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
;
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 error
= usermodehelper_disable();
618 /* Allocate memory management structures */
619 error
= create_basic_memory_bitmaps();
623 printk(KERN_INFO
"PM: Syncing filesystems ... ");
627 error
= freeze_processes();
631 error
= hibernation_snapshot(hibernation_mode
== HIBERNATION_PLATFORM
);
634 if (freezer_test_done
) {
635 freezer_test_done
= false;
640 unsigned int flags
= 0;
642 if (hibernation_mode
== HIBERNATION_PLATFORM
)
643 flags
|= SF_PLATFORM_MODE
;
645 flags
|= SF_NOCOMPRESS_MODE
;
647 flags
|= SF_CRC32_MODE
;
649 pr_debug("PM: writing image.\n");
650 error
= swsusp_write(flags
);
655 pm_restore_gfp_mask();
657 pr_debug("PM: Image restored successfully.\n");
663 free_basic_memory_bitmaps();
664 usermodehelper_enable();
666 pm_notifier_call_chain(PM_POST_HIBERNATION
);
667 pm_restore_console();
668 atomic_inc(&snapshot_device_available
);
670 unlock_system_sleep();
676 * software_resume - Resume from a saved hibernation image.
678 * This routine is called as a late initcall, when all devices have been
679 * discovered and initialized already.
681 * The image reading code is called to see if there is a hibernation image
682 * available for reading. If that is the case, devices are quiesced and the
683 * contents of memory is restored from the saved image.
685 * If this is successful, control reappears in the restored target kernel in
686 * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
687 * attempts to recover gracefully and make the kernel return to the normal mode
690 static int software_resume(void)
696 * If the user said "noresume".. bail out early.
702 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
703 * is configured into the kernel. Since the regular hibernate
704 * trigger path is via sysfs which takes a buffer mutex before
705 * calling hibernate functions (which take pm_mutex) this can
706 * cause lockdep to complain about a possible ABBA deadlock
707 * which cannot happen since we're in the boot code here and
708 * sysfs can't be invoked yet. Therefore, we use a subclass
709 * here to avoid lockdep complaining.
711 mutex_lock_nested(&pm_mutex
, SINGLE_DEPTH_NESTING
);
713 if (swsusp_resume_device
)
716 if (!strlen(resume_file
)) {
721 pr_debug("PM: Checking hibernation image partition %s\n", resume_file
);
724 printk(KERN_INFO
"Waiting %dsec before reading resume device...\n",
726 ssleep(resume_delay
);
729 /* Check if the device is there */
730 swsusp_resume_device
= name_to_dev_t(resume_file
);
731 if (!swsusp_resume_device
) {
733 * Some device discovery might still be in progress; we need
734 * to wait for this to finish.
736 wait_for_device_probe();
739 while ((swsusp_resume_device
= name_to_dev_t(resume_file
)) == 0)
741 async_synchronize_full();
745 * We can't depend on SCSI devices being available after loading
746 * one of their modules until scsi_complete_async_scans() is
747 * called and the resume device usually is a SCSI one.
749 scsi_complete_async_scans();
751 swsusp_resume_device
= name_to_dev_t(resume_file
);
752 if (!swsusp_resume_device
) {
759 pr_debug("PM: Hibernation image partition %d:%d present\n",
760 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
762 pr_debug("PM: Looking for hibernation image.\n");
763 error
= swsusp_check();
767 /* The snapshot device should not be opened while we're running */
768 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
770 swsusp_close(FMODE_READ
);
774 pm_prepare_console();
775 error
= pm_notifier_call_chain(PM_RESTORE_PREPARE
);
779 error
= usermodehelper_disable();
783 error
= create_basic_memory_bitmaps();
785 usermodehelper_enable();
789 pr_debug("PM: Preparing processes for restore.\n");
790 error
= freeze_processes();
792 swsusp_close(FMODE_READ
);
796 pr_debug("PM: Loading hibernation image.\n");
798 error
= swsusp_read(&flags
);
799 swsusp_close(FMODE_READ
);
801 hibernation_restore(flags
& SF_PLATFORM_MODE
);
803 printk(KERN_ERR
"PM: Failed to load hibernation image, recovering.\n");
807 free_basic_memory_bitmaps();
808 usermodehelper_enable();
810 pm_notifier_call_chain(PM_POST_RESTORE
);
811 pm_restore_console();
812 atomic_inc(&snapshot_device_available
);
813 /* For success case, the suspend path will release the lock */
815 mutex_unlock(&pm_mutex
);
816 pr_debug("PM: Hibernation image not present or could not be loaded.\n");
819 swsusp_close(FMODE_READ
);
823 late_initcall(software_resume
);
826 static const char * const hibernation_modes
[] = {
827 [HIBERNATION_PLATFORM
] = "platform",
828 [HIBERNATION_SHUTDOWN
] = "shutdown",
829 [HIBERNATION_REBOOT
] = "reboot",
833 * /sys/power/disk - Control hibernation mode.
