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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
8 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
9 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
10 */
11
12#define pr_fmt(fmt) "PM: hibernation: " fmt
13
14#include <linux/export.h>
15#include <linux/suspend.h>
16#include <linux/reboot.h>
17#include <linux/string.h>
18#include <linux/device.h>
19#include <linux/async.h>
20#include <linux/delay.h>
21#include <linux/fs.h>
22#include <linux/mount.h>
23#include <linux/pm.h>
24#include <linux/nmi.h>
25#include <linux/console.h>
26#include <linux/cpu.h>
27#include <linux/freezer.h>
28#include <linux/gfp.h>
29#include <linux/syscore_ops.h>
30#include <linux/ctype.h>
31#include <linux/genhd.h>
32#include <linux/ktime.h>
33#include <linux/security.h>
34#include <trace/events/power.h>
35
36#include "power.h"
37
38
39static int nocompress;
40static int noresume;
41static int nohibernate;
42static int resume_wait;
43static unsigned int resume_delay;
44static char resume_file[256] = CONFIG_PM_STD_PARTITION;
45dev_t swsusp_resume_device;
46sector_t swsusp_resume_block;
47__visible int in_suspend __nosavedata;
48
49enum {
50 HIBERNATION_INVALID,
51 HIBERNATION_PLATFORM,
52 HIBERNATION_SHUTDOWN,
53 HIBERNATION_REBOOT,
54#ifdef CONFIG_SUSPEND
55 HIBERNATION_SUSPEND,
56#endif
57 HIBERNATION_TEST_RESUME,
58 /* keep last */
59 __HIBERNATION_AFTER_LAST
60};
61#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
62#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
63
64static int hibernation_mode = HIBERNATION_SHUTDOWN;
65
66bool freezer_test_done;
67
68static const struct platform_hibernation_ops *hibernation_ops;
69
70static atomic_t hibernate_atomic = ATOMIC_INIT(1);
71
72bool hibernate_acquire(void)
73{
74 return atomic_add_unless(&hibernate_atomic, -1, 0);
75}
76
77void hibernate_release(void)
78{
79 atomic_inc(&hibernate_atomic);
80}
81
82bool hibernation_available(void)
83{
84 return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
85}
86
87/**
88 * hibernation_set_ops - Set the global hibernate operations.
89 * @ops: Hibernation operations to use in subsequent hibernation transitions.
90 */
91void hibernation_set_ops(const struct platform_hibernation_ops *ops)
92{
93 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
94 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
95 && ops->restore_cleanup && ops->leave)) {
96 WARN_ON(1);
97 return;
98 }
99 lock_system_sleep();
100 hibernation_ops = ops;
101 if (ops)
102 hibernation_mode = HIBERNATION_PLATFORM;
103 else if (hibernation_mode == HIBERNATION_PLATFORM)
104 hibernation_mode = HIBERNATION_SHUTDOWN;
105
106 unlock_system_sleep();
107}
108EXPORT_SYMBOL_GPL(hibernation_set_ops);
109
110static bool entering_platform_hibernation;
111
112bool system_entering_hibernation(void)
113{
114 return entering_platform_hibernation;
115}
116EXPORT_SYMBOL(system_entering_hibernation);
117
118#ifdef CONFIG_PM_DEBUG
119static void hibernation_debug_sleep(void)
120{
121 pr_info("debug: Waiting for 5 seconds.\n");
122 mdelay(5000);
123}
124
125static int hibernation_test(int level)
126{
127 if (pm_test_level == level) {
128 hibernation_debug_sleep();
129 return 1;
130 }
131 return 0;
132}
133#else /* !CONFIG_PM_DEBUG */
134static int hibernation_test(int level) { return 0; }
135#endif /* !CONFIG_PM_DEBUG */
136
137/**
138 * platform_begin - Call platform to start hibernation.
139 * @platform_mode: Whether or not to use the platform driver.
140 */
141static int platform_begin(int platform_mode)
142{
143 return (platform_mode && hibernation_ops) ?
144 hibernation_ops->begin(PMSG_FREEZE) : 0;
145}
146
147/**
148 * platform_end - Call platform to finish transition to the working state.
149 * @platform_mode: Whether or not to use the platform driver.
150 */
151static void platform_end(int platform_mode)
152{
153 if (platform_mode && hibernation_ops)
154 hibernation_ops->end();
155}
156
157/**
158 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
159 * @platform_mode: Whether or not to use the platform driver.
160 *
161 * Use the platform driver to prepare the system for creating a hibernate image,
162 * if so configured, and return an error code if that fails.
163 */
164
165static int platform_pre_snapshot(int platform_mode)
166{
167 return (platform_mode && hibernation_ops) ?
168 hibernation_ops->pre_snapshot() : 0;
169}
170
171/**
172 * platform_leave - Call platform to prepare a transition to the working state.
173 * @platform_mode: Whether or not to use the platform driver.
174 *
175 * Use the platform driver prepare to prepare the machine for switching to the
176 * normal mode of operation.
177 *
178 * This routine is called on one CPU with interrupts disabled.
179 */
180static void platform_leave(int platform_mode)
181{
182 if (platform_mode && hibernation_ops)
183 hibernation_ops->leave();
184}
185
186/**
187 * platform_finish - Call platform to switch the system to the working state.
188 * @platform_mode: Whether or not to use the platform driver.
189 *
190 * Use the platform driver to switch the machine to the normal mode of
191 * operation.
192 *
193 * This routine must be called after platform_prepare().
194 */
195static void platform_finish(int platform_mode)
196{
197 if (platform_mode && hibernation_ops)
198 hibernation_ops->finish();
199}
200
201/**
202 * platform_pre_restore - Prepare for hibernate image restoration.
203 * @platform_mode: Whether or not to use the platform driver.
204 *
205 * Use the platform driver to prepare the system for resume from a hibernation
206 * image.
207 *
208 * If the restore fails after this function has been called,
209 * platform_restore_cleanup() must be called.
210 */
211static int platform_pre_restore(int platform_mode)
212{
213 return (platform_mode && hibernation_ops) ?
214 hibernation_ops->pre_restore() : 0;
215}
216
217/**
218 * platform_restore_cleanup - Switch to the working state after failing restore.
219 * @platform_mode: Whether or not to use the platform driver.
220 *
221 * Use the platform driver to switch the system to the normal mode of operation
222 * after a failing restore.
223 *
224 * If platform_pre_restore() has been called before the failing restore, this
225 * function must be called too, regardless of the result of
226 * platform_pre_restore().
227 */
228static void platform_restore_cleanup(int platform_mode)
229{
230 if (platform_mode && hibernation_ops)
231 hibernation_ops->restore_cleanup();
232}
233
234/**
235 * platform_recover - Recover from a failure to suspend devices.
236 * @platform_mode: Whether or not to use the platform driver.
237 */
238static void platform_recover(int platform_mode)
239{
240 if (platform_mode && hibernation_ops && hibernation_ops->recover)
241 hibernation_ops->recover();
242}
243
244/**
245 * swsusp_show_speed - Print time elapsed between two events during hibernation.
246 * @start: Starting event.
247 * @stop: Final event.
248 * @nr_pages: Number of memory pages processed between @start and @stop.
249 * @msg: Additional diagnostic message to print.
250 */
251void swsusp_show_speed(ktime_t start, ktime_t stop,
252 unsigned nr_pages, char *msg)
253{
254 ktime_t diff;
255 u64 elapsed_centisecs64;
256 unsigned int centisecs;
257 unsigned int k;
258 unsigned int kps;
259
260 diff = ktime_sub(stop, start);
261 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
262 centisecs = elapsed_centisecs64;
263 if (centisecs == 0)
264 centisecs = 1; /* avoid div-by-zero */
265 k = nr_pages * (PAGE_SIZE / 1024);
266 kps = (k * 100) / centisecs;
267 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
268 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
269 (kps % 1000) / 10);
270}
271
272__weak int arch_resume_nosmt(void)
273{
274 return 0;
275}
276
277/**
278 * create_image - Create a hibernation image.
279 * @platform_mode: Whether or not to use the platform driver.
280 *
281 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
282 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
283 *
284 * Control reappears in this routine after the subsequent restore.
