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>
24 extern suspend_disk_method_t pm_disk_mode;
25 extern struct pm_ops * pm_ops;
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 local_irq_save(flags);
57 case PM_DISK_PLATFORM:
59 error = pm_ops->enter(PM_SUSPEND_DISK);
61 case PM_DISK_SHUTDOWN:
69 /* Valid image is on the disk, if we continue we risk serious data corruption
71 printk(KERN_CRIT "Please power me down manually\n");
76 static int in_suspend __nosavedata = 0;
80 * free_some_memory - Try to free as much memory as possible
82 * ... but do not OOM-kill anyone
84 * Notice: all userland should be stopped at this point, or
85 * livelock is possible.
88 static void free_some_memory(void)
92 unsigned long pages = 0;
95 printk("Freeing memory... ");
96 while ((tmp = shrink_all_memory(10000))) {
103 printk("\bdone (%li pages freed)\n", pages);
107 static inline void platform_finish(void)
109 if (pm_disk_mode == PM_DISK_PLATFORM) {
110 if (pm_ops && pm_ops->finish)
111 pm_ops->finish(PM_SUSPEND_DISK);
115 static void finish(void)
120 enable_nonboot_cpus();
121 pm_restore_console();
125 static int prepare_processes(void)
129 pm_prepare_console();
133 disable_nonboot_cpus();
135 if (freeze_processes()) {
140 if (pm_disk_mode == PM_DISK_PLATFORM) {
141 if (pm_ops && pm_ops->prepare) {
142 if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
147 /* Free memory before shutting down devices. */
152 enable_nonboot_cpus();
153 pm_restore_console();
157 static void unprepare_processes(void)
161 enable_nonboot_cpus();
162 pm_restore_console();
165 static int prepare_devices(void)
169 if ((error = device_suspend(PMSG_FREEZE)))
170 printk("Some devices failed to suspend\n");
175 * pm_suspend_disk - The granpappy of power management.
177 * If we're going through the firmware, then get it over with quickly.
179 * If not, then call swsusp to do its thing, then figure out how
180 * to power down the system.
183 int pm_suspend_disk(void)
187 error = prepare_processes();
190 error = prepare_devices();
193 unprepare_processes();
197 pr_debug("PM: Attempting to suspend to disk.\n");
198 if (pm_disk_mode == PM_DISK_FIRMWARE)
199 return pm_ops->enter(PM_SUSPEND_DISK);
201 pr_debug("PM: snapshotting memory.\n");
203 if ((error = swsusp_suspend()))
207 pr_debug("PM: writing image.\n");
208 error = swsusp_write();
210 power_down(pm_disk_mode);
212 pr_debug("PM: Image restored successfully.\n");
221 * software_resume - Resume from a saved image.
223 * Called as a late_initcall (so all devices are discovered and
224 * initialized), we call swsusp to see if we have a saved image or not.
225 * If so, we quiesce devices, the restore the saved image. We will
226 * return above (in pm_suspend_disk() ) if everything goes well.
227 * Otherwise, we fail gracefully and return to the normally
232 static int software_resume(void)
237 if (!swsusp_resume_device) {
238 if (!strlen(resume_file)) {
242 swsusp_resume_device = name_to_dev_t(resume_file);
243 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
245 pr_debug("swsusp: Resume From Partition %d:%d\n",
246 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
251 * FIXME: If noresume is specified, we need to find the partition
252 * and reset it back to normal swap space.
258 pr_debug("PM: Checking swsusp image.\n");
260 if ((error = swsusp_check()))
263 pr_debug("PM: Preparing processes for restore.\n");
265 if ((error = prepare_processes())) {
270 pr_debug("PM: Reading swsusp image.\n");
272 if ((error = swsusp_read()))
275 pr_debug("PM: Preparing devices for restore.\n");
277 if ((error = prepare_devices()))
282 pr_debug("PM: Restoring saved image.\n");
284 pr_debug("PM: Restore failed, recovering.n");
289 unprepare_processes();
291 /* For success case, the suspend path will release the lock */
293 pr_debug("PM: Resume from disk failed.\n");
297 late_initcall(software_resume);
300 static char * pm_disk_modes[] = {
301 [PM_DISK_FIRMWARE] = "firmware",
302 [PM_DISK_PLATFORM] = "platform",
303 [PM_DISK_SHUTDOWN] = "shutdown",
304 [PM_DISK_REBOOT] = "reboot",
308 * disk - Control suspend-to-disk mode
310 * Suspend-to-disk can be handled in several ways. The greatest
311 * distinction is who writes memory to disk - the firmware or the OS.
312 * If the firmware does it, we assume that it also handles suspending
314 * If the OS does it, then we have three options for putting the system
315 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
316 * powering off the system or rebooting the system (for testing).
318 * The system will support either 'firmware' or 'platform', and that is
319 * known a priori (and encoded in pm_ops). But, the user may choose
320 * 'shutdown' or 'reboot' as alternatives.
322 * show() will display what the mode is currently set to.
323 * store() will accept one of
330 * It will only change to 'firmware' or 'platform' if the system
331 * supports it (as determined from pm_ops->pm_disk_mode).
334 static ssize_t disk_show(struct subsystem * subsys, char * buf)
336 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
340 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
346 suspend_disk_method_t mode = 0;
348 p = memchr(buf, '\n', n);
349 len = p ? p - buf : n;
352 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
353 if (!strncmp(buf, pm_disk_modes[i], len)) {
359 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
362 if (pm_ops && pm_ops->enter &&
363 (mode == pm_ops->pm_disk_mode))
371 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
372 pm_disk_modes[mode]);
374 return error ? error : n;
379 static ssize_t resume_show(struct subsystem * subsys, char *buf)
381 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
382 MINOR(swsusp_resume_device));
385 static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
389 unsigned int maj, min;
393 p = memchr(buf, '\n', n);
394 len = p ? p - buf : n;
396 if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
397 res = MKDEV(maj,min);
398 if (maj == MAJOR(res) && min == MINOR(res)) {
400 swsusp_resume_device = res;
402 printk("Attempting manual resume\n");
408 return error >= 0 ? n : error;
413 static struct attribute * g[] = {
420 static struct attribute_group attr_group = {
425 static int __init pm_disk_init(void)
427 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
430 core_initcall(pm_disk_init);
433 static int __init resume_setup(char *str)
438 strncpy( resume_file, str, 255 );
442 static int __init noresume_setup(char *str)
448 __setup("noresume", noresume_setup);
449 __setup("resume=", resume_setup);