Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/power/user.c |
| 3 | * |
| 4 | * This file provides the user space interface for software suspend/resume. |
| 5 | * |
| 6 | * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> |
| 7 | * |
| 8 | * This file is released under the GPLv2. |
| 9 | * |
| 10 | */ |
| 11 | |
| 12 | #include <linux/suspend.h> |
| 13 | #include <linux/syscalls.h> |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 14 | #include <linux/reboot.h> |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 15 | #include <linux/string.h> |
| 16 | #include <linux/device.h> |
| 17 | #include <linux/miscdevice.h> |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/swap.h> |
| 20 | #include <linux/swapops.h> |
| 21 | #include <linux/pm.h> |
| 22 | #include <linux/fs.h> |
Rafael J. Wysocki | 97c7801 | 2006-10-11 01:20:45 -0700 | [diff] [blame] | 23 | #include <linux/console.h> |
Rafael J. Wysocki | e3920fb | 2006-09-25 23:32:48 -0700 | [diff] [blame] | 24 | #include <linux/cpu.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 25 | #include <linux/freezer.h> |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 26 | |
| 27 | #include <asm/uaccess.h> |
| 28 | |
| 29 | #include "power.h" |
| 30 | |
| 31 | #define SNAPSHOT_MINOR 231 |
| 32 | |
| 33 | static struct snapshot_data { |
| 34 | struct snapshot_handle handle; |
| 35 | int swap; |
| 36 | struct bitmap_page *bitmap; |
| 37 | int mode; |
| 38 | char frozen; |
| 39 | char ready; |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 40 | char platform_suspend; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 41 | } snapshot_state; |
| 42 | |
| 43 | static atomic_t device_available = ATOMIC_INIT(1); |
| 44 | |
| 45 | static int snapshot_open(struct inode *inode, struct file *filp) |
| 46 | { |
| 47 | struct snapshot_data *data; |
| 48 | |
| 49 | if (!atomic_add_unless(&device_available, -1, 0)) |
| 50 | return -EBUSY; |
| 51 | |
| 52 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) |
| 53 | return -ENOSYS; |
| 54 | |
| 55 | nonseekable_open(inode, filp); |
| 56 | data = &snapshot_state; |
| 57 | filp->private_data = data; |
| 58 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); |
| 59 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { |
Rafael J. Wysocki | 915bae9 | 2006-12-06 20:34:07 -0800 | [diff] [blame] | 60 | data->swap = swsusp_resume_device ? |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 61 | swap_type_of(swsusp_resume_device, 0, NULL) : -1; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 62 | data->mode = O_RDONLY; |
| 63 | } else { |
| 64 | data->swap = -1; |
| 65 | data->mode = O_WRONLY; |
| 66 | } |
| 67 | data->bitmap = NULL; |
| 68 | data->frozen = 0; |
| 69 | data->ready = 0; |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 70 | data->platform_suspend = 0; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 71 | |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | static int snapshot_release(struct inode *inode, struct file *filp) |
| 76 | { |
| 77 | struct snapshot_data *data; |
| 78 | |
| 79 | swsusp_free(); |
| 80 | data = filp->private_data; |
| 81 | free_all_swap_pages(data->swap, data->bitmap); |
| 82 | free_bitmap(data->bitmap); |
| 83 | if (data->frozen) { |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 84 | mutex_lock(&pm_mutex); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 85 | thaw_processes(); |
| 86 | enable_nonboot_cpus(); |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 87 | mutex_unlock(&pm_mutex); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 88 | } |
