Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * kobject.c - library routines for handling generic kernel objects |
| 3 | * |
| 4 | * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> |
| 5 | * |
| 6 | * This file is released under the GPLv2. |
| 7 | * |
| 8 | * |
| 9 | * Please see the file Documentation/kobject.txt for critical information |
| 10 | * about using the kobject interface. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/kobject.h> |
| 14 | #include <linux/string.h> |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/stat.h> |
Tim Schmielau | 4e57b68 | 2005-10-30 15:03:48 -0800 | [diff] [blame] | 17 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | |
| 19 | /** |
| 20 | * populate_dir - populate directory with attributes. |
| 21 | * @kobj: object we're working on. |
| 22 | * |
| 23 | * Most subsystems have a set of default attributes that |
| 24 | * are associated with an object that registers with them. |
| 25 | * This is a helper called during object registration that |
| 26 | * loops through the default attributes of the subsystem |
| 27 | * and creates attributes files for them in sysfs. |
| 28 | * |
| 29 | */ |
| 30 | |
| 31 | static int populate_dir(struct kobject * kobj) |
| 32 | { |
| 33 | struct kobj_type * t = get_ktype(kobj); |
| 34 | struct attribute * attr; |
| 35 | int error = 0; |
| 36 | int i; |
| 37 | |
| 38 | if (t && t->default_attrs) { |
| 39 | for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { |
| 40 | if ((error = sysfs_create_file(kobj,attr))) |
| 41 | break; |
| 42 | } |
| 43 | } |
| 44 | return error; |
| 45 | } |
| 46 | |
| 47 | static int create_dir(struct kobject * kobj) |
| 48 | { |
| 49 | int error = 0; |
| 50 | if (kobject_name(kobj)) { |
| 51 | error = sysfs_create_dir(kobj); |
| 52 | if (!error) { |
| 53 | if ((error = populate_dir(kobj))) |
| 54 | sysfs_remove_dir(kobj); |
| 55 | } |
| 56 | } |
| 57 | return error; |
| 58 | } |
| 59 | |
| 60 | static inline struct kobject * to_kobj(struct list_head * entry) |
| 61 | { |
| 62 | return container_of(entry,struct kobject,entry); |
| 63 | } |
| 64 | |
| 65 | static int get_kobj_path_length(struct kobject *kobj) |
| 66 | { |
| 67 | int length = 1; |
| 68 | struct kobject * parent = kobj; |
| 69 | |
| 70 | /* walk up the ancestors until we hit the one pointing to the |
| 71 | * root. |
| 72 | * Add 1 to strlen for leading '/' of each level. |
| 73 | */ |
| 74 | do { |
Chuck Ebbert | b365b3d | 2006-01-12 20:02:00 -0500 | [diff] [blame] | 75 | if (kobject_name(parent) == NULL) |
| 76 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | length += strlen(kobject_name(parent)) + 1; |
| 78 | parent = parent->parent; |
| 79 | } while (parent); |
| 80 | return length; |
| 81 | } |
| 82 | |
| 83 | static void fill_kobj_path(struct kobject *kobj, char *path, int length) |
| 84 | { |
| 85 | struct kobject * parent; |
| 86 | |
| 87 | --length; |
| 88 | for (parent = kobj; parent; parent = parent->parent) { |
| 89 | int cur = strlen(kobject_name(parent)); |
| 90 | /* back up enough to print this name with '/' */ |
| 91 | length -= cur; |
| 92 | strncpy (path + length, kobject_name(parent), cur); |
| 93 | *(path + --length) = '/'; |
| 94 | } |
| 95 | |
| 96 | pr_debug("%s: path = '%s'\n",__FUNCTION__,path); |
| 97 | } |
| 98 | |
| 99 | /** |
| 100 | * kobject_get_path - generate and return the path associated with a given kobj |
