![Randy Dunlap](/assets/img/avatar_default.png)
Fix @key parameter to mutex_init() and one of its callers. Warning(linux-2.6.26-git11//drivers/base/class.c:210): No description found for parameter 'key' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
425 lines
10 KiB
C
425 lines
10 KiB
C
/*
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* class.c - basic device class management
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* Copyright (c) 2002-3 Open Source Development Labs
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* Copyright (c) 2003-2004 Greg Kroah-Hartman
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* Copyright (c) 2003-2004 IBM Corp.
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*
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* This file is released under the GPLv2
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*
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/string.h>
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#include <linux/kdev_t.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/genhd.h>
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#include <linux/mutex.h>
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#include "base.h"
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#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
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static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr,
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char *buf)
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{
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struct class_attribute *class_attr = to_class_attr(attr);
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struct class_private *cp = to_class(kobj);
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ssize_t ret = -EIO;
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if (class_attr->show)
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ret = class_attr->show(cp->class, buf);
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return ret;
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}
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static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr,
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const char *buf, size_t count)
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{
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struct class_attribute *class_attr = to_class_attr(attr);
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struct class_private *cp = to_class(kobj);
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ssize_t ret = -EIO;
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if (class_attr->store)
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ret = class_attr->store(cp->class, buf, count);
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return ret;
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}
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static void class_release(struct kobject *kobj)
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{
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struct class_private *cp = to_class(kobj);
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struct class *class = cp->class;
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pr_debug("class '%s': release.\n", class->name);
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if (class->class_release)
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class->class_release(class);
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else
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pr_debug("class '%s' does not have a release() function, "
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"be careful\n", class->name);
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}
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static struct sysfs_ops class_sysfs_ops = {
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.show = class_attr_show,
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.store = class_attr_store,
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};
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static struct kobj_type class_ktype = {
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.sysfs_ops = &class_sysfs_ops,
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.release = class_release,
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};
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/* Hotplug events for classes go to the class class_subsys */
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static struct kset *class_kset;
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int class_create_file(struct class *cls, const struct class_attribute *attr)
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{
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int error;
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if (cls)
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error = sysfs_create_file(&cls->p->class_subsys.kobj,
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&attr->attr);
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else
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error = -EINVAL;
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return error;
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}
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void class_remove_file(struct class *cls, const struct class_attribute *attr)
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{
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if (cls)
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sysfs_remove_file(&cls->p->class_subsys.kobj, &attr->attr);
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}
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static struct class *class_get(struct class *cls)
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{
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if (cls)
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kset_get(&cls->p->class_subsys);
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return cls;
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}
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static void class_put(struct class *cls)
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{
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if (cls)
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kset_put(&cls->p->class_subsys);
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}
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static int add_class_attrs(struct class *cls)
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{
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int i;
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int error = 0;
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if (cls->class_attrs) {
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for (i = 0; attr_name(cls->class_attrs[i]); i++) {
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error = class_create_file(cls, &cls->class_attrs[i]);
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if (error)
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goto error;
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}
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}
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done:
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return error;
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error:
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while (--i >= 0)
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class_remove_file(cls, &cls->class_attrs[i]);
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goto done;
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}
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static void remove_class_attrs(struct class *cls)
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{
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int i;
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if (cls->class_attrs) {
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for (i = 0; attr_name(cls->class_attrs[i]); i++)
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class_remove_file(cls, &cls->class_attrs[i]);
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}
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}
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int __class_register(struct class *cls, struct lock_class_key *key)
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{
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struct class_private *cp;
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int error;
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pr_debug("device class '%s': registering\n", cls->name);
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cp = kzalloc(sizeof(*cp), GFP_KERNEL);
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if (!cp)
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return -ENOMEM;
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INIT_LIST_HEAD(&cp->class_devices);
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INIT_LIST_HEAD(&cp->class_interfaces);
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kset_init(&cp->class_dirs);
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__mutex_init(&cp->class_mutex, "struct class mutex", key);
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error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name);
