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/stat.h>
  21 #include <linux/atomic.h>
  22
  23 struct kobject;
  24 struct module;
  25 struct bin_attribute;
  26 enum kobj_ns_type;
  27
  28 struct attribute {
  29         const char              *name;
  30         umode_t                 mode;
  31 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  32         bool                    ignore_lockdep:1;
  33         struct lock_class_key   *key;
  34         struct lock_class_key   skey;
  35 #endif
  36 };
  37
  38 /**
  39  *      sysfs_attr_init - initialize a dynamically allocated sysfs attribute
  40  *      @attr: struct attribute to initialize
  41  *
  42  *      Initialize a dynamically allocated struct attribute so we can
  43  *      make lockdep happy.  This is a new requirement for attributes
  44  *      and initially this is only needed when lockdep is enabled.
  45  *      Lockdep gives a nice error when your attribute is added to
  46  *      sysfs if you don't have this.
  47  */
  48 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  49 #define sysfs_attr_init(attr)                           \
  50 do {                                                    \
  51         static struct lock_class_key __key;             \
  52                                                         \
  53         (attr)->key = &__key;                           \
  54 } while(0)
  55 #else
  56 #define sysfs_attr_init(attr) do {} while(0)
  57 #endif
  58
  59 struct attribute_group {
  60         const char              *name;
  61         umode_t                 (*is_visible)(struct kobject *,
  62                                               struct attribute *, int);
  63         struct attribute        **attrs;
  64         struct bin_attribute    **bin_attrs;
  65 };
  66
  67 /**
  68  * Use these macros to make defining attributes easier. See include/linux/device.h
  69  * for examples..
  70  */
  71
  72 #define __ATTR(_name,_mode,_show,_store) {                              \
  73         .attr = {.name = __stringify(_name), .mode = _mode },           \
  74         .show   = _show,                                                \
  75         .store  = _store,                                               \
  76 }
  77
  78 #define __ATTR_RO(_name) {                                              \
  79         .attr   = { .name = __stringify(_name), .mode = S_IRUGO },      \
  80         .show   = _name##_show,                                         \
  81 }
  82
  83 #define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO),             \
  84                          _name##_show, _name##_store)
  85
  86 #define __ATTR_NULL { .attr = { .name = NULL } }
  87
  88 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  89 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {    \
  90         .attr = {.name = __stringify(_name), .mode = _mode,     \
  91                         .ignore_lockdep = true },               \
  92         .show           = _show,                                \
  93         .store          = _store,                               \
  94 }
  95 #else
  96 #define __ATTR_IGNORE_LOCKDEP   __ATTR
  97 #endif
  98
  99 #define __ATTRIBUTE_GROUPS(_name)                               \
 100 static const struct attribute_group *_name##_groups[] = {       \
 101         &_name##_group,                                         \
 102         NULL,                                                   \
 103 }
 104
 105 #define ATTRIBUTE_GROUPS(_name)                                 \
 106 static const struct attribute_group _name##_group = {           \
 107         .attrs = _name##_attrs,                                 \
 108 };                                                              \
 109 __ATTRIBUTE_GROUPS(_name)
 110
 111 #define attr_name(_attr) (_attr).attr.name
 112
 113 struct file;
 114 struct vm_area_struct;
 115
 116 struct bin_attribute {
 117         struct attribute        attr;
 118         size_t                  size;
 119         void                    *private;
 120         ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
 121                         char *, loff_t, size_t);
 122         ssize_t (*write)(struct file *,struct kobject *, struct bin_attribute *,
 123                          char *, loff_t, size_t);
 124         int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
 125                     struct vm_area_struct *vma);
 126 };
 127
 128 /**
 129  *      sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
 130  *      @attr: struct bin_attribute to initialize
 131  *
 132  *      Initialize a dynamically allocated struct bin_attribute so we
 133  *      can make lockdep happy.  This is a new requirement for
 134  *      attributes and initially this is only needed when lockdep is
 135  *      enabled.  Lockdep gives a nice error when your attribute is
 136  *      added to sysfs if you don't have this.
