core.c 41.8 KB
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/*
 * drivers/base/core.c - core driver model code (device registration, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2006 Novell, Inc.
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 *
 * This file is released under the GPLv2
 *
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/string.h>
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#include <linux/kdev_t.h>
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#include <linux/notifier.h>
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#include <linux/genhd.h>
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#include <linux/kallsyms.h>
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#include <linux/semaphore.h>
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#include <linux/mutex.h>
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#include "base.h"
#include "power/power.h"

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int (*platform_notify)(struct device *dev) = NULL;
int (*platform_notify_remove)(struct device *dev) = NULL;
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static struct kobject *dev_kobj;
struct kobject *sysfs_dev_char_kobj;
struct kobject *sysfs_dev_block_kobj;
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#ifdef CONFIG_BLOCK
static inline int device_is_not_partition(struct device *dev)
{
	return !(dev->type == &part_type);
}
#else
static inline int device_is_not_partition(struct device *dev)
{
	return 1;
}
#endif
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/**
 * dev_driver_string - Return a device's driver name, if at all possible
 * @dev: struct device to get the name of
 *
 * Will return the device's driver's name if it is bound to a device.  If
 * the device is not bound to a device, it will return the name of the bus
 * it is attached to.  If it is not attached to a bus either, an empty
 * string will be returned.
 */
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const char *dev_driver_string(const struct device *dev)
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{
	return dev->driver ? dev->driver->name :
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			(dev->bus ? dev->bus->name :
			(dev->class ? dev->class->name : ""));
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}
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EXPORT_SYMBOL(dev_driver_string);
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#define to_dev(obj) container_of(obj, struct device, kobj)
#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)

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static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
			     char *buf)
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{
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	struct device_attribute *dev_attr = to_dev_attr(attr);
	struct device *dev = to_dev(kobj);
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	ssize_t ret = -EIO;
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	if (dev_attr->show)
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		ret = dev_attr->show(dev, dev_attr, buf);
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	if (ret >= (ssize_t)PAGE_SIZE) {
		print_symbol("dev_attr_show: %s returned bad count\n",
				(unsigned long)dev_attr->show);
	}
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	return ret;
}

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static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
			      const char *buf, size_t count)
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{
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	struct device_attribute *dev_attr = to_dev_attr(attr);
	struct device *dev = to_dev(kobj);
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	ssize_t ret = -EIO;
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	if (dev_attr->store)
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		ret = dev_attr->store(dev, dev_attr, buf, count);
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	return ret;
}

static struct sysfs_ops dev_sysfs_ops = {
	.show	= dev_attr_show,
	.store	= dev_attr_store,
};


/**
 *	device_release - free device structure.
 *	@kobj:	device's kobject.
 *
 *	This is called once the reference count for the object
 *	reaches 0. We forward the call to the device's release
 *	method, which should handle actually freeing the structure.
 */
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static void device_release(struct kobject *kobj)
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{
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	struct device *dev = to_dev(kobj);
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	struct device_private *p = dev->p;
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	if (dev->release)
		dev->release(dev);
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	else if (dev->type && dev->type->release)
		dev->type->release(dev);
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	else if (dev->class && dev->class->dev_release)
		dev->class->dev_release(dev);
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	else
		WARN(1, KERN_ERR "Device '%s' does not have a release() "
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			"function, it is broken and must be fixed.\n",
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			dev_name(dev));
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	kfree(p);
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}

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static struct kobj_type device_ktype = {
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	.release	= device_release,
	.sysfs_ops	= &dev_sysfs_ops,
};


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static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
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{
	struct kobj_type *ktype = get_ktype(kobj);

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	if (ktype == &device_ktype) {
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		struct device *dev = to_dev(kobj);
		if (dev->bus)
			return 1;
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		if (dev->class)
			return 1;
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	}
	return 0;
}

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static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
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{
	struct device *dev = to_dev(kobj);

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	if (dev->bus)
		return dev->bus->name;
	if (dev->class)
		return dev->class->name;
	return NULL;
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}

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static int dev_uevent(struct kset *kset, struct kobject *kobj,
		      struct kobj_uevent_env *env)
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{
	struct device *dev = to_dev(kobj);
	int retval = 0;

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	/* add the major/minor if present */
	if (MAJOR(dev->devt)) {
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		add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
		add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
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	}

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	if (dev->type && dev->type->name)
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		add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
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	if (dev->driver)
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		add_uevent_var(env, "DRIVER=%s", dev->driver->name);
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#ifdef CONFIG_SYSFS_DEPRECATED
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	if (dev->class) {
		struct device *parent = dev->parent;

		/* find first bus device in parent chain */
		while (parent && !parent->bus)
			parent = parent->parent;
		if (parent && parent->bus) {
			const char *path;

			path = kobject_get_path(&parent->kobj, GFP_KERNEL);
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			if (path) {
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				add_uevent_var(env, "PHYSDEVPATH=%s", path);
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				kfree(path);
			}
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			add_uevent_var(env, "PHYSDEVBUS=%s", parent->bus->name);
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			if (parent->driver)
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				add_uevent_var(env, "PHYSDEVDRIVER=%s",
					       parent->driver->name);
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		}
	} else if (dev->bus) {
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		add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
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		if (dev->driver)
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			add_uevent_var(env, "PHYSDEVDRIVER=%s",
				       dev->driver->name);
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	}
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#endif
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	/* have the bus specific function add its stuff */
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	if (dev->bus && dev->bus->uevent) {
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		retval = dev->bus->uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: bus uevent() returned %d\n",
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				 dev_name(dev), __func__, retval);
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	}

