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 sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
 182                             void *data, struct module *owner);
 183
 184 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
 185 void sysfs_remove_dir(struct kobject *kobj);
 186 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
 187                                      const void *new_ns);
 188 int __must_check sysfs_move_dir_ns(struct kobject *kobj,
 189                                    struct kobject *new_parent_kobj,
 190                                    const void *new_ns);
 191
 192 int __must_check sysfs_create_file_ns(struct kobject *kobj,
 193                                       const struct attribute *attr,
 194                                       const void *ns);
 195 int __must_check sysfs_create_files(struct kobject *kobj,
 196                                    const struct attribute **attr);
 197 int __must_check sysfs_chmod_file(struct kobject *kobj,
 198                                   const struct attribute *attr, umode_t mode);
 199 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
 200                           const void *ns);
 201 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
 202
 203 int __must_check sysfs_create_bin_file(struct kobject *kobj,
 204                                        const struct bin_attribute *attr);
 205 void sysfs_remove_bin_file(struct kobject *kobj,
 206                            const struct bin_attribute *attr);
 207
 208 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
 209                                    const char *name);
 210 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
 211                                           struct kobject *target,
 212                                           const char *name);
 213 void sysfs_remove_link(struct kobject *kobj, const char *name);
 214
 215 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
 216                          const char *old_name, const char *new_name,
 217                          const void *new_ns);
 218
 219 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 220                         const char *name);
 221
 222 int __must_check sysfs_create_group(struct kobject *kobj,
 223                                     const struct attribute_group *grp);
 224 int __must_check sysfs_create_groups(struct kobject *kobj,
 225                                      const struct attribute_group **groups);
 226 int sysfs_update_group(struct kobject *kobj,
 227                        const struct attribute_group *grp);
 228 void sysfs_remove_group(struct kobject *kobj,
 229                         const struct attribute_group *grp);
 230 void sysfs_remove_groups(struct kobject *kobj,
 231                          const struct attribute_group **groups);
 232 int sysfs_add_file_to_group(struct kobject *kobj,
 233                         const struct attribute *attr, const char *group);
 234 void sysfs_remove_file_from_group(struct kobject *kobj,
 235                         const struct attribute *attr, const char *group);
 236 int sysfs_merge_group(struct kobject *kobj,
 237                        const struct attribute_group *grp);
 238 void sysfs_unmerge_group(struct kobject *kobj,
 239                        const struct attribute_group *grp);
 240 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
 241                             struct kobject *target, const char *link_name);
 242 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 243                                   const char *link_name);
 244
 245 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 246
 247 int __must_check sysfs_init(void);
 248
 249 #else /* CONFIG_SYSFS */
 250
 251 static inline int sysfs_schedule_callback(struct kobject *kobj,
 252                 void (*func)(void *), void *data, struct module *owner)
 253 {
 254         return -ENOSYS;
 255 }
 256
 257 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 258 {
 259         return 0;
 260 }
 261
 262 static inline void sysfs_remove_dir(struct kobject *kobj)
 263 {
 264 }
 265
 266 static inline int sysfs_rename_dir_ns(struct kobject *kobj,
 267                                       const char *new_name, const void *new_ns)
 268 {
 269         return 0;
 270 }
 271
 272 static inline int sysfs_move_dir_ns(struct kobject *kobj,
 273                                     struct kobject *new_parent_kobj,
 274                                     const void *new_ns)
 275 {
 276         return 0;
 277 }
 278
 279 static inline int sysfs_create_file_ns(struct kobject *kobj,
 280                                        const struct attribute *attr,
 281                                        const void *ns)
 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_ns(struct kobject *kobj,
 299                                         const struct attribute *attr,
