core.c 43.0 KB
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/*
 * drivers/base/core.c - core driver model code (device registration, etc)
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
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 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
 * Copyright (c) 2006 Novell, Inc.
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 *
 * This file is released under the GPLv2
 *
 */

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

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

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

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

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


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

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


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

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

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

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

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

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	/* add device node properties if present */
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	if (MAJOR(dev->devt)) {
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		const char *tmp;
		const char *name;

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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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		name = device_get_nodename(dev, &tmp);
		if (name) {
			add_uevent_var(env, "DEVNAME=%s", name);
			kfree(tmp);
		}
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	}

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

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

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

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

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

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	return retval;
}

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

	return 0;

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

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	return error;
}

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

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


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

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

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

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

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

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

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

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

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

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#ifdef CONFIG_SYSFS_DEPRECATED
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static struct kobject *get_device_parent(struct device *dev,
					 struct device *parent)
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{
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	/* class devices without a parent live in /sys/class/<classname>/ */
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	if (dev->class && (!parent || parent->class != dev->class))
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		return &dev->class->p->class_subsys.kobj;
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	/* all other devices keep their parent */
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	else if (parent)
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		return &parent->kobj;
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	return NULL;
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}
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static inline void cleanup_device_parent(struct device *dev) {}
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static inline void cleanup_glue_dir(struct device *dev,
				    struct kobject *glue_dir) {}
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#else
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static struct kobject *virtual_device_parent(struct device *dev)
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{
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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)
638 639 640
		return &parent->kobj;
	return NULL;
}
641

642
static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
643
{
644
	/* see if we live in a "glue" directory */
645
	if (!glue_dir || !dev->class ||
646
	    glue_dir->kset != &dev->class->p->class_dirs)
647 648
		return;

649
	kobject_put(glue_dir);
650
}
651 652 653 654 655

static void cleanup_device_parent(struct device *dev)
{
	cleanup_glue_dir(dev, dev->kobj.parent);
}
656
#endif
657

658
static void setup_parent(struct device *dev, struct device *parent)
659 660 661 662 663
{
	struct kobject *kobj;
	kobj = get_device_parent(dev, parent);
	if (kobj)
		dev->kobj.parent = kobj;
664 665
}

666 667 668 669 670 671
static int device_add_class_symlinks(struct device *dev)
{
	int error;

	if (!dev->class)
		return 0;
672

673 674
	error = sysfs_create_link(&dev->kobj,
				  &dev->class->p->class_subsys.kobj,
675 676 677
				  "subsystem");
	if (error)
		goto out;
678 679 680

#ifdef CONFIG_SYSFS_DEPRECATED
	/* stacked class devices need a symlink in the class directory */
681
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
682
	    device_is_not_partition(dev)) {
683
		error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
684
					  &dev->kobj, dev_name(dev));
685 686 687
		if (error)
			goto out_subsys;
	}
688

689
	if (dev->parent && device_is_not_partition(dev)) {
690 691
		struct device *parent = dev->parent;
		char *class_name;
692

693 694 695 696 697 698 699 700 701
		/*
		 * 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,
702 703 704
					  "device");
		if (error)
			goto out_busid;
705 706 707 708 709 710 711 712 713

		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;
714 715 716 717
	}
	return 0;

out_device:
718
	if (dev->parent && device_is_not_partition(dev))
719 720
		sysfs_remove_link(&dev->kobj, "device");
out_busid:
721
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
722
	    device_is_not_partition(dev))
723
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
724
				  dev_name(dev));
725 726
#else
	/* link in the class directory pointing to the device */
727
	error = sysfs_create_link(&dev->class->p->class_subsys.kobj,
728
				  &dev->kobj, dev_name(dev));
729 730 731
	if (error)
		goto out_subsys;

732
	if (dev->parent && device_is_not_partition(dev)) {
733 734 735 736 737 738 739 740
		error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
					  "device");
		if (error)
			goto out_busid;
	}
	return 0;

out_busid:
741
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
742 743
#endif

