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/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 struct attribute_group {
  61         const char              *name;
  62         umode_t                 (*is_visible)(struct kobject *,
  63                                               struct attribute *, int);
  64         struct attribute        **attrs;
  65         struct bin_attribute    **bin_attrs;
  66 };
  67
  68 /**
  69  * Use these macros to make defining attributes easier. See include/linux/device.h
  70  * for examples..
  71  */
  72
  73 #define __ATTR(_name, _mode, _show, _store) {                           \
  74         .attr = {.name = __stringify(_name), .mode = _mode },           \
  75         .show   = _show,                                                \
  76         .store  = _store,                                               \
  77 }
  78
  79 #define __ATTR_RO(_name) {                                              \
  80         .attr   = { .name = __stringify(_name), .mode = S_IRUGO },      \
  81         .show   = _name##_show,                                         \
  82 }
  83
  84 #define __ATTR_WO(_name) {                                              \
  85         .attr   = { .name = __stringify(_name), .mode = S_IWUSR },      \
  86         .store  = _name##_store,                                        \
  87 }
  88
  89 #define __ATTR_RW(_name) __ATTR(_name, (S_IWUSR | S_IRUGO),             \
  90                          _name##_show, _name##_store)
  91
  92 #define __ATTR_NULL { .attr = { .name = NULL } }
  93
  94 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  95 #define __ATTR_IGNORE_LOCKDEP(_name, _mode, _show, _store) {    \
  96         .attr = {.name = __stringify(_name), .mode = _mode,     \
  97                         .ignore_lockdep = true },               \
  98         .show           = _show,                                \
  99         .store          = _store,                               \
 100 }
 101 #else
 102 #define __ATTR_IGNORE_LOCKDEP   __ATTR
 103 #endif
 104
 105 #define __ATTRIBUTE_GROUPS(_name)                               \
 106 static const struct attribute_group *_name##_groups[] = {       \
 107         &_name##_group,                                         \
 108         NULL,                                                   \
 109 }
 110
 111 #define ATTRIBUTE_GROUPS(_name)                                 \
 112 static const struct attribute_group _name##_group = {           \
 113         .attrs = _name##_attrs,                                 \
 114 };                                                              \
 115 __ATTRIBUTE_GROUPS(_name)
 116
 117 struct file;
 118 struct vm_area_struct;
 119
 120 struct bin_attribute {
 121         struct attribute        attr;
 122         size_t                  size;
 123         void                    *private;
 124         ssize_t (*read)(struct file *, struct kobject *, struct bin_attribute *,
 125                         char *, loff_t, size_t);
 126         ssize_t (*write)(struct file *, struct kobject *, struct bin_attribute *,
 127                          char *, loff_t, size_t);
 128         int (*mmap)(struct file *, struct kobject *, struct bin_attribute *attr,
 129                     struct vm_area_struct *vma);
 130 };
 131
 132 /**
 133  *      sysfs_bin_attr_init - initialize a dynamically allocated bin_attribute
 134  *      @attr: struct bin_attribute to initialize
 135  *
 136  *      Initialize a dynamically allocated struct bin_attribute so we
 137  *      can make lockdep happy.  This is a new requirement for
 138  *      attributes and initially this is only needed when lockdep is
 139  *      enabled.  Lockdep gives a nice error when your attribute is
 140  *      added to sysfs if you don't have this.
 141  */
 142 #define sysfs_bin_attr_init(bin_attr) sysfs_attr_init(&(bin_attr)->attr)
 143
 144 /* macros to create static binary attributes easier */
 145 #define __BIN_ATTR(_name, _mode, _read, _write, _size) {                \
 146         .attr = { .name = __stringify(_name), .mode = _mode },          \
 147         .read   = _read,                                                \
 148         .write  = _write,                                               \
 149         .size   = _size,                                                \
 150 }
 151
 152 #define __BIN_ATTR_RO(_name, _size) {                                   \
 153         .attr   = { .name = __stringify(_name), .mode = S_IRUGO },      \
 154         .read   = _name##_read,                                         \
 155         .size   = _size,                                                \
 156 }
 157
 158 #define __BIN_ATTR_RW(_name, _size) __BIN_ATTR(_name,                   \
 159                                    (S_IWUSR | S_IRUGO), _name##_read,   \
 160                                    _name##_write, _size)
 161
 162 #define __BIN_ATTR_NULL __ATTR_NULL
 163
 164 #define BIN_ATTR(_name, _mode, _read, _write, _size)                    \
 165 struct bin_attribute bin_attr_##_name = __BIN_ATTR(_name, _mode, _read, \
 166                                         _write, _size)
 167
 168 #define BIN_ATTR_RO(_name, _size)                                       \
 169 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RO(_name, _size)
 170
 171 #define BIN_ATTR_RW(_name, _size)                                       \
 172 struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
 173
 174 struct sysfs_ops {
 175         ssize_t (*show)(struct kobject *, struct attribute *, char *);
 176         ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
 177 };
 178
 179 #ifdef CONFIG_SYSFS
 180
 181 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
 182 void sysfs_remove_dir(struct kobject *kobj);
 183 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
 184                                      const void *new_ns);
 185 int __must_check sysfs_move_dir_ns(struct kobject *kobj,
 186                                    struct kobject *new_parent_kobj,
 187                                    const void *new_ns);
 188
 189 int __must_check sysfs_create_file_ns(struct kobject *kobj,
 190                                       const struct attribute *attr,
 191                                       const void *ns);
 192 int __must_check sysfs_create_files(struct kobject *kobj,
 193                                    const struct attribute **attr);
