core.c 36.5 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 "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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#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->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 */
		spin_lock(&dev->class->class_dirs.list_lock);
		list_for_each_entry(k, &dev->class->class_dirs.list, entry)
			if (k->parent == parent_kobj) {
				kobj = kobject_get(k);
				break;
			}
		spin_unlock(&dev->class->class_dirs.list_lock);
		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;
		k->kset = &dev->class->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)
627
{
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	/* see if we live in a "glue" directory */
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	if (!glue_dir || !dev->class ||
	    glue_dir->kset != &dev->class->class_dirs)
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		return;

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	kobject_put(glue_dir);
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}
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static void cleanup_device_parent(struct device *dev)
{
	cleanup_glue_dir(dev, dev->kobj.parent);
}
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#endif
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642
static void setup_parent(struct device *dev, struct device *parent)
643 644 645 646 647
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (kobj)
		dev->kobj.parent = kobj;
648 649
}

650 651 652 653 654 655
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
656

657 658 659 660
	error = sysfs_create_link(&dev->kobj, &dev->class->subsys.kobj,
				  "subsystem");
	if (error)
		goto out;
661 662 663

#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
664
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
665
	    device_is_not_partition(dev)) {
666 667 668 669 670
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error)
			goto out_subsys;
	}
671

672
	if (dev->parent && device_is_not_partition(dev)) {
673 674
		struct device *parent = dev->parent;
		char *class_name;
675

676 677 678 679 680 681 682 683 684
		/*
		 * 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,
685 686 687
					  "device");
		if (error)
			goto out_busid;
688 689 690 691 692 693 694 695 696

		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;
697 698 699 700
	}
	return 0;

out_device:
701
	if (dev->parent && device_is_not_partition(dev))
702 703
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
704
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
705
	    device_is_not_partition(dev))
706
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
707 708 709 710 711 712 713
#else
	/* link in the class directory pointing to the device */
	error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
				  dev->bus_id);
	if (error)
		goto out_subsys;

714
	if (dev->parent && device_is_not_partition(dev)) {
715 716 717 718 719 720 721 722 723 724 725
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
	sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

726 727 728 729 730 731 732 733 734 735
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
736

737
#ifdef CONFIG_SYSFS_DEPRECATED
738
	if (dev->parent && device_is_not_partition(dev)) {
739 740 741 742 743 744 745 746 747
		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");
	}
748

749
	if (dev->kobj.parent != &dev->class->subsys.kobj &&
750
	    device_is_not_partition(dev))
751
		sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
752
#else
753
	if (dev->parent && device_is_not_partition(dev))
754 755 756 757 758
		sysfs_remove_link(&dev->kobj, "device");

	sysfs_remove_link(&dev->class->subsys.kobj, dev->bus_id);
#endif

759 760 761
	sysfs_remove_link(&dev->kobj, "subsystem");
}

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/**
763 764
 * device_add - add device to device hierarchy.
 * @dev: device.
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765
 *
766 767
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
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 *
769 770 771
 * 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;
776
	struct class_interface *class_intf;
777 778
	int error;

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	dev = get_device(dev);
780 781
	if (!dev || !strlen(dev->bus_id)) {
		error = -EINVAL;
782
		goto Done;
783
	}
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784

785
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
786

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	parent = get_device(dev->parent);
788
	setup_parent(dev, parent);
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790 791 792 793
	/* use parent numa_node */
	if (parent)
		set_dev_node(dev, dev_to_node(parent));

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	/* first, register with generic layer. */
795
	error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev->bus_id);
796
	if (error)
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		goto Error;
798

799 800 801 802
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

803 804
	/* notify clients of device entry (new way) */
	if (dev->bus)
805
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
806 807
					     BUS_NOTIFY_ADD_DEVICE, dev);

808
	error = device_create_file(dev, &uevent_attr);
809 810
	if (error)
		goto attrError;
811

812
	if (MAJOR(dev->devt)) {
813 814
		error = device_create_file(dev, &devt_attr);
		if (error)
815
			goto ueventattrError;
816 817
	}

818 819 820
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
821 822
	error = device_add_attrs(dev);
	if (error)
823
		goto AttrsError;
824 825
	error = bus_add_device(dev);
	if (error)
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		goto BusError;
827 828 829
	error = device_pm_add(dev);
	if (error)
		goto PMError;
830
	kobject_uevent(&dev->kobj, KOBJ_ADD);
831
	bus_attach_device(dev);
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	if (parent)
833
		klist_add_tail(&dev->knode_parent, &parent->klist_children);
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834

835 836
	if (dev->class) {
		down(&dev->class->sem);
837
		/* tie the class to the device */
838
		list_add_tail(&dev->node, &dev->class->devices);
839 840 841 842 843

		/* notify any interfaces that the device is here */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
844 845
		up(&dev->class->sem);
	}
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 Done:
	put_device(dev);
	return error;
 PMError:
850 851
	bus_remove_device(dev);
 BusError:
852
	if (dev->bus)
853
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
854
					     BUS_NOTIFY_DEL_DEVICE, dev);
855
	device_remove_attrs(dev);
856
 AttrsError:
857 858
	device_remove_class_symlinks(dev);
 SymlinkError:
859 860
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
861
 ueventattrError:
862
	device_remove_file(dev, &uevent_attr);
863
 attrError:
864
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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865 866
	kobject_del(&dev->kobj);
 Error:
867
	cleanup_device_parent(dev);
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	if (parent)
		put_device(parent);
	goto Done;
}