744 745 746 747 748 749 750 751 752 753
out_subsys:
	sysfs_remove_link(&dev->kobj, "subsystem");
out:
	return error;
}

static void device_remove_class_symlinks(struct device *dev)
{
	if (!dev->class)
		return;
754

755
#ifdef CONFIG_SYSFS_DEPRECATED
756
	if (dev->parent && device_is_not_partition(dev)) {
757 758 759 760 761 762 763 764 765
		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");
	}
766

767
	if (dev->kobj.parent != &dev->class->p->class_subsys.kobj &&
768
	    device_is_not_partition(dev))
769
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
770
				  dev_name(dev));
771
#else
772
	if (dev->parent && device_is_not_partition(dev))
773 774
		sysfs_remove_link(&dev->kobj, "device");

775
	sysfs_remove_link(&dev->class->p->class_subsys.kobj, dev_name(dev));
776 777
#endif

778 779 780
	sysfs_remove_link(&dev->kobj, "subsystem");
}

781 782 783
/**
 * dev_set_name - set a device name
 * @dev: device
784
 * @fmt: format string for the device's name
785 786 787 788
 */
int dev_set_name(struct device *dev, const char *fmt, ...)
{
	va_list vargs;
789
	int err;
790 791

	va_start(vargs, fmt);
792
	err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
793
	va_end(vargs);
794
	return err;
795 796 797
}
EXPORT_SYMBOL_GPL(dev_set_name);

798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845
/**
 * 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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846
/**
847 848
 * device_add - add device to device hierarchy.
 * @dev: device.
L
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849
 *
850 851
 * This is part 2 of device_register(), though may be called
 * separately _iff_ device_initialize() has been called separately.
L
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852
 *
853
 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
854 855
 * to the global and sibling lists for the device, then
 * adds it to the other relevant subsystems of the driver model.
856 857 858 859
 *
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up your
 * reference instead.
L
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860 861 862 863
 */
int device_add(struct device *dev)
{
	struct device *parent = NULL;
864
	struct class_interface *class_intf;
865
	int error = -EINVAL;
866

L
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867
	dev = get_device(dev);
868 869 870
	if (!dev)
		goto done;

871 872 873 874 875 876
	dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
	if (!dev->p) {
		error = -ENOMEM;
		goto done;
	}
	dev->p->device = dev;
877 878
	klist_init(&dev->p->klist_children, klist_children_get,
		   klist_children_put);
879

880 881 882 883 884 885
	/*
	 * for statically allocated devices, which should all be converted
	 * some day, we need to initialize the name. We prevent reading back
	 * the name, and force the use of dev_name()
	 */
	if (dev->init_name) {
886
		dev_set_name(dev, "%s", dev->init_name);
887 888
		dev->init_name = NULL;
	}
889

890
	if (!dev_name(dev))
891
		goto name_error;
L
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892

893
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
894

L
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895
	parent = get_device(dev->parent);
896
	setup_parent(dev, parent);
L
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897

898 899 900 901
	/* use parent numa_node */
	if (parent)
		set_dev_node(dev, dev_to_node(parent));

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902
	/* first, register with generic layer. */
903 904
	/* we require the name to be set before, and pass NULL */
	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
905
	if (error)
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906
		goto Error;
907

908 909 910 911
	/* notify platform of device entry */
	if (platform_notify)
		platform_notify(dev);

912
	error = device_create_file(dev, &uevent_attr);
913 914
	if (error)
		goto attrError;
915

916
	if (MAJOR(dev->devt)) {
917 918
		error = device_create_file(dev, &devt_attr);
		if (error)
919
			goto ueventattrError;
920 921 922 923

		error = device_create_sys_dev_entry(dev);
		if (error)
			goto devtattrError;
924 925
	}

