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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 lock_system_sleep();
79 s2idle_ops = ops;
80 unlock_system_sleep();
81}
82
83static void s2idle_begin(void)
84{
85 s2idle_state = S2IDLE_STATE_NONE;
86}
87
88static void s2idle_enter(void)
89{
90 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
91
92 raw_spin_lock_irq(&s2idle_lock);
93 if (pm_wakeup_pending())
94 goto out;
95
96 s2idle_state = S2IDLE_STATE_ENTER;
97 raw_spin_unlock_irq(&s2idle_lock);
98
99 get_online_cpus();
100 cpuidle_resume();
101
102 /* Push all the CPUs into the idle loop. */
103 wake_up_all_idle_cpus();
104 /* Make the current CPU wait so it can enter the idle loop too. */
105 swait_event_exclusive(s2idle_wait_head,
106 s2idle_state == S2IDLE_STATE_WAKE);
107
108 cpuidle_pause();
109 put_online_cpus();
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 s2idle_ops->wake();
136
137 if (pm_wakeup_pending())
138 break;
139
140 pm_wakeup_clear(false);
141
142 s2idle_enter();
143 }
144
145 pm_pr_dbg("resume from suspend-to-idle\n");
146}
147
148void s2idle_wake(void)
149{
150 unsigned long flags;
151
152 raw_spin_lock_irqsave(&s2idle_lock, flags);
153 if (s2idle_state > S2IDLE_STATE_NONE) {
154 s2idle_state = S2IDLE_STATE_WAKE;
155 swake_up_one(&s2idle_wait_head);
156 }
157 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
158}
159EXPORT_SYMBOL_GPL(s2idle_wake);
160
161static bool valid_state(suspend_state_t state)
162{
163 /*
164 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
165 * support and need to be valid to the low level
166 * implementation, no valid callback implies that none are valid.
167 */
168 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
169}
170
171void __init pm_states_init(void)
172{
173 /* "mem" and "freeze" are always present in /sys/power/state. */
174 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
175 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
176 /*
177 * Suspend-to-idle should be supported even without any suspend_ops,
178 * initialize mem_sleep_states[] accordingly here.
179 */
180 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
181}
182
183static int __init mem_sleep_default_setup(char *str)
184{
185 suspend_state_t state;
186
187 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
188 if (mem_sleep_labels[state] &&
189 !strcmp(str, mem_sleep_labels[state])) {
190 mem_sleep_default = state;
191 break;
192 }
193
194 return 1;
195}
196__setup("mem_sleep_default=", mem_sleep_default_setup);
197
198/**
199 * suspend_set_ops - Set the global suspend method table.
200 * @ops: Suspend operations to use.
201 */
202void suspend_set_ops(const struct platform_suspend_ops *ops)
203{
204 lock_system_sleep();
205
206 suspend_ops = ops;
207
208 if (valid_state(PM_SUSPEND_STANDBY)) {
209 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
210 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
211 if (mem_sleep_default == PM_SUSPEND_STANDBY)
212 mem_sleep_current = PM_SUSPEND_STANDBY;
213 }
214 if (valid_state(PM_SUSPEND_MEM)) {
215 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
216 if (mem_sleep_default >= PM_SUSPEND_MEM)
217 mem_sleep_current = PM_SUSPEND_MEM;
218 }
219
220 unlock_system_sleep();
221}
222EXPORT_SYMBOL_GPL(suspend_set_ops);
223
224/**
225 * suspend_valid_only_mem - Generic memory-only valid callback.
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 */
231int suspend_valid_only_mem(suspend_state_t state)
232{
233 return state == PM_SUSPEND_MEM;
234}
235EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
236
237static bool sleep_state_supported(suspend_state_t state)
238{
239 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
240}
241
242static int platform_suspend_prepare(suspend_state_t state)
243{
244 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
245 suspend_ops->prepare() : 0;
246}
247
248static int platform_suspend_prepare_late(suspend_state_t state)
249{
250 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
251 s2idle_ops->prepare() : 0;
252}
253
254static int platform_suspend_prepare_noirq(suspend_state_t state)
255{
256 if (state == PM_SUSPEND_TO_IDLE)
257 return s2idle_ops && s2idle_ops->prepare_late ?
