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
10 #define pr_fmt(fmt) "PM: " fmt
11
12 #include <linux/string.h>
13 #include <linux/delay.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/console.h>
17 #include <linux/cpu.h>
18 #include <linux/cpuidle.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/swait.h>
29 #include <linux/ftrace.h>
30 #include <trace/events/power.h>
31 #include <linux/compiler.h>
32 #include <linux/moduleparam.h>
33 #include <linux/wakeup_reason.h>
34
35 #include "power.h"
36
37 const char * const pm_labels[] = {
38 [PM_SUSPEND_TO_IDLE] = "freeze",
39 [PM_SUSPEND_STANDBY] = "standby",
40 [PM_SUSPEND_MEM] = "mem",
41 };
42 const char *pm_states[PM_SUSPEND_MAX];
43 static const char * const mem_sleep_labels[] = {
44 [PM_SUSPEND_TO_IDLE] = "s2idle",
45 [PM_SUSPEND_STANDBY] = "shallow",
46 [PM_SUSPEND_MEM] = "deep",
47 };
48 const char *mem_sleep_states[PM_SUSPEND_MAX];
49
50 suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
51 suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
52 suspend_state_t pm_suspend_target_state;
53 EXPORT_SYMBOL_GPL(pm_suspend_target_state);
54
55 unsigned int pm_suspend_global_flags;
56 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
57
58 static const struct platform_suspend_ops *suspend_ops;
59 static const struct platform_s2idle_ops *s2idle_ops;
60 static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
61
62 enum s2idle_states __read_mostly s2idle_state;
63 static DEFINE_RAW_SPINLOCK(s2idle_lock);
64
65 /**
66 * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
67 *
68 * Return 'true' if suspend-to-idle has been selected as the default system
69 * suspend method.
70 */
pm_suspend_default_s2idle(void)71 bool pm_suspend_default_s2idle(void)
72 {
73 return mem_sleep_current == PM_SUSPEND_TO_IDLE;
74 }
75 EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
76
s2idle_set_ops(const struct platform_s2idle_ops * ops)77 void s2idle_set_ops(const struct platform_s2idle_ops *ops)
78 {
79 lock_system_sleep();
80 s2idle_ops = ops;
81 unlock_system_sleep();
82 }
83
s2idle_begin(void)84 static void s2idle_begin(void)
85 {
86 s2idle_state = S2IDLE_STATE_NONE;
87 }
88
s2idle_enter(void)89 static void s2idle_enter(void)
90 {
91 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
92
93 raw_spin_lock_irq(&s2idle_lock);
94 if (pm_wakeup_pending())
95 goto out;
96
97 s2idle_state = S2IDLE_STATE_ENTER;
98 raw_spin_unlock_irq(&s2idle_lock);
99
100 cpus_read_lock();
101 cpuidle_resume();
102
103 /* Push all the CPUs into the idle loop. */
104 wake_up_all_idle_cpus();
105 /* Make the current CPU wait so it can enter the idle loop too. */
106 swait_event_exclusive(s2idle_wait_head,
107 s2idle_state == S2IDLE_STATE_WAKE);
108
109 cpuidle_pause();
110 cpus_read_unlock();
111
112 raw_spin_lock_irq(&s2idle_lock);
113
114 out:
115 s2idle_state = S2IDLE_STATE_NONE;
116 raw_spin_unlock_irq(&s2idle_lock);
117
118 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
119 }
120
s2idle_loop(void)121 static void s2idle_loop(void)
122 {
123 pm_pr_dbg("suspend-to-idle\n");
124
125 /*
126 * Suspend-to-idle equals:
127 * frozen processes + suspended devices + idle processors.
128 * Thus s2idle_enter() should be called right after all devices have
129 * been suspended.
130 *
131 * Wakeups during the noirq suspend of devices may be spurious, so try
132 * to avoid them upfront.
