2 * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
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.
9 * This file is released under the GPLv2.
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>
20 #include <linux/mount.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 #include <asm/suspend.h>
33 static int nocompress = 0;
34 static int noresume = 0;
35 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
36 dev_t swsusp_resume_device;
37 sector_t swsusp_resume_block;
38 int in_suspend __nosavedata = 0;
48 __HIBERNATION_AFTER_LAST
50 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
51 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
53 static int hibernation_mode = HIBERNATION_SHUTDOWN;
55 static const struct platform_hibernation_ops *hibernation_ops;
58 * hibernation_set_ops - set the global hibernate operations
59 * @ops: the hibernation operations to use in subsequent hibernation transitions
62 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
64 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
65 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
66 && ops->restore_cleanup && ops->leave)) {
70 mutex_lock(&pm_mutex);
71 hibernation_ops = ops;
73 hibernation_mode = HIBERNATION_PLATFORM;
74 else if (hibernation_mode == HIBERNATION_PLATFORM)
75 hibernation_mode = HIBERNATION_SHUTDOWN;
77 mutex_unlock(&pm_mutex);
80 static bool entering_platform_hibernation;
82 bool system_entering_hibernation(void)
84 return entering_platform_hibernation;
86 EXPORT_SYMBOL(system_entering_hibernation);
88 #ifdef CONFIG_PM_DEBUG
89 static void hibernation_debug_sleep(void)
91 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
95 static int hibernation_testmode(int mode)
97 if (hibernation_mode == mode) {
98 hibernation_debug_sleep();
104 static int hibernation_test(int level)
106 if (pm_test_level == level) {
107 hibernation_debug_sleep();
112 #else /* !CONFIG_PM_DEBUG */
113 static int hibernation_testmode(int mode) { return 0; }
114 static int hibernation_test(int level) { return 0; }
115 #endif /* !CONFIG_PM_DEBUG */
118 * platform_begin - tell the platform driver that we're starting
122 static int platform_begin(int platform_mode)
124 return (platform_mode && hibernation_ops) ?
125 hibernation_ops->begin() : 0;
129 * platform_end - tell the platform driver that we've entered the
133 static void platform_end(int platform_mode)
135 if (platform_mode && hibernation_ops)
136 hibernation_ops->end();
140 * platform_pre_snapshot - prepare the machine for hibernation using the
141 * platform driver if so configured and return an error code if it fails
144 static int platform_pre_snapshot(int platform_mode)
146 return (platform_mode && hibernation_ops) ?
147 hibernation_ops->pre_snapshot() : 0;
151 * platform_leave - prepare the machine for switching to the normal mode
152 * of operation using the platform driver (called with interrupts disabled)
155 static void platform_leave(int platform_mode)
157 if (platform_mode && hibernation_ops)
158 hibernation_ops->leave();
162 * platform_finish - switch the machine to the normal mode of operation
163 * using the platform driver (must be called after platform_prepare())
166 static void platform_finish(int platform_mode)
168 if (platform_mode && hibernation_ops)
169 hibernation_ops->finish();
173 * platform_pre_restore - prepare the platform for the restoration from a
174 * hibernation image. If the restore fails after this function has been
175 * called, platform_restore_cleanup() must be called.
178 static int platform_pre_restore(int platform_mode)
180 return (platform_mode && hibernation_ops) ?
181 hibernation_ops->pre_restore() : 0;
185 * platform_restore_cleanup - switch the platform to the normal mode of
186 * operation after a failing restore. If platform_pre_restore() has been
187 * called before the failing restore, this function must be called too,
188 * regardless of the result of platform_pre_restore().
191 static void platform_restore_cleanup(int platform_mode)
193 if (platform_mode && hibernation_ops)
194 hibernation_ops->restore_cleanup();
198 * platform_recover - recover the platform from a failure to suspend
202 static void platform_recover(int platform_mode)
204 if (platform_mode && hibernation_ops && hibernation_ops->recover)
205 hibernation_ops->recover();
209 * swsusp_show_speed - print the time elapsed between two events.
