blob: 0e011eb91b5d7523c1774c1e786dab9fe0809720 [file] [log] [blame]
David Howells607ca462012-10-13 10:46:48 +01001#ifndef _UAPI_LINUX_SWAB_H
2#define _UAPI_LINUX_SWAB_H
3
4#include <linux/types.h>
5#include <linux/compiler.h>
6#include <asm/swab.h>
7
8/*
9 * casts are necessary for constants, because we never know how for sure
10 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
11 */
12#define ___constant_swab16(x) ((__u16)( \
13 (((__u16)(x) & (__u16)0x00ffU) << 8) | \
14 (((__u16)(x) & (__u16)0xff00U) >> 8)))
15
16#define ___constant_swab32(x) ((__u32)( \
17 (((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
18 (((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
19 (((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
20 (((__u32)(x) & (__u32)0xff000000UL) >> 24)))
21
22#define ___constant_swab64(x) ((__u64)( \
23 (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) | \
24 (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) | \
25 (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) | \
26 (((__u64)(x) & (__u64)0x00000000ff000000ULL) << 8) | \
27 (((__u64)(x) & (__u64)0x000000ff00000000ULL) >> 8) | \
28 (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) | \
29 (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) | \
30 (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
31
32#define ___constant_swahw32(x) ((__u32)( \
33 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \
34 (((__u32)(x) & (__u32)0xffff0000UL) >> 16)))
35
36#define ___constant_swahb32(x) ((__u32)( \
37 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \
38 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8)))
39
40/*
41 * Implement the following as inlines, but define the interface using
42 * macros to allow constant folding when possible:
43 * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32
44 */
45
46static inline __attribute_const__ __u16 __fswab16(__u16 val)
47{
David Woodhousecf66bb92012-12-03 16:25:40 +000048#ifdef __HAVE_BUILTIN_BSWAP16__
49 return __builtin_bswap16(val);
50#elif defined (__arch_swab16)
David Howells607ca462012-10-13 10:46:48 +010051 return __arch_swab16(val);
52#else
53 return ___constant_swab16(val);
54#endif
55}
56
57static inline __attribute_const__ __u32 __fswab32(__u32 val)
58{
David Woodhousecf66bb92012-12-03 16:25:40 +000059#ifdef __HAVE_BUILTIN_BSWAP32__
60 return __builtin_bswap32(val);
61#elif defined(__arch_swab32)
David Howells607ca462012-10-13 10:46:48 +010062 return __arch_swab32(val);
63#else
64 return ___constant_swab32(val);
65#endif
66}
67
68static inline __attribute_const__ __u64 __fswab64(__u64 val)
69{
David Woodhousecf66bb92012-12-03 16:25:40 +000070#ifdef __HAVE_BUILTIN_BSWAP64__
71 return __builtin_bswap64(val);
72#elif defined (__arch_swab64)
David Howells607ca462012-10-13 10:46:48 +010073 return __arch_swab64(val);
74#elif defined(__SWAB_64_THRU_32__)
75 __u32 h = val >> 32;
76 __u32 l = val & ((1ULL << 32) - 1);
77 return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h)));
78#else
79 return ___constant_swab64(val);
80#endif
81}
82
83static inline __attribute_const__ __u32 __fswahw32(__u32 val)
84{
85#ifdef __arch_swahw32
86 return __arch_swahw32(val);
87#else
88 return ___constant_swahw32(val);
89#endif
90}
91
92static inline __attribute_const__ __u32 __fswahb32(__u32 val)
93{
94#ifdef __arch_swahb32
95 return __arch_swahb32(val);
96#else
97 return ___constant_swahb32(val);
98#endif
99}
100
101/**
102 * __swab16 - return a byteswapped 16-bit value
103 * @x: value to byteswap
104 */
105#define __swab16(x) \
106 (__builtin_constant_p((__u16)(x)) ? \
107 ___constant_swab16(x) : \
108 __fswab16(x))
109
110/**
111 * __swab32 - return a byteswapped 32-bit value
112 * @x: value to byteswap
113 */
114#define __swab32(x) \
115 (__builtin_constant_p((__u32)(x)) ? \
116 ___constant_swab32(x) : \
117 __fswab32(x))
118
119/**
