xref: /openbmc/linux/drivers/vfio/mdev/mdev_driver.c (revision 2cf1c348)
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 
16 static int mdev_probe(struct device *dev)
17 {
18 	struct mdev_driver *drv =
19 		container_of(dev->driver, struct mdev_driver, driver);
20 
21 	if (!drv->probe)
22 		return 0;
23 	return drv->probe(to_mdev_device(dev));
24 }
25 
26 static void mdev_remove(struct device *dev)
27 {
28 	struct mdev_driver *drv =
29 		container_of(dev->driver, struct mdev_driver, driver);
30 
31 	if (drv->remove)
32 		drv->remove(to_mdev_device(dev));
33 }
34 
35 static int mdev_match(struct device *dev, struct device_driver *drv)
36 {
37 	/*
38 	 * No drivers automatically match. Drivers are only bound by explicit
39 	 * device_driver_attach()
40 	 */
41 	return 0;
42 }
43 
44 struct bus_type mdev_bus_type = {
45 	.name		= "mdev",
46 	.probe		= mdev_probe,
47 	.remove		= mdev_remove,
48 	.match		= mdev_match,
49 };
50 EXPORT_SYMBOL_GPL(mdev_bus_type);
51 
52 /**
53  * mdev_register_driver - register a new MDEV driver
54  * @drv: the driver to register
55  *
56  * Returns a negative value on error, otherwise 0.
57  **/
58 int mdev_register_driver(struct mdev_driver *drv)
59 {
60 	/* initialize common driver fields */
61 	drv->driver.bus = &mdev_bus_type;
62 
63 	/* register with core */
64 	return driver_register(&drv->driver);
65 }
66 EXPORT_SYMBOL(mdev_register_driver);
67 
68 /*
69  * mdev_unregister_driver - unregister MDEV driver
70  * @drv: the driver to unregister
71  */
72 void mdev_unregister_driver(struct mdev_driver *drv)
73 {
74 	driver_unregister(&drv->driver);
75 }
76 EXPORT_SYMBOL(mdev_unregister_driver);
77 
78 int mdev_bus_register(void)
79 {
80 	return bus_register(&mdev_bus_type);
81 }
82 
83 void mdev_bus_unregister(void)
84 {
85 	bus_unregister(&mdev_bus_type);
86 }
87