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mac80211: remove vif debugfs driver callbacks
[linux.git] / net / mac80211 / rc80211_minstrel_ht.c
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ec8aa669 1/*
a0497f9f 2 * Copyright (C) 2010-2013 Felix Fietkau <[email protected]>
ec8aa669
FF		 3 *
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.
7 */
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/ieee80211.h>
14#include <net/mac80211.h>
15#include "rate.h"
16#include "rc80211_minstrel.h"
17#include "rc80211_minstrel_ht.h"
18
19#define AVG_PKT_SIZE 1200
ec8aa669
FF		 20
21/* Number of bits for an average sized packet */
22#define MCS_NBITS (AVG_PKT_SIZE << 3)
23
24/* Number of symbols for a packet with (bps) bits per symbol */
25#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
26
ed97a13c 27/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
ec8aa669
FF		 28#define MCS_SYMBOL_TIME(sgi, syms) \
29 (sgi ? \
ed97a13c
FF		 30 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
31 ((syms) * 1000) << 2 /* syms * 4 us */ \
ec8aa669
FF		 32 )
33
34/* Transmit duration for the raw data part of an average sized packet */
35#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
36
a5f69d94
HS		 37/*
38 * Define group sort order: HT40 -> SGI -> #streams
39 */
40#define GROUP_IDX(_streams, _sgi, _ht40) \
41 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
42 MINSTREL_MAX_STREAMS * _sgi + \
43 _streams - 1
44
ec8aa669 45/* MCS rate information for an MCS group */
a5f69d94
HS		 46#define MCS_GROUP(_streams, _sgi, _ht40) \
47 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
ec8aa669
FF		 48 .streams = _streams, \
49 .flags = \
50 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
51 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
52 .duration = { \
53 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
54 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
55 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
56 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
57 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
58 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
59 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
60 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
61 } \
62}
63
a0497f9f 64#define CCK_DURATION(_bitrate, _short, _len) \
ed97a13c 65 (1000 * (10 /* SIFS */ + \
a0497f9f 66 (_short ? 72 + 24 : 144 + 48 ) + \
ed97a13c 67 (8 * (_len + 4) * 10) / (_bitrate)))
a0497f9f
FF		 68
69#define CCK_ACK_DURATION(_bitrate, _short) \
70 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
71 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
72
73#define CCK_DURATION_LIST(_short) \
74 CCK_ACK_DURATION(10, _short), \
75 CCK_ACK_DURATION(20, _short), \
76 CCK_ACK_DURATION(55, _short), \
77 CCK_ACK_DURATION(110, _short)
78
79#define CCK_GROUP \
80 [MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS] = { \
81 .streams = 0, \
82 .duration = { \
83 CCK_DURATION_LIST(false), \
84 CCK_DURATION_LIST(true) \
85 } \
86 }
87
ec8aa669
FF		 88/*
89 * To enable sufficiently targeted rate sampling, MCS rates are divided into
90 * groups, based on the number of streams and flags (HT40, SGI) that they
91 * use.
