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/delay.h>
21 #include <linux/mount.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
25 #include <linux/freezer.h>
26 #include <linux/gfp.h>
27 #include <linux/syscore_ops.h>
28 #include <linux/ctype.h>
29 #include <linux/genhd.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;
49 __HIBERNATION_AFTER_LAST
51 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
52 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
54 static int hibernation_mode = HIBERNATION_SHUTDOWN;
56 bool freezer_test_done;
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)) {
73 hibernation_ops = ops;
75 hibernation_mode = HIBERNATION_PLATFORM;
76 else if (hibernation_mode == HIBERNATION_PLATFORM)
77 hibernation_mode = HIBERNATION_SHUTDOWN;
79 unlock_system_sleep();
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_test(int level)
99 if (pm_test_level == level) {
100 hibernation_debug_sleep();
105 #else /* !CONFIG_PM_DEBUG */
106 static int hibernation_test(int level) { return 0; }
107 #endif /* !CONFIG_PM_DEBUG */
110 * platform_begin - Call platform to start hibernation.
111 * @platform_mode: Whether or not to use the platform driver.
113 static int platform_begin(int platform_mode)
115 return (platform_mode && hibernation_ops) ?
116 hibernation_ops->begin() : 0;
120 * platform_end - Call platform to finish transition to the working state.
121 * @platform_mode: Whether or not to use the platform driver.
123 static void platform_end(int platform_mode)
125 if (platform_mode && hibernation_ops)
126 hibernation_ops->end();
130 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
131 * @platform_mode: Whether or not to use the platform driver.
133 * Use the platform driver to prepare the system for creating a hibernate image,
134 * if so configured, and return an error code if that fails.
137 static int platform_pre_snapshot(int platform_mode)
139 return (platform_mode && hibernation_ops) ?
140 hibernation_ops->pre_snapshot() : 0;
144 * platform_leave - Call platform to prepare a transition to the working state.
145 * @platform_mode: Whether or not to use the platform driver.
147 * Use the platform driver prepare to prepare the machine for switching to the
148 * normal mode of operation.
150 * This routine is called on one CPU with interrupts disabled.
152 static void platform_leave(int platform_mode)
154 if (platform_mode && hibernation_ops)
155 hibernation_ops->leave();
159 * platform_finish - Call platform to switch the system to the working state.
160 * @platform_mode: Whether or not to use the platform driver.
162 * Use the platform driver to switch the machine to the normal mode of
165 * This routine must be called after platform_prepare().
167 static void platform_finish(int platform_mode)
169 if (platform_mode && hibernation_ops)
170 hibernation_ops->finish();
174 * platform_pre_restore - Prepare for hibernate image restoration.
175 * @platform_mode: Whether or not to use the platform driver.
177 * Use the platform driver to prepare the system for resume from a hibernation
180 * If the restore fails after this function has been called,
181 * platform_restore_cleanup() must be called.
183 static int platform_pre_restore(int platform_mode)
185 return (platform_mode && hibernation_ops) ?
186 hibernation_ops->pre_restore() : 0;
190 * platform_restore_cleanup - Switch to the working state after failing restore.
191 * @platform_mode: Whether or not to use the platform driver.
193 * Use the platform driver to switch the system to the normal mode of operation
194 * after a failing restore.
196 * If platform_pre_restore() has been called before the failing restore, this
197 * function must be called too, regardless of the result of
198 * platform_pre_restore().
200 static void platform_restore_cleanup(int platform_mode)
202 if (platform_mode && hibernation_ops)
203 hibernation_ops->restore_cleanup();
207 * platform_recover - Recover from a failure to suspend devices.
208 * @platform_mode: Whether or not to use the platform driver.
210 static void platform_recover(int platform_mode)
212 if (platform_mode && hibernation_ops && hibernation_ops->recover)
213 hibernation_ops->recover();
217 * swsusp_show_speed - Print time elapsed between two events during hibernation.
218 * @start: Starting event.
219 * @stop: Final event.
220 * @nr_pages: Number of memory pages processed between @start and @stop.
221 * @msg: Additional diagnostic message to print.
223 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
224 unsigned nr_pages, char *msg)
226 s64 elapsed_centisecs64;
231 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
232 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
233 centisecs = elapsed_centisecs64;
235 centisecs = 1; /* avoid div-by-zero */
236 k = nr_pages * (PAGE_SIZE / 1024);
237 kps = (k * 100) / centisecs;
238 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
240 centisecs / 100, centisecs % 100,
241 kps / 1000, (kps % 1000) / 10);
245 * create_image - Create a hibernation image.
246 * @platform_mode: Whether or not to use the platform driver.
248 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
249 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
251 * Control reappears in this routine after the subsequent restore.
