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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 lock_system_sleep();
79 s2idle_ops = ops;
80 unlock_system_sleep();
81}
82
83static void s2idle_begin(void)
84{
85 s2idle_state = S2IDLE_STATE_NONE;
86}
87
88static void s2idle_enter(void)
89{
90 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
91
92 raw_spin_lock_irq(&s2idle_lock);
93 if (pm_wakeup_pending())
94 goto out;
95
96 s2idle_state = S2IDLE_STATE_ENTER;
97 raw_spin_unlock_irq(&s2idle_lock);
98
99 get_online_cpus();
100 cpuidle_resume();
101
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);
107
108 cpuidle_pause();
109 put_online_cpus();
110
111 raw_spin_lock_irq(&s2idle_lock);
112
113 out:
114 s2idle_state = S2IDLE_STATE_NONE;
115 raw_spin_unlock_irq(&s2idle_lock);
116
117 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
118}
119
120static void s2idle_loop(void)
121{
122 pm_pr_dbg("suspend-to-idle\n");
123
124 /*
125 * Suspend-to-idle equals:
126 * frozen processes + suspended devices + idle processors.
127 * Thus s2idle_enter() should be called right after all devices have
128 * been suspended.
129 *
130 * Wakeups during the noirq suspend of devices may be spurious, so try
131 * to avoid them upfront.
132 */
133 for (;;) {
134 if (s2idle_ops && s2idle_ops->wake) {
135 if (s2idle_ops->wake())
136 break;
137 } else if (pm_wakeup_pending()) {
138 break;
139 }
140
141 pm_wakeup_clear(false);
142
143 s2idle_enter();
144 }
145
146 pm_pr_dbg("resume from suspend-to-idle\n");
147}
148
149void s2idle_wake(void)
150{
151 unsigned long flags;
152
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);
157 }
158 raw_spin_unlock_irqrestore(&s2idle_lock, flags);
159}
160EXPORT_SYMBOL_GPL(s2idle_wake);
161
162static bool valid_state(suspend_state_t state)
163{
164 /*
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.
168 */
169 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
170}
171
172void __init pm_states_init(void)
173{
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];
177 /*
178 * Suspend-to-idle should be supported even without any suspend_ops,
179 * initialize mem_sleep_states[] accordingly here.
180 */
181 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
182}
183
184static int __init mem_sleep_default_setup(char *str)
185{
186 suspend_state_t state;
187
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;
192 break;
193 }
194
195 return 1;
196}
197__setup("mem_sleep_default=", mem_sleep_default_setup);
198
199/**
200 * suspend_set_ops - Set the global suspend method table.
201 * @ops: Suspend operations to use.
202 */
203void suspend_set_ops(const struct platform_suspend_ops *ops)
204{
205 lock_system_sleep();
206
207 suspend_ops = ops;
208
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;
214 }
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;
219 }
220
221 unlock_system_sleep();
222}
223EXPORT_SYMBOL_GPL(suspend_set_ops);
224
225/**
226 * suspend_valid_only_mem - Generic memory-only valid callback.
227 * @state: Target system sleep state.
228 *
229 * Platform drivers that implement mem suspend only and only need to check for
230 * that in their .valid() callback can use this instead of rolling their own
231 * .valid() callback.
232 */
233int suspend_valid_only_mem(suspend_state_t state)
234{
235 return state == PM_SUSPEND_MEM;
236}
237EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
238
239static bool sleep_state_supported(suspend_state_t state)
240{
241 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
242}
243
244static int platform_suspend_prepare(suspend_state_t state)
245{
246 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
247 suspend_ops->prepare() : 0;
248}
249
250static int platform_suspend_prepare_late(suspend_state_t state)
251{
252 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
253 s2idle_ops->prepare() : 0;
254}
255
256static int platform_suspend_prepare_noirq(suspend_state_t state)
257{
258 if (state == PM_SUSPEND_TO_IDLE)
259 return s2idle_ops && s2idle_ops->prepare_late ?
