1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * sysfs.h - definitions for the device driver filesystem 4 * 5 * Copyright (c) 2001,2002 Patrick Mochel 6 * Copyright (c) 2004 Silicon Graphics, Inc. 7 * Copyright (c) 2007 SUSE Linux Products GmbH 8 * Copyright (c) 2007 Tejun Heo <teheo@suse.de> 9 * 10 * Please see Documentation/filesystems/sysfs.txt for more information. 11 */ 12 13 #ifndef _SYSFS_H_ 14 #define _SYSFS_H_ 15 16 #include <linux/kernfs.h> 17 #include <linux/compiler.h> 18 #include <linux/errno.h> 19 #include <linux/list.h> 20 #include <linux/lockdep.h> 21 #include <linux/kobject_ns.h> 22 #include <linux/stat.h> 23 #include <linux/atomic.h> 24 25 struct kobject; 26 struct module; 27 struct bin_attribute; 28 enum kobj_ns_type; 29 30 struct attribute { 31 const char *name; 32 umode_t mode; 33 #ifdef CONFIG_DEBUG_LOCK_ALLOC 34 bool ignore_lockdep:1; 35 struct lock_class_key *key; 36 struct lock_class_key skey; 37 #endif 38 }; 39 40 /** 41 * sysfs_attr_init - initialize a dynamically allocated sysfs attribute 42 * @attr: struct attribute to initialize 43 * 44 * Initialize a dynamically allocated struct attribute so we can 45 * make lockdep happy. This is a new requirement for attributes 46 * and initially this is only needed when lockdep is enabled. 47 * Lockdep gives a nice error when your attribute is added to 48 * sysfs if you don't have this. 49 */ 50 #ifdef CONFIG_DEBUG_LOCK_ALLOC 51 #define sysfs_attr_init(attr) \ 52 do { \ 53 static struct lock_class_key __key; \ 54 \ 55 (attr)->key = &__key; \ 56 } while (0) 57 #else 58 #define sysfs_attr_init(attr) do {} while (0) 59 #endif 60 61 /** 62 * struct attribute_group - data structure used to declare an attribute group. 63 * @name: Optional: Attribute group name 64 * If specified, the attribute group will be created in 65 * a new subdirectory with this name. 66 * @is_visible: Optional: Function to return permissions associated with an 67 * attribute of the group. Will be called repeatedly for each 68 * non-binary attribute in the group. Only read/write 69 * permissions as well as SYSFS_PREALLOC are accepted. Must 70 * return 0 if an attribute is not visible. The returned value 71 * will replace static permissions defined in struct attribute. 72 * @is_bin_visible: 73 * Optional: Function to return permissions associated with a 74 * binary attribute of the group. Will be called repeatedly 75 * for each binary attribute in the group. Only read/write 76 * permissions as well as SYSFS_PREALLOC are accepted. Must 77 * return 0 if a binary attribute is not visible. The returned 78 * value will replace static permissions defined in 79 * struct bin_attribute. 80 * @attrs: Pointer to NULL terminated list of attributes. 81 * @bin_attrs: Pointer to NULL terminated list of binary attributes. 82 * Either attrs or bin_attrs or both must be provided. 83 */ 84 struct attribute_group { 85 const char *name; 86 umode_t (*is_visible)(struct kobject *, 87 struct attribute *, int); 88 umode_t (*is_bin_visible)(struct kobject *, 89 struct bin_attribute *, int); 90 struct attribute **attrs; 91 struct bin_attribute **bin_attrs; 92 }; 93 94 /** 95 * Use these macros to make defining attributes easier. See include/linux/device.h 96 * for examples.. 97 */ 98 99 #define SYSFS_PREALLOC 010000 100 101 #define __ATTR(_name, _mode, _show, _store) { \ 102 .attr = {.name = __stringify(_name), \ 103 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ 104 .show = _show, \ 105 .store = _store, \ 106 } 107 108 #define __ATTR_PREALLOC(_name, _mode, _show, _store) { \ 109 .attr = {.name = __stringify(_name), \ 110 .mode = SYSFS_PREALLOC | VERIFY_OCTAL_PERMISSIONS(_mode) },\ 111 .show = _show, \ 112 .store = _store, \ 113 } 114 115 #define __ATTR_RO(_name) { \ 116 .attr = { .name = __stringify(_name), .mode = S_IRUGO }, \ 117 .show = _name##_show, \ 118 } 119 120 #define __ATTR_WO(_name) { \ 121 .attr = { .name = __stringify(_name), .mode = S_IWUSR }, \ 122 .store = _name##_store, \ 123 } 124 125 #define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO), \ 126 _name##_show, _name##_store) 127 128 #define __ATTR_NULL { .attr = { .name = NULL } } 129 130 #ifdef CONFIG_DEBUG_LOCK_ALLOC 131 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) { \ 132 .attr = {.name = __stringify(_name), .mode = _mode, \ 133 .ignore_lockdep = true }, \ 134 .show = _show, \ 135 .store = _store, \ 136 } 137 #else 138 #define __ATTR_IGNORE_LOCKDEP __ATTR 139 #endif 140 141 #define __ATTRIBUTE_GROUPS(_name) \ 142 static const struct attribute_group *_name##_groups[] = { \ 143 &_name##_group, \ 144 NULL, \ 145 } 146 147 #define ATTRIBUTE_GROUPS(_name) \ 148 static const struct attribute_group _name##_group = { \ 149 .attrs = _name##_attrs, \ 150 }; \ 151 __ATTRIBUTE_GROUPS(_name) 152 153 struct file; 154 struct vm_area_struct; 155 156 struct bin_attribute { 157 struct attribute attr; 158 size_t size; 159 void *private; 160 ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *, 161 char *, loff_t, size_t); 162 ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *, 163 char *, loff_t, size_t); 164 int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr, 165 struct vm_area_struct *vma); 166 }; 167 168 /** 169 * sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute 170 * @attr: struct bin_attribute to initialize 171 * 172 * Initialize a dynamically allocated struct bin_attribute so we 173 * can make lockdep happy. This is a new requirement for 174 * attributes and initially this is only needed when lockdep is 175 * enabled. Lockdep gives a nice error when your attribute is 176 * added to sysfs if you don't have this. 177 */ 178 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr) 179 180 /* macros to create static binary attributes easier */ 181 #define __BIN_ATTR(_name, _mode, _read, _write, _size) { \ 182 .attr = { .name = __stringify(_name), .mode = _mode }, \ 183 .read = _read, \ 184 .write = _write, \ 185 .size = _size, \ 186 } 187 188 #define __BIN_ATTR_RO(_name, _size) { \ 189 .attr = { .name = __stringify(_name), .mode = S_IRUGO }, \ 190 .read = _name##_read, \ 191 .size = _size, \ 192 } 193 194 #define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name, \ 195 (S_IWUSR | S_IRUGO), _name##_read, \ 196 _name##_write, _size) 197 198 #define __BIN_ATTR_NULL __ATTR_NULL 199 200 #define BIN_ATTR(_name, _mode, _read, _write, _size) \ 201 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \ 202 _write, _size) 203 204 #define BIN_ATTR_RO(_name, _size) \ 205 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size) 206 207 #define BIN_ATTR_RW(_name, _size) \ 208 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size) 209 210 struct sysfs_ops { 211 ssize_t (*show)(struct kobject *, struct attribute *, char *); 212 ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t); 213 }; 214 215 #ifdef CONFIG_SYSFS 216 217 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns); 218 void sysfs_remove_dir(struct kobject *kobj); 219 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, 220 const void *new_ns); 221 int __must_check sysfs_move_dir_ns(struct kobject *kobj, 222 struct kobject *new_parent_kobj, 223 const void *new_ns); 224 int __must_check sysfs_create_mount_point(struct kobject *parent_kobj, 225 const char *name); 226 void sysfs_remove_mount_point(struct kobject *parent_kobj, 227 const char *name); 228 229 int __must_check sysfs_create_file_ns(struct kobject *kobj, 230 const struct attribute *attr, 231 const void *ns); 232 int __must_check sysfs_create_files(struct kobject *kobj, 233 const struct attribute **attr); 234 int __must_check sysfs_chmod_file(struct kobject *kobj, 235 const struct attribute *attr, umode_t mode); 236 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, 