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#include <linux/device.h> 26 27static ssize_t default_read_file(struct file *file, char __user *buf, 28 size_t count, loff_t *ppos) 29{ 30 return 0; 31} 32 33static ssize_t default_write_file(struct file *file, const char __user *buf, 34 size_t count, loff_t *ppos) 35{ 36 return count; 37} 38 39const struct file_operations debugfs_file_operations = { 40 .read = default_read_file, 41 .write = default_write_file, 42 .open = simple_open, 43 .llseek = noop_llseek, 44}; 45 46static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd) 47{ 48 nd_set_link(nd, d_inode(dentry)->i_private); 49 return NULL; 50} 51 52const struct inode_operations debugfs_link_operations = { 53 .readlink = generic_readlink, 54 .follow_link = debugfs_follow_link, 55}; 56 57static int debugfs_u8_set(void *data, u64 val) 58{ 59 *(u8 *)data = val; 60 return 0; 61} 62static int debugfs_u8_get(void *data, u64 *val) 63{ 64 *val = *(u8 *)data; 65 return 0; 66} 67DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n"); 68DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n"); 69DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n"); 70 71/** 72 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value 73 * @name: a pointer to a string containing the name of the file to create. 74 * @mode: the permission that the file should have 75 * @parent: a pointer to the parent dentry for this file. This should be a 76 * directory dentry if set. If this parameter is %NULL, then the 77 * file will be created in the root of the debugfs filesystem. 78 * @value: a pointer to the variable that the file should read to and write 79 * from. 80 * 81 * This function creates a file in debugfs with the given name that 82 * contains the value of the variable @value. If the @mode variable is so 83 * set, it can be read from, and written to. 84 * 85 * This function will return a pointer to a dentry if it succeeds. This 86 * pointer must be passed to the debugfs_remove() function when the file is 87 * to be removed (no automatic cleanup happens if your module is unloaded, 88 * you are responsible here.) If an error occurs, %NULL will be returned. 89 * 90 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 91 * returned. It is not wise to check for this value, but rather, check for 92 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 93 * code. 94 */ 95struct dentry *debugfs_create_u8(const char *name, umode_t mode, 96 struct dentry *parent, u8 *value) 97{ 98 /* if there are no write bits set, make read only */ 99 if (!(mode & S_IWUGO)) 100 return debugfs_create_file(name, mode, parent, value, &fops_u8_ro); 101 /* if there are no read bits set, make write only */ 102 if (!(mode & S_IRUGO)) 103 return debugfs_create_file(name, mode, parent, value, &fops_u8_wo); 104 105 return debugfs_create_file(name, mode, parent, value, &fops_u8); 106} 107EXPORT_SYMBOL_GPL(debugfs_create_u8); 108 109static int debugfs_u16_set(void *data, u64 val) 110{ 111 *(u16 *)data = val; 112 return 0; 113} 114static int debugfs_u16_get(void *data, u64 *val) 115{ 116 *val = *(u16 *)data; 117 return 0; 118} 119DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n"); 120DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n"); 121DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n"); 122 123/** 124 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value 125 * @name: a pointer to a string containing the name of the file to create. 126 * @mode: the permission that the file should have 127 * @parent: a pointer to the parent dentry for this file. This should be a 128 * directory dentry if set. If this parameter is %NULL, then the 129 * file will be created in the root of the debugfs filesystem. 130 * @value: a pointer to the variable that the file should read to and write 131 * from. 132 * 133 * This function creates a file in debugfs with the given name that 134 * contains the value of the variable @value. If the @mode variable is so 135 * set, it can be read from, and written to. 136 * 137 * This function will return a pointer to a dentry if it succeeds. This 138 * pointer must be passed to the debugfs_remove() function when the file is 139 * to be removed (no automatic cleanup happens if your module is unloaded, 140 * you are responsible here.) If an error occurs, %NULL will be returned. 