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>
29 static int noresume
= 0;
30 static char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
31 dev_t swsusp_resume_device
;
32 sector_t swsusp_resume_block
;
42 __HIBERNATION_AFTER_LAST
44 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
45 #define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
47 static int hibernation_mode
= HIBERNATION_SHUTDOWN
;
49 static struct platform_hibernation_ops
*hibernation_ops
;
52 * hibernation_set_ops - set the global hibernate operations
53 * @ops: the hibernation operations to use in subsequent hibernation transitions
56 void hibernation_set_ops(struct platform_hibernation_ops
*ops
)
58 if (ops
&& !(ops
->begin
&& ops
->end
&& ops
->pre_snapshot
59 && ops
->prepare
&& ops
->finish
&& ops
->enter
&& ops
->pre_restore
60 && ops
->restore_cleanup
)) {
64 mutex_lock(&pm_mutex
);
65 hibernation_ops
= ops
;
67 hibernation_mode
= HIBERNATION_PLATFORM
;
68 else if (hibernation_mode
== HIBERNATION_PLATFORM
)
69 hibernation_mode
= HIBERNATION_SHUTDOWN
;
71 mutex_unlock(&pm_mutex
);
74 static bool entering_platform_hibernation
;
76 bool system_entering_hibernation(void)
78 return entering_platform_hibernation
;
80 EXPORT_SYMBOL(system_entering_hibernation
);
82 #ifdef CONFIG_PM_DEBUG
83 static void hibernation_debug_sleep(void)
85 printk(KERN_INFO
"hibernation debug: Waiting for 5 seconds.\n");
89 static int hibernation_testmode(int mode
)
91 if (hibernation_mode
== mode
) {
92 hibernation_debug_sleep();
98 static int hibernation_test(int level
)
100 if (pm_test_level
== level
) {
101 hibernation_debug_sleep();
106 #else /* !CONFIG_PM_DEBUG */
107 static int hibernation_testmode(int mode
) { return 0; }
108 static int hibernation_test(int level
) { return 0; }
109 #endif /* !CONFIG_PM_DEBUG */
112 * platform_begin - tell the platform driver that we're starting
116 static int platform_begin(int platform_mode
)
118 return (platform_mode
&& hibernation_ops
) ?
119 hibernation_ops
->begin() : 0;
123 * platform_end - tell the platform driver that we've entered the
127 static void platform_end(int platform_mode
)
129 if (platform_mode
&& hibernation_ops
)
130 hibernation_ops
->end();
134 * platform_pre_snapshot - prepare the machine for hibernation using the
135 * platform driver if so configured and return an error code if it fails
138 static int platform_pre_snapshot(int platform_mode
)
140 return (platform_mode
&& hibernation_ops
) ?
141 hibernation_ops
->pre_snapshot() : 0;
145 * platform_leave - prepare the machine for switching to the normal mode
146 * of operation using the platform driver (called with interrupts disabled)
149 static void platform_leave(int platform_mode
)
151 if (platform_mode
&& hibernation_ops
)
152 hibernation_ops
->leave();
156 * platform_finish - switch the machine to the normal mode of operation
157 * using the platform driver (must be called after platform_prepare())
160 static void platform_finish(int platform_mode
)
162 if (platform_mode
&& hibernation_ops
)
163 hibernation_ops
->finish();
167 * platform_pre_restore - prepare the platform for the restoration from a
168 * hibernation image. If the restore fails after this function has been
169 * called, platform_restore_cleanup() must be called.
172 static int platform_pre_restore(int platform_mode
)
174 return (platform_mode
&& hibernation_ops
) ?
175 hibernation_ops
->pre_restore() : 0;
179 * platform_restore_cleanup - switch the platform to the normal mode of
180 * operation after a failing restore. If platform_pre_restore() has been
181 * called before the failing restore, this function must be called too,
182 * regardless of the result of platform_pre_restore().
185 static void platform_restore_cleanup(int platform_mode
)
187 if (platform_mode
&& hibernation_ops
)
188 hibernation_ops
->restore_cleanup();
192 * platform_recover - recover the platform from a failure to suspend
196 static void platform_recover(int platform_mode
)
198 if (platform_mode
&& hibernation_ops
&& hibernation_ops
->recover
)
199 hibernation_ops
->recover();
203 * create_image - freeze devices that need to be frozen with interrupts
204 * off, create the hibernation image and thaw those devices. Control
205 * reappears in this routine after a restore.
