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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/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 *pm_labels[] = { "mem", "standby", "freeze", NULL };
36const char *pm_states[PM_SUSPEND_MAX];
37
38unsigned int pm_suspend_global_flags;
39EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
40
41static const struct platform_suspend_ops *suspend_ops;
42static const struct platform_freeze_ops *freeze_ops;
43static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
44
45enum freeze_state __read_mostly suspend_freeze_state;
46static DEFINE_SPINLOCK(suspend_freeze_lock);
47
48void freeze_set_ops(const struct platform_freeze_ops *ops)
49{
50 lock_system_sleep();
51 freeze_ops = ops;
52 unlock_system_sleep();
53}
54
55static void freeze_begin(void)
56{
57 suspend_freeze_state = FREEZE_STATE_NONE;
58}
59
60static void freeze_enter(void)
61{
62 spin_lock_irq(&suspend_freeze_lock);
63 if (pm_wakeup_pending())
64 goto out;
65
66 suspend_freeze_state = FREEZE_STATE_ENTER;
67 spin_unlock_irq(&suspend_freeze_lock);
68
69 get_online_cpus();
70 cpuidle_resume();
71
72 /* Push all the CPUs into the idle loop. */
73 wake_up_all_idle_cpus();
74 pr_debug("PM: suspend-to-idle\n");
75 /* Make the current CPU wait so it can enter the idle loop too. */
76 wait_event(suspend_freeze_wait_head,
77 suspend_freeze_state == FREEZE_STATE_WAKE);
78 pr_debug("PM: resume from suspend-to-idle\n");
79
80 cpuidle_pause();
81 put_online_cpus();
82
83 spin_lock_irq(&suspend_freeze_lock);
84
85 out:
86 suspend_freeze_state = FREEZE_STATE_NONE;
87 spin_unlock_irq(&suspend_freeze_lock);
88}
89
90void freeze_wake(void)
91{
92 unsigned long flags;
93
94 spin_lock_irqsave(&suspend_freeze_lock, flags);
95 if (suspend_freeze_state > FREEZE_STATE_NONE) {
96 suspend_freeze_state = FREEZE_STATE_WAKE;
97 wake_up(&suspend_freeze_wait_head);
98 }
99 spin_unlock_irqrestore(&suspend_freeze_lock, flags);
100}
101EXPORT_SYMBOL_GPL(freeze_wake);
102
103static bool valid_state(suspend_state_t state)
104{
105 /*
106 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
107 * support and need to be valid to the low level
108 * implementation, no valid callback implies that none are valid.
109 */
110 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
111}
112
113/*
114 * If this is set, the "mem" label always corresponds to the deepest sleep state
115 * available, the "standby" label corresponds to the second deepest sleep state
116 * available (if any), and the "freeze" label corresponds to the remaining
117 * available sleep state (if there is one).
118 */
119static bool relative_states;
120
121static int __init sleep_states_setup(char *str)
122{
123 relative_states = !strncmp(str, "1", 1);
124 pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
125 return 1;
126}
127
128__setup("relative_sleep_states=", sleep_states_setup);
129
130/**
131 * suspend_set_ops - Set the global suspend method table.
132 * @ops: Suspend operations to use.
133 */
134void suspend_set_ops(const struct platform_suspend_ops *ops)
135{
136 suspend_state_t i;
137 int j = 0;
138
139 lock_system_sleep();
140
141 suspend_ops = ops;
142 for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
143 if (valid_state(i)) {
144 pm_states[i] = pm_labels[j++];
145 } else if (!relative_states) {
146 pm_states[i] = NULL;
147 j++;
148 }
149
150 pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
151
152 unlock_system_sleep();
153}
154EXPORT_SYMBOL_GPL(suspend_set_ops);
155
156/**
157 * suspend_valid_only_mem - Generic memory-only valid callback.
158 *
159 * Platform drivers that implement mem suspend only and only need to check for
160 * that in their .valid() callback can use this instead of rolling their own
161 * .valid() callback.
