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) 237 238 239 #define __BIN_ATTR_ADMIN_RO(_name, _size) { \ 240 .attr = { .name = __stringify(_name), .mode = 0400 }, \ 241 .read = _name##_read, \ 242 .size = _size, \ 243 } 244 245 #define __BIN_ATTR_ADMIN_RW(_name, _size) \ 246 __BIN_ATTR(_name, 0600, _name##_read, _name##_write, _size) 247 248 #define BIN_ATTR_ADMIN_RO(_name, _size) \ 249 struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size) 250 251 #define BIN_ATTR_ADMIN_RW(_name, _size) \ 252 struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size) 253 254 struct sysfs_ops { 255 ssize_t (*show)(struct kobject *, struct attribute *, char *); 256 ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t); 257 }; 258 259 #ifdef CONFIG_SYSFS 260 261 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns); 262 void sysfs_remove_dir(struct kobject *kobj); 263 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name, 264 const void *new_ns); 265 int __must_check sysfs_move_dir_ns(struct kobject *kobj, 266 struct kobject *new_parent_kobj, 267 const void *new_ns); 268 int __must_check sysfs_create_mount_point(struct kobject *parent_kobj, 269 const char *name); 270 void sysfs_remove_mount_point(struct kobject *parent_kobj, 271 const char *name); 272 273 int __must_check sysfs_create_file_ns(struct kobject *kobj, 274 const struct attribute *attr, 275 const void *ns); 276 int __must_check sysfs_create_files(struct kobject *kobj, 277 const struct attribute * const *attr); 278 int __must_check sysfs_chmod_file(struct kobject *kobj, 279 const struct attribute *attr, umode_t mode); 280 struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, 281 const struct attribute *attr); 282 void sysfs_unbreak_active_protection(struct kernfs_node *kn); 283 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, 284 const void *ns); 285 bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr); 286 void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr); 287 288 int __must_check sysfs_create_bin_file(struct kobject *kobj, 289 const struct bin_attribute *attr); 290 void sysfs_remove_bin_file(struct kobject *kobj, 291 const struct bin_attribute *attr); 292 293 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target, 294 const char *name); 295 int __must_check sysfs_create_link_nowarn(struct kobject *kobj, 296 struct kobject *target, 297 const char *name); 298 void sysfs_remove_link(struct kobject *kobj, const char *name); 299 300 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target, 301 const char *old_name, const char *new_name, 302 const void *new_ns); 303 304 void sysfs_delete_link(struct kobject *dir, struct kobject *targ, 305 const char *name); 306 307 int __must_check sysfs_create_group(struct kobject *kobj, 308 const struct attribute_group *grp); 309 int __must_check sysfs_create_groups(struct kobject *kobj, 310 const struct attribute_group **groups); 311 int __must_check sysfs_update_groups(struct kobject *kobj, 312 const struct attribute_group **groups); 313 int sysfs_update_group(struct kobject *kobj, 314 const struct attribute_group *grp); 315 void sysfs_remove_group(struct kobject *kobj, 316 const struct attribute_group *grp); 317 void sysfs_remove_groups(struct kobject *kobj, 318 const struct attribute_group **groups); 319 int sysfs_add_file_to_group(struct kobject *kobj, 320 const struct attribute *attr, const char *group); 321 void sysfs_remove_file_from_group(struct kobject *kobj, 322 const struct attribute *attr, const char *group); 323 int sysfs_merge_group(struct kobject *kobj, 324 const struct attribute_group *grp); 325 void sysfs_unmerge_group(struct kobject *kobj, 326 const struct attribute_group *grp); 327 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name, 328 struct kobject *target, const char *link_name); 329 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, 330 const char *link_name); 331 