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/seq_file.h> 19 #include <linux/pagemap.h> 20 #include <linux/namei.h> 21 #include <linux/debugfs.h> 22 #include <linux/io.h> 23 #include <linux/slab.h> 24 #include <linux/atomic.h> 25 26 static ssize_t default_read_file(struct file *file, char __user *buf, 27 size_t count, loff_t *ppos) 28 { 29 return 0; 30 } 31 32 static ssize_t default_write_file(struct file *file, const char __user *buf, 33 size_t count, loff_t *ppos) 34 { 35 return count; 36 } 37 38 const struct file_operations debugfs_file_operations = { 39 .read = default_read_file, 40 .write = default_write_file, 41 .open = simple_open, 42 .llseek = noop_llseek, 43 }; 44 45 static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd) 46 { 47 nd_set_link(nd, dentry->d_inode->i_private); 48 return NULL; 49 } 50 51 const struct inode_operations debugfs_link_operations = { 52 .readlink = generic_readlink, 53 .follow_link = debugfs_follow_link, 54 }; 55 56 static int debugfs_u8_set(void *data, u64 val) 57 { 58 *(u8 *)data = val; 59 return 0; 60 } 61 static int debugfs_u8_get(void *data, u64 *val) 62 { 63 *val = *(u8 *)data; 64 return 0; 65 } 66 DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); 67 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); 68 DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); 69 70 /** 71 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value 72 * @name: a pointer to a string containing the name of the file to create. 73 * @mode: the permission that the file should have 74 * @parent: a pointer to the parent dentry for this file. This should be a 75 * directory dentry if set. If this parameter is %NULL, then the 76 * file will be created in the root of the debugfs filesystem. 77 * @value: a pointer to the variable that the file should read to and write 78 * from. 79 * 80 * This function creates a file in debugfs with the given name that 81 * contains the value of the variable @value. If the @mode variable is so 82 * set, it can be read from, and written to. 83 * 84 * This function will return a pointer to a dentry if it succeeds. This 85 * pointer must be passed to the debugfs_remove() function when the file is 86 * to be removed (no automatic cleanup happens if your module is unloaded, 87 * you are responsible here.) If an error occurs, %NULL will be returned. 88 * 89 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 90 * returned. It is not wise to check for this value, but rather, check for 91 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 92 * code. 93 */ 94 struct dentry *debugfs_create_u8(const char *name, umode_t mode, 95 struct dentry *parent, u8 *value) 96 { 97 /* if there are no write bits set, make read only */ 98 if (!(mode & S_IWUGO)) 99 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro); 100 /* if there are no read bits set, make write only */ 101 if (!(mode & S_IRUGO)) 102 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo); 103 104 return debugfs_create_file(name, mode, parent, value, &fops_u8); 105 } 106 EXPORT_SYMBOL_GPL(debugfs_create_u8); 107 108 static int debugfs_u16_set(void *data, u64 val) 109 { 110 *(u16 *)data = val; 111 return 0; 112 } 113 static int debugfs_u16_get(void *data, u64 *val) 114 { 115 *val = *(u16 *)data; 116 return 0; 117 } 118 DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); 119 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); 120 DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); 121 122 /** 123 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value 124 * @name: a pointer to a string containing the name of the file to create. 125 * @mode: the permission that the file should have 126 * @parent: a pointer to the parent dentry for this file. This should be a 127 * directory dentry if set. If this parameter is %NULL, then the 128 * file will be created in the root of the debugfs filesystem. 129 * @value: a pointer to the variable that the file should read to and write 130 * from. 131 * 132 * This function creates a file in debugfs with the given name that 133 * contains the value of the variable @value. If the @mode variable is so 134 * set, it can be read from, and written to. 135 * 136 * This function will return a pointer to a dentry if it succeeds. This 137 * pointer must be passed to the debugfs_remove() function when the file is 138 * to be removed (no automatic cleanup happens if your module is unloaded, 139 * you are responsible here.) If an error occurs, %NULL will be returned. 140 * 141 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 142 * returned. It is not wise to check for this value, but rather, check for 143 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 144 * code. 145 */ 146 struct dentry *debugfs_create_u16(const char *name, umode_t mode, 147 struct dentry *parent, u16 *value) 148 { 149 /* if there are no write bits set, make read only */ 150 if (!