210 * @start: Starting event.
211 * @stop: Final event.
212 * @nr_pages - number of pages processed between @start and @stop
213 * @msg - introductory message to print
216 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
217 unsigned nr_pages, char *msg)
219 s64 elapsed_centisecs64;
224 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
225 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
226 centisecs = elapsed_centisecs64;
228 centisecs = 1; /* avoid div-by-zero */
229 k = nr_pages * (PAGE_SIZE / 1024);
230 kps = (k * 100) / centisecs;
231 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
233 centisecs / 100, centisecs % 100,
234 kps / 1000, (kps % 1000) / 10);
238 * create_image - freeze devices that need to be frozen with interrupts
239 * off, create the hibernation image and thaw those devices. Control
240 * reappears in this routine after a restore.
243 static int create_image(int platform_mode)
247 error = arch_prepare_suspend();
251 error = dpm_suspend_noirq(PMSG_FREEZE);
253 printk(KERN_ERR "PM: Some devices failed to power down, "
254 "aborting hibernation\n");
258 error = platform_pre_snapshot(platform_mode);
259 if (error || hibernation_test(TEST_PLATFORM))
260 goto Platform_finish;
262 error = disable_nonboot_cpus();
263 if (error || hibernation_test(TEST_CPUS)
264 || hibernation_testmode(HIBERNATION_TEST))
269 error = syscore_suspend();
271 printk(KERN_ERR "PM: Some system devices failed to power down, "
272 "aborting hibernation\n");
276 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
280 save_processor_state();
281 error = swsusp_arch_suspend();
283 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
285 /* Restore control flow magically appears here */
286 restore_processor_state();
288 events_check_enabled = false;
289 platform_leave(platform_mode);
299 enable_nonboot_cpus();
302 platform_finish(platform_mode);
304 dpm_resume_noirq(in_suspend ?
305 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
311 * hibernation_snapshot - quiesce devices and create the hibernation
313 * @platform_mode - if set, use the platform driver, if available, to
314 * prepare the platform firmware for the power transition.
316 * Must be called with pm_mutex held
319 int hibernation_snapshot(int platform_mode)
321 pm_message_t msg = PMSG_RECOVER;
324 error = platform_begin(platform_mode);
328 error = dpm_prepare(PMSG_FREEZE);
330 goto Complete_devices;
332 /* Preallocate image memory before shutting down devices. */
333 error = hibernate_preallocate_memory();
335 goto Complete_devices;
338 pm_restrict_gfp_mask();
339 error = dpm_suspend(PMSG_FREEZE);
341 goto Recover_platform;
343 if (hibernation_test(TEST_DEVICES))
344 goto Recover_platform;
346 error = create_image(platform_mode);
348 * Control returns here (1) after the image has been created or the
349 * image creation has failed and (2) after a successful restore.
353 /* We may need to release the preallocated image pages here. */
354 if (error || !in_suspend)
357 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
360 if (error || !in_suspend)
361 pm_restore_gfp_mask();
369 platform_end(platform_mode);
373 platform_recover(platform_mode);
378 * resume_target_kernel - prepare devices that need to be suspended with
379 * interrupts off, restore the contents of highmem that have not been
380 * restored yet from the image and run the low level code that will restore
381 * the remaining contents of memory and switch to the just restored target
385 static int resume_target_kernel(bool platform_mode)
389 error = dpm_suspend_noirq(PMSG_QUIESCE);
391 printk(KERN_ERR "PM: Some devices failed to power down, "
392 "aborting resume\n");
396 error = platform_pre_restore(platform_mode);
400 error = disable_nonboot_cpus();
406 error = syscore_suspend();
410 save_processor_state();
411 error = restore_highmem();
413 error = swsusp_arch_resume();
415 * The code below is only ever reached in case of a failure.
