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>
27 #include <scsi/scsi_scan.h>
29 #include <asm/uaccess.h>
34 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
35 * will be removed in the future. They are only preserved here for
36 * compatibility with existing userland utilities.
38 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
39 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
41 #define PMOPS_PREPARE 1
43 #define PMOPS_FINISH 3
46 * NOTE: The following ioctl definitions are wrong and have been replaced with
47 * correct ones. They are only preserved here for compatibility with existing
48 * userland utilities and will be removed in the future.
50 #define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
51 #define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
52 #define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
53 #define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
56 #define SNAPSHOT_MINOR 231
58 static struct snapshot_data {
59 struct snapshot_handle handle;
64 char platform_support;
67 atomic_t snapshot_device_available = ATOMIC_INIT(1);
69 static int snapshot_open(struct inode *inode, struct file *filp)
71 struct snapshot_data *data;
74 mutex_lock(&pm_mutex);
76 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
81 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
82 atomic_inc(&snapshot_device_available);
86 if(create_basic_memory_bitmaps()) {
87 atomic_inc(&snapshot_device_available);
91 nonseekable_open(inode, filp);
92 data = &snapshot_state;
93 filp->private_data = data;
94 memset(&data->handle, 0, sizeof(struct snapshot_handle));
95 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
96 /* Hibernating. The image device should be accessible. */
97 data->swap = swsusp_resume_device ?
98 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
99 data->mode = O_RDONLY;
100 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
102 pm_notifier_call_chain(PM_POST_HIBERNATION);
105 * Resuming. We may need to wait for the image device to
108 wait_for_device_probe();
109 scsi_complete_async_scans();
112 data->mode = O_WRONLY;
113 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
115 pm_notifier_call_chain(PM_POST_RESTORE);
118 atomic_inc(&snapshot_device_available);
121 data->platform_support = 0;
124 mutex_unlock(&pm_mutex);
129 static int snapshot_release(struct inode *inode, struct file *filp)
131 struct snapshot_data *data;
133 mutex_lock(&pm_mutex);
136 free_basic_memory_bitmaps();
137 data = filp->private_data;
138 free_all_swap_pages(data->swap);
141 pm_notifier_call_chain(data->mode == O_WRONLY ?
142 PM_POST_HIBERNATION : PM_POST_RESTORE);
143 atomic_inc(&snapshot_device_available);
145 mutex_unlock(&pm_mutex);
150 static ssize_t snapshot_read(struct file *filp, char __user *buf,
151 size_t count, loff_t *offp)
153 struct snapshot_data *data;
156 mutex_lock(&pm_mutex);
158 data = filp->private_data;
163 res = snapshot_read_next(&data->handle, count);
165 if (copy_to_user(buf, data_of(data->handle), res))
168 *offp = data->handle.offset;
172 mutex_unlock(&pm_mutex);
177 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
178 size_t count, loff_t *offp)
180 struct snapshot_data *data;
183 mutex_lock(&pm_mutex);
185 data = filp->private_data;
186 res = snapshot_write_next(&data->handle, count);
188 if (copy_from_user(data_of(data->handle), buf, res))
191 *offp = data->handle.offset;
194 mutex_unlock(&pm_mutex);
199 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
203 struct snapshot_data *data;
207 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
209 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
211 if (!capable(CAP_SYS_ADMIN))
214 if (!mutex_trylock(&pm_mutex))
217 data = filp->private_data;
221 case SNAPSHOT_FREEZE:
225 printk("Syncing filesystems ... ");
229 error = usermodehelper_disable();
233 error = freeze_processes();
236 usermodehelper_enable();
242 case SNAPSHOT_UNFREEZE:
243 if (!data->frozen || data->ready)
246 usermodehelper_enable();
250 case SNAPSHOT_CREATE_IMAGE:
251 case SNAPSHOT_ATOMIC_SNAPSHOT:
252 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
256 error = hibernation_snapshot(data->platform_support);
258 error = put_user(in_suspend, (int __user *)arg);
263 case SNAPSHOT_ATOMIC_RESTORE:
264 snapshot_write_finalize(&data->handle);
265 if (data->mode != O_WRONLY || !data->frozen ||
266 !snapshot_image_loaded(&data->handle)) {
270 error = hibernation_restore(data->platform_support);
275 memset(&data->handle, 0, sizeof(struct snapshot_handle));
279 case SNAPSHOT_PREF_IMAGE_SIZE:
280 case SNAPSHOT_SET_IMAGE_SIZE:
284 case SNAPSHOT_GET_IMAGE_SIZE:
289 size = snapshot_get_image_size();
291 error = put_user(size, (loff_t __user *)arg);
294 case SNAPSHOT_AVAIL_SWAP_SIZE:
295 case SNAPSHOT_AVAIL_SWAP:
296 size = count_swap_pages(data->swap, 1);
298 error = put_user(size, (loff_t __user *)arg);
301 case SNAPSHOT_ALLOC_SWAP_PAGE:
302 case SNAPSHOT_GET_SWAP_PAGE:
303 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
307 offset = alloc_swapdev_block(data->swap);
309 offset <<= PAGE_SHIFT;
310 error = put_user(offset, (loff_t __user *)arg);
316 case SNAPSHOT_FREE_SWAP_PAGES:
317 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
321 free_all_swap_pages(data->swap);
324 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
325 if (!swsusp_swap_in_use()) {
327 * User space encodes device types as two-byte values,
328 * so we need to recode them
330 if (old_decode_dev(arg)) {
331 data->swap = swap_type_of(old_decode_dev(arg),
350 * Tasks are frozen and the notifiers have been called with
351 * PM_HIBERNATION_PREPARE
353 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
356 case SNAPSHOT_PLATFORM_SUPPORT:
357 data->platform_support = !!arg;
360 case SNAPSHOT_POWER_OFF:
361 if (data->platform_support)
362 error = hibernation_platform_enter();
365 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
371 data->platform_support = 1;
376 if (data->platform_support)
377 error = hibernation_platform_enter();
381 if (data->platform_support)
386 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
391 case SNAPSHOT_SET_SWAP_AREA:
392 if (swsusp_swap_in_use()) {
395 struct resume_swap_area swap_area;
398 error = copy_from_user(&swap_area, (void __user *)arg,
399 sizeof(struct resume_swap_area));
406 * User space encodes device types as two-byte values,
407 * so we need to recode them
409 swdev = old_decode_dev(swap_area.dev);
411 offset = swap_area.offset;
412 data->swap = swap_type_of(swdev, offset, NULL);
427 mutex_unlock(&pm_mutex);
432 static const struct file_operations snapshot_fops = {
433 .open = snapshot_open,
434 .release = snapshot_release,
435 .read = snapshot_read,
436 .write = snapshot_write,
438 .unlocked_ioctl = snapshot_ioctl,
441 static struct miscdevice snapshot_device = {
442 .minor = SNAPSHOT_MINOR,
444 .fops = &snapshot_fops,
447 static int __init snapshot_device_init(void)
449 return misc_register(&snapshot_device);
452 device_initcall(snapshot_device_init);