xref: /linux-6.15/include/linux/mdev.h (revision 2fd585f4)
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 mdev_type *mtype);
51 struct device *mtype_get_parent_dev(struct mdev_type *mtype);
52 
53 /**
54  * struct mdev_parent_ops - Structure to be registered for each parent device to
55  * register the device to mdev module.
56  *
57  * @owner:		The module owner.
58  * @device_driver:	Which device driver to probe() on newly created devices
59  * @dev_attr_groups:	Attributes of the parent device.
60  * @mdev_attr_groups:	Attributes of the mediated device.
61  * @supported_type_groups: Attributes to define supported types. It is mandatory
62  *			to provide supported types.
63  * @create:		Called to allocate basic resources in parent device's
64  *			driver for a particular mediated device. It is
65  *			mandatory to provide create ops.
66  *			@mdev: mdev_device structure on of mediated device
67  *			      that is being created
68  *			Returns integer: success (0) or error (< 0)
69  * @remove:		Called to free resources in parent device's driver for
70  *			a mediated device. It is mandatory to provide 'remove'
71  *			ops.
72  *			@mdev: mdev_device device structure which is being
73  *			       destroyed
74  *			Returns integer: success (0) or error (< 0)
75  * @open:		Open mediated device.
76  *			@mdev: mediated device.
77  *			Returns integer: success (0) or error (< 0)
78  * @release:		release mediated device
79  *			@mdev: mediated device.
80  * @read:		Read emulation callback
81  *			@mdev: mediated device structure
82  *			@buf: read buffer
83  *			@count: number of bytes to read
84  *			@ppos: address.
85  *			Retuns number on bytes read on success or error.
86  * @write:		Write emulation callback
87  *			@mdev: mediated device structure
88  *			@buf: write buffer
89  *			@count: number of bytes to be written
90  *			@ppos: address.
91  *			Retuns number on bytes written on success or error.
92  * @ioctl:		IOCTL callback
93  *			@mdev: mediated device structure
94  *			@cmd: ioctl command
95  *			@arg: arguments to ioctl
96  * @mmap:		mmap callback
97  *			@mdev: mediated device structure
98  *			@vma: vma structure
99  * @request:		request callback to release device
100  *			@mdev: mediated device structure
101  *			@count: request sequence number
102  * Parent device that support mediated device should be registered with mdev
103  * module with mdev_parent_ops structure.
104  **/
105 struct mdev_parent_ops {
106 	struct module   *owner;
107 	struct mdev_driver *device_driver;
108 	const struct attribute_group **dev_attr_groups;
109 	const struct attribute_group **mdev_attr_groups;
110 	struct attribute_group **supported_type_groups;
111 
112 	int     (*create)(struct mdev_device *mdev);
113 	int     (*remove)(struct mdev_device *mdev);
114 	int     (*open_device)(struct mdev_device *mdev);
115 	void    (*close_device)(struct mdev_device *mdev);
116 	int     (*open)(struct mdev_device *mdev);
117 	void    (*release)(struct mdev_device *mdev);
118 	ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
119 			size_t count, loff_t *ppos);
120 	ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
121 			 size_t count, loff_t *ppos);
122 	long	(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
123 			 unsigned long arg);
124 	int	(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
125 	void	(*request)(struct mdev_device *mdev, unsigned int count);
126 };
127 
128 /* interface for exporting mdev supported type attributes */
129 struct mdev_type_attribute {
130 	struct attribute attr;
131 	ssize_t (*show)(struct mdev_type *mtype,
132 			struct mdev_type_attribute *attr, char *buf);
133 	ssize_t (*store)(struct mdev_type *mtype,
134 			 struct mdev_type_attribute *attr, const char *buf,
135 			 size_t count);
136 };
137 
138 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
139 struct mdev_type_attribute mdev_type_attr_##_name =		\
140 	__ATTR(_name, _mode, _show, _store)
141 #define MDEV_TYPE_ATTR_RW(_name) \
142 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
143 #define MDEV_TYPE_ATTR_RO(_name) \
144 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
145 #define MDEV_TYPE_ATTR_WO(_name) \
146 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
147 
148 /**
149  * struct mdev_driver - Mediated device driver
150  * @probe: called when new device created
151  * @remove: called when device removed
152  * @driver: device driver structure
153  *
154  **/
155 struct mdev_driver {
156 	int (*probe)(struct mdev_device *dev);
157 	void (*remove)(struct mdev_device *dev);
158 	struct device_driver driver;
159 };
160 
161 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
162 {
163 	return mdev->driver_data;
164 }
165 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
166 {
167 	mdev->driver_data = data;
168 }
169 static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
170 {
171 	return &mdev->uuid;
172 }
173 
174 extern struct bus_type mdev_bus_type;
175 
176 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
177 void mdev_unregister_device(struct device *dev);
178 
179 int mdev_register_driver(struct mdev_driver *drv);
180 void mdev_unregister_driver(struct mdev_driver *drv);
181 
182 struct device *mdev_parent_dev(struct mdev_device *mdev);
183 static inline struct device *mdev_dev(struct mdev_device *mdev)
184 {
185 	return &mdev->dev;
186 }
187 static inline struct mdev_device *mdev_from_dev(struct device *dev)
188 {
189 	return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
190 }
191 
192 #endif /* MDEV_H */
193