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.rst 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. 96 * See include/linux/device.h 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 = 0444 }, \ 117 .show = _name##_show, \ 118 } 119 120 #define __ATTR_RO_MODE(_name, _mode) { \ 121 .attr = { .name = __stringify(_name), \ 122 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ 123 .show = _name##_show, \ 124 } 125 126 #define __ATTR_RW_MODE(_name, _mode) { \ 127 .attr = { .name = __stringify(_name), \ 128 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ 129 .show = _name##_show, \ 130 .store = _name##_store, \ 131 } 132 133 #define __ATTR_WO(_name) { \ 134 .attr = { .name = __stringify(_name), .mode = 0200 }, \ 135 .store = _name##_store, \ 136 } 137 138 #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store) 139 140 #define __ATTR_NULL { .attr = { .name = NULL } } 141 142 #ifdef CONFIG_DEBUG_LOCK_ALLOC 143 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) { \ 144 .attr = {.name = __stringify(_name), .mode = _mode, \ 145 .ignore_lockdep = true }, \ 146 .show = _show, \ 147 .store = _store, \ 148 } 149 #else 150 #define __ATTR_IGNORE_LOCKDEP __ATTR 151 #endif 152 153 #define __ATTRIBUTE_GROUPS(_name) \ 154 static const struct attribute_group *_name##_groups[] = { \ 155 &_name##_group, \ 156 NULL, \ 157 } 158 159 #define ATTRIBUTE_GROUPS(_name) \ 160 static const struct attribute_group _name##_group = { \ 161 .attrs = _name##_attrs, \ 162 }; \ 163 __ATTRIBUTE_GROUPS(_name) 164 165 #define BIN_ATTRIBUTE_GROUPS(_name) \ 166 static const struct attribute_group _name##_group = { \ 167 .bin_attrs = _name##_attrs, \ 168 }; \ 169 __ATTRIBUTE_GROUPS(_name) 170 171 struct file; 172 struct vm_area_struct; 173 struct address_space; 174 175 struct bin_attribute { 176 struct attribute attr; 177 size_t size; 178 void *private; 179 struct address_space *(*f_mapping)(void); 180 ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *, 181 char *, loff_t, size_t); 182 ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *, 183 char *, loff_t, size_t); 184 int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr, 185 struct vm_area_struct *vma); 186 }; 187 188 /** 189 * sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute 190 * @attr: struct bin_attribute to initialize 191 * 192 * Initialize a dynamically allocated struct bin_attribute so we 193 * can make lockdep happy. This is a new requirement for 194 * attributes and initially this is only needed when lockdep is 195 * enabled. Lockdep gives a nice error when your attribute is 196 * added to sysfs if you don't have this. 197 */ 198 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr) 199 200 /* macros to create static binary attributes easier */ 201 #define __BIN_ATTR(_name, _mode, _read, _write, _size) { \ 202 .attr = { .name = __stringify(_name), .mode = _mode }, \ 203 .read = _read, \ 204 .write = _write, \ 205 .size = _size, \ 206 } 207 208 #define __BIN_ATTR_RO(_name, _size) { \ 209 .attr = { .name = __stringify(_name), .mode = 0444 }, \ 210 .read = _name##_read, \ 211 .size = _size, \ 212 } 213 214 #define __BIN_ATTR_WO(_name, _size) { \ 215 .attr = { .name = __stringify(_name), .mode = 0200 }, \ 216 .write = _name##_write, \ 217 .size = _size, \ 218 } 219 220 #define __BIN_ATTR_RW(_name, _size) \ 221 __BIN_ATTR(_name, 0644, _name##_read, _name##_write, _size) 222 223 #define __BIN_ATTR_NULL __ATTR_NULL 224 225 #define BIN_ATTR(_name, _mode, _read, _write, _size) \ 226 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \ 227 _write, _size) 228 229 #define BIN_ATTR_RO(_name, _size) \ 230 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size) 231 232 #define BIN_ATTR_WO(_name, _size) \ 233 struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size) 234 235 #define BIN_ATTR_RW(_name, _size) \ 236 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size) 237 238 struct sysfs_ops { 239 ssize_t (*show)(struct kobject *, struct attribute *, char *); 240 ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t); 241 }; 242 243 #ifdef CONFIG_SYSFS 244 245 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns); 246 void sysfs_remove_dir(struct kobject *kobj); 247 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, 248 const void *new_ns); 249 int __must_check sysfs_move_dir_ns(struct kobject *kobj, 250 struct kobject *new_parent_kobj, 251 const void *new_ns); 252 int __must_check sysfs_create_mount_point(struct kobject *parent_kobj, 253 const char *name); 254 void sysfs_remove_mount_point(struct kobject *parent_kobj, 255 const char *name); 256 257 int __must_check sysfs_create_file_ns(struct kobject *kobj, 258 const struct attribute *attr, 259 const void *ns); 260 int __must_check sysfs_create_files(struct kobject *kobj, 261 const struct attribute * const *attr); 262 int __must_check sysfs_chmod_file(struct kobject *kobj, 263 const struct attribute *attr, umode_t mode); 264 struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, 265 const struct attribute *attr); 