| 1 | /* |
| 2 | * file.c - part of debugfs, a tiny little debug file system |
| 3 | * |
| 4 | * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> |
| 5 | * Copyright (C) 2004 IBM Inc. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License version |
| 9 | * 2 as published by the Free Software Foundation. |
| 10 | * |
| 11 | * debugfs is for people to use instead of /proc or /sys. |
| 12 | * See Documentation/DocBook/filesystems for more details. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/namei.h> |
| 20 | #include <linux/debugfs.h> |
| 21 | |
| 22 | static ssize_t default_read_file(struct file *file, char __user *buf, |
| 23 | size_t count, loff_t *ppos) |
| 24 | { |
| 25 | return 0; |
| 26 | } |
| 27 | |
| 28 | static ssize_t default_write_file(struct file *file, const char __user *buf, |
| 29 | size_t count, loff_t *ppos) |
| 30 | { |
| 31 | return count; |
| 32 | } |
| 33 | |
| 34 | static int default_open(struct inode *inode, struct file *file) |
| 35 | { |
| 36 | if (inode->i_private) |
| 37 | file->private_data = inode->i_private; |
| 38 | |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | const struct file_operations debugfs_file_operations = { |
| 43 | .read = default_read_file, |
| 44 | .write = default_write_file, |
| 45 | .open = default_open, |
| 46 | .llseek = noop_llseek, |
| 47 | }; |
| 48 | |
| 49 | static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd) |
| 50 | { |
| 51 | nd_set_link(nd, dentry->d_inode->i_private); |
| 52 | return NULL; |
| 53 | } |
| 54 | |
| 55 | const struct inode_operations debugfs_link_operations = { |
| 56 | .readlink = generic_readlink, |
| 57 | .follow_link = debugfs_follow_link, |
| 58 | }; |
| 59 | |
| 60 | static int debugfs_u8_set(void *data, u64 val) |
| 61 | { |
| 62 | *(u8 *)data = val; |
| 63 | return 0; |
| 64 | } |
| 65 | static int debugfs_u8_get(void *data, u64 *val) |
| 66 | { |
| 67 | *val = *(u8 *)data; |
| 68 | return 0; |
| 69 | } |
| 70 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); |
| 71 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); |
| 72 | DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); |
| 73 | |
| 74 | /** |
| 75 | * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value |
| 76 | * @name: a pointer to a string containing the name of the file to create. |
| 77 | * @mode: the permission that the file should have |
| 78 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 79 | * directory dentry if set. If this parameter is %NULL, then the |
| 80 | * file will be created in the root of the debugfs filesystem. |
| 81 | * @value: a pointer to the variable that the file should read to and write |
| 82 | * from. |
| 83 | * |
| 84 | * This function creates a file in debugfs with the given name that |
| 85 | * contains the value of the variable @value. If the @mode variable is so |
| 86 | * set, it can be read from, and written to. |
| 87 | * |
| 88 | * This function will return a pointer to a dentry if it succeeds. This |
| 89 | * pointer must be passed to the debugfs_remove() function when the file is |
| 90 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 91 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 92 | * |
| 93 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 94 | * returned. It is not wise to check for this value, but rather, check for |
| 95 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 96 | * code. |
| 97 | */ |
| 98 | struct dentry *debugfs_create_u8(const char *name, mode_t mode, |
| 99 | struct dentry *parent, u8 *value) |
| 100 | { |
| 101 | /* if there are no write bits set, make read only */ |
| 102 | if (!(mode & S_IWUGO)) |
| 103 | return debugfs_create_file(name, mode, parent, value, &fops_u8_ro); |
| 104 | /* if there are no read bits set, make write only */ |
| 105 | if (!(mode & S_IRUGO)) |
| 106 | return debugfs_create_file(name, mode, parent, value, &fops_u8_wo); |
| 107 | |
| 108 | return debugfs_create_file(name, mode, parent, value, &fops_u8); |
| 109 | } |
| 110 | EXPORT_SYMBOL_GPL(debugfs_create_u8); |
| 111 | |
| 112 | static int debugfs_u16_set(void *data, u64 val) |
| 113 | { |
| 114 | *(u16 *)data = val; |
| 115 | return 0; |
| 116 | } |
| 117 | static int debugfs_u16_get(void *data, u64 *val) |
| 118 | { |
| 119 | *val = *(u16 *)data; |
| 120 | return 0; |
| 121 | } |
| 122 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); |
| 123 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); |
| 124 | DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); |
| 125 | |
| 126 | /** |
| 127 | * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value |