258 s2idle_ops->prepare_late() : 0;
259
260 return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
261}
262
263static void platform_resume_noirq(suspend_state_t state)
264{
265 if (state == PM_SUSPEND_TO_IDLE) {
266 if (s2idle_ops && s2idle_ops->restore_early)
267 s2idle_ops->restore_early();
268 } else if (suspend_ops->wake) {
269 suspend_ops->wake();
270 }
271}
272
273static void platform_resume_early(suspend_state_t state)
274{
275 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
276 s2idle_ops->restore();
277}
278
279static void platform_resume_finish(suspend_state_t state)
280{
281 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
282 suspend_ops->finish();
283}
284
285static int platform_suspend_begin(suspend_state_t state)
286{
287 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
288 return s2idle_ops->begin();
289 else if (suspend_ops && suspend_ops->begin)
290 return suspend_ops->begin(state);
291 else
292 return 0;
293}
294
295static void platform_resume_end(suspend_state_t state)
296{
297 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
298 s2idle_ops->end();
299 else if (suspend_ops && suspend_ops->end)
300 suspend_ops->end();
301}
302
303static void platform_recover(suspend_state_t state)
304{
305 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
306 suspend_ops->recover();
307}
308
309static bool platform_suspend_again(suspend_state_t state)
310{
311 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
312 suspend_ops->suspend_again() : false;
313}
314
315#ifdef CONFIG_PM_DEBUG
316static unsigned int pm_test_delay = 5;
317module_param(pm_test_delay, uint, 0644);
318MODULE_PARM_DESC(pm_test_delay,
319 "Number of seconds to wait before resuming from suspend test");
320#endif
321
322static 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 *
338 * Common code run for every system sleep state that can be entered (except for
339 * hibernation). Run suspend notifiers, allocate the "suspend" console and
340 * freeze processes.
341 */
342static int suspend_prepare(suspend_state_t state)
343{
344 int error, nr_calls = 0;
345
346 if (!sleep_state_supported(state))
347 return -EPERM;
348
349 pm_prepare_console();
350
351 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
352 if (error) {
353 nr_calls--;
354 goto Finish;
355 }
356
357 trace_suspend_resume(TPS("freeze_processes"), 0, true);
358 error = suspend_freeze_processes();
359 trace_suspend_resume(TPS("freeze_processes"), 0, false);
360 if (!error)
361 return 0;
362
363 suspend_stats.failed_freeze++;
364 dpm_save_failed_step(SUSPEND_FREEZE);
365 Finish:
366 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
367 pm_restore_console();
368 return error;
369}
370
371/* default implementation */
372void __weak arch_suspend_disable_irqs(void)
373{
374 local_irq_disable();
375}
376
377/* default implementation */
378void __weak arch_suspend_enable_irqs(void)
379{
380 local_irq_enable();
381}
382
383/**
384 * suspend_enter - Make the system enter the given sleep state.
385 * @state: System sleep state to enter.
386 * @wakeup: Returns information that the sleep state should not be re-entered.
387 *
388 * This function should be called after devices have been suspended.
