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/delay.h>
19 #include <linux/mount.h>
21 #include <linux/console.h>
22 #include <linux/cpu.h>
23 #include <linux/freezer.h>
28 static int noresume
= 0;
29 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
30 dev_t swsusp_resume_device
;
31 sector_t swsusp_resume_block
;
34 * platform_prepare - prepare the machine for hibernation using the
35 * platform driver if so configured and return an error code if it fails
38 static inline int platform_prepare(void)
42 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
43 if (pm_ops
&& pm_ops
->prepare
)
44 error
= pm_ops
->prepare(PM_SUSPEND_DISK
);
50 * power_down - Shut machine down for hibernate.
51 * @mode: Suspend-to-disk mode
53 * Use the platform driver, if configured so, and return gracefully if it
55 * Otherwise, try to power off and reboot. If they fail, halt the machine,
56 * there ain't no turning back.
59 static void power_down(suspend_disk_method_t mode
)
62 case PM_DISK_PLATFORM
:
63 if (pm_ops
&& pm_ops
->enter
) {
64 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
65 pm_ops
->enter(PM_SUSPEND_DISK
);
68 case PM_DISK_SHUTDOWN
:
76 /* Valid image is on the disk, if we continue we risk serious data corruption
78 printk(KERN_CRIT
"Please power me down manually\n");
82 static inline void platform_finish(void)
84 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
85 if (pm_ops
&& pm_ops
->finish
)
86 pm_ops
->finish(PM_SUSPEND_DISK
);
90 static void unprepare_processes(void)
96 static int prepare_processes(void)
100 pm_prepare_console();
101 if (freeze_processes()) {
103 unprepare_processes();
109 * pm_suspend_disk - The granpappy of hibernation power management.
111 * If we're going through the firmware, then get it over with quickly.
113 * If not, then call swsusp to do its thing, then figure out how
114 * to power down the system.
117 int pm_suspend_disk(void)
121 error
= prepare_processes();
125 if (pm_disk_mode
== PM_DISK_TESTPROC
) {
126 printk("swsusp debug: Waiting for 5 seconds.\n");
130 /* Free memory before shutting down devices. */
131 error
= swsusp_shrink_memory();
135 error
= platform_prepare();
140 error
= device_suspend(PMSG_FREEZE
);
142 printk(KERN_ERR
"PM: Some devices failed to suspend\n");
145 error
= disable_nonboot_cpus();
149 if (pm_disk_mode
== PM_DISK_TEST
) {
150 printk("swsusp debug: Waiting for 5 seconds.\n");
155 pr_debug("PM: snapshotting memory.\n");
157 error
= swsusp_suspend();
162 enable_nonboot_cpus();
166 pr_debug("PM: writing image.\n");
167 error
= swsusp_write();
169 power_down(pm_disk_mode
);
175 pr_debug("PM: Image restored successfully.\n");
180 enable_nonboot_cpus();
186 unprepare_processes();
192 * software_resume - Resume from a saved image.
194 * Called as a late_initcall (so all devices are discovered and
195 * initialized), we call swsusp to see if we have a saved image or not.
196 * If so, we quiesce devices, the restore the saved image. We will
197 * return above (in pm_suspend_disk() ) if everything goes well.
198 * Otherwise, we fail gracefully and return to the normally
203 static int software_resume(void)
207 mutex_lock(&pm_mutex
);
208 if (!swsusp_resume_device
) {
209 if (!strlen(resume_file
)) {
210 mutex_unlock(&pm_mutex
);
213 swsusp_resume_device
= name_to_dev_t(resume_file
);
214 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
216 pr_debug("swsusp: Resume From Partition %d:%d\n",
217 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
222 * FIXME: If noresume is specified, we need to find the partition
223 * and reset it back to normal swap space.
