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kernel_optimize_test/kernel/power/user.c
Rafael J. Wysocki 37b2ba12df [PATCH] swsusp: add ioctl for swap files support 
To be able to use swap files as suspend storage from the userland suspend
tools we need an additional ioctl() that will allow us to provide the kernel
with both the swap header's offset and the identification of the resume
partition.

The new ioctl() should be regarded as a replacement for the
SNAPSHOT_SET_SWAP_FILE ioctl() that from now on will be considered as
obsolete, but has to stay for backwards compatibility of the interface.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07 08:39:27 -08:00

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/*
* linux/kernel/power/user.c
*
* This file provides the user space interface for software suspend/resume.
*
* Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
*
* 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/miscdevice.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <asm/uaccess.h>
#include "power.h"
#define SNAPSHOT_MINOR 231
static struct snapshot_data {
struct snapshot_handle handle;
int swap;
struct bitmap_page *bitmap;
int mode;
char frozen;
char ready;
} snapshot_state;
static atomic_t device_available = ATOMIC_INIT(1);
static int snapshot_open(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
if (!atomic_add_unless(&device_available, -1, 0))
return -EBUSY;
if ((filp->f_flags & O_ACCMODE) == O_RDWR)
return -ENOSYS;
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) {
data->swap = swsusp_resume_device ?
swap_type_of(swsusp_resume_device, 0) : -1;
data->mode = O_RDONLY;
} else {
data->swap = -1;
data->mode = O_WRONLY;
}
data->bitmap = NULL;
data->frozen = 0;
data->ready = 0;
return 0;
}
static int snapshot_release(struct inode *inode, struct file *filp)
{
struct snapshot_data *data;
swsusp_free();
data = filp->private_data;
free_all_swap_pages(data->swap, data->bitmap);
free_bitmap(data->bitmap);
if (data->frozen) {
down(&pm_sem);
thaw_processes();
enable_nonboot_cpus();
up(&pm_sem);
}
atomic_inc(&device_available);
return 0;
}
static ssize_t snapshot_read(struct file *filp, char __user *buf,
size_t count, loff_t *offp)
{
struct snapshot_data *data;
ssize_t res;
data = filp->private_data;
res = snapshot_read_next(&data->handle, count);
if (res > 0) {
if (copy_to_user(buf, data_of(data->handle), res))
res = -EFAULT;
else
*offp = data->handle.offset;
}
return res;
}
static ssize_t snapshot_write(struct file *filp, const char __user *buf,
size_t count, loff_t *offp)
{
struct snapshot_data *data;
ssize_t res;
data = filp->private_data;
res = snapshot_write_next(&data->handle, count);
if (res > 0) {
if (copy_from_user(data_of(data->handle), buf, res))
res = -EFAULT;
else
*offp = data->handle.offset;
}
return res;
}
static int snapshot_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
int error = 0;
struct snapshot_data *data;
loff_t avail;
sector_t offset;
if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
return -ENOTTY;
if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
return -ENOTTY;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
data = filp->private_data;
switch (cmd) {
case SNAPSHOT_FREEZE:
if (data->frozen)
break;
down(&pm_sem);
error = disable_nonboot_cpus();
if (!error) {
error = freeze_processes();
if (error) {
thaw_processes();
enable_nonboot_cpus();
error = -EBUSY;
}
}
up(&pm_sem);
if (!error)
data->frozen = 1;
break;
case SNAPSHOT_UNFREEZE:
if (!data->frozen)
break;
down(&pm_sem);
thaw_processes();
enable_nonboot_cpus();
up(&pm_sem);
data->frozen = 0;
break;
case SNAPSHOT_ATOMIC_SNAPSHOT:
if (data->mode != O_RDONLY || !data->frozen || data->ready) {
error = -EPERM;
break;
}
down(&pm_sem);
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (!error) {
suspend_console();
error = device_suspend(PMSG_FREEZE);
if (!error) {
in_suspend = 1;
error = swsusp_suspend();
device_resume();
