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001: #ifndef _LINUX_SWAB_H
002: #define _LINUX_SWAB_H
003: 
004: #include <linux/types.h>
005: 
006: #include <asm/swab.h>
007: 
008: /*
009:  * casts are necessary for constants, because we never know how for sure
010:  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
011:  */
012: #define ___constant_swab16(x) ((__u16)(                         \
013:         (((__u16)(x) & (__u16)0x00ffU) << 8) |                  \
014:         (((__u16)(x) & (__u16)0xff00U) >> 8)))
015: 
016: #define ___constant_swab32(x) ((__u32)(                         \
017:         (((__u32)(x) & (__u32)0x000000ffUL) << 24) |            \
018:         (((__u32)(x) & (__u32)0x0000ff00UL) <<  8) |            \
019:         (((__u32)(x) & (__u32)0x00ff0000UL) >>  8) |            \
020:         (((__u32)(x) & (__u32)0xff000000UL) >> 24)))
021: 
022: #define ___constant_swab64(x) ((__u64)(                         \
023:         (((__u64)(x) & (__u64)0x00000000000000ffULL) << 56) |   \
024:         (((__u64)(x) & (__u64)0x000000000000ff00ULL) << 40) |   \
025:         (((__u64)(x) & (__u64)0x0000000000ff0000ULL) << 24) |   \
026:         (((__u64)(x) & (__u64)0x00000000ff000000ULL) <<  8) |   \
027:         (((__u64)(x) & (__u64)0x000000ff00000000ULL) >>  8) |   \
028:         (((__u64)(x) & (__u64)0x0000ff0000000000ULL) >> 24) |   \
029:         (((__u64)(x) & (__u64)0x00ff000000000000ULL) >> 40) |   \
030:         (((__u64)(x) & (__u64)0xff00000000000000ULL) >> 56)))
031: 
032: #define ___constant_swahw32(x) ((__u32)(                        \
033:         (((__u32)(x) & (__u32)0x0000ffffUL) << 16) |            \
034:         (((__u32)(x) & (__u32)0xffff0000UL) >> 16)))
035: 
036: #define ___constant_swahb32(x) ((__u32)(                        \
037:         (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) |             \
038:         (((__u32)(x) & (__u32)0xff00ff00UL) >> 8)))
039: 
040: /*
041:  * Implement the following as inlines, but define the interface using
042:  * macros to allow constant folding when possible:
043:  * ___swab16, ___swab32, ___swab64, ___swahw32, ___swahb32
044:  */
045: 
046: static __inline__ __u16 __fswab16(__u16 val)
047: {
048: #ifdef __arch_swab16
049:         return __arch_swab16(val);
050: #else
051:         return ___constant_swab16(val);
052: #endif
053: }
054: 
055: static __inline__ __u32 __fswab32(__u32 val)
056: {
057: #ifdef __arch_swab32
058:         return __arch_swab32(val);
059: #else
060:         return ___constant_swab32(val);
061: #endif
062: }
063: 
064: static __inline__ __u64 __fswab64(__u64 val)
065: {
066: #ifdef __arch_swab64
067:         return __arch_swab64(val);
068: #elif defined(__SWAB_64_THRU_32__)
069:         __u32 h = val >> 32;
070:         __u32 l = val & ((1ULL << 32) - 1);
071:         return (((__u64)__fswab32(l)) << 32) | ((__u64)(__fswab32(h)));
072: #else
073:         return ___constant_swab64(val);
074: #endif
075: }
076: 
077: static __inline__ __u32 __fswahw32(__u32 val)
078: {
079: #ifdef __arch_swahw32
080:         return __arch_swahw32(val);
081: #else
082:         return ___constant_swahw32(val);
083: #endif
084: }
085: 
086: static __inline__ __u32 __fswahb32(__u32 val)
087: {
088: #ifdef __arch_swahb32
089:         return __arch_swahb32(val);
090: #else
091:         return ___constant_swahb32(val);
092: #endif
093: }
094: 
095: /**
096:  * __swab16 - return a byteswapped 16-bit value
097:  * @x: value to byteswap
098:  */
099: #define __swab16(x)                             \
100:         (__builtin_constant_p((__u16)(x)) ?     \
101:         ___constant_swab16(x) :                 \
102:         __fswab16(x))
103: 
104: /**
105:  * __swab32 - return a byteswapped 32-bit value
106:  * @x: value to byteswap
107:  */
108: #define __swab32(x)                             \
109:         (__builtin_constant_p((__u32)(x)) ?     \
110:         ___constant_swab32(x) :                 \
111:         __fswab32(x))
112: 
113: /**
114:  * __swab64 - return a byteswapped 64-bit value
115:  * @x: value to byteswap
116:  */
117: #define __swab64(x)                             \
118:         (__builtin_constant_p((__u64)(x)) ?     \
119:         ___constant_swab64(x) :                 \
120:         __fswab64(x))
121: 
122: /**
123:  * __swahw32 - return a word-swapped 32-bit value
