| 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> |
| 14 | #include <linux/reboot.h> |
| 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> |
| 23 | #include <linux/console.h> |
| 24 | #include <linux/cpu.h> |
| 25 | #include <linux/freezer.h> |
| 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; |
| 40 | char platform_suspend; |
| 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 | if(create_basic_memory_bitmaps()) |
| 56 | return -ENOMEM; |
| 57 | |
| 58 | nonseekable_open(inode, filp); |
| 59 | data = &snapshot_state; |
| 60 | filp->private_data = data; |
| 61 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); |
| 62 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { |
| 63 | data->swap = swsusp_resume_device ? |
| 64 | swap_type_of(swsusp_resume_device, 0, NULL) : -1; |
| 65 | data->mode = O_RDONLY; |
| 66 | } else { |
| 67 | data->swap = -1; |
| 68 | data->mode = O_WRONLY; |
| 69 | } |
| 70 | data->bitmap = NULL; |
| 71 | data->frozen = 0; |
| 72 | data->ready = 0; |
| 73 | data->platform_suspend = 0; |
| 74 | |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | static int snapshot_release(struct inode *inode, struct file *filp) |
| 79 | { |
| 80 | struct snapshot_data *data; |
| 81 | |
| 82 | swsusp_free(); |
| 83 | free_basic_memory_bitmaps(); |
| 84 | data = filp->private_data; |
| 85 | free_all_swap_pages(data->swap, data->bitmap); |
| 86 | free_bitmap(data->bitmap); |
| 87 | if (data->frozen) { |
| 88 | mutex_lock(&pm_mutex); |
| 89 | thaw_processes(); |
| 90 | enable_nonboot_cpus(); |
| 91 | mutex_unlock(&pm_mutex); |
| 92 | } |
| 93 | atomic_inc(&device_available); |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | static ssize_t snapshot_read(struct file *filp, char __user *buf, |
| 98 | size_t count, loff_t *offp) |
| 99 | { |
| 100 | struct snapshot_data *data; |
| 101 | ssize_t res; |
| 102 | |
| 103 | data = filp->private_data; |
| 104 | res = snapshot_read_next(&data->handle, count); |
| 105 | if (res > 0) { |
| 106 | if (copy_to_user(buf, data_of(data->handle), res)) |
| 107 | res = -EFAULT; |
| 108 | else |
| 109 | *offp = data->handle.offset; |
| 110 | } |
| 111 | return res; |
| 112 | } |
| 113 | |
| 114 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, |
| 115 | size_t count, loff_t *offp) |
| 116 | { |
| 117 | struct snapshot_data *data; |
| 118 | ssize_t res; |
| 119 | |
| 120 | data = filp->private_data; |
| 121 | res = snapshot_write_next(&data->handle, count); |
| 122 | if (res > 0) { |
| 123 | if (copy_from_user(data_of(data->handle), buf, res)) |
| 124 | res = -EFAULT; |
| 125 | else |
| 126 | *offp = data->handle.offset; |
| 127 | } |
| 128 | return res; |
| 129 | } |
| 130 | |
| 131 | static inline int platform_prepare(void) |
| 132 | { |
| 133 | int error = 0; |
| 134 | |
| 135 | if (pm_ops && pm_ops->prepare) |
| 136 | error = pm_ops->prepare(PM_SUSPEND_DISK); |
| 137 | |
| 138 | return error; |
| 139 | } |
| 140 | |
| 141 | static inline void platform_finish(void) |
| 142 | { |
| 143 | if (pm_ops && pm_ops->finish) |
| 144 | pm_ops->finish(PM_SUSPEND_DISK); |
| 145 | } |
