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ath9k_hw: Remove BTCOEX initvals
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / mac80211 / rc80211_minstrel_ht.c
CommitLineData
ec8aa669
FF		 1/*
2 * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
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
20#define SAMPLE_COLUMNS 10
21#define EWMA_LEVEL 75
22
23/* Number of bits for an average sized packet */
24#define MCS_NBITS (AVG_PKT_SIZE << 3)
25
26/* Number of symbols for a packet with (bps) bits per symbol */
27#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
28
29/* Transmission time for a packet containing (syms) symbols */
30#define MCS_SYMBOL_TIME(sgi, syms) \
31 (sgi ? \
32 ((syms) * 18 + 4) / 5 : /* syms * 3.6 us */ \
33 (syms) << 2 /* syms * 4 us */ \
34 )
35
36/* Transmit duration for the raw data part of an average sized packet */
37#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
38
a5f69d94
HS		 39/*
40 * Define group sort order: HT40 -> SGI -> #streams
41 */
42#define GROUP_IDX(_streams, _sgi, _ht40) \
43 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
44 MINSTREL_MAX_STREAMS * _sgi + \
45 _streams - 1
46
ec8aa669 47/* MCS rate information for an MCS group */
a5f69d94
HS		 48#define MCS_GROUP(_streams, _sgi, _ht40) \
49 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
ec8aa669
FF		 50 .streams = _streams, \
51 .flags = \
52 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
53 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
54 .duration = { \
55 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
56 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
57 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
58 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
59 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
60 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
61 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
62 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
63 } \
64}
65
66/*
67 * To enable sufficiently targeted rate sampling, MCS rates are divided into
68 * groups, based on the number of streams and flags (HT40, SGI) that they
69 * use.
a5f69d94
HS		 70 *
71 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
72 * HT40 -> SGI -> #streams
ec8aa669
FF		 73 */
74const struct mcs_group minstrel_mcs_groups[] = {
75 MCS_GROUP(1, 0, 0),
76 MCS_GROUP(2, 0, 0),
77#if MINSTREL_MAX_STREAMS >= 3
78 MCS_GROUP(3, 0, 0),
79#endif
80
81 MCS_GROUP(1, 1, 0),
82 MCS_GROUP(2, 1, 0),
83#if MINSTREL_MAX_STREAMS >= 3
84 MCS_GROUP(3, 1, 0),
85#endif
86
87 MCS_GROUP(1, 0, 1),
88 MCS_GROUP(2, 0, 1),
89#if MINSTREL_MAX_STREAMS >= 3
90 MCS_GROUP(3, 0, 1),
91#endif
92
93 MCS_GROUP(1, 1, 1),
94 MCS_GROUP(2, 1, 1),
95#if MINSTREL_MAX_STREAMS >= 3
96 MCS_GROUP(3, 1, 1),
97#endif
98};
99
100static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
101
102/*
103 * Perform EWMA (Exponentially Weighted Moving Average) calculation
104 */
105static int
106minstrel_ewma(int old, int new, int weight)
107{
108 return (new * (100 - weight) + old * weight) / 100;
109}
110
111/*
112 * Look up an MCS group index based on mac80211 rate information
113 */
114static int
115minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
116{
a5f69d94
HS		 117 return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
118 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
119 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
ec8aa669
FF		 120}
121
122static inline struct minstrel_rate_stats *
123minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
124{
125 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
126}
127
128
129/*
130 * Recalculate success probabilities and counters for a rate using EWMA
131 */
132static void
6048d763 133minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
ec8aa669
FF		 134{
135 if (unlikely(mr->attempts > 0)) {
136 mr->sample_skipped = 0;
137 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
138 if (!mr->att_hist)
139 mr->probability = mr->cur_prob;
140 else
141 mr->probability = minstrel_ewma(mr->probability,
142 mr->cur_prob, EWMA_LEVEL);
