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linux
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
20#define DRIVER_VERSION "0.1"
21#define DRIVER_AUTHOR "NVIDIA Corporation"
22#define DRIVER_DESC "VFIO based driver for Mediated device"
23
24static int vfio_mdev_open(void *device_data)
25{
26 struct mdev_device *mdev = device_data;
27 struct mdev_parent *parent = mdev->parent;
28 int ret;
29
30 if (unlikely(!parent->ops->open))
31 return -EINVAL;
32
33 if (!try_module_get(THIS_MODULE))
34 return -ENODEV;
35
36 ret = parent->ops->open(mdev);
37 if (ret)
38 module_put(THIS_MODULE);
39
40 return ret;
41}
42
43static void vfio_mdev_release(void *device_data)
44{
45 struct mdev_device *mdev = device_data;
46 struct mdev_parent *parent = mdev->parent;
47
48 if (likely(parent->ops->release))
49 parent->ops->release(mdev);
50
51 module_put(THIS_MODULE);
52}
53
54static long vfio_mdev_unlocked_ioctl(void *device_data,
55 unsigned int cmd, unsigned long arg)
56{
57 struct mdev_device *mdev = device_data;
58 struct mdev_parent *parent = mdev->parent;
59
60 if (unlikely(!parent->ops->ioctl))
61 return -EINVAL;
62
63 return parent->ops->ioctl(mdev, cmd, arg);
64}
65
66static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
67 size_t count, loff_t *ppos)
68{
69 struct mdev_device *mdev = device_data;
70 struct mdev_parent *parent = mdev->parent;
71
72 if (unlikely(!parent->ops->read))
73 return -EINVAL;
74
75 return parent->ops->read(mdev, buf, count, ppos);
76}
77
78static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
79 size_t count, loff_t *ppos)
80{
81 struct mdev_device *mdev = device_data;
82 struct mdev_parent *parent = mdev->parent;
83
84 if (unlikely(!parent->ops->write))
85 return -EINVAL;
86
87 return parent->ops->write(mdev, buf, count, ppos);
88}
89
90static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
91{
92 struct mdev_device *mdev = device_data;
93 struct mdev_parent *parent = mdev->parent;
94
95 if (unlikely(!parent->ops->mmap))
96 return -EINVAL;
97
98 return parent->ops->mmap(mdev, vma);
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};
110
111static int vfio_mdev_probe(struct device *dev)
112{
113 struct mdev_device *mdev = to_mdev_device(dev);
114
115 return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
116}
117
118static void vfio_mdev_remove(struct device *dev)
119{
120 vfio_del_group_dev(dev);
121}
122
123static struct mdev_driver vfio_mdev_driver = {
124 .name = "vfio_mdev",
125 .probe = vfio_mdev_probe,
126 .remove = vfio_mdev_remove,
127};
128
129static int __init vfio_mdev_init(void)
130{
131 return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE);
132}
133
134static void __exit vfio_mdev_exit(void)
135{
136 mdev_unregister_driver(&vfio_mdev_driver);
137}
138
139module_init(vfio_mdev_init)
140module_exit(vfio_mdev_exit)
141
142MODULE_VERSION(DRIVER_VERSION);
143MODULE_LICENSE("GPL v2");
144MODULE_AUTHOR(DRIVER_AUTHOR);
145MODULE_DESCRIPTION(DRIVER_DESC);