xref: /linux/include/linux/mdev.h (revision 8ce936c2f1a68c3a4f46578eed016ff92a67fbc6)
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 	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  * @read:		Read emulation callback
76  *			@mdev: mediated device structure
77  *			@buf: read buffer
78  *			@count: number of bytes to read
79  *			@ppos: address.
80  *			Retuns number on bytes read on success or error.
81  * @write:		Write emulation callback
82  *			@mdev: mediated device structure
83  *			@buf: write buffer
84  *			@count: number of bytes to be written
85  *			@ppos: address.
86  *			Retuns number on bytes written on success or error.
87  * @ioctl:		IOCTL callback
88  *			@mdev: mediated device structure
89  *			@cmd: ioctl command
90  *			@arg: arguments to ioctl
91  * @mmap:		mmap callback
92  *			@mdev: mediated device structure
93  *			@vma: vma structure
94  * @request:		request callback to release device
95  *			@mdev: mediated device structure
96  *			@count: request sequence number
97  * Parent device that support mediated device should be registered with mdev
98  * module with mdev_parent_ops structure.
99  **/
100 struct mdev_parent_ops {
101 	struct module   *owner;
102 	struct mdev_driver *device_driver;
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 mdev_device *mdev);
108 	int     (*remove)(struct mdev_device *mdev);
109 	int     (*open_device)(struct mdev_device *mdev);
110 	void    (*close_device)(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 mdev_type *mtype,
125 			struct mdev_type_attribute *attr, char *buf);
126 	ssize_t (*store)(struct mdev_type *mtype,
127 			 struct mdev_type_attribute *attr, const char *buf,
128 			 size_t count);
129 };
130 
131 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
132 struct mdev_type_attribute mdev_type_attr_##_name =		\
133 	__ATTR(_name, _mode, _show, _store)
134 #define MDEV_TYPE_ATTR_RW(_name) \
135 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
136 #define MDEV_TYPE_ATTR_RO(_name) \
137 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
138 #define MDEV_TYPE_ATTR_WO(_name) \
139 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
140 
141 /**
142  * struct mdev_driver - Mediated device driver
143  * @probe: called when new device created
144  * @remove: called when device removed
145  * @driver: device driver structure
146  *
147  **/
148 struct mdev_driver {
149 	int (*probe)(struct mdev_device *dev);
150 	void (*remove)(struct mdev_device *dev);
151 	struct device_driver driver;
152 };
153 
154 static inline void *mdev_get_drvdata(struct mdev_device *mdev)
155 {
156 	return mdev->driver_data;
157 }
158 static inline void mdev_set_drvdata(struct mdev_device *mdev, void *data)
159 {
160 	mdev->driver_data = data;
161 }
162 static inline const guid_t *mdev_uuid(struct mdev_device *mdev)
163 {
164 	return &mdev->uuid;
165 }
166 
167 extern struct bus_type mdev_bus_type;
168 
169 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
170 void mdev_unregister_device(struct device *dev);
171 
172 int mdev_register_driver(struct mdev_driver *drv);
173 void mdev_unregister_driver(struct mdev_driver *drv);
174 
175 struct device *mdev_parent_dev(struct mdev_device *mdev);
176 static inline struct device *mdev_dev(struct mdev_device *mdev)
177 {
178 	return &mdev->dev;
179 }
180 static inline struct mdev_device *mdev_from_dev(struct device *dev)
181 {
182 	return dev->bus == &mdev_bus_type ? to_mdev_device(dev) : NULL;
183 }
184 
185 #endif /* MDEV_H */
186