 137  */
 138 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
 139
 140 /* macros to create static binary attributes easier */
 141 #define __BIN_ATTR(_name, _mode, _read, _write, _size) {                \
 142         .attr = { .name = __stringify(_name), .mode = _mode },          \
 143         .read   = _read,                                                \
 144         .write  = _write,                                               \
 145         .size   = _size,                                                \
 146 }
 147
 148 #define __BIN_ATTR_RO(_name, _size) {                                   \
 149         .attr   = { .name = __stringify(_name), .mode = S_IRUGO },      \
 150         .read   = _name##_read,                                         \
 151         .size   = _size,                                                \
 152 }
 153
 154 #define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name,                   \
 155                                    (S_IWUSR | S_IRUGO), _name##_read,   \
 156                                    _name##_write)
 157
 158 #define __BIN_ATTR_NULL __ATTR_NULL
 159
 160 #define BIN_ATTR(_name, _mode, _read, _write, _size)                    \
 161 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
 162                                         _write, _size)
 163
 164 #define BIN_ATTR_RO(_name, _size)                                       \
 165 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
 166
 167 #define BIN_ATTR_RW(_name, _size)                                       \
 168 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
 169
 170 struct sysfs_ops {
 171         ssize_t (*show)(struct kobject *, struct attribute *,char *);
 172         ssize_t (*store)(struct kobject *,struct attribute *,const char *, size_t);
 173         const void *(*namespace)(struct kobject *, const struct attribute *);
 174 };
 175
 176 struct sysfs_dirent;
 177
 178 #ifdef CONFIG_SYSFS
 179
 180 int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
 181                             void *data, struct module *owner);
 182
 183 int __must_check sysfs_create_dir(struct kobject *kobj);
 184 void sysfs_remove_dir(struct kobject *kobj);
 185 int __must_check sysfs_rename_dir(struct kobject *kobj, const char *new_name);
 186 int __must_check sysfs_move_dir(struct kobject *kobj,
 187                                 struct kobject *new_parent_kobj);
 188
 189 int __must_check sysfs_create_file(struct kobject *kobj,
 190                                    const struct attribute *attr);
 191 int __must_check sysfs_create_files(struct kobject *kobj,
 192                                    const struct attribute **attr);
 193 int __must_check sysfs_chmod_file(struct kobject *kobj,
 194                                   const struct attribute *attr, umode_t mode);
 195 void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr);
 196 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
 197
 198 int __must_check sysfs_create_bin_file(struct kobject *kobj,
 199                                        const struct bin_attribute *attr);
 200 void sysfs_remove_bin_file(struct kobject *kobj,
 201                            const struct bin_attribute *attr);
 202
 203 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
 204                                    const char *name);
 205 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
 206                                           struct kobject *target,
 207                                           const char *name);
 208 void sysfs_remove_link(struct kobject *kobj, const char *name);
 209
 210 int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 211                         const char *old_name, const char *new_name);
 212
 213 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 214                         const char *name);
 215
 216 int __must_check sysfs_create_group(struct kobject *kobj,
 217                                     const struct attribute_group *grp);
 218 int sysfs_update_group(struct kobject *kobj,
 219                        const struct attribute_group *grp);
 220 void sysfs_remove_group(struct kobject *kobj,
 221                         const struct attribute_group *grp);
 222 int sysfs_add_file_to_group(struct kobject *kobj,
 223                         const struct attribute *attr, const char *group);
 224 void sysfs_remove_file_from_group(struct kobject *kobj,
 225                         const struct attribute *attr, const char *group);
 226 int sysfs_merge_group(struct kobject *kobj,
 227                        const struct attribute_group *grp);
 228 void sysfs_unmerge_group(struct kobject *kobj,
 229                        const struct attribute_group *grp);
 230 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
 231                             struct kobject *target, const char *link_name);
 232 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 233                                   const char *link_name);
 234
 235 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 236 void sysfs_notify_dirent(struct sysfs_dirent *sd);
 237 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 238                                       const void *ns,