285 */
286static int create_image(int platform_mode)
287{
288 int error;
289
290 error = dpm_suspend_end(PMSG_FREEZE);
291 if (error) {
292 pr_err("Some devices failed to power down, aborting\n");
293 return error;
294 }
295
296 error = platform_pre_snapshot(platform_mode);
297 if (error || hibernation_test(TEST_PLATFORM))
298 goto Platform_finish;
299
300 error = suspend_disable_secondary_cpus();
301 if (error || hibernation_test(TEST_CPUS))
302 goto Enable_cpus;
303
304 local_irq_disable();
305
306 system_state = SYSTEM_SUSPEND;
307
308 error = syscore_suspend();
309 if (error) {
310 pr_err("Some system devices failed to power down, aborting\n");
311 goto Enable_irqs;
312 }
313
314 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
315 goto Power_up;
316
317 in_suspend = 1;
318 save_processor_state();
319 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
320 error = swsusp_arch_suspend();
321 /* Restore control flow magically appears here */
322 restore_processor_state();
323 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
324 if (error)
325 pr_err("Error %d creating image\n", error);
326
327 if (!in_suspend) {
328 events_check_enabled = false;
329 clear_free_pages();
330 }
331
332 platform_leave(platform_mode);
333
334 Power_up:
335 syscore_resume();
336
337 Enable_irqs:
338 system_state = SYSTEM_RUNNING;
339 local_irq_enable();
340
341 Enable_cpus:
342 suspend_enable_secondary_cpus();
343
344 /* Allow architectures to do nosmt-specific post-resume dances */
345 if (!in_suspend)
346 error = arch_resume_nosmt();
347
348 Platform_finish:
349 platform_finish(platform_mode);
350
351 dpm_resume_start(in_suspend ?
352 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
353
354 return error;
355}
356
357/**
358 * hibernation_snapshot - Quiesce devices and create a hibernation image.
359 * @platform_mode: If set, use platform driver to prepare for the transition.
360 *
361 * This routine must be called with system_transition_mutex held.
362 */
363int hibernation_snapshot(int platform_mode)
364{
365 pm_message_t msg;
366 int error;
367
368 pm_suspend_clear_flags();
369 error = platform_begin(platform_mode);
370 if (error)
371 goto Close;
372
373 /* Preallocate image memory before shutting down devices. */
374 error = hibernate_preallocate_memory();
375 if (error)
376 goto Close;
377
378 error = freeze_kernel_threads();
379 if (error)
380 goto Cleanup;
381
382 if (hibernation_test(TEST_FREEZER)) {
383
384 /*
385 * Indicate to the caller that we are returning due to a
386 * successful freezer test.
387 */
388 freezer_test_done = true;
389 goto Thaw;
390 }
391
392 error = dpm_prepare(PMSG_FREEZE);
393 if (error) {
394 dpm_complete(PMSG_RECOVER);
395 goto Thaw;
396 }
397
398 suspend_console();
399 pm_restrict_gfp_mask();
400
401 error = dpm_suspend(PMSG_FREEZE);
402
403 if (error || hibernation_test(TEST_DEVICES))
404 platform_recover(platform_mode);
405 else
406 error = create_image(platform_mode);
407
408 /*
409 * In the case that we call create_image() above, the control
410 * returns here (1) after the image has been created or the
411 * image creation has failed and (2) after a successful restore.
412 */
413
414 /* We may need to release the preallocated image pages here. */
415 if (error || !in_suspend)
416 swsusp_free();
417
418 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
419 dpm_resume(msg);
420
421 if (error || !in_suspend)
422 pm_restore_gfp_mask();
423
424 resume_console();
425 dpm_complete(msg);
426
427 Close:
428 platform_end(platform_mode);
429 return error;
430
431 Thaw:
432 thaw_kernel_threads();
433 Cleanup:
434 swsusp_free();
435 goto Close;
436}
437
438int __weak hibernate_resume_nonboot_cpu_disable(void)
439{
440 return suspend_disable_secondary_cpus();
441}
442
443/**
444 * resume_target_kernel - Restore system state from a hibernation image.
445 * @platform_mode: Whether or not to use the platform driver.
446 *
447 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
448 * contents of highmem that have not been restored yet from the image and run
449 * the low-level code that will restore the remaining contents of memory and
450 * switch to the just restored target kernel.
451 */
452static int resume_target_kernel(bool platform_mode)
453{
454 int error;
455
456 error = dpm_suspend_end(PMSG_QUIESCE);
457 if (error) {
458 pr_err("Some devices failed to power down, aborting resume\n");
459 return error;
460 }
461
462 error = platform_pre_restore(platform_mode);
463 if (error)
464 goto Cleanup;
465
466 error = hibernate_resume_nonboot_cpu_disable();
467 if (error)
468 goto Enable_cpus;
469
470 local_irq_disable();
471 system_state = SYSTEM_SUSPEND;
472
473 error = syscore_suspend();
474 if (error)
475 goto Enable_irqs;
476
477 save_processor_state();
478 error = restore_highmem();
479 if (!error) {
480 error = swsusp_arch_resume();
481 /*
482 * The code below is only ever reached in case of a failure.
483 * Otherwise, execution continues at the place where
484 * swsusp_arch_suspend() was called.
485 */
486 BUG_ON(!error);
487 /*
488 * This call to restore_highmem() reverts the changes made by
489 * the previous one.
490 */
491 restore_highmem();
492 }
493 /*
494 * The only reason why swsusp_arch_resume() can fail is memory being
495 * very tight, so we have to free it as soon as we can to avoid
496 * subsequent failures.
497 */
498 swsusp_free();
499 restore_processor_state();
500 touch_softlockup_watchdog();
501
502 syscore_resume();
503
504 Enable_irqs:
505 system_state = SYSTEM_RUNNING;
506 local_irq_enable();
507
508 Enable_cpus:
509 suspend_enable_secondary_cpus();
510
511 Cleanup:
512 platform_restore_cleanup(platform_mode);
513
514 dpm_resume_start(PMSG_RECOVER);
515
516 return error;
517}
518
519/**
520 * hibernation_restore - Quiesce devices and restore from a hibernation image.
521 * @platform_mode: If set, use platform driver to prepare for the transition.
522 *
523 * This routine must be called with system_transition_mutex held. If it is
524 * successful, control reappears in the restored target kernel in
525 * hibernation_snapshot().
526 */
527int hibernation_restore(int platform_mode)
528{
529 int error;
530
531 pm_prepare_console();
532 suspend_console();
533 pm_restrict_gfp_mask();
534 error = dpm_suspend_start(PMSG_QUIESCE);
535 if (!error) {
536 error = resume_target_kernel(platform_mode);
537 /*
538 * The above should either succeed and jump to the new kernel,
539 * or return with an error. Otherwise things are just
540 * undefined, so let's be paranoid.
541 */
542 BUG_ON(!error);
543 }
544 dpm_resume_end(PMSG_RECOVER);
545 pm_restore_gfp_mask();
546 resume_console();
547 pm_restore_console();
548 return error;
549}
550
551/**
552 * hibernation_platform_enter - Power off the system using the platform driver.
553 */
554int hibernation_platform_enter(void)
555{
556 int error;
557
558 if (!hibernation_ops)
559 return -ENOSYS;
560
561 /*
562 * We have cancelled the power transition by running
563 * hibernation_ops->finish() before saving the image, so we should let
564 * the firmware know that we're going to enter the sleep state after all
565 */
566 error = hibernation_ops->begin(PMSG_HIBERNATE);
567 if (error)
568 goto Close;
569
570 entering_platform_hibernation = true;
571 suspend_console();
572 error = dpm_suspend_start(PMSG_HIBERNATE);
573 if (error) {
574 if (hibernation_ops->recover)
575 hibernation_ops->recover();
576 goto Resume_devices;
577 }
578
579 error = dpm_suspend_end(PMSG_HIBERNATE);
580 if (error)
581 goto Resume_devices;
582
583 error = hibernation_ops->prepare();
584 if (error)
585 goto Platform_finish;
586
587 error = suspend_disable_secondary_cpus();
588 if (error)
589 goto Enable_cpus;
590
591 local_irq_disable();
592 system_state = SYSTEM_SUSPEND;
593 syscore_suspend();
594 if (pm_wakeup_pending()) {
595 error = -EAGAIN;
596 goto Power_up;
597 }
598
599 hibernation_ops->enter();
600 /* We should never get here */
601 while (1);
602
603 Power_up:
604 syscore_resume();
605 system_state = SYSTEM_RUNNING;
606 local_irq_enable();
607
608 Enable_cpus:
609 suspend_enable_secondary_cpus();
610
611 Platform_finish:
612 hibernation_ops->finish();
613
614 dpm_resume_start(PMSG_RESTORE);
615
616 Resume_devices:
617 entering_platform_hibernation = false;
618 dpm_resume_end(PMSG_RESTORE);
619 resume_console();
620
621 Close:
622 hibernation_ops->end();
623
624 return error;
625}
626
627/**
628 * power_down - Shut the machine down for hibernation.
