diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /lib/kobject.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'lib/kobject.c')
-rw-r--r-- | lib/kobject.c | 544 |
1 files changed, 544 insertions, 0 deletions
diff --git a/lib/kobject.c b/lib/kobject.c new file mode 100644 index 000000000000..ff9491986b38 --- /dev/null +++ b/lib/kobject.c | |||
@@ -0,0 +1,544 @@ | |||
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> | ||
17 | |||
18 | /** | ||
19 | * populate_dir - populate directory with attributes. | ||
20 | * @kobj: object we're working on. | ||
21 | * | ||
22 | * Most subsystems have a set of default attributes that | ||
23 | * are associated with an object that registers with them. | ||
24 | * This is a helper called during object registration that | ||
25 | * loops through the default attributes of the subsystem | ||
26 | * and creates attributes files for them in sysfs. | ||
27 | * | ||
28 | */ | ||
29 | |||
30 | static int populate_dir(struct kobject * kobj) | ||
31 | { | ||
32 | struct kobj_type * t = get_ktype(kobj); | ||
33 | struct attribute * attr; | ||
34 | int error = 0; | ||
35 | int i; | ||
36 | |||
37 | if (t && t->default_attrs) { | ||
38 | for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { | ||
39 | if ((error = sysfs_create_file(kobj,attr))) | ||
40 | break; | ||
41 | } | ||
42 | } | ||
43 | return error; | ||
44 | } | ||
45 | |||
46 | static int create_dir(struct kobject * kobj) | ||
47 | { | ||
48 | int error = 0; | ||
49 | if (kobject_name(kobj)) { | ||
50 | error = sysfs_create_dir(kobj); | ||
51 | if (!error) { | ||
52 | if ((error = populate_dir(kobj))) | ||
53 | sysfs_remove_dir(kobj); | ||
54 | } | ||
55 | } | ||
56 | return error; | ||
57 | } | ||
58 | |||
59 | static inline struct kobject * to_kobj(struct list_head * entry) | ||
60 | { | ||
61 | return container_of(entry,struct kobject,entry); | ||
62 | } | ||
63 | |||
64 | static int get_kobj_path_length(struct kobject *kobj) | ||
65 | { | ||
66 | int length = 1; | ||
67 | struct kobject * parent = kobj; | ||
68 | |||
69 | /* walk up the ancestors until we hit the one pointing to the | ||
70 | * root. | ||
71 | * Add 1 to strlen for leading '/' of each level. | ||
72 | */ | ||
73 | do { | ||
74 | length += strlen(kobject_name(parent)) + 1; | ||
75 | parent = parent->parent; | ||
76 | } while (parent); | ||
77 | return length; | ||
78 | } | ||
79 | |||
80 | static void fill_kobj_path(struct kobject *kobj, char *path, int length) | ||
81 | { | ||
82 | struct kobject * parent; | ||
83 | |||
84 | --length; | ||
85 | for (parent = kobj; parent; parent = parent->parent) { | ||
86 | int cur = strlen(kobject_name(parent)); | ||
87 | /* back up enough to print this name with '/' */ | ||
88 | length -= cur; | ||
89 | strncpy (path + length, kobject_name(parent), cur); | ||
90 | *(path + --length) = '/'; | ||
91 | } | ||
92 | |||
93 | pr_debug("%s: path = '%s'\n",__FUNCTION__,path); | ||
94 | } | ||
95 | |||
96 | /** | ||
97 | * kobject_get_path - generate and return the path associated with a given kobj | ||
98 | * and kset pair. The result must be freed by the caller with kfree(). | ||
99 | * | ||
100 | * @kobj: kobject in question, with which to build the path | ||
101 | * @gfp_mask: the allocation type used to allocate the path | ||
