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();
218 /* At this point, dpm_suspend_start() has been called, but *not*
219 * dpm_suspend_noirq(). We *must* call dpm_suspend_noirq() now.
220 * Otherwise, drivers for some devices (e.g. interrupt controllers)
221 * become desynchronized with the actual state of the hardware
222 * at resume time, and evil weirdness ensues.
224 error
= dpm_suspend_noirq(PMSG_FREEZE
);
226 printk(KERN_ERR
"PM: Some devices failed to power down, "
227 "aborting hibernation\n");
231 error
= platform_pre_snapshot(platform_mode
);
232 if (error
|| hibernation_test(TEST_PLATFORM
))
233 goto Platform_finish
;
235 error
= disable_nonboot_cpus();
236 if (error
|| hibernation_test(TEST_CPUS
)
237 || hibernation_testmode(HIBERNATION_TEST
))
242 error
= sysdev_suspend(PMSG_FREEZE
);
244 printk(KERN_ERR
"PM: Some system devices failed to power down, "
245 "aborting hibernation\n");
249 if (hibernation_test(TEST_CORE
))
253 save_processor_state();
254 error
= swsusp_arch_suspend();
256 printk(KERN_ERR
"PM: Error %d creating hibernation image\n",
258 /* Restore control flow magically appears here */
259 restore_processor_state();
261 platform_leave(platform_mode
);
265 /* NOTE: dpm_resume_noirq() is just a resume() for devices
266 * that suspended with irqs off ... no overall powerup.
273 enable_nonboot_cpus();
276 platform_finish(platform_mode
);
278 dpm_resume_noirq(in_suspend
?
279 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
285 * hibernation_snapshot - quiesce devices and create the hibernation
287 * @platform_mode - if set, use the platform driver, if available, to
288 * prepare the platform firmware for the power transition.
290 * Must be called with pm_mutex held
293 int hibernation_snapshot(int platform_mode
)
297 error
= platform_begin(platform_mode
);
301 /* Free memory before shutting down devices. */
302 error
= swsusp_shrink_memory();
307 error
= dpm_suspend_start(PMSG_FREEZE
);
309 goto Recover_platform
;
311 if (hibernation_test(TEST_DEVICES
))
312 goto Recover_platform
;
314 error
= create_image(platform_mode
);
315 /* Control returns here after successful restore */
318 dpm_resume_end(in_suspend
?
319 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
322 platform_end(platform_mode
);
326 platform_recover(platform_mode
);
331 * resume_target_kernel - prepare devices that need to be suspended with
332 * interrupts off, restore the contents of highmem that have not been
333 * restored yet from the image and run the low level code that will restore
334 * the remaining contents of memory and switch to the just restored target
338 static int resume_target_kernel(bool platform_mode
)
342 error
= dpm_suspend_noirq(PMSG_QUIESCE
);
344 printk(KERN_ERR
"PM: Some devices failed to power down, "
345 "aborting resume\n");
349 error
= platform_pre_restore(platform_mode
);
353 error
= disable_nonboot_cpus();
359 error
= sysdev_suspend(PMSG_QUIESCE
);
363 /* We'll ignore saved state, but this gets preempt count (etc) right */
364 save_processor_state();
365 error
= restore_highmem();
367 error
= swsusp_arch_resume();
369 * The code below is only ever reached in case of a failure.
370 * Otherwise execution continues at place where
371 * swsusp_arch_suspend() was called
374 /* This call to restore_highmem() undos the previous one */
378 * The only reason why swsusp_arch_resume() can fail is memory being
379 * very tight, so we have to free it as soon as we can to avoid
380 * subsequent failures
383 restore_processor_state();
384 touch_softlockup_watchdog();
392 enable_nonboot_cpus();
395 platform_restore_cleanup(platform_mode
);
397 dpm_resume_noirq(PMSG_RECOVER
);
403 * hibernation_restore - quiesce devices and restore the hibernation
404 * snapshot image. If successful, control returns in hibernation_snaphot()
405 * @platform_mode - if set, use the platform driver, if available, to
406 * prepare the platform firmware for the transition.
408 * Must be called with pm_mutex held
411 int hibernation_restore(int platform_mode
)
415 pm_prepare_console();
417 error
= dpm_suspend_start(PMSG_QUIESCE
);
419 error
= resume_target_kernel(platform_mode
);
420 dpm_resume_end(PMSG_RECOVER
);
423 pm_restore_console();
428 * hibernation_platform_enter - enter the hibernation state using the
429 * platform driver (if available)
432 int hibernation_platform_enter(void)
436 if (!hibernation_ops
)
440 * We have cancelled the power transition by running
441 * hibernation_ops->finish() before saving the image, so we should let
442 * the firmware know that we're going to enter the sleep state after all
444 error
= hibernation_ops
->begin();
448 entering_platform_hibernation
= true;
450 error
= dpm_suspend_start(PMSG_HIBERNATE
);
452 if (hibernation_ops
->recover
)
453 hibernation_ops
->recover();
457 error
= dpm_suspend_noirq(PMSG_HIBERNATE
);
461 error
= hibernation_ops
->prepare();
463 goto Platofrm_finish
;
465 error
= disable_nonboot_cpus();
467 goto Platofrm_finish
;
470 sysdev_suspend(PMSG_HIBERNATE
);
471 hibernation_ops
->enter();
472 /* We should never get here */
476 * We don't need to reenable the nonboot CPUs or resume consoles, since
477 * the system is going to be halted anyway.
