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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/export.h>
25#include <linux/suspend.h>
26#include <linux/syscore_ops.h>
27#include <linux/ftrace.h>
28#include <trace/events/power.h>
29
30#include "power.h"
31
32const char *const pm_states[PM_SUSPEND_MAX] = {
33 [PM_SUSPEND_STANDBY] = "standby",
34 [PM_SUSPEND_MEM] = "mem",
35};
36
37static const struct platform_suspend_ops *suspend_ops;
38
39/**
40 * suspend_set_ops - Set the global suspend method table.
41 * @ops: Suspend operations to use.
42 */
43void suspend_set_ops(const struct platform_suspend_ops *ops)
44{
45 lock_system_sleep();
46 suspend_ops = ops;
47 unlock_system_sleep();
48}
49EXPORT_SYMBOL_GPL(suspend_set_ops);
50
51bool valid_state(suspend_state_t state)
52{
53 /*
54 * All states need lowlevel support and need to be valid to the lowlevel
55 * implementation, no valid callback implies that none are valid.
56 */
57 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
58}
59
60/**
61 * suspend_valid_only_mem - Generic memory-only valid callback.
62 *
63 * Platform drivers that implement mem suspend only and only need to check for
64 * that in their .valid() callback can use this instead of rolling their own
65 * .valid() callback.
66 */
67int suspend_valid_only_mem(suspend_state_t state)
68{
69 return state == PM_SUSPEND_MEM;
70}
71EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
72
73static int suspend_test(int level)
74{
75#ifdef CONFIG_PM_DEBUG
76 if (pm_test_level == level) {
77 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
78 mdelay(5000);
79 return 1;
80 }
81#endif /* !CONFIG_PM_DEBUG */
82 return 0;
83}
84
85/**
86 * suspend_prepare - Prepare for entering system sleep state.
87 *
88 * Common code run for every system sleep state that can be entered (except for
89 * hibernation). Run suspend notifiers, allocate the "suspend" console and
90 * freeze processes.
91 */
92static int suspend_prepare(void)
93{
94 int error;
95
96 if (!suspend_ops || !suspend_ops->enter)
97 return -EPERM;
98
99 pm_prepare_console();
100
101 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
102 if (error)
103 goto Finish;
104
105 error = suspend_freeze_processes();
106 if (!error)
107 return 0;
108
109 suspend_stats.failed_freeze++;
110 dpm_save_failed_step(SUSPEND_FREEZE);
111 Finish:
112 pm_notifier_call_chain(PM_POST_SUSPEND);
113 pm_restore_console();
114 return error;
115}
116
117/* default implementation */
118void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
119{
120 local_irq_disable();
121}
122
123/* default implementation */
124void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
125{
126 local_irq_enable();
127}
128
129/**
130 * suspend_enter - Make the system enter the given sleep state.
131 * @state: System sleep state to enter.
132 * @wakeup: Returns information that the sleep state should not be re-entered.
133 *
134 * This function should be called after devices have been suspended.
135 */
136static int suspend_enter(suspend_state_t state, bool *wakeup)
137{
138 int error;
139
140 if (suspend_ops->prepare) {
141 error = suspend_ops->prepare();
142 if (error)
143 goto Platform_finish;
144 }
145
146 error = dpm_suspend_end(PMSG_SUSPEND);
147 if (error) {
148 printk(KERN_ERR "PM: Some devices failed to power down\n");
149 goto Platform_finish;
150 }
151
152 if (suspend_ops->prepare_late) {
153 error = suspend_ops->prepare_late();
154 if (error)
155 goto Platform_wake;
156 }
157
158 if (suspend_test(TEST_PLATFORM))
159 goto Platform_wake;
160
161 error = disable_nonboot_cpus();
162 if (error || suspend_test(TEST_CPUS))
163 goto Enable_cpus;
164
165 arch_suspend_disable_irqs();
166 BUG_ON(!irqs_disabled());
167
168 error = syscore_suspend();
169 if (!error) {
170 *wakeup = pm_wakeup_pending();
171 if (!(suspend_test(TEST_CORE) || *wakeup)) {
172 error = suspend_ops->enter(state);
173 events_check_enabled = false;
174 }
175 syscore_resume();
176 }
177
178 arch_suspend_enable_irqs();
179 BUG_ON(irqs_disabled());
180
181 Enable_cpus:
182 enable_nonboot_cpus();
183
184 Platform_wake:
185 if (suspend_ops->wake)
186 suspend_ops->wake();
187
188 dpm_resume_start(PMSG_RESUME);
189
190 Platform_finish:
191 if (suspend_ops->finish)
192 suspend_ops->finish();
193
194 return error;
195}
196
197/**
198 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
199 * @state: System sleep state to enter.
