File: /Users/paulross/dev/linux/linux-3.13/include/uapi/linux/swab.h

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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: 
      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: 
      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: 
      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: 
      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: 
      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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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:  */
     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: