static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
int i;
char *start = buf;
if (!hibernation_available())
return sprintf(buf, "[disabled]\n");
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (!hibernation_modes[i])
continue;
switch (i) {
case HIBERNATION_SHUTDOWN:
case HIBERNATION_REBOOT:
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
case HIBERNATION_TEST_RESUME:
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
break;
/* not a valid mode, continue with loop */
continue;
}
if (i == hibernation_mode)
buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
else
buf += sprintf(buf, "%s ", hibernation_modes[i]);
}
buf += sprintf(buf, "\n");
return buf-start;
}
static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
int error = 0;
int i;
int len;
char *p;
int mode = HIBERNATION_INVALID;
if (!hibernation_available())
return -EPERM;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
lock_system_sleep();
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (len == strlen(hibernation_modes[i])
&& !strncmp(buf, hibernation_modes[i], len)) {
mode = i;
break;
}
}
if (mode != HIBERNATION_INVALID) {
switch (mode) {
case HIBERNATION_SHUTDOWN:
case HIBERNATION_REBOOT:
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
case HIBERNATION_TEST_RESUME:
hibernation_mode = mode;
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
hibernation_mode = mode;
else
error = -EINVAL;
}
} else
error = -EINVAL;
if (!error)
pr_debug("Hibernation mode set to '%s'\n",
hibernation_modes[mode]);
unlock_system_sleep();
return error ? error : n;
}
/**
* state - control system sleep states.
*
* show() returns available sleep state labels, which may be "mem", "standby",
* "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a
* description of what they mean.
*
* store() accepts one of those strings, translates it into the proper
* enumerated value, and initiates a suspend transition.
*/
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
char *s = buf;
#ifdef CONFIG_SUSPEND
suspend_state_t i;
for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
if (pm_states[i])
s += sprintf(s,"%s ", pm_states[i]);
#endif
if (hibernation_available())
s += sprintf(s, "disk ");
if (s != buf)
/* convert the last space to a newline */
*(s-1) = '\n';
return (s - buf);
}
/**
* software_resume - Resume from a saved hibernation image.
*
* This routine is called as a late initcall, when all devices have been
* discovered and initialized already.
*
* The image reading code is called to see if there is a hibernation image
* available for reading. If that is the case, devices are quiesced and the
* contents of memory is restored from the saved image.
*
* If this is successful, control reappears in the restored target kernel in
* hibernation_snapshot() which returns to hibernate(). Otherwise, the routine
* attempts to recover gracefully and make the kernel return to the normal mode
* of operation.
*/
static int software_resume(void)
{
int error, nr_calls = 0;
/*
* If the user said "noresume".. bail out early.
*/
if (noresume || !hibernation_available())
return 0;
/*
* name_to_dev_t() below takes a sysfs buffer mutex when sysfs
* is configured into the kernel. Since the regular hibernate
* trigger path is via sysfs which takes a buffer mutex before
* calling hibernate functions (which take pm_mutex) this can
* cause lockdep to complain about a possible ABBA deadlock
* which cannot happen since we're in the boot code here and
* sysfs can't be invoked yet. Therefore, we use a subclass
* here to avoid lockdep complaining.
*/
mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
if (swsusp_resume_device)
goto Check_image;
if (!strlen(resume_file)) {
error = -ENOENT;
goto Unlock;
}
pr_debug("Checking hibernation image partition %s\n", resume_file);
if (resume_delay) {
pr_info("Waiting %dsec before reading resume device ...\n",
resume_delay);
ssleep(resume_delay);
}
/* Check if the device is there */
swsusp_resume_device = name_to_dev_t(resume_file);
/*
* name_to_dev_t is ineffective to verify parition if resume_file is in
* integer format. (e.g. major:minor)
*/
if (isdigit(resume_file[0]) && resume_wait) {
int partno;
while (!get_gendisk(swsusp_resume_device, &partno))
msleep(10);
}
if (!swsusp_resume_device) {
/*
* Some device discovery might still be in progress; we need
* to wait for this to finish.
