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>
32 static int nocompress = 0;
33 static int noresume = 0;
34 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
35 dev_t swsusp_resume_device;
36 sector_t swsusp_resume_block;
37 int in_suspend __nosavedata = 0;
47 __HIBERNATION_AFTER_LAST
49 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
50 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
52 static int hibernation_mode = HIBERNATION_SHUTDOWN;
54 static const struct platform_hibernation_ops *hibernation_ops;
57 * hibernation_set_ops - Set the global hibernate operations.
58 * @ops: Hibernation operations to use in subsequent hibernation transitions.
60 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
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)) {
68 mutex_lock(&pm_mutex);
69 hibernation_ops = ops;
71 hibernation_mode = HIBERNATION_PLATFORM;
72 else if (hibernation_mode == HIBERNATION_PLATFORM)
73 hibernation_mode = HIBERNATION_SHUTDOWN;
75 mutex_unlock(&pm_mutex);
78 static bool entering_platform_hibernation;
80 bool system_entering_hibernation(void)
82 return entering_platform_hibernation;
84 EXPORT_SYMBOL(system_entering_hibernation);
86 #ifdef CONFIG_PM_DEBUG
87 static void hibernation_debug_sleep(void)
89 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
93 static int hibernation_testmode(int mode)
95 if (hibernation_mode == mode) {
96 hibernation_debug_sleep();
102 static int hibernation_test(int level)
104 if (pm_test_level == level) {
105 hibernation_debug_sleep();
110 #else /* !CONFIG_PM_DEBUG */
111 static int hibernation_testmode(int mode) { return 0; }
112 static int hibernation_test(int level) { return 0; }
113 #endif /* !CONFIG_PM_DEBUG */
116 * platform_begin - Call platform to start hibernation.
117 * @platform_mode: Whether or not to use the platform driver.
119 static int platform_begin(int platform_mode)
121 return (platform_mode && hibernation_ops) ?
122 hibernation_ops->begin() : 0;
126 * platform_end - Call platform to finish transition to the working state.
127 * @platform_mode: Whether or not to use the platform driver.
129 static void platform_end(int platform_mode)
131 if (platform_mode && hibernation_ops)
132 hibernation_ops->end();
136 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
137 * @platform_mode: Whether or not to use the platform driver.
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.
143 static int platform_pre_snapshot(int platform_mode)
145 return (platform_mode && hibernation_ops) ?
146 hibernation_ops->pre_snapshot() : 0;
150 * platform_leave - Call platform to prepare a transition to the working state.
151 * @platform_mode: Whether or not to use the platform driver.
153 * Use the platform driver prepare to prepare the machine for switching to the
154 * normal mode of operation.
156 * This routine is called on one CPU with interrupts disabled.
158 static void platform_leave(int platform_mode)
160 if (platform_mode && hibernation_ops)
161 hibernation_ops->leave();
165 * platform_finish - Call platform to switch the system to the working state.
166 * @platform_mode: Whether or not to use the platform driver.
168 * Use the platform driver to switch the machine to the normal mode of
171 * This routine must be called after platform_prepare().
173 static void platform_finish(int platform_mode)
175 if (platform_mode && hibernation_ops)
176 hibernation_ops->finish();
180 * platform_pre_restore - Prepare for hibernate image restoration.
181 * @platform_mode: Whether or not to use the platform driver.
183 * Use the platform driver to prepare the system for resume from a hibernation
186 * If the restore fails after this function has been called,
187 * platform_restore_cleanup() must be called.
189 static int platform_pre_restore(int platform_mode)
191 return (platform_mode && hibernation_ops) ?
192 hibernation_ops->pre_restore() : 0;
196 * platform_restore_cleanup - Switch to the working state after failing restore.
197 * @platform_mode: Whether or not to use the platform driver.
199 * Use the platform driver to switch the system to the normal mode of operation
200 * after a failing restore.
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().
206 static void platform_restore_cleanup(int platform_mode)
208 if (platform_mode && hibernation_ops)
209 hibernation_ops->restore_cleanup();
213 * platform_recover - Recover from a failure to suspend devices.
