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 free_basic_memory_bitmaps();
118 atomic_inc(&snapshot_device_available);
122 data->platform_support = 0;
125 mutex_unlock(&pm_mutex);
130 static int snapshot_release(struct inode *inode, struct file *filp)
132 struct snapshot_data *data;
134 mutex_lock(&pm_mutex);
137 free_basic_memory_bitmaps();
138 data = filp->private_data;
139 free_all_swap_pages(data->swap);
141 pm_restore_gfp_mask();
144 pm_notifier_call_chain(data->mode == O_RDONLY ?
145 PM_POST_HIBERNATION : PM_POST_RESTORE);
146 atomic_inc(&snapshot_device_available);
148 mutex_unlock(&pm_mutex);
153 static ssize_t snapshot_read(struct file *filp, char __user *buf,
154 size_t count, loff_t *offp)
156 struct snapshot_data *data;
158 loff_t pg_offp = *offp & ~PAGE_MASK;
160 mutex_lock(&pm_mutex);
162 data = filp->private_data;
167 if (!pg_offp) { /* on page boundary? */
168 res = snapshot_read_next(&data->handle);
172 res = PAGE_SIZE - pg_offp;
175 res = simple_read_from_buffer(buf, count, &pg_offp,
176 data_of(data->handle), res);
181 mutex_unlock(&pm_mutex);
186 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
187 size_t count, loff_t *offp)
189 struct snapshot_data *data;
191 loff_t pg_offp = *offp & ~PAGE_MASK;
193 mutex_lock(&pm_mutex);
195 data = filp->private_data;
198 res = snapshot_write_next(&data->handle);
202 res = PAGE_SIZE - pg_offp;
205 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
210 mutex_unlock(&pm_mutex);
215 static void snapshot_deprecated_ioctl(unsigned int cmd)
217 if (printk_ratelimit())
218 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
219 "be removed soon, update your suspend-to-disk "
221 __builtin_return_address(0), cmd);
224 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
228 struct snapshot_data *data;
232 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
234 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
236 if (!capable(CAP_SYS_ADMIN))
239 if (!mutex_trylock(&pm_mutex))
242 data = filp->private_data;
246 case SNAPSHOT_FREEZE:
250 printk("Syncing filesystems ... ");
254 error = usermodehelper_disable();
258 error = freeze_processes();
261 usermodehelper_enable();
267 case SNAPSHOT_UNFREEZE:
268 if (!data->frozen || data->ready)
270 pm_restore_gfp_mask();
272 usermodehelper_enable();
276 case SNAPSHOT_ATOMIC_SNAPSHOT:
277 snapshot_deprecated_ioctl(cmd);
278 case SNAPSHOT_CREATE_IMAGE:
279 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
283 pm_restore_gfp_mask();
284 error = hibernation_snapshot(data->platform_support);
286 error = put_user(in_suspend, (int __user *)arg);
291 case SNAPSHOT_ATOMIC_RESTORE:
292 snapshot_write_finalize(&data->handle);
293 if (data->mode != O_WRONLY || !data->frozen ||
294 !snapshot_image_loaded(&data->handle)) {
298 error = hibernation_restore(data->platform_support);
303 memset(&data->handle, 0, sizeof(struct snapshot_handle));
307 case SNAPSHOT_SET_IMAGE_SIZE:
308 snapshot_deprecated_ioctl(cmd);
309 case SNAPSHOT_PREF_IMAGE_SIZE:
313 case SNAPSHOT_GET_IMAGE_SIZE:
318 size = snapshot_get_image_size();
320 error = put_user(size, (loff_t __user *)arg);
323 case SNAPSHOT_AVAIL_SWAP:
324 snapshot_deprecated_ioctl(cmd);
325 case SNAPSHOT_AVAIL_SWAP_SIZE:
326 size = count_swap_pages(data->swap, 1);
328 error = put_user(size, (loff_t __user *)arg);
331 case SNAPSHOT_GET_SWAP_PAGE:
332 snapshot_deprecated_ioctl(cmd);
333 case SNAPSHOT_ALLOC_SWAP_PAGE:
334 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
338 offset = alloc_swapdev_block(data->swap);
340 offset <<= PAGE_SHIFT;
341 error = put_user(offset, (loff_t __user *)arg);
347 case SNAPSHOT_FREE_SWAP_PAGES:
348 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
352 free_all_swap_pages(data->swap);
355 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
356 snapshot_deprecated_ioctl(cmd);
357 if (!swsusp_swap_in_use()) {
359 * User space encodes device types as two-byte values,
360 * so we need to recode them
362 if (old_decode_dev(arg)) {
363 data->swap = swap_type_of(old_decode_dev(arg),
382 * Tasks are frozen and the notifiers have been called with
383 * PM_HIBERNATION_PREPARE
385 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
389 case SNAPSHOT_PLATFORM_SUPPORT:
390 data->platform_support = !!arg;
393 case SNAPSHOT_POWER_OFF:
394 if (data->platform_support)
395 error = hibernation_platform_enter();
398 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
399 snapshot_deprecated_ioctl(cmd);
405 data->platform_support = 1;
410 if (data->platform_support)
411 error = hibernation_platform_enter();
415 if (data->platform_support)
420 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
425 case SNAPSHOT_SET_SWAP_AREA:
426 if (swsusp_swap_in_use()) {
429 struct resume_swap_area swap_area;
432 error = copy_from_user(&swap_area, (void __user *)arg,
433 sizeof(struct resume_swap_area));
440 * User space encodes device types as two-byte values,
441 * so we need to recode them
443 swdev = new_decode_dev(swap_area.dev);
445 offset = swap_area.offset;
446 data->swap = swap_type_of(swdev, offset, NULL);
461 mutex_unlock(&pm_mutex);
466 static const struct file_operations snapshot_fops = {
467 .open = snapshot_open,
468 .release = snapshot_release,
469 .read = snapshot_read,
470 .write = snapshot_write,
472 .unlocked_ioctl = snapshot_ioctl,
475 static struct miscdevice snapshot_device = {
476 .minor = SNAPSHOT_MINOR,
478 .fops = &snapshot_fops,
481 static int __init snapshot_device_init(void)
483 return misc_register(&snapshot_device);
486 device_initcall(snapshot_device_init);