1 /*
2  * sysfs.h - definitions for the device driver filesystem
3  *
4  * Copyright (c) 2001,2002 Patrick Mochel
5  * Copyright (c) 2004 Silicon Graphics, Inc.
6  * Copyright (c) 2007 SUSE Linux Products GmbH
7  * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
8  *
9  * Please see Documentation/filesystems/sysfs.txt for more information.
10  */
11 
12 #ifndef _SYSFS_H_
13 #define _SYSFS_H_
14 
15 #include <linux/kernfs.h>
16 #include <linux/compiler.h>
17 #include <linux/errno.h>
18 #include <linux/list.h>
19 #include <linux/lockdep.h>
20 #include <linux/kobject_ns.h>
21 #include <linux/stat.h>
22 #include <linux/atomic.h>
23 
24 struct kobject;
25 struct module;
26 struct bin_attribute;
27 enum kobj_ns_type;
28 
29 struct attribute {
30 	const char		*name;
31 	umode_t			mode;
32 #ifdef CONFIG_DEBUG_LOCK_ALLOC
33 	bool			ignore_lockdep:1;
34 	struct lock_class_key	*key;
35 	struct lock_class_key	skey;
36 #endif
37 };
38 
39 /**
40  *	sysfs_attr_init - initialize a dynamically allocated sysfs attribute
41  *	@attr: struct attribute to initialize
42  *
43  *	Initialize a dynamically allocated struct attribute so we can
44  *	make lockdep happy.  This is a new requirement for attributes
45  *	and initially this is only needed when lockdep is enabled.
46  *	Lockdep gives a nice error when your attribute is added to
47  *	sysfs if you don't have this.
48  */
49 #ifdef CONFIG_DEBUG_LOCK_ALLOC
50 #define sysfs_attr_init(attr)				\
51 do {							\
52 	static struct lock_class_key __key;		\
53 							\
54 	(attr)->key = &__key;				\
55 } while (0)
56 #else
57 #define sysfs_attr_init(attr) do {} while (0)
58 #endif
59 
60 /**
61  * struct attribute_group - data structure used to declare an attribute group.
62  * @name:	Optional: Attribute group name
63  *		If specified, the attribute group will be created in
64  *		a new subdirectory with this name.
65  * @is_visible:	Optional: Function to return permissions associated with an
66  *		attribute of the group. Will be called repeatedly for each
67  *		non-binary attribute in the group. Only read/write
68  *		permissions as well as SYSFS_PREALLOC are accepted. Must
69  *		return 0 if an attribute is not visible. The returned value
70  *		will replace static permissions defined in struct attribute.
71  * @is_bin_visible:
72  *		Optional: Function to return permissions associated with a
73  *		binary attribute of the group. Will be called repeatedly
74  *		for each binary attribute in the group. Only read/write
75  *		permissions as well as SYSFS_PREALLOC are accepted. Must
76  *		return 0 if a binary attribute is not visible. The returned
77  *		value will replace static permissions defined in
78  *		struct bin_attribute.
79  * @attrs:	Pointer to NULL terminated list of attributes.
80  * @bin_attrs:	Pointer to NULL terminated list of binary attributes.
81  *		Either attrs or bin_attrs or both must be provided.
82  */
83 struct attribute_group {
84 	const char		*name;
85 	umode_t			(*is_visible)(struct kobject *,
86 					      struct attribute *, int);
87 	umode_t			(*is_bin_visible)(struct kobject *,
88 						  struct bin_attribute *, int);
89 	struct attribute	**attrs;
90 	struct bin_attribute	**bin_attrs;
91 };
92 
93 /**
94  * Use these macros to make defining attributes easier. See include/linux/device.h
95  * for examples..
