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 <scsi/scsi_scan.h>
27 #include <asm/suspend.h>
32 static int noresume = 0;
33 static char resume_file[256] = CONFIG_PM_STD_PARTITION;
34 dev_t swsusp_resume_device;
35 sector_t swsusp_resume_block;
36 int in_suspend __nosavedata = 0;
46 __HIBERNATION_AFTER_LAST
48 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
49 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
51 static int hibernation_mode = HIBERNATION_SHUTDOWN;
53 static struct platform_hibernation_ops *hibernation_ops;
56 * hibernation_set_ops - set the global hibernate operations
57 * @ops: the hibernation operations to use in subsequent hibernation transitions
60 void hibernation_set_ops(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)) {
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 - tell the platform driver that we're starting
120 static int platform_begin(int platform_mode)
122 return (platform_mode && hibernation_ops) ?
123 hibernation_ops->begin() : 0;
127 * platform_end - tell the platform driver that we've entered the
131 static void platform_end(int platform_mode)
133 if (platform_mode && hibernation_ops)
134 hibernation_ops->end();
138 * platform_pre_snapshot - prepare the machine for hibernation using the
139 * platform driver if so configured and return an error code if it fails
142 static int platform_pre_snapshot(int platform_mode)
144 return (platform_mode && hibernation_ops) ?
145 hibernation_ops->pre_snapshot() : 0;
149 * platform_leave - prepare the machine for switching to the normal mode
150 * of operation using the platform driver (called with interrupts disabled)
153 static void platform_leave(int platform_mode)
155 if (platform_mode && hibernation_ops)
156 hibernation_ops->leave();
160 * platform_finish - switch the machine to the normal mode of operation
161 * using the platform driver (must be called after platform_prepare())
164 static void platform_finish(int platform_mode)
166 if (platform_mode && hibernation_ops)
167 hibernation_ops->finish();
171 * platform_pre_restore - prepare the platform for the restoration from a
172 * hibernation image. If the restore fails after this function has been
173 * called, platform_restore_cleanup() must be called.
176 static int platform_pre_restore(int platform_mode)
178 return (platform_mode && hibernation_ops) ?
179 hibernation_ops->pre_restore() : 0;
183 * platform_restore_cleanup - switch the platform to the normal mode of
184 * operation after a failing restore. If platform_pre_restore() has been
185 * called before the failing restore, this function must be called too,
186 * regardless of the result of platform_pre_restore().
189 static void platform_restore_cleanup(int platform_mode)
191 if (platform_mode && hibernation_ops)
192 hibernation_ops->restore_cleanup();
196 * platform_recover - recover the platform from a failure to suspend
200 static void platform_recover(int platform_mode)
202 if (platform_mode && hibernation_ops && hibernation_ops->recover)
203 hibernation_ops->recover();
207 * swsusp_show_speed - print the time elapsed between two events.
208 * @start: Starting event.
209 * @stop: Final event.
210 * @nr_pages - number of pages processed between @start and @stop
211 * @msg - introductory message to print
214 void swsusp_show_speed(struct timeval *start, struct timeval *stop,
215 unsigned nr_pages, char *msg)
217 s64 elapsed_centisecs64;
222 elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
223 do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
224 centisecs = elapsed_centisecs64;
226 centisecs = 1; /* avoid div-by-zero */
227 k = nr_pages * (PAGE_SIZE / 1024);
228 kps = (k * 100) / centisecs;
229 printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
231 centisecs / 100, centisecs % 100,
232 kps / 1000, (kps % 1000) / 10);
236 * create_image - freeze devices that need to be frozen with interrupts
237 * off, create the hibernation image and thaw those devices. Control
238 * reappears in this routine after a restore.
241 static int create_image(int platform_mode)
245 error = arch_prepare_suspend();
249 /* At this point, dpm_suspend_start() has been called, but *not*
250 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
251 * Otherwise, drivers for some devices (e.g. interrupt controllers)
252 * become desynchronized with the actual state of the hardware
253 * at resume time, and evil weirdness ensues.
255 error = dpm_suspend_noirq(PMSG_FREEZE);
257 printk(KERN_ERR "PM: Some devices failed to power down, "
258 "aborting hibernation\n");
262 error = platform_pre_snapshot(platform_mode);
263 if (error || hibernation_test(TEST_PLATFORM))
264 goto Platform_finish;
266 error = disable_nonboot_cpus();
267 if (error || hibernation_test(TEST_CPUS)
268 || hibernation_testmode(HIBERNATION_TEST))
273 error = sysdev_suspend(PMSG_FREEZE);
275 printk(KERN_ERR "PM: Some system devices failed to power down, "
276 "aborting hibernation\n");
280 if (hibernation_test(TEST_CORE) || !pm_check_wakeup_events())
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);
298 /* NOTE: dpm_resume_noirq() is just a resume() for devices
299 * that suspended with irqs off ... no overall powerup.
