Line data Source code
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 :
34 : #include "power.h"
35 :
36 : const char * const pm_labels[] = {
37 : [PM_SUSPEND_TO_IDLE] = "freeze",
38 : [PM_SUSPEND_STANDBY] = "standby",
39 : [PM_SUSPEND_MEM] = "mem",
40 : };
41 : const char *pm_states[PM_SUSPEND_MAX];
42 : static const char * const mem_sleep_labels[] = {
43 : [PM_SUSPEND_TO_IDLE] = "s2idle",
44 : [PM_SUSPEND_STANDBY] = "shallow",
45 : [PM_SUSPEND_MEM] = "deep",
46 : };
47 : const char *mem_sleep_states[PM_SUSPEND_MAX];
48 :
49 : suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
50 : suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
51 : suspend_state_t pm_suspend_target_state;
52 : EXPORT_SYMBOL_GPL(pm_suspend_target_state);
53 :
54 : unsigned int pm_suspend_global_flags;
55 : EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
56 :
57 : static const struct platform_suspend_ops *suspend_ops;
58 : static const struct platform_s2idle_ops *s2idle_ops;
59 : static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
60 :
61 : enum s2idle_states __read_mostly s2idle_state;
62 : static DEFINE_RAW_SPINLOCK(s2idle_lock);
63 :
64 : /**
65 : * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
66 : *
67 : * Return 'true' if suspend-to-idle has been selected as the default system
68 : * suspend method.
69 : */
70 0 : bool pm_suspend_default_s2idle(void)
71 : {
72 0 : return mem_sleep_current == PM_SUSPEND_TO_IDLE;
73 : }
74 : EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
75 :
76 0 : void s2idle_set_ops(const struct platform_s2idle_ops *ops)
77 : {
78 0 : lock_system_sleep();
79 0 : s2idle_ops = ops;
80 0 : unlock_system_sleep();
81 0 : }
82 :
83 : static void s2idle_begin(void)
84 : {
85 0 : s2idle_state = S2IDLE_STATE_NONE;
86 : }
87 :
88 0 : static void s2idle_enter(void)
89 : {
90 0 : trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
91 :
92 0 : raw_spin_lock_irq(&s2idle_lock);
93 0 : if (pm_wakeup_pending())
94 : goto out;
95 :
96 0 : s2idle_state = S2IDLE_STATE_ENTER;
97 0 : raw_spin_unlock_irq(&s2idle_lock);
98 :
99 : cpus_read_lock();
100 :
101 : /* Push all the CPUs into the idle loop. */
102 : wake_up_all_idle_cpus();
103 : /* Make the current CPU wait so it can enter the idle loop too. */
104 0 : swait_event_exclusive(s2idle_wait_head,
105 : s2idle_state == S2IDLE_STATE_WAKE);
106 :
107 : cpus_read_unlock();
108 :
109 0 : raw_spin_lock_irq(&s2idle_lock);
110 :
111 : out:
112 0 : s2idle_state = S2IDLE_STATE_NONE;
113 0 : raw_spin_unlock_irq(&s2idle_lock);
114 :
115 0 : trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
116 0 : }
117 :
118 0 : static void s2idle_loop(void)
119 : {
120 : pm_pr_dbg("suspend-to-idle\n");
121 :
122 : /*
123 : * Suspend-to-idle equals:
124 : * frozen processes + suspended devices + idle processors.
125 : * Thus s2idle_enter() should be called right after all devices have
126 : * been suspended.
127 : *
128 : * Wakeups during the noirq suspend of devices may be spurious, so try
129 : * to avoid them upfront.
