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 <scsi/scsi_scan.h>
33 static int nocompress;
35 static int resume_wait;
36 static int resume_delay;
37 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
38 dev_t swsusp_resume_device;
39 sector_t swsusp_resume_block;
40 int in_suspend __nosavedata;
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 bool freezer_test_done;
57 static const struct platform_hibernation_ops *hibernation_ops;
60 * hibernation_set_ops - Set the global hibernate operations.
61 * @ops: Hibernation operations to use in subsequent hibernation transitions.
63 void hibernation_set_ops(const struct platform_hibernation_ops *ops)
65 if (ops && !(ops->begin && ops->end && ops->pre_snapshot
66 && ops->prepare && ops->finish && ops->enter && ops->pre_restore
67 && ops->restore_cleanup && ops->leave)) {
72 hibernation_ops = ops;
74 hibernation_mode = HIBERNATION_PLATFORM;
75 else if (hibernation_mode == HIBERNATION_PLATFORM)
76 hibernation_mode = HIBERNATION_SHUTDOWN;
78 unlock_system_sleep();
81 static bool entering_platform_hibernation;
83 bool system_entering_hibernation(void)
85 return entering_platform_hibernation;
87 EXPORT_SYMBOL(system_entering_hibernation);
89 #ifdef CONFIG_PM_DEBUG
90 static void hibernation_debug_sleep(void)
92 printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
96 static int hibernation_test(int level)
98 if (pm_test_level == level) {
99 hibernation_debug_sleep();
104 #else /* !CONFIG_PM_DEBUG */
105 static int hibernation_test(int level) { return 0; }
106 #endif /* !CONFIG_PM_DEBUG */
109 * platform_begin - Call platform to start hibernation.
110 * @platform_mode: Whether or not to use the platform driver.
112 static int platform_begin(int platform_mode)
114 return (platform_mode && hibernation_ops) ?
115 hibernation_ops->begin() : 0;
119 * platform_end - Call platform to finish transition to the working state.
120 * @platform_mode: Whether or not to use the platform driver.
122 static void platform_end(int platform_mode)
124 if (platform_mode && hibernation_ops)
125 hibernation_ops->end();
129 * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
130 * @platform_mode: Whether or not to use the platform driver.
132 * Use the platform driver to prepare the system for creating a hibernate image,
133 * if so configured, and return an error code if that fails.
136 static int platform_pre_snapshot(int platform_mode)
138 return (platform_mode && hibernation_ops) ?
139 hibernation_ops->pre_snapshot() : 0;
143 * platform_leave - Call platform to prepare a transition to the working state.
144 * @platform_mode: Whether or not to use the platform driver.
146 * Use the platform driver prepare to prepare the machine for switching to the
147 * normal mode of operation.
149 * This routine is called on one CPU with interrupts disabled.
151 static void platform_leave(int platform_mode)
153 if (platform_mode && hibernation_ops)
154 hibernation_ops->leave();
158 * platform_finish - Call platform to switch the system to the working state.
159 * @platform_mode: Whether or not to use the platform driver.
161 * Use the platform driver to switch the machine to the normal mode of
164 * This routine 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 for hibernate image restoration.
174 * @platform_mode: Whether or not to use the platform driver.
176 * Use the platform driver to prepare the system for resume from a hibernation
179 * If the restore fails after this function has been called,
180 * platform_restore_cleanup() must be called.
182 static int platform_pre_restore(int platform_mode)
184 return (platform_mode && hibernation_ops) ?
185 hibernation_ops->pre_restore() : 0;
189 * platform_restore_cleanup - Switch to the working state after failing restore.
190 * @platform_mode: Whether or not to use the platform driver.
192 * Use the platform driver to switch the system to the normal mode of operation
193 * after a failing restore.
195 * If platform_pre_restore() has been called before the failing restore, this
196 * function must be called too, regardless of the result of
197 * platform_pre_restore().
199 static void platform_restore_cleanup(int platform_mode)
201 if (platform_mode && hibernation_ops)
202 hibernation_ops->restore_cleanup();
206 * platform_recover - Recover from a failure to suspend devices.
207 * @platform_mode: Whether or not to use the platform driver.
