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 : unsigned int sleep_flags;
79 :
80 0 : sleep_flags = lock_system_sleep();
81 0 : s2idle_ops = ops;
82 0 : unlock_system_sleep(sleep_flags);
83 0 : }
84 :
85 : static void s2idle_begin(void)
86 : {
87 0 : s2idle_state = S2IDLE_STATE_NONE;
88 : }
89 :
90 0 : static void s2idle_enter(void)
91 : {
92 0 : trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
93 :
94 0 : raw_spin_lock_irq(&s2idle_lock);
95 0 : if (pm_wakeup_pending())
96 : goto out;
97 :
98 0 : s2idle_state = S2IDLE_STATE_ENTER;
99 0 : raw_spin_unlock_irq(&s2idle_lock);
100 :
101 : cpus_read_lock();
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 0 : swait_event_exclusive(s2idle_wait_head,
107 : s2idle_state == S2IDLE_STATE_WAKE);
108 :
109 : cpus_read_unlock();
110 :
111 0 : raw_spin_lock_irq(&s2idle_lock);
112 :
113 : out:
114 0 : s2idle_state = S2IDLE_STATE_NONE;
115 0 : raw_spin_unlock_irq(&s2idle_lock);
116 :
117 0 : trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
118 0 : }
119 :
120 0 : static void s2idle_loop(void)
121 : {
122 : pm_pr_dbg("suspend-to-idle\n");
123 :
124 : /*
125 : * Suspend-to-idle equals:
126 : * frozen processes + suspended devices + idle processors.
127 : * Thus s2idle_enter() should be called right after all devices have
128 : * been suspended.
129 : *
130 : * Wakeups during the noirq suspend of devices may be spurious, so try
131 : * to avoid them upfront.
132 : */
133 : for (;;) {
134 0 : if (s2idle_ops && s2idle_ops->wake) {
135 0 : if (s2idle_ops->wake())
136 : break;
137 0 : } else if (pm_wakeup_pending()) {
138 : break;
139 : }
140 :
141 0 : if (s2idle_ops && s2idle_ops->check)
142 0 : s2idle_ops->check();
143 :
144 0 : s2idle_enter();
145 : }
146 :
147 : pm_pr_dbg("resume from suspend-to-idle\n");
148 0 : }
149 :
150 0 : void s2idle_wake(void)
151 : {
152 : unsigned long flags;
153 :
154 0 : raw_spin_lock_irqsave(&s2idle_lock, flags);
155 0 : if (s2idle_state > S2IDLE_STATE_NONE) {
156 0 : s2idle_state = S2IDLE_STATE_WAKE;
157 0 : swake_up_one(&s2idle_wait_head);
158 : }
159 0 : raw_spin_unlock_irqrestore(&s2idle_lock, flags);
160 0 : }
161 : EXPORT_SYMBOL_GPL(s2idle_wake);
162 :
163 : static bool valid_state(suspend_state_t state)
164 : {
165 : /*
166 : * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
167 : * support and need to be valid to the low-level implementation.
168 : *
169 : * No ->valid() or ->enter() callback implies that none are valid.
170 : */
171 3 : return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
172 1 : suspend_ops->enter;
173 : }
174 :
175 1 : void __init pm_states_init(void)
176 : {
177 : /* "mem" and "freeze" are always present in /sys/power/state. */
178 1 : pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
179 1 : pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
180 : /*
181 : * Suspend-to-idle should be supported even without any suspend_ops,
182 : * initialize mem_sleep_states[] accordingly here.
183 : */
184 1 : mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
185 1 : }
186 :
187 0 : static int __init mem_sleep_default_setup(char *str)
188 : {
189 : suspend_state_t state;
190 :
191 0 : for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
192 0 : if (mem_sleep_labels[state] &&
193 0 : !strcmp(str, mem_sleep_labels[state])) {
194 0 : mem_sleep_default = state;
195 0 : break;
196 : }
197 :
198 0 : return 1;
199 : }
200 : __setup("mem_sleep_default=", mem_sleep_default_setup);
201 :
202 : /**
203 : * suspend_set_ops - Set the global suspend method table.
204 : * @ops: Suspend operations to use.
205 : */
206 1 : void suspend_set_ops(const struct platform_suspend_ops *ops)
207 : {
208 : unsigned int sleep_flags;
209 :
210 1 : sleep_flags = lock_system_sleep();
211 :
212 1 : suspend_ops = ops;
213 :
214 1 : if (valid_state(PM_SUSPEND_STANDBY)) {
215 0 : mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
216 0 : pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
217 0 : if (mem_sleep_default == PM_SUSPEND_STANDBY)
218 0 : mem_sleep_current = PM_SUSPEND_STANDBY;
219 : }
220 1 : if (valid_state(PM_SUSPEND_MEM)) {
221 1 : mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
222 1 : if (mem_sleep_default >= PM_SUSPEND_MEM)
223 1 : mem_sleep_current = PM_SUSPEND_MEM;
224 : }
225 :
226 1 : unlock_system_sleep(sleep_flags);
227 1 : }
228 : EXPORT_SYMBOL_GPL(suspend_set_ops);
229 :
230 : /**
231 : * suspend_valid_only_mem - Generic memory-only valid callback.