143 mr->att_hist += mr->attempts;
144 mr->succ_hist += mr->success;
145 } else {
146 mr->sample_skipped++;
147 }
148 mr->last_success = mr->success;
149 mr->last_attempts = mr->attempts;
150 mr->success = 0;
151 mr->attempts = 0;
152}
153
154/*
155 * Calculate throughput based on the average A-MPDU length, taking into account
156 * the expected number of retransmissions and their expected length
157 */
158static void
6048d763 159minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
ec8aa669
FF		 160{
161 struct minstrel_rate_stats *mr;
162 unsigned int usecs;
163
164 mr = &mi->groups[group].rates[rate];
165
166 if (mr->probability < MINSTREL_FRAC(1, 10)) {
167 mr->cur_tp = 0;
168 return;
169 }
170
171 usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
172 usecs += minstrel_mcs_groups[group].duration[rate];
173 mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
174}
175
176/*
177 * Update rate statistics and select new primary rates
178 *
179 * Rules for rate selection:
180 * - max_prob_rate must use only one stream, as a tradeoff between delivery
181 * probability and throughput during strong fluctuations
182 * - as long as the max prob rate has a probability of more than 3/4, pick
183 * higher throughput rates, even if the probablity is a bit lower
184 */
185static void
186minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
187{
188 struct minstrel_mcs_group_data *mg;
189 struct minstrel_rate_stats *mr;
190 int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
191 int group, i, index;
192
193 if (mi->ampdu_packets > 0) {
194 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
195 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
196 mi->ampdu_len = 0;
197 mi->ampdu_packets = 0;
198 }
199
200 mi->sample_slow = 0;
201 mi->sample_count = 0;
202 mi->max_tp_rate = 0;
203 mi->max_tp_rate2 = 0;
204 mi->max_prob_rate = 0;
205
206 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
207 cur_prob = 0;
208 cur_prob_tp = 0;
209 cur_tp = 0;
210 cur_tp2 = 0;
211
212 mg = &mi->groups[group];
213 if (!mg->supported)
214 continue;
215
216 mg->max_tp_rate = 0;
217 mg->max_tp_rate2 = 0;
218 mg->max_prob_rate = 0;
219 mi->sample_count++;
220
221 for (i = 0; i < MCS_GROUP_RATES; i++) {
222 if (!(mg->supported & BIT(i)))
223 continue;
224
225 mr = &mg->rates[i];
226 mr->retry_updated = false;
227 index = MCS_GROUP_RATES * group + i;
6048d763
PK		 228 minstrel_calc_rate_ewma(mr);
229 minstrel_ht_calc_tp(mi, group, i);
ec8aa669
FF		 230
231 if (!mr->cur_tp)
232 continue;
233
234 /* ignore the lowest rate of each single-stream group */
235 if (!i && minstrel_mcs_groups[group].streams == 1)
236 continue;
237
238 if ((mr->cur_tp > cur_prob_tp && mr->probability >
239 MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
240 mg->max_prob_rate = index;
241 cur_prob = mr->probability;
009271f9 242 cur_prob_tp = mr->cur_tp;
ec8aa669
FF		 243 }
244
245 if (mr->cur_tp > cur_tp) {
246 swap(index, mg->max_tp_rate);
247 cur_tp = mr->cur_tp;
248 mr = minstrel_get_ratestats(mi, index);
249 }
250
251 if (index >= mg->max_tp_rate)
252 continue;
253
254 if (mr->cur_tp > cur_tp2) {
255 mg->max_tp_rate2 = index;
256 cur_tp2 = mr->cur_tp;
257 }
258 }
259 }
260
25985edc 261 /* try to sample up to half of the available rates during each interval */
ec8aa669
FF		 262 mi->sample_count *= 4;
263
264 cur_prob = 0;
265 cur_prob_tp = 0;
266 cur_tp = 0;
267 cur_tp2 = 0;
268 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
269 mg = &mi->groups[group];
270 if (!mg->supported)
271 continue;
272
273 mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
274 if (cur_prob_tp < mr->cur_tp &&
275 minstrel_mcs_groups[group].streams == 1) {
276 mi->max_prob_rate = mg->max_prob_rate;
277 cur_prob = mr->cur_prob;
009271f9 278 cur_prob_tp = mr->cur_tp;
ec8aa669
FF		 279 }
280
281 mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
282 if (cur_tp < mr->cur_tp) {
89888e36
LB		 283 mi->max_tp_rate2 = mi->max_tp_rate;
284 cur_tp2 = cur_tp;
ec8aa669
FF		 285 mi->max_tp_rate = mg->max_tp_rate;
286 cur_tp = mr->cur_tp;
287 }
288
289 mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