int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 332 struct kobject *target_kobj, 333 const char *target_name, 334 const char *symlink_name); 335 336 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr); 337 338 int __must_check sysfs_init(void); 339 340 static inline void sysfs_enable_ns(struct kernfs_node *kn) 341 { 342 return kernfs_enable_ns(kn); 343 } 344 345 int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid, 346 kgid_t kgid); 347 int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid); 348 int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ, 349 const char *name, kuid_t kuid, kgid_t kgid); 350 int sysfs_groups_change_owner(struct kobject *kobj, 351 const struct attribute_group **groups, 352 kuid_t kuid, kgid_t kgid); 353 int sysfs_group_change_owner(struct kobject *kobj, 354 const struct attribute_group *groups, kuid_t kuid, 355 kgid_t kgid); 356 __printf(2, 3) 357 int sysfs_emit(char *buf, const char *fmt, ...); 358 __printf(3, 4) 359 int sysfs_emit_at(char *buf, int at, const char *fmt, ...); 360 361 #else /* CONFIG_SYSFS */ 362 363 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) 364 { 365 return 0; 366 } 367 368 static inline void sysfs_remove_dir(struct kobject *kobj) 369 { 370 } 371 372 static inline int sysfs_rename_dir_ns(struct kobject *kobj, 373 const char *new_name, const void *new_ns) 374 { 375 return 0; 376 } 377 378 static inline int sysfs_move_dir_ns(struct kobject *kobj, 379 struct kobject *new_parent_kobj, 380 const void *new_ns) 381 { 382 return 0; 383 } 384 385 static inline int sysfs_create_mount_point(struct kobject *parent_kobj, 386 const char *name) 387 { 388 return 0; 389 } 390 391 static inline void sysfs_remove_mount_point(struct kobject *parent_kobj, 392 const char *name) 393 { 394 } 395 396 static inline int sysfs_create_file_ns(struct kobject *kobj, 397 const struct attribute *attr, 398 const void *ns) 399 { 400 return 0; 401 } 402 403 static inline int sysfs_create_files(struct kobject *kobj, 404 const struct attribute * const *attr) 405 { 406 return 0; 407 } 408 409 static inline int sysfs_chmod_file(struct kobject *kobj, 410 const struct attribute *attr, umode_t mode) 411 { 412 return 0; 413 } 414 415 static inline struct kernfs_node * 416 sysfs_break_active_protection(struct kobject *kobj, 417 const struct attribute *attr) 418 { 419 return NULL; 420 } 421 422 static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn) 423 { 424 } 425 426 static inline void sysfs_remove_file_ns(struct kobject *kobj, 427 const struct attribute *attr, 428 const void *ns) 429 { 430 } 431 432 static inline bool sysfs_remove_file_self(struct kobject *kobj, 433 const struct attribute *attr) 434 { 435 return false; 436 } 437 438 static inline void sysfs_remove_files(struct kobject *kobj, 439 const struct attribute * const *attr) 440 { 441 } 442 443 static inline int sysfs_create_bin_file(struct kobject *kobj, 444 const struct bin_attribute *attr) 445 { 446 return 0; 447 } 448 449 static inline void sysfs_remove_bin_file(struct kobject *kobj, 450 const struct bin_attribute *attr) 451 { 452 } 453 454 static inline int sysfs_create_link(struct kobject *kobj, 455 struct kobject *target, const char *name) 456 { 457 return 0; 458 } 459 460 static inline int sysfs_create_link_nowarn(struct kobject *kobj, 461 struct kobject *target, 462 const char *name) 463 { 464 return 0; 465 } 466 467 static inline void sysfs_remove_link(struct kobject *kobj, const char *name) 468 { 469 } 470 471 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t, 472 const char *old_name, 473 const char *new_name, const void *ns) 474 { 475 return 0; 476 } 477 478 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t, 479 const char *name) 480 { 481 } 482 483 static inline int sysfs_create_group(struct kobject *kobj, 484 const struct attribute_group *grp) 485 { 486 return 0; 487 } 488 489 static inline int sysfs_create_groups(struct kobject *kobj, 490 const struct