306 enable_nonboot_cpus();
309 platform_finish(platform_mode);
311 dpm_resume_noirq(in_suspend ?
312 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
318 * hibernation_snapshot - quiesce devices and create the hibernation
320 * @platform_mode - if set, use the platform driver, if available, to
321 * prepare the platform firmware for the power transition.
323 * Must be called with pm_mutex held
326 int hibernation_snapshot(int platform_mode)
330 error = platform_begin(platform_mode);
334 /* Preallocate image memory before shutting down devices. */
335 error = hibernate_preallocate_memory();
340 pm_restrict_gfp_mask();
341 error = dpm_suspend_start(PMSG_FREEZE);
343 goto Recover_platform;
345 if (hibernation_test(TEST_DEVICES))
346 goto Recover_platform;
348 error = create_image(platform_mode);
350 * Control returns here (1) after the image has been created or the
351 * image creation has failed and (2) after a successful restore.
355 /* We may need to release the preallocated image pages here. */
356 if (error || !in_suspend)
359 dpm_resume_end(in_suspend ?
360 (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
362 if (error || !in_suspend)
363 pm_restore_gfp_mask();
367 platform_end(platform_mode);
371 platform_recover(platform_mode);
376 * resume_target_kernel - prepare devices that need to be suspended with
377 * interrupts off, restore the contents of highmem that have not been
378 * restored yet from the image and run the low level code that will restore
379 * the remaining contents of memory and switch to the just restored target
383 static int resume_target_kernel(bool platform_mode)
387 error = dpm_suspend_noirq(PMSG_QUIESCE);
389 printk(KERN_ERR "PM: Some devices failed to power down, "
390 "aborting resume\n");
394 error = platform_pre_restore(platform_mode);
398 error = disable_nonboot_cpus();
404 error = sysdev_suspend(PMSG_QUIESCE);
408 /* We'll ignore saved state, but this gets preempt count (etc) right */
409 save_processor_state();
410 error = restore_highmem();
412 error = swsusp_arch_resume();
414 * The code below is only ever reached in case of a failure.
415 * Otherwise execution continues at place where
416 * swsusp_arch_suspend() was called
419 /* This call to restore_highmem() undos the previous one */
423 * The only reason why swsusp_arch_resume() can fail is memory being
424 * very tight, so we have to free it as soon as we can to avoid
425 * subsequent failures
428 restore_processor_state();
429 touch_softlockup_watchdog();
437 enable_nonboot_cpus();
440 platform_restore_cleanup(platform_mode);
442 dpm_resume_noirq(PMSG_RECOVER);
448 * hibernation_restore - quiesce devices and restore the hibernation
449 * snapshot image. If successful, control returns in hibernation_snaphot()
450 * @platform_mode - if set, use the platform driver, if available, to
451 * prepare the platform firmware for the transition.
453 * Must be called with pm_mutex held
456 int hibernation_restore(int platform_mode)
460 pm_prepare_console();
462 pm_restrict_gfp_mask();
463 error = dpm_suspend_start(PMSG_QUIESCE);
465 error = resume_target_kernel(platform_mode);
466 dpm_resume_end(PMSG_RECOVER);
468 pm_restore_gfp_mask();
470 pm_restore_console();
475 * hibernation_platform_enter - enter the hibernation state using the
476 * platform driver (if available)
479 int hibernation_platform_enter(void)
483 if (!hibernation_ops)
487 * We have cancelled the power transition by running
488 * hibernation_ops->finish() before saving the image, so we should let
489 * the firmware know that we're going to enter the sleep state after all
491 error = hibernation_ops->begin();
495 entering_platform_hibernation = true;
497 error = dpm_suspend_start(PMSG_HIBERNATE);
499 if (hibernation_ops->recover)
500 hibernation_ops->recover();
504 error = dpm_suspend_noirq(PMSG_HIBERNATE);
508 error = hibernation_ops->prepare();
510 goto Platform_finish;
512 error = disable_nonboot_cpus();
514 goto Platform_finish;
517 sysdev_suspend(PMSG_HIBERNATE);
518 if (!pm_check_wakeup_events()) {
523 hibernation_ops->enter();
524 /* We should never get here */
530 enable_nonboot_cpus();
533 hibernation_ops->finish();
535 dpm_resume_noirq(PMSG_RESTORE);
538 entering_platform_hibernation = false;
539 dpm_resume_end(PMSG_RESTORE);
543 hibernation_ops->end();
549 * power_down - Shut the machine down for hibernation.