96  */
97 
98 #define SYSFS_PREALLOC 010000
99 
100 #define __ATTR(_name, _mode, _show, _store) {				\
101 	.attr = {.name = __stringify(_name),				\
102 		 .mode = VERIFY_OCTAL_PERMISSIONS(_mode) },		\
103 	.show	= _show,						\
104 	.store	= _store,						\
105 }
106 
107 #define __ATTR_PREALLOC(_name, _mode, _show, _store) {			\
108 	.attr = {.name = __stringify(_name),				\
109 		 .mode = SYSFS_PREALLOC | VERIFY_OCTAL_PERMISSIONS(_mode) },\
110 	.show	= _show,						\
111 	.store	= _store,						\
112 }
113 
114 #define __ATTR_RO(_name) {						\
115 	.attr	= { .name = __stringify(_name), .mode = S_IRUGO },	\
116 	.show	= _name##_show,						\
117 }
118 
119 #define __ATTR_WO(_name) {						\
120 	.attr	= { .name = __stringify(_name), .mode = S_IWUSR },	\
121 	.store	= _name##_store,					\
122 }
123 
124 #define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO),		\
125 			 _name##_show, _name##_store)
126 
127 #define __ATTR_NULL { .attr = { .name = NULL } }
128 
129 #ifdef CONFIG_DEBUG_LOCK_ALLOC
130 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {	\
131 	.attr = {.name = __stringify(_name), .mode = _mode,	\
132 			.ignore_lockdep = true },		\
133 	.show		= _show,				\
134 	.store		= _store,				\
135 }
136 #else
137 #define __ATTR_IGNORE_LOCKDEP	__ATTR
138 #endif
139 
140 #define __ATTRIBUTE_GROUPS(_name)				\
141 static const struct attribute_group *_name##_groups[] = {	\
142 	&_name##_group,						\
143 	NULL,							\
144 }
145 
146 #define ATTRIBUTE_GROUPS(_name)					\
147 static const struct attribute_group _name##_group = {		\
148 	.attrs = _name##_attrs,					\
149 };								\
150 __ATTRIBUTE_GROUPS(_name)
151 
152 struct file;
153 struct vm_area_struct;
154 
155 struct bin_attribute {
156 	struct attribute	attr;
157 	size_t			size;
158 	void			*private;
159 	ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
160 			char *, loff_t, size_t);
161 	ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,
162 			 char *, loff_t, size_t);
163 	int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
164 		    struct vm_area_struct *vma);
165 };
166 
167 /**
168  *	sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
169  *	@attr: struct bin_attribute to initialize
170  *
171  *	Initialize a dynamically allocated struct bin_attribute so we
172  *	can make lockdep happy.  This is a new requirement for
173  *	attributes and initially this is only needed when lockdep is
174  *	enabled.  Lockdep gives a nice error when your attribute is
175  *	added to sysfs if you don't have this.
176  */
177 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
178 
179 /* macros to create static binary attributes easier */
180 #define __BIN_ATTR(_name, _mode, _read, _write, _size) {		\
181 	.attr = { .name = __stringify(_name), .mode = _mode },		\
182 	.read	= _read,						\
183 	.write	= _write,						\
184 	.size	= _size,						\
185 }
186 
187 #define __BIN_ATTR_RO(_name, _size) {					\
188 	.attr	= { .name = __stringify(_name), .mode = S_IRUGO },	\
189 	.read	= _name##_read,						\
190 	.size	= _size,						\
191 }
192 
193 #define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name,			\
194 				   (S_IWUSR | S_IRUGO), _name##_read,	\
195 				   _name##_write, _size)
196 
197 #define __BIN_ATTR_NULL __ATTR_NULL
198 
199 #define BIN_ATTR(_name, _mode, _read, _write, _size)			\
200 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read,	\
201 					_write, _size)
202 
203 #define BIN_ATTR_RO(_name, _size)					\
204 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
205 
206 #define BIN_ATTR_RW(_name, _size)					\
207 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
208 
209 struct sysfs_ops {
210 	ssize_t	(*show)(struct kobject *, struct attribute *, char *);
211 	ssize_t	(*store)(struct kobject *, struct attribute *, const char *, size_t);
212 };
213 
214 #ifdef CONFIG_SYSFS
215 
216 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
217 void sysfs_remove_dir(struct kobject *kobj);
218 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
