1/*- 2 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved. 3 * Copyright (c) 2014 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 _LINUX_MATH64_H 29#define _LINUX_MATH64_H 30 31#include <linux/types.h> 32#include <linux/bitops.h> 33 34#if BITS_PER_LONG == 64 35 36# define do_div(n, base) ({ \ 37 uint32_t __base = (base); \ 38 uint32_t __rem; \ 39 __rem = ((uint64_t)(n)) % __base; \ 40 (n) = ((uint64_t)(n)) / __base; \ 41 __rem; \ 42}) 43 44/** 45* div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder 46* 47* This is commonly provided by 32bit archs to provide an optimized 64bit 48* divide. 49*/ 50static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 51{ 52 *remainder = dividend % divisor; 53 return dividend / divisor; 54} 55 56 57#elif BITS_PER_LONG == 32 58 59static uint32_t __div64_32(uint64_t *n, uint32_t base) 60{ 61 uint64_t rem = *n; 62 uint64_t b = base; 63 uint64_t res, d = 1; 64 uint32_t high = rem >> 32; 65 66 /* Reduce the thing a bit first */ 67 res = 0; 68 if (high >= base) { 69 high /= base; 70 res = (uint64_t) high << 32; 71 rem -= (uint64_t) (high*base) << 32; 72 } 73 74 while ((int64_t)b > 0 && b < rem) { 75 b = b+b; 76 d = d+d; 77 } 78 79 do { 80 if (rem >= b) { 81 rem -= b; 82 res += d; 83 } 84 b >>= 1; 85 d >>= 1; 86 } while (d); 87 88 *n = res; 89 return rem; 90} 91 92# define do_div(n, base) ({ \ 93 uint32_t __base = (base); \ 94 uint32_t __rem; \ 95 (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ 96 if (likely(((n) >> 32) == 0)) { \ 97 __rem = (uint32_t)(n) % __base; \ 98 (n) = (uint32_t)(n) / __base; \ 99 } else \ 100 __rem = __div64_32(&(n), __base); \ 101 __rem; \ 102}) 103 104#ifndef div_u64_rem 105static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) 106{ 107 *remainder = do_div(dividend, divisor); 108 return dividend; 109} 110#endif 111 112 113#endif /* BITS_PER_LONG */ 114 115 116 117/** 118 ** div_u64 - unsigned 64bit divide with 32bit divisor 119 ** 120 ** This is the most common 64bit divide and should be used if possible, 121 ** as many 32bit archs can optimize this variant better than a full 64bit 122 ** divide. 123 * */ 124#ifndef div_u64 125 126static inline u64 div_u64(u64 dividend, u32 divisor) 127{ 128 u32 remainder; 129 return div_u64_rem(dividend, divisor, &remainder); 130} 131#endif 132 133#endif /* _LINUX_MATH64_H */ 134