629 *
630 * Use the platform driver, if configured, to put the system into the sleep
631 * state corresponding to hibernation, or try to power it off or reboot,
632 * depending on the value of hibernation_mode.
633 */
634static void power_down(void)
635{
636#ifdef CONFIG_SUSPEND
637 int error;
638
639 if (hibernation_mode == HIBERNATION_SUSPEND) {
640 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
641 if (error) {
642 hibernation_mode = hibernation_ops ?
643 HIBERNATION_PLATFORM :
644 HIBERNATION_SHUTDOWN;
645 } else {
646 /* Restore swap signature. */
647 error = swsusp_unmark();
648 if (error)
649 pr_err("Swap will be unusable! Try swapon -a.\n");
650
651 return;
652 }
653 }
654#endif
655
656 switch (hibernation_mode) {
657 case HIBERNATION_REBOOT:
658 kernel_restart(NULL);
659 break;
660 case HIBERNATION_PLATFORM:
661 hibernation_platform_enter();
662 fallthrough;
663 case HIBERNATION_SHUTDOWN:
664 if (pm_power_off)
665 kernel_power_off();
666 break;
667 }
668 kernel_halt();
669 /*
670 * Valid image is on the disk, if we continue we risk serious data
671 * corruption after resume.
672 */
673 pr_crit("Power down manually\n");
674 while (1)
675 cpu_relax();
676}
677
678static int load_image_and_restore(void)
679{
680 int error;
681 unsigned int flags;
682
683 pm_pr_dbg("Loading hibernation image.\n");
684
685 lock_device_hotplug();
686 error = create_basic_memory_bitmaps();
687 if (error)
688 goto Unlock;
689
690 error = swsusp_read(&flags);
691 swsusp_close(FMODE_READ);
692 if (!error)
693 error = hibernation_restore(flags & SF_PLATFORM_MODE);
694
695 pr_err("Failed to load image, recovering.\n");
696 swsusp_free();
697 free_basic_memory_bitmaps();
698 Unlock:
699 unlock_device_hotplug();
700
701 return error;
702}
703
704/**
705 * hibernate - Carry out system hibernation, including saving the image.
706 */
707int hibernate(void)
708{
709 int error, nr_calls = 0;
710 bool snapshot_test = false;
711
712 if (!hibernation_available()) {
713 pm_pr_dbg("Hibernation not available.\n");
714 return -EPERM;
715 }
716
717 lock_system_sleep();
718 /* The snapshot device should not be opened while we're running */
719 if (!hibernate_acquire()) {
720 error = -EBUSY;
721 goto Unlock;
722 }
723
724 pr_info("hibernation entry\n");
725 pm_prepare_console();
726 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
727 if (error) {
728 nr_calls--;
729 goto Exit;
730 }
731
732 ksys_sync_helper();
733
734 error = freeze_processes();
735 if (error)
736 goto Exit;
737
738 lock_device_hotplug();
739 /* Allocate memory management structures */
740 error = create_basic_memory_bitmaps();
741 if (error)
742 goto Thaw;
743
744 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
745 if (error || freezer_test_done)
746 goto Free_bitmaps;
747
748 if (in_suspend) {
749 unsigned int flags = 0;
750
751 if (hibernation_mode == HIBERNATION_PLATFORM)
752 flags |= SF_PLATFORM_MODE;
753 if (nocompress)
754 flags |= SF_NOCOMPRESS_MODE;
755 else
756 flags |= SF_CRC32_MODE;
757
758 pm_pr_dbg("Writing hibernation image.\n");
759 error = swsusp_write(flags);
760 swsusp_free();
761 if (!error) {
762 if (hibernation_mode == HIBERNATION_TEST_RESUME)
763 snapshot_test = true;
764 else
765 power_down();
766 }
767 in_suspend = 0;
768 pm_restore_gfp_mask();
769 } else {
770 pm_pr_dbg("Hibernation image restored successfully.\n");
771 }
772
773 Free_bitmaps:
774 free_basic_memory_bitmaps();
775 Thaw:
776 unlock_device_hotplug();
777 if (snapshot_test) {
778 pm_pr_dbg("Checking hibernation image\n");
779 error = swsusp_check();
780 if (!error)
781 error = load_image_and_restore();
782 }
783 thaw_processes();
784
785 /* Don't bother checking whether freezer_test_done is true */
786 freezer_test_done = false;
787 Exit:
788 __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
789 pm_restore_console();
790 hibernate_release();
791 Unlock:
792 unlock_system_sleep();
793 pr_info("hibernation exit\n");
794
795 return error;
796}
797
798/**
799 * hibernate_quiet_exec - Execute a function with all devices frozen.
800 * @func: Function to execute.
801 * @data: Data pointer to pass to @func.
802 *
803 * Return the @func return value or an error code if it cannot be executed.
804 */
805int hibernate_quiet_exec(int (*func)(void *data), void *data)
806{
807 int error, nr_calls = 0;
808
809 lock_system_sleep();
810
811 if (!hibernate_acquire()) {
812 error = -EBUSY;
813 goto unlock;
814 }
815
816 pm_prepare_console();
817
818 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
819 if (error) {
820 nr_calls--;
821 goto exit;
822 }
823
824 error = freeze_processes();
825 if (error)
826 goto exit;
827
828 lock_device_hotplug();
829
830 pm_suspend_clear_flags();
831
832 error = platform_begin(true);
833 if (error)
834 goto thaw;
835
836 error = freeze_kernel_threads();
837 if (error)
838 goto thaw;
839
840 error = dpm_prepare(PMSG_FREEZE);
841 if (error)
842 goto dpm_complete;
843
844 suspend_console();
845
846 error = dpm_suspend(PMSG_FREEZE);
847 if (error)
848 goto dpm_resume;
849
850 error = dpm_suspend_end(PMSG_FREEZE);
851 if (error)
852 goto dpm_resume;
853
854 error = platform_pre_snapshot(true);
855 if (error)
856 goto skip;
857
858 error = func(data);
859
860skip:
861 platform_finish(true);
862
863 dpm_resume_start(PMSG_THAW);
864
865dpm_resume:
866 dpm_resume(PMSG_THAW);
867
868 resume_console();
869
870dpm_complete:
871 dpm_complete(PMSG_THAW);
872
873 thaw_kernel_threads();
874
875thaw:
876 platform_end(true);
877
878 unlock_device_hotplug();
879
880 thaw_processes();
881
882exit:
883 __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
884
885 pm_restore_console();
886
887 hibernate_release();
888
889unlock:
890 unlock_system_sleep();
891
892 return error;
893}
894EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
895
896/**
897 * software_resume - Resume from a saved hibernation image.
898 *
899 * This routine is called as a late initcall, when all devices have been
900 * discovered and initialized already.
901 *
902 * The image reading code is called to see if there is a hibernation image
903 * available for reading. If that is the case, devices are quiesced and the
904 * contents of memory is restored from the saved image.
905 *
906 * If this is successful, control reappears in the restored target kernel in
907 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
908 * attempts to recover gracefully and make the kernel return to the normal mode
909 * of operation.
910 */
911static int software_resume(void)
912{
913 int error, nr_calls = 0;
914
915 /*
916 * If the user said "noresume".. bail out early.
917 */
918 if (noresume || !hibernation_available())
919 return 0;
920
921 /*
922 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
923 * is configured into the kernel. Since the regular hibernate
924 * trigger path is via sysfs which takes a buffer mutex before
925 * calling hibernate functions (which take system_transition_mutex)
926 * this can cause lockdep to complain about a possible ABBA deadlock
927 * which cannot happen since we're in the boot code here and
928 * sysfs can't be invoked yet. Therefore, we use a subclass
929 * here to avoid lockdep complaining.
