2 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 #include <linux/netdevice.h>
9 #include <linux/types.h>
10 #include <linux/skbuff.h>
11 #include <linux/debugfs.h>
12 #include <linux/random.h>
13 #include <linux/moduleparam.h>
14 #include <linux/ieee80211.h>
15 #include <net/mac80211.h>
18 #include "rc80211_minstrel.h"
19 #include "rc80211_minstrel_ht.h"
21 #define AVG_AMPDU_SIZE 16
22 #define AVG_PKT_SIZE 1200
24 /* Number of bits for an average sized packet */
25 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
27 /* Number of symbols for a packet with (bps) bits per symbol */
28 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
30 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
31 #define MCS_SYMBOL_TIME(sgi, syms) \
33 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
34 ((syms) * 1000) << 2 /* syms * 4 us */ \
37 /* Transmit duration for the raw data part of an average sized packet */
38 #define MCS_DURATION(streams, sgi, bps) \
39 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
46 * Define group sort order: HT40 -> SGI -> #streams
48 #define GROUP_IDX(_streams, _sgi, _ht40) \
49 MINSTREL_HT_GROUP_0 + \
50 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
51 MINSTREL_MAX_STREAMS * _sgi + \
54 #define _MAX(a, b) (((a)>(b))?(a):(b))
56 #define GROUP_SHIFT(duration) \
57 _MAX(0, 16 - __builtin_clz(duration))
59 /* MCS rate information for an MCS group */
60 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
61 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
62 .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, \
101 IEEE80211_TX_RC_VHT_MCS | \
102 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
103 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
104 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
106 MCS_DURATION(_streams, _sgi, \
107 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
112 MCS_DURATION(_streams, _sgi, \
113 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
114 MCS_DURATION(_streams, _sgi, \
115 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
116 MCS_DURATION(_streams, _sgi, \
117 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
118 MCS_DURATION(_streams, _sgi, \
119 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
120 MCS_DURATION(_streams, _sgi, \
121 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
122 MCS_DURATION(_streams, _sgi, \
123 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
124 MCS_DURATION(_streams, _sgi, \
125 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
129 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
130 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
131 BW2VBPS(_bw, 117, 54, 26)))
133 #define VHT_GROUP(_streams, _sgi, _bw) \
134 __VHT_GROUP(_streams, _sgi, _bw, \
135 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
137 #define CCK_DURATION(_bitrate, _short, _len) \
138 (1000 * (10 /* SIFS */ + \
139 (_short ? 72 + 24 : 144 + 48) + \
140 (8 * (_len + 4) * 10) / (_bitrate)))
142 #define CCK_ACK_DURATION(_bitrate, _short) \
143 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
144 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
146 #define CCK_DURATION_LIST(_short, _s) \
147 CCK_ACK_DURATION(10, _short) >> _s, \
148 CCK_ACK_DURATION(20, _short) >> _s, \
149 CCK_ACK_DURATION(55, _short) >> _s, \
150 CCK_ACK_DURATION(110, _short) >> _s
152 #define __CCK_GROUP(_s) \
153 [MINSTREL_CCK_GROUP] = { \
158 CCK_DURATION_LIST(false, _s), \
159 CCK_DURATION_LIST(true, _s) \
163 #define CCK_GROUP_SHIFT \
164 GROUP_SHIFT(CCK_ACK_DURATION(10, false))
166 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
169 static bool minstrel_vht_only = true;
170 module_param(minstrel_vht_only, bool, 0644);
171 MODULE_PARM_DESC(minstrel_vht_only,
172 "Use only VHT rates when VHT is supported by sta.");
175 * To enable sufficiently targeted rate sampling, MCS rates are divided into
176 * groups, based on the number of streams and flags (HT40, SGI) that they
179 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
180 * BW -> SGI -> #streams
182 const struct mcs_group minstrel_mcs_groups[] = {
183 MCS_GROUP(1, 0, BW_20),
184 MCS_GROUP(2, 0, BW_20),
185 MCS_GROUP(3, 0, BW_20),
186 MCS_GROUP(4, 0, BW_20),
188 MCS_GROUP(1, 1, BW_20),
189 MCS_GROUP(2, 1, BW_20),
190 MCS_GROUP(3, 1, BW_20),
191 MCS_GROUP(4, 1, BW_20),
193 MCS_GROUP(1, 0, BW_40),
194 MCS_GROUP(2, 0, BW_40),
195 MCS_GROUP(3, 0, BW_40),
196 MCS_GROUP(4, 0, BW_40),
198 MCS_GROUP(1, 1, BW_40),
199 MCS_GROUP(2, 1, BW_40),
200 MCS_GROUP(3, 1, BW_40),
201 MCS_GROUP(4, 1, BW_40),
205 VHT_GROUP(1, 0, BW_20),
206 VHT_GROUP(2, 0, BW_20),
207 VHT_GROUP(3, 0, BW_20),
208 VHT_GROUP(4, 0, BW_20),
210 VHT_GROUP(1, 1, BW_20),
211 VHT_GROUP(2, 1, BW_20),
