1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2019-2020 Intel Corporation
6 #include <linux/netdevice.h>
7 #include <linux/types.h>
8 #include <linux/skbuff.h>
9 #include <linux/debugfs.h>
10 #include <linux/random.h>
11 #include <linux/moduleparam.h>
12 #include <linux/ieee80211.h>
13 #include <net/mac80211.h>
16 #include "rc80211_minstrel_ht.h"
18 #define AVG_AMPDU_SIZE 16
19 #define AVG_PKT_SIZE 1200
21 #define SAMPLE_SWITCH_THR 100
23 /* Number of bits for an average sized packet */
24 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
26 /* Number of symbols for a packet with (bps) bits per symbol */
27 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
29 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
30 #define MCS_SYMBOL_TIME(sgi, syms) \
32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
33 ((syms) * 1000) << 2 /* syms * 4 us */ \
36 /* Transmit duration for the raw data part of an average sized packet */
37 #define MCS_DURATION(streams, sgi, bps) \
38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
45 * Define group sort order: HT40 -> SGI -> #streams
47 #define GROUP_IDX(_streams, _sgi, _ht40) \
48 MINSTREL_HT_GROUP_0 + \
49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
50 MINSTREL_MAX_STREAMS * _sgi + \
53 #define _MAX(a, b) (((a)>(b))?(a):(b))
55 #define GROUP_SHIFT(duration) \
56 _MAX(0, 16 - __builtin_clz(duration))
58 /* MCS rate information for an MCS group */
59 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
60 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
61 .streams = _streams, \
65 IEEE80211_TX_RC_MCS | \
66 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
67 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
72 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
73 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
74 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
75 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
76 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
80 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
81 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
83 #define MCS_GROUP(_streams, _sgi, _ht40) \
84 __MCS_GROUP(_streams, _sgi, _ht40, \
85 MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
87 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
88 (MINSTREL_VHT_GROUP_0 + \
89 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
90 MINSTREL_MAX_STREAMS * (_sgi) + \
93 #define BW2VBPS(_bw, r3, r2, r1) \
94 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
96 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \
97 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
98 .streams = _streams, \
102 IEEE80211_TX_RC_VHT_MCS | \
103 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
104 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
105 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
109 MCS_DURATION(_streams, _sgi, \
110 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
111 MCS_DURATION(_streams, _sgi, \
112 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
113 MCS_DURATION(_streams, _sgi, \
114 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
115 MCS_DURATION(_streams, _sgi, \
116 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
117 MCS_DURATION(_streams, _sgi, \
118 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
119 MCS_DURATION(_streams, _sgi, \
120 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
121 MCS_DURATION(_streams, _sgi, \
122 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
123 MCS_DURATION(_streams, _sgi, \
124 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
125 MCS_DURATION(_streams, _sgi, \
126 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
130 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
131 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
132 BW2VBPS(_bw, 117, 54, 26)))
134 #define VHT_GROUP(_streams, _sgi, _bw) \
135 __VHT_GROUP(_streams, _sgi, _bw, \
136 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
138 #define CCK_DURATION(_bitrate, _short) \
139 (1000 * (10 /* SIFS */ + \
140 (_short ? 72 + 24 : 144 + 48) + \
141 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
143 #define CCK_DURATION_LIST(_short, _s) \
144 CCK_DURATION(10, _short) >> _s, \
145 CCK_DURATION(20, _short) >> _s, \
146 CCK_DURATION(55, _short) >> _s, \
147 CCK_DURATION(110, _short) >> _s
149 #define __CCK_GROUP(_s) \
150 [MINSTREL_CCK_GROUP] = { \
155 CCK_DURATION_LIST(false, _s), \
156 CCK_DURATION_LIST(true, _s) \
160 #define CCK_GROUP_SHIFT \
161 GROUP_SHIFT(CCK_DURATION(10, false))
163 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
165 #define OFDM_DURATION(_bitrate) \
166 (1000 * (16 /* SIFS + signal ext */ + \
167 16 /* T_PREAMBLE */ + \
169 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) / \
172 #define OFDM_DURATION_LIST(_s) \
173 OFDM_DURATION(60) >> _s, \
174 OFDM_DURATION(90) >> _s, \
175 OFDM_DURATION(120) >> _s, \
176 OFDM_DURATION(180) >> _s, \
177 OFDM_DURATION(240) >> _s, \
178 OFDM_DURATION(360) >> _s, \
179 OFDM_DURATION(480) >> _s, \
180 OFDM_DURATION(540) >> _s
182 #define __OFDM_GROUP(_s) \
183 [MINSTREL_OFDM_GROUP] = { \
188 OFDM_DURATION_LIST(_s), \
192 #define OFDM_GROUP_SHIFT \
193 GROUP_SHIFT(OFDM_DURATION(60))
195 #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
198 static bool minstrel_vht_only = true;
199 module_param(minstrel_vht_only, bool, 0644);
200 MODULE_PARM_DESC(minstrel_vht_only,
201 "Use only VHT rates when VHT is supported by sta.");
204 * To enable sufficiently targeted rate sampling, MCS rates are divided into
205 * groups, based on the number of streams and flags (HT40, SGI) that they
208 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
