[mirror_ubuntu-artful-kernel.git] / drivers / vfio / mdev / mdev_core.c

/*
 * Mediated device Core Driver
 *
 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
 *     Author: Neo Jia <cjia@nvidia.com>
 *             Kirti Wankhede <kwankhede@nvidia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>

#include "mdev_private.h"

#define DRIVER_VERSION		"0.1"
#define DRIVER_AUTHOR		"NVIDIA Corporation"
#define DRIVER_DESC		"Mediated device Core Driver"

static LIST_HEAD(parent_list);
static DEFINE_MUTEX(parent_list_lock);
static struct class_compat *mdev_bus_compat_class;

static LIST_HEAD(mdev_list);
static DEFINE_MUTEX(mdev_list_lock);

struct device *mdev_parent_dev(struct mdev_device *mdev)
{
	return mdev->parent->dev;
}
EXPORT_SYMBOL(mdev_parent_dev);

void *mdev_get_drvdata(struct mdev_device *mdev)
{
	return mdev->driver_data;
}
EXPORT_SYMBOL(mdev_get_drvdata);

void mdev_set_drvdata(struct mdev_device *mdev, void *data)
{
	mdev->driver_data = data;
}
EXPORT_SYMBOL(mdev_set_drvdata);

struct device *mdev_dev(struct mdev_device *mdev)
{
	return &mdev->dev;
}
EXPORT_SYMBOL(mdev_dev);

struct mdev_device *mdev_from_dev(struct device *dev)
{
	return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
}
EXPORT_SYMBOL(mdev_from_dev);

uuid_le mdev_uuid(struct mdev_device *mdev)
{
	return mdev->uuid;
}
EXPORT_SYMBOL(mdev_uuid);

static int _find_mdev_device(struct device *dev, void *data)
{
	struct mdev_device *mdev;

	if (!dev_is_mdev(dev))
		return 0;

	mdev = to_mdev_device(dev);

	if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0)
		return 1;

	return 0;
}

static bool mdev_device_exist(struct mdev_parent *parent, uuid_le uuid)
{
	struct device *dev;

	dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
	if (dev) {
		put_device(dev);
		return true;
	}

	return false;
}

/* Should be called holding parent_list_lock */
static struct mdev_parent *__find_parent_device(struct device *dev)
{
	struct mdev_parent *parent;

	list_for_each_entry(parent, &parent_list, next) {
		if (parent->dev == dev)
			return parent;
	}
	return NULL;
}

static void mdev_release_parent(struct kref *kref)
{
	struct mdev_parent *parent = container_of(kref, struct mdev_parent,
						  ref);
	struct device *dev = parent->dev;

	kfree(parent);
	put_device(dev);
}

static
inline struct mdev_parent *mdev_get_parent(struct mdev_parent *parent)
{
	if (parent)
		kref_get(&parent->ref);

	return parent;
}

static inline void mdev_put_parent(struct mdev_parent *parent)
{
	if (parent)
		kref_put(&parent->ref, mdev_release_parent);
}

static int mdev_device_create_ops(struct kobject *kobj,
				  struct mdev_device *mdev)
{
	struct mdev_parent *parent = mdev->parent;
	int ret;

	ret = parent->ops->create(kobj, mdev);
	if (ret)
		return ret;

	ret = sysfs_create_groups(&mdev->dev.kobj,
				  parent->ops->mdev_attr_groups);
	if (ret)
		parent->ops->remove(mdev);

	return ret;
}

/*
 * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
 * device is being unregistered from mdev device framework.
 * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
 *   indicates that if the mdev device is active, used by VMM or userspace
 *   application, vendor driver could return error then don't remove the device.
 * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
 *   which indicate that parent device is being removed from mdev device
 *   framework so remove mdev device forcefully.
 */
static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
{
	struct mdev_parent *parent = mdev->parent;
	int ret;

	/*
	 * Vendor driver can return error if VMM or userspace application is
	 * using this mdev device.
	 */
	ret = parent->ops->remove(mdev);
	if (ret && !force_remove)
		return -EBUSY;

	sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
	return 0;
}

static int mdev_device_remove_cb(struct device *dev, void *data)
{
	if (!dev_is_mdev(dev))
		return 0;

	return mdev_device_remove(dev, data ? *(bool *)data : true);
}

/*
 * mdev_register_device : Register a device
 * @dev: device structure representing parent device.
 * @ops: Parent device operation structure to be registered.
 *
 * Add device to list of registered parent devices.
 * Returns a negative value on error, otherwise 0.
 */
int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
{
	int ret;
	struct mdev_parent *parent;