102 | */ | ||
103 | char *kobject_get_path(struct kobject *kobj, int gfp_mask) | ||
104 | { | ||
105 | char *path; | ||
106 | int len; | ||
107 | |||
108 | len = get_kobj_path_length(kobj); | ||
109 | path = kmalloc(len, gfp_mask); | ||
110 | if (!path) | ||
111 | return NULL; | ||
112 | memset(path, 0x00, len); | ||
113 | fill_kobj_path(kobj, path, len); | ||
114 | |||
115 | return path; | ||
116 | } | ||
117 | |||
118 | /** | ||
119 | * kobject_init - initialize object. | ||
120 | * @kobj: object in question. | ||
121 | */ | ||
122 | void kobject_init(struct kobject * kobj) | ||
123 | { | ||
124 | kref_init(&kobj->kref); | ||
125 | INIT_LIST_HEAD(&kobj->entry); | ||
126 | kobj->kset = kset_get(kobj->kset); | ||
127 | } | ||
128 | |||
129 | |||
130 | /** | ||
131 | * unlink - remove kobject from kset list. | ||
132 | * @kobj: kobject. | ||
133 | * | ||
134 | * Remove the kobject from the kset list and decrement | ||
135 | * its parent's refcount. | ||
136 | * This is separated out, so we can use it in both | ||
137 | * kobject_del() and kobject_add() on error. | ||
138 | */ | ||
139 | |||
140 | static void unlink(struct kobject * kobj) | ||
141 | { | ||
142 | if (kobj->kset) { | ||
143 | spin_lock(&kobj->kset->list_lock); | ||
144 | list_del_init(&kobj->entry); | ||
145 | spin_unlock(&kobj->kset->list_lock); | ||
146 | } | ||
147 | kobject_put(kobj); | ||
148 | } | ||
149 | |||
150 | /** | ||
151 | * kobject_add - add an object to the hierarchy. | ||
152 | * @kobj: object. | ||
153 | */ | ||
154 | |||
155 | int kobject_add(struct kobject * kobj) | ||
156 | { | ||
157 | int error = 0; | ||
158 | struct kobject * parent; | ||
159 | |||
160 | if (!(kobj = kobject_get(kobj))) | ||
161 | return -ENOENT; | ||
162 | if (!kobj->k_name) | ||
163 | kobj->k_name = kobj->name; | ||
164 | parent = kobject_get(kobj->parent); | ||
165 | |||
166 | pr_debug("kobject %s: registering. parent: %s, set: %s\n", | ||
167 | kobject_name(kobj), parent ? kobject_name(parent) : "<NULL>", | ||
168 | kobj->kset ? kobj->kset->kobj.name : "<NULL>" ); | ||
169 | |||
170 | if (kobj->kset) { | ||
171 | spin_lock(&kobj->kset->list_lock); | ||
172 | |||
173 | if (!parent) | ||
174 | parent = kobject_get(&kobj->kset->kobj); | ||
175 | |||
176 | list_add_tail(&kobj->entry,&kobj->kset->list); | ||
177 | spin_unlock(&kobj->kset->list_lock); | ||
178 | } | ||
179 | kobj->parent = parent; | ||
180 | |||
181 | error = create_dir(kobj); | ||
182 | if (error) { | ||
183 | /* unlink does the kobject_put() for us */ | ||
184 | unlink(kobj); | ||
185 | if (parent) | ||
186 | kobject_put(parent); | ||
187 | } else { | ||
188 | kobject_hotplug(kobj, KOBJ_ADD); | ||
189 | } | ||
190 | |||
191 | return error; | ||
192 | } | ||
193 | |||
194 | |||
195 | /** | ||
196 | * kobject_register - initialize and add an object. | ||
197 | * @kobj: object in question. | ||
198 | */ | ||
199 | |||
200 | int kobject_register(struct kobject * kobj) | ||
201 | { | ||
202 | int error = 0; | ||
203 | if (kobj) { | ||
204 | kobject_init(kobj); | ||
205 | error = kobject_add(kobj); | ||
206 | if (error) { | ||
207 | printk("kobject_register failed for %s (%d)\n", | ||
208 | kobject_name(kobj),error); | ||
209 | dump_stack(); | ||
210 | } | ||
211 | } else | ||
212 | error = -EINVAL; | ||
