Loading...
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/ktime.h>
32#include <linux/security.h>
33#include <linux/secretmem.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 &&
85 !security_locked_down(LOCKDOWN_HIBERNATION) &&
86 !secretmem_active() && !cxl_mem_active();
87}
88
89/**
90 * hibernation_set_ops - Set the global hibernate operations.
91 * @ops: Hibernation operations to use in subsequent hibernation transitions.
92 */
93void hibernation_set_ops(const struct platform_hibernation_ops *ops)
94{
95 unsigned int sleep_flags;
96
97 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
98 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
99 && ops->restore_cleanup && ops->leave)) {
100 WARN_ON(1);
101 return;
102 }
103
104 sleep_flags = lock_system_sleep();
105
106 hibernation_ops = ops;
107 if (ops)
108 hibernation_mode = HIBERNATION_PLATFORM;
109 else if (hibernation_mode == HIBERNATION_PLATFORM)
110 hibernation_mode = HIBERNATION_SHUTDOWN;
111
112 unlock_system_sleep(sleep_flags);
113}
114EXPORT_SYMBOL_GPL(hibernation_set_ops);
115
116static bool entering_platform_hibernation;
117
118bool system_entering_hibernation(void)
119{
120 return entering_platform_hibernation;
121}
122EXPORT_SYMBOL(system_entering_hibernation);
123
124#ifdef CONFIG_PM_DEBUG
125static void hibernation_debug_sleep(void)
126{
127 pr_info("debug: Waiting for 5 seconds.\n");
128 mdelay(5000);
129}
130
131static int hibernation_test(int level)
132{
133 if (pm_test_level == level) {
134 hibernation_debug_sleep();
135 return 1;
136 }
137 return 0;
138}
139#else /* !CONFIG_PM_DEBUG */
140static int hibernation_test(int level) { return 0; }
141#endif /* !CONFIG_PM_DEBUG */
142
143/**
144 * platform_begin - Call platform to start hibernation.
145 * @platform_mode: Whether or not to use the platform driver.
146 */
147static int platform_begin(int platform_mode)
148{
149 return (platform_mode && hibernation_ops) ?
150 hibernation_ops->begin(PMSG_FREEZE) : 0;
151}
152
153/**
154 * platform_end - Call platform to finish transition to the working state.
155 * @platform_mode: Whether or not to use the platform driver.
156 */
157static void platform_end(int platform_mode)
158{
159 if (platform_mode && hibernation_ops)
160 hibernation_ops->end();
161}
162
163/**
164 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
165 * @platform_mode: Whether or not to use the platform driver.
166 *
167 * Use the platform driver to prepare the system for creating a hibernate image,
168 * if so configured, and return an error code if that fails.
169 */
170
171static int platform_pre_snapshot(int platform_mode)
172{
173 return (platform_mode && hibernation_ops) ?
174 hibernation_ops->pre_snapshot() : 0;
175}
176
177/**
178 * platform_leave - Call platform to prepare a transition to the working state.
179 * @platform_mode: Whether or not to use the platform driver.
180 *
181 * Use the platform driver prepare to prepare the machine for switching to the
182 * normal mode of operation.
183 *
184 * This routine is called on one CPU with interrupts disabled.
185 */
186static void platform_leave(int platform_mode)
187{
188 if (platform_mode && hibernation_ops)
189 hibernation_ops->leave();
190}
191
192/**
193 * platform_finish - Call platform to switch the system to the working state.
194 * @platform_mode: Whether or not to use the platform driver.
195 *
196 * Use the platform driver to switch the machine to the normal mode of
197 * operation.
198 *
199 * This routine must be called after platform_prepare().
200 */
201static void platform_finish(int platform_mode)
202{
203 if (platform_mode && hibernation_ops)
204 hibernation_ops->finish();
205}
206
207/**
208 * platform_pre_restore - Prepare for hibernate image restoration.
209 * @platform_mode: Whether or not to use the platform driver.
210 *
211 * Use the platform driver to prepare the system for resume from a hibernation
212 * image.
213 *
214 * If the restore fails after this function has been called,
215 * platform_restore_cleanup() must be called.
216 */
217static int platform_pre_restore(int platform_mode)
218{
219 return (platform_mode && hibernation_ops) ?
220 hibernation_ops->pre_restore() : 0;
221}
222
223/**
224 * platform_restore_cleanup - Switch to the working state after failing restore.
225 * @platform_mode: Whether or not to use the platform driver.
226 *
227 * Use the platform driver to switch the system to the normal mode of operation
228 * after a failing restore.
229 *
230 * If platform_pre_restore() has been called before the failing restore, this
231 * function must be called too, regardless of the result of
232 * platform_pre_restore().
233 */
234static void platform_restore_cleanup(int platform_mode)
235{
236 if (platform_mode && hibernation_ops)
237 hibernation_ops->restore_cleanup();
238}
239
240/**
241 * platform_recover - Recover from a failure to suspend devices.
242 * @platform_mode: Whether or not to use the platform driver.
243 */
244static void platform_recover(int platform_mode)
245{
246 if (platform_mode && hibernation_ops && hibernation_ops->recover)
247 hibernation_ops->recover();
248}
249
250/**
251 * swsusp_show_speed - Print time elapsed between two events during hibernation.
252 * @start: Starting event.
253 * @stop: Final event.
254 * @nr_pages: Number of memory pages processed between @start and @stop.
255 * @msg: Additional diagnostic message to print.
256 */
257void swsusp_show_speed(ktime_t start, ktime_t stop,
258 unsigned nr_pages, char *msg)
259{
260 ktime_t diff;
261 u64 elapsed_centisecs64;
262 unsigned int centisecs;
263 unsigned int k;
264 unsigned int kps;
265
266 diff = ktime_sub(stop, start);
267 elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
268 centisecs = elapsed_centisecs64;
269 if (centisecs == 0)
270 centisecs = 1; /* avoid div-by-zero */
271 k = nr_pages * (PAGE_SIZE / 1024);
272 kps = (k * 100) / centisecs;
273 pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
274 msg, k, centisecs / 100, centisecs % 100, kps / 1000,
275 (kps % 1000) / 10);
276}
277
278__weak int arch_resume_nosmt(void)
279{
280 return 0;
281}
282
283/**
284 * create_image - Create a hibernation image.
285 * @platform_mode: Whether or not to use the platform driver.
286 *
287 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
288 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
289 *
290 * Control reappears in this routine after the subsequent restore.
291 */
292static int create_image(int platform_mode)
293{
294 int error;
295
296 error = dpm_suspend_end(PMSG_FREEZE);
297 if (error) {
298 pr_err("Some devices failed to power down, aborting\n");
299 return error;
300 }
301
302 error = platform_pre_snapshot(platform_mode);
303 if (error || hibernation_test(TEST_PLATFORM))
304 goto Platform_finish;
305
306 error = pm_sleep_disable_secondary_cpus();
307 if (error || hibernation_test(TEST_CPUS))
308 goto Enable_cpus;
309
310 local_irq_disable();
311
312 system_state = SYSTEM_SUSPEND;
313
314 error = syscore_suspend();
315 if (error) {
316 pr_err("Some system devices failed to power down, aborting\n");
317 goto Enable_irqs;
318 }
319
320 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
321 goto Power_up;
322
323 in_suspend = 1;
324 save_processor_state();
325 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
326 error = swsusp_arch_suspend();
327 /* Restore control flow magically appears here */
328 restore_processor_state();
329 trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
330 if (error)
331 pr_err("Error %d creating image\n", error);
332
333 if (!in_suspend) {
334 events_check_enabled = false;
335 clear_or_poison_free_pages();
336 }
337
338 platform_leave(platform_mode);
339
340 Power_up:
341 syscore_resume();
342
343 Enable_irqs:
344 system_state = SYSTEM_RUNNING;
345 local_irq_enable();
346
347 Enable_cpus:
348 pm_sleep_enable_secondary_cpus();
349
350 /* Allow architectures to do nosmt-specific post-resume dances */
351 if (!in_suspend)
352 error = arch_resume_nosmt();
353
354 Platform_finish:
355 platform_finish(platform_mode);
356
357 dpm_resume_start(in_suspend ?
