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 #define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) 25 #else 26 #define tfrc_pr_debug(format, a...) 27 #endif 28 29 /* integer-arithmetic divisions of type (a * 1000000)/b */ 30 static inline u64 scaled_div(u64 a, u64 b) 31 { 32 BUG_ON(b == 0); 33 return div64_u64(a * 1000000, b); 34 } 35 36 static inline u32 scaled_div32(u64 a, u64 b) 37 { 38 u64 result = scaled_div(a, b); 39 40 if (result > UINT_MAX) { 41 DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", 42 (unsigned long long)a, (unsigned long long)b); 43 return UINT_MAX; 44 } 45 return result; 46 } 47 48 /** 49 * tfrc_ewma - Exponentially weighted moving average 50 * @weight: Weight to be used as damping factor, in units of 1/10 51 */ 52 static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) 53 { 54 return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; 55 } 56 57 u32 tfrc_calc_x(u16 s, u32 R, u32 p); 58 u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 59 u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); 60 61 int tfrc_tx_packet_history_init(void); 62 void tfrc_tx_packet_history_exit(void); 63 int tfrc_rx_packet_history_init(void); 64 void tfrc_rx_packet_history_exit(void); 65 66 int tfrc_li_init(void); 67 void tfrc_li_exit(void); 68 69 #ifdef CONFIG_IP_DCCP_TFRC_LIB 70 int tfrc_lib_init(void); 71 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