1 // SPDX-License-Identifier: GPL-2.0-only
3 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
10 #define pr_fmt(fmt) "PM: " fmt
12 #include <linux/string.h>
13 #include <linux/delay.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/console.h>
17 #include <linux/cpu.h>
18 #include <linux/cpuidle.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/swait.h>
29 #include <linux/ftrace.h>
30 #include <trace/events/power.h>
31 #include <linux/compiler.h>
32 #include <linux/moduleparam.h>
36 const char * const pm_labels[] = {
37 [PM_SUSPEND_TO_IDLE] = "freeze",
38 [PM_SUSPEND_STANDBY] = "standby",
39 [PM_SUSPEND_MEM] = "mem",
41 const char *pm_states[PM_SUSPEND_MAX];
42 static const char * const mem_sleep_labels[] = {
43 [PM_SUSPEND_TO_IDLE] = "s2idle",
44 [PM_SUSPEND_STANDBY] = "shallow",
45 [PM_SUSPEND_MEM] = "deep",
47 const char *mem_sleep_states[PM_SUSPEND_MAX];
49 suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
50 suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
51 suspend_state_t pm_suspend_target_state;
52 EXPORT_SYMBOL_GPL(pm_suspend_target_state);
54 unsigned int pm_suspend_global_flags;
55 EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
57 static const struct platform_suspend_ops *suspend_ops;
58 static const struct platform_s2idle_ops *s2idle_ops;
59 static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
61 enum s2idle_states __read_mostly s2idle_state;
62 static DEFINE_RAW_SPINLOCK(s2idle_lock);
65 * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
67 * Return 'true' if suspend-to-idle has been selected as the default system
70 bool pm_suspend_default_s2idle(void)
72 return mem_sleep_current == PM_SUSPEND_TO_IDLE;
74 EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
76 void s2idle_set_ops(const struct platform_s2idle_ops *ops)
80 unlock_system_sleep();
83 static void s2idle_begin(void)
85 s2idle_state = S2IDLE_STATE_NONE;
88 static void s2idle_enter(void)
90 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
92 raw_spin_lock_irq(&s2idle_lock);
93 if (pm_wakeup_pending())
96 s2idle_state = S2IDLE_STATE_ENTER;
97 raw_spin_unlock_irq(&s2idle_lock);
101 /* Push all the CPUs into the idle loop. */
102 wake_up_all_idle_cpus();
103 /* Make the current CPU wait so it can enter the idle loop too. */
104 swait_event_exclusive(s2idle_wait_head,
105 s2idle_state == S2IDLE_STATE_WAKE);
109 raw_spin_lock_irq(&s2idle_lock);
112 s2idle_state = S2IDLE_STATE_NONE;
113 raw_spin_unlock_irq(&s2idle_lock);
115 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
118 static void s2idle_loop(void)
120 pm_pr_dbg("suspend-to-idle\n");
123 * Suspend-to-idle equals:
124 * frozen processes + suspended devices + idle processors.
125 * Thus s2idle_enter() should be called right after all devices have
128 * Wakeups during the noirq suspend of devices may be spurious, so try
129 * to avoid them upfront.
132 if (s2idle_ops && s2idle_ops->wake) {
133 if (s2idle_ops->wake())
135 } else if (pm_wakeup_pending()) {
142 pm_pr_dbg("resume from suspend-to-idle\n");
145 void s2idle_wake(void)
149 raw_spin_lock_irqsave(&s2idle_lock, flags);
150 if (s2idle_state > S2IDLE_STATE_NONE) {
151 s2idle_state = S2IDLE_STATE_WAKE;
152 swake_up_one(&s2idle_wait_head);
154 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
156 EXPORT_SYMBOL_GPL(s2idle_wake);
158 static bool valid_state(suspend_state_t state)
161 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
162 * support and need to be valid to the low-level implementation.
164 * No ->valid() or ->enter() callback implies that none are valid.
166 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
170 void __init pm_states_init(void)
172 /* "mem" and "freeze" are always present in /sys/power/state. */
173 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
174 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
176 * Suspend-to-idle should be supported even without any suspend_ops,
177 * initialize mem_sleep_states[] accordingly here.
179 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
182 static int __init mem_sleep_default_setup(char *str)
184 suspend_state_t state;
186 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
187 if (mem_sleep_labels[state] &&
188 !strcmp(str, mem_sleep_labels[state])) {
189 mem_sleep_default = state;
195 __setup("mem_sleep_default=", mem_sleep_default_setup);
198 * suspend_set_ops - Set the global suspend method table.
199 * @ops: Suspend operations to use.