130 : */
131 : for (;;) {
132 0 : if (s2idle_ops && s2idle_ops->wake) {
133 0 : if (s2idle_ops->wake())
134 : break;
135 0 : } else if (pm_wakeup_pending()) {
136 : break;
137 : }
138 :
139 0 : s2idle_enter();
140 : }
141 :
142 : pm_pr_dbg("resume from suspend-to-idle\n");
143 0 : }
144 :
145 0 : void s2idle_wake(void)
146 : {
147 : unsigned long flags;
148 :
149 0 : raw_spin_lock_irqsave(&s2idle_lock, flags);
150 0 : if (s2idle_state > S2IDLE_STATE_NONE) {
151 0 : s2idle_state = S2IDLE_STATE_WAKE;
152 0 : swake_up_one(&s2idle_wait_head);
153 : }
154 0 : raw_spin_unlock_irqrestore(&s2idle_lock, flags);
155 0 : }
156 : EXPORT_SYMBOL_GPL(s2idle_wake);
157 :
158 : static bool valid_state(suspend_state_t state)
159 : {
160 : /*
161 : * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
162 : * support and need to be valid to the low-level implementation.
163 : *
164 : * No ->valid() or ->enter() callback implies that none are valid.
165 : */
166 3 : return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
167 1 : suspend_ops->enter;
168 : }
169 :
170 1 : void __init pm_states_init(void)
171 : {
172 : /* "mem" and "freeze" are always present in /sys/power/state. */
173 1 : pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
174 1 : pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
175 : /*
176 : * Suspend-to-idle should be supported even without any suspend_ops,
177 : * initialize mem_sleep_states[] accordingly here.
178 : */
179 1 : mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
180 1 : }
181 :
182 0 : static int __init mem_sleep_default_setup(char *str)
183 : {
184 : suspend_state_t state;
185 :
186 0 : for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
187 0 : if (mem_sleep_labels[state] &&
188 0 : !strcmp(str, mem_sleep_labels[state])) {
189 0 : mem_sleep_default = state;
190 0 : break;
191 : }
192 :
193 0 : return 1;
194 : }
195 : __setup("mem_sleep_default=", mem_sleep_default_setup);
196 :
197 : /**
198 : * suspend_set_ops - Set the global suspend method table.
199 : * @ops: Suspend operations to use.
200 : */
201 1 : void suspend_set_ops(const struct platform_suspend_ops *ops)
202 : {
203 1 : lock_system_sleep();
204 :
205 1 : suspend_ops = ops;
206 :
207 1 : if (valid_state(PM_SUSPEND_STANDBY)) {
208 0 : mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
209 0 : pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
210 0 : if (mem_sleep_default == PM_SUSPEND_STANDBY)
211 0 : mem_sleep_current = PM_SUSPEND_STANDBY;
212 : }
213 1 : if (valid_state(PM_SUSPEND_MEM)) {
214 1 : mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
215 1 : if (mem_sleep_default >= PM_SUSPEND_MEM)
216 1 : mem_sleep_current = PM_SUSPEND_MEM;
217 : }
218 :
219 1 : unlock_system_sleep();
220 1 : }
221 : EXPORT_SYMBOL_GPL(suspend_set_ops);
222 :
223 : /**
224 : * suspend_valid_only_mem - Generic memory-only valid callback.
225 : * @state: Target system sleep state.
226 : *
227 : * Platform drivers that implement mem suspend only and only need to check for
228 : * that in their .valid() callback can use this instead of rolling their own
229 : * .valid() callback.
230 : */
231 0 : int suspend_valid_only_mem(suspend_state_t state)
232 : {
233 0 : return state == PM_SUSPEND_MEM;
234 : }
235 : EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
236 :
237 0 : static bool sleep_state_supported(suspend_state_t state)
238 : {
239 0 : return state == PM_SUSPEND_TO_IDLE || valid_state(state);
240 : }
241 :
242 : static int platform_suspend_prepare(suspend_state_t state)
243 : {
244 0 : return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
245 0 : suspend_ops->prepare() : 0;
246 : }
247 :
248 : static int platform_suspend_prepare_late(suspend_state_t state)
249 : {
250 0 : return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
251 0 : s2idle_ops->prepare() : 0;
252 : }
253 :
254 0 : static int platform_suspend_prepare_noirq(suspend_state_t state)
255 : {
256 0 : if (state == PM_SUSPEND_TO_IDLE)
257 0 : return s2idle_ops && s2idle_ops->prepare_late ?