a5f69d94
HS		 92 *
93 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
94 * HT40 -> SGI -> #streams
ec8aa669
FF		 95 */
96const struct mcs_group minstrel_mcs_groups[] = {
97 MCS_GROUP(1, 0, 0),
98 MCS_GROUP(2, 0, 0),
99#if MINSTREL_MAX_STREAMS >= 3
100 MCS_GROUP(3, 0, 0),
101#endif
102
103 MCS_GROUP(1, 1, 0),
104 MCS_GROUP(2, 1, 0),
105#if MINSTREL_MAX_STREAMS >= 3
106 MCS_GROUP(3, 1, 0),
107#endif
108
109 MCS_GROUP(1, 0, 1),
110 MCS_GROUP(2, 0, 1),
111#if MINSTREL_MAX_STREAMS >= 3
112 MCS_GROUP(3, 0, 1),
113#endif
114
115 MCS_GROUP(1, 1, 1),
116 MCS_GROUP(2, 1, 1),
117#if MINSTREL_MAX_STREAMS >= 3
118 MCS_GROUP(3, 1, 1),
119#endif
a0497f9f
FF		 120
121 /* must be last */
122 CCK_GROUP
ec8aa669
FF		 123};
124
a0497f9f
FF		 125#define MINSTREL_CCK_GROUP (ARRAY_SIZE(minstrel_mcs_groups) - 1)
126
ec8aa669
FF		 127static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
128
ec8aa669
FF		 129/*
130 * Look up an MCS group index based on mac80211 rate information
131 */
132static int
133minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
134{
a5f69d94
HS		 135 return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
136 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
137 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
ec8aa669
FF		 138}
139
a0497f9f
FF		 140static struct minstrel_rate_stats *
141minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
142 struct ieee80211_tx_rate *rate)
143{
144 int group, idx;
145
146 if (rate->flags & IEEE80211_TX_RC_MCS) {
147 group = minstrel_ht_get_group_idx(rate);
148 idx = rate->idx % MCS_GROUP_RATES;
149 } else {
150 group = MINSTREL_CCK_GROUP;
151
152 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
153 if (rate->idx == mp->cck_rates[idx])
154 break;
155
156 /* short preamble */
157 if (!(mi->groups[group].supported & BIT(idx)))
158 idx += 4;
159 }
160 return &mi->groups[group].rates[idx];
161}
162
ec8aa669
FF		 163static inline struct minstrel_rate_stats *
164minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
165{
166 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
167}
168
169
170/*
171 * Recalculate success probabilities and counters for a rate using EWMA
172 */
173static void
6048d763 174minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
ec8aa669
FF		 175{
176 if (unlikely(mr->attempts > 0)) {
177 mr->sample_skipped = 0;
178 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
179 if (!mr->att_hist)
180 mr->probability = mr->cur_prob;
181 else
182 mr->probability = minstrel_ewma(mr->probability,
183 mr->cur_prob, EWMA_LEVEL);
184 mr->att_hist += mr->attempts;
185 mr->succ_hist += mr->success;
186 } else {
187 mr->sample_skipped++;
188 }
189 mr->last_success = mr->success;
190 mr->last_attempts = mr->attempts;
191 mr->success = 0;
192 mr->attempts = 0;
193}
194
195/*
196 * Calculate throughput based on the average A-MPDU length, taking into account
197 * the expected number of retransmissions and their expected length
198 */
199static void
6048d763 200minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
ec8aa669
FF		 201{
202 struct minstrel_rate_stats *mr;
ed97a13c
FF		 203 unsigned int nsecs = 0;
204 unsigned int tp;
ec8aa669
FF		 205
206 mr = &mi->groups[group].rates[rate];
207
208 if (mr->probability < MINSTREL_FRAC(1, 10)) {
209 mr->cur_tp = 0;
210 return;
211 }
212
a0497f9f 213 if (group != MINSTREL_CCK_GROUP)
ed97a13c 214 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
a0497f9f 215
ed97a13c
FF		 216 nsecs += minstrel_mcs_groups[group].duration[rate];
217 tp = 1000000 * ((mr->probability * 1000) / nsecs);
218
219 mr->cur_tp = MINSTREL_TRUNC(tp);
ec8aa669
FF		 220}
221
222/*
223 * Update rate statistics and select new primary rates
224 *
225 * Rules for rate selection:
226 * - max_prob_rate must use only one stream, as a tradeoff between delivery