201 void suspend_set_ops(const struct platform_suspend_ops *ops)
207 if (valid_state(PM_SUSPEND_STANDBY)) {
208 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
209 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
210 if (mem_sleep_default == PM_SUSPEND_STANDBY)
211 mem_sleep_current = PM_SUSPEND_STANDBY;
213 if (valid_state(PM_SUSPEND_MEM)) {
214 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
215 if (mem_sleep_default >= PM_SUSPEND_MEM)
216 mem_sleep_current = PM_SUSPEND_MEM;
219 unlock_system_sleep();
221 EXPORT_SYMBOL_GPL(suspend_set_ops);
224 * suspend_valid_only_mem - Generic memory-only valid callback.
225 * @state: Target system sleep state.
227 * Platform drivers that implement mem suspend only and only need to check for
228 * that in their .valid() callback can use this instead of rolling their own
231 int suspend_valid_only_mem(suspend_state_t state)
233 return state == PM_SUSPEND_MEM;
235 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
237 static bool sleep_state_supported(suspend_state_t state)
239 return state == PM_SUSPEND_TO_IDLE ||
240 (valid_state(state) && !cxl_mem_active());
243 static int platform_suspend_prepare(suspend_state_t state)
245 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
246 suspend_ops->prepare() : 0;
249 static int platform_suspend_prepare_late(suspend_state_t state)
251 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
252 s2idle_ops->prepare() : 0;
255 static int platform_suspend_prepare_noirq(suspend_state_t state)
257 if (state == PM_SUSPEND_TO_IDLE)
258 return s2idle_ops && s2idle_ops->prepare_late ?
259 s2idle_ops->prepare_late() : 0;
261 return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
264 static void platform_resume_noirq(suspend_state_t state)
266 if (state == PM_SUSPEND_TO_IDLE) {
267 if (s2idle_ops && s2idle_ops->restore_early)
268 s2idle_ops->restore_early();
269 } else if (suspend_ops->wake) {
274 static void platform_resume_early(suspend_state_t state)
276 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
277 s2idle_ops->restore();
280 static void platform_resume_finish(suspend_state_t state)
282 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
283 suspend_ops->finish();
286 static int platform_suspend_begin(suspend_state_t state)
288 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
289 return s2idle_ops->begin();
290 else if (suspend_ops && suspend_ops->begin)
291 return suspend_ops->begin(state);
296 static void platform_resume_end(suspend_state_t state)
298 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
300 else if (suspend_ops && suspend_ops->end)
304 static void platform_recover(suspend_state_t state)
306 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
307 suspend_ops->recover();
310 static bool platform_suspend_again(suspend_state_t state)
312 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
313 suspend_ops->suspend_again() : false;
316 #ifdef CONFIG_PM_DEBUG
317 static unsigned int pm_test_delay = 5;
318 module_param(pm_test_delay, uint, 0644);
319 MODULE_PARM_DESC(pm_test_delay,
320 "Number of seconds to wait before resuming from suspend test");
323 static int suspend_test(int level)
325 #ifdef CONFIG_PM_DEBUG
326 if (pm_test_level == level) {
327 pr_info("suspend debug: Waiting for %d second(s).\n",
329 mdelay(pm_test_delay * 1000);
332 #endif /* !CONFIG_PM_DEBUG */
337 * suspend_prepare - Prepare for entering system sleep state.
338 * @state: Target system sleep state.
340 * Common code run for every system sleep state that can be entered (except for
341 * hibernation). Run suspend notifiers, allocate the "suspend" console and
344 static int suspend_prepare(suspend_state_t state)
348 if (!sleep_state_supported(state))
351 pm_prepare_console();
353 error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
357 trace_suspend_resume(TPS("freeze_processes"), 0, true);
358 error = suspend_freeze_processes();
359 trace_suspend_resume(TPS("freeze_processes"), 0, false);
363 suspend_stats.failed_freeze++;
364 dpm_save_failed_step(SUSPEND_FREEZE);
365 pm_notifier_call_chain(PM_POST_SUSPEND);
367 pm_restore_console();
371 /* default implementation */
372 void __weak arch_suspend_disable_irqs(void)
377 /* default implementation */
378 void __weak arch_suspend_enable_irqs(void)
384 * suspend_enter - Make the system enter the given sleep state.
385 * @state: System sleep state to enter.
386 * @wakeup: Returns information that the sleep state should not be re-entered.
388 * This function should be called after devices have been suspended.