225 mutex_unlock(&pm_mutex
);
229 pr_debug("PM: Checking swsusp image.\n");
231 error
= swsusp_check();
235 pr_debug("PM: Preparing processes for restore.\n");
237 error
= prepare_processes();
243 error
= platform_prepare();
249 pr_debug("PM: Reading swsusp image.\n");
251 error
= swsusp_read();
257 pr_debug("PM: Preparing devices for restore.\n");
260 error
= device_suspend(PMSG_PRETHAW
);
264 error
= disable_nonboot_cpus();
268 enable_nonboot_cpus();
275 printk(KERN_ERR
"PM: Restore failed, recovering.\n");
276 unprepare_processes();
278 /* For success case, the suspend path will release the lock */
279 mutex_unlock(&pm_mutex
);
280 pr_debug("PM: Resume from disk failed.\n");
284 late_initcall(software_resume
);
287 static const char * const pm_disk_modes
[] = {
288 [PM_DISK_FIRMWARE
] = "firmware",
289 [PM_DISK_PLATFORM
] = "platform",
290 [PM_DISK_SHUTDOWN
] = "shutdown",
291 [PM_DISK_REBOOT
] = "reboot",
292 [PM_DISK_TEST
] = "test",
293 [PM_DISK_TESTPROC
] = "testproc",
297 * disk - Control suspend-to-disk mode
299 * Suspend-to-disk can be handled in several ways. The greatest
300 * distinction is who writes memory to disk - the firmware or the OS.
301 * If the firmware does it, we assume that it also handles suspending
303 * If the OS does it, then we have three options for putting the system
304 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
305 * powering off the system or rebooting the system (for testing).
307 * The system will support either 'firmware' or 'platform', and that is
308 * known a priori (and encoded in pm_ops). But, the user may choose
309 * 'shutdown' or 'reboot' as alternatives.
311 * show() will display what the mode is currently set to.
312 * store() will accept one of
319 * It will only change to 'firmware' or 'platform' if the system
320 * supports it (as determined from pm_ops->pm_disk_mode).
323 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
325 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
329 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
335 suspend_disk_method_t mode
= 0;
337 p
= memchr(buf
, '\n', n
);
338 len
= p
? p
- buf
: n
;
340 mutex_lock(&pm_mutex
);
341 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
342 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
348 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
||
349 mode
== PM_DISK_TEST
|| mode
== PM_DISK_TESTPROC
) {
352 if (pm_ops
&& pm_ops
->enter
&&
353 (mode
== pm_ops
->pm_disk_mode
))
362 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
363 pm_disk_modes
[mode
]);
364 mutex_unlock(&pm_mutex
);
365 return error
? error
: n
;
370 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
372 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
373 MINOR(swsusp_resume_device
));
376 static ssize_t
resume_store(struct subsystem
*subsys
, const char *buf
, size_t n
)
378 unsigned int maj
, min
;
382 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
385 res
= MKDEV(maj
,min
);
386 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
389 mutex_lock(&pm_mutex
);
390 swsusp_resume_device
= res
;
391 mutex_unlock(&pm_mutex
);
392 printk("Attempting manual resume\n");
402 static ssize_t
image_size_show(struct subsystem
* subsys
, char *buf
)
404 return sprintf(buf
, "%lu\n", image_size
);
407 static ssize_t
image_size_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
411 if (sscanf(buf
, "%lu", &size
) == 1) {
419 power_attr(image_size
);
421 static struct attribute
* g
[] = {
424 &image_size_attr
.attr
,
429 static struct attribute_group attr_group
= {
434 static int __init
pm_disk_init(void)
436 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
439 core_initcall(pm_disk_init
);
442 static int __init
resume_setup(char *str
)
447 strncpy( resume_file
, str
, 255 );
451 static int __init
resume_offset_setup(char *str
)
453 unsigned long long offset
;
458 if (sscanf(str
, "%llu", &offset
) == 1)
459 swsusp_resume_block
= offset
;
464 static int __init
noresume_setup(char *str
)
470 __setup("noresume", noresume_setup
);
471 __setup("resume_offset=", resume_offset_setup
);
472 __setup("resume=", resume_setup
);