core.c 38.0 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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	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->bus_id);
}

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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);
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		if (dev->uevent_suppress)
			return 0;
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		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->bus_id, __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() "
				 "returned %d\n", dev->bus_id,
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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() "
				 "returned %d\n", dev->bus_id,
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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)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	get_device(dev);
}

static void klist_children_put(struct klist_node *n)
{
	struct device *dev = container_of(n, struct device, knode_parent);

	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,
 * including adding it to the device hierarchy.
 * It is the first half of device_register(), if called by
 * that, though it can also be called separately, so one
 * may use @dev's fields (e.g. the refcount).
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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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	klist_init(&dev->klist_children, klist_children_get,
		   klist_children_put);
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	INIT_LIST_HEAD(&dev->dma_pools);
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	INIT_LIST_HEAD(&dev->node);
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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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{
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	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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static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
630
{
631
	/* see if we live in a "glue" directory */
632
	if (!glue_dir || !dev->class ||
633
	    glue_dir->kset != &dev->class->p->class_dirs)
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		return;

636
	kobject_put(glue_dir);
637
}
638 639 640 641 642

static void cleanup_device_parent(struct device *dev)
{
	cleanup_glue_dir(dev, dev->kobj.parent);
}
643
#endif
644

645
static void setup_parent(struct device *dev, struct device *parent)
646 647 648 649 650
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (kobj)
		dev->kobj.parent = kobj;
651 652
}

653 654 655 656 657 658
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
659

660 661
	error = sysfs_create_link(&dev->kobj,
				  &dev->class->p->class_subsys.kobj,
662 663 664
				  "subsystem");
	if (error)
		goto out;
665 666 667

#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
668
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
669
	    device_is_not_partition(dev)) {
670
		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
671
					  &dev->kobj, dev->bus_id);
672 673 674
		if (error)
			goto out_subsys;
	}
675

676
	if (dev->parent && device_is_not_partition(dev)) {
677 678
		struct device *parent = dev->parent;
		char *class_name;
679

680 681 682 683 684 685 686 687 688
		/*
		 * 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,
689 690 691
					  "device");
		if (error)
			goto out_busid;
692 693 694 695 696 697 698 699 700

		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;
701 702 703 704
	}
	return 0;

out_device:
705
	if (dev->parent && device_is_not_partition(dev))
706 707
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
708
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
709
	    device_is_not_partition(dev))
710 711
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
				  dev->bus_id);
712 713
#else
	/* link in the class directory pointing to the device */
714 715
	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
				  &dev->kobj, dev->bus_id);
716 717 718
	if (error)
		goto out_subsys;

719
	if (dev->parent && device_is_not_partition(dev)) {
720 721 722 723 724 725 726 727
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
728
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
729 730
#endif

731 732 733 734 735 736 737 738 739 740
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
741

742
#ifdef CONFIG_SYSFS_DEPRECATED
743
	if (dev->parent && device_is_not_partition(dev)) {
744 745 746 747 748 749 750 751 752
		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");
	}
753

754
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
755
	    device_is_not_partition(dev))
756 757
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
				  dev->bus_id);
758
#else
759
	if (dev->parent && device_is_not_partition(dev))
760 761
		sysfs_remove_link(&dev->kobj, "device");

762
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
763 764
#endif

765 766 767
	sysfs_remove_link(&dev->kobj, "subsystem");
}

768 769 770
/**
 * dev_set_name - set a device name
 * @dev: device
771
 * @fmt: format string for the device's name
772 773 774 775 776 777 778 779 780 781 782 783
 */
int dev_set_name(struct device *dev, const char *fmt, ...)
{
	va_list vargs;

	va_start(vargs, fmt);
	vsnprintf(dev->bus_id, sizeof(dev->bus_id), fmt, vargs);
	va_end(vargs);
	return 0;
}
EXPORT_SYMBOL_GPL(dev_set_name);

784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831
/**
 * 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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832
/**
833 834
 * device_add - add device to device hierarchy.
 * @dev: device.
L
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835
 *
836 837
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
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838
 *
839 840 841
 * This adds it to the kobject hierarchy via kobject_add(), adds it
 * to the global and sibling lists for the device, then
 * adds it to the other relevant subsystems of the driver model.
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842 843 844 845
 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
846
	struct class_interface *class_intf;
847
	int error = -EINVAL;
848

