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