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_WO(_name) {                                              \
  84         .attr   = { .name = __stringify(_name), .mode = S_IWUSR },      \
  85         .store  = _name##_store,                                        \
  86 }
  87
  88 #define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO),             \
  89                          _name##_show, _name##_store)
  90
  91 #define __ATTR_NULL { .attr = { .name = NULL } }
  92
  93 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  94 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {    \
  95         .attr = {.name = __stringify(_name), .mode = _mode,     \
  96                         .ignore_lockdep = true },               \
  97         .show           = _show,                                \
  98         .store          = _store,                               \
  99 }
 100 #else
 101 #define __ATTR_IGNORE_LOCKDEP   __ATTR
 102 #endif
 103
 104 #define __ATTRIBUTE_GROUPS(_name)                               \
 105 static const struct attribute_group *_name##_groups[] = {       \
 106         &_name##_group,                                         \
 107         NULL,                                                   \
 108 }
 109
 110 #define ATTRIBUTE_GROUPS(_name)                                 \
 111 static const struct attribute_group _name##_group = {           \
 112         .attrs = _name##_attrs,                                 \
 113 };                                                              \
 114 __ATTRIBUTE_GROUPS(_name)
 115
 116 struct file;
 117 struct vm_area_struct;
 118
 119 struct bin_attribute {
 120         struct attribute        attr;
 121         size_t                  size;
 122         void                    *private;
 123         ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
 124                         char *, loff_t, size_t);
 125         ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,
 126                          char *, loff_t, size_t);
 127         int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
 128                     struct vm_area_struct *vma);
 129 };
 130
 131 /**
 132  *      sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
 133  *      @attr: struct bin_attribute to initialize
 134  *
 135  *      Initialize a dynamically allocated struct bin_attribute so we
 136  *      can make lockdep happy.  This is a new requirement for
 137  *      attributes and initially this is only needed when lockdep is
 138  *      enabled.  Lockdep gives a nice error when your attribute is
 139  *      added to sysfs if you don't have this.
 140  */
 141 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
 142
 143 /* macros to create static binary attributes easier */
 144 #define __BIN_ATTR(_name, _mode, _read, _write, _size) {                \
 145         .attr = { .name = __stringify(_name), .mode = _mode },          \
 146         .read   = _read,                                                \
 147         .write  = _write,                                               \
 148         .size   = _size,                                                \
 149 }
 150
 151 #define __BIN_ATTR_RO(_name, _size) {                                   \
 152         .attr   = { .name = __stringify(_name), .mode = S_IRUGO },      \
 153         .read   = _name##_read,                                         \
 154         .size   = _size,                                                \
 155 }
 156
 157 #define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name,                   \
 158                                    (S_IWUSR | S_IRUGO), _name##_read,   \
 159                                    _name##_write, _size)
 160
 161 #define __BIN_ATTR_NULL __ATTR_NULL
 162
 163 #define BIN_ATTR(_name, _mode, _read, _write, _size)                    \
 164 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
 165                                         _write, _size)
 166
 167 #define BIN_ATTR_RO(_name, _size)                                       \
 168 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
 169
 170 #define BIN_ATTR_RW(_name, _size)                                       \
 171 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
 172
 173 struct sysfs_ops {
 174         ssize_t (*show)(struct kobject *, struct attribute *, char *);
 175         ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
 176         const void *(*namespace)(struct kobject *, const struct attribute *);
 177 };
 178
 179 struct sysfs_dirent;
 180
 181 #ifdef CONFIG_SYSFS
 182
 183 int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
 184                             void *data, struct module *owner);
 185
 186 int __must_check sysfs_create_dir(struct kobject *kobj);
 187 void sysfs_remove_dir(struct kobject *kobj);
 188 int __must_check sysfs_rename_dir(struct kobject *kobj, const char *new_name);
 189 int __must_check sysfs_move_dir(struct kobject *kobj,
 190                                 struct kobject *new_parent_kobj);
 191
 192 int __must_check sysfs_create_file(struct kobject *kobj,
 193                                    const struct attribute *attr);
 194 int __must_check sysfs_create_files(struct kobject *kobj,
 195                                    const struct attribute **attr);
 196 int __must_check sysfs_chmod_file(struct kobject *kobj,
 197                                   const struct attribute *attr, umode_t mode);
 198 void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr);
 199 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
 200
 201 int __must_check sysfs_create_bin_file(struct kobject *kobj,
 202                                        const struct bin_attribute *attr);
 203 void sysfs_remove_bin_file(struct kobject *kobj,
 204                            const struct bin_attribute *attr);
 205
 206 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
 207                                    const char *name);
 208 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
 209                                           struct kobject *target,
 210                                           const char *name);
 211 void sysfs_remove_link(struct kobject *kobj, const char *name);
 212
 213 int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 214                         const char *old_name, const char *new_name);
 215
 216 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 217                         const char *name);
 218
 219 int __must_check sysfs_create_group(struct kobject *kobj,
 220                                     const struct attribute_group *grp);
 221 int __must_check sysfs_create_groups(struct kobject *kobj,
 222                                      const struct attribute_group **groups);
 223 int sysfs_update_group(struct kobject *kobj,
 224                        const struct attribute_group *grp);