133 */
134 for (;;) {
135 if (s2idle_ops && s2idle_ops->wake) {
136 if (s2idle_ops->wake())
137 break;
138 } else if (pm_wakeup_pending()) {
139 break;
140 }
141
142 clear_wakeup_reasons();
143 s2idle_enter();
144 }
145
146 pm_pr_dbg("resume from suspend-to-idle\n");
147 }
148
s2idle_wake(void)149 void s2idle_wake(void)
150 {
151 unsigned long flags;
152
153 raw_spin_lock_irqsave(&s2idle_lock, flags);
154 if (s2idle_state > S2IDLE_STATE_NONE) {
155 s2idle_state = S2IDLE_STATE_WAKE;
156 swake_up_one(&s2idle_wait_head);
157 }
158 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
159 }
160 EXPORT_SYMBOL_GPL(s2idle_wake);
161
valid_state(suspend_state_t state)162 static bool valid_state(suspend_state_t state)
163 {
164 /*
165 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
166 * support and need to be valid to the low level
167 * implementation, no valid callback implies that none are valid.
168 */
169 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
170 }
171
pm_states_init(void)172 void __init pm_states_init(void)
173 {
174 /* "mem" and "freeze" are always present in /sys/power/state. */
175 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
176 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
177 /*
178 * Suspend-to-idle should be supported even without any suspend_ops,
179 * initialize mem_sleep_states[] accordingly here.
180 */
181 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
182 }
183
mem_sleep_default_setup(char * str)184 static int __init mem_sleep_default_setup(char *str)
185 {
186 suspend_state_t state;
187
188 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
189 if (mem_sleep_labels[state] &&
190 !strcmp(str, mem_sleep_labels[state])) {
191 mem_sleep_default = state;
192 break;
193 }
194
195 return 1;
196 }
197 __setup("mem_sleep_default=", mem_sleep_default_setup);
198
199 /**
200 * suspend_set_ops - Set the global suspend method table.
201 * @ops: Suspend operations to use.
202 */
suspend_set_ops(const struct platform_suspend_ops * ops)203 void suspend_set_ops(const struct platform_suspend_ops *ops)
204 {
205 lock_system_sleep();
206
207 suspend_ops = ops;
208
209 if (valid_state(PM_SUSPEND_STANDBY)) {
210 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
211 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
212 if (mem_sleep_default == PM_SUSPEND_STANDBY)
213 mem_sleep_current = PM_SUSPEND_STANDBY;
214 }
215 if (valid_state(PM_SUSPEND_MEM)) {
216 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
217 if (mem_sleep_default >= PM_SUSPEND_MEM)
218 mem_sleep_current = PM_SUSPEND_MEM;
219 }
220
221 unlock_system_sleep();
222 }
223 EXPORT_SYMBOL_GPL(suspend_set_ops);
224
225 /**
226 * suspend_valid_only_mem - Generic memory-only valid callback.
227 * @state: Target system sleep state.
228 *
229 * Platform drivers that implement mem suspend only and only need to check for
230 * that in their .valid() callback can use this instead of rolling their own
231 * .valid() callback.
232 */
suspend_valid_only_mem(suspend_state_t state)233 int suspend_valid_only_mem(suspend_state_t state)
234 {
235 return state == PM_SUSPEND_MEM;
236 }
237 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
238
sleep_state_supported(suspend_state_t state)239 static bool sleep_state_supported(suspend_state_t state)
240 {
241 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
242 }
243
platform_suspend_prepare(suspend_state_t state)244 static int platform_suspend_prepare(suspend_state_t state)
245 {
246 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
247 suspend_ops->prepare() : 0;
248 }
249
platform_suspend_prepare_late(suspend_state_t state)250 static int platform_suspend_prepare_late(suspend_state_t state)
251 {
252 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
253 s2idle_ops->prepare() : 0;
254 }
255
platform_suspend_prepare_noirq(suspend_state_t state)256 static int platform_suspend_prepare_noirq(suspend_state_t state)
257 {
258 if (state == PM_SUSPEND_TO_IDLE)
259 return s2idle_ops && s2idle_ops->prepare_late ?
