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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/*
2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
7 *
8 * This file is released under the GPLv2.
9 */
10
11#include <linux/string.h>
12#include <linux/delay.h>
13#include <linux/errno.h>
14#include <linux/init.h>
15#include <linux/console.h>
16#include <linux/cpu.h>
17#include <linux/cpuidle.h>
18#include <linux/syscalls.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/ftrace.h>
29#include <trace/events/power.h>
30#include <linux/compiler.h>
31#include <linux/moduleparam.h>
32
33#include "power.h"
34
35const char * const pm_labels[] = {
36 [PM_SUSPEND_FREEZE] = "freeze",
37 [PM_SUSPEND_STANDBY] = "standby",
38 [PM_SUSPEND_MEM] = "mem",
39};
40const char *pm_states[PM_SUSPEND_MAX];
41static const char * const mem_sleep_labels[] = {
42 [PM_SUSPEND_FREEZE] = "s2idle",
43 [PM_SUSPEND_STANDBY] = "shallow",
44 [PM_SUSPEND_MEM] = "deep",
45};
46const char *mem_sleep_states[PM_SUSPEND_MAX];
47
48suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
49static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
50
51unsigned int pm_suspend_global_flags;
52EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
53
54static const struct platform_suspend_ops *suspend_ops;
55static const struct platform_freeze_ops *freeze_ops;
56static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
57
58enum freeze_state __read_mostly suspend_freeze_state;
59static DEFINE_SPINLOCK(suspend_freeze_lock);
60
61void freeze_set_ops(const struct platform_freeze_ops *ops)
62{
63 lock_system_sleep();
64 freeze_ops = ops;
65 unlock_system_sleep();
66}
67
68static void freeze_begin(void)
69{
70 suspend_freeze_state = FREEZE_STATE_NONE;
71}
72
73static void freeze_enter(void)
74{
75 spin_lock_irq(&suspend_freeze_lock);
76 if (pm_wakeup_pending())
77 goto out;
78
79 suspend_freeze_state = FREEZE_STATE_ENTER;
80 spin_unlock_irq(&suspend_freeze_lock);
81
82 get_online_cpus();
83 cpuidle_resume();
84
85 /* Push all the CPUs into the idle loop. */
86 wake_up_all_idle_cpus();
87 pr_debug("PM: suspend-to-idle\n");
88 /* Make the current CPU wait so it can enter the idle loop too. */
89 wait_event(suspend_freeze_wait_head,
90 suspend_freeze_state == FREEZE_STATE_WAKE);
91 pr_debug("PM: resume from suspend-to-idle\n");
92
93 cpuidle_pause();
94 put_online_cpus();
95
96 spin_lock_irq(&suspend_freeze_lock);
97
98 out:
99 suspend_freeze_state = FREEZE_STATE_NONE;
100 spin_unlock_irq(&suspend_freeze_lock);
101}
102
103void freeze_wake(void)
104{
105 unsigned long flags;
106
107 spin_lock_irqsave(&suspend_freeze_lock, flags);
108 if (suspend_freeze_state > FREEZE_STATE_NONE) {
109 suspend_freeze_state = FREEZE_STATE_WAKE;
110 wake_up(&suspend_freeze_wait_head);
111 }
112 spin_unlock_irqrestore(&suspend_freeze_lock, flags);
113}
114EXPORT_SYMBOL_GPL(freeze_wake);
115
116static bool valid_state(suspend_state_t state)
117{
118 /*
119 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
120 * support and need to be valid to the low level
121 * implementation, no valid callback implies that none are valid.
122 */
123 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
124}
125
126void __init pm_states_init(void)
127{
128 /* "mem" and "freeze" are always present in /sys/power/state. */
129 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
130 pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE];
131 /*
132 * Suspend-to-idle should be supported even without any suspend_ops,
133 * initialize mem_sleep_states[] accordingly here.
