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>
25 extern suspend_disk_method_t pm_disk_mode
;
27 extern int swsusp_suspend(void);
28 extern int swsusp_write(void);
29 extern int swsusp_check(void);
30 extern int swsusp_read(void);
31 extern void swsusp_close(void);
32 extern int swsusp_resume(void);
33 extern int swsusp_free(void);
36 static int noresume
= 0;
37 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
38 dev_t swsusp_resume_device
;
41 * power_down - Shut machine down for hibernate.
42 * @mode: Suspend-to-disk mode
44 * Use the platform driver, if configured so, and return gracefully if it
46 * Otherwise, try to power off and reboot. If they fail, halt the machine,
47 * there ain't no turning back.
50 static void power_down(suspend_disk_method_t mode
)
55 case PM_DISK_PLATFORM
:
56 kernel_power_off_prepare();
57 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
59 case PM_DISK_SHUTDOWN
:
67 /* Valid image is on the disk, if we continue we risk serious data corruption
69 printk(KERN_CRIT
"Please power me down manually\n");
74 static int in_suspend __nosavedata
= 0;
78 * free_some_memory - Try to free as much memory as possible
80 * ... but do not OOM-kill anyone
82 * Notice: all userland should be stopped at this point, or
83 * livelock is possible.
86 static void free_some_memory(void)
90 unsigned long pages
= 0;
93 printk("Freeing memory... ");
94 while ((tmp
= shrink_all_memory(10000))) {
101 printk("\bdone (%li pages freed)\n", pages
);
105 static inline void platform_finish(void)
107 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
108 if (pm_ops
&& pm_ops
->finish
)
109 pm_ops
->finish(PM_SUSPEND_DISK
);
113 static int prepare_processes(void)
117 pm_prepare_console();
119 disable_nonboot_cpus();
121 if (freeze_processes()) {
126 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
127 if (pm_ops
&& pm_ops
->prepare
) {
128 if ((error
= pm_ops
->prepare(PM_SUSPEND_DISK
)))
133 /* Free memory before shutting down devices. */
138 enable_nonboot_cpus();
139 pm_restore_console();
143 static void unprepare_processes(void)
147 enable_nonboot_cpus();
148 pm_restore_console();
152 * pm_suspend_disk - The granpappy of power management.
154 * If we're going through the firmware, then get it over with quickly.
156 * If not, then call swsusp to do its thing, then figure out how
157 * to power down the system.
160 int pm_suspend_disk(void)
164 error
= prepare_processes();
168 error
= device_suspend(PMSG_FREEZE
);
170 printk("Some devices failed to suspend\n");
171 unprepare_processes();
175 pr_debug("PM: snapshotting memory.\n");
177 if ((error
= swsusp_suspend()))
181 pr_debug("PM: writing image.\n");
182 error
= swsusp_write();
184 power_down(pm_disk_mode
);
186 /* swsusp_write can not fail in device_resume,
187 no need to do second device_resume */
189 unprepare_processes();
193 pr_debug("PM: Image restored successfully.\n");
198 unprepare_processes();
204 * software_resume - Resume from a saved image.
206 * Called as a late_initcall (so all devices are discovered and
207 * initialized), we call swsusp to see if we have a saved image or not.
208 * If so, we quiesce devices, the restore the saved image. We will
209 * return above (in pm_suspend_disk() ) if everything goes well.
210 * Otherwise, we fail gracefully and return to the normally
215 static int software_resume(void)
220 if (!swsusp_resume_device
) {
221 if (!strlen(resume_file
)) {
225 swsusp_resume_device
= name_to_dev_t(resume_file
);
226 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
228 pr_debug("swsusp: Resume From Partition %d:%d\n",
229 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
234 * FIXME: If noresume is specified, we need to find the partition
235 * and reset it back to normal swap space.
241 pr_debug("PM: Checking swsusp image.\n");
243 if ((error
= swsusp_check()))
246 pr_debug("PM: Preparing processes for restore.\n");
248 if ((error
= prepare_processes())) {
253 pr_debug("PM: Reading swsusp image.\n");
255 if ((error
= swsusp_read()))
258 pr_debug("PM: Preparing devices for restore.\n");
260 if ((error
= device_suspend(PMSG_FREEZE
))) {
261 printk("Some devices failed to suspend\n");
267 pr_debug("PM: Restoring saved image.\n");
269 pr_debug("PM: Restore failed, recovering.n");
274 unprepare_processes();
276 /* For success case, the suspend path will release the lock */
278 pr_debug("PM: Resume from disk failed.\n");
282 late_initcall(software_resume
);
285 static char * pm_disk_modes
[] = {
286 [PM_DISK_FIRMWARE
] = "firmware",
287 [PM_DISK_PLATFORM
] = "platform",
288 [PM_DISK_SHUTDOWN
] = "shutdown",
289 [PM_DISK_REBOOT
] = "reboot",
293 * disk - Control suspend-to-disk mode
295 * Suspend-to-disk can be handled in several ways. The greatest
296 * distinction is who writes memory to disk - the firmware or the OS.
297 * If the firmware does it, we assume that it also handles suspending
299 * If the OS does it, then we have three options for putting the system
300 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
301 * powering off the system or rebooting the system (for testing).
303 * The system will support either 'firmware' or 'platform', and that is
304 * known a priori (and encoded in pm_ops). But, the user may choose
305 * 'shutdown' or 'reboot' as alternatives.
307 * show() will display what the mode is currently set to.
308 * store() will accept one of
315 * It will only change to 'firmware' or 'platform' if the system
316 * supports it (as determined from pm_ops->pm_disk_mode).
319 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
321 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
325 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
331 suspend_disk_method_t mode
= 0;
333 p
= memchr(buf
, '\n', n
);
334 len
= p
? p
- buf
: n
;
337 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
338 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
344 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
)
347 if (pm_ops
&& pm_ops
->enter
&&
348 (mode
== pm_ops
->pm_disk_mode
))
356 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
357 pm_disk_modes
[mode
]);
359 return error
? error
: n
;
364 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
366 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
367 MINOR(swsusp_resume_device
));
370 static ssize_t
resume_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
374 unsigned int maj
, min
;
378 p
= memchr(buf
, '\n', n
);
379 len
= p
? p
- buf
: n
;
381 if (sscanf(buf
, "%u:%u", &maj
, &min
) == 2) {
382 res
= MKDEV(maj
,min
);
383 if (maj
== MAJOR(res
) && min
== MINOR(res
)) {
385 swsusp_resume_device
= res
;
387 printk("Attempting manual resume\n");
393 return error
>= 0 ? n
: error
;
398 static struct attribute
* g
[] = {
405 static struct attribute_group attr_group
= {
410 static int __init
pm_disk_init(void)
412 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
415 core_initcall(pm_disk_init
);
418 static int __init
resume_setup(char *str
)
423 strncpy( resume_file
, str
, 255 );
427 static int __init
noresume_setup(char *str
)
433 __setup("noresume", noresume_setup
);
434 __setup("resume=", resume_setup
);