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 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
156 error = freeze_processes();
161 pm_notifier_call_chain(PM_POST_HIBERNATION);
162 mutex_unlock(&pm_mutex);
167 case SNAPSHOT_UNFREEZE:
168 if (!data->frozen || data->ready)
170 mutex_lock(&pm_mutex);
172 pm_notifier_call_chain(PM_POST_HIBERNATION);
173 mutex_unlock(&pm_mutex);
177 case SNAPSHOT_ATOMIC_SNAPSHOT:
178 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
182 error = hibernation_snapshot(data->platform_suspend);
184 error = put_user(in_suspend, (unsigned int __user *)arg);
189 case SNAPSHOT_ATOMIC_RESTORE:
190 snapshot_write_finalize(&data->handle);
191 if (data->mode != O_WRONLY || !data->frozen ||
192 !snapshot_image_loaded(&data->handle)) {
196 error = hibernation_restore(data->platform_suspend);
201 memset(&data->handle, 0, sizeof(struct snapshot_handle));
205 case SNAPSHOT_SET_IMAGE_SIZE:
209 case SNAPSHOT_AVAIL_SWAP:
210 avail = count_swap_pages(data->swap, 1);
211 avail <<= PAGE_SHIFT;
212 error = put_user(avail, (loff_t __user *)arg);
215 case SNAPSHOT_GET_SWAP_PAGE:
216 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
220 offset = alloc_swapdev_block(data->swap);
222 offset <<= PAGE_SHIFT;
223 error = put_user(offset, (sector_t __user *)arg);
229 case SNAPSHOT_FREE_SWAP_PAGES:
230 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
234 free_all_swap_pages(data->swap);
237 case SNAPSHOT_SET_SWAP_FILE:
238 if (!swsusp_swap_in_use()) {
240 * User space encodes device types as two-byte values,
241 * so we need to recode them
243 if (old_decode_dev(arg)) {
244 data->swap = swap_type_of(old_decode_dev(arg),
268 if (!mutex_trylock(&pm_mutex)) {
273 if (pm_ops->prepare) {
274 error = pm_ops->prepare(PM_SUSPEND_MEM);
279 /* Put devices to sleep */
281 error = device_suspend(PMSG_SUSPEND);
283 printk(KERN_ERR "Failed to suspend some devices.\n");
285 error = disable_nonboot_cpus();
287 /* Enter S3, system is already frozen */
288 suspend_enter(PM_SUSPEND_MEM);
289 enable_nonboot_cpus();
291 /* Wake up devices */
296 pm_ops->finish(PM_SUSPEND_MEM);
299 mutex_unlock(&pm_mutex);
308 data->platform_suspend = 1;
313 if (data->platform_suspend)
314 error = hibernation_platform_enter();
319 if (data->platform_suspend)
325 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
330 case SNAPSHOT_SET_SWAP_AREA:
331 if (swsusp_swap_in_use()) {
334 struct resume_swap_area swap_area;
337 error = copy_from_user(&swap_area, (void __user *)arg,
338 sizeof(struct resume_swap_area));
345 * User space encodes device types as two-byte values,
346 * so we need to recode them
348 swdev = old_decode_dev(swap_area.dev);
350 offset = swap_area.offset;
351 data->swap = swap_type_of(swdev, offset, NULL);
369 static const struct file_operations snapshot_fops = {
370 .open = snapshot_open,
371 .release = snapshot_release,
372 .read = snapshot_read,
373 .write = snapshot_write,
375 .ioctl = snapshot_ioctl,
378 static struct miscdevice snapshot_device = {
379 .minor = SNAPSHOT_MINOR,
381 .fops = &snapshot_fops,
384 static int __init snapshot_device_init(void)
386 return misc_register(&snapshot_device);
389 device_initcall(snapshot_device_init);