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 free_basic_memory_bitmaps(); 118 atomic_inc(&snapshot_device_available); 119 } 120 data->frozen = 0; 121 data->ready = 0; 122 data->platform_support = 0; 123 124 Unlock: 125 mutex_unlock(&pm_mutex); 126 127 return error; 128 } 129 130 static int snapshot_release(struct inode *inode, struct file *filp) 131 { 132 struct snapshot_data *data; 133 134 mutex_lock(&pm_mutex); 135 136 swsusp_free(); 137 free_basic_memory_bitmaps(); 138 data = filp->private_data; 139 free_all_swap_pages(data->swap); 140 if (data->frozen) { 141 pm_restore_gfp_mask(); 142 thaw_processes(); 143 } 144 pm_notifier_call_chain(data->mode == O_RDONLY ? 145 PM_POST_HIBERNATION : PM_POST_RESTORE); 146 atomic_inc(&snapshot_device_available); 147 148 mutex_unlock(&pm_mutex); 149 150 return 0; 151 } 152 153 static ssize_t snapshot_read(struct file *filp, char __user *buf, 154 size_t count, loff_t *offp) 155 { 156 struct snapshot_data *data; 157 ssize_t res; 158 loff_t pg_offp = *offp & ~PAGE_MASK; 159 160 mutex_lock(&pm_mutex); 161 162 data = filp->private_data; 163 if (!data->ready) { 164 res = -ENODATA; 165 goto Unlock; 166 } 167 if (!pg_offp) { /* on page boundary? */ 168 res = snapshot_read_next(&data->handle); 169 if (res <= 0) 170 goto Unlock; 171 } else { 172 res = PAGE_SIZE - pg_offp; 173 } 174 175 res = simple_read_from_buffer(buf, count, &pg_offp, 176 data_of(data->handle), res); 177 if (res > 0) 178 *offp += res; 179 180 Unlock: 181 mutex_unlock(&pm_mutex); 182 183 return res; 184 } 185 186 static ssize_t snapshot_write(struct file *filp, const char __user *buf, 187 size_t count, loff_t *offp) 188 { 189 struct snapshot_data *data; 190 ssize_t res; 191 loff_t pg_offp = *offp & ~PAGE_MASK; 192 193 mutex_lock(&pm_mutex); 194 195 data = filp->private_data; 196 197 if (!pg_offp) { 198 res = snapshot_write_next(&data->handle); 199 if (res <= 0) 200 goto unlock; 201 } else { 202 res = PAGE_SIZE - pg_offp; 203 } 204 205 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, 206 buf, count); 207 if (res > 0) 208 *offp += res; 209 unlock: 210 mutex_unlock(&pm_mutex); 211 212 return res; 213 } 214 215 static void snapshot_deprecated_ioctl(unsigned int cmd) 216 { 217 if (printk_ratelimit()) 218 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will " 219 "be removed soon, update your suspend-to-disk " 220 "utilities\n", 221 __builtin_return_address(0), cmd); 222 } 223 224 static long snapshot_ioctl(struct file *filp, unsigned int cmd, 225 unsigned long arg) 226 { 227 int error = 0; 228 struct snapshot_data *data; 229 loff_t size; 230 sector_t offset; 231 232 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) 233 return -ENOTTY; 234 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) 235 return -ENOTTY; 236 if (!capable(CAP_SYS_ADMIN)) 237 return -EPERM; 238 239 if (!mutex_trylock(&pm_mutex)) 240 return -EBUSY; 241 242 data = filp->private_data; 243 244 switch (cmd) { 245 246 case SNAPSHOT_FREEZE: 247 if (data->frozen) 248 break; 249 250 printk("Syncing filesystems ... "); 251 sys_sync(); 252 printk("done.\n"); 253 254 error = usermodehelper_disable(); 255 if (error) 256 break; 257 258 error = freeze_processes(); 259 if (error) { 260 thaw_processes(); 261 usermodehelper_enable(); 262 } 263 if (!error) 264 data->frozen = 1; 265 break; 266 267 case SNAPSHOT_UNFREEZE: 268 if (!data->frozen || data->ready) 269 break; 270 pm_restore_gfp_mask(); 271 thaw_processes(); 272 usermodehelper_enable(); 273 data->frozen = 0; 274 break; 275 276 case SNAPSHOT_ATOMIC_SNAPSHOT: 277 snapshot_deprecated_ioctl(cmd); 278 case SNAPSHOT_CREATE_IMAGE: 279 if (data->mode != O_RDONLY || !data->frozen || data->ready) { 280 error = -EPERM; 281 break; 282 } 283 pm_restore_gfp_mask(); 284 error = hibernation_snapshot(data->platform_support); 285 if (!error) 286 error = put_user(in_suspend, (int __user *)arg); 287 if (!error) 288 data->ready = 1; 289 break; 290 291 case SNAPSHOT_ATOMIC_RESTORE: 292 snapshot_write_finalize(&data->handle); 293 if (data->mode != O_WRONLY || !data->frozen || 294 !snapshot_image_loaded(&data->handle)) { 295 error = -EPERM; 296 break; 297 } 298 error = hibernation_restore(data->platform_support); 299 break; 300 301 case SNAPSHOT_FREE: 302 swsusp_free(); 303 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 304 data->ready = 0; 305 break; 306 307 case SNAPSHOT_SET_IMAGE_SIZE: 308 snapshot_deprecated_ioctl(cmd); 309 case SNAPSHOT_PREF_IMAGE_SIZE: 310 image_size = arg; 311 break; 312 313 case SNAPSHOT_GET_IMAGE_SIZE: 314 if (!data->ready) { 315 error = -ENODATA; 316 break; 317 } 318 size = snapshot_get_image_size(); 319 size <<= PAGE_SHIFT; 320 error = put_user(size, (loff_t __user *)arg); 321 break; 322 323 case SNAPSHOT_AVAIL_SWAP: 324 snapshot_deprecated_ioctl(cmd); 325 case SNAPSHOT_AVAIL_SWAP_SIZE: 326 size = count_swap_pages(data->swap, 1); 327 size <<= PAGE_SHIFT; 328 error = put_user(size, (loff_t __user *)arg); 329 break; 330 331 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) { 335 error = -ENODEV; 336 break; 337 } 338 offset = alloc_swapdev_block(data->swap); 339 if (offset) { 340 offset <<= PAGE_SHIFT; 341 error = put_user(offset, (loff_t __user *)arg); 342 } else { 343 error = -ENOSPC; 344 } 345 break; 346 347 case SNAPSHOT_FREE_SWAP_PAGES: 348 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 349 error = -ENODEV; 350 break; 351 } 352 free_all_swap_pages(data->swap); 353 break; 354 355 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ 356 snapshot_deprecated_ioctl(cmd); 357 if (!swsusp_swap_in_use()) { 358 /* 359 * User space encodes device types as two-byte values, 360 * so we need to recode them 361 */ 362 if (old_decode_dev(arg)) { 363 data->swap = swap_type_of(old_decode_dev(arg), 364 0, NULL); 365 if (data->swap < 0) 366 error = -ENODEV; 367 } else { 368 data->swap = -1; 369 error = -EINVAL; 370 } 371 } else { 372 error = -EPERM; 373 } 374 break; 375 376 case SNAPSHOT_S2RAM: 377 if (!data->frozen) { 378 error = -EPERM; 379 break; 380 } 381 /* 382 * Tasks are frozen and the notifiers have been called with 383 * PM_HIBERNATION_PREPARE 384 */ 385 error = suspend_devices_and_enter(PM_SUSPEND_MEM); 386 data->ready = 0; 387 break; 388 389 case SNAPSHOT_PLATFORM_SUPPORT: 390 data->platform_support = !!arg; 391 break; 392 393 case SNAPSHOT_POWER_OFF: 394 if (data->platform_support) 395 error = hibernation_platform_enter(); 396 break; 397 398 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ 399 snapshot_deprecated_ioctl(cmd); 400 error = -EINVAL; 401 402 switch (arg) { 403 404 case PMOPS_PREPARE: 405 data->platform_support = 1; 406 error = 0; 407 break; 408 409 case PMOPS_ENTER: 410 if (data->platform_support) 411 error = hibernation_platform_enter(); 412 break; 413 414 case PMOPS_FINISH: 415 if (data->platform_support) 416 error = 0; 417 break; 418 419 default: 420 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); 421 422 } 423 break; 424 425 case SNAPSHOT_SET_SWAP_AREA: 426 if (swsusp_swap_in_use()) { 427 error = -EPERM; 428 } else { 429 struct resume_swap_area swap_area; 430 dev_t swdev; 431 432 error = copy_from_user(&swap_area, (void __user *)arg, 433 sizeof(struct resume_swap_area)); 434 if (error) { 435 error = -EFAULT; 436 break; 437 } 438 439 /* 440 * User space encodes device types as two-byte values, 441 * so we need to recode them 442 */ 443 swdev = new_decode_dev(swap_area.dev); 444 if (swdev) { 445 offset = swap_area.offset; 446 data->swap = swap_type_of(swdev, offset, NULL); 447 if (data->swap < 0) 448 error = -ENODEV; 449 } else { 450 data->swap = -1; 451 error = -EINVAL; 452 } 453 } 454 break; 455 456 default: 457 error = -ENOTTY; 458 459 } 460 461 mutex_unlock(&pm_mutex); 462 463 return error; 464 } 465 466 static const struct file_operations snapshot_fops = { 467 .open = snapshot_open, 468 .release = snapshot_release, 469 .read = snapshot_read, 470 .write = snapshot_write, 471 .llseek = no_llseek, 472 .unlocked_ioctl = snapshot_ioctl, 473 }; 474 475 static struct miscdevice snapshot_device = { 476 .minor = SNAPSHOT_MINOR, 477 .name = "snapshot", 478 .fops = &snapshot_fops, 479 }; 480 481 static int __init snapshot_device_init(void) 482 { 483 return misc_register(&snapshot_device); 484 }; 485 486 device_initcall(snapshot_device_init); 487