/* * 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);} staticinline 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);