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 24 extern bool 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 */ 31 static inline u64 scaled_div(u64 a, u64 b) 32 { 33 BUG_ON(b == 0); 34 return div64_u64(a * 1000000, b); 35 } 36 37 static 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 */ 53 static 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 58 u32 tfrc_calc_x(u16 s, u32 R, u32 p); 59 u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 60 u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); 61 62 int tfrc_tx_packet_history_init(void); 63 void tfrc_tx_packet_history_exit(void); 64 int tfrc_rx_packet_history_init(void); 65 void tfrc_rx_packet_history_exit(void); 66 67 int tfrc_li_init(void); 68 void tfrc_li_exit(void); 69 70 #ifdef CONFIG_IP_DCCP_TFRC_LIB 71 int tfrc_lib_init(void); 72 void tfrc_lib_exit(void); 73 #else 74 #define tfrc_lib_init() (0) 75 #define tfrc_lib_exit() 76 #endif 77 #endif /* _TFRC_H_ */ 78