xref: /linux/include/linux/mdev.h (revision cbac924200b838cfb8d8b1415113d788089dc50b)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Mediated device definition
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 #ifndef MDEV_H
11 #define MDEV_H
12 
13 struct mdev_type;
14 
15 struct mdev_device {
16 	struct device dev;
17 	guid_t uuid;
18 	void *driver_data;
19 	struct list_head next;
20 	struct mdev_type *type;
21 	bool active;
22 };
23 
24 static inline struct mdev_device *to_mdev_device(struct device *dev)
25 {
26 	return container_of(dev, struct mdev_device, dev);
27 }
28 
29 unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
30 unsigned int mtype_get_type_group_id(struct mdev_type *mtype);
31 struct device *mtype_get_parent_dev(struct mdev_type *mtype);
32 
33 /**
34  * struct mdev_parent_ops - Structure to be registered for each parent device to
35  * register the device to mdev module.
36  *
37  * @owner:		The module owner.
38  * @device_driver:	Which device driver to probe() on newly created devices
39  * @dev_attr_groups:	Attributes of the parent device.
40  * @mdev_attr_groups:	Attributes of the mediated device.
41  * @supported_type_groups: Attributes to define supported types. It is mandatory
42  *			to provide supported types.
43  * @create:		Called to allocate basic resources in parent device's
44  *			driver for a particular mediated device. It is
45  *			mandatory to provide create ops.
46  *			@mdev: mdev_device structure on of mediated device
47  *			      that is being created
48  *			Returns integer: success (0) or error (< 0)
49  * @remove:		Called to free resources in parent device's driver for
50  *			a mediated device. It is mandatory to provide 'remove'
51  *			ops.
52  *			@mdev: mdev_device device structure which is being
53  *			       destroyed
54  *			Returns integer: success (0) or error (< 0)
55  * @read:		Read emulation callback
56  *			@mdev: mediated device structure
57  *			@buf: read buffer
58  *			@count: number of bytes to read
59  *			@ppos: address.
60  *			Retuns number on bytes read on success or error.
61  * @write:		Write emulation callback
62  *			@mdev: mediated device structure
63  *			@buf: write buffer
64  *			@count: number of bytes to be written
65  *			@ppos: address.
66  *			Retuns number on bytes written on success or error.
67  * @ioctl:		IOCTL callback
68  *			@mdev: mediated device structure
69  *			@cmd: ioctl command
70  *			@arg: arguments to ioctl
71  * @mmap:		mmap callback
72  *			@mdev: mediated device structure
73  *			@vma: vma structure
74  * @request:		request callback to release device
75  *			@mdev: mediated device structure
76  *			@count: request sequence number
77  * Parent device that support mediated device should be registered with mdev
78  * module with mdev_parent_ops structure.
79  **/
80 struct mdev_parent_ops {
81 	struct module   *owner;
82 	struct mdev_driver *device_driver;
83 	const struct attribute_group **dev_attr_groups;
84 	const struct attribute_group **mdev_attr_groups;
85 	struct attribute_group **supported_type_groups;
86 
87 	int     (*create)(struct mdev_device *mdev);
88 	int     (*remove)(struct mdev_device *mdev);
89 	int     (*open_device)(struct mdev_device *mdev);
90 	void    (*close_device)(struct mdev_device *mdev);
91 	ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
92 			size_t count, loff_t *ppos);
93 	ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
94 			 size_t count, loff_t *ppos);
95 	long	(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
96 			 unsigned long arg);
97 	int	(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
98 	void	(*request)(struct mdev_device *mdev, unsigned int count);
99 };
100 
101 /* interface for exporting mdev supported type attributes */
102 struct mdev_type_attribute {
103 	struct attribute attr;
104 	ssize_t (*show)(struct mdev_type *mtype,
105 			struct mdev_type_attribute *attr, char *buf);
106 	ssize_t (*store)(struct mdev_type *mtype,
107 			 struct mdev_type_attribute *attr, const char *buf,
108 			 size_t count);
109 };
110 
111 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
112 struct mdev_type_attribute mdev_type_attr_##_name =		\
113 	__ATTR(_name, _mode, _show, _store)
114 #define MDEV_TYPE_ATTR_RW(_name) \
115 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
116 #define MDEV_TYPE_ATTR_RO(_name) \
117 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
118 #define MDEV_TYPE_ATTR_WO(_name) \
119 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
120 
121 /**
122  * struct mdev_driver - Mediated device driver
123  * @probe: called when new device created
124  * @remove: called when device removed
125  * @driver: device driver structure
126  *
127  **/
128 struct mdev_driver {
129 	int (*probe)(struct mdev_device *dev);
130 	void (*remove)(struct mdev_device *dev);
131 	struct device_driver driver;
132 };
133 
134 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
135 {
136 	return mdev->driver_data;
137 }
138 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
139 {
140 	mdev->driver_data = data;
141 }
142 static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
143 {
144 	return &mdev->uuid;
145 }
146 
147 extern struct bus_type mdev_bus_type;
148 
149 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
150 void mdev_unregister_device(struct device *dev);
151 
152 int mdev_register_driver(struct mdev_driver *drv);
153 void mdev_unregister_driver(struct mdev_driver *drv);
154 
155 struct device *mdev_parent_dev(struct mdev_device *mdev);
156 static inline struct device *mdev_dev(struct mdev_device *mdev)
157 {
158 	return &mdev->dev;
159 }
160 static inline struct mdev_device *mdev_from_dev(struct device *dev)
161 {
162 	return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
163 }
164 
165 #endif /* MDEV_H */
166