}
resume_console();
}
up(&pm_sem);
if (!error)
error = put_user(in_suspend, (unsigned int __user *)arg);
if (!error)
data->ready = 1;
break;
case SNAPSHOT_ATOMIC_RESTORE:
if (data->mode != O_WRONLY || !data->frozen ||
!snapshot_image_loaded(&data->handle)) {
error = -EPERM;
break;
}
snapshot_free_unused_memory(&data->handle);
down(&pm_sem);
pm_prepare_console();
suspend_console();
error = device_suspend(PMSG_PRETHAW);
if (!error) {
error = swsusp_resume();
device_resume();
}
resume_console();
pm_restore_console();
up(&pm_sem);
break;
case SNAPSHOT_FREE:
swsusp_free();
memset(&data->handle, 0, sizeof(struct snapshot_handle));
data->ready = 0;
break;
case SNAPSHOT_SET_IMAGE_SIZE:
image_size = arg;
break;
case SNAPSHOT_AVAIL_SWAP:
avail = count_swap_pages(data->swap, 1);
avail <<= PAGE_SHIFT;
error = put_user(avail, (loff_t __user *)arg);
break;
case SNAPSHOT_GET_SWAP_PAGE:
if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
error = -ENODEV;
break;
}
if (!data->bitmap) {
data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0));
if (!data->bitmap) {
error = -ENOMEM;
break;
}
}
offset = alloc_swapdev_block(data->swap, data->bitmap);
if (offset) {
offset <<= PAGE_SHIFT;
error = put_user(offset, (sector_t __user *)arg);
} else {
error = -ENOSPC;
}
break;
case SNAPSHOT_FREE_SWAP_PAGES:
if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
error = -ENODEV;
break;
}
free_all_swap_pages(data->swap, data->bitmap);
free_bitmap(data->bitmap);
data->bitmap = NULL;
break;
case SNAPSHOT_SET_SWAP_FILE:
if (!data->bitmap) {
/*
* User space encodes device types as two-byte values,
* so we need to recode them
*/
if (old_decode_dev(arg)) {
data->swap = swap_type_of(old_decode_dev(arg), 0);
if (data->swap < 0)
error = -ENODEV;
} else {
data->swap = -1;
error = -EINVAL;
}
} else {
error = -EPERM;
}
break;
case SNAPSHOT_S2RAM:
if (!data->frozen) {
error = -EPERM;
break;
}
if (down_trylock(&pm_sem)) {
error = -EBUSY;
break;
}
if (pm_ops->prepare) {
error = pm_ops->prepare(PM_SUSPEND_MEM);
if (error)
goto OutS3;
}
/* Put devices to sleep */
suspend_console();
error = device_suspend(PMSG_SUSPEND);
if (error) {
printk(KERN_ERR "Failed to suspend some devices.\n");
} else {
/* Enter S3, system is already frozen */
suspend_enter(PM_SUSPEND_MEM);
/* Wake up devices */
device_resume();
}
resume_console();
if (pm_ops->finish)
pm_ops->finish(PM_SUSPEND_MEM);
OutS3:
up(&pm_sem);
break;
case SNAPSHOT_PMOPS:
switch (arg) {
case PMOPS_PREPARE:
if (pm_ops->prepare) {
error = pm_ops->prepare(PM_SUSPEND_DISK);
}
break;
case PMOPS_ENTER:
kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
error = pm_ops->enter(PM_SUSPEND_DISK);
break;
case PMOPS_FINISH:
if (pm_ops && pm_ops->finish) {
pm_ops->finish(PM_SUSPEND_DISK);
}
break;
default:
printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
error = -EINVAL;
}
break;
case SNAPSHOT_SET_SWAP_AREA:
if (data->bitmap) {
error = -EPERM;
} else {
struct resume_swap_area swap_area;
dev_t swdev;
error = copy_from_user(&swap_area, (void __user *)arg,
sizeof(struct resume_swap_area));
if (error) {
error = -EFAULT;
break;
}
/*
* User space encodes device types as two-byte values,
* so we need to recode them
*/
swdev = old_decode_dev(swap_area.dev);
if (swdev) {
offset = swap_area.offset;
data->swap = swap_type_of(swdev, offset);
if (data->swap < 0)
error = -ENODEV;
} else {
data->swap = -1;
error = -EINVAL;
}
}
break;
default:
error = -ENOTTY;
}
return error;
}
static struct file_operations snapshot_fops = {
.open = snapshot_open,
.release = snapshot_release,
.read = snapshot_read,
.write = snapshot_write,
.llseek = no_llseek,
.ioctl = snapshot_ioctl,
};
static struct miscdevice snapshot_device = {
.minor = SNAPSHOT_MINOR,
.name = "snapshot",
.fops = &snapshot_fops,
};
static int __init snapshot_device_init(void)
{
return misc_register(&snapshot_device);
};
device_initcall(snapshot_device_init);
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