200 */
201int suspend_devices_and_enter(suspend_state_t state)
202{
203 int error;
204 bool wakeup = false;
205
206 if (!suspend_ops)
207 return -ENOSYS;
208
209 trace_machine_suspend(state);
210 if (suspend_ops->begin) {
211 error = suspend_ops->begin(state);
212 if (error)
213 goto Close;
214 }
215 suspend_console();
216 ftrace_stop();
217 suspend_test_start();
218 error = dpm_suspend_start(PMSG_SUSPEND);
219 if (error) {
220 printk(KERN_ERR "PM: Some devices failed to suspend\n");
221 goto Recover_platform;
222 }
223 suspend_test_finish("suspend devices");
224 if (suspend_test(TEST_DEVICES))
225 goto Recover_platform;
226
227 do {
228 error = suspend_enter(state, &wakeup);
229 } while (!error && !wakeup
230 && suspend_ops->suspend_again && suspend_ops->suspend_again());
231
232 Resume_devices:
233 suspend_test_start();
234 dpm_resume_end(PMSG_RESUME);
235 suspend_test_finish("resume devices");
236 ftrace_start();
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 - Clean up before finishing the suspend sequence.
252 *
253 * Call platform code to clean up, restart processes, and free the console that
254 * we've allocated. This routine is not called for hibernation.
255 */
256static void suspend_finish(void)
257{
258 suspend_thaw_processes();
259 pm_notifier_call_chain(PM_POST_SUSPEND);
260 pm_restore_console();
261}
262
263/**
264 * enter_state - Do common work needed to enter system sleep state.
265 * @state: System sleep state to enter.
266 *
267 * Make sure that no one else is trying to put the system into a sleep state.
268 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
269 * system enter the given sleep state and clean up after wakeup.
270 */
271static int enter_state(suspend_state_t state)
272{
273 int error;
274
275 if (!valid_state(state))
276 return -ENODEV;
277
278 if (!mutex_trylock(&pm_mutex))
279 return -EBUSY;
280
281 printk(KERN_INFO "PM: Syncing filesystems ... ");
282 sys_sync();
283 printk("done.\n");
284
285 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
286 error = suspend_prepare();
287 if (error)
288 goto Unlock;
289
290 if (suspend_test(TEST_FREEZER))
291 goto Finish;
292
293 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
294 pm_restrict_gfp_mask();
295 error = suspend_devices_and_enter(state);
296 pm_restore_gfp_mask();
297
298 Finish:
299 pr_debug("PM: Finishing wakeup.\n");
300 suspend_finish();
301 Unlock:
302 mutex_unlock(&pm_mutex);
303 return error;
304}
305
306/**
307 * pm_suspend - Externally visible function for suspending the system.
308 * @state: System sleep state to enter.
309 *
310 * Check if the value of @state represents one of the supported states,
311 * execute enter_state() and update system suspend statistics.