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	/* have the class specific function add its stuff */
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	if (dev->class && dev->class->dev_uevent) {
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		retval = dev->class->dev_uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: class uevent() "
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				 "returned %d\n", dev_name(dev),
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				 __func__, retval);
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	}

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	/* have the device type specific fuction add its stuff */
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	if (dev->type && dev->type->uevent) {
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		retval = dev->type->uevent(dev, env);
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		if (retval)
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			pr_debug("device: '%s': %s: dev_type uevent() "
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				 "returned %d\n", dev_name(dev),
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				 __func__, retval);
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	}

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	return retval;
}

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static struct kset_uevent_ops device_uevent_ops = {
	.filter =	dev_uevent_filter,
	.name =		dev_uevent_name,
	.uevent =	dev_uevent,
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};

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static ssize_t show_uevent(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct kobject *top_kobj;
	struct kset *kset;
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	struct kobj_uevent_env *env = NULL;
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	int i;
	size_t count = 0;
	int retval;

	/* search the kset, the device belongs to */
	top_kobj = &dev->kobj;
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	while (!top_kobj->kset && top_kobj->parent)
		top_kobj = top_kobj->parent;
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	if (!top_kobj->kset)
		goto out;
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	kset = top_kobj->kset;
	if (!kset->uevent_ops || !kset->uevent_ops->uevent)
		goto out;

	/* respect filter */
	if (kset->uevent_ops && kset->uevent_ops->filter)
		if (!kset->uevent_ops->filter(kset, &dev->kobj))
			goto out;

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	env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
	if (!env)
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		return -ENOMEM;

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	/* let the kset specific function add its keys */
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	retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
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	if (retval)
		goto out;

	/* copy keys to file */
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	for (i = 0; i < env->envp_idx; i++)
		count += sprintf(&buf[count], "%s\n", env->envp[i]);
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out:
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	kfree(env);
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	return count;
}

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static ssize_t store_uevent(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
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	enum kobject_action action;

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	if (kobject_action_type(buf, count, &action) == 0) {
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		kobject_uevent(&dev->kobj, action);
		goto out;
	}

	dev_err(dev, "uevent: unsupported action-string; this will "
		     "be ignored in a future kernel version\n");
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	kobject_uevent(&dev->kobj, KOBJ_ADD);
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out:
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	return count;
}

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static struct device_attribute uevent_attr =
	__ATTR(uevent, S_IRUGO | S_IWUSR, show_uevent, store_uevent);

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static int device_add_attributes(struct device *dev,
				 struct device_attribute *attrs)
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{
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	int error = 0;
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	int i;
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	if (attrs) {
		for (i = 0; attr_name(attrs[i]); i++) {
			error = device_create_file(dev, &attrs[i]);
			if (error)
				break;
		}
		if (error)
			while (--i >= 0)
				device_remove_file(dev, &attrs[i]);
	}
	return error;
}

static void device_remove_attributes(struct device *dev,
				     struct device_attribute *attrs)
{
	int i;

	if (attrs)
		for (i = 0; attr_name(attrs[i]); i++)
			device_remove_file(dev, &attrs[i]);
}

static int device_add_groups(struct device *dev,
			     struct attribute_group **groups)
{
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	int error = 0;
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	int i;
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	if (groups) {
		for (i = 0; groups[i]; i++) {
			error = sysfs_create_group(&dev->kobj, groups[i]);
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			if (error) {
				while (--i >= 0)
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					sysfs_remove_group(&dev->kobj,
							   groups[i]);
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				break;
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			}
		}
	}
	return error;
}

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static void device_remove_groups(struct device *dev,
				 struct attribute_group **groups)
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{
	int i;
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	if (groups)
		for (i = 0; groups[i]; i++)
			sysfs_remove_group(&dev->kobj, groups[i]);
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}

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static int device_add_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	int error;
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	if (class) {
		error = device_add_attributes(dev, class->dev_attrs);
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		if (error)
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			return error;
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	}
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	if (type) {
		error = device_add_groups(dev, type->groups);
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		if (error)
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			goto err_remove_class_attrs;
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	}

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	error = device_add_groups(dev, dev->groups);
	if (error)
		goto err_remove_type_groups;

	return 0;

 err_remove_type_groups:
	if (type)
		device_remove_groups(dev, type->groups);
 err_remove_class_attrs:
	if (class)
		device_remove_attributes(dev, class->dev_attrs);

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	return error;
}

static void device_remove_attrs(struct device *dev)
{
	struct class *class = dev->class;
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	struct device_type *type = dev->type;
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	device_remove_groups(dev, dev->groups);
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	if (type)
		device_remove_groups(dev, type->groups);

	if (class)
		device_remove_attributes(dev, class->dev_attrs);
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}


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static ssize_t show_dev(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	return print_dev_t(buf, dev->devt);
}

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static struct device_attribute devt_attr =
	__ATTR(dev, S_IRUGO, show_dev, NULL);

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/* kset to create /sys/devices/  */
struct kset *devices_kset;
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/**
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 * device_create_file - create sysfs attribute file for device.
 * @dev: device.
 * @attr: device attribute descriptor.
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 */
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int device_create_file(struct device *dev, struct device_attribute *attr)
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{
	int error = 0;
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	if (dev)
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		error = sysfs_create_file(&dev->kobj, &attr->attr);
	return error;
}

/**
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 * device_remove_file - remove sysfs attribute file.
 * @dev: device.
 * @attr: device attribute descriptor.
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 */
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void device_remove_file(struct device *dev, struct device_attribute *attr)
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{
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	if (dev)
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		sysfs_remove_file(&dev->kobj, &attr->attr);
}

