1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MDEV driver
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/device.h>
11 #include <linux/iommu.h>
12 #include <linux/mdev.h>
13
14 #include "mdev_private.h"
15
mdev_attach_iommu(struct mdev_device * mdev)16 static int mdev_attach_iommu(struct mdev_device *mdev)
17 {
18 int ret;
19 struct iommu_group *group;
20
21 group = iommu_group_alloc();
22 if (IS_ERR(group))
23 return PTR_ERR(group);
24
25 ret = iommu_group_add_device(group, &mdev->dev);
26 if (!ret)
27 dev_info(&mdev->dev, "MDEV: group_id = %d\n",
28 iommu_group_id(group));
29
30 iommu_group_put(group);
31 return ret;
32 }
33
mdev_detach_iommu(struct mdev_device * mdev)34 static void mdev_detach_iommu(struct mdev_device *mdev)
35 {
36 iommu_group_remove_device(&mdev->dev);
37 dev_info(&mdev->dev, "MDEV: detaching iommu\n");
38 }
39
mdev_probe(struct device * dev)40 static int mdev_probe(struct device *dev)
41 {
42 struct mdev_driver *drv = to_mdev_driver(dev->driver);
43 struct mdev_device *mdev = to_mdev_device(dev);
44 int ret;
45
46 ret = mdev_attach_iommu(mdev);
47 if (ret)
48 return ret;
49
50 if (drv && drv->probe) {
51 ret = drv->probe(dev);
52 if (ret)
53 mdev_detach_iommu(mdev);
54 }
55
56 return ret;
57 }
58
mdev_remove(struct device * dev)59 static int mdev_remove(struct device *dev)
60 {
61 struct mdev_driver *drv = to_mdev_driver(dev->driver);
62 struct mdev_device *mdev = to_mdev_device(dev);
63
64 if (drv && drv->remove)
65 drv->remove(dev);
66
67 mdev_detach_iommu(mdev);
68
69 return 0;
70 }
71
72 struct bus_type mdev_bus_type = {
73 .name = "mdev",
74 .probe = mdev_probe,
75 .remove = mdev_remove,
76 };
77 EXPORT_SYMBOL_GPL(mdev_bus_type);
78
79 /**
80 * mdev_register_driver - register a new MDEV driver
81 * @drv: the driver to register
82 * @owner: module owner of driver to be registered
83 *
84 * Returns a negative value on error, otherwise 0.
85 **/
mdev_register_driver(struct mdev_driver * drv,struct module * owner)86 int mdev_register_driver(struct mdev_driver *drv, struct module *owner)
87 {
88 /* initialize common driver fields */
89 drv->driver.name = drv->name;
90 drv->driver.bus = &mdev_bus_type;
91 drv->driver.owner = owner;
92
93 /* register with core */
94 return driver_register(&drv->driver);
95 }
96 EXPORT_SYMBOL(mdev_register_driver);
97
98 /*
99 * mdev_unregister_driver - unregister MDEV driver
100 * @drv: the driver to unregister
101 */
mdev_unregister_driver(struct mdev_driver * drv)102 void mdev_unregister_driver(struct mdev_driver *drv)
103 {
104 driver_unregister(&drv->driver);
105 }
106 EXPORT_SYMBOL(mdev_unregister_driver);
107
mdev_bus_register(void)108 int mdev_bus_register(void)
109 {
110 return bus_register(&mdev_bus_type);
111 }
112
mdev_bus_unregister(void)113 void mdev_bus_unregister(void)
114 {
115 bus_unregister(&mdev_bus_type);
116 }
117