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1/*
2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
3 *
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.
7 *
8 * This file is released under the GPLv2.
9 */
10
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>
19#include <linux/io.h>
20#include <linux/kernel.h>
21#include <linux/list.h>
22#include <linux/mm.h>
23#include <linux/slab.h>
24#include <linux/suspend.h>
25#include <linux/syscore_ops.h>
26#include <trace/events/power.h>
27
28#include "power.h"
29
30const char *const pm_states[PM_SUSPEND_MAX] = {
31 [PM_SUSPEND_STANDBY] = "standby",
32 [PM_SUSPEND_MEM] = "mem",
33};
34
35static const struct platform_suspend_ops *suspend_ops;
36
37/**
38 * suspend_set_ops - Set the global suspend method table.
39 * @ops: Pointer to ops structure.
40 */
41void suspend_set_ops(const struct platform_suspend_ops *ops)
42{
43 mutex_lock(&pm_mutex);
44 suspend_ops = ops;
45 mutex_unlock(&pm_mutex);
46}
47EXPORT_SYMBOL_GPL(suspend_set_ops);
48
49bool valid_state(suspend_state_t state)
50{
51 /*
52 * All states need lowlevel support and need to be valid to the lowlevel
53 * implementation, no valid callback implies that none are valid.
54 */
55 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
56}
57
58/**
59 * suspend_valid_only_mem - generic memory-only valid callback
60 *
61 * Platform drivers that implement mem suspend only and only need
62 * to check for that in their .valid callback can use this instead
63 * of rolling their own .valid callback.
64 */
65int suspend_valid_only_mem(suspend_state_t state)
66{
67 return state == PM_SUSPEND_MEM;
68}
69EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
70
71static int suspend_test(int level)
72{
73#ifdef CONFIG_PM_DEBUG
74 if (pm_test_level == level) {
75 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
76 mdelay(5000);
77 return 1;
78 }
79#endif /* !CONFIG_PM_DEBUG */
80 return 0;
81}
82
83/**
84 * suspend_prepare - Do prep work before entering low-power state.
85 *
86 * This is common code that is called for each state that we're entering.
87 * Run suspend notifiers, allocate a console and stop all processes.
88 */
89static int suspend_prepare(void)
90{
91 int error;
92
93 if (!suspend_ops || !suspend_ops->enter)
94 return -EPERM;
95
96 pm_prepare_console();
97
98 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
99 if (error)
100 goto Finish;
101
102 error = usermodehelper_disable();
103 if (error)
104 goto Finish;
105
106 error = suspend_freeze_processes();
107 if (!error)
108 return 0;
109
110 suspend_thaw_processes();
111 usermodehelper_enable();
112 Finish:
113 pm_notifier_call_chain(PM_POST_SUSPEND);
114 pm_restore_console();
115 return error;
116}
117
118/* default implementation */
119void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
120{
121 local_irq_disable();
122}
123
124/* default implementation */
125void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
126{
127 local_irq_enable();
128}
129
130/**
131 * suspend_enter - enter the desired system sleep state.
132 * @state: State to enter
133 * @wakeup: Returns information that suspend should not be entered again.
134 *
135 * This function should be called after devices have been suspended.
136 */
137static int suspend_enter(suspend_state_t state, bool *wakeup)
138{
139 int error;
140
141 if (suspend_ops->prepare) {
142 error = suspend_ops->prepare();
143 if (error)
144 goto Platform_finish;
145 }
146
147 error = dpm_suspend_noirq(PMSG_SUSPEND);
148 if (error) {
149 printk(KERN_ERR "PM: Some devices failed to power down\n");
150 goto Platform_finish;
151 }
152
153 if (suspend_ops->prepare_late) {
154 error = suspend_ops->prepare_late();
155 if (error)
156 goto Platform_wake;
157 }
158
159 if (suspend_test(TEST_PLATFORM))
160 goto Platform_wake;
161
162 error = disable_nonboot_cpus();
163 if (error || suspend_test(TEST_CPUS))
164 goto Enable_cpus;
165
166 arch_suspend_disable_irqs();
167 BUG_ON(!irqs_disabled());
168
169 error = syscore_suspend();
170 if (!error) {
171 *wakeup = pm_wakeup_pending();
172 if (!(suspend_test(TEST_CORE) || *wakeup)) {
173 error = suspend_ops->enter(state);
174 events_check_enabled = false;
175 }
176 syscore_resume();
177 }
178
179 arch_suspend_enable_irqs();
180 BUG_ON(irqs_disabled());
181
182 Enable_cpus:
183 enable_nonboot_cpus();
184
185 Platform_wake:
186 if (suspend_ops->wake)
187 suspend_ops->wake();
188
189 dpm_resume_noirq(PMSG_RESUME);
190
191 Platform_finish:
192 if (suspend_ops->finish)
193 suspend_ops->finish();
194
195 return error;
196}
197
198/**
199 * suspend_devices_and_enter - suspend devices and enter the desired system
200 * sleep state.
