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 #include <sys/systm.h> 33 34 #define do_div(n, base) ({ \ 35 uint32_t __base = (base); \ 36 uint32_t __rem; \ 37 __rem = ((uint64_t)(n)) % __base; \ 38 (n) = ((uint64_t)(n)) / __base; \ 39 __rem; \ 40 }) 41 42 static inline uint64_t 43 div64_u64_rem(uint64_t dividend, uint64_t divisor, uint64_t *remainder) 44 { 45 46 *remainder = dividend % divisor; 47 return (dividend / divisor); 48 } 49 50 static inline int64_t 51 div64_s64(int64_t dividend, int64_t divisor) 52 { 53 54 return (dividend / divisor); 55 } 56 57 static inline uint64_t 58 div64_u64(uint64_t dividend, uint64_t divisor) 59 { 60 61 return (dividend / divisor); 62 } 63 64 static inline uint64_t 65 div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder) 66 { 67 68 *remainder = dividend % divisor; 69 return (dividend / divisor); 70 } 71 72 static inline int64_t 73 div_s64(int64_t dividend, int32_t divisor) 74 { 75 76 return (dividend / divisor); 77 } 78 79 static inline uint64_t 80 div_u64(uint64_t dividend, uint32_t divisor) 81 { 82 83 return (dividend / divisor); 84 } 85 86 static inline uint64_t 87 mul_u32_u32(uint32_t a, uint32_t b) 88 { 89 90 return ((uint64_t)a * b); 91 } 92 93 static inline uint64_t 94 div64_u64_round_up(uint64_t dividend, uint64_t divisor) 95 { 96 return ((dividend + divisor - 1) / divisor); 97 } 98 99 #define DIV64_U64_ROUND_UP(...) \ 100 div64_u64_round_up(__VA_ARGS__) 101 102 static inline uint64_t 103 mul_u64_u32_div(uint64_t x, uint32_t y, uint32_t div) 104 { 105 const uint64_t rem = x % div; 106 107 return ((x / div) * y + (rem * y) / div); 108 } 109 110 static inline uint64_t 111 mul_u64_u64_div_u64(uint64_t x, uint64_t y, uint64_t z) 112 { 113 uint64_t res, rem; 114 uint64_t x1, y1, y1z; 115 116 res = rem = 0; 117 x1 = x; 118 y1z = y / z; 119 y1 = y - y1z * z; 120 121 /* 122 * INVARIANT: x * y = res * z + rem + (y1 + y1z * z) * x1 123 * INVARIANT: y1 < z 124 * INVARIANT: rem < z 125 */ 126 while (x1 > 0) { 127 /* Handle low bit. */ 128 if (x1 & 1) { 129 x1 &= ~1; 130 res += y1z; 131 rem += y1; 132 if ((rem < y1) || (rem >= z)) { 133 res += 1; 134 rem -= z; 135 } 136 } 137 138 /* Shift x1 right and (y1 + y1z * z) left */ 139 x1 >>= 1; 140 if ((y1 * 2 < y1) || (y1 * 2 >= z)) { 141 y1z = y1z * 2 + 1; 142 y1 = y1 * 2 - z; 143 } else { 144 y1z *= 2; 145 y1 *= 2; 146 } 147 } 148 149 KASSERT(res * z + rem == x * y, ("%s: res %ju * z %ju + rem %ju != " 150 "x %ju * y %ju", __func__, (uintmax_t)res, (uintmax_t)z, 151 (uintmax_t)rem, (uintmax_t)x, (uintmax_t)y)); 152 KASSERT(rem < z, ("%s: rem %ju >= z %ju\n", __func__, 153 (uintmax_t)rem, (uintmax_t)z)); 154 155 return (res); 156 } 157 158 static inline uint64_t 159 mul_u64_u32_shr(uint64_t x, uint32_t y, unsigned int shift) 160 { 161 uint32_t hi, lo; 162 hi = x >> 32; 163 lo = x & 0xffffffff; 164 165 return (mul_u32_u32(lo, y) >> shift) + 166 (mul_u32_u32(hi, y) << (32 - shift)); 167 } 168 169 #endif /* _LINUXKPI_LINUX_MATH64_H */ 170