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 bool 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 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 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 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 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 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 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