2 * linux/kernel/power/user.c
4 * This file provides the user space interface for software suspend/resume.
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
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/miscdevice.h>
19 #include <linux/swap.h>
20 #include <linux/swapops.h>
23 #include <linux/console.h>
24 #include <linux/cpu.h>
25 #include <linux/freezer.h>
27 #include <asm/uaccess.h>
31 #define SNAPSHOT_MINOR 231
33 static struct snapshot_data {
34 struct snapshot_handle handle;
39 char platform_suspend;
42 atomic_t snapshot_device_available = ATOMIC_INIT(1);
44 static int snapshot_open(struct inode *inode, struct file *filp)
46 struct snapshot_data *data;
48 if (!atomic_add_unless(&snapshot_device_available, -1, 0))
51 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
52 atomic_inc(&snapshot_device_available);
55 if(create_basic_memory_bitmaps()) {
56 atomic_inc(&snapshot_device_available);
59 nonseekable_open(inode, filp);
60 data = &snapshot_state;
61 filp->private_data = data;
62 memset(&data->handle, 0, sizeof(struct snapshot_handle));
63 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
64 data->swap = swsusp_resume_device ?
65 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
66 data->mode = O_RDONLY;
69 data->mode = O_WRONLY;
73 data->platform_suspend = 0;
78 static int snapshot_release(struct inode *inode, struct file *filp)
80 struct snapshot_data *data;
83 free_basic_memory_bitmaps();
84 data = filp->private_data;
85 free_all_swap_pages(data->swap);
87 mutex_lock(&pm_mutex);
89 mutex_unlock(&pm_mutex);
91 atomic_inc(&snapshot_device_available);
95 static ssize_t snapshot_read(struct file *filp, char __user *buf,
96 size_t count, loff_t *offp)
98 struct snapshot_data *data;
101 data = filp->private_data;
104 res = snapshot_read_next(&data->handle, count);
106 if (copy_to_user(buf, data_of(data->handle), res))
109 *offp = data->handle.offset;
114 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
115 size_t count, loff_t *offp)
117 struct snapshot_data *data;
120 data = filp->private_data;
121 res = snapshot_write_next(&data->handle, count);
123 if (copy_from_user(data_of(data->handle), buf, res))
126 *offp = data->handle.offset;
131 static int snapshot_ioctl(struct inode *inode, struct file *filp,
132 unsigned int cmd, unsigned long arg)
135 struct snapshot_data *data;
139 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
141 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
143 if (!capable(CAP_SYS_ADMIN))
146 data = filp->private_data;
150 case SNAPSHOT_FREEZE:
153 mutex_lock(&pm_mutex);
154 if (freeze_processes()) {
158 mutex_unlock(&pm_mutex);
163 case SNAPSHOT_UNFREEZE:
164 if (!data->frozen || data->ready)
166 mutex_lock(&pm_mutex);
168 mutex_unlock(&pm_mutex);
172 case SNAPSHOT_ATOMIC_SNAPSHOT:
173 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
177 error = hibernation_snapshot(data->platform_suspend);
179 error = put_user(in_suspend, (unsigned int __user *)arg);
184 case SNAPSHOT_ATOMIC_RESTORE:
185 snapshot_write_finalize(&data->handle);
186 if (data->mode != O_WRONLY || !data->frozen ||
187 !snapshot_image_loaded(&data->handle)) {
191 error = hibernation_restore(data->platform_suspend);
196 memset(&data->handle, 0, sizeof(struct snapshot_handle));
200 case SNAPSHOT_SET_IMAGE_SIZE:
204 case SNAPSHOT_AVAIL_SWAP:
205 avail = count_swap_pages(data->swap, 1);
206 avail <<= PAGE_SHIFT;
207 error = put_user(avail, (loff_t __user *)arg);
210 case SNAPSHOT_GET_SWAP_PAGE:
211 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
215 offset = alloc_swapdev_block(data->swap);
217 offset <<= PAGE_SHIFT;
218 error = put_user(offset, (sector_t __user *)arg);
224 case SNAPSHOT_FREE_SWAP_PAGES:
225 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
229 free_all_swap_pages(data->swap);
232 case SNAPSHOT_SET_SWAP_FILE:
233 if (!swsusp_swap_in_use()) {
235 * User space encodes device types as two-byte values,
236 * so we need to recode them
238 if (old_decode_dev(arg)) {
239 data->swap = swap_type_of(old_decode_dev(arg),
263 if (!mutex_trylock(&pm_mutex)) {
268 if (pm_ops->prepare) {
269 error = pm_ops->prepare(PM_SUSPEND_MEM);
274 /* Put devices to sleep */
276 error = device_suspend(PMSG_SUSPEND);
278 printk(KERN_ERR "Failed to suspend some devices.\n");
280 error = disable_nonboot_cpus();
282 /* Enter S3, system is already frozen */
283 suspend_enter(PM_SUSPEND_MEM);
284 enable_nonboot_cpus();
286 /* Wake up devices */
291 pm_ops->finish(PM_SUSPEND_MEM);
294 mutex_unlock(&pm_mutex);
303 data->platform_suspend = 1;
308 if (data->platform_suspend)
309 error = hibernation_platform_enter();
314 if (data->platform_suspend)
320 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
325 case SNAPSHOT_SET_SWAP_AREA:
326 if (swsusp_swap_in_use()) {
329 struct resume_swap_area swap_area;
332 error = copy_from_user(&swap_area, (void __user *)arg,
333 sizeof(struct resume_swap_area));
340 * User space encodes device types as two-byte values,
341 * so we need to recode them
343 swdev = old_decode_dev(swap_area.dev);
345 offset = swap_area.offset;
346 data->swap = swap_type_of(swdev, offset, NULL);
364 static const struct file_operations snapshot_fops = {
365 .open = snapshot_open,
366 .release = snapshot_release,
367 .read = snapshot_read,
368 .write = snapshot_write,
370 .ioctl = snapshot_ioctl,
373 static struct miscdevice snapshot_device = {
374 .minor = SNAPSHOT_MINOR,
376 .fops = &snapshot_fops,
379 static int __init snapshot_device_init(void)
381 return misc_register(&snapshot_device);
384 device_initcall(snapshot_device_init);