1 /*
2 * MDEV driver
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/device.h>
14 #include <linux/iommu.h>
15 #include <linux/mdev.h>
16
17 #include "mdev_private.h"
18
mdev_attach_iommu(struct mdev_device * mdev)19 static int mdev_attach_iommu(struct mdev_device *mdev)
20 {
21 int ret;
22 struct iommu_group *group;
23
24 group = iommu_group_alloc();
25 if (IS_ERR(group))
26 return PTR_ERR(group);
27
28 ret = iommu_group_add_device(group, &mdev->dev);
29 if (!ret)
30 dev_info(&mdev->dev, "MDEV: group_id = %d\n",
31 iommu_group_id(group));
32
33 iommu_group_put(group);
34 return ret;
35 }
36
mdev_detach_iommu(struct mdev_device * mdev)37 static void mdev_detach_iommu(struct mdev_device *mdev)
38 {
39 iommu_group_remove_device(&mdev->dev);
40 dev_info(&mdev->dev, "MDEV: detaching iommu\n");
41 }
42
mdev_probe(struct device * dev)43 static int mdev_probe(struct device *dev)
44 {
45 struct mdev_driver *drv = to_mdev_driver(dev->driver);
46 struct mdev_device *mdev = to_mdev_device(dev);
47 int ret;
48
49 ret = mdev_attach_iommu(mdev);
50 if (ret)
51 return ret;
52
53 if (drv && drv->probe) {
54 ret = drv->probe(dev);
55 if (ret)
56 mdev_detach_iommu(mdev);
57 }
58
59 return ret;
60 }
61
mdev_remove(struct device * dev)62 static int mdev_remove(struct device *dev)
63 {
64 struct mdev_driver *drv = to_mdev_driver(dev->driver);
65 struct mdev_device *mdev = to_mdev_device(dev);
66
67 if (drv && drv->remove)
68 drv->remove(dev);
69
70 mdev_detach_iommu(mdev);
71
72 return 0;
73 }
74
75 struct bus_type mdev_bus_type = {
76 .name = "mdev",
77 .probe = mdev_probe,
78 .remove = mdev_remove,
79 };
80 EXPORT_SYMBOL_GPL(mdev_bus_type);
81
82 /**
83 * mdev_register_driver - register a new MDEV driver
84 * @drv: the driver to register
85 * @owner: module owner of driver to be registered
86 *
87 * Returns a negative value on error, otherwise 0.
88 **/
mdev_register_driver(struct mdev_driver * drv,struct module * owner)89 int mdev_register_driver(struct mdev_driver *drv, struct module *owner)
90 {
91 /* initialize common driver fields */
92 drv->driver.name = drv->name;
93 drv->driver.bus = &mdev_bus_type;
94 drv->driver.owner = owner;
95
96 /* register with core */
97 return driver_register(&drv->driver);
98 }
99 EXPORT_SYMBOL(mdev_register_driver);
100
101 /*
102 * mdev_unregister_driver - unregister MDEV driver
103 * @drv: the driver to unregister
104 */
mdev_unregister_driver(struct mdev_driver * drv)105 void mdev_unregister_driver(struct mdev_driver *drv)
106 {
107 driver_unregister(&drv->driver);
108 }
109 EXPORT_SYMBOL(mdev_unregister_driver);
110
mdev_bus_register(void)111 int mdev_bus_register(void)
112 {
113 return bus_register(&mdev_bus_type);
114 }
115
mdev_bus_unregister(void)116 void mdev_bus_unregister(void)
117 {
118 bus_unregister(&mdev_bus_type);
119 }
120