209 * BW -> SGI -> #streams
211 const struct mcs_group minstrel_mcs_groups[] = {
212 MCS_GROUP(1, 0, BW_20),
213 MCS_GROUP(2, 0, BW_20),
214 MCS_GROUP(3, 0, BW_20),
215 MCS_GROUP(4, 0, BW_20),
217 MCS_GROUP(1, 1, BW_20),
218 MCS_GROUP(2, 1, BW_20),
219 MCS_GROUP(3, 1, BW_20),
220 MCS_GROUP(4, 1, BW_20),
222 MCS_GROUP(1, 0, BW_40),
223 MCS_GROUP(2, 0, BW_40),
224 MCS_GROUP(3, 0, BW_40),
225 MCS_GROUP(4, 0, BW_40),
227 MCS_GROUP(1, 1, BW_40),
228 MCS_GROUP(2, 1, BW_40),
229 MCS_GROUP(3, 1, BW_40),
230 MCS_GROUP(4, 1, BW_40),
235 VHT_GROUP(1, 0, BW_20),
236 VHT_GROUP(2, 0, BW_20),
237 VHT_GROUP(3, 0, BW_20),
238 VHT_GROUP(4, 0, BW_20),
240 VHT_GROUP(1, 1, BW_20),
241 VHT_GROUP(2, 1, BW_20),
242 VHT_GROUP(3, 1, BW_20),
243 VHT_GROUP(4, 1, BW_20),
245 VHT_GROUP(1, 0, BW_40),
246 VHT_GROUP(2, 0, BW_40),
247 VHT_GROUP(3, 0, BW_40),
248 VHT_GROUP(4, 0, BW_40),
250 VHT_GROUP(1, 1, BW_40),
251 VHT_GROUP(2, 1, BW_40),
252 VHT_GROUP(3, 1, BW_40),
253 VHT_GROUP(4, 1, BW_40),
255 VHT_GROUP(1, 0, BW_80),
256 VHT_GROUP(2, 0, BW_80),
257 VHT_GROUP(3, 0, BW_80),
258 VHT_GROUP(4, 0, BW_80),
260 VHT_GROUP(1, 1, BW_80),
261 VHT_GROUP(2, 1, BW_80),
262 VHT_GROUP(3, 1, BW_80),
263 VHT_GROUP(4, 1, BW_80),
266 const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
267 const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
268 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
271 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
274 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
275 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
277 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
280 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
285 if (nss != 3 && nss != 6)
287 } else if (bw == BW_80) {
288 if (nss == 3 || nss == 7)
293 WARN_ON(bw != BW_40);
296 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
297 case IEEE80211_VHT_MCS_SUPPORT_0_7:
300 case IEEE80211_VHT_MCS_SUPPORT_0_8:
303 case IEEE80211_VHT_MCS_SUPPORT_0_9:
309 return 0x3ff & ~mask;
313 minstrel_ht_is_legacy_group(int group)
315 return group == MINSTREL_CCK_GROUP ||
316 group == MINSTREL_OFDM_GROUP;
320 * Look up an MCS group index based on mac80211 rate information
323 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
325 return GROUP_IDX((rate->idx / 8) + 1,
326 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
327 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
331 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
333 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
334 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
335 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
336 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
339 static struct minstrel_rate_stats *
340 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
341 struct ieee80211_tx_rate *rate)
345 if (rate->flags & IEEE80211_TX_RC_MCS) {
346 group = minstrel_ht_get_group_idx(rate);
351 if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
352 group = minstrel_vht_get_group_idx(rate);
353 idx = ieee80211_rate_get_vht_mcs(rate);
357 group = MINSTREL_CCK_GROUP;
358 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
359 if (rate->idx != mp->cck_rates[idx])
363 if ((mi->supported[group] & BIT(idx + 4)) &&
364 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
369 group = MINSTREL_OFDM_GROUP;
370 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
371 if (rate->idx == mp->ofdm_rates[mi->band][idx])
376 return &mi->groups[group].rates[idx];
379 static inline struct minstrel_rate_stats *
380 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
382 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
385 static inline int minstrel_get_duration(int index)
387 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
388 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
390 return duration << group->shift;
394 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
398 if (mi->avg_ampdu_len)
399 return MINSTREL_TRUNC(mi->avg_ampdu_len);
401 if (minstrel_ht_is_legacy_group(mi->max_tp_rate[0] / MCS_GROUP_RATES))
404 duration = minstrel_get_duration(mi->max_tp_rate[0]);
406 if (duration > 400 * 1000)
409 if (duration > 250 * 1000)
412 if (duration > 150 * 1000)
419 * Return current throughput based on the average A-MPDU length, taking into
420 * account the expected number of retransmissions and their expected length
423 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
426 unsigned int nsecs = 0, overhead = mi->overhead;
427 unsigned int ampdu_len = 1;
429 /* do not account throughput if sucess prob is below 10% */
430 if (prob_avg < MINSTREL_FRAC(10, 100))
433 if (minstrel_ht_is_legacy_group(group))
434 overhead = mi->overhead_legacy;
436 ampdu_len = minstrel_ht_avg_ampdu_len(mi);
438 nsecs = 1000 * overhead / ampdu_len;
439 nsecs += minstrel_mcs_groups[group].duration[rate] <<
440 minstrel_mcs_groups[group].shift;
443 * For the throughput calculation, limit the probability value to 90% to
444 * account for collision related packet error rate fluctuation
445 * (prob is scaled - see MINSTREL_FRAC above)
447 if (prob_avg > MINSTREL_FRAC(90, 100))
448 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
451 return MINSTREL_TRUNC(100000 * ((prob_avg * 1000) / nsecs));
455 * Find & sort topmost throughput rates
457 * If multiple rates provide equal throughput the sorting is based on their
458 * current success probability. Higher success probability is preferred among
459 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
462 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
465 int cur_group, cur_idx, cur_tp_avg, cur_prob;
466 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
467 int j = MAX_THR_RATES;
469 cur_group = index / MCS_GROUP_RATES;
