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>
22 extern suspend_disk_method_t pm_disk_mode
;
23 extern struct pm_ops
* pm_ops
;
25 extern int swsusp_suspend(void);
26 extern int swsusp_write(void);
27 extern int swsusp_check(void);
28 extern int swsusp_read(void);
29 extern void swsusp_close(void);
30 extern int swsusp_resume(void);
31 extern int swsusp_free(void);
34 static int noresume
= 0;
35 char resume_file
[256] = CONFIG_PM_STD_PARTITION
;
36 dev_t swsusp_resume_device
;
39 * power_down - Shut machine down for hibernate.
40 * @mode: Suspend-to-disk mode
42 * Use the platform driver, if configured so, and return gracefully if it
44 * Otherwise, try to power off and reboot. If they fail, halt the machine,
45 * there ain't no turning back.
48 static void power_down(suspend_disk_method_t mode
)
53 local_irq_save(flags
);
55 case PM_DISK_PLATFORM
:
57 error
= pm_ops
->enter(PM_SUSPEND_DISK
);
59 case PM_DISK_SHUTDOWN
:
60 printk("Powering off system\n");
66 machine_restart(NULL
);
70 /* Valid image is on the disk, if we continue we risk serious data corruption
72 printk(KERN_CRIT
"Please power me down manually\n");
77 static int in_suspend __nosavedata
= 0;
81 * free_some_memory - Try to free as much memory as possible
83 * ... but do not OOM-kill anyone
85 * Notice: all userland should be stopped at this point, or
86 * livelock is possible.
89 static void free_some_memory(void)
93 unsigned long pages
= 0;
96 printk("Freeing memory... ");
97 while ((tmp
= shrink_all_memory(10000))) {
104 printk("\bdone (%li pages freed)\n", pages
);
108 static inline void platform_finish(void)
110 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
111 if (pm_ops
&& pm_ops
->finish
)
112 pm_ops
->finish(PM_SUSPEND_DISK
);
116 static void finish(void)
121 enable_nonboot_cpus();
122 pm_restore_console();
126 static int prepare_processes(void)
130 pm_prepare_console();
134 disable_nonboot_cpus();
136 if (freeze_processes()) {
141 if (pm_disk_mode
== PM_DISK_PLATFORM
) {
142 if (pm_ops
&& pm_ops
->prepare
) {
143 if ((error
= pm_ops
->prepare(PM_SUSPEND_DISK
)))
148 /* Free memory before shutting down devices. */
153 enable_nonboot_cpus();
154 pm_restore_console();
158 static void unprepare_processes(void)
162 enable_nonboot_cpus();
163 pm_restore_console();
166 static int prepare_devices(void)
170 if ((error
= device_suspend(PMSG_FREEZE
)))
171 printk("Some devices failed to suspend\n");
176 * pm_suspend_disk - The granpappy of power management.
178 * If we're going through the firmware, then get it over with quickly.
180 * If not, then call swsusp to do its thing, then figure out how
181 * to power down the system.
184 int pm_suspend_disk(void)
188 error
= prepare_processes();
191 error
= prepare_devices();
194 unprepare_processes();
198 pr_debug("PM: Attempting to suspend to disk.\n");
199 if (pm_disk_mode
== PM_DISK_FIRMWARE
)
200 return pm_ops
->enter(PM_SUSPEND_DISK
);
202 pr_debug("PM: snapshotting memory.\n");
204 if ((error
= swsusp_suspend()))
208 pr_debug("PM: writing image.\n");
209 error
= swsusp_write();
211 power_down(pm_disk_mode
);
213 pr_debug("PM: Image restored successfully.\n");
222 * software_resume - Resume from a saved image.
224 * Called as a late_initcall (so all devices are discovered and
225 * initialized), we call swsusp to see if we have a saved image or not.
226 * If so, we quiesce devices, the restore the saved image. We will
227 * return above (in pm_suspend_disk() ) if everything goes well.
228 * Otherwise, we fail gracefully and return to the normally
233 static int software_resume(void)
237 if (!swsusp_resume_device
) {
238 if (!strlen(resume_file
))
240 swsusp_resume_device
= name_to_dev_t(resume_file
);
241 pr_debug("swsusp: Resume From Partition %s\n", resume_file
);
243 pr_debug("swsusp: Resume From Partition %d:%d\n",
244 MAJOR(swsusp_resume_device
), MINOR(swsusp_resume_device
));
249 * FIXME: If noresume is specified, we need to find the partition
250 * and reset it back to normal swap space.
