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