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/**
 * device_create_bin_file - create sysfs binary attribute file for device.
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
int device_create_bin_file(struct device *dev, struct bin_attribute *attr)
{
	int error = -EINVAL;
	if (dev)
		error = sysfs_create_bin_file(&dev->kobj, attr);
	return error;
}
EXPORT_SYMBOL_GPL(device_create_bin_file);

/**
 * device_remove_bin_file - remove sysfs binary attribute file
 * @dev: device.
 * @attr: device binary attribute descriptor.
 */
void device_remove_bin_file(struct device *dev, struct bin_attribute *attr)
{
	if (dev)
		sysfs_remove_bin_file(&dev->kobj, attr);
}
EXPORT_SYMBOL_GPL(device_remove_bin_file);

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/**
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 * device_schedule_callback_owner - helper to schedule a callback for a device
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 * @dev: device.
 * @func: callback function to invoke later.
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 * @owner: module owning the callback routine
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 *
 * Attribute methods must not unregister themselves or their parent device
 * (which would amount to the same thing).  Attempts to do so will deadlock,
 * since unregistration is mutually exclusive with driver callbacks.
 *
 * Instead methods can call this routine, which will attempt to allocate
 * and schedule a workqueue request to call back @func with @dev as its
 * argument in the workqueue's process context.  @dev will be pinned until
 * @func returns.
 *
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 * This routine is usually called via the inline device_schedule_callback(),
 * which automatically sets @owner to THIS_MODULE.
 *
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 * Returns 0 if the request was submitted, -ENOMEM if storage could not
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 * be allocated, -ENODEV if a reference to @owner isn't available.
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 *
 * NOTE: This routine won't work if CONFIG_SYSFS isn't set!  It uses an
 * underlying sysfs routine (since it is intended for use by attribute
 * methods), and if sysfs isn't available you'll get nothing but -ENOSYS.
 */
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int device_schedule_callback_owner(struct device *dev,
		void (*func)(struct device *), struct module *owner)
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{
	return sysfs_schedule_callback(&dev->kobj,
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			(void (*)(void *)) func, dev, owner);
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}
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EXPORT_SYMBOL_GPL(device_schedule_callback_owner);
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static void klist_children_get(struct klist_node *n)
{
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	struct device_private *p = to_device_private_parent(n);
	struct device *dev = p->device;
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	get_device(dev);
}

static void klist_children_put(struct klist_node *n)
{
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	struct device_private *p = to_device_private_parent(n);
	struct device *dev = p->device;
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	put_device(dev);
}

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/**
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 * device_initialize - init device structure.
 * @dev: device.
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 *
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 * This prepares the device for use by other layers by initializing
 * its fields.
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 * It is the first half of device_register(), if called by
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 * that function, though it can also be called separately, so one
 * may use @dev's fields. In particular, get_device()/put_device()
 * may be used for reference counting of @dev after calling this
 * function.
 *
 * NOTE: Use put_device() to give up your reference instead of freeing
 * @dev directly once you have called this function.
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 */
void device_initialize(struct device *dev)
{
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	dev->kobj.kset = devices_kset;
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	kobject_init(&dev->kobj, &device_ktype);
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	INIT_LIST_HEAD(&dev->dma_pools);
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	init_MUTEX(&dev->sem);
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	spin_lock_init(&dev->devres_lock);
	INIT_LIST_HEAD(&dev->devres_head);
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	device_init_wakeup(dev, 0);
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	device_pm_init(dev);
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	set_dev_node(dev, -1);
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}

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#ifdef CONFIG_SYSFS_DEPRECATED
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static struct kobject *get_device_parent(struct device *dev,
					 struct device *parent)
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{
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	/* class devices without a parent live in /sys/class/<classname>/ */
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	if (dev->class && (!parent || parent->class != dev->class))
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		return &dev->class->p->class_subsys.kobj;
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	/* all other devices keep their parent */
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	else if (parent)
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		return &parent->kobj;
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	return NULL;
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}
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static inline void cleanup_device_parent(struct device *dev) {}
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static inline void cleanup_glue_dir(struct device *dev,
				    struct kobject *glue_dir) {}
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#else
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static struct kobject *virtual_device_parent(struct device *dev)
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{
572
	static struct kobject *virtual_dir = NULL;
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	if (!virtual_dir)
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		virtual_dir = kobject_create_and_add("virtual",
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						     &devices_kset->kobj);
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	return virtual_dir;
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}

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static struct kobject *get_device_parent(struct device *dev,
					 struct device *parent)
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{
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	int retval;

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	if (dev->class) {
		struct kobject *kobj = NULL;
		struct kobject *parent_kobj;
		struct kobject *k;

		/*
		 * If we have no parent, we live in "virtual".
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		 * Class-devices with a non class-device as parent, live
		 * in a "glue" directory to prevent namespace collisions.
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		 */
		if (parent == NULL)
			parent_kobj = virtual_device_parent(dev);
		else if (parent->class)
			return &parent->kobj;
		else
			parent_kobj = &parent->kobj;

		/* find our class-directory at the parent and reference it */
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		spin_lock(&dev->class->p->class_dirs.list_lock);
		list_for_each_entry(k, &dev->class->p->class_dirs.list, entry)
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			if (k->parent == parent_kobj) {
				kobj = kobject_get(k);
				break;
			}
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		spin_unlock(&dev->class->p->class_dirs.list_lock);
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		if (kobj)
			return kobj;

