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>
34 struct pm_sleep_state pm_states[PM_SUSPEND_MAX] = {
35 [PM_SUSPEND_FREEZE] = { .label = "freeze", .state = PM_SUSPEND_FREEZE },
36 [PM_SUSPEND_STANDBY] = { .label = "standby", },
37 [PM_SUSPEND_MEM] = { .label = "mem", },
40 static const struct platform_suspend_ops *suspend_ops;
41 static const struct platform_freeze_ops *freeze_ops;
43 static bool need_suspend_ops(suspend_state_t state)
45 return state > PM_SUSPEND_FREEZE;
48 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
49 static bool suspend_freeze_wake;
51 void freeze_set_ops(const struct platform_freeze_ops *ops)
55 unlock_system_sleep();
58 static void freeze_begin(void)
60 suspend_freeze_wake = false;
63 static void freeze_enter(void)
65 cpuidle_use_deepest_state(true);
67 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
69 cpuidle_use_deepest_state(false);
72 void freeze_wake(void)
74 suspend_freeze_wake = true;
75 wake_up(&suspend_freeze_wait_head);
77 EXPORT_SYMBOL_GPL(freeze_wake);
79 static bool valid_state(suspend_state_t state)
82 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
83 * support and need to be valid to the low level
84 * implementation, no valid callback implies that none are valid.
86 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
90 * If this is set, the "mem" label always corresponds to the deepest sleep state
91 * available, the "standby" label corresponds to the second deepest sleep state
92 * available (if any), and the "freeze" label corresponds to the remaining
93 * available sleep state (if there is one).
95 static bool relative_states;
97 static int __init sleep_states_setup(char *str)
99 relative_states = !strncmp(str, "1", 1);
100 if (relative_states) {
101 pm_states[PM_SUSPEND_MEM].state = PM_SUSPEND_FREEZE;
102 pm_states[PM_SUSPEND_FREEZE].state = 0;
107 __setup("relative_sleep_states=", sleep_states_setup);
110 * suspend_set_ops - Set the global suspend method table.
111 * @ops: Suspend operations to use.
113 void suspend_set_ops(const struct platform_suspend_ops *ops)
116 int j = PM_SUSPEND_MAX - 1;
121 for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
123 pm_states[j--].state = i;
124 else if (!relative_states)
125 pm_states[j--].state = 0;
127 pm_states[j--].state = PM_SUSPEND_FREEZE;
128 while (j >= PM_SUSPEND_MIN)
129 pm_states[j--].state = 0;
131 unlock_system_sleep();
133 EXPORT_SYMBOL_GPL(suspend_set_ops);
136 * suspend_valid_only_mem - Generic memory-only valid callback.
138 * Platform drivers that implement mem suspend only and only need to check for
139 * that in their .valid() callback can use this instead of rolling their own
142 int suspend_valid_only_mem(suspend_state_t state)
144 return state == PM_SUSPEND_MEM;
146 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
148 static int suspend_test(int level)
150 #ifdef CONFIG_PM_DEBUG
151 if (pm_test_level == level) {
152 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
156 #endif /* !CONFIG_PM_DEBUG */
161 * suspend_prepare - Prepare for entering system sleep state.
163 * Common code run for every system sleep state that can be entered (except for
164 * hibernation). Run suspend notifiers, allocate the "suspend" console and
167 static int suspend_prepare(suspend_state_t state)
171 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
174 pm_prepare_console();
176 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
180 trace_suspend_resume(TPS("freeze_processes"), 0, true);
181 error = suspend_freeze_processes();
182 trace_suspend_resume(TPS("freeze_processes"), 0, false);
186 suspend_stats.failed_freeze++;
187 dpm_save_failed_step(SUSPEND_FREEZE);
189 pm_notifier_call_chain(PM_POST_SUSPEND);
190 pm_restore_console();
194 /* default implementation */
195 void __weak arch_suspend_disable_irqs(void)
200 /* default implementation */
201 void __weak arch_suspend_enable_irqs(void)
207 * suspend_enter - Make the system enter the given sleep state.
208 * @state: System sleep state to enter.
209 * @wakeup: Returns information that the sleep state should not be re-entered.
211 * This function should be called after devices have been suspended.
213 static int suspend_enter(suspend_state_t state, bool *wakeup)
217 if (need_suspend_ops(state) && suspend_ops->prepare) {
218 error = suspend_ops->prepare();
220 goto Platform_finish;
223 error = dpm_suspend_end(PMSG_SUSPEND);
225 printk(KERN_ERR "PM: Some devices failed to power down\n");
226 goto Platform_finish;
229 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
230 error = suspend_ops->prepare_late();
235 if (suspend_test(TEST_PLATFORM))
239 * PM_SUSPEND_FREEZE equals
240 * frozen processes + suspended devices + idle processors.
