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pinctrl: make a copy of pinmux map
[linux/fpc-iii.git] / net / mac80211 / rc80211_minstrel_ht.c
blobcdb28535716b14d907d6423578c10db604d9c43f
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
39 /* MCS rate information for an MCS group */
40 #define MCS_GROUP(_streams, _sgi, _ht40) { \
41 .streams = _streams, \
42 .flags = \
43 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
44 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
45 .duration = { \
46 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
47 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
48 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
49 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
50 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
51 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
52 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
53 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
54 } \
55 }
56
57 /*
58 * To enable sufficiently targeted rate sampling, MCS rates are divided into
59 * groups, based on the number of streams and flags (HT40, SGI) that they
60 * use.
61 */
62 const struct mcs_group minstrel_mcs_groups[] = {
63 MCS_GROUP(1, 0, 0),
64 MCS_GROUP(2, 0, 0),
65 #if MINSTREL_MAX_STREAMS >= 3
66 MCS_GROUP(3, 0, 0),
67 #endif
68
69 MCS_GROUP(1, 1, 0),
70 MCS_GROUP(2, 1, 0),
71 #if MINSTREL_MAX_STREAMS >= 3
72 MCS_GROUP(3, 1, 0),
73 #endif
74
75 MCS_GROUP(1, 0, 1),
76 MCS_GROUP(2, 0, 1),
77 #if MINSTREL_MAX_STREAMS >= 3
78 MCS_GROUP(3, 0, 1),
79 #endif
80
81 MCS_GROUP(1, 1, 1),
82 MCS_GROUP(2, 1, 1),
83 #if MINSTREL_MAX_STREAMS >= 3
84 MCS_GROUP(3, 1, 1),
85 #endif
86 };
87
88 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
89
90 /*
91 * Perform EWMA (Exponentially Weighted Moving Average) calculation
92 */
93 static int
94 minstrel_ewma(int old, int new, int weight)
95 {
96 return (new * (100 - weight) + old * weight) / 100;
97 }
98
99 /*
100 * Look up an MCS group index based on mac80211 rate information
101 */
102 static int
103 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
104 {
105 int streams = (rate->idx / MCS_GROUP_RATES) + 1;
106 u32 flags = IEEE80211_TX_RC_SHORT_GI | IEEE80211_TX_RC_40_MHZ_WIDTH;
107 int i;
108
109 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
110 if (minstrel_mcs_groups[i].streams != streams)
111 continue;
112 if (minstrel_mcs_groups[i].flags != (rate->flags & flags))
113 continue;
114
115 return i;
116 }
117
118 WARN_ON(1);
119 return 0;
120 }
121
122 static inline struct minstrel_rate_stats *
123 minstrel_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 */
132 static void
133 minstrel_calc_rate_ewma(struct minstrel_priv *mp, struct minstrel_rate_stats *mr)
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 */
158 static void
159 minstrel_ht_calc_tp(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
160 int group, int rate)
161 {
162 struct minstrel_rate_stats *mr;
163 unsigned int usecs;
164
165 mr = &mi->groups[group].rates[rate];
166
167 if (mr->probability < MINSTREL_FRAC(1, 10)) {
168 mr->cur_tp = 0;
169 return;
170 }
171
172 usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
173 usecs += minstrel_mcs_groups[group].duration[rate];
174 mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
175 }
176
177 /*
178 * Update rate statistics and select new primary rates
179 *
180 * Rules for rate selection:
181 * - max_prob_rate must use only one stream, as a tradeoff between delivery
182 * probability and throughput during strong fluctuations
183 * - as long as the max prob rate has a probability of more than 3/4, pick
184 * higher throughput rates, even if the probablity is a bit lower
185 */
186 static void
187 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
188 {
189 struct minstrel_mcs_group_data *mg;
190 struct minstrel_rate_stats *mr;
191 int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
192 int group, i, index;
193
194 if (mi->ampdu_packets > 0) {
195 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
196 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
197 mi->ampdu_len = 0;
198 mi->ampdu_packets = 0;
199 }
200
201 mi->sample_slow = 0;
202 mi->sample_count = 0;
203 mi->max_tp_rate = 0;
204 mi->max_tp_rate2 = 0;
205 mi->max_prob_rate = 0;
206
207 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
208 cur_prob = 0;