209 static void platform_recover(int platform_mode)
211 if (platform_mode && hibernation_ops && hibernation_ops->recover)
212 hibernation_ops->recover();
216 * swsusp_show_speed - Print time elapsed between two events during hibernation.
217 * @start: Starting event.
218 * @stop: Final event.
219 * @nr_pages: Number of memory pages processed between @start and @stop.
220 * @msg: Additional diagnostic message to print.
222 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
223 unsigned nr_pages, char *msg)
225 s64 elapsed_centisecs64;
230 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
231 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
232 centisecs = elapsed_centisecs64;
234 centisecs = 1; /* avoid div-by-zero */
235 k = nr_pages * (PAGE_SIZE / 1024);
236 kps = (k * 100) / centisecs;
237 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
239 centisecs / 100, centisecs % 100,
240 kps / 1000, (kps % 1000) / 10);
244 * create_image - Create a hibernation image.
245 * @platform_mode: Whether or not to use the platform driver.
247 * Execute device drivers' "late" and "noirq" freeze callbacks, create a
248 * hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
250 * Control reappears in this routine after the subsequent restore.
252 static int create_image(int platform_mode)
256 error = dpm_suspend_end(PMSG_FREEZE);
258 printk(KERN_ERR "PM: Some devices failed to power down, "
259 "aborting hibernation\n");
263 error = platform_pre_snapshot(platform_mode);
264 if (error || hibernation_test(TEST_PLATFORM))
265 goto Platform_finish;
267 error = disable_nonboot_cpus();
268 if (error || hibernation_test(TEST_CPUS))
273 error = syscore_suspend();
275 printk(KERN_ERR "PM: Some system devices failed to power down, "
276 "aborting hibernation\n");
280 if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
284 save_processor_state();
285 error = swsusp_arch_suspend();
287 printk(KERN_ERR "PM: Error %d creating hibernation image\n",
289 /* Restore control flow magically appears here */
290 restore_processor_state();
292 events_check_enabled = false;
293 platform_leave(platform_mode);
303 enable_nonboot_cpus();
306 platform_finish(platform_mode);
308 dpm_resume_start(in_suspend ?
309 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
315 * hibernation_snapshot - Quiesce devices and create a hibernation image.
316 * @platform_mode: If set, use platform driver to prepare for the transition.
318 * This routine must be called with pm_mutex held.
320 int hibernation_snapshot(int platform_mode)
325 error = platform_begin(platform_mode);
329 /* Preallocate image memory before shutting down devices. */
330 error = hibernate_preallocate_memory();
334 error = freeze_kernel_threads();
338 if (hibernation_test(TEST_FREEZER)) {
341 * Indicate to the caller that we are returning due to a
342 * successful freezer test.
344 freezer_test_done = true;
348 error = dpm_prepare(PMSG_FREEZE);
350 dpm_complete(PMSG_RECOVER);
355 pm_restrict_gfp_mask();
357 error = dpm_suspend(PMSG_FREEZE);
359 if (error || hibernation_test(TEST_DEVICES))
360 platform_recover(platform_mode);
362 error = create_image(platform_mode);
365 * In the case that we call create_image() above, the control
366 * returns here (1) after the image has been created or the
367 * 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();
384 platform_end(platform_mode);
388 thaw_kernel_threads();
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' "noirq" and "late" freeze callbacks, restore the
399 * contents of highmem that have not been restored yet from the image and run
400 * the low-level code that will restore the remaining contents of memory and
401 * switch to the just restored target kernel.
403 static int resume_target_kernel(bool platform_mode)
407 error = dpm_suspend_end(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_start(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_end(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_start(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_REBOOT:
577 kernel_restart(NULL);
579 case HIBERNATION_PLATFORM:
580 hibernation_platform_enter();
581 case HIBERNATION_SHUTDOWN:
587 * Valid image is on the disk, if we continue we risk serious data
588 * corruption after resume.
590 printk(KERN_CRIT "PM: Please power down manually\n");
595 * hibernate - Carry out system hibernation, including saving the image.