/**
874 875
 * device_register - register a device with the system.
 * @dev: pointer to the device structure
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 *
877 878 879 880 881 882
 * 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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 */
int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}

/**
891 892
 * get_device - increment reference count for device.
 * @dev: device.
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 *
894 895 896
 * 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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 */
898
struct device *get_device(struct device *dev)
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{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}

/**
904 905
 * put_device - decrement reference count.
 * @dev: device in question.
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 */
907
void put_device(struct device *dev)
L
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908
{
909
	/* might_sleep(); */
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	if (dev)
		kobject_put(&dev->kobj);
}

/**
915 916
 * device_del - delete device from system.
 * @dev: device.
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917
 *
918 919 920 921 922
 * 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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923
 *
924 925
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
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926
 */
927
void device_del(struct device *dev)
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928
{
929
	struct device *parent = dev->parent;
930
	struct class_interface *class_intf;
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931

932
	device_pm_remove(dev);
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933
	if (parent)
934
		klist_del(&dev->knode_parent);
935 936
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
937
	if (dev->class) {
938
		device_remove_class_symlinks(dev);
939

940
		down(&dev->class->sem);
941 942 943 944 945
		/* notify any interfaces that the device is now gone */
		list_for_each_entry(class_intf, &dev->class->interfaces, node)
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
946 947
		list_del_init(&dev->node);
		up(&dev->class->sem);
948
	}
949
	device_remove_file(dev, &uevent_attr);
950
	device_remove_attrs(dev);
951
	bus_remove_device(dev);
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953 954 955 956 957 958 959
	/*
	 * 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);

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	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
965
	if (dev->bus)
966
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
967
					     BUS_NOTIFY_DEL_DEVICE, dev);
968
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
969
	cleanup_device_parent(dev);
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970
	kobject_del(&dev->kobj);
971
	put_device(parent);
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972 973 974
}

/**
975 976
 * device_unregister - unregister device from system.
 * @dev: device going away.
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977
 *
978 979 980 981 982 983
 * 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.
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984
 */
985
void device_unregister(struct device *dev)
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986
{
987
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
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988 989 990 991
	device_del(dev);
	put_device(dev);
}

992
static struct device *next_device(struct klist_iter *i)
993
{
994
	struct klist_node *n = klist_next(i);
995 996 997
	return n ? container_of(n, struct device, knode_parent) : NULL;
}

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998
/**
999 1000 1001 1002
 * device_for_each_child - device child iterator.
 * @parent: parent struct device.
 * @data: data for the callback.
 * @fn: function to be called for each device.
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1003
 *
1004 1005
 * Iterate over @parent's child devices, and call @fn for each,
 * passing it @data.
L
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1006
 *
1007 1008
 * 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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1009
 */
1010 1011
int device_for_each_child(struct device *parent, void *data,
			  int (*fn)(struct device *dev, void *data))
L
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1012
{
1013
	struct klist_iter i;
1014
	struct device *child;
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1015 1016
	int error = 0;

1017 1018 1019 1020
	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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1021 1022 1023
	return error;
}

1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038
/**
 * 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.
 */
1039 1040
struct device *device_find_child(struct device *parent, void *data,
				 int (*match)(struct device *dev, void *data))
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055
{
	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;
}

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1056 1057
int __init devices_init(void)
{
1058 1059 1060 1061
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
	return 0;
L
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1062 1063 1064
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1065
EXPORT_SYMBOL_GPL(device_find_child);
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1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077

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);
1078 1079 1080 1081


static void device_create_release(struct device *dev)
{
1082
	pr_debug("device: '%s': %s\n", dev->bus_id, __func__);
1083 1084 1085 1086
	kfree(dev);
}

/**
1087
 * device_create_vargs - creates a device and registers it with sysfs
1088 1089 1090
 * @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
1091
 * @drvdata: the data to be added to the device for callbacks
1092
 * @fmt: string for the device's name
1093
 * @args: va_list for the device's name
1094 1095 1096
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1097 1098 1099
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1100 1101 1102 1103
 * 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
1104 1105 1106 1107 1108
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1109 1110 1111
struct device *device_create_vargs(struct class *class, struct device *parent,
				   dev_t devt, void *drvdata, const char *fmt,
				   va_list args)
1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128
{
	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;
1129
	dev_set_drvdata(dev, drvdata);
1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141

	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);
}
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
EXPORT_SYMBOL_GPL(device_create_vargs);

/**
 * device_create_drvdata - creates a device and registers it with sysfs
 * @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().
 */
struct device *device_create_drvdata(struct class *class,
				     struct device *parent,
				     dev_t devt,
				     void *drvdata,
				     const char *fmt, ...)
{
	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;
}
EXPORT_SYMBOL_GPL(device_create_drvdata);