213 | return error; | ||
214 | } | ||
215 | |||
216 | |||
217 | /** | ||
218 | * kobject_set_name - Set the name of an object | ||
219 | * @kobj: object. | ||
220 | * @name: name. | ||
221 | * | ||
222 | * If strlen(name) >= KOBJ_NAME_LEN, then use a dynamically allocated | ||
223 | * string that @kobj->k_name points to. Otherwise, use the static | ||
224 | * @kobj->name array. | ||
225 | */ | ||
226 | |||
227 | int kobject_set_name(struct kobject * kobj, const char * fmt, ...) | ||
228 | { | ||
229 | int error = 0; | ||
230 | int limit = KOBJ_NAME_LEN; | ||
231 | int need; | ||
232 | va_list args; | ||
233 | char * name; | ||
234 | |||
235 | /* | ||
236 | * First, try the static array | ||
237 | */ | ||
238 | va_start(args,fmt); | ||
239 | need = vsnprintf(kobj->name,limit,fmt,args); | ||
240 | va_end(args); | ||
241 | if (need < limit) | ||
242 | name = kobj->name; | ||
243 | else { | ||
244 | /* | ||
245 | * Need more space? Allocate it and try again | ||
246 | */ | ||
247 | limit = need + 1; | ||
248 | name = kmalloc(limit,GFP_KERNEL); | ||
249 | if (!name) { | ||
250 | error = -ENOMEM; | ||
251 | goto Done; | ||
252 | } | ||
253 | va_start(args,fmt); | ||
254 | need = vsnprintf(name,limit,fmt,args); | ||
255 | va_end(args); | ||
256 | |||
257 | /* Still? Give up. */ | ||
258 | if (need >= limit) { | ||
259 | kfree(name); | ||
260 | error = -EFAULT; | ||
261 | goto Done; | ||
262 | } | ||
263 | } | ||
264 | |||
265 | /* Free the old name, if necessary. */ | ||
266 | if (kobj->k_name && kobj->k_name != kobj->name) | ||
267 | kfree(kobj->k_name); | ||
268 | |||
269 | /* Now, set the new name */ | ||
270 | kobj->k_name = name; | ||
271 | Done: | ||
272 | return error; | ||
273 | } | ||
274 | |||
275 | EXPORT_SYMBOL(kobject_set_name); | ||
276 | |||
277 | |||
278 | /** | ||
279 | * kobject_rename - change the name of an object | ||
280 | * @kobj: object in question. | ||
281 | * @new_name: object's new name | ||
282 | */ | ||
283 | |||
284 | int kobject_rename(struct kobject * kobj, char *new_name) | ||
285 | { | ||
286 | int error = 0; | ||
287 | |||
288 | kobj = kobject_get(kobj); | ||
289 | if (!kobj) | ||
290 | return -EINVAL; | ||
291 | error = sysfs_rename_dir(kobj, new_name); | ||
292 | kobject_put(kobj); | ||
293 | |||
294 | return error; | ||
295 | } | ||
296 | |||
297 | /** | ||
298 | * kobject_del - unlink kobject from hierarchy. | ||
299 | * @kobj: object. | ||
300 | */ | ||
301 | |||
302 | void kobject_del(struct kobject * kobj) | ||
303 | { | ||
304 | kobject_hotplug(kobj, KOBJ_REMOVE); | ||
305 | sysfs_remove_dir(kobj); | ||
306 | unlink(kobj); | ||
307 | } | ||
308 | |||
309 | /** | ||
310 | * kobject_unregister - remove object from hierarchy and decrement refcount. | ||
311 | * @kobj: object going away. | ||
312 | */ | ||
313 | |||
314 | void kobject_unregister(struct kobject * kobj) | ||
315 | { | ||
316 | pr_debug("kobject %s: unregistering\n",kobject_name(kobj)); | ||
317 | kobject_del(kobj); | ||
318 | kobject_put(kobj); | ||
319 | } | ||
320 | |||
321 | /** | ||
322 | * kobject_get - increment refcount for object. | ||
323 | * @kobj: object. | ||
324 | */ | ||
325 | |||
326 | struct kobject * kobject_get(struct kobject * kobj) | ||
327 | { | ||
328 | if (kobj) | ||
329 | kref_get(&kobj->kref); | ||