358 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
359
360 return error;
361}
362
363/**
364 * hibernation_snapshot - Quiesce devices and create a hibernation image.
365 * @platform_mode: If set, use platform driver to prepare for the transition.
366 *
367 * This routine must be called with system_transition_mutex held.
368 */
369int hibernation_snapshot(int platform_mode)
370{
371 pm_message_t msg;
372 int error;
373
374 pm_suspend_clear_flags();
375 error = platform_begin(platform_mode);
376 if (error)
377 goto Close;
378
379 /* Preallocate image memory before shutting down devices. */
380 error = hibernate_preallocate_memory();
381 if (error)
382 goto Close;
383
384 error = freeze_kernel_threads();
385 if (error)
386 goto Cleanup;
387
388 if (hibernation_test(TEST_FREEZER)) {
389
390 /*
391 * Indicate to the caller that we are returning due to a
392 * successful freezer test.
393 */
394 freezer_test_done = true;
395 goto Thaw;
396 }
397
398 error = dpm_prepare(PMSG_FREEZE);
399 if (error) {
400 dpm_complete(PMSG_RECOVER);
401 goto Thaw;
402 }
403
404 suspend_console();
405 pm_restrict_gfp_mask();
406
407 error = dpm_suspend(PMSG_FREEZE);
408
409 if (error || hibernation_test(TEST_DEVICES))
410 platform_recover(platform_mode);
411 else
412 error = create_image(platform_mode);
413
414 /*
415 * In the case that we call create_image() above, the control
416 * returns here (1) after the image has been created or the
417 * image creation has failed and (2) after a successful restore.
418 */
419
420 /* We may need to release the preallocated image pages here. */
421 if (error || !in_suspend)
422 swsusp_free();
423
424 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
425 dpm_resume(msg);
426
427 if (error || !in_suspend)
428 pm_restore_gfp_mask();
429
430 resume_console();
431 dpm_complete(msg);
432
433 Close:
434 platform_end(platform_mode);
435 return error;
436
437 Thaw:
438 thaw_kernel_threads();
439 Cleanup:
440 swsusp_free();
441 goto Close;
442}
443
444int __weak hibernate_resume_nonboot_cpu_disable(void)
445{
446 return suspend_disable_secondary_cpus();
447}
448
449/**
450 * resume_target_kernel - Restore system state from a hibernation image.
451 * @platform_mode: Whether or not to use the platform driver.
452 *
453 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
454 * contents of highmem that have not been restored yet from the image and run
455 * the low-level code that will restore the remaining contents of memory and
456 * switch to the just restored target kernel.
457 */
458static int resume_target_kernel(bool platform_mode)
459{
460 int error;
461
462 error = dpm_suspend_end(PMSG_QUIESCE);
463 if (error) {
464 pr_err("Some devices failed to power down, aborting resume\n");
465 return error;
466 }
467
468 error = platform_pre_restore(platform_mode);
469 if (error)
470 goto Cleanup;
471
472 cpuidle_pause();
473
474 error = hibernate_resume_nonboot_cpu_disable();
475 if (error)
476 goto Enable_cpus;
477
478 local_irq_disable();
479 system_state = SYSTEM_SUSPEND;
480
481 error = syscore_suspend();
482 if (error)
483 goto Enable_irqs;
484
485 save_processor_state();
486 error = restore_highmem();
487 if (!error) {
488 error = swsusp_arch_resume();
489 /*
490 * The code below is only ever reached in case of a failure.
491 * Otherwise, execution continues at the place where
492 * swsusp_arch_suspend() was called.
493 */
494 BUG_ON(!error);
495 /*
496 * This call to restore_highmem() reverts the changes made by
497 * the previous one.
498 */
499 restore_highmem();
500 }
501 /*
502 * The only reason why swsusp_arch_resume() can fail is memory being
503 * very tight, so we have to free it as soon as we can to avoid
504 * subsequent failures.
505 */
506 swsusp_free();
507 restore_processor_state();
508 touch_softlockup_watchdog();
509
510 syscore_resume();
511
512 Enable_irqs:
513 system_state = SYSTEM_RUNNING;
514 local_irq_enable();
515
516 Enable_cpus:
517 pm_sleep_enable_secondary_cpus();
518
519 Cleanup:
520 platform_restore_cleanup(platform_mode);
521
522 dpm_resume_start(PMSG_RECOVER);
523
524 return error;
525}
526
527/**
528 * hibernation_restore - Quiesce devices and restore from a hibernation image.
529 * @platform_mode: If set, use platform driver to prepare for the transition.
530 *
531 * This routine must be called with system_transition_mutex held. If it is
532 * successful, control reappears in the restored target kernel in
533 * hibernation_snapshot().
534 */
535int hibernation_restore(int platform_mode)
536{
537 int error;
538
539 pm_prepare_console();
540 suspend_console();
541 pm_restrict_gfp_mask();
542 error = dpm_suspend_start(PMSG_QUIESCE);
543 if (!error) {
544 error = resume_target_kernel(platform_mode);
545 /*
546 * The above should either succeed and jump to the new kernel,
547 * or return with an error. Otherwise things are just
548 * undefined, so let's be paranoid.
549 */
550 BUG_ON(!error);
551 }
552 dpm_resume_end(PMSG_RECOVER);
553 pm_restore_gfp_mask();
554 resume_console();
555 pm_restore_console();
556 return error;
557}
558
559/**
560 * hibernation_platform_enter - Power off the system using the platform driver.
561 */
562int hibernation_platform_enter(void)
563{
564 int error;
565
566 if (!hibernation_ops)
567 return -ENOSYS;
568
569 /*
570 * We have cancelled the power transition by running
571 * hibernation_ops->finish() before saving the image, so we should let
572 * the firmware know that we're going to enter the sleep state after all
573 */
574 error = hibernation_ops->begin(PMSG_HIBERNATE);
575 if (error)
576 goto Close;
577
578 entering_platform_hibernation = true;
579 suspend_console();
580 error = dpm_suspend_start(PMSG_HIBERNATE);
581 if (error) {
582 if (hibernation_ops->recover)
583 hibernation_ops->recover();
584 goto Resume_devices;
585 }
586
587 error = dpm_suspend_end(PMSG_HIBERNATE);
588 if (error)
589 goto Resume_devices;
590
591 error = hibernation_ops->prepare();
592 if (error)
593 goto Platform_finish;
594
595 error = pm_sleep_disable_secondary_cpus();
596 if (error)
597 goto Enable_cpus;
598
599 local_irq_disable();
600 system_state = SYSTEM_SUSPEND;
601 syscore_suspend();
602 if (pm_wakeup_pending()) {
603 error = -EAGAIN;
604 goto Power_up;
605 }
606
607 hibernation_ops->enter();
608 /* We should never get here */
609 while (1);
610
611 Power_up:
612 syscore_resume();
613 system_state = SYSTEM_RUNNING;
614 local_irq_enable();
615
616 Enable_cpus:
617 pm_sleep_enable_secondary_cpus();
618
619 Platform_finish:
620 hibernation_ops->finish();
621
622 dpm_resume_start(PMSG_RESTORE);
623
624 Resume_devices:
625 entering_platform_hibernation = false;
626 dpm_resume_end(PMSG_RESTORE);
627 resume_console();
628
629 Close:
630 hibernation_ops->end();
631
632 return error;
633}
634
635/**
636 * power_down - Shut the machine down for hibernation.
637 *
638 * Use the platform driver, if configured, to put the system into the sleep
639 * state corresponding to hibernation, or try to power it off or reboot,
640 * depending on the value of hibernation_mode.
641 */
642static void power_down(void)
643{
644#ifdef CONFIG_SUSPEND
645 int error;
646
647 if (hibernation_mode == HIBERNATION_SUSPEND) {
648 error = suspend_devices_and_enter(mem_sleep_current);
649 if (error) {
650 hibernation_mode = hibernation_ops ?