		/* or create a new class-directory at the parent device */
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		k = kobject_create();
		if (!k)
			return NULL;
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		k->kset = &dev->class->p->class_dirs;
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		retval = kobject_add(k, parent_kobj, "%s", dev->class->name);
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		if (retval < 0) {
			kobject_put(k);
			return NULL;
		}
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		/* do not emit an uevent for this simple "glue" directory */
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		return k;
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	}

	if (parent)
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		return &parent->kobj;
	return NULL;
}
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633
static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
634
{
635
	/* see if we live in a "glue" directory */
636
	if (!glue_dir || !dev->class ||
637
	    glue_dir->kset != &dev->class->p->class_dirs)
638 639
		return;

640
	kobject_put(glue_dir);
641
}
642 643 644 645 646

static void cleanup_device_parent(struct device *dev)
{
	cleanup_glue_dir(dev, dev->kobj.parent);
}
647
#endif
648

649
static void setup_parent(struct device *dev, struct device *parent)
650 651 652 653 654
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (kobj)
		dev->kobj.parent = kobj;
655 656
}

657 658 659 660 661 662
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
663

664 665
	error = sysfs_create_link(&dev->kobj,
				  &dev->class->p->class_subsys.kobj,
666 667 668
				  "subsystem");
	if (error)
		goto out;
669 670 671

#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
672
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
673
	    device_is_not_partition(dev)) {
674
		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
675
					  &dev->kobj, dev_name(dev));
676 677 678
		if (error)
			goto out_subsys;
	}
679

680
	if (dev->parent && device_is_not_partition(dev)) {
681 682
		struct device *parent = dev->parent;
		char *class_name;
683

684 685 686 687 688 689 690 691 692
		/*
		 * stacked class devices have the 'device' link
		 * pointing to the bus device instead of the parent
		 */
		while (parent->class && !parent->bus && parent->parent)
			parent = parent->parent;

		error = sysfs_create_link(&dev->kobj,
					  &parent->kobj,
693 694 695
					  "device");
		if (error)
			goto out_busid;
696 697 698 699 700 701 702 703 704

		class_name = make_class_name(dev->class->name,
						&dev->kobj);
		if (class_name)
			error = sysfs_create_link(&dev->parent->kobj,
						&dev->kobj, class_name);
		kfree(class_name);
		if (error)
			goto out_device;
705 706 707 708
	}
	return 0;

out_device:
709
	if (dev->parent && device_is_not_partition(dev))
710 711
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
712
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
713
	    device_is_not_partition(dev))
714
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
715
				  dev_name(dev));
716 717
#else
	/* link in the class directory pointing to the device */
718
	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
719
				  &dev->kobj, dev_name(dev));
720 721 722
	if (error)
		goto out_subsys;

723
	if (dev->parent && device_is_not_partition(dev)) {
724 725 726 727 728 729 730 731
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
732
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
733 734
#endif

735 736 737 738 739 740 741 742 743 744
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
745

746
#ifdef CONFIG_SYSFS_DEPRECATED
747
	if (dev->parent && device_is_not_partition(dev)) {
748 749 750 751 752 753 754 755 756
		char *class_name;

		class_name = make_class_name(dev->class->name, &dev->kobj);
		if (class_name) {
			sysfs_remove_link(&dev->parent->kobj, class_name);
			kfree(class_name);
		}
		sysfs_remove_link(&dev->kobj, "device");
	}
757

758
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
759
	    device_is_not_partition(dev))
760
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
761
				  dev_name(dev));
762
#else
763
	if (dev->parent && device_is_not_partition(dev))
764 765
		sysfs_remove_link(&dev->kobj, "device");

766
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
767 768
#endif

769 770 771
	sysfs_remove_link(&dev->kobj, "subsystem");
}

772 773 774
/**
 * dev_set_name - set a device name
 * @dev: device
775
 * @fmt: format string for the device's name
776 777 778 779
 */
int dev_set_name(struct device *dev, const char *fmt, ...)
{
	va_list vargs;
780
	int err;
781 782

	va_start(vargs, fmt);
783
	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
784
	va_end(vargs);
785
	return err;
786 787 788
}
EXPORT_SYMBOL_GPL(dev_set_name);

789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836
/**
 * device_to_dev_kobj - select a /sys/dev/ directory for the device
 * @dev: device
 *
 * By default we select char/ for new entries.  Setting class->dev_obj
 * to NULL prevents an entry from being created.  class->dev_kobj must
 * be set (or cleared) before any devices are registered to the class
 * otherwise device_create_sys_dev_entry() and
 * device_remove_sys_dev_entry() will disagree about the the presence
 * of the link.
 */
static struct kobject *device_to_dev_kobj(struct device *dev)
{
	struct kobject *kobj;

	if (dev->class)
		kobj = dev->class->dev_kobj;
	else
		kobj = sysfs_dev_char_kobj;

	return kobj;
}

static int device_create_sys_dev_entry(struct device *dev)
{
	struct kobject *kobj = device_to_dev_kobj(dev);
	int error = 0;
	char devt_str[15];

	if (kobj) {
		format_dev_t(devt_str, dev->devt);
		error = sysfs_create_link(kobj, &dev->kobj, devt_str);
	}

	return error;
}

static void device_remove_sys_dev_entry(struct device *dev)
{
	struct kobject *kobj = device_to_dev_kobj(dev);
	char devt_str[15];

	if (kobj) {
		format_dev_t(devt_str, dev->devt);
		sysfs_remove_link(kobj, devt_str);
	}
}

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837
/**
838 839
 * device_add - add device to device hierarchy.
 * @dev: device.
L
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840
 *
841 842
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
L
Linus Torvalds 已提交
843
 *
844
 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
845 846
 * to the global and sibling lists for the device, then
 * adds it to the other relevant subsystems of the driver model.
847 848 849 850
 *
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up your
 * reference instead.
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 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
855
	struct class_interface *class_intf;
856
	int error = -EINVAL;
857