232 : * @state: Target system sleep state.
233 : *
234 : * Platform drivers that implement mem suspend only and only need to check for
235 : * that in their .valid() callback can use this instead of rolling their own
236 : * .valid() callback.
237 : */
238 0 : int suspend_valid_only_mem(suspend_state_t state)
239 : {
240 0 : return state == PM_SUSPEND_MEM;
241 : }
242 : EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
243 :
244 0 : static bool sleep_state_supported(suspend_state_t state)
245 : {
246 0 : return state == PM_SUSPEND_TO_IDLE ||
247 0 : (valid_state(state) && !cxl_mem_active());
248 : }
249 :
250 : static int platform_suspend_prepare(suspend_state_t state)
251 : {
252 0 : return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
253 0 : suspend_ops->prepare() : 0;
254 : }
255 :
256 : static int platform_suspend_prepare_late(suspend_state_t state)
257 : {
258 0 : return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
259 0 : s2idle_ops->prepare() : 0;
260 : }
261 :
262 0 : static int platform_suspend_prepare_noirq(suspend_state_t state)
263 : {
264 0 : if (state == PM_SUSPEND_TO_IDLE)
265 0 : return s2idle_ops && s2idle_ops->prepare_late ?
266 0 : s2idle_ops->prepare_late() : 0;
267 :
268 0 : return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
269 : }
270 :
271 0 : static void platform_resume_noirq(suspend_state_t state)
272 : {
273 0 : if (state == PM_SUSPEND_TO_IDLE) {
274 0 : if (s2idle_ops && s2idle_ops->restore_early)
275 0 : s2idle_ops->restore_early();
276 0 : } else if (suspend_ops->wake) {
277 0 : suspend_ops->wake();
278 : }
279 0 : }
280 :
281 : static void platform_resume_early(suspend_state_t state)
282 : {
283 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
284 0 : s2idle_ops->restore();
285 : }
286 :
287 : static void platform_resume_finish(suspend_state_t state)
288 : {
289 0 : if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
290 0 : suspend_ops->finish();
291 : }
292 :
293 0 : static int platform_suspend_begin(suspend_state_t state)
294 : {
295 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
296 0 : return s2idle_ops->begin();
297 0 : else if (suspend_ops && suspend_ops->begin)
298 0 : return suspend_ops->begin(state);
299 : else
300 : return 0;
301 : }
302 :
303 0 : static void platform_resume_end(suspend_state_t state)
304 : {
305 0 : if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
306 0 : s2idle_ops->end();
307 0 : else if (suspend_ops && suspend_ops->end)
308 0 : suspend_ops->end();
309 0 : }
310 :
311 : static void platform_recover(suspend_state_t state)
312 : {
313 0 : if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
314 0 : suspend_ops->recover();
315 : }
316 :
317 : static bool platform_suspend_again(suspend_state_t state)
318 : {
319 0 : return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
320 0 : suspend_ops->suspend_again() : false;
321 : }
322 :
323 : #ifdef CONFIG_PM_DEBUG
324 : static unsigned int pm_test_delay = 5;
325 : module_param(pm_test_delay, uint, 0644);
326 : MODULE_PARM_DESC(pm_test_delay,
327 : "Number of seconds to wait before resuming from suspend test");
328 : #endif
329 :
330 : static int suspend_test(int level)
331 : {
332 : #ifdef CONFIG_PM_DEBUG
333 : if (pm_test_level == level) {
334 : pr_info("suspend debug: Waiting for %d second(s).\n",
335 : pm_test_delay);
336 : mdelay(pm_test_delay * 1000);
337 : return 1;
338 : }
339 : #endif /* !CONFIG_PM_DEBUG */
340 : return 0;
341 : }
342 :
343 : /**
344 : * suspend_prepare - Prepare for entering system sleep state.
345 : * @state: Target system sleep state.
346 : *
347 : * Common code run for every system sleep state that can be entered (except for
348 : * hibernation). Run suspend notifiers, allocate the "suspend" console and
349 : * freeze processes.
