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
);
102 /* Push all the CPUs into the idle loop. */
103 wake_up_all_idle_cpus();
104 /* Make the current CPU wait so it can enter the idle loop too. */
105 swait_event_exclusive(s2idle_wait_head
,
106 s2idle_state
== S2IDLE_STATE_WAKE
);
111 raw_spin_lock_irq(&s2idle_lock
);
114 s2idle_state
= S2IDLE_STATE_NONE
;
115 raw_spin_unlock_irq(&s2idle_lock
);
117 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE
, false);
120 static void s2idle_loop(void)
122 pm_pr_dbg("suspend-to-idle\n");
125 * Suspend-to-idle equals:
126 * frozen processes + suspended devices + idle processors.
127 * Thus s2idle_enter() should be called right after all devices have
130 * Wakeups during the noirq suspend of devices may be spurious, so try
131 * to avoid them upfront.
134 if (s2idle_ops
&& s2idle_ops
->wake
) {
135 if (s2idle_ops
->wake())
137 } else if (pm_wakeup_pending()) {
141 pm_wakeup_clear(false);
146 pm_pr_dbg("resume from suspend-to-idle\n");
149 void s2idle_wake(void)
153 raw_spin_lock_irqsave(&s2idle_lock
, flags
);
154 if (s2idle_state
> S2IDLE_STATE_NONE
) {
155 s2idle_state
= S2IDLE_STATE_WAKE
;
156 swake_up_one(&s2idle_wait_head
);
158 raw_spin_unlock_irqrestore(&s2idle_lock
, flags
);
160 EXPORT_SYMBOL_GPL(s2idle_wake
);
162 static bool valid_state(suspend_state_t state
)
165 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
166 * support and need to be valid to the low level
167 * implementation, no valid callback implies that none are valid.
169 return suspend_ops
&& suspend_ops
->valid
&& suspend_ops
->valid(state
);
172 void __init
pm_states_init(void)
174 /* "mem" and "freeze" are always present in /sys/power/state. */
175 pm_states
[PM_SUSPEND_MEM
] = pm_labels
[PM_SUSPEND_MEM
];
176 pm_states
[PM_SUSPEND_TO_IDLE
] = pm_labels
[PM_SUSPEND_TO_IDLE
];
178 * Suspend-to-idle should be supported even without any suspend_ops,
179 * initialize mem_sleep_states[] accordingly here.
181 mem_sleep_states
[PM_SUSPEND_TO_IDLE
] = mem_sleep_labels
[PM_SUSPEND_TO_IDLE
];
184 static int __init
mem_sleep_default_setup(char *str
)
186 suspend_state_t state
;
188 for (state
= PM_SUSPEND_TO_IDLE
; state
<= PM_SUSPEND_MEM
; state
++)
189 if (mem_sleep_labels
[state
] &&
190 !strcmp(str
, mem_sleep_labels
[state
])) {
191 mem_sleep_default
= state
;
197 __setup("mem_sleep_default=", mem_sleep_default_setup
);
200 * suspend_set_ops - Set the global suspend method table.
201 * @ops: Suspend operations to use.
203 void suspend_set_ops(const struct platform_suspend_ops
*ops
)
209 if (valid_state(PM_SUSPEND_STANDBY
)) {
210 mem_sleep_states
[PM_SUSPEND_STANDBY
] = mem_sleep_labels
[PM_SUSPEND_STANDBY
];
211 pm_states
[PM_SUSPEND_STANDBY
] = pm_labels
[PM_SUSPEND_STANDBY
];
212 if (mem_sleep_default
== PM_SUSPEND_STANDBY
)
213 mem_sleep_current
= PM_SUSPEND_STANDBY
;
215 if (valid_state(PM_SUSPEND_MEM
)) {
216 mem_sleep_states
[PM_SUSPEND_MEM
] = mem_sleep_labels
[PM_SUSPEND_MEM
];
217 if (mem_sleep_default
>= PM_SUSPEND_MEM
)
218 mem_sleep_current
= PM_SUSPEND_MEM
;
221 unlock_system_sleep();
223 EXPORT_SYMBOL_GPL(suspend_set_ops
);
226 * suspend_valid_only_mem - Generic memory-only valid callback.
228 * Platform drivers that implement mem suspend only and only need to check for
229 * that in their .valid() callback can use this instead of rolling their own
232 int suspend_valid_only_mem(suspend_state_t state
)
234 return state
== PM_SUSPEND_MEM
;
236 EXPORT_SYMBOL_GPL(suspend_valid_only_mem
);
238 static bool sleep_state_supported(suspend_state_t state
)
240 return state
== PM_SUSPEND_TO_IDLE
|| (suspend_ops
&& suspend_ops
->enter
);
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.
339 * Common code run for every system sleep state that can be entered (except for
340 * hibernation). Run suspend notifiers, allocate the "suspend" console and
343 static int suspend_prepare(suspend_state_t state
)
347 if (!sleep_state_supported(state
))
350 pm_prepare_console();
352 error
= pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE
, PM_POST_SUSPEND
);
356 trace_suspend_resume(TPS("freeze_processes"), 0, true);
357 error
= suspend_freeze_processes();
358 trace_suspend_resume(TPS("freeze_processes"), 0, false);
362 suspend_stats
.failed_freeze
++;
363 dpm_save_failed_step(SUSPEND_FREEZE
);
364 pm_notifier_call_chain(PM_POST_SUSPEND
);
366 pm_restore_console();
370 /* default implementation */
371 void __weak
arch_suspend_disable_irqs(void)
376 /* default implementation */
377 void __weak
arch_suspend_enable_irqs(void)
383 * suspend_enter - Make the system enter the given sleep state.
384 * @state: System sleep state to enter.