201 * @state: state to enter
202 */
203int suspend_devices_and_enter(suspend_state_t state)
204{
205 int error;
206 bool wakeup = false;
207
208 if (!suspend_ops)
209 return -ENOSYS;
210
211 trace_machine_suspend(state);
212 if (suspend_ops->begin) {
213 error = suspend_ops->begin(state);
214 if (error)
215 goto Close;
216 }
217 suspend_console();
218 suspend_test_start();
219 error = dpm_suspend_start(PMSG_SUSPEND);
220 if (error) {
221 printk(KERN_ERR "PM: Some devices failed to suspend\n");
222 goto Recover_platform;
223 }
224 suspend_test_finish("suspend devices");
225 if (suspend_test(TEST_DEVICES))
226 goto Recover_platform;
227
228 do {
229 error = suspend_enter(state, &wakeup);
230 } while (!error && !wakeup
231 && suspend_ops->suspend_again && suspend_ops->suspend_again());
232
233 Resume_devices:
234 suspend_test_start();
235 dpm_resume_end(PMSG_RESUME);
236 suspend_test_finish("resume devices");
237 resume_console();
238 Close:
239 if (suspend_ops->end)
240 suspend_ops->end();
241 trace_machine_suspend(PWR_EVENT_EXIT);
242 return error;
243
244 Recover_platform:
245 if (suspend_ops->recover)
246 suspend_ops->recover();
247 goto Resume_devices;
248}
249
250/**
251 * suspend_finish - Do final work before exiting suspend sequence.
252 *
253 * Call platform code to clean up, restart processes, and free the
254 * console that we've allocated. This is not called for suspend-to-disk.
255 */
256static void suspend_finish(void)
257{
258 suspend_thaw_processes();
259 usermodehelper_enable();
260 pm_notifier_call_chain(PM_POST_SUSPEND);
261 pm_restore_console();
262}
263
264/**
265 * enter_state - Do common work of entering low-power state.
266 * @state: pm_state structure for state we're entering.
267 *
268 * Make sure we're the only ones trying to enter a sleep state. Fail
269 * if someone has beat us to it, since we don't want anything weird to
270 * happen when we wake up.
271 * Then, do the setup for suspend, enter the state, and cleaup (after
272 * we've woken up).
273 */
274int enter_state(suspend_state_t state)
275{
276 int error;
277
278 if (!valid_state(state))
279 return -ENODEV;
280
281 if (!mutex_trylock(&pm_mutex))
282 return -EBUSY;
283
284 printk(KERN_INFO "PM: Syncing filesystems ... ");
285 sys_sync();
286 printk("done.\n");
287
288 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
289 error = suspend_prepare();
290 if (error)
291 goto Unlock;
292
293 if (suspend_test(TEST_FREEZER))
294 goto Finish;
295
296 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
297 pm_restrict_gfp_mask();
298 error = suspend_devices_and_enter(state);
299 pm_restore_gfp_mask();
300
301 Finish:
302 pr_debug("PM: Finishing wakeup.\n");
303 suspend_finish();
304 Unlock:
305 mutex_unlock(&pm_mutex);
306 return error;
307}
308
309/**
310 * pm_suspend - Externally visible function for suspending system.
311 * @state: Enumerated value of state to enter.
312 *
313 * Determine whether or not value is within range, get state
314 * structure, and enter (above).
315 */
316int pm_suspend(suspend_state_t state)
317{
318 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
319 return enter_state(state);
320 return -EINVAL;
321}
322EXPORT_SYMBOL(pm_suspend);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
4 *
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.
