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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 /*
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);
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#define pr_fmt(fmt) "PM: " fmt
12
13#include <linux/string.h>
14#include <linux/delay.h>
15#include <linux/errno.h>
16#include <linux/init.h>
17#include <linux/console.h>
18#include <linux/cpu.h>
19#include <linux/cpuidle.h>
20#include <linux/syscalls.h>
21#include <linux/gfp.h>
22#include <linux/io.h>
23#include <linux/kernel.h>
24#include <linux/list.h>
25#include <linux/mm.h>
26#include <linux/slab.h>
27#include <linux/export.h>
28#include <linux/suspend.h>
29#include <linux/syscore_ops.h>
30#include <linux/ftrace.h>
31#include <trace/events/power.h>
32#include <linux/compiler.h>
33#include <linux/moduleparam.h>
34
35#include "power.h"
36
37const char * const pm_labels[] = {
38 [PM_SUSPEND_TO_IDLE] = "freeze",
39 [PM_SUSPEND_STANDBY] = "standby",
40 [PM_SUSPEND_MEM] = "mem",
41};
42const char *pm_states[PM_SUSPEND_MAX];
43static const char * const mem_sleep_labels[] = {
44 [PM_SUSPEND_TO_IDLE] = "s2idle",
45 [PM_SUSPEND_STANDBY] = "shallow",
46 [PM_SUSPEND_MEM] = "deep",
47};
48const char *mem_sleep_states[PM_SUSPEND_MAX];
49
50suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
51suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
52suspend_state_t pm_suspend_target_state;
53EXPORT_SYMBOL_GPL(pm_suspend_target_state);
54
55unsigned int pm_suspend_global_flags;
56EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
57
58static const struct platform_suspend_ops *suspend_ops;
59static const struct platform_s2idle_ops *s2idle_ops;
60static DECLARE_WAIT_QUEUE_HEAD(s2idle_wait_head);
61
62enum s2idle_states __read_mostly s2idle_state;
63static DEFINE_SPINLOCK(s2idle_lock);
64
65void s2idle_set_ops(const struct platform_s2idle_ops *ops)
66{
67 lock_system_sleep();
68 s2idle_ops = ops;
69 unlock_system_sleep();
70}
71
72static void s2idle_begin(void)
73{
74 s2idle_state = S2IDLE_STATE_NONE;
75}
76
77static void s2idle_enter(void)
78{
79 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
80
81 spin_lock_irq(&s2idle_lock);
82 if (pm_wakeup_pending())
83 goto out;
84
85 s2idle_state = S2IDLE_STATE_ENTER;
86 spin_unlock_irq(&s2idle_lock);
87
88 get_online_cpus();
89 cpuidle_resume();
90
91 /* Push all the CPUs into the idle loop. */
92 wake_up_all_idle_cpus();
93 /* Make the current CPU wait so it can enter the idle loop too. */
94 wait_event(s2idle_wait_head,
95 s2idle_state == S2IDLE_STATE_WAKE);
96
97 cpuidle_pause();
98 put_online_cpus();
99
100 spin_lock_irq(&s2idle_lock);
101
102 out:
103 s2idle_state = S2IDLE_STATE_NONE;
104 spin_unlock_irq(&s2idle_lock);
105
106 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
107}
108
109static void s2idle_loop(void)
110{
111 pm_pr_dbg("suspend-to-idle\n");
112
113 for (;;) {
114 int error;
115
116 dpm_noirq_begin();
117
118 /*
119 * Suspend-to-idle equals
120 * frozen processes + suspended devices + idle processors.
121 * Thus s2idle_enter() should be called right after
122 * all devices have been suspended.
123 *
124 * Wakeups during the noirq suspend of devices may be spurious,
125 * so prevent them from terminating the loop right away.