(mode & S_IWUGO)) 151 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro); 152 /* if there are no read bits set, make write only */ 153 if (!(mode & S_IRUGO)) 154 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo); 155 156 return debugfs_create_file(name, mode, parent, value, &fops_u16); 157 } 158 EXPORT_SYMBOL_GPL(debugfs_create_u16); 159 160 static int debugfs_u32_set(void *data, u64 val) 161 { 162 *(u32 *)data = val; 163 return 0; 164 } 165 static int debugfs_u32_get(void *data, u64 *val) 166 { 167 *val = *(u32 *)data; 168 return 0; 169 } 170 DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); 171 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); 172 DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); 173 174 /** 175 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value 176 * @name: a pointer to a string containing the name of the file to create. 177 * @mode: the permission that the file should have 178 * @parent: a pointer to the parent dentry for this file. This should be a 179 * directory dentry if set. If this parameter is %NULL, then the 180 * file will be created in the root of the debugfs filesystem. 181 * @value: a pointer to the variable that the file should read to and write 182 * from. 183 * 184 * This function creates a file in debugfs with the given name that 185 * contains the value of the variable @value. If the @mode variable is so 186 * set, it can be read from, and written to. 187 * 188 * This function will return a pointer to a dentry if it succeeds. This 189 * pointer must be passed to the debugfs_remove() function when the file is 190 * to be removed (no automatic cleanup happens if your module is unloaded, 191 * you are responsible here.) If an error occurs, %NULL will be returned. 192 * 193 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 194 * returned. It is not wise to check for this value, but rather, check for 195 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 196 * code. 197 */ 198 struct dentry *debugfs_create_u32(const char *name, umode_t mode, 199 struct dentry *parent, u32 *value) 200 { 201 /* if there are no write bits set, make read only */ 202 if (!(mode & S_IWUGO)) 203 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro); 204 /* if there are no read bits set, make write only */ 205 if (!(mode & S_IRUGO)) 206 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo); 207 208 return debugfs_create_file(name, mode, parent, value, &fops_u32); 209 } 210 EXPORT_SYMBOL_GPL(debugfs_create_u32); 211 212 static int debugfs_u64_set(void *data, u64 val) 213 { 214 *(u64 *)data = val; 215 return 0; 216 } 217 218 static int debugfs_u64_get(void *data, u64 *val) 219 { 220 *val = *(u64 *)data; 221 return 0; 222 } 223 DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); 224 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); 225 DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); 226 227 /** 228 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value 229 * @name: a pointer to a string containing the name of the file to create. 230 * @mode: the permission that the file should have 231 * @parent: a pointer to the parent dentry for this file. This should be a 232 * directory dentry if set. If this parameter is %NULL, then the 233 * file will be created in the root of the debugfs filesystem. 234 * @value: a pointer to the variable that the file should read to and write 235 * from. 236 * 237 * This function creates a file in debugfs with the given name that 238 * contains the value of the variable @value. If the @mode variable is so 239 * set, it can be read from, and written to. 240 * 241 * This function will return a pointer to a dentry if it succeeds. This 242 * pointer must be passed to the debugfs_remove() function when the file is 243 * to be removed (no automatic cleanup happens if your module is unloaded, 244 * you are responsible here.) If an error occurs, %NULL will be returned. 245 * 246 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 247 * returned. It is not wise to check for this value, but rather, check for 248 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 249 * code. 250 */ 251 struct dentry *debugfs_create_u64(const char *name, umode_t mode, 252 struct dentry *parent, u64 *value) 253 { 254 /* if there are no write bits set, make read only */ 255 if (!(mode & S_IWUGO)) 256 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro); 257 /* if there are no read bits set, make write only */ 258 if (!