260 s2idle_ops->prepare_late() : 0;
261
262 return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
263}
264
265static void platform_resume_noirq(suspend_state_t state)
266{
267 if (state == PM_SUSPEND_TO_IDLE) {
268 if (s2idle_ops && s2idle_ops->restore_early)
269 s2idle_ops->restore_early();
270 } else if (suspend_ops->wake) {
271 suspend_ops->wake();
272 }
273}
274
275static void platform_resume_early(suspend_state_t state)
276{
277 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
278 s2idle_ops->restore();
279}
280
281static void platform_resume_finish(suspend_state_t state)
282{
283 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
284 suspend_ops->finish();
285}
286
287static int platform_suspend_begin(suspend_state_t state)
288{
289 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
290 return s2idle_ops->begin();
291 else if (suspend_ops && suspend_ops->begin)
292 return suspend_ops->begin(state);
293 else
294 return 0;
295}
296
297static void platform_resume_end(suspend_state_t state)
298{
299 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
300 s2idle_ops->end();
301 else if (suspend_ops && suspend_ops->end)
302 suspend_ops->end();
303}
304
305static void platform_recover(suspend_state_t state)
306{
307 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
308 suspend_ops->recover();
309}
310
311static bool platform_suspend_again(suspend_state_t state)
312{
313 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
314 suspend_ops->suspend_again() : false;
315}
316
317#ifdef CONFIG_PM_DEBUG
318static unsigned int pm_test_delay = 5;
319module_param(pm_test_delay, uint, 0644);
320MODULE_PARM_DESC(pm_test_delay,
321 "Number of seconds to wait before resuming from suspend test");
322#endif
323
324static int suspend_test(int level)
325{
326#ifdef CONFIG_PM_DEBUG
327 if (pm_test_level == level) {
328 pr_info("suspend debug: Waiting for %d second(s).\n",
329 pm_test_delay);
330 mdelay(pm_test_delay * 1000);
331 return 1;
332 }
333#endif /* !CONFIG_PM_DEBUG */
334 return 0;
335}
336
337/**
338 * suspend_prepare - Prepare for entering system sleep state.
339 * @state: Target system sleep state.
340 *
341 * Common code run for every system sleep state that can be entered (except for
342 * hibernation). Run suspend notifiers, allocate the "suspend" console and
343 * freeze processes.
344 */
345static int suspend_prepare(suspend_state_t state)
346{
347 int error;
348
349 if (!sleep_state_supported(state))
350 return -EPERM;
351
352 pm_prepare_console();
353
354 error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
355 if (error)
356 goto Restore;
357
358 trace_suspend_resume(TPS("freeze_processes"), 0, true);
359 error = suspend_freeze_processes();
360 trace_suspend_resume(TPS("freeze_processes"), 0, false);
361 if (!error)
362 return 0;
363
364 suspend_stats.failed_freeze++;
365 dpm_save_failed_step(SUSPEND_FREEZE);
366 pm_notifier_call_chain(PM_POST_SUSPEND);
367 Restore:
368 pm_restore_console();
369 return error;
370}
371
372/* default implementation */
373void __weak arch_suspend_disable_irqs(void)
374{
375 local_irq_disable();
376}
377
378/* default implementation */
379void __weak arch_suspend_enable_irqs(void)
380{
381 local_irq_enable();
382}
383
384/**
385 * suspend_enter - Make the system enter the given sleep state.
386 * @state: System sleep state to enter.
387 * @wakeup: Returns information that the sleep state should not be re-entered.
388 *
389 * This function should be called after devices have been suspended.
390 */
391static int suspend_enter(suspend_state_t state, bool *wakeup)
392{
393 int error;
394
395 error = platform_suspend_prepare(state);
396 if (error)
397 goto Platform_finish;
398
399 error = dpm_suspend_late(PMSG_SUSPEND);
400 if (error) {
401 pr_err("late suspend of devices failed\n");
402 goto Platform_finish;
403 }
404 error = platform_suspend_prepare_late(state);
405 if (error)
406 goto Devices_early_resume;
407
408 error = dpm_suspend_noirq(PMSG_SUSPEND);
409 if (error) {
410 pr_err("noirq suspend of devices failed\n");
411 goto Platform_early_resume;
412 }
413 error = platform_suspend_prepare_noirq(state);
414 if (error)
415 goto Platform_wake;
416
417 if (suspend_test(TEST_PLATFORM))
418 goto Platform_wake;
419
420 if (state == PM_SUSPEND_TO_IDLE) {
421 s2idle_loop();
422 goto Platform_wake;
423 }
424
425 error = suspend_disable_secondary_cpus();
426 if (error || suspend_test(TEST_CPUS))
427 goto Enable_cpus;
428
429 arch_suspend_disable_irqs();
430 BUG_ON(!irqs_disabled());
431
432 system_state = SYSTEM_SUSPEND;
433
434 error = syscore_suspend();
435 if (!error) {
436 *wakeup = pm_wakeup_pending();
437 if (!(suspend_test(TEST_CORE) || *wakeup)) {
438 trace_suspend_resume(TPS("machine_suspend"),
439 state, true);
440 error = suspend_ops->enter(state);
441 trace_suspend_resume(TPS("machine_suspend"),
442 state, false);
443 } else if (*wakeup) {
444 error = -EBUSY;
445 }
446 syscore_resume();
447 }
448
449 system_state = SYSTEM_RUNNING;
450
451 arch_suspend_enable_irqs();
452 BUG_ON(irqs_disabled());
453
454 Enable_cpus:
455 suspend_enable_secondary_cpus();
456
457 Platform_wake:
458 platform_resume_noirq(state);
459 dpm_resume_noirq(PMSG_RESUME);
460
461 Platform_early_resume:
462 platform_resume_early(state);
463
464 Devices_early_resume:
465 dpm_resume_early(PMSG_RESUME);
466
467 Platform_finish:
468 platform_resume_finish(state);
469 return error;
470}
471
472/**
473 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
474 * @state: System sleep state to enter.