926 927 928
	error = device_add_class_symlinks(dev);
	if (error)
		goto SymlinkError;
929 930
	error = device_add_attrs(dev);
	if (error)
931
		goto AttrsError;
932 933
	error = bus_add_device(dev);
	if (error)
L
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934
		goto BusError;
935
	error = dpm_sysfs_add(dev);
936
	if (error)
937 938
		goto DPMError;
	device_pm_add(dev);
939 940 941 942 943 944 945 946

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

947
	kobject_uevent(&dev->kobj, KOBJ_ADD);
948
	bus_probe_device(dev);
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949
	if (parent)
950 951
		klist_add_tail(&dev->p->knode_parent,
			       &parent->p->klist_children);
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952

953
	if (dev->class) {
954
		mutex_lock(&dev->class->p->class_mutex);
955
		/* tie the class to the device */
956 957
		klist_add_tail(&dev->knode_class,
			       &dev->class->p->class_devices);
958 959

		/* notify any interfaces that the device is here */
960 961
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
962 963
			if (class_intf->add_dev)
				class_intf->add_dev(dev, class_intf);
964
		mutex_unlock(&dev->class->p->class_mutex);
965
	}
966
done:
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967 968
	put_device(dev);
	return error;
969
 DPMError:
970 971
	bus_remove_device(dev);
 BusError:
972
	device_remove_attrs(dev);
973
 AttrsError:
974 975
	device_remove_class_symlinks(dev);
 SymlinkError:
976 977 978
	if (MAJOR(dev->devt))
		device_remove_sys_dev_entry(dev);
 devtattrError:
979 980
	if (MAJOR(dev->devt))
		device_remove_file(dev, &devt_attr);
981
 ueventattrError:
982
	device_remove_file(dev, &uevent_attr);
983
 attrError:
984
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
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985 986
	kobject_del(&dev->kobj);
 Error:
987
	cleanup_device_parent(dev);
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988 989
	if (parent)
		put_device(parent);
990 991 992
name_error:
	kfree(dev->p);
	dev->p = NULL;
993
	goto done;
L
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994 995 996
}

/**
997 998
 * device_register - register a device with the system.
 * @dev: pointer to the device structure
L
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999
 *
1000 1001 1002 1003 1004 1005
 * 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.
1006 1007 1008 1009
 *
 * NOTE: _Never_ directly free @dev after calling this function, even
 * if it returned an error! Always use put_device() to give up the
 * reference initialized in this function instead.
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1010 1011 1012 1013 1014 1015 1016 1017
 */
int device_register(struct device *dev)
{
	device_initialize(dev);
	return device_add(dev);
}

/**
1018 1019
 * get_device - increment reference count for device.
 * @dev: device.
L
Linus Torvalds 已提交
1020
 *
1021 1022 1023
 * 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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1024
 */
1025
struct device *get_device(struct device *dev)
L
Linus Torvalds 已提交
1026 1027 1028 1029 1030
{
	return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
}

/**
1031 1032
 * put_device - decrement reference count.
 * @dev: device in question.
L
Linus Torvalds 已提交
1033
 */
1034
void put_device(struct device *dev)
L
Linus Torvalds 已提交
1035
{
1036
	/* might_sleep(); */
L
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1037 1038 1039 1040 1041
	if (dev)
		kobject_put(&dev->kobj);
}

/**
1042 1043
 * device_del - delete device from system.
 * @dev: device.
L
Linus Torvalds 已提交
1044
 *
1045 1046 1047 1048 1049
 * 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.
L
Linus Torvalds 已提交
1050
 *
1051 1052
 * NOTE: this should be called manually _iff_ device_add() was
 * also called manually.
L
Linus Torvalds 已提交
1053
 */
1054
void device_del(struct device *dev)
L
Linus Torvalds 已提交
1055
{
1056
	struct device *parent = dev->parent;
1057
	struct class_interface *class_intf;
L
Linus Torvalds 已提交
1058