214 * @platform_mode: Whether or not to use the platform driver.
216 static void platform_recover(int platform_mode)
218 if (platform_mode && hibernation_ops && hibernation_ops->recover)
219 hibernation_ops->recover();
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.
229 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
230 unsigned nr_pages, char *msg)
232 s64 elapsed_centisecs64;
237 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
238 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
239 centisecs = elapsed_centisecs64;
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",
246 centisecs / 100, centisecs % 100,
247 kps / 1000, (kps % 1000) / 10);
251 * create_image - Create a hibernation image.
252 * @platform_mode: Whether or not to use the platform driver.
254 * Execute device drivers' .freeze_noirq() callbacks, create a hibernation image
255 * and execute the drivers' .thaw_noirq() callbacks.
257 * Control reappears in this routine after the subsequent restore.
259 static int create_image(int platform_mode)
263 error = dpm_suspend_noirq(PMSG_FREEZE);
265 printk(KERN_ERR "PM: Some devices failed to power down, "
266 "aborting hibernation\n");
270 error = platform_pre_snapshot(platform_mode);
271 if (error || hibernation_test(TEST_PLATFORM))
272 goto Platform_finish;
274 error = disable_nonboot_cpus();
275 if (error || hibernation_test(TEST_CPUS)
276 || hibernation_testmode(HIBERNATION_TEST))
281 error = syscore_suspend();
283 printk(KERN_ERR "PM: Some system devices failed to power down, "
284 "aborting hibernation\n");
288 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
292 save_processor_state();
293 error = swsusp_arch_suspend();
295 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
297 /* Restore control flow magically appears here */
298 restore_processor_state();
300 events_check_enabled = false;
301 platform_leave(platform_mode);
311 enable_nonboot_cpus();
314 platform_finish(platform_mode);
316 dpm_resume_noirq(in_suspend ?
317 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
323 * hibernation_snapshot - Quiesce devices and create a hibernation image.
324 * @platform_mode: If set, use platform driver to prepare for the transition.
326 * This routine must be called with pm_mutex held.
328 int hibernation_snapshot(int platform_mode)
330 pm_message_t msg = PMSG_RECOVER;
333 error = platform_begin(platform_mode);
337 error = dpm_prepare(PMSG_FREEZE);
339 goto Complete_devices;
341 /* Preallocate image memory before shutting down devices. */
342 error = hibernate_preallocate_memory();
344 goto Complete_devices;
348 pm_restrict_gfp_mask();
349 error = dpm_suspend(PMSG_FREEZE);
351 goto Recover_platform;
353 if (hibernation_test(TEST_DEVICES))
354 goto Recover_platform;
356 error = create_image(platform_mode);
358 * Control returns here (1) after the image has been created or the
359 * image creation has failed and (2) after a successful restore.
363 /* We may need to release the preallocated image pages here. */
364 if (error || !in_suspend)
367 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
370 if (error || !in_suspend)
371 pm_restore_gfp_mask();
380 platform_end(platform_mode);
384 platform_recover(platform_mode);
389 * resume_target_kernel - Restore system state from a hibernation image.
390 * @platform_mode: Whether or not to use the platform driver.
392 * Execute device drivers' .freeze_noirq() callbacks, restore the contents of
393 * highmem that have not been restored yet from the image and run the low-level
394 * code that will restore the remaining contents of memory and switch to the
395 * just restored target kernel.
397 static int resume_target_kernel(bool platform_mode)
401 error = dpm_suspend_noirq(PMSG_QUIESCE);
403 printk(KERN_ERR "PM: Some devices failed to power down, "
404 "aborting resume\n");
408 error = platform_pre_restore(platform_mode);
412 error = disable_nonboot_cpus();
418 error = syscore_suspend();
422 save_processor_state();
423 error = restore_highmem();
425 error = swsusp_arch_resume();
427 * The code below is only ever reached in case of a failure.
