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(PM_SUSPEND_DISK);
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(PM_SUSPEND_DISK)))
154 enable_nonboot_cpus();
156 pm_restore_console();
162 * pm_suspend_disk - The granpappy of power management.
164 * If we're going through the firmware, then get it over with quickly.
166 * If not, then call swsusp to do it's thing, then figure out how
167 * to power down the system.
170 int pm_suspend_disk(void)
174 if ((error = prepare()))
177 pr_debug("PM: Attempting to suspend to disk.\n");
178 if (pm_disk_mode == PM_DISK_FIRMWARE)
179 return pm_ops->enter(PM_SUSPEND_DISK);
181 pr_debug("PM: snapshotting memory.\n");
183 if ((error = swsusp_suspend()))
187 pr_debug("PM: writing image.\n");
188 error = swsusp_write();
190 power_down(pm_disk_mode);
192 pr_debug("PM: Image restored successfully.\n");
201 * software_resume - Resume from a saved image.
203 * Called as a late_initcall (so all devices are discovered and
204 * initialized), we call pmdisk to see if we have a saved image or not.
205 * If so, we quiesce devices, the restore the saved image. We will
206 * return above (in pm_suspend_disk() ) if everything goes well.
207 * Otherwise, we fail gracefully and return to the normally
212 static int software_resume(void)
218 * FIXME: If noresume is specified, we need to find the partition
219 * and reset it back to normal swap space.
224 pr_debug("PM: Reading pmdisk image.\n");
226 if ((error = swsusp_read()))
229 pr_debug("PM: Preparing system for restore.\n");
231 if ((error = prepare()))
237 pr_debug("PM: Restoring saved image.\n");
239 pr_debug("PM: Restore failed, recovering.n");
244 pr_debug("PM: Resume from disk failed.\n");
248 late_initcall(software_resume);
251 static char * pm_disk_modes[] = {
252 [PM_DISK_FIRMWARE] = "firmware",
253 [PM_DISK_PLATFORM] = "platform",
254 [PM_DISK_SHUTDOWN] = "shutdown",
255 [PM_DISK_REBOOT] = "reboot",
259 * disk - Control suspend-to-disk mode
261 * Suspend-to-disk can be handled in several ways. The greatest
262 * distinction is who writes memory to disk - the firmware or the OS.
263 * If the firmware does it, we assume that it also handles suspending
265 * If the OS does it, then we have three options for putting the system
266 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
267 * powering off the system or rebooting the system (for testing).
269 * The system will support either 'firmware' or 'platform', and that is
270 * known a priori (and encoded in pm_ops). But, the user may choose
271 * 'shutdown' or 'reboot' as alternatives.
273 * show() will display what the mode is currently set to.
274 * store() will accept one of
281 * It will only change to 'firmware' or 'platform' if the system
282 * supports it (as determined from pm_ops->pm_disk_mode).
285 static ssize_t disk_show(struct subsystem * subsys, char * buf)
287 return sprintf(buf,"%s\n",pm_disk_modes[pm_disk_mode]);
291 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
297 suspend_disk_method_t mode = 0;
299 p = memchr(buf, '\n', n);
300 len = p ? p - buf : n;
303 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
304 if (!strncmp(buf, pm_disk_modes[i], len)) {
310 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
313 if (pm_ops && pm_ops->enter &&
314 (mode == pm_ops->pm_disk_mode))
322 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
323 pm_disk_modes[mode]);
325 return error ? error : n;
330 static struct attribute * g[] = {
336 static struct attribute_group attr_group = {
341 static int __init pm_disk_init(void)
343 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
346 core_initcall(pm_disk_init);
349 static int __init resume_setup(char *str)
354 strncpy( resume_file, str, 255 );
358 static int __init noresume_setup(char *str)
364 __setup("noresume", noresume_setup);
365 __setup("resume=", resume_setup);