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 bool freezer_test_done;
60 static const struct platform_hibernation_ops *hibernation_ops;
63 * hibernation_set_ops - Set the global hibernate operations.
64 * @ops: Hibernation operations to use in subsequent hibernation transitions.
66 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
68 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
69 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
70 && ops->restore_cleanup && ops->leave)) {
74 mutex_lock(&pm_mutex);
75 hibernation_ops = ops;
77 hibernation_mode = HIBERNATION_PLATFORM;
78 else if (hibernation_mode == HIBERNATION_PLATFORM)
79 hibernation_mode = HIBERNATION_SHUTDOWN;
81 mutex_unlock(&pm_mutex);
84 static bool entering_platform_hibernation;
86 bool system_entering_hibernation(void)
88 return entering_platform_hibernation;
90 EXPORT_SYMBOL(system_entering_hibernation);
92 #ifdef CONFIG_PM_DEBUG
93 static void hibernation_debug_sleep(void)
95 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
99 static int hibernation_testmode(int mode)
101 if (hibernation_mode == mode) {
102 hibernation_debug_sleep();
108 static int hibernation_test(int level)
110 if (pm_test_level == level) {
111 hibernation_debug_sleep();
116 #else /* !CONFIG_PM_DEBUG */
117 static int hibernation_testmode(int mode) { return 0; }
118 static int hibernation_test(int level) { return 0; }
119 #endif /* !CONFIG_PM_DEBUG */
122 * platform_begin - Call platform to start hibernation.
123 * @platform_mode: Whether or not to use the platform driver.
125 static int platform_begin(int platform_mode)
127 return (platform_mode && hibernation_ops) ?
128 hibernation_ops->begin() : 0;
132 * platform_end - Call platform to finish transition to the working state.
133 * @platform_mode: Whether or not to use the platform driver.
135 static void platform_end(int platform_mode)
137 if (platform_mode && hibernation_ops)
138 hibernation_ops->end();
142 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
143 * @platform_mode: Whether or not to use the platform driver.
145 * Use the platform driver to prepare the system for creating a hibernate image,
146 * if so configured, and return an error code if that fails.
149 static int platform_pre_snapshot(int platform_mode)
151 return (platform_mode && hibernation_ops) ?
152 hibernation_ops->pre_snapshot() : 0;
156 * platform_leave - Call platform to prepare a transition to the working state.
157 * @platform_mode: Whether or not to use the platform driver.
159 * Use the platform driver prepare to prepare the machine for switching to the
160 * normal mode of operation.
162 * This routine is called on one CPU with interrupts disabled.
164 static void platform_leave(int platform_mode)
166 if (platform_mode && hibernation_ops)
167 hibernation_ops->leave();
171 * platform_finish - Call platform to switch the system to the working state.
172 * @platform_mode: Whether or not to use the platform driver.
174 * Use the platform driver to switch the machine to the normal mode of
177 * This routine must be called after platform_prepare().
179 static void platform_finish(int platform_mode)
181 if (platform_mode && hibernation_ops)
182 hibernation_ops->finish();
186 * platform_pre_restore - Prepare for hibernate image restoration.
187 * @platform_mode: Whether or not to use the platform driver.
189 * Use the platform driver to prepare the system for resume from a hibernation
192 * If the restore fails after this function has been called,
193 * platform_restore_cleanup() must be called.
195 static int platform_pre_restore(int platform_mode)
197 return (platform_mode && hibernation_ops) ?
198 hibernation_ops->pre_restore() : 0;
202 * platform_restore_cleanup - Switch to the working state after failing restore.
203 * @platform_mode: Whether or not to use the platform driver.
205 * Use the platform driver to switch the system to the normal mode of operation
206 * after a failing restore.
208 * If platform_pre_restore() has been called before the failing restore, this
209 * function must be called too, regardless of the result of
210 * platform_pre_restore().
212 static void platform_restore_cleanup(int platform_mode)
214 if (platform_mode && hibernation_ops)
215 hibernation_ops->restore_cleanup();
219 * platform_recover - Recover from a failure to suspend devices.
220 * @platform_mode: Whether or not to use the platform driver.
