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