2 * kernel/power/disk.c - 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@suse.cz>
8 * 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 <scsi/scsi_scan.h>
26 #include <asm/suspend.h>
31 static int noresume
= 0;
32 static char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
33 dev_t swsusp_resume_device
;
34 sector_t swsusp_resume_block
;
44 __HIBERNATION_AFTER_LAST
46 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
47 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
49 static int hibernation_mode
= HIBERNATION_SHUTDOWN
;
51 static struct platform_hibernation_ops
*hibernation_ops
;
54 * hibernation_set_ops - set the global hibernate operations
55 * @ops: the hibernation operations to use in subsequent hibernation transitions
58 void hibernation_set_ops(struct platform_hibernation_ops
*ops
)
60 if (ops
&& !(ops
->begin
&& ops
->end
&& ops
->pre_snapshot
61 && ops
->prepare
&& ops
->finish
&& ops
->enter
&& ops
->pre_restore
62 && ops
->restore_cleanup
)) {
66 mutex_lock(&pm_mutex
);
67 hibernation_ops
= ops
;
69 hibernation_mode
= HIBERNATION_PLATFORM
;
70 else if (hibernation_mode
== HIBERNATION_PLATFORM
)
71 hibernation_mode
= HIBERNATION_SHUTDOWN
;
73 mutex_unlock(&pm_mutex
);
76 static bool entering_platform_hibernation
;
78 bool system_entering_hibernation(void)
80 return entering_platform_hibernation
;
82 EXPORT_SYMBOL(system_entering_hibernation
);
84 #ifdef CONFIG_PM_DEBUG
85 static void hibernation_debug_sleep(void)
87 printk(KERN_INFO
"hibernation debug: Waiting for 5 seconds.\n");
91 static int hibernation_testmode(int mode
)
93 if (hibernation_mode
== mode
) {
94 hibernation_debug_sleep();
100 static int hibernation_test(int level
)
102 if (pm_test_level
== level
) {
103 hibernation_debug_sleep();
108 #else /* !CONFIG_PM_DEBUG */
109 static int hibernation_testmode(int mode
) { return 0; }
110 static int hibernation_test(int level
) { return 0; }
111 #endif /* !CONFIG_PM_DEBUG */
114 * platform_begin - tell the platform driver that we're starting
118 static int platform_begin(int platform_mode
)
120 return (platform_mode
&& hibernation_ops
) ?
121 hibernation_ops
->begin() : 0;
125 * platform_end - tell the platform driver that we've entered the
129 static void platform_end(int platform_mode
)
131 if (platform_mode
&& hibernation_ops
)
132 hibernation_ops
->end();
136 * platform_pre_snapshot - prepare the machine for hibernation using the
137 * platform driver if so configured and return an error code if it fails
140 static int platform_pre_snapshot(int platform_mode
)
142 return (platform_mode
&& hibernation_ops
) ?
143 hibernation_ops
->pre_snapshot() : 0;
147 * platform_leave - prepare the machine for switching to the normal mode
148 * of operation using the platform driver (called with interrupts disabled)
151 static void platform_leave(int platform_mode
)
153 if (platform_mode
&& hibernation_ops
)
154 hibernation_ops
->leave();
158 * platform_finish - switch the machine to the normal mode of operation
159 * using the platform driver (must be called after platform_prepare())
162 static void platform_finish(int platform_mode
)
164 if (platform_mode
&& hibernation_ops
)
165 hibernation_ops
->finish();
169 * platform_pre_restore - prepare the platform for the restoration from a
170 * hibernation image. If the restore fails after this function has been
171 * called, platform_restore_cleanup() must be called.
174 static int platform_pre_restore(int platform_mode
)
176 return (platform_mode
&& hibernation_ops
) ?
177 hibernation_ops
->pre_restore() : 0;
181 * platform_restore_cleanup - switch the platform to the normal mode of
182 * operation after a failing restore. If platform_pre_restore() has been
183 * called before the failing restore, this function must be called too,
184 * regardless of the result of platform_pre_restore().
