summaryrefslogtreecommitdiffstats
path: root/include/linux/swab.h
blob: ea0c02fd5163c2b865d2041cc0a2f5e43e7c7743 (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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
#ifndef _LINUX_SWAB_H
#define _LINUX_SWAB_H

#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/swab.h>

/*
 * casts are necessary for constants, because we never know how for sure
 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
 */
#define ___constant_swab16(x) ((__u16)(				\
	(((__u16)(x) & (__u16)0x00ffU) << 8) |			\
	(((__u16)(x) & (__u16)0xff00U) >> 8)))

#define ___constant_swab32(x) ((__u32)(				\
	(((__u32)(x) & (__u32)0x000000ffUL) << 24) |		\
	(((__u32)(x) & (__u32)0x0000ff00UL) <<  8) |		\
	(((__u32)(x) & (__u32)0x00ff0000UL) >>  8) |		\
	(((__u32)(x) & (__u32)0xff000000UL) >> 24)))

#define ___constant_swab64(x) ((__u64)(				\
	(((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) |	\
	(((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) |	\
	(((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) |	\
	(((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) |	\
	(((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) |	\
	(((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) |	\
	(((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) |	\
	(((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))

#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)))

/*
 * Implement the following as inlines, but define the interface using
 * macros to allow constant folding when possible:
 * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32
 */

static inline __attribute_const__ __u16 __fswab16(__u16 val)
{
#ifdef __arch_swab16
	return __arch_swab16(val);
#else
	return ___constant_swab16(val);
#endif
}

static inline __attribute_const__ __u32 __fswab32(__u32 val)
{
#ifdef __arch_swab32
	return __arch_swab32(val);
#else
	return ___constant_swab32(val);
#endif
}

static inline __attribute_const__ __u64 __fswab64(__u64 val)
{
#ifdef __arch_swab64
	return __arch_swab64(val);
#elif defined(__SWAB_64_THRU_32__)
	__u32 h = val >> 32;
	__u32 l = val & ((1ULL << 32) - 1);
	return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h)));
#else
	return ___constant_swab64(val);
#endif
}

static inline __attribute_const__ __u32 __fswahw32(__u32 val)
{
#ifdef __arch_swahw32
	return __arch_swahw32(val);
#else
	return ___constant_swahw32(val);
#endif
}

static inline __attribute_const__ __u32 __fswahb32(__u32 val)
{
#ifdef __arch_swahb32
	return __arch_swahb32(val);
#else
	return ___constant_swahb32(val);
#endif
}

/**
 * __swab16 - return a byteswapped 16-bit value
 * @x: value to byteswap
 */
#define __swab16(x)				\
	(__builtin_constant_p((__u16)(x)) ?	\
	___constant_swab16(x) :			\
	__fswab16(x))

/**
 * __swab32 - return a byteswapped 32-bit value
 * @x: value to byteswap
 */
#define __swab32(x)				\
	(__builtin_constant_p((__u32)(x)) ?	\
	___constant_swab32(x) :			\
	__fswab32(x))

/**
 * __swab64 - return a byteswapped 64-bit value
 * @x: value to byteswap
 */
#define __swab64(x)				\
	(__builtin_constant_p((__u64)(x)) ?	\
	___constant_swab64(x) :			\
	__fswab64(x))

/**
 * __swahw32 - return a word-swapped 32-bit value
 * @x: value to wordswap
 *
 * __swahw32(0x12340000) is 0x00001234
 */
#define __swahw32(x)				\
	(__builtin_constant_p((__u32)(x)) ?	\
	___constant_swahw32(x) :		\
	__fswahw32(x))

/**
 * __swahb32 - return a high and low byte-swapped 32-bit value
 * @x: value to byteswap
 *
 * __swahb32(0x12345678) is 0x34127856
 */
#define __swahb32(x)				\
	(__builtin_constant_p((__u32)(x)) ?	\
	___constant_swahb32(x) :		\
	__fswahb32(x))