222 static void platform_recover(int platform_mode)
224 if (platform_mode && hibernation_ops && hibernation_ops->recover)
225 hibernation_ops->recover();
229 * swsusp_show_speed - Print time elapsed between two events during hibernation.
230 * @start: Starting event.
231 * @stop: Final event.
232 * @nr_pages: Number of memory pages processed between @start and @stop.
233 * @msg: Additional diagnostic message to print.
235 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
236 unsigned nr_pages, char *msg)
238 s64 elapsed_centisecs64;
243 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
244 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
245 centisecs = elapsed_centisecs64;
247 centisecs = 1; /* avoid div-by-zero */
248 k = nr_pages * (PAGE_SIZE / 1024);
249 kps = (k * 100) / centisecs;
250 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
252 centisecs / 100, centisecs % 100,
253 kps / 1000, (kps % 1000) / 10);
257 * create_image - Create a hibernation image.
258 * @platform_mode: Whether or not to use the platform driver.
260 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
261 * and execute the drivers' .thaw_noirq() callbacks.
263 * Control reappears in this routine after the subsequent restore.
265 static int create_image(int platform_mode)
269 error = dpm_suspend_noirq(PMSG_FREEZE);
271 printk(KERN_ERR "PM: Some devices failed to power down, "
272 "aborting hibernation\n");
276 error = platform_pre_snapshot(platform_mode);
277 if (error || hibernation_test(TEST_PLATFORM))
278 goto Platform_finish;
280 error = disable_nonboot_cpus();
281 if (error || hibernation_test(TEST_CPUS)
282 || hibernation_testmode(HIBERNATION_TEST))
287 error = syscore_suspend();
289 printk(KERN_ERR "PM: Some system devices failed to power down, "
290 "aborting hibernation\n");
294 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
298 save_processor_state();
299 error = swsusp_arch_suspend();
301 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
303 /* Restore control flow magically appears here */
304 restore_processor_state();
306 events_check_enabled = false;
307 platform_leave(platform_mode);
317 enable_nonboot_cpus();
320 platform_finish(platform_mode);
322 dpm_resume_noirq(in_suspend ?
323 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
329 * hibernation_snapshot - Quiesce devices and create a hibernation image.
330 * @platform_mode: If set, use platform driver to prepare for the transition.
332 * This routine must be called with pm_mutex held.
334 int hibernation_snapshot(int platform_mode)
336 pm_message_t msg = PMSG_RECOVER;
339 error = platform_begin(platform_mode);
343 /* Preallocate image memory before shutting down devices. */
344 error = hibernate_preallocate_memory();
348 error = freeze_kernel_threads();
352 if (hibernation_test(TEST_FREEZER) ||
353 hibernation_testmode(HIBERNATION_TESTPROC)) {
356 * Indicate to the caller that we are returning due to a
357 * successful freezer test.
359 freezer_test_done = true;
363 error = dpm_prepare(PMSG_FREEZE);
370 pm_restrict_gfp_mask();
371 error = dpm_suspend(PMSG_FREEZE);
373 goto Recover_platform;
375 if (hibernation_test(TEST_DEVICES))
376 goto Recover_platform;
378 error = create_image(platform_mode);
380 * Control returns here (1) after the image has been created or the
381 * image creation has failed and (2) after a successful restore.
385 /* We may need to release the preallocated image pages here. */
386 if (error || !in_suspend)
389 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
392 if (error || !in_suspend)
393 pm_restore_gfp_mask();
399 platform_end(platform_mode);
403 platform_recover(platform_mode);
412 * resume_target_kernel - Restore system state from a hibernation image.
413 * @platform_mode: Whether or not to use the platform driver.
415 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
416 * highmem that have not been restored yet from the image and run the low-level
417 * code that will restore the remaining contents of memory and switch to the
418 * just restored target kernel.
420 static int resume_target_kernel(bool platform_mode)
424 error = dpm_suspend_noirq(PMSG_QUIESCE);
426 printk(KERN_ERR "PM: Some devices failed to power down, "
427 "aborting resume\n");
431 error = platform_pre_restore(platform_mode);
435 error = disable_nonboot_cpus();
441 error = syscore_suspend();
445 save_processor_state();
446 error = restore_highmem();
448 error = swsusp_arch_resume();
450 * The code below is only ever reached in case of a failure.