260 s2idle_ops->prepare_late() : 0;
261
262 return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
263 }
264
platform_resume_noirq(suspend_state_t state)265 static void platform_resume_noirq(suspend_state_t state)
266 {
267 if (state == PM_SUSPEND_TO_IDLE) {
268 if (s2idle_ops && s2idle_ops->restore_early)
269 s2idle_ops->restore_early();
270 } else if (suspend_ops->wake) {
271 suspend_ops->wake();
272 }
273 }
274
platform_resume_early(suspend_state_t state)275 static void platform_resume_early(suspend_state_t state)
276 {
277 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
278 s2idle_ops->restore();
279 }
280
platform_resume_finish(suspend_state_t state)281 static void platform_resume_finish(suspend_state_t state)
282 {
283 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
284 suspend_ops->finish();
285 }
286
platform_suspend_begin(suspend_state_t state)287 static int platform_suspend_begin(suspend_state_t state)
288 {
289 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
290 return s2idle_ops->begin();
291 else if (suspend_ops && suspend_ops->begin)
292 return suspend_ops->begin(state);
293 else
294 return 0;
295 }
296
platform_resume_end(suspend_state_t state)297 static void platform_resume_end(suspend_state_t state)
298 {
299 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
300 s2idle_ops->end();
301 else if (suspend_ops && suspend_ops->end)
302 suspend_ops->end();
303 }
304
platform_recover(suspend_state_t state)305 static void platform_recover(suspend_state_t state)
306 {
307 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
308 suspend_ops->recover();
309 }
310
platform_suspend_again(suspend_state_t state)311 static bool platform_suspend_again(suspend_state_t state)
312 {
313 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
314 suspend_ops->suspend_again() : false;
315 }
316
317 #ifdef CONFIG_PM_DEBUG
318 static unsigned int pm_test_delay = 5;
319 module_param(pm_test_delay, uint, 0644);
320 MODULE_PARM_DESC(pm_test_delay,
321 "Number of seconds to wait before resuming from suspend test");
322 #endif
323
suspend_test(int level)324 static int suspend_test(int level)
325 {
326 #ifdef CONFIG_PM_DEBUG
327 if (pm_test_level == level) {
328 pr_info("suspend debug: Waiting for %d second(s).\n",
329 pm_test_delay);
330 mdelay(pm_test_delay * 1000);
331 return 1;
332 }
333 #endif /* !CONFIG_PM_DEBUG */
334 return 0;
335 }
336
337 /**
338 * suspend_prepare - Prepare for entering system sleep state.
339 * @state: Target system sleep state.
340 *
341 * Common code run for every system sleep state that can be entered (except for
342 * hibernation). Run suspend notifiers, allocate the "suspend" console and
343 * freeze processes.
344 */
suspend_prepare(suspend_state_t state)345 static int suspend_prepare(suspend_state_t state)
346 {
347 int error;
348
349 if (!sleep_state_supported(state))
350 return -EPERM;
351
352 pm_prepare_console();
353
354 error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
355 if (error)
356 goto Restore;
357
358 trace_suspend_resume(TPS("freeze_processes"), 0, true);
359 error = suspend_freeze_processes();
360 trace_suspend_resume(TPS("freeze_processes"), 0, false);
361 if (!error)
362 return 0;
363
364 log_suspend_abort_reason("One or more tasks refusing to freeze");
365 suspend_stats.failed_freeze++;
366 dpm_save_failed_step(SUSPEND_FREEZE);
367 pm_notifier_call_chain(PM_POST_SUSPEND);
368 Restore:
369 pm_restore_console();
370 return error;
371 }
372
373 /* default implementation */
arch_suspend_disable_irqs(void)374 void __weak arch_suspend_disable_irqs(void)
375 {
376 local_irq_disable();
377 }
378
379 /* default implementation */
arch_suspend_enable_irqs(void)380 void __weak arch_suspend_enable_irqs(void)
381 {
382 local_irq_enable();
383 }
384
385 /**
386 * suspend_enter - Make the system enter the given sleep state.
