xref: /linux/include/linux/mdev.h (revision 4fd18fc38757217c746aa063ba9e4729814dc737)
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_device;
14 
15 /*
16  * Called by the parent device driver to set the device which represents
17  * this mdev in iommu protection scope. By default, the iommu device is
18  * NULL, that indicates using vendor defined isolation.
19  *
20  * @dev: the mediated device that iommu will isolate.
21  * @iommu_device: a pci device which represents the iommu for @dev.
22  *
23  * Return 0 for success, otherwise negative error value.
24  */
25 int mdev_set_iommu_device(struct device *dev, struct device *iommu_device);
26 
27 struct device *mdev_get_iommu_device(struct device *dev);
28 
29 /**
30  * struct mdev_parent_ops - Structure to be registered for each parent device to
31  * register the device to mdev module.
32  *
33  * @owner:		The module owner.
34  * @dev_attr_groups:	Attributes of the parent device.
35  * @mdev_attr_groups:	Attributes of the mediated device.
36  * @supported_type_groups: Attributes to define supported types. It is mandatory
37  *			to provide supported types.
38  * @create:		Called to allocate basic resources in parent device's
39  *			driver for a particular mediated device. It is
40  *			mandatory to provide create ops.
41  *			@kobj: kobject of type for which 'create' is called.
42  *			@mdev: mdev_device structure on of mediated device
43  *			      that is being created
44  *			Returns integer: success (0) or error (< 0)
45  * @remove:		Called to free resources in parent device's driver for a
46  *			a mediated device. It is mandatory to provide 'remove'
47  *			ops.
48  *			@mdev: mdev_device device structure which is being
49  *			       destroyed
50  *			Returns integer: success (0) or error (< 0)
51  * @open:		Open mediated device.
52  *			@mdev: mediated device.
53  *			Returns integer: success (0) or error (< 0)
54  * @release:		release mediated device
55  *			@mdev: mediated device.
56  * @read:		Read emulation callback
57  *			@mdev: mediated device structure
58  *			@buf: read buffer
59  *			@count: number of bytes to read
60  *			@ppos: address.
61  *			Retuns number on bytes read on success or error.
62  * @write:		Write emulation callback
63  *			@mdev: mediated device structure
64  *			@buf: write buffer
65  *			@count: number of bytes to be written
66  *			@ppos: address.
67  *			Retuns number on bytes written on success or error.
68  * @ioctl:		IOCTL callback
69  *			@mdev: mediated device structure
70  *			@cmd: ioctl command
71  *			@arg: arguments to ioctl
72  * @mmap:		mmap callback
73  *			@mdev: mediated device structure
74  *			@vma: vma structure
75  * @request:		request callback to release device
76  *			@mdev: mediated device structure
77  *			@count: request sequence number
78  * Parent device that support mediated device should be registered with mdev
79  * module with mdev_parent_ops structure.
80  **/
81 struct mdev_parent_ops {
82 	struct module   *owner;
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 kobject *kobj, struct mdev_device *mdev);
88 	int     (*remove)(struct mdev_device *mdev);
89 	int     (*open)(struct mdev_device *mdev);
90 	void    (*release)(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 kobject *kobj, struct device *dev, char *buf);
105 	ssize_t (*store)(struct kobject *kobj, struct device *dev,
106 			 const char *buf, size_t count);
107 };
108 
109 #define MDEV_TYPE_ATTR(_name, _mode, _show, _store)		\
110 struct mdev_type_attribute mdev_type_attr_##_name =		\
111 	__ATTR(_name, _mode, _show, _store)
112 #define MDEV_TYPE_ATTR_RW(_name) \
113 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RW(_name)
114 #define MDEV_TYPE_ATTR_RO(_name) \
115 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_RO(_name)
116 #define MDEV_TYPE_ATTR_WO(_name) \
117 	struct mdev_type_attribute mdev_type_attr_##_name = __ATTR_WO(_name)
118 
119 /**
120  * struct mdev_driver - Mediated device driver
121  * @name: driver name
122  * @probe: called when new device created
123  * @remove: called when device removed
124  * @driver: device driver structure
125  *
126  **/
127 struct mdev_driver {
128 	const char *name;
129 	int  (*probe)(struct device *dev);
130 	void (*remove)(struct device *dev);
131 	struct device_driver driver;
132 };
133 
134 #define to_mdev_driver(drv)	container_of(drv, struct mdev_driver, driver)
135 
136 void *mdev_get_drvdata(struct mdev_device *mdev);
137 void mdev_set_drvdata(struct mdev_device *mdev, void *data);
138 const guid_t *mdev_uuid(struct mdev_device *mdev);
139 
140 extern struct bus_type mdev_bus_type;
141 
142 int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
143 void mdev_unregister_device(struct device *dev);
144 
145 int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
146 void mdev_unregister_driver(struct mdev_driver *drv);
147 
148 struct device *mdev_parent_dev(struct mdev_device *mdev);
149 struct device *mdev_dev(struct mdev_device *mdev);
150 struct mdev_device *mdev_from_dev(struct device *dev);
151 
152 #endif /* MDEV_H */
153