// 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 = to_mdev_driver(dev->driver); struct mdev_device *mdev = to_mdev_device(dev); int ret; ret = mdev_attach_iommu(mdev); if (ret) return ret; if (drv && drv->probe) { ret = drv->probe(dev); if (ret) mdev_detach_iommu(mdev); } return ret; } static int mdev_remove(struct device *dev) { struct mdev_driver *drv = to_mdev_driver(dev->driver); struct mdev_device *mdev = to_mdev_device(dev); if (drv && drv->remove) drv->remove(dev); 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 * @owner: module owner of driver to be registered * * Returns a negative value on error, otherwise 0. **/ int mdev_register_driver(struct mdev_driver *drv, struct module *owner) { /* initialize common driver fields */ drv->driver.name = drv->name; drv->driver.bus = &mdev_bus_type; drv->driver.owner = owner; /* 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); }