8 */
9
10#define pr_fmt(fmt) "PM: " fmt
11
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>
20#include <linux/io.h>
21#include <linux/kernel.h>
22#include <linux/list.h>
23#include <linux/mm.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>
33
34#include "power.h"
35
36const char * const pm_labels[] = {
37 [PM_SUSPEND_TO_IDLE] = "freeze",
38 [PM_SUSPEND_STANDBY] = "standby",
39 [PM_SUSPEND_MEM] = "mem",
40};
41const char *pm_states[PM_SUSPEND_MAX];
42static const char * const mem_sleep_labels[] = {
43 [PM_SUSPEND_TO_IDLE] = "s2idle",
44 [PM_SUSPEND_STANDBY] = "shallow",
45 [PM_SUSPEND_MEM] = "deep",
46};
47const char *mem_sleep_states[PM_SUSPEND_MAX];
48
49suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
50suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
51suspend_state_t pm_suspend_target_state;
52EXPORT_SYMBOL_GPL(pm_suspend_target_state);
53
54unsigned int pm_suspend_global_flags;
55EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
56
57static const struct platform_suspend_ops *suspend_ops;
58static const struct platform_s2idle_ops *s2idle_ops;
59static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
60
61enum s2idle_states __read_mostly s2idle_state;
62static DEFINE_RAW_SPINLOCK(s2idle_lock);
63
64/**
65 * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
66 *
67 * Return 'true' if suspend-to-idle has been selected as the default system
68 * suspend method.
69 */
70bool pm_suspend_default_s2idle(void)
71{
72 return mem_sleep_current == PM_SUSPEND_TO_IDLE;
73}
74EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
75
76void s2idle_set_ops(const struct platform_s2idle_ops *ops)
77{
78 unsigned int sleep_flags;
79
80 sleep_flags = lock_system_sleep();
81 s2idle_ops = ops;
82 unlock_system_sleep(sleep_flags);
83}
84
85static void s2idle_begin(void)
86{
87 s2idle_state = S2IDLE_STATE_NONE;
88}
89
90static void s2idle_enter(void)
91{
92 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
93
94 raw_spin_lock_irq(&s2idle_lock);
95 if (pm_wakeup_pending())
96 goto out;
97
98 s2idle_state = S2IDLE_STATE_ENTER;
99 raw_spin_unlock_irq(&s2idle_lock);
100
101 cpus_read_lock();
102
103 /* Push all the CPUs into the idle loop. */
104 wake_up_all_idle_cpus();
105 /* Make the current CPU wait so it can enter the idle loop too. */
106 swait_event_exclusive(s2idle_wait_head,
107 s2idle_state == S2IDLE_STATE_WAKE);
108
109 /*
110 * Kick all CPUs to ensure that they resume their timers and restore
111 * consistent system state.
112 */
113 wake_up_all_idle_cpus();
114
115 cpus_read_unlock();
116
117 raw_spin_lock_irq(&s2idle_lock);
118
119 out:
120 s2idle_state = S2IDLE_STATE_NONE;
121 raw_spin_unlock_irq(&s2idle_lock);
122
123 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
124}
125
126static void s2idle_loop(void)
127{
128 pm_pr_dbg("suspend-to-idle\n");
129
130 /*
131 * Suspend-to-idle equals:
132 * frozen processes + suspended devices + idle processors.
133 * Thus s2idle_enter() should be called right after all devices have
134 * been suspended.
135 *
136 * Wakeups during the noirq suspend of devices may be spurious, so try
137 * to avoid them upfront.
138 */
139 for (;;) {
140 if (s2idle_ops && s2idle_ops->wake) {
141 if (s2idle_ops->wake())
142 break;
143 } else if (pm_wakeup_pending()) {
144 break;
145 }
146
147 if (s2idle_ops && s2idle_ops->check)
148 s2idle_ops->check();
149
150 s2idle_enter();
151 }
152
153 pm_pr_dbg("resume from suspend-to-idle\n");
154}
155
156void s2idle_wake(void)
157{
158 unsigned long flags;
159
160 raw_spin_lock_irqsave(&s2idle_lock, flags);
161 if (s2idle_state > S2IDLE_STATE_NONE) {
162 s2idle_state = S2IDLE_STATE_WAKE;
163 swake_up_one(&s2idle_wait_head);
164 }
165 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
166}
167EXPORT_SYMBOL_GPL(s2idle_wake);
168
169static bool valid_state(suspend_state_t state)
170{
171 /*
172 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
173 * support and need to be valid to the low-level implementation.
