tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
16static 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
34static 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
40static int mdev_probe(struct device *dev)
41{
42 struct mdev_driver *drv =
43 container_of(dev->driver, struct mdev_driver, driver);
44 struct mdev_device *mdev = to_mdev_device(dev);
45 int ret;
46
47 ret = mdev_attach_iommu(mdev);
48 if (ret)
49 return ret;
50
51 if (drv->probe) {
52 ret = drv->probe(mdev);
53 if (ret)
54 mdev_detach_iommu(mdev);
55 }
56
57 return ret;
58}
59
60static void mdev_remove(struct device *dev)
61{
62 struct mdev_driver *drv =
63 container_of(dev->driver, struct mdev_driver, driver);
64 struct mdev_device *mdev = to_mdev_device(dev);
65
66 if (drv->remove)
67 drv->remove(mdev);
68
69 mdev_detach_iommu(mdev);
70}
71
72static int mdev_match(struct device *dev, struct device_driver *drv)
73{
74 /*
75 * No drivers automatically match. Drivers are only bound by explicit
76 * device_driver_attach()
77 */
78 return 0;
79}
80
81struct bus_type mdev_bus_type = {
82 .name = "mdev",
83 .probe = mdev_probe,
84 .remove = mdev_remove,
85 .match = mdev_match,
86};
87EXPORT_SYMBOL_GPL(mdev_bus_type);
88
89/**
90 * mdev_register_driver - register a new MDEV driver
91 * @drv: the driver to register
92 *
93 * Returns a negative value on error, otherwise 0.
94 **/
95int mdev_register_driver(struct mdev_driver *drv)
96{
97 /* initialize common driver fields */
98 drv->driver.bus = &mdev_bus_type;
99
100 /* register with core */
101 return driver_register(&drv->driver);
102}
103EXPORT_SYMBOL(mdev_register_driver);
104
105/*
106 * mdev_unregister_driver - unregister MDEV driver
107 * @drv: the driver to unregister
108 */
109void mdev_unregister_driver(struct mdev_driver *drv)
110{
111 driver_unregister(&drv->driver);
112}
113EXPORT_SYMBOL(mdev_unregister_driver);
114
115int mdev_bus_register(void)
116{
117 return bus_register(&mdev_bus_type);
118}
119
120void mdev_bus_unregister(void)
121{
122 bus_unregister(&mdev_bus_type);
123}