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 21 /* internal includes that this library exports: */ 22 #include "loss_interval.h" 23 #include "packet_history.h" 24 25 #ifdef CONFIG_IP_DCCP_TFRC_DEBUG 26 extern int tfrc_debug; 27 #define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) 28 #else 29 #define tfrc_pr_debug(format, a...) 30 #endif 31 32 /* integer-arithmetic divisions of type (a * 1000000)/b */ 33 static inline u64 scaled_div(u64 a, u64 b) 34 { 35 BUG_ON(b==0); 36 return div64_u64(a * 1000000, b); 37 } 38 39 static inline u32 scaled_div32(u64 a, u64 b) 40 { 41 u64 result = scaled_div(a, b); 42 43 if (result > UINT_MAX) { 44 DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", 45 (unsigned long long)a, (unsigned long long)b); 46 return UINT_MAX; 47 } 48 return result; 49 } 50 51 /** 52 * tfrc_ewma - Exponentially weighted moving average 53 * @weight: Weight to be used as damping factor, in units of 1/10 54 */ 55 static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) 56 { 57 return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; 58 } 59 60 extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); 61 extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); 62 63 extern int tfrc_tx_packet_history_init(void); 64 extern void tfrc_tx_packet_history_exit(void); 65 extern int tfrc_rx_packet_history_init(void); 66 extern void tfrc_rx_packet_history_exit(void); 67 68 extern int tfrc_li_init(void); 69 extern void tfrc_li_exit(void); 70 71 #ifdef CONFIG_IP_DCCP_TFRC_LIB 72 extern int tfrc_lib_init(void); 73 extern void tfrc_lib_exit(void); 74 #else 75 #define tfrc_lib_init() (0) 76 #define tfrc_lib_exit() 77 #endif 78 #endif /* _TFRC_H_ */ 79