projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 36729c1a ACM |
1 | #ifndef _TFRC_H_ |
| 2 | #define _TFRC_H_ | |
| 3 | /* | |
| 4 | * net/dccp/ccids/lib/tfrc.h | |
| 5 | * | |
| c40616c5 GR |
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 | |
| 36729c1a ACM |
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 | */ | |
| 36729c1a | 17 | #include <linux/types.h> |
| 7deb0f85 | 18 | #include <linux/math64.h> |
| c40616c5 | 19 | #include "../../dccp.h" |
| 8a9c7e92 GR |
20 | /* internal includes that this module exports: */ |
| 21 | #include "loss_interval.h" | |
| 22 | #include "packet_history.h" | |
| c40616c5 GR |
23 | |
| 24 | #ifdef CONFIG_IP_DCCP_TFRC_DEBUG | |
| 25 | extern int tfrc_debug; | |
| 26 | #define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a) | |
| 27 | #else | |
| 28 | #define tfrc_pr_debug(format, a...) | |
| 29 | #endif | |
| d63d8364 GR |
30 | |
| 31 | /* integer-arithmetic divisions of type (a * 1000000)/b */ | |
| 7deb0f85 | 32 | static inline u64 scaled_div(u64 a, u64 b) |
| d63d8364 GR |
33 | { |
| 34 | BUG_ON(b==0); | |
| 7deb0f85 | 35 | return div64_u64(a * 1000000, b); |
| d63d8364 GR |
36 | } |
| 37 | ||
| 7deb0f85 | 38 | static inline u32 scaled_div32(u64 a, u64 b) |
| d63d8364 GR |
39 | { |
| 40 | u64 result = scaled_div(a, b); | |
| 41 | ||
| 42 | if (result > UINT_MAX) { | |
| 7deb0f85 GR |
43 | DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX", |
| 44 | (unsigned long long)a, (unsigned long long)b); | |
| d63d8364 GR |
45 | return UINT_MAX; |
| 46 | } | |
| 47 | return result; | |
| 48 | } | |
| 36729c1a | 49 | |
| a3cbdde8 GR |
50 | /** |
| 51 | * tfrc_scaled_sqrt - Compute scaled integer sqrt(x) for 0 < x < 2^22-1 | |
| 52 | * Uses scaling to improve accuracy of the integer approximation of sqrt(). The | |
| 53 | * scaling factor of 2^10 limits the maximum @sample to 4e6; this is okay for | |
| 54 | * clamped RTT samples (dccp_sample_rtt). | |
| 55 | * Should best be used for expressions of type sqrt(x)/sqrt(y), since then the | |
| 56 | * scaling factor is neutralised. For this purpose, it avoids returning zero. | |
| 57 | */ | |
| 58 | static inline u16 tfrc_scaled_sqrt(const u32 sample) | |
| 59 | { | |
| 60 | const unsigned long non_zero_sample = sample ? : 1; | |
| 61 | ||
| 62 | return int_sqrt(non_zero_sample << 10); | |
| 63 | } | |
| 64 | ||
| c3ada46a GR |
65 | /** |
| 66 | * tfrc_ewma - Exponentially weighted moving average | |
| 67 | * @weight: Weight to be used as damping factor, in units of 1/10 | |
| 68 | */ | |
| 69 | static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight) | |
| 70 | { | |
| 71 | return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval; | |
| 72 | } | |
| 73 | ||
| 1e2f0e5e GR |
74 | extern u32 tfrc_calc_x(u16 s, u32 R, u32 p); |
| 75 | extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue); | |
| 535c55df | 76 | extern u32 tfrc_invert_loss_event_rate(u32 loss_event_rate); |
| 36729c1a | 77 | |
| 1e2f0e5e GR |
78 | extern int tfrc_tx_packet_history_init(void); |
| 79 | extern void tfrc_tx_packet_history_exit(void); | |
| 80 | extern int tfrc_rx_packet_history_init(void); | |
| 81 | extern void tfrc_rx_packet_history_exit(void); | |
| 82 | ||
| 83 | extern int tfrc_li_init(void); | |
| 84 | extern void tfrc_li_exit(void); | |
| 36729c1a | 85 | #endif /* _TFRC_H_ */ |