Line data Source code
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 0 : 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 1154 : 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 3 : 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 : {
635 711 : kernfs_get(kn);
636 : return kn;
637 : }
638 :
639 : static inline void sysfs_put(struct kernfs_node *kn)
640 : {
641 1 : kernfs_put(kn);
642 : }
643 :
644 : #endif /* _SYSFS_H_ */
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