651 HIBERNATION_PLATFORM :
652 HIBERNATION_SHUTDOWN;
653 } else {
654 /* Restore swap signature. */
655 error = swsusp_unmark();
656 if (error)
657 pr_err("Swap will be unusable! Try swapon -a.\n");
658
659 return;
660 }
661 }
662#endif
663
664 switch (hibernation_mode) {
665 case HIBERNATION_REBOOT:
666 kernel_restart(NULL);
667 break;
668 case HIBERNATION_PLATFORM:
669 hibernation_platform_enter();
670 fallthrough;
671 case HIBERNATION_SHUTDOWN:
672 if (kernel_can_power_off())
673 kernel_power_off();
674 break;
675 }
676 kernel_halt();
677 /*
678 * Valid image is on the disk, if we continue we risk serious data
679 * corruption after resume.
680 */
681 pr_crit("Power down manually\n");
682 while (1)
683 cpu_relax();
684}
685
686static int load_image_and_restore(void)
687{
688 int error;
689 unsigned int flags;
690
691 pm_pr_dbg("Loading hibernation image.\n");
692
693 lock_device_hotplug();
694 error = create_basic_memory_bitmaps();
695 if (error) {
696 swsusp_close(FMODE_READ | FMODE_EXCL);
697 goto Unlock;
698 }
699
700 error = swsusp_read(&flags);
701 swsusp_close(FMODE_READ | FMODE_EXCL);
702 if (!error)
703 error = hibernation_restore(flags & SF_PLATFORM_MODE);
704
705 pr_err("Failed to load image, recovering.\n");
706 swsusp_free();
707 free_basic_memory_bitmaps();
708 Unlock:
709 unlock_device_hotplug();
710
711 return error;
712}
713
714/**
715 * hibernate - Carry out system hibernation, including saving the image.
716 */
717int hibernate(void)
718{
719 bool snapshot_test = false;
720 unsigned int sleep_flags;
721 int error;
722
723 if (!hibernation_available()) {
724 pm_pr_dbg("Hibernation not available.\n");
725 return -EPERM;
726 }
727
728 sleep_flags = lock_system_sleep();
729 /* The snapshot device should not be opened while we're running */
730 if (!hibernate_acquire()) {
731 error = -EBUSY;
732 goto Unlock;
733 }
734
735 pr_info("hibernation entry\n");
736 pm_prepare_console();
737 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
738 if (error)
739 goto Restore;
740
741 ksys_sync_helper();
742
743 error = freeze_processes();
744 if (error)
745 goto Exit;
746
747 lock_device_hotplug();
748 /* Allocate memory management structures */
749 error = create_basic_memory_bitmaps();
750 if (error)
751 goto Thaw;
752
753 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
754 if (error || freezer_test_done)
755 goto Free_bitmaps;
756
757 if (in_suspend) {
758 unsigned int flags = 0;
759
760 if (hibernation_mode == HIBERNATION_PLATFORM)
761 flags |= SF_PLATFORM_MODE;
762 if (nocompress)
763 flags |= SF_NOCOMPRESS_MODE;
764 else
765 flags |= SF_CRC32_MODE;
766
767 pm_pr_dbg("Writing hibernation image.\n");
768 error = swsusp_write(flags);
769 swsusp_free();
770 if (!error) {
771 if (hibernation_mode == HIBERNATION_TEST_RESUME)
772 snapshot_test = true;
773 else
774 power_down();
775 }
776 in_suspend = 0;
777 pm_restore_gfp_mask();
778 } else {
779 pm_pr_dbg("Hibernation image restored successfully.\n");
780 }
781
782 Free_bitmaps:
783 free_basic_memory_bitmaps();
784 Thaw:
785 unlock_device_hotplug();
786 if (snapshot_test) {
787 pm_pr_dbg("Checking hibernation image\n");
788 error = swsusp_check();
789 if (!error)
790 error = load_image_and_restore();
791 }
792 thaw_processes();
793
794 /* Don't bother checking whether freezer_test_done is true */
795 freezer_test_done = false;
796 Exit:
797 pm_notifier_call_chain(PM_POST_HIBERNATION);
798 Restore:
799 pm_restore_console();
800 hibernate_release();
801 Unlock:
802 unlock_system_sleep(sleep_flags);
803 pr_info("hibernation exit\n");
804
805 return error;
806}
807
808/**
809 * hibernate_quiet_exec - Execute a function with all devices frozen.
810 * @func: Function to execute.
811 * @data: Data pointer to pass to @func.
812 *
813 * Return the @func return value or an error code if it cannot be executed.
814 */
815int hibernate_quiet_exec(int (*func)(void *data), void *data)
816{
817 unsigned int sleep_flags;
818 int error;
819
820 sleep_flags = lock_system_sleep();
821
822 if (!hibernate_acquire()) {
823 error = -EBUSY;
824 goto unlock;
825 }
826
827 pm_prepare_console();
828
829 error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
830 if (error)
831 goto restore;
832
833 error = freeze_processes();
834 if (error)
835 goto exit;
836
837 lock_device_hotplug();
838
839 pm_suspend_clear_flags();
840
841 error = platform_begin(true);
842 if (error)
843 goto thaw;
844
845 error = freeze_kernel_threads();
846 if (error)
847 goto thaw;
848
849 error = dpm_prepare(PMSG_FREEZE);
850 if (error)
851 goto dpm_complete;
852
853 suspend_console();
854
855 error = dpm_suspend(PMSG_FREEZE);
856 if (error)
857 goto dpm_resume;
858
859 error = dpm_suspend_end(PMSG_FREEZE);
860 if (error)
861 goto dpm_resume;
862
863 error = platform_pre_snapshot(true);
864 if (error)
865 goto skip;
866
867 error = func(data);
868
869skip:
870 platform_finish(true);
871
872 dpm_resume_start(PMSG_THAW);
873
874dpm_resume:
875 dpm_resume(PMSG_THAW);
876
877 resume_console();
878
879dpm_complete:
880 dpm_complete(PMSG_THAW);
881
882 thaw_kernel_threads();
883
884thaw:
885 platform_end(true);
886
887 unlock_device_hotplug();
888
889 thaw_processes();
890
891exit:
892 pm_notifier_call_chain(PM_POST_HIBERNATION);
893
894restore:
895 pm_restore_console();
896
897 hibernate_release();
898
899unlock:
900 unlock_system_sleep(sleep_flags);
901
902 return error;
903}
904EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
905
906/**
907 * software_resume - Resume from a saved hibernation image.
908 *
909 * This routine is called as a late initcall, when all devices have been
910 * discovered and initialized already.
911 *
912 * The image reading code is called to see if there is a hibernation image
913 * available for reading. If that is the case, devices are quiesced and the
914 * contents of memory is restored from the saved image.
915 *
916 * If this is successful, control reappears in the restored target kernel in
917 * hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
918 * attempts to recover gracefully and make the kernel return to the normal mode
919 * of operation.
920 */
921static int software_resume(void)
922{
923 int error;
924
925 /*
926 * If the user said "noresume".. bail out early.
927 */
928 if (noresume || !hibernation_available())
929 return 0;
930
931 /*
932 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
933 * is configured into the kernel. Since the regular hibernate
934 * trigger path is via sysfs which takes a buffer mutex before
935 * calling hibernate functions (which take system_transition_mutex)
936 * this can cause lockdep to complain about a possible ABBA deadlock
937 * which cannot happen since we're in the boot code here and
938 * sysfs can't be invoked yet. Therefore, we use a subclass
939 * here to avoid lockdep complaining.