227 * probability and throughput during strong fluctuations
228 * - as long as the max prob rate has a probability of more than 3/4, pick
229 * higher throughput rates, even if the probablity is a bit lower
230 */
231static void
232minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
233{
234 struct minstrel_mcs_group_data *mg;
235 struct minstrel_rate_stats *mr;
236 int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
237 int group, i, index;
238
239 if (mi->ampdu_packets > 0) {
240 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
241 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
242 mi->ampdu_len = 0;
243 mi->ampdu_packets = 0;
244 }
245
246 mi->sample_slow = 0;
247 mi->sample_count = 0;
248 mi->max_tp_rate = 0;
249 mi->max_tp_rate2 = 0;
250 mi->max_prob_rate = 0;
251
252 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
253 cur_prob = 0;
254 cur_prob_tp = 0;
255 cur_tp = 0;
256 cur_tp2 = 0;
257
258 mg = &mi->groups[group];
259 if (!mg->supported)
260 continue;
261
262 mg->max_tp_rate = 0;
263 mg->max_tp_rate2 = 0;
264 mg->max_prob_rate = 0;
265 mi->sample_count++;
266
267 for (i = 0; i < MCS_GROUP_RATES; i++) {
268 if (!(mg->supported & BIT(i)))
269 continue;
270
271 mr = &mg->rates[i];
272 mr->retry_updated = false;
273 index = MCS_GROUP_RATES * group + i;
6048d763
PK		 274 minstrel_calc_rate_ewma(mr);
275 minstrel_ht_calc_tp(mi, group, i);
ec8aa669
FF		 276
277 if (!mr->cur_tp)
278 continue;
279
ec8aa669
FF		 280 if ((mr->cur_tp > cur_prob_tp && mr->probability >
281 MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
282 mg->max_prob_rate = index;
283 cur_prob = mr->probability;
009271f9 284 cur_prob_tp = mr->cur_tp;
ec8aa669
FF		 285 }
286
287 if (mr->cur_tp > cur_tp) {
288 swap(index, mg->max_tp_rate);
289 cur_tp = mr->cur_tp;
290 mr = minstrel_get_ratestats(mi, index);
291 }
292
293 if (index >= mg->max_tp_rate)
294 continue;
295
296 if (mr->cur_tp > cur_tp2) {
297 mg->max_tp_rate2 = index;
298 cur_tp2 = mr->cur_tp;
299 }
300 }
301 }
302
96d4ac3f
FF		 303 /* try to sample all available rates during each interval */
304 mi->sample_count *= 8;
ec8aa669
FF		 305
306 cur_prob = 0;
307 cur_prob_tp = 0;
308 cur_tp = 0;
309 cur_tp2 = 0;
310 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
311 mg = &mi->groups[group];
312 if (!mg->supported)
313 continue;
314
ec8aa669
FF		 315 mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
316 if (cur_tp < mr->cur_tp) {
89888e36
LB		 317 mi->max_tp_rate2 = mi->max_tp_rate;
318 cur_tp2 = cur_tp;
ec8aa669
FF		 319 mi->max_tp_rate = mg->max_tp_rate;
320 cur_tp = mr->cur_tp;
965237ab 321 mi->max_prob_streams = minstrel_mcs_groups[group].streams - 1;
ec8aa669
FF		 322 }
323
324 mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
325 if (cur_tp2 < mr->cur_tp) {
326 mi->max_tp_rate2 = mg->max_tp_rate2;
327 cur_tp2 = mr->cur_tp;
328 }
329 }
330
965237ab
FF		 331 if (mi->max_prob_streams < 1)
332 mi->max_prob_streams = 1;
a299c6d5
FF		 333
334 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
335 mg = &mi->groups[group];
336 if (!mg->supported)
337 continue;
338 mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
339 if (cur_prob_tp < mr->cur_tp &&
965237ab 340 minstrel_mcs_groups[group].streams <= mi->max_prob_streams) {
a299c6d5
FF		 341 mi->max_prob_rate = mg->max_prob_rate;
342 cur_prob = mr->cur_prob;
343 cur_prob_tp = mr->cur_tp;
344 }
345 }
346
347
ec8aa669
FF		 348 mi->stats_update = jiffies;
349}
350
351static bool
a0497f9f 352minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
ec8aa669 353{
b79296be 354 if (rate->idx < 0)
ec8aa669
FF		 355 return false;
356
b79296be 357 if (!rate->count)
ec8aa669
FF		 358 return false;
359
a0497f9f
FF		 360 if (rate->flags & IEEE80211_TX_RC_MCS)
361 return true;
362
363 return rate->idx == mp->cck_rates[0] ||
364 rate->idx == mp->cck_rates[1] ||