187 static void platform_restore_cleanup(int platform_mode
)
189 if (platform_mode
&& hibernation_ops
)
190 hibernation_ops
->restore_cleanup();
194 * platform_recover - recover the platform from a failure to suspend
198 static void platform_recover(int platform_mode
)
200 if (platform_mode
&& hibernation_ops
&& hibernation_ops
->recover
)
201 hibernation_ops
->recover();
205 * create_image - freeze devices that need to be frozen with interrupts
206 * off, create the hibernation image and thaw those devices. Control
207 * reappears in this routine after a restore.
210 static int create_image(int platform_mode
)
214 error
= arch_prepare_suspend();
220 /* At this point, device_suspend() has been called, but *not*
221 * device_power_down(). We *must* call device_power_down() now.
222 * Otherwise, drivers for some devices (e.g. interrupt controllers)
223 * become desynchronized with the actual state of the hardware
224 * at resume time, and evil weirdness ensues.
226 error
= device_power_down(PMSG_FREEZE
);
228 printk(KERN_ERR
"PM: Some devices failed to power down, "
229 "aborting hibernation\n");
233 error
= platform_pre_snapshot(platform_mode
);
234 if (error
|| hibernation_test(TEST_PLATFORM
))
235 goto Platform_finish
;
237 error
= disable_nonboot_cpus();
238 if (error
|| hibernation_test(TEST_CPUS
)
239 || hibernation_testmode(HIBERNATION_TEST
))
244 sysdev_suspend(PMSG_FREEZE
);
246 printk(KERN_ERR
"PM: Some devices failed to power down, "
247 "aborting hibernation\n");
251 if (hibernation_test(TEST_CORE
))
255 save_processor_state();
256 error
= swsusp_arch_suspend();
258 printk(KERN_ERR
"PM: Error %d creating hibernation image\n",
260 /* Restore control flow magically appears here */
261 restore_processor_state();
263 platform_leave(platform_mode
);
267 /* NOTE: device_power_up() is just a resume() for devices
268 * that suspended with irqs off ... no overall powerup.
275 enable_nonboot_cpus();
278 platform_finish(platform_mode
);
280 device_power_up(in_suspend
?
281 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
290 * hibernation_snapshot - quiesce devices and create the hibernation
292 * @platform_mode - if set, use the platform driver, if available, to
293 * prepare the platform firmware for the power transition.
295 * Must be called with pm_mutex held
298 int hibernation_snapshot(int platform_mode
)
302 error
= platform_begin(platform_mode
);
306 /* Free memory before shutting down devices. */
307 error
= swsusp_shrink_memory();
312 error
= device_suspend(PMSG_FREEZE
);
314 goto Recover_platform
;
316 if (hibernation_test(TEST_DEVICES
))
317 goto Recover_platform
;
319 error
= create_image(platform_mode
);
320 /* Control returns here after successful restore */
323 device_resume(in_suspend
?
324 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
327 platform_end(platform_mode
);
331 platform_recover(platform_mode
);
336 * resume_target_kernel - prepare devices that need to be suspended with
337 * interrupts off, restore the contents of highmem that have not been
338 * restored yet from the image and run the low level code that will restore
339 * the remaining contents of memory and switch to the just restored target
343 static int resume_target_kernel(bool platform_mode
)
349 error
= device_power_down(PMSG_QUIESCE
);
351 printk(KERN_ERR
"PM: Some devices failed to power down, "
352 "aborting resume\n");
356 error
= platform_pre_restore(platform_mode
);
360 error
= disable_nonboot_cpus();
366 error
= sysdev_suspend(PMSG_QUIESCE
);
370 /* We'll ignore saved state, but this gets preempt count (etc) right */
371 save_processor_state();
372 error
= restore_highmem();
374 error
= swsusp_arch_resume();
376 * The code below is only ever reached in case of a failure.