(mode & S_IRUGO)) 259 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo); 260 261 return debugfs_create_file(name, mode, parent, value, &fops_u64); 262 } 263 EXPORT_SYMBOL_GPL(debugfs_create_u64); 264 265 DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); 266 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); 267 DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); 268 269 DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); 270 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); 271 DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); 272 273 DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); 274 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); 275 DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); 276 277 DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); 278 279 /* 280 * 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 281 * 282 * These functions are exactly the same as the above functions (but use a hex 283 * output for the decimal challenged). For details look at the above unsigned 284 * decimal functions. 285 */ 286 287 /** 288 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value 289 * @name: a pointer to a string containing the name of the file to create. 290 * @mode: the permission that the file should have 291 * @parent: a pointer to the parent dentry for this file. This should be a 292 * directory dentry if set. If this parameter is %NULL, then the 293 * file will be created in the root of the debugfs filesystem. 294 * @value: a pointer to the variable that the file should read to and write 295 * from. 296 */ 297 struct dentry *debugfs_create_x8(const char *name, umode_t mode, 298 struct dentry *parent, u8 *value) 299 { 300 /* if there are no write bits set, make read only */ 301 if (!(mode & S_IWUGO)) 302 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro); 303 /* if there are no read bits set, make write only */ 304 if (!(mode & S_IRUGO)) 305 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo); 306 307 return debugfs_create_file(name, mode, parent, value, &fops_x8); 308 } 309 EXPORT_SYMBOL_GPL(debugfs_create_x8); 310 311 /** 312 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value 313 * @name: a pointer to a string containing the name of the file to create. 314 * @mode: the permission that the file should have 315 * @parent: a pointer to the parent dentry for this file. This should be a 316 * directory dentry if set. If this parameter is %NULL, then the 317 * file will be created in the root of the debugfs filesystem. 318 * @value: a pointer to the variable that the file should read to and write 319 * from. 320 */ 321 struct dentry *debugfs_create_x16(const char *name, umode_t mode, 322 struct dentry *parent, u16 *value) 323 { 324 /* if there are no write bits set, make read only */ 325 if (!(mode & S_IWUGO)) 326 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro); 327 /* if there are no read bits set, make write only */ 328 if (!(mode & S_IRUGO)) 329 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo); 330 331 return debugfs_create_file(name, mode, parent, value, &fops_x16); 332 } 333 EXPORT_SYMBOL_GPL(debugfs_create_x16); 334 335 /** 336 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value 337 * @name: a pointer to a string containing the name of the file to create. 338 * @mode: the permission that the file should have 339 * @parent: a pointer to the parent dentry for this file. This should be a 340 * directory dentry if set. If this parameter is %NULL, then the 341 * file will be created in the root of the debugfs filesystem. 342 * @value: a pointer to the variable that the file should read to and write 343 * from. 344 */ 345 struct dentry *debugfs_create_x32(const char *name, umode_t mode, 346 struct dentry *parent, u32 *value) 347 { 348 /* if there are no write bits set, make read only */ 349 if (!(mode & S_IWUGO)) 350 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro); 351 /* if there are no read bits set, make write only */ 352 if (!(mode & S_IRUGO)) 353 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo); 354 355 return debugfs_create_file(name, mode, parent, value, &fops_x32); 356 } 357 EXPORT_SYMBOL_GPL(debugfs_create_x32); 358 359 /** 360 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value 361 * @name: a pointer to a string containing the name of the file to create. 362 * @mode: the permission that the file should have 363 * @parent: a pointer to the parent dentry for this file. This should be a 364 * directory dentry if set. If this parameter is %NULL, then the 365 * file will be created in the root of the debugfs filesystem. 