253 static int create_image(int platform_mode)
257 error = dpm_suspend_end(PMSG_FREEZE);
259 printk(KERN_ERR "PM: Some devices failed to power down, "
260 "aborting hibernation\n");
264 error = platform_pre_snapshot(platform_mode);
265 if (error || hibernation_test(TEST_PLATFORM))
266 goto Platform_finish;
268 error = disable_nonboot_cpus();
269 if (error || hibernation_test(TEST_CPUS))
274 error = syscore_suspend();
276 printk(KERN_ERR "PM: Some system devices failed to power down, "
277 "aborting hibernation\n");
281 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
285 save_processor_state();
286 error = swsusp_arch_suspend();
288 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
290 /* Restore control flow magically appears here */
291 restore_processor_state();
293 events_check_enabled = false;
294 platform_leave(platform_mode);
304 enable_nonboot_cpus();
307 platform_finish(platform_mode);
309 dpm_resume_start(in_suspend ?
310 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
316 * hibernation_snapshot - Quiesce devices and create a hibernation image.
317 * @platform_mode: If set, use platform driver to prepare for the transition.
319 * This routine must be called with pm_mutex held.
321 int hibernation_snapshot(int platform_mode)
326 error = platform_begin(platform_mode);
330 /* Preallocate image memory before shutting down devices. */
331 error = hibernate_preallocate_memory();
335 error = freeze_kernel_threads();
339 if (hibernation_test(TEST_FREEZER)) {
342 * Indicate to the caller that we are returning due to a
343 * successful freezer test.
345 freezer_test_done = true;
349 error = dpm_prepare(PMSG_FREEZE);
351 dpm_complete(PMSG_RECOVER);
356 pm_restrict_gfp_mask();
358 error = dpm_suspend(PMSG_FREEZE);
360 if (error || hibernation_test(TEST_DEVICES))
361 platform_recover(platform_mode);
363 error = create_image(platform_mode);
366 * In the case that we call create_image() above, the control
367 * returns here (1) after the image has been created or the
368 * image creation has failed and (2) after a successful restore.
371 /* We may need to release the preallocated image pages here. */
372 if (error || !in_suspend)
375 msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
378 if (error || !in_suspend)
379 pm_restore_gfp_mask();
385 platform_end(platform_mode);
389 thaw_kernel_threads();
396 * resume_target_kernel - Restore system state from a hibernation image.
397 * @platform_mode: Whether or not to use the platform driver.
399 * Execute device drivers' "noirq" and "late" freeze callbacks, restore the
400 * contents of highmem that have not been restored yet from the image and run
401 * the low-level code that will restore the remaining contents of memory and
402 * switch to the just restored target kernel.
404 static int resume_target_kernel(bool platform_mode)
408 error = dpm_suspend_end(PMSG_QUIESCE);
410 printk(KERN_ERR "PM: Some devices failed to power down, "
411 "aborting resume\n");
415 error = platform_pre_restore(platform_mode);
419 error = disable_nonboot_cpus();
425 error = syscore_suspend();
429 save_processor_state();
430 error = restore_highmem();
432 error = swsusp_arch_resume();
434 * The code below is only ever reached in case of a failure.
435 * Otherwise, execution continues at the place where
436 * swsusp_arch_suspend() was called.
440 * This call to restore_highmem() reverts the changes made by
446 * The only reason why swsusp_arch_resume() can fail is memory being
447 * very tight, so we have to free it as soon as we can to avoid
448 * subsequent failures.
451 restore_processor_state();
452 touch_softlockup_watchdog();
460 enable_nonboot_cpus();
463 platform_restore_cleanup(platform_mode);
465 dpm_resume_start(PMSG_RECOVER);
471 * hibernation_restore - Quiesce devices and restore from a hibernation image.
472 * @platform_mode: If set, use platform driver to prepare for the transition.
474 * This routine must be called with pm_mutex held. If it is successful, control
475 * reappears in the restored target kernel in hibernation_snapshot().
477 int hibernation_restore(int platform_mode)
481 pm_prepare_console();
483 pm_restrict_gfp_mask();
484 error = dpm_suspend_start(PMSG_QUIESCE);
486 error = resume_target_kernel(platform_mode);
487 dpm_resume_end(PMSG_RECOVER);
489 pm_restore_gfp_mask();
491 pm_restore_console();
496 * hibernation_platform_enter - Power off the system using the platform driver.