| 146 | |
| 147 | static inline int snapshot_suspend(int platform_suspend) |
| 148 | { |
| 149 | int error; |
| 150 | |
| 151 | mutex_lock(&pm_mutex); |
| 152 | /* Free memory before shutting down devices. */ |
| 153 | error = swsusp_shrink_memory(); |
| 154 | if (error) |
| 155 | goto Finish; |
| 156 | |
| 157 | if (platform_suspend) { |
| 158 | error = platform_prepare(); |
| 159 | if (error) |
| 160 | goto Finish; |
| 161 | } |
| 162 | suspend_console(); |
| 163 | error = device_suspend(PMSG_FREEZE); |
| 164 | if (error) |
| 165 | goto Resume_devices; |
| 166 | |
| 167 | error = disable_nonboot_cpus(); |
| 168 | if (!error) { |
| 169 | in_suspend = 1; |
| 170 | error = swsusp_suspend(); |
| 171 | } |
| 172 | enable_nonboot_cpus(); |
| 173 | Resume_devices: |
| 174 | if (platform_suspend) |
| 175 | platform_finish(); |
| 176 | |
| 177 | device_resume(); |
| 178 | resume_console(); |
| 179 | Finish: |
| 180 | mutex_unlock(&pm_mutex); |
| 181 | return error; |
| 182 | } |
| 183 | |
| 184 | static inline int snapshot_restore(int platform_suspend) |
| 185 | { |
| 186 | int error; |
| 187 | |
| 188 | mutex_lock(&pm_mutex); |
| 189 | pm_prepare_console(); |
| 190 | if (platform_suspend) { |
| 191 | error = platform_prepare(); |
| 192 | if (error) |
| 193 | goto Finish; |
| 194 | } |
| 195 | suspend_console(); |
| 196 | error = device_suspend(PMSG_PRETHAW); |
| 197 | if (error) |
| 198 | goto Resume_devices; |
| 199 | |
| 200 | error = disable_nonboot_cpus(); |
| 201 | if (!error) |
| 202 | error = swsusp_resume(); |
| 203 | |
| 204 | enable_nonboot_cpus(); |
| 205 | Resume_devices: |
| 206 | if (platform_suspend) |
| 207 | platform_finish(); |
| 208 | |
| 209 | device_resume(); |
| 210 | resume_console(); |
| 211 | Finish: |
| 212 | pm_restore_console(); |
| 213 | mutex_unlock(&pm_mutex); |
| 214 | return error; |
| 215 | } |
| 216 | |
| 217 | static int snapshot_ioctl(struct inode *inode, struct file *filp, |
| 218 | unsigned int cmd, unsigned long arg) |
| 219 | { |
| 220 | int error = 0; |
| 221 | struct snapshot_data *data; |
| 222 | loff_t avail; |
| 223 | sector_t offset; |
| 224 | |
| 225 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) |
| 226 | return -ENOTTY; |
| 227 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) |
| 228 | return -ENOTTY; |
| 229 | if (!capable(CAP_SYS_ADMIN)) |
| 230 | return -EPERM; |
| 231 | |
| 232 | data = filp->private_data; |
| 233 | |
| 234 | switch (cmd) { |
| 235 | |
| 236 | case SNAPSHOT_FREEZE: |
| 237 | if (data->frozen) |
| 238 | break; |
| 239 | mutex_lock(&pm_mutex); |
| 240 | if (freeze_processes()) { |
| 241 | thaw_processes(); |
| 242 | error = -EBUSY; |
| 243 | } |
| 244 | mutex_unlock(&pm_mutex); |
| 245 | if (!error) |
| 246 | data->frozen = 1; |
| 247 | break; |
| 248 | |
| 249 | case SNAPSHOT_UNFREEZE: |
| 250 | if (!data->frozen) |
| 251 | break; |
| 252 | mutex_lock(&pm_mutex); |
| 253 | thaw_processes(); |
| 254 | mutex_unlock(&pm_mutex); |
| 255 | data->frozen = 0; |
| 256 | break; |
| 257 | |
| 258 | case SNAPSHOT_ATOMIC_SNAPSHOT: |
| 259 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
