xref: /freebsd/sys/arm/include/endian.h (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2001 David E. O'Brien
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  *	@(#)endian.h	8.1 (Berkeley) 6/10/93
31  * $NetBSD: endian.h,v 1.7 1999/08/21 05:53:51 simonb Exp $
32  * $FreeBSD$
33  */
34 
35 #ifndef _ENDIAN_H_
36 #define	_ENDIAN_H_
37 
38 #include <sys/_types.h>
39 
40 /*
41  * Definitions for byte order, according to byte significance from low
42  * address to high.
43  */
44 #define _LITTLE_ENDIAN  1234    /* LSB first: i386, vax */
45 #define _BIG_ENDIAN     4321    /* MSB first: 68000, ibm, net */
46 #define _PDP_ENDIAN     3412    /* LSB first in word, MSW first in long */
47 
48 #ifdef __ARMEB__
49 #define _BYTE_ORDER	_BIG_ENDIAN
50 #else
51 #define	_BYTE_ORDER	_LITTLE_ENDIAN
52 #endif /* __ARMEB__ */
53 
54 #if __BSD_VISIBLE
55 #define LITTLE_ENDIAN   _LITTLE_ENDIAN
56 #define BIG_ENDIAN      _BIG_ENDIAN
57 #define PDP_ENDIAN      _PDP_ENDIAN
58 #define BYTE_ORDER      _BYTE_ORDER
59 #endif
60 
61 #ifdef __ARMEB__
62 #define _QUAD_HIGHWORD 0
63 #define _QUAD_LOWWORD 1
64 #define __ntohl(x)	((__uint32_t)(x))
65 #define __ntohs(x)	((__uint16_t)(x))
66 #define __htonl(x)	((__uint32_t)(x))
67 #define __htons(x)	((__uint16_t)(x))
68 #else
69 #define _QUAD_HIGHWORD  1
70 #define _QUAD_LOWWORD 0
71 #define __ntohl(x)        (__bswap32(x))
72 #define __ntohs(x)        (__bswap16(x))
73 #define __htonl(x)        (__bswap32(x))
74 #define __htons(x)        (__bswap16(x))
75 #endif /* __ARMEB__ */
76 
77 static __inline __uint64_t
78 __bswap64(__uint64_t _x)
79 {
80 
81 	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
82 	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
83 	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
84 	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
85 }
86 
87 static __inline __uint32_t
88 __bswap32_var(__uint32_t v)
89 {
90 	__uint32_t t1;
91 
92 	__asm __volatile("eor %1, %0, %0, ror #16\n"
93 	    		"bic %1, %1, #0x00ff0000\n"
94 			"mov %0, %0, ror #8\n"
95 			"eor %0, %0, %1, lsr #8\n"
96 			 : "+r" (v), "=r" (t1));
97 
98 	return (v);
99 }
100 
101 static __inline __uint16_t
102 __bswap16_var(__uint16_t v)
103 {
104 	__uint32_t ret = v & 0xffff;
105 
106 	__asm __volatile(
107 	    "mov    %0, %0, ror #8\n"
108 	    "orr    %0, %0, %0, lsr #16\n"
109 	    "bic    %0, %0, %0, lsl #16"
110 	    : "+r" (ret));
111 
112 	return ((__uint16_t)ret);
113 }
114 
115 #ifdef __OPTIMIZE__
116 
117 #define __bswap32_constant(x)	\
118     ((((x) & 0xff000000U) >> 24) |	\
119      (((x) & 0x00ff0000U) >>  8) |	\
120      (((x) & 0x0000ff00U) <<  8) |	\
121      (((x) & 0x000000ffU) << 24))
122 
123 #define __bswap16_constant(x)	\
124     ((((x) & 0xff00) >> 8) |		\
125      (((x) & 0x00ff) << 8))
126 
127 #define __bswap16(x)	\
128     ((__uint16_t)(__builtin_constant_p(x) ?	\
129      __bswap16_constant(x) :			\
130      __bswap16_var(x)))
131 
132 #define __bswap32(x)	\
133     ((__uint32_t)(__builtin_constant_p(x) ? 	\
134      __bswap32_constant(x) :			\
135      __bswap32_var(x)))
136 
137 #else
138 #define __bswap16(x)	__bswap16_var(x)
139 #define __bswap32(x)	__bswap32_var(x)
140 
141 #endif /* __OPTIMIZE__ */
142 #endif /* !_ENDIAN_H_ */
143