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