835 * Hibernation can be handled in several ways. There are a few different ways
836 * to put the system into the sleep state: using the platform driver (e.g. ACPI
837 * or other hibernation_ops), powering it off or rebooting it (for testing
840 * The sysfs file /sys/power/disk provides an interface for selecting the
841 * hibernation mode to use. Reading from this file causes the available modes
842 * to be printed. There are 3 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
:
871 case HIBERNATION_PLATFORM
:
874 /* not a valid mode, continue with loop */
877 if (i
== hibernation_mode
)
878 buf
+= sprintf(buf
, "[%s] ", hibernation_modes
[i
]);
880 buf
+= sprintf(buf
, "%s ", hibernation_modes
[i
]);
882 buf
+= sprintf(buf
, "\n");
886 static ssize_t
disk_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
887 const char *buf
, size_t n
)
893 int mode
= HIBERNATION_INVALID
;
895 p
= memchr(buf
, '\n', n
);
896 len
= p
? p
- buf
: n
;
899 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
900 if (len
== strlen(hibernation_modes
[i
])
901 && !strncmp(buf
, hibernation_modes
[i
], len
)) {
906 if (mode
!= HIBERNATION_INVALID
) {
908 case HIBERNATION_SHUTDOWN
:
909 case HIBERNATION_REBOOT
:
910 hibernation_mode
= mode
;
912 case HIBERNATION_PLATFORM
:
914 hibernation_mode
= mode
;
922 pr_debug("PM: Hibernation mode set to '%s'\n",
923 hibernation_modes
[mode
]);
924 unlock_system_sleep();
925 return error
? error
: n
;
930 static ssize_t
resume_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
933 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
934 MINOR(swsusp_resume_device
));
937 static ssize_t
resume_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
938 const char *buf
, size_t n
)
940 unsigned int maj
, min
;
944 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
947 res
= MKDEV(maj
,min
);
948 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
952 swsusp_resume_device
= res
;
953 unlock_system_sleep();
954 printk(KERN_INFO
"PM: Starting manual resume from disk\n");
964 static ssize_t
image_size_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
967 return sprintf(buf
, "%lu\n", image_size
);
970 static ssize_t
image_size_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
971 const char *buf
, size_t n
)
975 if (sscanf(buf
, "%lu", &size
) == 1) {
983 power_attr(image_size
);
985 static ssize_t
reserved_size_show(struct kobject
*kobj
,
986 struct kobj_attribute
*attr
, char *buf
)
988 return sprintf(buf
, "%lu\n", reserved_size
);
991 static ssize_t
reserved_size_store(struct kobject
*kobj
,
992 struct kobj_attribute
*attr
,
993 const char *buf
, size_t n
)
997 if (sscanf(buf
, "%lu", &size
) == 1) {
998 reserved_size
= size
;
1005 power_attr(reserved_size
);
1007 static struct attribute
* g
[] = {
1010 &image_size_attr
.attr
,
1011 &reserved_size_attr
.attr
,
1016 static struct attribute_group attr_group
= {
1021 static int __init
pm_disk_init(void)
1023 return sysfs_create_group(power_kobj
, &attr_group
);
1026 core_initcall(pm_disk_init
);
1029 static int __init
resume_setup(char *str
)
1034 strncpy( resume_file
, str
, 255 );
1038 static int __init
resume_offset_setup(char *str
)
1040 unsigned long long offset
;
1045 if (sscanf(str
, "%llu", &offset
) == 1)
1046 swsusp_resume_block
= offset
;
1051 static int __init
hibernate_setup(char *str
)
1053 if (!strncmp(str
, "noresume", 8))
1055 else if (!strncmp(str
, "nocompress", 10))
1060 static int __init
noresume_setup(char *str
)
1066 static int __init
resumewait_setup(char *str
)
1072 static int __init
resumedelay_setup(char *str
)
1074 resume_delay
= simple_strtoul(str
, NULL
, 0);
1078 __setup("noresume", noresume_setup
);
1079 __setup("resume_offset=", resume_offset_setup
);
1080 __setup("resume=", resume_setup
);
1081 __setup("hibernate=", hibernate_setup
);
1082 __setup("resumewait", resumewait_setup
);
1083 __setup("resumedelay=", resumedelay_setup
);