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 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) \
226struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
227 _write, _size)
228
229#define BIN_ATTR_RO(_name, _size) \
230struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
231
232#define BIN_ATTR_WO(_name, _size) \
233struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)
234
235#define BIN_ATTR_RW(_name, _size) \
236struct 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) \
249struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size)
250
251#define BIN_ATTR_ADMIN_RW(_name, _size) \
252struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size)
253
254struct 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
261int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
262void sysfs_remove_dir(struct kobject *kobj);
263int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
264 const void *new_ns);
265int __must_check sysfs_move_dir_ns(struct kobject *kobj,
266 struct kobject *new_parent_kobj,
267 const void *new_ns);
268int __must_check sysfs_create_mount_point(struct kobject *parent_kobj,
269 const char *name);
270void sysfs_remove_mount_point(struct kobject *parent_kobj,
271 const char *name);
272
273int __must_check sysfs_create_file_ns(struct kobject *kobj,
274 const struct attribute *attr,
275 const void *ns);
276int __must_check sysfs_create_files(struct kobject *kobj,
277 const struct attribute * const *attr);
278int __must_check sysfs_chmod_file(struct kobject *kobj,
279 const struct attribute *attr, umode_t mode);
280struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
281 const struct attribute *attr);
282void sysfs_unbreak_active_protection(struct kernfs_node *kn);
283void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
284 const void *ns);
285bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
286void sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attr);
287
288int __must_check sysfs_create_bin_file(struct kobject *kobj,
289 const struct bin_attribute *attr);
290void sysfs_remove_bin_file(struct kobject *kobj,
291 const struct bin_attribute *attr);
292
293int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
294 const char *name);
295int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
296 struct kobject *target,
297 const char *name);
298void sysfs_remove_link(struct kobject *kobj, const char *name);
299
300int 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
304void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
305 const char *name);
306
307int __must_check sysfs_create_group(struct kobject *kobj,
308 const struct attribute_group *grp);
309int __must_check sysfs_create_groups(struct kobject *kobj,
310 const struct attribute_group **groups);
311int __must_check sysfs_update_groups(struct kobject *kobj,
312 const struct attribute_group **groups);
313int sysfs_update_group(struct kobject *kobj,
314 const struct attribute_group *grp);
315void sysfs_remove_group(struct kobject *kobj,
316 const struct attribute_group *grp);
317void sysfs_remove_groups(struct kobject *kobj,
318 const struct attribute_group **groups);
319int sysfs_add_file_to_group(struct kobject *kobj,
320 const struct attribute *attr, const char *group);
321void sysfs_remove_file_from_group(struct kobject *kobj,
322 const struct attribute *attr, const char *group);
323int sysfs_merge_group(struct kobject *kobj,
324 const struct attribute_group *grp);
325void sysfs_unmerge_group(struct kobject *kobj,
326 const struct attribute_group *grp);
327int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
328 struct kobject *target, const char *link_name);
329void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
330 const char *link_name);
331int 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
336void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
337
338int __must_check sysfs_init(void);
339
340static inline void sysfs_enable_ns(struct kernfs_node *kn)
341{
342 return kernfs_enable_ns(kn);
343}
344
345int sysfs_file_change_owner(struct kobject *kobj, const char *name, kuid_t kuid,
346 kgid_t kgid);
347int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid);
348int sysfs_link_change_owner(struct kobject *kobj, struct kobject *targ,
349 const char *name, kuid_t kuid, kgid_t kgid);
350int sysfs_groups_change_owner(struct kobject *kobj,
351 const struct attribute_group **groups,
352 kuid_t kuid, kgid_t kgid);
353int sysfs_group_change_owner(struct kobject *kobj,
354 const struct attribute_group *groups, kuid_t kuid,
355 kgid_t kgid);
356__printf(2, 3)
357int sysfs_emit(char *buf, const char *fmt, ...);
358__printf(3, 4)
359int sysfs_emit_at(char *buf, int at, const char *fmt, ...);
360
361#else /* CONFIG_SYSFS */
362
363static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
364{
365 return 0;
366}
367
368static inline void sysfs_remove_dir(struct kobject *kobj)
369{
370}
371
372static inline int sysfs_rename_dir_ns(struct kobject *kobj,
373 const char *new_name, const void *new_ns)
374{
375 return 0;
376}
377
378static 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
385static inline int sysfs_create_mount_point(struct kobject *parent_kobj,
386 const char *name)
387{
388 return 0;
389}