141 * 142 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 143 * returned. It is not wise to check for this value, but rather, check for 144 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 145 * code. 146 */ 147struct dentry *debugfs_create_u16(const char *name, umode_t mode, 148 struct dentry *parent, u16 *value) 149{ 150 /* if there are no write bits set, make read only */ 151 if (!(mode & S_IWUGO)) 152 return debugfs_create_file(name, mode, parent, value, &fops_u16_ro); 153 /* if there are no read bits set, make write only */ 154 if (!(mode & S_IRUGO)) 155 return debugfs_create_file(name, mode, parent, value, &fops_u16_wo); 156 157 return debugfs_create_file(name, mode, parent, value, &fops_u16); 158} 159EXPORT_SYMBOL_GPL(debugfs_create_u16); 160 161static int debugfs_u32_set(void *data, u64 val) 162{ 163 *(u32 *)data = val; 164 return 0; 165} 166static int debugfs_u32_get(void *data, u64 *val) 167{ 168 *val = *(u32 *)data; 169 return 0; 170} 171DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n"); 172DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n"); 173DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n"); 174 175/** 176 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value 177 * @name: a pointer to a string containing the name of the file to create. 178 * @mode: the permission that the file should have 179 * @parent: a pointer to the parent dentry for this file. This should be a 180 * directory dentry if set. If this parameter is %NULL, then the 181 * file will be created in the root of the debugfs filesystem. 182 * @value: a pointer to the variable that the file should read to and write 183 * from. 184 * 185 * This function creates a file in debugfs with the given name that 186 * contains the value of the variable @value. If the @mode variable is so 187 * set, it can be read from, and written to. 188 * 189 * This function will return a pointer to a dentry if it succeeds. This 190 * pointer must be passed to the debugfs_remove() function when the file is 191 * to be removed (no automatic cleanup happens if your module is unloaded, 192 * you are responsible here.) If an error occurs, %NULL will be returned. 193 * 194 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 195 * returned. It is not wise to check for this value, but rather, check for 196 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 197 * code. 198 */ 199struct dentry *debugfs_create_u32(const char *name, umode_t mode, 200 struct dentry *parent, u32 *value) 201{ 202 /* if there are no write bits set, make read only */ 203 if (!(mode & S_IWUGO)) 204 return debugfs_create_file(name, mode, parent, value, &fops_u32_ro); 205 /* if there are no read bits set, make write only */ 206 if (!(mode & S_IRUGO)) 207 return debugfs_create_file(name, mode, parent, value, &fops_u32_wo); 208 209 return debugfs_create_file(name, mode, parent, value, &fops_u32); 210} 211EXPORT_SYMBOL_GPL(debugfs_create_u32); 212 213static int debugfs_u64_set(void *data, u64 val) 214{ 215 *(u64 *)data = val; 216 return 0; 217} 218 219static int debugfs_u64_get(void *data, u64 *val) 220{ 221 *val = *(u64 *)data; 222 return 0; 223} 224DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n"); 225DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n"); 226DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n"); 227 228/** 229 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value 230 * @name: a pointer to a string containing the name of the file to create. 231 * @mode: the permission that the file should have 232 * @parent: a pointer to the parent dentry for this file. This should be a 233 * directory dentry if set. If this parameter is %NULL, then the 234 * file will be created in the root of the debugfs filesystem. 235 * @value: a pointer to the variable that the file should read to and write 236 * from. 237 * 238 * This function creates a file in debugfs with the given name that 239 * contains the value of the variable @value. If the @mode variable is so 240 * set, it can be read from, and written to. 241 * 242 * This function will return a pointer to a dentry if it succeeds. This 243 * pointer must be passed to the debugfs_remove() function when the file is 244 * to be removed (no automatic cleanup happens if your module is unloaded, 245 * you are responsible here.) If an error occurs, %NULL will be returned. 