1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2014, Bryan Venteicher <bryanv@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#ifndef _VIRTIO_H_
32#define _VIRTIO_H_
33
34#include <dev/virtio/virtio_ids.h>
35#include <dev/virtio/virtio_config.h>
36
37struct vq_alloc_info;
38
39/*
40 * Each virtqueue indirect descriptor list must be physically contiguous.
41 * To allow us to malloc(9) each list individually, limit the number
42 * supported to what will fit in one page. With 4KB pages, this is a limit
43 * of 256 descriptors. If there is ever a need for more, we can switch to
44 * contigmalloc(9) for the larger allocations, similar to what
45 * bus_dmamem_alloc(9) does.
46 *
47 * Note the sizeof(struct vring_desc) is 16 bytes.
48 */
49#define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
50
51/*
52 * VirtIO instance variables indices.
53 */
54#define VIRTIO_IVAR_DEVTYPE		1
55#define VIRTIO_IVAR_FEATURE_DESC	2
56#define VIRTIO_IVAR_VENDOR		3
57#define VIRTIO_IVAR_DEVICE		4
58#define VIRTIO_IVAR_SUBVENDOR		5
59#define VIRTIO_IVAR_SUBDEVICE		6
60
61struct virtio_feature_desc {
62	uint64_t	 vfd_val;
63	const char	*vfd_str;
64};
65
66const char *virtio_device_name(uint16_t devid);
67void	 virtio_describe(device_t dev, const char *msg,
68	     uint64_t features, struct virtio_feature_desc *feature_desc);
69
70/*
71 * VirtIO Bus Methods.
72 */
73void	 virtio_read_ivar(device_t dev, int ivar, uintptr_t *val);
74void	 virtio_write_ivar(device_t dev, int ivar, uintptr_t val);
75uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
76int	 virtio_alloc_virtqueues(device_t dev, int flags, int nvqs,
77	     struct vq_alloc_info *info);
78int	 virtio_setup_intr(device_t dev, enum intr_type type);
79int	 virtio_with_feature(device_t dev, uint64_t feature);
80void	 virtio_stop(device_t dev);
81int	 virtio_config_generation(device_t dev);
82int	 virtio_reinit(device_t dev, uint64_t features);
83void	 virtio_reinit_complete(device_t dev);
84
85/*
86 * Read/write a variable amount from the device specific (ie, network)
87 * configuration region. This region is encoded in the same endian as
88 * the guest.
89 */
90void	 virtio_read_device_config(device_t dev, bus_size_t offset,
91	     void *dst, int length);
92void	 virtio_write_device_config(device_t dev, bus_size_t offset,
93	     void *src, int length);
94
95/* Inlined device specific read/write functions for common lengths. */
96#define VIRTIO_RDWR_DEVICE_CONFIG(size, type)				\
97static inline type							\
98__CONCAT(virtio_read_dev_config_,size)(device_t dev,			\
99    bus_size_t offset)							\
100{									\
101	type val;							\
102	virtio_read_device_config(dev, offset, &val, sizeof(type));	\
103	return (val);							\
104}									\
105									\
106static inline void							\
107__CONCAT(virtio_write_dev_config_,size)(device_t dev,			\
108    bus_size_t offset, type val)					\
109{									\
110	virtio_write_device_config(dev, offset, &val, sizeof(type));	\
111}
112
113VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
114VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
115VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
116
117#undef VIRTIO_RDWR_DEVICE_CONFIG
118
119#define VIRTIO_READ_IVAR(name, ivar)					\
120static inline int							\
121__CONCAT(virtio_get_,name)(device_t dev)				\
122{									\
123	uintptr_t val;							\
124	virtio_read_ivar(dev, ivar, &val);				\
125	return ((int) val);						\
126}
127
128VIRTIO_READ_IVAR(device_type,	VIRTIO_IVAR_DEVTYPE);
129VIRTIO_READ_IVAR(vendor,	VIRTIO_IVAR_VENDOR);
130VIRTIO_READ_IVAR(device,	VIRTIO_IVAR_DEVICE);
131VIRTIO_READ_IVAR(subvendor,	VIRTIO_IVAR_SUBVENDOR);
132VIRTIO_READ_IVAR(subdevice,	VIRTIO_IVAR_SUBDEVICE);
133
134#undef VIRTIO_READ_IVAR
135
136#define VIRTIO_WRITE_IVAR(name, ivar)					\
137static inline void							\
138__CONCAT(virtio_set_,name)(device_t dev, void *val)			\
139{									\
140	virtio_write_ivar(dev, ivar, (uintptr_t) val);			\
141}
142
143VIRTIO_WRITE_IVAR(feature_desc,	VIRTIO_IVAR_FEATURE_DESC);
144
145#undef VIRTIO_WRITE_IVAR
146
147#endif /* _VIRTIO_H_ */
148