 225 void sysfs_remove_group(struct kobject *kobj,
 226                         const struct attribute_group *grp);
 227 void sysfs_remove_groups(struct kobject *kobj,
 228                          const struct attribute_group **groups);
 229 int sysfs_add_file_to_group(struct kobject *kobj,
 230                         const struct attribute *attr, const char *group);
 231 void sysfs_remove_file_from_group(struct kobject *kobj,
 232                         const struct attribute *attr, const char *group);
 233 int sysfs_merge_group(struct kobject *kobj,
 234                        const struct attribute_group *grp);
 235 void sysfs_unmerge_group(struct kobject *kobj,
 236                        const struct attribute_group *grp);
 237 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
 238                             struct kobject *target, const char *link_name);
 239 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 240                                   const char *link_name);
 241
 242 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 243 void sysfs_notify_dirent(struct sysfs_dirent *sd);
 244 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 245                                       const void *ns,
 246                                       const unsigned char *name);
 247 struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd);
 248 void sysfs_put(struct sysfs_dirent *sd);
 249
 250 int __must_check sysfs_init(void);
 251
 252 #else /* CONFIG_SYSFS */
 253
 254 static inline int sysfs_schedule_callback(struct kobject *kobj,
 255                 void (*func)(void *), void *data, struct module *owner)
 256 {
 257         return -ENOSYS;
 258 }
 259
 260 static inline int sysfs_create_dir(struct kobject *kobj)
 261 {
 262         return 0;
 263 }
 264
 265 static inline void sysfs_remove_dir(struct kobject *kobj)
 266 {
 267 }
 268
 269 static inline int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
 270 {
 271         return 0;
 272 }
 273
 274 static inline int sysfs_move_dir(struct kobject *kobj,
 275                                  struct kobject *new_parent_kobj)
 276 {
 277         return 0;
 278 }
 279
 280 static inline int sysfs_create_file(struct kobject *kobj,
 281                                     const struct attribute *attr)
 282 {
 283         return 0;
 284 }
 285
 286 static inline int sysfs_create_files(struct kobject *kobj,
 287                                     const struct attribute **attr)
 288 {
 289         return 0;
 290 }
 291
 292 static inline int sysfs_chmod_file(struct kobject *kobj,
 293                                    const struct attribute *attr, umode_t mode)
 294 {
 295         return 0;
 296 }
 297
 298 static inline void sysfs_remove_file(struct kobject *kobj,
 299                                      const struct attribute *attr)
 300 {
 301 }
 302
 303 static inline void sysfs_remove_files(struct kobject *kobj,
 304                                      const struct attribute **attr)
 305 {
 306 }
 307
 308 static inline int sysfs_create_bin_file(struct kobject *kobj,
 309                                         const struct bin_attribute *attr)
 310 {
 311         return 0;
 312 }
 313
 314 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 315                                          const struct bin_attribute *attr)
 316 {
 317 }
 318
 319 static inline int sysfs_create_link(struct kobject *kobj,
 320                                     struct kobject *target, const char *name)
 321 {
 322         return 0;
 323 }
 324
 325 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 326                                            struct kobject *target,
 327                                            const char *name)
 328 {
 329         return 0;
 330 }
 331
 332 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 333 {
 334 }
 335
 336 static inline int sysfs_rename_link(struct kobject *k, struct kobject *t,
 337                                     const char *old_name, const char *new_name)
 338 {
 339         return 0;
 340 }
 341
 342 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 343                                      const char *name)
 344 {
 345 }
 346
 347 static inline int sysfs_create_group(struct kobject *kobj,
 348                                      const struct attribute_group *grp)
 349 {
 350         return 0;
 351 }
 352
 353 static inline int sysfs_create_groups(struct kobject *kobj,
 354                                       const struct attribute_group **groups)
 355 {
 356         return 0;
 357 }
 358
 359 static inline int sysfs_update_group(struct kobject *kobj,
 360                                 const struct attribute_group *grp)
 361 {
 362         return 0;
 363 }
 364
 365 static inline void sysfs_remove_group(struct kobject *kobj,
 366                                       const struct attribute_group *grp)
 367 {
 368 }
 369
 370 static inline void sysfs_remove_groups(struct kobject *kobj,
 371                                        const struct attribute_group **groups)
 372 {
 373 }
 374
 375 static inline int sysfs_add_file_to_group(struct kobject *kobj,
 376                 const struct attribute *attr, const char *group)
 377 {
 378         return 0;
 379 }
 380
 381 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
 382                 const struct attribute *attr, const char *group)
 383 {
 384 }
 385
 386 static inline int sysfs_merge_group(struct kobject *kobj,
 387                        const struct attribute_group *grp)
 388 {
 389         return 0;
 390 }
 391
 392 static inline void sysfs_unmerge_group(struct kobject *kobj,
 393                        const struct attribute_group *grp)
 394 {
 395 }
 396
 397 static inline int sysfs_add_link_to_group(struct kobject *kobj,
 398                 const char *group_name, struct kobject *target,
 399                 const char *link_name)
 400 {
 401         return 0;
 402 }
 403
 404 static inline void sysfs_remove_link_from_group(struct kobject *kobj,
 405                 const char *group_name, const char *link_name)
 406 {
 407 }
 408
 409 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 410                                 const char *attr)
 411 {
 412 }
 413 static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)
 414 {
 415 }
 416 static inline
 417 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
 418                                       const void *ns,
 419                                       const unsigned char *name)
 420 {
 421         return NULL;
 422 }
 423 static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 424 {
 425         return NULL;
 426 }
 427 static inline void sysfs_put(struct sysfs_dirent *sd)
 428 {
 429 }
 430
 431 static inline int __must_check sysfs_init(void)
 432 {
 433         return 0;
 434 }
 435
 436 #endif /* CONFIG_SYSFS */
 437
 438 #endif /* _SYSFS_H_ */