aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/byteorder/swabb.h
blob: d5f2a320510930ce7d673ed11ed2f30c96d5994f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
#ifndef _LINUX_BYTEORDER_SWABB_H
#define _LINUX_BYTEORDER_SWABB_H

/*
 * linux/byteorder/swabb.h
 * SWAp Bytes Bizarrely
 *	swaHHXX[ps]?(foo)
 *
 * Support for obNUXIous pdp-endian and other bizarre architectures.
 * Will Linux ever run on such ancient beasts? if not, this file
 * will be but a programming pearl. Still, it's a reminder that we
 * shouldn't be making too many assumptions when trying to be portable.
 *
 */

/*
 * Meaning of the names I chose (vaxlinux people feel free to correct them):
 * swahw32	swap 16-bit half-words in a 32-bit word
 * swahb32	swap 8-bit halves of each 16-bit half-word in a 32-bit word
 *
 * No 64-bit support yet. I don't know NUXI conventions for long longs.
 * I guarantee it will be a mess when it's there, though :->
 * It will be even worse if there are conflicting 64-bit conventions.
 * Hopefully, no one ever used 64-bit objects on NUXI machines.
 *
 */

#define ___swahw32(x) \
({ \
	__u32 __x = (x); \
	((__u32)( \
		(((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \
		(((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \
})
#define ___swahb32(x) \
({ \
	__u32 __x = (x); \
	((__u32)( \
		(((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \
		(((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \
})

#define ___constant_swahw32(x) \
	((__u32)( \
		(((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
		(((__u32)(x) & (__u32)0xffff0000UL) >> 16) ))
#define ___constant_swahb32(x) \
	((__u32)( \
		(((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
		(((__u32)(x) & (__u32)0xff00ff00UL) >> 8) ))

/*
 * provide defaults when no architecture-specific optimization is detected
 */
#ifndef __arch__swahw32
#  define __arch__swahw32(x) ___swahw32(x)
#endif
#ifndef __arch__swahb32
#  define __arch__swahb32(x) ___swahb32(x)
#endif

#ifndef __arch__swahw32p
#  define __arch__swahw32p(x) __swahw32(*(x))
#endif
#ifndef __arch__swahb32p
#  define __arch__swahb32p(x) __swahb32(*(x))
#endif

#ifndef __arch__swahw32s
#  define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0)
#endif
#ifndef __arch__swahb32s
#  define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0)
#endif


/*
 * Allow constant folding
 */
#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
#  define __swahw32(x) \
(__builtin_constant_p((__u32)(x)) ? \
 ___swahw32((x)) : \
 __fswahw32((x)))
#  define __swahb32(x) \
(__builtin_constant_p((__u32)(x)) ? \
 ___swahb32((x)) : \
 __fswahb32((x)))
#else
#  define __swahw32(x) __fswahw32(x)
#  define __swahb32(x) __fswahb32(x)
#endif /* OPTIMIZE */


static inline __u32 __fswahw32(__u32 x)
{
	return __arch__swahw32(x);
}

static inline __u32 __swahw32p(__u32 *x)
{
	return __arch__swahw32p(x);
}

static inline void __swahw32s(__u32 *addr)
{
	__arch__swahw32s(addr);
}

static inline __u32 __fswahb32(__u32 x)
{
	return __arch__swahb32(x);
}

static inline __u32 __swahb32p(__u32 *x)
{
	return __arch__swahb32p(x);
}

static inline void __swahb32s(__u32 *addr)
{
	__arch__swahb32s(addr);
}

#ifdef __BYTEORDER_HAS_U64__
/*
 * Not supported yet
 */
#endif /* __BYTEORDER_HAS_U64__ */

#if defined(__KERNEL__)
#define swahw32 __swahw32
#define swahb32 __swahb32
#define swahw32p __swahw32p
#define swahb32p __swahb32p
#define swahw32s __swahw32s
#define swahb32s __swahb32s
#endif

#endif /* _LINUX_BYTEORDER_SWABB_H */