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);