| 128 | * @name: a pointer to a string containing the name of the file to create. |
| 129 | * @mode: the permission that the file should have |
| 130 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 131 | * directory dentry if set. If this parameter is %NULL, then the |
| 132 | * file will be created in the root of the debugfs filesystem. |
| 133 | * @value: a pointer to the variable that the file should read to and write |
| 134 | * from. |
| 135 | * |
| 136 | * This function creates a file in debugfs with the given name that |
| 137 | * contains the value of the variable @value. If the @mode variable is so |
| 138 | * set, it can be read from, and written to. |
| 139 | * |
| 140 | * This function will return a pointer to a dentry if it succeeds. This |
| 141 | * pointer must be passed to the debugfs_remove() function when the file is |
| 142 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 143 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 144 | * |
| 145 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 146 | * returned. It is not wise to check for this value, but rather, check for |
| 147 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 148 | * code. |
| 149 | */ |
| 150 | struct dentry *debugfs_create_u16(const char *name, mode_t mode, |
| 151 | struct dentry *parent, u16 *value) |
| 152 | { |
| 153 | /* if there are no write bits set, make read only */ |
| 154 | if (!(mode & S_IWUGO)) |
| 155 | return debugfs_create_file(name, mode, parent, value, &fops_u16_ro); |
| 156 | /* if there are no read bits set, make write only */ |
| 157 | if (!(mode & S_IRUGO)) |
| 158 | return debugfs_create_file(name, mode, parent, value, &fops_u16_wo); |
| 159 | |
| 160 | return debugfs_create_file(name, mode, parent, value, &fops_u16); |
| 161 | } |
| 162 | EXPORT_SYMBOL_GPL(debugfs_create_u16); |
| 163 | |
| 164 | static int debugfs_u32_set(void *data, u64 val) |
| 165 | { |
| 166 | *(u32 *)data = val; |
| 167 | return 0; |
| 168 | } |
| 169 | static int debugfs_u32_get(void *data, u64 *val) |
| 170 | { |
| 171 | *val = *(u32 *)data; |
| 172 | return 0; |
| 173 | } |
| 174 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); |
| 175 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); |
| 176 | DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); |
| 177 | |
| 178 | /** |
| 179 | * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value |
| 180 | * @name: a pointer to a string containing the name of the file to create. |
| 181 | * @mode: the permission that the file should have |
| 182 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 183 | * directory dentry if set. If this parameter is %NULL, then the |
| 184 | * file will be created in the root of the debugfs filesystem. |
| 185 | * @value: a pointer to the variable that the file should read to and write |
| 186 | * from. |
| 187 | * |
| 188 | * This function creates a file in debugfs with the given name that |
| 189 | * contains the value of the variable @value. If the @mode variable is so |
| 190 | * set, it can be read from, and written to. |
| 191 | * |
| 192 | * This function will return a pointer to a dentry if it succeeds. This |
| 193 | * pointer must be passed to the debugfs_remove() function when the file is |
| 194 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 195 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 196 | * |
| 197 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 198 | * returned. It is not wise to check for this value, but rather, check for |
| 199 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 200 | * code. |
| 201 | */ |
| 202 | struct dentry *debugfs_create_u32(const char *name, mode_t mode, |
| 203 | struct dentry *parent, u32 *value) |
| 204 | { |
| 205 | /* if there are no write bits set, make read only */ |
| 206 | if (!(mode & S_IWUGO)) |
| 207 | return debugfs_create_file(name, mode, parent, value, &fops_u32_ro); |
| 208 | /* if there are no read bits set, make write only */ |
| 209 | if (!(mode & S_IRUGO)) |
| 210 | return debugfs_create_file(name, mode, parent, value, &fops_u32_wo); |
| 211 | |
| 212 | return debugfs_create_file(name, mode, parent, value, &fops_u32); |
| 213 | } |
| 214 | EXPORT_SYMBOL_GPL(debugfs_create_u32); |
| 215 | |
| 216 | static int debugfs_u64_set(void *data, u64 val) |
| 217 | { |
| 218 | *(u64 *)data = val; |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | static int debugfs_u64_get(void *data, u64 *val) |
| 223 | { |
| 224 | *val = *(u64 *)data; |
| 225 | return 0; |
| 226 | } |
| 227 | DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); |