| 89 | atomic_inc(&device_available); |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static ssize_t snapshot_read(struct file *filp, char __user *buf, |
| 94 | size_t count, loff_t *offp) |
| 95 | { |
| 96 | struct snapshot_data *data; |
| 97 | ssize_t res; |
| 98 | |
| 99 | data = filp->private_data; |
| 100 | res = snapshot_read_next(&data->handle, count); |
| 101 | if (res > 0) { |
| 102 | if (copy_to_user(buf, data_of(data->handle), res)) |
| 103 | res = -EFAULT; |
| 104 | else |
| 105 | *offp = data->handle.offset; |
| 106 | } |
| 107 | return res; |
| 108 | } |
| 109 | |
| 110 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, |
| 111 | size_t count, loff_t *offp) |
| 112 | { |
| 113 | struct snapshot_data *data; |
| 114 | ssize_t res; |
| 115 | |
| 116 | data = filp->private_data; |
| 117 | res = snapshot_write_next(&data->handle, count); |
| 118 | if (res > 0) { |
| 119 | if (copy_from_user(data_of(data->handle), buf, res)) |
| 120 | res = -EFAULT; |
| 121 | else |
| 122 | *offp = data->handle.offset; |
| 123 | } |
| 124 | return res; |
| 125 | } |
| 126 | |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 127 | static inline int platform_prepare(void) |
| 128 | { |
| 129 | int error = 0; |
| 130 | |
| 131 | if (pm_ops && pm_ops->prepare) |
| 132 | error = pm_ops->prepare(PM_SUSPEND_DISK); |
| 133 | |
| 134 | return error; |
| 135 | } |
| 136 | |
| 137 | static inline void platform_finish(void) |
| 138 | { |
| 139 | if (pm_ops && pm_ops->finish) |
| 140 | pm_ops->finish(PM_SUSPEND_DISK); |
| 141 | } |
| 142 | |
| 143 | static inline int snapshot_suspend(int platform_suspend) |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 144 | { |
| 145 | int error; |
| 146 | |
| 147 | mutex_lock(&pm_mutex); |
| 148 | /* Free memory before shutting down devices. */ |
| 149 | error = swsusp_shrink_memory(); |
| 150 | if (error) |
| 151 | goto Finish; |
| 152 | |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 153 | if (platform_suspend) { |
| 154 | error = platform_prepare(); |
| 155 | if (error) |
| 156 | goto Finish; |
| 157 | } |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 158 | suspend_console(); |
| 159 | error = device_suspend(PMSG_FREEZE); |
| 160 | if (error) |
| 161 | goto Resume_devices; |
| 162 | |
| 163 | error = disable_nonboot_cpus(); |
| 164 | if (!error) { |
| 165 | in_suspend = 1; |
| 166 | error = swsusp_suspend(); |
| 167 | } |
| 168 | enable_nonboot_cpus(); |
| 169 | Resume_devices: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 170 | if (platform_suspend) |
| 171 | platform_finish(); |
| 172 | |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 173 | device_resume(); |
| 174 | resume_console(); |
| 175 | Finish: |
| 176 | mutex_unlock(&pm_mutex); |
| 177 | return error; |
| 178 | } |
| 179 | |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 180 | static inline int snapshot_restore(int platform_suspend) |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 181 | { |
| 182 | int error; |
| 183 | |
| 184 | mutex_lock(&pm_mutex); |
| 185 | pm_prepare_console(); |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 186 | if (platform_suspend) { |
| 187 | error = platform_prepare(); |
| 188 | if (error) |
| 189 | goto Finish; |
| 190 | } |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 191 | suspend_console(); |
| 192 | error = device_suspend(PMSG_PRETHAW); |
| 193 | if (error) |
| 194 | goto Resume_devices; |
| 195 | |
| 196 | error = disable_nonboot_cpus(); |
| 197 | if (!error) |
| 198 | error = swsusp_resume(); |
| 199 | |
| 200 | enable_nonboot_cpus(); |
