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 57static 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 66atomic_t snapshot_device_available = ATOMIC_INIT(1); 67 68static 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 128static 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_RDONLY ? 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 149static 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 182static 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; 205unlock: 206 mutex_unlock(&pm_mutex); 207 208 return res; 209} 210 211static 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 220static 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 pm_restore_gfp_mask(); 267 thaw_processes(); 268 usermodehelper_enable(); 269 data->frozen = 0; 270 break; 271 272 case SNAPSHOT_ATOMIC_SNAPSHOT: 273 snapshot_deprecated_ioctl(cmd); 274 case SNAPSHOT_CREATE_IMAGE: 275 if (data->mode != O_RDONLY || !data->frozen || data->ready) { 276 error = -EPERM; 277 break; 278 } 279 pm_restore_gfp_mask(); 280 error = hibernation_snapshot(data->platform_support); 281 if (!error) 282 error = put_user(in_suspend, (int __user *)arg); 283 if (!error) 284 data->ready = 1; 285 break; 286 287 case SNAPSHOT_ATOMIC_RESTORE: 288 snapshot_write_finalize(&data->handle); 289 if (data->mode != O_WRONLY || !data->frozen || 290 !snapshot_image_loaded(&data->handle)) { 291 error = -EPERM; 292 break; 293 } 294 error = hibernation_restore(data->platform_support); 295 break; 296 297 case SNAPSHOT_FREE: 298 swsusp_free(); 299 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 300 data->ready = 0; 301 break; 302 303 case SNAPSHOT_SET_IMAGE_SIZE: 304 snapshot_deprecated_ioctl(cmd); 305 case SNAPSHOT_PREF_IMAGE_SIZE: 306 image_size = arg; 307 break; 308 309 case SNAPSHOT_GET_IMAGE_SIZE: 310 if (!data->ready) { 311 error = -ENODATA; 312 break; 313 } 314 size = snapshot_get_image_size(); 315 size <<= PAGE_SHIFT; 316 error = put_user(size, (loff_t __user *)arg); 317 break; 318 319 case SNAPSHOT_AVAIL_SWAP: 320 snapshot_deprecated_ioctl(cmd); 321 case SNAPSHOT_AVAIL_SWAP_SIZE: 322 size = count_swap_pages(data->swap, 1); 323 size <<= PAGE_SHIFT; 324 error = put_user(size, (loff_t __user *)arg); 325 break; 326 327 case SNAPSHOT_GET_SWAP_PAGE: 328 snapshot_deprecated_ioctl(cmd); 329 case SNAPSHOT_ALLOC_SWAP_PAGE: 330 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 331 error = -ENODEV; 332 break; 333 } 334 offset = alloc_swapdev_block(data->swap); 335 if (offset) { 336 offset <<= PAGE_SHIFT; 337 error = put_user(offset, (loff_t __user *)arg); 338 } else { 339 error = -ENOSPC; 340 } 341 break; 342 343 case SNAPSHOT_FREE_SWAP_PAGES: 344 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 345 error = -ENODEV; 346 break; 347 } 348 free_all_swap_pages(data->swap); 349 break; 350 351 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ 352 snapshot_deprecated_ioctl(cmd); 353 if (!swsusp_swap_in_use()) { 354 /* 355 * User space encodes device types as two-byte values, 356 * so we need to recode them 357 */ 358 if (old_decode_dev(arg)) { 359 data->swap = swap_type_of(old_decode_dev(arg), 360 0, NULL); 361 if (data->swap < 0) 362 error = -ENODEV; 363 } else { 364 data->swap = -1; 365 error = -EINVAL; 366 } 367 } else { 368 error = -EPERM; 369 } 370 break; 371 372 case SNAPSHOT_S2RAM: 373 if (!data->frozen) { 374 error = -EPERM; 375 break; 376 } 377 /* 378 * Tasks are frozen and the notifiers have been called with 379 * PM_HIBERNATION_PREPARE 380 */ 381 error = suspend_devices_and_enter(PM_SUSPEND_MEM); 382 break; 383 384 case SNAPSHOT_PLATFORM_SUPPORT: 385 data->platform_support = !!arg; 386 break; 387 388 case SNAPSHOT_POWER_OFF: 389 if (data->platform_support) 390 error = hibernation_platform_enter(); 391 break; 392 393 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ 394 snapshot_deprecated_ioctl(cmd); 395 error = -EINVAL; 396 397 switch (arg) { 398 399 case PMOPS_PREPARE: 400 data->platform_support = 1; 401 error = 0; 402 break; 403 404 case PMOPS_ENTER: 405 if (data->platform_support) 406 error = hibernation_platform_enter(); 407 break; 408 409 case PMOPS_FINISH: 410 if (data->platform_support) 411 error = 0; 412 break; 413 414 default: 415 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); 416 417 } 418 break; 419 420 case SNAPSHOT_SET_SWAP_AREA: 421 if (swsusp_swap_in_use()) { 422 error = -EPERM; 423 } else { 424 struct resume_swap_area swap_area; 425 dev_t swdev; 426 427 error = copy_from_user(&swap_area, (void __user *)arg, 428 sizeof(struct resume_swap_area)); 429 if (error) { 430 error = -EFAULT; 431 break; 432 } 433 434 /* 435 * User space encodes device types as two-byte values, 436 * so we need to recode them 437 */ 438 swdev = new_decode_dev(swap_area.dev); 439 if (swdev) { 440 offset = swap_area.offset; 441 data->swap = swap_type_of(swdev, offset, NULL); 442 if (data->swap < 0) 443 error = -ENODEV; 444 } else { 445 data->swap = -1; 446 error = -EINVAL; 447 } 448 } 449 break; 450 451 default: 452 error = -ENOTTY; 453 454 } 455 456 mutex_unlock(&pm_mutex); 457 458 return error; 459} 460 461static const struct file_operations snapshot_fops = { 462 .open = snapshot_open, 463 .release = snapshot_release, 464 .read = snapshot_read, 465 .write = snapshot_write, 466 .llseek = no_llseek, 467 .unlocked_ioctl = snapshot_ioctl, 468}; 469 470static struct miscdevice snapshot_device = { 471 .minor = SNAPSHOT_MINOR, 472 .name = "snapshot", 473 .fops = &snapshot_fops, 474}; 475 476static int __init snapshot_device_init(void) 477{ 478 return misc_register(&snapshot_device); 479}; 480 481device_initcall(snapshot_device_init); 482