134 */
135 mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE];
136}
137
138static int __init mem_sleep_default_setup(char *str)
139{
140 suspend_state_t state;
141
142 for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++)
143 if (mem_sleep_labels[state] &&
144 !strcmp(str, mem_sleep_labels[state])) {
145 mem_sleep_default = state;
146 break;
147 }
148
149 return 1;
150}
151__setup("mem_sleep_default=", mem_sleep_default_setup);
152
153/**
154 * suspend_set_ops - Set the global suspend method table.
155 * @ops: Suspend operations to use.
156 */
157void suspend_set_ops(const struct platform_suspend_ops *ops)
158{
159 lock_system_sleep();
160
161 suspend_ops = ops;
162
163 if (valid_state(PM_SUSPEND_STANDBY)) {
164 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
165 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
166 if (mem_sleep_default == PM_SUSPEND_STANDBY)
167 mem_sleep_current = PM_SUSPEND_STANDBY;
168 }
169 if (valid_state(PM_SUSPEND_MEM)) {
170 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
171 if (mem_sleep_default == PM_SUSPEND_MEM)
172 mem_sleep_current = PM_SUSPEND_MEM;
173 }
174
175 unlock_system_sleep();
176}
177EXPORT_SYMBOL_GPL(suspend_set_ops);
178
179/**
180 * suspend_valid_only_mem - Generic memory-only valid callback.
181 *
182 * Platform drivers that implement mem suspend only and only need to check for
183 * that in their .valid() callback can use this instead of rolling their own
184 * .valid() callback.
185 */
186int suspend_valid_only_mem(suspend_state_t state)
187{
188 return state == PM_SUSPEND_MEM;
189}
190EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
191
192static bool sleep_state_supported(suspend_state_t state)
193{
194 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
195}
196
197static int platform_suspend_prepare(suspend_state_t state)
198{
199 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
200 suspend_ops->prepare() : 0;
201}
202
203static int platform_suspend_prepare_late(suspend_state_t state)
204{
205 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
206 freeze_ops->prepare() : 0;
207}
208
209static int platform_suspend_prepare_noirq(suspend_state_t state)
210{
211 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
212 suspend_ops->prepare_late() : 0;
213}
214
215static void platform_resume_noirq(suspend_state_t state)
216{
217 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
218 suspend_ops->wake();
219}
220
221static void platform_resume_early(suspend_state_t state)
222{
223 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
224 freeze_ops->restore();
225}
226
227static void platform_resume_finish(suspend_state_t state)
228{
229 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
230 suspend_ops->finish();
231}
232
233static int platform_suspend_begin(suspend_state_t state)
234{
235 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
236 return freeze_ops->begin();
237 else if (suspend_ops && suspend_ops->begin)
238 return suspend_ops->begin(state);
239 else
240 return 0;
241}
242
243static void platform_resume_end(suspend_state_t state)
244{
245 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
246 freeze_ops->end();
247 else if (suspend_ops && suspend_ops->end)
248 suspend_ops->end();
249}
250
251static void platform_recover(suspend_state_t state)
252{
253 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
254 suspend_ops->recover();
255}
256
257static bool platform_suspend_again(suspend_state_t state)
258{
259 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
260 suspend_ops->suspend_again() : false;
261}
262
263#ifdef CONFIG_PM_DEBUG
264static unsigned int pm_test_delay = 5;
265module_param(pm_test_delay, uint, 0644);
266MODULE_PARM_DESC(pm_test_delay,
267 "Number of seconds to wait before resuming from suspend test");
268#endif
269
270static int suspend_test(int level)
271{
272#ifdef CONFIG_PM_DEBUG
273 if (pm_test_level == level) {
274 pr_info("suspend debug: Waiting for %d second(s).\n",
275 pm_test_delay);
276 mdelay(pm_test_delay * 1000);
277 return 1;
278 }
279#endif /* !CONFIG_PM_DEBUG */
280 return 0;
281}
282
283/**
284 * suspend_prepare - Prepare for entering system sleep state.
285 *
286 * Common code run for every system sleep state that can be entered (except for
287 * hibernation). Run suspend notifiers, allocate the "suspend" console and
288 * freeze processes.
