Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[muen/linux.git] / kernel / power / suspend.c
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/swait.h>
31 #include <linux/ftrace.h>
32 #include <trace/events/power.h>
33 #include <linux/compiler.h>
34 #include <linux/moduleparam.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_SWAIT_QUEUE_HEAD(s2idle_wait_head);
62
63 enum s2idle_states __read_mostly s2idle_state;
64 static DEFINE_RAW_SPINLOCK(s2idle_lock);
65
66 bool pm_suspend_via_s2idle(void)
67 {
68         return mem_sleep_current == PM_SUSPEND_TO_IDLE;
69 }
70 EXPORT_SYMBOL_GPL(pm_suspend_via_s2idle);
71
72 void s2idle_set_ops(const struct platform_s2idle_ops *ops)
73 {
74         lock_system_sleep();
75         s2idle_ops = ops;
76         unlock_system_sleep();
77 }
78
79 static void s2idle_begin(void)
80 {
81         s2idle_state = S2IDLE_STATE_NONE;
82 }
83
84 static void s2idle_enter(void)
85 {
86         trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
87
88         raw_spin_lock_irq(&s2idle_lock);
89         if (pm_wakeup_pending())
90                 goto out;
91
92         s2idle_state = S2IDLE_STATE_ENTER;
93         raw_spin_unlock_irq(&s2idle_lock);
94
95         get_online_cpus();
96         cpuidle_resume();
97
98         /* Push all the CPUs into the idle loop. */
99         wake_up_all_idle_cpus();
100         /* Make the current CPU wait so it can enter the idle loop too. */
101         swait_event_exclusive(s2idle_wait_head,
102                     s2idle_state == S2IDLE_STATE_WAKE);
103
104         cpuidle_pause();
105         put_online_cpus();
106
107         raw_spin_lock_irq(&s2idle_lock);
108
109  out:
110         s2idle_state = S2IDLE_STATE_NONE;
111         raw_spin_unlock_irq(&s2idle_lock);
112
113         trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
114 }
115
116 static void s2idle_loop(void)
117 {
118         pm_pr_dbg("suspend-to-idle\n");
119
120         for (;;) {
121                 int error;
122
123                 dpm_noirq_begin();
124
125                 /*
126                  * Suspend-to-idle equals
127                  * frozen processes + suspended devices + idle processors.
128                  * Thus s2idle_enter() should be called right after
129                  * all devices have been suspended.
130                  *
131                  * Wakeups during the noirq suspend of devices may be spurious,
132                  * so prevent them from terminating the loop right away.
133                  */
134                 error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
135                 if (!error)
136                         s2idle_enter();
137                 else if (error == -EBUSY && pm_wakeup_pending())
138                         error = 0;
139
140                 if (!error && s2idle_ops && s2idle_ops->wake)
141                         s2idle_ops->wake();
142
143                 dpm_noirq_resume_devices(PMSG_RESUME);
144
145                 dpm_noirq_end();
146
147                 if (error)
148                         break;
149
150                 if (s2idle_ops && s2idle_ops->sync)
151                         s2idle_ops->sync();
152
153                 if (pm_wakeup_pending())
154                         break;
155
156                 pm_wakeup_clear(false);
157         }
158
159         pm_pr_dbg("resume from suspend-to-idle\n");
160 }
161
162 void s2idle_wake(void)
163 {
164         unsigned long flags;
165
166         raw_spin_lock_irqsave(&s2idle_lock, flags);
167         if (s2idle_state > S2IDLE_STATE_NONE) {
168                 s2idle_state = S2IDLE_STATE_WAKE;
169                 swake_up_one(&s2idle_wait_head);
170         }
171         raw_spin_unlock_irqrestore(&s2idle_lock, flags);
172 }
173 EXPORT_SYMBOL_GPL(s2idle_wake);
174
175 static bool valid_state(suspend_state_t state)
176 {
177         /*
178          * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
179          * support and need to be valid to the low level
180          * implementation, no valid callback implies that none are valid.
181          */
182         return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
183 }
184
185 void __init pm_states_init(void)
186 {
187         /* "mem" and "freeze" are always present in /sys/power/state. */
188         pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
189         pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
190         /*
191          * Suspend-to-idle should be supported even without any suspend_ops,
192          * initialize mem_sleep_states[] accordingly here.