 239                                       const unsigned char *name);
 240 struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd);
 241 void sysfs_put(struct sysfs_dirent *sd);
 242
 243 int __must_check sysfs_init(void);
 244
 245 #else /* CONFIG_SYSFS */
 246
 247 static inline int sysfs_schedule_callback(struct kobject *kobj,
 248                 void (*func)(void *), void *data, struct module *owner)
 249 {
 250         return -ENOSYS;
 251 }
 252
 253 static inline int sysfs_create_dir(struct kobject *kobj)
 254 {
 255         return 0;
 256 }
 257
 258 static inline void sysfs_remove_dir(struct kobject *kobj)
 259 {
 260 }
 261
 262 static inline int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
 263 {
 264         return 0;
 265 }
 266
 267 static inline int sysfs_move_dir(struct kobject *kobj,
 268                                  struct kobject *new_parent_kobj)
 269 {
 270         return 0;
 271 }
 272
 273 static inline int sysfs_create_file(struct kobject *kobj,
 274                                     const struct attribute *attr)
 275 {
 276         return 0;
 277 }
 278
 279 static inline int sysfs_create_files(struct kobject *kobj,
 280                                     const struct attribute **attr)
 281 {
 282         return 0;
 283 }
 284
 285 static inline int sysfs_chmod_file(struct kobject *kobj,
 286                                    const struct attribute *attr, umode_t mode)
 287 {
 288         return 0;
 289 }
 290
 291 static inline void sysfs_remove_file(struct kobject *kobj,
 292                                      const struct attribute *attr)
 293 {
 294 }
 295
 296 static inline void sysfs_remove_files(struct kobject *kobj,
 297                                      const struct attribute **attr)
 298 {
 299 }
 300
 301 static inline int sysfs_create_bin_file(struct kobject *kobj,
 302                                         const struct bin_attribute *attr)
 303 {
 304         return 0;
 305 }
 306
 307 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 308                                          const struct bin_attribute *attr)
 309 {
 310 }
 311
 312 static inline int sysfs_create_link(struct kobject *kobj,
 313                                     struct kobject *target, const char *name)
 314 {
 315         return 0;
 316 }
 317
 318 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 319                                            struct kobject *target,
 320                                            const char *name)
 321 {
 322         return 0;
 323 }
 324
 325 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 326 {
 327 }
 328
 329 static inline int sysfs_rename_link(struct kobject *k, struct kobject *t,
 330                                     const char *old_name, const char *new_name)
 331 {
 332         return 0;
 333 }
 334
 335 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 336                                      const char *name)
 337 {
 338 }
 339
 340 static inline int sysfs_create_group(struct kobject *kobj,
 341                                      const struct attribute_group *grp)
 342 {
 343         return 0;
 344 }
 345
 346 static inline int sysfs_update_group(struct kobject *kobj,
 347                                 const struct attribute_group *grp)
 348 {
 349         return 0;
 350 }
 351
 352 static inline void sysfs_remove_group(struct kobject *kobj,
 353                                       const struct attribute_group *grp)
 354 {
 355 }
 356
 357 static inline int sysfs_add_file_to_group(struct kobject *kobj,
 358                 const struct attribute *attr, const char *group)
 359 {
 360         return 0;
 361 }
 362
 363 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
 364                 const struct attribute *attr, const char *group)
 365 {
 366 }
 367
 368 static inline int sysfs_merge_group(struct kobject *kobj,
 369                        const struct attribute_group *grp)
 370 {
 371         return 0;
 372 }
 373
 374 static inline void sysfs_unmerge_group(struct kobject *kobj,
 375                        const struct attribute_group *grp)
 376 {
 377 }
 378
 379 static inline int sysfs_add_link_to_group(struct kobject *kobj,
 380                 const char *group_name, struct kobject *target,
 381                 const char *link_name)
 382 {
 383         return 0;
 384 }
 385
 386 static inline void sysfs_remove_link_from_group(struct kobject *kobj,
 387                 const char *group_name, const char *link_name)
 388 {
 389 }
 390
 391 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 392                                 const char *attr)
 393 {
 394 }
 395 static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)
 396 {
 397 }
 398 static inline
 399 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 400                                       const void *ns,
 401                                       const unsigned char *name)
 402 {
 403         return NULL;
 404 }
 405 static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 406 {
 407         return NULL;
 408 }
 409 static inline void sysfs_put(struct sysfs_dirent *sd)
 410 {
 411 }
 412
 413 static inline int __must_check sysfs_init(void)
 414 {
 415         return 0;
 416 }
 417
 418 #endif /* CONFIG_SYSFS */
 419
 420 #endif /* _SYSFS_H_ */