124:  * @x: value to wordswap
125:  *
126:  * __swahw32(0x12340000) is 0x00001234
127:  */
128: #define __swahw32(x)                            \
129:         (__builtin_constant_p((__u32)(x)) ?     \
130:         ___constant_swahw32(x) :                \
131:         __fswahw32(x))
132: 
133: /**
134:  * __swahb32 - return a high and low byte-swapped 32-bit value
135:  * @x: value to byteswap
136:  *
137:  * __swahb32(0x12345678) is 0x34127856
138:  */
139: #define __swahb32(x)                            \
140:         (__builtin_constant_p((__u32)(x)) ?     \
141:         ___constant_swahb32(x) :                \
142:         __fswahb32(x))
143: 
144: /**
145:  * __swab16p - return a byteswapped 16-bit value from a pointer
146:  * @p: pointer to a naturally-aligned 16-bit value
147:  */
148: static __inline__ __u16 __swab16p(const __u16 *p)
149: {
150: #ifdef __arch_swab16p
151:         return __arch_swab16p(p);
152: #else
153:         return __swab16(*p);
154: #endif
155: }
156: 
157: /**
158:  * __swab32p - return a byteswapped 32-bit value from a pointer
159:  * @p: pointer to a naturally-aligned 32-bit value
160:  */
161: static __inline__ __u32 __swab32p(const __u32 *p)
162: {
163: #ifdef __arch_swab32p
164:         return __arch_swab32p(p);
165: #else
166:         return __swab32(*p);
167: #endif
168: }
169: 
170: /**
171:  * __swab64p - return a byteswapped 64-bit value from a pointer
172:  * @p: pointer to a naturally-aligned 64-bit value
173:  */
174: static __inline__ __u64 __swab64p(const __u64 *p)
175: {
176: #ifdef __arch_swab64p
177:         return __arch_swab64p(p);
178: #else
179:         return __swab64(*p);
180: #endif
181: }
182: 
183: /**
184:  * __swahw32p - return a wordswapped 32-bit value from a pointer
185:  * @p: pointer to a naturally-aligned 32-bit value
186:  *
187:  * See __swahw32() for details of wordswapping.
188:  */
189: static __inline__ __u32 __swahw32p(const __u32 *p)
190: {
191: #ifdef __arch_swahw32p
192:         return __arch_swahw32p(p);
193: #else
194:         return __swahw32(*p);
195: #endif
196: }
197: 
198: /**
199:  * __swahb32p - return a high and low byteswapped 32-bit value from a pointer
200:  * @p: pointer to a naturally-aligned 32-bit value
201:  *
202:  * See __swahb32() for details of high/low byteswapping.
203:  */
204: static __inline__ __u32 __swahb32p(const __u32 *p)
205: {
206: #ifdef __arch_swahb32p
207:         return __arch_swahb32p(p);
208: #else
209:         return __swahb32(*p);
210: #endif
211: }
212: 
213: /**
214:  * __swab16s - byteswap a 16-bit value in-place
215:  * @p: pointer to a naturally-aligned 16-bit value
216:  */
217: static __inline__ void __swab16s(__u16 *p)
218: {
219: #ifdef __arch_swab16s
220:         __arch_swab16s(p);
221: #else
222:         *p = __swab16p(p);
223: #endif
224: }
225: /**
226:  * __swab32s - byteswap a 32-bit value in-place
227:  * @p: pointer to a naturally-aligned 32-bit value
228:  */
229: static __inline__ void __swab32s(__u32 *p)
230: {
231: #ifdef __arch_swab32s
232:         __arch_swab32s(p);
233: #else
234:         *p = __swab32p(p);
235: #endif
236: }
237: 
238: /**
239:  * __swab64s - byteswap a 64-bit value in-place
240:  * @p: pointer to a naturally-aligned 64-bit value
241:  */
242: static __inline__ void __swab64s(__u64 *p)
243: {
244: #ifdef __arch_swab64s
245:         __arch_swab64s(p);
246: #else
247:         *p = __swab64p(p);
248: #endif
249: }
250: 
251: /**
252:  * __swahw32s - wordswap a 32-bit value in-place
253:  * @p: pointer to a naturally-aligned 32-bit value
254:  *
255:  * See __swahw32() for details of wordswapping
256:  */
257: static __inline__ void __swahw32s(__u32 *p)
258: {
259: #ifdef __arch_swahw32s
260:         __arch_swahw32s(p);
261: #else
262:         *p = __swahw32p(p);
263: #endif
264: }
265: 
266: /**
267:  * __swahb32s - high and low byteswap a 32-bit value in-place
268:  * @p: pointer to a naturally-aligned 32-bit value
269:  *
270:  * See __swahb32() for details of high and low byte swapping
271:  */
272: static __inline__ void __swahb32s(__u32 *p)
273: {
274: #ifdef __arch_swahb32s
275:         __arch_swahb32s(p);
276: #else
277:         *p = __swahb32p(p);
278: #endif
279: }
280: 
281: 
282: #endif /* _LINUX_SWAB_H */
283: 

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