	/* check for mandatory ops */
	if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
		return -EINVAL;

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

	mutex_lock(&parent_list_lock);

	/* Check for duplicate */
	parent = __find_parent_device(dev);
	if (parent) {
		ret = -EEXIST;
		goto add_dev_err;
	}

	parent = kzalloc(sizeof(*parent), GFP_KERNEL);
	if (!parent) {
		ret = -ENOMEM;
		goto add_dev_err;
	}

	kref_init(&parent->ref);
	mutex_init(&parent->lock);

	parent->dev = dev;
	parent->ops = ops;

	if (!mdev_bus_compat_class) {
		mdev_bus_compat_class = class_compat_register("mdev_bus");
		if (!mdev_bus_compat_class) {
			ret = -ENOMEM;
			goto add_dev_err;
		}
	}

	ret = parent_create_sysfs_files(parent);
	if (ret)
		goto add_dev_err;

	ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
	if (ret)
		dev_warn(dev, "Failed to create compatibility class link\n");

	list_add(&parent->next, &parent_list);
	mutex_unlock(&parent_list_lock);

	dev_info(dev, "MDEV: Registered\n");
	return 0;

add_dev_err:
	mutex_unlock(&parent_list_lock);
	if (parent)
		mdev_put_parent(parent);
	else
		put_device(dev);
	return ret;
}
EXPORT_SYMBOL(mdev_register_device);

/*
 * mdev_unregister_device : Unregister a parent device
 * @dev: device structure representing parent device.
 *
 * Remove device from list of registered parent devices. Give a chance to free
 * existing mediated devices for given device.
 */

void mdev_unregister_device(struct device *dev)
{
	struct mdev_parent *parent;
	bool force_remove = true;

	mutex_lock(&parent_list_lock);
	parent = __find_parent_device(dev);

	if (!parent) {
		mutex_unlock(&parent_list_lock);
		return;
	}
	dev_info(dev, "MDEV: Unregistering\n");

	list_del(&parent->next);
	class_compat_remove_link(mdev_bus_compat_class, dev, NULL);

	device_for_each_child(dev, (void *)&force_remove,
			      mdev_device_remove_cb);

	parent_remove_sysfs_files(parent);

	mutex_unlock(&parent_list_lock);
	mdev_put_parent(parent);
}
EXPORT_SYMBOL(mdev_unregister_device);

static void mdev_device_release(struct device *dev)
{
	struct mdev_device *mdev = to_mdev_device(dev);

	dev_dbg(&mdev->dev, "MDEV: destroying\n");
	kfree(mdev);
}

int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
{
	int ret;
	struct mdev_device *mdev;
	struct mdev_parent *parent;
	struct mdev_type *type = to_mdev_type(kobj);

	parent = mdev_get_parent(type->parent);
	if (!parent)
		return -EINVAL;

	mutex_lock(&parent->lock);

	/* Check for duplicate */
	if (mdev_device_exist(parent, uuid)) {
		ret = -EEXIST;
		goto create_err;
	}

	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	if (!mdev) {
		ret = -ENOMEM;
		goto create_err;
	}

	memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
	mdev->parent = parent;
	kref_init(&mdev->ref);

	mdev->dev.parent  = dev;
	mdev->dev.bus     = &mdev_bus_type;
	mdev->dev.release = mdev_device_release;
	dev_set_name(&mdev->dev, "%pUl", uuid.b);

	ret = device_register(&mdev->dev);
	if (ret) {
		put_device(&mdev->dev);
		goto create_err;
	}

	ret = mdev_device_create_ops(kobj, mdev);
	if (ret)
		goto create_failed;

	ret = mdev_create_sysfs_files(&mdev->dev, type);
	if (ret) {
		mdev_device_remove_ops(mdev, true);
		goto create_failed;
	}

	mdev->type_kobj = kobj;
	dev_dbg(&mdev->dev, "MDEV: created\n");

	mutex_unlock(&parent->lock);