377 * Otherwise execution continues at place where
378 * swsusp_arch_suspend() was called
381 /* This call to restore_highmem() undos the previous one */
385 * The only reason why swsusp_arch_resume() can fail is memory being
386 * very tight, so we have to free it as soon as we can to avoid
387 * subsequent failures
390 restore_processor_state();
391 touch_softlockup_watchdog();
399 enable_nonboot_cpus();
402 platform_restore_cleanup(platform_mode
);
404 device_power_up(PMSG_RECOVER
);
413 * hibernation_restore - quiesce devices and restore the hibernation
414 * snapshot image. If successful, control returns in hibernation_snaphot()
415 * @platform_mode - if set, use the platform driver, if available, to
416 * prepare the platform firmware for the transition.
418 * Must be called with pm_mutex held
421 int hibernation_restore(int platform_mode
)
425 pm_prepare_console();
427 error
= device_suspend(PMSG_QUIESCE
);
429 error
= resume_target_kernel(platform_mode
);
430 device_resume(PMSG_RECOVER
);
433 pm_restore_console();
438 * hibernation_platform_enter - enter the hibernation state using the
439 * platform driver (if available)
442 int hibernation_platform_enter(void)
446 if (!hibernation_ops
)
450 * We have cancelled the power transition by running
451 * hibernation_ops->finish() before saving the image, so we should let
452 * the firmware know that we're going to enter the sleep state after all
454 error
= hibernation_ops
->begin();
458 entering_platform_hibernation
= true;
460 error
= device_suspend(PMSG_HIBERNATE
);
462 if (hibernation_ops
->recover
)
463 hibernation_ops
->recover();
469 error
= device_power_down(PMSG_HIBERNATE
);
473 error
= hibernation_ops
->prepare();
475 goto Platofrm_finish
;
477 error
= disable_nonboot_cpus();
479 goto Platofrm_finish
;
482 sysdev_suspend(PMSG_HIBERNATE
);
483 hibernation_ops
->enter();
484 /* We should never get here */
488 * We don't need to reenable the nonboot CPUs or resume consoles, since
489 * the system is going to be halted anyway.
492 hibernation_ops
->finish();
494 device_power_up(PMSG_RESTORE
);
500 entering_platform_hibernation
= false;
501 device_resume(PMSG_RESTORE
);
505 hibernation_ops
->end();
511 * power_down - Shut the machine down for hibernation.
513 * Use the platform driver, if configured so; otherwise try
514 * to power off or reboot.
517 static void power_down(void)
519 switch (hibernation_mode
) {
520 case HIBERNATION_TEST
:
521 case HIBERNATION_TESTPROC
:
523 case HIBERNATION_REBOOT
:
524 kernel_restart(NULL
);
526 case HIBERNATION_PLATFORM
:
527 hibernation_platform_enter();
528 case HIBERNATION_SHUTDOWN
:
534 * Valid image is on the disk, if we continue we risk serious data
535 * corruption after resume.
537 printk(KERN_CRIT
"PM: Please power down manually\n");
541 static int prepare_processes(void)
545 if (freeze_processes()) {
553 * hibernate - The granpappy of the built-in hibernation management
560 mutex_lock(&pm_mutex
);
561 /* The snapshot device should not be opened while we're running */
562 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
567 pm_prepare_console();
568 error
= pm_notifier_call_chain(PM_HIBERNATION_PREPARE
);
572 error
= usermodehelper_disable();
576 /* Allocate memory management structures */
577 error
= create_basic_memory_bitmaps();
581 printk(KERN_INFO
"PM: Syncing filesystems ... ");
585 error
= prepare_processes();
589 if (hibernation_test(TEST_FREEZER
))
592 if (hibernation_testmode(HIBERNATION_TESTPROC
))
595 error
= hibernation_snapshot(hibernation_mode
== HIBERNATION_PLATFORM
);
596 if (in_suspend
&& !error
) {
597 unsigned int flags
= 0;
599 if (hibernation_mode
== HIBERNATION_PLATFORM
)
600 flags
|= SF_PLATFORM_MODE
;
601 pr_debug("PM: writing image.\n");
602 error
= swsusp_write(flags
);
607 pr_debug("PM: Image restored successfully.\n");
613 free_basic_memory_bitmaps();
614 usermodehelper_enable();
616 pm_notifier_call_chain(PM_POST_HIBERNATION
);
617 pm_restore_console();
618 atomic_inc(&snapshot_device_available
);
620 mutex_unlock(&pm_mutex
);
626 * software_resume - Resume from a saved image.
