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1 #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 
__fswab16(__u16 val)46 static inline __attribute_const__ __u16 __fswab16(__u16 val)
47 {
48 #if defined (__arch_swab16)
49 	return __arch_swab16(val);
50 #else
51 	return ___constant_swab16(val);
52 #endif
53 }
54 
__fswab32(__u32 val)55 static inline __attribute_const__ __u32 __fswab32(__u32 val)
56 {
57 #if defined(__arch_swab32)
58 	return __arch_swab32(val);
59 #else
60 	return ___constant_swab32(val);
61 #endif
62 }
63 
__fswab64(__u64 val)64 static inline __attribute_const__ __u64 __fswab64(__u64 val)
65 {
66 #if defined (__arch_swab64)
67 	return __arch_swab64(val);
68 #elif defined(__SWAB_64_THRU_32__)
69 	__u32 h = val >> 32;
70 	__u32 l = val & ((1ULL << 32) - 1);
71 	return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h)));
72 #else
73 	return ___constant_swab64(val);
74 #endif
75 }
76 
__fswahw32(__u32 val)77 static inline __attribute_const__ __u32 __fswahw32(__u32 val)
78 {
79 #ifdef __arch_swahw32
80 	return __arch_swahw32(val);
81 #else
82 	return ___constant_swahw32(val);
83 #endif
84 }
85 
__fswahb32(__u32 val)86 static inline __attribute_const__ __u32 __fswahb32(__u32 val)
87 {
88 #ifdef __arch_swahb32
89 	return __arch_swahb32(val);
90 #else
91 	return ___constant_swahb32(val);
92 #endif
93 }
94 
95 /**
96  * __swab16 - return a byteswapped 16-bit value
97  * @x: value to byteswap
98  */
99 #ifdef __HAVE_BUILTIN_BSWAP16__
100 #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
101 #else
102 #define __swab16(x)				\
103 	(__builtin_constant_p((__u16)(x)) ?	\
104 	___constant_swab16(x) :			\
105 	__fswab16(x))
106 #endif
107 
108 /**
109  * __swab32 - return a byteswapped 32-bit value
110  * @x: value to byteswap
111  */
112 #ifdef __HAVE_BUILTIN_BSWAP32__
113 #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
114 #else
115 #define __swab32(x)				\
116 	(__builtin_constant_p((__u32)(x)) ?	\
117 	___constant_swab32(x) :			\
118 	__fswab32(x))
119 #endif
120 
121 /**
122  * __swab64 - return a byteswapped 64-bit value
123  * @x: value to byteswap
124  */
125 #ifdef __HAVE_BUILTIN_BSWAP64__
126 #define __swab64(x) (__u64)__builtin_bswap64((__u64)(x))
127 #else
128 #define __swab64(x)				\
129 	(__builtin_constant_p((__u64)(x)) ?	\
130 	___constant_swab64(x) :			\
131 	__fswab64(x))
132 #endif
133 
134 /**
135  * __swahw32 - return a word-swapped 32-bit value
136  * @x: value to wordswap
137  *
138  * __swahw32(0x12340000) is 0x00001234
139  */
140 #define __swahw32(x)				\
141 	(__builtin_constant_p((__u32)(x)) ?	\
142 	___constant_swahw32(x) :		\
143 	__fswahw32(x))
144 
145 /**
146  * __swahb32 - return a high and low byte-swapped 32-bit value
147  * @x: value to byteswap
148  *
149  * __swahb32(0x12345678) is 0x34127856
150  */
151 #define __swahb32(x)				\
152 	(__builtin_constant_p((__u32)(x)) ?	\
153 	___constant_swahb32(x) :		\
154 	__fswahb32(x))
155 
156 /**
157  * __swab16p - return a byteswapped 16-bit value from a pointer
158  * @p: pointer to a naturally-aligned 16-bit value
159  */
__swab16p(const __u16 * p)160 static __always_inline __u16 __swab16p(const __u16 *p)
161 {
162 #ifdef __arch_swab16p
163 	return __arch_swab16p(p);
164 #else
165 	return __swab16(*p);
166 #endif
167 }
168 
169 /**
170  * __swab32p - return a byteswapped 32-bit value from a pointer
171  * @p: pointer to a naturally-aligned 32-bit value
172  */
__swab32p(const __u32 * p)173 static __always_inline __u32 __swab32p(const __u32 *p)
174 {
175 #ifdef __arch_swab32p
176 	return __arch_swab32p(p);
177 #else
178 	return __swab32(*p);
179 #endif
180 }
181 
182 /**
183  * __swab64p - return a byteswapped 64-bit value from a pointer
184  * @p: pointer to a naturally-aligned 64-bit value
185  */
__swab64p(const __u64 * p)186 static __always_inline __u64 __swab64p(const __u64 *p)
187 {
188 #ifdef __arch_swab64p
189 	return __arch_swab64p(p);
190 #else
191 	return __swab64(*p);
192 #endif
193 }
194 
195 /**
196  * __swahw32p - return a wordswapped 32-bit value from a pointer
197  * @p: pointer to a naturally-aligned 32-bit value
198  *
199  * See __swahw32() for details of wordswapping.