940 */
941 mutex_lock_nested(&system_transition_mutex, SINGLE_DEPTH_NESTING);
942
943 if (swsusp_resume_device)
944 goto Check_image;
945
946 if (!strlen(resume_file)) {
947 error = -ENOENT;
948 goto Unlock;
949 }
950
951 pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
952
953 if (resume_delay) {
954 pr_info("Waiting %dsec before reading resume device ...\n",
955 resume_delay);
956 ssleep(resume_delay);
957 }
958
959 /* Check if the device is there */
960 swsusp_resume_device = name_to_dev_t(resume_file);
961 if (!swsusp_resume_device) {
962 /*
963 * Some device discovery might still be in progress; we need
964 * to wait for this to finish.
965 */
966 wait_for_device_probe();
967
968 if (resume_wait) {
969 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
970 msleep(10);
971 async_synchronize_full();
972 }
973
974 swsusp_resume_device = name_to_dev_t(resume_file);
975 if (!swsusp_resume_device) {
976 error = -ENODEV;
977 goto Unlock;
978 }
979 }
980
981 Check_image:
982 pm_pr_dbg("Hibernation image partition %d:%d present\n",
983 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
984
985 pm_pr_dbg("Looking for hibernation image.\n");
986 error = swsusp_check();
987 if (error)
988 goto Unlock;
989
990 /* The snapshot device should not be opened while we're running */
991 if (!hibernate_acquire()) {
992 error = -EBUSY;
993 swsusp_close(FMODE_READ | FMODE_EXCL);
994 goto Unlock;
995 }
996
997 pr_info("resume from hibernation\n");
998 pm_prepare_console();
999 error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
1000 if (error)
1001 goto Restore;
1002
1003 pm_pr_dbg("Preparing processes for hibernation restore.\n");
1004 error = freeze_processes();
1005 if (error)
1006 goto Close_Finish;
1007
1008 error = freeze_kernel_threads();
1009 if (error) {
1010 thaw_processes();
1011 goto Close_Finish;
1012 }
1013
1014 error = load_image_and_restore();
1015 thaw_processes();
1016 Finish:
1017 pm_notifier_call_chain(PM_POST_RESTORE);
1018 Restore:
1019 pm_restore_console();
1020 pr_info("resume failed (%d)\n", error);
1021 hibernate_release();
1022 /* For success case, the suspend path will release the lock */
1023 Unlock:
1024 mutex_unlock(&system_transition_mutex);
1025 pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
1026 return error;
1027 Close_Finish:
1028 swsusp_close(FMODE_READ | FMODE_EXCL);
1029 goto Finish;
1030}
1031
1032late_initcall_sync(software_resume);
1033
1034
1035static const char * const hibernation_modes[] = {
1036 [HIBERNATION_PLATFORM] = "platform",
1037 [HIBERNATION_SHUTDOWN] = "shutdown",
1038 [HIBERNATION_REBOOT] = "reboot",
1039#ifdef CONFIG_SUSPEND
1040 [HIBERNATION_SUSPEND] = "suspend",
1041#endif
1042 [HIBERNATION_TEST_RESUME] = "test_resume",
1043};
1044
1045/*
1046 * /sys/power/disk - Control hibernation mode.
1047 *
1048 * Hibernation can be handled in several ways. There are a few different ways
1049 * to put the system into the sleep state: using the platform driver (e.g. ACPI
1050 * or other hibernation_ops), powering it off or rebooting it (for testing
1051 * mostly).
1052 *
1053 * The sysfs file /sys/power/disk provides an interface for selecting the
1054 * hibernation mode to use. Reading from this file causes the available modes
1055 * to be printed. There are 3 modes that can be supported:
1056 *
1057 * 'platform'
1058 * 'shutdown'
1059 * 'reboot'
1060 *
1061 * If a platform hibernation driver is in use, 'platform' will be supported
1062 * and will be used by default. Otherwise, 'shutdown' will be used by default.
1063 * The selected option (i.e. the one corresponding to the current value of
1064 * hibernation_mode) is enclosed by a square bracket.
1065 *
1066 * To select a given hibernation mode it is necessary to write the mode's
1067 * string representation (as returned by reading from /sys/power/disk) back
1068 * into /sys/power/disk.
1069 */
1070
1071static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
1072 char *buf)
1073{
1074 int i;
1075 char *start = buf;
1076
1077 if (!hibernation_available())
1078 return sprintf(buf, "[disabled]\n");
1079
1080 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1081 if (!hibernation_modes[i])
1082 continue;
1083 switch (i) {
1084 case HIBERNATION_SHUTDOWN:
1085 case HIBERNATION_REBOOT:
1086#ifdef CONFIG_SUSPEND
1087 case HIBERNATION_SUSPEND:
1088#endif
1089 case HIBERNATION_TEST_RESUME:
1090 break;
1091 case HIBERNATION_PLATFORM:
1092 if (hibernation_ops)
1093 break;
1094 /* not a valid mode, continue with loop */
1095 continue;
1096 }
1097 if (i == hibernation_mode)
1098 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
1099 else
1100 buf += sprintf(buf, "%s ", hibernation_modes[i]);
1101 }
1102 buf += sprintf(buf, "\n");
1103 return buf-start;
1104}
1105
1106static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
1107 const char *buf, size_t n)
1108{
1109 int mode = HIBERNATION_INVALID;
1110 unsigned int sleep_flags;
1111 int error = 0;
1112 int len;
1113 char *p;
1114 int i;
1115
1116 if (!hibernation_available())
1117 return -EPERM;
1118
1119 p = memchr(buf, '\n', n);
1120 len = p ? p - buf : n;
1121
1122 sleep_flags = lock_system_sleep();
1123 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
1124 if (len == strlen(hibernation_modes[i])
1125 && !strncmp(buf, hibernation_modes[i], len)) {
1126 mode = i;
1127 break;
1128 }
1129 }
1130 if (mode != HIBERNATION_INVALID) {
1131 switch (mode) {
1132 case HIBERNATION_SHUTDOWN:
1133 case HIBERNATION_REBOOT:
1134#ifdef CONFIG_SUSPEND
1135 case HIBERNATION_SUSPEND:
1136#endif
1137 case HIBERNATION_TEST_RESUME:
1138 hibernation_mode = mode;
1139 break;
1140 case HIBERNATION_PLATFORM:
1141 if (hibernation_ops)
1142 hibernation_mode = mode;
1143 else
1144 error = -EINVAL;
1145 }
1146 } else
1147 error = -EINVAL;
1148
1149 if (!error)
1150 pm_pr_dbg("Hibernation mode set to '%s'\n",
1151 hibernation_modes[mode]);
1152 unlock_system_sleep(sleep_flags);
1153 return error ? error : n;
1154}
1155
1156power_attr(disk);
1157
1158static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
1159 char *buf)
1160{
1161 return sprintf(buf, "%d:%d\n", MAJOR(swsusp_resume_device),
1162 MINOR(swsusp_resume_device));
1163}
1164
1165static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
1166 const char *buf, size_t n)
1167{
1168 unsigned int sleep_flags;
1169 int len = n;
1170 char *name;
1171 dev_t res;
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 sleep_flags = lock_system_sleep();
1185 swsusp_resume_device = res;
1186 unlock_system_sleep(sleep_flags);
1187
1188 pm_pr_dbg("Configured hibernation resume from disk to %u\n",
1189 swsusp_resume_device);
1190 noresume = 0;
1191 software_resume();
1192 return n;
1193}
1194
1195power_attr(resume);
1196
1197static ssize_t resume_offset_show(struct kobject *kobj,
1198 struct kobj_attribute *attr, char *buf)
1199{
1200 return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
1201}
1202
1203static ssize_t resume_offset_store(struct kobject *kobj,
1204 struct kobj_attribute *attr, const char *buf,
1205 size_t n)
1206{
1207 unsigned long long offset;
1208 int rc;
1209
1210 rc = kstrtoull(buf, 0, &offset);
1211 if (rc)
1212 return rc;
1213 swsusp_resume_block = offset;
1214
1215 return n;
1216}
1217
1218power_attr(resume_offset);
1219
1220static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1221 char *buf)
1222{
1223 return sprintf(buf, "%lu\n", image_size);
1224}
1225