1059 1060 1061 1062 1063 1064
	/* Notify clients of device removal.  This call must come
	 * before dpm_sysfs_remove().
	 */
	if (dev->bus)
		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
					     BUS_NOTIFY_DEL_DEVICE, dev);
1065
	device_pm_remove(dev);
1066
	dpm_sysfs_remove(dev);
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1067
	if (parent)
1068
		klist_del(&dev->p->knode_parent);
1069 1070
	if (MAJOR(dev->devt)) {
		device_remove_sys_dev_entry(dev);
1071
		device_remove_file(dev, &devt_attr);
1072
	}
1073
	if (dev->class) {
1074
		device_remove_class_symlinks(dev);
1075

1076
		mutex_lock(&dev->class->p->class_mutex);
1077
		/* notify any interfaces that the device is now gone */
1078 1079
		list_for_each_entry(class_intf,
				    &dev->class->p->class_interfaces, node)
1080 1081 1082
			if (class_intf->remove_dev)
				class_intf->remove_dev(dev, class_intf);
		/* remove the device from the class list */
1083
		klist_del(&dev->knode_class);
1084
		mutex_unlock(&dev->class->p->class_mutex);
1085
	}
1086
	device_remove_file(dev, &uevent_attr);
1087
	device_remove_attrs(dev);
1088
	bus_remove_device(dev);
L
Linus Torvalds 已提交
1089

1090 1091 1092 1093 1094 1095 1096
	/*
	 * 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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1097 1098 1099 1100 1101
	/* Notify the platform of the removal, in case they
	 * need to do anything...
	 */
	if (platform_notify_remove)
		platform_notify_remove(dev);
1102
	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1103
	cleanup_device_parent(dev);
L
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1104
	kobject_del(&dev->kobj);
1105
	put_device(parent);
L
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1106 1107 1108
}

/**
1109 1110
 * device_unregister - unregister device from system.
 * @dev: device going away.
L
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1111
 *
1112 1113 1114 1115 1116 1117
 * We do this in two parts, like we do device_register(). First,
 * we remove it from all the subsystems with device_del(), then
 * we decrement the reference count via put_device(). If that
 * is the final reference count, the device will be cleaned up
 * via device_release() above. Otherwise, the structure will
 * stick around until the final reference to the device is dropped.
L
Linus Torvalds 已提交
1118
 */
1119
void device_unregister(struct device *dev)
L
Linus Torvalds 已提交
1120
{
1121
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
L
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1122 1123 1124 1125
	device_del(dev);
	put_device(dev);
}

1126
static struct device *next_device(struct klist_iter *i)
1127
{
1128
	struct klist_node *n = klist_next(i);
1129 1130 1131 1132 1133 1134 1135 1136
	struct device *dev = NULL;
	struct device_private *p;

	if (n) {
		p = to_device_private_parent(n);
		dev = p->device;
	}
	return dev;
1137 1138
}

1139 1140 1141 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
/**
 * device_get_nodename - path of device node file
 * @dev: device
 * @tmp: possibly allocated string
 *
 * Return the relative path of a possible device node.
 * Non-default names may need to allocate a memory to compose
 * a name. This memory is returned in tmp and needs to be
 * freed by the caller.
 */
const char *device_get_nodename(struct device *dev, const char **tmp)
{
	char *s;

	*tmp = NULL;

	/* the device type may provide a specific name */
	if (dev->type && dev->type->nodename)
		*tmp = dev->type->nodename(dev);
	if (*tmp)
		return *tmp;

	/* the class may provide a specific name */
	if (dev->class && dev->class->nodename)
		*tmp = dev->class->nodename(dev);
	if (*tmp)
		return *tmp;

	/* return name without allocation, tmp == NULL */
	if (strchr(dev_name(dev), '!') == NULL)
		return dev_name(dev);

	/* replace '!' in the name with '/' */
	*tmp = kstrdup(dev_name(dev), GFP_KERNEL);
	if (!*tmp)
		return NULL;
	while ((s = strchr(*tmp, '!')))
		s[0] = '/';
	return *tmp;
}