162 */
163int suspend_valid_only_mem(suspend_state_t state)
164{
165 return state == PM_SUSPEND_MEM;
166}
167EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
168
169static bool sleep_state_supported(suspend_state_t state)
170{
171 return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter);
172}
173
174static int platform_suspend_prepare(suspend_state_t state)
175{
176 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
177 suspend_ops->prepare() : 0;
178}
179
180static int platform_suspend_prepare_late(suspend_state_t state)
181{
182 return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
183 freeze_ops->prepare() : 0;
184}
185
186static int platform_suspend_prepare_noirq(suspend_state_t state)
187{
188 return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
189 suspend_ops->prepare_late() : 0;
190}
191
192static void platform_resume_noirq(suspend_state_t state)
193{
194 if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
195 suspend_ops->wake();
196}
197
198static void platform_resume_early(suspend_state_t state)
199{
200 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
201 freeze_ops->restore();
202}
203
204static void platform_resume_finish(suspend_state_t state)
205{
206 if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
207 suspend_ops->finish();
208}
209
210static int platform_suspend_begin(suspend_state_t state)
211{
212 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
213 return freeze_ops->begin();
214 else if (suspend_ops->begin)
215 return suspend_ops->begin(state);
216 else
217 return 0;
218}
219
220static void platform_resume_end(suspend_state_t state)
221{
222 if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
223 freeze_ops->end();
224 else if (suspend_ops->end)
225 suspend_ops->end();
226}
227
228static void platform_recover(suspend_state_t state)
229{
230 if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
231 suspend_ops->recover();
232}
233
234static bool platform_suspend_again(suspend_state_t state)
235{
236 return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
237 suspend_ops->suspend_again() : false;
238}
239
240#ifdef CONFIG_PM_DEBUG
241static unsigned int pm_test_delay = 5;
242module_param(pm_test_delay, uint, 0644);
243MODULE_PARM_DESC(pm_test_delay,
244 "Number of seconds to wait before resuming from suspend test");
245#endif
246
247static int suspend_test(int level)
248{
249#ifdef CONFIG_PM_DEBUG
250 if (pm_test_level == level) {
251 pr_info("suspend debug: Waiting for %d second(s).\n",
252 pm_test_delay);
253 mdelay(pm_test_delay * 1000);
254 return 1;
255 }
256#endif /* !CONFIG_PM_DEBUG */
257 return 0;
258}
259
260/**
261 * suspend_prepare - Prepare for entering system sleep state.
262 *
263 * Common code run for every system sleep state that can be entered (except for
264 * hibernation). Run suspend notifiers, allocate the "suspend" console and
265 * freeze processes.
266 */
267static int suspend_prepare(suspend_state_t state)
268{
269 int error;
270
271 if (!sleep_state_supported(state))
272 return -EPERM;
273
274 pm_prepare_console();
275
276 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
277 if (error)
278 goto Finish;
279
280 trace_suspend_resume(TPS("freeze_processes"), 0, true);
281 error = suspend_freeze_processes();
282 trace_suspend_resume(TPS("freeze_processes"), 0, false);
283 if (!error)
284 return 0;
285
286 suspend_stats.failed_freeze++;
287 dpm_save_failed_step(SUSPEND_FREEZE);
288 Finish:
289 pm_notifier_call_chain(PM_POST_SUSPEND);
290 pm_restore_console();
291 return error;
292}
293
294/* default implementation */
295void __weak arch_suspend_disable_irqs(void)
296{
297 local_irq_disable();
298}
299
300/* default implementation */
301void __weak arch_suspend_enable_irqs(void)
302{
303 local_irq_enable();
304}
305
306/**
307 * suspend_enter - Make the system enter the given sleep state.
308 * @state: System sleep state to enter.
309 * @wakeup: Returns information that the sleep state should not be re-entered.
310 *
311 * This function should be called after devices have been suspended.