	mutex_lock(&mdev_list_lock);
	list_add(&mdev->next, &mdev_list);
	mutex_unlock(&mdev_list_lock);

	return ret;

create_failed:
	device_unregister(&mdev->dev);

create_err:
	mutex_unlock(&parent->lock);
	mdev_put_parent(parent);
	return ret;
}

int mdev_device_remove(struct device *dev, bool force_remove)
{
	struct mdev_device *mdev, *tmp;
	struct mdev_parent *parent;
	struct mdev_type *type;
	int ret;
	bool found = false;

	mdev = to_mdev_device(dev);

	mutex_lock(&mdev_list_lock);
	list_for_each_entry(tmp, &mdev_list, next) {
		if (tmp == mdev) {
			found = true;
			break;
		}
	}

	if (found)
		list_del(&mdev->next);

	mutex_unlock(&mdev_list_lock);

	if (!found)
		return -ENODEV;

	type = to_mdev_type(mdev->type_kobj);
	parent = mdev->parent;
	mutex_lock(&parent->lock);

	ret = mdev_device_remove_ops(mdev, force_remove);
	if (ret) {
		mutex_unlock(&parent->lock);

		mutex_lock(&mdev_list_lock);
		list_add(&mdev->next, &mdev_list);
		mutex_unlock(&mdev_list_lock);

		return ret;
	}

	mdev_remove_sysfs_files(dev, type);
	device_unregister(dev);
	mutex_unlock(&parent->lock);
	mdev_put_parent(parent);

	return 0;
}

static int __init mdev_init(void)
{
	int ret;

	ret = mdev_bus_register();

	/*
	 * Attempt to load known vfio_mdev.  This gives us a working environment
	 * without the user needing to explicitly load vfio_mdev driver.
	 */
	if (!ret)
		request_module_nowait("vfio_mdev");

	return ret;
}

static void __exit mdev_exit(void)
{
	if (mdev_bus_compat_class)
		class_compat_unregister(mdev_bus_compat_class);

	mdev_bus_unregister();
}

module_init(mdev_init)
module_exit(mdev_exit)

MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
Commit	Line	Data
7b96953b KW	1	/*
	2	* Mediated device Core Driver
	3	*
	4	* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
	5	* Author: Neo Jia <cjia@nvidia.com>
	6	* Kirti Wankhede <kwankhede@nvidia.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/device.h>
	15	#include <linux/slab.h>
	16	#include <linux/uuid.h>
	17	#include <linux/sysfs.h>
	18	#include <linux/mdev.h>
	19
	20	#include "mdev_private.h"
	21
	22	#define DRIVER_VERSION "0.1"
	23	#define DRIVER_AUTHOR "NVIDIA Corporation"
	24	#define DRIVER_DESC "Mediated device Core Driver"
	25
	26	static LIST_HEAD(parent_list);
	27	static DEFINE_MUTEX(parent_list_lock);
	28	static struct class_compat *mdev_bus_compat_class;
	29
49550787 AW	30	static LIST_HEAD(mdev_list);
	31	static DEFINE_MUTEX(mdev_list_lock);
	32
9372e6fe AW	33	struct device mdev_parent_dev(struct mdev_device mdev)
	34	{
	35	return mdev->parent->dev;
	36	}
	37	EXPORT_SYMBOL(mdev_parent_dev);
	38
99e3123e AW	39	void mdev_get_drvdata(struct mdev_device mdev)
	40	{
	41	return mdev->driver_data;
	42	}
	43	EXPORT_SYMBOL(mdev_get_drvdata);
	44
	45	void mdev_set_drvdata(struct mdev_device mdev, void data)
	46	{
	47	mdev->driver_data = data;
	48	}
	49	EXPORT_SYMBOL(mdev_set_drvdata);
	50
	51	struct device mdev_dev(struct mdev_device mdev)
	52	{
	53	return &mdev->dev;
	54	}
	55	EXPORT_SYMBOL(mdev_dev);
	56
	57	struct mdev_device mdev_from_dev(struct device dev)
	58	{
	59	return dev_is_mdev(dev) ? to_mdev_device(dev) : NULL;
	60	}
	61	EXPORT_SYMBOL(mdev_from_dev);
	62
	63	uuid_le mdev_uuid(struct mdev_device *mdev)
	64	{
	65	return mdev->uuid;
	66	}
	67	EXPORT_SYMBOL(mdev_uuid);
	68
7b96953b KW	69	static int _find_mdev_device(struct device dev, void data)
	70	{
	71	struct mdev_device *mdev;
	72
	73	if (!dev_is_mdev(dev))
	74	return 0;
	75
	76	mdev = to_mdev_device(dev);
	77
	78	if (uuid_le_cmp(mdev->uuid, (uuid_le )data) == 0)
	79	return 1;
	80
	81	return 0;
	82	}
	83
42930553	84	static bool mdev_device_exist(struct mdev_parent *parent, uuid_le uuid)
7b96953b KW	85	{
	86	struct device *dev;
	87
	88	dev = device_find_child(parent->dev, &uuid, _find_mdev_device);
	89	if (dev) {
	90	put_device(dev);
	91	return true;
	92	}
	93
	94	return false;
	95	}
	96
	97	/* Should be called holding parent_list_lock */
42930553	98	static struct mdev_parent __find_parent_device(struct device dev)
7b96953b	99	{
42930553	100	struct mdev_parent *parent;
7b96953b KW	101
	102	list_for_each_entry(parent, &parent_list, next) {
	103	if (parent->dev == dev)
	104	return parent;
	105	}
	106	return NULL;
	107	}
	108
	109	static void mdev_release_parent(struct kref *kref)
	110	{
42930553 AW	111	struct mdev_parent *parent = container_of(kref, struct mdev_parent,
42930553 AW	112	ref);
7b96953b KW	113	struct device *dev = parent->dev;
	114
	115	kfree(parent);
	116	put_device(dev);
	117	}
	118
	119	static
42930553	120	inline struct mdev_parent mdev_get_parent(struct mdev_parent parent)
7b96953b KW	121	{
	122	if (parent)
	123	kref_get(&parent->ref);
	124
	125	return parent;
	126	}
	127
42930553	128	static inline void mdev_put_parent(struct mdev_parent *parent)
7b96953b KW	129	{
	130	if (parent)
	131	kref_put(&parent->ref, mdev_release_parent);
	132	}
	133
	134	static int mdev_device_create_ops(struct kobject *kobj,
	135	struct mdev_device *mdev)
	136	{
42930553	137	struct mdev_parent *parent = mdev->parent;
7b96953b KW	138	int ret;
	139
	140	ret = parent->ops->create(kobj, mdev);
	141	if (ret)
	142	return ret;
	143
	144	ret = sysfs_create_groups(&mdev->dev.kobj,
	145	parent->ops->mdev_attr_groups);
	146	if (ret)
	147	parent->ops->remove(mdev);
	148
	149	return ret;
	150	}
	151
	152	/*
	153	* mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
	154	* device is being unregistered from mdev device framework.
	155	* - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