451 * Otherwise, execution continues at the place where
452 * swsusp_arch_suspend() was called.
456 * This call to restore_highmem() reverts the changes made by
462 * The only reason why swsusp_arch_resume() can fail is memory being
463 * very tight, so we have to free it as soon as we can to avoid
464 * subsequent failures.
467 restore_processor_state();
468 touch_softlockup_watchdog();
476 enable_nonboot_cpus();
479 platform_restore_cleanup(platform_mode);
481 dpm_resume_noirq(PMSG_RECOVER);
487 * hibernation_restore - Quiesce devices and restore from a hibernation image.
488 * @platform_mode: If set, use platform driver to prepare for the transition.
490 * This routine must be called with pm_mutex held. If it is successful, control
491 * reappears in the restored target kernel in hibernation_snapshot().
493 int hibernation_restore(int platform_mode)
497 pm_prepare_console();
499 pm_restrict_gfp_mask();
500 error = dpm_suspend_start(PMSG_QUIESCE);
502 error = resume_target_kernel(platform_mode);
503 dpm_resume_end(PMSG_RECOVER);
505 pm_restore_gfp_mask();
507 pm_restore_console();
512 * hibernation_platform_enter - Power off the system using the platform driver.
514 int hibernation_platform_enter(void)
518 if (!hibernation_ops)
522 * We have cancelled the power transition by running
523 * hibernation_ops->finish() before saving the image, so we should let
524 * the firmware know that we're going to enter the sleep state after all
526 error = hibernation_ops->begin();
530 entering_platform_hibernation = true;
532 error = dpm_suspend_start(PMSG_HIBERNATE);
534 if (hibernation_ops->recover)
535 hibernation_ops->recover();
539 error = dpm_suspend_noirq(PMSG_HIBERNATE);
543 error = hibernation_ops->prepare();
545 goto Platform_finish;
547 error = disable_nonboot_cpus();
549 goto Platform_finish;
553 if (pm_wakeup_pending()) {
558 hibernation_ops->enter();
559 /* We should never get here */
565 enable_nonboot_cpus();
568 hibernation_ops->finish();
570 dpm_resume_noirq(PMSG_RESTORE);
573 entering_platform_hibernation = false;
574 dpm_resume_end(PMSG_RESTORE);
578 hibernation_ops->end();
584 * power_down - Shut the machine down for hibernation.
586 * Use the platform driver, if configured, to put the system into the sleep
587 * state corresponding to hibernation, or try to power it off or reboot,
588 * depending on the value of hibernation_mode.
590 static void power_down(void)
592 switch (hibernation_mode) {
593 case HIBERNATION_TEST:
594 case HIBERNATION_TESTPROC:
596 case HIBERNATION_REBOOT:
597 kernel_restart(NULL);
599 case HIBERNATION_PLATFORM:
600 hibernation_platform_enter();
601 case HIBERNATION_SHUTDOWN:
607 * Valid image is on the disk, if we continue we risk serious data
608 * corruption after resume.
610 printk(KERN_CRIT "PM: Please power down manually\n");
615 * hibernate - Carry out system hibernation, including saving the image.
621 mutex_lock(&pm_mutex);
622 /* The snapshot device should not be opened while we're running */
623 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
628 pm_prepare_console();
629 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
633 error = usermodehelper_disable();
637 /* Allocate memory management structures */
638 error = create_basic_memory_bitmaps();
642 printk(KERN_INFO "PM: Syncing filesystems ... ");
646 error = freeze_processes();
650 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
653 if (freezer_test_done) {
654 freezer_test_done = false;
659 unsigned int flags = 0;
661 if (hibernation_mode == HIBERNATION_PLATFORM)
662 flags |= SF_PLATFORM_MODE;
664 flags |= SF_NOCOMPRESS_MODE;
666 flags |= SF_CRC32_MODE;
668 pr_debug("PM: writing image.\n");
669 error = swsusp_write(flags);
674 pm_restore_gfp_mask();
676 pr_debug("PM: Image restored successfully.\n");
682 free_basic_memory_bitmaps();
683 usermodehelper_enable();
685 pm_notifier_call_chain(PM_POST_HIBERNATION);
686 pm_restore_console();
687 atomic_inc(&snapshot_device_available);
689 mutex_unlock(&pm_mutex);
695 * software_resume - Resume from a saved hibernation image.