| 260 | error = -EPERM; |
| 261 | break; |
| 262 | } |
| 263 | error = snapshot_suspend(data->platform_suspend); |
| 264 | if (!error) |
| 265 | error = put_user(in_suspend, (unsigned int __user *)arg); |
| 266 | if (!error) |
| 267 | data->ready = 1; |
| 268 | break; |
| 269 | |
| 270 | case SNAPSHOT_ATOMIC_RESTORE: |
| 271 | snapshot_write_finalize(&data->handle); |
| 272 | if (data->mode != O_WRONLY || !data->frozen || |
| 273 | !snapshot_image_loaded(&data->handle)) { |
| 274 | error = -EPERM; |
| 275 | break; |
| 276 | } |
| 277 | error = snapshot_restore(data->platform_suspend); |
| 278 | break; |
| 279 | |
| 280 | case SNAPSHOT_FREE: |
| 281 | swsusp_free(); |
| 282 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); |
| 283 | data->ready = 0; |
| 284 | break; |
| 285 | |
| 286 | case SNAPSHOT_SET_IMAGE_SIZE: |
| 287 | image_size = arg; |
| 288 | break; |
| 289 | |
| 290 | case SNAPSHOT_AVAIL_SWAP: |
| 291 | avail = count_swap_pages(data->swap, 1); |
| 292 | avail <<= PAGE_SHIFT; |
| 293 | error = put_user(avail, (loff_t __user *)arg); |
| 294 | break; |
| 295 | |
| 296 | case SNAPSHOT_GET_SWAP_PAGE: |
| 297 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
| 298 | error = -ENODEV; |
| 299 | break; |
| 300 | } |
| 301 | if (!data->bitmap) { |
| 302 | data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); |
| 303 | if (!data->bitmap) { |
| 304 | error = -ENOMEM; |
| 305 | break; |
| 306 | } |
| 307 | } |
| 308 | offset = alloc_swapdev_block(data->swap, data->bitmap); |
| 309 | if (offset) { |
| 310 | offset <<= PAGE_SHIFT; |
| 311 | error = put_user(offset, (sector_t __user *)arg); |
| 312 | } else { |
| 313 | error = -ENOSPC; |
| 314 | } |
| 315 | break; |
| 316 | |
| 317 | case SNAPSHOT_FREE_SWAP_PAGES: |
| 318 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
| 319 | error = -ENODEV; |
| 320 | break; |
| 321 | } |
| 322 | free_all_swap_pages(data->swap, data->bitmap); |
| 323 | free_bitmap(data->bitmap); |
| 324 | data->bitmap = NULL; |
| 325 | break; |
| 326 | |
| 327 | case SNAPSHOT_SET_SWAP_FILE: |
| 328 | if (!data->bitmap) { |
| 329 | /* |
| 330 | * User space encodes device types as two-byte values, |
| 331 | * so we need to recode them |
| 332 | */ |
| 333 | if (old_decode_dev(arg)) { |
| 334 | data->swap = swap_type_of(old_decode_dev(arg), |
| 335 | 0, NULL); |
| 336 | if (data->swap < 0) |
| 337 | error = -ENODEV; |
| 338 | } else { |
| 339 | data->swap = -1; |
| 340 | error = -EINVAL; |
| 341 | } |
| 342 | } else { |
| 343 | error = -EPERM; |
| 344 | } |
| 345 | break; |
| 346 | |
| 347 | case SNAPSHOT_S2RAM: |
| 348 | if (!pm_ops) { |
| 349 | error = -ENOSYS; |
| 350 | break; |
| 351 | } |
| 352 | |
| 353 | if (!data->frozen) { |
| 354 | error = -EPERM; |
| 355 | break; |
| 356 | } |
| 357 | |
| 358 | if (!mutex_trylock(&pm_mutex)) { |
| 359 | error = -EBUSY; |
| 360 | break; |
| 361 | } |
| 362 | |
| 363 | if (pm_ops->prepare) { |
| 364 | error = pm_ops->prepare(PM_SUSPEND_MEM); |
| 365 | if (error) |
| 366 | goto OutS3; |
| 367 | } |
| 368 | |
| 369 | /* Put devices to sleep */ |
| 370 | suspend_console(); |