attribute_group **groups) 491 { 492 return 0; 493 } 494 495 static inline int sysfs_update_groups(struct kobject *kobj, 496 const struct attribute_group **groups) 497 { 498 return 0; 499 } 500 501 static inline int sysfs_update_group(struct kobject *kobj, 502 const struct attribute_group *grp) 503 { 504 return 0; 505 } 506 507 static inline void sysfs_remove_group(struct kobject *kobj, 508 const struct attribute_group *grp) 509 { 510 } 511 512 static inline void sysfs_remove_groups(struct kobject *kobj, 513 const struct attribute_group **groups) 514 { 515 } 516 517 static inline int sysfs_add_file_to_group(struct kobject *kobj, 518 const struct attribute *attr, const char *group) 519 { 520 return 0; 521 } 522 523 static inline void sysfs_remove_file_from_group(struct kobject *kobj, 524 const struct attribute *attr, const char *group) 525 { 526 } 527 528 static inline int sysfs_merge_group(struct kobject *kobj, 529 const struct attribute_group *grp) 530 { 531 return 0; 532 } 533 534 static inline void sysfs_unmerge_group(struct kobject *kobj, 535 const struct attribute_group *grp) 536 { 537 } 538 539 static inline int sysfs_add_link_to_group(struct kobject *kobj, 540 const char *group_name, struct kobject *target, 541 const char *link_name) 542 { 543 return 0; 544 } 545 546 static inline void sysfs_remove_link_from_group(struct kobject *kobj, 547 const char *group_name, const char *link_name) 548 { 549 } 550 551 static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, 552 struct kobject *target_kobj, 553 const char *target_name, 554 const char *symlink_name) 555 { 556 return 0; 557 } 558 559 static inline void sysfs_notify(struct kobject *kobj, const char *dir, 560 const char *attr) 561 { 562 } 563 564 static inline int __must_check sysfs_init(void) 565 { 566 return 0; 567 } 568 569 static inline void sysfs_enable_ns(struct kernfs_node *kn) 570 { 571 } 572 573 static inline int sysfs_file_change_owner(struct kobject *kobj, 574 const char *name, kuid_t kuid, 575 kgid_t kgid) 576 { 577 return 0; 578 } 579 580 static inline int sysfs_link_change_owner(struct kobject *kobj, 581 struct kobject *targ, 582 const char *name, kuid_t kuid, 583 kgid_t kgid) 584 { 585 return 0; 586 } 587 588 static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid) 589 { 590 return 0; 591 } 592 593 static inline int sysfs_groups_change_owner(struct kobject *kobj, 594 const struct attribute_group **groups, 595 kuid_t kuid, kgid_t kgid) 596 { 597 return 0; 598 } 599 600 static inline int sysfs_group_change_owner(struct kobject *kobj, 601 const struct attribute_group *groups, 602 kuid_t kuid, kgid_t kgid) 603 { 604 return 0; 605 } 606 607 __printf(2, 3) 608 static inline int sysfs_emit(char *buf, const char *fmt, ...) 609 { 610 return 0; 611 } 612 613 __printf(3, 4) 614 static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...) 615 { 616 return 0; 617 } 618 #endif /* CONFIG_SYSFS */ 619 620 static inline int __must_check sysfs_create_file(struct kobject *kobj, 621 const struct attribute *attr) 622 { 623 return sysfs_create_file_ns(kobj, attr, NULL); 624 } 625 626 static inline void sysfs_remove_file(struct kobject *kobj, 627 const struct attribute *attr) 628 { 629 sysfs_remove_file_ns(kobj, attr, NULL); 630 } 631 632 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target, 633 const char *old_name, const char *new_name) 634 { 635 return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL); 636 } 637 638 static inline void sysfs_notify_dirent(struct kernfs_node *kn) 639 { 640 kernfs_notify(kn); 641 } 642 643 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent, 644 const char *name) 645 { 646 return kernfs_find_and_get(parent, name); 647 } 648 649 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn) 650 { 651 kernfs_get(kn); 652 return kn; 653 } 654 655 static inline void sysfs_put(struct kernfs_node *kn) 656 { 657 kernfs_put(kn); 658 } 659 660 #endif /* _SYSFS_H_ */ 661