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