/**
 * __swab16p - return a byteswapped 16-bit value from a pointer
 * @p: pointer to a naturally-aligned 16-bit value
 */
static inline __u16 __swab16p(const __u16 *p)
{
#ifdef __arch_swab16p
	return __arch_swab16p(p);
#else
	return __swab16(*p);
#endif
}

/**
 * __swab32p - return a byteswapped 32-bit value from a pointer
 * @p: pointer to a naturally-aligned 32-bit value
 */
static inline __u32 __swab32p(const __u32 *p)
{
#ifdef __arch_swab32p
	return __arch_swab32p(p);
#else
	return __swab32(*p);
#endif
}

/**
 * __swab64p - return a byteswapped 64-bit value from a pointer
 * @p: pointer to a naturally-aligned 64-bit value
 */
static inline __u64 __swab64p(const __u64 *p)
{
#ifdef __arch_swab64p
	return __arch_swab64p(p);
#else
	return __swab64(*p);
#endif
}

/**
 * __swahw32p - return a wordswapped 32-bit value from a pointer
 * @p: pointer to a naturally-aligned 32-bit value
 *
 * See __swahw32() for details of wordswapping.
 */
static inline __u32 __swahw32p(const __u32 *p)
{
#ifdef __arch_swahw32p
	return __arch_swahw32p(p);
#else
	return __swahw32(*p);
#endif
}

/**
 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer
 * @p: pointer to a naturally-aligned 32-bit value
 *
 * See __swahb32() for details of high/low byteswapping.
 */
static inline __u32 __swahb32p(const __u32 *p)
{
#ifdef __arch_swahb32p
	return __arch_swahb32p(p);
#else
	return __swahb32(*p);
#endif
}

/**
 * __swab16s - byteswap a 16-bit value in-place
 * @p: pointer to a naturally-aligned 16-bit value
 */
static inline void __swab16s(__u16 *p)
{
#ifdef __arch_swab16s
	__arch_swab16s(p);
#else
	*p = __swab16p(p);
#endif
}
/**
 * __swab32s - byteswap a 32-bit value in-place
 * @p: pointer to a naturally-aligned 32-bit value
 */
static inline void __swab32s(__u32 *p)
{
#ifdef __arch_swab32s
	__arch_swab32s(p);
#else
	*p = __swab32p(p);
#endif
}

/**
 * __swab64s - byteswap a 64-bit value in-place
 * @p: pointer to a naturally-aligned 64-bit value
 */
static inline void __swab64s(__u64 *p)
{
#ifdef __arch_swab64s
	__arch_swab64s(p);
#else
	*p = __swab64p(p);
#endif
}

/**
 * __swahw32s - wordswap a 32-bit value in-place
 * @p: pointer to a naturally-aligned 32-bit value
 *
 * See __swahw32() for details of wordswapping
 */
static inline void __swahw32s(__u32 *p)
{
#ifdef __arch_swahw32s
	__arch_swahw32s(p);
#else
	*p = __swahw32p(p);
#endif
}

/**
 * __swahb32s - high and low byteswap a 32-bit value in-place
 * @p: pointer to a naturally-aligned 32-bit value
 *
 * See __swahb32() for details of high and low byte swapping
 */
static inline void __swahb32s(__u32 *p)
{
#ifdef __arch_swahb32s
	__arch_swahb32s(p);
#else
	*p = __swahb32p(p);
#endif
}

#ifdef __KERNEL__
# define swab16 __swab16
# define swab32 __swab32
# define swab64 __swab64
# define swahw32 __swahw32
# define swahb32 __swahb32
# define swab16p __swab16p
# define swab32p __swab32p
# define swab64p __swab64p
# define swahw32p __swahw32p
# define swahb32p __swahb32p
# define swab16s __swab16s
# define swab32s __swab32s
# define swab64s __swab64s
# define swahw32s __swahw32s
# define swahb32s __swahb32s
#endif /* __KERNEL__ */

#endif /* _LINUX_SWAB_H */