289 */
290static int suspend_prepare(suspend_state_t state)
291{
292 int error, nr_calls = 0;
293
294 if (!sleep_state_supported(state))
295 return -EPERM;
296
297 pm_prepare_console();
298
299 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
300 if (error) {
301 nr_calls--;
302 goto Finish;
303 }
304
305 trace_suspend_resume(TPS("freeze_processes"), 0, true);
306 error = suspend_freeze_processes();
307 trace_suspend_resume(TPS("freeze_processes"), 0, false);
308 if (!error)
309 return 0;
310
311 suspend_stats.failed_freeze++;
312 dpm_save_failed_step(SUSPEND_FREEZE);
313 Finish:
314 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
315 pm_restore_console();
316 return error;
317}
318
319/* default implementation */
320void __weak arch_suspend_disable_irqs(void)
321{
322 local_irq_disable();
323}
324
325/* default implementation */
326void __weak arch_suspend_enable_irqs(void)
327{
328 local_irq_enable();
329}
330
331/**
332 * suspend_enter - Make the system enter the given sleep state.
333 * @state: System sleep state to enter.
334 * @wakeup: Returns information that the sleep state should not be re-entered.
335 *
336 * This function should be called after devices have been suspended.
337 */
338static int suspend_enter(suspend_state_t state, bool *wakeup)
339{
340 int error;
341
342 error = platform_suspend_prepare(state);
343 if (error)
344 goto Platform_finish;
345
346 error = dpm_suspend_late(PMSG_SUSPEND);
347 if (error) {
348 pr_err("PM: late suspend of devices failed\n");
349 goto Platform_finish;
350 }
351 error = platform_suspend_prepare_late(state);
352 if (error)
353 goto Devices_early_resume;
354
355 error = dpm_suspend_noirq(PMSG_SUSPEND);
356 if (error) {
357 pr_err("PM: noirq suspend of devices failed\n");
358 goto Platform_early_resume;
359 }
360 error = platform_suspend_prepare_noirq(state);
361 if (error)
362 goto Platform_wake;
363
364 if (suspend_test(TEST_PLATFORM))
365 goto Platform_wake;
366
367 /*
368 * PM_SUSPEND_FREEZE equals
369 * frozen processes + suspended devices + idle processors.
370 * Thus we should invoke freeze_enter() soon after
371 * all the devices are suspended.
372 */
373 if (state == PM_SUSPEND_FREEZE) {
374 trace_suspend_resume(TPS("machine_suspend"), state, true);
375 freeze_enter();
376 trace_suspend_resume(TPS("machine_suspend"), state, false);
377 goto Platform_wake;
378 }
379
380 error = disable_nonboot_cpus();
381 if (error || suspend_test(TEST_CPUS))
382 goto Enable_cpus;
383
384 arch_suspend_disable_irqs();
385 BUG_ON(!irqs_disabled());
386
387 error = syscore_suspend();
388 if (!error) {
389 *wakeup = pm_wakeup_pending();
390 if (!(suspend_test(TEST_CORE) || *wakeup)) {
391 trace_suspend_resume(TPS("machine_suspend"),
392 state, true);
393 error = suspend_ops->enter(state);
394 trace_suspend_resume(TPS("machine_suspend"),
395 state, false);
396 events_check_enabled = false;
397 } else if (*wakeup) {
398 error = -EBUSY;
399 }
400 syscore_resume();
401 }
402
403 arch_suspend_enable_irqs();
404 BUG_ON(irqs_disabled());
405
406 Enable_cpus:
407 enable_nonboot_cpus();
408
409 Platform_wake:
410 platform_resume_noirq(state);
411 dpm_resume_noirq(PMSG_RESUME);
412
413 Platform_early_resume:
414 platform_resume_early(state);
415
416 Devices_early_resume:
417 dpm_resume_early(PMSG_RESUME);
418
419 Platform_finish:
420 platform_resume_finish(state);
421 return error;
422}
423
424/**
425 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
426 * @state: System sleep state to enter.