470 cur_idx = index % MCS_GROUP_RATES;
471 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
472 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
475 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
476 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
477 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
478 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
480 if (cur_tp_avg < tmp_tp_avg ||
481 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
486 if (j < MAX_THR_RATES - 1) {
487 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
488 (MAX_THR_RATES - (j + 1))));
490 if (j < MAX_THR_RATES)
495 * Find and set the topmost probability rate per sta and per group
498 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
500 struct minstrel_mcs_group_data *mg;
501 struct minstrel_rate_stats *mrs;
502 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
503 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
504 int max_gpr_group, max_gpr_idx;
505 int max_gpr_tp_avg, max_gpr_prob;
507 cur_group = index / MCS_GROUP_RATES;
508 cur_idx = index % MCS_GROUP_RATES;
509 mg = &mi->groups[index / MCS_GROUP_RATES];
510 mrs = &mg->rates[index % MCS_GROUP_RATES];
512 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
513 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
514 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
515 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
517 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
518 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
519 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
520 if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES) &&
521 !minstrel_ht_is_legacy_group(max_tp_group))
524 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
525 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
526 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
528 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
529 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
531 if (cur_tp_avg > tmp_tp_avg)
532 mi->max_prob_rate = index;
534 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
537 if (cur_tp_avg > max_gpr_tp_avg)
538 mg->max_group_prob_rate = index;
540 if (mrs->prob_avg > tmp_prob)
541 mi->max_prob_rate = index;
542 if (mrs->prob_avg > max_gpr_prob)
543 mg->max_group_prob_rate = index;
549 * Assign new rate set per sta and use CCK rates only if the fastest
550 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
551 * rate sets where MCS and CCK rates are mixed, because CCK rates can
552 * not use aggregation.
555 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
556 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
557 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
559 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
562 tmp_group = tmp_legacy_tp_rate[0] / MCS_GROUP_RATES;
563 tmp_idx = tmp_legacy_tp_rate[0] % MCS_GROUP_RATES;
564 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
565 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
567 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
568 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
569 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
570 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
572 if (tmp_cck_tp > tmp_mcs_tp) {
573 for(i = 0; i < MAX_THR_RATES; i++) {
574 minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
582 * Try to increase robustness of max_prob rate by decrease number of
583 * streams if possible.
586 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
588 struct minstrel_mcs_group_data *mg;
589 int tmp_max_streams, group, tmp_idx, tmp_prob;
592 if (!mi->sta->ht_cap.ht_supported)
595 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
596 MCS_GROUP_RATES].streams;
597 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
598 mg = &mi->groups[group];
599 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
602 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
603 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
605 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
606 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
607 mi->max_prob_rate = mg->max_group_prob_rate;
608 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
616 minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group,
617 int tp_idx, const struct mcs_group *group)
619 if (group->bw < tp_group->bw)
622 if (group->streams == tp_group->streams)
625 if (tp_idx < 4 && group->streams == tp_group->streams - 1)
628 return group->streams == tp_group->streams + 1;
632 minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates,
635 const struct mcs_group *group, *tp_group;
639 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES];
640 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES;
642 max_dur = minstrel_get_duration(mi->max_tp_rate[0]);
644 max_dur -= max_dur / 16;
646 for (g = 0; g < MINSTREL_GROUPS_NB; g++) {
647 u16 supported = mi->supported[g];
652 group = &minstrel_mcs_groups[g];
653 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group))
656 for (i = 0; supported; supported >>= 1, i++) {
659 if (!(supported & 1))
662 if ((group->duration[i] << group->shift) > max_dur)
665 idx = g * MCS_GROUP_RATES + i;
666 if (idx == mi->max_tp_rate[0])
669 rates[(*n_rates)++] = idx;
676 minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
677 struct minstrel_ht_sta *mi)
679 struct minstrel_rate_stats *mrs;
680 u16 rates[MINSTREL_GROUPS_NB];
688 * Use rate switching instead of probing packets for devices with
689 * little control over retry fallback behavior
691 if (mp->hw->max_rates > 1)
695 * If the current EWMA prob is >75%, look for a rate that's 6.25%
696 * faster than the max tp rate.
