include/linux/sysfs.h

   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/compiler.h>
  16 #include <linux/errno.h>
  17 #include <linux/list.h>
  18 #include <linux/lockdep.h>
  19 #include <linux/kobject_ns.h>
  20 #include <linux/atomic.h>
  21
  22 struct kobject;
  23 struct module;
  24 enum kobj_ns_type;
  25
  26 struct attribute {
  27         const char              *name;
  28         umode_t                 mode;
  29 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  30         bool                    ignore_lockdep:1;
  31         struct lock_class_key   *key;
  32         struct lock_class_key   skey;
  33 #endif
  34 };
  35
  36 /**
  37  *      sysfs_attr_init - initialize a dynamically allocated sysfs attribute
  38  *      @attr: struct attribute to initialize
  39  *
  40  *      Initialize a dynamically allocated struct attribute so we can
  41  *      make lockdep happy.  This is a new requirement for attributes
  42  *      and initially this is only needed when lockdep is enabled.
  43  *      Lockdep gives a nice error when your attribute is added to
  44  *      sysfs if you don't have this.
  45  */
  46 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  47 #define sysfs_attr_init(attr)                           \
  48 do {                                                    \
  49         static struct lock_class_key __key;             \
  50                                                         \
  51         (attr)->key = &__key;                           \
  52 } while(0)
  53 #else
  54 #define sysfs_attr_init(attr) do {} while(0)
  55 #endif
  56
  57 struct attribute_group {
  58         const char              *name;
  59         umode_t                 (*is_visible)(struct kobject *,
  60                                               struct attribute *, int);
  61         struct attribute        **attrs;
  62 };
  63
  64
  65
  66 /**
  67  * Use these macros to make defining attributes easier. See include/linux/device.h
  68  * for examples..
  69  */
  70
  71 #define __ATTR(_name,_mode,_show,_store) { \
  72         .attr = {.name = __stringify(_name), .mode = _mode },   \
  73         .show   = _show,                                        \
  74         .store  = _store,                                       \
  75 }
  76
  77 #define __ATTR_RO(_name) { \
  78         .attr   = { .name = __stringify(_name), .mode = 0444 }, \
  79         .show   = _name##_show,                                 \
  80 }
  81
  82 #define __ATTR_NULL { .attr = { .name = NULL } }
  83
  84 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  85 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {    \
  86         .attr = {.name = __stringify(_name), .mode = _mode,     \
  87                         .ignore_lockdep = true },               \
  88         .show           = _show,                                \
  89         .store          = _store,                               \
  90 }
  91 #else
  92 #define __ATTR_IGNORE_LOCKDEP   __ATTR
  93 #endif
  94
  95 #define attr_name(_attr) (_attr).attr.name
  96
  97 struct file;
  98 struct vm_area_struct;
  99
 100 struct bin_attribute {
 101         struct attribute        attr;
 102         size_t                  size;
 103         void                    *private;
 104         ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
 105                         char *, loff_t, size_t);
 106         ssize_t (*write)(struct file *,struct kobject *, struct bin_attribute *,
 107                          char *, loff_t, size_t);
 108         int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
 109                     struct vm_area_struct *vma);
 110 };
 111
 112 /**
 113  *      sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
 114  *      @attr: struct bin_attribute to initialize
 115  *
 116  *      Initialize a dynamically allocated struct bin_attribute so we
 117  *      can make lockdep happy.  This is a new requirement for
 118  *      attributes and initially this is only needed when lockdep is
 119  *      enabled.  Lockdep gives a nice error when your attribute is
 120  *      added to sysfs if you don't have this.
 121  */
 122 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
 123
 124 struct sysfs_ops {
 125         ssize_t (*show)(struct kobject *, struct attribute *,char *);
 126         ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t);
 127         const void *(*namespace)(struct kobject *, const struct attribute *);
 128 };
 129
 130 struct sysfs_dirent;
 131
 132 #ifdef CONFIG_SYSFS
 133
 134 int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
 135                             void *data, struct module *owner);
 136
 137 int __must_check sysfs_create_dir(struct kobject *kobj);
 138 void sysfs_remove_dir(struct kobject *kobj);
 139 int __must_check sysfs_rename_dir(struct kobject *kobj, const char *new_name);
 140 int __must_check sysfs_move_dir(struct kobject *kobj,
 141                                 struct kobject *new_parent_kobj);
 142
 143 int __must_check sysfs_create_file(struct kobject *kobj,
 144                                    const struct attribute *attr);
 145 int __must_check sysfs_create_files(struct kobject *kobj,
 146                                    const struct attribute **attr);
 147 int __must_check sysfs_chmod_file(struct kobject *kobj,
 148                                   const struct attribute *attr, umode_t mode);
 149 void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr);
 150 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
 151
 152 int __must_check sysfs_create_bin_file(struct kobject *kobj,
 153                                        const struct bin_attribute *attr);
 154 void sysfs_remove_bin_file(struct kobject *kobj,
 155                            const struct bin_attribute *attr);
 156
 157 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
 158                                    const char *name);
 159 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
 160                                           struct kobject *target,
 161                                           const char *name);
 162 void sysfs_remove_link(struct kobject *kobj, const char *name);
 163