498 int hibernation_platform_enter(void)
502 if (!hibernation_ops)
506 * We have cancelled the power transition by running
507 * hibernation_ops->finish() before saving the image, so we should let
508 * the firmware know that we're going to enter the sleep state after all
510 error = hibernation_ops->begin();
514 entering_platform_hibernation = true;
516 error = dpm_suspend_start(PMSG_HIBERNATE);
518 if (hibernation_ops->recover)
519 hibernation_ops->recover();
523 error = dpm_suspend_end(PMSG_HIBERNATE);
527 error = hibernation_ops->prepare();
529 goto Platform_finish;
531 error = disable_nonboot_cpus();
533 goto Platform_finish;
537 if (pm_wakeup_pending()) {
542 hibernation_ops->enter();
543 /* We should never get here */
549 enable_nonboot_cpus();
552 hibernation_ops->finish();
554 dpm_resume_start(PMSG_RESTORE);
557 entering_platform_hibernation = false;
558 dpm_resume_end(PMSG_RESTORE);
562 hibernation_ops->end();
568 * power_down - Shut the machine down for hibernation.
570 * Use the platform driver, if configured, to put the system into the sleep
571 * state corresponding to hibernation, or try to power it off or reboot,
572 * depending on the value of hibernation_mode.
574 static void power_down(void)
576 switch (hibernation_mode) {
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");
596 * hibernate - Carry out system hibernation, including saving the image.
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 /* Allocate memory management structures */
615 error = create_basic_memory_bitmaps();
619 printk(KERN_INFO "PM: Syncing filesystems ... ");
623 error = freeze_processes();
627 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
628 if (error || freezer_test_done)
632 unsigned int flags = 0;
634 if (hibernation_mode == HIBERNATION_PLATFORM)
635 flags |= SF_PLATFORM_MODE;
637 flags |= SF_NOCOMPRESS_MODE;
639 flags |= SF_CRC32_MODE;
641 pr_debug("PM: writing image.\n");
642 error = swsusp_write(flags);
647 pm_restore_gfp_mask();
649 pr_debug("PM: Image restored successfully.\n");
655 /* Don't bother checking whether freezer_test_done is true */
656 freezer_test_done = false;
659 free_basic_memory_bitmaps();
661 pm_notifier_call_chain(PM_POST_HIBERNATION);
662 pm_restore_console();
663 atomic_inc(&snapshot_device_available);
665 unlock_system_sleep();
671 * software_resume - Resume from a saved hibernation image.
673 * This routine is called as a late initcall, when all devices have been
674 * discovered and initialized already.
676 * The image reading code is called to see if there is a hibernation image
677 * available for reading. If that is the case, devices are quiesced and the
678 * contents of memory is restored from the saved image.
680 * If this is successful, control reappears in the restored target kernel in
681 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
682 * attempts to recover gracefully and make the kernel return to the normal mode
685 static int software_resume(void)
691 * If the user said "noresume".. bail out early.
697 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
698 * is configured into the kernel. Since the regular hibernate
699 * trigger path is via sysfs which takes a buffer mutex before
700 * calling hibernate functions (which take pm_mutex) this can
701 * cause lockdep to complain about a possible ABBA deadlock
702 * which cannot happen since we're in the boot code here and
703 * sysfs can't be invoked yet. Therefore, we use a subclass
704 * here to avoid lockdep complaining.
706 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
708 if (swsusp_resume_device)
711 if (!strlen(resume_file)) {
716 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
719 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
721 ssleep(resume_delay);
724 /* Check if the device is there */
725 swsusp_resume_device = name_to_dev_t(resume_file);
728 * name_to_dev_t is ineffective to verify parition if resume_file is in
729 * integer format. (e.g. major:minor)
731 if (isdigit(resume_file[0]) && resume_wait) {
733 while (!get_gendisk(swsusp_resume_device, &partno))
737 if (!swsusp_resume_device) {
739 * Some device discovery might still be in progress; we need
740 * to wait for this to finish.
742 wait_for_device_probe();
745 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
747 async_synchronize_full();
750 swsusp_resume_device = name_to_dev_t(resume_file);
751 if (!swsusp_resume_device) {
758 pr_debug("PM: Hibernation image partition %d:%d present\n",
759 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
761 pr_debug("PM: Looking for hibernation image.\n");
762 error = swsusp_check();
766 /* The snapshot device should not be opened while we're running */
767 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
769 swsusp_close(FMODE_READ);
773 pm_prepare_console();
774 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
778 error = create_basic_memory_bitmaps();
782 pr_debug("PM: Preparing processes for restore.\n");
783 error = freeze_processes();
785 swsusp_close(FMODE_READ);
789 pr_debug("PM: Loading hibernation image.\n");
791 error = swsusp_read(&flags);
792 swsusp_close(FMODE_READ);
794 hibernation_restore(flags & SF_PLATFORM_MODE);
796 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
800 free_basic_memory_bitmaps();
802 pm_notifier_call_chain(PM_POST_RESTORE);
803 pm_restore_console();
804 atomic_inc(&snapshot_device_available);
805 /* For success case, the suspend path will release the lock */
807 mutex_unlock(&pm_mutex);
808 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
811 swsusp_close(FMODE_READ);
815 late_initcall(software_resume);
818 static const char * const hibernation_modes[] = {
819 [HIBERNATION_PLATFORM] = "platform",
820 [HIBERNATION_SHUTDOWN] = "shutdown",
821 [HIBERNATION_REBOOT] = "reboot",
825 * /sys/power/disk - Control hibernation mode.