416 * Otherwise, execution continues at the place where
417 * swsusp_arch_suspend() was called.
421 * This call to restore_highmem() reverts the changes made by
427 * The only reason why swsusp_arch_resume() can fail is memory being
428 * very tight, so we have to free it as soon as we can to avoid
429 * subsequent failures.
432 restore_processor_state();
433 touch_softlockup_watchdog();
441 enable_nonboot_cpus();
444 platform_restore_cleanup(platform_mode);
446 dpm_resume_noirq(PMSG_RECOVER);
452 * hibernation_restore - quiesce devices and restore the hibernation
453 * snapshot image. If successful, control returns in hibernation_snaphot()
454 * @platform_mode - if set, use the platform driver, if available, to
455 * prepare the platform firmware for the transition.
457 * Must be called with pm_mutex held
460 int hibernation_restore(int platform_mode)
464 pm_prepare_console();
466 pm_restrict_gfp_mask();
467 error = dpm_suspend_start(PMSG_QUIESCE);
469 error = resume_target_kernel(platform_mode);
470 dpm_resume_end(PMSG_RECOVER);
472 pm_restore_gfp_mask();
474 pm_restore_console();
479 * hibernation_platform_enter - enter the hibernation state using the
480 * platform driver (if available)
483 int hibernation_platform_enter(void)
487 if (!hibernation_ops)
491 * We have cancelled the power transition by running
492 * hibernation_ops->finish() before saving the image, so we should let
493 * the firmware know that we're going to enter the sleep state after all
495 error = hibernation_ops->begin();
499 entering_platform_hibernation = true;
501 error = dpm_suspend_start(PMSG_HIBERNATE);
503 if (hibernation_ops->recover)
504 hibernation_ops->recover();
508 error = dpm_suspend_noirq(PMSG_HIBERNATE);
512 error = hibernation_ops->prepare();
514 goto Platform_finish;
516 error = disable_nonboot_cpus();
518 goto Platform_finish;
522 if (pm_wakeup_pending()) {
527 hibernation_ops->enter();
528 /* We should never get here */
534 enable_nonboot_cpus();
537 hibernation_ops->finish();
539 dpm_resume_noirq(PMSG_RESTORE);
542 entering_platform_hibernation = false;
543 dpm_resume_end(PMSG_RESTORE);
547 hibernation_ops->end();
553 * power_down - Shut the machine down for hibernation.
555 * Use the platform driver, if configured so; otherwise try
556 * to power off or reboot.
559 static void power_down(void)
561 switch (hibernation_mode) {
562 case HIBERNATION_TEST:
563 case HIBERNATION_TESTPROC:
565 case HIBERNATION_REBOOT:
566 kernel_restart(NULL);
568 case HIBERNATION_PLATFORM:
569 hibernation_platform_enter();
570 case HIBERNATION_SHUTDOWN:
576 * Valid image is on the disk, if we continue we risk serious data
577 * corruption after resume.
579 printk(KERN_CRIT "PM: Please power down manually\n");
583 static int prepare_processes(void)
587 if (freeze_processes()) {
595 * hibernate - The granpappy of the built-in hibernation management
602 mutex_lock(&pm_mutex);
603 /* The snapshot device should not be opened while we're running */
604 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
609 pm_prepare_console();
610 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
614 error = usermodehelper_disable();
618 /* Allocate memory management structures */
619 error = create_basic_memory_bitmaps();
623 printk(KERN_INFO "PM: Syncing filesystems ... ");
627 error = prepare_processes();
631 if (hibernation_test(TEST_FREEZER))
634 if (hibernation_testmode(HIBERNATION_TESTPROC))
637 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
642 unsigned int flags = 0;
644 if (hibernation_mode == HIBERNATION_PLATFORM)
645 flags |= SF_PLATFORM_MODE;
647 flags |= SF_NOCOMPRESS_MODE;
648 pr_debug("PM: writing image.\n");
649 error = swsusp_write(flags);
654 pm_restore_gfp_mask();
656 pr_debug("PM: Image restored successfully.\n");
662 free_basic_memory_bitmaps();
663 usermodehelper_enable();
665 pm_notifier_call_chain(PM_POST_HIBERNATION);
666 pm_restore_console();
667 atomic_inc(&snapshot_device_available);
669 mutex_unlock(&pm_mutex);
675 * software_resume - Resume from a saved image.
