1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | #ifndef _TFRC_H_ |
3 | #define _TFRC_H_ |
4 | /* |
5 | * Copyright (c) 2007 The University of Aberdeen, Scotland, UK |
6 | * Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand. |
7 | * Copyright (c) 2005-6 Ian McDonald <ian.mcdonald@jandi.co.nz> |
8 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
9 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon |
10 | */ |
11 | #include <linux/types.h> |
12 | #include <linux/math64.h> |
13 | #include "../../dccp.h" |
14 | |
15 | /* internal includes that this library exports: */ |
16 | #include "loss_interval.h" |
17 | #include "packet_history.h" |
18 | |
19 | #ifdef CONFIG_IP_DCCP_TFRC_DEBUG |
20 | extern bool tfrc_debug; |
21 | #define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) |
22 | #else |
23 | #define tfrc_pr_debug(format, a...) |
24 | #endif |
25 | |
26 | /* integer-arithmetic divisions of type (a * 1000000)/b */ |
27 | static inline u64 scaled_div(u64 a, u64 b) |
28 | { |
29 | BUG_ON(b == 0); |
30 | return div64_u64(dividend: a * 1000000, divisor: b); |
31 | } |
32 | |
33 | static inline u32 scaled_div32(u64 a, u64 b) |
34 | { |
35 | u64 result = scaled_div(a, b); |
36 | |
37 | if (result > UINT_MAX) { |
38 | DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX" , |
39 | (unsigned long long)a, (unsigned long long)b); |
40 | return UINT_MAX; |
41 | } |
42 | return result; |
43 | } |
44 | |
45 | /** |
46 | * tfrc_ewma - Exponentially weighted moving average |
47 | * @weight: Weight to be used as damping factor, in units of 1/10 |
48 | */ |
49 | static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) |
50 | { |
51 | return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; |
52 | } |
53 | |
54 | u32 tfrc_calc_x(u16 s, u32 R, u32 p); |
55 | u32 tfrc_calc_x_reverse_lookup(u32 fvalue); |
56 | u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); |
57 | |
58 | int tfrc_tx_packet_history_init(void); |
59 | void tfrc_tx_packet_history_exit(void); |
60 | int tfrc_rx_packet_history_init(void); |
61 | void tfrc_rx_packet_history_exit(void); |
62 | |
63 | int tfrc_li_init(void); |
64 | void tfrc_li_exit(void); |
65 | |
66 | #ifdef CONFIG_IP_DCCP_TFRC_LIB |
67 | int tfrc_lib_init(void); |
68 | void tfrc_lib_exit(void); |
69 | #else |
70 | #define tfrc_lib_init() (0) |
71 | #define tfrc_lib_exit() |
72 | #endif |
73 | #endif /* _TFRC_H_ */ |
74 | |