697 * This routine is called as a late initcall, when all devices have been
698 * discovered and initialized already.
700 * The image reading code is called to see if there is a hibernation image
701 * available for reading. If that is the case, devices are quiesced and the
702 * contents of memory is restored from the saved image.
704 * If this is successful, control reappears in the restored target kernel in
705 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
706 * attempts to recover gracefully and make the kernel return to the normal mode
709 static int software_resume(void)
715 * If the user said "noresume".. bail out early.
721 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
722 * is configured into the kernel. Since the regular hibernate
723 * trigger path is via sysfs which takes a buffer mutex before
724 * calling hibernate functions (which take pm_mutex) this can
725 * cause lockdep to complain about a possible ABBA deadlock
726 * which cannot happen since we're in the boot code here and
727 * sysfs can't be invoked yet. Therefore, we use a subclass
728 * here to avoid lockdep complaining.
730 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
732 if (swsusp_resume_device)
735 if (!strlen(resume_file)) {
740 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
743 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
745 ssleep(resume_delay);
748 /* Check if the device is there */
749 swsusp_resume_device = name_to_dev_t(resume_file);
750 if (!swsusp_resume_device) {
752 * Some device discovery might still be in progress; we need
753 * to wait for this to finish.
755 wait_for_device_probe();
758 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
760 async_synchronize_full();
764 * We can't depend on SCSI devices being available after loading
765 * one of their modules until scsi_complete_async_scans() is
766 * called and the resume device usually is a SCSI one.
768 scsi_complete_async_scans();
770 swsusp_resume_device = name_to_dev_t(resume_file);
771 if (!swsusp_resume_device) {
778 pr_debug("PM: Hibernation image partition %d:%d present\n",
779 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
781 pr_debug("PM: Looking for hibernation image.\n");
782 error = swsusp_check();
786 /* The snapshot device should not be opened while we're running */
787 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
789 swsusp_close(FMODE_READ);
793 pm_prepare_console();
794 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
798 error = usermodehelper_disable();
802 error = create_basic_memory_bitmaps();
806 pr_debug("PM: Preparing processes for restore.\n");
807 error = freeze_processes();
809 swsusp_close(FMODE_READ);
813 pr_debug("PM: Loading hibernation image.\n");
815 error = swsusp_read(&flags);
816 swsusp_close(FMODE_READ);
818 hibernation_restore(flags & SF_PLATFORM_MODE);
820 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
824 free_basic_memory_bitmaps();
825 usermodehelper_enable();
827 pm_notifier_call_chain(PM_POST_RESTORE);
828 pm_restore_console();
829 atomic_inc(&snapshot_device_available);
830 /* For success case, the suspend path will release the lock */
832 mutex_unlock(&pm_mutex);
833 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
836 swsusp_close(FMODE_READ);
840 late_initcall(software_resume);
843 static const char * const hibernation_modes[] = {
844 [HIBERNATION_PLATFORM] = "platform",
845 [HIBERNATION_SHUTDOWN] = "shutdown",
846 [HIBERNATION_REBOOT] = "reboot",
847 [HIBERNATION_TEST] = "test",
848 [HIBERNATION_TESTPROC] = "testproc",
852 * /sys/power/disk - Control hibernation mode.
854 * Hibernation can be handled in several ways. There are a few different ways
855 * to put the system into the sleep state: using the platform driver (e.g. ACPI
856 * or other hibernation_ops), powering it off or rebooting it (for testing
857 * mostly), or using one of the two available test modes.
859 * The sysfs file /sys/power/disk provides an interface for selecting the
860 * hibernation mode to use. Reading from this file causes the available modes
861 * to be printed. There are 5 modes that can be supported:
869 * If a platform hibernation driver is in use, 'platform' will be supported
870 * and will be used by default. Otherwise, 'shutdown' will be used by default.
