1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2017, Bryan Venteicher <[email protected]>
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 bool
virtio_swap_endian(bool modern)46 virtio_swap_endian(bool modern)
47 {
48 #if _BYTE_ORDER == _LITTLE_ENDIAN
49 return (false);
50 #else
51 return (modern);
52 #endif
53 }
54
55 static inline uint16_t
virtio_htog16(bool modern,uint16_t val)56 virtio_htog16(bool modern, uint16_t val)
57 {
58 if (virtio_swap_endian(modern))
59 return (le16toh(val));
60 else
61 return (val);
62 }
63
64 static inline uint16_t
virtio_gtoh16(bool modern,uint16_t val)65 virtio_gtoh16(bool modern, uint16_t val)
66 {
67 if (virtio_swap_endian(modern))
68 return (htole16(val));
69 else
70 return (val);
71 }
72
73 static inline uint32_t
virtio_htog32(bool modern,uint32_t val)74 virtio_htog32(bool modern, uint32_t val)
75 {
76 if (virtio_swap_endian(modern))
77 return (le32toh(val));
78 else
79 return (val);
80 }
81
82 static inline uint32_t
virtio_gtoh32(bool modern,uint32_t val)83 virtio_gtoh32(bool modern, uint32_t val)
84 {
85 if (virtio_swap_endian(modern))
86 return (htole32(val));
87 else
88 return (val);
89 }
90
91 static inline uint64_t
virtio_htog64(bool modern,uint64_t val)92 virtio_htog64(bool modern, uint64_t val)
93 {
94 if (virtio_swap_endian(modern))
95 return (le64toh(val));
96 else
97 return (val);
98 }
99
100 static inline uint64_t
virtio_gtoh64(bool modern,uint64_t val)101 virtio_gtoh64(bool modern, uint64_t val)
102 {
103 if (virtio_swap_endian(modern))
104 return (htole64(val));
105 else
106 return (val);
107 }
108
109 #endif /* _VIRTIO_ENDIAN_H_ */
110