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 };
 177
 178 struct sysfs_dirent;
 179
 180 #ifdef CONFIG_SYSFS
 181
 182 int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *),
 183                             void *data, struct module *owner);
 184
 185 int __must_check sysfs_create_dir_ns(struct kobject *kobj, const void *ns);
 186 void sysfs_remove_dir(struct kobject *kobj);
 187 int __must_check sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
 188                                      const void *new_ns);
 189 int __must_check sysfs_move_dir_ns(struct kobject *kobj,
 190                                    struct kobject *new_parent_kobj,
 191                                    const void *new_ns);
 192
 193 int __must_check sysfs_create_file_ns(struct kobject *kobj,
 194                                       const struct attribute *attr,
 195                                       const void *ns);
 196 int __must_check sysfs_create_files(struct kobject *kobj,
 197                                    const struct attribute **attr);
 198 int __must_check sysfs_chmod_file(struct kobject *kobj,
 199                                   const struct attribute *attr, umode_t mode);
 200 void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
 201                           const void *ns);
 202 void sysfs_remove_files(struct kobject *kobj, const struct attribute **attr);
 203
 204 int __must_check sysfs_create_bin_file(struct kobject *kobj,
 205                                        const struct bin_attribute *attr);
 206 void sysfs_remove_bin_file(struct kobject *kobj,
 207                            const struct bin_attribute *attr);
 208
 209 int __must_check sysfs_create_link(struct kobject *kobj, struct kobject *target,
 210                                    const char *name);
 211 int __must_check sysfs_create_link_nowarn(struct kobject *kobj,
 212                                           struct kobject *target,
 213                                           const char *name);
 214 void sysfs_remove_link(struct kobject *kobj, const char *name);
 215
 216 int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *target,
 217                          const char *old_name, const char *new_name,
 218                          const void *new_ns);
 219
 220 void sysfs_delete_link(struct kobject *dir, struct kobject *targ,
 221                         const char *name);
 222
 223 int __must_check sysfs_create_group(struct kobject *kobj,
 224                                     const struct attribute_group *grp);
 225 int __must_check sysfs_create_groups(struct kobject *kobj,
 226                                      const struct attribute_group **groups);
 227 int sysfs_update_group(struct kobject *kobj,
 228                        const struct attribute_group *grp);
 229 void sysfs_remove_group(struct kobject *kobj,
 230                         const struct attribute_group *grp);
 231 void sysfs_remove_groups(struct kobject *kobj,
 232                          const struct attribute_group **groups);
 233 int sysfs_add_file_to_group(struct kobject *kobj,
 234                         const struct attribute *attr, const char *group);
 235 void sysfs_remove_file_from_group(struct kobject *kobj,
 236                         const struct attribute *attr, const char *group);
 237 int sysfs_merge_group(struct kobject *kobj,
 238                        const struct attribute_group *grp);
 239 void sysfs_unmerge_group(struct kobject *kobj,
 240                        const struct attribute_group *grp);
 241 int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
 242                             struct kobject *target, const char *link_name);
 243 void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
 244                                   const char *link_name);
 245
 246 void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr);
 247 void sysfs_notify_dirent(struct sysfs_dirent *sd);
 248 struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd,
 249                                          const unsigned char *name,
 250                                          const void *ns);
 251 struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd);
 252 void sysfs_put(struct sysfs_dirent *sd);
 253
 254 int __must_check sysfs_init(void);
 255
 256 #else /* CONFIG_SYSFS */
 257
 258 static inline int sysfs_schedule_callback(struct kobject *kobj,
 259                 void (*func)(void *), void *data, struct module *owner)
 260 {
 261         return -ENOSYS;
 262 }
 263
 264 static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
 265 {
 266         return 0;
 267 }
 268
 269 static inline void sysfs_remove_dir(struct kobject *kobj)
 270 {
 271 }
 272
 273 static inline int sysfs_rename_dir_ns(struct kobject *kobj,
 274                                       const char *new_name, const void *new_ns)
 275 {
 276         return 0;
 277 }
 278
 279 static inline int sysfs_move_dir_ns(struct kobject *kobj,
 280                                     struct kobject *new_parent_kobj,
 281                                     const void *new_ns)
 282 {
 283         return 0;
 284 }
 285
 286 static inline int sysfs_create_file_ns(struct kobject *kobj,
 287                                        const struct attribute *attr,
 288                                        const void *ns)
 289 {
 290         return 0;
 291 }
 292
 293 static inline int sysfs_create_files(struct kobject *kobj,
 294                                     const struct attribute **attr)
 295 {