212 VHT_GROUP(3, 1, BW_20),
213 VHT_GROUP(4, 1, BW_20),
215 VHT_GROUP(1, 0, BW_40),
216 VHT_GROUP(2, 0, BW_40),
217 VHT_GROUP(3, 0, BW_40),
218 VHT_GROUP(4, 0, BW_40),
220 VHT_GROUP(1, 1, BW_40),
221 VHT_GROUP(2, 1, BW_40),
222 VHT_GROUP(3, 1, BW_40),
223 VHT_GROUP(4, 1, BW_40),
225 VHT_GROUP(1, 0, BW_80),
226 VHT_GROUP(2, 0, BW_80),
227 VHT_GROUP(3, 0, BW_80),
228 VHT_GROUP(4, 0, BW_80),
230 VHT_GROUP(1, 1, BW_80),
231 VHT_GROUP(2, 1, BW_80),
232 VHT_GROUP(3, 1, BW_80),
233 VHT_GROUP(4, 1, BW_80),
236 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
239 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
242 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
243 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
245 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
248 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
253 if (nss != 3 && nss != 6)
255 } else if (bw == BW_80) {
256 if (nss == 3 || nss == 7)
261 WARN_ON(bw != BW_40);
264 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
265 case IEEE80211_VHT_MCS_SUPPORT_0_7:
268 case IEEE80211_VHT_MCS_SUPPORT_0_8:
271 case IEEE80211_VHT_MCS_SUPPORT_0_9:
277 return 0x3ff & ~mask;
281 * Look up an MCS group index based on mac80211 rate information
284 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
286 return GROUP_IDX((rate->idx / 8) + 1,
287 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
288 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
292 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
294 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
295 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
296 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
297 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
300 static struct minstrel_rate_stats *
301 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
302 struct ieee80211_tx_rate *rate)
306 if (rate->flags & IEEE80211_TX_RC_MCS) {
307 group = minstrel_ht_get_group_idx(rate);
309 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
310 group = minstrel_vht_get_group_idx(rate);
311 idx = ieee80211_rate_get_vht_mcs(rate);
313 group = MINSTREL_CCK_GROUP;
315 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
316 if (rate->idx == mp->cck_rates[idx])
320 if ((mi->supported[group] & BIT(idx + 4)) &&
321 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
324 return &mi->groups[group].rates[idx];
327 static inline struct minstrel_rate_stats *
328 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
330 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
334 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
336 if (!mi->avg_ampdu_len)
337 return AVG_AMPDU_SIZE;
339 return MINSTREL_TRUNC(mi->avg_ampdu_len);
343 * Return current throughput based on the average A-MPDU length, taking into
344 * account the expected number of retransmissions and their expected length
347 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
350 unsigned int nsecs = 0;
352 /* do not account throughput if sucess prob is below 10% */
353 if (prob_ewma < MINSTREL_FRAC(10, 100))
356 if (group != MINSTREL_CCK_GROUP)
357 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
359 nsecs += minstrel_mcs_groups[group].duration[rate] <<
360 minstrel_mcs_groups[group].shift;
363 * For the throughput calculation, limit the probability value to 90% to
364 * account for collision related packet error rate fluctuation
365 * (prob is scaled - see MINSTREL_FRAC above)
367 if (prob_ewma > MINSTREL_FRAC(90, 100))
368 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
371 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
375 * Find & sort topmost throughput rates
377 * If multiple rates provide equal throughput the sorting is based on their
378 * current success probability. Higher success probability is preferred among
379 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
382 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
385 int cur_group, cur_idx, cur_tp_avg, cur_prob;
386 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
387 int j = MAX_THR_RATES;
389 cur_group = index / MCS_GROUP_RATES;
390 cur_idx = index % MCS_GROUP_RATES;
391 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
392 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
395 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
396 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
397 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
398 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
400 if (cur_tp_avg < tmp_tp_avg ||
401 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
406 if (j < MAX_THR_RATES - 1) {
407 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
408 (MAX_THR_RATES - (j + 1))));
410 if (j < MAX_THR_RATES)
