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
25struct kobject;
26struct module;
27struct bin_attribute;
28enum kobj_ns_type;
29
30struct 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) \
52do { \
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 */
84struct 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) \
154static const struct attribute_group *_name##_groups[] = { \
155 &_name##_group, \
156 NULL, \
157}
158
159#define ATTRIBUTE_GROUPS(_name) \
160static const struct attribute_group _name##_group = { \
161 .attrs = _name##_attrs, \
162}; \
163__ATTRIBUTE_GROUPS(_name)
164
165#define BIN_ATTRIBUTE_GROUPS(_name) \
166static const struct attribute_group _name##_group = { \
167 .bin_attrs = _name##_attrs, \
168}; \
169__ATTRIBUTE_GROUPS(_name)
170
171struct file;
172struct vm_area_struct;
173struct address_space;
174
175struct 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 loff_t (*llseek)(struct file *, struct kobject *, struct bin_attribute *,
185 loff_t, int);
186 int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
187 struct vm_area_struct *vma);
188};
189
190/**
191 * sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
192 * @attr: struct bin_attribute to initialize
193 *
194 * Initialize a dynamically allocated struct bin_attribute so we
195 * can make lockdep happy. This is a new requirement for
196 * attributes and initially this is only needed when lockdep is
197 * enabled. Lockdep gives a nice error when your attribute is
198 * added to sysfs if you don't have this.
199 */
200#define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
201
202/* macros to create static binary attributes easier */
203#define __BIN_ATTR(_name, _mode, _read, _write, _size) { \
204 .attr = { .name = __stringify(_name), .mode = _mode }, \
205 .read = _read, \
206 .write = _write, \
207 .size = _size, \
208}
209
210#define __BIN_ATTR_RO(_name, _size) { \
211 .attr = { .name = __stringify(_name), .mode = 0444 }, \
212 .read = _name##_read, \
213 .size = _size, \
214}
215
216#define __BIN_ATTR_WO(_name, _size) { \
217 .attr = { .name = __stringify(_name), .mode = 0200 }, \
218 .write = _name##_write, \
219 .size = _size, \
220}
221
222#define __BIN_ATTR_RW(_name, _size) \
223 __BIN_ATTR(_name, 0644, _name##_read, _name##_write, _size)
224
225#define __BIN_ATTR_NULL __ATTR_NULL
226
227#define BIN_ATTR(_name, _mode, _read, _write, _size) \
228struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
229 _write, _size)
230
231#define BIN_ATTR_RO(_name, _size) \
232struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
233
234#define BIN_ATTR_WO(_name, _size) \
235struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)
236
237#define BIN_ATTR_RW(_name, _size) \
238struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
239
240
241#define __BIN_ATTR_ADMIN_RO(_name, _size) { \
242 .attr = { .name = __stringify(_name), .mode = 0400 }, \
243 .read = _name##_read, \
244 .size = _size, \
245}
246
247#define __BIN_ATTR_ADMIN_RW(_name, _size) \
248 __BIN_ATTR(_name, 0600, _name##_read, _name##_write, _size)
249
250#define BIN_ATTR_ADMIN_RO(_name, _size) \
251struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size)
252
253#define BIN_ATTR_ADMIN_RW(_name, _size) \
254struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size)
255
256struct sysfs_ops {
257 ssize_t (*show)(struct kobject *, struct attribute *, char *);
258 ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
259};
260
261#ifdef CONFIG_SYSFS
262
263int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
264void sysfs_remove_dir(struct kobject *kobj);
265int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
266 const void *new_ns);
267int __must_check sysfs_move_dir_ns(struct kobject *kobj,
268 struct kobject *new_parent_kobj,
269 const void *new_ns);
270int __must_check sysfs_create_mount_point(struct kobject *parent_kobj,
271 const char *name);
272void sysfs_remove_mount_point(struct kobject *parent_kobj,
273 const char *name);
274
275int __must_check sysfs_create_file_ns(struct kobject *kobj,
276 const struct attribute *attr,
277 const void *ns);
278int __must_check sysfs_create_files(struct kobject *kobj,
279 const struct attribute * const *attr);
280int __must_check sysfs_chmod_file(struct kobject *kobj,
281 const struct attribute *attr, umode_t mode);
282struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
283 const struct attribute *attr);
284void sysfs_unbreak_active_protection(struct kernfs_node *kn);
285void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
286 const void *ns);
287bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
288void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr);
289
290int __must_check sysfs_create_bin_file(struct kobject *kobj,