174 *
175 * No ->valid() or ->enter() callback implies that none are valid.
176 */
177 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
178 suspend_ops->enter;
179}
180
181void __init pm_states_init(void)
182{
183 /* "mem" and "freeze" are always present in /sys/power/state. */
184 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
185 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
186 /*
187 * Suspend-to-idle should be supported even without any suspend_ops,
188 * initialize mem_sleep_states[] accordingly here.
189 */
190 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
191}
192
193static int __init mem_sleep_default_setup(char *str)
194{
195 suspend_state_t state;
196
197 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
198 if (mem_sleep_labels[state] &&
199 !strcmp(str, mem_sleep_labels[state])) {
200 mem_sleep_default = state;
201 mem_sleep_current = state;
202 break;
203 }
204
205 return 1;
206}
207__setup("mem_sleep_default=", mem_sleep_default_setup);
208
209/**
210 * suspend_set_ops - Set the global suspend method table.
211 * @ops: Suspend operations to use.
212 */
213void suspend_set_ops(const struct platform_suspend_ops *ops)
214{
215 unsigned int sleep_flags;
216
217 sleep_flags = lock_system_sleep();
218
219 suspend_ops = ops;
220
221 if (valid_state(PM_SUSPEND_STANDBY)) {
222 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
223 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
224 if (mem_sleep_default == PM_SUSPEND_STANDBY)
225 mem_sleep_current = PM_SUSPEND_STANDBY;
226 }
227 if (valid_state(PM_SUSPEND_MEM)) {
228 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
229 if (mem_sleep_default >= PM_SUSPEND_MEM)
230 mem_sleep_current = PM_SUSPEND_MEM;
231 }
232
233 unlock_system_sleep(sleep_flags);
234}
235EXPORT_SYMBOL_GPL(suspend_set_ops);
236
237/**
238 * suspend_valid_only_mem - Generic memory-only valid callback.
239 * @state: Target system sleep state.
240 *
241 * Platform drivers that implement mem suspend only and only need to check for
242 * that in their .valid() callback can use this instead of rolling their own
243 * .valid() callback.
244 */
245int suspend_valid_only_mem(suspend_state_t state)
246{
247 return state == PM_SUSPEND_MEM;
248}
249EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
250
251static bool sleep_state_supported(suspend_state_t state)
252{
253 return state == PM_SUSPEND_TO_IDLE ||
254 (valid_state(state) && !cxl_mem_active());
255}
256
257static int platform_suspend_prepare(suspend_state_t state)
258{
259 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
260 suspend_ops->prepare() : 0;
261}
262
263static int platform_suspend_prepare_late(suspend_state_t state)
264{
265 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
266 s2idle_ops->prepare() : 0;
267}
268
269static int platform_suspend_prepare_noirq(suspend_state_t state)
270{
271 if (state == PM_SUSPEND_TO_IDLE)
272 return s2idle_ops && s2idle_ops->prepare_late ?
273 s2idle_ops->prepare_late() : 0;
274
275 return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
276}
277
278static void platform_resume_noirq(suspend_state_t state)
279{
280 if (state == PM_SUSPEND_TO_IDLE) {
281 if (s2idle_ops && s2idle_ops->restore_early)
282 s2idle_ops->restore_early();
283 } else if (suspend_ops->wake) {
284 suspend_ops->wake();
285 }
286}
287
288static void platform_resume_early(suspend_state_t state)
289{
290 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
291 s2idle_ops->restore();
292}
293
294static void platform_resume_finish(suspend_state_t state)
295{
296 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
297 suspend_ops->finish();
298}
299
300static int platform_suspend_begin(suspend_state_t state)
301{
302 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
303 return s2idle_ops->begin();
304 else if (suspend_ops && suspend_ops->begin)
305 return suspend_ops->begin(state);
306 else
307 return 0;
308}
309
310static void platform_resume_end(suspend_state_t state)
311{
312 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
313 s2idle_ops->end();
314 else if (suspend_ops && suspend_ops->end)
315 suspend_ops->end();
316}
317
318static void platform_recover(suspend_state_t state)
319{
320 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
321 suspend_ops->recover();
322}
323
324static bool platform_suspend_again(suspend_state_t state)
325{
326 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
327 suspend_ops->suspend_again() : false;
328}
329
330#ifdef CONFIG_PM_DEBUG
331static unsigned int pm_test_delay = 5;
332module_param(pm_test_delay, uint, 0644);
333MODULE_PARM_DESC(pm_test_delay,
334 "Number of seconds to wait before resuming from suspend test");
335#endif
336
337static int suspend_test(int level)
338{
339#ifdef CONFIG_PM_DEBUG
340 if (pm_test_level == level) {
341 pr_info("suspend debug: Waiting for %d second(s).\n",
342 pm_test_delay);
343 mdelay(pm_test_delay * 1000);
344 return 1;
345 }
346#endif /* !CONFIG_PM_DEBUG */
347 return 0;
348}
349
350/**
351 * suspend_prepare - Prepare for entering system sleep state.
