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 #include <scsi/scsi_scan.h> 27 28 #include <asm/uaccess.h> 29 30 #include "power.h" 31 32 /* 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. 36 */ 37 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int) 38 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int) 39 40 #define PMOPS_PREPARE 1 41 #define PMOPS_ENTER 2 42 #define PMOPS_FINISH 3 43 44 /* 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. 48 */ 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 *) 53 54 55 #define SNAPSHOT_MINOR 231 56 57 static struct snapshot_data { 58 struct snapshot_handle handle; 59 int swap; 60 int mode; 61 char frozen; 62 char ready; 63 char platform_support; 64 } snapshot_state; 65 66 atomic_t snapshot_device_available = ATOMIC_INIT(1); 67 68 static int snapshot_open(struct inode *inode, struct file *filp) 69 { 70 struct snapshot_data *data; 71 int error; 72 73 mutex_lock(&pm_mutex); 74 75 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { 76 error = -EBUSY; 77 goto Unlock; 78 } 79 80 if ((filp->f_flags & O_ACCMODE) == O_RDWR) { 81 atomic_inc(&snapshot_device_available); 82 error = -ENOSYS; 83 goto Unlock; 84 } 85 if(create_basic_memory_bitmaps()) { 86 atomic_inc(&snapshot_device_available); 87 error = -ENOMEM; 88 goto Unlock; 89 } 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); 100 if (error) 101 pm_notifier_call_chain(PM_POST_HIBERNATION); 102 } else { 103 /* 104 * Resuming. We may need to wait for the image device to 105 * appear. 106 */ 107 wait_for_device_probe(); 108 scsi_complete_async_scans(); 109 110 data->swap = -1; 111 data->mode = O_WRONLY; 112 error = pm_notifier_call_chain(PM_RESTORE_PREPARE); 113 if (error) 114 pm_notifier_call_chain(PM_POST_RESTORE); 115 } 116 if (error) 117 atomic_inc(&snapshot_device_available); 118 data->frozen = 0; 119 data->ready = 0; 120 data->platform_support = 0; 121 122 Unlock: 123 mutex_unlock(&pm_mutex); 124 125 return error; 126 } 127 128 static int snapshot_release(struct inode *inode, struct file *filp) 129 { 130 struct snapshot_data *data; 131 132 mutex_lock(&pm_mutex); 133 134 swsusp_free(); 135 free_basic_memory_bitmaps(); 136 data = filp->private_data; 137 free_all_swap_pages(data->swap); 138 if (data->frozen) 139 thaw_processes(); 140 pm_notifier_call_chain(data->mode == O_WRONLY ? 141 PM_POST_HIBERNATION : PM_POST_RESTORE); 142 atomic_inc(&snapshot_device_available); 143 144 mutex_unlock(&pm_mutex); 145 146 return 0; 147 } 148 149 static ssize_t snapshot_read(struct file *filp, char __user *buf, 150 size_t count, loff_t *offp) 151 { 152 struct snapshot_data *data; 153 ssize_t res; 154 loff_t pg_offp = *offp & ~PAGE_MASK; 155 156 mutex_lock(&pm_mutex); 157 158 data = filp->private_data; 159 if (!data->ready) { 160 res = -ENODATA; 161 goto Unlock; 162 } 163 if (!pg_offp) { /* on page boundary? */ 164 res = snapshot_read_next(&data->handle); 165 if (res <= 0) 166 goto Unlock; 167 } else { 168 res = PAGE_SIZE - pg_offp; 169 } 170 171 res = simple_read_from_buffer(buf, count, &pg_offp, 172 data_of(data->handle), res); 173 if (res > 0) 174 *offp += res; 175 176 Unlock: 177 mutex_unlock(&pm_mutex); 178 179 return res; 180 } 181 182 static ssize_t snapshot_write(struct file *filp, const char __user *buf, 183 size_t count, loff_t *offp) 184 { 