| 371 | error = device_suspend(PMSG_SUSPEND); |
| 372 | if (error) { |
| 373 | printk(KERN_ERR "Failed to suspend some devices.\n"); |
| 374 | } else { |
| 375 | error = disable_nonboot_cpus(); |
| 376 | if (!error) { |
| 377 | /* Enter S3, system is already frozen */ |
| 378 | suspend_enter(PM_SUSPEND_MEM); |
| 379 | enable_nonboot_cpus(); |
| 380 | } |
| 381 | /* Wake up devices */ |
| 382 | device_resume(); |
| 383 | } |
| 384 | resume_console(); |
| 385 | if (pm_ops->finish) |
| 386 | pm_ops->finish(PM_SUSPEND_MEM); |
| 387 | |
| 388 | OutS3: |
| 389 | mutex_unlock(&pm_mutex); |
| 390 | break; |
| 391 | |
| 392 | case SNAPSHOT_PMOPS: |
| 393 | error = -EINVAL; |
| 394 | |
| 395 | switch (arg) { |
| 396 | |
| 397 | case PMOPS_PREPARE: |
| 398 | if (pm_ops && pm_ops->enter) { |
| 399 | data->platform_suspend = 1; |
| 400 | error = 0; |
| 401 | } else { |
| 402 | error = -ENOSYS; |
| 403 | } |
| 404 | break; |
| 405 | |
| 406 | case PMOPS_ENTER: |
| 407 | if (data->platform_suspend) { |
| 408 | kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK); |
| 409 | error = pm_ops->enter(PM_SUSPEND_DISK); |
| 410 | error = 0; |
| 411 | } |
| 412 | break; |
| 413 | |
| 414 | case PMOPS_FINISH: |
| 415 | if (data->platform_suspend) |
| 416 | error = 0; |
| 417 | |
| 418 | break; |
| 419 | |
| 420 | default: |
| 421 | printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); |
| 422 | |
| 423 | } |
| 424 | break; |
| 425 | |
| 426 | case SNAPSHOT_SET_SWAP_AREA: |
| 427 | if (data->bitmap) { |
| 428 | error = -EPERM; |
| 429 | } else { |
| 430 | struct resume_swap_area swap_area; |
| 431 | dev_t swdev; |
| 432 | |
| 433 | error = copy_from_user(&swap_area, (void __user *)arg, |
| 434 | sizeof(struct resume_swap_area)); |
| 435 | if (error) { |
| 436 | error = -EFAULT; |
| 437 | break; |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | * User space encodes device types as two-byte values, |
| 442 | * so we need to recode them |
| 443 | */ |
| 444 | swdev = old_decode_dev(swap_area.dev); |
| 445 | if (swdev) { |
| 446 | offset = swap_area.offset; |
| 447 | data->swap = swap_type_of(swdev, offset, NULL); |
| 448 | if (data->swap < 0) |
| 449 | error = -ENODEV; |
| 450 | } else { |
| 451 | data->swap = -1; |
| 452 | error = -EINVAL; |
| 453 | } |
| 454 | } |
| 455 | break; |
| 456 | |
| 457 | default: |
| 458 | error = -ENOTTY; |
| 459 | |
| 460 | } |
| 461 | |
| 462 | return error; |
| 463 | } |
| 464 | |
| 465 | static const struct file_operations snapshot_fops = { |
| 466 | .open = snapshot_open, |
| 467 | .release = snapshot_release, |
| 468 | .read = snapshot_read, |
| 469 | .write = snapshot_write, |
| 470 | .llseek = no_llseek, |
| 471 | .ioctl = snapshot_ioctl, |
| 472 | }; |
| 473 | |
| 474 | static struct miscdevice snapshot_device = { |
| 475 | .minor = SNAPSHOT_MINOR, |
| 476 | .name = "snapshot", |
| 477 | .fops = &snapshot_fops, |
| 478 | }; |
| 479 | |
| 480 | static int __init snapshot_device_init(void) |
| 481 | { |
| 482 | return misc_register(&snapshot_device); |
| 483 | }; |
| 484 | |
| 485 | device_initcall(snapshot_device_init); |