387 * @state: System sleep state to enter.
388 * @wakeup: Returns information that the sleep state should not be re-entered.
389 *
390 * This function should be called after devices have been suspended.
391 */
suspend_enter(suspend_state_t state,bool * wakeup)392 static int suspend_enter(suspend_state_t state, bool *wakeup)
393 {
394 int error, last_dev;
395
396 error = platform_suspend_prepare(state);
397 if (error)
398 goto Platform_finish;
399
400 error = dpm_suspend_late(PMSG_SUSPEND);
401 if (error) {
402 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
403 last_dev %= REC_FAILED_NUM;
404 pr_err("late suspend of devices failed\n");
405 log_suspend_abort_reason("late suspend of %s device failed",
406 suspend_stats.failed_devs[last_dev]);
407 goto Platform_finish;
408 }
409 error = platform_suspend_prepare_late(state);
410 if (error)
411 goto Devices_early_resume;
412
413 error = dpm_suspend_noirq(PMSG_SUSPEND);
414 if (error) {
415 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
416 last_dev %= REC_FAILED_NUM;
417 pr_err("noirq suspend of devices failed\n");
418 log_suspend_abort_reason("noirq suspend of %s device failed",
419 suspend_stats.failed_devs[last_dev]);
420 goto Platform_early_resume;
421 }
422 error = platform_suspend_prepare_noirq(state);
423 if (error)
424 goto Platform_wake;
425
426 if (suspend_test(TEST_PLATFORM))
427 goto Platform_wake;
428
429 if (state == PM_SUSPEND_TO_IDLE) {
430 s2idle_loop();
431 goto Platform_wake;
432 }
433
434 error = suspend_disable_secondary_cpus();
435 if (error || suspend_test(TEST_CPUS)) {
436 log_suspend_abort_reason("Disabling non-boot cpus failed");
437 goto Enable_cpus;
438 }
439
440 arch_suspend_disable_irqs();
441 BUG_ON(!irqs_disabled());
442
443 system_state = SYSTEM_SUSPEND;
444
445 error = syscore_suspend();
446 if (!error) {
447 *wakeup = pm_wakeup_pending();
448 if (!(suspend_test(TEST_CORE) || *wakeup)) {
449 trace_suspend_resume(TPS("machine_suspend"),
450 state, true);
451 error = suspend_ops->enter(state);
452 trace_suspend_resume(TPS("machine_suspend"),
453 state, false);
454 } else if (*wakeup) {
455 error = -EBUSY;
456 }
457 syscore_resume();
458 }
459
460 system_state = SYSTEM_RUNNING;
461
462 arch_suspend_enable_irqs();
463 BUG_ON(irqs_disabled());
464
465 Enable_cpus:
466 suspend_enable_secondary_cpus();
467
468 Platform_wake:
469 platform_resume_noirq(state);
470 dpm_resume_noirq(PMSG_RESUME);
471
472 Platform_early_resume:
473 platform_resume_early(state);
474
475 Devices_early_resume:
476 dpm_resume_early(PMSG_RESUME);
477
478 Platform_finish:
479 platform_resume_finish(state);
480 return error;
481 }
482
483 /**
484 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
485 * @state: System sleep state to enter.
