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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/*
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#define pr_fmt(fmt) "PM: " fmt
12
13#include <linux/string.h>
14#include <linux/delay.h>
15#include <linux/errno.h>
16#include <linux/init.h>
17#include <linux/console.h>
18#include <linux/cpu.h>
19#include <linux/cpuidle.h>
20#include <linux/syscalls.h>
21#include <linux/gfp.h>
22#include <linux/io.h>
23#include <linux/kernel.h>
24#include <linux/list.h>
25#include <linux/mm.h>
26#include <linux/slab.h>
27#include <linux/export.h>
28#include <linux/suspend.h>
29#include <linux/syscore_ops.h>
30#include <linux/ftrace.h>
31#include <trace/events/power.h>
32#include <linux/compiler.h>
33#include <linux/moduleparam.h>
34
35#include "power.h"
36
37const char * const pm_labels[] = {
38 [PM_SUSPEND_TO_IDLE] = "freeze",
39 [PM_SUSPEND_STANDBY] = "standby",
40 [PM_SUSPEND_MEM] = "mem",
41};
42const char *pm_states[PM_SUSPEND_MAX];
43static const char * const mem_sleep_labels[] = {
44 [PM_SUSPEND_TO_IDLE] = "s2idle",
45 [PM_SUSPEND_STANDBY] = "shallow",
46 [PM_SUSPEND_MEM] = "deep",
47};
48const char *mem_sleep_states[PM_SUSPEND_MAX];
49
50suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
51suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
52suspend_state_t pm_suspend_target_state;
53EXPORT_SYMBOL_GPL(pm_suspend_target_state);
54
55unsigned int pm_suspend_global_flags;
56EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
57
58static const struct platform_suspend_ops *suspend_ops;
59static const struct platform_s2idle_ops *s2idle_ops;
60static DECLARE_WAIT_QUEUE_HEAD(s2idle_wait_head);
61
62enum s2idle_states __read_mostly s2idle_state;
63static DEFINE_SPINLOCK(s2idle_lock);
64
65void s2idle_set_ops(const struct platform_s2idle_ops *ops)
66{
67 lock_system_sleep();
68 s2idle_ops = ops;
69 unlock_system_sleep();
70}
71
72static void s2idle_begin(void)
73{
74 s2idle_state = S2IDLE_STATE_NONE;
75}
76
77static void s2idle_enter(void)
78{
79 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
80
81 spin_lock_irq(&s2idle_lock);
82 if (pm_wakeup_pending())
83 goto out;
84
85 s2idle_state = S2IDLE_STATE_ENTER;
86 spin_unlock_irq(&s2idle_lock);
87
88 get_online_cpus();
89 cpuidle_resume();
90
91 /* Push all the CPUs into the idle loop. */
92 wake_up_all_idle_cpus();
93 /* Make the current CPU wait so it can enter the idle loop too. */
94 wait_event(s2idle_wait_head,
95 s2idle_state == S2IDLE_STATE_WAKE);
96
97 cpuidle_pause();
98 put_online_cpus();
99
100 spin_lock_irq(&s2idle_lock);
101
102 out:
103 s2idle_state = S2IDLE_STATE_NONE;
104 spin_unlock_irq(&s2idle_lock);
105
106 trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
107}
108
109static void s2idle_loop(void)
110{
111 pm_pr_dbg("suspend-to-idle\n");
112
113 for (;;) {
114 int error;
115
116 dpm_noirq_begin();
117
118 /*
119 * Suspend-to-idle equals
120 * frozen processes + suspended devices + idle processors.
121 * Thus s2idle_enter() should be called right after
122 * all devices have been suspended.
123 *
124 * Wakeups during the noirq suspend of devices may be spurious,
125 * so prevent them from terminating the loop right away.