697 * If that fails, look again for a rate that is at least as fast
699 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
700 faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100);
701 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
702 if (!n_rates && faster_rate)
703 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
705 /* If no suitable rate was found, try to pick the next one in the group */
707 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES;
708 u16 supported = mi->supported[g_idx];
710 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES;
711 for (i = 0; supported; supported >>= 1, i++) {
712 if (!(supported & 1))
715 probe_rate = mi->max_tp_rate[0] + i;
724 random = prandom_u32();
725 i = random % n_rates;
727 probe_rate = rates[i];
730 mi->sample_rate = probe_rate;
731 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE;
735 minstrel_ewma(int old, int new, int weight)
740 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
745 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
759 val = MINSTREL_AVG_COEFF1 * in;
760 val += MINSTREL_AVG_COEFF2 * out_1;
761 val += MINSTREL_AVG_COEFF3 * out_2;
762 val >>= MINSTREL_SCALE;
764 if (val > 1 << MINSTREL_SCALE)
765 val = 1 << MINSTREL_SCALE;
777 * Recalculate statistics and counters of a given rate
780 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
781 struct minstrel_rate_stats *mrs)
783 unsigned int cur_prob;
785 if (unlikely(mrs->attempts > 0)) {
786 mrs->sample_skipped = 0;
787 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
788 minstrel_filter_avg_add(&mrs->prob_avg,
789 &mrs->prob_avg_1, cur_prob);
790 mrs->att_hist += mrs->attempts;
791 mrs->succ_hist += mrs->success;
793 mrs->sample_skipped++;
796 mrs->last_success = mrs->success;
797 mrs->last_attempts = mrs->attempts;
803 * Update rate statistics and select new primary rates
805 * Rules for rate selection:
806 * - max_prob_rate must use only one stream, as a tradeoff between delivery
807 * probability and throughput during strong fluctuations
808 * - as long as the max prob rate has a probability of more than 75%, pick
809 * higher throughput rates, even if the probablity is a bit lower
812 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
815 struct minstrel_mcs_group_data *mg;
816 struct minstrel_rate_stats *mrs;
817 int group, i, j, cur_prob;
818 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
819 u16 tmp_legacy_tp_rate[MAX_THR_RATES], index;
820 bool ht_supported = mi->sta->ht_cap.ht_supported;
822 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
825 mi->total_packets_cur = mi->total_packets -
826 mi->total_packets_last;
827 mi->total_packets_last = mi->total_packets;
829 if (!mp->sample_switch)
831 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1)
834 if (mi->ampdu_packets > 0) {
835 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
836 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
837 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
840 mi->avg_ampdu_len = 0;
842 mi->ampdu_packets = 0;
846 mi->sample_count = 0;
848 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate));
849 memset(tmp_legacy_tp_rate, 0, sizeof(tmp_legacy_tp_rate));
850 if (mi->supported[MINSTREL_CCK_GROUP])
851 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
852 tmp_legacy_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
853 else if (mi->supported[MINSTREL_OFDM_GROUP])
854 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
855 tmp_legacy_tp_rate[j] = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;
857 if (mi->supported[MINSTREL_VHT_GROUP_0])
858 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES;
859 else if (ht_supported)
860 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES;
861 else if (mi->supported[MINSTREL_CCK_GROUP])
862 index = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
864 index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;
866 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
867 tmp_mcs_tp_rate[j] = index;
869 /* Find best rate sets within all MCS groups*/
870 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
871 u16 *tp_rate = tmp_mcs_tp_rate;
873 mg = &mi->groups[group];
874 if (!mi->supported[group])
879 /* (re)Initialize group rate indexes */
880 for(j = 0; j < MAX_THR_RATES; j++)
881 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
883 if (group == MINSTREL_CCK_GROUP && ht_supported)
884 tp_rate = tmp_legacy_tp_rate;
886 for (i = 0; i < MCS_GROUP_RATES; i++) {
887 if (!(mi->supported[group] & BIT(i)))
890 index = MCS_GROUP_RATES * group + i;
893 mrs->retry_updated = false;
894 minstrel_ht_calc_rate_stats(mp, mrs);
895 cur_prob = mrs->prob_avg;
897 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
900 /* Find max throughput rate set */
901 minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
903 /* Find max throughput rate set within a group */
904 minstrel_ht_sort_best_tp_rates(mi, index,
907 /* Find max probability rate per group and global */
908 minstrel_ht_set_best_prob_rate(mi, index);
911 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
912 sizeof(mg->max_group_tp_rate));
915 /* Assign new rate set per sta */
916 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
918 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
920 /* Try to increase robustness of max_prob_rate*/
921 minstrel_ht_prob_rate_reduce_streams(mi);
923 /* try to sample half of all available rates during each interval */
924 mi->sample_count *= 4;
927 minstrel_ht_rate_sample_switch(mp, mi);
929 #ifdef CONFIG_MAC80211_DEBUGFS
930 /* use fixed index if set */
931 if (mp->fixed_rate_idx != -1) {
932 for (i = 0; i < 4; i++)
