suspend, or early wake event detected\n");
  426. log_suspend_abort_reason(
  427. "Some devices failed to suspend, or early wake event detected");
  428. goto Recover_platform;
  429. }
  430. suspend_test_finish("suspend devices");
  431. if (suspend_test(TEST_DEVICES))
  432. goto Recover_platform;
  433. do {
  434. error = suspend_enter(state, &wakeup);
  435. } while (!error && !wakeup && platform_suspend_again(state));
  436. Resume_devices:
  437. suspend_test_start();
  438. dpm_resume_end(PMSG_RESUME);
  439. suspend_test_finish("resume devices");
  440. trace_suspend_resume(TPS("resume_console"), state, true);
  441. resume_console();
  442. trace_suspend_resume(TPS("resume_console"), state, false);
  443. Close:
  444. platform_resume_end(state);
  445. pm_suspend_target_state = PM_SUSPEND_ON;
  446. return error;
  447. Recover_platform:
  448. platform_recover(state);
  449. goto Resume_devices;
  450. }
  451. /**
  452. * suspend_finish - Clean up before finishing the suspend sequence.
  453. *
  454. * Call platform code to clean up, restart processes, and free the console that
  455. * we've allocated. This routine is not called for hibernation.
  456. */
  457. static void suspend_finish(void)
  458. {
  459. suspend_thaw_processes();
  460. pm_notifier_call_chain(PM_POST_SUSPEND);
  461. pm_restore_console();
  462. }
  463. /**
  464. * enter_state - Do common work needed to enter system sleep state.
  465. * @state: System sleep state to enter.
  466. *
  467. * Make sure that no one else is trying to put the system into a sleep state.
  468. * Fail if that's not the case. Otherwise, prepare for system suspend, make the
  469. * system enter the given sleep state and clean up after wakeup.
  470. */
  471. static int enter_state(suspend_state_t state)
  472. {
  473. int error;
  474. trace_suspend_resume(TPS("suspend_enter"), state, true);
  475. if (state == PM_SUSPEND_TO_IDLE) {
  476. #ifdef CONFIG_PM_DEBUG
  477. if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
  478. pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
  479. return -EAGAIN;
  480. }
  481. #endif
  482. } else if (!valid_state(state)) {
  483. return -EINVAL;
  484. }
  485. if (!mutex_trylock(&system_transition_mutex))
  486. return -EBUSY;
  487. if (state == PM_SUSPEND_TO_IDLE)
  488. s2idle_begin();
  489. if (sync_on_suspend_enabled) {
  490. trace_suspend_resume(TPS("sync_filesystems"), 0, true);
  491. ksys_sync_helper();
  492. trace_suspend_resume(TPS("sync_filesystems"), 0, false);
  493. }
  494. pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
  495. pm_suspend_clear_flags();
  496. error = suspend_prepare(state);
  497. if (error)
  498. goto Unlock;
  499. if (suspend_test(TEST_FREEZER))
  500. goto Finish;
  501. trace_suspend_resume(TPS("suspend_enter"), state, false);
  502. pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
  503. pm_restrict_gfp_mask();
  504. error = suspend_devices_and_enter(state);
  505. pm_restore_gfp_mask();
  506. Finish:
  507. events_check_enabled = false;
  508. pm_pr_dbg("Finishing wakeup.\n");
  509. suspend_finish();
  510. Unlock:
  511. mutex_unlock(&system_transition_mutex);
  512. return error;
  513. }
  514. /**
  515. * pm_suspend - Externally visible function for suspending the system.
  516. * @state: System sleep state to enter.
  517. *
  518. * Check if the value of @state represents one of the supported states,
  519. * execute enter_state() and update system suspend statistics.
  520. */
  521. int pm_suspend(suspend_state_t state)
  522. {
  523. int error;
  524. if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
  525. return -EINVAL;
  526. pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
  527. error = enter_state(state);
  528. if (error) {
  529. suspend_stats.fail++;
  530. dpm_save_failed_errno(error);
  531. } else {
  532. suspend_stats.success++;
  533. }
  534. pr_info("suspend exit\n");
  535. return error;
  536. }
  537. EXPORT_SYMBOL(pm_suspend);