1226static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1227 const char *buf, size_t n)
1228{
1229 unsigned long size;
1230
1231 if (sscanf(buf, "%lu", &size) == 1) {
1232 image_size = size;
1233 return n;
1234 }
1235
1236 return -EINVAL;
1237}
1238
1239power_attr(image_size);
1240
1241static ssize_t reserved_size_show(struct kobject *kobj,
1242 struct kobj_attribute *attr, char *buf)
1243{
1244 return sprintf(buf, "%lu\n", reserved_size);
1245}
1246
1247static ssize_t reserved_size_store(struct kobject *kobj,
1248 struct kobj_attribute *attr,
1249 const char *buf, size_t n)
1250{
1251 unsigned long size;
1252
1253 if (sscanf(buf, "%lu", &size) == 1) {
1254 reserved_size = size;
1255 return n;
1256 }
1257
1258 return -EINVAL;
1259}
1260
1261power_attr(reserved_size);
1262
1263static struct attribute *g[] = {
1264 &disk_attr.attr,
1265 &resume_offset_attr.attr,
1266 &resume_attr.attr,
1267 &image_size_attr.attr,
1268 &reserved_size_attr.attr,
1269 NULL,
1270};
1271
1272
1273static const struct attribute_group attr_group = {
1274 .attrs = g,
1275};
1276
1277
1278static int __init pm_disk_init(void)
1279{
1280 return sysfs_create_group(power_kobj, &attr_group);
1281}
1282
1283core_initcall(pm_disk_init);
1284
1285
1286static int __init resume_setup(char *str)
1287{
1288 if (noresume)
1289 return 1;
1290
1291 strncpy(resume_file, str, 255);
1292 return 1;
1293}
1294
1295static int __init resume_offset_setup(char *str)
1296{
1297 unsigned long long offset;
1298
1299 if (noresume)
1300 return 1;
1301
1302 if (sscanf(str, "%llu", &offset) == 1)
1303 swsusp_resume_block = offset;
1304
1305 return 1;
1306}
1307
1308static int __init hibernate_setup(char *str)
1309{
1310 if (!strncmp(str, "noresume", 8)) {
1311 noresume = 1;
1312 } else if (!strncmp(str, "nocompress", 10)) {
1313 nocompress = 1;
1314 } else if (!strncmp(str, "no", 2)) {
1315 noresume = 1;
1316 nohibernate = 1;
1317 } else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
1318 && !strncmp(str, "protect_image", 13)) {
1319 enable_restore_image_protection();
1320 }
1321 return 1;
1322}
1323
1324static int __init noresume_setup(char *str)
1325{
1326 noresume = 1;
1327 return 1;
1328}
1329
1330static int __init resumewait_setup(char *str)
1331{
1332 resume_wait = 1;
1333 return 1;
1334}
1335
1336static int __init resumedelay_setup(char *str)
1337{
1338 int rc = kstrtouint(str, 0, &resume_delay);
1339
1340 if (rc)
1341 pr_warn("resumedelay: bad option string '%s'\n", str);
1342 return 1;
1343}
1344
1345static int __init nohibernate_setup(char *str)
1346{
1347 noresume = 1;
1348 nohibernate = 1;
1349 return 1;
1350}
1351
1352__setup("noresume", noresume_setup);
1353__setup("resume_offset=", resume_offset_setup);
1354__setup("resume=", resume_setup);
1355__setup("hibernate=", hibernate_setup);
1356__setup("resumewait", resumewait_setup);
1357__setup("resumedelay=", resumedelay_setup);
1358__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 *
9 * This file is released under the GPLv2.
10 */
11
12#include <linux/suspend.h>
13#include <linux/syscalls.h>
14#include <linux/reboot.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/kmod.h>
18#include <linux/delay.h>
19#include <linux/fs.h>
20#include <linux/mount.h>
21#include <linux/pm.h>
22#include <linux/console.h>
23#include <linux/cpu.h>
24#include <linux/freezer.h>
25#include <linux/gfp.h>
26#include <linux/syscore_ops.h>
27#include <scsi/scsi_scan.h>
28
29#include "power.h"
30
31
32static int nocompress = 0;
33static int noresume = 0;
34static char resume_file[256] = CONFIG_PM_STD_PARTITION;
35dev_t swsusp_resume_device;
36sector_t swsusp_resume_block;
37int in_suspend __nosavedata = 0;
38
39enum {
40 HIBERNATION_INVALID,
41 HIBERNATION_PLATFORM,
42 HIBERNATION_TEST,
43 HIBERNATION_TESTPROC,
44 HIBERNATION_SHUTDOWN,
45 HIBERNATION_REBOOT,
46 /* keep last */
47 __HIBERNATION_AFTER_LAST
48};
49#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
50#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
51
52static int hibernation_mode = HIBERNATION_SHUTDOWN;
53
54static const struct platform_hibernation_ops *hibernation_ops;
55
56/**
57 * hibernation_set_ops - Set the global hibernate operations.
58 * @ops: Hibernation operations to use in subsequent hibernation transitions.
59 */
60void hibernation_set_ops(const struct platform_hibernation_ops *ops)
61{
62 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
63 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
64 && ops->restore_cleanup && ops->leave)) {
65 WARN_ON(1);
66 return;
67 }
68 mutex_lock(&pm_mutex);
69 hibernation_ops = ops;
70 if (ops)
71 hibernation_mode = HIBERNATION_PLATFORM;
72 else if (hibernation_mode == HIBERNATION_PLATFORM)
73 hibernation_mode = HIBERNATION_SHUTDOWN;
74
75 mutex_unlock(&pm_mutex);
76}
77
78static bool entering_platform_hibernation;
79
80bool system_entering_hibernation(void)
81{
82 return entering_platform_hibernation;
83}
84EXPORT_SYMBOL(system_entering_hibernation);
85
86#ifdef CONFIG_PM_DEBUG
87static void hibernation_debug_sleep(void)
88{
89 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
90 mdelay(5000);
91}
92
93static int hibernation_testmode(int mode)
94{
95 if (hibernation_mode == mode) {
96 hibernation_debug_sleep();
97 return 1;
98 }
99 return 0;
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_testmode(int mode) { return 0; }
112static int hibernation_test(int level) { return 0; }
113#endif /* !CONFIG_PM_DEBUG */
114
115/**
116 * platform_begin - Call platform to start hibernation.
117 * @platform_mode: Whether or not to use the platform driver.
118 */
119static int platform_begin(int platform_mode)
120{
121 return (platform_mode && hibernation_ops) ?
122 hibernation_ops->begin() : 0;
123}
124
125/**
126 * platform_end - Call platform to finish transition to the working state.
127 * @platform_mode: Whether or not to use the platform driver.
128 */
129static void platform_end(int platform_mode)
130{
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->end();
133}
134
135/**
136 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
137 * @platform_mode: Whether or not to use the platform driver.
138 *
139 * Use the platform driver to prepare the system for creating a hibernate image,
140 * if so configured, and return an error code if that fails.
141 */
142
143static int platform_pre_snapshot(int platform_mode)
144{
145 return (platform_mode && hibernation_ops) ?
146 hibernation_ops->pre_snapshot() : 0;
147}
148
149/**
150 * platform_leave - Call platform to prepare a transition to the working state.
151 * @platform_mode: Whether or not to use the platform driver.
152 *
153 * Use the platform driver prepare to prepare the machine for switching to the
154 * normal mode of operation.
155 *
156 * This routine is called on one CPU with interrupts disabled.
157 */
158static void platform_leave(int platform_mode)
159{
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->leave();
162}
163
164/**
165 * platform_finish - Call platform to switch the system to the working state.
166 * @platform_mode: Whether or not to use the platform driver.
167 *
168 * Use the platform driver to switch the machine to the normal mode of
169 * operation.
170 *
171 * This routine must be called after platform_prepare().
172 */
173static void platform_finish(int platform_mode)
174{
175 if (platform_mode && hibernation_ops)
176 hibernation_ops->finish();
177}
178
179/**
180 * platform_pre_restore - Prepare for hibernate image restoration.