389 */
390static int suspend_enter(suspend_state_t state, bool *wakeup)
391{
392 int error;
393
394 error = platform_suspend_prepare(state);
395 if (error)
396 goto Platform_finish;
397
398 error = dpm_suspend_late(PMSG_SUSPEND);
399 if (error) {
400 pr_err("late suspend of devices failed\n");
401 goto Platform_finish;
402 }
403 error = platform_suspend_prepare_late(state);
404 if (error)
405 goto Devices_early_resume;
406
407 error = dpm_suspend_noirq(PMSG_SUSPEND);
408 if (error) {
409 pr_err("noirq suspend of devices failed\n");
410 goto Platform_early_resume;
411 }
412 error = platform_suspend_prepare_noirq(state);
413 if (error)
414 goto Platform_wake;
415
416 if (suspend_test(TEST_PLATFORM))
417 goto Platform_wake;
418
419 if (state == PM_SUSPEND_TO_IDLE) {
420 s2idle_loop();
421 goto Platform_wake;
422 }
423
424 error = suspend_disable_secondary_cpus();
425 if (error || suspend_test(TEST_CPUS))
426 goto Enable_cpus;
427
428 arch_suspend_disable_irqs();
429 BUG_ON(!irqs_disabled());
430
431 system_state = SYSTEM_SUSPEND;
432
433 error = syscore_suspend();
434 if (!error) {
435 *wakeup = pm_wakeup_pending();
436 if (!(suspend_test(TEST_CORE) || *wakeup)) {
437 trace_suspend_resume(TPS("machine_suspend"),
438 state, true);
439 error = suspend_ops->enter(state);
440 trace_suspend_resume(TPS("machine_suspend"),
441 state, false);
442 } else if (*wakeup) {
443 error = -EBUSY;
444 }
445 syscore_resume();
446 }
447
448 system_state = SYSTEM_RUNNING;
449
450 arch_suspend_enable_irqs();
451 BUG_ON(irqs_disabled());
452
453 Enable_cpus:
454 suspend_enable_secondary_cpus();
455
456 Platform_wake:
457 platform_resume_noirq(state);
458 dpm_resume_noirq(PMSG_RESUME);
459
460 Platform_early_resume:
461 platform_resume_early(state);
462
463 Devices_early_resume:
464 dpm_resume_early(PMSG_RESUME);
465
466 Platform_finish:
467 platform_resume_finish(state);
468 return error;
469}
470
471/**
472 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
473 * @state: System sleep state to enter.
474 */
475int suspend_devices_and_enter(suspend_state_t state)
476{
477 int error;
478 bool wakeup = false;
479
480 if (!sleep_state_supported(state))
481 return -ENOSYS;
482
483 pm_suspend_target_state = state;
484
485 if (state == PM_SUSPEND_TO_IDLE)
486 pm_set_suspend_no_platform();
487
488 error = platform_suspend_begin(state);
489 if (error)
490 goto Close;
491
492 suspend_console();
493 suspend_test_start();
494 error = dpm_suspend_start(PMSG_SUSPEND);
495 if (error) {
496 pr_err("Some devices failed to suspend, or early wake event detected\n");
497 goto Recover_platform;
498 }
499 suspend_test_finish("suspend devices");
500 if (suspend_test(TEST_DEVICES))
501 goto Recover_platform;
502
503 do {
504 error = suspend_enter(state, &wakeup);
505 } while (!error && !wakeup && platform_suspend_again(state));
506
507 Resume_devices:
508 suspend_test_start();
509 dpm_resume_end(PMSG_RESUME);
510 suspend_test_finish("resume devices");
511 trace_suspend_resume(TPS("resume_console"), state, true);
512 resume_console();
513 trace_suspend_resume(TPS("resume_console"), state, false);
514
515 Close:
516 platform_resume_end(state);
517 pm_suspend_target_state = PM_SUSPEND_ON;
518 return error;
519
520 Recover_platform:
521 platform_recover(state);
522 goto Resume_devices;
523}
524
525/**
526 * suspend_finish - Clean up before finishing the suspend sequence.
527 *
528 * Call platform code to clean up, restart processes, and free the console that
529 * we've allocated. This routine is not called for hibernation.
530 */
531static void suspend_finish(void)
532{
533 suspend_thaw_processes();
534 pm_notifier_call_chain(PM_POST_SUSPEND);
535 pm_restore_console();
536}
537
538/**
539 * enter_state - Do common work needed to enter system sleep state.
540 * @state: System sleep state to enter.
541 *
542 * Make sure that no one else is trying to put the system into a sleep state.
543 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
544 * system enter the given sleep state and clean up after wakeup.