390
391static inline void sysfs_remove_mount_point(struct kobject *parent_kobj,
392 const char *name)
393{
394}
395
396static inline int sysfs_create_file_ns(struct kobject *kobj,
397 const struct attribute *attr,
398 const void *ns)
399{
400 return 0;
401}
402
403static inline int sysfs_create_files(struct kobject *kobj,
404 const struct attribute * const *attr)
405{
406 return 0;
407}
408
409static inline int sysfs_chmod_file(struct kobject *kobj,
410 const struct attribute *attr, umode_t mode)
411{
412 return 0;
413}
414
415static inline struct kernfs_node *
416sysfs_break_active_protection(struct kobject *kobj,
417 const struct attribute *attr)
418{
419 return NULL;
420}
421
422static inline void sysfs_unbreak_active_protection(struct kernfs_node *kn)
423{
424}
425
426static inline void sysfs_remove_file_ns(struct kobject *kobj,
427 const struct attribute *attr,
428 const void *ns)
429{
430}
431
432static inline bool sysfs_remove_file_self(struct kobject *kobj,
433 const struct attribute *attr)
434{
435 return false;
436}
437
438static inline void sysfs_remove_files(struct kobject *kobj,
439 const struct attribute * const *attr)
440{
441}
442
443static inline int sysfs_create_bin_file(struct kobject *kobj,
444 const struct bin_attribute *attr)
445{
446 return 0;
447}
448
449static inline void sysfs_remove_bin_file(struct kobject *kobj,
450 const struct bin_attribute *attr)
451{
452}
453
454static inline int sysfs_create_link(struct kobject *kobj,
455 struct kobject *target, const char *name)
456{
457 return 0;
458}
459
460static inline int sysfs_create_link_nowarn(struct kobject *kobj,
461 struct kobject *target,
462 const char *name)
463{
464 return 0;
465}
466
467static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
468{
469}
470
471static 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
478static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
479 const char *name)
480{
481}
482
483static inline int sysfs_create_group(struct kobject *kobj,
484 const struct attribute_group *grp)
485{
486 return 0;
487}
488
489static inline int sysfs_create_groups(struct kobject *kobj,
490 const struct attribute_group **groups)
491{
492 return 0;
493}
494
495static inline int sysfs_update_groups(struct kobject *kobj,
496 const struct attribute_group **groups)
497{
498 return 0;
499}
500
501static inline int sysfs_update_group(struct kobject *kobj,
502 const struct attribute_group *grp)
503{
504 return 0;
505}
506
507static inline void sysfs_remove_group(struct kobject *kobj,
508 const struct attribute_group *grp)
509{
510}
511
512static inline void sysfs_remove_groups(struct kobject *kobj,
513 const struct attribute_group **groups)
514{
515}
516
517static inline int sysfs_add_file_to_group(struct kobject *kobj,
518 const struct attribute *attr, const char *group)
519{
520 return 0;
521}
522
523static inline void sysfs_remove_file_from_group(struct kobject *kobj,
524 const struct attribute *attr, const char *group)
525{
526}
527
528static inline int sysfs_merge_group(struct kobject *kobj,
529 const struct attribute_group *grp)
530{
531 return 0;
532}
533
534static inline void sysfs_unmerge_group(struct kobject *kobj,
535 const struct attribute_group *grp)
536{
537}
538
539static 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
546static inline void sysfs_remove_link_from_group(struct kobject *kobj,
547 const char *group_name, const char *link_name)
548{
549}
550
551static 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
559static inline void sysfs_notify(struct kobject *kobj, const char *dir,
560 const char *attr)
561{
562}
563
564static inline int __must_check sysfs_init(void)
565{
566 return 0;
567}
568
569static inline void sysfs_enable_ns(struct kernfs_node *kn)
570{
571}
572
573static 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
580static 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
588static inline int sysfs_change_owner(struct kobject *kobj, kuid_t kuid, kgid_t kgid)
589{
590 return 0;
591}
592
593static 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
600static 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)
608static inline int sysfs_emit(char *buf, const char *fmt, ...)
609{
610 return 0;
611}
612
613__printf(3, 4)
614static inline int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
615{
616 return 0;
617}
618#endif /* CONFIG_SYSFS */
619
620static 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
626static inline void sysfs_remove_file(struct kobject *kobj,
627 const struct attribute *attr)
628{
629 sysfs_remove_file_ns(kobj, attr, NULL);
630}
631
632static 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(k: kobj, t: target, old_name, new_name, NULL);
636}
637
638static inline void sysfs_notify_dirent(struct kernfs_node *kn)
639{
640 kernfs_notify(kn);
641}
642
643static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
644 const char *name)
645{
646 return kernfs_find_and_get(kn: parent, name);
647}
648
649static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
650{
651 kernfs_get(kn);
652 return kn;
653}
654
655static inline void sysfs_put(struct kernfs_node *kn)
656{
657 kernfs_put(kn);
658}
659
660#endif /* _SYSFS_H_ */
661

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