193          */
194         mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
195 }
196
197 static int __init mem_sleep_default_setup(char *str)
198 {
199         suspend_state_t state;
200
201         for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
202                 if (mem_sleep_labels[state] &&
203                     !strcmp(str, mem_sleep_labels[state])) {
204                         mem_sleep_default = state;
205                         break;
206                 }
207
208         return 1;
209 }
210 __setup("mem_sleep_default=", mem_sleep_default_setup);
211
212 /**
213  * suspend_set_ops - Set the global suspend method table.
214  * @ops: Suspend operations to use.
215  */
216 void suspend_set_ops(const struct platform_suspend_ops *ops)
217 {
218         lock_system_sleep();
219
220         suspend_ops = ops;
221
222         if (valid_state(PM_SUSPEND_STANDBY)) {
223                 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
224                 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
225                 if (mem_sleep_default == PM_SUSPEND_STANDBY)
226                         mem_sleep_current = PM_SUSPEND_STANDBY;
227         }
228         if (valid_state(PM_SUSPEND_MEM)) {
229                 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
230                 if (mem_sleep_default >= PM_SUSPEND_MEM)
231                         mem_sleep_current = PM_SUSPEND_MEM;
232         }
233
234         unlock_system_sleep();
235 }
236 EXPORT_SYMBOL_GPL(suspend_set_ops);
237
238 /**
239  * suspend_valid_only_mem - Generic memory-only valid callback.
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  */
245 int suspend_valid_only_mem(suspend_state_t state)
246 {
247         return state == PM_SUSPEND_MEM;
248 }
249 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
250
251 static bool sleep_state_supported(suspend_state_t state)
252 {
253         return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
254 }
255
256 static int platform_suspend_prepare(suspend_state_t state)
257 {
258         return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
259                 suspend_ops->prepare() : 0;
260 }
261
262 static int platform_suspend_prepare_late(suspend_state_t state)
263 {
264         return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
265                 s2idle_ops->prepare() : 0;
266 }
267
268 static int platform_suspend_prepare_noirq(suspend_state_t state)
269 {
270         return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
271                 suspend_ops->prepare_late() : 0;
272 }
273
274 static void platform_resume_noirq(suspend_state_t state)
275 {
276         if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
277                 suspend_ops->wake();
278 }
279
280 static void platform_resume_early(suspend_state_t state)
281 {
282         if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
283                 s2idle_ops->restore();
284 }
285
286 static void platform_resume_finish(suspend_state_t state)
287 {
288         if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
289                 suspend_ops->finish();
290 }
291
292 static int platform_suspend_begin(suspend_state_t state)
293 {
294         if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
295                 return s2idle_ops->begin();
296         else if (suspend_ops && suspend_ops->begin)
297                 return suspend_ops->begin(state);
298         else
299                 return 0;
300 }
301
302 static void platform_resume_end(suspend_state_t state)
303 {
304         if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
305                 s2idle_ops->end();
306         else if (suspend_ops && suspend_ops->end)
307                 suspend_ops->end();
308 }
309
310 static void platform_recover(suspend_state_t state)
311 {
312         if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
313                 suspend_ops->recover();
314 }
315
316 static bool platform_suspend_again(suspend_state_t state)
317 {
318         return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
319                 suspend_ops->suspend_again() : false;
320 }
321
322 #ifdef CONFIG_PM_DEBUG
323 static unsigned int pm_test_delay = 5;
324 module_param(pm_test_delay, uint, 0644);
325 MODULE_PARM_DESC(pm_test_delay,
326                  "Number of seconds to wait before resuming from suspend test");
327 #endif
328
329 static int suspend_test(int level)
330 {
331 #ifdef CONFIG_PM_DEBUG
332         if (pm_test_level == level) {
333                 pr_info("suspend debug: Waiting for %d second(s).\n",
334                                 pm_test_delay);
335                 mdelay(pm_test_delay * 1000);
336                 return 1;
337         }
338 #endif /* !CONFIG_PM_DEBUG */
339         return 0;
340 }
341
342 /**
343  * suspend_prepare - Prepare for entering system sleep state.