330 | return kobj; | ||
331 | } | ||
332 | |||
333 | /** | ||
334 | * kobject_cleanup - free kobject resources. | ||
335 | * @kobj: object. | ||
336 | */ | ||
337 | |||
338 | void kobject_cleanup(struct kobject * kobj) | ||
339 | { | ||
340 | struct kobj_type * t = get_ktype(kobj); | ||
341 | struct kset * s = kobj->kset; | ||
342 | struct kobject * parent = kobj->parent; | ||
343 | |||
344 | pr_debug("kobject %s: cleaning up\n",kobject_name(kobj)); | ||
345 | if (kobj->k_name != kobj->name) | ||
346 | kfree(kobj->k_name); | ||
347 | kobj->k_name = NULL; | ||
348 | if (t && t->release) | ||
349 | t->release(kobj); | ||
350 | if (s) | ||
351 | kset_put(s); | ||
352 | if (parent) | ||
353 | kobject_put(parent); | ||
354 | } | ||
355 | |||
356 | static void kobject_release(struct kref *kref) | ||
357 | { | ||
358 | kobject_cleanup(container_of(kref, struct kobject, kref)); | ||
359 | } | ||
360 | |||
361 | /** | ||
362 | * kobject_put - decrement refcount for object. | ||
363 | * @kobj: object. | ||
364 | * | ||
365 | * Decrement the refcount, and if 0, call kobject_cleanup(). | ||
366 | */ | ||
367 | void kobject_put(struct kobject * kobj) | ||
368 | { | ||
369 | if (kobj) | ||
370 | kref_put(&kobj->kref, kobject_release); | ||
371 | } | ||
372 | |||
373 | |||
374 | /** | ||
375 | * kset_init - initialize a kset for use | ||
376 | * @k: kset | ||
377 | */ | ||
378 | |||
379 | void kset_init(struct kset * k) | ||
380 | { | ||
381 | kobject_init(&k->kobj); | ||
382 | INIT_LIST_HEAD(&k->list); | ||
383 | spin_lock_init(&k->list_lock); | ||
384 | } | ||
385 | |||
386 | |||
387 | /** | ||
388 | * kset_add - add a kset object to the hierarchy. | ||
389 | * @k: kset. | ||
390 | * | ||
391 | * Simply, this adds the kset's embedded kobject to the | ||
392 | * hierarchy. | ||
393 | * We also try to make sure that the kset's embedded kobject | ||
394 | * has a parent before it is added. We only care if the embedded | ||
395 | * kobject is not part of a kset itself, since kobject_add() | ||
396 | * assigns a parent in that case. | ||
397 | * If that is the case, and the kset has a controlling subsystem, | ||
398 | * then we set the kset's parent to be said subsystem. | ||
399 | */ | ||
400 | |||
401 | int kset_add(struct kset * k) | ||
402 | { | ||
403 | if (!k->kobj.parent && !k->kobj.kset && k->subsys) | ||
404 | k->kobj.parent = &k->subsys->kset.kobj; | ||
405 | |||
406 | return kobject_add(&k->kobj); | ||
407 | } | ||
408 | |||
409 | |||
410 | /** | ||
411 | * kset_register - initialize and add a kset. | ||
412 | * @k: kset. | ||
413 | */ | ||
414 | |||
415 | int kset_register(struct kset * k) | ||
416 | { | ||
417 | kset_init(k); | ||
418 | return kset_add(k); | ||
419 | } | ||
420 | |||
421 | |||
422 | /** | ||
423 | * kset_unregister - remove a kset. | ||
424 | * @k: kset. | ||
425 | */ | ||
426 | |||
427 | void kset_unregister(struct kset * k) | ||
428 | { | ||
429 | kobject_unregister(&k->kobj); | ||
430 | } | ||
431 | |||
432 | |||
433 | /** | ||
434 | * kset_find_obj - search for object in kset. | ||
435 | * @kset: kset we're looking in. | ||
436 | * @name: object's name. | ||
437 | * | ||
438 | * Lock kset via @kset->subsys, and iterate over @kset->list, | ||
439 | * looking for a matching kobject. If matching object is found | ||
