xref: /linux-6.15/include/linux/mdev.h (revision fbea4323)
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 <[email protected]>
7  *             Kirti Wankhede <[email protected]>
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 	struct device *iommu_device;
22 	bool active;
23 };
24 
25 static inline struct mdev_device *to_mdev_device(struct device *dev)
26 {
27 	return container_of(dev, struct mdev_device, dev);
28 }
29 
30 /*
31  * Called by the parent device driver to set the device which represents
32  * this mdev in iommu protection scope. By default, the iommu device is
33  * NULL, that indicates using vendor defined isolation.
34  *
35  * @dev: the mediated device that iommu will isolate.
36  * @iommu_device: a pci device which represents the iommu for @dev.
37  */
38 static inline void mdev_set_iommu_device(struct mdev_device *mdev,
39 					 struct device *iommu_device)
40 {
41 	mdev->iommu_device = iommu_device;
42 }
43 
44 static inline struct device *mdev_get_iommu_device(struct mdev_device *mdev)
45 {
46 	return mdev->iommu_device;
47 }
48 
49 /**
50  * struct mdev_parent_ops - Structure to be registered for each parent device to
51  * register the device to mdev module.
52  *
53  * @owner:		The module owner.
54  * @dev_attr_groups:	Attributes of the parent device.
55  * @mdev_attr_groups:	Attributes of the mediated device.
56  * @supported_type_groups: Attributes to define supported types. It is mandatory
57  *			to provide supported types.
58  * @create:		Called to allocate basic resources in parent device's
59  *			driver for a particular mediated device. It is
60  *			mandatory to provide create ops.
61  *			@kobj: kobject of type for which 'create' is called.
62  *			@mdev: mdev_device structure on of mediated device
63  *			      that is being created
64  *			Returns integer: success (0) or error (< 0)
65  * @remove:		Called to free resources in parent device's driver for
66  *			a mediated device. It is mandatory to provide 'remove'
67  *			ops.
68  *			@mdev: mdev_device device structure which is being
69  *			       destroyed
70  *			Returns integer: success (0) or error (< 0)
71  * @open:		Open mediated device.
72  *			@mdev: mediated device.
73  *			Returns integer: success (0) or error (< 0)
74  * @release:		release mediated device
75  *			@mdev: mediated device.
76  * @read:		Read emulation callback
77  *			@mdev: mediated device structure
78  *			@buf: read buffer
79  *			@count: number of bytes to read
80  *			@ppos: address.
81  *			Retuns number on bytes read on success or error.
82  * @write:		Write emulation callback
83  *			@mdev: mediated device structure
84  *			@buf: write buffer
85  *			@count: number of bytes to be written
86  *			@ppos: address.
87  *			Retuns number on bytes written on success or error.
88  * @ioctl:		IOCTL callback
89  *			@mdev: mediated device structure
90  *			@cmd: ioctl command
91  *			@arg: arguments to ioctl
92  * @mmap:		mmap callback
93  *			@mdev: mediated device structure
94  *			@vma: vma structure
95  * @request:		request callback to release device
96  *			@mdev: mediated device structure
97  *			@count: request sequence number
98  * Parent device that support mediated device should be registered with mdev
99  * module with mdev_parent_ops structure.
100  **/
101 struct mdev_parent_ops {
102 	struct module   *owner;
103 	const struct attribute_group **dev_attr_groups;
104 	const struct attribute_group **mdev_attr_groups;
105 	struct attribute_group **supported_type_groups;
106 
107 	int     (*create)(struct kobject *kobj, struct mdev_device *mdev);
108 	int     (*remove)(struct mdev_device *mdev);
109 	int     (*open)(struct mdev_device *mdev);
110 	void    (*release)(struct mdev_device *mdev);
111 	ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
112 			size_t count, loff_t *ppos);
113 	ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
114 			 size_t count, loff_t *ppos);
115 	long	(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
116 			 unsigned long arg);
117 	int	(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
118 	void	(*request)(struct mdev_device *mdev, unsigned int count);
119 };
120 
121 /* interface for exporting mdev supported type attributes */
122 struct mdev_type_attribute {
123 	struct attribute attr;
124 	ssize_t (*show)(struct kobject *kobj, struct device *dev, char *buf);
125 	ssize_t (*store)(struct kobject *kobj, struct device *dev,
126 			 const char *buf, size_t count);
127 };
128 
129 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
130 struct mdev_type_attribute mdev_type_attr_##_name =		\
131 	__ATTR(_name, _mode, _show, _store)
132 #define MDEV_TYPE_ATTR_RW(_name) \
133 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
134 #define MDEV_TYPE_ATTR_RO(_name) \
135 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
136 #define MDEV_TYPE_ATTR_WO(_name) \
137 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
138 
139 /**
140  * struct mdev_driver - Mediated device driver
141  * @probe: called when new device created
142  * @remove: called when device removed
143  * @driver: device driver structure
144  *
145  **/
146 struct mdev_driver {
147 	int (*probe)(struct mdev_device *dev);
148 	void (*remove)(struct mdev_device *dev);
149 	struct device_driver driver;
150 };
151 
152 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
153 {
154 	return mdev->driver_data;
155 }
156 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
157 {
158 	mdev->driver_data = data;
159 }
160 static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
161 {
162 	return &mdev->uuid;
163 }
164 
165 extern struct bus_type mdev_bus_type;
166 
167 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
168 void mdev_unregister_device(struct device *dev);
169 
170 int mdev_register_driver(struct mdev_driver *drv);
171 void mdev_unregister_driver(struct mdev_driver *drv);
172 
173 struct device *mdev_parent_dev(struct mdev_device *mdev);
174 static inline struct device *mdev_dev(struct mdev_device *mdev)
175 {
176 	return &mdev->dev;
177 }
178 static inline struct mdev_device *mdev_from_dev(struct device *dev)
179 {
180 	return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
181 }
182 
183 #endif /* MDEV_H */
184