551 * Use the platform driver, if configured so; otherwise try
552 * to power off or reboot.
555 static void power_down(void)
557 switch (hibernation_mode) {
558 case HIBERNATION_TEST:
559 case HIBERNATION_TESTPROC:
561 case HIBERNATION_REBOOT:
562 kernel_restart(NULL);
564 case HIBERNATION_PLATFORM:
565 hibernation_platform_enter();
566 case HIBERNATION_SHUTDOWN:
572 * Valid image is on the disk, if we continue we risk serious data
573 * corruption after resume.
575 printk(KERN_CRIT "PM: Please power down manually\n");
579 static int prepare_processes(void)
583 if (freeze_processes()) {
591 * hibernate - The granpappy of the built-in hibernation management
598 mutex_lock(&pm_mutex);
599 /* The snapshot device should not be opened while we're running */
600 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
605 pm_prepare_console();
606 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
610 error = usermodehelper_disable();
614 /* Allocate memory management structures */
615 error = create_basic_memory_bitmaps();
619 printk(KERN_INFO "PM: Syncing filesystems ... ");
623 error = prepare_processes();
627 if (hibernation_test(TEST_FREEZER))
630 if (hibernation_testmode(HIBERNATION_TESTPROC))
633 error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
638 unsigned int flags = 0;
640 if (hibernation_mode == HIBERNATION_PLATFORM)
641 flags |= SF_PLATFORM_MODE;
642 pr_debug("PM: writing image.\n");
643 error = swsusp_write(flags);
647 pm_restore_gfp_mask();
649 pr_debug("PM: Image restored successfully.\n");
655 free_basic_memory_bitmaps();
656 usermodehelper_enable();
658 pm_notifier_call_chain(PM_POST_HIBERNATION);
659 pm_restore_console();
660 atomic_inc(&snapshot_device_available);
662 mutex_unlock(&pm_mutex);
668 * software_resume - Resume from a saved image.
670 * Called as a late_initcall (so all devices are discovered and
671 * initialized), we call swsusp to see if we have a saved image or not.
672 * If so, we quiesce devices, the restore the saved image. We will
673 * return above (in hibernate() ) if everything goes well.
674 * Otherwise, we fail gracefully and return to the normally
679 static int software_resume(void)
685 * If the user said "noresume".. bail out early.
691 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
692 * is configured into the kernel. Since the regular hibernate
693 * trigger path is via sysfs which takes a buffer mutex before
694 * calling hibernate functions (which take pm_mutex) this can
695 * cause lockdep to complain about a possible ABBA deadlock
696 * which cannot happen since we're in the boot code here and
697 * sysfs can't be invoked yet. Therefore, we use a subclass
698 * here to avoid lockdep complaining.
700 mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
702 if (swsusp_resume_device)
705 if (!strlen(resume_file)) {
710 pr_debug("PM: Checking image partition %s\n", resume_file);
712 /* Check if the device is there */
713 swsusp_resume_device = name_to_dev_t(resume_file);
714 if (!swsusp_resume_device) {
716 * Some device discovery might still be in progress; we need
717 * to wait for this to finish.
719 wait_for_device_probe();
721 * We can't depend on SCSI devices being available after loading
722 * one of their modules until scsi_complete_async_scans() is
723 * called and the resume device usually is a SCSI one.