428 * Otherwise, execution continues at the place where
429 * swsusp_arch_suspend() was called.
433 * This call to restore_highmem() reverts the changes made by
439 * The only reason why swsusp_arch_resume() can fail is memory being
440 * very tight, so we have to free it as soon as we can to avoid
441 * subsequent failures.
444 restore_processor_state();
445 touch_softlockup_watchdog();
453 enable_nonboot_cpus();
456 platform_restore_cleanup(platform_mode);
458 dpm_resume_noirq(PMSG_RECOVER);
464 * hibernation_restore - Quiesce devices and restore from a hibernation image.
465 * @platform_mode: If set, use platform driver to prepare for the transition.
467 * This routine must be called with pm_mutex held. If it is successful, control
468 * reappears in the restored target kernel in hibernation_snaphot().
470 int hibernation_restore(int platform_mode)
474 pm_prepare_console();
477 pm_restrict_gfp_mask();
478 error = dpm_suspend_start(PMSG_QUIESCE);
480 error = resume_target_kernel(platform_mode);
481 dpm_resume_end(PMSG_RECOVER);
483 pm_restore_gfp_mask();
486 pm_restore_console();
491 * hibernation_platform_enter - Power off the system using the platform driver.
493 int hibernation_platform_enter(void)
497 if (!hibernation_ops)
501 * We have cancelled the power transition by running
502 * hibernation_ops->finish() before saving the image, so we should let
503 * the firmware know that we're going to enter the sleep state after all
505 error = hibernation_ops->begin();
509 entering_platform_hibernation = true;
512 error = dpm_suspend_start(PMSG_HIBERNATE);
514 if (hibernation_ops->recover)
515 hibernation_ops->recover();
519 error = dpm_suspend_noirq(PMSG_HIBERNATE);
523 error = hibernation_ops->prepare();
525 goto Platform_finish;
527 error = disable_nonboot_cpus();
529 goto Platform_finish;
533 if (pm_wakeup_pending()) {
538 hibernation_ops->enter();
539 /* We should never get here */
545 enable_nonboot_cpus();
548 hibernation_ops->finish();
550 dpm_resume_noirq(PMSG_RESTORE);
553 entering_platform_hibernation = false;
554 dpm_resume_end(PMSG_RESTORE);
559 hibernation_ops->end();
565 * power_down - Shut the machine down for hibernation.
567 * Use the platform driver, if configured, to put the system into the sleep
568 * state corresponding to hibernation, or try to power it off or reboot,
569 * depending on the value of hibernation_mode.
571 static void power_down(void)
573 switch (hibernation_mode) {
574 case HIBERNATION_TEST:
575 case HIBERNATION_TESTPROC:
577 case HIBERNATION_REBOOT:
578 kernel_restart(NULL);
580 case HIBERNATION_PLATFORM:
581 hibernation_platform_enter();
582 case HIBERNATION_SHUTDOWN:
588 * Valid image is on the disk, if we continue we risk serious data
589 * corruption after resume.
591 printk(KERN_CRIT "PM: Please power down manually\n");
595 static int prepare_processes(void)
599 if (freeze_processes()) {
607 * hibernate - Carry out system hibernation, including saving the image.
613 mutex_lock(&pm_mutex);
614 /* The snapshot device should not be opened while we're running */
615 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
620 pm_prepare_console();
621 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
625 error = usermodehelper_disable();
629 /* Allocate memory management structures */
630 error = create_basic_memory_bitmaps();
634 printk(KERN_INFO "PM: Syncing filesystems ... ");
638 error = prepare_processes();
642 if (hibernation_test(TEST_FREEZER))
645 if (hibernation_testmode(HIBERNATION_TESTPROC))
648 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
653 unsigned int flags = 0;
655 if (hibernation_mode == HIBERNATION_PLATFORM)
656 flags |= SF_PLATFORM_MODE;
658 flags |= SF_NOCOMPRESS_MODE;
659 pr_debug("PM: writing image.\n");
660 error = swsusp_write(flags);
665 pm_restore_gfp_mask();
667 pr_debug("PM: Image restored successfully.\n");
673 free_basic_memory_bitmaps();
675 usermodehelper_enable();
677 pm_notifier_call_chain(PM_POST_HIBERNATION);
678 pm_restore_console();
679 atomic_inc(&snapshot_device_available);
681 mutex_unlock(&pm_mutex);
687 * software_resume - Resume from a saved hibernation image.