480 hibernation_ops
->finish();
482 dpm_suspend_noirq(PMSG_RESTORE
);
485 entering_platform_hibernation
= false;
486 dpm_resume_end(PMSG_RESTORE
);
490 hibernation_ops
->end();
496 * power_down - Shut the machine down for hibernation.
498 * Use the platform driver, if configured so; otherwise try
499 * to power off or reboot.
502 static void power_down(void)
504 switch (hibernation_mode
) {
505 case HIBERNATION_TEST
:
506 case HIBERNATION_TESTPROC
:
508 case HIBERNATION_REBOOT
:
509 kernel_restart(NULL
);
511 case HIBERNATION_PLATFORM
:
512 hibernation_platform_enter();
513 case HIBERNATION_SHUTDOWN
:
519 * Valid image is on the disk, if we continue we risk serious data
520 * corruption after resume.
522 printk(KERN_CRIT
"PM: Please power down manually\n");
526 static int prepare_processes(void)
530 if (freeze_processes()) {
538 * hibernate - The granpappy of the built-in hibernation management
545 mutex_lock(&pm_mutex
);
546 /* The snapshot device should not be opened while we're running */
547 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
552 pm_prepare_console();
553 error
= pm_notifier_call_chain(PM_HIBERNATION_PREPARE
);
557 error
= usermodehelper_disable();
561 /* Allocate memory management structures */
562 error
= create_basic_memory_bitmaps();
566 printk(KERN_INFO
"PM: Syncing filesystems ... ");
570 error
= prepare_processes();
574 if (hibernation_test(TEST_FREEZER
))
577 if (hibernation_testmode(HIBERNATION_TESTPROC
))
580 error
= hibernation_snapshot(hibernation_mode
== HIBERNATION_PLATFORM
);
581 if (in_suspend
&& !error
) {
582 unsigned int flags
= 0;
584 if (hibernation_mode
== HIBERNATION_PLATFORM
)
585 flags
|= SF_PLATFORM_MODE
;
586 pr_debug("PM: writing image.\n");
587 error
= swsusp_write(flags
);
592 pr_debug("PM: Image restored successfully.\n");
598 free_basic_memory_bitmaps();
599 usermodehelper_enable();
601 pm_notifier_call_chain(PM_POST_HIBERNATION
);
602 pm_restore_console();
603 atomic_inc(&snapshot_device_available
);
605 mutex_unlock(&pm_mutex
);
611 * software_resume - Resume from a saved image.
613 * Called as a late_initcall (so all devices are discovered and
614 * initialized), we call swsusp to see if we have a saved image or not.
615 * If so, we quiesce devices, the restore the saved image. We will
616 * return above (in hibernate() ) if everything goes well.
617 * Otherwise, we fail gracefully and return to the normally
622 static int software_resume(void)
628 * If the user said "noresume".. bail out early.
634 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
635 * is configured into the kernel. Since the regular hibernate
636 * trigger path is via sysfs which takes a buffer mutex before
637 * calling hibernate functions (which take pm_mutex) this can
638 * cause lockdep to complain about a possible ABBA deadlock
639 * which cannot happen since we're in the boot code here and
640 * sysfs can't be invoked yet. Therefore, we use a subclass
641 * here to avoid lockdep complaining.
643 mutex_lock_nested(&pm_mutex
, SINGLE_DEPTH_NESTING
);
645 if (swsusp_resume_device
)
648 if (!strlen(resume_file
)) {
653 pr_debug("PM: Checking image partition %s\n", resume_file
);
655 /* Check if the device is there */
656 swsusp_resume_device
= name_to_dev_t(resume_file
);
657 if (!swsusp_resume_device
) {
659 * Some device discovery might still be in progress; we need
660 * to wait for this to finish.
662 wait_for_device_probe();
664 * We can't depend on SCSI devices being available after loading
665 * one of their modules until scsi_complete_async_scans() is
666 * called and the resume device usually is a SCSI one.