602 /* The snapshot device should not be opened while we're running */
603 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
608 pm_prepare_console();
609 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
613 /* Allocate memory management structures */
614 error = create_basic_memory_bitmaps();
618 printk(KERN_INFO "PM: Syncing filesystems ... ");
622 error = freeze_processes();
626 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
627 if (error || freezer_test_done)
631 unsigned int flags = 0;
633 if (hibernation_mode == HIBERNATION_PLATFORM)
634 flags |= SF_PLATFORM_MODE;
636 flags |= SF_NOCOMPRESS_MODE;
638 flags |= SF_CRC32_MODE;
640 pr_debug("PM: writing image.\n");
641 error = swsusp_write(flags);
646 pm_restore_gfp_mask();
648 pr_debug("PM: Image restored successfully.\n");
654 /* Don't bother checking whether freezer_test_done is true */
655 freezer_test_done = false;
658 free_basic_memory_bitmaps();
660 pm_notifier_call_chain(PM_POST_HIBERNATION);
661 pm_restore_console();
662 atomic_inc(&snapshot_device_available);
664 unlock_system_sleep();
670 * software_resume - Resume from a saved hibernation image.
672 * This routine is called as a late initcall, when all devices have been
673 * discovered and initialized already.
675 * The image reading code is called to see if there is a hibernation image
676 * available for reading. If that is the case, devices are quiesced and the
677 * contents of memory is restored from the saved image.
679 * If this is successful, control reappears in the restored target kernel in
680 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
681 * attempts to recover gracefully and make the kernel return to the normal mode
684 static int software_resume(void)
690 * If the user said "noresume".. bail out early.
696 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
697 * is configured into the kernel. Since the regular hibernate
698 * trigger path is via sysfs which takes a buffer mutex before
699 * calling hibernate functions (which take pm_mutex) this can
700 * cause lockdep to complain about a possible ABBA deadlock
701 * which cannot happen since we're in the boot code here and
702 * sysfs can't be invoked yet. Therefore, we use a subclass
703 * here to avoid lockdep complaining.
705 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
707 if (swsusp_resume_device)
710 if (!strlen(resume_file)) {
715 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
718 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
720 ssleep(resume_delay);
723 /* Check if the device is there */
724 swsusp_resume_device = name_to_dev_t(resume_file);
725 if (!swsusp_resume_device) {
727 * Some device discovery might still be in progress; we need
728 * to wait for this to finish.
730 wait_for_device_probe();
733 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
735 async_synchronize_full();
739 * We can't depend on SCSI devices being available after loading
740 * one of their modules until scsi_complete_async_scans() is
741 * called and the resume device usually is a SCSI one.
743 scsi_complete_async_scans();
745 swsusp_resume_device = name_to_dev_t(resume_file);
746 if (!swsusp_resume_device) {
753 pr_debug("PM: Hibernation image partition %d:%d present\n",
754 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
756 pr_debug("PM: Looking for hibernation image.\n");
757 error = swsusp_check();
761 /* The snapshot device should not be opened while we're running */
762 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
764 swsusp_close(FMODE_READ);
768 pm_prepare_console();
769 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
773 error = create_basic_memory_bitmaps();
777 pr_debug("PM: Preparing processes for restore.\n");
778 error = freeze_processes();
780 swsusp_close(FMODE_READ);
784 pr_debug("PM: Loading hibernation image.\n");
786 error = swsusp_read(&flags);
787 swsusp_close(FMODE_READ);
789 hibernation_restore(flags & SF_PLATFORM_MODE);
791 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
795 free_basic_memory_bitmaps();
797 pm_notifier_call_chain(PM_POST_RESTORE);
798 pm_restore_console();
799 atomic_inc(&snapshot_device_available);
800 /* For success case, the suspend path will release the lock */
802 mutex_unlock(&pm_mutex);
803 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
806 swsusp_close(FMODE_READ);
810 late_initcall(software_resume);
813 static const char * const hibernation_modes[] = {
814 [HIBERNATION_PLATFORM] = "platform",
815 [HIBERNATION_SHUTDOWN] = "shutdown",
816 [HIBERNATION_REBOOT] = "reboot",
820 * /sys/power/disk - Control hibernation mode.
