1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2013-2015 Mellanox Technologies, Ltd. 5 * Copyright (c) 2014-2015 François Tigeot 6 * Copyright (c) 2016 Matt Macy <mmacy@FreeBSD.org> 7 * Copyright (c) 2019 Johannes Lundberg <johalun@FreeBSD.org> 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #ifndef _LINUXKPI_LINUX_MATH_H_ 32 #define _LINUXKPI_LINUX_MATH_H_ 33 34 #include <linux/types.h> 35 36 /* 37 * This looks more complex than it should be. But we need to 38 * get the type for the ~ right in round_down (it needs to be 39 * as wide as the result!), and we want to evaluate the macro 40 * arguments just once each. 41 */ 42 #define __round_mask(x, y) ((__typeof__(x))((y)-1)) 43 #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) 44 #define round_down(x, y) ((x) & ~__round_mask(x, y)) 45 46 #define DIV_ROUND_UP(x, n) howmany(x, n) 47 #define DIV_ROUND_UP_ULL(x, n) DIV_ROUND_UP((unsigned long long)(x), (n)) 48 #define DIV_ROUND_DOWN_ULL(x, n) (((unsigned long long)(x) / (n)) * (n)) 49 50 #define DIV_ROUND_CLOSEST(x, divisor) (((x) + ((divisor) / 2)) / (divisor)) 51 #define DIV_ROUND_CLOSEST_ULL(x, divisor) ({ \ 52 __typeof(divisor) __d = (divisor); \ 53 unsigned long long __ret = (x) + (__d) / 2; \ 54 __ret /= __d; \ 55 __ret; \ 56 }) 57 58 static inline uintmax_t 59 mult_frac(uintmax_t x, uintmax_t multiplier, uintmax_t divisor) 60 { 61 uintmax_t q = (x / divisor); 62 uintmax_t r = (x % divisor); 63 64 return ((q * multiplier) + ((r * multiplier) / divisor)); 65 } 66 67 #endif /* _LINUXKPI_LINUX_MATH_H_ */ 68