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