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/export.h>
13 #include <linux/suspend.h>
14 #include <linux/syscalls.h>
15 #include <linux/reboot.h>
16 #include <linux/string.h>
17 #include <linux/device.h>
18 #include <linux/async.h>
19 #include <linux/kmod.h>
20 #include <linux/delay.h>
22 #include <linux/mount.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 <scsi/scsi_scan.h>
34 static int nocompress;
36 static int resume_wait;
37 static int resume_delay;
38 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
39 dev_t swsusp_resume_device;
40 sector_t swsusp_resume_block;
41 int in_suspend __nosavedata;
51 __HIBERNATION_AFTER_LAST
53 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
54 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
56 static int hibernation_mode = HIBERNATION_SHUTDOWN;
58 static const struct platform_hibernation_ops *hibernation_ops;
61 * hibernation_set_ops - Set the global hibernate operations.
62 * @ops: Hibernation operations to use in subsequent hibernation transitions.
64 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
66 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
67 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
68 && ops->restore_cleanup && ops->leave)) {
72 mutex_lock(&pm_mutex);
73 hibernation_ops = ops;
75 hibernation_mode = HIBERNATION_PLATFORM;
76 else if (hibernation_mode == HIBERNATION_PLATFORM)
77 hibernation_mode = HIBERNATION_SHUTDOWN;
79 mutex_unlock(&pm_mutex);
82 static bool entering_platform_hibernation;
84 bool system_entering_hibernation(void)
86 return entering_platform_hibernation;
88 EXPORT_SYMBOL(system_entering_hibernation);
90 #ifdef CONFIG_PM_DEBUG
91 static void hibernation_debug_sleep(void)
93 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
97 static int hibernation_testmode(int mode)
99 if (hibernation_mode == mode) {
100 hibernation_debug_sleep();
106 static int hibernation_test(int level)
108 if (pm_test_level == level) {
109 hibernation_debug_sleep();
114 #else /* !CONFIG_PM_DEBUG */
115 static int hibernation_testmode(int mode) { return 0; }
116 static int hibernation_test(int level) { return 0; }
117 #endif /* !CONFIG_PM_DEBUG */
120 * platform_begin - Call platform to start hibernation.
121 * @platform_mode: Whether or not to use the platform driver.
123 static int platform_begin(int platform_mode)
125 return (platform_mode && hibernation_ops) ?
126 hibernation_ops->begin() : 0;
130 * platform_end - Call platform to finish transition to the working state.
131 * @platform_mode: Whether or not to use the platform driver.
133 static void platform_end(int platform_mode)
135 if (platform_mode && hibernation_ops)
136 hibernation_ops->end();
140 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
141 * @platform_mode: Whether or not to use the platform driver.
143 * Use the platform driver to prepare the system for creating a hibernate image,
144 * if so configured, and return an error code if that fails.
147 static int platform_pre_snapshot(int platform_mode)
149 return (platform_mode && hibernation_ops) ?
150 hibernation_ops->pre_snapshot() : 0;
154 * platform_leave - Call platform to prepare a transition to the working state.
155 * @platform_mode: Whether or not to use the platform driver.
157 * Use the platform driver prepare to prepare the machine for switching to the
158 * normal mode of operation.
160 * This routine is called on one CPU with interrupts disabled.
162 static void platform_leave(int platform_mode)
164 if (platform_mode && hibernation_ops)
165 hibernation_ops->leave();
169 * platform_finish - Call platform to switch the system to the working state.
170 * @platform_mode: Whether or not to use the platform driver.
172 * Use the platform driver to switch the machine to the normal mode of
175 * This routine must be called after platform_prepare().
177 static void platform_finish(int platform_mode)
179 if (platform_mode && hibernation_ops)
180 hibernation_ops->finish();
184 * platform_pre_restore - Prepare for hibernate image restoration.
185 * @platform_mode: Whether or not to use the platform driver.
187 * Use the platform driver to prepare the system for resume from a hibernation
190 * If the restore fails after this function has been called,
191 * platform_restore_cleanup() must be called.
193 static int platform_pre_restore(int platform_mode)
195 return (platform_mode && hibernation_ops) ?
196 hibernation_ops->pre_restore() : 0;
200 * platform_restore_cleanup - Switch to the working state after failing restore.
