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 @@
+/*
+ * 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);