689 * This routine is called as a late initcall, when all devices have been
690 * discovered and initialized already.
692 * The image reading code is called to see if there is a hibernation image
693 * available for reading. If that is the case, devices are quiesced and the
694 * contents of memory is restored from the saved image.
696 * If this is successful, control reappears in the restored target kernel in
697 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
698 * attempts to recover gracefully and make the kernel return to the normal mode
701 static int software_resume(void)
707 * If the user said "noresume".. bail out early.
713 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
714 * is configured into the kernel. Since the regular hibernate
715 * trigger path is via sysfs which takes a buffer mutex before
716 * calling hibernate functions (which take pm_mutex) this can
717 * cause lockdep to complain about a possible ABBA deadlock
718 * which cannot happen since we're in the boot code here and
719 * sysfs can't be invoked yet. Therefore, we use a subclass
720 * here to avoid lockdep complaining.
722 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
724 if (swsusp_resume_device)
727 if (!strlen(resume_file)) {
732 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
734 /* Check if the device is there */
735 swsusp_resume_device = name_to_dev_t(resume_file);
736 if (!swsusp_resume_device) {
738 * Some device discovery might still be in progress; we need
739 * to wait for this to finish.
741 wait_for_device_probe();
743 * We can't depend on SCSI devices being available after loading
744 * one of their modules until scsi_complete_async_scans() is
745 * called and the resume device usually is a SCSI one.
747 scsi_complete_async_scans();
749 swsusp_resume_device = name_to_dev_t(resume_file);
750 if (!swsusp_resume_device) {
757 pr_debug("PM: Hibernation image partition %d:%d present\n",
758 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
760 pr_debug("PM: Looking for hibernation image.\n");
761 error = swsusp_check();
765 /* The snapshot device should not be opened while we're running */
766 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
768 swsusp_close(FMODE_READ);
772 pm_prepare_console();
773 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
777 error = usermodehelper_disable();
781 error = create_basic_memory_bitmaps();
785 pr_debug("PM: Preparing processes for restore.\n");
786 error = prepare_processes();
788 swsusp_close(FMODE_READ);
792 pr_debug("PM: Loading hibernation image.\n");
794 error = swsusp_read(&flags);
795 swsusp_close(FMODE_READ);
797 hibernation_restore(flags & SF_PLATFORM_MODE);
799 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
803 free_basic_memory_bitmaps();
804 usermodehelper_enable();
806 pm_notifier_call_chain(PM_POST_RESTORE);
807 pm_restore_console();
808 atomic_inc(&snapshot_device_available);
809 /* For success case, the suspend path will release the lock */
811 mutex_unlock(&pm_mutex);
812 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
815 swsusp_close(FMODE_READ);
819 late_initcall(software_resume);
822 static const char * const hibernation_modes[] = {
823 [HIBERNATION_PLATFORM] = "platform",
824 [HIBERNATION_SHUTDOWN] = "shutdown",
825 [HIBERNATION_REBOOT] = "reboot",
826 [HIBERNATION_TEST] = "test",
827 [HIBERNATION_TESTPROC] = "testproc",
831 * /sys/power/disk - Control hibernation mode.
833 * Hibernation can be handled in several ways. There are a few different ways
834 * to put the system into the sleep state: using the platform driver (e.g. ACPI
835 * or other hibernation_ops), powering it off or rebooting it (for testing
836 * mostly), or using one of the two available test modes.
838 * The sysfs file /sys/power/disk provides an interface for selecting the
839 * hibernation mode to use. Reading from this file causes the available modes
840 * to be printed. There are 5 modes that can be supported:
848 * If a platform hibernation driver is in use, 'platform' will be supported
849 * and will be used by default. Otherwise, 'shutdown' will be used by default.
