// SPDX-License-Identifier: GPL-2.0-only/* * MDEV driver * * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. *     Author: Neo Jia <cjia@nvidia.com> *             Kirti Wankhede <kwankhede@nvidia.com> */ #include <linux/device.h>#include <linux/iommu.h>#include <linux/mdev.h> #include "mdev_private.h" static int mdev_attach_iommu(struct mdev_device *mdev){	int ret;	struct iommu_group *group; 	group = iommu_group_alloc();	if (IS_ERR(group))		return PTR_ERR(group); 	ret = iommu_group_add_device(group, &mdev->dev);	if (!ret)		dev_info(&mdev->dev, "MDEV: group_id = %d\n",			 iommu_group_id(group)); 	iommu_group_put(group);	return ret;} static void mdev_detach_iommu(struct mdev_device *mdev){	iommu_group_remove_device(&mdev->dev);	dev_info(&mdev->dev, "MDEV: detaching iommu\n");} static int mdev_probe(struct device *dev){	struct mdev_driver *drv =		container_of(dev->driver, struct mdev_driver, driver);	struct mdev_device *mdev = to_mdev_device(dev);	int ret; 	ret = mdev_attach_iommu(mdev);	if (ret)		return ret; 	if (drv->probe) {		ret = drv->probe(mdev);		if (ret)			mdev_detach_iommu(mdev);	} 	return ret;} static int mdev_remove(struct device *dev){	struct mdev_driver *drv =		container_of(dev->driver, struct mdev_driver, driver);	struct mdev_device *mdev = to_mdev_device(dev); 	if (drv->remove)		drv->remove(mdev); 	mdev_detach_iommu(mdev); 	return 0;} struct bus_type mdev_bus_type = {	.name		= "mdev",	.probe		= mdev_probe,	.remove		= mdev_remove,};EXPORT_SYMBOL_GPL(mdev_bus_type); /** * mdev_register_driver - register a new MDEV driver * @drv: the driver to register * * Returns a negative value on error, otherwise 0. **/int mdev_register_driver(struct mdev_driver *drv){	/* initialize common driver fields */	drv->driver.bus = &mdev_bus_type; 	/* register with core */	return driver_register(&drv->driver);}EXPORT_SYMBOL(mdev_register_driver); /* * mdev_unregister_driver - unregister MDEV driver * @drv: the driver to unregister */void mdev_unregister_driver(struct mdev_driver *drv){	driver_unregister(&drv->driver);}EXPORT_SYMBOL(mdev_unregister_driver); int mdev_bus_register(void){	return bus_register(&mdev_bus_type);} void mdev_bus_unregister(void){	bus_unregister(&mdev_bus_type);}