1 #ifndef _LINUX_BYTEORDER_SWABB_H 2 #define _LINUX_BYTEORDER_SWABB_H 3 4 /* 5 * linux/byteorder/swabb.h 6 * SWAp Bytes Bizarrely 7 * swaHHXX[ps]?(foo) 8 * 9 * Support for obNUXIous pdp-endian and other bizarre architectures. 10 * Will Linux ever run on such ancient beasts? if not, this file 11 * will be but a programming pearl. Still, it's a reminder that we 12 * shouldn't be making too many assumptions when trying to be portable. 13 * 14 */ 15 16 /* 17 * Meaning of the names I chose (vaxlinux people feel free to correct them): 18 * swahw32 swap 16-bit half-words in a 32-bit word 19 * swahb32 swap 8-bit halves of each 16-bit half-word in a 32-bit word 20 * 21 * No 64-bit support yet. I don't know NUXI conventions for long longs. 22 * I guarantee it will be a mess when it's there, though :-> 23 * It will be even worse if there are conflicting 64-bit conventions. 24 * Hopefully, no one ever used 64-bit objects on NUXI machines. 25 * 26 */ 27 28 #define ___swahw32(x) \ 29 ({ \ 30 __u32 __x = (x); \ 31 ((__u32)( \ 32 (((__u32)(__x) & (__u32)0x0000ffffUL) << 16) | \ 33 (((__u32)(__x) & (__u32)0xffff0000UL) >> 16) )); \ 34 }) 35 #define ___swahb32(x) \ 36 ({ \ 37 __u32 __x = (x); \ 38 ((__u32)( \ 39 (((__u32)(__x) & (__u32)0x00ff00ffUL) << 8) | \ 40 (((__u32)(__x) & (__u32)0xff00ff00UL) >> 8) )); \ 41 }) 42 43 #define ___constant_swahw32(x) \ 44 ((__u32)( \ 45 (((__u32)(x) & (__u32)0x0000ffffUL) << 16) | \ 46 (((__u32)(x) & (__u32)0xffff0000UL) >> 16) )) 47 #define ___constant_swahb32(x) \ 48 ((__u32)( \ 49 (((__u32)(x) & (__u32)0x00ff00ffUL) << 8) | \ 50 (((__u32)(x) & (__u32)0xff00ff00UL) >> 8) )) 51 52 /* 53 * provide defaults when no architecture-specific optimization is detected 54 */ 55 #ifndef __arch__swahw32 56 # define __arch__swahw32(x) ___swahw32(x) 57 #endif 58 #ifndef __arch__swahb32 59 # define __arch__swahb32(x) ___swahb32(x) 60 #endif 61 62 #ifndef __arch__swahw32p 63 # define __arch__swahw32p(x) __swahw32(*(x)) 64 #endif 65 #ifndef __arch__swahb32p 66 # define __arch__swahb32p(x) __swahb32(*(x)) 67 #endif 68 69 #ifndef __arch__swahw32s 70 # define __arch__swahw32s(x) do { *(x) = __swahw32p((x)); } while (0) 71 #endif 72 #ifndef __arch__swahb32s 73 # define __arch__swahb32s(x) do { *(x) = __swahb32p((x)); } while (0) 74 #endif 75 76 77 /* 78 * Allow constant folding 79 */ 80 #if defined(__GNUC__) && defined(__OPTIMIZE__) 81 # define __swahw32(x) \ 82 (__builtin_constant_p((__u32)(x)) ? \ 83 ___swahw32((x)) : \ 84 __fswahw32((x))) 85 # define __swahb32(x) \ 86 (__builtin_constant_p((__u32)(x)) ? \ 87 ___swahb32((x)) : \ 88 __fswahb32((x))) 89 #else 90 # define __swahw32(x) __fswahw32(x) 91 # define __swahb32(x) __fswahb32(x) 92 #endif /* OPTIMIZE */ 93 94 __fswahw32(__u32 x)95static inline __u32 __fswahw32(__u32 x) 96 { 97 return __arch__swahw32(x); 98 } 99 __swahw32p(__u32 * x)100static inline __u32 __swahw32p(__u32 *x) 101 { 102 return __arch__swahw32p(x); 103 } 104 __swahw32s(__u32 * addr)105static inline void __swahw32s(__u32 *addr) 106 { 107 __arch__swahw32s(addr); 108 } 109 __fswahb32(__u32 x)110static inline __u32 __fswahb32(__u32 x) 111 { 112 return __arch__swahb32(x); 113 } 114 __swahb32p(__u32 * x)115static inline __u32 __swahb32p(__u32 *x) 116 { 117 return __arch__swahb32p(x); 118 } 119 __swahb32s(__u32 * addr)120static inline void __swahb32s(__u32 *addr) 121 { 122 __arch__swahb32s(addr); 123 } 124 125 #ifdef __BYTEORDER_HAS_U64__ 126 /* 127 * Not supported yet 128 */ 129 #endif /* __BYTEORDER_HAS_U64__ */ 130 131 #if defined(__KERNEL__) 132 #define swahw32 __swahw32 133 #define swahb32 __swahb32 134 #define swahw32p __swahw32p 135 #define swahb32p __swahb32p 136 #define swahw32s __swahw32s 137 #define swahb32s __swahb32s 138 #endif 139 140 #endif /* _LINUX_BYTEORDER_SWABB_H */ 141