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