| 201 | Resume_devices: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 202 | if (platform_suspend) |
| 203 | platform_finish(); |
| 204 | |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 205 | device_resume(); |
| 206 | resume_console(); |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 207 | Finish: |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 208 | pm_restore_console(); |
| 209 | mutex_unlock(&pm_mutex); |
| 210 | return error; |
| 211 | } |
| 212 | |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 213 | static int snapshot_ioctl(struct inode *inode, struct file *filp, |
| 214 | unsigned int cmd, unsigned long arg) |
| 215 | { |
| 216 | int error = 0; |
| 217 | struct snapshot_data *data; |
Rafael J. Wysocki | 3aef83e | 2006-12-06 20:34:10 -0800 | [diff] [blame] | 218 | loff_t avail; |
| 219 | sector_t offset; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 220 | |
| 221 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) |
| 222 | return -ENOTTY; |
| 223 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) |
| 224 | return -ENOTTY; |
| 225 | if (!capable(CAP_SYS_ADMIN)) |
| 226 | return -EPERM; |
| 227 | |
| 228 | data = filp->private_data; |
| 229 | |
| 230 | switch (cmd) { |
| 231 | |
| 232 | case SNAPSHOT_FREEZE: |
| 233 | if (data->frozen) |
| 234 | break; |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 235 | mutex_lock(&pm_mutex); |
Rafael J. Wysocki | 2591305 | 2007-02-10 01:43:33 -0800 | [diff] [blame] | 236 | if (freeze_processes()) { |
| 237 | thaw_processes(); |
| 238 | error = -EBUSY; |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 239 | } |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 240 | mutex_unlock(&pm_mutex); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 241 | if (!error) |
| 242 | data->frozen = 1; |
| 243 | break; |
| 244 | |
| 245 | case SNAPSHOT_UNFREEZE: |
| 246 | if (!data->frozen) |
| 247 | break; |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 248 | mutex_lock(&pm_mutex); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 249 | thaw_processes(); |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 250 | mutex_unlock(&pm_mutex); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 251 | data->frozen = 0; |
| 252 | break; |
| 253 | |
| 254 | case SNAPSHOT_ATOMIC_SNAPSHOT: |
| 255 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
| 256 | error = -EPERM; |
| 257 | break; |
| 258 | } |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 259 | error = snapshot_suspend(data->platform_suspend); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 260 | if (!error) |
| 261 | error = put_user(in_suspend, (unsigned int __user *)arg); |
| 262 | if (!error) |
| 263 | data->ready = 1; |
| 264 | break; |
| 265 | |
| 266 | case SNAPSHOT_ATOMIC_RESTORE: |
Rafael J. Wysocki | 8357376 | 2006-12-06 20:34:18 -0800 | [diff] [blame] | 267 | snapshot_write_finalize(&data->handle); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 268 | if (data->mode != O_WRONLY || !data->frozen || |
| 269 | !snapshot_image_loaded(&data->handle)) { |
| 270 | error = -EPERM; |
| 271 | break; |
| 272 | } |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 273 | error = snapshot_restore(data->platform_suspend); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 274 | break; |
| 275 | |
| 276 | case SNAPSHOT_FREE: |
| 277 | swsusp_free(); |
| 278 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); |
| 279 | data->ready = 0; |
| 280 | break; |
| 281 | |
| 282 | case SNAPSHOT_SET_IMAGE_SIZE: |
| 283 | image_size = arg; |
| 284 | break; |
| 285 | |
| 286 | case SNAPSHOT_AVAIL_SWAP: |