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if (error) {
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kfree(cp);
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return error;
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}
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/* set the default /sys/dev directory for devices of this class */
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if (!cls->dev_kobj)
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cls->dev_kobj = sysfs_dev_char_kobj;
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#if defined(CONFIG_SYSFS_DEPRECATED) && defined(CONFIG_BLOCK)
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/* let the block class directory show up in the root of sysfs */
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if (cls != &block_class)
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cp->class_subsys.kobj.kset = class_kset;
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#else
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cp->class_subsys.kobj.kset = class_kset;
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#endif
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cp->class_subsys.kobj.ktype = &class_ktype;
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cp->class = cls;
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cls->p = cp;
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error = kset_register(&cp->class_subsys);
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if (error) {
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kfree(cp);
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return error;
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}
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error = add_class_attrs(class_get(cls));
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class_put(cls);
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return error;
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}
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EXPORT_SYMBOL_GPL(__class_register);
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void class_unregister(struct class *cls)
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{
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pr_debug("device class '%s': unregistering\n", cls->name);
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remove_class_attrs(cls);
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kset_unregister(&cls->p->class_subsys);
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}
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static void class_create_release(struct class *cls)
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{
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pr_debug("%s called for %s\n", __func__, cls->name);
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kfree(cls);
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}
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/**
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* class_create - create a struct class structure
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* @owner: pointer to the module that is to "own" this struct class
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* @name: pointer to a string for the name of this class.
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* @key: the lock_class_key for this class; used by mutex lock debugging
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*
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* This is used to create a struct class pointer that can then be used
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* in calls to device_create().
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*
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* Note, the pointer created here is to be destroyed when finished by
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* making a call to class_destroy().
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*/
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struct class *__class_create(struct module *owner, const char *name,
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struct lock_class_key *key)
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{
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struct class *cls;
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int retval;
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cls = kzalloc(sizeof(*cls), GFP_KERNEL);
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if (!cls) {
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retval = -ENOMEM;
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goto error;
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}
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cls->name = name;
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cls->owner = owner;
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cls->class_release = class_create_release;
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retval = __class_register(cls, key);
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if (retval)
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goto error;
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return cls;
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error:
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kfree(cls);
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return ERR_PTR(retval);
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}
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EXPORT_SYMBOL_GPL(__class_create);
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/**
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* class_destroy - destroys a struct class structure
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* @cls: pointer to the struct class that is to be destroyed
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*
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* Note, the pointer to be destroyed must have been created with a call
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* to class_create().
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*/
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void class_destroy(struct class *cls)
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{
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if ((cls == NULL) || (IS_ERR(cls)))
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return;
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class_unregister(cls);
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}
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#ifdef CONFIG_SYSFS_DEPRECATED
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char *make_class_name(const char *name, struct kobject *kobj)
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{
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char *class_name;
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int size;
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size = strlen(name) + strlen(kobject_name(kobj)) + 2;
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class_name = kmalloc(size, GFP_KERNEL);
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if (!class_name)
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return NULL;
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strcpy(class_name, name);
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strcat(class_name, ":");
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strcat(class_name, kobject_name(kobj));
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return class_name;
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}
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#endif
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/**
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* class_for_each_device - device iterator
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* @class: the class we're iterating
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* @start: the device to start with in the list, if any.
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* @data: data for the callback
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* @fn: function to be called for each device
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*
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* Iterate over @class's list of devices, and call @fn for each,
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* passing it @data. If @start is set, the list iteration will start
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* there, otherwise if it is NULL, the iteration starts at the
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* beginning of the list.
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*
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* We check the return of @fn each time. If it returns anything
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* other than 0, we break out and return that value.
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*
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* Note, we hold class->class_mutex in this function, so it can not be
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* re-acquired in @fn, otherwise it will self-deadlocking. For
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* example, calls to add or remove class members would be verboten.