201 * @platform_mode: Whether or not to use the platform driver.
203 * Use the platform driver to switch the system to the normal mode of operation
204 * after a failing restore.
206 * If platform_pre_restore() has been called before the failing restore, this
207 * function must be called too, regardless of the result of
208 * platform_pre_restore().
210 static void platform_restore_cleanup(int platform_mode)
212 if (platform_mode && hibernation_ops)
213 hibernation_ops->restore_cleanup();
217 * platform_recover - Recover from a failure to suspend devices.
218 * @platform_mode: Whether or not to use the platform driver.
220 static void platform_recover(int platform_mode)
222 if (platform_mode && hibernation_ops && hibernation_ops->recover)
223 hibernation_ops->recover();
227 * swsusp_show_speed - Print time elapsed between two events during hibernation.
228 * @start: Starting event.
229 * @stop: Final event.
230 * @nr_pages: Number of memory pages processed between @start and @stop.
231 * @msg: Additional diagnostic message to print.
233 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
234 unsigned nr_pages, char *msg)
236 s64 elapsed_centisecs64;
241 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
242 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
243 centisecs = elapsed_centisecs64;
245 centisecs = 1; /* avoid div-by-zero */
246 k = nr_pages * (PAGE_SIZE / 1024);
247 kps = (k * 100) / centisecs;
248 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
250 centisecs / 100, centisecs % 100,
251 kps / 1000, (kps % 1000) / 10);
255 * create_image - Create a hibernation image.
256 * @platform_mode: Whether or not to use the platform driver.
258 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
259 * and execute the drivers' .thaw_noirq() callbacks.
261 * Control reappears in this routine after the subsequent restore.
263 static int create_image(int platform_mode)
267 error = dpm_suspend_noirq(PMSG_FREEZE);
269 printk(KERN_ERR "PM: Some devices failed to power down, "
270 "aborting hibernation\n");
274 error = platform_pre_snapshot(platform_mode);
275 if (error || hibernation_test(TEST_PLATFORM))
276 goto Platform_finish;
278 error = disable_nonboot_cpus();
279 if (error || hibernation_test(TEST_CPUS)
280 || hibernation_testmode(HIBERNATION_TEST))
285 error = syscore_suspend();
287 printk(KERN_ERR "PM: Some system devices failed to power down, "
288 "aborting hibernation\n");
292 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
296 save_processor_state();
297 error = swsusp_arch_suspend();
299 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
301 /* Restore control flow magically appears here */
302 restore_processor_state();
304 events_check_enabled = false;
305 platform_leave(platform_mode);
315 enable_nonboot_cpus();
318 platform_finish(platform_mode);
320 dpm_resume_noirq(in_suspend ?
321 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
327 * hibernation_snapshot - Quiesce devices and create a hibernation image.
328 * @platform_mode: If set, use platform driver to prepare for the transition.
330 * This routine must be called with pm_mutex held.
332 int hibernation_snapshot(int platform_mode)
334 pm_message_t msg = PMSG_RECOVER;
337 error = platform_begin(platform_mode);
341 /* Preallocate image memory before shutting down devices. */
342 error = hibernate_preallocate_memory();
346 error = freeze_kernel_threads();
350 error = dpm_prepare(PMSG_FREEZE);
352 goto Complete_devices;
355 pm_restrict_gfp_mask();
356 error = dpm_suspend(PMSG_FREEZE);
358 goto Recover_platform;
360 if (hibernation_test(TEST_DEVICES))
361 goto Recover_platform;
363 error = create_image(platform_mode);
365 * Control returns here (1) after the image has been created or the
366 * image creation has failed and (2) after a successful restore.
370 /* We may need to release the preallocated image pages here. */
371 if (error || !in_suspend)
374 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
377 if (error || !in_suspend)
378 pm_restore_gfp_mask();
386 platform_end(platform_mode);
390 platform_recover(platform_mode);
395 * resume_target_kernel - Restore system state from a hibernation image.
396 * @platform_mode: Whether or not to use the platform driver.
398 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
399 * highmem that have not been restored yet from the image and run the low-level
400 * code that will restore the remaining contents of memory and switch to the
401 * just restored target kernel.