246 * 247 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 248 * returned. It is not wise to check for this value, but rather, check for 249 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 250 * code. 251 */ 252struct dentry *debugfs_create_u64(const char *name, umode_t mode, 253 struct dentry *parent, u64 *value) 254{ 255 /* if there are no write bits set, make read only */ 256 if (!(mode & S_IWUGO)) 257 return debugfs_create_file(name, mode, parent, value, &fops_u64_ro); 258 /* if there are no read bits set, make write only */ 259 if (!(mode & S_IRUGO)) 260 return debugfs_create_file(name, mode, parent, value, &fops_u64_wo); 261 262 return debugfs_create_file(name, mode, parent, value, &fops_u64); 263} 264EXPORT_SYMBOL_GPL(debugfs_create_u64); 265 266DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n"); 267DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n"); 268DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n"); 269 270DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n"); 271DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n"); 272DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n"); 273 274DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n"); 275DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n"); 276DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n"); 277 278DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n"); 279 280/* 281 * 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 282 * 283 * These functions are exactly the same as the above functions (but use a hex 284 * output for the decimal challenged). For details look at the above unsigned 285 * decimal functions. 286 */ 287 288/** 289 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value 290 * @name: a pointer to a string containing the name of the file to create. 291 * @mode: the permission that the file should have 292 * @parent: a pointer to the parent dentry for this file. This should be a 293 * directory dentry if set. If this parameter is %NULL, then the 294 * file will be created in the root of the debugfs filesystem. 295 * @value: a pointer to the variable that the file should read to and write 296 * from. 297 */ 298struct dentry *debugfs_create_x8(const char *name, umode_t mode, 299 struct dentry *parent, u8 *value) 300{ 301 /* if there are no write bits set, make read only */ 302 if (!(mode & S_IWUGO)) 303 return debugfs_create_file(name, mode, parent, value, &fops_x8_ro); 304 /* if there are no read bits set, make write only */ 305 if (!(mode & S_IRUGO)) 306 return debugfs_create_file(name, mode, parent, value, &fops_x8_wo); 307 308 return debugfs_create_file(name, mode, parent, value, &fops_x8); 309} 310EXPORT_SYMBOL_GPL(debugfs_create_x8); 311 312/** 313 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value 314 * @name: a pointer to a string containing the name of the file to create. 315 * @mode: the permission that the file should have 316 * @parent: a pointer to the parent dentry for this file. This should be a 317 * directory dentry if set. If this parameter is %NULL, then the 318 * file will be created in the root of the debugfs filesystem. 319 * @value: a pointer to the variable that the file should read to and write 320 * from. 321 */ 322struct dentry *debugfs_create_x16(const char *name, umode_t mode, 323 struct dentry *parent, u16 *value) 324{ 325 /* if there are no write bits set, make read only */ 326 if (!(mode & S_IWUGO)) 327 return debugfs_create_file(name, mode, parent, value, &fops_x16_ro); 328 /* if there are no read bits set, make write only */ 329 if (!(mode & S_IRUGO)) 330 return debugfs_create_file(name, mode, parent, value, &fops_x16_wo); 331 332 return debugfs_create_file(name, mode, parent, value, &fops_x16); 333} 334EXPORT_SYMBOL_GPL(debugfs_create_x16); 335 336/** 337 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value 338 * @name: a pointer to a string containing the name of the file to create. 