| 101 | * and kset pair. The result must be freed by the caller with kfree(). |
| 102 | * |
| 103 | * @kobj: kobject in question, with which to build the path |
| 104 | * @gfp_mask: the allocation type used to allocate the path |
| 105 | */ |
Al Viro | fd4f2df | 2005-10-21 03:18:50 -0400 | [diff] [blame] | 106 | char *kobject_get_path(struct kobject *kobj, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | { |
| 108 | char *path; |
| 109 | int len; |
| 110 | |
| 111 | len = get_kobj_path_length(kobj); |
Chuck Ebbert | b365b3d | 2006-01-12 20:02:00 -0500 | [diff] [blame] | 112 | if (len == 0) |
| 113 | return NULL; |
Burman Yan | 4668edc | 2006-12-06 20:38:51 -0800 | [diff] [blame] | 114 | path = kzalloc(len, gfp_mask); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | if (!path) |
| 116 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | fill_kobj_path(kobj, path, len); |
| 118 | |
| 119 | return path; |
| 120 | } |
Dmitry Torokhov | 80fc9f5 | 2006-10-11 01:43:58 -0400 | [diff] [blame] | 121 | EXPORT_SYMBOL_GPL(kobject_get_path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
| 123 | /** |
| 124 | * kobject_init - initialize object. |
| 125 | * @kobj: object in question. |
| 126 | */ |
| 127 | void kobject_init(struct kobject * kobj) |
| 128 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 129 | if (!kobj) |
| 130 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | kref_init(&kobj->kref); |
| 132 | INIT_LIST_HEAD(&kobj->entry); |
NeilBrown | 4508a7a | 2006-03-20 17:53:53 +1100 | [diff] [blame] | 133 | init_waitqueue_head(&kobj->poll); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 134 | kobj->kset = kset_get(kobj->kset); |
| 135 | } |
| 136 | |
| 137 | |
| 138 | /** |
| 139 | * unlink - remove kobject from kset list. |
| 140 | * @kobj: kobject. |
| 141 | * |
| 142 | * Remove the kobject from the kset list and decrement |
| 143 | * its parent's refcount. |
| 144 | * This is separated out, so we can use it in both |
| 145 | * kobject_del() and kobject_add() on error. |
| 146 | */ |
| 147 | |
| 148 | static void unlink(struct kobject * kobj) |
| 149 | { |
| 150 | if (kobj->kset) { |
| 151 | spin_lock(&kobj->kset->list_lock); |
| 152 | list_del_init(&kobj->entry); |
| 153 | spin_unlock(&kobj->kset->list_lock); |
| 154 | } |
| 155 | kobject_put(kobj); |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * kobject_add - add an object to the hierarchy. |
| 160 | * @kobj: object. |
| 161 | */ |
| 162 | |
| 163 | int kobject_add(struct kobject * kobj) |
| 164 | { |
| 165 | int error = 0; |
| 166 | struct kobject * parent; |
| 167 | |
| 168 | if (!(kobj = kobject_get(kobj))) |
| 169 | return -ENOENT; |
| 170 | if (!kobj->k_name) |
| 171 | kobj->k_name = kobj->name; |
Greg Kroah-Hartman | c171fef | 2006-01-20 14:08:59 -0800 | [diff] [blame] | 172 | if (!kobj->k_name) { |
| 173 | pr_debug("kobject attempted to be registered with no name!\n"); |
| 174 | WARN_ON(1); |
| 175 | return -EINVAL; |
| 176 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | parent = kobject_get(kobj->parent); |
| 178 | |
| 179 | pr_debug("kobject %s: registering. parent: %s, set: %s\n", |
| 180 | kobject_name(kobj), parent ? kobject_name(parent) : "<NULL>", |
| 181 | kobj->kset ? kobj->kset->kobj.name : "<NULL>" ); |
| 182 | |
| 183 | if (kobj->kset) { |
| 184 | spin_lock(&kobj->kset->list_lock); |
| 185 | |
