1 /*- 2 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved. 3 * Copyright (c) 2014-2015 Mellanox Technologies, Ltd. All rights reserved. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice unmodified, this list of conditions, and the following 11 * disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef _LINUXKPI_LINUX_MATH64_H 29 #define _LINUXKPI_LINUX_MATH64_H 30 31 #include <sys/stdint.h> 32 33 #define do_div(n, base) ({ \ 34 uint32_t __base = (base); \ 35 uint32_t __rem; \ 36 __rem = ((uint64_t)(n)) % __base; \ 37 (n) = ((uint64_t)(n)) / __base; \ 38 __rem; \ 39 }) 40 41 static inline uint64_t 42 div64_u64_rem(uint64_t dividend, uint64_t divisor, uint64_t *remainder) 43 { 44 45 *remainder = dividend % divisor; 46 return (dividend / divisor); 47 } 48 49 static inline int64_t 50 div64_s64(int64_t dividend, int64_t divisor) 51 { 52 53 return (dividend / divisor); 54 } 55 56 static inline uint64_t 57 div64_u64(uint64_t dividend, uint64_t divisor) 58 { 59 60 return (dividend / divisor); 61 } 62 63 static inline uint64_t 64 div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder) 65 { 66 67 *remainder = dividend % divisor; 68 return (dividend / divisor); 69 } 70 71 static inline int64_t 72 div_s64(int64_t dividend, int32_t divisor) 73 { 74 75 return (dividend / divisor); 76 } 77 78 static inline uint64_t 79 div_u64(uint64_t dividend, uint32_t divisor) 80 { 81 82 return (dividend / divisor); 83 } 84 85 static inline uint64_t 86 mul_u32_u32(uint32_t a, uint32_t b) 87 { 88 89 return ((uint64_t)a * b); 90 } 91 92 static inline uint64_t 93 div64_u64_round_up(uint64_t dividend, uint64_t divisor) 94 { 95 return ((dividend + divisor - 1) / divisor); 96 } 97 98 #define DIV64_U64_ROUND_UP(...) \ 99 div64_u64_round_up(__VA_ARGS__) 100 101 static inline uint64_t 102 mul_u64_u32_div(uint64_t x, uint32_t y, uint32_t div) 103 { 104 const uint64_t rem = x % div; 105 106 return ((x / div) * y + (rem * y) / div); 107 } 108 109 static inline uint64_t 110 mul_u64_u64_div_u64(uint64_t x, uint64_t y, uint64_t z) 111 { 112 uint64_t res, rem; 113 uint64_t x1, y1, y1z; 114 115 res = rem = 0; 116 x1 = x; 117 y1z = y / z; 118 y1 = y - y1z * z; 119 120 /* 121 * INVARIANT: x * y = res * z + rem + (y1 + y1z * z) * x1 122 * INVARIANT: y1 < z 123 * INVARIANT: rem < z 124 */ 125 while (x1 > 0) { 126 /* Handle low bit. */ 127 if (x1 & 1) { 128 x1 &= ~1; 129 res += y1z; 130 rem += y1; 131 if ((rem < y1) || (rem >= z)) { 132 res += 1; 133 rem -= z; 134 } 135 } 136 137 /* Shift x1 right and (y1 + y1z * z) left */ 138 x1 >>= 1; 139 if ((y1 * 2 < y1) || (y1 * 2 >= z)) { 140 y1z = y1z * 2 + 1; 141 y1 = y1 * 2 - z; 142 } else { 143 y1z *= 2; 144 y1 *= 2; 145 } 146 } 147 148 KASSERT(res * z + rem == x * y, ("%s: res %ju * z %ju + rem %ju != " 149 "x %ju * y %ju", __func__, (uintmax_t)res, (uintmax_t)z, 150 (uintmax_t)rem, (uintmax_t)x, (uintmax_t)y)); 151 KASSERT(rem < z, ("%s: rem %ju >= z %ju\n", __func__, 152 (uintmax_t)rem, (uintmax_t)z)); 153 154 return (res); 155 } 156 157 static inline uint64_t 158 mul_u64_u32_shr(uint64_t x, uint32_t y, unsigned int shift) 159 { 160 uint32_t hi, lo; 161 hi = x >> 32; 162 lo = x & 0xffffffff; 163 164 return (mul_u32_u32(lo, y) >> shift) + 165 (mul_u32_u32(hi, y) << (32 - shift)); 166 } 167 168 #endif /* _LINUXKPI_LINUX_MATH64_H */ 169