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 #include <linux/wakeup_reason.h>
35
36 #include "power.h"
37
38 const char * const pm_labels[] = {
39 [PM_SUSPEND_TO_IDLE] = "freeze",
40 [PM_SUSPEND_STANDBY] = "standby",
41 [PM_SUSPEND_MEM] = "mem",
42 };
43 const char *pm_states[PM_SUSPEND_MAX];
44 static const char * const mem_sleep_labels[] = {
45 [PM_SUSPEND_TO_IDLE] = "s2idle",
46 [PM_SUSPEND_STANDBY] = "shallow",
47 [PM_SUSPEND_MEM] = "deep",
48 };
49 const char *mem_sleep_states[PM_SUSPEND_MAX];
50
51 suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
52 suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
53 suspend_state_t pm_suspend_target_state;
54 EXPORT_SYMBOL_GPL(pm_suspend_target_state);
55
56 unsigned int pm_suspend_global_flags;
57 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
58
59 static const struct platform_suspend_ops *suspend_ops;
60 static const struct platform_s2idle_ops *s2idle_ops;
61 static DECLARE_WAIT_QUEUE_HEAD(s2idle_wait_head);
62
63 enum s2idle_states __read_mostly s2idle_state;
64 static DEFINE_RAW_SPINLOCK(s2idle_lock);
65
s2idle_set_ops(const struct platform_s2idle_ops * ops)66 void s2idle_set_ops(const struct platform_s2idle_ops *ops)
67 {
68 lock_system_sleep();
69 s2idle_ops = ops;
70 unlock_system_sleep();
71 }
72
s2idle_begin(void)73 static void s2idle_begin(void)
74 {
75 s2idle_state = S2IDLE_STATE_NONE;
76 }
77
s2idle_enter(void)78 static void s2idle_enter(void)
79 {
80 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
81
82 raw_spin_lock_irq(&s2idle_lock);
83 if (pm_wakeup_pending())
84 goto out;
85
86 s2idle_state = S2IDLE_STATE_ENTER;
87 raw_spin_unlock_irq(&s2idle_lock);
88
89 get_online_cpus();
90 cpuidle_resume();
91
92 /* Push all the CPUs into the idle loop. */
93 wake_up_all_idle_cpus();
94 /* Make the current CPU wait so it can enter the idle loop too. */
95 wait_event(s2idle_wait_head,
96 s2idle_state == S2IDLE_STATE_WAKE);
97
98 cpuidle_pause();
99 put_online_cpus();
100
101 raw_spin_lock_irq(&s2idle_lock);
102
103 out:
104 s2idle_state = S2IDLE_STATE_NONE;
105 raw_spin_unlock_irq(&s2idle_lock);
106
107 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
108 }
109
s2idle_loop(void)110 static void s2idle_loop(void)
111 {
112 pm_pr_dbg("suspend-to-idle\n");
113
114 for (;;) {
115 int error;
116
117 dpm_noirq_begin();
118
119 /*
120 * Suspend-to-idle equals
121 * frozen processes + suspended devices + idle processors.
122 * Thus s2idle_enter() should be called right after
123 * all devices have been suspended.
124 *
125 * Wakeups during the noirq suspend of devices may be spurious,
126 * so prevent them from terminating the loop right away.
127 */
128 error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
129 if (!error)
130 s2idle_enter();
131 else if (error == -EBUSY && pm_wakeup_pending())
132 error = 0;
133
134 if (!error && s2idle_ops && s2idle_ops->wake)
135 s2idle_ops->wake();
136
137 dpm_noirq_resume_devices(PMSG_RESUME);
138
139 dpm_noirq_end();
140
141 if (error)
142 break;
143
144 if (s2idle_ops && s2idle_ops->sync)
145 s2idle_ops->sync();
146
147 if (pm_wakeup_pending())
148 break;
149
150 pm_wakeup_clear(false);
151 }
152
153 pm_pr_dbg("resume from suspend-to-idle\n");
154 }
155
s2idle_wake(void)156 void 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 wake_up(&s2idle_wait_head);
164 }
165 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
166 }
167 EXPORT_SYMBOL_GPL(s2idle_wake);
168
valid_state(suspend_state_t state)169 static bool valid_state(suspend_state_t state)
170 {
171 /*
172 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
173 * support and need to be valid to the low level
174 * implementation, no valid callback implies that none are valid.
