core.c 37.8 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.
 */
const char *dev_driver_string(struct device *dev)
{
	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 {
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		printk(KERN_ERR "Device '%s' does not have a release() "
			"function, it is broken and must be fixed.\n",
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			dev->bus_id);
		WARN_ON(1);
	}
}

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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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	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)
631
{
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	/* see if we live in a "glue" directory */
633
	if (!glue_dir || !dev->class ||
634
	    glue_dir->kset != &dev->class->p->class_dirs)
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		return;

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	kobject_put(glue_dir);
638
}
639 640 641 642 643

static void cleanup_device_parent(struct device *dev)
{
	cleanup_glue_dir(dev, dev->kobj.parent);
}
644
#endif
645

646
static void setup_parent(struct device *dev, struct device *parent)
647 648 649 650 651
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (kobj)
		dev->kobj.parent = kobj;
652 653
}

654 655 656 657 658 659
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
660

661 662
	error = sysfs_create_link(&dev->kobj,
				  &dev->class->p->class_subsys.kobj,
663 664 665
				  "subsystem");
	if (error)
		goto out;
666 667 668

#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
669
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
670
	    device_is_not_partition(dev)) {
671
		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
672
					  &dev->kobj, dev->bus_id);
673 674 675
		if (error)
			goto out_subsys;
	}
676

677
	if (dev->parent && device_is_not_partition(dev)) {
678 679
		struct device *parent = dev->parent;
		char *class_name;
680

681 682 683 684 685 686 687 688 689
		/*
		 * 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,
690 691 692
					  "device");
		if (error)
			goto out_busid;
693 694 695 696 697 698 699 700 701

		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;
702 703 704 705
	}
	return 0;

out_device:
706
	if (dev->parent && device_is_not_partition(dev))
707 708
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
709
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
710
	    device_is_not_partition(dev))
711 712
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
				  dev->bus_id);
713 714
#else
	/* link in the class directory pointing to the device */
715 716
	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
				  &dev->kobj, dev->bus_id);
717 718 719
	if (error)
		goto out_subsys;

720
	if (dev->parent && device_is_not_partition(dev)) {
721 722 723 724 725 726 727 728
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
729
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
730 731
#endif

732 733 734 735 736 737 738 739 740 741
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
742

743
#ifdef CONFIG_SYSFS_DEPRECATED
744
	if (dev->parent && device_is_not_partition(dev)) {
745 746 747 748 749 750 751 752 753
		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");
	}
754

755
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
756
	    device_is_not_partition(dev))
757 758
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
				  dev->bus_id);
759
#else
760
	if (dev->parent && device_is_not_partition(dev))
761 762
		sysfs_remove_link(&dev->kobj, "device");

763
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev->bus_id);
764 765
#endif

766 767 768
	sysfs_remove_link(&dev->kobj, "subsystem");
}

769 770 771
/**
 * dev_set_name - set a device name
 * @dev: device
772
 * @fmt: format string for the device's name
773 774 775 776 777 778 779 780 781 782 783 784
 */
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);

785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832
/**
 * 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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833
/**
834 835
 * device_add - add device to device hierarchy.
 * @dev: device.
L
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836
 *
837 838
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
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839
 *
840 841 842
 * 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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 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
847
	struct class_interface *class_intf;
848 849
	int error;

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850
	dev = get_device(dev);
851 852
	if (!dev || !strlen(dev->bus_id)) {
		error = -EINVAL;
853
		goto Done;
854
	}
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855

856
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
857

L
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858
	parent = get_device(dev->parent);
859
	setup_parent(dev, parent);
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860

861 862 863 864
	/* use parent numa_node */
	if (parent)
		set_dev_node(dev, dev_to_node(parent));

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865
	/* first, register with generic layer. */
866
	error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
867
	if (error)
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868
		goto Error;
869

870 871 872 873
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

874 875
	/* notify clients of device entry (new way) */
	if (dev->bus)
876
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
877 878
					     BUS_NOTIFY_ADD_DEVICE, dev);

879
	error = device_create_file(dev, &uevent_attr);
880 881
	if (error)
		goto attrError;
882

883
	if (MAJOR(dev->devt)) {
884 885
		error = device_create_file(dev, &devt_attr);
		if (error)
886
			goto ueventattrError;
887 888 889 890

		error = device_create_sys_dev_entry(dev);
		if (error)
			goto devtattrError;
891 892
	}

893 894 895
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
896 897
	error = device_add_attrs(dev);
	if (error)
898
		goto AttrsError;
899 900
	error = bus_add_device(dev);
	if (error)
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901
		goto BusError;
902 903 904
	error = device_pm_add(dev);
	if (error)
		goto PMError;
905
	kobject_uevent(&dev->kobj, KOBJ_ADD);
906
	bus_attach_device(dev);
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907
	if (parent)
908
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
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909

910
	if (dev->class) {
911
		mutex_lock(&dev->class->p->class_mutex);
912
		/* tie the class to the device */
913
		list_add_tail(&dev->node, &dev->class->p->class_devices);
914 915