| 186 | if (!parent) |
| 187 | parent = kobject_get(&kobj->kset->kobj); |
| 188 | |
| 189 | list_add_tail(&kobj->entry,&kobj->kset->list); |
| 190 | spin_unlock(&kobj->kset->list_lock); |
| 191 | } |
| 192 | kobj->parent = parent; |
| 193 | |
| 194 | error = create_dir(kobj); |
| 195 | if (error) { |
| 196 | /* unlink does the kobject_put() for us */ |
| 197 | unlink(kobj); |
Mariusz Kozlowski | b067db4 | 2007-01-02 13:44:44 +0100 | [diff] [blame] | 198 | kobject_put(parent); |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 199 | |
| 200 | /* be noisy on error issues */ |
| 201 | if (error == -EEXIST) |
Greg Kroah-Hartman | 183bd5b | 2006-05-18 10:39:21 -0700 | [diff] [blame] | 202 | printk("kobject_add failed for %s with -EEXIST, " |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 203 | "don't try to register things with the " |
| 204 | "same name in the same directory.\n", |
| 205 | kobject_name(kobj)); |
| 206 | else |
Greg Kroah-Hartman | 183bd5b | 2006-05-18 10:39:21 -0700 | [diff] [blame] | 207 | printk("kobject_add failed for %s (%d)\n", |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 208 | kobject_name(kobj), error); |
Greg Kroah-Hartman | 183bd5b | 2006-05-18 10:39:21 -0700 | [diff] [blame] | 209 | dump_stack(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | } |
| 211 | |
| 212 | return error; |
| 213 | } |
| 214 | |
| 215 | |
| 216 | /** |
| 217 | * kobject_register - initialize and add an object. |
| 218 | * @kobj: object in question. |
| 219 | */ |
| 220 | |
| 221 | int kobject_register(struct kobject * kobj) |
| 222 | { |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 223 | int error = -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | if (kobj) { |
| 225 | kobject_init(kobj); |
| 226 | error = kobject_add(kobj); |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 227 | if (!error) |
Kay Sievers | 312c004 | 2005-11-16 09:00:00 +0100 | [diff] [blame] | 228 | kobject_uevent(kobj, KOBJ_ADD); |
Greg Kroah-Hartman | dcd0da0 | 2006-03-20 13:17:13 -0800 | [diff] [blame] | 229 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | return error; |
| 231 | } |
| 232 | |
| 233 | |
| 234 | /** |
| 235 | * kobject_set_name - Set the name of an object |
| 236 | * @kobj: object. |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 237 | * @fmt: format string used to build the name |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | * |
| 239 | * If strlen(name) >= KOBJ_NAME_LEN, then use a dynamically allocated |
| 240 | * string that @kobj->k_name points to. Otherwise, use the static |
| 241 | * @kobj->name array. |
| 242 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | int kobject_set_name(struct kobject * kobj, const char * fmt, ...) |
| 244 | { |
| 245 | int error = 0; |
| 246 | int limit = KOBJ_NAME_LEN; |
| 247 | int need; |
| 248 | va_list args; |
| 249 | char * name; |
| 250 | |
| 251 | /* |
| 252 | * First, try the static array |
| 253 | */ |
| 254 | va_start(args,fmt); |
| 255 | need = vsnprintf(kobj->name,limit,fmt,args); |
| 256 | va_end(args); |
| 257 | if (need < limit) |
| 258 | name = kobj->name; |
| 259 | else { |
| 260 | /* |
| 261 | * Need more space? Allocate it and try again |
| 262 | */ |
| 263 | limit = need + 1; |
| 264 | name = kmalloc(limit,GFP_KERNEL); |
| 265 | if (!name) { |
| 266 | error = -ENOMEM; |
| 267 | goto Done; |
| 268 | } |
| 269 | va_start(args,fmt); |