175 */
176 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
177 }
178
pm_states_init(void)179 void __init pm_states_init(void)
180 {
181 /* "mem" and "freeze" are always present in /sys/power/state. */
182 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
183 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
184 /*
185 * Suspend-to-idle should be supported even without any suspend_ops,
186 * initialize mem_sleep_states[] accordingly here.
187 */
188 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
189 }
190
mem_sleep_default_setup(char * str)191 static int __init mem_sleep_default_setup(char *str)
192 {
193 suspend_state_t state;
194
195 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
196 if (mem_sleep_labels[state] &&
197 !strcmp(str, mem_sleep_labels[state])) {
198 mem_sleep_default = state;
199 break;
200 }
201
202 return 1;
203 }
204 __setup("mem_sleep_default=", mem_sleep_default_setup);
205
206 /**
207 * suspend_set_ops - Set the global suspend method table.
208 * @ops: Suspend operations to use.
209 */
suspend_set_ops(const struct platform_suspend_ops * ops)210 void suspend_set_ops(const struct platform_suspend_ops *ops)
211 {
212 lock_system_sleep();
213
214 suspend_ops = ops;
215
216 if (valid_state(PM_SUSPEND_STANDBY)) {
217 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
218 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
219 if (mem_sleep_default == PM_SUSPEND_STANDBY)
220 mem_sleep_current = PM_SUSPEND_STANDBY;
221 }
222 if (valid_state(PM_SUSPEND_MEM)) {
223 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
224 if (mem_sleep_default >= PM_SUSPEND_MEM)
225 mem_sleep_current = PM_SUSPEND_MEM;
226 }
227
228 unlock_system_sleep();
229 }
230 EXPORT_SYMBOL_GPL(suspend_set_ops);
231
232 /**
233 * suspend_valid_only_mem - Generic memory-only valid callback.
234 *
235 * Platform drivers that implement mem suspend only and only need to check for
236 * that in their .valid() callback can use this instead of rolling their own
237 * .valid() callback.
238 */
suspend_valid_only_mem(suspend_state_t state)239 int suspend_valid_only_mem(suspend_state_t state)
240 {
241 return state == PM_SUSPEND_MEM;
242 }
243 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
244
sleep_state_supported(suspend_state_t state)245 static bool sleep_state_supported(suspend_state_t state)
246 {
247 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
248 }
249
platform_suspend_prepare(suspend_state_t state)250 static int platform_suspend_prepare(suspend_state_t state)
251 {
252 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
253 suspend_ops->prepare() : 0;
254 }
255
platform_suspend_prepare_late(suspend_state_t state)256 static int platform_suspend_prepare_late(suspend_state_t state)
257 {
258 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
259 s2idle_ops->prepare() : 0;
260 }
261
platform_suspend_prepare_noirq(suspend_state_t state)262 static int platform_suspend_prepare_noirq(suspend_state_t state)
263 {
264 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
265 suspend_ops->prepare_late() : 0;
266 }
267
platform_resume_noirq(suspend_state_t state)268 static void platform_resume_noirq(suspend_state_t state)
269 {
270 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
271 suspend_ops->wake();
272 }
273
platform_resume_early(suspend_state_t state)274 static 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
platform_resume_finish(suspend_state_t state)280 static 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
platform_suspend_begin(suspend_state_t state)286 static 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