290 if (cur_tp2 < mr->cur_tp) {
291 mi->max_tp_rate2 = mg->max_tp_rate2;
292 cur_tp2 = mr->cur_tp;
293 }
294 }
295
296 mi->stats_update = jiffies;
297}
298
299static bool
300minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
301{
b79296be 302 if (rate->idx < 0)
ec8aa669
FF		 303 return false;
304
b79296be 305 if (!rate->count)
ec8aa669
FF		 306 return false;
307
308 return !!(rate->flags & IEEE80211_TX_RC_MCS);
309}
310
311static void
312minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
313{
314 struct minstrel_mcs_group_data *mg;
315
316 for (;;) {
317 mi->sample_group++;
318 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
319 mg = &mi->groups[mi->sample_group];
320
321 if (!mg->supported)
322 continue;
323
324 if (++mg->index >= MCS_GROUP_RATES) {
325 mg->index = 0;
326 if (++mg->column >= ARRAY_SIZE(sample_table))
327 mg->column = 0;
328 }
329 break;
330 }
331}
332
333static void
d5ece215
JL		 334minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
335 bool primary)
ec8aa669
FF		 336{
337 int group, orig_group;
338
339 orig_group = group = *idx / MCS_GROUP_RATES;
340 while (group > 0) {
341 group--;
342
343 if (!mi->groups[group].supported)
344 continue;
345
346 if (minstrel_mcs_groups[group].streams >
347 minstrel_mcs_groups[orig_group].streams)
348 continue;
349
350 if (primary)
351 *idx = mi->groups[group].max_tp_rate;
352 else
353 *idx = mi->groups[group].max_tp_rate2;
354 break;
355 }
356}
357
358static void
6048d763 359minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
ec8aa669
FF		 360{
361 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
362 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
363 u16 tid;
364
365 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
366 return;
367
368 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
369 return;
370
371 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
a622ab72 372 if (likely(sta->ampdu_mlme.tid_tx[tid]))
ec8aa669
FF		 373 return;
374
48124d1a
LR		 375 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
376 return;
377
bd2ce6e4 378 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
ec8aa669
FF		 379}
380
381static void
382minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
383 struct ieee80211_sta *sta, void *priv_sta,
384 struct sk_buff *skb)
385{
386 struct minstrel_ht_sta_priv *msp = priv_sta;
387 struct minstrel_ht_sta *mi = &msp->ht;
388 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
389 struct ieee80211_tx_rate *ar = info->status.rates;
390 struct minstrel_rate_stats *rate, *rate2;
391 struct minstrel_priv *mp = priv;
392 bool last = false;
393 int group;
394 int i = 0;
395
396 if (!msp->is_ht)
397 return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
398
399 /* This packet was aggregated but doesn't carry status info */
400 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
401 !(info->flags & IEEE80211_TX_STAT_AMPDU))
402 return;
403
15d46f38
BS		 404 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
405 info->status.ampdu_ack_len =
406 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
ec8aa669
FF		 407 info->status.ampdu_len = 1;
408 }
409
410 mi->ampdu_packets++;
411 mi->ampdu_len += info->status.ampdu_len;
412
413 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
c7317e41
FF		 414 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
415 mi->sample_tries = 2;
ec8aa669
FF		 416 mi->sample_count--;
417 }
418
8d5eab5a 419 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
ec8aa669 420 mi->sample_packets += info->status.ampdu_len;
ec8aa669
FF		 421
422 for (i = 0; !last; i++) {
423 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
424 !minstrel_ht_txstat_valid(&ar[i + 1]);
425
426 if (!minstrel_ht_txstat_valid(&ar[i]))
427 break;
428
429 group = minstrel_ht_get_group_idx(&ar[i]);
430 rate = &mi->groups[group].rates[ar[i].idx % 8];
431
15d46f38 432 if (last)
ec8aa669
FF		 433 rate->success += info->status.ampdu_ack_len;
434
435 rate->attempts += ar[i].count * info->status.ampdu_len;
436 }
437
438 /*
439 * check for sudden death of spatial multiplexing,
440 * downgrade to a lower number of streams if necessary.