L
Linus Torvalds 已提交
1180
/**
1181 1182 1183 1184
 * device_for_each_child - device child iterator.
 * @parent: parent struct device.
 * @data: data for the callback.
 * @fn: function to be called for each device.
L
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1185
 *
1186 1187
 * Iterate over @parent's child devices, and call @fn for each,
 * passing it @data.
L
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1188
 *
1189 1190
 * 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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1191
 */
1192 1193
int device_for_each_child(struct device *parent, void *data,
			  int (*fn)(struct device *dev, void *data))
L
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1194
{
1195
	struct klist_iter i;
1196
	struct device *child;
L
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1197 1198
	int error = 0;

1199 1200 1201
	if (!parent->p)
		return 0;

1202
	klist_iter_init(&parent->p->klist_children, &i);
1203 1204 1205
	while ((child = next_device(&i)) && !error)
		error = fn(child, data);
	klist_iter_exit(&i);
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1206 1207 1208
	return error;
}

1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223
/**
 * 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.
 */
1224 1225
struct device *device_find_child(struct device *parent, void *data,
				 int (*match)(struct device *dev, void *data))
1226 1227 1228 1229 1230 1231 1232
{
	struct klist_iter i;
	struct device *child;

	if (!parent)
		return NULL;

1233
	klist_iter_init(&parent->p->klist_children, &i);
1234 1235 1236 1237 1238 1239 1240
	while ((child = next_device(&i)))
		if (match(child, data) && get_device(child))
			break;
	klist_iter_exit(&i);
	return child;
}

L
Linus Torvalds 已提交
1241 1242
int __init devices_init(void)
{
1243 1244 1245
	devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
	if (!devices_kset)
		return -ENOMEM;
1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
	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;

1256
	return 0;
1257 1258 1259 1260 1261 1262 1263 1264

 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
Linus Torvalds 已提交
1265 1266 1267
}

EXPORT_SYMBOL_GPL(device_for_each_child);
1268
EXPORT_SYMBOL_GPL(device_find_child);
L
Linus Torvalds 已提交
1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280

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);
1281

1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323
struct root_device
{
	struct device dev;
	struct module *owner;
};

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

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

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

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

1324
	err = dev_set_name(&root->dev, "%s", name);
1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356
	if (err) {
		kfree(root);
		return ERR_PTR(err);
	}

	root->dev.release = root_device_release;

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

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

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

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

/**
 * root_device_unregister - unregister and free a root device
1357
 * @dev: device going away
1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372
 *
 * This function unregisters and cleans up a device that was created by
 * root_device_register().
 */
void root_device_unregister(struct device *dev)
{
	struct root_device *root = to_root_device(dev);

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

	device_unregister(dev);
}
EXPORT_SYMBOL_GPL(root_device_unregister);

1373 1374 1375

static void device_create_release(struct device *dev)
{
1376
	pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1377 1378 1379 1380
	kfree(dev);
}

/**
1381
 * device_create_vargs - creates a device and registers it with sysfs
1382 1383 1384
 * @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
1385
 * @drvdata: the data to be added to the device for callbacks
1386
 * @fmt: string for the device's name
1387
 * @args: va_list for the device's name
1388 1389 1390
 *
 * This function can be used by char device classes.  A struct device
 * will be created in sysfs, registered to the specified class.
1391 1392 1393
 *
 * A "dev" file will be created, showing the dev_t for the device, if
 * the dev_t is not 0,0.
1394 1395 1396 1397
 * 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
1398 1399 1400 1401 1402
 * pointer.
 *
 * Note: the struct class passed to this function must have previously
 * been created with a call to class_create().
 */
1403 1404 1405
struct device *device_create_vargs(struct class *class, struct device *parent,
				   dev_t devt, void *drvdata, const char *fmt,
				   va_list args)
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
{
	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;
1423
	dev_set_drvdata(dev, drvdata);
1424