| 228 | DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); |
| 229 | DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); |
| 230 | |
| 231 | /** |
| 232 | * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value |
| 233 | * @name: a pointer to a string containing the name of the file to create. |
| 234 | * @mode: the permission that the file should have |
| 235 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 236 | * directory dentry if set. If this parameter is %NULL, then the |
| 237 | * file will be created in the root of the debugfs filesystem. |
| 238 | * @value: a pointer to the variable that the file should read to and write |
| 239 | * from. |
| 240 | * |
| 241 | * This function creates a file in debugfs with the given name that |
| 242 | * contains the value of the variable @value. If the @mode variable is so |
| 243 | * set, it can be read from, and written to. |
| 244 | * |
| 245 | * This function will return a pointer to a dentry if it succeeds. This |
| 246 | * pointer must be passed to the debugfs_remove() function when the file is |
| 247 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 248 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 249 | * |
| 250 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 251 | * returned. It is not wise to check for this value, but rather, check for |
| 252 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 253 | * code. |
| 254 | */ |
| 255 | struct dentry *debugfs_create_u64(const char *name, mode_t mode, |
| 256 | struct dentry *parent, u64 *value) |
| 257 | { |
| 258 | /* if there are no write bits set, make read only */ |
| 259 | if (!(mode & S_IWUGO)) |
| 260 | return debugfs_create_file(name, mode, parent, value, &fops_u64_ro); |
| 261 | /* if there are no read bits set, make write only */ |
| 262 | if (!(mode & S_IRUGO)) |
| 263 | return debugfs_create_file(name, mode, parent, value, &fops_u64_wo); |
| 264 | |
| 265 | return debugfs_create_file(name, mode, parent, value, &fops_u64); |
| 266 | } |
| 267 | EXPORT_SYMBOL_GPL(debugfs_create_u64); |
| 268 | |
| 269 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); |
| 270 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); |
| 271 | DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); |
| 272 | |
| 273 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); |
| 274 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); |
| 275 | DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); |
| 276 | |
| 277 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); |
| 278 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); |
| 279 | DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); |
| 280 | |
| 281 | DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); |
| 282 | |
| 283 | /* |
| 284 | * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value |
| 285 | * |
| 286 | * These functions are exactly the same as the above functions (but use a hex |
| 287 | * output for the decimal challenged). For details look at the above unsigned |
| 288 | * decimal functions. |
| 289 | */ |
| 290 | |
| 291 | /** |
| 292 | * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value |
| 293 | * @name: a pointer to a string containing the name of the file to create. |
| 294 | * @mode: the permission that the file should have |
| 295 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 296 | * directory dentry if set. If this parameter is %NULL, then the |
| 297 | * file will be created in the root of the debugfs filesystem. |
| 298 | * @value: a pointer to the variable that the file should read to and write |
| 299 | * from. |
| 300 | */ |
| 301 | struct dentry *debugfs_create_x8(const char *name, mode_t mode, |
| 302 | struct dentry *parent, u8 *value) |
| 303 | { |
| 304 | /* if there are no write bits set, make read only */ |
| 305 | if (!(mode & S_IWUGO)) |
| 306 | return debugfs_create_file(name, mode, parent, value, &fops_x8_ro); |
| 307 | /* if there are no read bits set, make write only */ |
| 308 | if (!(mode & S_IRUGO)) |
| 309 | return debugfs_create_file(name, mode, parent, value, &fops_x8_wo); |
| 310 | |
| 311 | return debugfs_create_file(name, mode, parent, value, &fops_x8); |
| 312 | } |
| 313 | EXPORT_SYMBOL_GPL(debugfs_create_x8); |
| 314 | |
| 315 | /** |
| 316 | * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value |
| 317 | * @name: a pointer to a string containing the name of the file to create. |
| 318 | * @mode: the permission that the file should have |
| 319 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 320 | * directory dentry if set. If this parameter is %NULL, then the |