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858
	dev = get_device(dev);
859 860 861
	if (!dev)
		goto done;

862 863 864 865 866 867
	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
	if (!dev->p) {
		error = -ENOMEM;
		goto done;
	}
	dev->p->device = dev;
868 869
	klist_init(&dev->p->klist_children, klist_children_get,
		   klist_children_put);
870

871 872 873 874 875 876 877 878 879
	/*
	 * for statically allocated devices, which should all be converted
	 * some day, we need to initialize the name. We prevent reading back
	 * the name, and force the use of dev_name()
	 */
	if (dev->init_name) {
		dev_set_name(dev, dev->init_name);
		dev->init_name = NULL;
	}
880

881
	if (!dev_name(dev))
882
		goto done;
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883

884
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
885

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886
	parent = get_device(dev->parent);
887
	setup_parent(dev, parent);
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888

889 890 891 892
	/* use parent numa_node */
	if (parent)
		set_dev_node(dev, dev_to_node(parent));

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893
	/* first, register with generic layer. */
894 895
	/* we require the name to be set before, and pass NULL */
	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
896
	if (error)
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897
		goto Error;
898

899 900 901 902
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

903
	error = device_create_file(dev, &uevent_attr);
904 905
	if (error)
		goto attrError;
906

907
	if (MAJOR(dev->devt)) {
908 909
		error = device_create_file(dev, &devt_attr);
		if (error)
910
			goto ueventattrError;
911 912 913 914

		error = device_create_sys_dev_entry(dev);
		if (error)
			goto devtattrError;
915 916
	}

917 918 919
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
920 921
	error = device_add_attrs(dev);
	if (error)
922
		goto AttrsError;
923 924
	error = bus_add_device(dev);
	if (error)
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925
		goto BusError;
926
	error = dpm_sysfs_add(dev);
927
	if (error)
928 929
		goto DPMError;
	device_pm_add(dev);
930 931 932 933 934 935 936 937

	/* Notify clients of device addition.  This call must come
	 * after dpm_sysf_add() and before kobject_uevent().
	 */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_ADD_DEVICE, dev);

938
	kobject_uevent(&dev->kobj, KOBJ_ADD);
939
	bus_attach_device(dev);
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	if (parent)
941 942
		klist_add_tail(&dev->p->knode_parent,
			       &parent->p->klist_children);
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943

944
	if (dev->class) {
945
		mutex_lock(&dev->class->p->class_mutex);
946
		/* tie the class to the device */
947 948
		klist_add_tail(&dev->knode_class,
			       &dev->class->p->class_devices);
949 950

		/* notify any interfaces that the device is here */
951 952
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
953 954
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
955
		mutex_unlock(&dev->class->p->class_mutex);
956
	}
957
done:
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958 959
	put_device(dev);
	return error;
960
 DPMError:
961 962
	bus_remove_device(dev);
 BusError:
963
	device_remove_attrs(dev);
964
 AttrsError:
965 966
	device_remove_class_symlinks(dev);
 SymlinkError:
967 968 969
	if (MAJOR(dev->devt))
		device_remove_sys_dev_entry(dev);
 devtattrError:
970 971
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
972
 ueventattrError:
973
	device_remove_file(dev, &uevent_attr);
974
 attrError:
975
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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976 977
	kobject_del(&dev->kobj);
 Error:
978
	cleanup_device_parent(dev);
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979 980
	if (parent)
		put_device(parent);
981
	goto done;
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982 983 984
}

/**
985 986
 * device_register - register a device with the system.
 * @dev: pointer to the device structure
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987
 *
988 989 990 991 992 993
 * This happens in two clean steps - initialize the device
 * and add it to the system. The two steps can be called
 * separately, but this is the easiest and most common.
 * I.e. you should only call the two helpers separately if
 * have a clearly defined need to use and refcount the device
 * before it is added to the hierarchy.
994 995 996 997
 *
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up the
 * reference initialized in this function instead.
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 */
int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}

/**
1006 1007
 * get_device - increment reference count for device.
 * @dev: device.
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1008
 *
1009 1010 1011
 * This simply forwards the call to kobject_get(), though
 * we do take care to provide for the case that we get a NULL
 * pointer passed in.
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1012
 */
1013
struct device *get_device(struct device *dev)
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1014 1015 1016 1017 1018
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}

/**
1019 1020
 * put_device - decrement reference count.
 * @dev: device in question.
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1021
 */
1022
void put_device(struct device *dev)
L
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1023
{
1024
	/* might_sleep(); */
L
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1025 1026 1027 1028 1029
	if (dev)
		kobject_put(&dev->kobj);
}

/**
1030 1031
 * device_del - delete device from system.
 * @dev: device.
L
Linus Torvalds 已提交
1032
 *
1033 1034 1035 1036 1037
 * This is the first part of the device unregistration
 * sequence. This removes the device from the lists we control
 * from here, has it removed from the other driver model
 * subsystems it was added to in device_add(), and removes it
 * from the kobject hierarchy.
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1038
 *
1039 1040
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
L
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1041
 */
1042
void device_del(struct device *dev)
L
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1043
{
1044
	struct device *parent = dev->parent;
1045
	struct class_interface *class_intf;
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1046

1047 1048 1049 1050 1051 1052
	/* Notify clients of device removal.  This call must come
	 * before dpm_sysfs_remove().
	 */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
1053
	device_pm_remove(dev);
1054
	dpm_sysfs_remove(dev);
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1055
	if (parent)
1056
		klist_del(&dev->p->knode_parent);
1057 1058
	if (MAJOR(dev->devt)) {
		device_remove_sys_dev_entry(dev);
1059
		device_remove_file(dev, &devt_attr);
1060
	}
1061
	if (dev->class) {
1062
		device_remove_class_symlinks(dev);
1063