677 * Called as a late_initcall (so all devices are discovered and
678 * initialized), we call swsusp to see if we have a saved image or not.
679 * If so, we quiesce devices, the restore the saved image. We will
680 * return above (in hibernate() ) if everything goes well.
681 * Otherwise, we fail gracefully and return to the normally
686 static int software_resume(void)
692 * If the user said "noresume".. bail out early.
698 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
699 * is configured into the kernel. Since the regular hibernate
700 * trigger path is via sysfs which takes a buffer mutex before
701 * calling hibernate functions (which take pm_mutex) this can
702 * cause lockdep to complain about a possible ABBA deadlock
703 * which cannot happen since we're in the boot code here and
704 * sysfs can't be invoked yet. Therefore, we use a subclass
705 * here to avoid lockdep complaining.
707 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
709 if (swsusp_resume_device)
712 if (!strlen(resume_file)) {
717 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
719 /* Check if the device is there */
720 swsusp_resume_device = name_to_dev_t(resume_file);
721 if (!swsusp_resume_device) {
723 * Some device discovery might still be in progress; we need
724 * to wait for this to finish.
726 wait_for_device_probe();
728 * We can't depend on SCSI devices being available after loading
729 * one of their modules until scsi_complete_async_scans() is
730 * called and the resume device usually is a SCSI one.
732 scsi_complete_async_scans();
734 swsusp_resume_device = name_to_dev_t(resume_file);
735 if (!swsusp_resume_device) {
742 pr_debug("PM: Hibernation image partition %d:%d present\n",
743 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
745 pr_debug("PM: Looking for hibernation image.\n");
746 error = swsusp_check();
750 /* The snapshot device should not be opened while we're running */
751 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
753 swsusp_close(FMODE_READ);
757 pm_prepare_console();
758 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
762 error = usermodehelper_disable();
766 error = create_basic_memory_bitmaps();
770 pr_debug("PM: Preparing processes for restore.\n");
771 error = prepare_processes();
773 swsusp_close(FMODE_READ);
777 pr_debug("PM: Loading hibernation image.\n");
779 error = swsusp_read(&flags);
780 swsusp_close(FMODE_READ);
782 hibernation_restore(flags & SF_PLATFORM_MODE);
784 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
788 free_basic_memory_bitmaps();
789 usermodehelper_enable();
791 pm_notifier_call_chain(PM_POST_RESTORE);
792 pm_restore_console();
793 atomic_inc(&snapshot_device_available);
794 /* For success case, the suspend path will release the lock */
796 mutex_unlock(&pm_mutex);
797 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
800 swsusp_close(FMODE_READ);
804 late_initcall(software_resume);
807 static const char * const hibernation_modes[] = {
808 [HIBERNATION_PLATFORM] = "platform",
809 [HIBERNATION_SHUTDOWN] = "shutdown",
810 [HIBERNATION_REBOOT] = "reboot",
811 [HIBERNATION_TEST] = "test",
812 [HIBERNATION_TESTPROC] = "testproc",
816 * disk - Control hibernation mode
818 * Suspend-to-disk can be handled in several ways. We have a few options
819 * for putting the system to sleep - using the platform driver (e.g. ACPI
820 * or other hibernation_ops), powering off the system or rebooting the
821 * system (for testing) as well as the two test modes.