628 * Called as a late_initcall (so all devices are discovered and
629 * initialized), we call swsusp to see if we have a saved image or not.
630 * If so, we quiesce devices, the restore the saved image. We will
631 * return above (in hibernate() ) if everything goes well.
632 * Otherwise, we fail gracefully and return to the normally
637 static int software_resume(void)
643 * If the user said "noresume".. bail out early.
649 * We can't depend on SCSI devices being available after loading one of
650 * their modules if scsi_complete_async_scans() is not called and the
651 * resume device usually is a SCSI one.
653 scsi_complete_async_scans();
656 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
657 * is configured into the kernel. Since the regular hibernate
658 * trigger path is via sysfs which takes a buffer mutex before
659 * calling hibernate functions (which take pm_mutex) this can
660 * cause lockdep to complain about a possible ABBA deadlock
661 * which cannot happen since we're in the boot code here and
662 * sysfs can't be invoked yet. Therefore, we use a subclass
663 * here to avoid lockdep complaining.
665 mutex_lock_nested(&pm_mutex
, SINGLE_DEPTH_NESTING
);
666 if (!swsusp_resume_device
) {
667 if (!strlen(resume_file
)) {
668 mutex_unlock(&pm_mutex
);
672 * Some device discovery might still be in progress; we need
673 * to wait for this to finish.
675 wait_for_device_probe();
676 swsusp_resume_device
= name_to_dev_t(resume_file
);
677 pr_debug("PM: Resume from partition %s\n", resume_file
);
679 pr_debug("PM: Resume from partition %d:%d\n",
680 MAJOR(swsusp_resume_device
),
681 MINOR(swsusp_resume_device
));
686 * FIXME: If noresume is specified, we need to find the
687 * partition and reset it back to normal swap space.
689 mutex_unlock(&pm_mutex
);
693 pr_debug("PM: Checking hibernation image.\n");
694 error
= swsusp_check();
698 /* The snapshot device should not be opened while we're running */
699 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
704 pm_prepare_console();
705 error
= pm_notifier_call_chain(PM_RESTORE_PREPARE
);
709 error
= usermodehelper_disable();
713 error
= create_basic_memory_bitmaps();
717 pr_debug("PM: Preparing processes for restore.\n");
718 error
= prepare_processes();
720 swsusp_close(FMODE_READ
);
724 pr_debug("PM: Reading hibernation image.\n");
726 error
= swsusp_read(&flags
);
728 hibernation_restore(flags
& SF_PLATFORM_MODE
);
730 printk(KERN_ERR
"PM: Restore failed, recovering.\n");
734 free_basic_memory_bitmaps();
735 usermodehelper_enable();
737 pm_notifier_call_chain(PM_POST_RESTORE
);
738 pm_restore_console();
739 atomic_inc(&snapshot_device_available
);
740 /* For success case, the suspend path will release the lock */
742 mutex_unlock(&pm_mutex
);
743 pr_debug("PM: Resume from disk failed.\n");
747 late_initcall(software_resume
);
750 static const char * const hibernation_modes
[] = {
751 [HIBERNATION_PLATFORM
] = "platform",
752 [HIBERNATION_SHUTDOWN
] = "shutdown",
753 [HIBERNATION_REBOOT
] = "reboot",
754 [HIBERNATION_TEST
] = "test",
755 [HIBERNATION_TESTPROC
] = "testproc",
759 * disk - Control hibernation mode
761 * Suspend-to-disk can be handled in several ways. We have a few options
762 * for putting the system to sleep - using the platform driver (e.g. ACPI
763 * or other hibernation_ops), powering off the system or rebooting the
764 * system (for testing) as well as the two test modes.
