xref: /linux-6.15/include/linux/mdev.h (revision 15fcc44b)
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 unsigned int mdev_get_type_group_id(struct mdev_device *mdev);
50 unsigned int mtype_get_type_group_id(struct kobject *mtype_kobj);
51 
52 /**
53  * struct mdev_parent_ops - Structure to be registered for each parent device to
54  * register the device to mdev module.
55  *
56  * @owner:		The module owner.
57  * @dev_attr_groups:	Attributes of the parent device.
58  * @mdev_attr_groups:	Attributes of the mediated device.
59  * @supported_type_groups: Attributes to define supported types. It is mandatory
60  *			to provide supported types.
61  * @create:		Called to allocate basic resources in parent device's
62  *			driver for a particular mediated device. It is
63  *			mandatory to provide create ops.
64  *			@kobj: kobject of type for which 'create' is called.
65  *			@mdev: mdev_device structure on of mediated device
66  *			      that is being created
67  *			Returns integer: success (0) or error (< 0)
68  * @remove:		Called to free resources in parent device's driver for
69  *			a mediated device. It is mandatory to provide 'remove'
70  *			ops.
71  *			@mdev: mdev_device device structure which is being
72  *			       destroyed
73  *			Returns integer: success (0) or error (< 0)
74  * @open:		Open mediated device.
75  *			@mdev: mediated device.
76  *			Returns integer: success (0) or error (< 0)
77  * @release:		release mediated device
78  *			@mdev: mediated device.
79  * @read:		Read emulation callback
80  *			@mdev: mediated device structure
81  *			@buf: read buffer
82  *			@count: number of bytes to read
83  *			@ppos: address.
84  *			Retuns number on bytes read on success or error.
85  * @write:		Write emulation callback
86  *			@mdev: mediated device structure
87  *			@buf: write buffer
88  *			@count: number of bytes to be written
89  *			@ppos: address.
90  *			Retuns number on bytes written on success or error.
91  * @ioctl:		IOCTL callback
92  *			@mdev: mediated device structure
93  *			@cmd: ioctl command
94  *			@arg: arguments to ioctl
95  * @mmap:		mmap callback
96  *			@mdev: mediated device structure
97  *			@vma: vma structure
98  * @request:		request callback to release device
99  *			@mdev: mediated device structure
100  *			@count: request sequence number
101  * Parent device that support mediated device should be registered with mdev
102  * module with mdev_parent_ops structure.
103  **/
104 struct mdev_parent_ops {
105 	struct module   *owner;
106 	const struct attribute_group **dev_attr_groups;
107 	const struct attribute_group **mdev_attr_groups;
108 	struct attribute_group **supported_type_groups;
109 
110 	int     (*create)(struct kobject *kobj, struct mdev_device *mdev);
111 	int     (*remove)(struct mdev_device *mdev);
112 	int     (*open)(struct mdev_device *mdev);
113 	void    (*release)(struct mdev_device *mdev);
114 	ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
115 			size_t count, loff_t *ppos);
116 	ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
117 			 size_t count, loff_t *ppos);
118 	long	(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
119 			 unsigned long arg);
120 	int	(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
121 	void	(*request)(struct mdev_device *mdev, unsigned int count);
122 };
123 
124 /* interface for exporting mdev supported type attributes */
125 struct mdev_type_attribute {
126 	struct attribute attr;
127 	ssize_t (*show)(struct kobject *kobj, struct device *dev, char *buf);
128 	ssize_t (*store)(struct kobject *kobj, struct device *dev,
129 			 const char *buf, size_t count);
130 };
131 
132 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
133 struct mdev_type_attribute mdev_type_attr_##_name =		\
134 	__ATTR(_name, _mode, _show, _store)
135 #define MDEV_TYPE_ATTR_RW(_name) \
136 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
137 #define MDEV_TYPE_ATTR_RO(_name) \
138 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
139 #define MDEV_TYPE_ATTR_WO(_name) \
140 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
141 
142 /**
143  * struct mdev_driver - Mediated device driver
144  * @probe: called when new device created
145  * @remove: called when device removed
146  * @driver: device driver structure
147  *
148  **/
149 struct mdev_driver {
150 	int (*probe)(struct mdev_device *dev);
151 	void (*remove)(struct mdev_device *dev);
152 	struct device_driver driver;
153 };
154 
155 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
156 {
157 	return mdev->driver_data;
158 }
159 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
160 {
161 	mdev->driver_data = data;
162 }
163 static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
164 {
165 	return &mdev->uuid;
166 }
167 
168 extern struct bus_type mdev_bus_type;
169 
170 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
171 void mdev_unregister_device(struct device *dev);
172 
173 int mdev_register_driver(struct mdev_driver *drv);
174 void mdev_unregister_driver(struct mdev_driver *drv);
175 
176 struct device *mdev_parent_dev(struct mdev_device *mdev);
177 static inline struct device *mdev_dev(struct mdev_device *mdev)
178 {
179 	return &mdev->dev;
180 }
181 static inline struct mdev_device *mdev_from_dev(struct device *dev)
182 {
183 	return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
184 }
185 
186 #endif /* MDEV_H */
187