441 */
442 rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
443 if (rate->attempts > 30 &&
444 MINSTREL_FRAC(rate->success, rate->attempts) <
445 MINSTREL_FRAC(20, 100))
446 minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
447
448 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
ecc3d5ae
ML		 449 if (rate2->attempts > 30 &&
450 MINSTREL_FRAC(rate2->success, rate2->attempts) <
ec8aa669
FF		 451 MINSTREL_FRAC(20, 100))
452 minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
453
454 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
455 minstrel_ht_update_stats(mp, mi);
64ed5cf0 456 if (!(info->flags & IEEE80211_TX_CTL_AMPDU))
6048d763 457 minstrel_aggr_check(sta, skb);
ec8aa669
FF		 458 }
459}
460
461static void
462minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
463 int index)
464{
465 struct minstrel_rate_stats *mr;
466 const struct mcs_group *group;
467 unsigned int tx_time, tx_time_rtscts, tx_time_data;
468 unsigned int cw = mp->cw_min;
8fddddff 469 unsigned int ctime = 0;
ec8aa669
FF		 470 unsigned int t_slot = 9; /* FIXME */
471 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
472
473 mr = minstrel_get_ratestats(mi, index);
474 if (mr->probability < MINSTREL_FRAC(1, 10)) {
475 mr->retry_count = 1;
476 mr->retry_count_rtscts = 1;
477 return;
478 }
479
480 mr->retry_count = 2;
481 mr->retry_count_rtscts = 2;
482 mr->retry_updated = true;
483
484 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
485 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
8fddddff
DH		 486
487 /* Contention time for first 2 tries */
488 ctime = (t_slot * cw) >> 1;
489 cw = min((cw << 1) | 1, mp->cw_max);
490 ctime += (t_slot * cw) >> 1;
491 cw = min((cw << 1) | 1, mp->cw_max);
492
493 /* Total TX time for data and Contention after first 2 tries */
494 tx_time = ctime + 2 * (mi->overhead + tx_time_data);
495 tx_time_rtscts = ctime + 2 * (mi->overhead_rtscts + tx_time_data);
496
497 /* See how many more tries we can fit inside segment size */
ec8aa669 498 do {
8fddddff
DH		 499 /* Contention time for this try */
500 ctime = (t_slot * cw) >> 1;
501 cw = min((cw << 1) | 1, mp->cw_max);
502
503 /* Total TX time after this try */
504 tx_time += ctime + mi->overhead + tx_time_data;
505 tx_time_rtscts += ctime + mi->overhead_rtscts + tx_time_data;
506
ec8aa669
FF		 507 if (tx_time_rtscts < mp->segment_size)
508 mr->retry_count_rtscts++;
509 } while ((tx_time < mp->segment_size) &&
510 (++mr->retry_count < mp->max_retry));
511}
512
513
514static void
515minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
516 struct ieee80211_tx_rate *rate, int index,
ec8aa669
FF		 517 bool sample, bool rtscts)
518{
519 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
520 struct minstrel_rate_stats *mr;
521
522 mr = minstrel_get_ratestats(mi, index);
523 if (!mr->retry_updated)
524 minstrel_calc_retransmit(mp, mi, index);
525
c7317e41
FF		 526 if (sample)
527 rate->count = 1;
528 else if (mr->probability < MINSTREL_FRAC(20, 100))
ec8aa669
FF		 529 rate->count = 2;
530 else if (rtscts)
531 rate->count = mr->retry_count_rtscts;
532 else
533 rate->count = mr->retry_count;
534
535 rate->flags = IEEE80211_TX_RC_MCS | group->flags;
9d468d22 536 if (rtscts)
ec8aa669
FF		 537 rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