		/* notify any interfaces that the device is here */
916 917
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
918 919
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
920
		mutex_unlock(&dev->class->p->class_mutex);
921
	}
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922 923 924 925
 Done:
	put_device(dev);
	return error;
 PMError:
926 927
	bus_remove_device(dev);
 BusError:
928
	if (dev->bus)
929
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
930
					     BUS_NOTIFY_DEL_DEVICE, dev);
931
	device_remove_attrs(dev);
932
 AttrsError:
933 934
	device_remove_class_symlinks(dev);
 SymlinkError:
935 936 937
	if (MAJOR(dev->devt))
		device_remove_sys_dev_entry(dev);
 devtattrError:
938 939
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
940
 ueventattrError:
941
	device_remove_file(dev, &uevent_attr);
942
 attrError:
943
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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944 945
	kobject_del(&dev->kobj);
 Error:
946
	cleanup_device_parent(dev);
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947 948 949 950 951 952
	if (parent)
		put_device(parent);
	goto Done;
}

/**
953 954
 * device_register - register a device with the system.
 * @dev: pointer to the device structure
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955
 *
956 957 958 959 960 961
 * 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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962 963 964 965 966 967 968 969
 */
int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}

/**
970 971
 * get_device - increment reference count for device.
 * @dev: device.
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972
 *
973 974 975
 * 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.
L
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976
 */
977
struct device *get_device(struct device *dev)
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978 979 980 981 982
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}

/**
983 984
 * put_device - decrement reference count.
 * @dev: device in question.
L
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985
 */
986
void put_device(struct device *dev)
L
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987
{
988
	/* might_sleep(); */
L
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989 990 991 992 993
	if (dev)
		kobject_put(&dev->kobj);
}

/**
994 995
 * device_del - delete device from system.
 * @dev: device.
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996
 *
997 998 999 1000 1001
 * 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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1002
 *
1003 1004
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
L
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1005
 */
1006
void device_del(struct device *dev)
L
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1007
{
1008
	struct device *parent = dev->parent;
1009
	struct class_interface *class_intf;
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1010

1011
	device_pm_remove(dev);
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1012
	if (parent)
1013
		klist_del(&dev->knode_parent);
1014 1015
	if (MAJOR(dev->devt)) {
		device_remove_sys_dev_entry(dev);
1016
		device_remove_file(dev, &devt_attr);
1017
	}
1018
	if (dev->class) {
1019
		device_remove_class_symlinks(dev);
1020

1021
		mutex_lock(&dev->class->p->class_mutex);
1022
		/* notify any interfaces that the device is now gone */
1023 1024
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
1025 1026 1027
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
1028
		list_del_init(&dev->node);
1029
		mutex_unlock(&dev->class->p->class_mutex);
1030
	}
1031
	device_remove_file(dev, &uevent_attr);
1032
	device_remove_attrs(dev);
1033
	bus_remove_device(dev);
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Linus Torvalds 已提交
1034

1035 1036 1037 1038 1039 1040 1041
	/*
	 * 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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1042 1043 1044 1045 1046
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
1047
	if (dev->bus)
1048
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1049
					     BUS_NOTIFY_DEL_DEVICE, dev);
1050
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1051
	cleanup_device_parent(dev);
L
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1052
	kobject_del(&dev->kobj);
1053
	put_device(parent);
L
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1054 1055 1056
}

/**
1057 1058
 * device_unregister - unregister device from system.
 * @dev: device going away.
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1059
 *
1060 1061 1062 1063 1064 1065
 * 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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1066
 */
1067
void device_unregister(struct device *dev)
L
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1068
{
1069
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
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1070 1071 1072 1073
	device_del(dev);
	put_device(dev);
}

1074
static struct device *next_device(struct klist_iter *i)
1075
{
1076
	struct klist_node *n = klist_next(i);
1077 1078 1079
	return n ? container_of(n, struct device, knode_parent) : NULL;
}

L
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1080
/**
1081 1082 1083 1084
 * 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
1085
 *
1086 1087
 * Iterate over @parent's child devices, and call @fn for each,
 * passing it @data.
L
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1088
 *
1089 1090
 * 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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1091
 */
1092 1093
int device_for_each_child(struct device *parent, void *data,
			  int (*fn)(struct device *dev, void *data))
L
Linus Torvalds 已提交
1094
{
1095
	struct klist_iter i;
1096
	struct device *child;
L
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1097 1098
	int error = 0;

1099 1100 1101 1102
	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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1103 1104 1105
	return error;
}

1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
/**
 * 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.
 */
1121 1122
struct device *device_find_child(struct device *parent, void *data,
				 int (*match)(struct device *dev, void *data))
1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
{
	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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1138 1139
int __init devices_init(void)
{
1140 1141 1142
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
	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;

1153
	return 0;
1154 1155 1156 1157 1158 1159 1160 1161

 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;
L
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1162 1163 1164
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1165
EXPORT_SYMBOL_GPL(device_find_child);
L
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1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177

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);
1178 1179 1180 1181


static void device_create_release(struct device *dev)
{
1182
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1183 1184 1185 1186
	kfree(dev);
}

