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 #ifdef __HAVE_BUILTIN_BSWAP16__
49 	return __builtin_bswap16(val);
50 #elif defined (__arch_swab16)
51 	return __arch_swab16(val);
52 #else
53 	return ___constant_swab16(val);
54 #endif
55 }
56 
__fswab32(__u32 val)57 static inline __attribute_const__ __u32 __fswab32(__u32 val)
58 {
59 #ifdef __HAVE_BUILTIN_BSWAP32__
60 	return __builtin_bswap32(val);
61 #elif defined(__arch_swab32)
62 	return __arch_swab32(val);
63 #else
64 	return ___constant_swab32(val);
65 #endif
66 }
67 
__fswab64(__u64 val)68 static inline __attribute_const__ __u64 __fswab64(__u64 val)
69 {
70 #ifdef __HAVE_BUILTIN_BSWAP64__
71 	return __builtin_bswap64(val);
72 #elif defined (__arch_swab64)
73 	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 
__fswahw32(__u32 val)83 static 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 
__fswahb32(__u32 val)92 static 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  */
__swab16p(const __u16 * p)154 static 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  */
__swab32p(const __u32 * p)167 static 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  */
__swab64p(const __u64 * p)180 static 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  */
__swahw32p(const __u32 * p)195 static 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  */
__swahb32p(const __u32 * p)210 static 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  */
__swab16s(__u16 * p)223 static 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  */
__swab32s(__u32 * p)235 static 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  */
__swab64s(__u64 * p)248 static 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  */
__swahw32s(__u32 * p)263 static 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  */
__swahb32s(__u32 * p)278 static 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 */
289