| 270 | need = vsnprintf(name,limit,fmt,args); |
| 271 | va_end(args); |
| 272 | |
| 273 | /* Still? Give up. */ |
| 274 | if (need >= limit) { |
| 275 | kfree(name); |
| 276 | error = -EFAULT; |
| 277 | goto Done; |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | /* Free the old name, if necessary. */ |
| 282 | if (kobj->k_name && kobj->k_name != kobj->name) |
| 283 | kfree(kobj->k_name); |
| 284 | |
| 285 | /* Now, set the new name */ |
| 286 | kobj->k_name = name; |
| 287 | Done: |
| 288 | return error; |
| 289 | } |
| 290 | |
| 291 | EXPORT_SYMBOL(kobject_set_name); |
| 292 | |
| 293 | |
| 294 | /** |
| 295 | * kobject_rename - change the name of an object |
| 296 | * @kobj: object in question. |
| 297 | * @new_name: object's new name |
| 298 | */ |
| 299 | |
Dmitry Torokhov | f3b4f3c | 2005-04-26 02:32:00 -0500 | [diff] [blame] | 300 | int kobject_rename(struct kobject * kobj, const char *new_name) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | { |
| 302 | int error = 0; |
| 303 | |
| 304 | kobj = kobject_get(kobj); |
| 305 | if (!kobj) |
| 306 | return -EINVAL; |
| 307 | error = sysfs_rename_dir(kobj, new_name); |
| 308 | kobject_put(kobj); |
| 309 | |
| 310 | return error; |
| 311 | } |
| 312 | |
| 313 | /** |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 314 | * kobject_move - move object to another parent |
| 315 | * @kobj: object in question. |
Cornelia Huck | c744aea | 2007-01-08 20:16:44 +0100 | [diff] [blame] | 316 | * @new_parent: object's new parent (can be NULL) |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 317 | */ |
| 318 | |
| 319 | int kobject_move(struct kobject *kobj, struct kobject *new_parent) |
| 320 | { |
| 321 | int error; |
| 322 | struct kobject *old_parent; |
| 323 | const char *devpath = NULL; |
| 324 | char *devpath_string = NULL; |
| 325 | char *envp[2]; |
| 326 | |
| 327 | kobj = kobject_get(kobj); |
| 328 | if (!kobj) |
| 329 | return -EINVAL; |
| 330 | new_parent = kobject_get(new_parent); |
| 331 | if (!new_parent) { |
Cornelia Huck | c744aea | 2007-01-08 20:16:44 +0100 | [diff] [blame] | 332 | if (kobj->kset) |
| 333 | new_parent = kobject_get(&kobj->kset->kobj); |
Cornelia Huck | 8a82472 | 2006-11-20 17:07:51 +0100 | [diff] [blame] | 334 | } |
| 335 | /* old object path */ |
| 336 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 337 | if (!devpath) { |
| 338 | error = -ENOMEM; |
| 339 | goto out; |
| 340 | } |
| 341 | devpath_string = kmalloc(strlen(devpath) + 15, GFP_KERNEL); |
| 342 | if (!devpath_string) { |
| 343 | error = -ENOMEM; |
| 344 | goto out; |
| 345 | } |
| 346 | sprintf(devpath_string, "DEVPATH_OLD=%s", devpath); |
| 347 | envp[0] = devpath_string; |
| 348 | envp[1] = NULL; |
| 349 | error = sysfs_move_dir(kobj, new_parent); |
| 350 | if (error) |
| 351 | goto out; |
| 352 | old_parent = kobj->parent; |
| 353 | kobj->parent = new_parent; |
| 354 | kobject_put(old_parent); |
| 355 | kobject_uevent_env(kobj, KOBJ_MOVE, envp); |
| 356 | out: |
| 357 | kobject_put(kobj); |
| 358 | kfree(devpath_string); |
| 359 | kfree(devpath); |
| 360 | return error; |
| 361 | } |
| 362 | |
| 363 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | * kobject_del - unlink kobject from hierarchy. |
| 365 | * @kobj: object. |
| 366 | */ |
| 367 | |
| 368 | void kobject_del(struct kobject * kobj) |
| 369 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 370 | if (!kobj) |
