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");
614 static int prepare_processes(void)
618 if (freeze_processes()) {
626 * hibernate - Carry out system hibernation, including saving the image.
632 mutex_lock(&pm_mutex);
633 /* The snapshot device should not be opened while we're running */
634 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
639 pm_prepare_console();
640 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
644 error = usermodehelper_disable();
648 /* Allocate memory management structures */
649 error = create_basic_memory_bitmaps();
653 printk(KERN_INFO "PM: Syncing filesystems ... ");
657 error = prepare_processes();
661 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
664 if (freezer_test_done) {
665 freezer_test_done = false;
670 unsigned int flags = 0;
672 if (hibernation_mode == HIBERNATION_PLATFORM)
673 flags |= SF_PLATFORM_MODE;
675 flags |= SF_NOCOMPRESS_MODE;
677 flags |= SF_CRC32_MODE;
679 pr_debug("PM: writing image.\n");
680 error = swsusp_write(flags);
685 pm_restore_gfp_mask();
687 pr_debug("PM: Image restored successfully.\n");
693 free_basic_memory_bitmaps();
694 usermodehelper_enable();
696 pm_notifier_call_chain(PM_POST_HIBERNATION);
697 pm_restore_console();
698 atomic_inc(&snapshot_device_available);
700 mutex_unlock(&pm_mutex);
706 * software_resume - Resume from a saved hibernation image.
708 * This routine is called as a late initcall, when all devices have been
709 * discovered and initialized already.
711 * The image reading code is called to see if there is a hibernation image
712 * available for reading. If that is the case, devices are quiesced and the
713 * contents of memory is restored from the saved image.
715 * If this is successful, control reappears in the restored target kernel in
716 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
717 * attempts to recover gracefully and make the kernel return to the normal mode
720 static int software_resume(void)
726 * If the user said "noresume".. bail out early.
732 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
733 * is configured into the kernel. Since the regular hibernate
734 * trigger path is via sysfs which takes a buffer mutex before
735 * calling hibernate functions (which take pm_mutex) this can
736 * cause lockdep to complain about a possible ABBA deadlock
737 * which cannot happen since we're in the boot code here and
738 * sysfs can't be invoked yet. Therefore, we use a subclass
739 * here to avoid lockdep complaining.
741 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
743 if (swsusp_resume_device)
746 if (!strlen(resume_file)) {
751 pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
754 printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
756 ssleep(resume_delay);
759 /* Check if the device is there */
760 swsusp_resume_device = name_to_dev_t(resume_file);
761 if (!swsusp_resume_device) {
763 * Some device discovery might still be in progress; we need
764 * to wait for this to finish.
766 wait_for_device_probe();
769 while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
771 async_synchronize_full();
775 * We can't depend on SCSI devices being available after loading
776 * one of their modules until scsi_complete_async_scans() is
777 * called and the resume device usually is a SCSI one.
779 scsi_complete_async_scans();
781 swsusp_resume_device = name_to_dev_t(resume_file);
782 if (!swsusp_resume_device) {
789 pr_debug("PM: Hibernation image partition %d:%d present\n",
790 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
792 pr_debug("PM: Looking for hibernation image.\n");
793 error = swsusp_check();
797 /* The snapshot device should not be opened while we're running */
798 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
800 swsusp_close(FMODE_READ);
804 pm_prepare_console();
805 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
809 error = usermodehelper_disable();
813 error = create_basic_memory_bitmaps();
817 pr_debug("PM: Preparing processes for restore.\n");
818 error = prepare_processes();
820 swsusp_close(FMODE_READ);
824 pr_debug("PM: Loading hibernation image.\n");
826 error = swsusp_read(&flags);
827 swsusp_close(FMODE_READ);
829 hibernation_restore(flags & SF_PLATFORM_MODE);
831 printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
835 free_basic_memory_bitmaps();
836 usermodehelper_enable();
838 pm_notifier_call_chain(PM_POST_RESTORE);
839 pm_restore_console();
840 atomic_inc(&snapshot_device_available);
841 /* For success case, the suspend path will release the lock */
843 mutex_unlock(&pm_mutex);
844 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
847 swsusp_close(FMODE_READ);
851 late_initcall(software_resume);
854 static const char * const hibernation_modes[] = {
855 [HIBERNATION_PLATFORM] = "platform",
856 [HIBERNATION_SHUTDOWN] = "shutdown",
857 [HIBERNATION_REBOOT] = "reboot",
858 [HIBERNATION_TEST] = "test",
859 [HIBERNATION_TESTPROC] = "testproc",
863 * /sys/power/disk - Control hibernation mode.
