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>
21 #include <linux/console.h>
22 #include <linux/cpu.h>
23 #include <linux/freezer.h>
28 static int noresume = 0;
29 char resume_file[256] = CONFIG_PM_STD_PARTITION;
30 dev_t swsusp_resume_device;
31 sector_t swsusp_resume_block;
34 * platform_prepare - prepare the machine for hibernation using the
35 * platform driver if so configured and return an error code if it fails
38 static inline int platform_prepare(void)
42 if (pm_disk_mode == PM_DISK_PLATFORM) {
43 if (pm_ops && pm_ops->prepare)
44 error = pm_ops->prepare(PM_SUSPEND_DISK);
50 * power_down - Shut machine down for hibernate.
51 * @mode: Suspend-to-disk mode
53 * Use the platform driver, if configured so, and return gracefully if it
55 * Otherwise, try to power off and reboot. If they fail, halt the machine,
56 * there ain't no turning back.
59 static void power_down(suspend_disk_method_t mode)
61 disable_nonboot_cpus();
63 case PM_DISK_PLATFORM:
64 if (pm_ops && pm_ops->enter) {
65 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
66 pm_ops->enter(PM_SUSPEND_DISK);
69 case PM_DISK_SHUTDOWN:
77 /* Valid image is on the disk, if we continue we risk serious data corruption
79 printk(KERN_CRIT "Please power me down manually\n");
83 static inline void platform_finish(void)
85 if (pm_disk_mode == PM_DISK_PLATFORM) {
86 if (pm_ops && pm_ops->finish)
87 pm_ops->finish(PM_SUSPEND_DISK);
91 static void unprepare_processes(void)
97 static int prepare_processes(void)
101 pm_prepare_console();
102 if (freeze_processes()) {
104 unprepare_processes();
110 * pm_suspend_disk - The granpappy of hibernation power management.
112 * If we're going through the firmware, then get it over with quickly.
114 * If not, then call swsusp to do its thing, then figure out how
115 * to power down the system.
118 int pm_suspend_disk(void)
122 error = prepare_processes();
126 if (pm_disk_mode == PM_DISK_TESTPROC) {
127 printk("swsusp debug: Waiting for 5 seconds.\n");
131 /* Free memory before shutting down devices. */
132 error = swsusp_shrink_memory();
136 error = platform_prepare();
141 error = device_suspend(PMSG_FREEZE);
143 printk(KERN_ERR "PM: Some devices failed to suspend\n");
146 error = disable_nonboot_cpus();
150 if (pm_disk_mode == PM_DISK_TEST) {
151 printk("swsusp debug: Waiting for 5 seconds.\n");
156 pr_debug("PM: snapshotting memory.\n");
158 error = swsusp_suspend();
163 enable_nonboot_cpus();
167 pr_debug("PM: writing image.\n");
168 error = swsusp_write();
170 power_down(pm_disk_mode);
176 pr_debug("PM: Image restored successfully.\n");
181 enable_nonboot_cpus();
187 unprepare_processes();
193 * software_resume - Resume from a saved image.
195 * Called as a late_initcall (so all devices are discovered and
196 * initialized), we call swsusp to see if we have a saved image or not.
197 * If so, we quiesce devices, the restore the saved image. We will
198 * return above (in pm_suspend_disk() ) if everything goes well.
199 * Otherwise, we fail gracefully and return to the normally
204 static int software_resume(void)
208 mutex_lock(&pm_mutex);
209 if (!swsusp_resume_device) {
210 if (!strlen(resume_file)) {
211 mutex_unlock(&pm_mutex);
214 swsusp_resume_device = name_to_dev_t(resume_file);
215 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
217 pr_debug("swsusp: Resume From Partition %d:%d\n",
218 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
223 * FIXME: If noresume is specified, we need to find the partition
224 * and reset it back to normal swap space.