| 321 | * file will be created in the root of the debugfs filesystem. |
| 322 | * @value: a pointer to the variable that the file should read to and write |
| 323 | * from. |
| 324 | */ |
| 325 | struct dentry *debugfs_create_x16(const char *name, mode_t mode, |
| 326 | struct dentry *parent, u16 *value) |
| 327 | { |
| 328 | /* if there are no write bits set, make read only */ |
| 329 | if (!(mode & S_IWUGO)) |
| 330 | return debugfs_create_file(name, mode, parent, value, &fops_x16_ro); |
| 331 | /* if there are no read bits set, make write only */ |
| 332 | if (!(mode & S_IRUGO)) |
| 333 | return debugfs_create_file(name, mode, parent, value, &fops_x16_wo); |
| 334 | |
| 335 | return debugfs_create_file(name, mode, parent, value, &fops_x16); |
| 336 | } |
| 337 | EXPORT_SYMBOL_GPL(debugfs_create_x16); |
| 338 | |
| 339 | /** |
| 340 | * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value |
| 341 | * @name: a pointer to a string containing the name of the file to create. |
| 342 | * @mode: the permission that the file should have |
| 343 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 344 | * directory dentry if set. If this parameter is %NULL, then the |
| 345 | * file will be created in the root of the debugfs filesystem. |
| 346 | * @value: a pointer to the variable that the file should read to and write |
| 347 | * from. |
| 348 | */ |
| 349 | struct dentry *debugfs_create_x32(const char *name, mode_t mode, |
| 350 | struct dentry *parent, u32 *value) |
| 351 | { |
| 352 | /* if there are no write bits set, make read only */ |
| 353 | if (!(mode & S_IWUGO)) |
| 354 | return debugfs_create_file(name, mode, parent, value, &fops_x32_ro); |
| 355 | /* if there are no read bits set, make write only */ |
| 356 | if (!(mode & S_IRUGO)) |
| 357 | return debugfs_create_file(name, mode, parent, value, &fops_x32_wo); |
| 358 | |
| 359 | return debugfs_create_file(name, mode, parent, value, &fops_x32); |
| 360 | } |
| 361 | EXPORT_SYMBOL_GPL(debugfs_create_x32); |
| 362 | |
| 363 | /** |
| 364 | * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value |
| 365 | * @name: a pointer to a string containing the name of the file to create. |
| 366 | * @mode: the permission that the file should have |
| 367 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 368 | * directory dentry if set. If this parameter is %NULL, then the |
| 369 | * file will be created in the root of the debugfs filesystem. |
| 370 | * @value: a pointer to the variable that the file should read to and write |
| 371 | * from. |
| 372 | */ |
| 373 | struct dentry *debugfs_create_x64(const char *name, mode_t mode, |
| 374 | struct dentry *parent, u64 *value) |
| 375 | { |
| 376 | return debugfs_create_file(name, mode, parent, value, &fops_x64); |
| 377 | } |
| 378 | EXPORT_SYMBOL_GPL(debugfs_create_x64); |
| 379 | |
| 380 | |
| 381 | static int debugfs_size_t_set(void *data, u64 val) |
| 382 | { |
| 383 | *(size_t *)data = val; |
| 384 | return 0; |
| 385 | } |
| 386 | static int debugfs_size_t_get(void *data, u64 *val) |
| 387 | { |
| 388 | *val = *(size_t *)data; |
| 389 | return 0; |
| 390 | } |
| 391 | DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, |
| 392 | "%llu\n"); /* %llu and %zu are more or less the same */ |
| 393 | |
| 394 | /** |
| 395 | * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value |
| 396 | * @name: a pointer to a string containing the name of the file to create. |
| 397 | * @mode: the permission that the file should have |
| 398 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 399 | * directory dentry if set. If this parameter is %NULL, then the |
| 400 | * file will be created in the root of the debugfs filesystem. |
| 401 | * @value: a pointer to the variable that the file should read to and write |
| 402 | * from. |
| 403 | */ |
| 404 | struct dentry *debugfs_create_size_t(const char *name, mode_t mode, |
| 405 | struct dentry *parent, size_t *value) |
| 406 | { |
| 407 | return debugfs_create_file(name, mode, parent, value, &fops_size_t); |
| 408 | } |
| 409 | EXPORT_SYMBOL_GPL(debugfs_create_size_t); |
| 410 | |
| 411 | |
| 412 | static ssize_t read_file_bool(struct file *file, char __user *user_buf, |
| 413 | size_t count, loff_t *ppos) |
| 414 | { |
| 415 | char buf[3]; |
| 416 | u32 *val = file->private_data; |
| 417 | |
| 418 | if (*val) |
| 419 | buf[0] = 'Y'; |
| 420 | else |
| 421 | buf[0] = 'N'; |
| 422 | buf[1] = '\n'; |
| 423 | buf[2] = 0x00; |
| 424 | return simple_read_from_buffer(user_buf, count, ppos, buf, 2); |
| 425 | } |
| 426 | |
| 427 | static ssize_t write_file_bool(struct file *file, const char __user *user_buf, |