126 */
127 error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
128 if (!error)
129 s2idle_enter();
130 else if (error == -EBUSY && pm_wakeup_pending())
131 error = 0;
132
133 if (!error && s2idle_ops && s2idle_ops->wake)
134 s2idle_ops->wake();
135
136 dpm_noirq_resume_devices(PMSG_RESUME);
137
138 dpm_noirq_end();
139
140 if (error)
141 break;
142
143 if (s2idle_ops && s2idle_ops->sync)
144 s2idle_ops->sync();
145
146 if (pm_wakeup_pending())
147 break;
148
149 pm_wakeup_clear(false);
150 }
151
152 pm_pr_dbg("resume from suspend-to-idle\n");
153}
154
155void s2idle_wake(void)
156{
157 unsigned long flags;
158
159 spin_lock_irqsave(&s2idle_lock, flags);
160 if (s2idle_state > S2IDLE_STATE_NONE) {
161 s2idle_state = S2IDLE_STATE_WAKE;
162 wake_up(&s2idle_wait_head);
163 }
164 spin_unlock_irqrestore(&s2idle_lock, flags);
165}
166EXPORT_SYMBOL_GPL(s2idle_wake);
167
168static bool valid_state(suspend_state_t state)
169{
170 /*
171 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
172 * support and need to be valid to the low level
173 * implementation, no valid callback implies that none are valid.
174 */
175 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
176}
177
178void __init pm_states_init(void)
179{
180 /* "mem" and "freeze" are always present in /sys/power/state. */
181 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
182 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
183 /*
184 * Suspend-to-idle should be supported even without any suspend_ops,
185 * initialize mem_sleep_states[] accordingly here.
186 */
187 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
188}
189
190static int __init mem_sleep_default_setup(char *str)
191{
192 suspend_state_t state;
193
194 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
195 if (mem_sleep_labels[state] &&
196 !strcmp(str, mem_sleep_labels[state])) {
197 mem_sleep_default = state;
198 break;
199 }
200
201 return 1;
202}
203__setup("mem_sleep_default=", mem_sleep_default_setup);
204
205/**
206 * suspend_set_ops - Set the global suspend method table.
207 * @ops: Suspend operations to use.
208 */
209void suspend_set_ops(const struct platform_suspend_ops *ops)
210{
211 lock_system_sleep();
212
213 suspend_ops = ops;
214
215 if (valid_state(PM_SUSPEND_STANDBY)) {
216 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
217 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
218 if (mem_sleep_default == PM_SUSPEND_STANDBY)
219 mem_sleep_current = PM_SUSPEND_STANDBY;
220 }
221 if (valid_state(PM_SUSPEND_MEM)) {
222 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
223 if (mem_sleep_default >= PM_SUSPEND_MEM)
224 mem_sleep_current = PM_SUSPEND_MEM;
225 }
226
227 unlock_system_sleep();
228}
229EXPORT_SYMBOL_GPL(suspend_set_ops);
230
231/**
232 * suspend_valid_only_mem - Generic memory-only valid callback.
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 || (suspend_ops && suspend_ops->enter);
247}
248
249static int platform_suspend_prepare(suspend_state_t state)
250{
251 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
252 suspend_ops->prepare() : 0;
253}
254
255static int platform_suspend_prepare_late(suspend_state_t state)
256{
257 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
258 s2idle_ops->prepare() : 0;
259}
260
261static int platform_suspend_prepare_noirq(suspend_state_t state)
262{
263 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
264 suspend_ops->prepare_late() : 0;
265}
266
267static void platform_resume_noirq(suspend_state_t state)
268{
269 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
270 suspend_ops->wake();
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 if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
408 s2idle_loop();
409 goto Platform_early_resume;
410 }
411
412 error = dpm_suspend_noirq(PMSG_SUSPEND);
413 if (error) {
414 pr_err("noirq suspend of devices failed\n");
415 goto Platform_early_resume;
416 }
417 error = platform_suspend_prepare_noirq(state);
418 if (error)
419 goto Platform_wake;
420
421 if (suspend_test(TEST_PLATFORM))
422 goto Platform_wake;
423
424 error = disable_nonboot_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 error = syscore_suspend();
432 if (!error) {
433 *wakeup = pm_wakeup_pending();
434 if (!(suspend_test(TEST_CORE) || *wakeup)) {
435 trace_suspend_resume(TPS("machine_suspend"),
436 state, true);
437 error = suspend_ops->enter(state);
438 trace_suspend_resume(TPS("machine_suspend"),
439 state, false);
440 } else if (*wakeup) {
441 error = -EBUSY;
442 }
443 syscore_resume();
444 }
445
446 arch_suspend_enable_irqs();
447 BUG_ON(irqs_disabled());
448
449 Enable_cpus:
450 enable_nonboot_cpus();
451
452 Platform_wake:
453 platform_resume_noirq(state);
454 dpm_resume_noirq(PMSG_RESUME);
455
456 Platform_early_resume:
457 platform_resume_early(state);
458
459 Devices_early_resume:
460 dpm_resume_early(PMSG_RESUME);
461
462 Platform_finish:
463 platform_resume_finish(state);
464 return error;
465}
466
467/**
468 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
469 * @state: System sleep state to enter.