1064
		mutex_lock(&dev->class->p->class_mutex);
1065
		/* notify any interfaces that the device is now gone */
1066 1067
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
1068 1069 1070
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
1071
		klist_del(&dev->knode_class);
1072
		mutex_unlock(&dev->class->p->class_mutex);
1073
	}
1074
	device_remove_file(dev, &uevent_attr);
1075
	device_remove_attrs(dev);
1076
	bus_remove_device(dev);
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1077

1078 1079 1080 1081 1082 1083 1084
	/*
	 * Some platform devices are driven without driver attached
	 * and managed resources may have been acquired.  Make sure
	 * all resources are released.
	 */
	devres_release_all(dev);

L
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1085 1086 1087 1088 1089
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
1090
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1091
	cleanup_device_parent(dev);
L
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1092
	kobject_del(&dev->kobj);
1093
	put_device(parent);
L
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1094 1095 1096
}

/**
1097 1098
 * device_unregister - unregister device from system.
 * @dev: device going away.
L
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1099
 *
1100 1101 1102 1103 1104 1105
 * We do this in two parts, like we do device_register(). First,
 * we remove it from all the subsystems with device_del(), then
 * we decrement the reference count via put_device(). If that
 * is the final reference count, the device will be cleaned up
 * via device_release() above. Otherwise, the structure will
 * stick around until the final reference to the device is dropped.
L
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1106
 */
1107
void device_unregister(struct device *dev)
L
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1108
{
1109
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
L
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1110 1111 1112 1113
	device_del(dev);
	put_device(dev);
}

1114
static struct device *next_device(struct klist_iter *i)
1115
{
1116
	struct klist_node *n = klist_next(i);
1117 1118 1119 1120 1121 1122 1123 1124
	struct device *dev = NULL;
	struct device_private *p;

	if (n) {
		p = to_device_private_parent(n);
		dev = p->device;
	}
	return dev;
1125 1126
}

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1127
/**
1128 1129 1130 1131
 * device_for_each_child - device child iterator.
 * @parent: parent struct device.
 * @data: data for the callback.
 * @fn: function to be called for each device.
L
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1132
 *
1133 1134
 * Iterate over @parent's child devices, and call @fn for each,
 * passing it @data.
L
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1135
 *
1136 1137
 * We check the return of @fn each time. If it returns anything
 * other than 0, we break out and return that value.
L
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1138
 */
1139 1140
int device_for_each_child(struct device *parent, void *data,
			  int (*fn)(struct device *dev, void *data))
L
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1141
{
1142
	struct klist_iter i;
1143
	struct device *child;
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1144 1145
	int error = 0;

1146 1147 1148
	if (!parent->p)
		return 0;

1149
	klist_iter_init(&parent->p->klist_children, &i);
1150 1151 1152
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
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1153 1154 1155
	return error;
}

1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170
/**
 * device_find_child - device iterator for locating a particular device.
 * @parent: parent struct device
 * @data: Data to pass to match function
 * @match: Callback function to check device
 *
 * This is similar to the device_for_each_child() function above, but it
 * returns a reference to a device that is 'found' for later use, as
 * determined by the @match callback.
 *
 * The callback should return 0 if the device doesn't match and non-zero
 * if it does.  If the callback returns non-zero and a reference to the
 * current device can be obtained, this function will return to the caller
 * and not iterate over any more devices.
 */
1171 1172
struct device *device_find_child(struct device *parent, void *data,
				 int (*match)(struct device *dev, void *data))
1173 1174 1175 1176 1177 1178 1179
{
	struct klist_iter i;
	struct device *child;

	if (!parent)
		return NULL;

1180
	klist_iter_init(&parent->p->klist_children, &i);
1181 1182 1183 1184 1185 1186 1187
	while ((child = next_device(&i)))
		if (match(child, data) && get_device(child))
			break;
	klist_iter_exit(&i);
	return child;
}

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1188 1189
int __init devices_init(void)
{
1190 1191 1192
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
	dev_kobj = kobject_create_and_add("dev", NULL);
	if (!dev_kobj)
		goto dev_kobj_err;
	sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
	if (!sysfs_dev_block_kobj)
		goto block_kobj_err;
	sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
	if (!sysfs_dev_char_kobj)
		goto char_kobj_err;

1203
	return 0;
1204 1205 1206 1207 1208 1209 1210 1211

 char_kobj_err:
	kobject_put(sysfs_dev_block_kobj);
 block_kobj_err:
	kobject_put(dev_kobj);
 dev_kobj_err:
	kset_unregister(devices_kset);
	return -ENOMEM;
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1212 1213 1214
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1215
EXPORT_SYMBOL_GPL(device_find_child);
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1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227

EXPORT_SYMBOL_GPL(device_initialize);
EXPORT_SYMBOL_GPL(device_add);
EXPORT_SYMBOL_GPL(device_register);

EXPORT_SYMBOL_GPL(device_del);
EXPORT_SYMBOL_GPL(device_unregister);
EXPORT_SYMBOL_GPL(get_device);
EXPORT_SYMBOL_GPL(put_device);

EXPORT_SYMBOL_GPL(device_create_file);
EXPORT_SYMBOL_GPL(device_remove_file);
1228

1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
struct root_device
{
	struct device dev;
	struct module *owner;
};

#define to_root_device(dev) container_of(dev, struct root_device, dev)

static void root_device_release(struct device *dev)
{
	kfree(to_root_device(dev));
}

