1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * VFIO based driver for Mediated device
  4 *
  5 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
  6 *     Author: Neo Jia <cjia@nvidia.com>
  7 *             Kirti Wankhede <kwankhede@nvidia.com>
  8 */
  9
 10#include <linux/init.h>
 11#include <linux/module.h>
 12#include <linux/device.h>
 13#include <linux/kernel.h>
 14#include <linux/slab.h>
 15#include <linux/vfio.h>
 16#include <linux/mdev.h>
 17
 18#include "mdev_private.h"
 19
 20static int vfio_mdev_open(struct vfio_device *core_vdev)
 21{
 22	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 23	struct mdev_parent *parent = mdev->type->parent;
 24
 25	if (unlikely(!parent->ops->open))
 26		return -EINVAL;
 27
 28	return parent->ops->open(mdev);
 29}
 30
 31static void vfio_mdev_release(struct vfio_device *core_vdev)
 32{
 33	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 34	struct mdev_parent *parent = mdev->type->parent;
 35
 36	if (likely(parent->ops->release))
 37		parent->ops->release(mdev);
 38}
 39
 40static long vfio_mdev_unlocked_ioctl(struct vfio_device *core_vdev,
 41				     unsigned int cmd, unsigned long arg)
 42{
 43	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 44	struct mdev_parent *parent = mdev->type->parent;
 45
 46	if (unlikely(!parent->ops->ioctl))
 47		return -EINVAL;
 48
 49	return parent->ops->ioctl(mdev, cmd, arg);
 50}
 51
 52static ssize_t vfio_mdev_read(struct vfio_device *core_vdev, char __user *buf,
 53			      size_t count, loff_t *ppos)
 54{
 55	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 56	struct mdev_parent *parent = mdev->type->parent;
 57
 58	if (unlikely(!parent->ops->read))
 59		return -EINVAL;
 60
 61	return parent->ops->read(mdev, buf, count, ppos);
 62}
 63
 64static ssize_t vfio_mdev_write(struct vfio_device *core_vdev,
 65			       const char __user *buf, size_t count,
 66			       loff_t *ppos)
 67{
 68	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 69	struct mdev_parent *parent = mdev->type->parent;
 70
 71	if (unlikely(!parent->ops->write))
 72		return -EINVAL;
 73
 74	return parent->ops->write(mdev, buf, count, ppos);
 75}
 76
 77static int vfio_mdev_mmap(struct vfio_device *core_vdev,
 78			  struct vm_area_struct *vma)
 79{
 80	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 81	struct mdev_parent *parent = mdev->type->parent;
 82
 83	if (unlikely(!parent->ops->mmap))
 84		return -EINVAL;
 85
 86	return parent->ops->mmap(mdev, vma);
 87}
 88
 89static void vfio_mdev_request(struct vfio_device *core_vdev, unsigned int count)
 90{
 91	struct mdev_device *mdev = to_mdev_device(core_vdev->dev);
 92	struct mdev_parent *parent = mdev->type->parent;
 93
 94	if (parent->ops->request)
 95		parent->ops->request(mdev, count);
 96	else if (count == 0)
 97		dev_notice(mdev_dev(mdev),
 98			   "No mdev vendor driver request callback support, blocked until released by user\n");
 99}
100
101static const struct vfio_device_ops vfio_mdev_dev_ops = {
102	.name		= "vfio-mdev",
103	.open		= vfio_mdev_open,
104	.release	= vfio_mdev_release,
105	.ioctl		= vfio_mdev_unlocked_ioctl,
106	.read		= vfio_mdev_read,
107	.write		= vfio_mdev_write,
108	.mmap		= vfio_mdev_mmap,
109	.request	= vfio_mdev_request,
110};
111
112static int vfio_mdev_probe(struct mdev_device *mdev)
113{
114	struct vfio_device *vdev;
115	int ret;
116
117	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
118	if (!vdev)
119		return -ENOMEM;
120
121	vfio_init_group_dev(vdev, &mdev->dev, &vfio_mdev_dev_ops);
122	ret = vfio_register_group_dev(vdev);
123	if (ret) {
124		kfree(vdev);
125		return ret;
126	}
127	dev_set_drvdata(&mdev->dev, vdev);
128	return 0;
129}
130
131static void vfio_mdev_remove(struct mdev_device *mdev)
132{
133	struct vfio_device *vdev = dev_get_drvdata(&mdev->dev);
134
135	vfio_unregister_group_dev(vdev);
136	kfree(vdev);
137}
138
139struct mdev_driver vfio_mdev_driver = {
140	.driver = {
141		.name = "vfio_mdev",
142		.owner = THIS_MODULE,
143		.mod_name = KBUILD_MODNAME,
144	},
145	.probe	= vfio_mdev_probe,
146	.remove	= vfio_mdev_remove,
147};