255 pr_debug("PM: Checking swsusp image.\n");
257 if ((error
= swsusp_check()))
260 pr_debug("PM: Preparing processes for restore.\n");
262 if ((error
= prepare_processes())) {
267 pr_debug("PM: Reading swsusp image.\n");
269 if ((error
= swsusp_read()))
272 pr_debug("PM: Preparing devices for restore.\n");
274 if ((error
= prepare_devices()))
279 pr_debug("PM: Restoring saved image.\n");
281 pr_debug("PM: Restore failed, recovering.n");
286 unprepare_processes();
288 pr_debug("PM: Resume from disk failed.\n");
292 late_initcall(software_resume
);
295 static char * pm_disk_modes
[] = {
296 [PM_DISK_FIRMWARE
] = "firmware",
297 [PM_DISK_PLATFORM
] = "platform",
298 [PM_DISK_SHUTDOWN
] = "shutdown",
299 [PM_DISK_REBOOT
] = "reboot",
303 * disk - Control suspend-to-disk mode
305 * Suspend-to-disk can be handled in several ways. The greatest
306 * distinction is who writes memory to disk - the firmware or the OS.
307 * If the firmware does it, we assume that it also handles suspending
309 * If the OS does it, then we have three options for putting the system
310 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
311 * powering off the system or rebooting the system (for testing).
313 * The system will support either 'firmware' or 'platform', and that is
314 * known a priori (and encoded in pm_ops). But, the user may choose
315 * 'shutdown' or 'reboot' as alternatives.
317 * show() will display what the mode is currently set to.
318 * store() will accept one of
325 * It will only change to 'firmware' or 'platform' if the system
326 * supports it (as determined from pm_ops->pm_disk_mode).
329 static ssize_t
disk_show(struct subsystem
* subsys
, char * buf
)
331 return sprintf(buf
, "%s\n", pm_disk_modes
[pm_disk_mode
]);
335 static ssize_t
disk_store(struct subsystem
* s
, const char * buf
, size_t n
)
341 suspend_disk_method_t mode
= 0;
343 p
= memchr(buf
, '\n', n
);
344 len
= p
? p
- buf
: n
;
347 for (i
= PM_DISK_FIRMWARE
; i
< PM_DISK_MAX
; i
++) {
348 if (!strncmp(buf
, pm_disk_modes
[i
], len
)) {
354 if (mode
== PM_DISK_SHUTDOWN
|| mode
== PM_DISK_REBOOT
)
357 if (pm_ops
&& pm_ops
->enter
&&
358 (mode
== pm_ops
->pm_disk_mode
))
366 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
367 pm_disk_modes
[mode
]);
369 return error
? error
: n
;
374 static ssize_t
resume_show(struct subsystem
* subsys
, char *buf
)
376 return sprintf(buf
,"%d:%d\n", MAJOR(swsusp_resume_device
),
377 MINOR(swsusp_resume_device
));
380 static ssize_t
resume_store(struct subsystem
* subsys
, const char * buf
, size_t n
)
384 unsigned int maj
, min
;
388 p
= memchr(buf
, '\n', n
);
389 len
= p
? p
- buf
: n
;
391 if (sscanf(buf
, "%u:%u", &maj
, &min
) == 2) {
392 res
= MKDEV(maj
,min
);
393 if (maj
== MAJOR(res
) && min
== MINOR(res
)) {
394 swsusp_resume_device
= res
;
395 printk("Attempting manual resume\n");
401 return error
>= 0 ? n
: error
;
406 static struct attribute
* g
[] = {
413 static struct attribute_group attr_group
= {
418 static int __init
pm_disk_init(void)
420 return sysfs_create_group(&power_subsys
.kset
.kobj
,&attr_group
);
423 core_initcall(pm_disk_init
);
426 static int __init
resume_setup(char *str
)
431 strncpy( resume_file
, str
, 255 );
435 static int __init
noresume_setup(char *str
)
441 __setup("noresume", noresume_setup
);
442 __setup("resume=", resume_setup
);