1 #ifndef _LINUX_BITREV_H 2 #define _LINUX_BITREV_H 3 4 #include <linux/types.h> 5 6 #ifdef CONFIG_HAVE_ARCH_BITREVERSE 7 #include <asm/bitrev.h> 8 9 #define __bitrev32 __arch_bitrev32 10 #define __bitrev16 __arch_bitrev16 11 #define __bitrev8 __arch_bitrev8 12 13 #else 14 extern u8 const byte_rev_table[256]; 15 static inline u8 __bitrev8(u8 byte) 16 { 17 return byte_rev_table[byte]; 18 } 19 20 static inline u16 __bitrev16(u16 x) 21 { 22 return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8); 23 } 24 25 static inline u32 __bitrev32(u32 x) 26 { 27 return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16); 28 } 29 30 #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ 31 32 #define __constant_bitrev32(x) \ 33 ({ \ 34 u32 __x = x; \ 35 __x = (__x >> 16) | (__x << 16); \ 36 __x = ((__x & (u32)0xFF00FF00UL) >> 8) | ((__x & (u32)0x00FF00FFUL) << 8); \ 37 __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \ 38 __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \ 39 __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \ 40 __x; \ 41 }) 42 43 #define __constant_bitrev16(x) \ 44 ({ \ 45 u16 __x = x; \ 46 __x = (__x >> 8) | (__x << 8); \ 47 __x = ((__x & (u16)0xF0F0U) >> 4) | ((__x & (u16)0x0F0FU) << 4); \ 48 __x = ((__x & (u16)0xCCCCU) >> 2) | ((__x & (u16)0x3333U) << 2); \ 49 __x = ((__x & (u16)0xAAAAU) >> 1) | ((__x & (u16)0x5555U) << 1); \ 50 __x; \ 51 }) 52 53 #define __constant_bitrev8(x) \ 54 ({ \ 55 u8 __x = x; \ 56 __x = (__x >> 4) | (__x << 4); \ 57 __x = ((__x & (u8)0xCCU) >> 2) | ((__x & (u8)0x33U) << 2); \ 58 __x = ((__x & (u8)0xAAU) >> 1) | ((__x & (u8)0x55U) << 1); \ 59 __x; \ 60 }) 61 62 #define bitrev32(x) \ 63 ({ \ 64 u32 __x = x; \ 65 __builtin_constant_p(__x) ? \ 66 __constant_bitrev32(__x) : \ 67 __bitrev32(__x); \ 68 }) 69 70 #define bitrev16(x) \ 71 ({ \ 72 u16 __x = x; \ 73 __builtin_constant_p(__x) ? \ 74 __constant_bitrev16(__x) : \ 75 __bitrev16(__x); \ 76 }) 77 78 #define bitrev8(x) \ 79 ({ \ 80 u8 __x = x; \ 81 __builtin_constant_p(__x) ? \ 82 __constant_bitrev8(__x) : \ 83 __bitrev8(__x) ; \ 84 }) 85 #endif /* _LINUX_BITREV_H */ 86