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849
	dev = get_device(dev);
850 851 852 853 854 855 856 857 858 859
	if (!dev)
		goto done;

	/* Temporarily support init_name if it is set.
	 * It will override bus_id for now */
	if (dev->init_name)
		dev_set_name(dev, "%s", dev->init_name);

	if (!strlen(dev->bus_id))
		goto done;
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860

861
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
862

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863
	parent = get_device(dev->parent);
864
	setup_parent(dev, parent);
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865

866 867 868 869
	/* use parent numa_node */
	if (parent)
		set_dev_node(dev, dev_to_node(parent));

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870
	/* first, register with generic layer. */
871
	error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
872
	if (error)
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873
		goto Error;
874

875 876 877 878
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

879 880
	/* notify clients of device entry (new way) */
	if (dev->bus)
881
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
882 883
					     BUS_NOTIFY_ADD_DEVICE, dev);

884
	error = device_create_file(dev, &uevent_attr);
885 886
	if (error)
		goto attrError;
887

888
	if (MAJOR(dev->devt)) {
889 890
		error = device_create_file(dev, &devt_attr);
		if (error)
891
			goto ueventattrError;
892 893 894 895

		error = device_create_sys_dev_entry(dev);
		if (error)
			goto devtattrError;
896 897
	}

898 899 900
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
901 902
	error = device_add_attrs(dev);
	if (error)
903
		goto AttrsError;
904 905
	error = bus_add_device(dev);
	if (error)
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906
		goto BusError;
907
	error = dpm_sysfs_add(dev);
908
	if (error)
909 910
		goto DPMError;
	device_pm_add(dev);
911
	kobject_uevent(&dev->kobj, KOBJ_ADD);
912
	bus_attach_device(dev);
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913
	if (parent)
914
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
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915

916
	if (dev->class) {
917
		mutex_lock(&dev->class->p->class_mutex);
918
		/* tie the class to the device */
919
		list_add_tail(&dev->node, &dev->class->p->class_devices);
920 921

		/* notify any interfaces that the device is here */
922 923
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
924 925
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
926
		mutex_unlock(&dev->class->p->class_mutex);
927
	}
928
done:
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929 930
	put_device(dev);
	return error;
931
 DPMError:
932 933
	bus_remove_device(dev);
 BusError:
934
	if (dev->bus)
935
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
936
					     BUS_NOTIFY_DEL_DEVICE, dev);
937
	device_remove_attrs(dev);
938
 AttrsError:
939 940
	device_remove_class_symlinks(dev);
 SymlinkError:
941 942 943
	if (MAJOR(dev->devt))
		device_remove_sys_dev_entry(dev);
 devtattrError:
944 945
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
946
 ueventattrError:
947
	device_remove_file(dev, &uevent_attr);
948
 attrError:
949
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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950 951
	kobject_del(&dev->kobj);
 Error:
952
	cleanup_device_parent(dev);
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953 954
	if (parent)
		put_device(parent);
955
	goto done;
L
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956 957 958
}

/**
959 960
 * device_register - register a device with the system.
 * @dev: pointer to the device structure
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961
 *
962 963 964 965 966 967
 * 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.
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968 969 970 971 972 973 974 975
 */
int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}

/**
976 977
 * get_device - increment reference count for device.
 * @dev: device.
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978
 *
979 980 981
 * 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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982
 */
983
struct device *get_device(struct device *dev)
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984 985 986 987 988
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}

/**
989 990
 * put_device - decrement reference count.
 * @dev: device in question.
L
Linus Torvalds 已提交
991
 */
992
void put_device(struct device *dev)
L
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993
{
994
	/* might_sleep(); */
L
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995 996 997 998 999
	if (dev)
		kobject_put(&dev->kobj);
}

/**
1000 1001
 * device_del - delete device from system.
 * @dev: device.
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1002
 *
1003 1004 1005 1006 1007
 * 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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1008
 *
1009 1010
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
L
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1011
 */
1012
void device_del(struct device *dev)
L
Linus Torvalds 已提交
1013
{
1014
	struct device *parent = dev->parent;
1015
	struct class_interface *class_intf;
L
Linus Torvalds 已提交
1016

1017
	device_pm_remove(dev);
1018
	dpm_sysfs_remove(dev);
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1019
	if (parent)
1020
		klist_del(&dev->knode_parent);
1021 1022
	if (MAJOR(dev->devt)) {
		device_remove_sys_dev_entry(dev);
1023
		device_remove_file(dev, &devt_attr);
1024
	}
1025
	if (dev->class) {
1026
		device_remove_class_symlinks(dev);
1027

