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 /* 32 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and 33 * will be removed in the future. They are only preserved here for 34 * compatibility with existing userland utilities. 35 */ 36 #define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int) 37 #define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int) 38 39 #define PMOPS_PREPARE 1 40 #define PMOPS_ENTER 2 41 #define PMOPS_FINISH 3 42 43 /* 44 * NOTE: The following ioctl definitions are wrong and have been replaced with 45 * correct ones. They are only preserved here for compatibility with existing 46 * userland utilities and will be removed in the future. 47 */ 48 #define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *) 49 #define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long) 50 #define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *) 51 #define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *) 52 53 54 #define SNAPSHOT_MINOR 231 55 56 static struct snapshot_data { 57 struct snapshot_handle handle; 58 int swap; 59 int mode; 60 char frozen; 61 char ready; 62 char platform_support; 63 } snapshot_state; 64 65 atomic_t snapshot_device_available = ATOMIC_INIT(1); 66 67 static int snapshot_open(struct inode *inode, struct file *filp) 68 { 69 struct snapshot_data *data; 70 int error; 71 72 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) 73 return -EBUSY; 74 75 if ((filp->f_flags & O_ACCMODE) == O_RDWR) { 76 atomic_inc(&snapshot_device_available); 77 return -ENOSYS; 78 } 79 if(create_basic_memory_bitmaps()) { 80 atomic_inc(&snapshot_device_available); 81 return -ENOMEM; 82 } 83 nonseekable_open(inode, filp); 84 data = &snapshot_state; 85 filp->private_data = data; 86 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 87 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { 88 data->swap = swsusp_resume_device ? 89 swap_type_of(swsusp_resume_device, 0, NULL) : -1; 90 data->mode = O_RDONLY; 91 error = pm_notifier_call_chain(PM_RESTORE_PREPARE); 92 if (error) 93 pm_notifier_call_chain(PM_POST_RESTORE); 94 } else { 95 data->swap = -1; 96 data->mode = O_WRONLY; 97 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE); 98 if (error) 99 pm_notifier_call_chain(PM_POST_HIBERNATION); 100 } 101 if (error) { 102 atomic_inc(&snapshot_device_available); 103 return error; 104 } 105 data->frozen = 0; 106 data->ready = 0; 107 data->platform_support = 0; 108 109 return 0; 110 } 111 112 static int snapshot_release(struct inode *inode, struct file *filp) 113 { 114 struct snapshot_data *data; 115 116 swsusp_free(); 117 free_basic_memory_bitmaps(); 118 data = filp->private_data; 119 free_all_swap_pages(data->swap); 120 if (data->frozen) { 121 mutex_lock(&pm_mutex); 122 thaw_processes(); 123 mutex_unlock(&pm_mutex); 124 } 125 pm_notifier_call_chain(data->mode == O_WRONLY ? 126 PM_POST_HIBERNATION : PM_POST_RESTORE); 127 atomic_inc(&snapshot_device_available); 128 return 0; 129 } 130 131 static ssize_t snapshot_read(struct file *filp, char __user *buf, 132 size_t count, loff_t *offp) 133 { 134 struct snapshot_data *data; 135 ssize_t res; 136 137 data = filp->private_data; 138 if (!data->ready) 139 return -ENODATA; 140 res = snapshot_read_next(&data->handle, count); 141 if (res > 0) { 142 if (copy_to_user(buf, data_of(data->handle), res)) 143 res = -EFAULT; 144 else 145 *offp = data->handle.offset; 146 } 147 return res; 148 } 149 150 static ssize_t snapshot_write(struct file *filp, const char __user *buf, 151 size_t count, loff_t *offp) 152 { 153 struct snapshot_data *data; 154 ssize_t res; 155 156 data = filp->private_data; 157 res = snapshot_write_next(&data->handle, count); 158 if (res > 0) { 159 if (copy_from_user(data_of(data->handle), buf, res)) 160 res = -EFAULT; 161 else 162 *offp = data->handle.offset; 163 } 164 return res; 165 } 166 167 static int snapshot_ioctl(struct inode *inode, struct file *filp, 168 unsigned int cmd, unsigned long arg) 169 { 170 int error = 0; 171 struct snapshot_data *data; 172 loff_t size; 173 sector_t offset; 174 175 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) 176 return -ENOTTY; 177 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) 178 return -ENOTTY; 179 if (!capable(CAP_SYS_ADMIN)) 180 return -EPERM; 181 182 data = filp->private_data; 183 184 switch (cmd) { 185 186 case SNAPSHOT_FREEZE: 187 if (data->frozen) 188 break; 189 mutex_lock(&pm_mutex); 190 printk("Syncing filesystems ... "); 191 sys_sync(); 192 printk("done.