| 371 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | sysfs_remove_dir(kobj); |
| 373 | unlink(kobj); |
| 374 | } |
| 375 | |
| 376 | /** |
| 377 | * kobject_unregister - remove object from hierarchy and decrement refcount. |
| 378 | * @kobj: object going away. |
| 379 | */ |
| 380 | |
| 381 | void kobject_unregister(struct kobject * kobj) |
| 382 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 383 | if (!kobj) |
| 384 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | pr_debug("kobject %s: unregistering\n",kobject_name(kobj)); |
Kay Sievers | 312c004 | 2005-11-16 09:00:00 +0100 | [diff] [blame] | 386 | kobject_uevent(kobj, KOBJ_REMOVE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | kobject_del(kobj); |
| 388 | kobject_put(kobj); |
| 389 | } |
| 390 | |
| 391 | /** |
| 392 | * kobject_get - increment refcount for object. |
| 393 | * @kobj: object. |
| 394 | */ |
| 395 | |
| 396 | struct kobject * kobject_get(struct kobject * kobj) |
| 397 | { |
| 398 | if (kobj) |
| 399 | kref_get(&kobj->kref); |
| 400 | return kobj; |
| 401 | } |
| 402 | |
| 403 | /** |
| 404 | * kobject_cleanup - free kobject resources. |
| 405 | * @kobj: object. |
| 406 | */ |
| 407 | |
| 408 | void kobject_cleanup(struct kobject * kobj) |
| 409 | { |
| 410 | struct kobj_type * t = get_ktype(kobj); |
| 411 | struct kset * s = kobj->kset; |
| 412 | struct kobject * parent = kobj->parent; |
| 413 | |
| 414 | pr_debug("kobject %s: cleaning up\n",kobject_name(kobj)); |
| 415 | if (kobj->k_name != kobj->name) |
| 416 | kfree(kobj->k_name); |
| 417 | kobj->k_name = NULL; |
| 418 | if (t && t->release) |
| 419 | t->release(kobj); |
| 420 | if (s) |
| 421 | kset_put(s); |
Mariusz Kozlowski | b067db4 | 2007-01-02 13:44:44 +0100 | [diff] [blame] | 422 | kobject_put(parent); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
| 424 | |
| 425 | static void kobject_release(struct kref *kref) |
| 426 | { |
| 427 | kobject_cleanup(container_of(kref, struct kobject, kref)); |
| 428 | } |
| 429 | |
| 430 | /** |
| 431 | * kobject_put - decrement refcount for object. |
| 432 | * @kobj: object. |
| 433 | * |
| 434 | * Decrement the refcount, and if 0, call kobject_cleanup(). |
| 435 | */ |
| 436 | void kobject_put(struct kobject * kobj) |
| 437 | { |
| 438 | if (kobj) |
| 439 | kref_put(&kobj->kref, kobject_release); |
| 440 | } |
| 441 | |
| 442 | |
Jun'ichi Nomura | 7423172 | 2006-03-13 17:14:25 -0500 | [diff] [blame] | 443 | static void dir_release(struct kobject *kobj) |
| 444 | { |
| 445 | kfree(kobj); |
| 446 | } |
| 447 | |
| 448 | static struct kobj_type dir_ktype = { |
| 449 | .release = dir_release, |
| 450 | .sysfs_ops = NULL, |
| 451 | .default_attrs = NULL, |
| 452 | }; |
| 453 | |
| 454 | /** |
| 455 | * kobject_add_dir - add sub directory of object. |
| 456 | * @parent: object in which a directory is created. |
| 457 | * @name: directory name. |
| 458 | * |
| 459 | * Add a plain directory object as child of given object. |
| 460 | */ |
| 461 | struct kobject *kobject_add_dir(struct kobject *parent, const char *name) |
| 462 | { |
| 463 | struct kobject *k; |
Randy Dunlap | 1018801 | 2006-07-11 20:49:41 -0700 | [diff] [blame] | 464 | int ret; |
Jun'ichi Nomura | 7423172 | 2006-03-13 17:14:25 -0500 | [diff] [blame] | 465 | |
| 466 | if (!parent) |
| 467 | return NULL; |
| 468 | |
| 469 | k = kzalloc(sizeof(*k), GFP_KERNEL); |