/**
 * __root_device_register - allocate and register a root device
 * @name: root device name
 * @owner: owner module of the root device, usually THIS_MODULE
 *
 * This function allocates a root device and registers it
 * using device_register(). In order to free the returned
 * device, use root_device_unregister().
 *
 * Root devices are dummy devices which allow other devices
 * to be grouped under /sys/devices. Use this function to
 * allocate a root device and then use it as the parent of
 * any device which should appear under /sys/devices/{name}
 *
 * The /sys/devices/{name} directory will also contain a
 * 'module' symlink which points to the @owner directory
 * in sysfs.
 *
 * Note: You probably want to use root_device_register().
 */
struct device *__root_device_register(const char *name, struct module *owner)
{
	struct root_device *root;
	int err = -ENOMEM;

	root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
	if (!root)
		return ERR_PTR(err);

	err = dev_set_name(&root->dev, name);
	if (err) {
		kfree(root);
		return ERR_PTR(err);
	}

	root->dev.release = root_device_release;

	err = device_register(&root->dev);
	if (err) {
		put_device(&root->dev);
		return ERR_PTR(err);
	}

#ifdef CONFIG_MODULE	/* gotta find a "cleaner" way to do this */
	if (owner) {
		struct module_kobject *mk = &owner->mkobj;

		err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
		if (err) {
			device_unregister(&root->dev);
			return ERR_PTR(err);
		}
		root->owner = owner;
	}
#endif

	return &root->dev;
}
EXPORT_SYMBOL_GPL(__root_device_register);

/**
 * root_device_unregister - unregister and free a root device
1304
 * @dev: device going away
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319
 *
 * This function unregisters and cleans up a device that was created by
 * root_device_register().
 */
void root_device_unregister(struct device *dev)
{
	struct root_device *root = to_root_device(dev);

	if (root->owner)
		sysfs_remove_link(&root->dev.kobj, "module");

	device_unregister(dev);
}
EXPORT_SYMBOL_GPL(root_device_unregister);

1320 1321 1322

static void device_create_release(struct device *dev)
{
1323
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1324 1325 1326 1327
	kfree(dev);
}

/**
1328
 * device_create_vargs - creates a device and registers it with sysfs
1329 1330 1331
 * @class: pointer to the struct class that this device should be registered to
 * @parent: pointer to the parent struct device of this new device, if any
 * @devt: the dev_t for the char device to be added
1332
 * @drvdata: the data to be added to the device for callbacks
1333
 * @fmt: string for the device's name
1334
 * @args: va_list for the device's name
1335 1336 1337
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1338 1339 1340
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1341 1342 1343 1344
 * If a pointer to a parent struct device is passed in, the newly created
 * struct device will be a child of that device in sysfs.
 * The pointer to the struct device will be returned from the call.
 * Any further sysfs files that might be required can be created using this
1345 1346 1347 1348 1349
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1350 1351 1352
struct device *device_create_vargs(struct class *class, struct device *parent,
				   dev_t devt, void *drvdata, const char *fmt,
				   va_list args)
1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369
{
	struct device *dev = NULL;
	int retval = -ENODEV;

	if (class == NULL || IS_ERR(class))
		goto error;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev) {
		retval = -ENOMEM;
		goto error;
	}

	dev->devt = devt;
	dev->class = class;
	dev->parent = parent;
	dev->release = device_create_release;
1370
	dev_set_drvdata(dev, drvdata);
1371

1372 1373 1374 1375
	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
	if (retval)
		goto error;

1376 1377 1378 1379 1380 1381 1382
	retval = device_register(dev);
	if (retval)
		goto error;

	return dev;

error:
1383
	put_device(dev);
1384 1385
	return ERR_PTR(retval);
}
1386 1387 1388
EXPORT_SYMBOL_GPL(device_create_vargs);

/**
1389
 * device_create - creates a device and registers it with sysfs
1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409
 * @class: pointer to the struct class that this device should be registered to
 * @parent: pointer to the parent struct device of this new device, if any
 * @devt: the dev_t for the char device to be added
 * @drvdata: the data to be added to the device for callbacks
 * @fmt: string for the device's name
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
 * If a pointer to a parent struct device is passed in, the newly created
 * struct device will be a child of that device in sysfs.
 * The pointer to the struct device will be returned from the call.
 * Any further sysfs files that might be required can be created using this
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1410 1411
struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, void *drvdata, const char *fmt, ...)
1412 1413 1414 1415 1416 1417 1418 1419 1420
{
	va_list vargs;
	struct device *dev;

	va_start(vargs, fmt);
	dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
	va_end(vargs);
	return dev;
}
1421
EXPORT_SYMBOL_GPL(device_create);
1422

1423
static int __match_devt(struct device *dev, void *data)
1424
{
1425
	dev_t *devt = data;
1426

1427
	return dev->devt == *devt;
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440
}

/**
 * device_destroy - removes a device that was created with device_create()
 * @class: pointer to the struct class that this device was registered with
 * @devt: the dev_t of the device that was previously registered
 *
 * This call unregisters and cleans up a device that was created with a
 * call to device_create().
 */
void device_destroy(struct class *class, dev_t devt)
{
	struct device *dev;
1441

1442
	dev = class_find_device(class, NULL, &devt, __match_devt);
1443 1444
	if (dev) {
		put_device(dev);
1445
		device_unregister(dev);
1446
	}
1447 1448
}
EXPORT_SYMBOL_GPL(device_destroy);
1449 1450 1451 1452 1453