181 * @platform_mode: Whether or not to use the platform driver.
182 *
183 * Use the platform driver to prepare the system for resume from a hibernation
184 * image.
185 *
186 * If the restore fails after this function has been called,
187 * platform_restore_cleanup() must be called.
188 */
189static int platform_pre_restore(int platform_mode)
190{
191 return (platform_mode && hibernation_ops) ?
192 hibernation_ops->pre_restore() : 0;
193}
194
195/**
196 * platform_restore_cleanup - Switch to the working state after failing restore.
197 * @platform_mode: Whether or not to use the platform driver.
198 *
199 * Use the platform driver to switch the system to the normal mode of operation
200 * after a failing restore.
201 *
202 * If platform_pre_restore() has been called before the failing restore, this
203 * function must be called too, regardless of the result of
204 * platform_pre_restore().
205 */
206static void platform_restore_cleanup(int platform_mode)
207{
208 if (platform_mode && hibernation_ops)
209 hibernation_ops->restore_cleanup();
210}
211
212/**
213 * platform_recover - Recover from a failure to suspend devices.
214 * @platform_mode: Whether or not to use the platform driver.
215 */
216static void platform_recover(int platform_mode)
217{
218 if (platform_mode && hibernation_ops && hibernation_ops->recover)
219 hibernation_ops->recover();
220}
221
222/**
223 * swsusp_show_speed - Print time elapsed between two events during hibernation.
224 * @start: Starting event.
225 * @stop: Final event.
226 * @nr_pages: Number of memory pages processed between @start and @stop.
227 * @msg: Additional diagnostic message to print.
228 */
229void swsusp_show_speed(struct timeval *start, struct timeval *stop,
230 unsigned nr_pages, char *msg)
231{
232 s64 elapsed_centisecs64;
233 int centisecs;
234 int k;
235 int kps;
236
237 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
238 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
239 centisecs = elapsed_centisecs64;
240 if (centisecs == 0)
241 centisecs = 1; /* avoid div-by-zero */
242 k = nr_pages * (PAGE_SIZE / 1024);
243 kps = (k * 100) / centisecs;
244 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
245 msg, k,
246 centisecs / 100, centisecs % 100,
247 kps / 1000, (kps % 1000) / 10);
248}
249
250/**
251 * create_image - Create a hibernation image.
252 * @platform_mode: Whether or not to use the platform driver.
253 *
254 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
255 * and execute the drivers' .thaw_noirq() callbacks.
256 *
257 * Control reappears in this routine after the subsequent restore.
258 */
259static int create_image(int platform_mode)
260{
261 int error;
262
263 error = dpm_suspend_noirq(PMSG_FREEZE);
264 if (error) {
265 printk(KERN_ERR "PM: Some devices failed to power down, "
266 "aborting hibernation\n");
267 return error;
268 }
269
270 error = platform_pre_snapshot(platform_mode);
271 if (error || hibernation_test(TEST_PLATFORM))
272 goto Platform_finish;
273
274 error = disable_nonboot_cpus();
275 if (error || hibernation_test(TEST_CPUS)
276 || hibernation_testmode(HIBERNATION_TEST))
277 goto Enable_cpus;
278
279 local_irq_disable();
280
281 error = syscore_suspend();
282 if (error) {
283 printk(KERN_ERR "PM: Some system devices failed to power down, "
284 "aborting hibernation\n");
285 goto Enable_irqs;
286 }
287
288 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
289 goto Power_up;
290
291 in_suspend = 1;
292 save_processor_state();
293 error = swsusp_arch_suspend();
294 if (error)
295 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
296 error);
297 /* Restore control flow magically appears here */
298 restore_processor_state();
299 if (!in_suspend) {
300 events_check_enabled = false;
301 platform_leave(platform_mode);
302 }
303
304 Power_up:
305 syscore_resume();
306
307 Enable_irqs:
308 local_irq_enable();
309
310 Enable_cpus:
311 enable_nonboot_cpus();
312
313 Platform_finish:
314 platform_finish(platform_mode);
315
316 dpm_resume_noirq(in_suspend ?
317 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
318
319 return error;
320}
321
322/**
323 * hibernation_snapshot - Quiesce devices and create a hibernation image.
324 * @platform_mode: If set, use platform driver to prepare for the transition.
325 *
326 * This routine must be called with pm_mutex held.
327 */
328int hibernation_snapshot(int platform_mode)
329{
330 pm_message_t msg = PMSG_RECOVER;
331 int error;
332
333 error = platform_begin(platform_mode);
334 if (error)
335 goto Close;
336
337 error = dpm_prepare(PMSG_FREEZE);
338 if (error)
339 goto Complete_devices;
340
341 /* Preallocate image memory before shutting down devices. */
342 error = hibernate_preallocate_memory();
343 if (error)
344 goto Complete_devices;
345
346 suspend_console();
347 pm_restrict_gfp_mask();
348 error = dpm_suspend(PMSG_FREEZE);
349 if (error)
350 goto Recover_platform;
351
352 if (hibernation_test(TEST_DEVICES))
353 goto Recover_platform;
354
355 error = create_image(platform_mode);
356 /*
357 * Control returns here (1) after the image has been created or the
358 * image creation has failed and (2) after a successful restore.
359 */
360
361 Resume_devices:
362 /* We may need to release the preallocated image pages here. */
363 if (error || !in_suspend)
364 swsusp_free();
365
366 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
367 dpm_resume(msg);
368
369 if (error || !in_suspend)
370 pm_restore_gfp_mask();
371
372 resume_console();
373
374 Complete_devices:
375 dpm_complete(msg);
376
377 Close:
378 platform_end(platform_mode);
379 return error;
380
381 Recover_platform:
382 platform_recover(platform_mode);
383 goto Resume_devices;
384}
385
386/**
387 * resume_target_kernel - Restore system state from a hibernation image.
388 * @platform_mode: Whether or not to use the platform driver.
389 *
390 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
391 * highmem that have not been restored yet from the image and run the low-level
392 * code that will restore the remaining contents of memory and switch to the
393 * just restored target kernel.
394 */
395static int resume_target_kernel(bool platform_mode)
396{
397 int error;
398
399 error = dpm_suspend_noirq(PMSG_QUIESCE);
400 if (error) {
401 printk(KERN_ERR "PM: Some devices failed to power down, "
402 "aborting resume\n");
403 return error;
404 }
405
406 error = platform_pre_restore(platform_mode);
407 if (error)
408 goto Cleanup;
409
410 error = disable_nonboot_cpus();
411 if (error)
412 goto Enable_cpus;
413
414 local_irq_disable();
415
416 error = syscore_suspend();
417 if (error)
418 goto Enable_irqs;
419
420 save_processor_state();
421 error = restore_highmem();
422 if (!error) {
423 error = swsusp_arch_resume();
424 /*
425 * The code below is only ever reached in case of a failure.
426 * Otherwise, execution continues at the place where
427 * swsusp_arch_suspend() was called.
428 */
429 BUG_ON(!error);
430 /*
431 * This call to restore_highmem() reverts the changes made by
432 * the previous one.
433 */
434 restore_highmem();
435 }
436 /*
437 * The only reason why swsusp_arch_resume() can fail is memory being
438 * very tight, so we have to free it as soon as we can to avoid
439 * subsequent failures.
440 */
441 swsusp_free();
442 restore_processor_state();
443 touch_softlockup_watchdog();
444
445 syscore_resume();
446
447 Enable_irqs:
448 local_irq_enable();
449
450 Enable_cpus:
451 enable_nonboot_cpus();
452
453 Cleanup:
454 platform_restore_cleanup(platform_mode);
455
456 dpm_resume_noirq(PMSG_RECOVER);
457
458 return error;
459}
460
461/**
462 * hibernation_restore - Quiesce devices and restore from a hibernation image.
463 * @platform_mode: If set, use platform driver to prepare for the transition.
464 *
465 * This routine must be called with pm_mutex held. If it is successful, control
466 * reappears in the restored target kernel in hibernation_snaphot().