403 static int resume_target_kernel(bool platform_mode)
407 error = dpm_suspend_noirq(PMSG_QUIESCE);
409 printk(KERN_ERR "PM: Some devices failed to power down, "
410 "aborting resume\n");
414 error = platform_pre_restore(platform_mode);
418 error = disable_nonboot_cpus();
424 error = syscore_suspend();
428 save_processor_state();
429 error = restore_highmem();
431 error = swsusp_arch_resume();
433 * The code below is only ever reached in case of a failure.
434 * Otherwise, execution continues at the place where
435 * swsusp_arch_suspend() was called.
439 * This call to restore_highmem() reverts the changes made by
445 * The only reason why swsusp_arch_resume() can fail is memory being
446 * very tight, so we have to free it as soon as we can to avoid
447 * subsequent failures.
450 restore_processor_state();
451 touch_softlockup_watchdog();
459 enable_nonboot_cpus();
462 platform_restore_cleanup(platform_mode);
464 dpm_resume_noirq(PMSG_RECOVER);
470 * hibernation_restore - Quiesce devices and restore from a hibernation image.
471 * @platform_mode: If set, use platform driver to prepare for the transition.
473 * This routine must be called with pm_mutex held. If it is successful, control
474 * reappears in the restored target kernel in hibernation_snapshot().
476 int hibernation_restore(int platform_mode)
480 pm_prepare_console();
482 pm_restrict_gfp_mask();
483 error = dpm_suspend_start(PMSG_QUIESCE);
485 error = resume_target_kernel(platform_mode);
486 dpm_resume_end(PMSG_RECOVER);
488 pm_restore_gfp_mask();
490 pm_restore_console();
495 * hibernation_platform_enter - Power off the system using the platform driver.
497 int hibernation_platform_enter(void)
501 if (!hibernation_ops)
505 * We have cancelled the power transition by running
506 * hibernation_ops->finish() before saving the image, so we should let
507 * the firmware know that we're going to enter the sleep state after all
509 error = hibernation_ops->begin();
513 entering_platform_hibernation = true;
515 error = dpm_suspend_start(PMSG_HIBERNATE);
517 if (hibernation_ops->recover)
518 hibernation_ops->recover();
522 error = dpm_suspend_noirq(PMSG_HIBERNATE);
526 error = hibernation_ops->prepare();
528 goto Platform_finish;
530 error = disable_nonboot_cpus();
532 goto Platform_finish;
536 if (pm_wakeup_pending()) {
541 hibernation_ops->enter();
542 /* We should never get here */
548 enable_nonboot_cpus();
551 hibernation_ops->finish();
553 dpm_resume_noirq(PMSG_RESTORE);
556 entering_platform_hibernation = false;
557 dpm_resume_end(PMSG_RESTORE);
561 hibernation_ops->end();
567 * power_down - Shut the machine down for hibernation.
569 * Use the platform driver, if configured, to put the system into the sleep
570 * state corresponding to hibernation, or try to power it off or reboot,
571 * depending on the value of hibernation_mode.
573 static void power_down(void)
575 switch (hibernation_mode) {
576 case HIBERNATION_TEST:
577 case HIBERNATION_TESTPROC:
579 case HIBERNATION_REBOOT:
580 kernel_restart(NULL);
582 case HIBERNATION_PLATFORM:
583 hibernation_platform_enter();
584 case HIBERNATION_SHUTDOWN:
590 * Valid image is on the disk, if we continue we risk serious data
591 * corruption after resume.
593 printk(KERN_CRIT "PM: Please power down manually\n");
597 static int prepare_processes(void)
601 if (freeze_processes()) {
609 * hibernate - Carry out system hibernation, including saving the image.
615 mutex_lock(&pm_mutex);
616 /* The snapshot device should not be opened while we're running */
617 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
622 pm_prepare_console();
623 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
627 error = usermodehelper_disable();
631 /* Allocate memory management structures */
632 error = create_basic_memory_bitmaps();
636 printk(KERN_INFO "PM: Syncing filesystems ... ");
640 error = prepare_processes();
644 if (hibernation_test(TEST_FREEZER))
647 if (hibernation_testmode(HIBERNATION_TESTPROC))
650 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
655 unsigned int flags = 0;
657 if (hibernation_mode == HIBERNATION_PLATFORM)
658 flags |= SF_PLATFORM_MODE;
660 flags |= SF_NOCOMPRESS_MODE;
662 flags |= SF_CRC32_MODE;
664 pr_debug("PM: writing image.\n");
665 error = swsusp_write(flags);
670 pm_restore_gfp_mask();
672 pr_debug("PM: Image restored successfully.\n");
678 free_basic_memory_bitmaps();
679 usermodehelper_enable();
681 pm_notifier_call_chain(PM_POST_HIBERNATION);
682 pm_restore_console();
683 atomic_inc(&snapshot_device_available);
685 mutex_unlock(&pm_mutex);
691 * software_resume - Resume from a saved hibernation image.