344  *
345  * Common code run for every system sleep state that can be entered (except for
346  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
347  * freeze processes.
348  */
349 static int suspend_prepare(suspend_state_t state)
350 {
351         int error, nr_calls = 0;
352
353         if (!sleep_state_supported(state))
354                 return -EPERM;
355
356         pm_prepare_console();
357
358         error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
359         if (error) {
360                 nr_calls--;
361                 goto Finish;
362         }
363
364         trace_suspend_resume(TPS("freeze_processes"), 0, true);
365         error = suspend_freeze_processes();
366         trace_suspend_resume(TPS("freeze_processes"), 0, false);
367         if (!error)
368                 return 0;
369
370         suspend_stats.failed_freeze++;
371         dpm_save_failed_step(SUSPEND_FREEZE);
372  Finish:
373         __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
374         pm_restore_console();
375         return error;
376 }
377
378 /* default implementation */
379 void __weak arch_suspend_disable_irqs(void)
380 {
381         local_irq_disable();
382 }
383
384 /* default implementation */
385 void __weak arch_suspend_enable_irqs(void)
386 {
387         local_irq_enable();
388 }
389
390 /**
391  * suspend_enter - Make the system enter the given sleep state.
392  * @state: System sleep state to enter.
393  * @wakeup: Returns information that the sleep state should not be re-entered.
394  *
395  * This function should be called after devices have been suspended.
396  */
397 static int suspend_enter(suspend_state_t state, bool *wakeup)
398 {
399         int error;
400
401         error = platform_suspend_prepare(state);
402         if (error)
403                 goto Platform_finish;
404
405         error = dpm_suspend_late(PMSG_SUSPEND);
406         if (error) {
407                 pr_err("late suspend of devices failed\n");
408                 goto Platform_finish;
409         }
410         error = platform_suspend_prepare_late(state);
411         if (error)
412                 goto Devices_early_resume;
413
414         if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
415                 s2idle_loop();
416                 goto Platform_early_resume;
417         }
418
419         error = dpm_suspend_noirq(PMSG_SUSPEND);
420         if (error) {
421                 pr_err("noirq suspend of devices failed\n");
422                 goto Platform_early_resume;
423         }
424         error = platform_suspend_prepare_noirq(state);
425         if (error)
426                 goto Platform_wake;
427
428         if (suspend_test(TEST_PLATFORM))
429                 goto Platform_wake;
430
431         error = disable_nonboot_cpus();
432         if (error || suspend_test(TEST_CPUS))
433                 goto Enable_cpus;
434
435         arch_suspend_disable_irqs();
436         BUG_ON(!irqs_disabled());
437
438         system_state = SYSTEM_SUSPEND;
439
440         error = syscore_suspend();
441         if (!error) {
442                 *wakeup = pm_wakeup_pending();
443                 if (!(suspend_test(TEST_CORE) || *wakeup)) {
444                         trace_suspend_resume(TPS("machine_suspend"),
445                                 state, true);
446                         error = suspend_ops->enter(state);
447                         trace_suspend_resume(TPS("machine_suspend"),
448                                 state, false);
449                 } else if (*wakeup) {
450                         error = -EBUSY;
451                 }
452                 syscore_resume();
453         }
454
455         system_state = SYSTEM_RUNNING;
456
457         arch_suspend_enable_irqs();
458         BUG_ON(irqs_disabled());
459
460  Enable_cpus:
461         enable_nonboot_cpus();
462
463  Platform_wake:
464         platform_resume_noirq(state);
465         dpm_resume_noirq(PMSG_RESUME);
466
467  Platform_early_resume:
468         platform_resume_early(state);
469
470  Devices_early_resume:
471         dpm_resume_early(PMSG_RESUME);
472
473  Platform_finish:
474         platform_resume_finish(state);
475         return error;
476 }
477
478 /**
479  * suspend_devices_and_enter - Suspend devices and enter system sleep state.
480  * @state: System sleep state to enter.