| 287 | avail = count_swap_pages(data->swap, 1); |
| 288 | avail <<= PAGE_SHIFT; |
| 289 | error = put_user(avail, (loff_t __user *)arg); |
| 290 | break; |
| 291 | |
| 292 | case SNAPSHOT_GET_SWAP_PAGE: |
| 293 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
| 294 | error = -ENODEV; |
| 295 | break; |
| 296 | } |
| 297 | if (!data->bitmap) { |
| 298 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); |
| 299 | if (!data->bitmap) { |
| 300 | error = -ENOMEM; |
| 301 | break; |
| 302 | } |
| 303 | } |
Rafael J. Wysocki | 3aef83e | 2006-12-06 20:34:10 -0800 | [diff] [blame] | 304 | offset = alloc_swapdev_block(data->swap, data->bitmap); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 305 | if (offset) { |
| 306 | offset <<= PAGE_SHIFT; |
Rafael J. Wysocki | 3aef83e | 2006-12-06 20:34:10 -0800 | [diff] [blame] | 307 | error = put_user(offset, (sector_t __user *)arg); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 308 | } else { |
| 309 | error = -ENOSPC; |
| 310 | } |
| 311 | break; |
| 312 | |
| 313 | case SNAPSHOT_FREE_SWAP_PAGES: |
| 314 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
| 315 | error = -ENODEV; |
| 316 | break; |
| 317 | } |
| 318 | free_all_swap_pages(data->swap, data->bitmap); |
| 319 | free_bitmap(data->bitmap); |
| 320 | data->bitmap = NULL; |
| 321 | break; |
| 322 | |
| 323 | case SNAPSHOT_SET_SWAP_FILE: |
| 324 | if (!data->bitmap) { |
| 325 | /* |
| 326 | * User space encodes device types as two-byte values, |
| 327 | * so we need to recode them |
| 328 | */ |
| 329 | if (old_decode_dev(arg)) { |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 330 | data->swap = swap_type_of(old_decode_dev(arg), |
| 331 | 0, NULL); |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 332 | if (data->swap < 0) |
| 333 | error = -ENODEV; |
| 334 | } else { |
| 335 | data->swap = -1; |
| 336 | error = -EINVAL; |
| 337 | } |
| 338 | } else { |
| 339 | error = -EPERM; |
| 340 | } |
| 341 | break; |
| 342 | |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 343 | case SNAPSHOT_S2RAM: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 344 | if (!pm_ops) { |
| 345 | error = -ENOSYS; |
| 346 | break; |
| 347 | } |
| 348 | |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 349 | if (!data->frozen) { |
| 350 | error = -EPERM; |
| 351 | break; |
| 352 | } |
| 353 | |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 354 | if (!mutex_trylock(&pm_mutex)) { |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 355 | error = -EBUSY; |
| 356 | break; |
| 357 | } |
| 358 | |
| 359 | if (pm_ops->prepare) { |
| 360 | error = pm_ops->prepare(PM_SUSPEND_MEM); |
| 361 | if (error) |
| 362 | goto OutS3; |
| 363 | } |
| 364 | |
| 365 | /* Put devices to sleep */ |
Rafael J. Wysocki | 97c7801 | 2006-10-11 01:20:45 -0700 | [diff] [blame] | 366 | suspend_console(); |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 367 | error = device_suspend(PMSG_SUSPEND); |
| 368 | if (error) { |
| 369 | printk(KERN_ERR "Failed to suspend some devices.\n"); |
| 370 | } else { |
| 371 | /* Enter S3, system is already frozen */ |
| 372 | suspend_enter(PM_SUSPEND_MEM); |
| 373 | |
| 374 | /* Wake up devices */ |
| 375 | device_resume(); |
| 376 | } |
Rafael J. Wysocki | 97c7801 | 2006-10-11 01:20:45 -0700 | [diff] [blame] | 377 | resume_console(); |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 378 | if (pm_ops->finish) |
| 379 | pm_ops->finish(PM_SUSPEND_MEM); |
| 380 | |
Rafael J. Wysocki | 59a49335 | 2006-12-06 20:34:44 -0800 | [diff] [blame] | 381 | OutS3: |