209 cur_prob_tp = 0;
210 cur_tp = 0;
211 cur_tp2 = 0;
212
213 mg = &mi->groups[group];
214 if (!mg->supported)
215 continue;
216
217 mg->max_tp_rate = 0;
218 mg->max_tp_rate2 = 0;
219 mg->max_prob_rate = 0;
220 mi->sample_count++;
221
222 for (i = 0; i < MCS_GROUP_RATES; i++) {
223 if (!(mg->supported & BIT(i)))
224 continue;
225
226 mr = &mg->rates[i];
227 mr->retry_updated = false;
228 index = MCS_GROUP_RATES * group + i;
229 minstrel_calc_rate_ewma(mp, mr);
230 minstrel_ht_calc_tp(mp, mi, group, i);
231
232 if (!mr->cur_tp)
233 continue;
234
235 /* ignore the lowest rate of each single-stream group */
236 if (!i && minstrel_mcs_groups[group].streams == 1)
237 continue;
238
239 if ((mr->cur_tp > cur_prob_tp && mr->probability >
240 MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
241 mg->max_prob_rate = index;
242 cur_prob = mr->probability;
243 cur_prob_tp = mr->cur_tp;
244 }
245
246 if (mr->cur_tp > cur_tp) {
247 swap(index, mg->max_tp_rate);
248 cur_tp = mr->cur_tp;
249 mr = minstrel_get_ratestats(mi, index);
250 }
251
252 if (index >= mg->max_tp_rate)
253 continue;
254
255 if (mr->cur_tp > cur_tp2) {
256 mg->max_tp_rate2 = index;
257 cur_tp2 = mr->cur_tp;
258 }
259 }
260 }
261
262 /* try to sample up to half of the available rates during each interval */
263 mi->sample_count *= 4;
264
265 cur_prob = 0;
266 cur_prob_tp = 0;
267 cur_tp = 0;
268 cur_tp2 = 0;
269 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
270 mg = &mi->groups[group];
271 if (!mg->supported)
272 continue;
273
274 mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
275 if (cur_prob_tp < mr->cur_tp &&
276 minstrel_mcs_groups[group].streams == 1) {
277 mi->max_prob_rate = mg->max_prob_rate;
278 cur_prob = mr->cur_prob;
279 cur_prob_tp = mr->cur_tp;
280 }
281
282 mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
283 if (cur_tp < mr->cur_tp) {
284 mi->max_tp_rate2 = mi->max_tp_rate;
285 cur_tp2 = cur_tp;
286 mi->max_tp_rate = mg->max_tp_rate;
287 cur_tp = mr->cur_tp;
288 }
289
290 mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
291 if (cur_tp2 < mr->cur_tp) {
292 mi->max_tp_rate2 = mg->max_tp_rate2;
293 cur_tp2 = mr->cur_tp;
294 }
295 }
296
297 mi->stats_update = jiffies;
298 }
299
300 static bool
301 minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
302 {
303 if (!rate->count)
304 return false;
305
306 if (rate->idx < 0)
307 return false;
308
309 return !!(rate->flags & IEEE80211_TX_RC_MCS);
310 }
311
312 static void
313 minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
314 {
315 struct minstrel_mcs_group_data *mg;
316
317 for (;;) {
318 mi->sample_group++;
319 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
320 mg = &mi->groups[mi->sample_group];
321
322 if (!mg->supported)
323 continue;
324
325 if (++mg->index >= MCS_GROUP_RATES) {
326 mg->index = 0;
327 if (++mg->column >= ARRAY_SIZE(sample_table))
328 mg->column = 0;
329 }
330 break;
331 }
332 }
333
334 static void
335 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, unsigned int *idx,
336 bool primary)
337 {
338 int group, orig_group;
339
340 orig_group = group = *idx / MCS_GROUP_RATES;
341 while (group > 0) {
342 group--;
343
344 if (!mi->groups[group].supported)
345 continue;
346
347 if (minstrel_mcs_groups[group].streams >
348 minstrel_mcs_groups[orig_group].streams)
349 continue;
350
351 if (primary)
352 *idx = mi->groups[group].max_tp_rate;
353 else
354 *idx = mi->groups[group].max_tp_rate2;
355 break;
356 }
357 }
358
359 static void
360 minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
361 {
362 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
363 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
364 u16 tid;
365
366 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
367 return;
368
369 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
370 return;
371
372 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
373 if (likely(sta->ampdu_mlme.tid_tx[tid]))
374 return;
375
376 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
377 return;
378
379 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
380 }
381
382 static void
383 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
384 struct ieee80211_sta *sta, void *priv_sta,
385 struct sk_buff *skb)
386 {
387 struct minstrel_ht_sta_priv *msp = priv_sta;
388 struct minstrel_ht_sta *mi = &msp->ht;
389 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