467 */
468int hibernation_restore(int platform_mode)
469{
470 int error;
471
472 pm_prepare_console();
473 suspend_console();
474 pm_restrict_gfp_mask();
475 error = dpm_suspend_start(PMSG_QUIESCE);
476 if (!error) {
477 error = resume_target_kernel(platform_mode);
478 dpm_resume_end(PMSG_RECOVER);
479 }
480 pm_restore_gfp_mask();
481 resume_console();
482 pm_restore_console();
483 return error;
484}
485
486/**
487 * hibernation_platform_enter - Power off the system using the platform driver.
488 */
489int hibernation_platform_enter(void)
490{
491 int error;
492
493 if (!hibernation_ops)
494 return -ENOSYS;
495
496 /*
497 * We have cancelled the power transition by running
498 * hibernation_ops->finish() before saving the image, so we should let
499 * the firmware know that we're going to enter the sleep state after all
500 */
501 error = hibernation_ops->begin();
502 if (error)
503 goto Close;
504
505 entering_platform_hibernation = true;
506 suspend_console();
507 error = dpm_suspend_start(PMSG_HIBERNATE);
508 if (error) {
509 if (hibernation_ops->recover)
510 hibernation_ops->recover();
511 goto Resume_devices;
512 }
513
514 error = dpm_suspend_noirq(PMSG_HIBERNATE);
515 if (error)
516 goto Resume_devices;
517
518 error = hibernation_ops->prepare();
519 if (error)
520 goto Platform_finish;
521
522 error = disable_nonboot_cpus();
523 if (error)
524 goto Platform_finish;
525
526 local_irq_disable();
527 syscore_suspend();
528 if (pm_wakeup_pending()) {
529 error = -EAGAIN;
530 goto Power_up;
531 }
532
533 hibernation_ops->enter();
534 /* We should never get here */
535 while (1);
536
537 Power_up:
538 syscore_resume();
539 local_irq_enable();
540 enable_nonboot_cpus();
541
542 Platform_finish:
543 hibernation_ops->finish();
544
545 dpm_resume_noirq(PMSG_RESTORE);
546
547 Resume_devices:
548 entering_platform_hibernation = false;
549 dpm_resume_end(PMSG_RESTORE);
550 resume_console();
551
552 Close:
553 hibernation_ops->end();
554
555 return error;
556}
557
558/**
559 * power_down - Shut the machine down for hibernation.
560 *
561 * Use the platform driver, if configured, to put the system into the sleep
562 * state corresponding to hibernation, or try to power it off or reboot,
563 * depending on the value of hibernation_mode.
564 */
565static void power_down(void)
566{
567 switch (hibernation_mode) {
568 case HIBERNATION_TEST:
569 case HIBERNATION_TESTPROC:
570 break;
571 case HIBERNATION_REBOOT:
572 kernel_restart(NULL);
573 break;
574 case HIBERNATION_PLATFORM:
575 hibernation_platform_enter();
576 case HIBERNATION_SHUTDOWN:
577 kernel_power_off();
578 break;
579 }
580 kernel_halt();
581 /*
582 * Valid image is on the disk, if we continue we risk serious data
583 * corruption after resume.
584 */
585 printk(KERN_CRIT "PM: Please power down manually\n");
586 while(1);
587}
588
589static int prepare_processes(void)
590{
591 int error = 0;
592
593 if (freeze_processes()) {
594 error = -EBUSY;
595 thaw_processes();
596 }
597 return error;
598}
599
600/**
601 * hibernate - Carry out system hibernation, including saving the image.
602 */
603int hibernate(void)
604{
605 int error;
606
607 mutex_lock(&pm_mutex);
608 /* The snapshot device should not be opened while we're running */
609 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
610 error = -EBUSY;
611 goto Unlock;
612 }
613
614 pm_prepare_console();
615 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
616 if (error)
617 goto Exit;
618
619 error = usermodehelper_disable();
620 if (error)
621 goto Exit;
622
623 /* Allocate memory management structures */
624 error = create_basic_memory_bitmaps();
625 if (error)
626 goto Exit;
627
628 printk(KERN_INFO "PM: Syncing filesystems ... ");
629 sys_sync();
630 printk("done.\n");
631
632 error = prepare_processes();
633 if (error)
634 goto Finish;
635
636 if (hibernation_test(TEST_FREEZER))
637 goto Thaw;
638
639 if (hibernation_testmode(HIBERNATION_TESTPROC))
640 goto Thaw;
641
642 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
643 if (error)
644 goto Thaw;
645
646 if (in_suspend) {
647 unsigned int flags = 0;
648
649 if (hibernation_mode == HIBERNATION_PLATFORM)
650 flags |= SF_PLATFORM_MODE;
651 if (nocompress)
652 flags |= SF_NOCOMPRESS_MODE;
653 pr_debug("PM: writing image.\n");
654 error = swsusp_write(flags);
655 swsusp_free();
656 if (!error)
657 power_down();
658 in_suspend = 0;
659 pm_restore_gfp_mask();
660 } else {
661 pr_debug("PM: Image restored successfully.\n");
662 }
663
664 Thaw:
665 thaw_processes();
666 Finish:
667 free_basic_memory_bitmaps();
668 usermodehelper_enable();
669 Exit:
670 pm_notifier_call_chain(PM_POST_HIBERNATION);
671 pm_restore_console();
672 atomic_inc(&snapshot_device_available);
673 Unlock:
674 mutex_unlock(&pm_mutex);
675 return error;
676}
677
678
679/**
680 * software_resume - Resume from a saved hibernation image.
681 *
682 * This routine is called as a late initcall, when all devices have been
683 * discovered and initialized already.
684 *
685 * The image reading code is called to see if there is a hibernation image
686 * available for reading. If that is the case, devices are quiesced and the
687 * contents of memory is restored from the saved image.
688 *
689 * If this is successful, control reappears in the restored target kernel in
690 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
691 * attempts to recover gracefully and make the kernel return to the normal mode
692 * of operation.
693 */
694static int software_resume(void)
695{
696 int error;
697 unsigned int flags;
698
699 /*
700 * If the user said "noresume".. bail out early.
701 */
702 if (noresume)
703 return 0;
704
705 /*
706 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
707 * is configured into the kernel. Since the regular hibernate
708 * trigger path is via sysfs which takes a buffer mutex before
709 * calling hibernate functions (which take pm_mutex) this can
710 * cause lockdep to complain about a possible ABBA deadlock
711 * which cannot happen since we're in the boot code here and
712 * sysfs can't be invoked yet. Therefore, we use a subclass
713 * here to avoid lockdep complaining.
714 */
715 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
716
717 if (swsusp_resume_device)
718 goto Check_image;
719
720 if (!strlen(resume_file)) {
721 error = -ENOENT;
722 goto Unlock;
723 }
724
725 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
726
727 /* Check if the device is there */
728 swsusp_resume_device = name_to_dev_t(resume_file);
729 if (!swsusp_resume_device) {
730 /*
731 * Some device discovery might still be in progress; we need
732 * to wait for this to finish.
733 */
734 wait_for_device_probe();
735 /*
736 * We can't depend on SCSI devices being available after loading
737 * one of their modules until scsi_complete_async_scans() is
738 * called and the resume device usually is a SCSI one.
