2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
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.
8 * This file is released under the GPLv2.
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>
21 #include <linux/kernel.h>
22 #include <linux/list.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 #include <linux/moduleparam.h>
35 const char * const pm_labels[] = {
36 [PM_SUSPEND_FREEZE] = "freeze",
37 [PM_SUSPEND_STANDBY] = "standby",
38 [PM_SUSPEND_MEM] = "mem",
40 const char *pm_states[PM_SUSPEND_MAX];
41 static const char * const mem_sleep_labels[] = {
42 [PM_SUSPEND_FREEZE] = "s2idle",
43 [PM_SUSPEND_STANDBY] = "shallow",
44 [PM_SUSPEND_MEM] = "deep",
46 const char *mem_sleep_states[PM_SUSPEND_MAX];
48 suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
49 static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
51 unsigned int pm_suspend_global_flags;
52 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
54 static const struct platform_suspend_ops *suspend_ops;
55 static const struct platform_freeze_ops *freeze_ops;
56 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
58 enum freeze_state __read_mostly suspend_freeze_state;
59 static DEFINE_SPINLOCK(suspend_freeze_lock);
61 void freeze_set_ops(const struct platform_freeze_ops *ops)
65 unlock_system_sleep();
68 static void freeze_begin(void)
70 suspend_freeze_state = FREEZE_STATE_NONE;
73 static void freeze_enter(void)
75 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, true);
77 spin_lock_irq(&suspend_freeze_lock);
78 if (pm_wakeup_pending())
81 suspend_freeze_state = FREEZE_STATE_ENTER;
82 spin_unlock_irq(&suspend_freeze_lock);
87 /* Push all the CPUs into the idle loop. */
88 wake_up_all_idle_cpus();
89 pr_debug("PM: suspend-to-idle\n");
90 /* Make the current CPU wait so it can enter the idle loop too. */
91 wait_event(suspend_freeze_wait_head,
92 suspend_freeze_state == FREEZE_STATE_WAKE);
93 pr_debug("PM: resume from suspend-to-idle\n");
98 spin_lock_irq(&suspend_freeze_lock);
101 suspend_freeze_state = FREEZE_STATE_NONE;
102 spin_unlock_irq(&suspend_freeze_lock);
104 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_FREEZE, false);
107 static void s2idle_loop(void)
112 if (freeze_ops && freeze_ops->wake)
115 dpm_resume_noirq(PMSG_RESUME);
116 if (freeze_ops && freeze_ops->sync)
119 if (pm_wakeup_pending())
122 pm_wakeup_clear(false);
123 } while (!dpm_suspend_noirq(PMSG_SUSPEND));
126 void freeze_wake(void)
130 spin_lock_irqsave(&suspend_freeze_lock, flags);
131 if (suspend_freeze_state > FREEZE_STATE_NONE) {
132 suspend_freeze_state = FREEZE_STATE_WAKE;
133 wake_up(&suspend_freeze_wait_head);
135 spin_unlock_irqrestore(&suspend_freeze_lock, flags);
137 EXPORT_SYMBOL_GPL(freeze_wake);
139 static bool valid_state(suspend_state_t state)
142 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
143 * support and need to be valid to the low level
144 * implementation, no valid callback implies that none are valid.
146 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
149 void __init pm_states_init(void)
151 /* "mem" and "freeze" are always present in /sys/power/state. */
152 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
153 pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE];
155 * Suspend-to-idle should be supported even without any suspend_ops,
156 * initialize mem_sleep_states[] accordingly here.
158 mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE];
161 static int __init mem_sleep_default_setup(char *str)
163 suspend_state_t state;
165 for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++)
166 if (mem_sleep_labels[state] &&
167 !strcmp(str, mem_sleep_labels[state])) {
168 mem_sleep_default = state;
174 __setup("mem_sleep_default=", mem_sleep_default_setup);
177 * suspend_set_ops - Set the global suspend method table.
178 * @ops: Suspend operations to use.