390 struct ieee80211_tx_rate *ar = info->status.rates;
391 struct minstrel_rate_stats *rate, *rate2;
392 struct minstrel_priv *mp = priv;
393 bool last = false;
394 int group;
395 int i = 0;
396
397 if (!msp->is_ht)
398 return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
399
400 /* This packet was aggregated but doesn't carry status info */
401 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
402 !(info->flags & IEEE80211_TX_STAT_AMPDU))
403 return;
404
405 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
406 info->status.ampdu_ack_len =
407 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
408 info->status.ampdu_len = 1;
409 }
410
411 mi->ampdu_packets++;
412 mi->ampdu_len += info->status.ampdu_len;
413
414 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
415 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
416 mi->sample_tries = 2;
417 mi->sample_count--;
418 }
419
420 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
421 mi->sample_packets += info->status.ampdu_len;
422
423 for (i = 0; !last; i++) {
424 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
425 !minstrel_ht_txstat_valid(&ar[i + 1]);
426
427 if (!minstrel_ht_txstat_valid(&ar[i]))
428 break;
429
430 group = minstrel_ht_get_group_idx(&ar[i]);
431 rate = &mi->groups[group].rates[ar[i].idx % 8];
432
433 if (last)
434 rate->success += info->status.ampdu_ack_len;
435
436 rate->attempts += ar[i].count * info->status.ampdu_len;
437 }
438
439 /*
440 * check for sudden death of spatial multiplexing,
441 * downgrade to a lower number of streams if necessary.
442 */
443 rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
444 if (rate->attempts > 30 &&
445 MINSTREL_FRAC(rate->success, rate->attempts) <
446 MINSTREL_FRAC(20, 100))
447 minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
448
449 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
450 if (rate2->attempts > 30 &&
451 MINSTREL_FRAC(rate2->success, rate2->attempts) <
452 MINSTREL_FRAC(20, 100))
453 minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
454
455 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
456 minstrel_ht_update_stats(mp, mi);
457 if (!(info->flags & IEEE80211_TX_CTL_AMPDU))
458 minstrel_aggr_check(mp, sta, skb);
459 }
460 }
461
462 static void
463 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
464 int index)
465 {
466 struct minstrel_rate_stats *mr;
467 const struct mcs_group *group;
468 unsigned int tx_time, tx_time_rtscts, tx_time_data;
469 unsigned int cw = mp->cw_min;
470 unsigned int ctime = 0;
471 unsigned int t_slot = 9; /* FIXME */
472 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
473
474 mr = minstrel_get_ratestats(mi, index);
475 if (mr->probability < MINSTREL_FRAC(1, 10)) {
476 mr->retry_count = 1;
477 mr->retry_count_rtscts = 1;
478 return;
479 }
480
481 mr->retry_count = 2;
482 mr->retry_count_rtscts = 2;
483 mr->retry_updated = true;
484
485 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
486 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
487
488 /* Contention time for first 2 tries */
489 ctime = (t_slot * cw) >> 1;
490 cw = min((cw << 1) | 1, mp->cw_max);
491 ctime += (t_slot * cw) >> 1;
492 cw = min((cw << 1) | 1, mp->cw_max);
493
494 /* Total TX time for data and Contention after first 2 tries */
495 tx_time = ctime + 2 * (mi->overhead + tx_time_data);
496 tx_time_rtscts = ctime + 2 * (mi->overhead_rtscts + tx_time_data);
497
498 /* See how many more tries we can fit inside segment size */
499 do {
500 /* Contention time for this try */
501 ctime = (t_slot * cw) >> 1;
502 cw = min((cw << 1) | 1, mp->cw_max);
503
504 /* Total TX time after this try */
505 tx_time += ctime + mi->overhead + tx_time_data;
506 tx_time_rtscts += ctime + mi->overhead_rtscts + tx_time_data;
507
508 if (tx_time_rtscts < mp->segment_size)
509 mr->retry_count_rtscts++;
510 } while ((tx_time < mp->segment_size) &&
511 (++mr->retry_count < mp->max_retry));
512 }
513
514
515 static void
516 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
517 struct ieee80211_tx_rate *rate, int index,
518 struct ieee80211_tx_rate_control *txrc,
519 bool sample, bool rtscts)
520 {
521 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
522 struct minstrel_rate_stats *mr;
523
524 mr = minstrel_get_ratestats(mi, index);
525 if (!mr->retry_updated)
526 minstrel_calc_retransmit(mp, mi, index);