933 mi->max_tp_rate[i] = mp->fixed_rate_idx;
934 mi->max_prob_rate = mp->fixed_rate_idx;
935 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
939 /* Reset update timer */
940 mi->last_stats_update = jiffies;
944 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
945 struct ieee80211_tx_rate *rate)
955 if (rate->flags & IEEE80211_TX_RC_MCS ||
956 rate->flags & IEEE80211_TX_RC_VHT_MCS)
959 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
960 if (rate->idx == mp->cck_rates[i])
963 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
964 if (rate->idx == mp->ofdm_rates[mi->band][i])
971 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
973 struct minstrel_mcs_group_data *mg;
977 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
978 mg = &mi->groups[mi->sample_group];
980 if (!mi->supported[mi->sample_group])
983 if (++mg->index >= MCS_GROUP_RATES) {
985 if (++mg->column >= ARRAY_SIZE(sample_table))
993 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
995 int group, orig_group;
997 orig_group = group = *idx / MCS_GROUP_RATES;
1001 if (!mi->supported[group])
1004 if (minstrel_mcs_groups[group].streams >
1005 minstrel_mcs_groups[orig_group].streams)
1009 *idx = mi->groups[group].max_group_tp_rate[0];
1011 *idx = mi->groups[group].max_group_tp_rate[1];
1017 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
1019 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1020 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
1023 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
1026 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
1029 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
1032 tid = ieee80211_get_tid(hdr);
1033 if (likely(sta->ampdu_mlme.tid_tx[tid]))
1036 ieee80211_start_tx_ba_session(pubsta, tid, 0);
1040 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1041 void *priv_sta, struct ieee80211_tx_status *st)
1043 struct ieee80211_tx_info *info = st->info;
1044 struct minstrel_ht_sta *mi = priv_sta;
1045 struct ieee80211_tx_rate *ar = info->status.rates;
1046 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL;
1047 struct minstrel_priv *mp = priv;
1048 u32 update_interval = mp->update_interval;
1049 bool last, update = false;
1050 bool sample_status = false;
1053 /* This packet was aggregated but doesn't carry status info */
1054 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1055 !(info->flags & IEEE80211_TX_STAT_AMPDU))
1058 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1059 info->status.ampdu_ack_len =
1060 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1061 info->status.ampdu_len = 1;
1064 mi->ampdu_packets++;
1065 mi->ampdu_len += info->status.ampdu_len;
1067 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
1068 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1070 mi->sample_wait = 16 + 2 * avg_ampdu_len;
1071 mi->sample_tries = 1;
1075 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1076 mi->sample_packets += info->status.ampdu_len;
1078 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
1079 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
1081 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1082 for (i = 0; !last; i++) {
1083 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1084 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1086 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1087 if (rate == rate_sample)
1088 sample_status = true;
1091 rate->success += info->status.ampdu_ack_len;
1093 rate->attempts += ar[i].count * info->status.ampdu_len;
1096 switch (mi->sample_mode) {
1097 case MINSTREL_SAMPLE_IDLE:
1098 if (mp->hw->max_rates > 1 ||
1099 mi->total_packets_cur < SAMPLE_SWITCH_THR)
1100 update_interval /= 2;
1103 case MINSTREL_SAMPLE_ACTIVE:
1107 mi->sample_mode = MINSTREL_SAMPLE_PENDING;
1111 case MINSTREL_SAMPLE_PENDING:
1116 minstrel_ht_update_stats(mp, mi, false);
1121 if (mp->hw->max_rates > 1) {
1123 * check for sudden death of spatial multiplexing,
1124 * downgrade to a lower number of streams if necessary.
1126 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1127 if (rate->attempts > 30 &&
1128 rate->success < rate->attempts / 4) {
1129 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1133 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1134 if (rate2->attempts > 30 &&
1135 rate2->success < rate2->attempts / 4) {
1136 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1141 if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1143 minstrel_ht_update_stats(mp, mi, true);
1147 minstrel_ht_update_rates(mp, mi);
1151 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1154 struct minstrel_rate_stats *mrs;
1155 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1156 unsigned int cw = mp->cw_min;
1157 unsigned int ctime = 0;
1158 unsigned int t_slot = 9; /* FIXME */
1159 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1160 unsigned int overhead = 0, overhead_rtscts = 0;
1162 mrs = minstrel_get_ratestats(mi, index);
1163 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1164 mrs->retry_count = 1;
1165 mrs->retry_count_rtscts = 1;
1169 mrs->retry_count = 2;
1170 mrs->retry_count_rtscts = 2;
1171 mrs->retry_updated = true;
1173 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1175 /* Contention time for first 2 tries */
1176 ctime = (t_slot * cw) >> 1;
1177 cw = min((cw << 1) | 1, mp->cw_max);
1178 ctime += (t_slot * cw) >> 1;
1179 cw = min((cw << 1) | 1, mp->cw_max);
1181 if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES)) {
1182 overhead = mi->overhead_legacy;
1183 overhead_rtscts = mi->overhead_legacy_rtscts;
1185 overhead = mi->overhead;
1186 overhead_rtscts = mi->overhead_rtscts;
1189 /* Total TX time for data and Contention after first 2 tries */
