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 36 /* 37 * VirtIO V1 (modern) uses little endian, while legacy VirtIO uses the guest's 38 * native endian. These functions convert to and from the Guest's (driver's) 39 * and the Host's (device's) endianness when needed. 40 */ 41 42 static inline bool 43 virtio_swap_endian(bool modern) 44 { 45 #if _BYTE_ORDER == _LITTLE_ENDIAN 46 return (false); 47 #else 48 return (modern); 49 #endif 50 } 51 52 static inline uint16_t 53 virtio_htog16(bool modern, uint16_t val) 54 { 55 if (virtio_swap_endian(modern)) 56 return (le16toh(val)); 57 else 58 return (val); 59 } 60 61 static inline uint16_t 62 virtio_gtoh16(bool modern, uint16_t val) 63 { 64 if (virtio_swap_endian(modern)) 65 return (htole16(val)); 66 else 67 return (val); 68 } 69 70 static inline uint32_t 71 virtio_htog32(bool modern, uint32_t val) 72 { 73 if (virtio_swap_endian(modern)) 74 return (le32toh(val)); 75 else 76 return (val); 77 } 78 79 static inline uint32_t 80 virtio_gtoh32(bool modern, uint32_t val) 81 { 82 if (virtio_swap_endian(modern)) 83 return (htole32(val)); 84 else 85 return (val); 86 } 87 88 static inline uint64_t 89 virtio_htog64(bool modern, uint64_t val) 90 { 91 if (virtio_swap_endian(modern)) 92 return (le64toh(val)); 93 else 94 return (val); 95 } 96 97 static inline uint64_t 98 virtio_gtoh64(bool modern, uint64_t val) 99 { 100 if (virtio_swap_endian(modern)) 101 return (htole64(val)); 102 else 103 return (val); 104 } 105 106 #endif /* _VIRTIO_ENDIAN_H_ */ 107