352 * @state: Target system sleep state.
353 *
354 * Common code run for every system sleep state that can be entered (except for
355 * hibernation). Run suspend notifiers, allocate the "suspend" console and
356 * freeze processes.
357 */
358static int suspend_prepare(suspend_state_t state)
359{
360 int error;
361
362 if (!sleep_state_supported(state))
363 return -EPERM;
364
365 pm_prepare_console();
366
367 error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
368 if (error)
369 goto Restore;
370
371 trace_suspend_resume(TPS("freeze_processes"), 0, true);
372 error = suspend_freeze_processes();
373 trace_suspend_resume(TPS("freeze_processes"), 0, false);
374 if (!error)
375 return 0;
376
377 dpm_save_failed_step(SUSPEND_FREEZE);
378 pm_notifier_call_chain(PM_POST_SUSPEND);
379 Restore:
380 pm_restore_console();
381 return error;
382}
383
384/* default implementation */
385void __weak arch_suspend_disable_irqs(void)
386{
387 local_irq_disable();
388}
389
390/* default implementation */
391void __weak arch_suspend_enable_irqs(void)
392{
393 local_irq_enable();
394}
395
396/**
397 * suspend_enter - Make the system enter the given sleep state.
398 * @state: System sleep state to enter.
399 * @wakeup: Returns information that the sleep state should not be re-entered.
400 *
401 * This function should be called after devices have been suspended.
402 */
403static int suspend_enter(suspend_state_t state, bool *wakeup)
404{
405 int error;
406
407 error = platform_suspend_prepare(state);
408 if (error)
409 goto Platform_finish;
410
411 error = dpm_suspend_late(PMSG_SUSPEND);
412 if (error) {
413 pr_err("late suspend of devices failed\n");
414 goto Platform_finish;
415 }
416 error = platform_suspend_prepare_late(state);
417 if (error)
418 goto Devices_early_resume;
419
420 error = dpm_suspend_noirq(PMSG_SUSPEND);
421 if (error) {
422 pr_err("noirq suspend of devices failed\n");
423 goto Platform_early_resume;
424 }
425 error = platform_suspend_prepare_noirq(state);
426 if (error)
427 goto Platform_wake;
428
429 if (suspend_test(TEST_PLATFORM))
430 goto Platform_wake;
431
432 if (state == PM_SUSPEND_TO_IDLE) {
433 s2idle_loop();
434 goto Platform_wake;
435 }
436
437 error = pm_sleep_disable_secondary_cpus();
438 if (error || suspend_test(TEST_CPUS))
439 goto Enable_cpus;
440
441 arch_suspend_disable_irqs();
442 BUG_ON(!irqs_disabled());
443
444 system_state = SYSTEM_SUSPEND;
445
446 error = syscore_suspend();
447 if (!error) {
448 *wakeup = pm_wakeup_pending();
449 if (!(suspend_test(TEST_CORE) || *wakeup)) {
450 trace_suspend_resume(TPS("machine_suspend"),
451 state, true);
452 error = suspend_ops->enter(state);
453 trace_suspend_resume(TPS("machine_suspend"),
454 state, false);
455 } else if (*wakeup) {
456 error = -EBUSY;
457 }
458 syscore_resume();
459 }
460
461 system_state = SYSTEM_RUNNING;
462
463 arch_suspend_enable_irqs();
464 BUG_ON(irqs_disabled());
465
466 Enable_cpus:
467 pm_sleep_enable_secondary_cpus();
468
469 Platform_wake:
470 platform_resume_noirq(state);
471 dpm_resume_noirq(PMSG_RESUME);
472
473 Platform_early_resume:
474 platform_resume_early(state);
475
476 Devices_early_resume:
477 dpm_resume_early(PMSG_RESUME);
478
479 Platform_finish:
480 platform_resume_finish(state);
481 return error;
482}
483
484/**
485 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
486 * @state: System sleep state to enter.
