1 /*
2 * VFIO based driver for Mediated device
3 *
4 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
5 * Author: Neo Jia <cjia@nvidia.com>
6 * Kirti Wankhede <kwankhede@nvidia.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/device.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18 #include <linux/vfio.h>
19 #include <linux/mdev.h>
20
21 #include "mdev_private.h"
22
23 #define DRIVER_VERSION "0.1"
24 #define DRIVER_AUTHOR "NVIDIA Corporation"
25 #define DRIVER_DESC "VFIO based driver for Mediated device"
26
vfio_mdev_open(void * device_data)27 static int vfio_mdev_open(void *device_data)
28 {
29 struct mdev_device *mdev = device_data;
30 struct mdev_parent *parent = mdev->parent;
31 int ret;
32
33 if (unlikely(!parent->ops->open))
34 return -EINVAL;
35
36 if (!try_module_get(THIS_MODULE))
37 return -ENODEV;
38
39 ret = parent->ops->open(mdev);
40 if (ret)
41 module_put(THIS_MODULE);
42
43 return ret;
44 }
45
vfio_mdev_release(void * device_data)46 static void vfio_mdev_release(void *device_data)
47 {
48 struct mdev_device *mdev = device_data;
49 struct mdev_parent *parent = mdev->parent;
50
51 if (likely(parent->ops->release))
52 parent->ops->release(mdev);
53
54 module_put(THIS_MODULE);
55 }
56
vfio_mdev_unlocked_ioctl(void * device_data,unsigned int cmd,unsigned long arg)57 static long vfio_mdev_unlocked_ioctl(void *device_data,
58 unsigned int cmd, unsigned long arg)
59 {
60 struct mdev_device *mdev = device_data;
61 struct mdev_parent *parent = mdev->parent;
62
63 if (unlikely(!parent->ops->ioctl))
64 return -EINVAL;
65
66 return parent->ops->ioctl(mdev, cmd, arg);
67 }
68
vfio_mdev_read(void * device_data,char __user * buf,size_t count,loff_t * ppos)69 static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
70 size_t count, loff_t *ppos)
71 {
72 struct mdev_device *mdev = device_data;
73 struct mdev_parent *parent = mdev->parent;
74
75 if (unlikely(!parent->ops->read))
76 return -EINVAL;
77
78 return parent->ops->read(mdev, buf, count, ppos);
79 }
80
vfio_mdev_write(void * device_data,const char __user * buf,size_t count,loff_t * ppos)81 static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
82 size_t count, loff_t *ppos)
83 {
84 struct mdev_device *mdev = device_data;
85 struct mdev_parent *parent = mdev->parent;
86
87 if (unlikely(!parent->ops->write))
88 return -EINVAL;
89
90 return parent->ops->write(mdev, buf, count, ppos);
91 }
92
vfio_mdev_mmap(void * device_data,struct vm_area_struct * vma)93 static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
94 {
95 struct mdev_device *mdev = device_data;
96 struct mdev_parent *parent = mdev->parent;
97
98 if (unlikely(!parent->ops->mmap))
99 return -EINVAL;
100
101 return parent->ops->mmap(mdev, vma);
102 }
103
104 static const struct vfio_device_ops vfio_mdev_dev_ops = {
105 .name = "vfio-mdev",
106 .open = vfio_mdev_open,
107 .release = vfio_mdev_release,
108 .ioctl = vfio_mdev_unlocked_ioctl,
109 .read = vfio_mdev_read,
110 .write = vfio_mdev_write,
111 .mmap = vfio_mdev_mmap,
112 };
113
vfio_mdev_probe(struct device * dev)114 static int vfio_mdev_probe(struct device *dev)
115 {
116 struct mdev_device *mdev = to_mdev_device(dev);
117
118 return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
119 }
120
vfio_mdev_remove(struct device * dev)121 static void vfio_mdev_remove(struct device *dev)
122 {
123 vfio_del_group_dev(dev);
124 }
125
126 static struct mdev_driver vfio_mdev_driver = {
127 .name = "vfio_mdev",
128 .probe = vfio_mdev_probe,
129 .remove = vfio_mdev_remove,
130 };
131
vfio_mdev_init(void)132 static int __init vfio_mdev_init(void)
133 {
134 return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE);
135 }
136
vfio_mdev_exit(void)137 static void __exit vfio_mdev_exit(void)
138 {
139 mdev_unregister_driver(&vfio_mdev_driver);
140 }
141
142 module_init(vfio_mdev_init)
143 module_exit(vfio_mdev_exit)
144
145 MODULE_VERSION(DRIVER_VERSION);
146 MODULE_LICENSE("GPL v2");
147 MODULE_AUTHOR(DRIVER_AUTHOR);
148 MODULE_DESCRIPTION(DRIVER_DESC);
149