platform_resume_end(suspend_state_t state)296 static 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
platform_recover(suspend_state_t state)304 static void platform_recover(suspend_state_t state)
305 {
306 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
307 suspend_ops->recover();
308 }
309
platform_suspend_again(suspend_state_t state)310 static 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
317 static unsigned int pm_test_delay = 5;
318 module_param(pm_test_delay, uint, 0644);
319 MODULE_PARM_DESC(pm_test_delay,
320 "Number of seconds to wait before resuming from suspend test");
321 #endif
322
suspend_test(int level)323 static 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 */
suspend_prepare(suspend_state_t state)343 static 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 */
arch_suspend_disable_irqs(void)373 void __weak arch_suspend_disable_irqs(void)
374 {
375 local_irq_disable();
376 }
377
378 /* default implementation */
arch_suspend_enable_irqs(void)379 void __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 */
suspend_enter(suspend_state_t state,bool * wakeup)391 static int suspend_enter(suspend_state_t state, bool *wakeup)
392 {
393 char suspend_abort[MAX_SUSPEND_ABORT_LEN];
394 int error, last_dev;
395
396 error = platform_suspend_prepare(state);
397 if (error)
398 goto Platform_finish;
399
400 error = dpm_suspend_late(PMSG_SUSPEND);
401 if (error) {
402 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
403 last_dev %= REC_FAILED_NUM;
404 pr_err("late suspend of devices failed\n");
405 log_suspend_abort_reason("%s device failed to power down",
406 suspend_stats.failed_devs[last_dev]);
407 goto Platform_finish;
408 }
409 error = platform_suspend_prepare_late(state);
410 if (error)
411 goto Devices_early_resume;
412
413 if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
414 s2idle_loop();
415 goto Platform_early_resume;
416 }
417
418 error = dpm_suspend_noirq(PMSG_SUSPEND);
419 if (error) {
420 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
421 last_dev %= REC_FAILED_NUM;
422 pr_err("noirq suspend of devices failed\n");
423 log_suspend_abort_reason("noirq suspend of %s device failed",
424 suspend_stats.failed_devs[last_dev]);
425 goto Platform_early_resume;
426 }
427 error = platform_suspend_prepare_noirq(state);
428 if (error)
429 goto Platform_wake;
430
431 if (suspend_test(TEST_PLATFORM))
432 goto Platform_wake;
433
434 error = disable_nonboot_cpus();
435 if (error || suspend_test(TEST_CPUS)) {
436 log_suspend_abort_reason("Disabling non-boot cpus failed");
437 goto Enable_cpus;
438 }
439
440 arch_suspend_disable_irqs();
441 BUG_ON(!irqs_disabled());
442
443 error = syscore_suspend();
444 if (!error) {
445 *wakeup = pm_wakeup_pending();
446 if (!(suspend_test(TEST_CORE) || *wakeup)) {
447 trace_suspend_resume(TPS("machine_suspend"),
448 state, true);
449 error = suspend_ops->enter(state);
450 trace_suspend_resume(TPS("machine_suspend"),
451 state, false);
452 } else if (*wakeup) {
453 pm_get_active_wakeup_sources(suspend_abort,
454 MAX_SUSPEND_ABORT_LEN);
455 log_suspend_abort_reason(suspend_abort);
456 error = -EBUSY;
457 }
458 syscore_resume();
459 }
460
461 arch_suspend_enable_irqs();
462 BUG_ON(irqs_disabled());
463
464 Enable_cpus:
465 enable_nonboot_cpus();
466
467 Platform_wake:
468 platform_resume_noirq(state);
469 dpm_resume_noirq(PMSG_RESUME);
470
471 Platform_early_resume:
472 platform_resume_early(state);
473
474 Devices_early_resume:
475 dpm_resume_early(PMSG_RESUME);
476
477 Platform_finish:
478 platform_resume_finish(state);
479 return error;
480 }
481
482 /**
483 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
484 * @state: System sleep state to enter.
