1#ifndef _TFRC_H_ 2#define _TFRC_H_ 3/* 4 * net/dccp/ccids/lib/tfrc.h 5 * 6 * Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand. 7 * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz> 8 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> 9 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 */ 16#include <linux/types.h> 17#include <asm/div64.h> 18 19/* integer-arithmetic divisions of type (a * 1000000)/b */ 20static inline u64 scaled_div(u64 a, u32 b) 21{ 22 BUG_ON(b==0); 23 a *= 1000000; 24 do_div(a, b); 25 return a; 26} 27 28static inline u32 scaled_div32(u64 a, u32 b) 29{ 30 u64 result = scaled_div(a, b); 31 32 if (result > UINT_MAX) { 33 DCCP_CRIT("Overflow: a(%llu)/b(%u) > ~0U", 34 (unsigned long long)a, b); 35 return UINT_MAX; 36 } 37 return result; 38} 39 40extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); 41extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 42 43#endif /* _TFRC_H_ */ 44