415 * Find and set the topmost probability rate per sta and per group
418 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
420 struct minstrel_mcs_group_data *mg;
421 struct minstrel_rate_stats *mrs;
422 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
423 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
424 int max_gpr_group, max_gpr_idx;
425 int max_gpr_tp_avg, max_gpr_prob;
427 cur_group = index / MCS_GROUP_RATES;
428 cur_idx = index % MCS_GROUP_RATES;
429 mg = &mi->groups[index / MCS_GROUP_RATES];
430 mrs = &mg->rates[index % MCS_GROUP_RATES];
432 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
433 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
434 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
435 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
437 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
438 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
439 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
440 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
441 (max_tp_group != MINSTREL_CCK_GROUP))
444 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
445 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
446 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
448 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
449 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
451 if (cur_tp_avg > tmp_tp_avg)
452 mi->max_prob_rate = index;
454 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
457 if (cur_tp_avg > max_gpr_tp_avg)
458 mg->max_group_prob_rate = index;
460 if (mrs->prob_ewma > tmp_prob)
461 mi->max_prob_rate = index;
462 if (mrs->prob_ewma > max_gpr_prob)
463 mg->max_group_prob_rate = index;
469 * Assign new rate set per sta and use CCK rates only if the fastest
470 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
471 * rate sets where MCS and CCK rates are mixed, because CCK rates can
472 * not use aggregation.
475 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
476 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
477 u16 tmp_cck_tp_rate[MAX_THR_RATES])
479 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
482 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
483 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
484 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
485 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
487 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
488 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
489 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
490 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
492 if (tmp_cck_tp > tmp_mcs_tp) {
493 for(i = 0; i < MAX_THR_RATES; i++) {
494 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
502 * Try to increase robustness of max_prob rate by decrease number of
503 * streams if possible.
506 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
508 struct minstrel_mcs_group_data *mg;
509 int tmp_max_streams, group, tmp_idx, tmp_prob;
512 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
513 MCS_GROUP_RATES].streams;
514 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
515 mg = &mi->groups[group];
516 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
519 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
520 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
522 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
523 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
524 mi->max_prob_rate = mg->max_group_prob_rate;
525 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
533 * Update rate statistics and select new primary rates
535 * Rules for rate selection:
536 * - max_prob_rate must use only one stream, as a tradeoff between delivery
537 * probability and throughput during strong fluctuations
538 * - as long as the max prob rate has a probability of more than 75%, pick
539 * higher throughput rates, even if the probablity is a bit lower
542 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
544 struct minstrel_mcs_group_data *mg;
545 struct minstrel_rate_stats *mrs;
546 int group, i, j, cur_prob;
547 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
548 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
550 if (mi->ampdu_packets > 0) {
551 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
552 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
553 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
556 mi->avg_ampdu_len = 0;
558 mi->ampdu_packets = 0;
562 mi->sample_count = 0;
564 /* Initialize global rate indexes */
565 for(j = 0; j < MAX_THR_RATES; j++){
566 tmp_mcs_tp_rate[j] = 0;
567 tmp_cck_tp_rate[j] = 0;
570 /* Find best rate sets within all MCS groups*/
571 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
