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/syscalls.h>
18 #include <linux/gfp.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/export.h>
25 #include <linux/suspend.h>
26 #include <linux/syscore_ops.h>
27 #include <linux/ftrace.h>
28 #include <trace/events/power.h>
29 #include <linux/compiler.h>
33 const char *const pm_states[PM_SUSPEND_MAX] = {
34 [PM_SUSPEND_FREEZE] = "freeze",
35 [PM_SUSPEND_STANDBY] = "standby",
36 [PM_SUSPEND_MEM] = "mem",
39 static const struct platform_suspend_ops *suspend_ops;
41 static bool need_suspend_ops(suspend_state_t state)
43 return state > PM_SUSPEND_FREEZE;
46 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
47 static bool suspend_freeze_wake;
49 static void freeze_begin(void)
51 suspend_freeze_wake = false;
54 static void freeze_enter(void)
56 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
59 void freeze_wake(void)
61 suspend_freeze_wake = true;
62 wake_up(&suspend_freeze_wait_head);
64 EXPORT_SYMBOL_GPL(freeze_wake);
67 * suspend_set_ops - Set the global suspend method table.
68 * @ops: Suspend operations to use.
70 void suspend_set_ops(const struct platform_suspend_ops *ops)
74 unlock_system_sleep();
76 EXPORT_SYMBOL_GPL(suspend_set_ops);
78 bool valid_state(suspend_state_t state)
80 if (state == PM_SUSPEND_FREEZE) {
81 #ifdef CONFIG_PM_DEBUG
82 if (pm_test_level != TEST_NONE &&
83 pm_test_level != TEST_FREEZER &&
84 pm_test_level != TEST_DEVICES &&
85 pm_test_level != TEST_PLATFORM) {
86 printk(KERN_WARNING "Unsupported pm_test mode for "
87 "freeze state, please choose "
88 "none/freezer/devices/platform.\n");
95 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
96 * support and need to be valid to the lowlevel
97 * implementation, no valid callback implies that none are valid.
99 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
103 * suspend_valid_only_mem - Generic memory-only valid callback.
105 * Platform drivers that implement mem suspend only and only need to check for
106 * that in their .valid() callback can use this instead of rolling their own
109 int suspend_valid_only_mem(suspend_state_t state)
111 return state == PM_SUSPEND_MEM;
113 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
115 static int suspend_test(int level)
117 #ifdef CONFIG_PM_DEBUG
118 if (pm_test_level == level) {
119 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
123 #endif /* !CONFIG_PM_DEBUG */
128 * suspend_prepare - Prepare for entering system sleep state.
130 * Common code run for every system sleep state that can be entered (except for
131 * hibernation). Run suspend notifiers, allocate the "suspend" console and
134 static int suspend_prepare(suspend_state_t state)
138 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
141 pm_prepare_console();
143 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
147 error = suspend_freeze_processes();
151 suspend_stats.failed_freeze++;
152 dpm_save_failed_step(SUSPEND_FREEZE);
154 pm_notifier_call_chain(PM_POST_SUSPEND);
155 pm_restore_console();
159 /* default implementation */
160 void __weak arch_suspend_disable_irqs(void)
165 /* default implementation */
166 void __weak arch_suspend_enable_irqs(void)
172 * suspend_enter - Make the system enter the given sleep state.
173 * @state: System sleep state to enter.
174 * @wakeup: Returns information that the sleep state should not be re-entered.
176 * This function should be called after devices have been suspended.
178 static int suspend_enter(suspend_state_t state, bool *wakeup)
182 if (need_suspend_ops(state) && suspend_ops->prepare) {
183 error = suspend_ops->prepare();
185 goto Platform_finish;
188 error = dpm_suspend_end(PMSG_SUSPEND);
190 printk(KERN_ERR "PM: Some devices failed to power down\n");
191 goto Platform_finish;
194 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
195 error = suspend_ops->prepare_late();
200 if (suspend_test(TEST_PLATFORM))
204 * PM_SUSPEND_FREEZE equals
205 * frozen processes + suspended devices + idle processors.