470 */
471int suspend_devices_and_enter(suspend_state_t state)
472{
473 int error;
474 bool wakeup = false;
475
476 if (!sleep_state_supported(state))
477 return -ENOSYS;
478
479 pm_suspend_target_state = state;
480
481 error = platform_suspend_begin(state);
482 if (error)
483 goto Close;
484
485 suspend_console();
486 suspend_test_start();
487 error = dpm_suspend_start(PMSG_SUSPEND);
488 if (error) {
489 pr_err("Some devices failed to suspend, or early wake event detected\n");
490 goto Recover_platform;
491 }
492 suspend_test_finish("suspend devices");
493 if (suspend_test(TEST_DEVICES))
494 goto Recover_platform;
495
496 do {
497 error = suspend_enter(state, &wakeup);
498 } while (!error && !wakeup && platform_suspend_again(state));
499
500 Resume_devices:
501 suspend_test_start();
502 dpm_resume_end(PMSG_RESUME);
503 suspend_test_finish("resume devices");
504 trace_suspend_resume(TPS("resume_console"), state, true);
505 resume_console();
506 trace_suspend_resume(TPS("resume_console"), state, false);
507
508 Close:
509 platform_resume_end(state);
510 pm_suspend_target_state = PM_SUSPEND_ON;
511 return error;
512
513 Recover_platform:
514 platform_recover(state);
515 goto Resume_devices;
516}
517
518/**
519 * suspend_finish - Clean up before finishing the suspend sequence.
520 *
521 * Call platform code to clean up, restart processes, and free the console that
522 * we've allocated. This routine is not called for hibernation.
523 */
524static void suspend_finish(void)
525{
526 suspend_thaw_processes();
527 pm_notifier_call_chain(PM_POST_SUSPEND);
528 pm_restore_console();
529}
530
531/**
532 * enter_state - Do common work needed to enter system sleep state.
533 * @state: System sleep state to enter.
534 *
535 * Make sure that no one else is trying to put the system into a sleep state.
536 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
537 * system enter the given sleep state and clean up after wakeup.
538 */
539static int enter_state(suspend_state_t state)
540{
541 int error;
542
543 trace_suspend_resume(TPS("suspend_enter"), state, true);
544 if (state == PM_SUSPEND_TO_IDLE) {
545#ifdef CONFIG_PM_DEBUG
546 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
547 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
548 return -EAGAIN;
549 }
550#endif
551 } else if (!valid_state(state)) {
552 return -EINVAL;
553 }
554 if (!mutex_trylock(&pm_mutex))
555 return -EBUSY;
556
557 if (state == PM_SUSPEND_TO_IDLE)
558 s2idle_begin();
559
560#ifndef CONFIG_SUSPEND_SKIP_SYNC
561 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
562 pr_info("Syncing filesystems ... ");
563 ksys_sync();
564 pr_cont("done.\n");
565 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
566#endif
567
568 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
569 pm_suspend_clear_flags();
570 error = suspend_prepare(state);
571 if (error)
572 goto Unlock;
573
574 if (suspend_test(TEST_FREEZER))
575 goto Finish;
576
577 trace_suspend_resume(TPS("suspend_enter"), state, false);
578 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
579 pm_restrict_gfp_mask();
580 error = suspend_devices_and_enter(state);
581 pm_restore_gfp_mask();
582
583 Finish:
584 events_check_enabled = false;
585 pm_pr_dbg("Finishing wakeup.\n");
586 suspend_finish();
587 Unlock:
588 mutex_unlock(&pm_mutex);
589 return error;
590}
591
592/**
593 * pm_suspend - Externally visible function for suspending the system.
594 * @state: System sleep state to enter.
595 *
596 * Check if the value of @state represents one of the supported states,
597 * execute enter_state() and update system suspend statistics.
598 */
599int pm_suspend(suspend_state_t state)
600{
601 int error;
602
603 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
604 return -EINVAL;
605
606 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
607 error = enter_state(state);
608 if (error) {
609 suspend_stats.fail++;
610 dpm_save_failed_errno(error);
611 } else {
612 suspend_stats.success++;
613 }
614 pr_info("suspend exit\n");
615 return error;
616}
617EXPORT_SYMBOL(pm_suspend);