485 */
suspend_devices_and_enter(suspend_state_t state)486 int suspend_devices_and_enter(suspend_state_t state)
487 {
488 int error;
489 bool wakeup = false;
490
491 if (!sleep_state_supported(state))
492 return -ENOSYS;
493
494 pm_suspend_target_state = state;
495
496 error = platform_suspend_begin(state);
497 if (error)
498 goto Close;
499
500 suspend_console();
501 suspend_test_start();
502 error = dpm_suspend_start(PMSG_SUSPEND);
503 if (error) {
504 pr_err("Some devices failed to suspend, or early wake event detected\n");
505 log_suspend_abort_reason("Some devices failed to suspend, or early wake event detected");
506 goto Recover_platform;
507 }
508 suspend_test_finish("suspend devices");
509 if (suspend_test(TEST_DEVICES))
510 goto Recover_platform;
511
512 do {
513 error = suspend_enter(state, &wakeup);
514 } while (!error && !wakeup && platform_suspend_again(state));
515
516 Resume_devices:
517 suspend_test_start();
518 dpm_resume_end(PMSG_RESUME);
519 suspend_test_finish("resume devices");
520 trace_suspend_resume(TPS("resume_console"), state, true);
521 resume_console();
522 trace_suspend_resume(TPS("resume_console"), state, false);
523
524 Close:
525 platform_resume_end(state);
526 pm_suspend_target_state = PM_SUSPEND_ON;
527 return error;
528
529 Recover_platform:
530 platform_recover(state);
531 goto Resume_devices;
532 }
533
534 /**
535 * suspend_finish - Clean up before finishing the suspend sequence.
536 *
537 * Call platform code to clean up, restart processes, and free the console that
538 * we've allocated. This routine is not called for hibernation.
539 */
suspend_finish(void)540 static void suspend_finish(void)
541 {
542 suspend_thaw_processes();
543 pm_notifier_call_chain(PM_POST_SUSPEND);
544 pm_restore_console();
545 }
546
547 /**
548 * enter_state - Do common work needed to enter system sleep state.
549 * @state: System sleep state to enter.
550 *
551 * Make sure that no one else is trying to put the system into a sleep state.
552 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
553 * system enter the given sleep state and clean up after wakeup.
554 */
enter_state(suspend_state_t state)555 static int enter_state(suspend_state_t state)
556 {
557 int error;
558
559 trace_suspend_resume(TPS("suspend_enter"), state, true);
560 if (state == PM_SUSPEND_TO_IDLE) {
561 #ifdef CONFIG_PM_DEBUG
562 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
563 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
564 return -EAGAIN;
565 }
566 #endif
567 } else if (!valid_state(state)) {
568 return -EINVAL;
569 }
570 if (!mutex_trylock(&pm_mutex))
571 return -EBUSY;
572
573 if (state == PM_SUSPEND_TO_IDLE)
574 s2idle_begin();
575
576 #ifndef CONFIG_SUSPEND_SKIP_SYNC
577 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
578 pr_info("Syncing filesystems ... ");
579 sys_sync();
580 pr_cont("done.\n");
581 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
582 #endif
583
584 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
585 pm_suspend_clear_flags();
586 error = suspend_prepare(state);
587 if (error)
588 goto Unlock;
589
590 if (suspend_test(TEST_FREEZER))
591 goto Finish;
592
593 trace_suspend_resume(TPS("suspend_enter"), state, false);
594 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
595 pm_restrict_gfp_mask();
596 error = suspend_devices_and_enter(state);
597 pm_restore_gfp_mask();
598
599 Finish:
600 events_check_enabled = false;
601 pm_pr_dbg("Finishing wakeup.\n");
602 suspend_finish();
603 Unlock:
604 mutex_unlock(&pm_mutex);
605 return error;
606 }
607
608 /**
609 * pm_suspend - Externally visible function for suspending the system.
610 * @state: System sleep state to enter.
611 *
612 * Check if the value of @state represents one of the supported states,
613 * execute enter_state() and update system suspend statistics.
614 */
pm_suspend(suspend_state_t state)615 int pm_suspend(suspend_state_t state)
616 {
617 int error;
618
619 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
620 return -EINVAL;
621
622 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
623 error = enter_state(state);
624 if (error) {
625 suspend_stats.fail++;
626 dpm_save_failed_errno(error);
627 } else {
628 suspend_stats.success++;
629 }
630 pr_info("suspend exit\n");
631 return error;
632 }
633 EXPORT_SYMBOL(pm_suspend);
634