930 */
931 mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
932
933 if (swsusp_resume_device)
934 goto Check_image;
935
936 if (!strlen(resume_file)) {
937 error = -ENOENT;
938 goto Unlock;
939 }
940
941 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
942
943 if (resume_delay) {
944 pr_info("Waiting %dsec before reading resume device ...\n",
945 resume_delay);
946 ssleep(resume_delay);
947 }
948
949 /* Check if the device is there */
950 swsusp_resume_device = name_to_dev_t(resume_file);
951
952 /*
953 * name_to_dev_t is ineffective to verify parition if resume_file is in
954 * integer format. (e.g. major:minor)
955 */
956 if (isdigit(resume_file[0]) && resume_wait) {
957 int partno;
958 while (!get_gendisk(swsusp_resume_device, &partno))
959 msleep(10);
960 }
961
962 if (!swsusp_resume_device) {
963 /*
964 * Some device discovery might still be in progress; we need
965 * to wait for this to finish.
966 */
967 wait_for_device_probe();
968
969 if (resume_wait) {
970 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
971 msleep(10);
972 async_synchronize_full();
973 }
974
975 swsusp_resume_device = name_to_dev_t(resume_file);
976 if (!swsusp_resume_device) {
977 error = -ENODEV;
978 goto Unlock;
979 }
980 }
981
982 Check_image:
983 pm_pr_dbg("Hibernation image partition %d:%d present\n",
984 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
985
986 pm_pr_dbg("Looking for hibernation image.\n");
987 error = swsusp_check();
988 if (error)
989 goto Unlock;
990
991 /* The snapshot device should not be opened while we're running */
992 if (!hibernate_acquire()) {
993 error = -EBUSY;
994 swsusp_close(FMODE_READ);
995 goto Unlock;
996 }
997
998 pr_info("resume from hibernation\n");
999 pm_prepare_console();
1000 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
1001 if (error) {
1002 nr_calls--;
1003 goto Close_Finish;
1004 }
1005
1006 pm_pr_dbg("Preparing processes for hibernation restore.\n");
1007 error = freeze_processes();
1008 if (error)
1009 goto Close_Finish;
1010
1011 error = freeze_kernel_threads();
1012 if (error) {
1013 thaw_processes();
1014 goto Close_Finish;
1015 }
1016
1017 error = load_image_and_restore();
1018 thaw_processes();
1019 Finish:
1020 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
1021 pm_restore_console();
1022 pr_info("resume failed (%d)\n", error);
1023 hibernate_release();
1024 /* For success case, the suspend path will release the lock */
1025 Unlock:
1026 mutex_unlock(&system_transition_mutex);
1027 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1028 return error;
1029 Close_Finish:
1030 swsusp_close(FMODE_READ);
1031 goto Finish;
1032}
1033
1034late_initcall_sync(software_resume);
1035
1036
1037static const char * const hibernation_modes[] = {
1038 [HIBERNATION_PLATFORM] = "platform",
1039 [HIBERNATION_SHUTDOWN] = "shutdown",
1040 [HIBERNATION_REBOOT] = "reboot",
1041#ifdef CONFIG_SUSPEND
1042 [HIBERNATION_SUSPEND] = "suspend",
1043#endif
1044 [HIBERNATION_TEST_RESUME] = "test_resume",
1045};
1046
1047/*
1048 * /sys/power/disk - Control hibernation mode.
1049 *
1050 * Hibernation can be handled in several ways. There are a few different ways
1051 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1052 * or other hibernation_ops), powering it off or rebooting it (for testing
1053 * mostly).
1054 *
1055 * The sysfs file /sys/power/disk provides an interface for selecting the
1056 * hibernation mode to use. Reading from this file causes the available modes
1057 * to be printed. There are 3 modes that can be supported:
1058 *
1059 * 'platform'
1060 * 'shutdown'
1061 * 'reboot'
1062 *
1063 * If a platform hibernation driver is in use, 'platform' will be supported
1064 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1065 * The selected option (i.e. the one corresponding to the current value of
1066 * hibernation_mode) is enclosed by a square bracket.
1067 *
1068 * To select a given hibernation mode it is necessary to write the mode's
1069 * string representation (as returned by reading from /sys/power/disk) back
1070 * into /sys/power/disk.
1071 */
1072
1073static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1074 char *buf)
1075{
1076 int i;
1077 char *start = buf;
1078
1079 if (!hibernation_available())
1080 return sprintf(buf, "[disabled]\n");
1081
1082 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1083 if (!hibernation_modes[i])
1084 continue;
1085 switch (i) {
1086 case HIBERNATION_SHUTDOWN:
1087 case HIBERNATION_REBOOT:
1088#ifdef CONFIG_SUSPEND
1089 case HIBERNATION_SUSPEND:
1090#endif
1091 case HIBERNATION_TEST_RESUME:
1092 break;
1093 case HIBERNATION_PLATFORM:
1094 if (hibernation_ops)
1095 break;
1096 /* not a valid mode, continue with loop */
1097 continue;
1098 }
1099 if (i == hibernation_mode)
1100 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1101 else
1102 buf += sprintf(buf, "%s ", hibernation_modes[i]);
1103 }
1104 buf += sprintf(buf, "\n");
1105 return buf-start;
1106}
1107
1108static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1109 const char *buf, size_t n)
1110{
1111 int error = 0;
1112 int i;
1113 int len;
1114 char *p;
1115 int mode = HIBERNATION_INVALID;
1116
1117 if (!hibernation_available())
1118 return -EPERM;
1119
1120 p = memchr(buf, '\n', n);
1121 len = p ? p - buf : n;
1122
1123 lock_system_sleep();
1124 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1125 if (len == strlen(hibernation_modes[i])
1126 && !strncmp(buf, hibernation_modes[i], len)) {
1127 mode = i;
1128 break;
1129 }
1130 }
1131 if (mode != HIBERNATION_INVALID) {
1132 switch (mode) {
1133 case HIBERNATION_SHUTDOWN:
1134 case HIBERNATION_REBOOT:
1135#ifdef CONFIG_SUSPEND
1136 case HIBERNATION_SUSPEND:
1137#endif
1138 case HIBERNATION_TEST_RESUME:
1139 hibernation_mode = mode;
1140 break;
1141 case HIBERNATION_PLATFORM:
1142 if (hibernation_ops)
1143 hibernation_mode = mode;
1144 else
1145 error = -EINVAL;
1146 }
1147 } else
1148 error = -EINVAL;
1149
1150 if (!error)
1151 pm_pr_dbg("Hibernation mode set to '%s'\n",
1152 hibernation_modes[mode]);
1153 unlock_system_sleep();
1154 return error ? error : n;
1155}
1156
1157power_attr(disk);
1158
1159static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1160 char *buf)
1161{
1162 return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1163 MINOR(swsusp_resume_device));
1164}
1165
1166static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1167 const char *buf, size_t n)
1168{
1169 dev_t res;
1170 int len = n;
1171 char *name;
1172
1173 if (len && buf[len-1] == '\n')
1174 len--;
1175 name = kstrndup(buf, len, GFP_KERNEL);
1176 if (!name)
1177 return -ENOMEM;
1178
1179 res = name_to_dev_t(name);
1180 kfree(name);
1181 if (!res)
1182 return -EINVAL;
1183
1184 lock_system_sleep();
1185 swsusp_resume_device = res;
1186 unlock_system_sleep();
1187 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1188 swsusp_resume_device);
1189 noresume = 0;
1190 software_resume();
1191 return n;
1192}
1193
1194power_attr(resume);
1195
1196static ssize_t resume_offset_show(struct kobject *kobj,
1197 struct kobj_attribute *attr, char *buf)
1198{
1199 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1200}
1201
1202static ssize_t resume_offset_store(struct kobject *kobj,
1203 struct kobj_attribute *attr, const char *buf,
1204 size_t n)
1205{
1206 unsigned long long offset;
1207 int rc;
1208
1209 rc = kstrtoull(buf, 0, &offset);
1210 if (rc)
1211 return rc;
1212 swsusp_resume_block = offset;
1213
1214 return n;
1215}
1216
1217power_attr(resume_offset);
1218
1219static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1220 char *buf)
1221{
1222 return sprintf(buf, "%lu\n", image_size);
1223}
1224
1225static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1226 const char *buf, size_t n)
1227{
1228 unsigned long size;
1229
1230 if (sscanf(buf, "%lu", &size) == 1) {
