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 <linux/rtc.h>
29 #include <trace/events/power.h>
30 #include <linux/wakeup_reason.h>
34 const char *const pm_states[PM_SUSPEND_MAX] = {
35 [PM_SUSPEND_FREEZE] = "freeze",
36 [PM_SUSPEND_STANDBY] = "standby",
37 [PM_SUSPEND_MEM] = "mem",
40 static const struct platform_suspend_ops *suspend_ops;
42 static bool need_suspend_ops(suspend_state_t state)
44 return !!(state > PM_SUSPEND_FREEZE);
47 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
48 static bool suspend_freeze_wake;
50 static void freeze_begin(void)
52 suspend_freeze_wake = false;
55 static void freeze_enter(void)
57 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
60 void freeze_wake(void)
62 suspend_freeze_wake = true;
63 wake_up(&suspend_freeze_wait_head);
65 EXPORT_SYMBOL_GPL(freeze_wake);
68 * suspend_set_ops - Set the global suspend method table.
69 * @ops: Suspend operations to use.
71 void suspend_set_ops(const struct platform_suspend_ops *ops)
75 unlock_system_sleep();
77 EXPORT_SYMBOL_GPL(suspend_set_ops);
79 bool valid_state(suspend_state_t state)
81 if (state == PM_SUSPEND_FREEZE) {
82 #ifdef CONFIG_PM_DEBUG
83 if (pm_test_level != TEST_NONE &&
84 pm_test_level != TEST_FREEZER &&
85 pm_test_level != TEST_DEVICES &&
86 pm_test_level != TEST_PLATFORM) {
87 printk(KERN_WARNING "Unsupported pm_test mode for "
88 "freeze state, please choose "
89 "none/freezer/devices/platform.\n");
96 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
97 * support and need to be valid to the lowlevel
98 * implementation, no valid callback implies that none are valid.
100 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
104 * suspend_valid_only_mem - Generic memory-only valid callback.
106 * Platform drivers that implement mem suspend only and only need to check for
107 * that in their .valid() callback can use this instead of rolling their own
110 int suspend_valid_only_mem(suspend_state_t state)
112 return state == PM_SUSPEND_MEM;
114 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
116 static int suspend_test(int level)
118 #ifdef CONFIG_PM_DEBUG
119 if (pm_test_level == level) {
120 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
124 #endif /* !CONFIG_PM_DEBUG */
129 * suspend_prepare - Prepare for entering system sleep state.
131 * Common code run for every system sleep state that can be entered (except for
132 * hibernation). Run suspend notifiers, allocate the "suspend" console and
135 static int suspend_prepare(suspend_state_t state)
139 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
142 pm_prepare_console();
144 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
148 error = suspend_freeze_processes();
151 log_suspend_abort_reason("One or more tasks refusing to freeze");
152 suspend_stats.failed_freeze++;
153 dpm_save_failed_step(SUSPEND_FREEZE);
155 pm_notifier_call_chain(PM_POST_SUSPEND);
156 pm_restore_console();
160 /* default implementation */
161 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
166 /* default implementation */
167 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
173 * suspend_enter - Make the system enter the given sleep state.
174 * @state: System sleep state to enter.
175 * @wakeup: Returns information that the sleep state should not be re-entered.
177 * This function should be called after devices have been suspended.
179 static int suspend_enter(suspend_state_t state, bool *wakeup)
181 char suspend_abort[MAX_SUSPEND_ABORT_LEN];
184 if (need_suspend_ops(state) && suspend_ops->prepare) {
185 error = suspend_ops->prepare();
187 goto Platform_finish;
190 error = dpm_suspend_end(PMSG_SUSPEND);
192 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
193 last_dev %= REC_FAILED_NUM;
194 printk(KERN_ERR "PM: Some devices failed to power down\n");
195 log_suspend_abort_reason("%s device failed to power down",
196 suspend_stats.failed_devs[last_dev]);
197 goto Platform_finish;
200 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
201 error = suspend_ops->prepare_late();
206 if (suspend_test(TEST_PLATFORM))
210 * PM_SUSPEND_FREEZE equals
211 * frozen processes + suspended devices + idle processors.
212 * Thus we should invoke freeze_enter() soon after
213 * all the devices are suspended.