481  */
482 int suspend_devices_and_enter(suspend_state_t state)
483 {
484         int error;
485         bool wakeup = false;
486
487         if (!sleep_state_supported(state))
488                 return -ENOSYS;
489
490         pm_suspend_target_state = state;
491
492         error = platform_suspend_begin(state);
493         if (error)
494                 goto Close;
495
496         suspend_console();
497         suspend_test_start();
498         error = dpm_suspend_start(PMSG_SUSPEND);
499         if (error) {
500                 pr_err("Some devices failed to suspend, or early wake event detected\n");
501                 goto Recover_platform;
502         }
503         suspend_test_finish("suspend devices");
504         if (suspend_test(TEST_DEVICES))
505                 goto Recover_platform;
506
507         do {
508                 error = suspend_enter(state, &wakeup);
509         } while (!error && !wakeup && platform_suspend_again(state));
510
511  Resume_devices:
512         suspend_test_start();
513         dpm_resume_end(PMSG_RESUME);
514         suspend_test_finish("resume devices");
515         trace_suspend_resume(TPS("resume_console"), state, true);
516         resume_console();
517         trace_suspend_resume(TPS("resume_console"), state, false);
518
519  Close:
520         platform_resume_end(state);
521         pm_suspend_target_state = PM_SUSPEND_ON;
522         return error;
523
524  Recover_platform:
525         platform_recover(state);
526         goto Resume_devices;
527 }
528
529 /**
530  * suspend_finish - Clean up before finishing the suspend sequence.
531  *
532  * Call platform code to clean up, restart processes, and free the console that
533  * we've allocated. This routine is not called for hibernation.
534  */
535 static void suspend_finish(void)
536 {
537         suspend_thaw_processes();
538         pm_notifier_call_chain(PM_POST_SUSPEND);
539         pm_restore_console();
540 }
541
542 /**
543  * enter_state - Do common work needed to enter system sleep state.
544  * @state: System sleep state to enter.
545  *
546  * Make sure that no one else is trying to put the system into a sleep state.
547  * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
548  * system enter the given sleep state and clean up after wakeup.
549  */
550 static int enter_state(suspend_state_t state)
551 {
552         int error;
553
554         trace_suspend_resume(TPS("suspend_enter"), state, true);
555         if (state == PM_SUSPEND_TO_IDLE) {
556 #ifdef CONFIG_PM_DEBUG
557                 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
558                         pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
559                         return -EAGAIN;
560                 }
561 #endif
562         } else if (!valid_state(state)) {
563                 return -EINVAL;
564         }
565         if (!mutex_trylock(&system_transition_mutex))
566                 return -EBUSY;
567
568         if (state == PM_SUSPEND_TO_IDLE)
569                 s2idle_begin();
570
571 #ifndef CONFIG_SUSPEND_SKIP_SYNC
572         trace_suspend_resume(TPS("sync_filesystems"), 0, true);
573         pr_info("Syncing filesystems ... ");
574         ksys_sync();
575         pr_cont("done.\n");
576         trace_suspend_resume(TPS("sync_filesystems"), 0, false);
577 #endif
578
579         pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
580         pm_suspend_clear_flags();
581         error = suspend_prepare(state);
582         if (error)
583                 goto Unlock;
584
585         if (suspend_test(TEST_FREEZER))
586                 goto Finish;
587
588         trace_suspend_resume(TPS("suspend_enter"), state, false);
589         pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
590         pm_restrict_gfp_mask();
591         error = suspend_devices_and_enter(state);
592         pm_restore_gfp_mask();
593
594  Finish:
595         events_check_enabled = false;
596         pm_pr_dbg("Finishing wakeup.\n");
597         suspend_finish();
598  Unlock:
599         mutex_unlock(&system_transition_mutex);
600         return error;
601 }
602
603 /**
604  * pm_suspend - Externally visible function for suspending the system.
605  * @state: System sleep state to enter.
606  *
607  * Check if the value of @state represents one of the supported states,
608  * execute enter_state() and update system suspend statistics.
609  */
610 int pm_suspend(suspend_state_t state)
611 {
612         int error;
613
614         if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
615                 return -EINVAL;
616
617         pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
618         error = enter_state(state);
619         if (error) {
620                 suspend_stats.fail++;
621                 dpm_save_failed_errno(error);
622         } else {
623                 suspend_stats.success++;
624         }
625         pr_info("suspend exit\n");
626         return error;
627 }
628 EXPORT_SYMBOL(pm_suspend);