573 mg = &mi->groups[group];
574 if (!mi->supported[group])
579 /* (re)Initialize group rate indexes */
580 for(j = 0; j < MAX_THR_RATES; j++)
581 tmp_group_tp_rate[j] = group;
583 for (i = 0; i < MCS_GROUP_RATES; i++) {
584 if (!(mi->supported[group] & BIT(i)))
587 index = MCS_GROUP_RATES * group + i;
590 mrs->retry_updated = false;
591 minstrel_calc_rate_stats(mrs);
592 cur_prob = mrs->prob_ewma;
594 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
597 /* Find max throughput rate set */
598 if (group != MINSTREL_CCK_GROUP) {
599 minstrel_ht_sort_best_tp_rates(mi, index,
601 } else if (group == MINSTREL_CCK_GROUP) {
602 minstrel_ht_sort_best_tp_rates(mi, index,
606 /* Find max throughput rate set within a group */
607 minstrel_ht_sort_best_tp_rates(mi, index,
610 /* Find max probability rate per group and global */
611 minstrel_ht_set_best_prob_rate(mi, index);
614 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
615 sizeof(mg->max_group_tp_rate));
618 /* Assign new rate set per sta */
619 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
620 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
622 /* Try to increase robustness of max_prob_rate*/
623 minstrel_ht_prob_rate_reduce_streams(mi);
625 /* try to sample all available rates during each interval */
626 mi->sample_count *= 8;
628 #ifdef CONFIG_MAC80211_DEBUGFS
629 /* use fixed index if set */
630 if (mp->fixed_rate_idx != -1) {
631 for (i = 0; i < 4; i++)
632 mi->max_tp_rate[i] = mp->fixed_rate_idx;
633 mi->max_prob_rate = mp->fixed_rate_idx;
637 /* Reset update timer */
638 mi->last_stats_update = jiffies;
642 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
650 if (rate->flags & IEEE80211_TX_RC_MCS ||
651 rate->flags & IEEE80211_TX_RC_VHT_MCS)
654 return rate->idx == mp->cck_rates[0] ||
655 rate->idx == mp->cck_rates[1] ||
656 rate->idx == mp->cck_rates[2] ||
657 rate->idx == mp->cck_rates[3];
661 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
663 struct minstrel_mcs_group_data *mg;
667 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
668 mg = &mi->groups[mi->sample_group];
670 if (!mi->supported[mi->sample_group])
673 if (++mg->index >= MCS_GROUP_RATES) {
675 if (++mg->column >= ARRAY_SIZE(sample_table))
683 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
685 int group, orig_group;
687 orig_group = group = *idx / MCS_GROUP_RATES;
691 if (!mi->supported[group])
694 if (minstrel_mcs_groups[group].streams >
695 minstrel_mcs_groups[orig_group].streams)
699 *idx = mi->groups[group].max_group_tp_rate[0];
701 *idx = mi->groups[group].max_group_tp_rate[1];
707 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
709 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
710 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
713 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
716 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
719 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
722 tid = ieee80211_get_tid(hdr);
723 if (likely(sta->ampdu_mlme.tid_tx[tid]))
726 ieee80211_start_tx_ba_session(pubsta, tid, 0);
730 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
731 void *priv_sta, struct ieee80211_tx_status *st)
733 struct ieee80211_tx_info *info = st->info;
734 struct minstrel_ht_sta_priv *msp = priv_sta;
735 struct minstrel_ht_sta *mi = &msp->ht;
736 struct ieee80211_tx_rate *ar = info->status.rates;
737 struct minstrel_rate_stats *rate, *rate2;
738 struct minstrel_priv *mp = priv;
739 bool last, update = false;
743 return mac80211_minstrel.tx_status_ext(priv, sband,
746 /* This packet was aggregated but doesn't carry status info */
747 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
748 !(info->flags & IEEE80211_TX_STAT_AMPDU))
751 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
752 info->status.ampdu_ack_len =
753 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
754 info->status.ampdu_len = 1;
758 mi->ampdu_len += info->status.ampdu_len;
760 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
761 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
763 mi->sample_wait = 16 + 2 * avg_ampdu_len;
764 mi->sample_tries = 1;
768 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
769 mi->sample_packets += info->status.ampdu_len;
771 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
772 for (i = 0; !last; i++) {
773 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
774 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
776 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
779 rate->success += info->status.ampdu_ack_len;
781 rate->attempts += ar[i].count * info->status.ampdu_len;
785 * check for sudden death of spatial multiplexing,
786 * downgrade to a lower number of streams if necessary.
