diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /lib/kobject.c |
Linux-2.6.12-rc2v2.6.12-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 00000000000..ff9491986b3 --- /dev/null +++ b/lib/kobject.c @@ -0,0 +1,544 @@ +/* + * kobject.c - library routines for handling generic kernel objects + * + * Copyright (c) 2002-2003 Patrick Mochel <mochel@osdl.org> + * + * This file is released under the GPLv2. + * + * + * Please see the file Documentation/kobject.txt for critical information + * about using the kobject interface. + */ + +#include <linux/kobject.h> +#include <linux/string.h> +#include <linux/module.h> +#include <linux/stat.h> + +/** + * populate_dir - populate directory with attributes. + * @kobj: object we're working on. + * + * Most subsystems have a set of default attributes that + * are associated with an object that registers with them. + * This is a helper called during object registration that + * loops through the default attributes of the subsystem + * and creates attributes files for them in sysfs. + * + */ + +static int populate_dir(struct kobject * kobj) +{ + struct kobj_type * t = get_ktype(kobj); + struct attribute * attr; + int error = 0; + int i; + + if (t && t->default_attrs) { + for (i = 0; (attr = t->default_attrs[i]) != NULL; i++) { + if ((error = sysfs_create_file(kobj,attr))) + break; + } + } + return error; +} + +static int create_dir(struct kobject * kobj) +{ + int error = 0; + if (kobject_name(kobj)) { + error = sysfs_create_dir(kobj); + if (!error) { + if ((error = populate_dir(kobj))) + sysfs_remove_dir(kobj); + } + } + return error; +} + +static inline struct kobject * to_kobj(struct list_head * entry) +{ + return container_of(entry,struct kobject,entry); +} + +static int get_kobj_path_length(struct kobject *kobj) +{ + int length = 1; + struct kobject * parent = kobj; + + /* walk up the ancestors until we hit the one pointing to the + * root. + * Add 1 to strlen for leading '/' of each level. + */ + do { + length += strlen(kobject_name(parent)) + 1; + parent = parent->parent; + } while (parent); + return length; +} + +static void fill_kobj_path(struct kobject *kobj, char *path, int length) +{ + struct kobject * parent; + + --length; + for (parent = kobj; parent; parent = parent->parent) { + int cur = strlen(kobject_name(parent)); + /* back up enough to print this name with '/' */ + length -= cur; + strncpy (path + length, kobject_name(parent), cur); + *(path + --length) = '/'; + } + + pr_debug("%s: path = '%s'\n",__FUNCTION__,path); +} + +/** + * kobject_get_path - generate and return the path associated with a given kobj + * and kset pair. The result must be freed by the caller with kfree(). + * + * @kobj: kobject in question, with which to build the path + * @gfp_mask: the allocation type used to allocate the path + */ +char *kobject_get_path(struct kobject *kobj, int gfp_mask) +{ + char *path; + int len; + + len = get_kobj_path_length(kobj); + path = kmalloc(len, gfp_mask); + if (!path) + return NULL; + memset(path, 0x00, len); + fill_kobj_path(kobj, path, len); + + return path; +} + +/** + * kobject_init - initialize object. + * @kobj: object in question. + */ +void kobject_init(struct kobject * kobj) +{ + kref_init(&kobj->kref); + INIT_LIST_HEAD(&kobj->entry); + kobj->kset = kset_get(kobj->kset); +} + + +/** + * unlink - remove kobject from kset list. + * @kobj: kobject. + * + * Remove the kobject from the kset list and decrement + * its parent's refcount. + * This is separated out, so we can use it in both + * kobject_del() and kobject_add() on error. + */ + +static void unlink(struct kobject * kobj) +{ + if (kobj->kset) { + spin_lock(&kobj->kset->list_lock); + list_del_init(&kobj->entry); + spin_unlock(&kobj->kset->list_lock); + } + kobject_put(kobj); +} + +/** + * kobject_add - add an object to the hierarchy. + * @kobj: object. + */ + +int kobject_add(struct kobject * kobj) +{ + int error = 0; + struct kobject * parent; + + if (!