266 void sysfs_unbreak_active_protection(struct kernfs_node *kn); 267 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, 268 const void *ns); 269 bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr); 270 void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr); 271 272 int __must_check sysfs_create_bin_file(struct kobject *kobj, 273 const struct bin_attribute *attr); 274 void sysfs_remove_bin_file(struct kobject *kobj, 275 const struct bin_attribute *attr); 276 277 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target, 278 const char *name); 279 int __must_check sysfs_create_link_nowarn(struct kobject *kobj, 280 struct kobject *target, 281 const char *name); 282 void sysfs_remove_link(struct kobject *kobj, const char *name); 283 284 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target, 285 const char *old_name, const char *new_name, 286 const void *new_ns); 287 288 void sysfs_delete_link(struct kobject *dir, struct kobject *targ, 289 const char *name); 290 291 int __must_check sysfs_create_group(struct kobject *kobj, 292 const struct attribute_group *grp); 293 int __must_check sysfs_create_groups(struct kobject *kobj, 294 const struct attribute_group **groups); 295 int __must_check sysfs_update_groups(struct kobject *kobj, 296 const struct attribute_group **groups); 297 int sysfs_update_group(struct kobject *kobj, 298 const struct attribute_group *grp); 299 void sysfs_remove_group(struct kobject *kobj, 300 const struct attribute_group *grp); 301 void sysfs_remove_groups(struct kobject *kobj, 302 const struct attribute_group **groups); 303 int sysfs_add_file_to_group(struct kobject *kobj, 304 const struct attribute *attr, const char *group); 305 void sysfs_remove_file_from_group(struct kobject *kobj, 306 const struct attribute *attr, const char *group); 307 int sysfs_merge_group(struct kobject *kobj, 308 const struct attribute_group *grp); 309 void sysfs_unmerge_group(struct kobject *kobj, 310 const struct attribute_group *grp); 311 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, 312 struct kobject *target, const char *link_name); 313 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, 314 const char *link_name); 315 int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 316 struct kobject *target_kobj, 317 const char *target_name, 318 const char *symlink_name); 319 320 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); 321 322 int __must_check sysfs_init(void); 323 324 static inline void sysfs_enable_ns(struct kernfs_node *kn) 325 { 326 return kernfs_enable_ns(kn); 327 } 328 329 int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid, 330 kgid_t kgid); 331 int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid); 332 int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ, 333 const char *name, kuid_t kuid, kgid_t kgid); 334 int sysfs_groups_change_owner(struct kobject *kobj, 335 const struct attribute_group **groups, 336 kuid_t kuid, kgid_t kgid); 337 int sysfs_group_change_owner(struct kobject *kobj, 338 const struct attribute_group *groups, kuid_t kuid, 339 kgid_t kgid); 340 __printf(2, 3) 341 int sysfs_emit(char *buf, const char *fmt, ...); 342 __printf(3, 4) 343 int sysfs_emit_at(char *buf, int at, const char *fmt, ...); 344 345 #else /* CONFIG_SYSFS */ 346 347 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) 348 { 349 return 0; 350 } 351 352 static inline void sysfs_remove_dir(struct kobject *kobj) 353 { 354 } 355 356 static inline int sysfs_rename_dir_ns(struct kobject *kobj, 357 const char *new_name, const void *new_ns) 358 { 359 return 0; 360 } 361 362 static inline int sysfs_move_dir_ns(struct kobject *kobj, 363 struct kobject *new_parent_kobj, 364 const void *new_ns) 365 { 366 return 0; 367 } 368 369 static inline int sysfs_create_mount_point(struct kobject *parent_kobj, 370 const char *name) 371 { 372 return 0; 373 } 374 375 static inline void sysfs_remove_mount_point(struct kobject *parent_kobj, 376 const char *name) 377 { 378 } 379 380 static inline int sysfs_create_file_ns(struct kobject *kobj, 381 const struct attribute *attr, 382 const void *ns) 383 { 384 return 0; 385 } 386 387 static inline int sysfs_create_files(struct kobject *kobj, 388 const struct attribute * const *attr) 389 { 390 return 0; 391 } 392 393 static inline int sysfs_chmod_file(struct kobject *kobj, 394 const struct attribute *attr, umode_t mode) 395 { 396 return 0; 397 } 398 399 static inline struct kernfs_node * 400 sysfs_break_active_protection(struct kobject *kobj, 401 const struct attribute *attr) 402 { 403 return NULL; 404 } 405 406 static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn) 407 { 408 } 409 410 static inline void sysfs_remove_file_ns(struct kobject *kobj, 411 const struct attribute *attr, 412 const void *ns) 413 { 414 } 415 416 static inline bool sysfs_remove_file_self(struct kobject *kobj, 417 const struct attribute *attr) 418 { 419 return false; 420 } 421 422 static inline void sysfs_remove_files(struct kobject *kobj, 423 const struct attribute * const *attr) 424 { 425 } 426 427 