| 470 | if (!k) |
| 471 | return NULL; |
| 472 | |
| 473 | k->parent = parent; |
| 474 | k->ktype = &dir_ktype; |
| 475 | kobject_set_name(k, name); |
Randy Dunlap | 1018801 | 2006-07-11 20:49:41 -0700 | [diff] [blame] | 476 | ret = kobject_register(k); |
| 477 | if (ret < 0) { |
| 478 | printk(KERN_WARNING "kobject_add_dir: " |
| 479 | "kobject_register error: %d\n", ret); |
| 480 | kobject_del(k); |
| 481 | return NULL; |
| 482 | } |
Jun'ichi Nomura | 7423172 | 2006-03-13 17:14:25 -0500 | [diff] [blame] | 483 | |
| 484 | return k; |
| 485 | } |
Jun'ichi Nomura | 7423172 | 2006-03-13 17:14:25 -0500 | [diff] [blame] | 486 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | /** |
| 488 | * kset_init - initialize a kset for use |
| 489 | * @k: kset |
| 490 | */ |
| 491 | |
| 492 | void kset_init(struct kset * k) |
| 493 | { |
| 494 | kobject_init(&k->kobj); |
| 495 | INIT_LIST_HEAD(&k->list); |
| 496 | spin_lock_init(&k->list_lock); |
| 497 | } |
| 498 | |
| 499 | |
| 500 | /** |
| 501 | * kset_add - add a kset object to the hierarchy. |
| 502 | * @k: kset. |
| 503 | * |
| 504 | * Simply, this adds the kset's embedded kobject to the |
| 505 | * hierarchy. |
| 506 | * We also try to make sure that the kset's embedded kobject |
| 507 | * has a parent before it is added. We only care if the embedded |
| 508 | * kobject is not part of a kset itself, since kobject_add() |
| 509 | * assigns a parent in that case. |
| 510 | * If that is the case, and the kset has a controlling subsystem, |
| 511 | * then we set the kset's parent to be said subsystem. |
| 512 | */ |
| 513 | |
| 514 | int kset_add(struct kset * k) |
| 515 | { |
| 516 | if (!k->kobj.parent && !k->kobj.kset && k->subsys) |
| 517 | k->kobj.parent = &k->subsys->kset.kobj; |
| 518 | |
| 519 | return kobject_add(&k->kobj); |
| 520 | } |
| 521 | |
| 522 | |
| 523 | /** |
| 524 | * kset_register - initialize and add a kset. |
| 525 | * @k: kset. |
| 526 | */ |
| 527 | |
| 528 | int kset_register(struct kset * k) |
| 529 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 530 | if (!k) |
| 531 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | kset_init(k); |
| 533 | return kset_add(k); |
| 534 | } |
| 535 | |
| 536 | |
| 537 | /** |
| 538 | * kset_unregister - remove a kset. |
| 539 | * @k: kset. |
| 540 | */ |
| 541 | |
| 542 | void kset_unregister(struct kset * k) |
| 543 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 544 | if (!k) |
| 545 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 546 | kobject_unregister(&k->kobj); |
| 547 | } |
| 548 | |
| 549 | |
| 550 | /** |
| 551 | * kset_find_obj - search for object in kset. |
| 552 | * @kset: kset we're looking in. |
| 553 | * @name: object's name. |
| 554 | * |
| 555 | * Lock kset via @kset->subsys, and iterate over @kset->list, |
| 556 | * looking for a matching kobject. If matching object is found |
| 557 | * take a reference and return the object. |
| 558 | */ |
| 559 | |
| 560 | struct kobject * kset_find_obj(struct kset * kset, const char * name) |
| 561 | { |
| 562 | struct list_head * entry; |
| 563 | struct kobject * ret = NULL; |
| 564 | |
| 565 | spin_lock(&kset->list_lock); |
| 566 | list_for_each(entry,&kset->list) { |
| 567 | struct kobject * k = to_kobj(entry); |
| 568 | if (kobject_name(k) && !strcmp(kobject_name(k),name)) { |
| 569 | ret = kobject_get(k); |