365 rate->idx == mp->cck_rates[2] ||
366 rate->idx == mp->cck_rates[3];
ec8aa669
FF		 367}
368
369static void
370minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
371{
372 struct minstrel_mcs_group_data *mg;
373
374 for (;;) {
375 mi->sample_group++;
376 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
377 mg = &mi->groups[mi->sample_group];
378
379 if (!mg->supported)
380 continue;
381
382 if (++mg->index >= MCS_GROUP_RATES) {
383 mg->index = 0;
384 if (++mg->column >= ARRAY_SIZE(sample_table))
385 mg->column = 0;
386 }
387 break;
388 }
389}
390
391static void
d5ece215
JL		 392minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
393 bool primary)
ec8aa669
FF		 394{
395 int group, orig_group;
396
397 orig_group = group = *idx / MCS_GROUP_RATES;
398 while (group > 0) {
399 group--;
400
401 if (!mi->groups[group].supported)
402 continue;
403
404 if (minstrel_mcs_groups[group].streams >
405 minstrel_mcs_groups[orig_group].streams)
406 continue;
407
408 if (primary)
409 *idx = mi->groups[group].max_tp_rate;
410 else
411 *idx = mi->groups[group].max_tp_rate2;
412 break;
413 }
414}
415
416static void
6048d763 417minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
ec8aa669
FF		 418{
419 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
420 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
421 u16 tid;
422
423 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
424 return;
425
426 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
427 return;
428
429 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
a622ab72 430 if (likely(sta->ampdu_mlme.tid_tx[tid]))
ec8aa669
FF		 431 return;
432
48124d1a
LR		 433 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
434 return;
435
bd2ce6e4 436 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
ec8aa669
FF		 437}
438
439static void
440minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
441 struct ieee80211_sta *sta, void *priv_sta,
442 struct sk_buff *skb)
443{
444 struct minstrel_ht_sta_priv *msp = priv_sta;
445 struct minstrel_ht_sta *mi = &msp->ht;
446 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
447 struct ieee80211_tx_rate *ar = info->status.rates;
448 struct minstrel_rate_stats *rate, *rate2;
449 struct minstrel_priv *mp = priv;
a544ab7f 450 bool last;
a544ab7f 451 int i;
ec8aa669
FF		 452
453 if (!msp->is_ht)
454 return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
455
456 /* This packet was aggregated but doesn't carry status info */
457 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
458 !(info->flags & IEEE80211_TX_STAT_AMPDU))
459 return;
460
15d46f38
BS		 461 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
462 info->status.ampdu_ack_len =
463 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
ec8aa669
FF		 464 info->status.ampdu_len = 1;
465 }
466
467 mi->ampdu_packets++;
468 mi->ampdu_len += info->status.ampdu_len;
469
470 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
c7317e41 471 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
52c00a37 472 mi->sample_tries = 1;
ec8aa669
FF		 473 mi->sample_count--;
474 }
475
8d5eab5a 476 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
ec8aa669 477 mi->sample_packets += info->status.ampdu_len;
ec8aa669 478
a0497f9f 479 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
ec8aa669
FF		 480 for (i = 0; !last; i++) {
481 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
a0497f9f 482 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
ec8aa669 483
a0497f9f 484 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
ec8aa669 485
15d46f38 486 if (last)
ec8aa669
FF		 487 rate->success += info->status.ampdu_ack_len;
488
489 rate->attempts += ar[i].count * info->status.ampdu_len;
490 }
491
492 /*
493 * check for sudden death of spatial multiplexing,
494 * downgrade to a lower number of streams if necessary.