180 void suspend_set_ops(const struct platform_suspend_ops *ops)
186 if (valid_state(PM_SUSPEND_STANDBY)) {
187 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
188 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
189 if (mem_sleep_default == PM_SUSPEND_STANDBY)
190 mem_sleep_current = PM_SUSPEND_STANDBY;
192 if (valid_state(PM_SUSPEND_MEM)) {
193 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
194 if (mem_sleep_default == PM_SUSPEND_MEM)
195 mem_sleep_current = PM_SUSPEND_MEM;
198 unlock_system_sleep();
200 EXPORT_SYMBOL_GPL(suspend_set_ops);
203 * suspend_valid_only_mem - Generic memory-only valid callback.
205 * Platform drivers that implement mem suspend only and only need to check for
206 * that in their .valid() callback can use this instead of rolling their own
209 int suspend_valid_only_mem(suspend_state_t state)
211 return state == PM_SUSPEND_MEM;
213 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
215 static bool sleep_state_supported(suspend_state_t state)
217 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
220 static int platform_suspend_prepare(suspend_state_t state)
222 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
223 suspend_ops->prepare() : 0;
226 static int platform_suspend_prepare_late(suspend_state_t state)
228 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
229 freeze_ops->prepare() : 0;
232 static int platform_suspend_prepare_noirq(suspend_state_t state)
234 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
235 suspend_ops->prepare_late() : 0;
238 static void platform_resume_noirq(suspend_state_t state)
240 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
244 static void platform_resume_early(suspend_state_t state)
246 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
247 freeze_ops->restore();
250 static void platform_resume_finish(suspend_state_t state)
252 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
253 suspend_ops->finish();
256 static int platform_suspend_begin(suspend_state_t state)
258 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
259 return freeze_ops->begin();
260 else if (suspend_ops && suspend_ops->begin)
261 return suspend_ops->begin(state);
266 static void platform_resume_end(suspend_state_t state)
268 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
270 else if (suspend_ops && suspend_ops->end)
274 static void platform_recover(suspend_state_t state)
276 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
277 suspend_ops->recover();
280 static bool platform_suspend_again(suspend_state_t state)
282 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
283 suspend_ops->suspend_again() : false;
286 #ifdef CONFIG_PM_DEBUG
287 static unsigned int pm_test_delay = 5;
288 module_param(pm_test_delay, uint, 0644);
289 MODULE_PARM_DESC(pm_test_delay,
290 "Number of seconds to wait before resuming from suspend test");
293 static int suspend_test(int level)
295 #ifdef CONFIG_PM_DEBUG
296 if (pm_test_level == level) {
297 pr_info("suspend debug: Waiting for %d second(s).\n",
299 mdelay(pm_test_delay * 1000);
302 #endif /* !CONFIG_PM_DEBUG */
307 * suspend_prepare - Prepare for entering system sleep state.
309 * Common code run for every system sleep state that can be entered (except for
310 * hibernation). Run suspend notifiers, allocate the "suspend" console and
313 static int suspend_prepare(suspend_state_t state)
315 int error, nr_calls = 0;
317 if (!sleep_state_supported(state))
320 pm_prepare_console();
322 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
328 trace_suspend_resume(TPS("freeze_processes"), 0, true);
329 error = suspend_freeze_processes();
330 trace_suspend_resume(TPS("freeze_processes"), 0, false);
334 suspend_stats.failed_freeze++;
335 dpm_save_failed_step(SUSPEND_FREEZE);
337 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
338 pm_restore_console();
342 /* default implementation */
343 void __weak arch_suspend_disable_irqs(void)
348 /* default implementation */
349 void __weak arch_suspend_enable_irqs(void)
355 * suspend_enter - Make the system enter the given sleep state.
356 * @state: System sleep state to enter.
357 * @wakeup: Returns information that the sleep state should not be re-entered.
359 * This function should be called after devices have been suspended.
361 static int suspend_enter(suspend_state_t state, bool *wakeup)
365 error = platform_suspend_prepare(state);
367 goto Platform_finish;
369 error = dpm_suspend_late(PMSG_SUSPEND);
371 pr_err("PM: late suspend of devices failed\n");
372 goto Platform_finish;
374 error = platform_suspend_prepare_late(state);
376 goto Devices_early_resume;
378 error = dpm_suspend_noirq(PMSG_SUSPEND);
380 pr_err("PM: noirq suspend of devices failed\n");
381 goto Platform_early_resume;
383 error = platform_suspend_prepare_noirq(state);
387 if (suspend_test(TEST_PLATFORM))
391 * PM_SUSPEND_FREEZE equals
392 * frozen processes + suspended devices + idle processors.