| 570 | break; |
| 571 | } |
| 572 | } |
| 573 | spin_unlock(&kset->list_lock); |
| 574 | return ret; |
| 575 | } |
| 576 | |
| 577 | |
| 578 | void subsystem_init(struct subsystem * s) |
| 579 | { |
| 580 | init_rwsem(&s->rwsem); |
| 581 | kset_init(&s->kset); |
| 582 | } |
| 583 | |
| 584 | /** |
| 585 | * subsystem_register - register a subsystem. |
| 586 | * @s: the subsystem we're registering. |
| 587 | * |
| 588 | * Once we register the subsystem, we want to make sure that |
| 589 | * the kset points back to this subsystem for correct usage of |
| 590 | * the rwsem. |
| 591 | */ |
| 592 | |
| 593 | int subsystem_register(struct subsystem * s) |
| 594 | { |
| 595 | int error; |
| 596 | |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 597 | if (!s) |
| 598 | return -EINVAL; |
| 599 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | subsystem_init(s); |
| 601 | pr_debug("subsystem %s: registering\n",s->kset.kobj.name); |
| 602 | |
| 603 | if (!(error = kset_add(&s->kset))) { |
| 604 | if (!s->kset.subsys) |
| 605 | s->kset.subsys = s; |
| 606 | } |
| 607 | return error; |
| 608 | } |
| 609 | |
| 610 | void subsystem_unregister(struct subsystem * s) |
| 611 | { |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 612 | if (!s) |
| 613 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | pr_debug("subsystem %s: unregistering\n",s->kset.kobj.name); |
| 615 | kset_unregister(&s->kset); |
| 616 | } |
| 617 | |
| 618 | |
| 619 | /** |
| 620 | * subsystem_create_file - export sysfs attribute file. |
| 621 | * @s: subsystem. |
| 622 | * @a: subsystem attribute descriptor. |
| 623 | */ |
| 624 | |
| 625 | int subsys_create_file(struct subsystem * s, struct subsys_attribute * a) |
| 626 | { |
| 627 | int error = 0; |
Greg Kroah-Hartman | 31b9025 | 2007-01-18 12:23:51 -0800 | [diff] [blame] | 628 | |
| 629 | if (!s || !a) |
| 630 | return -EINVAL; |
| 631 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | if (subsys_get(s)) { |
| 633 | error = sysfs_create_file(&s->kset.kobj,&a->attr); |
| 634 | subsys_put(s); |
| 635 | } |
| 636 | return error; |
| 637 | } |
| 638 | |
| 639 | |
| 640 | /** |
| 641 | * subsystem_remove_file - remove sysfs attribute file. |
| 642 | * @s: subsystem. |
| 643 | * @a: attribute desciptor. |
| 644 | */ |
Adrian Bunk | 5b3ef14 | 2006-04-22 12:14:44 +0200 | [diff] [blame] | 645 | #if 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | void subsys_remove_file(struct subsystem * s, struct subsys_attribute * a) |
| 647 | { |
| 648 | if (subsys_get(s)) { |
| 649 | sysfs_remove_file(&s->kset.kobj,&a->attr); |
| 650 | subsys_put(s); |
| 651 | } |
| 652 | } |
Adrian Bunk | 5b3ef14 | 2006-04-22 12:14:44 +0200 | [diff] [blame] | 653 | #endif /* 0 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | |
| 655 | EXPORT_SYMBOL(kobject_init); |
| 656 | EXPORT_SYMBOL(kobject_register); |
| 657 | EXPORT_SYMBOL(kobject_unregister); |
| 658 | EXPORT_SYMBOL(kobject_get); |
| 659 | EXPORT_SYMBOL(kobject_put); |
| 660 | EXPORT_SYMBOL(kobject_add); |
| 661 | EXPORT_SYMBOL(kobject_del); |
| 662 | |
| 663 | EXPORT_SYMBOL(kset_register); |
| 664 | EXPORT_SYMBOL(kset_unregister); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 665 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | EXPORT_SYMBOL(subsystem_register); |
| 667 | EXPORT_SYMBOL(subsystem_unregister); |
| 668 | EXPORT_SYMBOL(subsys_create_file); |