206 * Thus we should invoke freeze_enter() soon after
207 * all the devices are suspended.
209 if (state == PM_SUSPEND_FREEZE) {
215 error = disable_nonboot_cpus();
216 if (error || suspend_test(TEST_CPUS))
219 arch_suspend_disable_irqs();
220 BUG_ON(!irqs_disabled());
222 error = syscore_suspend();
224 *wakeup = pm_wakeup_pending();
225 if (!(suspend_test(TEST_CORE) || *wakeup)) {
226 error = suspend_ops->enter(state);
227 events_check_enabled = false;
232 arch_suspend_enable_irqs();
233 BUG_ON(irqs_disabled());
236 enable_nonboot_cpus();
240 if (need_suspend_ops(state) && suspend_ops->wake)
243 dpm_resume_start(PMSG_RESUME);
246 if (need_suspend_ops(state) && suspend_ops->finish)
247 suspend_ops->finish();
253 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
254 * @state: System sleep state to enter.
256 int suspend_devices_and_enter(suspend_state_t state)
261 if (need_suspend_ops(state) && !suspend_ops)
264 trace_machine_suspend(state);
265 if (need_suspend_ops(state) && suspend_ops->begin) {
266 error = suspend_ops->begin(state);
271 suspend_test_start();
272 error = dpm_suspend_start(PMSG_SUSPEND);
274 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
275 goto Recover_platform;
277 suspend_test_finish("suspend devices");
278 if (suspend_test(TEST_DEVICES))
279 goto Recover_platform;
282 error = suspend_enter(state, &wakeup);
283 } while (!error && !wakeup && need_suspend_ops(state)
284 && suspend_ops->suspend_again && suspend_ops->suspend_again());
287 suspend_test_start();
288 dpm_resume_end(PMSG_RESUME);
289 suspend_test_finish("resume devices");
292 if (need_suspend_ops(state) && suspend_ops->end)
294 trace_machine_suspend(PWR_EVENT_EXIT);
298 if (need_suspend_ops(state) && suspend_ops->recover)
299 suspend_ops->recover();
304 * suspend_finish - Clean up before finishing the suspend sequence.
306 * Call platform code to clean up, restart processes, and free the console that
307 * we've allocated. This routine is not called for hibernation.
309 static void suspend_finish(void)
311 suspend_thaw_processes();
312 pm_notifier_call_chain(PM_POST_SUSPEND);
313 pm_restore_console();
317 * enter_state - Do common work needed to enter system sleep state.
318 * @state: System sleep state to enter.
320 * Make sure that no one else is trying to put the system into a sleep state.
321 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
322 * system enter the given sleep state and clean up after wakeup.
324 static int enter_state(suspend_state_t state)
328 if (!valid_state(state))
331 if (!mutex_trylock(&pm_mutex))
334 if (state == PM_SUSPEND_FREEZE)
337 printk(KERN_INFO "PM: Syncing filesystems ... ");
341 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
342 error = suspend_prepare(state);
346 if (suspend_test(TEST_FREEZER))
349 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
350 pm_restrict_gfp_mask();
351 error = suspend_devices_and_enter(state);
352 pm_restore_gfp_mask();
355 pr_debug("PM: Finishing wakeup.\n");
358 mutex_unlock(&pm_mutex);
363 * pm_suspend - Externally visible function for suspending the system.
364 * @state: System sleep state to enter.
366 * Check if the value of @state represents one of the supported states,
367 * execute enter_state() and update system suspend statistics.
369 int pm_suspend(suspend_state_t state)
373 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
376 error = enter_state(state);
378 suspend_stats.fail++;
379 dpm_save_failed_errno(error);
381 suspend_stats.success++;
385 EXPORT_SYMBOL(pm_suspend);