237 const void *ns); 238 bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr); 239 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr); 240 241 int __must_check sysfs_create_bin_file(struct kobject *kobj, 242 const struct bin_attribute *attr); 243 void sysfs_remove_bin_file(struct kobject *kobj, 244 const struct bin_attribute *attr); 245 246 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target, 247 const char *name); 248 int __must_check sysfs_create_link_nowarn(struct kobject *kobj, 249 struct kobject *target, 250 const char *name); 251 void sysfs_remove_link(struct kobject *kobj, const char *name); 252 253 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target, 254 const char *old_name, const char *new_name, 255 const void *new_ns); 256 257 void sysfs_delete_link(struct kobject *dir, struct kobject *targ, 258 const char *name); 259 260 int __must_check sysfs_create_group(struct kobject *kobj, 261 const struct attribute_group *grp); 262 int __must_check sysfs_create_groups(struct kobject *kobj, 263 const struct attribute_group **groups); 264 int sysfs_update_group(struct kobject *kobj, 265 const struct attribute_group *grp); 266 void sysfs_remove_group(struct kobject *kobj, 267 const struct attribute_group *grp); 268 void sysfs_remove_groups(struct kobject *kobj, 269 const struct attribute_group **groups); 270 int sysfs_add_file_to_group(struct kobject *kobj, 271 const struct attribute *attr, const char *group); 272 void sysfs_remove_file_from_group(struct kobject *kobj, 273 const struct attribute *attr, const char *group); 274 int sysfs_merge_group(struct kobject *kobj, 275 const struct attribute_group *grp); 276 void sysfs_unmerge_group(struct kobject *kobj, 277 const struct attribute_group *grp); 278 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, 279 struct kobject *target, const char *link_name); 280 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, 281 const char *link_name); 282 int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 283 struct kobject *target_kobj, 284 const char *target_name); 285 286 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); 287 288 int __must_check sysfs_init(void); 289 290 static inline void sysfs_enable_ns(struct kernfs_node *kn) 291 { 292 return kernfs_enable_ns(kn); 293 } 294 295 #else /* CONFIG_SYSFS */ 296 297 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) 298 { 299 return 0; 300 } 301 302 static inline void sysfs_remove_dir(struct kobject *kobj) 303 { 304 } 305 306 static inline int sysfs_rename_dir_ns(struct kobject *kobj, 307 const char *new_name, const void *new_ns) 308 { 309 return 0; 310 } 311 312 static inline int sysfs_move_dir_ns(struct kobject *kobj, 313 struct kobject *new_parent_kobj, 314 const void *new_ns) 315 { 316 return 0; 317 } 318 319 static inline int sysfs_create_mount_point(struct kobject *parent_kobj, 320 const char *name) 321 { 322 return 0; 323 } 324 325 static inline void sysfs_remove_mount_point(struct kobject *parent_kobj, 326 const char *name) 327 { 328 } 329 330 static inline int sysfs_create_file_ns(struct kobject *kobj, 331 const struct attribute *attr, 332 const void *ns) 333 { 334 return 0; 335 } 336 337 static inline int sysfs_create_files(struct kobject *kobj, 338 const struct attribute **attr) 339 { 340 return 0; 341 } 342 343 static inline int sysfs_chmod_file(struct kobject *kobj, 344 const struct attribute *attr, umode_t mode) 345 { 346 return 0; 347 } 348 349 static inline void sysfs_remove_file_ns(struct kobject *kobj, 350 const struct attribute *attr, 351 const void *ns) 352 { 353 } 354 355 static inline bool sysfs_remove_file_self(struct kobject *kobj, 356 const struct attribute *attr) 357 { 358 return false; 359 } 360 361 static inline void sysfs_remove_files(struct kobject *kobj, 362 const struct attribute **attr) 363 { 364 } 365 366 static inline int