/**
 * device_rename - renames a device
 * @dev: the pointer to the struct device to be renamed
 * @new_name: the new name of the device
1454 1455 1456 1457 1458
 *
 * It is the responsibility of the caller to provide mutual
 * exclusion between two different calls of device_rename
 * on the same device to ensure that new_name is valid and
 * won't conflict with other devices.
1459 1460 1461 1462 1463
 */
int device_rename(struct device *dev, char *new_name)
{
	char *old_class_name = NULL;
	char *new_class_name = NULL;
1464
	char *old_device_name = NULL;
1465 1466 1467 1468 1469 1470
	int error;

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

1471
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1472
		 __func__, new_name);
1473

1474
#ifdef CONFIG_SYSFS_DEPRECATED
1475 1476
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1477
#endif
1478

1479
	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1480 1481 1482
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1483 1484 1485
	}

	error = kobject_rename(&dev->kobj, new_name);
1486
	if (error)
1487
		goto out;
1488

1489
#ifdef CONFIG_SYSFS_DEPRECATED
1490 1491 1492
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1493 1494 1495
			error = sysfs_create_link_nowarn(&dev->parent->kobj,
							 &dev->kobj,
							 new_class_name);
1496 1497
			if (error)
				goto out;
1498 1499 1500
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1501
#else
1502
	if (dev->class) {
1503
		error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1504
						 &dev->kobj, dev_name(dev));
1505 1506
		if (error)
			goto out;
1507
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1508
				  old_device_name);
1509
	}
1510 1511
#endif

1512
out:
1513 1514 1515
	put_device(dev);

	kfree(new_class_name);
1516
	kfree(old_class_name);
1517
	kfree(old_device_name);
1518 1519 1520

	return error;
}
1521
EXPORT_SYMBOL_GPL(device_rename);
1522 1523 1524 1525 1526

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1527
	int error = 0;
1528 1529 1530 1531 1532
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1533
		error = -ENOMEM;
1534 1535 1536 1537 1538 1539
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1540 1541 1542 1543 1544 1545 1546 1547 1548
	if (new_parent) {
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
		if (error)
			goto out;
		error = sysfs_create_link(&new_parent->kobj, &dev->kobj,
					  class_name);
		if (error)
			sysfs_remove_link(&dev->kobj, "device");
1549
	} else
1550
		error = 0;
1551 1552 1553 1554
out:
	kfree(class_name);
	return error;
#else
1555 1556 1557 1558 1559 1560
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1561 1562 1563 1564 1565 1566
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1567
 * @new_parent: the new parent of the device (can by NULL)
1568
 * @dpm_order: how to reorder the dpm_list
1569
 */
1570 1571
int device_move(struct device *dev, struct device *new_parent,
		enum dpm_order dpm_order)
1572 1573 1574
{
	int error;
	struct device *old_parent;
1575
	struct kobject *new_parent_kobj;
1576 1577 1578 1579 1580

	dev = get_device(dev);
	if (!dev)
		return -EINVAL;

1581
	device_pm_lock();
1582
	new_parent = get_device(new_parent);
1583
	new_parent_kobj = get_device_parent(dev, new_parent);
1584

1585 1586
	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
		 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1587
	error = kobject_move(&dev->kobj, new_parent_kobj);
1588
	if (error) {
1589
		cleanup_glue_dir(dev, new_parent_kobj);
1590 1591 1592 1593 1594 1595
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1596
		klist_remove(&dev->p->knode_parent);
1597
	if (new_parent) {
1598 1599
		klist_add_tail(&dev->p->knode_parent,
			       &new_parent->p->klist_children);
1600 1601 1602
		set_dev_node(dev, dev_to_node(new_parent));
	}

1603 1604 1605 1606 1607 1608 1609
	if (!dev->class)
		goto out_put;
	error = device_move_class_links(dev, old_parent, new_parent);
	if (error) {
		/* We ignore errors on cleanup since we're hosed anyway... */
		device_move_class_links(dev, new_parent, old_parent);
		if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1610
			if (new_parent)
1611
				klist_remove(&dev->p->knode_parent);
1612 1613
			dev->parent = old_parent;
			if (old_parent) {
1614 1615
				klist_add_tail(&dev->p->knode_parent,
					       &old_parent->p->klist_children);
1616 1617
				set_dev_node(dev, dev_to_node(old_parent));
			}
1618
		}
1619
		cleanup_glue_dir(dev, new_parent_kobj);
1620 1621 1622
		put_device(new_parent);
		goto out;
	}
1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635
	switch (dpm_order) {
	case DPM_ORDER_NONE:
		break;
	case DPM_ORDER_DEV_AFTER_PARENT:
		device_pm_move_after(dev, new_parent);
		break;
	case DPM_ORDER_PARENT_BEFORE_DEV:
		device_pm_move_before(new_parent, dev);
		break;
	case DPM_ORDER_DEV_LAST:
		device_pm_move_last(dev);
		break;
	}
1636 1637 1638
out_put:
	put_device(old_parent);
out:
1639
	device_pm_unlock();
1640 1641 1642 1643
	put_device(dev);
	return error;
}
EXPORT_SYMBOL_GPL(device_move);
1644 1645 1646 1647 1648 1649

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
1650
	struct device *dev, *devn;
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661

	list_for_each_entry_safe_reverse(dev, devn, &devices_kset->list,
				kobj.entry) {
		if (dev->bus && dev->bus->shutdown) {
			dev_dbg(dev, "shutdown\n");
			dev->bus->shutdown(dev);
		} else if (dev->driver && dev->driver->shutdown) {
			dev_dbg(dev, "shutdown\n");
			dev->driver->shutdown(dev);
		}
	}
1662 1663 1664
	kobject_put(sysfs_dev_char_kobj);
	kobject_put(sysfs_dev_block_kobj);
	kobject_put(dev_kobj);
1665
}