219 				     const void *new_ns);
220 int __must_check sysfs_move_dir_ns(struct kobject *kobj,
221 				   struct kobject *new_parent_kobj,
222 				   const void *new_ns);
223 int __must_check sysfs_create_mount_point(struct kobject *parent_kobj,
224 					  const char *name);
225 void sysfs_remove_mount_point(struct kobject *parent_kobj,
226 			      const char *name);
227 
228 int __must_check sysfs_create_file_ns(struct kobject *kobj,
229 				      const struct attribute *attr,
230 				      const void *ns);
231 int __must_check sysfs_create_files(struct kobject *kobj,
232 				   const struct attribute **attr);
233 int __must_check sysfs_chmod_file(struct kobject *kobj,
234 				  const struct attribute *attr, umode_t mode);
235 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
236 			  const void *ns);
237 bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr);
238 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
239 
240 int __must_check sysfs_create_bin_file(struct kobject *kobj,
241 				       const struct bin_attribute *attr);
242 void sysfs_remove_bin_file(struct kobject *kobj,
243 			   const struct bin_attribute *attr);
244 
245 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
246 				   const char *name);
247 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
248 					  struct kobject *target,
249 					  const char *name);
250 void sysfs_remove_link(struct kobject *kobj, const char *name);
251 
252 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
253 			 const char *old_name, const char *new_name,
254 			 const void *new_ns);
255 
256 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
257 			const char *name);
258 
259 int __must_check sysfs_create_group(struct kobject *kobj,
260 				    const struct attribute_group *grp);
261 int __must_check sysfs_create_groups(struct kobject *kobj,
262 				     const struct attribute_group **groups);
263 int sysfs_update_group(struct kobject *kobj,
264 		       const struct attribute_group *grp);
265 void sysfs_remove_group(struct kobject *kobj,
266 			const struct attribute_group *grp);
267 void sysfs_remove_groups(struct kobject *kobj,
268 			 const struct attribute_group **groups);
269 int sysfs_add_file_to_group(struct kobject *kobj,
270 			const struct attribute *attr, const char *group);
271 void sysfs_remove_file_from_group(struct kobject *kobj,
272 			const struct attribute *attr, const char *group);
273 int sysfs_merge_group(struct kobject *kobj,
274 		       const struct attribute_group *grp);
275 void sysfs_unmerge_group(struct kobject *kobj,
276 		       const struct attribute_group *grp);
277 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
278 			    struct kobject *target, const char *link_name);
279 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
280 				  const char *link_name);
281 int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
282 				      struct kobject *target_kobj,
283 				      const char *target_name);
284 
285 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
286 
287 int __must_check sysfs_init(void);
288 
sysfs_enable_ns(struct kernfs_node * kn)289 static inline void sysfs_enable_ns(struct kernfs_node *kn)
290 {
291 	return kernfs_enable_ns(kn);
292 }
293 
294 #else /* CONFIG_SYSFS */
295 
sysfs_create_dir_ns(struct kobject * kobj,const void * ns)296 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
297 {
298 	return 0;
299 }
300 
sysfs_remove_dir(struct kobject * kobj)301 static inline void sysfs_remove_dir(struct kobject *kobj)
302 {
303 }
304 
sysfs_rename_dir_ns(struct kobject * kobj,const char * new_name,const void * new_ns)305 static inline int sysfs_rename_dir_ns(struct kobject *kobj,
306 				      const char *new_name, const void *new_ns)
307 {
308 	return 0;
309 }
310 
sysfs_move_dir_ns(struct kobject * kobj,struct kobject * new_parent_kobj,const void * new_ns)311 static inline int sysfs_move_dir_ns(struct kobject *kobj,
312 				    struct kobject *new_parent_kobj,
313 				    const void *new_ns)
314 {