385 * @wakeup: Returns information that the sleep state should not be re-entered.
387 * This function should be called after devices have been suspended.
389 static int suspend_enter(suspend_state_t state
, bool *wakeup
)
393 error
= platform_suspend_prepare(state
);
395 goto Platform_finish
;
397 error
= dpm_suspend_late(PMSG_SUSPEND
);
399 pr_err("late suspend of devices failed\n");
400 goto Platform_finish
;
402 error
= platform_suspend_prepare_late(state
);
404 goto Devices_early_resume
;
406 error
= dpm_suspend_noirq(PMSG_SUSPEND
);
408 pr_err("noirq suspend of devices failed\n");
409 goto Platform_early_resume
;
411 error
= platform_suspend_prepare_noirq(state
);
415 if (suspend_test(TEST_PLATFORM
))
418 if (state
== PM_SUSPEND_TO_IDLE
) {
423 error
= suspend_disable_secondary_cpus();
424 if (error
|| suspend_test(TEST_CPUS
))
427 arch_suspend_disable_irqs();
428 BUG_ON(!irqs_disabled());
430 system_state
= SYSTEM_SUSPEND
;
432 error
= syscore_suspend();
434 *wakeup
= pm_wakeup_pending();
435 if (!(suspend_test(TEST_CORE
) || *wakeup
)) {
436 trace_suspend_resume(TPS("machine_suspend"),
438 error
= suspend_ops
->enter(state
);
439 trace_suspend_resume(TPS("machine_suspend"),
441 } else if (*wakeup
) {
447 system_state
= SYSTEM_RUNNING
;
449 arch_suspend_enable_irqs();
450 BUG_ON(irqs_disabled());
453 suspend_enable_secondary_cpus();
456 platform_resume_noirq(state
);
457 dpm_resume_noirq(PMSG_RESUME
);
459 Platform_early_resume
:
460 platform_resume_early(state
);
462 Devices_early_resume
:
463 dpm_resume_early(PMSG_RESUME
);
466 platform_resume_finish(state
);
471 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
472 * @state: System sleep state to enter.
474 int suspend_devices_and_enter(suspend_state_t state
)
479 if (!sleep_state_supported(state
))
482 pm_suspend_target_state
= state
;
484 if (state
== PM_SUSPEND_TO_IDLE
)
485 pm_set_suspend_no_platform();
487 error
= platform_suspend_begin(state
);
492 suspend_test_start();
493 error
= dpm_suspend_start(PMSG_SUSPEND
);
495 pr_err("Some devices failed to suspend, or early wake event detected\n");
496 goto Recover_platform
;
498 suspend_test_finish("suspend devices");
499 if (suspend_test(TEST_DEVICES
))
500 goto Recover_platform
;
503 error
= suspend_enter(state
, &wakeup
);
504 } while (!error
&& !wakeup
&& platform_suspend_again(state
));
507 suspend_test_start();
508 dpm_resume_end(PMSG_RESUME
);
509 suspend_test_finish("resume devices");
510 trace_suspend_resume(TPS("resume_console"), state
, true);
512 trace_suspend_resume(TPS("resume_console"), state
, false);
515 platform_resume_end(state
);
516 pm_suspend_target_state
= PM_SUSPEND_ON
;
520 platform_recover(state
);
525 * suspend_finish - Clean up before finishing the suspend sequence.
527 * Call platform code to clean up, restart processes, and free the console that
528 * we've allocated. This routine is not called for hibernation.
530 static void suspend_finish(void)
532 suspend_thaw_processes();
533 pm_notifier_call_chain(PM_POST_SUSPEND
);
534 pm_restore_console();
538 * enter_state - Do common work needed to enter system sleep state.
539 * @state: System sleep state to enter.
541 * Make sure that no one else is trying to put the system into a sleep state.
542 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
543 * system enter the given sleep state and clean up after wakeup.
545 static int enter_state(suspend_state_t state
)
549 trace_suspend_resume(TPS("suspend_enter"), state
, true);
550 if (state
== PM_SUSPEND_TO_IDLE
) {
551 #ifdef CONFIG_PM_DEBUG
552 if (pm_test_level
!= TEST_NONE
&& pm_test_level
<= TEST_CPUS
) {
553 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
557 } else if (!valid_state(state
)) {
560 if (!mutex_trylock(&system_transition_mutex
))
563 if (state
== PM_SUSPEND_TO_IDLE
)
566 if (sync_on_suspend_enabled
) {
567 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
569 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
572 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels
[state
]);
573 pm_suspend_clear_flags();
574 error
= suspend_prepare(state
);
578 if (suspend_test(TEST_FREEZER
))
581 trace_suspend_resume(TPS("suspend_enter"), state
, false);
582 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels
[state
]);
583 pm_restrict_gfp_mask();
584 error
= suspend_devices_and_enter(state
);
585 pm_restore_gfp_mask();
588 events_check_enabled
= false;
589 pm_pr_dbg("Finishing wakeup.\n");
592 mutex_unlock(&system_transition_mutex
);
597 * pm_suspend - Externally visible function for suspending the system.
598 * @state: System sleep state to enter.
600 * Check if the value of @state represents one of the supported states,
601 * execute enter_state() and update system suspend statistics.
603 int pm_suspend(suspend_state_t state
)
607 if (state
<= PM_SUSPEND_ON
|| state
>= PM_SUSPEND_MAX
)
610 pr_info("suspend entry (%s)\n", mem_sleep_labels
[state
]);
611 error
= enter_state(state
);
613 suspend_stats
.fail
++;
614 dpm_save_failed_errno(error
);
616 suspend_stats
.success
++;
618 pr_info("suspend exit\n");
621 EXPORT_SYMBOL(pm_suspend
);