427 */
428int suspend_devices_and_enter(suspend_state_t state)
429{
430 int error;
431 bool wakeup = false;
432
433 if (!sleep_state_supported(state))
434 return -ENOSYS;
435
436 error = platform_suspend_begin(state);
437 if (error)
438 goto Close;
439
440 suspend_console();
441 suspend_test_start();
442 error = dpm_suspend_start(PMSG_SUSPEND);
443 if (error) {
444 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
445 goto Recover_platform;
446 }
447 suspend_test_finish("suspend devices");
448 if (suspend_test(TEST_DEVICES))
449 goto Recover_platform;
450
451 do {
452 error = suspend_enter(state, &wakeup);
453 } while (!error && !wakeup && platform_suspend_again(state));
454
455 Resume_devices:
456 suspend_test_start();
457 dpm_resume_end(PMSG_RESUME);
458 suspend_test_finish("resume devices");
459 trace_suspend_resume(TPS("resume_console"), state, true);
460 resume_console();
461 trace_suspend_resume(TPS("resume_console"), state, false);
462
463 Close:
464 platform_resume_end(state);
465 return error;
466
467 Recover_platform:
468 platform_recover(state);
469 goto Resume_devices;
470}
471
472/**
473 * suspend_finish - Clean up before finishing the suspend sequence.
474 *
475 * Call platform code to clean up, restart processes, and free the console that
476 * we've allocated. This routine is not called for hibernation.
477 */
478static void suspend_finish(void)
479{
480 suspend_thaw_processes();
481 pm_notifier_call_chain(PM_POST_SUSPEND);
482 pm_restore_console();
483}
484
485/**
486 * enter_state - Do common work needed to enter system sleep state.
487 * @state: System sleep state to enter.
488 *
489 * Make sure that no one else is trying to put the system into a sleep state.
490 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
491 * system enter the given sleep state and clean up after wakeup.
492 */
493static int enter_state(suspend_state_t state)
494{
495 int error;
496
497 trace_suspend_resume(TPS("suspend_enter"), state, true);
498 if (state == PM_SUSPEND_FREEZE) {
499#ifdef CONFIG_PM_DEBUG
500 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
501 pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
502 return -EAGAIN;
503 }
504#endif
505 } else if (!valid_state(state)) {
506 return -EINVAL;
507 }
508 if (!mutex_trylock(&pm_mutex))
509 return -EBUSY;
510
511 if (state == PM_SUSPEND_FREEZE)
512 freeze_begin();
513
514#ifndef CONFIG_SUSPEND_SKIP_SYNC
515 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
516 pr_info("PM: Syncing filesystems ... ");
517 sys_sync();
518 pr_cont("done.\n");
519 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
520#endif
521
522 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
523 pm_suspend_clear_flags();
524 error = suspend_prepare(state);
525 if (error)
526 goto Unlock;
527
528 if (suspend_test(TEST_FREEZER))
529 goto Finish;
530
531 trace_suspend_resume(TPS("suspend_enter"), state, false);
532 pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
533 pm_restrict_gfp_mask();
534 error = suspend_devices_and_enter(state);
535 pm_restore_gfp_mask();
536
537 Finish:
538 pr_debug("PM: Finishing wakeup.\n");
539 suspend_finish();
540 Unlock:
541 mutex_unlock(&pm_mutex);
542 return error;
543}
544
545/**
546 * pm_suspend - Externally visible function for suspending the system.
547 * @state: System sleep state to enter.
548 *
549 * Check if the value of @state represents one of the supported states,
550 * execute enter_state() and update system suspend statistics.
551 */
552int pm_suspend(suspend_state_t state)
553{
554 int error;
555
556 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
557 return -EINVAL;
558
559 error = enter_state(state);
560 if (error) {
561 suspend_stats.fail++;
562 dpm_save_failed_errno(error);
563 } else {
564 suspend_stats.success++;
565 }
566 return error;
567}
568EXPORT_SYMBOL(pm_suspend);