350 : */
351 0 : static int suspend_prepare(suspend_state_t state)
352 : {
353 : int error;
354 :
355 0 : if (!sleep_state_supported(state))
356 : return -EPERM;
357 :
358 : pm_prepare_console();
359 :
360 0 : error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
361 0 : if (error)
362 : goto Restore;
363 :
364 0 : trace_suspend_resume(TPS("freeze_processes"), 0, true);
365 0 : error = suspend_freeze_processes();
366 0 : trace_suspend_resume(TPS("freeze_processes"), 0, false);
367 0 : if (!error)
368 : return 0;
369 :
370 0 : suspend_stats.failed_freeze++;
371 0 : dpm_save_failed_step(SUSPEND_FREEZE);
372 0 : pm_notifier_call_chain(PM_POST_SUSPEND);
373 : Restore:
374 : pm_restore_console();
375 : return error;
376 : }
377 :
378 : /* default implementation */
379 0 : void __weak arch_suspend_disable_irqs(void)
380 : {
381 : local_irq_disable();
382 0 : }
383 :
384 : /* default implementation */
385 0 : void __weak arch_suspend_enable_irqs(void)
386 : {
387 : local_irq_enable();
388 0 : }
389 :
390 : /**
391 : * suspend_enter - Make the system enter the given sleep state.
392 : * @state: System sleep state to enter.
393 : * @wakeup: Returns information that the sleep state should not be re-entered.
394 : *
395 : * This function should be called after devices have been suspended.
396 : */
397 0 : static int suspend_enter(suspend_state_t state, bool *wakeup)
398 : {
399 : int error;
400 :
401 0 : error = platform_suspend_prepare(state);
402 0 : if (error)
403 : goto Platform_finish;
404 :
405 0 : error = dpm_suspend_late(PMSG_SUSPEND);
406 0 : if (error) {
407 0 : pr_err("late suspend of devices failed\n");
408 0 : goto Platform_finish;
409 : }
410 0 : error = platform_suspend_prepare_late(state);
411 0 : if (error)
412 : goto Devices_early_resume;
413 :
414 0 : error = dpm_suspend_noirq(PMSG_SUSPEND);
415 0 : if (error) {
416 0 : pr_err("noirq suspend of devices failed\n");
417 0 : goto Platform_early_resume;
418 : }
419 0 : error = platform_suspend_prepare_noirq(state);
420 0 : if (error)
421 : goto Platform_wake;
422 :
423 0 : if (suspend_test(TEST_PLATFORM))
424 : goto Platform_wake;
425 :
426 0 : if (state == PM_SUSPEND_TO_IDLE) {
427 0 : s2idle_loop();
428 0 : goto Platform_wake;
429 : }
430 :
431 0 : error = pm_sleep_disable_secondary_cpus();
432 0 : if (error || suspend_test(TEST_CPUS))
433 : goto Enable_cpus;
434 :
435 0 : arch_suspend_disable_irqs();
436 0 : BUG_ON(!irqs_disabled());
437 :
438 0 : system_state = SYSTEM_SUSPEND;
439 :
440 0 : error = syscore_suspend();
441 0 : if (!error) {
442 0 : *wakeup = pm_wakeup_pending();
443 0 : if (!(suspend_test(TEST_CORE) || *wakeup)) {
444 0 : trace_suspend_resume(TPS("machine_suspend"),
445 : state, true);
446 0 : error = suspend_ops->enter(state);
447 : trace_suspend_resume(TPS("machine_suspend"),
448 : state, false);
449 : } else if (*wakeup) {
450 : error = -EBUSY;
451 : }
452 0 : syscore_resume();
453 : }
454 :
455 0 : system_state = SYSTEM_RUNNING;
456 :
457 0 : arch_suspend_enable_irqs();
458 0 : BUG_ON(irqs_disabled());
459 :
460 : Enable_cpus:
461 : pm_sleep_enable_secondary_cpus();
462 :
463 : Platform_wake:
464 0 : platform_resume_noirq(state);
465 0 : dpm_resume_noirq(PMSG_RESUME);
466 :
467 : Platform_early_resume:
468 : platform_resume_early(state);
469 :
470 : Devices_early_resume:
471 0 : dpm_resume_early(PMSG_RESUME);
472 :
473 : Platform_finish:
474 0 : platform_resume_finish(state);
475 0 : return error;
476 : }
477 :
478 : /**
479 : * suspend_devices_and_enter - Suspend devices and enter system sleep state.
480 : * @state: System sleep state to enter.
