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