339 * @mode: the permission that the file should have 340 * @parent: a pointer to the parent dentry for this file. This should be a 341 * directory dentry if set. If this parameter is %NULL, then the 342 * file will be created in the root of the debugfs filesystem. 343 * @value: a pointer to the variable that the file should read to and write 344 * from. 345 */ 346struct dentry *debugfs_create_x32(const char *name, umode_t mode, 347 struct dentry *parent, u32 *value) 348{ 349 /* if there are no write bits set, make read only */ 350 if (!(mode & S_IWUGO)) 351 return debugfs_create_file(name, mode, parent, value, &fops_x32_ro); 352 /* if there are no read bits set, make write only */ 353 if (!(mode & S_IRUGO)) 354 return debugfs_create_file(name, mode, parent, value, &fops_x32_wo); 355 356 return debugfs_create_file(name, mode, parent, value, &fops_x32); 357} 358EXPORT_SYMBOL_GPL(debugfs_create_x32); 359 360/** 361 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value 362 * @name: a pointer to a string containing the name of the file to create. 363 * @mode: the permission that the file should have 364 * @parent: a pointer to the parent dentry for this file. This should be a 365 * directory dentry if set. If this parameter is %NULL, then the 366 * file will be created in the root of the debugfs filesystem. 367 * @value: a pointer to the variable that the file should read to and write 368 * from. 369 */ 370struct dentry *debugfs_create_x64(const char *name, umode_t mode, 371 struct dentry *parent, u64 *value) 372{ 373 return debugfs_create_file(name, mode, parent, value, &fops_x64); 374} 375EXPORT_SYMBOL_GPL(debugfs_create_x64); 376 377 378static int debugfs_size_t_set(void *data, u64 val) 379{ 380 *(size_t *)data = val; 381 return 0; 382} 383static int debugfs_size_t_get(void *data, u64 *val) 384{ 385 *val = *(size_t *)data; 386 return 0; 387} 388DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set, 389 "%llu\n"); /* %llu and %zu are more or less the same */ 390 391/** 392 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value 393 * @name: a pointer to a string containing the name of the file to create. 394 * @mode: the permission that the file should have 395 * @parent: a pointer to the parent dentry for this file. This should be a 396 * directory dentry if set. If this parameter is %NULL, then the 397 * file will be created in the root of the debugfs filesystem. 398 * @value: a pointer to the variable that the file should read to and write 399 * from. 400 */ 401struct dentry *debugfs_create_size_t(const char *name, umode_t mode, 402 struct dentry *parent, size_t *value) 403{ 404 return debugfs_create_file(name, mode, parent, value, &fops_size_t); 405} 406EXPORT_SYMBOL_GPL(debugfs_create_size_t); 407 408static int debugfs_atomic_t_set(void *data, u64 val) 409{ 410 atomic_set((atomic_t *)data, val); 411 return 0; 412} 413static int debugfs_atomic_t_get(void *data, u64 *val) 414{ 415 *val = atomic_read((atomic_t *)data); 416 return 0; 417} 418DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get, 419 debugfs_atomic_t_set, "%lld\n"); 420DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n"); 421DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n"); 422 423/** 424 * debugfs_create_atomic_t - create a debugfs file that is used to read and 425 * write an atomic_t value 426 * @name: a pointer to a string containing the name of the file to create. 427 * @mode: the permission that the file should have 428 * @parent: a pointer to the parent dentry for this file. This should be a 429 * directory dentry if set. If this parameter is %NULL, then the 430 * file will be created in the root of the debugfs filesystem. 431 * @value: a pointer to the variable that the file should read to and write 432 * from. 433 */ 434struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode, 435 struct dentry *parent, atomic_t *value) 436{ 437 /* if there are no write bits set, make read only */ 438 if (!(mode & S_IWUGO)) 439 return debugfs_create_file(name, mode, parent, value, 440 &fops_atomic_t_ro); 441 /* if there are no read bits set, make write only */ 442 if (!