258 0 : s2idle_ops->prepare_late() : 0;
259 :
260 0 : return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
261 : }
262 :
263 0 : static void platform_resume_noirq(suspend_state_t state)
264 : {
265 0 : if (state == PM_SUSPEND_TO_IDLE) {
266 0 : if (s2idle_ops && s2idle_ops->restore_early)
267 0 : s2idle_ops->restore_early();
268 0 : } else if (suspend_ops->wake) {
269 0 : suspend_ops->wake();
270 : }
271 0 : }
272 :
273 : static void platform_resume_early(suspend_state_t state)
274 : {
275 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
276 0 : s2idle_ops->restore();
277 : }
278 :
279 : static void platform_resume_finish(suspend_state_t state)
280 : {
281 0 : if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
282 0 : suspend_ops->finish();
283 : }
284 :
285 0 : static int platform_suspend_begin(suspend_state_t state)
286 : {
287 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
288 0 : return s2idle_ops->begin();
289 0 : else if (suspend_ops && suspend_ops->begin)
290 0 : return suspend_ops->begin(state);
291 : else
292 : return 0;
293 : }
294 :
295 0 : static void platform_resume_end(suspend_state_t state)
296 : {
297 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
298 0 : s2idle_ops->end();
299 0 : else if (suspend_ops && suspend_ops->end)
300 0 : suspend_ops->end();
301 0 : }
302 :
303 : static void platform_recover(suspend_state_t state)
304 : {
305 0 : if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
306 0 : suspend_ops->recover();
307 : }
308 :
309 : static bool platform_suspend_again(suspend_state_t state)
310 : {
311 0 : return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
312 0 : suspend_ops->suspend_again() : false;
313 : }
314 :
315 : #ifdef CONFIG_PM_DEBUG
316 : static unsigned int pm_test_delay = 5;
317 : module_param(pm_test_delay, uint, 0644);
318 : MODULE_PARM_DESC(pm_test_delay,
319 : "Number of seconds to wait before resuming from suspend test");
320 : #endif
321 :
322 : static int suspend_test(int level)
323 : {
324 : #ifdef CONFIG_PM_DEBUG
325 : if (pm_test_level == level) {
326 : pr_info("suspend debug: Waiting for %d second(s).\n",
327 : pm_test_delay);
328 : mdelay(pm_test_delay * 1000);
329 : return 1;
330 : }
331 : #endif /* !CONFIG_PM_DEBUG */
332 : return 0;
333 : }
334 :
335 : /**
336 : * suspend_prepare - Prepare for entering system sleep state.
337 : * @state: Target system sleep state.
338 : *
339 : * Common code run for every system sleep state that can be entered (except for
340 : * hibernation). Run suspend notifiers, allocate the "suspend" console and
341 : * freeze processes.
342 : */
343 0 : static int suspend_prepare(suspend_state_t state)
344 : {
345 : int error;
346 :
347 0 : if (!sleep_state_supported(state))
348 : return -EPERM;
349 :
350 : pm_prepare_console();
351 :
352 0 : error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
353 0 : if (error)
354 : goto Restore;
355 :
356 0 : trace_suspend_resume(TPS("freeze_processes"), 0, true);
357 0 : error = suspend_freeze_processes();
358 0 : trace_suspend_resume(TPS("freeze_processes"), 0, false);
359 0 : if (!error)
360 : return 0;
361 :
362 0 : suspend_stats.failed_freeze++;
363 0 : dpm_save_failed_step(SUSPEND_FREEZE);
364 0 : pm_notifier_call_chain(PM_POST_SUSPEND);
365 : Restore:
366 : pm_restore_console();
367 : return error;
368 : }
369 :
370 : /* default implementation */
371 0 : void __weak arch_suspend_disable_irqs(void)
372 : {
373 : local_irq_disable();
374 0 : }
375 :
376 : /* default implementation */
377 0 : void __weak arch_suspend_enable_irqs(void)
378 : {
379 : local_irq_enable();
380 0 : }
381 :
382 : /**
383 : * suspend_enter - Make the system enter the given sleep state.
384 : * @state: System sleep state to enter.
385 : * @wakeup: Returns information that the sleep state should not be re-entered.
386 : *
387 : * This function should be called after devices have been suspended.