312 */
313static int suspend_enter(suspend_state_t state, bool *wakeup)
314{
315 int error;
316
317 error = platform_suspend_prepare(state);
318 if (error)
319 goto Platform_finish;
320
321 error = dpm_suspend_late(PMSG_SUSPEND);
322 if (error) {
323 pr_err("PM: late suspend of devices failed\n");
324 goto Platform_finish;
325 }
326 error = platform_suspend_prepare_late(state);
327 if (error)
328 goto Devices_early_resume;
329
330 error = dpm_suspend_noirq(PMSG_SUSPEND);
331 if (error) {
332 pr_err("PM: noirq suspend of devices failed\n");
333 goto Platform_early_resume;
334 }
335 error = platform_suspend_prepare_noirq(state);
336 if (error)
337 goto Platform_wake;
338
339 if (suspend_test(TEST_PLATFORM))
340 goto Platform_wake;
341
342 /*
343 * PM_SUSPEND_FREEZE equals
344 * frozen processes + suspended devices + idle processors.
345 * Thus we should invoke freeze_enter() soon after
346 * all the devices are suspended.
347 */
348 if (state == PM_SUSPEND_FREEZE) {
349 trace_suspend_resume(TPS("machine_suspend"), state, true);
350 freeze_enter();
351 trace_suspend_resume(TPS("machine_suspend"), state, false);
352 goto Platform_wake;
353 }
354
355 error = disable_nonboot_cpus();
356 if (error || suspend_test(TEST_CPUS))
357 goto Enable_cpus;
358
359 arch_suspend_disable_irqs();
360 BUG_ON(!irqs_disabled());
361
362 error = syscore_suspend();
363 if (!error) {
364 *wakeup = pm_wakeup_pending();
365 if (!(suspend_test(TEST_CORE) || *wakeup)) {
366 trace_suspend_resume(TPS("machine_suspend"),
367 state, true);
368 error = suspend_ops->enter(state);
369 trace_suspend_resume(TPS("machine_suspend"),
370 state, false);
371 events_check_enabled = false;
372 } else if (*wakeup) {
373 error = -EBUSY;
374 }
375 syscore_resume();
376 }
377
378 arch_suspend_enable_irqs();
379 BUG_ON(irqs_disabled());
380
381 Enable_cpus:
382 enable_nonboot_cpus();
383
384 Platform_wake:
385 platform_resume_noirq(state);
386 dpm_resume_noirq(PMSG_RESUME);
387
388 Platform_early_resume:
389 platform_resume_early(state);
390
391 Devices_early_resume:
392 dpm_resume_early(PMSG_RESUME);
393
394 Platform_finish:
395 platform_resume_finish(state);
396 return error;
397}
398
399/**
400 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
401 * @state: System sleep state to enter.
402 */
403int suspend_devices_and_enter(suspend_state_t state)
404{
405 int error;
406 bool wakeup = false;
407
408 if (!sleep_state_supported(state))
409 return -ENOSYS;
410
411 error = platform_suspend_begin(state);
412 if (error)
413 goto Close;
414
415 suspend_console();
416 suspend_test_start();
417 error = dpm_suspend_start(PMSG_SUSPEND);
418 if (error) {
419 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
420 goto Recover_platform;
421 }
422 suspend_test_finish("suspend devices");
423 if (suspend_test(TEST_DEVICES))
424 goto Recover_platform;
425
426 do {
427 error = suspend_enter(state, &wakeup);
428 } while (!error && !wakeup && platform_suspend_again(state));
429
430 Resume_devices:
431 suspend_test_start();
432 dpm_resume_end(PMSG_RESUME);
433 suspend_test_finish("resume devices");
434 trace_suspend_resume(TPS("resume_console"), state, true);
435 resume_console();
436 trace_suspend_resume(TPS("resume_console"), state, false);
437
438 Close:
439 platform_resume_end(state);
440 return error;
441
442 Recover_platform:
443 platform_recover(state);
444 goto Resume_devices;
445}
446
447/**
448 * suspend_finish - Clean up before finishing the suspend sequence.
449 *
450 * Call platform code to clean up, restart processes, and free the console that
451 * we've allocated. This routine is not called for hibernation.
452 */
453static void suspend_finish(void)
454{
455 suspend_thaw_processes();
456 pm_notifier_call_chain(PM_POST_SUSPEND);
457 pm_restore_console();
458}
459
460/**
461 * enter_state - Do common work needed to enter system sleep state.
462 * @state: System sleep state to enter.
463 *
464 * Make sure that no one else is trying to put the system into a sleep state.