366 * @value: a pointer to the variable that the file should read to and write 367 * from. 368 */ 369 struct dentry *debugfs_create_x64(const char *name, umode_t mode, 370 struct dentry *parent, u64 *value) 371 { 372 return debugfs_create_file(name, mode, parent, value, &fops_x64); 373 } 374 EXPORT_SYMBOL_GPL(debugfs_create_x64); 375 376 377 static int debugfs_size_t_set(void *data, u64 val) 378 { 379 *(size_t *)data = val; 380 return 0; 381 } 382 static int debugfs_size_t_get(void *data, u64 *val) 383 { 384 *val = *(size_t *)data; 385 return 0; 386 } 387 DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, 388 "%llu\n"); /* %llu and %zu are more or less the same */ 389 390 /** 391 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value 392 * @name: a pointer to a string containing the name of the file to create. 393 * @mode: the permission that the file should have 394 * @parent: a pointer to the parent dentry for this file. This should be a 395 * directory dentry if set. If this parameter is %NULL, then the 396 * file will be created in the root of the debugfs filesystem. 397 * @value: a pointer to the variable that the file should read to and write 398 * from. 399 */ 400 struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 401 struct dentry *parent, size_t *value) 402 { 403 return debugfs_create_file(name, mode, parent, value, &fops_size_t); 404 } 405 EXPORT_SYMBOL_GPL(debugfs_create_size_t); 406 407 static int debugfs_atomic_t_set(void *data, u64 val) 408 { 409 atomic_set((atomic_t *)data, val); 410 return 0; 411 } 412 static int debugfs_atomic_t_get(void *data, u64 *val) 413 { 414 *val = atomic_read((atomic_t *)data); 415 return 0; 416 } 417 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, 418 debugfs_atomic_t_set, "%lld\n"); 419 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n"); 420 DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); 421 422 /** 423 * debugfs_create_atomic_t - create a debugfs file that is used to read and 424 * write an atomic_t value 425 * @name: a pointer to a string containing the name of the file to create. 426 * @mode: the permission that the file should have 427 * @parent: a pointer to the parent dentry for this file. This should be a 428 * directory dentry if set. If this parameter is %NULL, then the 429 * file will be created in the root of the debugfs filesystem. 430 * @value: a pointer to the variable that the file should read to and write 431 * from. 432 */ 433 struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 434 struct dentry *parent, atomic_t *value) 435 { 436 /* if there are no write bits set, make read only */ 437 if (!(mode & S_IWUGO)) 438 return debugfs_create_file(name, mode, parent, value, 439 &fops_atomic_t_ro); 440 /* if there are no read bits set, make write only */ 441 if (!(mode & S_IRUGO)) 442 return debugfs_create_file(name, mode, parent, value, 443 &fops_atomic_t_wo); 444 445 return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); 446 } 447 EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); 448 449 static ssize_t read_file_bool(struct file *file, char __user *user_buf, 450 size_t count, loff_t *ppos) 451 { 452 char buf[3]; 453 u32 *val = file->private_data; 454 455 if (*val) 456 buf[0] = 'Y'; 457 else 458 buf[0] = 'N'; 459 buf[1] = '\n'; 460 buf[2] = 0x00; 461 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 462 } 463 464 static ssize_t write_file_bool(struct file *file, const char __user *user_buf, 465 size_t count, loff_t *ppos) 466 { 467 char buf[32]; 468 size_t buf_size; 469 bool bv; 470 u32 *val = file->private_data; 471 472 buf_size = min(count, (sizeof(buf)-1)); 473 if (copy_from_user(buf, user_buf, buf_size)) 474 return -EFAULT; 475 476 buf[buf_size] = '\0'; 477 if (strtobool(buf, &bv) == 0) 478 *val = bv; 479 480 return count; 481 } 482 483 static const struct file_operations fops_bool = { 484 .read = read_file_bool, 485 .write = write_file_bool, 486 .open = simple_open, 487 .llseek = default_llseek, 488 }; 489 490 /** 491 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value 492 * @name: a pointer to a string containing the name of the file to create. 493 * @mode: the permission that the file should have 494 * @parent: a pointer to the parent dentry for this file. This should be a 495 * directory dentry if set. If this parameter is %NULL, then the 496 * file will be created in the root of the debugfs filesystem. 497 * @value: a pointer to the variable that the file should read to and write 498 * from. 499 * 500 * This function creates a file in debugfs with the given name that 501 * contains the value of the variable @value. If the @mode variable is so 502 * set, it can be read from, and written to. 503 * 504 * This function will return a pointer to a dentry if it succeeds. This 505 * pointer must be passed to the debugfs_remove() function when the file is 506 * to be removed (no automatic cleanup happens if your module is unloaded, 507 * you are responsible here.) If an error occurs, %NULL will be returned. 