388 : */
389 0 : static int suspend_enter(suspend_state_t state, bool *wakeup)
390 : {
391 : int error;
392 :
393 0 : error = platform_suspend_prepare(state);
394 0 : if (error)
395 : goto Platform_finish;
396 :
397 0 : error = dpm_suspend_late(PMSG_SUSPEND);
398 0 : if (error) {
399 0 : pr_err("late suspend of devices failed\n");
400 0 : goto Platform_finish;
401 : }
402 0 : error = platform_suspend_prepare_late(state);
403 0 : if (error)
404 : goto Devices_early_resume;
405 :
406 0 : error = dpm_suspend_noirq(PMSG_SUSPEND);
407 0 : if (error) {
408 0 : pr_err("noirq suspend of devices failed\n");
409 0 : goto Platform_early_resume;
410 : }
411 0 : error = platform_suspend_prepare_noirq(state);
412 0 : if (error)
413 : goto Platform_wake;
414 :
415 0 : if (suspend_test(TEST_PLATFORM))
416 : goto Platform_wake;
417 :
418 0 : if (state == PM_SUSPEND_TO_IDLE) {
419 0 : s2idle_loop();
420 0 : goto Platform_wake;
421 : }
422 :
423 0 : error = pm_sleep_disable_secondary_cpus();
424 0 : if (error || suspend_test(TEST_CPUS))
425 : goto Enable_cpus;
426 :
427 0 : arch_suspend_disable_irqs();
428 0 : BUG_ON(!irqs_disabled());
429 :
430 0 : system_state = SYSTEM_SUSPEND;
431 :
432 0 : error = syscore_suspend();
433 0 : if (!error) {
434 0 : *wakeup = pm_wakeup_pending();
435 0 : if (!(suspend_test(TEST_CORE) || *wakeup)) {
436 0 : trace_suspend_resume(TPS("machine_suspend"),
437 : state, true);
438 0 : error = suspend_ops->enter(state);
439 : trace_suspend_resume(TPS("machine_suspend"),
440 : state, false);
441 : } else if (*wakeup) {
442 : error = -EBUSY;
443 : }
444 0 : syscore_resume();
445 : }
446 :
447 0 : system_state = SYSTEM_RUNNING;
448 :
449 0 : arch_suspend_enable_irqs();
450 0 : BUG_ON(irqs_disabled());
451 :
452 : Enable_cpus:
453 : pm_sleep_enable_secondary_cpus();
454 :
455 : Platform_wake:
456 0 : platform_resume_noirq(state);
457 0 : dpm_resume_noirq(PMSG_RESUME);
458 :
459 : Platform_early_resume:
460 : platform_resume_early(state);
461 :
462 : Devices_early_resume:
463 0 : dpm_resume_early(PMSG_RESUME);
464 :
465 : Platform_finish:
466 0 : platform_resume_finish(state);
467 0 : return error;
468 : }
469 :
470 : /**
471 : * suspend_devices_and_enter - Suspend devices and enter system sleep state.
472 : * @state: System sleep state to enter.
473 : */
474 0 : int suspend_devices_and_enter(suspend_state_t state)
475 : {
476 : int error;
477 0 : bool wakeup = false;
478 :
479 0 : if (!sleep_state_supported(state))
480 : return -ENOSYS;
481 :
482 0 : pm_suspend_target_state = state;
483 :
484 0 : if (state == PM_SUSPEND_TO_IDLE)
485 : pm_set_suspend_no_platform();
486 :
487 0 : error = platform_suspend_begin(state);
488 0 : if (error)
489 : goto Close;
490 :
491 0 : suspend_console();
492 : suspend_test_start();
493 0 : error = dpm_suspend_start(PMSG_SUSPEND);
494 0 : if (error) {
495 0 : pr_err("Some devices failed to suspend, or early wake event detected\n");
496 : goto Recover_platform;
497 : }
498 : suspend_test_finish("suspend devices");
499 : if (suspend_test(TEST_DEVICES))
500 : goto Recover_platform;
501 :
502 : do {
503 0 : error = suspend_enter(state, &wakeup);
504 0 : } while (!error && !wakeup && platform_suspend_again(state));
505 :
506 : Resume_devices:
507 : suspend_test_start();
508 0 : dpm_resume_end(PMSG_RESUME);
509 0 : suspend_test_finish("resume devices");
510 0 : trace_suspend_resume(TPS("resume_console"), state, true);
511 0 : resume_console();
512 : trace_suspend_resume(TPS("resume_console"), state, false);
513 :
514 : Close:
515 0 : platform_resume_end(state);
516 0 : pm_suspend_target_state = PM_SUSPEND_ON;
517 0 : return error;
518 :
519 : Recover_platform:
520 : platform_recover(state);
521 : goto Resume_devices;
522 : }
523 :
524 : /**
525 : * suspend_finish - Clean up before finishing the suspend sequence.