static inline int sysfs_create_bin_file(struct kobject *kobj, 428 const struct bin_attribute *attr) 429 { 430 return 0; 431 } 432 433 static inline void sysfs_remove_bin_file(struct kobject *kobj, 434 const struct bin_attribute *attr) 435 { 436 } 437 438 static inline int sysfs_create_link(struct kobject *kobj, 439 struct kobject *target, const char *name) 440 { 441 return 0; 442 } 443 444 static inline int sysfs_create_link_nowarn(struct kobject *kobj, 445 struct kobject *target, 446 const char *name) 447 { 448 return 0; 449 } 450 451 static inline void sysfs_remove_link(struct kobject *kobj, const char *name) 452 { 453 } 454 455 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t, 456 const char *old_name, 457 const char *new_name, const void *ns) 458 { 459 return 0; 460 } 461 462 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t, 463 const char *name) 464 { 465 } 466 467 static inline int sysfs_create_group(struct kobject *kobj, 468 const struct attribute_group *grp) 469 { 470 return 0; 471 } 472 473 static inline int sysfs_create_groups(struct kobject *kobj, 474 const struct attribute_group **groups) 475 { 476 return 0; 477 } 478 479 static inline int sysfs_update_groups(struct kobject *kobj, 480 const struct attribute_group **groups) 481 { 482 return 0; 483 } 484 485 static inline int sysfs_update_group(struct kobject *kobj, 486 const struct attribute_group *grp) 487 { 488 return 0; 489 } 490 491 static inline void sysfs_remove_group(struct kobject *kobj, 492 const struct attribute_group *grp) 493 { 494 } 495 496 static inline void sysfs_remove_groups(struct kobject *kobj, 497 const struct attribute_group **groups) 498 { 499 } 500 501 static inline int sysfs_add_file_to_group(struct kobject *kobj, 502 const struct attribute *attr, const char *group) 503 { 504 return 0; 505 } 506 507 static inline void sysfs_remove_file_from_group(struct kobject *kobj, 508 const struct attribute *attr, const char *group) 509 { 510 } 511 512 static inline int sysfs_merge_group(struct kobject *kobj, 513 const struct attribute_group *grp) 514 { 515 return 0; 516 } 517 518 static inline void sysfs_unmerge_group(struct kobject *kobj, 519 const struct attribute_group *grp) 520 { 521 } 522 523 static inline int sysfs_add_link_to_group(struct kobject *kobj, 524 const char *group_name, struct kobject *target, 525 const char *link_name) 526 { 527 return 0; 528 } 529 530 static inline void sysfs_remove_link_from_group(struct kobject *kobj, 531 const char *group_name, const char *link_name) 532 { 533 } 534 535 static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 536 struct kobject *target_kobj, 537 const char *target_name, 538 const char *symlink_name) 539 { 540 return 0; 541 } 542 543 static inline void sysfs_notify(struct kobject *kobj, const char *dir, 544 const char *attr) 545 { 546 } 547 548 static inline int __must_check sysfs_init(void) 549 { 550 return 0; 551 } 552 553 static inline void sysfs_enable_ns(struct kernfs_node *kn) 554 { 555 } 556 557 static inline int sysfs_file_change_owner(struct kobject *kobj, 558 const char *name, kuid_t kuid, 559 kgid_t kgid) 560 { 561 return 0; 562 } 563 564 static inline int sysfs_link_change_owner(struct kobject *kobj, 565 struct kobject *targ, 566 const char *name, kuid_t kuid, 567 kgid_t kgid) 568 { 569 return 0; 570 } 571 572 static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid) 573 { 574 return 0; 575 } 576 577 static inline int sysfs_groups_change_owner(struct kobject *kobj, 578 const struct attribute_group **groups, 579 kuid_t kuid, kgid_t kgid) 580 { 581 return 0; 582 } 583 584 static inline int sysfs_group_change_owner(struct kobject *kobj, 585 const struct attribute_group *groups, 586 kuid_t kuid, kgid_t kgid) 587 { 588 return 0; 589 } 590 591 __printf(2, 3) 592 static inline int sysfs_emit(char *buf, const char *fmt, ...) 593 { 594 return 0; 595 } 596 597 __printf(3, 4) 598 static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...) 599 { 600 return 0; 601 } 602 #endif /* CONFIG_SYSFS */ 603 604 static inline int __must_check sysfs_create_file(struct kobject *kobj, 605 const struct attribute *attr) 606 { 607 return sysfs_create_file_ns(kobj, attr, NULL); 608 } 609 610 static inline void sysfs_remove_file(struct kobject *kobj, 611 const struct attribute *attr) 612 { 613 sysfs_remove_file_ns(kobj, attr, NULL); 614 } 615 616 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target, 617 const char *old_name, const char *new_name) 618 { 619 return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL); 620 } 621 622 static inline void sysfs_notify_dirent(struct kernfs_node *kn) 623 { 624 kernfs_notify(kn); 625 } 626 627 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent, 628 const char *name) 629 { 630 return kernfs_find_and_get(parent, name); 631 } 632 633 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn) 634 { 635 kernfs_get(kn); 636 return kn; 637 } 638 639 static inline void sysfs_put(struct kernfs_node *kn) 640 { 641 kernfs_put(kn); 642 } 643 644 #endif /* _SYSFS_H_ */ 645