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 static int noresume = 0;
26 char resume_file[256] = CONFIG_PM_STD_PARTITION;
27 dev_t swsusp_resume_device;
30 * power_down - Shut machine down for hibernate.
31 * @mode: Suspend-to-disk mode
33 * Use the platform driver, if configured so, and return gracefully if it
35 * Otherwise, try to power off and reboot. If they fail, halt the machine,
36 * there ain't no turning back.
39 static void power_down(suspend_disk_method_t mode)
44 case PM_DISK_PLATFORM:
45 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
46 error = pm_ops->enter(PM_SUSPEND_DISK);
48 case PM_DISK_SHUTDOWN:
56 /* Valid image is on the disk, if we continue we risk serious data corruption
58 printk(KERN_CRIT "Please power me down manually\n");
62 static inline void platform_finish(void)
64 if (pm_disk_mode == PM_DISK_PLATFORM) {
65 if (pm_ops && pm_ops->finish)
66 pm_ops->finish(PM_SUSPEND_DISK);
70 static int prepare_processes(void)
75 disable_nonboot_cpus();
77 if (freeze_processes()) {
82 /* Free memory before shutting down devices. */
83 if (!(error = swsusp_shrink_memory()))
87 enable_nonboot_cpus();
92 static void unprepare_processes(void)
96 enable_nonboot_cpus();
101 * pm_suspend_disk - The granpappy of power management.
103 * If we're going through the firmware, then get it over with quickly.
105 * If not, then call swsusp to do its thing, then figure out how
106 * to power down the system.
109 int pm_suspend_disk(void)
113 error = prepare_processes();
117 error = device_suspend(PMSG_FREEZE);
119 printk("Some devices failed to suspend\n");
120 unprepare_processes();
124 pr_debug("PM: snapshotting memory.\n");
126 if ((error = swsusp_suspend()))
131 pr_debug("PM: writing image.\n");
132 error = swsusp_write();
134 power_down(pm_disk_mode);
137 unprepare_processes();
141 pr_debug("PM: Image restored successfully.\n");
146 unprepare_processes();
152 * software_resume - Resume from a saved image.
154 * Called as a late_initcall (so all devices are discovered and
155 * initialized), we call swsusp to see if we have a saved image or not.
156 * If so, we quiesce devices, the restore the saved image. We will
157 * return above (in pm_suspend_disk() ) if everything goes well.
158 * Otherwise, we fail gracefully and return to the normally
163 static int software_resume(void)
168 if (!swsusp_resume_device) {
169 if (!strlen(resume_file)) {
173 swsusp_resume_device = name_to_dev_t(resume_file);
174 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
176 pr_debug("swsusp: Resume From Partition %d:%d\n",
177 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
182 * FIXME: If noresume is specified, we need to find the partition
183 * and reset it back to normal swap space.
189 pr_debug("PM: Checking swsusp image.\n");
191 if ((error = swsusp_check()))
194 pr_debug("PM: Preparing processes for restore.\n");
196 if ((error = prepare_processes())) {
201 pr_debug("PM: Reading swsusp image.\n");
203 if ((error = swsusp_read())) {
208 pr_debug("PM: Preparing devices for restore.\n");
210 if ((error = device_suspend(PMSG_FREEZE))) {
211 printk("Some devices failed to suspend\n");
218 pr_debug("PM: Restoring saved image.\n");
220 pr_debug("PM: Restore failed, recovering.n");
223 unprepare_processes();
225 /* For success case, the suspend path will release the lock */
227 pr_debug("PM: Resume from disk failed.\n");
231 late_initcall(software_resume);
234 static char * pm_disk_modes[] = {
235 [PM_DISK_FIRMWARE] = "firmware",
236 [PM_DISK_PLATFORM] = "platform",
237 [PM_DISK_SHUTDOWN] = "shutdown",
238 [PM_DISK_REBOOT] = "reboot",
242 * disk - Control suspend-to-disk mode
244 * Suspend-to-disk can be handled in several ways. The greatest
245 * distinction is who writes memory to disk - the firmware or the OS.
246 * If the firmware does it, we assume that it also handles suspending
248 * If the OS does it, then we have three options for putting the system
249 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
250 * powering off the system or rebooting the system (for testing).
252 * The system will support either 'firmware' or 'platform', and that is
253 * known a priori (and encoded in pm_ops). But, the user may choose
254 * 'shutdown' or 'reboot' as alternatives.
256 * show() will display what the mode is currently set to.
257 * store() will accept one of
264 * It will only change to 'firmware' or 'platform' if the system
265 * supports it (as determined from pm_ops->pm_disk_mode).
268 static ssize_t disk_show(struct subsystem * subsys, char * buf)
270 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
274 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
280 suspend_disk_method_t mode = 0;
282 p = memchr(buf, '\n', n);
283 len = p ? p - buf : n;
286 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
287 if (!strncmp(buf, pm_disk_modes[i], len)) {
293 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
296 if (pm_ops && pm_ops->enter &&
297 (mode == pm_ops->pm_disk_mode))
305 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
306 pm_disk_modes[mode]);
308 return error ? error : n;
313 static ssize_t resume_show(struct subsystem * subsys, char *buf)
315 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
316 MINOR(swsusp_resume_device));
319 static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
321 unsigned int maj, min;
325 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
328 res = MKDEV(maj,min);
329 if (maj != MAJOR(res) || min != MINOR(res))
333 swsusp_resume_device = res;
335 printk("Attempting manual resume\n");
345 static ssize_t image_size_show(struct subsystem * subsys, char *buf)
347 return sprintf(buf, "%lu\n", image_size);
350 static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
354 if (sscanf(buf, "%lu", &size) == 1) {
362 power_attr(image_size);
364 static struct attribute * g[] = {
367 &image_size_attr.attr,
372 static struct attribute_group attr_group = {
377 static int __init pm_disk_init(void)
379 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
382 core_initcall(pm_disk_init);
385 static int __init resume_setup(char *str)
390 strncpy( resume_file, str, 255 );
394 static int __init noresume_setup(char *str)
400 __setup("noresume", noresume_setup);
401 __setup("resume=", resume_setup);