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>
27 static int noresume = 0;
28 char resume_file[256] = CONFIG_PM_STD_PARTITION;
29 dev_t swsusp_resume_device;
30 sector_t swsusp_resume_block;
33 * platform_prepare - prepare the machine for hibernation using the
34 * platform driver if so configured and return an error code if it fails
37 static inline int platform_prepare(void)
41 if (pm_disk_mode == PM_DISK_PLATFORM) {
42 if (pm_ops && pm_ops->prepare)
43 error = pm_ops->prepare(PM_SUSPEND_DISK);
49 * power_down - Shut machine down for hibernate.
50 * @mode: Suspend-to-disk mode
52 * Use the platform driver, if configured so, and return gracefully if it
54 * Otherwise, try to power off and reboot. If they fail, halt the machine,
55 * there ain't no turning back.
58 static void power_down(suspend_disk_method_t mode)
63 case PM_DISK_PLATFORM:
64 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
65 error = pm_ops->enter(PM_SUSPEND_DISK);
67 case PM_DISK_SHUTDOWN:
75 /* Valid image is on the disk, if we continue we risk serious data corruption
77 printk(KERN_CRIT "Please power me down manually\n");
81 static inline void platform_finish(void)
83 if (pm_disk_mode == PM_DISK_PLATFORM) {
84 if (pm_ops && pm_ops->finish)
85 pm_ops->finish(PM_SUSPEND_DISK);
89 static int prepare_processes(void)
95 error = disable_nonboot_cpus();
99 if (freeze_processes()) {
104 if (pm_disk_mode == PM_DISK_TESTPROC) {
105 printk("swsusp debug: Waiting for 5 seconds.\n");
110 error = platform_prepare();
114 /* Free memory before shutting down devices. */
115 if (!(error = swsusp_shrink_memory()))
122 enable_nonboot_cpus();
123 pm_restore_console();
127 static void unprepare_processes(void)
131 enable_nonboot_cpus();
132 pm_restore_console();
136 * pm_suspend_disk - The granpappy of hibernation power management.
138 * If we're going through the firmware, then get it over with quickly.
140 * If not, then call swsusp to do its thing, then figure out how
141 * to power down the system.
144 int pm_suspend_disk(void)
148 error = prepare_processes();
152 if (pm_disk_mode == PM_DISK_TESTPROC)
156 error = device_suspend(PMSG_FREEZE);
159 printk("Some devices failed to suspend\n");
163 if (pm_disk_mode == PM_DISK_TEST) {
164 printk("swsusp debug: Waiting for 5 seconds.\n");
169 pr_debug("PM: snapshotting memory.\n");
171 if ((error = swsusp_suspend()))
177 pr_debug("PM: writing image.\n");
178 error = swsusp_write();
180 power_down(pm_disk_mode);
186 pr_debug("PM: Image restored successfully.\n");
194 unprepare_processes();
200 * software_resume - Resume from a saved image.
202 * Called as a late_initcall (so all devices are discovered and
203 * initialized), we call swsusp to see if we have a saved image or not.
204 * If so, we quiesce devices, the restore the saved image. We will
205 * return above (in pm_suspend_disk() ) if everything goes well.
206 * Otherwise, we fail gracefully and return to the normally
211 static int software_resume(void)
216 if (!swsusp_resume_device) {
217 if (!strlen(resume_file)) {
221 swsusp_resume_device = name_to_dev_t(resume_file);
222 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
224 pr_debug("swsusp: Resume From Partition %d:%d\n",
225 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
230 * FIXME: If noresume is specified, we need to find the partition
231 * and reset it back to normal swap space.
237 pr_debug("PM: Checking swsusp image.\n");
239 if ((error = swsusp_check()))
242 pr_debug("PM: Preparing processes for restore.\n");
244 if ((error = prepare_processes())) {
249 pr_debug("PM: Reading swsusp image.\n");
251 if ((error = swsusp_read())) {
256 pr_debug("PM: Preparing devices for restore.\n");
259 if ((error = device_suspend(PMSG_PRETHAW))) {
261 printk("Some devices failed to suspend\n");
268 pr_debug("PM: Restoring saved image.\n");
270 pr_debug("PM: Restore failed, recovering.n");
274 unprepare_processes();
276 /* For success case, the suspend path will release the lock */
278 pr_debug("PM: Resume from disk failed.\n");
282 late_initcall(software_resume);
285 static const char * const pm_disk_modes[] = {
286 [PM_DISK_FIRMWARE] = "firmware",
287 [PM_DISK_PLATFORM] = "platform",
288 [PM_DISK_SHUTDOWN] = "shutdown",
289 [PM_DISK_REBOOT] = "reboot",
290 [PM_DISK_TEST] = "test",
291 [PM_DISK_TESTPROC] = "testproc",
295 * disk - Control suspend-to-disk mode
297 * Suspend-to-disk can be handled in several ways. The greatest
298 * distinction is who writes memory to disk - the firmware or the OS.
299 * If the firmware does it, we assume that it also handles suspending
301 * If the OS does it, then we have three options for putting the system
302 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
303 * powering off the system or rebooting the system (for testing).
305 * The system will support either 'firmware' or 'platform', and that is
306 * known a priori (and encoded in pm_ops). But, the user may choose
307 * 'shutdown' or 'reboot' as alternatives.
309 * show() will display what the mode is currently set to.
310 * store() will accept one of
317 * It will only change to 'firmware' or 'platform' if the system
318 * supports it (as determined from pm_ops->pm_disk_mode).
321 static ssize_t disk_show(struct subsystem * subsys, char * buf)
323 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
327 static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
333 suspend_disk_method_t mode = 0;
335 p = memchr(buf, '\n', n);
336 len = p ? p - buf : n;
339 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
340 if (!strncmp(buf, pm_disk_modes[i], len)) {
346 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
347 mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
350 if (pm_ops && pm_ops->enter &&
351 (mode == pm_ops->pm_disk_mode))
360 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
361 pm_disk_modes[mode]);
363 return error ? error : n;
368 static ssize_t resume_show(struct subsystem * subsys, char *buf)
370 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
371 MINOR(swsusp_resume_device));
374 static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
376 unsigned int maj, min;
380 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
383 res = MKDEV(maj,min);
384 if (maj != MAJOR(res) || min != MINOR(res))
388 swsusp_resume_device = res;
390 printk("Attempting manual resume\n");
400 static ssize_t image_size_show(struct subsystem * subsys, char *buf)
402 return sprintf(buf, "%lu\n", image_size);
405 static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
409 if (sscanf(buf, "%lu", &size) == 1) {
417 power_attr(image_size);
419 static struct attribute * g[] = {
422 &image_size_attr.attr,
427 static struct attribute_group attr_group = {
432 static int __init pm_disk_init(void)
434 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
437 core_initcall(pm_disk_init);
440 static int __init resume_setup(char *str)
445 strncpy( resume_file, str, 255 );
449 static int __init resume_offset_setup(char *str)
451 unsigned long long offset;
456 if (sscanf(str, "%llu", &offset) == 1)
457 swsusp_resume_block = offset;
462 static int __init noresume_setup(char *str)
468 __setup("noresume", noresume_setup);
469 __setup("resume_offset=", resume_offset_setup);
470 __setup("resume=", resume_setup);