871 * The selected option (i.e. the one corresponding to the current value of
872 * hibernation_mode) is enclosed by a square bracket.
874 * To select a given hibernation mode it is necessary to write the mode's
875 * string representation (as returned by reading from /sys/power/disk) back
876 * into /sys/power/disk.
879 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
885 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
886 if (!hibernation_modes[i])
889 case HIBERNATION_SHUTDOWN:
890 case HIBERNATION_REBOOT:
891 case HIBERNATION_TEST:
892 case HIBERNATION_TESTPROC:
894 case HIBERNATION_PLATFORM:
897 /* not a valid mode, continue with loop */
900 if (i == hibernation_mode)
901 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
903 buf += sprintf(buf, "%s ", hibernation_modes[i]);
905 buf += sprintf(buf, "\n");
909 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
910 const char *buf, size_t n)
916 int mode = HIBERNATION_INVALID;
918 p = memchr(buf, '\n', n);
919 len = p ? p - buf : n;
921 mutex_lock(&pm_mutex);
922 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
923 if (len == strlen(hibernation_modes[i])
924 && !strncmp(buf, hibernation_modes[i], len)) {
929 if (mode != HIBERNATION_INVALID) {
931 case HIBERNATION_SHUTDOWN:
932 case HIBERNATION_REBOOT:
933 case HIBERNATION_TEST:
934 case HIBERNATION_TESTPROC:
935 hibernation_mode = mode;
937 case HIBERNATION_PLATFORM:
939 hibernation_mode = mode;
947 pr_debug("PM: Hibernation mode set to '%s'\n",
948 hibernation_modes[mode]);
949 mutex_unlock(&pm_mutex);
950 return error ? error : n;
955 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
958 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
959 MINOR(swsusp_resume_device));
962 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
963 const char *buf, size_t n)
965 unsigned int maj, min;
969 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
972 res = MKDEV(maj,min);
973 if (maj != MAJOR(res) || min != MINOR(res))
976 mutex_lock(&pm_mutex);
977 swsusp_resume_device = res;
978 mutex_unlock(&pm_mutex);
979 printk(KERN_INFO "PM: Starting manual resume from disk\n");
989 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
992 return sprintf(buf, "%lu\n", image_size);
995 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
996 const char *buf, size_t n)
1000 if (sscanf(buf, "%lu", &size) == 1) {
1008 power_attr(image_size);
1010 static ssize_t reserved_size_show(struct kobject *kobj,
1011 struct kobj_attribute *attr, char *buf)
1013 return sprintf(buf, "%lu\n", reserved_size);
1016 static ssize_t reserved_size_store(struct kobject *kobj,
1017 struct kobj_attribute *attr,
1018 const char *buf, size_t n)
1022 if (sscanf(buf, "%lu", &size) == 1) {
1023 reserved_size = size;
1030 power_attr(reserved_size);
1032 static struct attribute * g[] = {
1035 &image_size_attr.attr,
1036 &reserved_size_attr.attr,
1041 static struct attribute_group attr_group = {
1046 static int __init pm_disk_init(void)
1048 return sysfs_create_group(power_kobj, &attr_group);
1051 core_initcall(pm_disk_init);
1054 static int __init resume_setup(char *str)
1059 strncpy( resume_file, str, 255 );
1063 static int __init resume_offset_setup(char *str)
1065 unsigned long long offset;
1070 if (sscanf(str, "%llu", &offset) == 1)
1071 swsusp_resume_block = offset;
1076 static int __init hibernate_setup(char *str)
1078 if (!strncmp(str, "noresume", 8))
1080 else if (!strncmp(str, "nocompress", 10))
1085 static int __init noresume_setup(char *str)
1091 static int __init resumewait_setup(char *str)
1097 static int __init resumedelay_setup(char *str)
1099 resume_delay = simple_strtoul(str, NULL, 0);
1103 __setup("noresume", noresume_setup);
1104 __setup("resume_offset=", resume_offset_setup);
1105 __setup("resume=", resume_setup);
1106 __setup("hibernate=", hibernate_setup);
1107 __setup("resumewait", resumewait_setup);
1108 __setup("resumedelay=", resumedelay_setup);