1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_BITREV_H 3 #define _LINUX_BITREV_H 4 5 #include <linux/types.h> 6 7 #ifdef CONFIG_HAVE_ARCH_BITREVERSE 8 #include <asm/bitrev.h> 9 10 #define __bitrev32 __arch_bitrev32 11 #define __bitrev16 __arch_bitrev16 12 #define __bitrev8 __arch_bitrev8 13 14 #else 15 extern u8 const byte_rev_table[256]; 16 static inline u8 __bitrev8(u8 byte) 17 { 18 return byte_rev_table[byte]; 19 } 20 21 static inline u16 __bitrev16(u16 x) 22 { 23 return (__bitrev8(x & 0xff) << 8) | __bitrev8(x >> 8); 24 } 25 26 static inline u32 __bitrev32(u32 x) 27 { 28 return (__bitrev16(x & 0xffff) << 16) | __bitrev16(x >> 16); 29 } 30 31 #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ 32 33 #define __bitrev8x4(x) (__bitrev32(swab32(x))) 34 35 #define __constant_bitrev32(x) \ 36 ({ \ 37 u32 ___x = x; \ 38 ___x = (___x >> 16) | (___x << 16); \ 39 ___x = ((___x & (u32)0xFF00FF00UL) >> 8) | ((___x & (u32)0x00FF00FFUL) << 8); \ 40 ___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4); \ 41 ___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2); \ 42 ___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1); \ 43 ___x; \ 44 }) 45 46 #define __constant_bitrev16(x) \ 47 ({ \ 48 u16 ___x = x; \ 49 ___x = (___x >> 8) | (___x << 8); \ 50 ___x = ((___x & (u16)0xF0F0U) >> 4) | ((___x & (u16)0x0F0FU) << 4); \ 51 ___x = ((___x & (u16)0xCCCCU) >> 2) | ((___x & (u16)0x3333U) << 2); \ 52 ___x = ((___x & (u16)0xAAAAU) >> 1) | ((___x & (u16)0x5555U) << 1); \ 53 ___x; \ 54 }) 55 56 #define __constant_bitrev8x4(x) \ 57 ({ \ 58 u32 ___x = x; \ 59 ___x = ((___x & (u32)0xF0F0F0F0UL) >> 4) | ((___x & (u32)0x0F0F0F0FUL) << 4); \ 60 ___x = ((___x & (u32)0xCCCCCCCCUL) >> 2) | ((___x & (u32)0x33333333UL) << 2); \ 61 ___x = ((___x & (u32)0xAAAAAAAAUL) >> 1) | ((___x & (u32)0x55555555UL) << 1); \ 62 ___x; \ 63 }) 64 65 #define __constant_bitrev8(x) \ 66 ({ \ 67 u8 ___x = x; \ 68 ___x = (___x >> 4) | (___x << 4); \ 69 ___x = ((___x & (u8)0xCCU) >> 2) | ((___x & (u8)0x33U) << 2); \ 70 ___x = ((___x & (u8)0xAAU) >> 1) | ((___x & (u8)0x55U) << 1); \ 71 ___x; \ 72 }) 73 74 #define bitrev32(x) \ 75 ({ \ 76 u32 __x = x; \ 77 __builtin_constant_p(__x) ? \ 78 __constant_bitrev32(__x) : \ 79 __bitrev32(__x); \ 80 }) 81 82 #define bitrev16(x) \ 83 ({ \ 84 u16 __x = x; \ 85 __builtin_constant_p(__x) ? \ 86 __constant_bitrev16(__x) : \ 87 __bitrev16(__x); \ 88 }) 89 90 #define bitrev8x4(x) \ 91 ({ \ 92 u32 __x = x; \ 93 __builtin_constant_p(__x) ? \ 94 __constant_bitrev8x4(__x) : \ 95 __bitrev8x4(__x); \ 96 }) 97 98 #define bitrev8(x) \ 99 ({ \ 100 u8 __x = x; \ 101 __builtin_constant_p(__x) ? \ 102 __constant_bitrev8(__x) : \ 103 __bitrev8(__x) ; \ 104 }) 105 #endif /* _LINUX_BITREV_H */ 106