208 static int create_image(int platform_mode
)
212 error
= arch_prepare_suspend();
218 /* At this point, device_suspend() has been called, but *not*
219 * device_power_down(). We *must* call device_power_down() 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
= device_power_down(PMSG_FREEZE
);
226 printk(KERN_ERR
"PM: Some devices failed to power down, "
227 "aborting hibernation\n");
231 if (hibernation_test(TEST_CORE
))
235 save_processor_state();
236 error
= swsusp_arch_suspend();
238 printk(KERN_ERR
"PM: Error %d creating hibernation image\n",
240 /* Restore control flow magically appears here */
241 restore_processor_state();
243 platform_leave(platform_mode
);
245 /* NOTE: device_power_up() is just a resume() for devices
246 * that suspended with irqs off ... no overall powerup.
248 device_power_up(in_suspend
?
249 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
257 * hibernation_snapshot - quiesce devices and create the hibernation
259 * @platform_mode - if set, use the platform driver, if available, to
260 * prepare the platform frimware for the power transition.
262 * Must be called with pm_mutex held
265 int hibernation_snapshot(int platform_mode
)
269 error
= platform_begin(platform_mode
);
273 /* Free memory before shutting down devices. */
274 error
= swsusp_shrink_memory();
279 error
= device_suspend(PMSG_FREEZE
);
281 goto Recover_platform
;
283 if (hibernation_test(TEST_DEVICES
))
284 goto Recover_platform
;
286 error
= platform_pre_snapshot(platform_mode
);
287 if (error
|| hibernation_test(TEST_PLATFORM
))
290 error
= disable_nonboot_cpus();
292 if (hibernation_test(TEST_CPUS
))
295 if (hibernation_testmode(HIBERNATION_TEST
))
298 error
= create_image(platform_mode
);
299 /* Control returns here after successful restore */
302 enable_nonboot_cpus();
304 platform_finish(platform_mode
);
306 device_resume(in_suspend
?
307 (error
? PMSG_RECOVER
: PMSG_THAW
) : PMSG_RESTORE
);
310 platform_end(platform_mode
);
314 platform_recover(platform_mode
);
319 * resume_target_kernel - prepare devices that need to be suspended with
320 * interrupts off, restore the contents of highmem that have not been
321 * restored yet from the image and run the low level code that will restore
322 * the remaining contents of memory and switch to the just restored target
326 static int resume_target_kernel(void)
332 error
= device_power_down(PMSG_QUIESCE
);
334 printk(KERN_ERR
"PM: Some devices failed to power down, "
335 "aborting resume\n");
338 /* We'll ignore saved state, but this gets preempt count (etc) right */
339 save_processor_state();
340 error
= restore_highmem();
342 error
= swsusp_arch_resume();
344 * The code below is only ever reached in case of a failure.
345 * Otherwise execution continues at place where
346 * swsusp_arch_suspend() was called
349 /* This call to restore_highmem() undos the previous one */
353 * The only reason why swsusp_arch_resume() can fail is memory being
354 * very tight, so we have to free it as soon as we can to avoid
355 * subsequent failures
358 restore_processor_state();
359 touch_softlockup_watchdog();
360 device_power_up(PMSG_RECOVER
);
368 * hibernation_restore - quiesce devices and restore the hibernation
369 * snapshot image. If successful, control returns in hibernation_snaphot()
370 * @platform_mode - if set, use the platform driver, if available, to
371 * prepare the platform frimware for the transition.
373 * Must be called with pm_mutex held
376 int hibernation_restore(int platform_mode
)
380 pm_prepare_console();
382 error
= device_suspend(PMSG_QUIESCE
);
386 error
= platform_pre_restore(platform_mode
);
388 error
= disable_nonboot_cpus();
390 error
= resume_target_kernel();
391 enable_nonboot_cpus();
393 platform_restore_cleanup(platform_mode
);
394 device_resume(PMSG_RECOVER
);
397 pm_restore_console();
402 * hibernation_platform_enter - enter the hibernation state using the
403 * platform driver (if available)
406 int hibernation_platform_enter(void)
410 if (!hibernation_ops
)
414 * We have cancelled the power transition by running
415 * hibernation_ops->finish() before saving the image, so we should let
416 * the firmware know that we're going to enter the sleep state after all
418 error
= hibernation_ops
->begin();
422 entering_platform_hibernation
= true;
424 error
= device_suspend(PMSG_HIBERNATE
);
426 if (hibernation_ops
->recover
)
427 hibernation_ops
->recover();
431 error
= hibernation_ops
->prepare();
435 error
= disable_nonboot_cpus();
441 error
= device_power_down(PMSG_HIBERNATE
);
443 hibernation_ops
->enter();
444 /* We should never get here */
451 * We don't need to reenable the nonboot CPUs or resume consoles, since
452 * the system is going to be halted anyway.
455 hibernation_ops
->finish();
457 entering_platform_hibernation
= false;
458 device_resume(PMSG_RESTORE
);
461 hibernation_ops
->end();
466 * power_down - Shut the machine down for hibernation.