241 * Thus we should invoke freeze_enter() soon after
242 * all the devices are suspended.
244 if (state == PM_SUSPEND_FREEZE) {
245 trace_suspend_resume(TPS("machine_suspend"), state, true);
247 trace_suspend_resume(TPS("machine_suspend"), state, false);
252 error = disable_nonboot_cpus();
253 if (error || suspend_test(TEST_CPUS))
256 arch_suspend_disable_irqs();
257 BUG_ON(!irqs_disabled());
259 error = syscore_suspend();
261 *wakeup = pm_wakeup_pending();
262 if (!(suspend_test(TEST_CORE) || *wakeup)) {
263 trace_suspend_resume(TPS("machine_suspend"),
265 error = suspend_ops->enter(state);
266 trace_suspend_resume(TPS("machine_suspend"),
268 events_check_enabled = false;
273 arch_suspend_enable_irqs();
274 BUG_ON(irqs_disabled());
277 enable_nonboot_cpus();
281 if (need_suspend_ops(state) && suspend_ops->wake)
284 dpm_resume_start(PMSG_RESUME);
287 if (need_suspend_ops(state) && suspend_ops->finish)
288 suspend_ops->finish();
294 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
295 * @state: System sleep state to enter.
297 int suspend_devices_and_enter(suspend_state_t state)
302 if (need_suspend_ops(state) && !suspend_ops)
305 if (need_suspend_ops(state) && suspend_ops->begin) {
306 error = suspend_ops->begin(state);
309 } else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin) {
310 error = freeze_ops->begin();
315 suspend_test_start();
316 error = dpm_suspend_start(PMSG_SUSPEND);
318 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
319 goto Recover_platform;
321 suspend_test_finish("suspend devices");
322 if (suspend_test(TEST_DEVICES))
323 goto Recover_platform;
326 error = suspend_enter(state, &wakeup);
327 } while (!error && !wakeup && need_suspend_ops(state)
328 && suspend_ops->suspend_again && suspend_ops->suspend_again());
331 suspend_test_start();
332 dpm_resume_end(PMSG_RESUME);
333 suspend_test_finish("resume devices");
336 if (need_suspend_ops(state) && suspend_ops->end)
338 else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
344 if (need_suspend_ops(state) && suspend_ops->recover)
345 suspend_ops->recover();
350 * suspend_finish - Clean up before finishing the suspend sequence.
352 * Call platform code to clean up, restart processes, and free the console that
353 * we've allocated. This routine is not called for hibernation.
355 static void suspend_finish(void)
357 suspend_thaw_processes();
358 pm_notifier_call_chain(PM_POST_SUSPEND);
359 pm_restore_console();
363 * enter_state - Do common work needed to enter system sleep state.
364 * @state: System sleep state to enter.
366 * Make sure that no one else is trying to put the system into a sleep state.
367 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
368 * system enter the given sleep state and clean up after wakeup.
370 static int enter_state(suspend_state_t state)
374 trace_suspend_resume(TPS("suspend_enter"), state, true);
375 if (state == PM_SUSPEND_FREEZE) {
376 #ifdef CONFIG_PM_DEBUG
377 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
378 pr_warning("PM: Unsupported test mode for freeze state,"
379 "please choose none/freezer/devices/platform.\n");
383 } else if (!valid_state(state)) {
386 if (!mutex_trylock(&pm_mutex))
389 if (state == PM_SUSPEND_FREEZE)
392 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
393 printk(KERN_INFO "PM: Syncing filesystems ... ");
396 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
398 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state].label);
399 error = suspend_prepare(state);
403 if (suspend_test(TEST_FREEZER))
406 trace_suspend_resume(TPS("suspend_enter"), state, false);
407 pr_debug("PM: Entering %s sleep\n", pm_states[state].label);
408 pm_restrict_gfp_mask();
409 error = suspend_devices_and_enter(state);
410 pm_restore_gfp_mask();
413 pr_debug("PM: Finishing wakeup.\n");
416 mutex_unlock(&pm_mutex);
421 * pm_suspend - Externally visible function for suspending the system.
422 * @state: System sleep state to enter.
424 * Check if the value of @state represents one of the supported states,
425 * execute enter_state() and update system suspend statistics.
427 int pm_suspend(suspend_state_t state)
431 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
434 error = enter_state(state);
436 suspend_stats.fail++;
437 dpm_save_failed_errno(error);
439 suspend_stats.success++;
443 EXPORT_SYMBOL(pm_suspend);