1190 tx_time = ctime + 2 * (overhead + tx_time_data);
1191 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1193 /* See how many more tries we can fit inside segment size */
1195 /* Contention time for this try */
1196 ctime = (t_slot * cw) >> 1;
1197 cw = min((cw << 1) | 1, mp->cw_max);
1199 /* Total TX time after this try */
1200 tx_time += ctime + overhead + tx_time_data;
1201 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1203 if (tx_time_rtscts < mp->segment_size)
1204 mrs->retry_count_rtscts++;
1205 } while ((tx_time < mp->segment_size) &&
1206 (++mrs->retry_count < mp->max_retry));
1211 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1212 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1214 int group_idx = index / MCS_GROUP_RATES;
1215 const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1216 struct minstrel_rate_stats *mrs;
1218 u16 flags = group->flags;
1220 mrs = minstrel_get_ratestats(mi, index);
1221 if (!mrs->retry_updated)
1222 minstrel_calc_retransmit(mp, mi, index);
1224 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1225 ratetbl->rate[offset].count = 2;
1226 ratetbl->rate[offset].count_rts = 2;
1227 ratetbl->rate[offset].count_cts = 2;
1229 ratetbl->rate[offset].count = mrs->retry_count;
1230 ratetbl->rate[offset].count_cts = mrs->retry_count;
1231 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1234 index %= MCS_GROUP_RATES;
1235 if (group_idx == MINSTREL_CCK_GROUP)
1236 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1237 else if (group_idx == MINSTREL_OFDM_GROUP)
1238 idx = mp->ofdm_rates[mi->band][index %
1239 ARRAY_SIZE(mp->ofdm_rates[0])];
1240 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1241 idx = ((group->streams - 1) << 4) |
1244 idx = index + (group->streams - 1) * 8;
1246 /* enable RTS/CTS if needed:
1247 * - if station is in dynamic SMPS (and streams > 1)
1248 * - for fallback rates, to increase chances of getting through
1251 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
1252 group->streams > 1)) {
1253 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1254 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1257 ratetbl->rate[offset].idx = idx;
1258 ratetbl->rate[offset].flags = flags;
1262 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1264 int group = rate / MCS_GROUP_RATES;
1265 rate %= MCS_GROUP_RATES;
1266 return mi->groups[group].rates[rate].prob_avg;
1270 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1272 int group = mi->max_prob_rate / MCS_GROUP_RATES;
1273 const struct mcs_group *g = &minstrel_mcs_groups[group];
1274 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
1275 unsigned int duration;
1277 /* Disable A-MSDU if max_prob_rate is bad */
1278 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1281 duration = g->duration[rate];
1282 duration <<= g->shift;
1284 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1285 if (duration > MCS_DURATION(1, 0, 52))
1289 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1292 if (duration > MCS_DURATION(1, 0, 104))
1296 * If the rate is slower than single-stream MCS7, or if the max throughput
1297 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1300 if (duration > MCS_DURATION(1, 0, 260) ||
1301 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1302 MINSTREL_FRAC(75, 100)))
1306 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1307 * Since aggregation sessions are started/stopped without txq flush, use
1308 * the limit here to avoid the complexity of having to de-aggregate
1309 * packets in the queue.
1311 if (!mi->sta->vht_cap.vht_supported)
1312 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1319 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1321 struct ieee80211_sta_rates *rates;
1322 u16 first_rate = mi->max_tp_rate[0];
1325 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE)
1326 first_rate = mi->sample_rate;
1328 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1332 /* Start with max_tp_rate[0] */
1333 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate);
1335 if (mp->hw->max_rates >= 3) {
1336 /* At least 3 tx rates supported, use max_tp_rate[1] next */
1337 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1340 if (mp->hw->max_rates >= 2) {
1341 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1344 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1345 rates->rate[i].idx = -1;
1346 rate_control_set_rates(mp->hw, mi->sta, rates);
1350 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1352 struct minstrel_rate_stats *mrs;
1353 struct minstrel_mcs_group_data *mg;
1354 unsigned int sample_dur, sample_group, cur_max_tp_streams;
1355 int tp_rate1, tp_rate2;
1358 if (mp->hw->max_rates == 1 && mp->sample_switch &&
1359 (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
1360 mp->sample_switch == 1))
1363 if (mi->sample_wait > 0) {
1368 if (!mi->sample_tries)
1371 sample_group = mi->sample_group;
1372 mg = &mi->groups[sample_group];
1373 sample_idx = sample_table[mg->column][mg->index];
1374 minstrel_set_next_sample_idx(mi);
1376 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1379 mrs = &mg->rates[sample_idx];
1380 sample_idx += sample_group * MCS_GROUP_RATES;
1382 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1383 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1384 minstrel_get_duration(mi->max_tp_rate[1])) {
1385 tp_rate1 = mi->max_tp_rate[1];
1386 tp_rate2 = mi->max_tp_rate[0];
1388 tp_rate1 = mi->max_tp_rate[0];
1389 tp_rate2 = mi->max_tp_rate[1];
1393 * Sampling might add some overhead (RTS, no aggregation)
1394 * to the frame. Hence, don't use sampling for the highest currently
1395 * used highest throughput or probability rate.