(kobj = kobject_get(kobj))) + return -ENOENT; + if (!kobj->k_name) + kobj->k_name = kobj->name; + parent = kobject_get(kobj->parent); + + pr_debug("kobject %s: registering. parent: %s, set: %s\n", + kobject_name(kobj), parent ? kobject_name(parent) : "<NULL>", + kobj->kset ? kobj->kset->kobj.name : "<NULL>" ); + + if (kobj->kset) { + spin_lock(&kobj->kset->list_lock); + + if (!parent) + parent = kobject_get(&kobj->kset->kobj); + + list_add_tail(&kobj->entry,&kobj->kset->list); + spin_unlock(&kobj->kset->list_lock); + } + kobj->parent = parent; + + error = create_dir(kobj); + if (error) { + /* unlink does the kobject_put() for us */ + unlink(kobj); + if (parent) + kobject_put(parent); + } else { + kobject_hotplug(kobj, KOBJ_ADD); + } + + return error; +} + + +/** + * kobject_register - initialize and add an object. + * @kobj: object in question. + */ + +int kobject_register(struct kobject * kobj) +{ + int error = 0; + if (kobj) { + kobject_init(kobj); + error = kobject_add(kobj); + if (error) { + printk("kobject_register failed for %s (%d)\n", + kobject_name(kobj),error); + dump_stack(); + } + } else + error = -EINVAL; + return error; +} + + +/** + * kobject_set_name - Set the name of an object + * @kobj: object. + * @name: name. + * + * If strlen(name) >= KOBJ_NAME_LEN, then use a dynamically allocated + * string that @kobj->k_name points to. Otherwise, use the static + * @kobj->name array. + */ + +int kobject_set_name(struct kobject * kobj, const char * fmt, ...) +{ + int error = 0; + int limit = KOBJ_NAME_LEN; + int need; + va_list args; + char * name; + + /* + * First, try the static array + */ + va_start(args,fmt); + need = vsnprintf(kobj->name,limit,fmt,args); + va_end(args); + if (need < limit) + name = kobj->name; + else { + /* + * Need more space? Allocate it and try again + */ + limit = need + 1; + name = kmalloc(limit,GFP_KERNEL); + if (!name) { + error = -ENOMEM; + goto Done; + } + va_start(args,fmt); + need = vsnprintf(name,limit,fmt,args); + va_end(args); + + /* Still? Give up. */ + if (need >= limit) { + kfree(name); + error = -EFAULT; + goto Done; + } + } + + /* Free the old name, if necessary. */ + if (kobj->k_name && kobj->k_name != kobj->name) + kfree(kobj->k_name); + + /* Now, set the new name */ + kobj->k_name = name; + Done: + return error; +} + +EXPORT_SYMBOL(kobject_set_name); + + +/** + * kobject_rename - change the name of an object + * @kobj: object in question. + * @new_name: object's new name + */ + +int kobject_rename(struct kobject * kobj, char *new_name) +{ + int error = 0; + + kobj = kobject_get(kobj); + if (!kobj) + return -EINVAL; + error = sysfs_rename_dir(kobj, new_name); + kobject_put(kobj); + + return error; +} + +/** + * kobject_del - unlink kobject from hierarchy. + * @kobj: object. + */ + +void kobject_del(struct kobject * kobj) +{ + kobject_hotplug(kobj, KOBJ_REMOVE); + sysfs_remove_dir(kobj); + unlink(kobj); +} + +/** + * kobject_unregister - remove object from hierarchy and decrement refcount. + * @kobj: object going away. + */ + +void kobject_unregister(struct kobject * kobj) +{ + pr_debug("kobject %s: unregistering\n",kobject_name(kobj)); + kobject_del(kobj); + kobject_put(kobj); +} + +/** + * kobject_get - increment refcount for object. + * @kobj: object. + */ + +struct kobject * kobject_get(struct kobject * kobj) +{ + if (kobj) + kref_get(&kobj->kref); + return kobj; +} + +/** + * kobject_cleanup - free kobject resources. + * @kobj: object. + */ + +void kobject_cleanup(struct kobject * kobj) +{ + struct kobj_type * t = get_ktype(kobj); + struct kset * s = kobj->kset; + struct kobject * parent = kobj->parent; + + pr_debug("kobject %s: cleaning up\n",kobject_name(kobj)); + if (kobj->k_name != kobj->name) + kfree(kobj->k_name); + kobj->k_name = NULL; + if (t && t->release) + t->release(kobj); + if (s) + kset_put(s); + if (parent) + kobject_put(parent); +} + +static void kobject_release(struct kref *kref) +{ + kobject_cleanup(container_of(kref, struct kobject, kref)); +} + +/** + * kobject_put - decrement refcount for object. + * @kobj: object. + * + * Decrement the refcount, and if 0, call kobject_cleanup(). + */ +void kobject_put(struct kobject * kobj) +{ + if (kobj) + kref_put(&kobj->kref, kobject_release); +} + + +/** + * kset_init - initialize a kset for use + * @k: kset + */ + +void kset_init(struct kset * k) +{ + kobject_init(&k->kobj); + INIT_LIST_HEAD(&k->list); + spin_lock_init(&k->list_lock); +} + + +/** + * kset_add - add a kset object to the hierarchy. + * @k: kset. + * + * Simply, this adds the kset's embedded kobject to the + * hierarchy. + * We also try to make sure that the kset's embedded kobject + * has a parent before it is added. We only care if the embedded + * kobject is not part of a kset itself, since kobject_add() + * assigns a parent in that case. + * If that is the case, and the kset has a controlling subsystem, + * then we set the kset's parent to be said subsystem. + */ + +int kset_add(struct kset * k) +{ + if (!k->kobj.parent && !k->kobj.kset && k->subsys) + k->kobj.parent = &k->subsys->kset.kobj; + + return kobject_add(&k->kobj); +} + + +/** + * kset_register - initialize and add a kset. + * @k: kset. + */ + +int kset_register(struct kset * k) +{ + kset_init(k); + return kset_add(k); +} + + +/** + * kset_unregister - remove a kset. + * @k: kset. + */ + +void kset_unregister(struct kset * k) +{ + kobject_unregister(&k->kobj); +} + + +/** + * kset_find_obj - search for object in kset. + * @kset: kset we're looking in. + * @name: object's name. + * + * Lock kset via @kset->subsys, and iterate over @kset->list, + * looking for a matching kobject. If matching object is found + * take a reference and return the object. + */ + +struct kobject * kset_find_obj(struct kset * kset, const char * name) +{ + struct list_head * entry; + struct kobject * ret = NULL; + + spin_lock(&kset->list_lock); + list_for_each(entry,&kset->list) { + struct kobject * k = to_kobj(entry); + if (kobject_name(k) && !strcmp(kobject_name(k),name)) { + ret = kobject_get(k); + break; + } + } + spin_unlock(&kset->list_lock); + return ret; +} + + +void subsystem_init(struct subsystem * s) +{ + init_rwsem(&s->rwsem); + kset_init(&s->kset); +} + +/** + * subsystem_register - register a subsystem. + * @s: the subsystem we're registering. + * + * Once we register the subsystem, we want to make sure that + * the kset points back to this subsystem for correct usage of + * the rwsem. + */ + +int subsystem_register(struct subsystem * s) +{ + int error; + + subsystem_init(s); + pr_debug("subsystem %s: registering\n",s->kset.kobj.name); + + if (!(error = kset_add(&s->kset))) { + if (!s->kset.subsys) + s->kset.subsys = s; + } + return error; +} + +void subsystem_unregister(struct subsystem * s) +{ + pr_debug("subsystem %s: unregistering\n",s->kset.kobj.name); + kset_unregister(&s->kset); +} + + +/** + * subsystem_create_file - export sysfs attribute file. + * @s: subsystem. + * @a: subsystem attribute descriptor. + */ + +int subsys_create_file(struct subsystem * s, struct subsys_attribute * a) +{ + int error = 0; + if (subsys_get(s)) { + error = sysfs_create_file(&s->kset.kobj,&a->attr); + subsys_put(s); + } + return error; +} + + +/** + * subsystem_remove_file - remove sysfs attribute file. + * @s: subsystem. + * @a: attribute desciptor. + */ + +void subsys_remove_file(struct subsystem * s, struct subsys_attribute * a) +{ + if (subsys_get(s)) { + sysfs_remove_file(&s->kset.kobj,&a->attr); + subsys_put(s); + } +} + +EXPORT_SYMBOL(kobject_init); +EXPORT_SYMBOL(kobject_register); +EXPORT_SYMBOL(kobject_unregister); +EXPORT_SYMBOL(kobject_get); +EXPORT_SYMBOL(kobject_put); +EXPORT_SYMBOL(kobject_add); +EXPORT_SYMBOL(kobject_del); + +EXPORT_SYMBOL(kset_register); +EXPORT_SYMBOL(kset_unregister); +EXPORT_SYMBOL(kset_find_obj); + +EXPORT_SYMBOL(subsystem_init); +EXPORT_SYMBOL(subsystem_register); +EXPORT_SYMBOL(subsystem_unregister); +EXPORT_SYMBOL(subsys_create_file); +EXPORT_SYMBOL(subsys_remove_file); |