538 rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
539}
540
541static inline int
542minstrel_get_duration(int index)
543{
544 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
545 return group->duration[index % MCS_GROUP_RATES];
546}
547
548static int
549minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
550{
551 struct minstrel_rate_stats *mr;
552 struct minstrel_mcs_group_data *mg;
553 int sample_idx = 0;
554
555 if (mi->sample_wait > 0) {
556 mi->sample_wait--;
557 return -1;
558 }
559
560 if (!mi->sample_tries)
561 return -1;
562
563 mi->sample_tries--;
564 mg = &mi->groups[mi->sample_group];
565 sample_idx = sample_table[mg->column][mg->index];
566 mr = &mg->rates[sample_idx];
567 sample_idx += mi->sample_group * MCS_GROUP_RATES;
8d5eab5a 568 minstrel_next_sample_idx(mi);
ec8aa669 569
ba6fa29c
HS		 570 /*
571 * Sampling might add some overhead (RTS, no aggregation)
572 * to the frame. Hence, don't use sampling for the currently
573 * used max TP rate.
574 */
575 if (sample_idx == mi->max_tp_rate)
576 return -1;
ec8aa669
FF		 577 /*
578 * When not using MRR, do not sample if the probability is already
579 * higher than 95% to avoid wasting airtime
580 */
581 if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
8d5eab5a 582 return -1;
ec8aa669
FF		 583
584 /*
585 * Make sure that lower rates get sampled only occasionally,
586 * if the link is working perfectly.
587 */
588 if (minstrel_get_duration(sample_idx) >
589 minstrel_get_duration(mi->max_tp_rate)) {
c7317e41 590 if (mr->sample_skipped < 20)
8d5eab5a 591 return -1;
ec8aa669
FF		 592
593 if (mi->sample_slow++ > 2)
8d5eab5a 594 return -1;
ec8aa669
FF		 595 }
596
597 return sample_idx;
ec8aa669
FF		 598}
599
600static void
601minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
602 struct ieee80211_tx_rate_control *txrc)
603{
604 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
605 struct ieee80211_tx_rate *ar = info->status.rates;
606 struct minstrel_ht_sta_priv *msp = priv_sta;
607 struct minstrel_ht_sta *mi = &msp->ht;
608 struct minstrel_priv *mp = priv;
609 int sample_idx;
c7317e41 610 bool sample = false;
ec8aa669
FF		 611
612 if (rate_control_send_low(sta, priv_sta, txrc))
613 return;
614
615 if (!msp->is_ht)
616 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
617
618 info->flags |= mi->tx_flags;
6de062ce
HS		 619
620 /* Don't use EAPOL frames for sampling on non-mrr hw */
621 if (mp->hw->max_rates == 1 &&
622 txrc->skb->protocol == cpu_to_be16(ETH_P_PAE))
623 sample_idx = -1;
624 else
625 sample_idx = minstrel_get_sample_rate(mp, mi);
24f7580e
ZK		 626
627#ifdef CONFIG_MAC80211_DEBUGFS
628 /* use fixed index if set */
629 if (mp->fixed_rate_idx != -1)
630 sample_idx = mp->fixed_rate_idx;
631#endif
632
ec8aa669 633 if (sample_idx >= 0) {
c7317e41 634 sample = true;
ec8aa669 635 minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
6048d763 636 true, false);
ec8aa669
FF		 637 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
638 } else {
639 minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
6048d763 640 false, false);
ec8aa669 641 }
ec8aa669 642
cf28d793
HS		 643 if (mp->hw->max_rates >= 3) {
644 /*
645 * At least 3 tx rates supported, use
646 * sample_rate -> max_tp_rate -> max_prob_rate for sampling and
647 * max_tp_rate -> max_tp_rate2 -> max_prob_rate by default.