1397 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1401 * Do not sample if the probability is already higher than 95%,
1402 * or if the rate is 3 times slower than the current max probability
1403 * rate, to avoid wasting airtime.
1405 sample_dur = minstrel_get_duration(sample_idx);
1406 if (mrs->prob_avg > MINSTREL_FRAC(95, 100) ||
1407 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1412 * For devices with no configurable multi-rate retry, skip sampling
1413 * below the per-group max throughput rate, and only use one sampling
1416 if (mp->hw->max_rates == 1 &&
1417 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur ||
1421 /* Skip already sampled slow rates */
1422 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts)
1426 * Make sure that lower rates get sampled only occasionally,
1427 * if the link is working perfectly.
1430 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1431 MCS_GROUP_RATES].streams;
1432 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1433 (cur_max_tp_streams - 1 <
1434 minstrel_mcs_groups[sample_group].streams ||
1435 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1436 if (mrs->sample_skipped < 20)
1439 if (mi->sample_slow++ > 2)
1448 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1449 struct ieee80211_tx_rate_control *txrc)
1451 const struct mcs_group *sample_group;
1452 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1453 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1454 struct minstrel_ht_sta *mi = priv_sta;
1455 struct minstrel_priv *mp = priv;
1458 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1459 !minstrel_ht_is_legacy_group(mi->max_prob_rate / MCS_GROUP_RATES))
1460 minstrel_aggr_check(sta, txrc->skb);
1462 info->flags |= mi->tx_flags;
1464 #ifdef CONFIG_MAC80211_DEBUGFS
1465 if (mp->fixed_rate_idx != -1)
1469 /* Don't use EAPOL frames for sampling on non-mrr hw */
1470 if (mp->hw->max_rates == 1 &&
1471 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1474 sample_idx = minstrel_get_sample_rate(mp, mi);
1476 mi->total_packets++;
1479 if (mi->total_packets == ~0) {
1480 mi->total_packets = 0;
1481 mi->sample_packets = 0;
1487 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1488 sample_idx %= MCS_GROUP_RATES;
1490 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1491 (sample_idx >= 4) != txrc->short_preamble)
1494 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1497 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1498 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1499 rate->idx = mp->cck_rates[idx];
1500 } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1501 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1502 rate->idx = mp->ofdm_rates[mi->band][idx];
1503 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1504 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1505 sample_group->streams);
1507 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1510 rate->flags = sample_group->flags;
1514 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1515 struct ieee80211_supported_band *sband,
1516 struct ieee80211_sta *sta)
1520 if (sband->band != NL80211_BAND_2GHZ)
1523 if (sta->ht_cap.ht_supported &&
1524 !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1527 for (i = 0; i < 4; i++) {
1528 if (mp->cck_rates[i] == 0xff ||
1529 !rate_supported(sta, sband->band, mp->cck_rates[i]))
1532 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1533 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1534 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1539 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1540 struct ieee80211_supported_band *sband,
1541 struct ieee80211_sta *sta)
1546 if (sta->ht_cap.ht_supported)
1549 rates = mp->ofdm_rates[sband->band];
1550 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1551 if (rates[i] == 0xff ||
1552 !rate_supported(sta, sband->band, rates[i]))
1555 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1560 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1561 struct cfg80211_chan_def *chandef,
1562 struct ieee80211_sta *sta, void *priv_sta)
1564 struct minstrel_priv *mp = priv;
1565 struct minstrel_ht_sta *mi = priv_sta;
1566 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1567 u16 ht_cap = sta->ht_cap.cap;
1568 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1569 const struct ieee80211_rate *ctl_rate;
1572 int n_supported = 0;
1577 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1579 if (vht_cap->vht_supported)
1580 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1584 memset(mi, 0, sizeof(*mi));
1587 mi->band = sband->band;
1588 mi->last_stats_update = jiffies;
1590 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1591 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1592 mi->overhead += ack_dur;
1593 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1595 ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1596 erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1597 ack_dur = ieee80211_frame_duration(sband->band, 10,
1598 ctl_rate->bitrate, erp, 1,
1599 ieee80211_chandef_get_shift(chandef));
1600 mi->overhead_legacy = ack_dur;
1601 mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1603 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1605 /* When using MRR, sample more on the first attempt, without delay */
1607 mi->sample_count = 16;
1608 mi->sample_wait = 0;
1610 mi->sample_count = 8;
1611 mi->sample_wait = 8;
1613 mi->sample_tries = 4;
1616 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1617 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1619 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1621 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1622 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1624 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1627 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1629 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1631 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1632 u32 gflags = minstrel_mcs_groups[i].flags;
1635 mi->supported[i] = 0;
1636 if (minstrel_ht_is_legacy_group(i))
1639 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1640 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1641 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1644 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1649 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1650 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1653 nss = minstrel_mcs_groups[i].streams;
