xref: /netbsd-src/sys/arch/riscv/include/byte_swap.h (revision 42413888fc5ab6f5c8cc8ee05b701eeb4d3c5372)
1 /* $NetBSD: byte_swap.h,v 1.5 2020/04/04 21:13:20 christos Exp $ */
2 
3 /*-
4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _RISCV_BYTE_SWAP_H_
33 #define	_RISCV_BYTE_SWAP_H_
34 
35 #ifdef _LOCORE
36 
37 #define	BSWAP16(_src, _dst, _tmp)	\
38 	andi	_dst, _src, 0xff	;\
39 	slli	_dst, _dst, 8		;\
40 	srli	_tmp, _src, 8		;\
41 	and	_tmp, _tmp, 0xff	;\
42 	ori	_dst, _dst, _tmp
43 
44 #define BSWAP32(_src, _dst, _tmp)	\
45 	li	v1, 0xff00		;\
46 	slli	_dst, _src, 24		;\
47 	srli	_tmp, _src, 24		;\
48 	ori	_dst, _dst, _tmp	;\
49 	and	_tmp, _src, v1		;\
50 	slli	_tmp, _src, 8		;\
51 	ori	_dst, _dst, _tmp	;\
52 	srli	_tmp, _src, 8		;\
53 	and	_tmp, _tmp, v1		;\
54 	ori	_dst, _dst, _tmp
55 
56 #else
57 
58 #include <sys/types.h>
59 __BEGIN_DECLS
60 
61 #define	__BYTE_SWAP_U64_VARIABLE __byte_swap_u64_variable
62 static __inline uint64_t
__byte_swap_u64_variable(uint64_t v)63 __byte_swap_u64_variable(uint64_t v)
64 {
65 	const uint64_t m1 = 0x0000ffff0000ffffull;
66 	const uint64_t m0 = 0x00ff00ff00ff00ffull;
67 
68 	v = (v >> 32) | (v << 32);
69 	v = ((v >> 16) & m1) | ((v & m1) << 16);
70 	v = ((v >> 8) & m0) | ((v & m0) << 8);
71 
72 	return v;
73 }
74 
75 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
76 static __inline uint32_t
__byte_swap_u32_variable(uint32_t v)77 __byte_swap_u32_variable(uint32_t v)
78 {
79 	const uint32_t m = 0xff00ff;
80 
81 	v = (v >> 16) | (v << 16);
82 	v = ((v >> 8) & m) | ((v & m) << 8);
83 
84 	return v;
85 }
86 
87 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
88 static __inline uint16_t
__byte_swap_u16_variable(uint16_t v)89 __byte_swap_u16_variable(uint16_t v)
90 {
91 	/*LINTED*/
92 	return (uint16_t)((v >> 8) | (v << 8));
93 }
94 
95 __END_DECLS
96 
97 #endif	/* _LOCORE */
98 
99 #endif /* _RISCV_BYTE_SWAP_H_ */
100