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 pm_restore_gfp_mask(); 140 thaw_processes(); 141 } 142 pm_notifier_call_chain(data->mode == O_RDONLY ? 143 PM_POST_HIBERNATION : PM_POST_RESTORE); 144 atomic_inc(&snapshot_device_available); 145 146 mutex_unlock(&pm_mutex); 147 148 return 0; 149 } 150 151 static ssize_t snapshot_read(struct file *filp, char __user *buf, 152 size_t count, loff_t *offp) 153 { 154 struct snapshot_data *data; 155 ssize_t res; 156 loff_t pg_offp = *offp & ~PAGE_MASK; 157 158 mutex_lock(&pm_mutex); 159 160 data = filp->private_data; 161 if (!data->ready) { 162 res = -ENODATA; 163 goto Unlock; 164 } 165 if (!pg_offp) { /* on page boundary? */ 166 res = snapshot_read_next(&data->handle); 167 if (res <= 0) 168 goto Unlock; 169 } else { 170 res = PAGE_SIZE - pg_offp; 171 } 172 173 res = simple_read_from_buffer(buf, count, &pg_offp, 174 data_of(data->handle), res); 175 if (res > 0) 176 *offp += res; 177 178 Unlock: 179 mutex_unlock(&pm_mutex); 180 181 return res; 182 } 183 184 static ssize_t snapshot_write(struct file *filp, const char __user *buf, 185 size_t count, loff_t *offp) 186 { 187 struct snapshot_data *data; 188 ssize_t res; 189 loff_t pg_offp = *offp & ~PAGE_MASK; 190 191 mutex_lock(&pm_mutex); 192 193 data = filp->private_data; 194 195 if (!pg_offp) { 196 res = snapshot_write_next(&data->handle); 197 if (res <= 0) 198 goto unlock; 199 } else { 200 res = PAGE_SIZE - pg_offp; 201 } 202 203 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, 204 buf, count); 205 if (res > 0) 206 *offp += res; 207 unlock: 208 mutex_unlock(&pm_mutex); 209 210 return res; 211 } 212 213 static void snapshot_deprecated_ioctl(unsigned int cmd) 214 { 215 if (printk_ratelimit()) 216 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will " 217 "be removed soon, update your suspend-to-disk " 218 "utilities\n", 219 __builtin_return_address(0), cmd); 220 } 221 222 static long snapshot_ioctl(struct file *filp, unsigned int cmd, 223 unsigned long arg) 224 { 225 int error = 0; 226 struct snapshot_data *data; 227 loff_t size; 228 sector_t offset; 229 230 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) 231 return -ENOTTY; 232 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) 233 return -ENOTTY; 234 if (!capable(CAP_SYS_ADMIN)) 235 return -EPERM; 236 237 if (!mutex_trylock(&pm_mutex)) 238 return -EBUSY; 239 240 data = filp->private_data; 241 242 switch (cmd) { 243 244 case SNAPSHOT_FREEZE: 245 if (data->frozen) 246 break; 247 248 printk("Syncing filesystems ... "); 249 sys_sync(); 250 printk("done.\n"); 251 252 error = usermodehelper_disable(); 253 if (error) 254 break; 255 256 error = freeze_processes(); 257 if (error) { 258 thaw_processes(); 259 usermodehelper_enable(); 260 } 261 if (!error) 262 data->frozen = 1; 263 break; 264 265 case SNAPSHOT_UNFREEZE: 266 if (!data->frozen || data->ready) 267 break; 268 pm_restore_gfp_mask(); 269 thaw_processes(); 270 usermodehelper_enable(); 271 data->frozen = 0; 272 break; 273 274 case SNAPSHOT_ATOMIC_SNAPSHOT: 275 snapshot_deprecated_ioctl(cmd); 276 case SNAPSHOT_CREATE_IMAGE: 277 if (data->mode != O_RDONLY || !data->frozen || data->ready) { 278 error = -EPERM; 279 break; 280 } 281 pm_restore_gfp_mask(); 282 error = hibernation_snapshot(data->platform_support); 283 if (!error) 284 error = put_user(in_suspend, (int __user *)arg); 285 if (!error) 286 data->ready = 1; 287 break; 288 289 case SNAPSHOT_ATOMIC_RESTORE: 290 snapshot_write_finalize(&data->handle); 291 if (data->mode != O_WRONLY || !data->frozen || 292 !snapshot_image_loaded(&data->handle)) { 293 error = -EPERM; 294 break; 295 } 296 error = hibernation_restore(data->platform_support); 297 break; 298 299 case SNAPSHOT_FREE: 300 swsusp_free(); 301 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 302 data->ready = 0; 303 break; 304 305 case SNAPSHOT_SET_IMAGE_SIZE: 306 snapshot_deprecated_ioctl(cmd); 307 case SNAPSHOT_PREF_IMAGE_SIZE: 308 image_size = arg; 309 break; 310 311 case SNAPSHOT_GET_IMAGE_SIZE: 312 if (!data->ready) { 313 error = -ENODATA; 314 break; 315 } 316 size = snapshot_get_image_size(); 317 size <<= PAGE_SHIFT; 318 error = put_user(size, (loff_t __user *)arg); 319 break; 320 321 case SNAPSHOT_AVAIL_SWAP: 322 snapshot_deprecated_ioctl(cmd); 323 case SNAPSHOT_AVAIL_SWAP_SIZE: 324 size = count_swap_pages(data->swap, 1); 325 size <<= PAGE_SHIFT; 326 error = put_user(size, (loff_t __user *)arg); 327 break; 328 329 case SNAPSHOT_GET_SWAP_PAGE: 330 snapshot_deprecated_ioctl(cmd); 331 case SNAPSHOT_ALLOC_SWAP_PAGE: 332 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 333 error = -ENODEV; 334 break; 335 } 336 offset = alloc_swapdev_block(data->swap); 337 if (offset) { 338 offset <<= PAGE_SHIFT; 339 error = put_user(offset, (loff_t __user *)arg); 340 } else { 341 error = -ENOSPC; 342 } 343 break; 344 345 case SNAPSHOT_FREE_SWAP_PAGES: 346 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 347 error = -ENODEV; 348 break; 349 } 350 free_all_swap_pages(data->swap); 351 break; 352 353 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ 354 snapshot_deprecated_ioctl(cmd); 355 if (!swsusp_swap_in_use()) { 356 /* 357 * User space encodes device types as two-byte values, 358 * so we need to recode them 359 */ 360 if (old_decode_dev(arg)) { 361 data->swap = swap_type_of(old_decode_dev(arg), 362 0, NULL); 363 if (data->swap < 0) 364 error = -ENODEV; 365 } else { 366 data->swap = -1; 367 error = -EINVAL; 368 } 369 } else { 370 error = -EPERM; 371 } 372 break; 373 374 case SNAPSHOT_S2RAM: 375 if (!data->frozen) { 376 error = -EPERM; 377 break; 378 } 379 /* 380 * Tasks are frozen and the notifiers have been called with 381 * PM_HIBERNATION_PREPARE 382 */ 383 error = suspend_devices_and_enter(PM_SUSPEND_MEM); 384 data->ready = 0; 385 break; 386 387 case SNAPSHOT_PLATFORM_SUPPORT: 388 data->platform_support = !!arg; 389 break; 390 391 case SNAPSHOT_POWER_OFF: 392 if (data->platform_support) 393 error = hibernation_platform_enter(); 394 break; 395 396 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ 397 snapshot_deprecated_ioctl(cmd); 398 error = -EINVAL; 399 400 switch (arg) { 401 402 case PMOPS_PREPARE: 403 data->platform_support = 1; 404 error = 0; 405 break; 406 407 case PMOPS_ENTER: 408 if (data->platform_support) 409 error = hibernation_platform_enter(); 410 break; 411 412 case PMOPS_FINISH: 413 if (data->platform_support) 414 error = 0; 415 break; 416 417 default: 418 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); 419 420 } 421 break; 422 423 case SNAPSHOT_SET_SWAP_AREA: 424 if (swsusp_swap_in_use()) { 425 error = -EPERM; 426 } else { 427 struct resume_swap_area swap_area; 428 dev_t swdev; 429 430 error = copy_from_user(&swap_area, (void __user *)arg, 431 sizeof(struct resume_swap_area)); 432 if (error) { 433 error = -EFAULT; 434 break; 435 } 436 437 /* 438 * User space encodes device types as two-byte values, 439 * so we need to recode them 440 */ 441 swdev = new_decode_dev(swap_area.dev); 442 if (swdev) { 443 offset = swap_area.offset; 444 data->swap = swap_type_of(swdev, offset, NULL); 445 if (data->swap < 0) 446 error = -ENODEV; 447 } else { 448 data->swap = -1; 449 error = -EINVAL; 450 } 451 } 452 break; 453 454 default: 455 error = -ENOTTY; 456 457 } 458 459 mutex_unlock(&pm_mutex); 460 461 return error; 462 } 463 464 static const struct file_operations snapshot_fops = { 465 .open = snapshot_open, 466 .release = snapshot_release, 467 .read = snapshot_read, 468 .write = snapshot_write, 469 .llseek = no_llseek, 470 .unlocked_ioctl = snapshot_ioctl, 471 }; 472 473 static struct miscdevice snapshot_device = { 474 .minor = SNAPSHOT_MINOR, 475 .name = "snapshot", 476 .fops = &snapshot_fops, 477 }; 478 479 static int __init snapshot_device_init(void) 480 { 481 return misc_register(&snapshot_device); 482 }; 483 484 device_initcall(snapshot_device_init); 485