822 * Hibernation can be handled in several ways. There are a few different ways
823 * to put the system into the sleep state: using the platform driver (e.g. ACPI
824 * or other hibernation_ops), powering it off or rebooting it (for testing
827 * The sysfs file /sys/power/disk provides an interface for selecting the
828 * hibernation mode to use. Reading from this file causes the available modes
829 * to be printed. There are 3 modes that can be supported:
835 * If a platform hibernation driver is in use, 'platform' will be supported
836 * and will be used by default. Otherwise, 'shutdown' will be used by default.
837 * The selected option (i.e. the one corresponding to the current value of
838 * hibernation_mode) is enclosed by a square bracket.
840 * To select a given hibernation mode it is necessary to write the mode's
841 * string representation (as returned by reading from /sys/power/disk) back
842 * into /sys/power/disk.
845 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
851 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
852 if (!hibernation_modes[i])
855 case HIBERNATION_SHUTDOWN:
856 case HIBERNATION_REBOOT:
858 case HIBERNATION_PLATFORM:
861 /* not a valid mode, continue with loop */
864 if (i == hibernation_mode)
865 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
867 buf += sprintf(buf, "%s ", hibernation_modes[i]);
869 buf += sprintf(buf, "\n");
873 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
874 const char *buf, size_t n)
880 int mode = HIBERNATION_INVALID;
882 p = memchr(buf, '\n', n);
883 len = p ? p - buf : n;
886 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
887 if (len == strlen(hibernation_modes[i])
888 && !strncmp(buf, hibernation_modes[i], len)) {
893 if (mode != HIBERNATION_INVALID) {
895 case HIBERNATION_SHUTDOWN:
896 case HIBERNATION_REBOOT:
897 hibernation_mode = mode;
899 case HIBERNATION_PLATFORM:
901 hibernation_mode = mode;
909 pr_debug("PM: Hibernation mode set to '%s'\n",
910 hibernation_modes[mode]);
911 unlock_system_sleep();
912 return error ? error : n;
917 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
920 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
921 MINOR(swsusp_resume_device));
924 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
925 const char *buf, size_t n)
927 unsigned int maj, min;
931 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
934 res = MKDEV(maj,min);
935 if (maj != MAJOR(res) || min != MINOR(res))
939 swsusp_resume_device = res;
940 unlock_system_sleep();
941 printk(KERN_INFO "PM: Starting manual resume from disk\n");
951 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
954 return sprintf(buf, "%lu\n", image_size);
957 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
958 const char *buf, size_t n)
962 if (sscanf(buf, "%lu", &size) == 1) {
970 power_attr(image_size);
972 static ssize_t reserved_size_show(struct kobject *kobj,
973 struct kobj_attribute *attr, char *buf)
975 return sprintf(buf, "%lu\n", reserved_size);
978 static ssize_t reserved_size_store(struct kobject *kobj,
979 struct kobj_attribute *attr,
980 const char *buf, size_t n)
984 if (sscanf(buf, "%lu", &size) == 1) {
985 reserved_size = size;
992 power_attr(reserved_size);
994 static struct attribute * g[] = {
997 &image_size_attr.attr,
998 &reserved_size_attr.attr,
1003 static struct attribute_group attr_group = {
1008 static int __init pm_disk_init(void)
1010 return sysfs_create_group(power_kobj, &attr_group);
1013 core_initcall(pm_disk_init);
1016 static int __init resume_setup(char *str)
1021 strncpy( resume_file, str, 255 );
1025 static int __init resume_offset_setup(char *str)
1027 unsigned long long offset;
1032 if (sscanf(str, "%llu", &offset) == 1)
1033 swsusp_resume_block = offset;
1038 static int __init hibernate_setup(char *str)
1040 if (!strncmp(str, "noresume", 8))
1042 else if (!strncmp(str, "nocompress", 10))
1047 static int __init noresume_setup(char *str)
1053 static int __init resumewait_setup(char *str)
1059 static int __init resumedelay_setup(char *str)
1061 resume_delay = simple_strtoul(str, NULL, 0);
1065 __setup("noresume", noresume_setup);
1066 __setup("resume_offset=", resume_offset_setup);
1067 __setup("resume=", resume_setup);
1068 __setup("hibernate=", hibernate_setup);
1069 __setup("resumewait", resumewait_setup);
1070 __setup("resumedelay=", resumedelay_setup);