tfrc.h (2011B)
1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2#ifndef _TFRC_H_ 3#define _TFRC_H_ 4/* 5 * Copyright (c) 2007 The University of Aberdeen, Scotland, UK 6 * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. 7 * Copyright (c) 2005-6 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#include <linux/types.h> 12#include <linux/math64.h> 13#include "../../dccp.h" 14 15/* internal includes that this library exports: */ 16#include "loss_interval.h" 17#include "packet_history.h" 18 19#ifdef CONFIG_IP_DCCP_TFRC_DEBUG 20extern bool tfrc_debug; 21#define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) 22#else 23#define tfrc_pr_debug(format, a...) 24#endif 25 26/* integer-arithmetic divisions of type (a * 1000000)/b */ 27static inline u64 scaled_div(u64 a, u64 b) 28{ 29 BUG_ON(b == 0); 30 return div64_u64(a * 1000000, b); 31} 32 33static inline u32 scaled_div32(u64 a, u64 b) 34{ 35 u64 result = scaled_div(a, b); 36 37 if (result > UINT_MAX) { 38 DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", 39 (unsigned long long)a, (unsigned long long)b); 40 return UINT_MAX; 41 } 42 return result; 43} 44 45/** 46 * tfrc_ewma - Exponentially weighted moving average 47 * @weight: Weight to be used as damping factor, in units of 1/10 48 */ 49static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) 50{ 51 return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; 52} 53 54u32 tfrc_calc_x(u16 s, u32 R, u32 p); 55u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 56u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); 57 58int tfrc_tx_packet_history_init(void); 59void tfrc_tx_packet_history_exit(void); 60int tfrc_rx_packet_history_init(void); 61void tfrc_rx_packet_history_exit(void); 62 63int tfrc_li_init(void); 64void tfrc_li_exit(void); 65 66#ifdef CONFIG_IP_DCCP_TFRC_LIB 67int tfrc_lib_init(void); 68void tfrc_lib_exit(void); 69#else 70#define tfrc_lib_init() (0) 71#define tfrc_lib_exit() 72#endif 73#endif /* _TFRC_H_ */