468 * Use the platform driver, if configured so; otherwise try
469 * to power off or reboot.
472 static void power_down(void)
474 switch (hibernation_mode
) {
475 case HIBERNATION_TEST
:
476 case HIBERNATION_TESTPROC
:
478 case HIBERNATION_REBOOT
:
479 kernel_restart(NULL
);
481 case HIBERNATION_PLATFORM
:
482 hibernation_platform_enter();
483 case HIBERNATION_SHUTDOWN
:
489 * Valid image is on the disk, if we continue we risk serious data
490 * corruption after resume.
492 printk(KERN_CRIT
"PM: Please power down manually\n");
496 static int prepare_processes(void)
500 if (freeze_processes()) {
508 * hibernate - The granpappy of the built-in hibernation management
515 mutex_lock(&pm_mutex
);
516 /* The snapshot device should not be opened while we're running */
517 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
522 pm_prepare_console();
523 error
= pm_notifier_call_chain(PM_HIBERNATION_PREPARE
);
527 error
= usermodehelper_disable();
531 /* Allocate memory management structures */
532 error
= create_basic_memory_bitmaps();
536 printk(KERN_INFO
"PM: Syncing filesystems ... ");
540 error
= prepare_processes();
544 if (hibernation_test(TEST_FREEZER
))
547 if (hibernation_testmode(HIBERNATION_TESTPROC
))
550 error
= hibernation_snapshot(hibernation_mode
== HIBERNATION_PLATFORM
);
551 if (in_suspend
&& !error
) {
552 unsigned int flags
= 0;
554 if (hibernation_mode
== HIBERNATION_PLATFORM
)
555 flags
|= SF_PLATFORM_MODE
;
556 pr_debug("PM: writing image.\n");
557 error
= swsusp_write(flags
);
562 pr_debug("PM: Image restored successfully.\n");
568 free_basic_memory_bitmaps();
569 usermodehelper_enable();
571 pm_notifier_call_chain(PM_POST_HIBERNATION
);
572 pm_restore_console();
573 atomic_inc(&snapshot_device_available
);
575 mutex_unlock(&pm_mutex
);
581 * software_resume - Resume from a saved image.
583 * Called as a late_initcall (so all devices are discovered and
584 * initialized), we call swsusp to see if we have a saved image or not.
585 * If so, we quiesce devices, the restore the saved image. We will
586 * return above (in hibernate() ) if everything goes well.
587 * Otherwise, we fail gracefully and return to the normally
592 static int software_resume(void)
598 * If the user said "noresume".. bail out early.
604 * name_to_dev_t() below takes a sysfs buffer mutex when sysfs
605 * is configured into the kernel. Since the regular hibernate
606 * trigger path is via sysfs which takes a buffer mutex before
607 * calling hibernate functions (which take pm_mutex) this can
608 * cause lockdep to complain about a possible ABBA deadlock
609 * which cannot happen since we're in the boot code here and
610 * sysfs can't be invoked yet. Therefore, we use a subclass
611 * here to avoid lockdep complaining.
613 mutex_lock_nested(&pm_mutex
, SINGLE_DEPTH_NESTING
);
614 if (!swsusp_resume_device
) {
615 if (!strlen(resume_file
)) {
616 mutex_unlock(&pm_mutex
);
620 * Some device discovery might still be in progress; we need
621 * to wait for this to finish.
623 wait_for_device_probe();
624 swsusp_resume_device
= name_to_dev_t(resume_file
);
625 pr_debug("PM: Resume from partition %s\n", resume_file
);
627 pr_debug("PM: Resume from partition %d:%d\n",
628 MAJOR(swsusp_resume_device
),
629 MINOR(swsusp_resume_device
));
634 * FIXME: If noresume is specified, we need to find the
635 * partition and reset it back to normal swap space.
