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>
27 static int noresume
= 0;
28 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
29 dev_t swsusp_resume_device
;
32 * power_down - Shut machine down for hibernate.
33 * @mode: Suspend-to-disk mode
35 * Use the platform driver, if configured so, and return gracefully if it
37 * Otherwise, try to power off and reboot. If they fail, halt the machine,
38 * there ain't no turning back.
41 static void power_down(suspend_disk_method_t mode
)
46 case PM_DISK_PLATFORM
:
47 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
48 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
50 case PM_DISK_SHUTDOWN
:
58 /* Valid image is on the disk, if we continue we risk serious data corruption
60 printk(KERN_CRIT
"Please power me down manually\n");
64 static inline void platform_finish(void)
66 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
67 if (pm_ops
&& pm_ops
->finish
)
68 pm_ops
->finish(PM_SUSPEND_DISK
);
72 static int prepare_processes(void)
78 error
= disable_nonboot_cpus();
82 if (freeze_processes()) {
87 /* Free memory before shutting down devices. */
88 if (!(error
= swsusp_shrink_memory()))
93 enable_nonboot_cpus();
98 static void unprepare_processes(void)
102 enable_nonboot_cpus();
103 pm_restore_console();
107 * pm_suspend_disk - The granpappy of hibernation power management.
109 * If we're going through the firmware, then get it over with quickly.
111 * If not, then call swsusp to do its thing, then figure out how
112 * to power down the system.
115 int pm_suspend_disk(void)
119 error
= prepare_processes();
124 error
= device_suspend(PMSG_FREEZE
);
127 printk("Some devices failed to suspend\n");
128 unprepare_processes();
132 pr_debug("PM: snapshotting memory.\n");
134 if ((error
= swsusp_suspend()))
140 pr_debug("PM: writing image.\n");
141 error
= swsusp_write();
143 power_down(pm_disk_mode
);
146 unprepare_processes();
150 pr_debug("PM: Image restored successfully.\n");
156 unprepare_processes();
162 * software_resume - Resume from a saved image.
164 * Called as a late_initcall (so all devices are discovered and
165 * initialized), we call swsusp to see if we have a saved image or not.
166 * If so, we quiesce devices, the restore the saved image. We will
167 * return above (in pm_suspend_disk() ) if everything goes well.
168 * Otherwise, we fail gracefully and return to the normally
173 static int software_resume(void)
178 if (!swsusp_resume_device
) {
179 if (!strlen(resume_file
)) {
183 swsusp_resume_device
= name_to_dev_t(resume_file
);
184 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
186 pr_debug("swsusp: Resume From Partition %d:%d\n",
187 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
192 * FIXME: If noresume is specified, we need to find the partition
193 * and reset it back to normal swap space.
199 pr_debug("PM: Checking swsusp image.\n");
201 if ((error
= swsusp_check()))
204 pr_debug("PM: Preparing processes for restore.\n");
206 if ((error
= prepare_processes())) {
211 pr_debug("PM: Reading swsusp image.\n");
213 if ((error
= swsusp_read())) {
218 pr_debug("PM: Preparing devices for restore.\n");
221 if ((error
= device_suspend(PMSG_PRETHAW
))) {
223 printk("Some devices failed to suspend\n");
230 pr_debug("PM: Restoring saved image.\n");
232 pr_debug("PM: Restore failed, recovering.n");
236 unprepare_processes();
238 /* For success case, the suspend path will release the lock */
240 pr_debug("PM: Resume from disk failed.\n");
244 late_initcall(software_resume
);
247 static const char * const pm_disk_modes
[] = {
248 [PM_DISK_FIRMWARE
] = "firmware",
249 [PM_DISK_PLATFORM
] = "platform",
250 [PM_DISK_SHUTDOWN
] = "shutdown",
251 [PM_DISK_REBOOT
] = "reboot",
255 * disk - Control suspend-to-disk mode
257 * Suspend-to-disk can be handled in several ways. The greatest
258 * distinction is who writes memory to disk - the firmware or the OS.
259 * If the firmware does it, we assume that it also handles suspending
261 * If the OS does it, then we have three options for putting the system
262 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
263 * powering off the system or rebooting the system (for testing).
265 * The system will support either 'firmware' or 'platform', and that is
266 * known a priori (and encoded in pm_ops). But, the user may choose
267 * 'shutdown' or 'reboot' as alternatives.
269 * show() will display what the mode is currently set to.
270 * store() will accept one of
277 * It will only change to 'firmware' or 'platform' if the system
278 * supports it (as determined from pm_ops->pm_disk_mode).
281 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
283 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
287 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
293 suspend_disk_method_t mode
= 0;
295 p
= memchr(buf
, '\n', n
);
296 len
= p
? p
- buf
: n
;
299 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
300 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
306 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
)
309 if (pm_ops
&& pm_ops
->enter
&&
310 (mode
== pm_ops
->pm_disk_mode
))
318 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
319 pm_disk_modes
[mode
]);
321 return error
? error
: n
;
326 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
328 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
329 MINOR(swsusp_resume_device
));
332 static ssize_t
resume_store(struct subsystem
*subsys
, const char *buf
, size_t n
)
334 unsigned int maj
, min
;
338 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
341 res
= MKDEV(maj
,min
);
342 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
346 swsusp_resume_device
= res
;
348 printk("Attempting manual resume\n");
358 static ssize_t
image_size_show(struct subsystem
* subsys
, char *buf
)
360 return sprintf(buf
, "%lu\n", image_size
);
363 static ssize_t
image_size_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
367 if (sscanf(buf
, "%lu", &size
) == 1) {
375 power_attr(image_size
);
377 static struct attribute
* g
[] = {
380 &image_size_attr
.attr
,
385 static struct attribute_group attr_group
= {
390 static int __init
pm_disk_init(void)
392 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
395 core_initcall(pm_disk_init
);
398 static int __init
resume_setup(char *str
)
403 strncpy( resume_file
, str
, 255 );
407 static int __init
noresume_setup(char *str
)
413 __setup("noresume", noresume_setup
);
414 __setup("resume=", resume_setup
);