827 * Hibernation can be handled in several ways. There are a few different ways
828 * to put the system into the sleep state: using the platform driver (e.g. ACPI
829 * or other hibernation_ops), powering it off or rebooting it (for testing
832 * The sysfs file /sys/power/disk provides an interface for selecting the
833 * hibernation mode to use. Reading from this file causes the available modes
834 * to be printed. There are 3 modes that can be supported:
840 * If a platform hibernation driver is in use, 'platform' will be supported
841 * and will be used by default. Otherwise, 'shutdown' will be used by default.
842 * The selected option (i.e. the one corresponding to the current value of
843 * hibernation_mode) is enclosed by a square bracket.
845 * To select a given hibernation mode it is necessary to write the mode's
846 * string representation (as returned by reading from /sys/power/disk) back
847 * into /sys/power/disk.
850 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
856 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
857 if (!hibernation_modes[i])
860 case HIBERNATION_SHUTDOWN:
861 case HIBERNATION_REBOOT:
863 case HIBERNATION_PLATFORM:
866 /* not a valid mode, continue with loop */
869 if (i == hibernation_mode)
870 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
872 buf += sprintf(buf, "%s ", hibernation_modes[i]);
874 buf += sprintf(buf, "\n");
878 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
879 const char *buf, size_t n)
885 int mode = HIBERNATION_INVALID;
887 p = memchr(buf, '\n', n);
888 len = p ? p - buf : n;
891 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
892 if (len == strlen(hibernation_modes[i])
893 && !strncmp(buf, hibernation_modes[i], len)) {
898 if (mode != HIBERNATION_INVALID) {
900 case HIBERNATION_SHUTDOWN:
901 case HIBERNATION_REBOOT:
902 hibernation_mode = mode;
904 case HIBERNATION_PLATFORM:
906 hibernation_mode = mode;
914 pr_debug("PM: Hibernation mode set to '%s'\n",
915 hibernation_modes[mode]);
916 unlock_system_sleep();
917 return error ? error : n;
922 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
925 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
926 MINOR(swsusp_resume_device));
929 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
930 const char *buf, size_t n)
932 unsigned int maj, min;
936 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
939 res = MKDEV(maj,min);
940 if (maj != MAJOR(res) || min != MINOR(res))
944 swsusp_resume_device = res;
945 unlock_system_sleep();
946 printk(KERN_INFO "PM: Starting manual resume from disk\n");
956 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
959 return sprintf(buf, "%lu\n", image_size);
962 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
963 const char *buf, size_t n)
967 if (sscanf(buf, "%lu", &size) == 1) {
975 power_attr(image_size);
977 static ssize_t reserved_size_show(struct kobject *kobj,
978 struct kobj_attribute *attr, char *buf)
980 return sprintf(buf, "%lu\n", reserved_size);
983 static ssize_t reserved_size_store(struct kobject *kobj,
984 struct kobj_attribute *attr,
985 const char *buf, size_t n)
989 if (sscanf(buf, "%lu", &size) == 1) {
990 reserved_size = size;
997 power_attr(reserved_size);
999 static struct attribute * g[] = {
1002 &image_size_attr.attr,
1003 &reserved_size_attr.attr,
1008 static struct attribute_group attr_group = {
1013 static int __init pm_disk_init(void)
1015 return sysfs_create_group(power_kobj, &attr_group);
1018 core_initcall(pm_disk_init);
1021 static int __init resume_setup(char *str)
1026 strncpy( resume_file, str, 255 );
1030 static int __init resume_offset_setup(char *str)
1032 unsigned long long offset;
1037 if (sscanf(str, "%llu", &offset) == 1)
1038 swsusp_resume_block = offset;
1043 static int __init hibernate_setup(char *str)
1045 if (!strncmp(str, "noresume", 8))
1047 else if (!strncmp(str, "nocompress", 10))
1052 static int __init noresume_setup(char *str)
1058 static int __init resumewait_setup(char *str)
1064 static int __init resumedelay_setup(char *str)
1066 resume_delay = simple_strtoul(str, NULL, 0);
1070 __setup("noresume", noresume_setup);
1071 __setup("resume_offset=", resume_offset_setup);
1072 __setup("resume=", resume_setup);
1073 __setup("hibernate=", hibernate_setup);
1074 __setup("resumewait", resumewait_setup);
1075 __setup("resumedelay=", resumedelay_setup);