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 <linux/rtc.h>
30 #include <trace/events/power.h>
31 #include <linux/compiler.h>
32 #include <linux/moduleparam.h>
33 #include <linux/wakeup_reason.h>
37 const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
38 const char *pm_states[PM_SUSPEND_MAX];
40 unsigned int pm_suspend_global_flags;
41 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
43 static const struct platform_suspend_ops *suspend_ops;
44 static const struct platform_freeze_ops *freeze_ops;
45 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
47 enum freeze_state __read_mostly suspend_freeze_state;
48 static DEFINE_SPINLOCK(suspend_freeze_lock);
50 void freeze_set_ops(const struct platform_freeze_ops *ops)
54 unlock_system_sleep();
57 static void freeze_begin(void)
59 suspend_freeze_state = FREEZE_STATE_NONE;
62 static void freeze_enter(void)
64 spin_lock_irq(&suspend_freeze_lock);
65 if (pm_wakeup_pending())
68 suspend_freeze_state = FREEZE_STATE_ENTER;
69 spin_unlock_irq(&suspend_freeze_lock);
74 /* Push all the CPUs into the idle loop. */
75 wake_up_all_idle_cpus();
76 pr_debug("PM: suspend-to-idle\n");
77 /* Make the current CPU wait so it can enter the idle loop too. */
78 wait_event(suspend_freeze_wait_head,
79 suspend_freeze_state == FREEZE_STATE_WAKE);
80 pr_debug("PM: resume from suspend-to-idle\n");
85 spin_lock_irq(&suspend_freeze_lock);
88 suspend_freeze_state = FREEZE_STATE_NONE;
89 spin_unlock_irq(&suspend_freeze_lock);
92 void freeze_wake(void)
96 spin_lock_irqsave(&suspend_freeze_lock, flags);
97 if (suspend_freeze_state > FREEZE_STATE_NONE) {
98 suspend_freeze_state = FREEZE_STATE_WAKE;
99 wake_up(&suspend_freeze_wait_head);
101 spin_unlock_irqrestore(&suspend_freeze_lock, flags);
103 EXPORT_SYMBOL_GPL(freeze_wake);
105 static bool valid_state(suspend_state_t state)
108 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
109 * support and need to be valid to the low level
110 * implementation, no valid callback implies that none are valid.
112 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
116 * If this is set, the "mem" label always corresponds to the deepest sleep state
117 * available, the "standby" label corresponds to the second deepest sleep state
118 * available (if any), and the "freeze" label corresponds to the remaining
119 * available sleep state (if there is one).
121 static bool relative_states;
123 static int __init sleep_states_setup(char *str)
125 relative_states = !strncmp(str, "1", 1);
126 pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
130 __setup("relative_sleep_states=", sleep_states_setup);
133 * suspend_set_ops - Set the global suspend method table.
134 * @ops: Suspend operations to use.
136 void suspend_set_ops(const struct platform_suspend_ops *ops)
144 for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
145 if (valid_state(i)) {
146 pm_states[i] = pm_labels[j++];
147 } else if (!relative_states) {
152 pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
154 unlock_system_sleep();
156 EXPORT_SYMBOL_GPL(suspend_set_ops);
159 * suspend_valid_only_mem - Generic memory-only valid callback.