440 | * take a reference and return the object. | ||
441 | */ | ||
442 | |||
443 | struct kobject * kset_find_obj(struct kset * kset, const char * name) | ||
444 | { | ||
445 | struct list_head * entry; | ||
446 | struct kobject * ret = NULL; | ||
447 | |||
448 | spin_lock(&kset->list_lock); | ||
449 | list_for_each(entry,&kset->list) { | ||
450 | struct kobject * k = to_kobj(entry); | ||
451 | if (kobject_name(k) && !strcmp(kobject_name(k),name)) { | ||
452 | ret = kobject_get(k); | ||
453 | break; | ||
454 | } | ||
455 | } | ||
456 | spin_unlock(&kset->list_lock); | ||
457 | return ret; | ||
458 | } | ||
459 | |||
460 | |||
461 | void subsystem_init(struct subsystem * s) | ||
462 | { | ||
463 | init_rwsem(&s->rwsem); | ||
464 | kset_init(&s->kset); | ||
465 | } | ||
466 | |||
467 | /** | ||
468 | * subsystem_register - register a subsystem. | ||
469 | * @s: the subsystem we're registering. | ||
470 | * | ||
471 | * Once we register the subsystem, we want to make sure that | ||
472 | * the kset points back to this subsystem for correct usage of | ||
473 | * the rwsem. | ||
474 | */ | ||
475 | |||
476 | int subsystem_register(struct subsystem * s) | ||
477 | { | ||
478 | int error; | ||
479 | |||
480 | subsystem_init(s); | ||
481 | pr_debug("subsystem %s: registering\n",s->kset.kobj.name); | ||
482 | |||
483 | if (!(error = kset_add(&s->kset))) { | ||
484 | if (!s->kset.subsys) | ||
485 | s->kset.subsys = s; | ||
486 | } | ||
487 | return error; | ||
488 | } | ||
489 | |||
490 | void subsystem_unregister(struct subsystem * s) | ||
491 | { | ||
492 | pr_debug("subsystem %s: unregistering\n",s->kset.kobj.name); | ||
493 | kset_unregister(&s->kset); | ||
494 | } | ||
495 | |||
496 | |||
497 | /** | ||
498 | * subsystem_create_file - export sysfs attribute file. | ||
499 | * @s: subsystem. | ||
500 | * @a: subsystem attribute descriptor. | ||
501 | */ | ||
502 | |||
503 | int subsys_create_file(struct subsystem * s, struct subsys_attribute * a) | ||
504 | { | ||
505 | int error = 0; | ||
506 | if (subsys_get(s)) { | ||
507 | error = sysfs_create_file(&s->kset.kobj,&a->attr); | ||
508 | subsys_put(s); | ||
509 | } | ||
510 | return error; | ||
511 | } | ||
512 | |||
513 | |||
514 | /** | ||
515 | * subsystem_remove_file - remove sysfs attribute file. | ||
516 | * @s: subsystem. | ||
517 | * @a: attribute desciptor. | ||
518 | */ | ||
519 | |||
520 | void subsys_remove_file(struct subsystem * s, struct subsys_attribute * a) | ||
521 | { | ||
522 | if (subsys_get(s)) { | ||
523 | sysfs_remove_file(&s->kset.kobj,&a->attr); | ||
524 | subsys_put(s); | ||
525 | } | ||
526 | } | ||
527 | |||
528 | EXPORT_SYMBOL(kobject_init); | ||
529 | EXPORT_SYMBOL(kobject_register); | ||
530 | EXPORT_SYMBOL(kobject_unregister); | ||
531 | EXPORT_SYMBOL(kobject_get); | ||
532 | EXPORT_SYMBOL(kobject_put); | ||
533 | EXPORT_SYMBOL(kobject_add); | ||
534 | EXPORT_SYMBOL(kobject_del); | ||
535 | |||
536 | EXPORT_SYMBOL(kset_register); | ||
537 | EXPORT_SYMBOL(kset_unregister); | ||
538 | EXPORT_SYMBOL(kset_find_obj); | ||
539 | |||
540 | EXPORT_SYMBOL(subsystem_init); | ||
541 | EXPORT_SYMBOL(subsystem_register); | ||
542 | EXPORT_SYMBOL(subsystem_unregister); | ||
543 | EXPORT_SYMBOL(subsys_create_file); | ||
544 | EXPORT_SYMBOL(subsys_remove_file); | ||