495 */
496 rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
497 if (rate->attempts > 30 &&
498 MINSTREL_FRAC(rate->success, rate->attempts) <
499 MINSTREL_FRAC(20, 100))
500 minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
501
502 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
ecc3d5ae
ML		 503 if (rate2->attempts > 30 &&
504 MINSTREL_FRAC(rate2->success, rate2->attempts) <
ec8aa669
FF		 505 MINSTREL_FRAC(20, 100))
506 minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
507
508 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
509 minstrel_ht_update_stats(mp, mi);
a0497f9f
FF		 510 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
511 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
6048d763 512 minstrel_aggr_check(sta, skb);
ec8aa669
FF		 513 }
514}
515
516static void
517minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
518 int index)
519{
520 struct minstrel_rate_stats *mr;
521 const struct mcs_group *group;
522 unsigned int tx_time, tx_time_rtscts, tx_time_data;
523 unsigned int cw = mp->cw_min;
8fddddff 524 unsigned int ctime = 0;
ec8aa669
FF		 525 unsigned int t_slot = 9; /* FIXME */
526 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
a0497f9f 527 unsigned int overhead = 0, overhead_rtscts = 0;
ec8aa669
FF		 528
529 mr = minstrel_get_ratestats(mi, index);
530 if (mr->probability < MINSTREL_FRAC(1, 10)) {
531 mr->retry_count = 1;
532 mr->retry_count_rtscts = 1;
533 return;
534 }
535
536 mr->retry_count = 2;
537 mr->retry_count_rtscts = 2;
538 mr->retry_updated = true;
539
540 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
ed97a13c 541 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
8fddddff
DH		 542
543 /* Contention time for first 2 tries */
544 ctime = (t_slot * cw) >> 1;
545 cw = min((cw << 1) | 1, mp->cw_max);
546 ctime += (t_slot * cw) >> 1;
547 cw = min((cw << 1) | 1, mp->cw_max);
548
a0497f9f
FF		 549 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
550 overhead = mi->overhead;
551 overhead_rtscts = mi->overhead_rtscts;
552 }
553
8fddddff 554 /* Total TX time for data and Contention after first 2 tries */
a0497f9f
FF		 555 tx_time = ctime + 2 * (overhead + tx_time_data);
556 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
8fddddff
DH		 557
558 /* See how many more tries we can fit inside segment size */
ec8aa669 559 do {
8fddddff
DH		 560 /* Contention time for this try */
561 ctime = (t_slot * cw) >> 1;
562 cw = min((cw << 1) | 1, mp->cw_max);
563
564 /* Total TX time after this try */
a0497f9f
FF		 565 tx_time += ctime + overhead + tx_time_data;
566 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
8fddddff 567
ec8aa669
FF		 568 if (tx_time_rtscts < mp->segment_size)
569 mr->retry_count_rtscts++;
570 } while ((tx_time < mp->segment_size) &&
571 (++mr->retry_count < mp->max_retry));
572}
573
574
575static void
576minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
577 struct ieee80211_tx_rate *rate, int index,
ec8aa669
FF		 578 bool sample, bool rtscts)
579{
580 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
581 struct minstrel_rate_stats *mr;
582
583 mr = minstrel_get_ratestats(mi, index);
584 if (!mr->retry_updated)
585 minstrel_calc_retransmit(mp, mi, index);
586
c7317e41
FF		 587 if (sample)
588 rate->count = 1;
589 else if (mr->probability < MINSTREL_FRAC(20, 100))
ec8aa669
FF		 590 rate->count = 2;
591 else if (rtscts)
592 rate->count = mr->retry_count_rtscts;
593 else
594 rate->count = mr->retry_count;
595
a0497f9f 596 rate->flags = 0;
9d468d22 597 if (rtscts)
ec8aa669 598 rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
a0497f9f
FF		 599
600 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
601 rate->idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
602 return;
603 }
604
605 rate->flags |= IEEE80211_TX_RC_MCS | group->flags;
ec8aa669
FF		 606 rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
607}
608
609static inline int
610minstrel_get_duration(int index)
611{
612 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
613 return group->duration[index % MCS_GROUP_RATES];
614}
615
616static int
617minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
618{
619 struct minstrel_rate_stats *mr;
620 struct minstrel_mcs_group_data *mg;
965237ab 621 unsigned int sample_dur, sample_group;
ec8aa669
FF		 622 int sample_idx = 0;
623
624 if (mi->sample_wait > 0) {
625 mi->sample_wait--;
626 return -1;
627 }
628
629 if (!mi->sample_tries)
630 return -1;
631
ec8aa669
FF		 632 mg = &mi->groups[mi->sample_group];
633 sample_idx = sample_table[mg->column][mg->index];
634 mr = &mg->rates[sample_idx];
965237ab
FF		 635 sample_group = mi->sample_group;
636 sample_idx += sample_group * MCS_GROUP_RATES;
8d5eab5a 637 minstrel_next_sample_idx(mi);
ec8aa669 638
ba6fa29c
HS		 639 /*
640 * Sampling might add some overhead (RTS, no aggregation)
641 * to the frame. Hence, don't use sampling for the currently
642 * used max TP rate.