508 * 509 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 510 * returned. It is not wise to check for this value, but rather, check for 511 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 512 * code. 513 */ 514 struct dentry *debugfs_create_bool(const char *name, umode_t mode, 515 struct dentry *parent, u32 *value) 516 { 517 return debugfs_create_file(name, mode, parent, value, &fops_bool); 518 } 519 EXPORT_SYMBOL_GPL(debugfs_create_bool); 520 521 static ssize_t read_file_blob(struct file *file, char __user *user_buf, 522 size_t count, loff_t *ppos) 523 { 524 struct debugfs_blob_wrapper *blob = file->private_data; 525 return simple_read_from_buffer(user_buf, count, ppos, blob->data, 526 blob->size); 527 } 528 529 static const struct file_operations fops_blob = { 530 .read = read_file_blob, 531 .open = simple_open, 532 .llseek = default_llseek, 533 }; 534 535 /** 536 * debugfs_create_blob - create a debugfs file that is used to read a binary blob 537 * @name: a pointer to a string containing the name of the file to create. 538 * @mode: the permission that the file should have 539 * @parent: a pointer to the parent dentry for this file. This should be a 540 * directory dentry if set. If this parameter is %NULL, then the 541 * file will be created in the root of the debugfs filesystem. 542 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer 543 * to the blob data and the size of the data. 544 * 545 * This function creates a file in debugfs with the given name that exports 546 * @blob->data as a binary blob. If the @mode variable is so set it can be 547 * read from. Writing is not supported. 548 * 549 * This function will return a pointer to a dentry if it succeeds. This 550 * pointer must be passed to the debugfs_remove() function when the file is 551 * to be removed (no automatic cleanup happens if your module is unloaded, 552 * you are responsible here.) If an error occurs, %NULL will be returned. 553 * 554 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 555 * returned. It is not wise to check for this value, but rather, check for 556 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 557 * code. 558 */ 559 struct dentry *debugfs_create_blob(const char *name, umode_t mode, 560 struct dentry *parent, 561 struct debugfs_blob_wrapper *blob) 562 { 563 return debugfs_create_file(name, mode, parent, blob, &fops_blob); 564 } 565 EXPORT_SYMBOL_GPL(debugfs_create_blob); 566 567 struct array_data { 568 void *array; 569 u32 elements; 570 }; 571 572 static size_t u32_format_array(char *buf, size_t bufsize, 573 u32 *array, int array_size) 574 { 575 size_t ret = 0; 576 577 while (--array_size >= 0) { 578 size_t len; 579 char term = array_size ? ' ' : '\n'; 580 581 len = snprintf(buf, bufsize, "%u%c", *array++, term); 582 ret += len; 583 584 buf += len; 585 bufsize -= len; 586 } 587 return ret; 588 } 589 590 static int u32_array_open(struct inode *inode, struct file *file) 591 { 592 struct array_data *data = inode->i_private; 593 int size, elements = data->elements; 594 char *buf; 595 596 /* 597 * Max size: 598 * - 10 digits + ' '/'\n' = 11 bytes per number 599 * - terminating NUL character 600 */ 601 size = elements*11; 602 buf = kmalloc(size+1, GFP_KERNEL); 603 if (!buf) 604 return -ENOMEM; 605 buf[size] = 0; 606 607 file->private_data = buf; 608 u32_format_array(buf, size, data->array, data->elements); 609 610 return nonseekable_open(inode, file); 611 } 612 613 static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, 614 loff_t *ppos) 615 { 616 size_t size = strlen(file->private_data); 617 618 return simple_read_from_buffer(buf, len, ppos, 619 file->private_data, size); 620 } 621 622 static int u32_array_release(struct inode *inode, struct file *file) 623 { 624 kfree(file->private_data); 625 626 return 0; 627 } 628 629 static const struct file_operations u32_array_fops = { 630 .owner = THIS_MODULE, 631 .open = u32_array_open, 632 .release = u32_array_release, 633 .read = u32_array_read, 634 .llseek = no_llseek, 635 }; 636 637 /** 638 * debugfs_create_u32_array - create a debugfs file that is used to read u32 639 * array. 640 * @name: a pointer to a string containing the name of the file to create. 641 * @mode: the permission that the file should have. 642 * @parent: a pointer to the parent dentry for this file. This should be a 643 * directory dentry if set. If this parameter is %NULL, then the 644 * file will be created in the root of the debugfs filesystem. 