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