1231 image_size = size;
1232 return n;
1233 }
1234
1235 return -EINVAL;
1236}
1237
1238power_attr(image_size);
1239
1240static ssize_t reserved_size_show(struct kobject *kobj,
1241 struct kobj_attribute *attr, char *buf)
1242{
1243 return sprintf(buf, "%lu\n", reserved_size);
1244}
1245
1246static ssize_t reserved_size_store(struct kobject *kobj,
1247 struct kobj_attribute *attr,
1248 const char *buf, size_t n)
1249{
1250 unsigned long size;
1251
1252 if (sscanf(buf, "%lu", &size) == 1) {
1253 reserved_size = size;
1254 return n;
1255 }
1256
1257 return -EINVAL;
1258}
1259
1260power_attr(reserved_size);
1261
1262static struct attribute *g[] = {
1263 &disk_attr.attr,
1264 &resume_offset_attr.attr,
1265 &resume_attr.attr,
1266 &image_size_attr.attr,
1267 &reserved_size_attr.attr,
1268 NULL,
1269};
1270
1271
1272static const struct attribute_group attr_group = {
1273 .attrs = g,
1274};
1275
1276
1277static int __init pm_disk_init(void)
1278{
1279 return sysfs_create_group(power_kobj, &attr_group);
1280}
1281
1282core_initcall(pm_disk_init);
1283
1284
1285static int __init resume_setup(char *str)
1286{
1287 if (noresume)
1288 return 1;
1289
1290 strncpy(resume_file, str, 255);
1291 return 1;
1292}
1293
1294static int __init resume_offset_setup(char *str)
1295{
1296 unsigned long long offset;
1297
1298 if (noresume)
1299 return 1;
1300
1301 if (sscanf(str, "%llu", &offset) == 1)
1302 swsusp_resume_block = offset;
1303
1304 return 1;
1305}
1306
1307static int __init hibernate_setup(char *str)
1308{
1309 if (!strncmp(str, "noresume", 8)) {
1310 noresume = 1;
1311 } else if (!strncmp(str, "nocompress", 10)) {
1312 nocompress = 1;
1313 } else if (!strncmp(str, "no", 2)) {
1314 noresume = 1;
1315 nohibernate = 1;
1316 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1317 && !strncmp(str, "protect_image", 13)) {
1318 enable_restore_image_protection();
1319 }
1320 return 1;
1321}
1322
1323static int __init noresume_setup(char *str)
1324{
1325 noresume = 1;
1326 return 1;
1327}
1328
1329static int __init resumewait_setup(char *str)
1330{
1331 resume_wait = 1;
1332 return 1;
1333}
1334
1335static int __init resumedelay_setup(char *str)
1336{
1337 int rc = kstrtouint(str, 0, &resume_delay);
1338
1339 if (rc)
1340 return rc;
1341 return 1;
1342}
1343
1344static int __init nohibernate_setup(char *str)
1345{
1346 noresume = 1;
1347 nohibernate = 1;
1348 return 1;
1349}
1350
1351__setup("noresume", noresume_setup);
1352__setup("resume_offset=", resume_offset_setup);
1353__setup("resume=", resume_setup);
1354__setup("hibernate=", hibernate_setup);
1355__setup("resumewait", resumewait_setup);
1356__setup("resumedelay=", resumedelay_setup);
1357__setup("nohibernate", nohibernate_setup);
1/*
2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
8 * Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
9 *
10 * This file is released under the GPLv2.
11 */
12
13#include <linux/export.h>
14#include <linux/suspend.h>
15#include <linux/syscalls.h>
16#include <linux/reboot.h>
17#include <linux/string.h>
18#include <linux/device.h>
19#include <linux/async.h>
20#include <linux/delay.h>
21#include <linux/fs.h>
22#include <linux/mount.h>
23#include <linux/pm.h>
24#include <linux/console.h>
25#include <linux/cpu.h>
26#include <linux/freezer.h>
27#include <linux/gfp.h>
28#include <linux/syscore_ops.h>
29#include <linux/ctype.h>
30#include <linux/genhd.h>
31
32#include "power.h"
33
34
35static int nocompress;
36static int noresume;
37static int resume_wait;
38static int resume_delay;
39static char resume_file[256] = CONFIG_PM_STD_PARTITION;
40dev_t swsusp_resume_device;
41sector_t swsusp_resume_block;
42__visible int in_suspend __nosavedata;
43
44enum {
45 HIBERNATION_INVALID,
46 HIBERNATION_PLATFORM,
47 HIBERNATION_SHUTDOWN,
48 HIBERNATION_REBOOT,
49#ifdef CONFIG_SUSPEND
50 HIBERNATION_SUSPEND,
51#endif
52 /* keep last */
53 __HIBERNATION_AFTER_LAST
54};
55#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
56#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
57
58static int hibernation_mode = HIBERNATION_SHUTDOWN;
59
60bool freezer_test_done;
61
62static const struct platform_hibernation_ops *hibernation_ops;
63
64/**
65 * hibernation_set_ops - Set the global hibernate operations.
66 * @ops: Hibernation operations to use in subsequent hibernation transitions.
67 */
68void hibernation_set_ops(const struct platform_hibernation_ops *ops)
69{
70 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
71 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
72 && ops->restore_cleanup && ops->leave)) {
73 WARN_ON(1);
74 return;
75 }
76 lock_system_sleep();
77 hibernation_ops = ops;
78 if (ops)
79 hibernation_mode = HIBERNATION_PLATFORM;
80 else if (hibernation_mode == HIBERNATION_PLATFORM)
81 hibernation_mode = HIBERNATION_SHUTDOWN;
82
83 unlock_system_sleep();
84}
85EXPORT_SYMBOL_GPL(hibernation_set_ops);
86
87static bool entering_platform_hibernation;
88
89bool system_entering_hibernation(void)
90{
91 return entering_platform_hibernation;
92}
93EXPORT_SYMBOL(system_entering_hibernation);
94
95#ifdef CONFIG_PM_DEBUG
96static void hibernation_debug_sleep(void)
97{
98 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
99 mdelay(5000);
100}
101
102static int hibernation_test(int level)
103{
104 if (pm_test_level == level) {
105 hibernation_debug_sleep();
106 return 1;
107 }
108 return 0;
109}
110#else /* !CONFIG_PM_DEBUG */
111static int hibernation_test(int level) { return 0; }
112#endif /* !CONFIG_PM_DEBUG */
113
114/**
115 * platform_begin - Call platform to start hibernation.
116 * @platform_mode: Whether or not to use the platform driver.
117 */
118static int platform_begin(int platform_mode)
119{
120 return (platform_mode && hibernation_ops) ?
121 hibernation_ops->begin() : 0;
122}
123
124/**
125 * platform_end - Call platform to finish transition to the working state.
126 * @platform_mode: Whether or not to use the platform driver.
127 */
128static void platform_end(int platform_mode)
129{
130 if (platform_mode && hibernation_ops)
131 hibernation_ops->end();
132}
133
134/**
135 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
136 * @platform_mode: Whether or not to use the platform driver.
137 *
138 * Use the platform driver to prepare the system for creating a hibernate image,
139 * if so configured, and return an error code if that fails.
140 */
141
142static int platform_pre_snapshot(int platform_mode)
143{
144 return (platform_mode && hibernation_ops) ?
145 hibernation_ops->pre_snapshot() : 0;
146}
147
148/**
149 * platform_leave - Call platform to prepare a transition to the working state.
150 * @platform_mode: Whether or not to use the platform driver.
151 *
152 * Use the platform driver prepare to prepare the machine for switching to the
153 * normal mode of operation.
154 *
155 * This routine is called on one CPU with interrupts disabled.
156 */
157static void platform_leave(int platform_mode)
158{
159 if (platform_mode && hibernation_ops)
160 hibernation_ops->leave();
161}
162
163/**
164 * platform_finish - Call platform to switch the system to the working state.
165 * @platform_mode: Whether or not to use the platform driver.
166 *
167 * Use the platform driver to switch the machine to the normal mode of
168 * operation.
169 *
170 * This routine must be called after platform_prepare().
171 */
172static void platform_finish(int platform_mode)
173{
174 if (platform_mode && hibernation_ops)
175 hibernation_ops->finish();
176}
177
178/**
179 * platform_pre_restore - Prepare for hibernate image restoration.
180 * @platform_mode: Whether or not to use the platform driver.
181 *
182 * Use the platform driver to prepare the system for resume from a hibernation
183 * image.
184 *
185 * If the restore fails after this function has been called,
186 * platform_restore_cleanup() must be called.