1425 1426 1427 1428
	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
	if (retval)
		goto error;

1429 1430 1431 1432 1433 1434 1435
	retval = device_register(dev);
	if (retval)
		goto error;

	return dev;

error:
1436
	put_device(dev);
1437 1438
	return ERR_PTR(retval);
}
1439 1440 1441
EXPORT_SYMBOL_GPL(device_create_vargs);

/**
1442
 * device_create - creates a device and registers it with sysfs
1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462
 * @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().
 */
1463 1464
struct device *device_create(struct class *class, struct device *parent,
			     dev_t devt, void *drvdata, const char *fmt, ...)
1465 1466 1467 1468 1469 1470 1471 1472 1473
{
	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;
}
1474
EXPORT_SYMBOL_GPL(device_create);
1475

1476
static int __match_devt(struct device *dev, void *data)
1477
{
1478
	dev_t *devt = data;
1479

1480
	return dev->devt == *devt;
1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493
}

/**
 * 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;
1494

1495
	dev = class_find_device(class, NULL, &devt, __match_devt);
1496 1497
	if (dev) {
		put_device(dev);
1498
		device_unregister(dev);
1499
	}
1500 1501
}
EXPORT_SYMBOL_GPL(device_destroy);
1502 1503 1504 1505 1506

/**
 * device_rename - renames a device
 * @dev: the pointer to the struct device to be renamed
 * @new_name: the new name of the device
1507 1508 1509 1510 1511
 *
 * It is the responsibility of the caller to provide mutual
 * exclusion between two different calls of device_rename
 * on the same device to ensure that new_name is valid and
 * won't conflict with other devices.
1512 1513 1514 1515 1516
 */
int device_rename(struct device *dev, char *new_name)
{
	char *old_class_name = NULL;
	char *new_class_name = NULL;
1517
	char *old_device_name = NULL;
1518 1519 1520 1521 1522 1523
	int error;

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

1524
	pr_debug("device: '%s': %s: renaming to '%s'\n", dev_name(dev),
1525
		 __func__, new_name);
1526

1527
#ifdef CONFIG_SYSFS_DEPRECATED
1528 1529
	if ((dev->class) && (dev->parent))
		old_class_name = make_class_name(dev->class->name, &dev->kobj);
1530
#endif
1531

1532
	old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1533 1534 1535
	if (!old_device_name) {
		error = -ENOMEM;
		goto out;
1536 1537 1538
	}

	error = kobject_rename(&dev->kobj, new_name);
1539
	if (error)
1540
		goto out;
1541

1542
#ifdef CONFIG_SYSFS_DEPRECATED
1543 1544 1545
	if (old_class_name) {
		new_class_name = make_class_name(dev->class->name, &dev->kobj);
		if (new_class_name) {
1546 1547 1548
			error = sysfs_create_link_nowarn(&dev->parent->kobj,
							 &dev->kobj,
							 new_class_name);
1549 1550
			if (error)
				goto out;
1551 1552 1553
			sysfs_remove_link(&dev->parent->kobj, old_class_name);
		}
	}
1554
#else
1555
	if (dev->class) {
1556
		error = sysfs_create_link_nowarn(&dev->class->p->class_subsys.kobj,
1557
						 &dev->kobj, dev_name(dev));
1558 1559
		if (error)
			goto out;
1560
		sysfs_remove_link(&dev->class->p->class_subsys.kobj,
1561
				  old_device_name);
1562
	}
1563 1564
#endif