788 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
789 if (rate->attempts > 30 &&
790 MINSTREL_FRAC(rate->success, rate->attempts) <
791 MINSTREL_FRAC(20, 100)) {
792 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
796 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
797 if (rate2->attempts > 30 &&
798 MINSTREL_FRAC(rate2->success, rate2->attempts) <
799 MINSTREL_FRAC(20, 100)) {
800 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
804 if (time_after(jiffies, mi->last_stats_update +
805 (mp->update_interval / 2 * HZ) / 1000)) {
807 minstrel_ht_update_stats(mp, mi);
811 minstrel_ht_update_rates(mp, mi);
815 minstrel_get_duration(int index)
817 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
818 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
819 return duration << group->shift;
823 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
826 struct minstrel_rate_stats *mrs;
827 unsigned int tx_time, tx_time_rtscts, tx_time_data;
828 unsigned int cw = mp->cw_min;
829 unsigned int ctime = 0;
830 unsigned int t_slot = 9; /* FIXME */
831 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
832 unsigned int overhead = 0, overhead_rtscts = 0;
834 mrs = minstrel_get_ratestats(mi, index);
835 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
836 mrs->retry_count = 1;
837 mrs->retry_count_rtscts = 1;
841 mrs->retry_count = 2;
842 mrs->retry_count_rtscts = 2;
843 mrs->retry_updated = true;
845 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
847 /* Contention time for first 2 tries */
848 ctime = (t_slot * cw) >> 1;
849 cw = min((cw << 1) | 1, mp->cw_max);
850 ctime += (t_slot * cw) >> 1;
851 cw = min((cw << 1) | 1, mp->cw_max);
853 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
854 overhead = mi->overhead;
855 overhead_rtscts = mi->overhead_rtscts;
858 /* Total TX time for data and Contention after first 2 tries */
859 tx_time = ctime + 2 * (overhead + tx_time_data);
860 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
862 /* See how many more tries we can fit inside segment size */
864 /* Contention time for this try */
865 ctime = (t_slot * cw) >> 1;
866 cw = min((cw << 1) | 1, mp->cw_max);
868 /* Total TX time after this try */
869 tx_time += ctime + overhead + tx_time_data;
870 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
872 if (tx_time_rtscts < mp->segment_size)
873 mrs->retry_count_rtscts++;
874 } while ((tx_time < mp->segment_size) &&
875 (++mrs->retry_count < mp->max_retry));
880 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
881 struct ieee80211_sta_rates *ratetbl, int offset, int index)
883 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
884 struct minstrel_rate_stats *mrs;
886 u16 flags = group->flags;
888 mrs = minstrel_get_ratestats(mi, index);
889 if (!mrs->retry_updated)
890 minstrel_calc_retransmit(mp, mi, index);
892 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
893 ratetbl->rate[offset].count = 2;
894 ratetbl->rate[offset].count_rts = 2;
895 ratetbl->rate[offset].count_cts = 2;
897 ratetbl->rate[offset].count = mrs->retry_count;
898 ratetbl->rate[offset].count_cts = mrs->retry_count;
899 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
902 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
903 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
904 else if (flags & IEEE80211_TX_RC_VHT_MCS)
905 idx = ((group->streams - 1) << 4) |
906 ((index % MCS_GROUP_RATES) & 0xF);
908 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
910 /* enable RTS/CTS if needed:
911 * - if station is in dynamic SMPS (and streams > 1)
912 * - for fallback rates, to increase chances of getting through
915 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
916 group->streams > 1)) {
917 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
918 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
921 ratetbl->rate[offset].idx = idx;
922 ratetbl->rate[offset].flags = flags;
926 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
928 int group = rate / MCS_GROUP_RATES;
929 rate %= MCS_GROUP_RATES;
930 return mi->groups[group].rates[rate].prob_ewma;
934 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
936 int group = mi->max_prob_rate / MCS_GROUP_RATES;
937 const struct mcs_group *g = &minstrel_mcs_groups[group];
938 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
939 unsigned int duration;
941 /* Disable A-MSDU if max_prob_rate is bad */
942 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
945 duration = g->duration[rate];
946 duration <<= g->shift;
948 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
949 if (duration > MCS_DURATION(1, 0, 52))
953 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
956 if (duration > MCS_DURATION(1, 0, 104))
960 * If the rate is slower than single-stream MCS7, or if the max throughput
961 * rate success probability is less than 75%, limit A-MSDU to twice the usual
964 if (duration > MCS_DURATION(1, 0, 260) ||
965 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
966 MINSTREL_FRAC(75, 100)))
970 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
971 * Since aggregation sessions are started/stopped without txq flush, use
972 * the limit here to avoid the complexity of having to de-aggregate
973 * packets in the queue.