187 */
188static int platform_pre_restore(int platform_mode)
189{
190 return (platform_mode && hibernation_ops) ?
191 hibernation_ops->pre_restore() : 0;
192}
193
194/**
195 * platform_restore_cleanup - Switch to the working state after failing restore.
196 * @platform_mode: Whether or not to use the platform driver.
197 *
198 * Use the platform driver to switch the system to the normal mode of operation
199 * after a failing restore.
200 *
201 * If platform_pre_restore() has been called before the failing restore, this
202 * function must be called too, regardless of the result of
203 * platform_pre_restore().
204 */
205static void platform_restore_cleanup(int platform_mode)
206{
207 if (platform_mode && hibernation_ops)
208 hibernation_ops->restore_cleanup();
209}
210
211/**
212 * platform_recover - Recover from a failure to suspend devices.
213 * @platform_mode: Whether or not to use the platform driver.
214 */
215static void platform_recover(int platform_mode)
216{
217 if (platform_mode && hibernation_ops && hibernation_ops->recover)
218 hibernation_ops->recover();
219}
220
221/**
222 * swsusp_show_speed - Print time elapsed between two events during hibernation.
223 * @start: Starting event.
224 * @stop: Final event.
225 * @nr_pages: Number of memory pages processed between @start and @stop.
226 * @msg: Additional diagnostic message to print.
227 */
228void swsusp_show_speed(struct timeval *start, struct timeval *stop,
229 unsigned nr_pages, char *msg)
230{
231 s64 elapsed_centisecs64;
232 int centisecs;
233 int k;
234 int kps;
235
236 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
237 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
238 centisecs = elapsed_centisecs64;
239 if (centisecs == 0)
240 centisecs = 1; /* avoid div-by-zero */
241 k = nr_pages * (PAGE_SIZE / 1024);
242 kps = (k * 100) / centisecs;
243 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
244 msg, k,
245 centisecs / 100, centisecs % 100,
246 kps / 1000, (kps % 1000) / 10);
247}
248
249/**
250 * create_image - Create a hibernation image.
251 * @platform_mode: Whether or not to use the platform driver.
252 *
253 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
254 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
255 *
256 * Control reappears in this routine after the subsequent restore.
257 */
258static int create_image(int platform_mode)
259{
260 int error;
261
262 error = dpm_suspend_end(PMSG_FREEZE);
263 if (error) {
264 printk(KERN_ERR "PM: Some devices failed to power down, "
265 "aborting hibernation\n");
266 return error;
267 }
268
269 error = platform_pre_snapshot(platform_mode);
270 if (error || hibernation_test(TEST_PLATFORM))
271 goto Platform_finish;
272
273 error = disable_nonboot_cpus();
274 if (error || hibernation_test(TEST_CPUS))
275 goto Enable_cpus;
276
277 local_irq_disable();
278
279 error = syscore_suspend();
280 if (error) {
281 printk(KERN_ERR "PM: Some system devices failed to power down, "
282 "aborting hibernation\n");
283 goto Enable_irqs;
284 }
285
286 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
287 goto Power_up;
288
289 in_suspend = 1;
290 save_processor_state();
291 error = swsusp_arch_suspend();
292 if (error)
293 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
294 error);
295 /* Restore control flow magically appears here */
296 restore_processor_state();
297 if (!in_suspend)
298 events_check_enabled = false;
299
300 platform_leave(platform_mode);
301
302 Power_up:
303 syscore_resume();
304
305 Enable_irqs:
306 local_irq_enable();
307
308 Enable_cpus:
309 enable_nonboot_cpus();
310
311 Platform_finish:
312 platform_finish(platform_mode);
313
314 dpm_resume_start(in_suspend ?
315 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
316
317 return error;
318}
319
320/**
321 * hibernation_snapshot - Quiesce devices and create a hibernation image.
322 * @platform_mode: If set, use platform driver to prepare for the transition.
323 *
324 * This routine must be called with pm_mutex held.
325 */
326int hibernation_snapshot(int platform_mode)
327{
328 pm_message_t msg;
329 int error;
330
331 error = platform_begin(platform_mode);
332 if (error)
333 goto Close;
334
335 /* Preallocate image memory before shutting down devices. */
336 error = hibernate_preallocate_memory();
337 if (error)
338 goto Close;
339
340 error = freeze_kernel_threads();
341 if (error)
342 goto Cleanup;
343
344 if (hibernation_test(TEST_FREEZER)) {
345
346 /*
347 * Indicate to the caller that we are returning due to a
348 * successful freezer test.
349 */
350 freezer_test_done = true;
351 goto Thaw;
352 }
353
354 error = dpm_prepare(PMSG_FREEZE);
355 if (error) {
356 dpm_complete(PMSG_RECOVER);
357 goto Thaw;
358 }
359
360 suspend_console();
361 ftrace_stop();
362 pm_restrict_gfp_mask();
363
364 error = dpm_suspend(PMSG_FREEZE);
365
366 if (error || hibernation_test(TEST_DEVICES))
367 platform_recover(platform_mode);
368 else
369 error = create_image(platform_mode);
370
371 /*
372 * In the case that we call create_image() above, the control
373 * returns here (1) after the image has been created or the
374 * image creation has failed and (2) after a successful restore.
375 */
376
377 /* We may need to release the preallocated image pages here. */
378 if (error || !in_suspend)
379 swsusp_free();
380
381 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
382 dpm_resume(msg);
383
384 if (error || !in_suspend)
385 pm_restore_gfp_mask();
386
387 ftrace_start();
388 resume_console();
389 dpm_complete(msg);
390
391 Close:
392 platform_end(platform_mode);
393 return error;
394
395 Thaw:
396 thaw_kernel_threads();
397 Cleanup:
398 swsusp_free();
399 goto Close;
400}
401
402/**
403 * resume_target_kernel - Restore system state from a hibernation image.
404 * @platform_mode: Whether or not to use the platform driver.
405 *
406 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
407 * contents of highmem that have not been restored yet from the image and run
408 * the low-level code that will restore the remaining contents of memory and
409 * switch to the just restored target kernel.
410 */
411static int resume_target_kernel(bool platform_mode)
412{
413 int error;
414
415 error = dpm_suspend_end(PMSG_QUIESCE);
416 if (error) {
417 printk(KERN_ERR "PM: Some devices failed to power down, "
418 "aborting resume\n");
419 return error;
420 }
421
422 error = platform_pre_restore(platform_mode);
423 if (error)
424 goto Cleanup;
425
426 error = disable_nonboot_cpus();
427 if (error)
428 goto Enable_cpus;
429
430 local_irq_disable();
431
432 error = syscore_suspend();
433 if (error)
434 goto Enable_irqs;
435
436 save_processor_state();
437 error = restore_highmem();
438 if (!error) {
439 error = swsusp_arch_resume();
440 /*
441 * The code below is only ever reached in case of a failure.
442 * Otherwise, execution continues at the place where
443 * swsusp_arch_suspend() was called.
444 */
445 BUG_ON(!error);
446 /*
447 * This call to restore_highmem() reverts the changes made by
448 * the previous one.
449 */
450 restore_highmem();
451 }
452 /*
453 * The only reason why swsusp_arch_resume() can fail is memory being
454 * very tight, so we have to free it as soon as we can to avoid
455 * subsequent failures.
456 */
457 swsusp_free();
458 restore_processor_state();
459 touch_softlockup_watchdog();
460
461 syscore_resume();
462
463 Enable_irqs:
464 local_irq_enable();
465
466 Enable_cpus:
467 enable_nonboot_cpus();
468
469 Cleanup:
470 platform_restore_cleanup(platform_mode);
471
472 dpm_resume_start(PMSG_RECOVER);
473
474 return error;
475}
476
477/**
478 * hibernation_restore - Quiesce devices and restore from a hibernation image.
479 * @platform_mode: If set, use platform driver to prepare for the transition.
480 *
481 * This routine must be called with pm_mutex held. If it is successful, control
482 * reappears in the restored target kernel in hibernation_snapshot().
483 */
484int hibernation_restore(int platform_mode)
485{
486 int error;
487
488 pm_prepare_console();
489 suspend_console();
490 ftrace_stop();
491 pm_restrict_gfp_mask();
492 error = dpm_suspend_start(PMSG_QUIESCE);
493 if (!error) {
494 error = resume_target_kernel(platform_mode);
495 dpm_resume_end(PMSG_RECOVER);
496 }
497 pm_restore_gfp_mask();
498 ftrace_start();
499 resume_console();
500 pm_restore_console();
501 return error;
502}
503
504/**
505 * hibernation_platform_enter - Power off the system using the platform driver.
