1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun #ifndef _DCCP_LI_HIST_
3*4882a593Smuzhiyun #define _DCCP_LI_HIST_
4*4882a593Smuzhiyun /*
5*4882a593Smuzhiyun * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
6*4882a593Smuzhiyun * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
7*4882a593Smuzhiyun * Copyright (c) 2005-7 Ian McDonald <ian.mcdonald@jandi.co.nz>
8*4882a593Smuzhiyun * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun #include <linux/ktime.h>
11*4882a593Smuzhiyun #include <linux/list.h>
12*4882a593Smuzhiyun #include <linux/slab.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun /*
15*4882a593Smuzhiyun * Number of loss intervals (RFC 4342, 8.6.1). The history size is one more than
16*4882a593Smuzhiyun * NINTERVAL, since the `open' interval I_0 is always stored as the first entry.
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun #define NINTERVAL 8
19*4882a593Smuzhiyun #define LIH_SIZE (NINTERVAL + 1)
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun /**
22*4882a593Smuzhiyun * tfrc_loss_interval - Loss history record for TFRC-based protocols
23*4882a593Smuzhiyun * @li_seqno: Highest received seqno before the start of loss
24*4882a593Smuzhiyun * @li_ccval: The CCVal belonging to @li_seqno
25*4882a593Smuzhiyun * @li_is_closed: Whether @li_seqno is older than 1 RTT
26*4882a593Smuzhiyun * @li_length: Loss interval sequence length
27*4882a593Smuzhiyun */
28*4882a593Smuzhiyun struct tfrc_loss_interval {
29*4882a593Smuzhiyun u64 li_seqno:48,
30*4882a593Smuzhiyun li_ccval:4,
31*4882a593Smuzhiyun li_is_closed:1;
32*4882a593Smuzhiyun u32 li_length;
33*4882a593Smuzhiyun };
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun /**
36*4882a593Smuzhiyun * tfrc_loss_hist - Loss record database
37*4882a593Smuzhiyun * @ring: Circular queue managed in LIFO manner
38*4882a593Smuzhiyun * @counter: Current count of entries (can be more than %LIH_SIZE)
39*4882a593Smuzhiyun * @i_mean: Current Average Loss Interval [RFC 3448, 5.4]
40*4882a593Smuzhiyun */
41*4882a593Smuzhiyun struct tfrc_loss_hist {
42*4882a593Smuzhiyun struct tfrc_loss_interval *ring[LIH_SIZE];
43*4882a593Smuzhiyun u8 counter;
44*4882a593Smuzhiyun u32 i_mean;
45*4882a593Smuzhiyun };
46*4882a593Smuzhiyun
tfrc_lh_init(struct tfrc_loss_hist * lh)47*4882a593Smuzhiyun static inline void tfrc_lh_init(struct tfrc_loss_hist *lh)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun memset(lh, 0, sizeof(struct tfrc_loss_hist));
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
tfrc_lh_is_initialised(struct tfrc_loss_hist * lh)52*4882a593Smuzhiyun static inline u8 tfrc_lh_is_initialised(struct tfrc_loss_hist *lh)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun return lh->counter > 0;
55*4882a593Smuzhiyun }
56*4882a593Smuzhiyun
tfrc_lh_length(struct tfrc_loss_hist * lh)57*4882a593Smuzhiyun static inline u8 tfrc_lh_length(struct tfrc_loss_hist *lh)
58*4882a593Smuzhiyun {
59*4882a593Smuzhiyun return min(lh->counter, (u8)LIH_SIZE);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun struct tfrc_rx_hist;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun int tfrc_lh_interval_add(struct tfrc_loss_hist *, struct tfrc_rx_hist *,
65*4882a593Smuzhiyun u32 (*first_li)(struct sock *), struct sock *);
66*4882a593Smuzhiyun u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *);
67*4882a593Smuzhiyun void tfrc_lh_cleanup(struct tfrc_loss_hist *lh);
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun #endif /* _DCCP_LI_HIST_ */
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