/**
 * device_create - creates a device and registers it with sysfs
 * @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
 * @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().
 */
struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, const char *fmt, ...)
{
	va_list vargs;
	struct device *dev;

	va_start(vargs, fmt);
	dev = device_create_vargs(class, parent, devt, NULL, fmt, vargs);
	va_end(vargs);
	return dev;
}
1214 1215
EXPORT_SYMBOL_GPL(device_create);

1216
static int __match_devt(struct device *dev, void *data)
1217
{
1218
	dev_t *devt = data;
1219

1220
	return dev->devt == *devt;
1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
}

/**
 * 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;
1234

1235 1236 1237
	dev = class_find_device(class, &devt, __match_devt);
	if (dev) {
		put_device(dev);
1238
		device_unregister(dev);
1239
	}
1240 1241
}
EXPORT_SYMBOL_GPL(device_destroy);
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251

/**
 * 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;
1252
	char *old_device_name = NULL;
1253 1254 1255 1256 1257 1258
	int error;

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

1259
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev->bus_id,
1260
		 __func__, new_name);
1261

1262
#ifdef CONFIG_SYSFS_DEPRECATED
1263 1264
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1265
#endif
1266

1267 1268 1269 1270
	old_device_name = kmalloc(BUS_ID_SIZE, GFP_KERNEL);
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1271
	}
1272
	strlcpy(old_device_name, dev->bus_id, BUS_ID_SIZE);
1273 1274 1275
	strlcpy(dev->bus_id, new_name, BUS_ID_SIZE);

	error = kobject_rename(&dev->kobj, new_name);
1276 1277 1278 1279
	if (error) {
		strlcpy(dev->bus_id, old_device_name, BUS_ID_SIZE);
		goto out;
	}
1280

1281
#ifdef CONFIG_SYSFS_DEPRECATED
1282 1283 1284
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1285 1286 1287 1288
			error = sysfs_create_link(&dev->parent->kobj,
						  &dev->kobj, new_class_name);
			if (error)
				goto out;
1289 1290 1291
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1292
#else
1293
	if (dev->class) {
1294 1295 1296 1297 1298
		sysfs_remove_link(&dev->class->subsys.kobj, old_device_name);
		error = sysfs_create_link(&dev->class->subsys.kobj, &dev->kobj,
					  dev->bus_id);
		if (error) {
			dev_err(dev, "%s: sysfs_create_symlink failed (%d)\n",
1299
				__func__, error);
1300
		}
1301
	}
1302 1303
#endif

1304
out:
1305 1306 1307
	put_device(dev);

	kfree(new_class_name);
1308
	kfree(old_class_name);
1309
	kfree(old_device_name);
1310 1311 1312

	return error;
}
1313
EXPORT_SYMBOL_GPL(device_rename);
1314 1315 1316 1317 1318

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1319
	int error = 0;
1320 1321 1322 1323 1324
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1325
		error = -ENOMEM;
1326 1327 1328 1329 1330 1331
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1332 1333 1334 1335 1336 1337 1338 1339 1340
	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");
1341
	} else
1342
		error = 0;
1343 1344 1345 1346
out:
	kfree(class_name);
	return error;
#else
1347 1348 1349 1350 1351 1352
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1353 1354 1355 1356 1357 1358
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1359
 * @new_parent: the new parent of the device (can by NULL)
1360 1361 1362 1363 1364
 */
int device_move(struct device *dev, struct device *new_parent)
{
	int error;
	struct device *old_parent;
1365
	struct kobject *new_parent_kobj;
1366 1367 1368 1369 1370 1371

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

	new_parent = get_device(new_parent);
1372
	new_parent_kobj = get_device_parent(dev, new_parent);
1373

1374
	pr_debug("device: '%s': %s: moving to '%s'\n", dev->bus_id,
1375
		 __func__, new_parent ? new_parent->bus_id : "<NULL>");
1376
	error = kobject_move(&dev->kobj, new_parent_kobj);
1377
	if (error) {
1378
		cleanup_glue_dir(dev, new_parent_kobj);
1379 1380 1381 1382 1383 1384
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1385
		klist_remove(&dev->knode_parent);
1386
	if (new_parent) {
1387
		klist_add_tail(&dev->knode_parent, &new_parent->klist_children);
1388 1389 1390
		set_dev_node(dev, dev_to_node(new_parent));
	}

1391 1392 1393 1394 1395 1396 1397
	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)) {
1398 1399
			if (new_parent)
				klist_remove(&dev->knode_parent);
1400 1401
			dev->parent = old_parent;
			if (old_parent) {
1402 1403
				klist_add_tail(&dev->knode_parent,
					       &old_parent->klist_children);
1404 1405
				set_dev_node(dev, dev_to_node(old_parent));
			}
1406
		}
1407
		cleanup_glue_dir(dev, new_parent_kobj);
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417
		put_device(new_parent);
		goto out;
	}
out_put:
	put_device(old_parent);
out:
	put_device(dev);
	return error;
}
EXPORT_SYMBOL_GPL(device_move);
1418 1419 1420 1421 1422 1423

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
1424
	struct device *dev, *devn;
1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436

	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);
		}
	}
}