1 /* $OpenBSD: bitops.h,v 1.5 2023/01/01 01:34:58 jsg Exp $ */ 2 /* 3 * Copyright (c) 2013, 2014, 2015 Mark Kettenis 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #ifndef _LINUX_BITOPS_H 19 #define _LINUX_BITOPS_H 20 21 #include <sys/types.h> 22 #include <sys/param.h> 23 #include <lib/libkern/libkern.h> 24 25 #include <asm/bitsperlong.h> 26 #include <linux/atomic.h> 27 28 #define BIT(x) (1UL << (x)) 29 #define BIT_ULL(x) (1ULL << (x)) 30 #define BIT_MASK(x) (1UL << ((x) % BITS_PER_LONG)) 31 #define BITS_PER_BYTE 8 32 33 #define GENMASK(h, l) (((~0UL) >> (BITS_PER_LONG - (h) - 1)) & ((~0UL) << (l))) 34 #define GENMASK_ULL(h, l) (((~0ULL) >> (BITS_PER_LONG_LONG - (h) - 1)) & ((~0ULL) << (l))) 35 36 #define BITS_PER_TYPE(x) (8 * sizeof(x)) 37 #define BITS_TO_LONGS(x) howmany((x), 8 * sizeof(long)) 38 39 /* despite the name these are really ctz */ 40 #define __ffs(x) __builtin_ctzl(x) 41 #define __ffs64(x) __builtin_ctzll(x) 42 #define ffz(x) __ffs(~(x)) 43 44 static inline uint8_t 45 hweight8(uint32_t x) 46 { 47 x = (x & 0x55) + ((x & 0xaa) >> 1); 48 x = (x & 0x33) + ((x & 0xcc) >> 2); 49 x = (x + (x >> 4)) & 0x0f; 50 return (x); 51 } 52 53 static inline uint16_t 54 hweight16(uint32_t x) 55 { 56 x = (x & 0x5555) + ((x & 0xaaaa) >> 1); 57 x = (x & 0x3333) + ((x & 0xcccc) >> 2); 58 x = (x + (x >> 4)) & 0x0f0f; 59 x = (x + (x >> 8)) & 0x00ff; 60 return (x); 61 } 62 63 static inline uint32_t 64 hweight32(uint32_t x) 65 { 66 x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1); 67 x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2); 68 x = (x + (x >> 4)) & 0x0f0f0f0f; 69 x = (x + (x >> 8)); 70 x = (x + (x >> 16)) & 0x000000ff; 71 return x; 72 } 73 74 static inline uint32_t 75 hweight64(uint64_t x) 76 { 77 x = (x & 0x5555555555555555ULL) + ((x & 0xaaaaaaaaaaaaaaaaULL) >> 1); 78 x = (x & 0x3333333333333333ULL) + ((x & 0xccccccccccccccccULL) >> 2); 79 x = (x + (x >> 4)) & 0x0f0f0f0f0f0f0f0fULL; 80 x = (x + (x >> 8)); 81 x = (x + (x >> 16)); 82 x = (x + (x >> 32)) & 0x000000ff; 83 return x; 84 } 85 86 static inline unsigned long 87 hweight_long(unsigned long x) 88 { 89 #ifdef __LP64__ 90 return hweight64(x); 91 #else 92 return hweight32(x); 93 #endif 94 } 95 96 static inline int64_t 97 sign_extend64(uint64_t value, int index) 98 { 99 uint8_t shift = 63 - index; 100 return (int64_t)(value << shift) >> shift; 101 } 102 103 static inline int 104 fls64(long long mask) 105 { 106 int bit; 107 108 if (mask == 0) 109 return (0); 110 for (bit = 1; mask != 1; bit++) 111 mask = (unsigned long long)mask >> 1; 112 return (bit); 113 } 114 115 static inline int 116 __fls(long mask) 117 { 118 return (flsl(mask) - 1); 119 } 120 121 static inline uint32_t 122 ror32(uint32_t word, unsigned int shift) 123 { 124 return (word >> shift) | (word << (32 - shift)); 125 } 126 127 #endif 128