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*/
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int class_for_each_device(struct class *class, struct device *start,
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void *data, int (*fn)(struct device *, void *))
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{
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struct device *dev;
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int error = 0;
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if (!class)
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return -EINVAL;
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mutex_lock(&class->p->class_mutex);
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list_for_each_entry(dev, &class->p->class_devices, node) {
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if (start) {
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if (start == dev)
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start = NULL;
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continue;
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}
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dev = get_device(dev);
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error = fn(dev, data);
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put_device(dev);
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if (error)
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break;
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}
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mutex_unlock(&class->p->class_mutex);
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return error;
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}
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EXPORT_SYMBOL_GPL(class_for_each_device);
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/**
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* class_find_device - device iterator for locating a particular device
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* @class: the class we're iterating
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* @start: Device to begin with
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* @data: data for the match function
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* @match: function to check device
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*
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* This is similar to the class_for_each_dev() function above, but it
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* returns a reference to a device that is 'found' for later use, as
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* determined by the @match callback.
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*
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* The callback should return 0 if the device doesn't match and non-zero
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* if it does. If the callback returns non-zero, this function will
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* return to the caller and not iterate over any more devices.
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*
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* Note, you will need to drop the reference with put_device() after use.
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*
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* We hold class->class_mutex in this function, so it can not be
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* re-acquired in @match, otherwise it will self-deadlocking. For
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* example, calls to add or remove class members would be verboten.
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*/
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struct device *class_find_device(struct class *class, struct device *start,
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void *data,
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int (*match)(struct device *, void *))
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{
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struct device *dev;
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int found = 0;
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if (!class)
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return NULL;
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mutex_lock(&class->p->class_mutex);
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list_for_each_entry(dev, &class->p->class_devices, node) {
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if (start) {
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if (start == dev)
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start = NULL;
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continue;
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}
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dev = get_device(dev);
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if (match(dev, data)) {
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found = 1;
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break;
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} else
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put_device(dev);
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}
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mutex_unlock(&class->p->class_mutex);
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return found ? dev : NULL;
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}
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EXPORT_SYMBOL_GPL(class_find_device);
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int class_interface_register(struct class_interface *class_intf)
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{
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struct class *parent;
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struct device *dev;
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if (!class_intf || !class_intf->class)
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return -ENODEV;
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parent = class_get(class_intf->class);
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if (!parent)
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return -EINVAL;
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mutex_lock(&parent->p->class_mutex);
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list_add_tail(&class_intf->node, &parent->p->class_interfaces);
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if (class_intf->add_dev) {
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list_for_each_entry(dev, &parent->p->class_devices, node)
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class_intf->add_dev(dev, class_intf);
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}
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mutex_unlock(&parent->p->class_mutex);
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return 0;
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}
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void class_interface_unregister(struct class_interface *class_intf)
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{
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struct class *parent = class_intf->class;
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struct device *dev;
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if (!parent)
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return;
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mutex_lock(&parent->p->class_mutex);
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list_del_init(&class_intf->node);
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if (class_intf->remove_dev) {
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list_for_each_entry(dev, &parent->p->class_devices, node)
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class_intf->remove_dev(dev, class_intf);
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}
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mutex_unlock(&parent->p->class_mutex);
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class_put(parent);
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}
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int __init classes_init(void)
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{
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class_kset = kset_create_and_add("class", NULL, NULL);
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if (!class_kset)
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return -ENOMEM;
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return 0;
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}
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EXPORT_SYMBOL_GPL(class_create_file);
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EXPORT_SYMBOL_GPL(class_remove_file);
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EXPORT_SYMBOL_GPL(class_unregister);
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EXPORT_SYMBOL_GPL(class_destroy);
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EXPORT_SYMBOL_GPL(class_interface_register);
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EXPORT_SYMBOL_GPL(class_interface_unregister);
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