(mode & S_IRUGO)) 443 return debugfs_create_file(name, mode, parent, value, 444 &fops_atomic_t_wo); 445 446 return debugfs_create_file(name, mode, parent, value, &fops_atomic_t); 447} 448EXPORT_SYMBOL_GPL(debugfs_create_atomic_t); 449 450static ssize_t read_file_bool(struct file *file, char __user *user_buf, 451 size_t count, loff_t *ppos) 452{ 453 char buf[3]; 454 u32 *val = file->private_data; 455 456 if (*val) 457 buf[0] = 'Y'; 458 else 459 buf[0] = 'N'; 460 buf[1] = '\n'; 461 buf[2] = 0x00; 462 return simple_read_from_buffer(user_buf, count, ppos, buf, 2); 463} 464 465static ssize_t write_file_bool(struct file *file, const char __user *user_buf, 466 size_t count, loff_t *ppos) 467{ 468 char buf[32]; 469 size_t buf_size; 470 bool bv; 471 u32 *val = file->private_data; 472 473 buf_size = min(count, (sizeof(buf)-1)); 474 if (copy_from_user(buf, user_buf, buf_size)) 475 return -EFAULT; 476 477 buf[buf_size] = '\0'; 478 if (strtobool(buf, &bv) == 0) 479 *val = bv; 480 481 return count; 482} 483 484static const struct file_operations fops_bool = { 485 .read = read_file_bool, 486 .write = write_file_bool, 487 .open = simple_open, 488 .llseek = default_llseek, 489}; 490 491/** 492 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value 493 * @name: a pointer to a string containing the name of the file to create. 494 * @mode: the permission that the file should have 495 * @parent: a pointer to the parent dentry for this file. This should be a 496 * directory dentry if set. If this parameter is %NULL, then the 497 * file will be created in the root of the debugfs filesystem. 498 * @value: a pointer to the variable that the file should read to and write 499 * from. 500 * 501 * This function creates a file in debugfs with the given name that 502 * contains the value of the variable @value. If the @mode variable is so 503 * set, it can be read from, and written to. 504 * 505 * This function will return a pointer to a dentry if it succeeds. This 506 * pointer must be passed to the debugfs_remove() function when the file is 507 * to be removed (no automatic cleanup happens if your module is unloaded, 508 * you are responsible here.) If an error occurs, %NULL will be returned. 509 * 510 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 511 * returned. It is not wise to check for this value, but rather, check for 512 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 513 * code. 514 */ 515struct dentry *debugfs_create_bool(const char *name, umode_t mode, 516 struct dentry *parent, u32 *value) 517{ 518 return debugfs_create_file(name, mode, parent, value, &fops_bool); 519} 520EXPORT_SYMBOL_GPL(debugfs_create_bool); 521 522static ssize_t read_file_blob(struct file *file, char __user *user_buf, 523 size_t count, loff_t *ppos) 524{ 525 struct debugfs_blob_wrapper *blob = file->private_data; 526 return simple_read_from_buffer(user_buf, count, ppos, blob->data, 527 blob->size); 528} 529 530static const struct file_operations fops_blob = { 531 .read = read_file_blob, 532 .open = simple_open, 533 .llseek = default_llseek, 534}; 535 536/** 537 * debugfs_create_blob - create a debugfs file that is used to read a binary blob 538 * @name: a pointer to a string containing the name of the file to create. 539 * @mode: the permission that the file should have 540 * @parent: a pointer to the parent dentry for this file. This should be a 541 * directory dentry if set. If this parameter is %NULL, then the 542 * file will be created in the root of the debugfs filesystem. 543 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer 544 * to the blob data and the size of the data. 545 * 546 * This function creates a file in debugfs with the given name that exports 547 * @blob->data as a binary blob. If the @mode variable is so set it can be 548 * read from. Writing is not supported. 549 * 550 * This function will return a pointer to a dentry if it succeeds. This 551 * pointer must be passed to the debugfs_remove() function when the file is 552 * to be removed (no automatic cleanup happens if your module is unloaded, 553 * you are responsible here.) If an error occurs, %NULL will be returned. 