465 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
466 * system enter the given sleep state and clean up after wakeup.
467 */
468static int enter_state(suspend_state_t state)
469{
470 int error;
471
472 trace_suspend_resume(TPS("suspend_enter"), state, true);
473 if (state == PM_SUSPEND_FREEZE) {
474#ifdef CONFIG_PM_DEBUG
475 if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
476 pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
477 return -EAGAIN;
478 }
479#endif
480 } else if (!valid_state(state)) {
481 return -EINVAL;
482 }
483 if (!mutex_trylock(&pm_mutex))
484 return -EBUSY;
485
486 if (state == PM_SUSPEND_FREEZE)
487 freeze_begin();
488
489#ifndef CONFIG_SUSPEND_SKIP_SYNC
490 trace_suspend_resume(TPS("sync_filesystems"), 0, true);
491 printk(KERN_INFO "PM: Syncing filesystems ... ");
492 sys_sync();
493 printk("done.\n");
494 trace_suspend_resume(TPS("sync_filesystems"), 0, false);
495#endif
496
497 pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
498 pm_suspend_clear_flags();
499 error = suspend_prepare(state);
500 if (error)
501 goto Unlock;
502
503 if (suspend_test(TEST_FREEZER))
504 goto Finish;
505
506 trace_suspend_resume(TPS("suspend_enter"), state, false);
507 pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
508 pm_restrict_gfp_mask();
509 error = suspend_devices_and_enter(state);
510 pm_restore_gfp_mask();
511
512 Finish:
513 pr_debug("PM: Finishing wakeup.\n");
514 suspend_finish();
515 Unlock:
516 mutex_unlock(&pm_mutex);
517 return error;
518}
519
520/**
521 * pm_suspend - Externally visible function for suspending the system.
522 * @state: System sleep state to enter.
523 *
524 * Check if the value of @state represents one of the supported states,
525 * execute enter_state() and update system suspend statistics.
526 */
527int pm_suspend(suspend_state_t state)
528{
529 int error;
530
531 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
532 return -EINVAL;
533
534 error = enter_state(state);
535 if (error) {
536 suspend_stats.fail++;
537 dpm_save_failed_errno(error);
538 } else {
539 suspend_stats.success++;
540 }
541 return error;
542}
543EXPORT_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
32#include "power.h"
33
34const char *const pm_states[PM_SUSPEND_MAX] = {
35 [PM_SUSPEND_FREEZE] = "freeze",
36 [PM_SUSPEND_STANDBY] = "standby",
37 [PM_SUSPEND_MEM] = "mem",
38};
39
40static const struct platform_suspend_ops *suspend_ops;
41
42static bool need_suspend_ops(suspend_state_t state)
43{
44 return state > PM_SUSPEND_FREEZE;
45}
46
47static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
48static bool suspend_freeze_wake;
49
50static void freeze_begin(void)
51{
52 suspend_freeze_wake = false;
53}
54
55static void freeze_enter(void)
56{
57 cpuidle_resume();
58 wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
59 cpuidle_pause();
60}
61
62void freeze_wake(void)
63{
64 suspend_freeze_wake = true;
65 wake_up(&suspend_freeze_wait_head);
66}
67EXPORT_SYMBOL_GPL(freeze_wake);
68
69/**
70 * suspend_set_ops - Set the global suspend method table.
71 * @ops: Suspend operations to use.
72 */
73void suspend_set_ops(const struct platform_suspend_ops *ops)
74{
75 lock_system_sleep();
76 suspend_ops = ops;
77 unlock_system_sleep();
78}
79EXPORT_SYMBOL_GPL(suspend_set_ops);
80
81bool valid_state(suspend_state_t state)
82{
83 if (state == PM_SUSPEND_FREEZE) {
84#ifdef CONFIG_PM_DEBUG
85 if (pm_test_level != TEST_NONE &&
86 pm_test_level != TEST_FREEZER &&
87 pm_test_level != TEST_DEVICES &&
88 pm_test_level != TEST_PLATFORM) {
89 printk(KERN_WARNING "Unsupported pm_test mode for "
90 "freeze state, please choose "
91 "none/freezer/devices/platform.\n");
92 return false;
93 }
94#endif
95 return true;
96 }
97 /*
98 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
99 * support and need to be valid to the lowlevel
100 * implementation, no valid callback implies that none are valid.