643 */
644 if (sample_idx == mi->max_tp_rate)
645 return -1;
ec8aa669
FF		 646 /*
647 * When not using MRR, do not sample if the probability is already
648 * higher than 95% to avoid wasting airtime
649 */
650 if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
8d5eab5a 651 return -1;
ec8aa669
FF		 652
653 /*
654 * Make sure that lower rates get sampled only occasionally,
655 * if the link is working perfectly.
656 */
965237ab
FF		 657 sample_dur = minstrel_get_duration(sample_idx);
658 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate2) &&
659 (mi->max_prob_streams <
660 minstrel_mcs_groups[sample_group].streams ||
661 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
c7317e41 662 if (mr->sample_skipped < 20)
8d5eab5a 663 return -1;
ec8aa669
FF		 664
665 if (mi->sample_slow++ > 2)
8d5eab5a 666 return -1;
ec8aa669 667 }
098b8afb 668 mi->sample_tries--;
ec8aa669
FF		 669
670 return sample_idx;
ec8aa669
FF		 671}
672
a0497f9f
FF		 673static void
674minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
675 struct minstrel_ht_sta *mi, bool val)
676{
677 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
678
679 if (!supported || !mi->cck_supported_short)
680 return;
681
682 if (supported & (mi->cck_supported_short << (val * 4)))
683 return;
684
685 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
686 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
687}
688
ec8aa669
FF		 689static void
690minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
691 struct ieee80211_tx_rate_control *txrc)
692{
693 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
694 struct ieee80211_tx_rate *ar = info->status.rates;
695 struct minstrel_ht_sta_priv *msp = priv_sta;
696 struct minstrel_ht_sta *mi = &msp->ht;
697 struct minstrel_priv *mp = priv;
698 int sample_idx;
c7317e41 699 bool sample = false;
ec8aa669
FF		 700
701 if (rate_control_send_low(sta, priv_sta, txrc))
702 return;
703
704 if (!msp->is_ht)
705 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
706
707 info->flags |= mi->tx_flags;
a0497f9f 708 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
6de062ce
HS		 709
710 /* Don't use EAPOL frames for sampling on non-mrr hw */
711 if (mp->hw->max_rates == 1 &&
712 txrc->skb->protocol == cpu_to_be16(ETH_P_PAE))
713 sample_idx = -1;
714 else
715 sample_idx = minstrel_get_sample_rate(mp, mi);
24f7580e
ZK		 716
717#ifdef CONFIG_MAC80211_DEBUGFS
718 /* use fixed index if set */
2a9e6c58
SRR		 719 if (mp->fixed_rate_idx != -1) {
720 mi->max_tp_rate = mp->fixed_rate_idx;
721 mi->max_tp_rate2 = mp->fixed_rate_idx;
722 mi->max_prob_rate = mp->fixed_rate_idx;
723 sample_idx = -1;
724 }
24f7580e
ZK		 725#endif
726
ec8aa669 727 if (sample_idx >= 0) {
c7317e41 728 sample = true;
ec8aa669 729 minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
6048d763 730 true, false);
ec8aa669
FF		 731 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
732 } else {
733 minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
6048d763 734 false, false);
ec8aa669 735 }
ec8aa669 736
cf28d793
HS		 737 if (mp->hw->max_rates >= 3) {
738 /*
739 * At least 3 tx rates supported, use
740 * sample_rate -> max_tp_rate -> max_prob_rate for sampling and
741 * max_tp_rate -> max_tp_rate2 -> max_prob_rate by default.