865 * Hibernation can be handled in several ways. There are a few different ways
866 * to put the system into the sleep state: using the platform driver (e.g. ACPI
867 * or other hibernation_ops), powering it off or rebooting it (for testing
868 * mostly), or using one of the two available test modes.
870 * The sysfs file /sys/power/disk provides an interface for selecting the
871 * hibernation mode to use. Reading from this file causes the available modes
872 * to be printed. There are 5 modes that can be supported:
880 * If a platform hibernation driver is in use, 'platform' will be supported
881 * and will be used by default. Otherwise, 'shutdown' will be used by default.
882 * The selected option (i.e. the one corresponding to the current value of
883 * hibernation_mode) is enclosed by a square bracket.
885 * To select a given hibernation mode it is necessary to write the mode's
886 * string representation (as returned by reading from /sys/power/disk) back
887 * into /sys/power/disk.
890 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
896 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
897 if (!hibernation_modes[i])
900 case HIBERNATION_SHUTDOWN:
901 case HIBERNATION_REBOOT:
902 case HIBERNATION_TEST:
903 case HIBERNATION_TESTPROC:
905 case HIBERNATION_PLATFORM:
908 /* not a valid mode, continue with loop */
911 if (i == hibernation_mode)
912 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
914 buf += sprintf(buf, "%s ", hibernation_modes[i]);
916 buf += sprintf(buf, "\n");
920 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
921 const char *buf, size_t n)
927 int mode = HIBERNATION_INVALID;
929 p = memchr(buf, '\n', n);
930 len = p ? p - buf : n;
932 mutex_lock(&pm_mutex);
933 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
934 if (len == strlen(hibernation_modes[i])
935 && !strncmp(buf, hibernation_modes[i], len)) {
940 if (mode != HIBERNATION_INVALID) {
942 case HIBERNATION_SHUTDOWN:
943 case HIBERNATION_REBOOT:
944 case HIBERNATION_TEST:
945 case HIBERNATION_TESTPROC:
946 hibernation_mode = mode;
948 case HIBERNATION_PLATFORM:
950 hibernation_mode = mode;
958 pr_debug("PM: Hibernation mode set to '%s'\n",
959 hibernation_modes[mode]);
960 mutex_unlock(&pm_mutex);
961 return error ? error : n;
966 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
969 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
970 MINOR(swsusp_resume_device));
973 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
974 const char *buf, size_t n)
976 unsigned int maj, min;
980 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
983 res = MKDEV(maj,min);
984 if (maj != MAJOR(res) || min != MINOR(res))
987 mutex_lock(&pm_mutex);
988 swsusp_resume_device = res;
989 mutex_unlock(&pm_mutex);
990 printk(KERN_INFO "PM: Starting manual resume from disk\n");
1000 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
1003 return sprintf(buf, "%lu\n", image_size);
1006 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
1007 const char *buf, size_t n)
1011 if (sscanf(buf, "%lu", &size) == 1) {
1019 power_attr(image_size);
1021 static ssize_t reserved_size_show(struct kobject *kobj,
1022 struct kobj_attribute *attr, char *buf)
1024 return sprintf(buf, "%lu\n", reserved_size);
1027 static ssize_t reserved_size_store(struct kobject *kobj,
1028 struct kobj_attribute *attr,
1029 const char *buf, size_t n)
1033 if (sscanf(buf, "%lu", &size) == 1) {
1034 reserved_size = size;
1041 power_attr(reserved_size);
1043 static struct attribute * g[] = {
1046 &image_size_attr.attr,
1047 &reserved_size_attr.attr,
1052 static struct attribute_group attr_group = {
1057 static int __init pm_disk_init(void)
1059 return sysfs_create_group(power_kobj, &attr_group);
1062 core_initcall(pm_disk_init);
1065 static int __init resume_setup(char *str)
1070 strncpy( resume_file, str, 255 );
1074 static int __init resume_offset_setup(char *str)
1076 unsigned long long offset;
1081 if (sscanf(str, "%llu", &offset) == 1)
1082 swsusp_resume_block = offset;
1087 static int __init hibernate_setup(char *str)
1089 if (!strncmp(str, "noresume", 8))
1091 else if (!strncmp(str, "nocompress", 10))
1096 static int __init noresume_setup(char *str)
1102 static int __init resumewait_setup(char *str)
1108 static int __init resumedelay_setup(char *str)
1110 resume_delay = simple_strtoul(str, NULL, 0);
1114 __setup("noresume", noresume_setup);
1115 __setup("resume_offset=", resume_offset_setup);
1116 __setup("resume=", resume_setup);
1117 __setup("hibernate=", hibernate_setup);
1118 __setup("resumewait", resumewait_setup);
1119 __setup("resumedelay=", resumedelay_setup);