554 * 555 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 556 * returned. It is not wise to check for this value, but rather, check for 557 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 558 * code. 559 */ 560struct dentry *debugfs_create_blob(const char *name, umode_t mode, 561 struct dentry *parent, 562 struct debugfs_blob_wrapper *blob) 563{ 564 return debugfs_create_file(name, mode, parent, blob, &fops_blob); 565} 566EXPORT_SYMBOL_GPL(debugfs_create_blob); 567 568struct array_data { 569 void *array; 570 u32 elements; 571}; 572 573static size_t u32_format_array(char *buf, size_t bufsize, 574 u32 *array, int array_size) 575{ 576 size_t ret = 0; 577 578 while (--array_size >= 0) { 579 size_t len; 580 char term = array_size ? ' ' : '\n'; 581 582 len = snprintf(buf, bufsize, "%u%c", *array++, term); 583 ret += len; 584 585 buf += len; 586 bufsize -= len; 587 } 588 return ret; 589} 590 591static int u32_array_open(struct inode *inode, struct file *file) 592{ 593 struct array_data *data = inode->i_private; 594 int size, elements = data->elements; 595 char *buf; 596 597 /* 598 * Max size: 599 * - 10 digits + ' '/'\n' = 11 bytes per number 600 * - terminating NUL character 601 */ 602 size = elements*11; 603 buf = kmalloc(size+1, GFP_KERNEL); 604 if (!buf) 605 return -ENOMEM; 606 buf[size] = 0; 607 608 file->private_data = buf; 609 u32_format_array(buf, size, data->array, data->elements); 610 611 return nonseekable_open(inode, file); 612} 613 614static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len, 615 loff_t *ppos) 616{ 617 size_t size = strlen(file->private_data); 618 619 return simple_read_from_buffer(buf, len, ppos, 620 file->private_data, size); 621} 622 623static int u32_array_release(struct inode *inode, struct file *file) 624{ 625 kfree(file->private_data); 626 627 return 0; 628} 629 630static const struct file_operations u32_array_fops = { 631 .owner = THIS_MODULE, 632 .open = u32_array_open, 633 .release = u32_array_release, 634 .read = u32_array_read, 635 .llseek = no_llseek, 636}; 637 638/** 639 * debugfs_create_u32_array - create a debugfs file that is used to read u32 640 * array. 641 * @name: a pointer to a string containing the name of the file to create. 642 * @mode: the permission that the file should have. 643 * @parent: a pointer to the parent dentry for this file. This should be a 644 * directory dentry if set. If this parameter is %NULL, then the 645 * file will be created in the root of the debugfs filesystem. 646 * @array: u32 array that provides data. 647 * @elements: total number of elements in the array. 648 * 649 * This function creates a file in debugfs with the given name that exports 650 * @array as data. If the @mode variable is so set it can be read from. 651 * Writing is not supported. Seek within the file is also not supported. 652 * Once array is created its size can not be changed. 653 * 654 * The function returns a pointer to dentry on success. If debugfs is not 655 * enabled in the kernel, the value -%ENODEV will be returned. 656 */ 657struct dentry *debugfs_create_u32_array(const char *name, umode_t mode, 658 struct dentry *parent, 659 u32 *array, u32 elements) 660{ 661 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL); 662 663 if (data == NULL) 664 return NULL; 665 666 data->array = array; 667 data->elements = elements; 668 669 return debugfs_create_file(name, mode, parent, data, &u32_array_fops); 670} 671EXPORT_SYMBOL_GPL(debugfs_create_u32_array); 672 673#ifdef CONFIG_HAS_IOMEM 674 675/* 676 * The regset32 stuff is used to print 32-bit registers using the 677 * seq_file utilities. We offer printing a register set in an already-opened 678 * sequential file or create a debugfs file that only prints a regset32. 679 */ 680 681/** 682 * debugfs_print_regs32 - use seq_print to describe a set of registers 683 * @s: the seq_file structure being used to generate output 684 * @regs: an array if struct debugfs_reg32 structures 685 * @nregs: the length of the above array 686 * @base: the base address to be used in reading the registers 687 * @prefix: a string to be prefixed to every output line 688 * 689 * This function outputs a text block describing the current values of 690 * some 32-bit hardware registers. It is meant to be used within debugfs 691 * files based on seq_file that need to show registers, intermixed with other 692 * information. The prefix argument may be used to specify a leading string, 693 * because some peripherals have several blocks of identical registers, 694 * for example configuration of dma channels 