	156	* indicates that if the mdev device is active, used by VMM or userspace
	157	* application, vendor driver could return error then don't remove the device.
	158	* - 'force_remove' is set to 'true' when called from mdev_unregister_device()
	159	* which indicate that parent device is being removed from mdev device
	160	* framework so remove mdev device forcefully.
	161	*/
	162	static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
	163	{
42930553	164	struct mdev_parent *parent = mdev->parent;
7b96953b KW	165	int ret;
	166
	167	/*
	168	* Vendor driver can return error if VMM or userspace application is
	169	* using this mdev device.
	170	*/
	171	ret = parent->ops->remove(mdev);
	172	if (ret && !force_remove)
	173	return -EBUSY;
	174
	175	sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
	176	return 0;
	177	}
	178
	179	static int mdev_device_remove_cb(struct device dev, void data)
	180	{
	181	if (!dev_is_mdev(dev))
	182	return 0;
	183
	184	return mdev_device_remove(dev, data ? (bool )data : true);
	185	}
	186
	187	/*
	188	* mdev_register_device : Register a device
	189	* @dev: device structure representing parent device.
	190	* @ops: Parent device operation structure to be registered.
	191	*
	192	* Add device to list of registered parent devices.
	193	* Returns a negative value on error, otherwise 0.
	194	*/
42930553	195	int mdev_register_device(struct device dev, const struct mdev_parent_ops ops)
7b96953b KW	196	{
7b96953b KW	197	int ret;
42930553	198	struct mdev_parent *parent;
7b96953b KW	199
	200	/* check for mandatory ops */
	201	if (!ops \|\| !ops->create \|\| !ops->remove \|\| !ops->supported_type_groups)
	202	return -EINVAL;
	203
	204	dev = get_device(dev);
	205	if (!dev)
	206	return -EINVAL;
	207
	208	mutex_lock(&parent_list_lock);
	209
	210	/* Check for duplicate */
	211	parent = __find_parent_device(dev);
	212	if (parent) {
	213	ret = -EEXIST;
	214	goto add_dev_err;
	215	}
	216
	217	parent = kzalloc(sizeof(*parent), GFP_KERNEL);
	218	if (!parent) {
	219	ret = -ENOMEM;
	220	goto add_dev_err;
	221	}
	222
	223	kref_init(&parent->ref);
	224	mutex_init(&parent->lock);
	225
	226	parent->dev = dev;
	227	parent->ops = ops;
	228
	229	if (!mdev_bus_compat_class) {
	230	mdev_bus_compat_class = class_compat_register("mdev_bus");
	231	if (!mdev_bus_compat_class) {
	232	ret = -ENOMEM;
	233	goto add_dev_err;
	234	}
	235	}
	236
	237	ret = parent_create_sysfs_files(parent);
	238	if (ret)
	239	goto add_dev_err;
	240
	241	ret = class_compat_create_link(mdev_bus_compat_class, dev, NULL);
	242	if (ret)
	243	dev_warn(dev, "Failed to create compatibility class link\n");
	244
	245	list_add(&parent->next, &parent_list);
	246	mutex_unlock(&parent_list_lock);
	247
	248	dev_info(dev, "MDEV: Registered\n");
	249	return 0;
	250
	251	add_dev_err:
	252	mutex_unlock(&parent_list_lock);
	253	if (parent)
	254	mdev_put_parent(parent);
	255	else
	256	put_device(dev);
	257	return ret;
	258	}
	259	EXPORT_SYMBOL(mdev_register_device);
	260
	261	/*
	262	* mdev_unregister_device : Unregister a parent device
263	* @dev: device structure representing parent device.
264	*
265	* Remove device from list of registered parent devices. Give a chance to free
266	* existing mediated devices for given device.
267	*/
268
269	void mdev_unregister_device(struct device *dev)
270	{
42930553	271	struct mdev_parent *parent;
7b96953b KW	272	bool force_remove = true;
	273
	274	mutex_lock(&parent_list_lock);
	275	parent = __find_parent_device(dev);
	276
	277	if (!parent) {
	278	mutex_unlock(&parent_list_lock);
	279	return;
	280	}
	281	dev_info(dev, "MDEV: Unregistering\n");
	282
	283	list_del(&parent->next);
	284	class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
	285
	286	device_for_each_child(dev, (void *)&force_remove,
	287	mdev_device_remove_cb);
	288
	289	parent_remove_sysfs_files(parent);
	290
	291	mutex_unlock(&parent_list_lock);
	292	mdev_put_parent(parent);
	293	}