545 */
546static int enter_state(suspend_state_t state)
547{
548 int error;
549
550 trace_suspend_resume(TPS("suspend_enter"), state, true);
551 if (state == PM_SUSPEND_TO_IDLE) {
552#ifdef CONFIG_PM_DEBUG
553 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
554 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
555 return -EAGAIN;
556 }
557#endif
558 } else if (!valid_state(state)) {
559 return -EINVAL;
560 }
561 if (!mutex_trylock(&system_transition_mutex))
562 return -EBUSY;
563
564 if (state == PM_SUSPEND_TO_IDLE)
565 s2idle_begin();
566
567 if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) {
568 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
569 ksys_sync_helper();
570 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
571 }
572
573 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
574 pm_suspend_clear_flags();
575 error = suspend_prepare(state);
576 if (error)
577 goto Unlock;
578
579 if (suspend_test(TEST_FREEZER))
580 goto Finish;
581
582 trace_suspend_resume(TPS("suspend_enter"), state, false);
583 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
584 pm_restrict_gfp_mask();
585 error = suspend_devices_and_enter(state);
586 pm_restore_gfp_mask();
587
588 Finish:
589 events_check_enabled = false;
590 pm_pr_dbg("Finishing wakeup.\n");
591 suspend_finish();
592 Unlock:
593 mutex_unlock(&system_transition_mutex);
594 return error;
595}
596
597/**
598 * pm_suspend - Externally visible function for suspending the system.
599 * @state: System sleep state to enter.
600 *
601 * Check if the value of @state represents one of the supported states,
602 * execute enter_state() and update system suspend statistics.
603 */
604int pm_suspend(suspend_state_t state)
605{
606 int error;
607
608 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
609 return -EINVAL;
610
611 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
612 error = enter_state(state);
613 if (error) {
614 suspend_stats.fail++;
615 dpm_save_failed_errno(error);
616 } else {
617 suspend_stats.success++;
618 }
619 pr_info("suspend exit\n");
620 return error;
621}
622EXPORT_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
32#include "power.h"
33
34const char *const pm_states[PM_SUSPEND_MAX] = {
35 [PM_SUSPEND_FREEZE] = "freeze",
36 [PM_SUSPEND_STANDBY] = "standby",
37 [PM_SUSPEND_MEM] = "mem",
38};
39
40static const struct platform_suspend_ops *suspend_ops;
41
42static bool need_suspend_ops(suspend_state_t state)
43{
44 return state > PM_SUSPEND_FREEZE;
45}
46
47static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
48static bool suspend_freeze_wake;
49
50static void freeze_begin(void)
51{
52 suspend_freeze_wake = false;
53}
54
55static void freeze_enter(void)
56{
57 cpuidle_resume();
58 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
59 cpuidle_pause();
60}
61
62void freeze_wake(void)
63{
64 suspend_freeze_wake = true;
65 wake_up(&suspend_freeze_wait_head);
66}
67EXPORT_SYMBOL_GPL(freeze_wake);
68
69/**
70 * suspend_set_ops - Set the global suspend method table.
71 * @ops: Suspend operations to use.
72 */
73void suspend_set_ops(const struct platform_suspend_ops *ops)
74{
75 lock_system_sleep();
76 suspend_ops = ops;
77 unlock_system_sleep();
78}
79EXPORT_SYMBOL_GPL(suspend_set_ops);
80
81bool valid_state(suspend_state_t state)
82{
83 if (state == PM_SUSPEND_FREEZE) {
84#ifdef CONFIG_PM_DEBUG
85 if (pm_test_level != TEST_NONE &&
86 pm_test_level != TEST_FREEZER &&
87 pm_test_level != TEST_DEVICES &&
88 pm_test_level != TEST_PLATFORM) {
89 printk(KERN_WARNING "Unsupported pm_test mode for "
90 "freeze state, please choose "
91 "none/freezer/devices/platform.\n");
92 return false;
93 }
94#endif
95 return true;
96 }
97 /*
98 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
99 * support and need to be valid to the lowlevel
100 * implementation, no valid callback implies that none are valid.
