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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#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);