215 if (state == PM_SUSPEND_FREEZE) {
220 error = disable_nonboot_cpus();
221 if (error || suspend_test(TEST_CPUS)) {
222 log_suspend_abort_reason("Disabling non-boot cpus failed");
226 arch_suspend_disable_irqs();
227 BUG_ON(!irqs_disabled());
229 error = syscore_suspend();
231 *wakeup = pm_wakeup_pending();
232 if (!(suspend_test(TEST_CORE) || *wakeup)) {
233 error = suspend_ops->enter(state);
234 events_check_enabled = false;
236 pm_get_active_wakeup_sources(suspend_abort,
237 MAX_SUSPEND_ABORT_LEN);
238 log_suspend_abort_reason(suspend_abort);
243 arch_suspend_enable_irqs();
244 BUG_ON(irqs_disabled());
247 enable_nonboot_cpus();
250 if (need_suspend_ops(state) && suspend_ops->wake)
253 dpm_resume_start(PMSG_RESUME);
256 if (need_suspend_ops(state) && suspend_ops->finish)
257 suspend_ops->finish();
263 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
264 * @state: System sleep state to enter.
266 int suspend_devices_and_enter(suspend_state_t state)
271 if (need_suspend_ops(state) && !suspend_ops)
274 trace_machine_suspend(state);
275 if (need_suspend_ops(state) && suspend_ops->begin) {
276 error = suspend_ops->begin(state);
282 suspend_test_start();
283 error = dpm_suspend_start(PMSG_SUSPEND);
285 printk(KERN_ERR "PM: Some devices failed to suspend\n");
286 log_suspend_abort_reason("Some devices failed to suspend");
287 goto Recover_platform;
289 suspend_test_finish("suspend devices");
290 if (suspend_test(TEST_DEVICES))
291 goto Recover_platform;
294 error = suspend_enter(state, &wakeup);
295 } while (!error && !wakeup && need_suspend_ops(state)
296 && suspend_ops->suspend_again && suspend_ops->suspend_again());
299 suspend_test_start();
300 dpm_resume_end(PMSG_RESUME);
301 suspend_test_finish("resume devices");
305 if (need_suspend_ops(state) && suspend_ops->end)
307 trace_machine_suspend(PWR_EVENT_EXIT);
311 if (need_suspend_ops(state) && suspend_ops->recover)
312 suspend_ops->recover();
317 * suspend_finish - Clean up before finishing the suspend sequence.
319 * Call platform code to clean up, restart processes, and free the console that
320 * we've allocated. This routine is not called for hibernation.
322 static void suspend_finish(void)
324 suspend_thaw_processes();
325 pm_notifier_call_chain(PM_POST_SUSPEND);
326 pm_restore_console();
330 * enter_state - Do common work needed to enter system sleep state.
331 * @state: System sleep state to enter.
333 * Make sure that no one else is trying to put the system into a sleep state.
334 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
335 * system enter the given sleep state and clean up after wakeup.
337 static int enter_state(suspend_state_t state)
341 if (!valid_state(state))
344 if (!mutex_trylock(&pm_mutex))
347 if (state == PM_SUSPEND_FREEZE)
350 printk(KERN_INFO "PM: Syncing filesystems ... ");
354 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
355 error = suspend_prepare(state);
359 if (suspend_test(TEST_FREEZER))
362 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
363 pm_restrict_gfp_mask();
364 error = suspend_devices_and_enter(state);
365 pm_restore_gfp_mask();
368 pr_debug("PM: Finishing wakeup.\n");
371 mutex_unlock(&pm_mutex);
375 static void pm_suspend_marker(char *annotation)
381 rtc_time_to_tm(ts.tv_sec, &tm);
382 pr_info("PM: suspend %s %d-%02d-%02d %02d:%02d:%02d.%09lu UTC\n",
383 annotation, tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
384 tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
388 * pm_suspend - Externally visible function for suspending the system.
389 * @state: System sleep state to enter.
391 * Check if the value of @state represents one of the supported states,
392 * execute enter_state() and update system suspend statistics.
394 int pm_suspend(suspend_state_t state)
398 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
401 pm_suspend_marker("entry");
402 error = enter_state(state);
404 suspend_stats.fail++;
405 dpm_save_failed_errno(error);
407 suspend_stats.success++;
409 pm_suspend_marker("exit");
412 EXPORT_SYMBOL(pm_suspend);