101 */
102 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
103}
104
105/**
106 * suspend_valid_only_mem - Generic memory-only valid callback.
107 *
108 * Platform drivers that implement mem suspend only and only need to check for
109 * that in their .valid() callback can use this instead of rolling their own
110 * .valid() callback.
111 */
112int suspend_valid_only_mem(suspend_state_t state)
113{
114 return state == PM_SUSPEND_MEM;
115}
116EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
117
118static int suspend_test(int level)
119{
120#ifdef CONFIG_PM_DEBUG
121 if (pm_test_level == level) {
122 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
123 mdelay(5000);
124 return 1;
125 }
126#endif /* !CONFIG_PM_DEBUG */
127 return 0;
128}
129
130/**
131 * suspend_prepare - Prepare for entering system sleep state.
132 *
133 * Common code run for every system sleep state that can be entered (except for
134 * hibernation). Run suspend notifiers, allocate the "suspend" console and
135 * freeze processes.
136 */
137static int suspend_prepare(suspend_state_t state)
138{
139 int error;
140
141 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
142 return -EPERM;
143
144 pm_prepare_console();
145
146 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
147 if (error)
148 goto Finish;
149
150 error = suspend_freeze_processes();
151 if (!error)
152 return 0;
153
154 suspend_stats.failed_freeze++;
155 dpm_save_failed_step(SUSPEND_FREEZE);
156 Finish:
157 pm_notifier_call_chain(PM_POST_SUSPEND);
158 pm_restore_console();
159 return error;
160}
161
162/* default implementation */
163void __weak arch_suspend_disable_irqs(void)
164{
165 local_irq_disable();
166}
167
168/* default implementation */
169void __weak arch_suspend_enable_irqs(void)
170{
171 local_irq_enable();
172}
173
174/**
175 * suspend_enter - Make the system enter the given sleep state.
176 * @state: System sleep state to enter.
177 * @wakeup: Returns information that the sleep state should not be re-entered.
178 *
179 * This function should be called after devices have been suspended.
180 */
181static int suspend_enter(suspend_state_t state, bool *wakeup)
182{
183 int error;
184
185 if (need_suspend_ops(state) && suspend_ops->prepare) {
186 error = suspend_ops->prepare();
187 if (error)
188 goto Platform_finish;
189 }
190
191 error = dpm_suspend_end(PMSG_SUSPEND);
192 if (error) {
193 printk(KERN_ERR "PM: Some devices failed to power down\n");
194 goto Platform_finish;
195 }
196
197 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
198 error = suspend_ops->prepare_late();
199 if (error)
200 goto Platform_wake;
201 }
202
203 if (suspend_test(TEST_PLATFORM))
204 goto Platform_wake;
205
206 /*
207 * PM_SUSPEND_FREEZE equals
208 * frozen processes + suspended devices + idle processors.
209 * Thus we should invoke freeze_enter() soon after
210 * all the devices are suspended.
211 */
212 if (state == PM_SUSPEND_FREEZE) {
213 freeze_enter();
214 goto Platform_wake;
215 }
216
217 ftrace_stop();
218 error = disable_nonboot_cpus();
219 if (error || suspend_test(TEST_CPUS))
220 goto Enable_cpus;
221
222 arch_suspend_disable_irqs();
223 BUG_ON(!irqs_disabled());
224
225 error = syscore_suspend();
226 if (!error) {
227 *wakeup = pm_wakeup_pending();
228 if (!(suspend_test(TEST_CORE) || *wakeup)) {
229 error = suspend_ops->enter(state);
230 events_check_enabled = false;
231 }
232 syscore_resume();
233 }
234
235 arch_suspend_enable_irqs();
236 BUG_ON(irqs_disabled());
237
238 Enable_cpus:
239 enable_nonboot_cpus();
240 ftrace_start();
241
242 Platform_wake:
243 if (need_suspend_ops(state) && suspend_ops->wake)
244 suspend_ops->wake();
245
246 dpm_resume_start(PMSG_RESUME);
247
248 Platform_finish:
249 if (need_suspend_ops(state) && suspend_ops->finish)
250 suspend_ops->finish();
251
252 return error;
253}
254
255/**
256 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
257 * @state: System sleep state to enter.
