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 <scsi/scsi_scan.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 mutex_lock(&pm_mutex);
75 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
80 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
81 atomic_inc(&snapshot_device_available);
85 if(create_basic_memory_bitmaps()) {
86 atomic_inc(&snapshot_device_available);
90 nonseekable_open(inode, filp);
91 data = &snapshot_state;
92 filp->private_data = data;
93 memset(&data->handle, 0, sizeof(struct snapshot_handle));
94 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
95 /* Hibernating. The image device should be accessible. */
96 data->swap = swsusp_resume_device ?
97 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
98 data->mode = O_RDONLY;
99 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
101 pm_notifier_call_chain(PM_POST_HIBERNATION);
104 * Resuming. We may need to wait for the image device to
107 wait_for_device_probe();
108 scsi_complete_async_scans();
111 data->mode = O_WRONLY;
112 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
114 pm_notifier_call_chain(PM_POST_RESTORE);
117 atomic_inc(&snapshot_device_available);
120 data->platform_support = 0;
123 mutex_unlock(&pm_mutex);
128 static int snapshot_release(struct inode *inode, struct file *filp)
130 struct snapshot_data *data;
132 mutex_lock(&pm_mutex);
135 free_basic_memory_bitmaps();
136 data = filp->private_data;
137 free_all_swap_pages(data->swap);
140 pm_notifier_call_chain(data->mode == O_WRONLY ?
141 PM_POST_HIBERNATION : PM_POST_RESTORE);
142 atomic_inc(&snapshot_device_available);
144 mutex_unlock(&pm_mutex);
149 static ssize_t snapshot_read(struct file *filp, char __user *buf,
150 size_t count, loff_t *offp)
152 struct snapshot_data *data;
155 mutex_lock(&pm_mutex);
157 data = filp->private_data;
162 res = snapshot_read_next(&data->handle, count);
164 if (copy_to_user(buf, data_of(data->handle), res))
167 *offp = data->handle.offset;
171 mutex_unlock(&pm_mutex);
176 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
177 size_t count, loff_t *offp)
179 struct snapshot_data *data;
182 mutex_lock(&pm_mutex);
184 data = filp->private_data;
185 res = snapshot_write_next(&data->handle, count);
187 if (copy_from_user(data_of(data->handle), buf, res))
190 *offp = data->handle.offset;
193 mutex_unlock(&pm_mutex);
198 static void snapshot_deprecated_ioctl(unsigned int cmd)
200 if (printk_ratelimit())
201 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
202 "be removed soon, update your suspend-to-disk "
204 __builtin_return_address(0), cmd);
207 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
211 struct snapshot_data *data;
215 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
217 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
219 if (!capable(CAP_SYS_ADMIN))
222 if (!mutex_trylock(&pm_mutex))
225 data = filp->private_data;
229 case SNAPSHOT_FREEZE:
233 printk("Syncing filesystems ... ");
237 error = usermodehelper_disable();
241 error = freeze_processes();
244 usermodehelper_enable();
250 case SNAPSHOT_UNFREEZE:
251 if (!data->frozen || data->ready)
254 usermodehelper_enable();
258 case SNAPSHOT_ATOMIC_SNAPSHOT:
259 snapshot_deprecated_ioctl(cmd);
260 case SNAPSHOT_CREATE_IMAGE:
261 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
265 error = hibernation_snapshot(data->platform_support);
267 error = put_user(in_suspend, (int __user *)arg);
272 case SNAPSHOT_ATOMIC_RESTORE:
273 snapshot_write_finalize(&data->handle);
274 if (data->mode != O_WRONLY || !data->frozen ||
275 !snapshot_image_loaded(&data->handle)) {
279 error = hibernation_restore(data->platform_support);
284 memset(&data->handle, 0, sizeof(struct snapshot_handle));
288 case SNAPSHOT_SET_IMAGE_SIZE:
289 snapshot_deprecated_ioctl(cmd);
290 case SNAPSHOT_PREF_IMAGE_SIZE:
294 case SNAPSHOT_GET_IMAGE_SIZE:
299 size = snapshot_get_image_size();
301 error = put_user(size, (loff_t __user *)arg);
304 case SNAPSHOT_AVAIL_SWAP:
305 snapshot_deprecated_ioctl(cmd);
306 case SNAPSHOT_AVAIL_SWAP_SIZE:
307 size = count_swap_pages(data->swap, 1);
309 error = put_user(size, (loff_t __user *)arg);
312 case SNAPSHOT_GET_SWAP_PAGE:
313 snapshot_deprecated_ioctl(cmd);
314 case SNAPSHOT_ALLOC_SWAP_PAGE:
315 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
319 offset = alloc_swapdev_block(data->swap);
321 offset <<= PAGE_SHIFT;
322 error = put_user(offset, (loff_t __user *)arg);
328 case SNAPSHOT_FREE_SWAP_PAGES:
329 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
333 free_all_swap_pages(data->swap);
336 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
337 snapshot_deprecated_ioctl(cmd);
338 if (!swsusp_swap_in_use()) {
340 * User space encodes device types as two-byte values,
341 * so we need to recode them
343 if (old_decode_dev(arg)) {
344 data->swap = swap_type_of(old_decode_dev(arg),
363 * Tasks are frozen and the notifiers have been called with
364 * PM_HIBERNATION_PREPARE
366 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
369 case SNAPSHOT_PLATFORM_SUPPORT:
370 data->platform_support = !!arg;
373 case SNAPSHOT_POWER_OFF:
374 if (data->platform_support)
375 error = hibernation_platform_enter();
378 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
379 snapshot_deprecated_ioctl(cmd);
385 data->platform_support = 1;
390 if (data->platform_support)
391 error = hibernation_platform_enter();
395 if (data->platform_support)
400 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
405 case SNAPSHOT_SET_SWAP_AREA:
406 if (swsusp_swap_in_use()) {
409 struct resume_swap_area swap_area;
412 error = copy_from_user(&swap_area, (void __user *)arg,
413 sizeof(struct resume_swap_area));
420 * User space encodes device types as two-byte values,
421 * so we need to recode them
423 swdev = old_decode_dev(swap_area.dev);
425 offset = swap_area.offset;
426 data->swap = swap_type_of(swdev, offset, NULL);
441 mutex_unlock(&pm_mutex);
446 static const struct file_operations snapshot_fops = {
447 .open = snapshot_open,
448 .release = snapshot_release,
449 .read = snapshot_read,
450 .write = snapshot_write,
452 .unlocked_ioctl = snapshot_ioctl,
455 static struct miscdevice snapshot_device = {
456 .minor = SNAPSHOT_MINOR,
458 .fops = &snapshot_fops,
461 static int __init snapshot_device_init(void)
463 return misc_register(&snapshot_device);
466 device_initcall(snapshot_device_init);