xref: /freebsd/sys/dev/virtio/virtio_endian.h (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2017, 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_ENDIAN_H_
32 #define _VIRTIO_ENDIAN_H_
33 
34 #include <sys/endian.h>
35 #ifndef _KERNEL
36 #include <stdbool.h>
37 #endif /* _KERNEL */
38 
39 /*
40  * VirtIO V1 (modern) uses little endian, while legacy VirtIO uses the guest's
41  * native endian. These functions convert to and from the Guest's (driver's)
42  * and the Host's (device's) endianness when needed.
43  */
44 
45 static inline uint16_t
46 virtio_htog16(bool modern, uint16_t val)
47 {
48 	if (modern)
49 		return (le16toh(val));
50 	else
51 		return (val);
52 }
53 
54 static inline uint16_t
55 virtio_gtoh16(bool modern, uint16_t val)
56 {
57 	if (modern)
58 		return (htole16(val));
59 	else
60 		return (val);
61 }
62 
63 static inline uint32_t
64 virtio_htog32(bool modern, uint32_t val)
65 {
66 	if (modern)
67 		return (le32toh(val));
68 	else
69 		return (val);
70 }
71 
72 static inline uint32_t
73 virtio_gtoh32(bool modern, uint32_t val)
74 {
75 	if (modern)
76 		return (htole32(val));
77 	else
78 		return (val);
79 }
80 
81 static inline uint64_t
82 virtio_htog64(bool modern, uint64_t val)
83 {
84 	if (modern)
85 		return (le64toh(val));
86 	else
87 		return (val);
88 }
89 
90 static inline uint64_t
91 virtio_gtoh64(bool modern, uint64_t val)
92 {
93 	if (modern)
94 		return (htole64(val));
95 	else
96 		return (val);
97 }
98 
99 #endif /* _VIRTIO_ENDIAN_H_ */
100