1/* $OpenBSD: ieee80211_ra_vht.h,v 1.1 2022/03/19 10:25:09 stsp Exp $ */
2
3/*
4 * Copyright (c) 2021 Christian Ehrhardt <ehrhardt@genua.de>
5 * Copyright (c) 2021, 2022 Stefan Sperling <stsp@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/*
21 * Goodput statistics struct. Measures the effective data rate of a rate.
22 * All uint64_t numbers in this struct use fixed-point arithmetic.
23 */
24struct ieee80211_ra_vht_goodput_stats {
25 uint64_t measured; /* Most recently measured goodput. */
26 uint64_t average; /* Average measured goodput. */
27 uint64_t stddeviation; /* Goodput standard deviation. */
28 uint64_t loss; /* This rate's loss percentage SFER. */
29 uint32_t nprobe_pkts; /* Number of packets in current probe. */
30 uint32_t nprobe_fail; /* Number of failed packets. */
31};
32
33/*
34 * Rate adaptation state.
35 *
36 * Drivers should not modify any fields of this structure directly.
37 * Use ieee80211_ra_vht_init() and ieee80211_ra_vht_add_stats() only.
38 */
39struct ieee80211_ra_vht_node {
40 /* Bitmaps for MCS 0-9 for a given number of spatial streams. */
41 uint16_t valid_probes[IEEE80211_VHT_NUM_SS];
42 uint16_t valid_rates[IEEE80211_VHT_NUM_SS];
43 uint16_t candidate_rates[IEEE80211_VHT_NUM_SS];
44 uint16_t probed_rates[IEEE80211_VHT_NUM_SS];
45
46 /* Maximum usable MCS per given number of spatial streams. */
47 int max_mcs[IEEE80211_VHT_NUM_SS];
48
49 /* Probing state. */
50 int probing;
51#define IEEE80211_RA_NOT_PROBING 0x0
52#define IEEE80211_RA_PROBING_DOWN 0x1
53#define IEEE80211_RA_PROBING_UP 0x2
54#define IEEE80211_RA_PROBING_INTER 0x4 /* combined with UP or DOWN */
55
56 /* The current best MCS,NSS found by probing. */
57 int best_mcs;
58 int best_nss;
59
60 /* Goodput statistics for each rate. */
61 struct ieee80211_ra_vht_goodput_stats
62 g[IEEE80211_VHT_NUM_RATESETS][IEEE80211_VHT_RATESET_MAX_NRATES];
63};
64
65/* Initialize rate adaptation state. */
66void ieee80211_ra_vht_node_init(struct ieee80211_ra_vht_node *);
67
68/*
69 * Drivers report information about 802.11ac/VHT Tx attempts here.
70 * mcs: The VHT MCS used during this Tx attempt.
71 * nss: The number of spatial streams used during this Tx attempt.
72 * total: How many Tx attempts (initial attempt + any retries) were made?
73 * fail: How many of these Tx attempts failed?
74 */
75void ieee80211_ra_vht_add_stats(struct ieee80211_ra_vht_node *,
76 struct ieee80211com *, struct ieee80211_node *,
77 int mcs, int nss, unsigned int total, unsigned int fail);
78
79/* Drivers call this function to update ni->ni_txmcs and ni->ni_vht_ss. */
80void ieee80211_ra_vht_choose(struct ieee80211_ra_vht_node *,
81 struct ieee80211com *, struct ieee80211_node *);
82
83/*
84 * Get the VHT rateset for a particular VHT MCS, NSS, with 40MHz, 80MHz,
85 * and/or SGI on/off.
86 */
87const struct ieee80211_vht_rateset * ieee80211_ra_vht_get_rateset(int mcs,
88 int nss, int chan40, int chan80, int sgi);
89
90/* Check whether SGI should be used. */
91int ieee80211_ra_vht_use_sgi(struct ieee80211_node *);