393 * Thus we should invoke freeze_enter() soon after
394 * all the devices are suspended.
396 if (state == PM_SUSPEND_FREEZE) {
398 goto Platform_early_resume;
401 error = disable_nonboot_cpus();
402 if (error || suspend_test(TEST_CPUS))
405 arch_suspend_disable_irqs();
406 BUG_ON(!irqs_disabled());
408 error = syscore_suspend();
410 *wakeup = pm_wakeup_pending();
411 if (!(suspend_test(TEST_CORE) || *wakeup)) {
412 trace_suspend_resume(TPS("machine_suspend"),
414 error = suspend_ops->enter(state);
415 trace_suspend_resume(TPS("machine_suspend"),
417 events_check_enabled = false;
418 } else if (*wakeup) {
424 arch_suspend_enable_irqs();
425 BUG_ON(irqs_disabled());
428 enable_nonboot_cpus();
431 platform_resume_noirq(state);
432 dpm_resume_noirq(PMSG_RESUME);
434 Platform_early_resume:
435 platform_resume_early(state);
437 Devices_early_resume:
438 dpm_resume_early(PMSG_RESUME);
441 platform_resume_finish(state);
446 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
447 * @state: System sleep state to enter.
449 int suspend_devices_and_enter(suspend_state_t state)
454 if (!sleep_state_supported(state))
457 error = platform_suspend_begin(state);
462 suspend_test_start();
463 error = dpm_suspend_start(PMSG_SUSPEND);
465 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
466 goto Recover_platform;
468 suspend_test_finish("suspend devices");
469 if (suspend_test(TEST_DEVICES))
470 goto Recover_platform;
473 error = suspend_enter(state, &wakeup);
474 } while (!error && !wakeup && platform_suspend_again(state));
477 suspend_test_start();
478 dpm_resume_end(PMSG_RESUME);
479 suspend_test_finish("resume devices");
480 trace_suspend_resume(TPS("resume_console"), state, true);
482 trace_suspend_resume(TPS("resume_console"), state, false);
485 platform_resume_end(state);
489 platform_recover(state);
494 * suspend_finish - Clean up before finishing the suspend sequence.
496 * Call platform code to clean up, restart processes, and free the console that
497 * we've allocated. This routine is not called for hibernation.
499 static void suspend_finish(void)
501 suspend_thaw_processes();
502 pm_notifier_call_chain(PM_POST_SUSPEND);
503 pm_restore_console();
507 * enter_state - Do common work needed to enter system sleep state.
508 * @state: System sleep state to enter.
510 * Make sure that no one else is trying to put the system into a sleep state.
511 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
512 * system enter the given sleep state and clean up after wakeup.
514 static int enter_state(suspend_state_t state)
518 trace_suspend_resume(TPS("suspend_enter"), state, true);
519 if (state == PM_SUSPEND_FREEZE) {
520 #ifdef CONFIG_PM_DEBUG
521 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
522 pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
526 } else if (!valid_state(state)) {
529 if (!mutex_trylock(&pm_mutex))
532 if (state == PM_SUSPEND_FREEZE)
535 #ifndef CONFIG_SUSPEND_SKIP_SYNC
536 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
537 pr_info("PM: Syncing filesystems ... ");
540 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
543 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
544 pm_suspend_clear_flags();
545 error = suspend_prepare(state);
549 if (suspend_test(TEST_FREEZER))
552 trace_suspend_resume(TPS("suspend_enter"), state, false);
553 pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
554 pm_restrict_gfp_mask();
555 error = suspend_devices_and_enter(state);
556 pm_restore_gfp_mask();
559 pr_debug("PM: Finishing wakeup.\n");
562 mutex_unlock(&pm_mutex);
567 * pm_suspend - Externally visible function for suspending the system.
568 * @state: System sleep state to enter.
570 * Check if the value of @state represents one of the supported states,
571 * execute enter_state() and update system suspend statistics.
573 int pm_suspend(suspend_state_t state)
577 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
580 error = enter_state(state);
582 suspend_stats.fail++;
583 dpm_save_failed_errno(error);
585 suspend_stats.success++;
589 EXPORT_SYMBOL(pm_suspend);