312 */
313int pm_suspend(suspend_state_t state)
314{
315 int error;
316
317 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
318 return -EINVAL;
319
320 error = enter_state(state);
321 if (error) {
322 suspend_stats.fail++;
323 dpm_save_failed_errno(error);
324 } else {
325 suspend_stats.success++;
326 }
327 return error;
328}
329EXPORT_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#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/cpuidle.h>
18#include <linux/syscalls.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/ftrace.h>
29#include <trace/events/power.h>
30#include <linux/compiler.h>
31#include <linux/moduleparam.h>
32
33#include "power.h"
34
35const char * const pm_labels[] = {
36 [PM_SUSPEND_FREEZE] = "freeze",
37 [PM_SUSPEND_STANDBY] = "standby",
38 [PM_SUSPEND_MEM] = "mem",
39};
40const char *pm_states[PM_SUSPEND_MAX];
41static const char * const mem_sleep_labels[] = {
42 [PM_SUSPEND_FREEZE] = "s2idle",
43 [PM_SUSPEND_STANDBY] = "shallow",
44 [PM_SUSPEND_MEM] = "deep",
45};
46const char *mem_sleep_states[PM_SUSPEND_MAX];
47
48suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE;
49static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM;
50
51unsigned int pm_suspend_global_flags;
52EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
53
54static const struct platform_suspend_ops *suspend_ops;
55static const struct platform_freeze_ops *freeze_ops;
56static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
57
58enum freeze_state __read_mostly suspend_freeze_state;
59static DEFINE_SPINLOCK(suspend_freeze_lock);
60
61void freeze_set_ops(const struct platform_freeze_ops *ops)
62{
63 lock_system_sleep();
64 freeze_ops = ops;
65 unlock_system_sleep();
66}
67
68static void freeze_begin(void)
69{
70 suspend_freeze_state = FREEZE_STATE_NONE;
71}
72
73static void freeze_enter(void)
74{
75 spin_lock_irq(&suspend_freeze_lock);
76 if (pm_wakeup_pending())
77 goto out;
78
79 suspend_freeze_state = FREEZE_STATE_ENTER;
80 spin_unlock_irq(&suspend_freeze_lock);
81
82 get_online_cpus();
83 cpuidle_resume();
84
85 /* Push all the CPUs into the idle loop. */
86 wake_up_all_idle_cpus();
87 pr_debug("PM: suspend-to-idle\n");
88 /* Make the current CPU wait so it can enter the idle loop too. */
89 wait_event(suspend_freeze_wait_head,
90 suspend_freeze_state == FREEZE_STATE_WAKE);
91 pr_debug("PM: resume from suspend-to-idle\n");
92
93 cpuidle_pause();
94 put_online_cpus();
95
96 spin_lock_irq(&suspend_freeze_lock);
97
98 out:
99 suspend_freeze_state = FREEZE_STATE_NONE;
100 spin_unlock_irq(&suspend_freeze_lock);
101}
102
103void freeze_wake(void)
104{
105 unsigned long flags;
106
107 spin_lock_irqsave(&suspend_freeze_lock, flags);
108 if (suspend_freeze_state > FREEZE_STATE_NONE) {
109 suspend_freeze_state = FREEZE_STATE_WAKE;
110 wake_up(&suspend_freeze_wait_head);
111 }
112 spin_unlock_irqrestore(&suspend_freeze_lock, flags);
113}
114EXPORT_SYMBOL_GPL(freeze_wake);
115
116static bool valid_state(suspend_state_t state)
117{
118 /*
119 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
120 * support and need to be valid to the low level
121 * implementation, no valid callback implies that none are valid.
122 */
123 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
124}
125
126void __init pm_states_init(void)
127{
128 /* "mem" and "freeze" are always present in /sys/power/state. */
129 pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
130 pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE];
131 /*
132 * Suspend-to-idle should be supported even without any suspend_ops,
133 * initialize mem_sleep_states[] accordingly here.
134 */
135 mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE];
136}
137
138static int __init mem_sleep_default_setup(char *str)
139{
140 suspend_state_t state;
141
142 for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++)
143 if (mem_sleep_labels[state] &&
144 !strcmp(str, mem_sleep_labels[state])) {
145 mem_sleep_default = state;
146 break;
147 }
148
149 return 1;
150}
151__setup("mem_sleep_default=", mem_sleep_default_setup);
152
153/**
154 * suspend_set_ops - Set the global suspend method table.
