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);
35 static int noresume
= 0;
36 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
37 dev_t swsusp_resume_device
;
40 * power_down - Shut machine down for hibernate.
41 * @mode: Suspend-to-disk mode
43 * Use the platform driver, if configured so, and return gracefully if it
45 * Otherwise, try to power off and reboot. If they fail, halt the machine,
46 * there ain't no turning back.
49 static void power_down(suspend_disk_method_t mode
)
54 case PM_DISK_PLATFORM
:
55 kernel_power_off_prepare();
56 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
58 case PM_DISK_SHUTDOWN
:
66 /* Valid image is on the disk, if we continue we risk serious data corruption
68 printk(KERN_CRIT
"Please power me down manually\n");
73 static int in_suspend __nosavedata
= 0;
77 * free_some_memory - Try to free as much memory as possible
79 * ... but do not OOM-kill anyone
81 * Notice: all userland should be stopped at this point, or
82 * livelock is possible.
85 static void free_some_memory(void)
89 unsigned long pages
= 0;
92 printk("Freeing memory... ");
93 while ((tmp
= shrink_all_memory(10000))) {
95 printk("\b%c", p
[i
++ % 4]);
97 printk("\bdone (%li pages freed)\n", pages
);
101 static inline void platform_finish(void)
103 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
104 if (pm_ops
&& pm_ops
->finish
)
105 pm_ops
->finish(PM_SUSPEND_DISK
);
109 static int prepare_processes(void)
113 pm_prepare_console();
115 disable_nonboot_cpus();
117 if (freeze_processes()) {
122 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
123 if (pm_ops
&& pm_ops
->prepare
) {
124 if ((error
= pm_ops
->prepare(PM_SUSPEND_DISK
)))
129 /* Free memory before shutting down devices. */
134 enable_nonboot_cpus();
135 pm_restore_console();
139 static void unprepare_processes(void)
143 enable_nonboot_cpus();
144 pm_restore_console();
148 * pm_suspend_disk - The granpappy of power management.
150 * If we're going through the firmware, then get it over with quickly.
152 * If not, then call swsusp to do its thing, then figure out how
153 * to power down the system.
156 int pm_suspend_disk(void)
160 error
= prepare_processes();
164 error
= device_suspend(PMSG_FREEZE
);
166 printk("Some devices failed to suspend\n");
167 unprepare_processes();
171 pr_debug("PM: snapshotting memory.\n");
173 if ((error
= swsusp_suspend()))
178 pr_debug("PM: writing image.\n");
179 error
= swsusp_write();
181 power_down(pm_disk_mode
);
184 unprepare_processes();
188 pr_debug("PM: Image restored successfully.\n");
193 unprepare_processes();
199 * software_resume - Resume from a saved image.
201 * Called as a late_initcall (so all devices are discovered and
202 * initialized), we call swsusp to see if we have a saved image or not.
203 * If so, we quiesce devices, the restore the saved image. We will
204 * return above (in pm_suspend_disk() ) if everything goes well.
205 * Otherwise, we fail gracefully and return to the normally
210 static int software_resume(void)
215 if (!swsusp_resume_device
) {
216 if (!strlen(resume_file
)) {
220 swsusp_resume_device
= name_to_dev_t(resume_file
);
221 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
223 pr_debug("swsusp: Resume From Partition %d:%d\n",
224 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
229 * FIXME: If noresume is specified, we need to find the partition
230 * and reset it back to normal swap space.
236 pr_debug("PM: Checking swsusp image.\n");
238 if ((error
= swsusp_check()))
241 pr_debug("PM: Preparing processes for restore.\n");
243 if ((error
= prepare_processes())) {
248 pr_debug("PM: Reading swsusp image.\n");
250 if ((error
= swsusp_read())) {
255 pr_debug("PM: Preparing devices for restore.\n");
257 if ((error
= device_suspend(PMSG_FREEZE
))) {
258 printk("Some devices failed to suspend\n");
265 pr_debug("PM: Restoring saved image.\n");
267 pr_debug("PM: Restore failed, recovering.n");
270 unprepare_processes();
272 /* For success case, the suspend path will release the lock */
274 pr_debug("PM: Resume from disk failed.\n");
278 late_initcall(software_resume
);
281 static char * pm_disk_modes
[] = {
282 [PM_DISK_FIRMWARE
] = "firmware",
283 [PM_DISK_PLATFORM
] = "platform",
284 [PM_DISK_SHUTDOWN
] = "shutdown",
285 [PM_DISK_REBOOT
] = "reboot",
289 * disk - Control suspend-to-disk mode
291 * Suspend-to-disk can be handled in several ways. The greatest
292 * distinction is who writes memory to disk - the firmware or the OS.
293 * If the firmware does it, we assume that it also handles suspending
295 * If the OS does it, then we have three options for putting the system
296 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
297 * powering off the system or rebooting the system (for testing).
299 * The system will support either 'firmware' or 'platform', and that is
300 * known a priori (and encoded in pm_ops). But, the user may choose
301 * 'shutdown' or 'reboot' as alternatives.
303 * show() will display what the mode is currently set to.
304 * store() will accept one of
311 * It will only change to 'firmware' or 'platform' if the system
312 * supports it (as determined from pm_ops->pm_disk_mode).
315 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
317 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
321 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
327 suspend_disk_method_t mode
= 0;
329 p
= memchr(buf
, '\n', n
);
330 len
= p
? p
- buf
: n
;
333 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
334 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
340 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
)
343 if (pm_ops
&& pm_ops
->enter
&&
344 (mode
== pm_ops
->pm_disk_mode
))
352 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
353 pm_disk_modes
[mode
]);
355 return error
? error
: n
;
360 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
362 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
363 MINOR(swsusp_resume_device
));
366 static ssize_t
resume_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
370 unsigned int maj
, min
;
374 p
= memchr(buf
, '\n', n
);
375 len
= p
? p
- buf
: n
;
377 if (sscanf(buf
, "%u:%u", &maj
, &min
) == 2) {
378 res
= MKDEV(maj
,min
);
379 if (maj
== MAJOR(res
) && min
== MINOR(res
)) {
381 swsusp_resume_device
= res
;
383 printk("Attempting manual resume\n");
389 return error
>= 0 ? n
: error
;
394 static struct attribute
* g
[] = {
401 static struct attribute_group attr_group
= {
406 static int __init
pm_disk_init(void)
408 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
411 core_initcall(pm_disk_init
);
414 static int __init
resume_setup(char *str
)
419 strncpy( resume_file
, str
, 255 );
423 static int __init
noresume_setup(char *str
)
429 __setup("noresume", noresume_setup
);
430 __setup("resume=", resume_setup
);