/*
* kernel/power/disk.c - Suspend-to-disk support.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
*
* This file is released under the GPLv2.
*
*/
#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include "power.h"
extern suspend_disk_method_t pm_disk_mode;
extern struct pm_ops * pm_ops;
extern int swsusp_suspend(void);
extern int swsusp_write(void);
extern int swsusp_check(void);
extern int swsusp_read(void);
extern void swsusp_close(void);
extern int swsusp_resume(void);
extern int swsusp_free(void);
static int noresume = 0;
char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
/**
* power_down - Shut machine down for hibernate.
* @mode: Suspend-to-disk mode
*
* Use the platform driver, if configured so, and return gracefully if it
* fails.
* Otherwise, try to power off and reboot. If they fail, halt the machine,
* there ain't no turning back.
*/
static void power_down(suspend_disk_method_t mode)
{
unsigned long flags;
int error = 0;
local_irq_save(flags);
switch(mode) {
case PM_DISK_PLATFORM:
device_shutdown();
error = pm_ops->enter(PM_SUSPEND_DISK);
break;
case PM_DISK_SHUTDOWN:
printk("Powering off system\n");
device_shutdown();
machine_power_off();
break;
case PM_DISK_REBOOT:
device_shutdown();
machine_restart(NULL);
break;
}
machine_halt();
/* Valid image is on the disk, if we continue we risk serious data corruption
after resume. */
printk(KERN_CRIT "Please power me down manually\n");
while(1);
}
static int in_suspend __nosavedata = 0;
/**
* free_some_memory - Try to free as much memory as possible
*
* ... but do not OOM-kill anyone
*
* Notice: all userland should be stopped at this point, or
* livelock is possible.
*/
static void free_some_memory(void)
{
unsigned int i = 0;
unsigned int tmp;
unsigned long pages = 0;
char *p = "-\\|/";
printk("Freeing memory... ");
while ((tmp = shrink_all_memory(10000))) {
pages += tmp;
printk("\b%c", p[i]);
i++;
if (i > 3)
i = 0;
}
printk("\bdone (%li pages freed)\n", pages);
}
static inline void platform_finish(void)
{
if (pm_disk_mode == PM_DISK_PLATFORM) {
if (pm_ops && pm_ops->finish)
pm_ops->finish(PM_SUSPEND_DISK);
}
}
static void finish(void)
{
device_resume();
platform_finish();
enable_nonboot_cpus();
thaw_processes();
pm_restore_console();
}
static int prepare_processes(void)
{
int error;
pm_prepare_console();
sys_sync();
if (freeze_processes()) {
error = -EBUSY;
return error;
}
if (pm_disk_mode == PM_DISK_PLATFORM) {
if (pm_ops && pm_ops->prepare) {
if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
return error;
}
}
/* Free memory before shutting down devices. */
free_some_memory();
return 0;
}
static void unprepare_processes(void)
{
enable_nonboot_cpus();
thaw_processes();
pm_restore_console();
}
static int prepare_devices(void)
{
int error;
disable_nonboot_cpus();
if ((error = device_suspend(PMSG_FREEZE))) {
printk("Some devices failed to suspend\n");
platform_finish();
enable_nonboot_cpus();
return error;
}
return 0;
}
/**
* pm_suspend_disk - The granpappy of power management.
*
* If we're going through the firmware, then get it over with quickly.
*
* If not, then call swsusp to do its thing, then figure out how
* to power down the system.
*/
int pm_suspend_disk(void)
{
int error;
error = prepare_processes();
if (!error) {
error = prepare_devices();
}
if (error) {
unprepare_processes();
return error;
}
pr_debug("PM: Attempting to suspend to disk.\n");
if (pm_disk_mode == PM_DISK_FIRMWARE)
return pm_ops->enter(PM_SUSPEND_DISK);
pr_debug("PM: snapshotting memory.\n");
in_suspend = 1;
if ((error = swsusp_suspend()))
goto Done;
if (in_suspend) {
pr_debug("PM: writing image.\n");
error = swsusp_write();
if (!error)
power_down(pm_disk_mode);
} else
pr_debug("PM: Image restored successfully.\n");
swsusp_free();
Done:
finish();
return error;
}
/**
* software_resume - Resume from a saved image.