155 * @ops: Suspend operations to use.
156 */
157void suspend_set_ops(const struct platform_suspend_ops *ops)
158{
159 lock_system_sleep();
160
161 suspend_ops = ops;
162
163 if (valid_state(PM_SUSPEND_STANDBY)) {
164 mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
165 pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
166 if (mem_sleep_default == PM_SUSPEND_STANDBY)
167 mem_sleep_current = PM_SUSPEND_STANDBY;
168 }
169 if (valid_state(PM_SUSPEND_MEM)) {
170 mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
171 if (mem_sleep_default == PM_SUSPEND_MEM)
172 mem_sleep_current = PM_SUSPEND_MEM;
173 }
174
175 unlock_system_sleep();
176}
177EXPORT_SYMBOL_GPL(suspend_set_ops);
178
179/**
180 * suspend_valid_only_mem - Generic memory-only valid callback.
181 *
182 * Platform drivers that implement mem suspend only and only need to check for
183 * that in their .valid() callback can use this instead of rolling their own
184 * .valid() callback.
185 */
186int suspend_valid_only_mem(suspend_state_t state)
187{
188 return state == PM_SUSPEND_MEM;
189}
190EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
191
192static bool sleep_state_supported(suspend_state_t state)
193{
194 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
195}
196
197static int platform_suspend_prepare(suspend_state_t state)
198{
199 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
200 suspend_ops->prepare() : 0;
201}
202
203static int platform_suspend_prepare_late(suspend_state_t state)
204{
205 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
206 freeze_ops->prepare() : 0;
207}
208
209static int platform_suspend_prepare_noirq(suspend_state_t state)
210{
211 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
212 suspend_ops->prepare_late() : 0;
213}
214
215static void platform_resume_noirq(suspend_state_t state)
216{
217 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
218 suspend_ops->wake();
219}
220
221static void platform_resume_early(suspend_state_t state)
222{
223 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
224 freeze_ops->restore();
225}
226
227static void platform_resume_finish(suspend_state_t state)
228{
229 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
230 suspend_ops->finish();
231}
232
233static int platform_suspend_begin(suspend_state_t state)
234{
235 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
236 return freeze_ops->begin();
237 else if (suspend_ops && suspend_ops->begin)
238 return suspend_ops->begin(state);
239 else
240 return 0;
241}
242
243static void platform_resume_end(suspend_state_t state)
244{
245 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
246 freeze_ops->end();
247 else if (suspend_ops && suspend_ops->end)
248 suspend_ops->end();
249}
250
251static void platform_recover(suspend_state_t state)
252{
253 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
254 suspend_ops->recover();
255}
256
257static bool platform_suspend_again(suspend_state_t state)
258{
259 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
260 suspend_ops->suspend_again() : false;
261}
262
263#ifdef CONFIG_PM_DEBUG
264static unsigned int pm_test_delay = 5;
265module_param(pm_test_delay, uint, 0644);
266MODULE_PARM_DESC(pm_test_delay,
267 "Number of seconds to wait before resuming from suspend test");
268#endif
269
270static int suspend_test(int level)
271{
272#ifdef CONFIG_PM_DEBUG
273 if (pm_test_level == level) {
274 pr_info("suspend debug: Waiting for %d second(s).\n",
275 pm_test_delay);
276 mdelay(pm_test_delay * 1000);
277 return 1;
278 }
279#endif /* !CONFIG_PM_DEBUG */
280 return 0;
281}
282
283/**
284 * suspend_prepare - Prepare for entering system sleep state.
285 *
286 * Common code run for every system sleep state that can be entered (except for
287 * hibernation). Run suspend notifiers, allocate the "suspend" console and
288 * freeze processes.