126 */
127 error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
128 if (!error)
129 s2idle_enter();
130 else if (error == -EBUSY && pm_wakeup_pending())
131 error = 0;
132
133 if (!error && s2idle_ops && s2idle_ops->wake)
134 s2idle_ops->wake();
135
136 dpm_noirq_resume_devices(PMSG_RESUME);
137
138 dpm_noirq_end();
139
140 if (error)
141 break;
142
143 if (s2idle_ops && s2idle_ops->sync)
144 s2idle_ops->sync();
145
146 if (pm_wakeup_pending())
147 break;
148
149 pm_wakeup_clear(false);
150 }
151
152 pm_pr_dbg("resume from suspend-to-idle\n");
153}
154
155void s2idle_wake(void)
156{
157 unsigned long flags;
158
159 spin_lock_irqsave(&s2idle_lock, flags);
160 if (s2idle_state > S2IDLE_STATE_NONE) {
161 s2idle_state = S2IDLE_STATE_WAKE;
162 wake_up(&s2idle_wait_head);
163 }
164 spin_unlock_irqrestore(&s2idle_lock, flags);
165}
166EXPORT_SYMBOL_GPL(s2idle_wake);
167
168static bool valid_state(suspend_state_t state)
169{
170 /*
171 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
172 * support and need to be valid to the low level
173 * implementation, no valid callback implies that none are valid.
174 */
175 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
176}
177
178void __init pm_states_init(void)
179{
180 /* "mem" and "freeze" are always present in /sys/power/state. */
181 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
182 pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
183 /*
184 * Suspend-to-idle should be supported even without any suspend_ops,
185 * initialize mem_sleep_states[] accordingly here.
186 */
187 mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
188}
189
190static int __init mem_sleep_default_setup(char *str)
191{
192 suspend_state_t state;
193
194 for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
195 if (mem_sleep_labels[state] &&
196 !strcmp(str, mem_sleep_labels[state])) {
197 mem_sleep_default = state;
198 break;
199 }
200
201 return 1;
202}
203__setup("mem_sleep_default=", mem_sleep_default_setup);
204
205/**
206 * suspend_set_ops - Set the global suspend method table.
207 * @ops: Suspend operations to use.
208 */
209void suspend_set_ops(const struct platform_suspend_ops *ops)
210{
211 lock_system_sleep();
212
213 suspend_ops = ops;
214
215 if (valid_state(PM_SUSPEND_STANDBY)) {
216 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
217 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
218 if (mem_sleep_default == PM_SUSPEND_STANDBY)
219 mem_sleep_current = PM_SUSPEND_STANDBY;
220 }
221 if (valid_state(PM_SUSPEND_MEM)) {
222 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
223 if (mem_sleep_default >= PM_SUSPEND_MEM)
224 mem_sleep_current = PM_SUSPEND_MEM;
225 }
226
227 unlock_system_sleep();
228}
229EXPORT_SYMBOL_GPL(suspend_set_ops);
230
231/**
232 * suspend_valid_only_mem - Generic memory-only valid callback.
233 *
234 * Platform drivers that implement mem suspend only and only need to check for
235 * that in their .valid() callback can use this instead of rolling their own
236 * .valid() callback.
237 */
238int suspend_valid_only_mem(suspend_state_t state)
239{
240 return state == PM_SUSPEND_MEM;
241}
242EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
243
244static bool sleep_state_supported(suspend_state_t state)
245{
246 return state == PM_SUSPEND_TO_IDLE || (suspend_ops && suspend_ops->enter);
247}
248
249static int platform_suspend_prepare(suspend_state_t state)
250{
251 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
252 suspend_ops->prepare() : 0;
253}
254
255static int platform_suspend_prepare_late(suspend_state_t state)
256{
257 return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
258 s2idle_ops->prepare() : 0;
259}
260
261static int platform_suspend_prepare_noirq(suspend_state_t state)
262{
263 return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
264 suspend_ops->prepare_late() : 0;
265}
266
267static void platform_resume_noirq(suspend_state_t state)
268{
269 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
270 suspend_ops->wake();
271}
272
273static void platform_resume_early(suspend_state_t state)
274{
275 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
276 s2idle_ops->restore();
277}
278
279static void platform_resume_finish(suspend_state_t state)
280{
281 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
282 suspend_ops->finish();
283}
284
285static int platform_suspend_begin(suspend_state_t state)
286{
287 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
288 return s2idle_ops->begin();
289 else if (suspend_ops && suspend_ops->begin)
290 return suspend_ops->begin(state);
291 else
292 return 0;
293}
294
295static void platform_resume_end(suspend_state_t state)
296{
297 if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
298 s2idle_ops->end();
299 else if (suspend_ops && suspend_ops->end)
300 suspend_ops->end();
301}
302
303static void platform_recover(suspend_state_t state)
304{
305 if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
306 suspend_ops->recover();
307}
308
309static bool platform_suspend_again(suspend_state_t state)
310{
311 return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
312 suspend_ops->suspend_again() : false;
313}
314
315#ifdef CONFIG_PM_DEBUG
316static unsigned int pm_test_delay = 5;
317module_param(pm_test_delay, uint, 0644);
318MODULE_PARM_DESC(pm_test_delay,
319 "Number of seconds to wait before resuming from suspend test");
320#endif
321
322static int suspend_test(int level)
323{
324#ifdef CONFIG_PM_DEBUG
325 if (pm_test_level == level) {
326 pr_info("suspend debug: Waiting for %d second(s).\n",
327 pm_test_delay);
328 mdelay(pm_test_delay * 1000);
329 return 1;
330 }
331#endif /* !CONFIG_PM_DEBUG */
332 return 0;
333}
334
335/**
336 * suspend_prepare - Prepare for entering system sleep state.