101 */
102 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
103}
104
105/**
106 * suspend_valid_only_mem - Generic memory-only valid callback.
107 *
108 * Platform drivers that implement mem suspend only and only need to check for
109 * that in their .valid() callback can use this instead of rolling their own
110 * .valid() callback.
111 */
112int suspend_valid_only_mem(suspend_state_t state)
113{
114 return state == PM_SUSPEND_MEM;
115}
116EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
117
118static int suspend_test(int level)
119{
120#ifdef CONFIG_PM_DEBUG
121 if (pm_test_level == level) {
122 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
123 mdelay(5000);
124 return 1;
125 }
126#endif /* !CONFIG_PM_DEBUG */
127 return 0;
128}
129
130/**
131 * suspend_prepare - Prepare for entering system sleep state.
132 *
133 * Common code run for every system sleep state that can be entered (except for
134 * hibernation). Run suspend notifiers, allocate the "suspend" console and
135 * freeze processes.
136 */
137static int suspend_prepare(suspend_state_t state)
138{
139 int error;
140
141 if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
142 return -EPERM;
143
144 pm_prepare_console();
145
146 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
147 if (error)
148 goto Finish;
149
150 error = suspend_freeze_processes();
151 if (!error)
152 return 0;
153
154 suspend_stats.failed_freeze++;
155 dpm_save_failed_step(SUSPEND_FREEZE);
156 Finish:
157 pm_notifier_call_chain(PM_POST_SUSPEND);
158 pm_restore_console();
159 return error;
160}
161
162/* default implementation */
163void __weak arch_suspend_disable_irqs(void)
164{
165 local_irq_disable();
166}
167
168/* default implementation */
169void __weak arch_suspend_enable_irqs(void)
170{
171 local_irq_enable();
172}
173
174/**
175 * suspend_enter - Make the system enter the given sleep state.
176 * @state: System sleep state to enter.
177 * @wakeup: Returns information that the sleep state should not be re-entered.
178 *
179 * This function should be called after devices have been suspended.
180 */
181static int suspend_enter(suspend_state_t state, bool *wakeup)
182{
183 int error;
184
185 if (need_suspend_ops(state) && suspend_ops->prepare) {
186 error = suspend_ops->prepare();
187 if (error)
188 goto Platform_finish;
189 }
190
191 error = dpm_suspend_end(PMSG_SUSPEND);
192 if (error) {
193 printk(KERN_ERR "PM: Some devices failed to power down\n");
194 goto Platform_finish;
195 }
196
197 if (need_suspend_ops(state) && suspend_ops->prepare_late) {
198 error = suspend_ops->prepare_late();
199 if (error)
200 goto Platform_wake;
201 }
202
203 if (suspend_test(TEST_PLATFORM))
204 goto Platform_wake;
205
206 /*
207 * PM_SUSPEND_FREEZE equals
208 * frozen processes + suspended devices + idle processors.
209 * Thus we should invoke freeze_enter() soon after
210 * all the devices are suspended.
211 */
212 if (state == PM_SUSPEND_FREEZE) {
213 freeze_enter();
214 goto Platform_wake;
215 }
216
217 ftrace_stop();
218 error = disable_nonboot_cpus();
219 if (error || suspend_test(TEST_CPUS))
220 goto Enable_cpus;
221
222 arch_suspend_disable_irqs();
223 BUG_ON(!irqs_disabled());
224
225 error = syscore_suspend();
226 if (!error) {
227 *wakeup = pm_wakeup_pending();
228 if (!(suspend_test(TEST_CORE) || *wakeup)) {
229 error = suspend_ops->enter(state);
230 events_check_enabled = false;
231 }
232 syscore_resume();
233 }
234
235 arch_suspend_enable_irqs();
236 BUG_ON(irqs_disabled());
237
238 Enable_cpus:
239 enable_nonboot_cpus();
240 ftrace_start();
241
242 Platform_wake:
243 if (need_suspend_ops(state) && suspend_ops->wake)
244 suspend_ops->wake();
245
246 dpm_resume_start(PMSG_RESUME);
247
248 Platform_finish:
249 if (need_suspend_ops(state) && suspend_ops->finish)
250 suspend_ops->finish();
251
252 return error;
253}
254
255/**
256 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
257 * @state: System sleep state to enter.