1655 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1656 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1660 if (gflags & IEEE80211_TX_RC_MCS) {
1661 if (use_vht && minstrel_vht_only)
1664 mi->supported[i] = mcs->rx_mask[nss - 1];
1665 if (mi->supported[i])
1671 if (!vht_cap->vht_supported ||
1672 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1673 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1676 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1677 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1678 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1679 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1684 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1686 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1691 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1692 vht_cap->vht_mcs.tx_mcs_map);
1694 if (mi->supported[i])
1698 minstrel_ht_update_cck(mp, mi, sband, sta);
1699 minstrel_ht_update_ofdm(mp, mi, sband, sta);
1701 /* create an initial rate table with the lowest supported rates */
1702 minstrel_ht_update_stats(mp, mi, true);
1703 minstrel_ht_update_rates(mp, mi);
1707 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1708 struct cfg80211_chan_def *chandef,
1709 struct ieee80211_sta *sta, void *priv_sta)
1711 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1715 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1716 struct cfg80211_chan_def *chandef,
1717 struct ieee80211_sta *sta, void *priv_sta,
1720 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1724 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1726 struct ieee80211_supported_band *sband;
1727 struct minstrel_ht_sta *mi;
1728 struct minstrel_priv *mp = priv;
1729 struct ieee80211_hw *hw = mp->hw;
1733 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1734 sband = hw->wiphy->bands[i];
1735 if (sband && sband->n_bitrates > max_rates)
1736 max_rates = sband->n_bitrates;
1739 return kzalloc(sizeof(*mi), gfp);
1743 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1749 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1750 const s16 *bitrates, int n_rates, u32 rate_flags)
1754 for (i = 0; i < sband->n_bitrates; i++) {
1755 struct ieee80211_rate *rate = &sband->bitrates[i];
1757 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1760 for (j = 0; j < n_rates; j++) {
1761 if (rate->bitrate != bitrates[j])
1771 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1773 static const s16 bitrates[4] = { 10, 20, 55, 110 };
1774 struct ieee80211_supported_band *sband;
1775 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1777 memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1778 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1782 BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1783 minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1784 minstrel_cck_bitrates,
1785 ARRAY_SIZE(minstrel_cck_bitrates),
1790 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1792 static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1793 struct ieee80211_supported_band *sband;
1794 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1796 memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1797 sband = mp->hw->wiphy->bands[band];
1801 BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1802 minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1803 minstrel_ofdm_bitrates,
1804 ARRAY_SIZE(minstrel_ofdm_bitrates),
1809 minstrel_ht_alloc(struct ieee80211_hw *hw)
1811 struct minstrel_priv *mp;
1814 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1818 mp->sample_switch = -1;
1820 /* contention window settings
1821 * Just an approximation. Using the per-queue values would complicate
1822 * the calculations and is probably unnecessary */
1826 /* maximum time that the hw is allowed to stay in one MRR segment */
1827 mp->segment_size = 6000;
1829 if (hw->max_rate_tries > 0)
1830 mp->max_retry = hw->max_rate_tries;
1832 /* safe default, does not necessarily have to match hw properties */
1835 if (hw->max_rates >= 4)
1839 mp->update_interval = HZ / 20;
1841 minstrel_ht_init_cck_rates(mp);
1842 for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1843 minstrel_ht_init_ofdm_rates(mp, i);
1848 #ifdef CONFIG_MAC80211_DEBUGFS
1849 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1850 struct dentry *debugfsdir)
1852 struct minstrel_priv *mp = priv;
1854 mp->fixed_rate_idx = (u32) -1;
1855 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1856 &mp->fixed_rate_idx);
1857 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir,
1858 &mp->sample_switch);
1863 minstrel_ht_free(void *priv)
1868 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1870 struct minstrel_ht_sta *mi = priv_sta;
1871 int i, j, prob, tp_avg;
1873 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1874 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1875 prob = mi->groups[i].rates[j].prob_avg;
1877 /* convert tp_avg from pkt per second in kbps */
1878 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1879 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1884 static const struct rate_control_ops mac80211_minstrel_ht = {
1885 .name = "minstrel_ht",
1886 .tx_status_ext = minstrel_ht_tx_status,
1887 .get_rate = minstrel_ht_get_rate,
1888 .rate_init = minstrel_ht_rate_init,
1889 .rate_update = minstrel_ht_rate_update,
1890 .alloc_sta = minstrel_ht_alloc_sta,
1891 .free_sta = minstrel_ht_free_sta,
1892 .alloc = minstrel_ht_alloc,
1893 .free = minstrel_ht_free,
1894 #ifdef CONFIG_MAC80211_DEBUGFS
1895 .add_debugfs = minstrel_ht_add_debugfs,
1896 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1898 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1902 static void __init init_sample_table(void)
1904 int col, i, new_idx;
1905 u8 rnd[MCS_GROUP_RATES];
1907 memset(sample_table, 0xff, sizeof(sample_table));
1908 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1909 prandom_bytes(rnd, sizeof(rnd));
1910 for (i = 0; i < MCS_GROUP_RATES; i++) {
1911 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1912 while (sample_table[col][new_idx] != 0xff)
1913 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1915 sample_table[col][new_idx] = i;
1921 rc80211_minstrel_init(void)
1923 init_sample_table();
1924 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1928 rc80211_minstrel_exit(void)
1930 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);