695 */ 696void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs, 697 int nregs, void __iomem *base, char *prefix) 698{ 699 int i; 700 701 for (i = 0; i < nregs; i++, regs++) { 702 if (prefix) 703 seq_printf(s, "%s", prefix); 704 seq_printf(s, "%s = 0x%08x\n", regs->name, 705 readl(base + regs->offset)); 706 if (seq_has_overflowed(s)) 707 break; 708 } 709} 710EXPORT_SYMBOL_GPL(debugfs_print_regs32); 711 712static int debugfs_show_regset32(struct seq_file *s, void *data) 713{ 714 struct debugfs_regset32 *regset = s->private; 715 716 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, ""); 717 return 0; 718} 719 720static int debugfs_open_regset32(struct inode *inode, struct file *file) 721{ 722 return single_open(file, debugfs_show_regset32, inode->i_private); 723} 724 725static const struct file_operations fops_regset32 = { 726 .open = debugfs_open_regset32, 727 .read = seq_read, 728 .llseek = seq_lseek, 729 .release = single_release, 730}; 731 732/** 733 * debugfs_create_regset32 - create a debugfs file that returns register values 734 * @name: a pointer to a string containing the name of the file to create. 735 * @mode: the permission that the file should have 736 * @parent: a pointer to the parent dentry for this file. This should be a 737 * directory dentry if set. If this parameter is %NULL, then the 738 * file will be created in the root of the debugfs filesystem. 739 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer 740 * to an array of register definitions, the array size and the base 741 * address where the register bank is to be found. 742 * 743 * This function creates a file in debugfs with the given name that reports 744 * the names and values of a set of 32-bit registers. If the @mode variable 745 * is so set it can be read from. Writing is not supported. 746 * 747 * This function will return a pointer to a dentry if it succeeds. This 748 * pointer must be passed to the debugfs_remove() function when the file is 749 * to be removed (no automatic cleanup happens if your module is unloaded, 750 * you are responsible here.) If an error occurs, %NULL will be returned. 751 * 752 * If debugfs is not enabled in the kernel, the value -%ENODEV will be 753 * returned. It is not wise to check for this value, but rather, check for 754 * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling 755 * code. 756 */ 757struct dentry *debugfs_create_regset32(const char *name, umode_t mode, 758 struct dentry *parent, 759 struct debugfs_regset32 *regset) 760{ 761 return debugfs_create_file(name, mode, parent, regset, &fops_regset32); 762} 763EXPORT_SYMBOL_GPL(debugfs_create_regset32); 764 765#endif /* CONFIG_HAS_IOMEM */ 766 767struct debugfs_devm_entry { 768 int (*read)(struct seq_file *seq, void *data); 769 struct device *dev; 770}; 771 772static int debugfs_devm_entry_open(struct inode *inode, struct file *f) 773{ 774 struct debugfs_devm_entry *entry = inode->i_private; 775 776 return single_open(f, entry->read, entry->dev); 777} 778 779static const struct file_operations debugfs_devm_entry_ops = { 780 .owner = THIS_MODULE, 781 .open = debugfs_devm_entry_open, 782 .release = single_release, 783 .read = seq_read, 784 .llseek = seq_lseek 785}; 786 787/** 788 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device. 789 * 790 * @dev: device related to this debugfs file. 791 * @name: name of the debugfs file. 792 * @parent: a pointer to the parent dentry for this file. This should be a 793 * directory dentry if set. If this parameter is %NULL, then the 794 * file will be created in the root of the debugfs filesystem. 795 * @read_fn: function pointer called to print the seq_file content. 796 */ 797struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name, 798 struct dentry *parent, 799 int (*read_fn)(struct seq_file *s, 800 void *data)) 801{ 802 struct debugfs_devm_entry *entry; 803 804 if (IS_ERR(parent)) 805 return ERR_PTR(-ENOENT); 806 807 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL); 808 if (!entry) 809 return ERR_PTR(-ENOMEM); 810 811 entry->read = read_fn; 812 entry->dev = dev; 813 814 return debugfs_create_file(name, S_IRUGO, parent, entry, 815 &debugfs_devm_entry_ops); 816} 817EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile); 818 819