850 * The selected option (i.e. the one corresponding to the current value of
851 * hibernation_mode) is enclosed by a square bracket.
853 * To select a given hibernation mode it is necessary to write the mode's
854 * string representation (as returned by reading from /sys/power/disk) back
855 * into /sys/power/disk.
858 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
864 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
865 if (!hibernation_modes[i])
868 case HIBERNATION_SHUTDOWN:
869 case HIBERNATION_REBOOT:
870 case HIBERNATION_TEST:
871 case HIBERNATION_TESTPROC:
873 case HIBERNATION_PLATFORM:
876 /* not a valid mode, continue with loop */
879 if (i == hibernation_mode)
880 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
882 buf += sprintf(buf, "%s ", hibernation_modes[i]);
884 buf += sprintf(buf, "\n");
888 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
889 const char *buf, size_t n)
895 int mode = HIBERNATION_INVALID;
897 p = memchr(buf, '\n', n);
898 len = p ? p - buf : n;
900 mutex_lock(&pm_mutex);
901 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
902 if (len == strlen(hibernation_modes[i])
903 && !strncmp(buf, hibernation_modes[i], len)) {
908 if (mode != HIBERNATION_INVALID) {
910 case HIBERNATION_SHUTDOWN:
911 case HIBERNATION_REBOOT:
912 case HIBERNATION_TEST:
913 case HIBERNATION_TESTPROC:
914 hibernation_mode = mode;
916 case HIBERNATION_PLATFORM:
918 hibernation_mode = mode;
926 pr_debug("PM: Hibernation mode set to '%s'\n",
927 hibernation_modes[mode]);
928 mutex_unlock(&pm_mutex);
929 return error ? error : n;
934 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
937 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
938 MINOR(swsusp_resume_device));
941 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
942 const char *buf, size_t n)
944 unsigned int maj, min;
948 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
951 res = MKDEV(maj,min);
952 if (maj != MAJOR(res) || min != MINOR(res))
955 mutex_lock(&pm_mutex);
956 swsusp_resume_device = res;
957 mutex_unlock(&pm_mutex);
958 printk(KERN_INFO "PM: Starting manual resume from disk\n");
968 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
971 return sprintf(buf, "%lu\n", image_size);
974 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
975 const char *buf, size_t n)
979 if (sscanf(buf, "%lu", &size) == 1) {
987 power_attr(image_size);
989 static ssize_t reserved_size_show(struct kobject *kobj,
990 struct kobj_attribute *attr, char *buf)
992 return sprintf(buf, "%lu\n", reserved_size);
995 static ssize_t reserved_size_store(struct kobject *kobj,
996 struct kobj_attribute *attr,
997 const char *buf, size_t n)
1001 if (sscanf(buf, "%lu", &size) == 1) {
1002 reserved_size = size;
1009 power_attr(reserved_size);
1011 static struct attribute * g[] = {
1014 &image_size_attr.attr,
1015 &reserved_size_attr.attr,
1020 static struct attribute_group attr_group = {
1025 static int __init pm_disk_init(void)
1027 return sysfs_create_group(power_kobj, &attr_group);
1030 core_initcall(pm_disk_init);
1033 static int __init resume_setup(char *str)
1038 strncpy( resume_file, str, 255 );
1042 static int __init resume_offset_setup(char *str)
1044 unsigned long long offset;
1049 if (sscanf(str, "%llu", &offset) == 1)
1050 swsusp_resume_block = offset;
1055 static int __init hibernate_setup(char *str)
1057 if (!strncmp(str, "noresume", 8))
1059 else if (!strncmp(str, "nocompress", 10))
1064 static int __init noresume_setup(char *str)
1070 __setup("noresume", noresume_setup);
1071 __setup("resume_offset=", resume_offset_setup);
1072 __setup("resume=", resume_setup);
1073 __setup("hibernate=", hibernate_setup);