291 const struct bin_attribute *attr);
292void sysfs_remove_bin_file(struct kobject *kobj,
293 const struct bin_attribute *attr);
294
295int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
296 const char *name);
297int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
298 struct kobject *target,
299 const char *name);
300void sysfs_remove_link(struct kobject *kobj, const char *name);
301
302int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
303 const char *old_name, const char *new_name,
304 const void *new_ns);
305
306void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
307 const char *name);
308
309int __must_check sysfs_create_group(struct kobject *kobj,
310 const struct attribute_group *grp);
311int __must_check sysfs_create_groups(struct kobject *kobj,
312 const struct attribute_group **groups);
313int __must_check sysfs_update_groups(struct kobject *kobj,
314 const struct attribute_group **groups);
315int sysfs_update_group(struct kobject *kobj,
316 const struct attribute_group *grp);
317void sysfs_remove_group(struct kobject *kobj,
318 const struct attribute_group *grp);
319void sysfs_remove_groups(struct kobject *kobj,
320 const struct attribute_group **groups);
321int sysfs_add_file_to_group(struct kobject *kobj,
322 const struct attribute *attr, const char *group);
323void sysfs_remove_file_from_group(struct kobject *kobj,
324 const struct attribute *attr, const char *group);
325int sysfs_merge_group(struct kobject *kobj,
326 const struct attribute_group *grp);
327void sysfs_unmerge_group(struct kobject *kobj,
328 const struct attribute_group *grp);
329int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
330 struct kobject *target, const char *link_name);
331void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
332 const char *link_name);
333int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
334 struct kobject *target_kobj,
335 const char *target_name,
336 const char *symlink_name);
337
338void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
339
340int __must_check sysfs_init(void);
341
342static inline void sysfs_enable_ns(struct kernfs_node *kn)
343{
344 return kernfs_enable_ns(kn);
345}
346
347int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid,
348 kgid_t kgid);
349int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid);
350int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ,
351 const char *name, kuid_t kuid, kgid_t kgid);
352int sysfs_groups_change_owner(struct kobject *kobj,
353 const struct attribute_group **groups,
354 kuid_t kuid, kgid_t kgid);
355int sysfs_group_change_owner(struct kobject *kobj,
356 const struct attribute_group *groups, kuid_t kuid,
357 kgid_t kgid);
358__printf(2, 3)
359int sysfs_emit(char *buf, const char *fmt, ...);
360__printf(3, 4)
361int sysfs_emit_at(char *buf, int at, const char *fmt, ...);
362
363#else /* CONFIG_SYSFS */
364
365static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
366{
367 return 0;
368}
369
370static inline void sysfs_remove_dir(struct kobject *kobj)
371{
372}
373
374static inline int sysfs_rename_dir_ns(struct kobject *kobj,
375 const char *new_name, const void *new_ns)
376{
377 return 0;
378}
379
380static inline int sysfs_move_dir_ns(struct kobject *kobj,
381 struct kobject *new_parent_kobj,
382 const void *new_ns)
383{
384 return 0;
385}
386
387static inline int sysfs_create_mount_point(struct kobject *parent_kobj,
388 const char *name)
389{
390 return 0;
391}
392
393static inline void sysfs_remove_mount_point(struct kobject *parent_kobj,
394 const char *name)
395{
396}
397
398static inline int sysfs_create_file_ns(struct kobject *kobj,
399 const struct attribute *attr,
400 const void *ns)
401{
402 return 0;
403}
404
405static inline int sysfs_create_files(struct kobject *kobj,
406 const struct attribute * const *attr)
407{
408 return 0;
409}
410
411static inline int sysfs_chmod_file(struct kobject *kobj,
412 const struct attribute *attr, umode_t mode)
413{
414 return 0;
415}
416
417static inline struct kernfs_node *
418sysfs_break_active_protection(struct kobject *kobj,
419 const struct attribute *attr)
420{
421 return NULL;
422}
423
424static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn)
425{
426}
427
428static inline void sysfs_remove_file_ns(struct kobject *kobj,
429 const struct attribute *attr,
430 const void *ns)
431{
432}
433
434static inline bool sysfs_remove_file_self(struct kobject *kobj,
435 const struct attribute *attr)
436{
437 return false;
438}
439
440static inline void sysfs_remove_files(struct kobject *kobj,
441 const struct attribute * const *attr)
442{
443}
444
445static inline int sysfs_create_bin_file(struct kobject *kobj,
446 const struct bin_attribute *attr)
447{
448 return 0;
449}
450
451static inline void sysfs_remove_bin_file(struct kobject *kobj,