526 : *
527 : * Call platform code to clean up, restart processes, and free the console that
528 : * we've allocated. This routine is not called for hibernation.
529 : */
530 : static void suspend_finish(void)
531 : {
532 : suspend_thaw_processes();
533 0 : pm_notifier_call_chain(PM_POST_SUSPEND);
534 : pm_restore_console();
535 : }
536 :
537 : /**
538 : * enter_state - Do common work needed to enter system sleep state.
539 : * @state: System sleep state to enter.
540 : *
541 : * Make sure that no one else is trying to put the system into a sleep state.
542 : * Fail if that's not the case. Otherwise, prepare for system suspend, make the
543 : * system enter the given sleep state and clean up after wakeup.
544 : */
545 0 : static int enter_state(suspend_state_t state)
546 : {
547 : int error;
548 :
549 0 : trace_suspend_resume(TPS("suspend_enter"), state, true);
550 0 : if (state == PM_SUSPEND_TO_IDLE) {
551 : #ifdef CONFIG_PM_DEBUG
552 : if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
553 : pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
554 : return -EAGAIN;
555 : }
556 : #endif
557 0 : } else if (!valid_state(state)) {
558 : return -EINVAL;
559 : }
560 0 : if (!mutex_trylock(&system_transition_mutex))
561 : return -EBUSY;
562 :
563 0 : if (state == PM_SUSPEND_TO_IDLE)
564 : s2idle_begin();
565 :
566 0 : if (sync_on_suspend_enabled) {
567 0 : trace_suspend_resume(TPS("sync_filesystems"), 0, true);
568 0 : ksys_sync_helper();
569 : trace_suspend_resume(TPS("sync_filesystems"), 0, false);
570 : }
571 :
572 : pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
573 : pm_suspend_clear_flags();
574 0 : error = suspend_prepare(state);
575 0 : if (error)
576 : goto Unlock;
577 :
578 0 : if (suspend_test(TEST_FREEZER))
579 : goto Finish;
580 :
581 0 : trace_suspend_resume(TPS("suspend_enter"), state, false);
582 : pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
583 0 : pm_restrict_gfp_mask();
584 0 : error = suspend_devices_and_enter(state);
585 0 : pm_restore_gfp_mask();
586 :
587 : Finish:
588 0 : events_check_enabled = false;
589 : pm_pr_dbg("Finishing wakeup.\n");
590 : suspend_finish();
591 : Unlock:
592 0 : mutex_unlock(&system_transition_mutex);
593 0 : return error;
594 : }
595 :
596 : /**
597 : * pm_suspend - Externally visible function for suspending the system.
598 : * @state: System sleep state to enter.
599 : *
600 : * Check if the value of @state represents one of the supported states,
601 : * execute enter_state() and update system suspend statistics.
602 : */
603 0 : int pm_suspend(suspend_state_t state)
604 : {
605 : int error;
606 :
607 0 : if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
608 : return -EINVAL;
609 :
610 0 : pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
611 0 : error = enter_state(state);
612 0 : if (error) {
613 0 : suspend_stats.fail++;
614 : dpm_save_failed_errno(error);
615 : } else {
616 0 : suspend_stats.success++;
617 : }
618 0 : pr_info("suspend exit\n");
619 0 : return error;
620 : }
621 : EXPORT_SYMBOL(pm_suspend);
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