258 */
259int suspend_devices_and_enter(suspend_state_t state)
260{
261 int error;
262 bool wakeup = false;
263
264 if (need_suspend_ops(state) && !suspend_ops)
265 return -ENOSYS;
266
267 trace_machine_suspend(state);
268 if (need_suspend_ops(state) && suspend_ops->begin) {
269 error = suspend_ops->begin(state);
270 if (error)
271 goto Close;
272 }
273 suspend_console();
274 suspend_test_start();
275 error = dpm_suspend_start(PMSG_SUSPEND);
276 if (error) {
277 pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
278 goto Recover_platform;
279 }
280 suspend_test_finish("suspend devices");
281 if (suspend_test(TEST_DEVICES))
282 goto Recover_platform;
283
284 do {
285 error = suspend_enter(state, &wakeup);
286 } while (!error && !wakeup && need_suspend_ops(state)
287 && suspend_ops->suspend_again && suspend_ops->suspend_again());
288
289 Resume_devices:
290 suspend_test_start();
291 dpm_resume_end(PMSG_RESUME);
292 suspend_test_finish("resume devices");
293 resume_console();
294 Close:
295 if (need_suspend_ops(state) && suspend_ops->end)
296 suspend_ops->end();
297 trace_machine_suspend(PWR_EVENT_EXIT);
298 return error;
299
300 Recover_platform:
301 if (need_suspend_ops(state) && suspend_ops->recover)
302 suspend_ops->recover();
303 goto Resume_devices;
304}
305
306/**
307 * suspend_finish - Clean up before finishing the suspend sequence.
308 *
309 * Call platform code to clean up, restart processes, and free the console that
310 * we've allocated. This routine is not called for hibernation.
311 */
312static void suspend_finish(void)
313{
314 suspend_thaw_processes();
315 pm_notifier_call_chain(PM_POST_SUSPEND);
316 pm_restore_console();
317}
318
319/**
320 * enter_state - Do common work needed to enter system sleep state.
321 * @state: System sleep state to enter.
322 *
323 * Make sure that no one else is trying to put the system into a sleep state.
324 * Fail if that's not the case. Otherwise, prepare for system suspend, make the
325 * system enter the given sleep state and clean up after wakeup.
326 */
327static int enter_state(suspend_state_t state)
328{
329 int error;
330
331 if (!valid_state(state))
332 return -ENODEV;
333
334 if (!mutex_trylock(&pm_mutex))
335 return -EBUSY;
336
337 if (state == PM_SUSPEND_FREEZE)
338 freeze_begin();
339
340 printk(KERN_INFO "PM: Syncing filesystems ... ");
341 sys_sync();
342 printk("done.\n");
343
344 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
345 error = suspend_prepare(state);
346 if (error)
347 goto Unlock;
348
349 if (suspend_test(TEST_FREEZER))
350 goto Finish;
351
352 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
353 pm_restrict_gfp_mask();
354 error = suspend_devices_and_enter(state);
355 pm_restore_gfp_mask();
356
357 Finish:
358 pr_debug("PM: Finishing wakeup.\n");
359 suspend_finish();
360 Unlock:
361 mutex_unlock(&pm_mutex);
362 return error;
363}
364
365/**
366 * pm_suspend - Externally visible function for suspending the system.
367 * @state: System sleep state to enter.
368 *
369 * Check if the value of @state represents one of the supported states,
370 * execute enter_state() and update system suspend statistics.
371 */
372int pm_suspend(suspend_state_t state)
373{
374 int error;
375
376 if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
377 return -EINVAL;
378
379 error = enter_state(state);
380 if (error) {
381 suspend_stats.fail++;
382 dpm_save_failed_errno(error);
383 } else {
384 suspend_stats.success++;
385 }
386 return error;
387}
388EXPORT_SYMBOL(pm_suspend);