161 * Platform drivers that implement mem suspend only and only need to check for
162 * that in their .valid() callback can use this instead of rolling their own
165 int suspend_valid_only_mem(suspend_state_t state)
167 return state == PM_SUSPEND_MEM;
169 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
171 static bool sleep_state_supported(suspend_state_t state)
173 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
176 static int platform_suspend_prepare(suspend_state_t state)
178 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
179 suspend_ops->prepare() : 0;
182 static int platform_suspend_prepare_late(suspend_state_t state)
184 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
185 freeze_ops->prepare() : 0;
188 static int platform_suspend_prepare_noirq(suspend_state_t state)
190 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
191 suspend_ops->prepare_late() : 0;
194 static void platform_resume_noirq(suspend_state_t state)
196 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
200 static void platform_resume_early(suspend_state_t state)
202 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
203 freeze_ops->restore();
206 static void platform_resume_finish(suspend_state_t state)
208 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
209 suspend_ops->finish();
212 static int platform_suspend_begin(suspend_state_t state)
214 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
215 return freeze_ops->begin();
216 else if (suspend_ops->begin)
217 return suspend_ops->begin(state);
222 static void platform_resume_end(suspend_state_t state)
224 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
226 else if (suspend_ops->end)
230 static void platform_recover(suspend_state_t state)
232 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
233 suspend_ops->recover();
236 static bool platform_suspend_again(suspend_state_t state)
238 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
239 suspend_ops->suspend_again() : false;
242 #ifdef CONFIG_PM_DEBUG
243 static unsigned int pm_test_delay = 5;
244 module_param(pm_test_delay, uint, 0644);
245 MODULE_PARM_DESC(pm_test_delay,
246 "Number of seconds to wait before resuming from suspend test");
249 static int suspend_test(int level)
251 #ifdef CONFIG_PM_DEBUG
252 if (pm_test_level == level) {
253 printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
255 mdelay(pm_test_delay * 1000);
258 #endif /* !CONFIG_PM_DEBUG */
263 * suspend_prepare - Prepare for entering system sleep state.
265 * Common code run for every system sleep state that can be entered (except for
266 * hibernation). Run suspend notifiers, allocate the "suspend" console and
269 static int suspend_prepare(suspend_state_t state)
273 if (!sleep_state_supported(state))
276 pm_prepare_console();
278 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
282 trace_suspend_resume(TPS("freeze_processes"), 0, true);
283 error = suspend_freeze_processes();
284 trace_suspend_resume(TPS("freeze_processes"), 0, false);
288 suspend_stats.failed_freeze++;
289 dpm_save_failed_step(SUSPEND_FREEZE);
291 pm_notifier_call_chain(PM_POST_SUSPEND);
292 pm_restore_console();
296 /* default implementation */
297 void __weak arch_suspend_disable_irqs(void)
302 /* default implementation */
303 void __weak arch_suspend_enable_irqs(void)
309 * suspend_enter - Make the system enter the given sleep state.
310 * @state: System sleep state to enter.
311 * @wakeup: Returns information that the sleep state should not be re-entered.
313 * This function should be called after devices have been suspended.
315 static int suspend_enter(suspend_state_t state, bool *wakeup)
317 char suspend_abort[MAX_SUSPEND_ABORT_LEN];
320 error = platform_suspend_prepare(state);
322 goto Platform_finish;
324 error = dpm_suspend_late(PMSG_SUSPEND);
326 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
327 last_dev %= REC_FAILED_NUM;
328 printk(KERN_ERR "PM: late suspend of devices failed\n");
329 log_suspend_abort_reason("%s device failed to power down",
330 suspend_stats.failed_devs[last_dev]);
331 goto Platform_finish;
333 error = platform_suspend_prepare_late(state);
335 goto Devices_early_resume;
337 error = dpm_suspend_noirq(PMSG_SUSPEND);
339 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
340 last_dev %= REC_FAILED_NUM;
341 printk(KERN_ERR "PM: noirq suspend of devices failed\n");
342 log_suspend_abort_reason("noirq suspend of %s device failed",
343 suspend_stats.failed_devs[last_dev]);
344 goto Platform_early_resume;
346 error = platform_suspend_prepare_noirq(state);
350 if (suspend_test(TEST_PLATFORM))
354 * PM_SUSPEND_FREEZE equals
355 * frozen processes + suspended devices + idle processors.
356 * Thus we should invoke freeze_enter() soon after
357 * all the devices are suspended.