1565
out:
1566 1567 1568
	put_device(dev);

	kfree(new_class_name);
1569
	kfree(old_class_name);
1570
	kfree(old_device_name);
1571 1572 1573

	return error;
}
1574
EXPORT_SYMBOL_GPL(device_rename);
1575 1576 1577 1578 1579

static int device_move_class_links(struct device *dev,
				   struct device *old_parent,
				   struct device *new_parent)
{
1580
	int error = 0;
1581 1582 1583 1584 1585
#ifdef CONFIG_SYSFS_DEPRECATED
	char *class_name;

	class_name = make_class_name(dev->class->name, &dev->kobj);
	if (!class_name) {
1586
		error = -ENOMEM;
1587 1588 1589 1590 1591 1592
		goto out;
	}
	if (old_parent) {
		sysfs_remove_link(&dev->kobj, "device");
		sysfs_remove_link(&old_parent->kobj, class_name);
	}
1593 1594 1595 1596 1597 1598 1599 1600 1601
	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");
1602
	} else
1603
		error = 0;
1604 1605 1606 1607
out:
	kfree(class_name);
	return error;
#else
1608 1609 1610 1611 1612 1613
	if (old_parent)
		sysfs_remove_link(&dev->kobj, "device");
	if (new_parent)
		error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
					  "device");
	return error;
1614 1615 1616 1617 1618 1619
#endif
}

/**
 * device_move - moves a device to a new parent
 * @dev: the pointer to the struct device to be moved
1620
 * @new_parent: the new parent of the device (can by NULL)
1621
 * @dpm_order: how to reorder the dpm_list
1622
 */
1623 1624
int device_move(struct device *dev, struct device *new_parent,
		enum dpm_order dpm_order)
1625 1626 1627
{
	int error;
	struct device *old_parent;
1628
	struct kobject *new_parent_kobj;
1629 1630 1631 1632 1633

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

1634
	device_pm_lock();
1635
	new_parent = get_device(new_parent);
1636
	new_parent_kobj = get_device_parent(dev, new_parent);
1637

1638 1639
	pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
		 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1640
	error = kobject_move(&dev->kobj, new_parent_kobj);
1641
	if (error) {
1642
		cleanup_glue_dir(dev, new_parent_kobj);
1643 1644 1645 1646 1647 1648
		put_device(new_parent);
		goto out;
	}
	old_parent = dev->parent;
	dev->parent = new_parent;
	if (old_parent)
1649
		klist_remove(&dev->p->knode_parent);
1650
	if (new_parent) {
1651 1652
		klist_add_tail(&dev->p->knode_parent,
			       &new_parent->p->klist_children);
1653 1654 1655
		set_dev_node(dev, dev_to_node(new_parent));
	}

1656 1657 1658 1659 1660 1661 1662
	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)) {
1663
			if (new_parent)
1664
				klist_remove(&dev->p->knode_parent);
1665 1666
			dev->parent = old_parent;
			if (old_parent) {
1667 1668
				klist_add_tail(&dev->p->knode_parent,
					       &old_parent->p->klist_children);
1669 1670
				set_dev_node(dev, dev_to_node(old_parent));
			}
1671
		}
1672
		cleanup_glue_dir(dev, new_parent_kobj);
1673 1674 1675
		put_device(new_parent);
		goto out;
	}
1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
	switch (dpm_order) {
	case DPM_ORDER_NONE:
		break;
	case DPM_ORDER_DEV_AFTER_PARENT:
		device_pm_move_after(dev, new_parent);
		break;
	case DPM_ORDER_PARENT_BEFORE_DEV:
		device_pm_move_before(new_parent, dev);
		break;
	case DPM_ORDER_DEV_LAST:
		device_pm_move_last(dev);
		break;
	}
1689 1690 1691
out_put:
	put_device(old_parent);
out:
1692
	device_pm_unlock();
1693 1694 1695 1696
	put_device(dev);
	return error;
}
EXPORT_SYMBOL_GPL(device_move);
1697 1698 1699 1700 1701 1702

/**
 * device_shutdown - call ->shutdown() on each device to shutdown.
 */
void device_shutdown(void)
{
1703
	struct device *dev, *devn;
1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714

	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);
		}
	}
1715 1716 1717
	kobject_put(sysfs_dev_char_kobj);
	kobject_put(sysfs_dev_block_kobj);
	kobject_put(dev_kobj);
1718
	async_synchronize_full();
1719
}