315 	return 0;
316 }
317 
sysfs_create_mount_point(struct kobject * parent_kobj,const char * name)318 static inline int sysfs_create_mount_point(struct kobject *parent_kobj,
319 					   const char *name)
320 {
321 	return 0;
322 }
323 
sysfs_remove_mount_point(struct kobject * parent_kobj,const char * name)324 static inline void sysfs_remove_mount_point(struct kobject *parent_kobj,
325 					    const char *name)
326 {
327 }
328 
sysfs_create_file_ns(struct kobject * kobj,const struct attribute * attr,const void * ns)329 static inline int sysfs_create_file_ns(struct kobject *kobj,
330 				       const struct attribute *attr,
331 				       const void *ns)
332 {
333 	return 0;
334 }
335 
sysfs_create_files(struct kobject * kobj,const struct attribute ** attr)336 static inline int sysfs_create_files(struct kobject *kobj,
337 				    const struct attribute **attr)
338 {
339 	return 0;
340 }
341 
sysfs_chmod_file(struct kobject * kobj,const struct attribute * attr,umode_t mode)342 static inline int sysfs_chmod_file(struct kobject *kobj,
343 				   const struct attribute *attr, umode_t mode)
344 {
345 	return 0;
346 }
347 
sysfs_remove_file_ns(struct kobject * kobj,const struct attribute * attr,const void * ns)348 static inline void sysfs_remove_file_ns(struct kobject *kobj,
349 					const struct attribute *attr,
350 					const void *ns)
351 {
352 }
353 
sysfs_remove_file_self(struct kobject * kobj,const struct attribute * attr)354 static inline bool sysfs_remove_file_self(struct kobject *kobj,
355 					  const struct attribute *attr)
356 {
357 	return false;
358 }
359 
sysfs_remove_files(struct kobject * kobj,const struct attribute ** attr)360 static inline void sysfs_remove_files(struct kobject *kobj,
361 				     const struct attribute **attr)
362 {
363 }
364 
sysfs_create_bin_file(struct kobject * kobj,const struct bin_attribute * attr)365 static inline int sysfs_create_bin_file(struct kobject *kobj,
366 					const struct bin_attribute *attr)
367 {
368 	return 0;
369 }
370 
sysfs_remove_bin_file(struct kobject * kobj,const struct bin_attribute * attr)371 static inline void sysfs_remove_bin_file(struct kobject *kobj,
372 					 const struct bin_attribute *attr)
373 {
374 }
375 
sysfs_create_link(struct kobject * kobj,struct kobject * target,const char * name)376 static inline int sysfs_create_link(struct kobject *kobj,
377 				    struct kobject *target, const char *name)
378 {
379 	return 0;
380 }
381 
sysfs_create_link_nowarn(struct kobject * kobj,struct kobject * target,const char * name)382 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
383 					   struct kobject *target,
384 					   const char *name)
385 {
386 	return 0;
387 }
388 
sysfs_remove_link(struct kobject * kobj,const char * name)389 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
390 {
391 }
392 
sysfs_rename_link_ns(struct kobject * k,struct kobject * t,const char * old_name,const char * new_name,const void * ns)393 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
394 				       const char *old_name,
395 				       const char *new_name, const void *ns)
396 {
397 	return 0;
398 }
399 
sysfs_delete_link(struct kobject * k,struct kobject * t,const char * name)400 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
401 				     const char *name)
402 {
403 }
404 
sysfs_create_group(struct kobject * kobj,const struct attribute_group * grp)405 static inline int sysfs_create_group(struct kobject *kobj,
406 				     const struct attribute_group *grp)
407 {
408 	return 0;
409 }
410 
sysfs_create_groups(struct kobject * kobj,const struct attribute_group ** groups)411 static inline int sysfs_create_groups(struct kobject *kobj,
412 				      const struct attribute_group **groups)
413 {
414 	return 0;
415 }
416 
sysfs_update_group(struct kobject * kobj,const struct attribute_group * grp)417 static inline int sysfs_update_group(struct kobject *kobj,
418 				const struct attribute_group *grp)
419 {
420 	return 0;
421 }
422 
