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
vfio_mdev_open(void * device_data)24 static 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
vfio_mdev_release(void * device_data)43 static 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
vfio_mdev_unlocked_ioctl(void * device_data,unsigned int cmd,unsigned long arg)54 static 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
vfio_mdev_read(void * device_data,char __user * buf,size_t count,loff_t * ppos)66 static 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
vfio_mdev_write(void * device_data,const char __user * buf,size_t count,loff_t * ppos)78 static 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
vfio_mdev_mmap(void * device_data,struct vm_area_struct * vma)90 static 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
101 static 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
vfio_mdev_probe(struct device * dev)111 static 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
vfio_mdev_remove(struct device * dev)118 static void vfio_mdev_remove(struct device *dev)
119 {
120 vfio_del_group_dev(dev);
121 }
122
123 static struct mdev_driver vfio_mdev_driver = {
124 .name = "vfio_mdev",
125 .probe = vfio_mdev_probe,
126 .remove = vfio_mdev_remove,
127 };
128
vfio_mdev_init(void)129 static int __init vfio_mdev_init(void)
130 {
131 return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE);
132 }
133
vfio_mdev_exit(void)134 static void __exit vfio_mdev_exit(void)
135 {
136 mdev_unregister_driver(&vfio_mdev_driver);
137 }
138
139 module_init(vfio_mdev_init)
140 module_exit(vfio_mdev_exit)
141
142 MODULE_VERSION(DRIVER_VERSION);
143 MODULE_LICENSE("GPL v2");
144 MODULE_AUTHOR(DRIVER_AUTHOR);
145 MODULE_DESCRIPTION(DRIVER_DESC);
146