| 428 | size_t count, loff_t *ppos) |
| 429 | { |
| 430 | char buf[32]; |
| 431 | int buf_size; |
| 432 | u32 *val = file->private_data; |
| 433 | |
| 434 | buf_size = min(count, (sizeof(buf)-1)); |
| 435 | if (copy_from_user(buf, user_buf, buf_size)) |
| 436 | return -EFAULT; |
| 437 | |
| 438 | switch (buf[0]) { |
| 439 | case 'y': |
| 440 | case 'Y': |
| 441 | case '1': |
| 442 | *val = 1; |
| 443 | break; |
| 444 | case 'n': |
| 445 | case 'N': |
| 446 | case '0': |
| 447 | *val = 0; |
| 448 | break; |
| 449 | } |
| 450 | |
| 451 | return count; |
| 452 | } |
| 453 | |
| 454 | static const struct file_operations fops_bool = { |
| 455 | .read = read_file_bool, |
| 456 | .write = write_file_bool, |
| 457 | .open = default_open, |
| 458 | .llseek = default_llseek, |
| 459 | }; |
| 460 | |
| 461 | /** |
| 462 | * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value |
| 463 | * @name: a pointer to a string containing the name of the file to create. |
| 464 | * @mode: the permission that the file should have |
| 465 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 466 | * directory dentry if set. If this parameter is %NULL, then the |
| 467 | * file will be created in the root of the debugfs filesystem. |
| 468 | * @value: a pointer to the variable that the file should read to and write |
| 469 | * from. |
| 470 | * |
| 471 | * This function creates a file in debugfs with the given name that |
| 472 | * contains the value of the variable @value. If the @mode variable is so |
| 473 | * set, it can be read from, and written to. |
| 474 | * |
| 475 | * This function will return a pointer to a dentry if it succeeds. This |
| 476 | * pointer must be passed to the debugfs_remove() function when the file is |
| 477 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 478 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 479 | * |
| 480 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 481 | * returned. It is not wise to check for this value, but rather, check for |
| 482 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 483 | * code. |
| 484 | */ |
| 485 | struct dentry *debugfs_create_bool(const char *name, mode_t mode, |
| 486 | struct dentry *parent, u32 *value) |
| 487 | { |
| 488 | return debugfs_create_file(name, mode, parent, value, &fops_bool); |
| 489 | } |
| 490 | EXPORT_SYMBOL_GPL(debugfs_create_bool); |
| 491 | |
| 492 | static ssize_t read_file_blob(struct file *file, char __user *user_buf, |
| 493 | size_t count, loff_t *ppos) |
| 494 | { |
| 495 | struct debugfs_blob_wrapper *blob = file->private_data; |
| 496 | return simple_read_from_buffer(user_buf, count, ppos, blob->data, |
| 497 | blob->size); |
| 498 | } |
| 499 | |
| 500 | static const struct file_operations fops_blob = { |
| 501 | .read = read_file_blob, |
| 502 | .open = default_open, |
| 503 | .llseek = default_llseek, |
| 504 | }; |
| 505 | |
| 506 | /** |
| 507 | * debugfs_create_blob - create a debugfs file that is used to read a binary blob |
| 508 | * @name: a pointer to a string containing the name of the file to create. |
| 509 | * @mode: the permission that the file should have |
| 510 | * @parent: a pointer to the parent dentry for this file. This should be a |
| 511 | * directory dentry if set. If this parameter is %NULL, then the |
| 512 | * file will be created in the root of the debugfs filesystem. |
| 513 | * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer |
| 514 | * to the blob data and the size of the data. |
| 515 | * |
| 516 | * This function creates a file in debugfs with the given name that exports |
| 517 | * @blob->data as a binary blob. If the @mode variable is so set it can be |
| 518 | * read from. Writing is not supported. |
| 519 | * |
| 520 | * This function will return a pointer to a dentry if it succeeds. This |
| 521 | * pointer must be passed to the debugfs_remove() function when the file is |
| 522 | * to be removed (no automatic cleanup happens if your module is unloaded, |
| 523 | * you are responsible here.) If an error occurs, %NULL will be returned. |
| 524 | * |
| 525 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
| 526 | * returned. It is not wise to check for this value, but rather, check for |
| 527 | * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling |
| 528 | * code. |
| 529 | */ |
| 530 | struct dentry *debugfs_create_blob(const char *name, mode_t mode, |
| 531 | struct dentry *parent, |
| 532 | struct debugfs_blob_wrapper *blob) |
| 533 | { |
| 534 | return debugfs_create_file(name, mode, parent, blob, &fops_blob); |
| 535 | } |
| 536 | EXPORT_SYMBOL_GPL(debugfs_create_blob); |