481 : */
482 0 : int suspend_devices_and_enter(suspend_state_t state)
483 : {
484 : int error;
485 0 : bool wakeup = false;
486 :
487 0 : if (!sleep_state_supported(state))
488 : return -ENOSYS;
489 :
490 0 : pm_suspend_target_state = state;
491 :
492 0 : if (state == PM_SUSPEND_TO_IDLE)
493 : pm_set_suspend_no_platform();
494 :
495 0 : error = platform_suspend_begin(state);
496 0 : if (error)
497 : goto Close;
498 :
499 0 : suspend_console();
500 : suspend_test_start();
501 0 : error = dpm_suspend_start(PMSG_SUSPEND);
502 0 : if (error) {
503 0 : pr_err("Some devices failed to suspend, or early wake event detected\n");
504 : goto Recover_platform;
505 : }
506 : suspend_test_finish("suspend devices");
507 : if (suspend_test(TEST_DEVICES))
508 : goto Recover_platform;
509 :
510 : do {
511 0 : error = suspend_enter(state, &wakeup);
512 0 : } while (!error && !wakeup && platform_suspend_again(state));
513 :
514 : Resume_devices:
515 : suspend_test_start();
516 0 : dpm_resume_end(PMSG_RESUME);
517 0 : suspend_test_finish("resume devices");
518 0 : trace_suspend_resume(TPS("resume_console"), state, true);
519 0 : resume_console();
520 : trace_suspend_resume(TPS("resume_console"), state, false);
521 :
522 : Close:
523 0 : platform_resume_end(state);
524 0 : pm_suspend_target_state = PM_SUSPEND_ON;
525 0 : return error;
526 :
527 : Recover_platform:
528 : platform_recover(state);
529 : goto Resume_devices;
530 : }
531 :
532 : /**
533 : * suspend_finish - Clean up before finishing the suspend sequence.
534 : *
535 : * Call platform code to clean up, restart processes, and free the console that
536 : * we've allocated. This routine is not called for hibernation.
537 : */
538 : static void suspend_finish(void)
539 : {
540 : suspend_thaw_processes();
541 0 : pm_notifier_call_chain(PM_POST_SUSPEND);
542 : pm_restore_console();
543 : }
544 :
545 : /**
546 : * enter_state - Do common work needed to enter system sleep state.
547 : * @state: System sleep state to enter.
548 : *
549 : * Make sure that no one else is trying to put the system into a sleep state.
550 : * Fail if that's not the case. Otherwise, prepare for system suspend, make the
551 : * system enter the given sleep state and clean up after wakeup.
552 : */
553 0 : static int enter_state(suspend_state_t state)
554 : {
555 : int error;
556 :
557 0 : trace_suspend_resume(TPS("suspend_enter"), state, true);
558 0 : if (state == PM_SUSPEND_TO_IDLE) {
559 : #ifdef CONFIG_PM_DEBUG
560 : if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
561 : pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
562 : return -EAGAIN;
563 : }
564 : #endif
565 0 : } else if (!valid_state(state)) {
566 : return -EINVAL;
567 : }
568 0 : if (!mutex_trylock(&system_transition_mutex))
569 : return -EBUSY;
570 :
571 0 : if (state == PM_SUSPEND_TO_IDLE)
572 : s2idle_begin();
573 :
574 0 : if (sync_on_suspend_enabled) {
575 0 : trace_suspend_resume(TPS("sync_filesystems"), 0, true);
576 0 : ksys_sync_helper();
577 : trace_suspend_resume(TPS("sync_filesystems"), 0, false);
578 : }
579 :
580 : pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
581 : pm_suspend_clear_flags();
582 0 : error = suspend_prepare(state);
583 0 : if (error)
584 : goto Unlock;
585 :
586 0 : if (suspend_test(TEST_FREEZER))
587 : goto Finish;
588 :
589 0 : trace_suspend_resume(TPS("suspend_enter"), state, false);
590 : pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
591 0 : pm_restrict_gfp_mask();
592 0 : error = suspend_devices_and_enter(state);
593 0 : pm_restore_gfp_mask();
594 :
595 : Finish:
596 0 : events_check_enabled = false;
597 : pm_pr_dbg("Finishing wakeup.\n");
598 : suspend_finish();
599 : Unlock:
600 0 : mutex_unlock(&system_transition_mutex);
601 0 : return error;
602 : }
603 :
604 : /**
605 : * pm_suspend - Externally visible function for suspending the system.
606 : * @state: System sleep state to enter.
607 : *
608 : * Check if the value of @state represents one of the supported states,
609 : * execute enter_state() and update system suspend statistics.
610 : */
611 0 : int pm_suspend(suspend_state_t state)
612 : {
613 : int error;
614 :
615 0 : if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
616 : return -EINVAL;
617 :
618 0 : pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
619 0 : error = enter_state(state);
620 0 : if (error) {
621 0 : suspend_stats.fail++;
622 : dpm_save_failed_errno(error);
623 : } else {
624 0 : suspend_stats.success++;
625 : }
626 0 : pr_info("suspend exit\n");
627 0 : return error;
628 : }
629 : EXPORT_SYMBOL(pm_suspend);
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