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wdenkb15cbc02000-08-21 15:05:47 +00001#ifndef _LINUX_BYTEORDER_SWAB_H
2#define _LINUX_BYTEORDER_SWAB_H
3
4/*
5 * linux/byteorder/swab.h
6 * Byte-swapping, independently from CPU endianness
7 * swabXX[ps]?(foo)
8 *
9 * Francois-Rene Rideau <fare@tunes.org> 19971205
10 * separated swab functions from cpu_to_XX,
11 * to clean up support for bizarre-endian architectures.
12 *
13 * See asm-i386/byteorder.h and suches for examples of how to provide
14 * architecture-dependent optimized versions
15 *
16 */
17
18/* casts are necessary for constants, because we never know how for sure
19 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
20 */
21#define ___swab16(x) \
22 ((__u16)( \
23 (((__u16)(x) & (__u16)0x00ffU) << 8) | \
24 (((__u16)(x) & (__u16)0xff00U) >> 8) ))
25#define ___swab32(x) \
26 ((__u32)( \
27 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
28 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
29 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
30 (((__u32)(x) & (__u32)0xff000000UL) >> 24) ))
31#define ___swab64(x) \
32 ((__u64)( \
33 (__u64)(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
34 (__u64)(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
35 (__u64)(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
36 (__u64)(((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \
wdenk8bde7f72003-06-27 21:31:46 +000037 (__u64)(((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \
wdenkb15cbc02000-08-21 15:05:47 +000038 (__u64)(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
39 (__u64)(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
40 (__u64)(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56) ))
41
42/*
43 * provide defaults when no architecture-specific optimization is detected
44 */
45#ifndef __arch__swab16
46# define __arch__swab16(x) ___swab16(x)
47#endif
48#ifndef __arch__swab32
49# define __arch__swab32(x) ___swab32(x)
50#endif
51#ifndef __arch__swab64
52# define __arch__swab64(x) ___swab64(x)
53#endif
54
55#ifndef __arch__swab16p
56# define __arch__swab16p(x) __swab16(*(x))
57#endif
58#ifndef __arch__swab32p
59# define __arch__swab32p(x) __swab32(*(x))
60#endif
61#ifndef __arch__swab64p
62# define __arch__swab64p(x) __swab64(*(x))
63#endif
64
65#ifndef __arch__swab16s
66# define __arch__swab16s(x) do { *(x) = __swab16p((x)); } while (0)
67#endif
68#ifndef __arch__swab32s
69# define __arch__swab32s(x) do { *(x) = __swab32p((x)); } while (0)
70#endif
71#ifndef __arch__swab64s
72# define __arch__swab64s(x) do { *(x) = __swab64p((x)); } while (0)
73#endif
74
75
76/*
77 * Allow constant folding
78 */
79#if defined(__GNUC__) && (__GNUC__ >= 2) && defined(__OPTIMIZE__)
80# define __swab16(x) \
81(__builtin_constant_p((__u16)(x)) ? \
82 ___swab16((x)) : \
83 __fswab16((x)))
84# define __swab32(x) \
85(__builtin_constant_p((__u32)(x)) ? \
86 ___swab32((x)) : \
87 __fswab32((x)))
88# define __swab64(x) \
89(__builtin_constant_p((__u64)(x)) ? \
90 ___swab64((x)) : \
91 __fswab64((x)))
92#else
93# define __swab16(x) __fswab16(x)
94# define __swab32(x) __fswab32(x)
95# define __swab64(x) __fswab64(x)
96#endif /* OPTIMIZE */
97
98
99extern __inline__ __const__ __u16 __fswab16(__u16 x)
100{
101 return __arch__swab16(x);
102}
103extern __inline__ __u16 __swab16p(__u16 *x)
104{
105 return __arch__swab16p(x);
106}
107extern __inline__ void __swab16s(__u16 *addr)
108{
109 __arch__swab16s(addr);
110}
111
112extern __inline__ __const__ __u32 __fswab32(__u32 x)
113{
114 return __arch__swab32(x);
115}
116extern __inline__ __u32 __swab32p(__u32 *x)
117{
118 return __arch__swab32p(x);
119}
120extern __inline__ void __swab32s(__u32 *addr)
121{
122 __arch__swab32s(addr);
123}
124
125#ifdef __BYTEORDER_HAS_U64__
126extern __inline__ __const__ __u64 __fswab64(__u64 x)
127{
128# ifdef __SWAB_64_THRU_32__
129 __u32 h = x >> 32;
wdenk8bde7f72003-06-27 21:31:46 +0000130 __u32 l = x & ((1ULL<<32)-1);
131 return (((__u64)__swab32(l)) << 32) | ((__u64)(__swab32(h)));
wdenkb15cbc02000-08-21 15:05:47 +0000132# else
133 return __arch__swab64(x);
134# endif
135}
136extern __inline__ __u64 __swab64p(__u64 *x)
137{
138 return __arch__swab64p(x);
139}
140extern __inline__ void __swab64s(__u64 *addr)
141{
142 __arch__swab64s(addr);
143}
144#endif /* __BYTEORDER_HAS_U64__ */
145
146#if defined(__KERNEL__)
147#define swab16 __swab16
148#define swab32 __swab32
149#define swab64 __swab64
150#define swab16p __swab16p
151#define swab32p __swab32p
152#define swab64p __swab64p
153#define swab16s __swab16s
154#define swab32s __swab32s
155#define swab64s __swab64s
156#endif
157
158#endif /* _LINUX_BYTEORDER_SWAB_H */