/**
1187
 * device_create_vargs - creates a device and registers it with sysfs
1188 1189 1190
 * @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
1191
 * @drvdata: the data to be added to the device for callbacks
1192
 * @fmt: string for the device's name
1193
 * @args: va_list for the device's name
1194 1195 1196
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1197 1198 1199
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1200 1201 1202 1203
 * 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
1204 1205 1206 1207 1208
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1209 1210 1211
struct device *device_create_vargs(struct class *class, struct device *parent,
				   dev_t devt, void *drvdata, const char *fmt,
				   va_list args)
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
{
	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;
1229
	dev_set_drvdata(dev, drvdata);
1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241

	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);
}
1242 1243 1244
EXPORT_SYMBOL_GPL(device_create_vargs);

/**
1245
 * device_create - creates a device and registers it with sysfs
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
 * @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().
 */
1266 1267
struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, void *drvdata, const char *fmt, ...)
1268 1269 1270 1271 1272 1273 1274 1275 1276
{
	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;
}
1277
EXPORT_SYMBOL_GPL(device_create);
1278

1279
static int __match_devt(struct device *dev, void *data)
1280
{
1281
	dev_t *devt = data;
1282

1283
	return dev->devt == *devt;
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296
}

/**
 * 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;
1297

1298
	dev = class_find_device(class, NULL, &devt, __match_devt);
1299 1300
	if (dev) {
		put_device(dev);
1301
		device_unregister(dev);
1302
	}
1303 1304
}
EXPORT_SYMBOL_GPL(device_destroy);
1305 1306 1307 1308 1309 1310 1311 1312 1313 1314

/**
 * 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;
1315
	char *old_device_name = NULL;
1316 1317 1318 1319 1320 1321
	int error;

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

1322
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1323
		 __func__, new_name);
1324

1325
#ifdef CONFIG_SYSFS_DEPRECATED
1326 1327
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1328
#endif
1329

1330 1331 1332 1333
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1334
	}
1335
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1336 1337 1338
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1339 1340 1341 1342
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1343

1344
#ifdef CONFIG_SYSFS_DEPRECATED
1345 1346 1347
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1348 1349 1350 1351
			error = sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, new_class_name);
			if (error)
				goto out;
1352 1353 1354
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1355
#else
1356
	if (dev->class) {
1357
		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
1358
					  &dev->kobj, dev->bus_id);
1359 1360
		if (error)
			goto out;
1361
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1362
				  old_device_name);
1363
	}
1364 1365
#endif

1366
out:
1367 1368 1369
	put_device(dev);

	kfree(new_class_name);
1370
	kfree(old_class_name);
1371
	kfree(old_device_name);
1372 1373 1374

	return error;
}
1375
EXPORT_SYMBOL_GPL(device_rename);
1376 1377 1378 1379 1380

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1381
	int error = 0;
1382 1383 1384 1385 1386
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1387
		error = -ENOMEM;
1388 1389 1390 1391 1392 1393
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1394 1395 1396 1397 1398 1399 1400 1401 1402
	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");
1403
	} else
1404
		error = 0;
1405 1406 1407 1408
out:
	kfree(class_name);
	return error;
#else
1409 1410 1411 1412 1413 1414
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1415 1416 1417 1418 1419 1420
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1421
 * @new_parent: the new parent of the device (can by NULL)
1422 1423 1424 1425 1426
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1427
	struct kobject *new_parent_kobj;
1428 1429 1430 1431 1432 1433

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

	new_parent = get_device(new_parent);
1434
	new_parent_kobj = get_device_parent(dev, new_parent);
1435

1436
	pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1437
		 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1438
	error = kobject_move(&dev->kobj, new_parent_kobj);
1439
	if (error) {
1440
		cleanup_glue_dir(dev, new_parent_kobj);
1441 1442 1443 1444 1445 1446
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1447
		klist_remove(&dev->knode_parent);
1448
	if (new_parent) {
1449
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1450 1451 1452
		set_dev_node(dev, dev_to_node(new_parent));
	}

1453 1454 1455 1456 1457 1458 1459
	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)) {
1460 1461
			if (new_parent)
				klist_remove(&dev->knode_parent);
1462 1463
			dev->parent = old_parent;
			if (old_parent) {
1464 1465
				klist_add_tail(&dev->knode_parent,
					       &old_parent->klist_children);
1466 1467
				set_dev_node(dev, dev_to_node(old_parent));
			}
1468
		}
1469
		cleanup_glue_dir(dev, new_parent_kobj);
1470 1471 1472 1473 1474 1475 1476 1477 1478 1479
		put_device(new_parent);
		goto out;
	}
out_put:
	put_device(old_parent);
out:
	put_device(dev);
	return error;
}
EXPORT_SYMBOL_GPL(device_move);
1480 1481 1482 1483 1484 1485

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
1486
	struct device *dev, *devn;
1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497

	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);
		}
	}
1498 1499 1500
	kobject_put(sysfs_dev_char_kobj);
	kobject_put(sysfs_dev_block_kobj);
	kobject_put(dev_kobj);
1501
}