226 mutex_unlock(&pm_mutex);
230 pr_debug("PM: Checking swsusp image.\n");
232 error = swsusp_check();
236 pr_debug("PM: Preparing processes for restore.\n");
238 error = prepare_processes();
244 error = platform_prepare();
250 pr_debug("PM: Reading swsusp image.\n");
252 error = swsusp_read();
259 pr_debug("PM: Preparing devices for restore.\n");
262 error = device_suspend(PMSG_PRETHAW);
266 error = disable_nonboot_cpus();
270 enable_nonboot_cpus();
277 printk(KERN_ERR "PM: Restore failed, recovering.\n");
278 unprepare_processes();
280 /* For success case, the suspend path will release the lock */
281 mutex_unlock(&pm_mutex);
282 pr_debug("PM: Resume from disk failed.\n");
286 late_initcall(software_resume);
289 static const char * const pm_disk_modes[] = {
290 [PM_DISK_FIRMWARE] = "firmware",
291 [PM_DISK_PLATFORM] = "platform",
292 [PM_DISK_SHUTDOWN] = "shutdown",
293 [PM_DISK_REBOOT] = "reboot",
294 [PM_DISK_TEST] = "test",
295 [PM_DISK_TESTPROC] = "testproc",
299 * disk - Control suspend-to-disk mode
301 * Suspend-to-disk can be handled in several ways. The greatest
302 * distinction is who writes memory to disk - the firmware or the OS.
303 * If the firmware does it, we assume that it also handles suspending
305 * If the OS does it, then we have three options for putting the system
306 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
307 * powering off the system or rebooting the system (for testing).
309 * The system will support either 'firmware' or 'platform', and that is
310 * known a priori (and encoded in pm_ops). But, the user may choose
311 * 'shutdown' or 'reboot' as alternatives.
313 * show() will display what the mode is currently set to.
314 * store() will accept one of
321 * It will only change to 'firmware' or 'platform' if the system
322 * supports it (as determined from pm_ops->pm_disk_mode).
325 static ssize_t disk_show(struct subsystem * subsys, char * buf)
327 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
331 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
337 suspend_disk_method_t mode = 0;
339 p = memchr(buf, '\n', n);
340 len = p ? p - buf : n;
342 mutex_lock(&pm_mutex);
343 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
344 if (!strncmp(buf, pm_disk_modes[i], len)) {
350 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
351 mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
354 if (pm_ops && pm_ops->enter &&
355 (mode == pm_ops->pm_disk_mode))
364 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
365 pm_disk_modes[mode]);
366 mutex_unlock(&pm_mutex);
367 return error ? error : n;
372 static ssize_t resume_show(struct subsystem * subsys, char *buf)
374 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
375 MINOR(swsusp_resume_device));
378 static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
380 unsigned int maj, min;
384 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
387 res = MKDEV(maj,min);
388 if (maj != MAJOR(res) || min != MINOR(res))
391 mutex_lock(&pm_mutex);
392 swsusp_resume_device = res;
393 mutex_unlock(&pm_mutex);
394 printk("Attempting manual resume\n");
404 static ssize_t image_size_show(struct subsystem * subsys, char *buf)
406 return sprintf(buf, "%lu\n", image_size);
409 static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
413 if (sscanf(buf, "%lu", &size) == 1) {
421 power_attr(image_size);
423 static struct attribute * g[] = {
426 &image_size_attr.attr,
431 static struct attribute_group attr_group = {
436 static int __init pm_disk_init(void)
438 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
441 core_initcall(pm_disk_init);
444 static int __init resume_setup(char *str)
449 strncpy( resume_file, str, 255 );
453 static int __init resume_offset_setup(char *str)
455 unsigned long long offset;
460 if (sscanf(str, "%llu", &offset) == 1)
461 swsusp_resume_block = offset;
466 static int __init noresume_setup(char *str)
472 __setup("noresume", noresume_setup);
473 __setup("resume_offset=", resume_offset_setup);
474 __setup("resume=", resume_setup);