1028
		mutex_lock(&dev->class->p->class_mutex);
1029
		/* notify any interfaces that the device is now gone */
1030 1031
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
1032 1033 1034
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
1035
		list_del_init(&dev->node);
1036
		mutex_unlock(&dev->class->p->class_mutex);
1037
	}
1038
	device_remove_file(dev, &uevent_attr);
1039
	device_remove_attrs(dev);
1040
	bus_remove_device(dev);
L
Linus Torvalds 已提交
1041

1042 1043 1044 1045 1046 1047 1048
	/*
	 * 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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1049 1050 1051 1052 1053
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
1054
	if (dev->bus)
1055
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1056
					     BUS_NOTIFY_DEL_DEVICE, dev);
1057
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1058
	cleanup_device_parent(dev);
L
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1059
	kobject_del(&dev->kobj);
1060
	put_device(parent);
L
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1061 1062 1063
}

/**
1064 1065
 * device_unregister - unregister device from system.
 * @dev: device going away.
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1066
 *
1067 1068 1069 1070 1071 1072
 * 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
Linus Torvalds 已提交
1073
 */
1074
void device_unregister(struct device *dev)
L
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1075
{
1076
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
L
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1077 1078 1079 1080
	device_del(dev);
	put_device(dev);
}

1081
static struct device *next_device(struct klist_iter *i)
1082
{
1083
	struct klist_node *n = klist_next(i);
1084 1085 1086
	return n ? container_of(n, struct device, knode_parent) : NULL;
}

L
Linus Torvalds 已提交
1087
/**
1088 1089 1090 1091
 * 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
Linus Torvalds 已提交
1092
 *
1093 1094
 * Iterate over @parent's child devices, and call @fn for each,
 * passing it @data.
L
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1095
 *
1096 1097
 * 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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1098
 */
1099 1100
int device_for_each_child(struct device *parent, void *data,
			  int (*fn)(struct device *dev, void *data))
L
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1101
{
1102
	struct klist_iter i;
1103
	struct device *child;
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1104 1105
	int error = 0;

1106 1107 1108 1109
	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
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1110 1111 1112
	return error;
}

1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127
/**
 * 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.
 */
1128 1129
struct device *device_find_child(struct device *parent, void *data,
				 int (*match)(struct device *dev, void *data))
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144
{
	struct klist_iter i;
	struct device *child;

	if (!parent)
		return NULL;

	klist_iter_init(&parent->klist_children, &i);
	while ((child = next_device(&i)))
		if (match(child, data) && get_device(child))
			break;
	klist_iter_exit(&i);
	return child;
}

L
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1145 1146
int __init devices_init(void)
{
1147 1148 1149
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
	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;

1160
	return 0;
1161 1162 1163 1164 1165 1166 1167 1168

 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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1169 1170 1171
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1172
EXPORT_SYMBOL_GPL(device_find_child);
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1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184

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);
1185 1186 1187 1188


static void device_create_release(struct device *dev)
{
1189
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1190 1191 1192 1193
	kfree(dev);
}

/**
1194
 * device_create_vargs - creates a device and registers it with sysfs
1195 1196 1197
 * @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
1198
 * @drvdata: the data to be added to the device for callbacks
1199
 * @fmt: string for the device's name
1200
 * @args: va_list for the device's name
1201 1202 1203
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1204 1205 1206
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1207 1208 1209 1210
 * 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
1211 1212 1213 1214 1215
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1216 1217 1218
struct device *device_create_vargs(struct class *class, struct device *parent,
				   dev_t devt, void *drvdata, const char *fmt,
				   va_list args)
1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235
{
	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;
1236
	dev_set_drvdata(dev, drvdata);
1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248

	vsnprintf(dev->bus_id, BUS_ID_SIZE, fmt, args);
	retval = device_register(dev);
	if (retval)
		goto error;

	return dev;

error:
	kfree(dev);
	return ERR_PTR(retval);
}
1249 1250 1251
EXPORT_SYMBOL_GPL(device_create_vargs);

/**
1252
 * device_create - creates a device and registers it with sysfs
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272
 * @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().
 */
1273 1274
struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, void *drvdata, const char *fmt, ...)
1275 1276 1277 1278 1279 1280 1281 1282 1283
{
	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;
}
1284
EXPORT_SYMBOL_GPL(device_create);
1285