 300                                         const void *ns)
 301 {
 302 }
 303
 304 static inline void sysfs_remove_files(struct kobject *kobj,
 305                                      const struct attribute **attr)
 306 {
 307 }
 308
 309 static inline int sysfs_create_bin_file(struct kobject *kobj,
 310                                         const struct bin_attribute *attr)
 311 {
 312         return 0;
 313 }
 314
 315 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 316                                          const struct bin_attribute *attr)
 317 {
 318 }
 319
 320 static inline int sysfs_create_link(struct kobject *kobj,
 321                                     struct kobject *target, const char *name)
 322 {
 323         return 0;
 324 }
 325
 326 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 327                                            struct kobject *target,
 328                                            const char *name)
 329 {
 330         return 0;
 331 }
 332
 333 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 334 {
 335 }
 336
 337 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
 338                                        const char *old_name,
 339                                        const char *new_name, const void *ns)
 340 {
 341         return 0;
 342 }
 343
 344 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 345                                      const char *name)
 346 {
 347 }
 348
 349 static inline int sysfs_create_group(struct kobject *kobj,
 350                                      const struct attribute_group *grp)
 351 {
 352         return 0;
 353 }
 354
 355 static inline int sysfs_create_groups(struct kobject *kobj,
 356                                       const struct attribute_group **groups)
 357 {
 358         return 0;
 359 }
 360
 361 static inline int sysfs_update_group(struct kobject *kobj,
 362                                 const struct attribute_group *grp)
 363 {
 364         return 0;
 365 }
 366
 367 static inline void sysfs_remove_group(struct kobject *kobj,
 368                                       const struct attribute_group *grp)
 369 {
 370 }
 371
 372 static inline void sysfs_remove_groups(struct kobject *kobj,
 373                                        const struct attribute_group **groups)
 374 {
 375 }
 376
 377 static inline int sysfs_add_file_to_group(struct kobject *kobj,
 378                 const struct attribute *attr, const char *group)
 379 {
 380         return 0;
 381 }
 382
 383 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
 384                 const struct attribute *attr, const char *group)
 385 {
 386 }
 387
 388 static inline int sysfs_merge_group(struct kobject *kobj,
 389                        const struct attribute_group *grp)
 390 {
 391         return 0;
 392 }
 393
 394 static inline void sysfs_unmerge_group(struct kobject *kobj,
 395                        const struct attribute_group *grp)
 396 {
 397 }
 398
 399 static inline int sysfs_add_link_to_group(struct kobject *kobj,
 400                 const char *group_name, struct kobject *target,
 401                 const char *link_name)
 402 {
 403         return 0;
 404 }
 405
 406 static inline void sysfs_remove_link_from_group(struct kobject *kobj,
 407                 const char *group_name, const char *link_name)
 408 {
 409 }
 410
 411 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 412                                 const char *attr)
 413 {
 414 }
 415
 416 static inline int __must_check sysfs_init(void)
 417 {
 418         return 0;
 419 }
 420
 421 #endif /* CONFIG_SYSFS */
 422
 423 static inline int __must_check sysfs_create_file(struct kobject *kobj,
 424                                                  const struct attribute *attr)
 425 {
 426         return sysfs_create_file_ns(kobj, attr, NULL);
 427 }
 428
 429 static inline void sysfs_remove_file(struct kobject *kobj,
 430                                      const struct attribute *attr)
 431 {
 432         return sysfs_remove_file_ns(kobj, attr, NULL);
 433 }
 434
 435 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 436                                     const char *old_name, const char *new_name)
 437 {
 438         return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
 439 }
 440
 441 static inline void sysfs_notify_dirent(struct kernfs_node *kn)
 442 {
 443         kernfs_notify(kn);
 444 }
 445
 446 static inline struct kernfs_node *sysfs_get_dirent(struct kernfs_node *parent,
 447                                                    const unsigned char *name)
 448 {
 449         return kernfs_find_and_get(parent, name);
 450 }
 451
 452 static inline struct kernfs_node *sysfs_get(struct kernfs_node *kn)
 453 {
 454         kernfs_get(kn);
 455         return kn;
 456 }
 457
 458 static inline void sysfs_put(struct kernfs_node *kn)
 459 {
 460         kernfs_put(kn);
 461 }
 462
 463 #endif /* _SYSFS_H_ */