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>
26 #include <linux/smp_lock.h>
28 #include <asm/uaccess.h>
33 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34 * will be removed in the future. They are only preserved here for
35 * compatibility with existing userland utilities.
37 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
38 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
40 #define PMOPS_PREPARE 1
42 #define PMOPS_FINISH 3
45 * NOTE: The following ioctl definitions are wrong and have been replaced with
46 * correct ones. They are only preserved here for compatibility with existing
47 * userland utilities and will be removed in the future.
49 #define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50 #define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51 #define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52 #define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
55 #define SNAPSHOT_MINOR 231
57 static struct snapshot_data {
58 struct snapshot_handle handle;
63 char platform_support;
66 atomic_t snapshot_device_available = ATOMIC_INIT(1);
68 static int snapshot_open(struct inode *inode, struct file *filp)
70 struct snapshot_data *data;
73 if (!atomic_add_unless(&snapshot_device_available, -1, 0))
76 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
77 atomic_inc(&snapshot_device_available);
80 if(create_basic_memory_bitmaps()) {
81 atomic_inc(&snapshot_device_available);
84 nonseekable_open(inode, filp);
85 data = &snapshot_state;
86 filp->private_data = data;
87 memset(&data->handle, 0, sizeof(struct snapshot_handle));
88 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
89 data->swap = swsusp_resume_device ?
90 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
91 data->mode = O_RDONLY;
92 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
94 pm_notifier_call_chain(PM_POST_RESTORE);
97 data->mode = O_WRONLY;
98 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
100 pm_notifier_call_chain(PM_POST_HIBERNATION);
103 atomic_inc(&snapshot_device_available);
108 data->platform_support = 0;
113 static int snapshot_release(struct inode *inode, struct file *filp)
115 struct snapshot_data *data;
118 free_basic_memory_bitmaps();
119 data = filp->private_data;
120 free_all_swap_pages(data->swap);
122 mutex_lock(&pm_mutex);
124 mutex_unlock(&pm_mutex);
126 pm_notifier_call_chain(data->mode == O_WRONLY ?
127 PM_POST_HIBERNATION : PM_POST_RESTORE);
128 atomic_inc(&snapshot_device_available);
132 static ssize_t snapshot_read(struct file *filp, char __user *buf,
133 size_t count, loff_t *offp)
135 struct snapshot_data *data;
138 data = filp->private_data;
141 res = snapshot_read_next(&data->handle, count);
143 if (copy_to_user(buf, data_of(data->handle), res))
146 *offp = data->handle.offset;
151 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
152 size_t count, loff_t *offp)
154 struct snapshot_data *data;
157 data = filp->private_data;
158 res = snapshot_write_next(&data->handle, count);
160 if (copy_from_user(data_of(data->handle), buf, res))
163 *offp = data->handle.offset;
168 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
172 struct snapshot_data *data;
176 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
178 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
180 if (!capable(CAP_SYS_ADMIN))
183 data = filp->private_data;
189 case SNAPSHOT_FREEZE:
192 mutex_lock(&pm_mutex);
193 printk("Syncing filesystems ... ");
197 error = freeze_processes();
200 mutex_unlock(&pm_mutex);
205 case SNAPSHOT_UNFREEZE:
206 if (!data->frozen || data->ready)
208 mutex_lock(&pm_mutex);
210 mutex_unlock(&pm_mutex);
214 case SNAPSHOT_CREATE_IMAGE:
215 case SNAPSHOT_ATOMIC_SNAPSHOT:
216 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
220 error = hibernation_snapshot(data->platform_support);
222 error = put_user(in_suspend, (int __user *)arg);
227 case SNAPSHOT_ATOMIC_RESTORE:
228 snapshot_write_finalize(&data->handle);
229 if (data->mode != O_WRONLY || !data->frozen ||
230 !snapshot_image_loaded(&data->handle)) {
234 error = hibernation_restore(data->platform_support);
239 memset(&data->handle, 0, sizeof(struct snapshot_handle));
243 case SNAPSHOT_PREF_IMAGE_SIZE:
244 case SNAPSHOT_SET_IMAGE_SIZE:
248 case SNAPSHOT_GET_IMAGE_SIZE:
253 size = snapshot_get_image_size();
255 error = put_user(size, (loff_t __user *)arg);
258 case SNAPSHOT_AVAIL_SWAP_SIZE:
259 case SNAPSHOT_AVAIL_SWAP:
260 size = count_swap_pages(data->swap, 1);
262 error = put_user(size, (loff_t __user *)arg);
265 case SNAPSHOT_ALLOC_SWAP_PAGE:
266 case SNAPSHOT_GET_SWAP_PAGE:
267 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
271 offset = alloc_swapdev_block(data->swap);
273 offset <<= PAGE_SHIFT;
274 error = put_user(offset, (loff_t __user *)arg);
280 case SNAPSHOT_FREE_SWAP_PAGES:
281 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
285 free_all_swap_pages(data->swap);
288 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
289 if (!swsusp_swap_in_use()) {
291 * User space encodes device types as two-byte values,
292 * so we need to recode them
294 if (old_decode_dev(arg)) {
295 data->swap = swap_type_of(old_decode_dev(arg),
313 if (!mutex_trylock(&pm_mutex)) {
318 * Tasks are frozen and the notifiers have been called with
319 * PM_HIBERNATION_PREPARE
321 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
322 mutex_unlock(&pm_mutex);
325 case SNAPSHOT_PLATFORM_SUPPORT:
326 data->platform_support = !!arg;
329 case SNAPSHOT_POWER_OFF:
330 if (data->platform_support)
331 error = hibernation_platform_enter();
334 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
340 data->platform_support = 1;
345 if (data->platform_support)
346 error = hibernation_platform_enter();
350 if (data->platform_support)
355 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
360 case SNAPSHOT_SET_SWAP_AREA:
361 if (swsusp_swap_in_use()) {
364 struct resume_swap_area swap_area;
367 error = copy_from_user(&swap_area, (void __user *)arg,
368 sizeof(struct resume_swap_area));
375 * User space encodes device types as two-byte values,
376 * so we need to recode them
378 swdev = old_decode_dev(swap_area.dev);
380 offset = swap_area.offset;
381 data->swap = swap_type_of(swdev, offset, NULL);
399 static const struct file_operations snapshot_fops = {
400 .open = snapshot_open,
401 .release = snapshot_release,
402 .read = snapshot_read,
403 .write = snapshot_write,
405 .unlocked_ioctl = snapshot_ioctl,
408 static struct miscdevice snapshot_device = {
409 .minor = SNAPSHOT_MINOR,
411 .fops = &snapshot_fops,
414 static int __init snapshot_device_init(void)
416 return misc_register(&snapshot_device);
419 device_initcall(snapshot_device_init);