Stephen Hemminger | a6d7098 | 2006-12-06 20:34:35 -0800 | [diff] [blame] | 382 | mutex_unlock(&pm_mutex); |
Luca Tettamanti | 9b23820 | 2006-03-23 03:00:09 -0800 | [diff] [blame] | 383 | break; |
| 384 | |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 385 | case SNAPSHOT_PMOPS: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 386 | error = -EINVAL; |
| 387 | |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 388 | switch (arg) { |
| 389 | |
| 390 | case PMOPS_PREPARE: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 391 | if (pm_ops && pm_ops->enter) { |
| 392 | data->platform_suspend = 1; |
| 393 | error = 0; |
| 394 | } else { |
| 395 | error = -ENOSYS; |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 396 | } |
| 397 | break; |
| 398 | |
| 399 | case PMOPS_ENTER: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 400 | if (data->platform_suspend) { |
| 401 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); |
| 402 | error = pm_ops->enter(PM_SUSPEND_DISK); |
| 403 | error = 0; |
| 404 | } |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 405 | break; |
| 406 | |
| 407 | case PMOPS_FINISH: |
Rafael J. Wysocki | 2b5b09b | 2007-02-10 01:43:35 -0800 | [diff] [blame^] | 408 | if (data->platform_suspend) |
| 409 | error = 0; |
| 410 | |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 411 | break; |
| 412 | |
| 413 | default: |
| 414 | printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); |
Stefan Seyfried | 3592695 | 2006-12-06 20:34:06 -0800 | [diff] [blame] | 415 | |
| 416 | } |
| 417 | break; |
| 418 | |
Rafael J. Wysocki | 37b2ba1 | 2006-12-06 20:34:15 -0800 | [diff] [blame] | 419 | case SNAPSHOT_SET_SWAP_AREA: |
| 420 | if (data->bitmap) { |
| 421 | error = -EPERM; |
| 422 | } else { |
| 423 | struct resume_swap_area swap_area; |
| 424 | dev_t swdev; |
| 425 | |
| 426 | error = copy_from_user(&swap_area, (void __user *)arg, |
| 427 | sizeof(struct resume_swap_area)); |
| 428 | if (error) { |
| 429 | error = -EFAULT; |
| 430 | break; |
| 431 | } |
| 432 | |
| 433 | /* |
| 434 | * User space encodes device types as two-byte values, |
| 435 | * so we need to recode them |
| 436 | */ |
| 437 | swdev = old_decode_dev(swap_area.dev); |
| 438 | if (swdev) { |
| 439 | offset = swap_area.offset; |
Rafael J. Wysocki | 7bf2368 | 2007-01-05 16:36:28 -0800 | [diff] [blame] | 440 | data->swap = swap_type_of(swdev, offset, NULL); |
Rafael J. Wysocki | 37b2ba1 | 2006-12-06 20:34:15 -0800 | [diff] [blame] | 441 | if (data->swap < 0) |
| 442 | error = -ENODEV; |
| 443 | } else { |
| 444 | data->swap = -1; |
| 445 | error = -EINVAL; |
| 446 | } |
| 447 | } |
| 448 | break; |
| 449 | |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 450 | default: |
| 451 | error = -ENOTTY; |
| 452 | |
| 453 | } |
| 454 | |
| 455 | return error; |
| 456 | } |
| 457 | |
Helge Deller | 15ad7cd | 2006-12-06 20:40:36 -0800 | [diff] [blame] | 458 | static const struct file_operations snapshot_fops = { |
Rafael J. Wysocki | 6e1819d | 2006-03-23 03:00:03 -0800 | [diff] [blame] | 459 | .open = snapshot_open, |
| 460 | .release = snapshot_release, |
| 461 | .read = snapshot_read, |
| 462 | .write = snapshot_write, |
| 463 | .llseek = no_llseek, |
| 464 | .ioctl = snapshot_ioctl, |
| 465 | }; |
| 466 | |
| 467 | static struct miscdevice snapshot_device = { |
| 468 | .minor = SNAPSHOT_MINOR, |
| 469 | .name = "snapshot", |
| 470 | .fops = &snapshot_fops, |
| 471 | }; |
| 472 | |
| 473 | static int __init snapshot_device_init(void) |
| 474 | { |
| 475 | return misc_register(&snapshot_device); |
| 476 | }; |
| 477 | |
| 478 | device_initcall(snapshot_device_init); |