823 * The system can support 'platform', and that is known a priori (and
824 * encoded by the presence of hibernation_ops). However, the user may
825 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
826 * test modes, 'test' or 'testproc'.
828 * show() will display what the mode is currently set to.
829 * store() will accept one of
837 * It will only change to 'platform' if the system
838 * supports it (as determined by having hibernation_ops).
841 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
847 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
848 if (!hibernation_modes[i])
851 case HIBERNATION_SHUTDOWN:
852 case HIBERNATION_REBOOT:
853 case HIBERNATION_TEST:
854 case HIBERNATION_TESTPROC:
856 case HIBERNATION_PLATFORM:
859 /* not a valid mode, continue with loop */
862 if (i == hibernation_mode)
863 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
865 buf += sprintf(buf, "%s ", hibernation_modes[i]);
867 buf += sprintf(buf, "\n");
872 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
873 const char *buf, size_t n)
879 int mode = HIBERNATION_INVALID;
881 p = memchr(buf, '\n', n);
882 len = p ? p - buf : n;
884 mutex_lock(&pm_mutex);
885 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
886 if (len == strlen(hibernation_modes[i])
887 && !strncmp(buf, hibernation_modes[i], len)) {
892 if (mode != HIBERNATION_INVALID) {
894 case HIBERNATION_SHUTDOWN:
895 case HIBERNATION_REBOOT:
896 case HIBERNATION_TEST:
897 case HIBERNATION_TESTPROC:
898 hibernation_mode = mode;
900 case HIBERNATION_PLATFORM:
902 hibernation_mode = mode;
910 pr_debug("PM: Hibernation mode set to '%s'\n",
911 hibernation_modes[mode]);
912 mutex_unlock(&pm_mutex);
913 return error ? error : n;
918 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
921 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
922 MINOR(swsusp_resume_device));
925 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
926 const char *buf, size_t n)
928 unsigned int maj, min;
932 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
935 res = MKDEV(maj,min);
936 if (maj != MAJOR(res) || min != MINOR(res))
939 mutex_lock(&pm_mutex);
940 swsusp_resume_device = res;
941 mutex_unlock(&pm_mutex);
942 printk(KERN_INFO "PM: Starting manual resume from disk\n");
952 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
955 return sprintf(buf, "%lu\n", image_size);
958 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
959 const char *buf, size_t n)
963 if (sscanf(buf, "%lu", &size) == 1) {
971 power_attr(image_size);
973 static ssize_t reserved_size_show(struct kobject *kobj,
974 struct kobj_attribute *attr, char *buf)
976 return sprintf(buf, "%lu\n", reserved_size);
979 static ssize_t reserved_size_store(struct kobject *kobj,
980 struct kobj_attribute *attr,
981 const char *buf, size_t n)
985 if (sscanf(buf, "%lu", &size) == 1) {
986 reserved_size = size;
993 power_attr(reserved_size);
995 static struct attribute * g[] = {
998 &image_size_attr.attr,
999 &reserved_size_attr.attr,
1004 static struct attribute_group attr_group = {
1009 static int __init pm_disk_init(void)
1011 return sysfs_create_group(power_kobj, &attr_group);
1014 core_initcall(pm_disk_init);
1017 static int __init resume_setup(char *str)
1022 strncpy( resume_file, str, 255 );
1026 static int __init resume_offset_setup(char *str)
1028 unsigned long long offset;
1033 if (sscanf(str, "%llu", &offset) == 1)
1034 swsusp_resume_block = offset;
1039 static int __init hibernate_setup(char *str)
1041 if (!strncmp(str, "noresume", 8))
1043 else if (!strncmp(str, "nocompress", 10))
1048 static int __init noresume_setup(char *str)
1054 __setup("noresume", noresume_setup);
1055 __setup("resume_offset=", resume_offset_setup);
1056 __setup("resume=", resume_setup);
1057 __setup("hibernate=", hibernate_setup);