739 */
740 scsi_complete_async_scans();
741
742 swsusp_resume_device = name_to_dev_t(resume_file);
743 if (!swsusp_resume_device) {
744 error = -ENODEV;
745 goto Unlock;
746 }
747 }
748
749 Check_image:
750 pr_debug("PM: Hibernation image partition %d:%d present\n",
751 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
752
753 pr_debug("PM: Looking for hibernation image.\n");
754 error = swsusp_check();
755 if (error)
756 goto Unlock;
757
758 /* The snapshot device should not be opened while we're running */
759 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
760 error = -EBUSY;
761 swsusp_close(FMODE_READ);
762 goto Unlock;
763 }
764
765 pm_prepare_console();
766 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
767 if (error)
768 goto close_finish;
769
770 error = usermodehelper_disable();
771 if (error)
772 goto close_finish;
773
774 error = create_basic_memory_bitmaps();
775 if (error)
776 goto close_finish;
777
778 pr_debug("PM: Preparing processes for restore.\n");
779 error = prepare_processes();
780 if (error) {
781 swsusp_close(FMODE_READ);
782 goto Done;
783 }
784
785 pr_debug("PM: Loading hibernation image.\n");
786
787 error = swsusp_read(&flags);
788 swsusp_close(FMODE_READ);
789 if (!error)
790 hibernation_restore(flags & SF_PLATFORM_MODE);
791
792 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
793 swsusp_free();
794 thaw_processes();
795 Done:
796 free_basic_memory_bitmaps();
797 usermodehelper_enable();
798 Finish:
799 pm_notifier_call_chain(PM_POST_RESTORE);
800 pm_restore_console();
801 atomic_inc(&snapshot_device_available);
802 /* For success case, the suspend path will release the lock */
803 Unlock:
804 mutex_unlock(&pm_mutex);
805 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
806 return error;
807close_finish:
808 swsusp_close(FMODE_READ);
809 goto Finish;
810}
811
812late_initcall(software_resume);
813
814
815static const char * const hibernation_modes[] = {
816 [HIBERNATION_PLATFORM] = "platform",
817 [HIBERNATION_SHUTDOWN] = "shutdown",
818 [HIBERNATION_REBOOT] = "reboot",
819 [HIBERNATION_TEST] = "test",
820 [HIBERNATION_TESTPROC] = "testproc",
821};
822
823/*
824 * /sys/power/disk - Control hibernation mode.
825 *
826 * Hibernation can be handled in several ways. There are a few different ways
827 * to put the system into the sleep state: using the platform driver (e.g. ACPI
828 * or other hibernation_ops), powering it off or rebooting it (for testing
829 * mostly), or using one of the two available test modes.
830 *
831 * The sysfs file /sys/power/disk provides an interface for selecting the
832 * hibernation mode to use. Reading from this file causes the available modes
833 * to be printed. There are 5 modes that can be supported:
834 *
835 * 'platform'
836 * 'shutdown'
837 * 'reboot'
838 * 'test'
839 * 'testproc'
840 *
841 * If a platform hibernation driver is in use, 'platform' will be supported
842 * and will be used by default. Otherwise, 'shutdown' will be used by default.
843 * The selected option (i.e. the one corresponding to the current value of
844 * hibernation_mode) is enclosed by a square bracket.
845 *
846 * To select a given hibernation mode it is necessary to write the mode's
847 * string representation (as returned by reading from /sys/power/disk) back
848 * into /sys/power/disk.
849 */
850
851static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
852 char *buf)
853{
854 int i;
855 char *start = buf;
856
857 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
858 if (!hibernation_modes[i])
859 continue;
860 switch (i) {
861 case HIBERNATION_SHUTDOWN:
862 case HIBERNATION_REBOOT:
863 case HIBERNATION_TEST:
864 case HIBERNATION_TESTPROC:
865 break;
866 case HIBERNATION_PLATFORM:
867 if (hibernation_ops)
868 break;
869 /* not a valid mode, continue with loop */
870 continue;
871 }
872 if (i == hibernation_mode)
873 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
874 else
875 buf += sprintf(buf, "%s ", hibernation_modes[i]);
876 }
877 buf += sprintf(buf, "\n");
878 return buf-start;
879}
880
881static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
882 const char *buf, size_t n)
883{
884 int error = 0;
885 int i;
886 int len;
887 char *p;
888 int mode = HIBERNATION_INVALID;
889
890 p = memchr(buf, '\n', n);
891 len = p ? p - buf : n;
892
893 mutex_lock(&pm_mutex);
894 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
895 if (len == strlen(hibernation_modes[i])
896 && !strncmp(buf, hibernation_modes[i], len)) {
897 mode = i;
898 break;
899 }
900 }
901 if (mode != HIBERNATION_INVALID) {
902 switch (mode) {
903 case HIBERNATION_SHUTDOWN:
904 case HIBERNATION_REBOOT:
905 case HIBERNATION_TEST:
906 case HIBERNATION_TESTPROC:
907 hibernation_mode = mode;
908 break;
909 case HIBERNATION_PLATFORM:
910 if (hibernation_ops)
911 hibernation_mode = mode;
912 else
913 error = -EINVAL;
914 }
915 } else
916 error = -EINVAL;
917
918 if (!error)
919 pr_debug("PM: Hibernation mode set to '%s'\n",
920 hibernation_modes[mode]);
921 mutex_unlock(&pm_mutex);
922 return error ? error : n;
923}
924
925power_attr(disk);
926
927static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
928 char *buf)
929{
930 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
931 MINOR(swsusp_resume_device));
932}
933
934static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
935 const char *buf, size_t n)
936{
937 unsigned int maj, min;
938 dev_t res;
939 int ret = -EINVAL;
940
941 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
942 goto out;
943
944 res = MKDEV(maj,min);
945 if (maj != MAJOR(res) || min != MINOR(res))
946 goto out;
947
948 mutex_lock(&pm_mutex);
949 swsusp_resume_device = res;
950 mutex_unlock(&pm_mutex);
951 printk(KERN_INFO "PM: Starting manual resume from disk\n");
952 noresume = 0;
953 software_resume();
954 ret = n;
955 out:
956 return ret;
957}
958
959power_attr(resume);
960
961static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
962 char *buf)
963{
964 return sprintf(buf, "%lu\n", image_size);
965}
966
967static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
968 const char *buf, size_t n)
969{
970 unsigned long size;
971
972 if (sscanf(buf, "%lu", &size) == 1) {
973 image_size = size;
974 return n;
975 }
976
977 return -EINVAL;
978}
979
980power_attr(image_size);
981
982static ssize_t reserved_size_show(struct kobject *kobj,
983 struct kobj_attribute *attr, char *buf)
984{
985 return sprintf(buf, "%lu\n", reserved_size);
986}
987
988static ssize_t reserved_size_store(struct kobject *kobj,
989 struct kobj_attribute *attr,
990 const char *buf, size_t n)
991{
992 unsigned long size;
993
994 if (sscanf(buf, "%lu", &size) == 1) {
995 reserved_size = size;
996 return n;
997 }
998
999 return -EINVAL;
1000}
1001
1002power_attr(reserved_size);
1003
1004static struct attribute * g[] = {
1005 &disk_attr.attr,
1006 &resume_attr.attr,
1007 &image_size_attr.attr,
1008 &reserved_size_attr.attr,
1009 NULL,
1010};
1011
1012
1013static struct attribute_group attr_group = {
1014 .attrs = g,
1015};
1016
1017
1018static int __init pm_disk_init(void)
1019{
1020 return sysfs_create_group(power_kobj, &attr_group);
1021}
1022
1023core_initcall(pm_disk_init);
1024
1025
1026static int __init resume_setup(char *str)
1027{
1028 if (noresume)
1029 return 1;
1030
1031 strncpy( resume_file, str, 255 );
1032 return 1;
1033}
1034
1035static int __init resume_offset_setup(char *str)
1036{
1037 unsigned long long offset;
1038
1039 if (noresume)
1040 return 1;
1041
1042 if (sscanf(str, "%llu", &offset) == 1)
1043 swsusp_resume_block = offset;
1044
1045 return 1;
1046}
1047
1048static int __init hibernate_setup(char *str)
1049{
1050 if (!strncmp(str, "noresume", 8))
1051 noresume = 1;
1052 else if (!strncmp(str, "nocompress", 10))
1053 nocompress = 1;
1054 return 1;
1055}
1056
1057static int __init noresume_setup(char *str)
1058{
1059 noresume = 1;
1060 return 1;
1061}
1062
1063__setup("noresume", noresume_setup);
1064__setup("resume_offset=", resume_offset_setup);
1065__setup("resume=", resume_setup);
1066__setup("hibernate=", hibernate_setup);