337 *
338 * Common code run for every system sleep state that can be entered (except for
339 * hibernation). Run suspend notifiers, allocate the "suspend" console and
340 * freeze processes.
341 */
342static int suspend_prepare(suspend_state_t state)
343{
344 int error, nr_calls = 0;
345
346 if (!sleep_state_supported(state))
347 return -EPERM;
348
349 pm_prepare_console();
350
351 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
352 if (error) {
353 nr_calls--;
354 goto Finish;
355 }
356
357 trace_suspend_resume(TPS("freeze_processes"), 0, true);
358 error = suspend_freeze_processes();
359 trace_suspend_resume(TPS("freeze_processes"), 0, false);
360 if (!error)
361 return 0;
362
363 suspend_stats.failed_freeze++;
364 dpm_save_failed_step(SUSPEND_FREEZE);
365 Finish:
366 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
367 pm_restore_console();
368 return error;
369}
370
371/* default implementation */
372void __weak arch_suspend_disable_irqs(void)
373{
374 local_irq_disable();
375}
376
377/* default implementation */
378void __weak arch_suspend_enable_irqs(void)
379{
380 local_irq_enable();
381}
382
383/**
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.
387 *
388 * This function should be called after devices have been suspended.
389 */
390static int suspend_enter(suspend_state_t state, bool *wakeup)
391{
392 int error;
393
394 error = platform_suspend_prepare(state);
395 if (error)
396 goto Platform_finish;
397
398 error = dpm_suspend_late(PMSG_SUSPEND);
399 if (error) {
400 pr_err("late suspend of devices failed\n");
401 goto Platform_finish;
402 }
403 error = platform_suspend_prepare_late(state);
404 if (error)
405 goto Devices_early_resume;
406
407 if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
408 s2idle_loop();
409 goto Platform_early_resume;
410 }
411
412 error = dpm_suspend_noirq(PMSG_SUSPEND);
413 if (error) {
414 pr_err("noirq suspend of devices failed\n");
415 goto Platform_early_resume;
416 }
417 error = platform_suspend_prepare_noirq(state);
418 if (error)
419 goto Platform_wake;
420
421 if (suspend_test(TEST_PLATFORM))
422 goto Platform_wake;
423
424 error = disable_nonboot_cpus();
425 if (error || suspend_test(TEST_CPUS))
426 goto Enable_cpus;
427
428 arch_suspend_disable_irqs();
429 BUG_ON(!irqs_disabled());
430
431 error = syscore_suspend();
432 if (!error) {
433 *wakeup = pm_wakeup_pending();
434 if (!(suspend_test(TEST_CORE) || *wakeup)) {
435 trace_suspend_resume(TPS("machine_suspend"),
436 state, true);
437 error = suspend_ops->enter(state);
438 trace_suspend_resume(TPS("machine_suspend"),
439 state, false);
440 } else if (*wakeup) {
441 error = -EBUSY;
442 }
443 syscore_resume();
444 }
445
446 arch_suspend_enable_irqs();
447 BUG_ON(irqs_disabled());
448
449 Enable_cpus:
450 enable_nonboot_cpus();
451
452 Platform_wake:
453 platform_resume_noirq(state);
454 dpm_resume_noirq(PMSG_RESUME);
455
456 Platform_early_resume:
457 platform_resume_early(state);
458
459 Devices_early_resume:
460 dpm_resume_early(PMSG_RESUME);
461
462 Platform_finish:
463 platform_resume_finish(state);
464 return error;
465}
466
467/**
468 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
469 * @state: System sleep state to enter.