258 */
259int suspend_devices_and_enter(suspend_state_t state)
260{
261 int error;
262 bool wakeup = false;
263
264 if (need_suspend_ops(state) && !suspend_ops)
265 return -ENOSYS;
266
267 trace_machine_suspend(state);
268 if (need_suspend_ops(state) && suspend_ops->begin) {
269 error = suspend_ops->begin(state);
270 if (error)
271 goto Close;
272 }
273 suspend_console();
274 suspend_test_start();
275 error = dpm_suspend_start(PMSG_SUSPEND);
276 if (error) {
277 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
278 goto Recover_platform;
279 }
280 suspend_test_finish("suspend devices");
281 if (suspend_test(TEST_DEVICES))
282 goto Recover_platform;
283
284 do {
285 error = suspend_enter(state, &wakeup);
286 } while (!error && !wakeup && need_suspend_ops(state)
287 && suspend_ops->suspend_again && suspend_ops->suspend_again());
288
289 Resume_devices:
290 suspend_test_start();
291 dpm_resume_end(PMSG_RESUME);
292 suspend_test_finish("resume devices");
293 resume_console();
294 Close:
295 if (need_suspend_ops(state) && suspend_ops->end)
296 suspend_ops->end();
297 trace_machine_suspend(PWR_EVENT_EXIT);
298 return error;
299
300 Recover_platform:
301 if (need_suspend_ops(state) && suspend_ops->recover)
302 suspend_ops->recover();
303 goto Resume_devices;
304}
305
306/**
307 * suspend_finish - Clean up before finishing the suspend sequence.
308 *
309 * Call platform code to clean up, restart processes, and free the console that
310 * we've allocated. This routine is not called for hibernation.
311 */
312static void suspend_finish(void)
313{
314 suspend_thaw_processes();
315 pm_notifier_call_chain(PM_POST_SUSPEND);
316 pm_restore_console();
317}
318
319/**
320 * enter_state - Do common work needed to enter system sleep state.
321 * @state: System sleep state to enter.
322 *
323 * Make sure that no one else is trying to put the system into a sleep state.
324 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
325 * system enter the given sleep state and clean up after wakeup.
326 */
327static int enter_state(suspend_state_t state)
328{
329 int error;
330
331 if (!valid_state(state))
332 return -ENODEV;
333
334 if (!mutex_trylock(&pm_mutex))
335 return -EBUSY;
336
337 if (state == PM_SUSPEND_FREEZE)
338 freeze_begin();
339
340 printk(KERN_INFO "PM: Syncing filesystems ... ");
341 sys_sync();
342 printk("done.\n");
343
344 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
345 error = suspend_prepare(state);
346 if (error)
347 goto Unlock;
348
349 if (suspend_test(TEST_FREEZER))
350 goto Finish;
351
352 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
353 pm_restrict_gfp_mask();
354 error = suspend_devices_and_enter(state);
355 pm_restore_gfp_mask();
356
357 Finish:
358 pr_debug("PM: Finishing wakeup.\n");
359 suspend_finish();
360 Unlock:
361 mutex_unlock(&pm_mutex);
362 return error;
363}
364
365/**
366 * pm_suspend - Externally visible function for suspending the system.
367 * @state: System sleep state to enter.
368 *
369 * Check if the value of @state represents one of the supported states,
370 * execute enter_state() and update system suspend statistics.
371 */
372int pm_suspend(suspend_state_t state)
373{
374 int error;
375
376 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
377 return -EINVAL;
378
379 error = enter_state(state);
380 if (error) {
381 suspend_stats.fail++;
382 dpm_save_failed_errno(error);
383 } else {
384 suspend_stats.success++;
385 }
386 return error;
387}
388EXPORT_SYMBOL(pm_suspend);