975 if (!mi->sta->vht_cap.vht_supported)
976 return IEEE80211_MAX_MPDU_LEN_HT_BA;
983 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
985 struct ieee80211_sta_rates *rates;
988 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
992 /* Start with max_tp_rate[0] */
993 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
995 if (mp->hw->max_rates >= 3) {
996 /* At least 3 tx rates supported, use max_tp_rate[1] next */
997 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1000 if (mp->hw->max_rates >= 2) {
1002 * At least 2 tx rates supported, use max_prob_rate next */
1003 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1006 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1007 rates->rate[i].idx = -1;
1008 rate_control_set_rates(mp->hw, mi->sta, rates);
1012 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1014 struct minstrel_rate_stats *mrs;
1015 struct minstrel_mcs_group_data *mg;
1016 unsigned int sample_dur, sample_group, cur_max_tp_streams;
1017 int tp_rate1, tp_rate2;
1020 if (mi->sample_wait > 0) {
1025 if (!mi->sample_tries)
1028 sample_group = mi->sample_group;
1029 mg = &mi->groups[sample_group];
1030 sample_idx = sample_table[mg->column][mg->index];
1031 minstrel_set_next_sample_idx(mi);
1033 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1036 mrs = &mg->rates[sample_idx];
1037 sample_idx += sample_group * MCS_GROUP_RATES;
1039 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1040 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1041 minstrel_get_duration(mi->max_tp_rate[1])) {
1042 tp_rate1 = mi->max_tp_rate[1];
1043 tp_rate2 = mi->max_tp_rate[0];
1045 tp_rate1 = mi->max_tp_rate[0];
1046 tp_rate2 = mi->max_tp_rate[1];
1050 * Sampling might add some overhead (RTS, no aggregation)
1051 * to the frame. Hence, don't use sampling for the highest currently
1052 * used highest throughput or probability rate.
1054 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1058 * Do not sample if the probability is already higher than 95%,
1059 * or if the rate is 3 times slower than the current max probability
1060 * rate, to avoid wasting airtime.
1062 sample_dur = minstrel_get_duration(sample_idx);
1063 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
1064 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1068 * Make sure that lower rates get sampled only occasionally,
1069 * if the link is working perfectly.