693 * This routine is called as a late initcall, when all devices have been
694 * discovered and initialized already.
696 * The image reading code is called to see if there is a hibernation image
697 * available for reading. If that is the case, devices are quiesced and the
698 * contents of memory is restored from the saved image.
700 * If this is successful, control reappears in the restored target kernel in
701 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
702 * attempts to recover gracefully and make the kernel return to the normal mode
705 static int software_resume(void)
711 * If the user said "noresume".. bail out early.
717 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
718 * is configured into the kernel. Since the regular hibernate
719 * trigger path is via sysfs which takes a buffer mutex before
720 * calling hibernate functions (which take pm_mutex) this can
721 * cause lockdep to complain about a possible ABBA deadlock
722 * which cannot happen since we're in the boot code here and
723 * sysfs can't be invoked yet. Therefore, we use a subclass
724 * here to avoid lockdep complaining.
726 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
728 if (swsusp_resume_device)
731 if (!strlen(resume_file)) {
736 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
739 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
741 ssleep(resume_delay);
744 /* Check if the device is there */
745 swsusp_resume_device = name_to_dev_t(resume_file);
746 if (!swsusp_resume_device) {
748 * Some device discovery might still be in progress; we need
749 * to wait for this to finish.
751 wait_for_device_probe();
754 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
756 async_synchronize_full();
760 * We can't depend on SCSI devices being available after loading
761 * one of their modules until scsi_complete_async_scans() is
762 * called and the resume device usually is a SCSI one.
764 scsi_complete_async_scans();
766 swsusp_resume_device = name_to_dev_t(resume_file);
767 if (!swsusp_resume_device) {
774 pr_debug("PM: Hibernation image partition %d:%d present\n",
775 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
777 pr_debug("PM: Looking for hibernation image.\n");
778 error = swsusp_check();
782 /* The snapshot device should not be opened while we're running */
783 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
785 swsusp_close(FMODE_READ);
789 pm_prepare_console();
790 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
794 error = usermodehelper_disable();
798 error = create_basic_memory_bitmaps();
802 pr_debug("PM: Preparing processes for restore.\n");
803 error = prepare_processes();
805 swsusp_close(FMODE_READ);
809 pr_debug("PM: Loading hibernation image.\n");
811 error = swsusp_read(&flags);
812 swsusp_close(FMODE_READ);
814 hibernation_restore(flags & SF_PLATFORM_MODE);
816 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
820 free_basic_memory_bitmaps();
821 usermodehelper_enable();
823 pm_notifier_call_chain(PM_POST_RESTORE);
824 pm_restore_console();
825 atomic_inc(&snapshot_device_available);
826 /* For success case, the suspend path will release the lock */
828 mutex_unlock(&pm_mutex);
829 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
832 swsusp_close(FMODE_READ);
836 late_initcall(software_resume);
839 static const char * const hibernation_modes[] = {
840 [HIBERNATION_PLATFORM] = "platform",
841 [HIBERNATION_SHUTDOWN] = "shutdown",
842 [HIBERNATION_REBOOT] = "reboot",
843 [HIBERNATION_TEST] = "test",
844 [HIBERNATION_TESTPROC] = "testproc",
848 * /sys/power/disk - Control hibernation mode.
850 * Hibernation can be handled in several ways. There are a few different ways
851 * to put the system into the sleep state: using the platform driver (e.g. ACPI
852 * or other hibernation_ops), powering it off or rebooting it (for testing
853 * mostly), or using one of the two available test modes.
855 * The sysfs file /sys/power/disk provides an interface for selecting the
856 * hibernation mode to use. Reading from this file causes the available modes
857 * to be printed. There are 5 modes that can be supported:
865 * If a platform hibernation driver is in use, 'platform' will be supported
866 * and will be used by default. Otherwise, 'shutdown' will be used by default.