*/
wait_for_device_probe();
if (resume_wait) {
while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
msleep(10);
async_synchronize_full();
}
swsusp_resume_device = name_to_dev_t(resume_file);
if (!swsusp_resume_device) {
error = -ENODEV;
goto Unlock;
}
}
Check_image:
pr_debug("Hibernation image partition %d:%d present\n",
MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
pr_debug("Looking for hibernation image.\n");
error = swsusp_check();
if (error)
goto Unlock;
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
swsusp_close(FMODE_READ);
goto Unlock;
}
pm_prepare_console();
error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
if (error) {
nr_calls--;
goto Close_Finish;
}
pr_debug("Preparing processes for restore.\n");
error = freeze_processes();
if (error)
goto Close_Finish;
error = load_image_and_restore();
thaw_processes();
Finish:
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
pm_restore_console();
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&pm_mutex);
pr_debug("Hibernation image not present or could not be loaded.\n");
return error;
Close_Finish:
swsusp_close(FMODE_READ);
goto Finish;
}
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
int hibernate(void)
{
int error, nr_calls = 0;
bool snapshot_test = false;
if (!hibernation_available()) {
pr_debug("Hibernation not available.\n");
return -EPERM;
}
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
goto Unlock;
}
pm_prepare_console();
error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
if (error) {
nr_calls--;
goto Exit;
}
pr_info("Syncing filesystems ... \n");
sys_sync();
pr_info("done.\n");
error = freeze_processes();
if (error)
goto Exit;
lock_device_hotplug();
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
goto Thaw;
error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
if (error || freezer_test_done)
goto Free_bitmaps;
if (in_suspend) {
unsigned int flags = 0;
if (hibernation_mode == HIBERNATION_PLATFORM)
flags |= SF_PLATFORM_MODE;
if (nocompress)
flags |= SF_NOCOMPRESS_MODE;
else
flags |= SF_CRC32_MODE;
pr_debug("Writing image.\n");
error = swsusp_write(flags);
swsusp_free();
if (!error) {
if (hibernation_mode == HIBERNATION_TEST_RESUME)
snapshot_test = true;
else
power_down();
}
in_suspend = 0;
pm_restore_gfp_mask();
} else {
pr_debug("Image restored successfully.\n");
}
Free_bitmaps:
free_basic_memory_bitmaps();
Thaw:
unlock_device_hotplug();
if (snapshot_test) {
pr_debug("Checking hibernation image\n");
error = swsusp_check();
if (!error)
error = load_image_and_restore();
}
thaw_processes();
/* Don't bother checking whether freezer_test_done is true */
freezer_test_done = false;
Exit:
__pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
pm_restore_console();
atomic_inc(&snapshot_device_available);
Unlock:
unlock_system_sleep();
return error;
}
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
int error, nr_calls = 0;
if (!hibernation_available())
return -EPERM;
lock_system_sleep();
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
goto Unlock;
}
if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
atomic_inc(&snapshot_device_available);
error = -ENOSYS;
goto Unlock;
}
nonseekable_open(inode, filp);
data = &snapshot_state;
filp->private_data = data;
memset(&data->handle, 0, sizeof(struct snapshot_handle));
if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
/* Hibernating. The image device should be accessible. */
data->swap = swsusp_resume_device ?
swap_type_of(swsusp_resume_device, 0, NULL) : -1;
data->mode = O_RDONLY;
data->free_bitmaps = false;
error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
if (error)
__pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
} else {
/*
* Resuming. We may need to wait for the image device to
* appear.
*/
wait_for_device_probe();
data->swap = -1;
data->mode = O_WRONLY;
error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
if (!error) {
error = create_basic_memory_bitmaps();
data->free_bitmaps = !error;
} else
nr_calls--;
if (error)
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
}
if (error)
atomic_inc(&snapshot_device_available);
data->frozen = false;
data->ready = false;
data->platform_support = false;
Unlock:
unlock_system_sleep();
return error;
}