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/cpu.h>
26 static int noresume
= 0;
27 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
28 dev_t swsusp_resume_device
;
31 * power_down - Shut machine down for hibernate.
32 * @mode: Suspend-to-disk mode
34 * Use the platform driver, if configured so, and return gracefully if it
36 * Otherwise, try to power off and reboot. If they fail, halt the machine,
37 * there ain't no turning back.
40 static void power_down(suspend_disk_method_t mode
)
45 case PM_DISK_PLATFORM
:
46 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK
);
47 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
49 case PM_DISK_SHUTDOWN
:
57 /* Valid image is on the disk, if we continue we risk serious data corruption
59 printk(KERN_CRIT
"Please power me down manually\n");
63 static inline void platform_finish(void)
65 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
66 if (pm_ops
&& pm_ops
->finish
)
67 pm_ops
->finish(PM_SUSPEND_DISK
);
71 static int prepare_processes(void)
77 error
= disable_nonboot_cpus();
81 if (freeze_processes()) {
86 /* Free memory before shutting down devices. */
87 if (!(error
= swsusp_shrink_memory()))
92 enable_nonboot_cpus();
97 static void unprepare_processes(void)
101 enable_nonboot_cpus();
102 pm_restore_console();
106 * pm_suspend_disk - The granpappy of hibernation power management.
108 * If we're going through the firmware, then get it over with quickly.
110 * If not, then call swsusp to do its thing, then figure out how
111 * to power down the system.
114 int pm_suspend_disk(void)
118 error
= prepare_processes();
122 error
= device_suspend(PMSG_FREEZE
);
124 printk("Some devices failed to suspend\n");
125 unprepare_processes();
129 pr_debug("PM: snapshotting memory.\n");
131 if ((error
= swsusp_suspend()))
136 pr_debug("PM: writing image.\n");
137 error
= swsusp_write();
139 power_down(pm_disk_mode
);
142 unprepare_processes();
146 pr_debug("PM: Image restored successfully.\n");
151 unprepare_processes();
157 * software_resume - Resume from a saved image.
159 * Called as a late_initcall (so all devices are discovered and
160 * initialized), we call swsusp to see if we have a saved image or not.
161 * If so, we quiesce devices, the restore the saved image. We will
162 * return above (in pm_suspend_disk() ) if everything goes well.
163 * Otherwise, we fail gracefully and return to the normally
168 static int software_resume(void)
173 if (!swsusp_resume_device
) {
174 if (!strlen(resume_file
)) {
178 swsusp_resume_device
= name_to_dev_t(resume_file
);
179 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
181 pr_debug("swsusp: Resume From Partition %d:%d\n",
182 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
187 * FIXME: If noresume is specified, we need to find the partition
188 * and reset it back to normal swap space.
194 pr_debug("PM: Checking swsusp image.\n");
196 if ((error
= swsusp_check()))
199 pr_debug("PM: Preparing processes for restore.\n");
201 if ((error
= prepare_processes())) {
206 pr_debug("PM: Reading swsusp image.\n");
208 if ((error
= swsusp_read())) {
213 pr_debug("PM: Preparing devices for restore.\n");
215 if ((error
= device_suspend(PMSG_PRETHAW
))) {
216 printk("Some devices failed to suspend\n");
223 pr_debug("PM: Restoring saved image.\n");
225 pr_debug("PM: Restore failed, recovering.n");
228 unprepare_processes();
230 /* For success case, the suspend path will release the lock */
232 pr_debug("PM: Resume from disk failed.\n");
236 late_initcall(software_resume
);
239 static const char * const pm_disk_modes
[] = {
240 [PM_DISK_FIRMWARE
] = "firmware",
241 [PM_DISK_PLATFORM
] = "platform",
242 [PM_DISK_SHUTDOWN
] = "shutdown",
243 [PM_DISK_REBOOT
] = "reboot",
247 * disk - Control suspend-to-disk mode
249 * Suspend-to-disk can be handled in several ways. The greatest
250 * distinction is who writes memory to disk - the firmware or the OS.
251 * If the firmware does it, we assume that it also handles suspending
253 * If the OS does it, then we have three options for putting the system
254 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
255 * powering off the system or rebooting the system (for testing).
257 * The system will support either 'firmware' or 'platform', and that is
258 * known a priori (and encoded in pm_ops). But, the user may choose
259 * 'shutdown' or 'reboot' as alternatives.
261 * show() will display what the mode is currently set to.
262 * store() will accept one of
269 * It will only change to 'firmware' or 'platform' if the system
270 * supports it (as determined from pm_ops->pm_disk_mode).
273 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
275 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
279 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
285 suspend_disk_method_t mode
= 0;
287 p
= memchr(buf
, '\n', n
);
288 len
= p
? p
- buf
: n
;
291 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
292 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
298 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
)
301 if (pm_ops
&& pm_ops
->enter
&&
302 (mode
== pm_ops
->pm_disk_mode
))
310 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
311 pm_disk_modes
[mode
]);
313 return error
? error
: n
;
318 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
320 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
321 MINOR(swsusp_resume_device
));
324 static ssize_t
resume_store(struct subsystem
*subsys
, const char *buf
, size_t n
)
326 unsigned int maj
, min
;
330 if (sscanf(buf
, "%u:%u", &maj
, &min
) != 2)
333 res
= MKDEV(maj
,min
);
334 if (maj
!= MAJOR(res
) || min
!= MINOR(res
))
338 swsusp_resume_device
= res
;
340 printk("Attempting manual resume\n");
350 static ssize_t
image_size_show(struct subsystem
* subsys
, char *buf
)
352 return sprintf(buf
, "%lu\n", image_size
);
355 static ssize_t
image_size_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
359 if (sscanf(buf
, "%lu", &size
) == 1) {
367 power_attr(image_size
);
369 static struct attribute
* g
[] = {
372 &image_size_attr
.attr
,
377 static struct attribute_group attr_group
= {
382 static int __init
pm_disk_init(void)
384 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
387 core_initcall(pm_disk_init
);
390 static int __init
resume_setup(char *str
)
395 strncpy( resume_file
, str
, 255 );
399 static int __init
noresume_setup(char *str
)
405 __setup("noresume", noresume_setup
);
406 __setup("resume=", resume_setup
);