470 */
471int suspend_devices_and_enter(suspend_state_t state)
472{
473 int error;
474 bool wakeup = false;
475
476 if (!sleep_state_supported(state))
477 return -ENOSYS;
478
479 pm_suspend_target_state = state;
480
481 error = platform_suspend_begin(state);
482 if (error)
483 goto Close;
484
485 suspend_console();
486 suspend_test_start();
487 error = dpm_suspend_start(PMSG_SUSPEND);
488 if (error) {
489 pr_err("Some devices failed to suspend, or early wake event detected\n");
490 goto Recover_platform;
491 }
492 suspend_test_finish("suspend devices");
493 if (suspend_test(TEST_DEVICES))
494 goto Recover_platform;
495
496 do {
497 error = suspend_enter(state, &wakeup);
498 } while (!error && !wakeup && platform_suspend_again(state));
499
500 Resume_devices:
501 suspend_test_start();
502 dpm_resume_end(PMSG_RESUME);
503 suspend_test_finish("resume devices");
504 trace_suspend_resume(TPS("resume_console"), state, true);
505 resume_console();
506 trace_suspend_resume(TPS("resume_console"), state, false);
507
508 Close:
509 platform_resume_end(state);
510 pm_suspend_target_state = PM_SUSPEND_ON;
511 return error;
512
513 Recover_platform:
514 platform_recover(state);
515 goto Resume_devices;
516}
517
518/**
519 * suspend_finish - Clean up before finishing the suspend sequence.
520 *
521 * Call platform code to clean up, restart processes, and free the console that
522 * we've allocated. This routine is not called for hibernation.
523 */
524static void suspend_finish(void)
525{
526 suspend_thaw_processes();
527 pm_notifier_call_chain(PM_POST_SUSPEND);
528 pm_restore_console();
529}
530
531/**
532 * enter_state - Do common work needed to enter system sleep state.
533 * @state: System sleep state to enter.
534 *
535 * Make sure that no one else is trying to put the system into a sleep state.
536 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
537 * system enter the given sleep state and clean up after wakeup.
538 */
539static int enter_state(suspend_state_t state)
540{
541 int error;
542
543 trace_suspend_resume(TPS("suspend_enter"), state, true);
544 if (state == PM_SUSPEND_TO_IDLE) {
545#ifdef CONFIG_PM_DEBUG
546 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
547 pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
548 return -EAGAIN;
549 }
550#endif
551 } else if (!valid_state(state)) {
552 return -EINVAL;
553 }
554 if (!mutex_trylock(&pm_mutex))
555 return -EBUSY;
556
557 if (state == PM_SUSPEND_TO_IDLE)
558 s2idle_begin();
559
560#ifndef CONFIG_SUSPEND_SKIP_SYNC
561 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
562 pr_info("Syncing filesystems ... ");
563 ksys_sync();
564 pr_cont("done.\n");
565 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
566#endif
567
568 pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
569 pm_suspend_clear_flags();
570 error = suspend_prepare(state);
571 if (error)
572 goto Unlock;
573
574 if (suspend_test(TEST_FREEZER))
575 goto Finish;
576
577 trace_suspend_resume(TPS("suspend_enter"), state, false);
578 pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
579 pm_restrict_gfp_mask();
580 error = suspend_devices_and_enter(state);
581 pm_restore_gfp_mask();
582
583 Finish:
584 events_check_enabled = false;
585 pm_pr_dbg("Finishing wakeup.\n");
586 suspend_finish();
587 Unlock:
588 mutex_unlock(&pm_mutex);
589 return error;
590}
591
592/**
593 * pm_suspend - Externally visible function for suspending the system.
594 * @state: System sleep state to enter.
595 *
596 * Check if the value of @state represents one of the supported states,
597 * execute enter_state() and update system suspend statistics.
598 */
599int pm_suspend(suspend_state_t state)
600{
601 int error;
602
603 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
604 return -EINVAL;
605
606 pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
607 error = enter_state(state);
608 if (error) {
609 suspend_stats.fail++;
610 dpm_save_failed_errno(error);
611 } else {
612 suspend_stats.success++;
613 }
614 pr_info("suspend exit\n");
615 return error;
616}
617EXPORT_SYMBOL(pm_suspend);