120 * __swab64 - return a byteswapped 64-bit value
121 * @x: value to byteswap
122 */
123#define __swab64(x) \
124 (__builtin_constant_p((__u64)(x)) ? \
125 ___constant_swab64(x) : \
126 __fswab64(x))
127
128/**
129 * __swahw32 - return a word-swapped 32-bit value
130 * @x: value to wordswap
131 *
132 * __swahw32(0x12340000) is 0x00001234
133 */
134#define __swahw32(x) \
135 (__builtin_constant_p((__u32)(x)) ? \
136 ___constant_swahw32(x) : \
137 __fswahw32(x))
138
139/**
140 * __swahb32 - return a high and low byte-swapped 32-bit value
141 * @x: value to byteswap
142 *
143 * __swahb32(0x12345678) is 0x34127856
144 */
145#define __swahb32(x) \
146 (__builtin_constant_p((__u32)(x)) ? \
147 ___constant_swahb32(x) : \
148 __fswahb32(x))
149
150/**
151 * __swab16p - return a byteswapped 16-bit value from a pointer
152 * @p: pointer to a naturally-aligned 16-bit value
153 */
154static inline __u16 __swab16p(const __u16 *p)
155{
156#ifdef __arch_swab16p
157 return __arch_swab16p(p);
158#else
159 return __swab16(*p);
160#endif
161}
162
163/**
164 * __swab32p - return a byteswapped 32-bit value from a pointer
165 * @p: pointer to a naturally-aligned 32-bit value
166 */
167static inline __u32 __swab32p(const __u32 *p)
168{
169#ifdef __arch_swab32p
170 return __arch_swab32p(p);
171#else
172 return __swab32(*p);
173#endif
174}
175
176/**
177 * __swab64p - return a byteswapped 64-bit value from a pointer
178 * @p: pointer to a naturally-aligned 64-bit value
179 */
180static inline __u64 __swab64p(const __u64 *p)
181{
182#ifdef __arch_swab64p
183 return __arch_swab64p(p);
184#else
185 return __swab64(*p);
186#endif
187}
188
189/**
190 * __swahw32p - return a wordswapped 32-bit value from a pointer
191 * @p: pointer to a naturally-aligned 32-bit value
192 *
193 * See __swahw32() for details of wordswapping.
194 */
195static inline __u32 __swahw32p(const __u32 *p)
196{
197#ifdef __arch_swahw32p
198 return __arch_swahw32p(p);
199#else
200 return __swahw32(*p);
201#endif
202}
203
204/**
205 * __swahb32p - return a high and low byteswapped 32-bit value from a pointer
206 * @p: pointer to a naturally-aligned 32-bit value
207 *
208 * See __swahb32() for details of high/low byteswapping.
209 */
210static inline __u32 __swahb32p(const __u32 *p)
211{
212#ifdef __arch_swahb32p
213 return __arch_swahb32p(p);
214#else
215 return __swahb32(*p);
216#endif
217}
218
219/**
220 * __swab16s - byteswap a 16-bit value in-place
221 * @p: pointer to a naturally-aligned 16-bit value
222 */
223static inline void __swab16s(__u16 *p)
224{
225#ifdef __arch_swab16s
226 __arch_swab16s(p);
227#else
228 *p = __swab16p(p);
229#endif
230}
231/**
232 * __swab32s - byteswap a 32-bit value in-place
233 * @p: pointer to a naturally-aligned 32-bit value
234 */
235static inline void __swab32s(__u32 *p)
236{
237#ifdef __arch_swab32s
238 __arch_swab32s(p);
239#else
240 *p = __swab32p(p);
241#endif
242}
243
244/**
245 * __swab64s - byteswap a 64-bit value in-place
246 * @p: pointer to a naturally-aligned 64-bit value
247 */
248static inline void __swab64s(__u64 *p)
249{
250#ifdef __arch_swab64s
251 __arch_swab64s(p);
252#else
253 *p = __swab64p(p);
254#endif
255}
256
257/**
258 * __swahw32s - wordswap a 32-bit value in-place
259 * @p: pointer to a naturally-aligned 32-bit value
260 *
261 * See __swahw32() for details of wordswapping
262 */
263static inline void __swahw32s(__u32 *p)
264{
265#ifdef __arch_swahw32s
266 __arch_swahw32s(p);
267#else
268 *p = __swahw32p(p);
269#endif
270}
271
272/**
273 * __swahb32s - high and low byteswap a 32-bit value in-place
274 * @p: pointer to a naturally-aligned 32-bit value
275 *
276 * See __swahb32() for details of high and low byte swapping
277 */
278static inline void __swahb32s(__u32 *p)
279{
280#ifdef __arch_swahb32s
281 __arch_swahb32s(p);
282#else
283 *p = __swahb32p(p);
284#endif
285}
286
287
288#endif /* _UAPI_LINUX_SWAB_H */