742 */
743 if (sample_idx >= 0)
744 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
6048d763 745 false, false);
cf28d793
HS		 746 else
747 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
6048d763 748 false, true);
cf28d793
HS		 749
750 minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate,
6048d763 751 false, !sample);
cf28d793
HS		 752
753 ar[3].count = 0;
754 ar[3].idx = -1;
755 } else if (mp->hw->max_rates == 2) {
756 /*
757 * Only 2 tx rates supported, use
758 * sample_rate -> max_prob_rate for sampling and
759 * max_tp_rate -> max_prob_rate by default.
760 */
761 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_prob_rate,
6048d763 762 false, !sample);
cf28d793
HS		 763
764 ar[2].count = 0;
765 ar[2].idx = -1;
766 } else {
767 /* Not using MRR, only use the first rate */
768 ar[1].count = 0;
769 ar[1].idx = -1;
770 }
ec8aa669
FF		 771
772 mi->total_packets++;
773
774 /* wraparound */
775 if (mi->total_packets == ~0) {
776 mi->total_packets = 0;
777 mi->sample_packets = 0;
778 }
779}
780
a0497f9f
FF		 781static void
782minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
783 struct ieee80211_supported_band *sband,
784 struct ieee80211_sta *sta)
785{
786 int i;
787
788 if (sband->band != IEEE80211_BAND_2GHZ)
789 return;
790
791 mi->cck_supported = 0;
792 mi->cck_supported_short = 0;
793 for (i = 0; i < 4; i++) {
794 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
795 continue;
796
797 mi->cck_supported |= BIT(i);
798 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
799 mi->cck_supported_short |= BIT(i);
800 }
801
802 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
803}
804
ec8aa669
FF		 805static void
806minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
64f68e5d 807 struct ieee80211_sta *sta, void *priv_sta)
ec8aa669
FF		 808{
809 struct minstrel_priv *mp = priv;
810 struct minstrel_ht_sta_priv *msp = priv_sta;
811 struct minstrel_ht_sta *mi = &msp->ht;
812 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
ec8aa669 813 u16 sta_cap = sta->ht_cap.cap;
4dc217df 814 int n_supported = 0;
ec8aa669
FF		 815 int ack_dur;
816 int stbc;
817 int i;
818
819 /* fall back to the old minstrel for legacy stations */
4dc217df
FF		 820 if (!sta->ht_cap.ht_supported)
821 goto use_legacy;
ec8aa669
FF		 822
823 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
a0497f9f 824 MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS + 1);
ec8aa669
FF		 825
826 msp->is_ht = true;
827 memset(mi, 0, sizeof(*mi));
828 mi->stats_update = jiffies;
829
4ee73f33
MK		 830 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
831 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1) + ack_dur;
ec8aa669
FF		 832 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
833
834 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
835
836 /* When using MRR, sample more on the first attempt, without delay */
837 if (mp->has_mrr) {
838 mi->sample_count = 16;
839 mi->sample_wait = 0;
840 } else {
841 mi->sample_count = 8;
842 mi->sample_wait = 8;
843 }
844 mi->sample_tries = 4;
845
846 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
847 IEEE80211_HT_CAP_RX_STBC_SHIFT;
848 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
849
850 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
851 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
852
ec8aa669 853 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
ec8aa669 854 mi->groups[i].supported = 0;
a0497f9f
FF		 855 if (i == MINSTREL_CCK_GROUP) {
856 minstrel_ht_update_cck(mp, mi, sband, sta);
857 continue;
858 }
859
ec8aa669 860 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
e1a0c6b3
JB		 861 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
862 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
863 continue;
864 } else {
865 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
866 continue;
867 }
ec8aa669
FF		 868 }
869
e1a0c6b3
JB		 870 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
871 sta->bandwidth < IEEE80211_STA_RX_BW_40)