452 const struct bin_attribute *attr)
453{
454}
455
456static inline int sysfs_create_link(struct kobject *kobj,
457 struct kobject *target, const char *name)
458{
459 return 0;
460}
461
462static inline int sysfs_create_link_nowarn(struct kobject *kobj,
463 struct kobject *target,
464 const char *name)
465{
466 return 0;
467}
468
469static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
470{
471}
472
473static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
474 const char *old_name,
475 const char *new_name, const void *ns)
476{
477 return 0;
478}
479
480static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
481 const char *name)
482{
483}
484
485static inline int sysfs_create_group(struct kobject *kobj,
486 const struct attribute_group *grp)
487{
488 return 0;
489}
490
491static inline int sysfs_create_groups(struct kobject *kobj,
492 const struct attribute_group **groups)
493{
494 return 0;
495}
496
497static inline int sysfs_update_groups(struct kobject *kobj,
498 const struct attribute_group **groups)
499{
500 return 0;
501}
502
503static inline int sysfs_update_group(struct kobject *kobj,
504 const struct attribute_group *grp)
505{
506 return 0;
507}
508
509static inline void sysfs_remove_group(struct kobject *kobj,
510 const struct attribute_group *grp)
511{
512}
513
514static inline void sysfs_remove_groups(struct kobject *kobj,
515 const struct attribute_group **groups)
516{
517}
518
519static inline int sysfs_add_file_to_group(struct kobject *kobj,
520 const struct attribute *attr, const char *group)
521{
522 return 0;
523}
524
525static inline void sysfs_remove_file_from_group(struct kobject *kobj,
526 const struct attribute *attr, const char *group)
527{
528}
529
530static inline int sysfs_merge_group(struct kobject *kobj,
531 const struct attribute_group *grp)
532{
533 return 0;
534}
535
536static inline void sysfs_unmerge_group(struct kobject *kobj,
537 const struct attribute_group *grp)
538{
539}
540
541static inline int sysfs_add_link_to_group(struct kobject *kobj,
542 const char *group_name, struct kobject *target,
543 const char *link_name)
544{
545 return 0;
546}
547
548static inline void sysfs_remove_link_from_group(struct kobject *kobj,
549 const char *group_name, const char *link_name)
550{
551}
552
553static inline int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
554 struct kobject *target_kobj,
555 const char *target_name,
556 const char *symlink_name)
557{
558 return 0;
559}
560
561static inline void sysfs_notify(struct kobject *kobj, const char *dir,
562 const char *attr)
563{
564}
565
566static inline int __must_check sysfs_init(void)
567{
568 return 0;
569}
570
571static inline void sysfs_enable_ns(struct kernfs_node *kn)
572{
573}
574
575static inline int sysfs_file_change_owner(struct kobject *kobj,
576 const char *name, kuid_t kuid,
577 kgid_t kgid)
578{
579 return 0;
580}
581
582static inline int sysfs_link_change_owner(struct kobject *kobj,
583 struct kobject *targ,
584 const char *name, kuid_t kuid,
585 kgid_t kgid)
586{
587 return 0;
588}
589
590static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid)
591{
592 return 0;
593}
594
595static inline int sysfs_groups_change_owner(struct kobject *kobj,
596 const struct attribute_group **groups,
597 kuid_t kuid, kgid_t kgid)
598{
599 return 0;
600}
601
602static inline int sysfs_group_change_owner(struct kobject *kobj,
603 const struct attribute_group *groups,
604 kuid_t kuid, kgid_t kgid)
605{
606 return 0;
607}
608
609__printf(2, 3)
610static inline int sysfs_emit(char *buf, const char *fmt, ...)
611{
612 return 0;
613}
614
615__printf(3, 4)
616static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
617{
618 return 0;
619}
620#endif /* CONFIG_SYSFS */
621
622static inline int __must_check sysfs_create_file(struct kobject *kobj,
623 const struct attribute *attr)
624{
625 return sysfs_create_file_ns(kobj, attr, NULL);
626}
627
628static inline void sysfs_remove_file(struct kobject *kobj,
629 const struct attribute *attr)
630{
631 sysfs_remove_file_ns(kobj, attr, NULL);
632}
633
634static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
635 const char *old_name, const char *new_name)
636{
637 return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
638}
639
640static inline void sysfs_notify_dirent(struct kernfs_node *kn)
641{
642 kernfs_notify(kn);
643}
644
645static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
646 const char *name)
647{
648 return kernfs_find_and_get(kn: parent, name);
649}
650
651static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
652{
653 kernfs_get(kn);
654 return kn;
655}
656
657static inline void sysfs_put(struct kernfs_node *kn)
658{
659 kernfs_put(kn);
660}
661
662#endif /* _SYSFS_H_ */
663

source code of linux/include/linux/sysfs.h