1#ifndef _TFRC_H_ 2#define _TFRC_H_ 3/* 4 * Copyright (c) 2007 The University of Aberdeen, Scotland, UK 5 * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. 6 * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz> 7 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> 8 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License as published by 12 * the Free Software Foundation; either version 2 of the License, or 13 * (at your option) any later version. 14 */ 15#include <linux/types.h> 16#include <linux/math64.h> 17#include "../../dccp.h" 18 19/* internal includes that this library exports: */ 20#include "loss_interval.h" 21#include "packet_history.h" 22 23#ifdef CONFIG_IP_DCCP_TFRC_DEBUG 24extern int tfrc_debug; 25#define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) 26#else 27#define tfrc_pr_debug(format, a...) 28#endif 29 30/* integer-arithmetic divisions of type (a * 1000000)/b */ 31static inline u64 scaled_div(u64 a, u64 b) 32{ 33 BUG_ON(b == 0); 34 return div64_u64(a * 1000000, b); 35} 36 37static inline u32 scaled_div32(u64 a, u64 b) 38{ 39 u64 result = scaled_div(a, b); 40 41 if (result > UINT_MAX) { 42 DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", 43 (unsigned long long)a, (unsigned long long)b); 44 return UINT_MAX; 45 } 46 return result; 47} 48 49/** 50 * tfrc_ewma - Exponentially weighted moving average 51 * @weight: Weight to be used as damping factor, in units of 1/10 52 */ 53static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) 54{ 55 return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; 56} 57 58extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); 59extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 60 61extern int tfrc_tx_packet_history_init(void); 62extern void tfrc_tx_packet_history_exit(void); 63extern int tfrc_rx_packet_history_init(void); 64extern void tfrc_rx_packet_history_exit(void); 65 66extern int tfrc_li_init(void); 67extern void tfrc_li_exit(void); 68 69#ifdef CONFIG_IP_DCCP_TFRC_LIB 70extern int tfrc_lib_init(void); 71extern void tfrc_lib_exit(void); 72#else 73#define tfrc_lib_init() (0) 74#define tfrc_lib_exit() 75#endif 76#endif /* _TFRC_H_ */ 77