185 struct snapshot_data *data; 186 ssize_t res; 187 loff_t pg_offp = *offp & ~PAGE_MASK; 188 189 mutex_lock(&pm_mutex); 190 191 data = filp->private_data; 192 193 if (!pg_offp) { 194 res = snapshot_write_next(&data->handle); 195 if (res <= 0) 196 goto unlock; 197 } else { 198 res = PAGE_SIZE - pg_offp; 199 } 200 201 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, 202 buf, count); 203 if (res > 0) 204 *offp += res; 205 unlock: 206 mutex_unlock(&pm_mutex); 207 208 return res; 209 } 210 211 static void snapshot_deprecated_ioctl(unsigned int cmd) 212 { 213 if (printk_ratelimit()) 214 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will " 215 "be removed soon, update your suspend-to-disk " 216 "utilities\n", 217 __builtin_return_address(0), cmd); 218 } 219 220 static long snapshot_ioctl(struct file *filp, unsigned int cmd, 221 unsigned long arg) 222 { 223 int error = 0; 224 struct snapshot_data *data; 225 loff_t size; 226 sector_t offset; 227 228 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) 229 return -ENOTTY; 230 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) 231 return -ENOTTY; 232 if (!capable(CAP_SYS_ADMIN)) 233 return -EPERM; 234 235 if (!mutex_trylock(&pm_mutex)) 236 return -EBUSY; 237 238 data = filp->private_data; 239 240 switch (cmd) { 241 242 case SNAPSHOT_FREEZE: 243 if (data->frozen) 244 break; 245 246 printk("Syncing filesystems ... "); 247 sys_sync(); 248 printk("done.\n"); 249 250 error = usermodehelper_disable(); 251 if (error) 252 break; 253 254 error = freeze_processes(); 255 if (error) { 256 thaw_processes(); 257 usermodehelper_enable(); 258 } 259 if (!error) 260 data->frozen = 1; 261 break; 262 263 case SNAPSHOT_UNFREEZE: 264 if (!data->frozen || data->ready) 265 break; 266 thaw_processes(); 267 usermodehelper_enable(); 268 data->frozen = 0; 269 break; 270 271 case SNAPSHOT_ATOMIC_SNAPSHOT: 272 snapshot_deprecated_ioctl(cmd); 273 case SNAPSHOT_CREATE_IMAGE: 274 if (data->mode != O_RDONLY || !data->frozen || data->ready) { 275 error = -EPERM; 276 break; 277 } 278 error = hibernation_snapshot(data->platform_support); 279 if (!error) 280 error = put_user(in_suspend, (int __user *)arg); 281 if (!error) 282 data->ready = 1; 283 break; 284 285 case SNAPSHOT_ATOMIC_RESTORE: 286 snapshot_write_finalize(&data->handle); 287 if (data->mode != O_WRONLY || !data->frozen || 288 !snapshot_image_loaded(&data->handle)) { 289 error = -EPERM; 290 break; 291 } 292 error = hibernation_restore(data->platform_support); 293 break; 294 295 case SNAPSHOT_FREE: 296 swsusp_free(); 297 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 298 data->ready = 0; 299 break; 300 301 case SNAPSHOT_SET_IMAGE_SIZE: 302 snapshot_deprecated_ioctl(cmd); 303 case SNAPSHOT_PREF_IMAGE_SIZE: 304 image_size = arg; 305 break; 306 307 case SNAPSHOT_GET_IMAGE_SIZE: 308 if (!data->ready) { 309 error = -ENODATA; 310 break; 311 } 312 size = snapshot_get_image_size(); 313 size <<= PAGE_SHIFT; 314 error = put_user(size, (loff_t __user *)arg); 315 break; 316 317 case SNAPSHOT_AVAIL_SWAP: 318 snapshot_deprecated_ioctl(cmd); 319 case SNAPSHOT_AVAIL_SWAP_SIZE: 320 size = count_swap_pages(data->swap, 1); 321 size <<= PAGE_SHIFT; 322 error = put_user(size, (loff_t __user *)arg); 323 break; 324 325 case SNAPSHOT_GET_SWAP_PAGE: 326 snapshot_deprecated_ioctl(cmd); 327 case