359 if (state == PM_SUSPEND_FREEZE) {
360 trace_suspend_resume(TPS("machine_suspend"), state, true);
362 trace_suspend_resume(TPS("machine_suspend"), state, false);
366 error = disable_nonboot_cpus();
367 if (error || suspend_test(TEST_CPUS)) {
368 log_suspend_abort_reason("Disabling non-boot cpus failed");
372 arch_suspend_disable_irqs();
373 BUG_ON(!irqs_disabled());
375 error = syscore_suspend();
377 *wakeup = pm_wakeup_pending();
378 if (!(suspend_test(TEST_CORE) || *wakeup)) {
379 trace_suspend_resume(TPS("machine_suspend"),
381 error = suspend_ops->enter(state);
382 trace_suspend_resume(TPS("machine_suspend"),
384 events_check_enabled = false;
385 } else if (*wakeup) {
386 pm_get_active_wakeup_sources(suspend_abort,
387 MAX_SUSPEND_ABORT_LEN);
388 log_suspend_abort_reason(suspend_abort);
394 arch_suspend_enable_irqs();
395 BUG_ON(irqs_disabled());
398 enable_nonboot_cpus();
401 platform_resume_noirq(state);
402 dpm_resume_noirq(PMSG_RESUME);
404 Platform_early_resume:
405 platform_resume_early(state);
407 Devices_early_resume:
408 dpm_resume_early(PMSG_RESUME);
411 platform_resume_finish(state);
416 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
417 * @state: System sleep state to enter.
419 int suspend_devices_and_enter(suspend_state_t state)
424 if (!sleep_state_supported(state))
427 error = platform_suspend_begin(state);
432 suspend_test_start();
433 error = dpm_suspend_start(PMSG_SUSPEND);
435 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
436 log_suspend_abort_reason("Some devices failed to suspend, or early wake event detected");
437 goto Recover_platform;
439 suspend_test_finish("suspend devices");
440 if (suspend_test(TEST_DEVICES))
441 goto Recover_platform;
444 error = suspend_enter(state, &wakeup);
445 } while (!error && !wakeup && platform_suspend_again(state));
448 suspend_test_start();
449 dpm_resume_end(PMSG_RESUME);
450 suspend_test_finish("resume devices");
451 trace_suspend_resume(TPS("resume_console"), state, true);
453 trace_suspend_resume(TPS("resume_console"), state, false);
456 platform_resume_end(state);
460 platform_recover(state);
465 * suspend_finish - Clean up before finishing the suspend sequence.
467 * Call platform code to clean up, restart processes, and free the console that
468 * we've allocated. This routine is not called for hibernation.
470 static void suspend_finish(void)
472 suspend_thaw_processes();
473 pm_notifier_call_chain(PM_POST_SUSPEND);
474 pm_restore_console();
478 * enter_state - Do common work needed to enter system sleep state.
479 * @state: System sleep state to enter.
481 * Make sure that no one else is trying to put the system into a sleep state.
482 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
483 * system enter the given sleep state and clean up after wakeup.
485 static int enter_state(suspend_state_t state)
489 trace_suspend_resume(TPS("suspend_enter"), state, true);
490 if (state == PM_SUSPEND_FREEZE) {
491 #ifdef CONFIG_PM_DEBUG
492 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
493 pr_warning("PM: Unsupported test mode for suspend to idle,"
494 "please choose none/freezer/devices/platform.\n");
498 } else if (!valid_state(state)) {
501 if (!mutex_trylock(&pm_mutex))
504 if (state == PM_SUSPEND_FREEZE)
507 #ifndef CONFIG_SUSPEND_SKIP_SYNC
508 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
509 printk(KERN_INFO "PM: Syncing filesystems ... ");
512 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
515 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
516 pm_suspend_clear_flags();
517 error = suspend_prepare(state);
521 if (suspend_test(TEST_FREEZER))
524 trace_suspend_resume(TPS("suspend_enter"), state, false);
525 pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
526 pm_restrict_gfp_mask();
527 error = suspend_devices_and_enter(state);
528 pm_restore_gfp_mask();
531 pr_debug("PM: Finishing wakeup.\n");
534 mutex_unlock(&pm_mutex);
538 static void pm_suspend_marker(char *annotation)
544 rtc_time_to_tm(ts.tv_sec, &tm);
545 pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
546 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
547 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
551 * pm_suspend - Externally visible function for suspending the system.
552 * @state: System sleep state to enter.
554 * Check if the value of @state represents one of the supported states,
555 * execute enter_state() and update system suspend statistics.
557 int pm_suspend(suspend_state_t state)
561 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
564 pm_suspend_marker("entry");
565 error = enter_state(state);
567 suspend_stats.fail++;
568 dpm_save_failed_errno(error);
570 suspend_stats.success++;
572 pm_suspend_marker("exit");
575 EXPORT_SYMBOL(pm_suspend);