ec8aa669
FF		 872 continue;
873
e9219779 874 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
af0ed69b 875 if (sta->smps_mode == IEEE80211_SMPS_STATIC &&
e9219779
HS		 876 minstrel_mcs_groups[i].streams > 1)
877 continue;
878
ec8aa669
FF		 879 mi->groups[i].supported =
880 mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
4dc217df
FF		 881
882 if (mi->groups[i].supported)
883 n_supported++;
ec8aa669 884 }
4dc217df
FF		 885
886 if (!n_supported)
887 goto use_legacy;
888
889 return;
890
891use_legacy:
892 msp->is_ht = false;
893 memset(&msp->legacy, 0, sizeof(msp->legacy));
894 msp->legacy.r = msp->ratelist;
895 msp->legacy.sample_table = msp->sample_table;
896 return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
ec8aa669
FF		 897}
898
899static void
900minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
901 struct ieee80211_sta *sta, void *priv_sta)
902{
64f68e5d 903 minstrel_ht_update_caps(priv, sband, sta, priv_sta);
ec8aa669
FF		 904}
905
906static void
907minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
908 struct ieee80211_sta *sta, void *priv_sta,
64f68e5d 909 u32 changed)
ec8aa669 910{
64f68e5d 911 minstrel_ht_update_caps(priv, sband, sta, priv_sta);
ec8aa669
FF		 912}
913
914static void *
915minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
916{
917 struct ieee80211_supported_band *sband;
918 struct minstrel_ht_sta_priv *msp;
919 struct minstrel_priv *mp = priv;
920 struct ieee80211_hw *hw = mp->hw;
921 int max_rates = 0;
922 int i;
923
924 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
925 sband = hw->wiphy->bands[i];
926 if (sband && sband->n_bitrates > max_rates)
927 max_rates = sband->n_bitrates;
928 }
929
472dd35c 930 msp = kzalloc(sizeof(*msp), gfp);
ec8aa669
FF		 931 if (!msp)
932 return NULL;
933
934 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
935 if (!msp->ratelist)
936 goto error;
937
938 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
939 if (!msp->sample_table)
940 goto error1;
941
942 return msp;
943
944error1:
7e988014 945 kfree(msp->ratelist);
ec8aa669
FF		 946error:
947 kfree(msp);
948 return NULL;
949}
950
951static void
952minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
953{
954 struct minstrel_ht_sta_priv *msp = priv_sta;
955
956 kfree(msp->sample_table);
957 kfree(msp->ratelist);
958 kfree(msp);
959}
960
961static void *
962minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
963{
964 return mac80211_minstrel.alloc(hw, debugfsdir);
965}
966
967static void
968minstrel_ht_free(void *priv)
969{
970 mac80211_minstrel.free(priv);
971}
972
973static struct rate_control_ops mac80211_minstrel_ht = {
974 .name = "minstrel_ht",
975 .tx_status = minstrel_ht_tx_status,
976 .get_rate = minstrel_ht_get_rate,
977 .rate_init = minstrel_ht_rate_init,
978 .rate_update = minstrel_ht_rate_update,
979 .alloc_sta = minstrel_ht_alloc_sta,
980 .free_sta = minstrel_ht_free_sta,
981 .alloc = minstrel_ht_alloc,
982 .free = minstrel_ht_free,
983#ifdef CONFIG_MAC80211_DEBUGFS
984 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
985 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
986#endif
987};
988
989
990static void
991init_sample_table(void)
992{
993 int col, i, new_idx;
994 u8 rnd[MCS_GROUP_RATES];
995
996 memset(sample_table, 0xff, sizeof(sample_table));
997 for (col = 0; col < SAMPLE_COLUMNS; col++) {
998 for (i = 0; i < MCS_GROUP_RATES; i++) {
999 get_random_bytes(rnd, sizeof(rnd));
1000 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1001
1002 while (sample_table[col][new_idx] != 0xff)
1003 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1004
1005 sample_table[col][new_idx] = i;
1006 }
1007 }
1008}
1009
1010int __init
1011rc80211_minstrel_ht_init(void)
1012{
1013 init_sample_table();
1014 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1015}
1016
1017void
1018rc80211_minstrel_ht_exit(void)
1019{
1020 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1021}
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