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