sysfs_remove_group(struct kobject * kobj,const struct attribute_group * grp)423 static inline void sysfs_remove_group(struct kobject *kobj,
424 				      const struct attribute_group *grp)
425 {
426 }
427 
sysfs_remove_groups(struct kobject * kobj,const struct attribute_group ** groups)428 static inline void sysfs_remove_groups(struct kobject *kobj,
429 				       const struct attribute_group **groups)
430 {
431 }
432 
sysfs_add_file_to_group(struct kobject * kobj,const struct attribute * attr,const char * group)433 static inline int sysfs_add_file_to_group(struct kobject *kobj,
434 		const struct attribute *attr, const char *group)
435 {
436 	return 0;
437 }
438 
sysfs_remove_file_from_group(struct kobject * kobj,const struct attribute * attr,const char * group)439 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
440 		const struct attribute *attr, const char *group)
441 {
442 }
443 
sysfs_merge_group(struct kobject * kobj,const struct attribute_group * grp)444 static inline int sysfs_merge_group(struct kobject *kobj,
445 		       const struct attribute_group *grp)
446 {
447 	return 0;
448 }
449 
sysfs_unmerge_group(struct kobject * kobj,const struct attribute_group * grp)450 static inline void sysfs_unmerge_group(struct kobject *kobj,
451 		       const struct attribute_group *grp)
452 {
453 }
454 
sysfs_add_link_to_group(struct kobject * kobj,const char * group_name,struct kobject * target,const char * link_name)455 static inline int sysfs_add_link_to_group(struct kobject *kobj,
456 		const char *group_name, struct kobject *target,
457 		const char *link_name)
458 {
459 	return 0;
460 }
461 
sysfs_remove_link_from_group(struct kobject * kobj,const char * group_name,const char * link_name)462 static inline void sysfs_remove_link_from_group(struct kobject *kobj,
463 		const char *group_name, const char *link_name)
464 {
465 }
466 
__compat_only_sysfs_link_entry_to_kobj(struct kobject * kobj,struct kobject * target_kobj,const char * target_name)467 static inline int __compat_only_sysfs_link_entry_to_kobj(
468 	struct kobject *kobj,
469 	struct kobject *target_kobj,
470 	const char *target_name)
471 {
472 	return 0;
473 }
474 
sysfs_notify(struct kobject * kobj,const char * dir,const char * attr)475 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
476 				const char *attr)
477 {
478 }
479 
sysfs_init(void)480 static inline int __must_check sysfs_init(void)
481 {
482 	return 0;
483 }
484 
sysfs_enable_ns(struct kernfs_node * kn)485 static inline void sysfs_enable_ns(struct kernfs_node *kn)
486 {
487 }
488 
489 #endif /* CONFIG_SYSFS */
490 
sysfs_create_file(struct kobject * kobj,const struct attribute * attr)491 static inline int __must_check sysfs_create_file(struct kobject *kobj,
492 						 const struct attribute *attr)
493 {
494 	return sysfs_create_file_ns(kobj, attr, NULL);
495 }
496 
sysfs_remove_file(struct kobject * kobj,const struct attribute * attr)497 static inline void sysfs_remove_file(struct kobject *kobj,
498 				     const struct attribute *attr)
499 {
500 	sysfs_remove_file_ns(kobj, attr, NULL);
501 }
502 
sysfs_rename_link(struct kobject * kobj,struct kobject * target,const char * old_name,const char * new_name)503 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
504 				    const char *old_name, const char *new_name)
505 {
506 	return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
507 }
508 
sysfs_notify_dirent(struct kernfs_node * kn)509 static inline void sysfs_notify_dirent(struct kernfs_node *kn)
510 {
511 	kernfs_notify(kn);
512 }
513 
sysfs_get_dirent(struct kernfs_node * parent,const unsigned char * name)514 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
515 						   const unsigned char *name)
516 {
517 	return kernfs_find_and_get(parent, name);
518 }
519 
sysfs_get(struct kernfs_node * kn)520 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
521 {
522 	kernfs_get(kn);
523 	return kn;
524 }
525 
sysfs_put(struct kernfs_node * kn)526 static inline void sysfs_put(struct kernfs_node *kn)
527 {
528 	kernfs_put(kn);
529 }
530 
531 #endif /* _SYSFS_H_ */
532