637 mutex_unlock(&pm_mutex
);
641 pr_debug("PM: Checking hibernation image.\n");
642 error
= swsusp_check();
646 /* The snapshot device should not be opened while we're running */
647 if (!atomic_add_unless(&snapshot_device_available
, -1, 0)) {
652 pm_prepare_console();
653 error
= pm_notifier_call_chain(PM_RESTORE_PREPARE
);
657 error
= usermodehelper_disable();
661 error
= create_basic_memory_bitmaps();
665 pr_debug("PM: Preparing processes for restore.\n");
666 error
= prepare_processes();
668 swsusp_close(FMODE_READ
);
672 pr_debug("PM: Reading hibernation image.\n");
674 error
= swsusp_read(&flags
);
676 hibernation_restore(flags
& SF_PLATFORM_MODE
);
678 printk(KERN_ERR
"PM: Restore failed, recovering.\n");
682 free_basic_memory_bitmaps();
683 usermodehelper_enable();
685 pm_notifier_call_chain(PM_POST_RESTORE
);
686 pm_restore_console();
687 atomic_inc(&snapshot_device_available
);
688 /* For success case, the suspend path will release the lock */
690 mutex_unlock(&pm_mutex
);
691 pr_debug("PM: Resume from disk failed.\n");
695 late_initcall(software_resume
);
698 static const char * const hibernation_modes
[] = {
699 [HIBERNATION_PLATFORM
] = "platform",
700 [HIBERNATION_SHUTDOWN
] = "shutdown",
701 [HIBERNATION_REBOOT
] = "reboot",
702 [HIBERNATION_TEST
] = "test",
703 [HIBERNATION_TESTPROC
] = "testproc",
707 * disk - Control hibernation mode
709 * Suspend-to-disk can be handled in several ways. We have a few options
710 * for putting the system to sleep - using the platform driver (e.g. ACPI
711 * or other hibernation_ops), powering off the system or rebooting the
712 * system (for testing) as well as the two test modes.
714 * The system can support 'platform', and that is known a priori (and
715 * encoded by the presence of hibernation_ops). However, the user may
716 * choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
717 * test modes, 'test' or 'testproc'.
719 * show() will display what the mode is currently set to.
720 * store() will accept one of
728 * It will only change to 'platform' if the system
729 * supports it (as determined by having hibernation_ops).
732 static ssize_t
disk_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
738 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
739 if (!hibernation_modes
[i
])
742 case HIBERNATION_SHUTDOWN
:
743 case HIBERNATION_REBOOT
:
744 case HIBERNATION_TEST
:
745 case HIBERNATION_TESTPROC
:
747 case HIBERNATION_PLATFORM
:
750 /* not a valid mode, continue with loop */
753 if (i
== hibernation_mode
)
754 buf
+= sprintf(buf
, "[%s] ", hibernation_modes
[i
]);
756 buf
+= sprintf(buf
, "%s ", hibernation_modes
[i
]);
758 buf
+= sprintf(buf
, "\n");
763 static ssize_t
disk_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
764 const char *buf
, size_t n
)
770 int mode
= HIBERNATION_INVALID
;
772 p
= memchr(buf
, '\n', n
);
773 len
= p
? p
- buf
: n
;
775 mutex_lock(&pm_mutex
);
776 for (i
= HIBERNATION_FIRST
; i
<= HIBERNATION_MAX
; i
++) {
777 if (len
== strlen(hibernation_modes
[i
])
778 && !strncmp(buf
, hibernation_modes
[i
], len
)) {
783 if (mode
!= HIBERNATION_INVALID
) {
785 case HIBERNATION_SHUTDOWN
:
786 case HIBERNATION_REBOOT
:
787 case HIBERNATION_TEST
:
788 case HIBERNATION_TESTPROC
:
789 hibernation_mode
= mode
;
791 case HIBERNATION_PLATFORM
:
793 hibernation_mode
= mode
;
801 pr_debug("PM: Hibernation mode set to '%s'\n",
802 hibernation_modes
[mode
]);
803 mutex_unlock(&pm_mutex
);
804 return error
? error
: n
;
809 static ssize_t
resume_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
812 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
813 MINOR(swsusp_resume_device
));
816 static ssize_t
resume_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
817 const char *buf
, size_t n
)
819 unsigned int maj
, min
;
823 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
826 res
= MKDEV(maj
,min
);
827 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
830 mutex_lock(&pm_mutex
);
831 swsusp_resume_device
= res
;
832 mutex_unlock(&pm_mutex
);
833 printk(KERN_INFO
"PM: Starting manual resume from disk\n");
843 static ssize_t
image_size_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
846 return sprintf(buf
, "%lu\n", image_size
);
849 static ssize_t
image_size_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
850 const char *buf
, size_t n
)
854 if (sscanf(buf
, "%lu", &size
) == 1) {
862 power_attr(image_size
);
864 static struct attribute
* g
[] = {
867 &image_size_attr
.attr
,
872 static struct attribute_group attr_group
= {
877 static int __init
pm_disk_init(void)
879 return sysfs_create_group(power_kobj
, &attr_group
);
882 core_initcall(pm_disk_init
);
885 static int __init
resume_setup(char *str
)
890 strncpy( resume_file
, str
, 255 );
894 static int __init
resume_offset_setup(char *str
)
896 unsigned long long offset
;
901 if (sscanf(str
, "%llu", &offset
) == 1)
902 swsusp_resume_block
= offset
;
907 static int __init
noresume_setup(char *str
)
913 __setup("noresume", noresume_setup
);
914 __setup("resume_offset=", resume_offset_setup
);
915 __setup("resume=", resume_setup
);