390 static int suspend_enter(suspend_state_t state, bool *wakeup)
394 error = platform_suspend_prepare(state);
396 goto Platform_finish;
398 error = dpm_suspend_late(PMSG_SUSPEND);
400 pr_err("late suspend of devices failed\n");
401 goto Platform_finish;
403 error = platform_suspend_prepare_late(state);
405 goto Devices_early_resume;
407 error = dpm_suspend_noirq(PMSG_SUSPEND);
409 pr_err("noirq suspend of devices failed\n");
410 goto Platform_early_resume;
412 error = platform_suspend_prepare_noirq(state);
416 if (suspend_test(TEST_PLATFORM))
419 if (state == PM_SUSPEND_TO_IDLE) {
424 error = pm_sleep_disable_secondary_cpus();
425 if (error || suspend_test(TEST_CPUS))
428 arch_suspend_disable_irqs();
429 BUG_ON(!irqs_disabled());
431 system_state = SYSTEM_SUSPEND;
433 error = syscore_suspend();
435 *wakeup = pm_wakeup_pending();
436 if (!(suspend_test(TEST_CORE) || *wakeup)) {
437 trace_suspend_resume(TPS("machine_suspend"),
439 error = suspend_ops->enter(state);
440 trace_suspend_resume(TPS("machine_suspend"),
442 } else if (*wakeup) {
448 system_state = SYSTEM_RUNNING;
450 arch_suspend_enable_irqs();
451 BUG_ON(irqs_disabled());
454 pm_sleep_enable_secondary_cpus();
457 platform_resume_noirq(state);
458 dpm_resume_noirq(PMSG_RESUME);
460 Platform_early_resume:
461 platform_resume_early(state);
463 Devices_early_resume:
464 dpm_resume_early(PMSG_RESUME);
467 platform_resume_finish(state);
472 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
473 * @state: System sleep state to enter.
475 int suspend_devices_and_enter(suspend_state_t state)
480 if (!sleep_state_supported(state))
483 pm_suspend_target_state = state;
485 if (state == PM_SUSPEND_TO_IDLE)
486 pm_set_suspend_no_platform();
488 error = platform_suspend_begin(state);
493 suspend_test_start();
494 error = dpm_suspend_start(PMSG_SUSPEND);
496 pr_err("Some devices failed to suspend, or early wake event detected\n");
497 goto Recover_platform;
499 suspend_test_finish("suspend devices");
500 if (suspend_test(TEST_DEVICES))
501 goto Recover_platform;
504 error = suspend_enter(state, &wakeup);
505 } while (!error && !wakeup && platform_suspend_again(state));
508 suspend_test_start();
509 dpm_resume_end(PMSG_RESUME);
510 suspend_test_finish("resume devices");
511 trace_suspend_resume(TPS("resume_console"), state, true);
513 trace_suspend_resume(TPS("resume_console"), state, false);
516 platform_resume_end(state);
517 pm_suspend_target_state = PM_SUSPEND_ON;
521 platform_recover(state);
526 * suspend_finish - Clean up before finishing the suspend sequence.
528 * Call platform code to clean up, restart processes, and free the console that
529 * we've allocated. This routine is not called for hibernation.
531 static void suspend_finish(void)
533 suspend_thaw_processes();
534 pm_notifier_call_chain(PM_POST_SUSPEND);
535 pm_restore_console();
539 * enter_state - Do common work needed to enter system sleep state.
540 * @state: System sleep state to enter.
542 * Make sure that no one else is trying to put the system into a sleep state.
543 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
544 * system enter the given sleep state and clean up after wakeup.
546 static int enter_state(suspend_state_t state)
550 trace_suspend_resume(TPS("suspend_enter"), state, true);
551 if (state == PM_SUSPEND_TO_IDLE) {
552 #ifdef CONFIG_PM_DEBUG
553 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
554 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
558 } else if (!valid_state(state)) {
561 if (!mutex_trylock(&system_transition_mutex))
564 if (state == PM_SUSPEND_TO_IDLE)
567 if (sync_on_suspend_enabled) {
568 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
570 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
573 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
574 pm_suspend_clear_flags();
575 error = suspend_prepare(state);
579 if (suspend_test(TEST_FREEZER))
582 trace_suspend_resume(TPS("suspend_enter"), state, false);
583 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
584 pm_restrict_gfp_mask();
585 error = suspend_devices_and_enter(state);
586 pm_restore_gfp_mask();
589 events_check_enabled = false;
590 pm_pr_dbg("Finishing wakeup.\n");
593 mutex_unlock(&system_transition_mutex);
598 * pm_suspend - Externally visible function for suspending the system.
599 * @state: System sleep state to enter.
601 * Check if the value of @state represents one of the supported states,
602 * execute enter_state() and update system suspend statistics.
604 int pm_suspend(suspend_state_t state)
608 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
611 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
612 error = enter_state(state);
614 suspend_stats.fail++;
615 dpm_save_failed_errno(error);
617 suspend_stats.success++;
619 pr_info("suspend exit\n");
622 EXPORT_SYMBOL(pm_suspend);