sysfs_create_bin_file(struct kobject *kobj, 367 const struct bin_attribute *attr) 368 { 369 return 0; 370 } 371 372 static inline void sysfs_remove_bin_file(struct kobject *kobj, 373 const struct bin_attribute *attr) 374 { 375 } 376 377 static inline int sysfs_create_link(struct kobject *kobj, 378 struct kobject *target, const char *name) 379 { 380 return 0; 381 } 382 383 static inline int sysfs_create_link_nowarn(struct kobject *kobj, 384 struct kobject *target, 385 const char *name) 386 { 387 return 0; 388 } 389 390 static inline void sysfs_remove_link(struct kobject *kobj, const char *name) 391 { 392 } 393 394 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t, 395 const char *old_name, 396 const char *new_name, const void *ns) 397 { 398 return 0; 399 } 400 401 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t, 402 const char *name) 403 { 404 } 405 406 static inline int sysfs_create_group(struct kobject *kobj, 407 const struct attribute_group *grp) 408 { 409 return 0; 410 } 411 412 static inline int sysfs_create_groups(struct kobject *kobj, 413 const struct attribute_group **groups) 414 { 415 return 0; 416 } 417 418 static inline int sysfs_update_group(struct kobject *kobj, 419 const struct attribute_group *grp) 420 { 421 return 0; 422 } 423 424 static inline void sysfs_remove_group(struct kobject *kobj, 425 const struct attribute_group *grp) 426 { 427 } 428 429 static inline void sysfs_remove_groups(struct kobject *kobj, 430 const struct attribute_group **groups) 431 { 432 } 433 434 static inline int sysfs_add_file_to_group(struct kobject *kobj, 435 const struct attribute *attr, const char *group) 436 { 437 return 0; 438 } 439 440 static inline void sysfs_remove_file_from_group(struct kobject *kobj, 441 const struct attribute *attr, const char *group) 442 { 443 } 444 445 static inline int sysfs_merge_group(struct kobject *kobj, 446 const struct attribute_group *grp) 447 { 448 return 0; 449 } 450 451 static inline void sysfs_unmerge_group(struct kobject *kobj, 452 const struct attribute_group *grp) 453 { 454 } 455 456 static inline int sysfs_add_link_to_group(struct kobject *kobj, 457 const char *group_name, struct kobject *target, 458 const char *link_name) 459 { 460 return 0; 461 } 462 463 static inline void sysfs_remove_link_from_group(struct kobject *kobj, 464 const char *group_name, const char *link_name) 465 { 466 } 467 468 static inline int __compat_only_sysfs_link_entry_to_kobj( 469 struct kobject *kobj, 470 struct kobject *target_kobj, 471 const char *target_name) 472 { 473 return 0; 474 } 475 476 static inline void sysfs_notify(struct kobject *kobj, const char *dir, 477 const char *attr) 478 { 479 } 480 481 static inline int __must_check sysfs_init(void) 482 { 483 return 0; 484 } 485 486 static inline void sysfs_enable_ns(struct kernfs_node *kn) 487 { 488 } 489 490 #endif /* CONFIG_SYSFS */ 491 492 static inline int __must_check sysfs_create_file(struct kobject *kobj, 493 const struct attribute *attr) 494 { 495 return sysfs_create_file_ns(kobj, attr, NULL); 496 } 497 498 static inline void sysfs_remove_file(struct kobject *kobj, 499 const struct attribute *attr) 500 { 501 sysfs_remove_file_ns(kobj, attr, NULL); 502 } 503 504 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target, 505 const char *old_name, const char *new_name) 506 { 507 return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL); 508 } 509 510 static inline void sysfs_notify_dirent(struct kernfs_node *kn) 511 { 512 kernfs_notify(kn); 513 } 514 515 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent, 516 const char *name) 517 { 518 return kernfs_find_and_get(parent, name); 519 } 520 521 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn) 522 { 523 kernfs_get(kn); 524 return kn; 525 } 526 527 static inline void sysfs_put(struct kernfs_node *kn) 528 { 529 kernfs_put(kn); 530 } 531 532 #endif /* _SYSFS_H_ */ 533