\n"); 193 194 error = freeze_processes(); 195 if (error) 196 thaw_processes(); 197 mutex_unlock(&pm_mutex); 198 if (!error) 199 data->frozen = 1; 200 break; 201 202 case SNAPSHOT_UNFREEZE: 203 if (!data->frozen || data->ready) 204 break; 205 mutex_lock(&pm_mutex); 206 thaw_processes(); 207 mutex_unlock(&pm_mutex); 208 data->frozen = 0; 209 break; 210 211 case SNAPSHOT_CREATE_IMAGE: 212 case SNAPSHOT_ATOMIC_SNAPSHOT: 213 if (data->mode != O_RDONLY || !data->frozen || data->ready) { 214 error = -EPERM; 215 break; 216 } 217 error = hibernation_snapshot(data->platform_support); 218 if (!error) 219 error = put_user(in_suspend, (int __user *)arg); 220 if (!error) 221 data->ready = 1; 222 break; 223 224 case SNAPSHOT_ATOMIC_RESTORE: 225 snapshot_write_finalize(&data->handle); 226 if (data->mode != O_WRONLY || !data->frozen || 227 !snapshot_image_loaded(&data->handle)) { 228 error = -EPERM; 229 break; 230 } 231 error = hibernation_restore(data->platform_support); 232 break; 233 234 case SNAPSHOT_FREE: 235 swsusp_free(); 236 memset(&data->handle, 0, sizeof(struct snapshot_handle)); 237 data->ready = 0; 238 break; 239 240 case SNAPSHOT_PREF_IMAGE_SIZE: 241 case SNAPSHOT_SET_IMAGE_SIZE: 242 image_size = arg; 243 break; 244 245 case SNAPSHOT_GET_IMAGE_SIZE: 246 if (!data->ready) { 247 error = -ENODATA; 248 break; 249 } 250 size = snapshot_get_image_size(); 251 size <<= PAGE_SHIFT; 252 error = put_user(size, (loff_t __user *)arg); 253 break; 254 255 case SNAPSHOT_AVAIL_SWAP_SIZE: 256 case SNAPSHOT_AVAIL_SWAP: 257 size = count_swap_pages(data->swap, 1); 258 size <<= PAGE_SHIFT; 259 error = put_user(size, (loff_t __user *)arg); 260 break; 261 262 case SNAPSHOT_ALLOC_SWAP_PAGE: 263 case SNAPSHOT_GET_SWAP_PAGE: 264 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 265 error = -ENODEV; 266 break; 267 } 268 offset = alloc_swapdev_block(data->swap); 269 if (offset) { 270 offset <<= PAGE_SHIFT; 271 error = put_user(offset, (loff_t __user *)arg); 272 } else { 273 error = -ENOSPC; 274 } 275 break; 276 277 case SNAPSHOT_FREE_SWAP_PAGES: 278 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { 279 error = -ENODEV; 280 break; 281 } 282 free_all_swap_pages(data->swap); 283 break; 284 285 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */ 286 if (!swsusp_swap_in_use()) { 287 /* 288 * User space encodes device types as two-byte values, 289 * so we need to recode them 290 */ 291 if (old_decode_dev(arg)) { 292 data->swap = swap_type_of(old_decode_dev(arg), 293 0, NULL); 294 if (data->swap < 0) 295 error = -ENODEV; 296 } else { 297 data->swap = -1; 298 error = -EINVAL; 299 } 300 } else { 301 error = -EPERM; 302 } 303 break; 304 305 case SNAPSHOT_S2RAM: 306 if (!data->frozen) { 307 error = -EPERM; 308 break; 309 } 310 if (!mutex_trylock(&pm_mutex)) { 311 error = -EBUSY; 312 break; 313 } 314 /* 315 * Tasks are frozen and the notifiers have been called with 316 * PM_HIBERNATION_PREPARE 317 */ 318 error = suspend_devices_and_enter(PM_SUSPEND_MEM); 319 mutex_unlock(&pm_mutex); 320 break; 321 322 case SNAPSHOT_PLATFORM_SUPPORT: 323 data->platform_support = !!arg; 324 break; 325 326 case SNAPSHOT_POWER_OFF: 327 if (data->platform_support) 328 error = hibernation_platform_enter(); 329 break; 330 331 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */ 332 error = -EINVAL; 333 334 switch (arg) { 335 336 case PMOPS_PREPARE: 337 data->platform_support = 1; 338 error = 0; 339 break; 340 341 case PMOPS_ENTER: 342 if (data->platform_support) 343 error = hibernation_platform_enter(); 344 break; 345 346 case PMOPS_FINISH: 347 if (data->platform_support) 348 error = 0; 349 break; 350 351 default: 352 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg); 353 354 } 355 break; 356 357 case SNAPSHOT_SET_SWAP_AREA: 358 if (swsusp_swap_in_use()) { 359 error = -EPERM; 360 } else { 361 struct resume_swap_area swap_area; 362 dev_t swdev; 363 364 error = copy_from_user(&swap_area, (void __user *)arg, 365 sizeof(struct resume_swap_area)); 366 if (error) { 367 error = -EFAULT; 368 break; 369 } 370 371 /* 372 * User space encodes device types as two-byte values, 373 * so we need to recode them 374 */ 375 swdev = old_decode_dev(swap_area.dev); 376 if (swdev) { 377 offset = swap_area.offset; 378 data->swap = swap_type_of(swdev, offset, NULL); 379 if (data->swap < 0) 380 error = -ENODEV; 381 } else { 382 data->swap = -1; 383 error = -EINVAL; 384 } 385 } 386 break; 387 388 default: 389 error = -ENOTTY; 390 391 } 392 393 return error; 394 } 395 396 static const struct file_operations snapshot_fops = { 397 .open = snapshot_open, 398 .release = snapshot_release, 399 .read = snapshot_read, 400 .write = snapshot_write, 401 .llseek = no_llseek, 402 .ioctl = snapshot_ioctl, 403 }; 404 405 static struct miscdevice snapshot_device = { 406 .minor = SNAPSHOT_MINOR, 407 .name = "snapshot", 408 .fops = &snapshot_fops, 409 }; 410 411 static int __init snapshot_device_init(void) 412 { 413 return misc_register(&snapshot_device); 414 }; 415 416 device_initcall(snapshot_device_init); 417