645 * @array: u32 array that provides data. 646 * @elements: total number of elements in the array. 647 * 648 * This function creates a file in debugfs with the given name that exports 649 * @array as data. If the @mode variable is so set it can be read from. 650 * Writing is not supported. Seek within the file is also not supported. 651 * Once array is created its size can not be changed. 652 * 653 * The function returns a pointer to dentry on success. If debugfs is not 654 * enabled in the kernel, the value -%ENODEV will be returned. 655 */ 656 struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 657 struct dentry *parent, 658 u32 *array, u32 elements) 659 { 660 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL); 661 662 if (data == NULL) 663 return NULL; 664 665 data->array = array; 666 data->elements = elements; 667 668 return debugfs_create_file(name, mode, parent, data, &u32_array_fops); 669 } 670 EXPORT_SYMBOL_GPL(debugfs_create_u32_array); 671 672 #ifdef CONFIG_HAS_IOMEM 673 674 /* 675 * The regset32 stuff is used to print 32-bit registers using the 676 * seq_file utilities. We offer printing a register set in an already-opened 677 * sequential file or create a debugfs file that only prints a regset32. 678 */ 679 680 /** 681 * debugfs_print_regs32 - use seq_print to describe a set of registers 682 * @s: the seq_file structure being used to generate output 683 * @regs: an array if struct debugfs_reg32 structures 684 * @nregs: the length of the above array 685 * @base: the base address to be used in reading the registers 686 * @prefix: a string to be prefixed to every output line 687 * 688 * This function outputs a text block describing the current values of 689 * some 32-bit hardware registers. It is meant to be used within debugfs 690 * files based on seq_file that need to show registers, intermixed with other 691 * information. The prefix argument may be used to specify a leading string, 692 * because some peripherals have several blocks of identical registers, 693 * for example configuration of dma channels 694 */ 695 int debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 696 int nregs, void __iomem *base, char *prefix) 697 { 698 int i, ret = 0; 699 700 for (i = 0; i < nregs; i++, regs++) { 701 if (prefix) 702 ret += seq_printf(s, "%s", prefix); 703 ret += seq_printf(s, "%s = 0x%08x\n", regs->name, 704 readl(base + regs->offset)); 705 } 706 return ret; 707 } 708 EXPORT_SYMBOL_GPL(debugfs_print_regs32); 709 710 static int debugfs_show_regset32(struct seq_file *s, void *data) 711 { 712 struct debugfs_regset32 *regset = s->private; 713 714 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, ""); 715 return 0; 716 } 717 718 static int debugfs_open_regset32(struct inode *inode, struct file *file) 719 { 720 return single_open(file, debugfs_show_regset32, inode->i_private); 721 } 722 723 static const struct file_operations fops_regset32 = { 724 .open = debugfs_open_regset32, 725 .read = seq_read, 726 .llseek = seq_lseek, 727 .release = single_release, 728 }; 729 730 /** 731 * debugfs_create_regset32 - create a debugfs file that returns register values 732 * @name: a pointer to a string containing the name of the file to create. 733 * @mode: the permission that the file should have 734 * @parent: a pointer to the parent dentry for this file. This should be a 735 * directory dentry if set. If this parameter is %NULL, then the 736 * file will be created in the root of the debugfs filesystem. 737 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer 738 * to an array of register definitions, the array size and the base 739 * address where the register bank is to be found. 740 * 741 * This function creates a file in debugfs with the given name that reports 742 * the names and values of a set of 32-bit registers. If the @mode variable 743 * is so set it can be read from. Writing is not supported. 744 * 745 * This function will return a pointer to a dentry if it succeeds. This 746 * pointer must be passed to the debugfs_remove() function when the file is 747 * to be removed (no automatic cleanup happens if your module is unloaded, 748 * you are responsible here.) If an error occurs, %NULL will be returned. 749 * 750 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 751 * returned. It is not wise to check for this value, but rather, check for 752 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 753 * code. 754 */ 755 struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 756 struct dentry *parent, 757 struct debugfs_regset32 *regset) 758 { 759 return debugfs_create_file(name, mode, parent, regset, &fops_regset32); 760 } 761 EXPORT_SYMBOL_GPL(debugfs_create_regset32); 762 763 #endif /* CONFIG_HAS_IOMEM */ 764