289 */
290static int suspend_prepare(suspend_state_t state)
291{
292 int error, nr_calls = 0;
293
294 if (!sleep_state_supported(state))
295 return -EPERM;
296
297 pm_prepare_console();
298
299 error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
300 if (error) {
301 nr_calls--;
302 goto Finish;
303 }
304
305 trace_suspend_resume(TPS("freeze_processes"), 0, true);
306 error = suspend_freeze_processes();
307 trace_suspend_resume(TPS("freeze_processes"), 0, false);
308 if (!error)
309 return 0;
310
311 suspend_stats.failed_freeze++;
312 dpm_save_failed_step(SUSPEND_FREEZE);
313 Finish:
314 __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
315 pm_restore_console();
316 return error;
317}
318
319/* default implementation */
320void __weak arch_suspend_disable_irqs(void)
321{
322 local_irq_disable();
323}
324
325/* default implementation */
326void __weak arch_suspend_enable_irqs(void)
327{
328 local_irq_enable();
329}
330
331/**
332 * suspend_enter - Make the system enter the given sleep state.
333 * @state: System sleep state to enter.
334 * @wakeup: Returns information that the sleep state should not be re-entered.
335 *
336 * This function should be called after devices have been suspended.
337 */
338static int suspend_enter(suspend_state_t state, bool *wakeup)
339{
340 int error;
341
342 error = platform_suspend_prepare(state);
343 if (error)
344 goto Platform_finish;
345
346 error = dpm_suspend_late(PMSG_SUSPEND);
347 if (error) {
348 pr_err("PM: late suspend of devices failed\n");
349 goto Platform_finish;
350 }
351 error = platform_suspend_prepare_late(state);
352 if (error)
353 goto Devices_early_resume;
354
355 error = dpm_suspend_noirq(PMSG_SUSPEND);
356 if (error) {
357 pr_err("PM: noirq suspend of devices failed\n");
358 goto Platform_early_resume;
359 }
360 error = platform_suspend_prepare_noirq(state);
361 if (error)
362 goto Platform_wake;
363
364 if (suspend_test(TEST_PLATFORM))
365 goto Platform_wake;
366
367 /*
368 * PM_SUSPEND_FREEZE equals
369 * frozen processes + suspended devices + idle processors.
370 * Thus we should invoke freeze_enter() soon after
371 * all the devices are suspended.
372 */
373 if (state == PM_SUSPEND_FREEZE) {
374 trace_suspend_resume(TPS("machine_suspend"), state, true);
375 freeze_enter();
376 trace_suspend_resume(TPS("machine_suspend"), state, false);
377 goto Platform_wake;
378 }
379
380 error = disable_nonboot_cpus();
381 if (error || suspend_test(TEST_CPUS))
382 goto Enable_cpus;
383
384 arch_suspend_disable_irqs();
385 BUG_ON(!irqs_disabled());
386
387 error = syscore_suspend();
388 if (!error) {
389 *wakeup = pm_wakeup_pending();
390 if (!(suspend_test(TEST_CORE) || *wakeup)) {
391 trace_suspend_resume(TPS("machine_suspend"),
392 state, true);
393 error = suspend_ops->enter(state);
394 trace_suspend_resume(TPS("machine_suspend"),
395 state, false);
396 events_check_enabled = false;
397 } else if (*wakeup) {
398 error = -EBUSY;
399 }
400 syscore_resume();
401 }
402
403 arch_suspend_enable_irqs();
404 BUG_ON(irqs_disabled());
405
406 Enable_cpus:
407 enable_nonboot_cpus();
408
409 Platform_wake:
410 platform_resume_noirq(state);
411 dpm_resume_noirq(PMSG_RESUME);
412
413 Platform_early_resume:
414 platform_resume_early(state);
415
416 Devices_early_resume:
417 dpm_resume_early(PMSG_RESUME);
418
419 Platform_finish:
420 platform_resume_finish(state);
421 return error;
422}
423
424/**
425 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
426 * @state: System sleep state to enter.