506 */
507int hibernation_platform_enter(void)
508{
509 int error;
510
511 if (!hibernation_ops)
512 return -ENOSYS;
513
514 /*
515 * We have cancelled the power transition by running
516 * hibernation_ops->finish() before saving the image, so we should let
517 * the firmware know that we're going to enter the sleep state after all
518 */
519 error = hibernation_ops->begin();
520 if (error)
521 goto Close;
522
523 entering_platform_hibernation = true;
524 suspend_console();
525 ftrace_stop();
526 error = dpm_suspend_start(PMSG_HIBERNATE);
527 if (error) {
528 if (hibernation_ops->recover)
529 hibernation_ops->recover();
530 goto Resume_devices;
531 }
532
533 error = dpm_suspend_end(PMSG_HIBERNATE);
534 if (error)
535 goto Resume_devices;
536
537 error = hibernation_ops->prepare();
538 if (error)
539 goto Platform_finish;
540
541 error = disable_nonboot_cpus();
542 if (error)
543 goto Platform_finish;
544
545 local_irq_disable();
546 syscore_suspend();
547 if (pm_wakeup_pending()) {
548 error = -EAGAIN;
549 goto Power_up;
550 }
551
552 hibernation_ops->enter();
553 /* We should never get here */
554 while (1);
555
556 Power_up:
557 syscore_resume();
558 local_irq_enable();
559 enable_nonboot_cpus();
560
561 Platform_finish:
562 hibernation_ops->finish();
563
564 dpm_resume_start(PMSG_RESTORE);
565
566 Resume_devices:
567 entering_platform_hibernation = false;
568 dpm_resume_end(PMSG_RESTORE);
569 ftrace_start();
570 resume_console();
571
572 Close:
573 hibernation_ops->end();
574
575 return error;
576}
577
578/**
579 * power_down - Shut the machine down for hibernation.
580 *
581 * Use the platform driver, if configured, to put the system into the sleep
582 * state corresponding to hibernation, or try to power it off or reboot,
583 * depending on the value of hibernation_mode.
584 */
585static void power_down(void)
586{
587#ifdef CONFIG_SUSPEND
588 int error;
589#endif
590
591 switch (hibernation_mode) {
592 case HIBERNATION_REBOOT:
593 kernel_restart(NULL);
594 break;
595 case HIBERNATION_PLATFORM:
596 hibernation_platform_enter();
597 case HIBERNATION_SHUTDOWN:
598 kernel_power_off();
599 break;
600#ifdef CONFIG_SUSPEND
601 case HIBERNATION_SUSPEND:
602 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
603 if (error) {
604 if (hibernation_ops)
605 hibernation_mode = HIBERNATION_PLATFORM;
606 else
607 hibernation_mode = HIBERNATION_SHUTDOWN;
608 power_down();
609 }
610 /*
611 * Restore swap signature.
612 */
613 error = swsusp_unmark();
614 if (error)
615 printk(KERN_ERR "PM: Swap will be unusable! "
616 "Try swapon -a.\n");
617 return;
618#endif
619 }
620 kernel_halt();
621 /*
622 * Valid image is on the disk, if we continue we risk serious data
623 * corruption after resume.
624 */
625 printk(KERN_CRIT "PM: Please power down manually\n");
626 while(1);
627}
628
629/**
630 * hibernate - Carry out system hibernation, including saving the image.
631 */
632int hibernate(void)
633{
634 int error;
635
636 lock_system_sleep();
637 /* The snapshot device should not be opened while we're running */
638 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
639 error = -EBUSY;
640 goto Unlock;
641 }
642
643 pm_prepare_console();
644 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
645 if (error)
646 goto Exit;
647
648 printk(KERN_INFO "PM: Syncing filesystems ... ");
649 sys_sync();
650 printk("done.\n");
651
652 error = freeze_processes();
653 if (error)
654 goto Exit;
655
656 lock_device_hotplug();
657 /* Allocate memory management structures */
658 error = create_basic_memory_bitmaps();
659 if (error)
660 goto Thaw;
661
662 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
663 if (error || freezer_test_done)
664 goto Free_bitmaps;
665
666 if (in_suspend) {
667 unsigned int flags = 0;
668
669 if (hibernation_mode == HIBERNATION_PLATFORM)
670 flags |= SF_PLATFORM_MODE;
671 if (nocompress)
672 flags |= SF_NOCOMPRESS_MODE;
673 else
674 flags |= SF_CRC32_MODE;
675
676 pr_debug("PM: writing image.\n");
677 error = swsusp_write(flags);
678 swsusp_free();
679 if (!error)
680 power_down();
681 in_suspend = 0;
682 pm_restore_gfp_mask();
683 } else {
684 pr_debug("PM: Image restored successfully.\n");
685 }
686
687 Free_bitmaps:
688 free_basic_memory_bitmaps();
689 Thaw:
690 unlock_device_hotplug();
691 thaw_processes();
692
693 /* Don't bother checking whether freezer_test_done is true */
694 freezer_test_done = false;
695 Exit:
696 pm_notifier_call_chain(PM_POST_HIBERNATION);
697 pm_restore_console();
698 atomic_inc(&snapshot_device_available);
699 Unlock:
700 unlock_system_sleep();
701 return error;
702}
703
704
705/**
706 * software_resume - Resume from a saved hibernation image.
707 *
708 * This routine is called as a late initcall, when all devices have been
709 * discovered and initialized already.
710 *
711 * The image reading code is called to see if there is a hibernation image
712 * available for reading. If that is the case, devices are quiesced and the
713 * contents of memory is restored from the saved image.
714 *
715 * If this is successful, control reappears in the restored target kernel in
716 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
717 * attempts to recover gracefully and make the kernel return to the normal mode
718 * of operation.
719 */
720static int software_resume(void)
721{
722 int error;
723 unsigned int flags;
724
725 /*
726 * If the user said "noresume".. bail out early.
727 */
728 if (noresume)
729 return 0;
730
731 /*
732 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
733 * is configured into the kernel. Since the regular hibernate
734 * trigger path is via sysfs which takes a buffer mutex before
735 * calling hibernate functions (which take pm_mutex) this can
736 * cause lockdep to complain about a possible ABBA deadlock
737 * which cannot happen since we're in the boot code here and
738 * sysfs can't be invoked yet. Therefore, we use a subclass
739 * here to avoid lockdep complaining.
740 */
741 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
742
743 if (swsusp_resume_device)
744 goto Check_image;
745
746 if (!strlen(resume_file)) {
747 error = -ENOENT;
748 goto Unlock;
749 }
750
751 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
752
753 if (resume_delay) {
754 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
755 resume_delay);
756 ssleep(resume_delay);
757 }
758
759 /* Check if the device is there */
760 swsusp_resume_device = name_to_dev_t(resume_file);
761
762 /*
763 * name_to_dev_t is ineffective to verify parition if resume_file is in
764 * integer format. (e.g. major:minor)
765 */
766 if (isdigit(resume_file[0]) && resume_wait) {
767 int partno;
768 while (!get_gendisk(swsusp_resume_device, &partno))
769 msleep(10);
770 }
771
772 if (!swsusp_resume_device) {
773 /*
774 * Some device discovery might still be in progress; we need
775 * to wait for this to finish.