648 */
649 if (sample_idx >= 0)
650 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
6048d763 651 false, false);
cf28d793
HS		 652 else
653 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
6048d763 654 false, true);
cf28d793
HS		 655
656 minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate,
6048d763 657 false, !sample);
cf28d793
HS		 658
659 ar[3].count = 0;
660 ar[3].idx = -1;
661 } else if (mp->hw->max_rates == 2) {
662 /*
663 * Only 2 tx rates supported, use
664 * sample_rate -> max_prob_rate for sampling and
665 * max_tp_rate -> max_prob_rate by default.
666 */
667 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_prob_rate,
6048d763 668 false, !sample);
cf28d793
HS		 669
670 ar[2].count = 0;
671 ar[2].idx = -1;
672 } else {
673 /* Not using MRR, only use the first rate */
674 ar[1].count = 0;
675 ar[1].idx = -1;
676 }
ec8aa669
FF		 677
678 mi->total_packets++;
679
680 /* wraparound */
681 if (mi->total_packets == ~0) {
682 mi->total_packets = 0;
683 mi->sample_packets = 0;
684 }
685}
686
687static void
688minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
64f68e5d 689 struct ieee80211_sta *sta, void *priv_sta)
ec8aa669
FF		 690{
691 struct minstrel_priv *mp = priv;
692 struct minstrel_ht_sta_priv *msp = priv_sta;
693 struct minstrel_ht_sta *mi = &msp->ht;
694 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
695 struct ieee80211_local *local = hw_to_local(mp->hw);
696 u16 sta_cap = sta->ht_cap.cap;
4dc217df 697 int n_supported = 0;
ec8aa669
FF		 698 int ack_dur;
699 int stbc;
700 int i;
e9219779 701 unsigned int smps;
ec8aa669
FF		 702
703 /* fall back to the old minstrel for legacy stations */
4dc217df
FF		 704 if (!sta->ht_cap.ht_supported)
705 goto use_legacy;
ec8aa669
FF		 706
707 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
708 MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
709
710 msp->is_ht = true;
711 memset(mi, 0, sizeof(*mi));
712 mi->stats_update = jiffies;
713
714 ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
715 mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
716 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
717
718 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
719
720 /* When using MRR, sample more on the first attempt, without delay */
721 if (mp->has_mrr) {
722 mi->sample_count = 16;
723 mi->sample_wait = 0;
724 } else {
725 mi->sample_count = 8;
726 mi->sample_wait = 8;
727 }
728 mi->sample_tries = 4;
729
730 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
731 IEEE80211_HT_CAP_RX_STBC_SHIFT;
732 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
733
734 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
735 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
736
e9219779
HS		 737 smps = (sta_cap & IEEE80211_HT_CAP_SM_PS) >>
738 IEEE80211_HT_CAP_SM_PS_SHIFT;
739
ec8aa669
FF		 740 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
741 u16 req = 0;
742
743 mi->groups[i].supported = 0;
744 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
745 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
746 req |= IEEE80211_HT_CAP_SGI_40;
747 else
748 req |= IEEE80211_HT_CAP_SGI_20;
749 }
750
751 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
752 req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
753
754 if ((sta_cap & req) != req)
755 continue;
756
e9219779
HS		 757 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
758 if (smps == WLAN_HT_CAP_SM_PS_STATIC &&
759 minstrel_mcs_groups[i].streams > 1)
760 continue;
761
ec8aa669
FF		 762 mi->groups[i].supported =
763 mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
4dc217df