668 scsi_complete_async_scans();
670 swsusp_resume_device
= name_to_dev_t(resume_file
);
671 if (!swsusp_resume_device
) {
678 pr_debug("PM: Resume from partition %d:%d\n",
679 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
681 pr_debug("PM: Checking hibernation image.\n");
682 error
= swsusp_check();
686 /* The snapshot device should not be opened while we're running */
687 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
692 pm_prepare_console();
693 error
= pm_notifier_call_chain(PM_RESTORE_PREPARE
);
697 error
= usermodehelper_disable();
701 error
= create_basic_memory_bitmaps();
705 pr_debug("PM: Preparing processes for restore.\n");
706 error
= prepare_processes();
708 swsusp_close(FMODE_READ
);
712 pr_debug("PM: Reading hibernation image.\n");
714 error
= swsusp_read(&flags
);
716 hibernation_restore(flags
& SF_PLATFORM_MODE
);
718 printk(KERN_ERR
"PM: Restore failed, recovering.\n");
722 free_basic_memory_bitmaps();
723 usermodehelper_enable();
725 pm_notifier_call_chain(PM_POST_RESTORE
);
726 pm_restore_console();
727 atomic_inc(&snapshot_device_available
);
728 /* For success case, the suspend path will release the lock */
730 mutex_unlock(&pm_mutex
);
731 pr_debug("PM: Resume from disk failed.\n");
735 late_initcall(software_resume
);
738 static const char * const hibernation_modes
[] = {
739 [HIBERNATION_PLATFORM
] = "platform",
740 [HIBERNATION_SHUTDOWN
] = "shutdown",
741 [HIBERNATION_REBOOT
] = "reboot",
742 [HIBERNATION_TEST
] = "test",
743 [HIBERNATION_TESTPROC
] = "testproc",
747 * disk - Control hibernation mode
749 * Suspend-to-disk can be handled in several ways. We have a few options
750 * for putting the system to sleep - using the platform driver (e.g. ACPI
751 * or other hibernation_ops), powering off the system or rebooting the
752 * system (for testing) as well as the two test modes.
754 * The system can support 'platform', and that is known a priori (and
755 * encoded by the presence of hibernation_ops). However, the user may
756 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
757 * test modes, 'test' or 'testproc'.
759 * show() will display what the mode is currently set to.
760 * store() will accept one of
768 * It will only change to 'platform' if the system
769 * supports it (as determined by having hibernation_ops).
772 static ssize_t
disk_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
778 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
779 if (!hibernation_modes
[i
])
782 case HIBERNATION_SHUTDOWN
:
783 case HIBERNATION_REBOOT
:
784 case HIBERNATION_TEST
:
785 case HIBERNATION_TESTPROC
:
787 case HIBERNATION_PLATFORM
:
790 /* not a valid mode, continue with loop */
793 if (i
== hibernation_mode
)
794 buf
+= sprintf(buf
, "[%s] ", hibernation_modes
[i
]);
796 buf
+= sprintf(buf
, "%s ", hibernation_modes
[i
]);
798 buf
+= sprintf(buf
, "\n");
803 static ssize_t
disk_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
804 const char *buf
, size_t n
)
810 int mode
= HIBERNATION_INVALID
;
812 p
= memchr(buf
, '\n', n
);
813 len
= p
? p
- buf
: n
;
815 mutex_lock(&pm_mutex
);
816 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
817 if (len
== strlen(hibernation_modes
[i
])
818 && !strncmp(buf
, hibernation_modes
[i
], len
)) {
823 if (mode
!= HIBERNATION_INVALID
) {
825 case HIBERNATION_SHUTDOWN
:
826 case HIBERNATION_REBOOT
:
827 case HIBERNATION_TEST
:
828 case HIBERNATION_TESTPROC
:
829 hibernation_mode
= mode
;
831 case HIBERNATION_PLATFORM
:
833 hibernation_mode
= mode
;
841 pr_debug("PM: Hibernation mode set to '%s'\n",
842 hibernation_modes
[mode
]);
843 mutex_unlock(&pm_mutex
);
844 return error
? error
: n
;
849 static ssize_t
resume_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
852 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
853 MINOR(swsusp_resume_device
));
856 static ssize_t
resume_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
857 const char *buf
, size_t n
)
859 unsigned int maj
, min
;
863 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
866 res
= MKDEV(maj
,min
);
867 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
870 mutex_lock(&pm_mutex
);
871 swsusp_resume_device
= res
;
872 mutex_unlock(&pm_mutex
);
873 printk(KERN_INFO
"PM: Starting manual resume from disk\n");
883 static ssize_t
image_size_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
886 return sprintf(buf
, "%lu\n", image_size
);
889 static ssize_t
image_size_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
890 const char *buf
, size_t n
)
894 if (sscanf(buf
, "%lu", &size
) == 1) {
902 power_attr(image_size
);
904 static struct attribute
* g
[] = {
907 &image_size_attr
.attr
,
912 static struct attribute_group attr_group
= {
917 static int __init
pm_disk_init(void)
919 return sysfs_create_group(power_kobj
, &attr_group
);
922 core_initcall(pm_disk_init
);
925 static int __init
resume_setup(char *str
)
930 strncpy( resume_file
, str
, 255 );
934 static int __init
resume_offset_setup(char *str
)
936 unsigned long long offset
;
941 if (sscanf(str
, "%llu", &offset
) == 1)
942 swsusp_resume_block
= offset
;
947 static int __init
noresume_setup(char *str
)
953 __setup("noresume", noresume_setup
);
954 __setup("resume_offset=", resume_offset_setup
);
955 __setup("resume=", resume_setup
);