 164 int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 165                         const char *old_name, const char *new_name);
 166
 167 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 168                         const char *name);
 169
 170 int __must_check sysfs_create_group(struct kobject *kobj,
 171                                     const struct attribute_group *grp);
 172 int sysfs_update_group(struct kobject *kobj,
 173                        const struct attribute_group *grp);
 174 void sysfs_remove_group(struct kobject *kobj,
 175                         const struct attribute_group *grp);
 176 int sysfs_add_file_to_group(struct kobject *kobj,
 177                         const struct attribute *attr, const char *group);
 178 void sysfs_remove_file_from_group(struct kobject *kobj,
 179                         const struct attribute *attr, const char *group);
 180 int sysfs_merge_group(struct kobject *kobj,
 181                        const struct attribute_group *grp);
 182 void sysfs_unmerge_group(struct kobject *kobj,
 183                        const struct attribute_group *grp);
 184
 185 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 186 void sysfs_notify_dirent(struct sysfs_dirent *sd);
 187 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 188                                       const void *ns,
 189                                       const unsigned char *name);
 190 struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd);
 191 void sysfs_put(struct sysfs_dirent *sd);
 192
 193 int __must_check sysfs_init(void);
 194
 195 #else /* CONFIG_SYSFS */
 196
 197 static inline int sysfs_schedule_callback(struct kobject *kobj,
 198                 void (*func)(void *), void *data, struct module *owner)
 199 {
 200         return -ENOSYS;
 201 }
 202
 203 static inline int sysfs_create_dir(struct kobject *kobj)
 204 {
 205         return 0;
 206 }
 207
 208 static inline void sysfs_remove_dir(struct kobject *kobj)
 209 {
 210 }
 211
 212 static inline int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
 213 {
 214         return 0;
 215 }
 216
 217 static inline int sysfs_move_dir(struct kobject *kobj,
 218                                  struct kobject *new_parent_kobj)
 219 {
 220         return 0;
 221 }
 222
 223 static inline int sysfs_create_file(struct kobject *kobj,
 224                                     const struct attribute *attr)
 225 {
 226         return 0;
 227 }
 228
 229 static inline int sysfs_create_files(struct kobject *kobj,
 230                                     const struct attribute **attr)
 231 {
 232         return 0;
 233 }
 234
 235 static inline int sysfs_chmod_file(struct kobject *kobj,
 236                                    const struct attribute *attr, umode_t mode)
 237 {
 238         return 0;
 239 }
 240
 241 static inline void sysfs_remove_file(struct kobject *kobj,
 242                                      const struct attribute *attr)
 243 {
 244 }
 245
 246 static inline void sysfs_remove_files(struct kobject *kobj,
 247                                      const struct attribute **attr)
 248 {
 249 }
 250
 251 static inline int sysfs_create_bin_file(struct kobject *kobj,
 252                                         const struct bin_attribute *attr)
 253 {
 254         return 0;
 255 }
 256
 257 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 258                                          const struct bin_attribute *attr)
 259 {
 260 }
 261
 262 static inline int sysfs_create_link(struct kobject *kobj,
 263                                     struct kobject *target, const char *name)
 264 {
 265         return 0;
 266 }
 267
 268 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 269                                            struct kobject *target,
 270                                            const char *name)
 271 {
 272         return 0;
 273 }
 274
 275 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 276 {
 277 }
 278
 279 static inline int sysfs_rename_link(struct kobject *k, struct kobject *t,
 280                                     const char *old_name, const char *new_name)
 281 {
 282         return 0;
 283 }
 284
 285 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 286                                      const char *name)
 287 {
 288 }
 289
 290 static inline int sysfs_create_group(struct kobject *kobj,
 291                                      const struct attribute_group *grp)
 292 {
 293         return 0;
 294 }
 295
 296 static inline int sysfs_update_group(struct kobject *kobj,
 297                                 const struct attribute_group *grp)
 298 {
 299         return 0;
 300 }
 301
 302 static inline void sysfs_remove_group(struct kobject *kobj,
 303                                       const struct attribute_group *grp)
 304 {
 305 }
 306
 307 static inline int sysfs_add_file_to_group(struct kobject *kobj,
 308                 const struct attribute *attr, const char *group)
 309 {
 310         return 0;
 311 }
 312
 313 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
 314                 const struct attribute *attr, const char *group)
 315 {
 316 }
 317
 318 static inline int sysfs_merge_group(struct kobject *kobj,
 319                        const struct attribute_group *grp)
 320 {
 321         return 0;
 322 }
 323
 324 static inline void sysfs_unmerge_group(struct kobject *kobj,
 325                        const struct attribute_group *grp)
 326 {
 327 }
 328
 329 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 330                                 const char *attr)
 331 {
 332 }
 333 static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)
 334 {
 335 }
 336 static inline
 337 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 338                                       const void *ns,
 339                                       const unsigned char *name)
 340 {
 341         return NULL;
 342 }
 343 static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 344 {
 345         return NULL;
 346 }
 347 static inline void sysfs_put(struct sysfs_dirent *sd)
 348 {
 349 }
 350
 351 static inline int __must_check sysfs_init(void)
 352 {
 353         return 0;
 354 }
 355
 356 #endif /* CONFIG_SYSFS */
 357
 358 #endif /* _SYSFS_H_ */