475 */
476int suspend_devices_and_enter(suspend_state_t state)
477{
478 int error;
479 bool wakeup = false;
480
481 if (!sleep_state_supported(state))
482 return -ENOSYS;
483
484 pm_suspend_target_state = state;
485
486 if (state == PM_SUSPEND_TO_IDLE)
487 pm_set_suspend_no_platform();
488
489 error = platform_suspend_begin(state);
490 if (error)
491 goto Close;
492
493 suspend_console();
494 suspend_test_start();
495 error = dpm_suspend_start(PMSG_SUSPEND);
496 if (error) {
497 pr_err("Some devices failed to suspend, or early wake event detected\n");
498 goto Recover_platform;
499 }
500 suspend_test_finish("suspend devices");
501 if (suspend_test(TEST_DEVICES))
502 goto Recover_platform;
503
504 do {
505 error = suspend_enter(state, &wakeup);
506 } while (!error && !wakeup && platform_suspend_again(state));
507
508 Resume_devices:
509 suspend_test_start();
510 dpm_resume_end(PMSG_RESUME);
511 suspend_test_finish("resume devices");
512 trace_suspend_resume(TPS("resume_console"), state, true);
513 resume_console();
514 trace_suspend_resume(TPS("resume_console"), state, false);
515
516 Close:
517 platform_resume_end(state);
518 pm_suspend_target_state = PM_SUSPEND_ON;
519 return error;
520
521 Recover_platform:
522 platform_recover(state);
523 goto Resume_devices;
524}
525
526/**
527 * suspend_finish - Clean up before finishing the suspend sequence.
528 *
529 * Call platform code to clean up, restart processes, and free the console that
530 * we've allocated. This routine is not called for hibernation.
531 */
532static void suspend_finish(void)
533{
534 suspend_thaw_processes();
535 pm_notifier_call_chain(PM_POST_SUSPEND);
536 pm_restore_console();
537}
538
539/**
540 * enter_state - Do common work needed to enter system sleep state.
541 * @state: System sleep state to enter.
542 *
543 * Make sure that no one else is trying to put the system into a sleep state.
544 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
545 * system enter the given sleep state and clean up after wakeup.
546 */
547static int enter_state(suspend_state_t state)
548{
549 int error;
550
551 trace_suspend_resume(TPS("suspend_enter"), state, true);
552 if (state == PM_SUSPEND_TO_IDLE) {
553#ifdef CONFIG_PM_DEBUG
554 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
555 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
556 return -EAGAIN;
557 }
558#endif
559 } else if (!valid_state(state)) {
560 return -EINVAL;
561 }
562 if (!mutex_trylock(&system_transition_mutex))
563 return -EBUSY;
564
565 if (state == PM_SUSPEND_TO_IDLE)
566 s2idle_begin();
567
568 if (sync_on_suspend_enabled) {
569 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
570 ksys_sync_helper();
571 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
572 }
573
574 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
575 pm_suspend_clear_flags();
576 error = suspend_prepare(state);
577 if (error)
578 goto Unlock;
579
580 if (suspend_test(TEST_FREEZER))
581 goto Finish;
582
583 trace_suspend_resume(TPS("suspend_enter"), state, false);
584 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
585 pm_restrict_gfp_mask();
586 error = suspend_devices_and_enter(state);
587 pm_restore_gfp_mask();
588
589 Finish:
590 events_check_enabled = false;
591 pm_pr_dbg("Finishing wakeup.\n");
592 suspend_finish();
593 Unlock:
594 mutex_unlock(&system_transition_mutex);
595 return error;
596}
597
598/**
599 * pm_suspend - Externally visible function for suspending the system.
600 * @state: System sleep state to enter.
601 *
602 * Check if the value of @state represents one of the supported states,
603 * execute enter_state() and update system suspend statistics.
604 */
605int pm_suspend(suspend_state_t state)
606{
607 int error;
608
609 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
610 return -EINVAL;
611
612 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
613 error = enter_state(state);
614 if (error) {
615 suspend_stats.fail++;
616 dpm_save_failed_errno(error);
617 } else {
618 suspend_stats.success++;
619 }
620 pr_info("suspend exit\n");
621 return error;
622}
623EXPORT_SYMBOL(pm_suspend);