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/device.h>
23 extern suspend_disk_method_t pm_disk_mode;
24 extern struct pm_ops * pm_ops;
26 extern int swsusp_suspend(void);
27 extern int swsusp_write(void);
28 extern int swsusp_read(void);
29 extern int swsusp_resume(void);
30 extern int swsusp_free(void);
33 static int noresume = 0;
34 char resume_file[256] = CONFIG_PM_STD_PARTITION;
37 * power_down - Shut machine down for hibernate.
38 * @mode: Suspend-to-disk mode
40 * Use the platform driver, if configured so, and return gracefully if it
42 * Otherwise, try to power off and reboot. If they fail, halt the machine,
43 * there ain't no turning back.
46 static void power_down(suspend_disk_method_t mode)
51 local_irq_save(flags);
53 case PM_DISK_PLATFORM:
54 device_power_down(PMSG_SUSPEND);
55 error = pm_ops->enter(PM_SUSPEND_DISK);
57 case PM_DISK_SHUTDOWN:
58 printk("Powering off system\n");
64 machine_restart(NULL);
68 /* Valid image is on the disk, if we continue we risk serious data corruption
70 printk(KERN_CRIT "Please power me down manually\n");
75 static int in_suspend __nosavedata = 0;
79 * free_some_memory - Try to free as much memory as possible
81 * ... but do not OOM-kill anyone
83 * Notice: all userland should be stopped at this point, or
84 * livelock is possible.
87 static void free_some_memory(void)
91 unsigned long pages = 0;
94 printk("Freeing memory... ");
95 while ((tmp = shrink_all_memory(10000))) {
102 printk("\bdone (%li pages freed)\n", pages);
106 static inline void platform_finish(void)
108 if (pm_disk_mode == PM_DISK_PLATFORM) {
109 if (pm_ops && pm_ops->finish)
110 pm_ops->finish(PM_SUSPEND_DISK);
114 static void finish(void)
118 enable_nonboot_cpus();
120 pm_restore_console();
124 static int prepare(void)
128 pm_prepare_console();
131 if (freeze_processes()) {
136 if (pm_disk_mode == PM_DISK_PLATFORM) {
137 if (pm_ops && pm_ops->prepare) {
138 if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
143 /* Free memory before shutting down devices. */
146 disable_nonboot_cpus();
147 if ((error = device_suspend(PMSG_FREEZE))) {
148 printk("Some devices failed to suspend\n");
156 enable_nonboot_cpus();
158 pm_restore_console();
164 * pm_suspend_disk - The granpappy of power management.
166 * If we're going through the firmware, then get it over with quickly.
168 * If not, then call swsusp to do its thing, then figure out how
169 * to power down the system.
172 int pm_suspend_disk(void)
176 if ((error = prepare()))
179 pr_debug("PM: Attempting to suspend to disk.\n");
180 if (pm_disk_mode == PM_DISK_FIRMWARE)
181 return pm_ops->enter(PM_SUSPEND_DISK);
183 pr_debug("PM: snapshotting memory.\n");
185 if ((error = swsusp_suspend()))
189 pr_debug("PM: writing image.\n");
190 error = swsusp_write();
192 power_down(pm_disk_mode);
194 pr_debug("PM: Image restored successfully.\n");
203 * software_resume - Resume from a saved image.
205 * Called as a late_initcall (so all devices are discovered and
206 * initialized), we call swsusp to see if we have a saved image or not.
207 * If so, we quiesce devices, the restore the saved image. We will
208 * return above (in pm_suspend_disk() ) if everything goes well.
209 * Otherwise, we fail gracefully and return to the normally
214 static int software_resume(void)
220 * FIXME: If noresume is specified, we need to find the partition
221 * and reset it back to normal swap space.
226 pr_debug("PM: Reading swsusp image.\n");
228 if ((error = swsusp_read()))
231 pr_debug("PM: Preparing system for restore.\n");
233 if ((error = prepare()))
239 pr_debug("PM: Restoring saved image.\n");
241 pr_debug("PM: Restore failed, recovering.n");
246 pr_debug("PM: Resume from disk failed.\n");
250 late_initcall(software_resume);
253 static char * pm_disk_modes[] = {
254 [PM_DISK_FIRMWARE] = "firmware",
255 [PM_DISK_PLATFORM] = "platform",
256 [PM_DISK_SHUTDOWN] = "shutdown",
257 [PM_DISK_REBOOT] = "reboot",
261 * disk - Control suspend-to-disk mode
263 * Suspend-to-disk can be handled in several ways. The greatest
264 * distinction is who writes memory to disk - the firmware or the OS.
265 * If the firmware does it, we assume that it also handles suspending
267 * If the OS does it, then we have three options for putting the system
268 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
269 * powering off the system or rebooting the system (for testing).
271 * The system will support either 'firmware' or 'platform', and that is
272 * known a priori (and encoded in pm_ops). But, the user may choose
273 * 'shutdown' or 'reboot' as alternatives.
275 * show() will display what the mode is currently set to.
276 * store() will accept one of
283 * It will only change to 'firmware' or 'platform' if the system
284 * supports it (as determined from pm_ops->pm_disk_mode).
287 static ssize_t disk_show(struct subsystem * subsys, char * buf)
289 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
293 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
299 suspend_disk_method_t mode = 0;
301 p = memchr(buf, '\n', n);
302 len = p ? p - buf : n;
305 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
306 if (!strncmp(buf, pm_disk_modes[i], len)) {
312 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
315 if (pm_ops && pm_ops->enter &&
316 (mode == pm_ops->pm_disk_mode))
324 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
325 pm_disk_modes[mode]);
327 return error ? error : n;
332 static struct attribute * g[] = {
338 static struct attribute_group attr_group = {
343 static int __init pm_disk_init(void)
345 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
348 core_initcall(pm_disk_init);
351 static int __init resume_setup(char *str)
356 strncpy( resume_file, str, 255 );
360 static int __init noresume_setup(char *str)
366 __setup("noresume", noresume_setup);
367 __setup("resume=", resume_setup);