*
* Called as a late_initcall (so all devices are discovered and
* initialized), we call swsusp to see if we have a saved image or not.
* If so, we quiesce devices, the restore the saved image. We will
* return above (in pm_suspend_disk() ) if everything goes well.
* Otherwise, we fail gracefully and return to the normally
* scheduled program.
*
*/
static int software_resume(void)
{
int error;
if (noresume) {
/**
* FIXME: If noresume is specified, we need to find the partition
* and reset it back to normal swap space.
*/
return 0;
}
pr_debug("PM: Checking swsusp image.\n");
if ((error = swsusp_check()))
goto Done;
pr_debug("PM: Preparing processes for restore.\n");
if ((error = prepare_processes())) {
swsusp_close();
goto Cleanup;
}
pr_debug("PM: Reading swsusp image.\n");
if ((error = swsusp_read()))
goto Cleanup;
pr_debug("PM: Preparing devices for restore.\n");
if ((error = prepare_devices()))
goto Free;
mb();
pr_debug("PM: Restoring saved image.\n");
swsusp_resume();
pr_debug("PM: Restore failed, recovering.n");
finish();
Free:
swsusp_free();
Cleanup:
unprepare_processes();
Done:
pr_debug("PM: Resume from disk failed.\n");
return 0;
}
late_initcall(software_resume);
static char * pm_disk_modes[] = {
[PM_DISK_FIRMWARE] = "firmware",
[PM_DISK_PLATFORM] = "platform",
[PM_DISK_SHUTDOWN] = "shutdown",
[PM_DISK_REBOOT] = "reboot",
};
/**
* disk - Control suspend-to-disk mode
*
* Suspend-to-disk can be handled in several ways. The greatest
* distinction is who writes memory to disk - the firmware or the OS.
* If the firmware does it, we assume that it also handles suspending
* the system.
* If the OS does it, then we have three options for putting the system
* to sleep - using the platform driver (e.g. ACPI or other PM registers),
* powering off the system or rebooting the system (for testing).
*
* The system will support either 'firmware' or 'platform', and that is
* known a priori (and encoded in pm_ops). But, the user may choose
* 'shutdown' or 'reboot' as alternatives.
*
* show() will display what the mode is currently set to.
* store() will accept one of
*
* 'firmware'
* 'platform'
* 'shutdown'
* 'reboot'
*
* It will only change to 'firmware' or 'platform' if the system
* supports it (as determined from pm_ops->pm_disk_mode).
*/
static ssize_t disk_show(struct subsystem * subsys, char * buf)
{
return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
}
static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
{
int error = 0;
int i;
int len;
char *p;
suspend_disk_method_t mode = 0;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
down(&pm_sem);
for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
if (!strncmp(buf, pm_disk_modes[i], len)) {
mode = i;
break;
}
}
if (mode) {
if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
pm_disk_mode = mode;
else {
if (pm_ops && pm_ops->enter &&
(mode == pm_ops->pm_disk_mode))
pm_disk_mode = mode;
else
error = -EINVAL;
}
} else
error = -EINVAL;
pr_debug("PM: suspend-to-disk mode set to '%s'\n",
pm_disk_modes[mode]);
up(&pm_sem);
return error ? error : n;
}
power_attr(disk);
static ssize_t resume_show(struct subsystem * subsys, char *buf)
{
return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
MINOR(swsusp_resume_device));
}
static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
{
int len;
char *p;
unsigned int maj, min;
int error = -EINVAL;
dev_t res;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
res = MKDEV(maj,min);
if (maj == MAJOR(res) && min == MINOR(res)) {
swsusp_resume_device = res;
printk("Attempting manual resume\n");
noresume = 0;
software_resume();
}
}
return error >= 0 ? n : error;
}
power_attr(resume);
static struct attribute * g[] = {
&disk_attr.attr,
&resume_attr.attr,
NULL,
};
static struct attribute_group attr_group = {
.attrs = g,
};
static int __init pm_disk_init(void)
{
return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
}
core_initcall(pm_disk_init);
static int __init resume_setup(char *str)
{
if (noresume)
return 1;
strncpy( resume_file, str, 255 );
return 1;
}
static int __init noresume_setup(char *str)
{
noresume = 1;
return 1;
}
__setup("noresume", noresume_setup);
__setup("resume=", resume_setup);