FF		 764
765 if (mi->groups[i].supported)
766 n_supported++;
ec8aa669 767 }
4dc217df
FF		 768
769 if (!n_supported)
770 goto use_legacy;
771
772 return;
773
774use_legacy:
775 msp->is_ht = false;
776 memset(&msp->legacy, 0, sizeof(msp->legacy));
777 msp->legacy.r = msp->ratelist;
778 msp->legacy.sample_table = msp->sample_table;
779 return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
ec8aa669
FF		 780}
781
782static void
783minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
784 struct ieee80211_sta *sta, void *priv_sta)
785{
64f68e5d 786 minstrel_ht_update_caps(priv, sband, sta, priv_sta);
ec8aa669
FF		 787}
788
789static void
790minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
791 struct ieee80211_sta *sta, void *priv_sta,
64f68e5d 792 u32 changed)
ec8aa669 793{
64f68e5d 794 minstrel_ht_update_caps(priv, sband, sta, priv_sta);
ec8aa669
FF		 795}
796
797static void *
798minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
799{
800 struct ieee80211_supported_band *sband;
801 struct minstrel_ht_sta_priv *msp;
802 struct minstrel_priv *mp = priv;
803 struct ieee80211_hw *hw = mp->hw;
804 int max_rates = 0;
805 int i;
806
807 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
808 sband = hw->wiphy->bands[i];
809 if (sband && sband->n_bitrates > max_rates)
810 max_rates = sband->n_bitrates;
811 }
812
813 msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
814 if (!msp)
815 return NULL;
816
817 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
818 if (!msp->ratelist)
819 goto error;
820
821 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
822 if (!msp->sample_table)
823 goto error1;
824
825 return msp;
826
827error1:
7e988014 828 kfree(msp->ratelist);
ec8aa669
FF		 829error:
830 kfree(msp);
831 return NULL;
832}
833
834static void
835minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
836{
837 struct minstrel_ht_sta_priv *msp = priv_sta;
838
839 kfree(msp->sample_table);
840 kfree(msp->ratelist);
841 kfree(msp);
842}
843
844static void *
845minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
846{
847 return mac80211_minstrel.alloc(hw, debugfsdir);
848}
849
850static void
851minstrel_ht_free(void *priv)
852{
853 mac80211_minstrel.free(priv);
854}
855
856static struct rate_control_ops mac80211_minstrel_ht = {
857 .name = "minstrel_ht",
858 .tx_status = minstrel_ht_tx_status,
859 .get_rate = minstrel_ht_get_rate,
860 .rate_init = minstrel_ht_rate_init,
861 .rate_update = minstrel_ht_rate_update,
862 .alloc_sta = minstrel_ht_alloc_sta,
863 .free_sta = minstrel_ht_free_sta,
864 .alloc = minstrel_ht_alloc,
865 .free = minstrel_ht_free,
866#ifdef CONFIG_MAC80211_DEBUGFS
867 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
868 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
869#endif
870};
871
872
873static void
874init_sample_table(void)
875{
876 int col, i, new_idx;
877 u8 rnd[MCS_GROUP_RATES];
878
879 memset(sample_table, 0xff, sizeof(sample_table));
880 for (col = 0; col < SAMPLE_COLUMNS; col++) {
881 for (i = 0; i < MCS_GROUP_RATES; i++) {
882 get_random_bytes(rnd, sizeof(rnd));
883 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
884
885 while (sample_table[col][new_idx] != 0xff)
886 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
887
888 sample_table[col][new_idx] = i;
889 }
890 }
891}
892
893int __init
894rc80211_minstrel_ht_init(void)
895{
896 init_sample_table();
897 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
898}
899
900void
901rc80211_minstrel_ht_exit(void)
902{
903 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
904}
kernel source for telekom puls (alcatel/mediatek)