 296         return 0;
 297 }
 298
 299 static inline int sysfs_chmod_file(struct kobject *kobj,
 300                                    const struct attribute *attr, umode_t mode)
 301 {
 302         return 0;
 303 }
 304
 305 static inline void sysfs_remove_file_ns(struct kobject *kobj,
 306                                         const struct attribute *attr,
 307                                         const void *ns)
 308 {
 309 }
 310
 311 static inline void sysfs_remove_files(struct kobject *kobj,
 312                                      const struct attribute **attr)
 313 {
 314 }
 315
 316 static inline int sysfs_create_bin_file(struct kobject *kobj,
 317                                         const struct bin_attribute *attr)
 318 {
 319         return 0;
 320 }
 321
 322 static inline void sysfs_remove_bin_file(struct kobject *kobj,
 323                                          const struct bin_attribute *attr)
 324 {
 325 }
 326
 327 static inline int sysfs_create_link(struct kobject *kobj,
 328                                     struct kobject *target, const char *name)
 329 {
 330         return 0;
 331 }
 332
 333 static inline int sysfs_create_link_nowarn(struct kobject *kobj,
 334                                            struct kobject *target,
 335                                            const char *name)
 336 {
 337         return 0;
 338 }
 339
 340 static inline void sysfs_remove_link(struct kobject *kobj, const char *name)
 341 {
 342 }
 343
 344 static inline int sysfs_rename_link_ns(struct kobject *k, struct kobject *t,
 345                                        const char *old_name,
 346                                        const char *new_name, const void *ns)
 347 {
 348         return 0;
 349 }
 350
 351 static inline void sysfs_delete_link(struct kobject *k, struct kobject *t,
 352                                      const char *name)
 353 {
 354 }
 355
 356 static inline int sysfs_create_group(struct kobject *kobj,
 357                                      const struct attribute_group *grp)
 358 {
 359         return 0;
 360 }
 361
 362 static inline int sysfs_create_groups(struct kobject *kobj,
 363                                       const struct attribute_group **groups)
 364 {
 365         return 0;
 366 }
 367
 368 static inline int sysfs_update_group(struct kobject *kobj,
 369                                 const struct attribute_group *grp)
 370 {
 371         return 0;
 372 }
 373
 374 static inline void sysfs_remove_group(struct kobject *kobj,
 375                                       const struct attribute_group *grp)
 376 {
 377 }
 378
 379 static inline void sysfs_remove_groups(struct kobject *kobj,
 380                                        const struct attribute_group **groups)
 381 {
 382 }
 383
 384 static inline int sysfs_add_file_to_group(struct kobject *kobj,
 385                 const struct attribute *attr, const char *group)
 386 {
 387         return 0;
 388 }
 389
 390 static inline void sysfs_remove_file_from_group(struct kobject *kobj,
 391                 const struct attribute *attr, const char *group)
 392 {
 393 }
 394
 395 static inline int sysfs_merge_group(struct kobject *kobj,
 396                        const struct attribute_group *grp)
 397 {
 398         return 0;
 399 }
 400
 401 static inline void sysfs_unmerge_group(struct kobject *kobj,
 402                        const struct attribute_group *grp)
 403 {
 404 }
 405
 406 static inline int sysfs_add_link_to_group(struct kobject *kobj,
 407                 const char *group_name, struct kobject *target,
 408                 const char *link_name)
 409 {
 410         return 0;
 411 }
 412
 413 static inline void sysfs_remove_link_from_group(struct kobject *kobj,
 414                 const char *group_name, const char *link_name)
 415 {
 416 }
 417
 418 static inline void sysfs_notify(struct kobject *kobj, const char *dir,
 419                                 const char *attr)
 420 {
 421 }
 422 static inline void sysfs_notify_dirent(struct sysfs_dirent *sd)
 423 {
 424 }
 425 static inline struct sysfs_dirent *
 426 sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd, const unsigned char *name,
 427                     const void *ns)
 428 {
 429         return NULL;
 430 }
 431 static inline struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
 432 {
 433         return NULL;
 434 }
 435 static inline void sysfs_put(struct sysfs_dirent *sd)
 436 {
 437 }
 438
 439 static inline int __must_check sysfs_init(void)
 440 {
 441         return 0;
 442 }
 443
 444 #endif /* CONFIG_SYSFS */
 445
 446 static inline int __must_check sysfs_create_file(struct kobject *kobj,
 447                                                  const struct attribute *attr)
 448 {
 449         return sysfs_create_file_ns(kobj, attr, NULL);
 450 }
 451
 452 static inline void sysfs_remove_file(struct kobject *kobj,
 453                                      const struct attribute *attr)
 454 {
 455         return sysfs_remove_file_ns(kobj, attr, NULL);
 456 }
 457
 458 static inline int sysfs_rename_link(struct kobject *kobj, struct kobject *target,
 459                                     const char *old_name, const char *new_name)
 460 {
 461         return sysfs_rename_link_ns(kobj, target, old_name, new_name, NULL);
 462 }
 463
 464 static inline struct sysfs_dirent *
 465 sysfs_get_dirent(struct sysfs_dirent *parent_sd, const unsigned char *name)
 466 {
 467         return sysfs_get_dirent_ns(parent_sd, name, NULL);
 468 }
 469
 470 #endif /* _SYSFS_H_ */