486 */
suspend_devices_and_enter(suspend_state_t state)487 int suspend_devices_and_enter(suspend_state_t state)
488 {
489 int error;
490 bool wakeup = false;
491
492 if (!sleep_state_supported(state))
493 return -ENOSYS;
494
495 pm_suspend_target_state = state;
496
497 if (state == PM_SUSPEND_TO_IDLE)
498 pm_set_suspend_no_platform();
499
500 error = platform_suspend_begin(state);
501 if (error)
502 goto Close;
503
504 suspend_console();
505 suspend_test_start();
506 error = dpm_suspend_start(PMSG_SUSPEND);
507 if (error) {
508 pr_err("Some devices failed to suspend, or early wake event detected\n");
509 log_suspend_abort_reason(
510 "Some devices failed to suspend, or early wake event detected");
511 goto Recover_platform;
512 }
513 suspend_test_finish("suspend devices");
514 if (suspend_test(TEST_DEVICES))
515 goto Recover_platform;
516
517 do {
518 error = suspend_enter(state, &wakeup);
519 } while (!error && !wakeup && platform_suspend_again(state));
520
521 Resume_devices:
522 suspend_test_start();
523 dpm_resume_end(PMSG_RESUME);
524 suspend_test_finish("resume devices");
525 trace_suspend_resume(TPS("resume_console"), state, true);
526 resume_console();
527 trace_suspend_resume(TPS("resume_console"), state, false);
528
529 Close:
530 platform_resume_end(state);
531 pm_suspend_target_state = PM_SUSPEND_ON;
532 return error;
533
534 Recover_platform:
535 platform_recover(state);
536 goto Resume_devices;
537 }
538
539 /**
540 * suspend_finish - Clean up before finishing the suspend sequence.
541 *
542 * Call platform code to clean up, restart processes, and free the console that
543 * we've allocated. This routine is not called for hibernation.
544 */
suspend_finish(void)545 static void suspend_finish(void)
546 {
547 suspend_thaw_processes();
548 pm_notifier_call_chain(PM_POST_SUSPEND);
549 pm_restore_console();
550 }
551
552 /**
553 * enter_state - Do common work needed to enter system sleep state.
554 * @state: System sleep state to enter.
555 *
556 * Make sure that no one else is trying to put the system into a sleep state.
557 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
558 * system enter the given sleep state and clean up after wakeup.
559 */
enter_state(suspend_state_t state)560 static int enter_state(suspend_state_t state)
561 {
562 int error;
563
564 trace_suspend_resume(TPS("suspend_enter"), state, true);
565 if (state == PM_SUSPEND_TO_IDLE) {
566 #ifdef CONFIG_PM_DEBUG
567 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
568 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
569 return -EAGAIN;
570 }
571 #endif
572 } else if (!valid_state(state)) {
573 return -EINVAL;
574 }
575 if (!mutex_trylock(&system_transition_mutex))
576 return -EBUSY;
577
578 if (state == PM_SUSPEND_TO_IDLE)
579 s2idle_begin();
580
581 if (sync_on_suspend_enabled) {
582 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
583 ksys_sync_helper();
584 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
585 }
586
587 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
588 pm_suspend_clear_flags();
589 error = suspend_prepare(state);
590 if (error)
591 goto Unlock;
592
593 if (suspend_test(TEST_FREEZER))
594 goto Finish;
595
596 trace_suspend_resume(TPS("suspend_enter"), state, false);
597 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
598 pm_restrict_gfp_mask();
599 error = suspend_devices_and_enter(state);
600 pm_restore_gfp_mask();
601
602 Finish:
603 events_check_enabled = false;
604 pm_pr_dbg("Finishing wakeup.\n");
605 suspend_finish();
606 Unlock:
607 mutex_unlock(&system_transition_mutex);
608 return error;
609 }
610
611 /**
612 * pm_suspend - Externally visible function for suspending the system.
613 * @state: System sleep state to enter.
614 *
615 * Check if the value of @state represents one of the supported states,
616 * execute enter_state() and update system suspend statistics.
617 */
pm_suspend(suspend_state_t state)618 int pm_suspend(suspend_state_t state)
619 {
620 int error;
621
622 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
623 return -EINVAL;
624
625 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
626 error = enter_state(state);
627 if (error) {
628 suspend_stats.fail++;
629 dpm_save_failed_errno(error);
630 } else {
631 suspend_stats.success++;
632 }
633 pr_info("suspend exit\n");
634 return error;
635 }
636 EXPORT_SYMBOL(pm_suspend);
637