 194 int __must_check sysfs_chmod_file(struct kobject *kobj,
 195                                   const struct attribute *attr, umode_t mode);
 196 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
 197                           const void *ns);
 198 bool sysfs_remove_file_self(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_ns(struct kobject *kobj, struct kobject *target,
 214                          const char *old_name, const char *new_name,
 215                          const void *new_ns);
 216
 217 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 218                         const char *name);
 219
 220 int __must_check sysfs_create_group(struct kobject *kobj,
 221                                     const struct attribute_group *grp);
 222 int __must_check sysfs_create_groups(struct kobject *kobj,
 223                                      const struct attribute_group **groups);
 224 int sysfs_update_group(struct kobject *kobj,
 225                        const struct attribute_group *grp);
 226 void sysfs_remove_group(struct kobject *kobj,
 227                         const struct attribute_group *grp);
 228 void sysfs_remove_groups(struct kobject *kobj,
 229                          const struct attribute_group **groups);
 230 int sysfs_add_file_to_group(struct kobject *kobj,
 231                         const struct attribute *attr, const char *group);
 232 void sysfs_remove_file_from_group(struct kobject *kobj,
 233                         const struct attribute *attr, const char *group);
 234 int sysfs_merge_group(struct kobject *kobj,
 235                        const struct attribute_group *grp);
 236 void sysfs_unmerge_group(struct kobject *kobj,
 237                        const struct attribute_group *grp);
 238 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
 239                             struct kobject *target, const char *link_name);
 240 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 241                                   const char *link_name);
 242
 243 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 244
 245 int __must_check sysfs_init(void);
 246
 247 #else /* CONFIG_SYSFS */
 248
 249 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 250 {
 251         return 0;
 252 }
 253
 254 static inline void sysfs_remove_dir(struct kobject *kobj)
 255 {
 256 }
 257
 258 static inline int sysfs_rename_dir_ns(struct kobject *kobj,
 259                                       const char *new_name, const void *new_ns)
 260 {
 261         return 0;
 262 }
 263
 264 static inline int sysfs_move_dir_ns(struct kobject *kobj,
 265                                     struct kobject *new_parent_kobj,
 266                                     const void *new_ns)
 267 {
 268         return 0;
 269 }
 270
 271 static inline int sysfs_create_file_ns(struct kobject *kobj,
 272                                        const struct attribute *attr,
 273                                        const void *ns)
 274 {
 275         return 0;
 276 }
 277
 278 static inline int sysfs_create_files(struct kobject *kobj,
 279                                     const struct attribute **attr)
 280 {
 281         return 0;
 282 }
 283
 284 static inline int sysfs_chmod_file(struct kobject *kobj,
 285                                    const struct attribute *attr, umode_t mode)
 286 {
 287         return 0;
 288 }
 289
 290 static inline void sysfs_remove_file_ns(struct kobject *kobj,
 291                                         const struct attribute *attr,
 292                                         const void *ns)
 293 {
 294 }
 295
 296 static inline bool sysfs_remove_file_self(struct kobject *kobj,
 297                                           const struct attribute *attr)
 298 {
 299         return false;
 300 }
 301
 302 static inline void sysfs_remove_files(struct kobject *kobj,
 303                                      const struct attribute **attr)
 304 {
 305 }
 306
 307 static inline int sysfs_create_bin_file(struct kobject *kobj,
 308                                         const struct bin_attribute *attr)
 309 {
 310         return 0;
 311 }
 312
 313 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 314                                          const struct bin_attribute *attr)
 315 {
 316 }
 317
 318 static inline int sysfs_create_link(struct kobject *kobj,
 319                                     struct kobject *target, const char *name)
 320 {
 321         return 0;
 322 }
 323
 324 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 325                                            struct kobject *target,
 326                                            const char *name)
 327 {
 328         return 0;
 329 }
 330
 331 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 332 {
 333 }
 334
 335 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
 336                                        const char *old_name,
 337                                        const char *new_name, const void *ns)
 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
 414 static inline int __must_check sysfs_init(void)
 415 {
 416         return 0;
 417 }
 418
 419 #endif /* CONFIG_SYSFS */
 420
 421 static inline int __must_check sysfs_create_file(struct kobject *kobj,
 422                                                  const struct attribute *attr)
 423 {
 424         return sysfs_create_file_ns(kobj, attr, NULL);
 425 }
 426
 427 static inline void sysfs_remove_file(struct kobject *kobj,
 428                                      const struct attribute *attr)
 429 {
 430         return sysfs_remove_file_ns(kobj, attr, NULL);
 431 }
 432
 433 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 434                                     const char *old_name, const char *new_name)
 435 {
 436         return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
 437 }
 438
 439 static inline void sysfs_notify_dirent(struct kernfs_node *kn)
 440 {
 441         kernfs_notify(kn);
 442 }
 443
 444 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
 445                                                    const unsigned char *name)
 446 {
 447         return kernfs_find_and_get(parent, name);
 448 }
 449
 450 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
 451 {
 452         kernfs_get(kn);
 453         return kn;
 454 }
 455
 456 static inline void sysfs_put(struct kernfs_node *kn)
 457 {
 458         kernfs_put(kn);
 459 }
 460
 461 #endif /* _SYSFS_H_ */