725 scsi_complete_async_scans();
727 swsusp_resume_device = name_to_dev_t(resume_file);
728 if (!swsusp_resume_device) {
735 pr_debug("PM: Resume from partition %d:%d\n",
736 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
738 pr_debug("PM: Checking hibernation image.\n");
739 error = swsusp_check();
743 /* The snapshot device should not be opened while we're running */
744 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
746 swsusp_close(FMODE_READ);
750 pm_prepare_console();
751 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
755 error = usermodehelper_disable();
759 error = create_basic_memory_bitmaps();
763 pr_debug("PM: Preparing processes for restore.\n");
764 error = prepare_processes();
766 swsusp_close(FMODE_READ);
770 pr_debug("PM: Reading hibernation image.\n");
772 error = swsusp_read(&flags);
773 swsusp_close(FMODE_READ);
775 hibernation_restore(flags & SF_PLATFORM_MODE);
777 printk(KERN_ERR "PM: Restore failed, recovering.\n");
781 free_basic_memory_bitmaps();
782 usermodehelper_enable();
784 pm_notifier_call_chain(PM_POST_RESTORE);
785 pm_restore_console();
786 atomic_inc(&snapshot_device_available);
787 /* For success case, the suspend path will release the lock */
789 mutex_unlock(&pm_mutex);
790 pr_debug("PM: Resume from disk failed.\n");
793 swsusp_close(FMODE_READ);
797 late_initcall(software_resume);
800 static const char * const hibernation_modes[] = {
801 [HIBERNATION_PLATFORM] = "platform",
802 [HIBERNATION_SHUTDOWN] = "shutdown",
803 [HIBERNATION_REBOOT] = "reboot",
804 [HIBERNATION_TEST] = "test",
805 [HIBERNATION_TESTPROC] = "testproc",
809 * disk - Control hibernation mode
811 * Suspend-to-disk can be handled in several ways. We have a few options
812 * for putting the system to sleep - using the platform driver (e.g. ACPI
813 * or other hibernation_ops), powering off the system or rebooting the
814 * system (for testing) as well as the two test modes.
816 * The system can support 'platform', and that is known a priori (and
817 * encoded by the presence of hibernation_ops). However, the user may
818 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
819 * test modes, 'test' or 'testproc'.
821 * show() will display what the mode is currently set to.
822 * store() will accept one of
830 * It will only change to 'platform' if the system
831 * supports it (as determined by having hibernation_ops).
834 static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
840 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
841 if (!hibernation_modes[i])
844 case HIBERNATION_SHUTDOWN:
845 case HIBERNATION_REBOOT:
846 case HIBERNATION_TEST:
847 case HIBERNATION_TESTPROC:
849 case HIBERNATION_PLATFORM:
852 /* not a valid mode, continue with loop */
855 if (i == hibernation_mode)
856 buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
858 buf += sprintf(buf, "%s ", hibernation_modes[i]);
860 buf += sprintf(buf, "\n");
865 static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
866 const char *buf, size_t n)
872 int mode = HIBERNATION_INVALID;
874 p = memchr(buf, '\n', n);
875 len = p ? p - buf : n;
877 mutex_lock(&pm_mutex);
878 for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
879 if (len == strlen(hibernation_modes[i])
880 && !strncmp(buf, hibernation_modes[i], len)) {
885 if (mode != HIBERNATION_INVALID) {
887 case HIBERNATION_SHUTDOWN:
888 case HIBERNATION_REBOOT:
889 case HIBERNATION_TEST:
890 case HIBERNATION_TESTPROC:
891 hibernation_mode = mode;
893 case HIBERNATION_PLATFORM:
895 hibernation_mode = mode;
903 pr_debug("PM: Hibernation mode set to '%s'\n",
904 hibernation_modes[mode]);
905 mutex_unlock(&pm_mutex);
906 return error ? error : n;
911 static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
914 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
915 MINOR(swsusp_resume_device));
918 static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
919 const char *buf, size_t n)
921 unsigned int maj, min;
925 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
928 res = MKDEV(maj,min);
929 if (maj != MAJOR(res) || min != MINOR(res))
932 mutex_lock(&pm_mutex);
933 swsusp_resume_device = res;
934 mutex_unlock(&pm_mutex);
935 printk(KERN_INFO "PM: Starting manual resume from disk\n");
945 static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
948 return sprintf(buf, "%lu\n", image_size);
951 static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
952 const char *buf, size_t n)
956 if (sscanf(buf, "%lu", &size) == 1) {
964 power_attr(image_size);
966 static struct attribute * g[] = {
969 &image_size_attr.attr,
974 static struct attribute_group attr_group = {
979 static int __init pm_disk_init(void)
981 return sysfs_create_group(power_kobj, &attr_group);
984 core_initcall(pm_disk_init);
987 static int __init resume_setup(char *str)
992 strncpy( resume_file, str, 255 );
996 static int __init resume_offset_setup(char *str)
998 unsigned long long offset;
1003 if (sscanf(str, "%llu", &offset) == 1)
1004 swsusp_resume_block = offset;
1009 static int __init noresume_setup(char *str)
1015 __setup("noresume", noresume_setup);
1016 __setup("resume_offset=", resume_offset_setup);
1017 __setup("resume=", resume_setup);