1072 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1073 MCS_GROUP_RATES].streams;
1074 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1075 (cur_max_tp_streams - 1 <
1076 minstrel_mcs_groups[sample_group].streams ||
1077 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1078 if (mrs->sample_skipped < 20)
1081 if (mi->sample_slow++ > 2)
1090 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1091 struct ieee80211_tx_rate_control *txrc)
1093 const struct mcs_group *sample_group;
1094 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1095 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1096 struct minstrel_ht_sta_priv *msp = priv_sta;
1097 struct minstrel_ht_sta *mi = &msp->ht;
1098 struct minstrel_priv *mp = priv;
1101 if (rate_control_send_low(sta, priv_sta, txrc))
1105 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1107 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1108 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1109 minstrel_aggr_check(sta, txrc->skb);
1111 info->flags |= mi->tx_flags;
1113 #ifdef CONFIG_MAC80211_DEBUGFS
1114 if (mp->fixed_rate_idx != -1)
1118 /* Don't use EAPOL frames for sampling on non-mrr hw */
1119 if (mp->hw->max_rates == 1 &&
1120 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1123 sample_idx = minstrel_get_sample_rate(mp, mi);
1125 mi->total_packets++;
1128 if (mi->total_packets == ~0) {
1129 mi->total_packets = 0;
1130 mi->sample_packets = 0;
1136 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1137 sample_idx %= MCS_GROUP_RATES;
1139 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1140 (sample_idx >= 4) != txrc->short_preamble)
1143 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1146 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1147 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1148 rate->idx = mp->cck_rates[idx];
1149 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1150 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1151 sample_group->streams);
1153 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1156 rate->flags = sample_group->flags;
1160 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1161 struct ieee80211_supported_band *sband,
1162 struct ieee80211_sta *sta)
1166 if (sband->band != NL80211_BAND_2GHZ)
1169 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1172 mi->cck_supported = 0;
1173 mi->cck_supported_short = 0;
1174 for (i = 0; i < 4; i++) {
1175 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1178 mi->cck_supported |= BIT(i);
1179 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1180 mi->cck_supported_short |= BIT(i);
1183 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1187 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1188 struct cfg80211_chan_def *chandef,
1189 struct ieee80211_sta *sta, void *priv_sta)
1191 struct minstrel_priv *mp = priv;
1192 struct minstrel_ht_sta_priv *msp = priv_sta;
1193 struct minstrel_ht_sta *mi = &msp->ht;
1194 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1195 u16 ht_cap = sta->ht_cap.cap;
1196 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1198 int n_supported = 0;
1204 /* fall back to the old minstrel for legacy stations */
1205 if (!sta->ht_cap.ht_supported)
1208 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1210 if (vht_cap->vht_supported)
1211 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1216 memset(mi, 0, sizeof(*mi));
1219 mi->last_stats_update = jiffies;
1221 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1222 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1223 mi->overhead += ack_dur;
1224 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1226 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1228 /* When using MRR, sample more on the first attempt, without delay */
1230 mi->sample_count = 16;
1231 mi->sample_wait = 0;
1233 mi->sample_count = 8;
1234 mi->sample_wait = 8;
1236 mi->sample_tries = 4;
1239 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1240 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1242 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1244 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1245 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1247 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1250 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1252 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1254 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1255 u32 gflags = minstrel_mcs_groups[i].flags;
1258 mi->supported[i] = 0;
1259 if (i == MINSTREL_CCK_GROUP) {
1260 minstrel_ht_update_cck(mp, mi, sband, sta);
1264 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1265 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1266 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1269 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1274 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1275 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1278 nss = minstrel_mcs_groups[i].streams;
1280 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1281 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1285 if (gflags & IEEE80211_TX_RC_MCS) {
1286 if (use_vht && minstrel_vht_only)
1289 mi->supported[i] = mcs->rx_mask[nss - 1];
1290 if (mi->supported[i])
1296 if (!vht_cap->vht_supported ||