	294	EXPORT_SYMBOL(mdev_unregister_device);
	295
	296	static void mdev_device_release(struct device *dev)
	297	{
	298	struct mdev_device *mdev = to_mdev_device(dev);
	299
	300	dev_dbg(&mdev->dev, "MDEV: destroying\n");
	301	kfree(mdev);
	302	}
	303
	304	int mdev_device_create(struct kobject kobj, struct device dev, uuid_le uuid)
	305	{
	306	int ret;
	307	struct mdev_device *mdev;
42930553	308	struct mdev_parent *parent;
7b96953b KW	309	struct mdev_type *type = to_mdev_type(kobj);
	310
	311	parent = mdev_get_parent(type->parent);
	312	if (!parent)
	313	return -EINVAL;
	314
	315	mutex_lock(&parent->lock);
	316
	317	/* Check for duplicate */
	318	if (mdev_device_exist(parent, uuid)) {
	319	ret = -EEXIST;
	320	goto create_err;
	321	}
	322
	323	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
	324	if (!mdev) {
	325	ret = -ENOMEM;
	326	goto create_err;
	327	}
	328
	329	memcpy(&mdev->uuid, &uuid, sizeof(uuid_le));
	330	mdev->parent = parent;
	331	kref_init(&mdev->ref);
	332
	333	mdev->dev.parent = dev;
	334	mdev->dev.bus = &mdev_bus_type;
	335	mdev->dev.release = mdev_device_release;
	336	dev_set_name(&mdev->dev, "%pUl", uuid.b);
	337
	338	ret = device_register(&mdev->dev);
	339	if (ret) {
	340	put_device(&mdev->dev);
	341	goto create_err;
	342	}
	343
	344	ret = mdev_device_create_ops(kobj, mdev);
	345	if (ret)
	346	goto create_failed;
	347
	348	ret = mdev_create_sysfs_files(&mdev->dev, type);
	349	if (ret) {
	350	mdev_device_remove_ops(mdev, true);
	351	goto create_failed;
	352	}
	353
	354	mdev->type_kobj = kobj;
	355	dev_dbg(&mdev->dev, "MDEV: created\n");
	356
	357	mutex_unlock(&parent->lock);
49550787 AW	358
	359	mutex_lock(&mdev_list_lock);
	360	list_add(&mdev->next, &mdev_list);
	361	mutex_unlock(&mdev_list_lock);
	362
7b96953b KW	363	return ret;
	364
	365	create_failed:
	366	device_unregister(&mdev->dev);
	367
	368	create_err:
	369	mutex_unlock(&parent->lock);
	370	mdev_put_parent(parent);
	371	return ret;
	372	}
	373
	374	int mdev_device_remove(struct device *dev, bool force_remove)
	375	{
49550787	376	struct mdev_device mdev, tmp;
42930553	377	struct mdev_parent *parent;
7b96953b KW	378	struct mdev_type *type;
7b96953b KW	379	int ret;
49550787	380	bool found = false;
7b96953b KW	381
7b96953b KW	382	mdev = to_mdev_device(dev);
49550787 AW	383
	384	mutex_lock(&mdev_list_lock);
	385	list_for_each_entry(tmp, &mdev_list, next) {
	386	if (tmp == mdev) {
	387	found = true;
	388	break;
	389	}
	390	}
	391
	392	if (found)
	393	list_del(&mdev->next);
	394
	395	mutex_unlock(&mdev_list_lock);
	396
	397	if (!found)
	398	return -ENODEV;
	399
7b96953b KW	400	type = to_mdev_type(mdev->type_kobj);
	401	parent = mdev->parent;
	402	mutex_lock(&parent->lock);
	403
	404	ret = mdev_device_remove_ops(mdev, force_remove);
	405	if (ret) {
	406	mutex_unlock(&parent->lock);
49550787 AW	407
	408	mutex_lock(&mdev_list_lock);
	409	list_add(&mdev->next, &mdev_list);
	410	mutex_unlock(&mdev_list_lock);
	411
7b96953b KW	412	return ret;
	413	}
	414
	415	mdev_remove_sysfs_files(dev, type);
	416	device_unregister(dev);
	417	mutex_unlock(&parent->lock);
	418	mdev_put_parent(parent);
49550787 AW	419
49550787 AW	420	return 0;
7b96953b KW	421	}
	422
	423	static int __init mdev_init(void)
	424	{
fa3da00c KW	425	int ret;
	426
	427	ret = mdev_bus_register();
	428
	429	/*
	430	* Attempt to load known vfio_mdev. This gives us a working environment
	431	* without the user needing to explicitly load vfio_mdev driver.
	432	*/
	433	if (!ret)
	434	request_module_nowait("vfio_mdev");
	435
	436	return ret;
7b96953b KW	437	}
	438
	439	static void __exit mdev_exit(void)
	440	{
	441	if (mdev_bus_compat_class)
	442	class_compat_unregister(mdev_bus_compat_class);
	443
	444	mdev_bus_unregister();
	445	}
	446
	447	module_init(mdev_init)
	448	module_exit(mdev_exit)
	449
	450	MODULE_VERSION(DRIVER_VERSION);
	451	MODULE_LICENSE("GPL v2");
	452	MODULE_AUTHOR(DRIVER_AUTHOR);
	453	MODULE_DESCRIPTION(DRIVER_DESC);