776 */
777 wait_for_device_probe();
778
779 if (resume_wait) {
780 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
781 msleep(10);
782 async_synchronize_full();
783 }
784
785 swsusp_resume_device = name_to_dev_t(resume_file);
786 if (!swsusp_resume_device) {
787 error = -ENODEV;
788 goto Unlock;
789 }
790 }
791
792 Check_image:
793 pr_debug("PM: Hibernation image partition %d:%d present\n",
794 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
795
796 pr_debug("PM: Looking for hibernation image.\n");
797 error = swsusp_check();
798 if (error)
799 goto Unlock;
800
801 /* The snapshot device should not be opened while we're running */
802 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
803 error = -EBUSY;
804 swsusp_close(FMODE_READ);
805 goto Unlock;
806 }
807
808 pm_prepare_console();
809 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
810 if (error)
811 goto Close_Finish;
812
813 pr_debug("PM: Preparing processes for restore.\n");
814 error = freeze_processes();
815 if (error)
816 goto Close_Finish;
817
818 pr_debug("PM: Loading hibernation image.\n");
819
820 lock_device_hotplug();
821 error = create_basic_memory_bitmaps();
822 if (error)
823 goto Thaw;
824
825 error = swsusp_read(&flags);
826 swsusp_close(FMODE_READ);
827 if (!error)
828 hibernation_restore(flags & SF_PLATFORM_MODE);
829
830 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
831 swsusp_free();
832 free_basic_memory_bitmaps();
833 Thaw:
834 unlock_device_hotplug();
835 thaw_processes();
836 Finish:
837 pm_notifier_call_chain(PM_POST_RESTORE);
838 pm_restore_console();
839 atomic_inc(&snapshot_device_available);
840 /* For success case, the suspend path will release the lock */
841 Unlock:
842 mutex_unlock(&pm_mutex);
843 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
844 return error;
845 Close_Finish:
846 swsusp_close(FMODE_READ);
847 goto Finish;
848}
849
850late_initcall_sync(software_resume);
851
852
853static const char * const hibernation_modes[] = {
854 [HIBERNATION_PLATFORM] = "platform",
855 [HIBERNATION_SHUTDOWN] = "shutdown",
856 [HIBERNATION_REBOOT] = "reboot",
857#ifdef CONFIG_SUSPEND
858 [HIBERNATION_SUSPEND] = "suspend",
859#endif
860};
861
862/*
863 * /sys/power/disk - Control hibernation mode.
864 *
865 * Hibernation can be handled in several ways. There are a few different ways
866 * to put the system into the sleep state: using the platform driver (e.g. ACPI
867 * or other hibernation_ops), powering it off or rebooting it (for testing
868 * mostly).
869 *
870 * The sysfs file /sys/power/disk provides an interface for selecting the
871 * hibernation mode to use. Reading from this file causes the available modes
872 * to be printed. There are 3 modes that can be supported:
873 *
874 * 'platform'
875 * 'shutdown'
876 * 'reboot'
877 *
878 * If a platform hibernation driver is in use, 'platform' will be supported
879 * and will be used by default. Otherwise, 'shutdown' will be used by default.
880 * The selected option (i.e. the one corresponding to the current value of
881 * hibernation_mode) is enclosed by a square bracket.
882 *
883 * To select a given hibernation mode it is necessary to write the mode's
884 * string representation (as returned by reading from /sys/power/disk) back
885 * into /sys/power/disk.
886 */
887
888static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
889 char *buf)
890{
891 int i;
892 char *start = buf;
893
894 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
895 if (!hibernation_modes[i])
896 continue;
897 switch (i) {
898 case HIBERNATION_SHUTDOWN:
899 case HIBERNATION_REBOOT:
900#ifdef CONFIG_SUSPEND
901 case HIBERNATION_SUSPEND:
902#endif
903 break;
904 case HIBERNATION_PLATFORM:
905 if (hibernation_ops)
906 break;
907 /* not a valid mode, continue with loop */
908 continue;
909 }
910 if (i == hibernation_mode)
911 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
912 else
913 buf += sprintf(buf, "%s ", hibernation_modes[i]);
914 }
915 buf += sprintf(buf, "\n");
916 return buf-start;
917}
918
919static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
920 const char *buf, size_t n)
921{
922 int error = 0;
923 int i;
924 int len;
925 char *p;
926 int mode = HIBERNATION_INVALID;
927
928 p = memchr(buf, '\n', n);
929 len = p ? p - buf : n;
930
931 lock_system_sleep();
932 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
933 if (len == strlen(hibernation_modes[i])
934 && !strncmp(buf, hibernation_modes[i], len)) {
935 mode = i;
936 break;
937 }
938 }
939 if (mode != HIBERNATION_INVALID) {
940 switch (mode) {
941 case HIBERNATION_SHUTDOWN:
942 case HIBERNATION_REBOOT:
943#ifdef CONFIG_SUSPEND
944 case HIBERNATION_SUSPEND:
945#endif
946 hibernation_mode = mode;
947 break;
948 case HIBERNATION_PLATFORM:
949 if (hibernation_ops)
950 hibernation_mode = mode;
951 else
952 error = -EINVAL;
953 }
954 } else
955 error = -EINVAL;
956
957 if (!error)
958 pr_debug("PM: Hibernation mode set to '%s'\n",
959 hibernation_modes[mode]);
960 unlock_system_sleep();
961 return error ? error : n;
962}
963
964power_attr(disk);
965
966static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
967 char *buf)
968{
969 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
970 MINOR(swsusp_resume_device));
971}
972
973static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
974 const char *buf, size_t n)
975{
976 dev_t res;
977 int len = n;
978 char *name;
979
980 if (len && buf[len-1] == '\n')
981 len--;
982 name = kstrndup(buf, len, GFP_KERNEL);
983 if (!name)
984 return -ENOMEM;
985
986 res = name_to_dev_t(name);
987 kfree(name);
988 if (!res)
989 return -EINVAL;
990
991 lock_system_sleep();
992 swsusp_resume_device = res;
993 unlock_system_sleep();
994 printk(KERN_INFO "PM: Starting manual resume from disk\n");
995 noresume = 0;
996 software_resume();
997 return n;
998}
999
1000power_attr(resume);
1001
1002static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1003 char *buf)
1004{
1005 return sprintf(buf, "%lu\n", image_size);
1006}
1007
1008static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1009 const char *buf, size_t n)
1010{
1011 unsigned long size;
1012
1013 if (sscanf(buf, "%lu", &size) == 1) {
1014 image_size = size;
1015 return n;
1016 }
1017
1018 return -EINVAL;
1019}
1020
1021power_attr(image_size);
1022
1023static ssize_t reserved_size_show(struct kobject *kobj,
1024 struct kobj_attribute *attr, char *buf)
1025{
1026 return sprintf(buf, "%lu\n", reserved_size);
1027}
1028
1029static ssize_t reserved_size_store(struct kobject *kobj,
1030 struct kobj_attribute *attr,
1031 const char *buf, size_t n)
1032{
1033 unsigned long size;
1034
1035 if (sscanf(buf, "%lu", &size) == 1) {
1036 reserved_size = size;
1037 return n;
1038 }
1039
1040 return -EINVAL;
1041}
1042
1043power_attr(reserved_size);
1044
1045static struct attribute * g[] = {
1046 &disk_attr.attr,
1047 &resume_attr.attr,
1048 &image_size_attr.attr,
1049 &reserved_size_attr.attr,
1050 NULL,
1051};
1052
1053
1054static struct attribute_group attr_group = {
1055 .attrs = g,
1056};
1057
1058
1059static int __init pm_disk_init(void)
1060{
1061 return sysfs_create_group(power_kobj, &attr_group);
1062}
1063
1064core_initcall(pm_disk_init);
1065
1066
1067static int __init resume_setup(char *str)
1068{
1069 if (noresume)
1070 return 1;
1071
1072 strncpy( resume_file, str, 255 );
1073 return 1;
1074}
1075
1076static int __init resume_offset_setup(char *str)
1077{
1078 unsigned long long offset;
1079
1080 if (noresume)
1081 return 1;
1082
1083 if (sscanf(str, "%llu", &offset) == 1)
1084 swsusp_resume_block = offset;
1085
1086 return 1;
1087}
1088
1089static int __init hibernate_setup(char *str)
1090{
1091 if (!strncmp(str, "noresume", 8))
1092 noresume = 1;
1093 else if (!strncmp(str, "nocompress", 10))
1094 nocompress = 1;
1095 return 1;
1096}
1097
1098static int __init noresume_setup(char *str)
1099{
1100 noresume = 1;
1101 return 1;
1102}
1103
1104static int __init resumewait_setup(char *str)
1105{
1106 resume_wait = 1;
1107 return 1;
1108}
1109
1110static int __init resumedelay_setup(char *str)
1111{
1112 resume_delay = simple_strtoul(str, NULL, 0);
1113 return 1;
1114}
1115
1116__setup("noresume", noresume_setup);
1117__setup("resume_offset=", resume_offset_setup);
1118__setup("resume=", resume_setup);
1119__setup("hibernate=", hibernate_setup);
1120__setup("resumewait", resumewait_setup);
1121__setup("resumedelay=", resumedelay_setup);