SNAPSHOT_ALLOC_SWAP_PAGE: 328 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 329 error = -ENODEV; 330 break; 331 } 332 offset = alloc_swapdev_block(data->swap); 333 if (offset) { 334 offset <<= PAGE_SHIFT; 335 error = put_user(offset, (loff_t __user *)arg); 336 } else { 337 error = -ENOSPC; 338 } 339 break; 340 341 case SNAPSHOT_FREE_SWAP_PAGES: 342 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 343 error = -ENODEV; 344 break; 345 } 346 free_all_swap_pages(data->swap); 347 break; 348 349 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ 350 snapshot_deprecated_ioctl(cmd); 351 if (!swsusp_swap_in_use()) { 352 /* 353 * User space encodes device types as two-byte values, 354 * so we need to recode them 355 */ 356 if (old_decode_dev(arg)) { 357 data->swap = swap_type_of(old_decode_dev(arg), 358 0, NULL); 359 if (data->swap < 0) 360 error = -ENODEV; 361 } else { 362 data->swap = -1; 363 error = -EINVAL; 364 } 365 } else { 366 error = -EPERM; 367 } 368 break; 369 370 case SNAPSHOT_S2RAM: 371 if (!data->frozen) { 372 error = -EPERM; 373 break; 374 } 375 /* 376 * Tasks are frozen and the notifiers have been called with 377 * PM_HIBERNATION_PREPARE 378 */ 379 error = suspend_devices_and_enter(PM_SUSPEND_MEM); 380 break; 381 382 case SNAPSHOT_PLATFORM_SUPPORT: 383 data->platform_support = !!arg; 384 break; 385 386 case SNAPSHOT_POWER_OFF: 387 if (data->platform_support) 388 error = hibernation_platform_enter(); 389 break; 390 391 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ 392 snapshot_deprecated_ioctl(cmd); 393 error = -EINVAL; 394 395 switch (arg) { 396 397 case PMOPS_PREPARE: 398 data->platform_support = 1; 399 error = 0; 400 break; 401 402 case PMOPS_ENTER: 403 if (data->platform_support) 404 error = hibernation_platform_enter(); 405 break; 406 407 case PMOPS_FINISH: 408 if (data->platform_support) 409 error = 0; 410 break; 411 412 default: 413 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); 414 415 } 416 break; 417 418 case SNAPSHOT_SET_SWAP_AREA: 419 if (swsusp_swap_in_use()) { 420 error = -EPERM; 421 } else { 422 struct resume_swap_area swap_area; 423 dev_t swdev; 424 425 error = copy_from_user(&swap_area, (void __user *)arg, 426 sizeof(struct resume_swap_area)); 427 if (error) { 428 error = -EFAULT; 429 break; 430 } 431 432 /* 433 * User space encodes device types as two-byte values, 434 * so we need to recode them 435 */ 436 swdev = new_decode_dev(swap_area.dev); 437 if (swdev) { 438 offset = swap_area.offset; 439 data->swap = swap_type_of(swdev, offset, NULL); 440 if (data->swap < 0) 441 error = -ENODEV; 442 } else { 443 data->swap = -1; 444 error = -EINVAL; 445 } 446 } 447 break; 448 449 default: 450 error = -ENOTTY; 451 452 } 453 454 mutex_unlock(&pm_mutex); 455 456 return error; 457 } 458 459 static const struct file_operations snapshot_fops = { 460 .open = snapshot_open, 461 .release = snapshot_release, 462 .read = snapshot_read, 463 .write = snapshot_write, 464 .llseek = no_llseek, 465 .unlocked_ioctl = snapshot_ioctl, 466 }; 467 468 static struct miscdevice snapshot_device = { 469 .minor = SNAPSHOT_MINOR, 470 .name = "snapshot", 471 .fops = &snapshot_fops, 472 }; 473 474 static int __init snapshot_device_init(void) 475 { 476 return misc_register(&snapshot_device); 477 }; 478 479 device_initcall(snapshot_device_init); 480