766 * The system can support 'platform', and that is known a priori (and
767 * encoded by the presence of hibernation_ops). However, the user may
768 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
769 * test modes, 'test' or 'testproc'.
771 * show() will display what the mode is currently set to.
772 * store() will accept one of
780 * It will only change to 'platform' if the system
781 * supports it (as determined by having hibernation_ops).
784 static ssize_t
disk_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
790 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
791 if (!hibernation_modes
[i
])
794 case HIBERNATION_SHUTDOWN
:
795 case HIBERNATION_REBOOT
:
796 case HIBERNATION_TEST
:
797 case HIBERNATION_TESTPROC
:
799 case HIBERNATION_PLATFORM
:
802 /* not a valid mode, continue with loop */
805 if (i
== hibernation_mode
)
806 buf
+= sprintf(buf
, "[%s] ", hibernation_modes
[i
]);
808 buf
+= sprintf(buf
, "%s ", hibernation_modes
[i
]);
810 buf
+= sprintf(buf
, "\n");
815 static ssize_t
disk_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
816 const char *buf
, size_t n
)
822 int mode
= HIBERNATION_INVALID
;
824 p
= memchr(buf
, '\n', n
);
825 len
= p
? p
- buf
: n
;
827 mutex_lock(&pm_mutex
);
828 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
829 if (len
== strlen(hibernation_modes
[i
])
830 && !strncmp(buf
, hibernation_modes
[i
], len
)) {
835 if (mode
!= HIBERNATION_INVALID
) {
837 case HIBERNATION_SHUTDOWN
:
838 case HIBERNATION_REBOOT
:
839 case HIBERNATION_TEST
:
840 case HIBERNATION_TESTPROC
:
841 hibernation_mode
= mode
;
843 case HIBERNATION_PLATFORM
:
845 hibernation_mode
= mode
;
853 pr_debug("PM: Hibernation mode set to '%s'\n",
854 hibernation_modes
[mode
]);
855 mutex_unlock(&pm_mutex
);
856 return error
? error
: n
;
861 static ssize_t
resume_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
864 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
865 MINOR(swsusp_resume_device
));
868 static ssize_t
resume_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
869 const char *buf
, size_t n
)
871 unsigned int maj
, min
;
875 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
878 res
= MKDEV(maj
,min
);
879 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
882 mutex_lock(&pm_mutex
);
883 swsusp_resume_device
= res
;
884 mutex_unlock(&pm_mutex
);
885 printk(KERN_INFO
"PM: Starting manual resume from disk\n");
895 static ssize_t
image_size_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
898 return sprintf(buf
, "%lu\n", image_size
);
901 static ssize_t
image_size_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
902 const char *buf
, size_t n
)
906 if (sscanf(buf
, "%lu", &size
) == 1) {
914 power_attr(image_size
);
916 static struct attribute
* g
[] = {
919 &image_size_attr
.attr
,
924 static struct attribute_group attr_group
= {
929 static int __init
pm_disk_init(void)
931 return sysfs_create_group(power_kobj
, &attr_group
);
934 core_initcall(pm_disk_init
);
937 static int __init
resume_setup(char *str
)
942 strncpy( resume_file
, str
, 255 );
946 static int __init
resume_offset_setup(char *str
)
948 unsigned long long offset
;
953 if (sscanf(str
, "%llu", &offset
) == 1)
954 swsusp_resume_block
= offset
;
959 static int __init
noresume_setup(char *str
)
965 __setup("noresume", noresume_setup
);
966 __setup("resume_offset=", resume_offset_setup
);
967 __setup("resume=", resume_setup
);