487 */
488int suspend_devices_and_enter(suspend_state_t state)
489{
490 int error;
491 bool wakeup = false;
492
493 if (!sleep_state_supported(state))
494 return -ENOSYS;
495
496 pm_suspend_target_state = state;
497
498 if (state == PM_SUSPEND_TO_IDLE)
499 pm_set_suspend_no_platform();
500
501 error = platform_suspend_begin(state);
502 if (error)
503 goto Close;
504
505 suspend_console();
506 suspend_test_start();
507 error = dpm_suspend_start(PMSG_SUSPEND);
508 if (error) {
509 pr_err("Some devices failed to suspend, or early wake event detected\n");
510 goto Recover_platform;
511 }
512 suspend_test_finish("suspend devices");
513 if (suspend_test(TEST_DEVICES))
514 goto Recover_platform;
515
516 do {
517 error = suspend_enter(state, &wakeup);
518 } while (!error && !wakeup && platform_suspend_again(state));
519
520 Resume_devices:
521 suspend_test_start();
522 dpm_resume_end(PMSG_RESUME);
523 suspend_test_finish("resume devices");
524 trace_suspend_resume(TPS("resume_console"), state, true);
525 resume_console();
526 trace_suspend_resume(TPS("resume_console"), state, false);
527
528 Close:
529 platform_resume_end(state);
530 pm_suspend_target_state = PM_SUSPEND_ON;
531 return error;
532
533 Recover_platform:
534 platform_recover(state);
535 goto Resume_devices;
536}
537
538/**
539 * suspend_finish - Clean up before finishing the suspend sequence.
540 *
541 * Call platform code to clean up, restart processes, and free the console that
542 * we've allocated. This routine is not called for hibernation.
543 */
544static void suspend_finish(void)
545{
546 suspend_thaw_processes();
547 pm_notifier_call_chain(PM_POST_SUSPEND);
548 pm_restore_console();
549}
550
551/**
552 * enter_state - Do common work needed to enter system sleep state.
553 * @state: System sleep state to enter.
554 *
555 * Make sure that no one else is trying to put the system into a sleep state.
556 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
557 * system enter the given sleep state and clean up after wakeup.
558 */
559static int enter_state(suspend_state_t state)
560{
561 int error;
562
563 trace_suspend_resume(TPS("suspend_enter"), state, true);
564 if (state == PM_SUSPEND_TO_IDLE) {
565#ifdef CONFIG_PM_DEBUG
566 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
567 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
568 return -EAGAIN;
569 }
570#endif
571 } else if (!valid_state(state)) {
572 return -EINVAL;
573 }
574 if (!mutex_trylock(&system_transition_mutex))
575 return -EBUSY;
576
577 if (state == PM_SUSPEND_TO_IDLE)
578 s2idle_begin();
579
580 if (sync_on_suspend_enabled) {
581 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
582 ksys_sync_helper();
583 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
584 }
585
586 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
587 pm_suspend_clear_flags();
588 error = suspend_prepare(state);
589 if (error)
590 goto Unlock;
591
592 if (suspend_test(TEST_FREEZER))
593 goto Finish;
594
595 trace_suspend_resume(TPS("suspend_enter"), state, false);
596 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
597 pm_restrict_gfp_mask();
598 error = suspend_devices_and_enter(state);
599 pm_restore_gfp_mask();
600
601 Finish:
602 events_check_enabled = false;
603 pm_pr_dbg("Finishing wakeup.\n");
604 suspend_finish();
605 Unlock:
606 mutex_unlock(&system_transition_mutex);
607 return error;
608}
609
610/**
611 * pm_suspend - Externally visible function for suspending the system.
612 * @state: System sleep state to enter.
613 *
614 * Check if the value of @state represents one of the supported states,
615 * execute enter_state() and update system suspend statistics.
616 */
617int pm_suspend(suspend_state_t state)
618{
619 int error;
620
621 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
622 return -EINVAL;
623
624 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
625 error = enter_state(state);
626 dpm_save_errno(error);
627 pr_info("suspend exit\n");
628 return error;
629}
630EXPORT_SYMBOL(pm_suspend);