200  */
__swahw32p(const __u32 * p)201 static inline __u32 __swahw32p(const __u32 *p)
202 {
203 #ifdef __arch_swahw32p
204 	return __arch_swahw32p(p);
205 #else
206 	return __swahw32(*p);
207 #endif
208 }
209 
210 /**
211  * __swahb32p - return a high and low byteswapped 32-bit value from a pointer
212  * @p: pointer to a naturally-aligned 32-bit value
213  *
214  * See __swahb32() for details of high/low byteswapping.
215  */
__swahb32p(const __u32 * p)216 static inline __u32 __swahb32p(const __u32 *p)
217 {
218 #ifdef __arch_swahb32p
219 	return __arch_swahb32p(p);
220 #else
221 	return __swahb32(*p);
222 #endif
223 }
224 
225 /**
226  * __swab16s - byteswap a 16-bit value in-place
227  * @p: pointer to a naturally-aligned 16-bit value
228  */
__swab16s(__u16 * p)229 static inline void __swab16s(__u16 *p)
230 {
231 #ifdef __arch_swab16s
232 	__arch_swab16s(p);
233 #else
234 	*p = __swab16p(p);
235 #endif
236 }
237 /**
238  * __swab32s - byteswap a 32-bit value in-place
239  * @p: pointer to a naturally-aligned 32-bit value
240  */
__swab32s(__u32 * p)241 static __always_inline void __swab32s(__u32 *p)
242 {
243 #ifdef __arch_swab32s
244 	__arch_swab32s(p);
245 #else
246 	*p = __swab32p(p);
247 #endif
248 }
249 
250 /**
251  * __swab64s - byteswap a 64-bit value in-place
252  * @p: pointer to a naturally-aligned 64-bit value
253  */
__swab64s(__u64 * p)254 static __always_inline void __swab64s(__u64 *p)
255 {
256 #ifdef __arch_swab64s
257 	__arch_swab64s(p);
258 #else
259 	*p = __swab64p(p);
260 #endif
261 }
262 
263 /**
264  * __swahw32s - wordswap a 32-bit value in-place
265  * @p: pointer to a naturally-aligned 32-bit value
266  *
267  * See __swahw32() for details of wordswapping
268  */
__swahw32s(__u32 * p)269 static inline void __swahw32s(__u32 *p)
270 {
271 #ifdef __arch_swahw32s
272 	__arch_swahw32s(p);
273 #else
274 	*p = __swahw32p(p);
275 #endif
276 }
277 
278 /**
279  * __swahb32s - high and low byteswap a 32-bit value in-place
280  * @p: pointer to a naturally-aligned 32-bit value
281  *
282  * See __swahb32() for details of high and low byte swapping
283  */
__swahb32s(__u32 * p)284 static inline void __swahb32s(__u32 *p)
285 {
286 #ifdef __arch_swahb32s
287 	__arch_swahb32s(p);
288 #else
289 	*p = __swahb32p(p);
290 #endif
291 }
292 
293 
294 #endif /* _UAPI_LINUX_SWAB_H */
295