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>
32 struct pm_sleep_state pm_states[PM_SUSPEND_MAX] = {
33 [PM_SUSPEND_FREEZE] = { .label = "freeze", .state = PM_SUSPEND_FREEZE },
34 [PM_SUSPEND_STANDBY] = { .label = "standby", },
35 [PM_SUSPEND_MEM] = { .label = "mem", },
38 static const struct platform_suspend_ops *suspend_ops;
40 static bool need_suspend_ops(suspend_state_t state)
42 return !!(state > PM_SUSPEND_FREEZE);
45 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
46 static bool suspend_freeze_wake;
48 static void freeze_begin(void)
50 suspend_freeze_wake = false;
53 static void freeze_enter(void)
55 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
58 void freeze_wake(void)
60 suspend_freeze_wake = true;
61 wake_up(&suspend_freeze_wait_head);
63 EXPORT_SYMBOL_GPL(freeze_wake);
65 static bool valid_state(suspend_state_t state)
68 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
69 * support and need to be valid to the low level
70 * implementation, no valid callback implies that none are valid.
72 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
76 * suspend_set_ops - Set the global suspend method table.
77 * @ops: Suspend operations to use.
79 void suspend_set_ops(const struct platform_suspend_ops *ops)
86 for (i = PM_SUSPEND_STANDBY; i <= PM_SUSPEND_MEM; i++)
87 pm_states[i].state = valid_state(i) ? i : 0;
89 unlock_system_sleep();
91 EXPORT_SYMBOL_GPL(suspend_set_ops);
94 * suspend_valid_only_mem - Generic memory-only valid callback.
96 * Platform drivers that implement mem suspend only and only need to check for
97 * that in their .valid() callback can use this instead of rolling their own
100 int suspend_valid_only_mem(suspend_state_t state)
102 return state == PM_SUSPEND_MEM;
104 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
106 static int suspend_test(int level)
108 #ifdef CONFIG_PM_DEBUG
109 if (pm_test_level == level) {
110 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
114 #endif /* !CONFIG_PM_DEBUG */
119 * suspend_prepare - Prepare for entering system sleep state.
121 * Common code run for every system sleep state that can be entered (except for
122 * hibernation). Run suspend notifiers, allocate the "suspend" console and
125 static int suspend_prepare(suspend_state_t state)
129 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
132 pm_prepare_console();
134 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
138 error = suspend_freeze_processes();
142 suspend_stats.failed_freeze++;
143 dpm_save_failed_step(SUSPEND_FREEZE);
145 pm_notifier_call_chain(PM_POST_SUSPEND);
146 pm_restore_console();
150 /* default implementation */
151 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
156 /* default implementation */
157 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
163 * suspend_enter - Make the system enter the given sleep state.
164 * @state: System sleep state to enter.
165 * @wakeup: Returns information that the sleep state should not be re-entered.
167 * This function should be called after devices have been suspended.
169 static int suspend_enter(suspend_state_t state, bool *wakeup)
173 if (need_suspend_ops(state) && suspend_ops->prepare) {
174 error = suspend_ops->prepare();
176 goto Platform_finish;
179 error = dpm_suspend_end(PMSG_SUSPEND);
181 printk(KERN_ERR "PM: Some devices failed to power down\n");
182 goto Platform_finish;
185 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
186 error = suspend_ops->prepare_late();
191 if (suspend_test(TEST_PLATFORM))
195 * PM_SUSPEND_FREEZE equals
196 * frozen processes + suspended devices + idle processors.
197 * Thus we should invoke freeze_enter() soon after
198 * all the devices are suspended.
200 if (state == PM_SUSPEND_FREEZE) {
205 error = disable_nonboot_cpus();
206 if (error || suspend_test(TEST_CPUS))
209 arch_suspend_disable_irqs();
210 BUG_ON(!irqs_disabled());
212 error = syscore_suspend();
214 *wakeup = pm_wakeup_pending();
215 if (!(suspend_test(TEST_CORE) || *wakeup)) {
216 error = suspend_ops->enter(state);
217 events_check_enabled = false;
222 arch_suspend_enable_irqs();
223 BUG_ON(irqs_disabled());
226 enable_nonboot_cpus();
229 if (need_suspend_ops(state) && suspend_ops->wake)
232 dpm_resume_start(PMSG_RESUME);
235 if (need_suspend_ops(state) && suspend_ops->finish)
236 suspend_ops->finish();
242 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
243 * @state: System sleep state to enter.
245 int suspend_devices_and_enter(suspend_state_t state)
250 if (need_suspend_ops(state) && !suspend_ops)
253 trace_machine_suspend(state);
254 if (need_suspend_ops(state) && suspend_ops->begin) {
255 error = suspend_ops->begin(state);
261 suspend_test_start();
262 error = dpm_suspend_start(PMSG_SUSPEND);
264 printk(KERN_ERR "PM: Some devices failed to suspend\n");
265 goto Recover_platform;
267 suspend_test_finish("suspend devices");
268 if (suspend_test(TEST_DEVICES))
269 goto Recover_platform;
272 error = suspend_enter(state, &wakeup);
273 } while (!error && !wakeup && need_suspend_ops(state)
274 && suspend_ops->suspend_again && suspend_ops->suspend_again());
277 suspend_test_start();
278 dpm_resume_end(PMSG_RESUME);
279 suspend_test_finish("resume devices");
283 if (need_suspend_ops(state) && suspend_ops->end)
285 trace_machine_suspend(PWR_EVENT_EXIT);
289 if (need_suspend_ops(state) && suspend_ops->recover)
290 suspend_ops->recover();
295 * suspend_finish - Clean up before finishing the suspend sequence.
297 * Call platform code to clean up, restart processes, and free the console that
298 * we've allocated. This routine is not called for hibernation.
300 static void suspend_finish(void)
302 suspend_thaw_processes();
303 pm_notifier_call_chain(PM_POST_SUSPEND);
304 pm_restore_console();
308 * enter_state - Do common work needed to enter system sleep state.
309 * @state: System sleep state to enter.
311 * Make sure that no one else is trying to put the system into a sleep state.
312 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
313 * system enter the given sleep state and clean up after wakeup.
315 static int enter_state(suspend_state_t state)
319 if (state == PM_SUSPEND_FREEZE) {
320 #ifdef CONFIG_PM_DEBUG
321 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
322 pr_warning("PM: Unsupported test mode for freeze state,"
323 "please choose none/freezer/devices/platform.\n");
327 } else if (!valid_state(state)) {
330 if (!mutex_trylock(&pm_mutex))
333 if (state == PM_SUSPEND_FREEZE)
336 printk(KERN_INFO "PM: Syncing filesystems ... ");
340 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label);
341 error = suspend_prepare(state);
345 if (suspend_test(TEST_FREEZER))
348 pr_debug("PM: Entering %s sleep\n", pm_states[state].label);
349 pm_restrict_gfp_mask();
350 error = suspend_devices_and_enter(state);
351 pm_restore_gfp_mask();
354 pr_debug("PM: Finishing wakeup.\n");
357 mutex_unlock(&pm_mutex);
362 * pm_suspend - Externally visible function for suspending the system.
363 * @state: System sleep state to enter.
365 * Check if the value of @state represents one of the supported states,
366 * execute enter_state() and update system suspend statistics.
368 int pm_suspend(suspend_state_t state)
372 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
375 error = enter_state(state);
377 suspend_stats.fail++;
378 dpm_save_failed_errno(error);
380 suspend_stats.success++;
384 EXPORT_SYMBOL(pm_suspend);