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 #define div64_ul(x, y) div64_u64((x), (y)) 65 66 static inline uint64_t 67 div_u64_rem(uint64_t dividend, uint32_t divisor, uint32_t *remainder) 68 { 69 70 *remainder = dividend % divisor; 71 return (dividend / divisor); 72 } 73 74 static inline int64_t 75 div_s64(int64_t dividend, int32_t divisor) 76 { 77 78 return (dividend / divisor); 79 } 80 81 static inline uint64_t 82 div_u64(uint64_t dividend, uint32_t divisor) 83 { 84 85 return (dividend / divisor); 86 } 87 88 static inline uint64_t 89 mul_u32_u32(uint32_t a, uint32_t b) 90 { 91 92 return ((uint64_t)a * b); 93 } 94 95 static inline uint64_t 96 div64_u64_round_up(uint64_t dividend, uint64_t divisor) 97 { 98 return ((dividend + divisor - 1) / divisor); 99 } 100 101 #define DIV64_U64_ROUND_UP(...) \ 102 div64_u64_round_up(__VA_ARGS__) 103 104 static inline uint64_t 105 mul_u64_u32_div(uint64_t x, uint32_t y, uint32_t div) 106 { 107 const uint64_t rem = x % div; 108 109 return ((x / div) * y + (rem * y) / div); 110 } 111 112 static inline uint64_t 113 mul_u64_u64_div_u64(uint64_t x, uint64_t y, uint64_t z) 114 { 115 uint64_t res, rem; 116 uint64_t x1, y1, y1z; 117 118 res = rem = 0; 119 x1 = x; 120 y1z = y / z; 121 y1 = y - y1z * z; 122 123 /* 124 * INVARIANT: x * y = res * z + rem + (y1 + y1z * z) * x1 125 * INVARIANT: y1 < z 126 * INVARIANT: rem < z 127 */ 128 while (x1 > 0) { 129 /* Handle low bit. */ 130 if (x1 & 1) { 131 x1 &= ~1; 132 res += y1z; 133 rem += y1; 134 if ((rem < y1) || (rem >= z)) { 135 res += 1; 136 rem -= z; 137 } 138 } 139 140 /* Shift x1 right and (y1 + y1z * z) left */ 141 x1 >>= 1; 142 if ((y1 * 2 < y1) || (y1 * 2 >= z)) { 143 y1z = y1z * 2 + 1; 144 y1 = y1 * 2 - z; 145 } else { 146 y1z *= 2; 147 y1 *= 2; 148 } 149 } 150 151 KASSERT(res * z + rem == x * y, ("%s: res %ju * z %ju + rem %ju != " 152 "x %ju * y %ju", __func__, (uintmax_t)res, (uintmax_t)z, 153 (uintmax_t)rem, (uintmax_t)x, (uintmax_t)y)); 154 KASSERT(rem < z, ("%s: rem %ju >= z %ju\n", __func__, 155 (uintmax_t)rem, (uintmax_t)z)); 156 157 return (res); 158 } 159 160 static inline uint64_t 161 mul_u64_u32_shr(uint64_t x, uint32_t y, unsigned int shift) 162 { 163 uint32_t hi, lo; 164 hi = x >> 32; 165 lo = x & 0xffffffff; 166 167 return (mul_u32_u32(lo, y) >> shift) + 168 (mul_u32_u32(hi, y) << (32 - shift)); 169 } 170 171 #endif /* _LINUXKPI_LINUX_MATH64_H */ 172