1286
static int __match_devt(struct device *dev, void *data)
1287
{
1288
	dev_t *devt = data;
1289

1290
	return dev->devt == *devt;
1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303
}

/**
 * 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;
1304

1305
	dev = class_find_device(class, NULL, &devt, __match_devt);
1306 1307
	if (dev) {
		put_device(dev);
1308
		device_unregister(dev);
1309
	}
1310 1311
}
EXPORT_SYMBOL_GPL(device_destroy);
1312 1313 1314 1315 1316 1317 1318 1319 1320 1321

/**
 * device_rename - renames a device
 * @dev: the pointer to the struct device to be renamed
 * @new_name: the new name of the device
 */
int device_rename(struct device *dev, char *new_name)
{
	char *old_class_name = NULL;
	char *new_class_name = NULL;
1322
	char *old_device_name = NULL;
1323 1324 1325 1326 1327 1328
	int error;

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

1329
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1330
		 __func__, new_name);
1331

1332
#ifdef CONFIG_SYSFS_DEPRECATED
1333 1334
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1335
#endif
1336

1337 1338 1339 1340
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1341
	}
1342
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1343 1344 1345
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1346 1347 1348 1349
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1350

1351
#ifdef CONFIG_SYSFS_DEPRECATED
1352 1353 1354
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1355 1356 1357
			error = sysfs_create_link_nowarn(&dev->parent->kobj,
							 &dev->kobj,
							 new_class_name);
1358 1359
			if (error)
				goto out;
1360 1361 1362
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1363
#else
1364
	if (dev->class) {
1365 1366
		error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
						 &dev->kobj, dev->bus_id);
1367 1368
		if (error)
			goto out;
1369
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1370
				  old_device_name);
1371
	}
1372 1373
#endif

1374
out:
1375 1376 1377
	put_device(dev);

	kfree(new_class_name);
1378
	kfree(old_class_name);
1379
	kfree(old_device_name);
1380 1381 1382

	return error;
}
1383
EXPORT_SYMBOL_GPL(device_rename);
1384 1385 1386 1387 1388

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1389
	int error = 0;
1390 1391 1392 1393 1394
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1395
		error = -ENOMEM;
1396 1397 1398 1399 1400 1401
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1402 1403 1404 1405 1406 1407 1408 1409 1410
	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");
1411
	} else
1412
		error = 0;
1413 1414 1415 1416
out:
	kfree(class_name);
	return error;
#else
1417 1418 1419 1420 1421 1422
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1423 1424 1425 1426 1427 1428
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1429
 * @new_parent: the new parent of the device (can by NULL)
1430 1431 1432 1433 1434
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1435
	struct kobject *new_parent_kobj;
1436 1437 1438 1439 1440 1441

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

	new_parent = get_device(new_parent);
1442
	new_parent_kobj = get_device_parent(dev, new_parent);
1443

1444
	pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1445
		 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1446
	error = kobject_move(&dev->kobj, new_parent_kobj);
1447
	if (error) {
1448
		cleanup_glue_dir(dev, new_parent_kobj);
1449 1450 1451 1452 1453 1454
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1455
		klist_remove(&dev->knode_parent);
1456
	if (new_parent) {
1457
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1458 1459 1460
		set_dev_node(dev, dev_to_node(new_parent));
	}

1461 1462 1463 1464 1465 1466 1467
	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)) {
1468 1469
			if (new_parent)
				klist_remove(&dev->knode_parent);
1470 1471
			dev->parent = old_parent;
			if (old_parent) {
1472 1473
				klist_add_tail(&dev->knode_parent,
					       &old_parent->klist_children);
1474 1475
				set_dev_node(dev, dev_to_node(old_parent));
			}
1476
		}
1477
		cleanup_glue_dir(dev, new_parent_kobj);
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487
		put_device(new_parent);
		goto out;
	}
out_put:
	put_device(old_parent);
out:
	put_device(dev);
	return error;
}
EXPORT_SYMBOL_GPL(device_move);
1488 1489 1490 1491 1492 1493

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
1494
	struct device *dev, *devn;
1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505

	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);
		}
	}
1506 1507 1508
	kobject_put(sysfs_dev_char_kobj);
	kobject_put(sysfs_dev_block_kobj);
	kobject_put(dev_kobj);
1509
}