427 */
428int suspend_devices_and_enter(suspend_state_t state)
429{
430 int error;
431 bool wakeup = false;
432
433 if (!sleep_state_supported(state))
434 return -ENOSYS;
435
436 error = platform_suspend_begin(state);
437 if (error)
438 goto Close;
439
440 suspend_console();
441 suspend_test_start();
442 error = dpm_suspend_start(PMSG_SUSPEND);
443 if (error) {
444 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
445 goto Recover_platform;
446 }
447 suspend_test_finish("suspend devices");
448 if (suspend_test(TEST_DEVICES))
449 goto Recover_platform;
450
451 do {
452 error = suspend_enter(state, &wakeup);
453 } while (!error && !wakeup && platform_suspend_again(state));
454
455 Resume_devices:
456 suspend_test_start();
457 dpm_resume_end(PMSG_RESUME);
458 suspend_test_finish("resume devices");
459 trace_suspend_resume(TPS("resume_console"), state, true);
460 resume_console();
461 trace_suspend_resume(TPS("resume_console"), state, false);
462
463 Close:
464 platform_resume_end(state);
465 return error;
466
467 Recover_platform:
468 platform_recover(state);
469 goto Resume_devices;
470}
471
472/**
473 * suspend_finish - Clean up before finishing the suspend sequence.
474 *
475 * Call platform code to clean up, restart processes, and free the console that
476 * we've allocated. This routine is not called for hibernation.
477 */
478static void suspend_finish(void)
479{
480 suspend_thaw_processes();
481 pm_notifier_call_chain(PM_POST_SUSPEND);
482 pm_restore_console();
483}
484
485/**
486 * enter_state - Do common work needed to enter system sleep state.
487 * @state: System sleep state to enter.
488 *
489 * Make sure that no one else is trying to put the system into a sleep state.
490 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
491 * system enter the given sleep state and clean up after wakeup.
492 */
493static int enter_state(suspend_state_t state)
494{
495 int error;
496
497 trace_suspend_resume(TPS("suspend_enter"), state, true);
498 if (state == PM_SUSPEND_FREEZE) {
499#ifdef CONFIG_PM_DEBUG
500 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
501 pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
502 return -EAGAIN;
503 }
504#endif
505 } else if (!valid_state(state)) {
506 return -EINVAL;
507 }
508 if (!mutex_trylock(&pm_mutex))
509 return -EBUSY;
510
511 if (state == PM_SUSPEND_FREEZE)
512 freeze_begin();
513
514#ifndef CONFIG_SUSPEND_SKIP_SYNC
515 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
516 pr_info("PM: Syncing filesystems ... ");
517 sys_sync();
518 pr_cont("done.\n");
519 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
520#endif
521
522 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
523 pm_suspend_clear_flags();
524 error = suspend_prepare(state);
525 if (error)
526 goto Unlock;
527
528 if (suspend_test(TEST_FREEZER))
529 goto Finish;
530
531 trace_suspend_resume(TPS("suspend_enter"), state, false);
532 pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
533 pm_restrict_gfp_mask();
534 error = suspend_devices_and_enter(state);
535 pm_restore_gfp_mask();
536
537 Finish:
538 pr_debug("PM: Finishing wakeup.\n");
539 suspend_finish();
540 Unlock:
541 mutex_unlock(&pm_mutex);
542 return error;
543}
544
545/**
546 * pm_suspend - Externally visible function for suspending the system.
547 * @state: System sleep state to enter.
548 *
549 * Check if the value of @state represents one of the supported states,
550 * execute enter_state() and update system suspend statistics.
551 */
552int pm_suspend(suspend_state_t state)
553{
554 int error;
555
556 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
557 return -EINVAL;
558
559 error = enter_state(state);
560 if (error) {
561 suspend_stats.fail++;
562 dpm_save_failed_errno(error);
563 } else {
564 suspend_stats.success++;
565 }
566 return error;
567}
568EXPORT_SYMBOL(pm_suspend);