867 * The selected option (i.e. the one corresponding to the current value of
868 * hibernation_mode) is enclosed by a square bracket.
870 * To select a given hibernation mode it is necessary to write the mode's
871 * string representation (as returned by reading from /sys/power/disk) back
872 * into /sys/power/disk.
875 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
881 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
882 if (!hibernation_modes[i])
885 case HIBERNATION_SHUTDOWN:
886 case HIBERNATION_REBOOT:
887 case HIBERNATION_TEST:
888 case HIBERNATION_TESTPROC:
890 case HIBERNATION_PLATFORM:
893 /* not a valid mode, continue with loop */
896 if (i == hibernation_mode)
897 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
899 buf += sprintf(buf, "%s ", hibernation_modes[i]);
901 buf += sprintf(buf, "\n");
905 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
906 const char *buf, size_t n)
912 int mode = HIBERNATION_INVALID;
914 p = memchr(buf, '\n', n);
915 len = p ? p - buf : n;
917 mutex_lock(&pm_mutex);
918 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
919 if (len == strlen(hibernation_modes[i])
920 && !strncmp(buf, hibernation_modes[i], len)) {
925 if (mode != HIBERNATION_INVALID) {
927 case HIBERNATION_SHUTDOWN:
928 case HIBERNATION_REBOOT:
929 case HIBERNATION_TEST:
930 case HIBERNATION_TESTPROC:
931 hibernation_mode = mode;
933 case HIBERNATION_PLATFORM:
935 hibernation_mode = mode;
943 pr_debug("PM: Hibernation mode set to '%s'\n",
944 hibernation_modes[mode]);
945 mutex_unlock(&pm_mutex);
946 return error ? error : n;
951 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
954 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
955 MINOR(swsusp_resume_device));
958 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
959 const char *buf, size_t n)
961 unsigned int maj, min;
965 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
968 res = MKDEV(maj,min);
969 if (maj != MAJOR(res) || min != MINOR(res))
972 mutex_lock(&pm_mutex);
973 swsusp_resume_device = res;
974 mutex_unlock(&pm_mutex);
975 printk(KERN_INFO "PM: Starting manual resume from disk\n");
985 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
988 return sprintf(buf, "%lu\n", image_size);
991 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
992 const char *buf, size_t n)
996 if (sscanf(buf, "%lu", &size) == 1) {
1004 power_attr(image_size);
1006 static ssize_t reserved_size_show(struct kobject *kobj,
1007 struct kobj_attribute *attr, char *buf)
1009 return sprintf(buf, "%lu\n", reserved_size);
1012 static ssize_t reserved_size_store(struct kobject *kobj,
1013 struct kobj_attribute *attr,
1014 const char *buf, size_t n)
1018 if (sscanf(buf, "%lu", &size) == 1) {
1019 reserved_size = size;
1026 power_attr(reserved_size);
1028 static struct attribute * g[] = {
1031 &image_size_attr.attr,
1032 &reserved_size_attr.attr,
1037 static struct attribute_group attr_group = {
1042 static int __init pm_disk_init(void)
1044 return sysfs_create_group(power_kobj, &attr_group);
1047 core_initcall(pm_disk_init);
1050 static int __init resume_setup(char *str)
1055 strncpy( resume_file, str, 255 );
1059 static int __init resume_offset_setup(char *str)
1061 unsigned long long offset;
1066 if (sscanf(str, "%llu", &offset) == 1)
1067 swsusp_resume_block = offset;
1072 static int __init hibernate_setup(char *str)
1074 if (!strncmp(str, "noresume", 8))
1076 else if (!strncmp(str, "nocompress", 10))
1081 static int __init noresume_setup(char *str)
1087 static int __init resumewait_setup(char *str)
1093 static int __init resumedelay_setup(char *str)
1095 resume_delay = simple_strtoul(str, NULL, 0);
1099 __setup("noresume", noresume_setup);
1100 __setup("resume_offset=", resume_offset_setup);
1101 __setup("resume=", resume_setup);
1102 __setup("hibernate=", hibernate_setup);
1103 __setup("resumewait", resumewait_setup);
1104 __setup("resumedelay=", resumedelay_setup);