1297 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1298 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1301 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1302 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1303 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1304 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1309 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1311 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1316 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1317 vht_cap->vht_mcs.tx_mcs_map);
1319 if (mi->supported[i])
1326 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1328 /* create an initial rate table with the lowest supported rates */
1329 minstrel_ht_update_stats(mp, mi);
1330 minstrel_ht_update_rates(mp, mi);
1336 memset(&msp->legacy, 0, sizeof(msp->legacy));
1337 msp->legacy.r = msp->ratelist;
1338 msp->legacy.sample_table = msp->sample_table;
1339 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1344 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1345 struct cfg80211_chan_def *chandef,
1346 struct ieee80211_sta *sta, void *priv_sta)
1348 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1352 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1353 struct cfg80211_chan_def *chandef,
1354 struct ieee80211_sta *sta, void *priv_sta,
1357 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1361 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1363 struct ieee80211_supported_band *sband;
1364 struct minstrel_ht_sta_priv *msp;
1365 struct minstrel_priv *mp = priv;
1366 struct ieee80211_hw *hw = mp->hw;
1370 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1371 sband = hw->wiphy->bands[i];
1372 if (sband && sband->n_bitrates > max_rates)
1373 max_rates = sband->n_bitrates;
1376 msp = kzalloc(sizeof(*msp), gfp);
1380 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1384 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1385 if (!msp->sample_table)
1391 kfree(msp->ratelist);
1398 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1400 struct minstrel_ht_sta_priv *msp = priv_sta;
1402 kfree(msp->sample_table);
1403 kfree(msp->ratelist);
1408 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1410 static const int bitrates[4] = { 10, 20, 55, 110 };
1411 struct ieee80211_supported_band *sband;
1412 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1415 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1419 for (i = 0; i < sband->n_bitrates; i++) {
1420 struct ieee80211_rate *rate = &sband->bitrates[i];
1422 if (rate->flags & IEEE80211_RATE_ERP_G)
1425 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1428 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1429 if (rate->bitrate != bitrates[j])
1432 mp->cck_rates[j] = i;
1439 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1441 struct minstrel_priv *mp;
1443 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1447 /* contention window settings
1448 * Just an approximation. Using the per-queue values would complicate
1449 * the calculations and is probably unnecessary */
1453 /* number of packets (in %) to use for sampling other rates
1454 * sample less often for non-mrr packets, because the overhead
1455 * is much higher than with mrr */
1456 mp->lookaround_rate = 5;
1457 mp->lookaround_rate_mrr = 10;
1459 /* maximum time that the hw is allowed to stay in one MRR segment */
1460 mp->segment_size = 6000;
1462 if (hw->max_rate_tries > 0)
1463 mp->max_retry = hw->max_rate_tries;
1465 /* safe default, does not necessarily have to match hw properties */
1468 if (hw->max_rates >= 4)
1472 mp->update_interval = 100;
1474 #ifdef CONFIG_MAC80211_DEBUGFS
1475 mp->fixed_rate_idx = (u32) -1;
1476 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1477 &mp->fixed_rate_idx);
1480 minstrel_ht_init_cck_rates(mp);
1486 minstrel_ht_free(void *priv)
1491 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1493 struct minstrel_ht_sta_priv *msp = priv_sta;
1494 struct minstrel_ht_sta *mi = &msp->ht;
1495 int i, j, prob, tp_avg;
1498 return mac80211_minstrel.get_expected_throughput(priv_sta);
1500 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1501 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1502 prob = mi->groups[i].rates[j].prob_ewma;
1504 /* convert tp_avg from pkt per second in kbps */
1505 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1506 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1511 static const struct rate_control_ops mac80211_minstrel_ht = {
1512 .name = "minstrel_ht",
1513 .tx_status_ext = minstrel_ht_tx_status,
1514 .get_rate = minstrel_ht_get_rate,
1515 .rate_init = minstrel_ht_rate_init,
1516 .rate_update = minstrel_ht_rate_update,
1517 .alloc_sta = minstrel_ht_alloc_sta,
1518 .free_sta = minstrel_ht_free_sta,
1519 .alloc = minstrel_ht_alloc,
1520 .free = minstrel_ht_free,
1521 #ifdef CONFIG_MAC80211_DEBUGFS
1522 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1524 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1528 static void __init init_sample_table(void)
1530 int col, i, new_idx;
1531 u8 rnd[MCS_GROUP_RATES];
1533 memset(sample_table, 0xff, sizeof(sample_table));
1534 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1535 prandom_bytes(rnd, sizeof(rnd));
1536 for (i = 0; i < MCS_GROUP_RATES; i++) {
1537 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1538 while (sample_table[col][new_idx] != 0xff)
1539 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1541 sample_table[col][new_idx] = i;
1547 rc80211_minstrel_init(void)
1549 init_sample_table();
1550 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1554 rc80211_minstrel_exit(void)
1556 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);