527
528 if (sample)
529 rate->count = 1;
530 else if (mr->probability < MINSTREL_FRAC(20, 100))
531 rate->count = 2;
532 else if (rtscts)
533 rate->count = mr->retry_count_rtscts;
534 else
535 rate->count = mr->retry_count;
536
537 rate->flags = IEEE80211_TX_RC_MCS | group->flags;
538 if (rtscts)
539 rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
540 rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
541 }
542
543 static inline int
544 minstrel_get_duration(int index)
545 {
546 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
547 return group->duration[index % MCS_GROUP_RATES];
548 }
549
550 static int
551 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
552 {
553 struct minstrel_rate_stats *mr;
554 struct minstrel_mcs_group_data *mg;
555 int sample_idx = 0;
556
557 if (mi->sample_wait > 0) {
558 mi->sample_wait--;
559 return -1;
560 }
561
562 if (!mi->sample_tries)
563 return -1;
564
565 mi->sample_tries--;
566 mg = &mi->groups[mi->sample_group];
567 sample_idx = sample_table[mg->column][mg->index];
568 mr = &mg->rates[sample_idx];
569 sample_idx += mi->sample_group * MCS_GROUP_RATES;
570 minstrel_next_sample_idx(mi);
571
572 /*
573 * When not using MRR, do not sample if the probability is already
574 * higher than 95% to avoid wasting airtime
575 */
576 if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
577 return -1;
578
579 /*
580 * Make sure that lower rates get sampled only occasionally,
581 * if the link is working perfectly.
582 */
583 if (minstrel_get_duration(sample_idx) >
584 minstrel_get_duration(mi->max_tp_rate)) {
585 if (mr->sample_skipped < 20)
586 return -1;
587
588 if (mi->sample_slow++ > 2)
589 return -1;
590 }
591
592 return sample_idx;
593 }
594
595 static void
596 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
597 struct ieee80211_tx_rate_control *txrc)
598 {
599 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
600 struct ieee80211_tx_rate *ar = info->status.rates;
601 struct minstrel_ht_sta_priv *msp = priv_sta;
602 struct minstrel_ht_sta *mi = &msp->ht;
603 struct minstrel_priv *mp = priv;
604 int sample_idx;
605 bool sample = false;
606
607 if (rate_control_send_low(sta, priv_sta, txrc))
608 return;
609
610 if (!msp->is_ht)
611 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
612
613 info->flags |= mi->tx_flags;
614
615 /* Don't use EAPOL frames for sampling on non-mrr hw */
616 if (mp->hw->max_rates == 1 &&
617 txrc->skb->protocol == cpu_to_be16(ETH_P_PAE))
618 sample_idx = -1;
619 else
620 sample_idx = minstrel_get_sample_rate(mp, mi);
621
622 #ifdef CONFIG_MAC80211_DEBUGFS
623 /* use fixed index if set */
624 if (mp->fixed_rate_idx != -1)
625 sample_idx = mp->fixed_rate_idx;
626 #endif
627
628 if (sample_idx >= 0) {
629 sample = true;
630 minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
631 txrc, true, false);
632 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
633 } else {
634 minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
635 txrc, false, false);
636 }
637
638 if (mp->hw->max_rates >= 3) {
639 /*
640 * At least 3 tx rates supported, use
641 * sample_rate -> max_tp_rate -> max_prob_rate for sampling and
642 * max_tp_rate -> max_tp_rate2 -> max_prob_rate by default.
643 */
644 if (sample_idx >= 0)
645 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
646 txrc, false, false);
647 else
648 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
649 txrc, false, true);
650
651 minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate,
652 txrc, false, !sample);
653
654 ar[3].count = 0;
655 ar[3].idx = -1;
656 } else if (mp->hw->max_rates == 2) {
657 /*
658 * Only 2 tx rates supported, use
659 * sample_rate -> max_prob_rate for sampling and
660 * max_tp_rate -> max_prob_rate by default.
661 */
662 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_prob_rate,
663 txrc, false, !sample);
664
665 ar[2].count = 0;
666 ar[2].idx = -1;
667 } else {
668 /* Not using MRR, only use the first rate */
669 ar[1].count = 0;
670 ar[1].idx = -1;
671 }
672
673 mi->total_packets++;
674
675 /* wraparound */
676 if (mi->total_packets == ~0) {
677 mi->total_packets = 0;
678 mi->sample_packets = 0;
679 }
680 }
681
682 static void
683 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
684 struct ieee80211_sta *sta, void *priv_sta,
685 enum nl80211_channel_type oper_chan_type)
686 {
687 struct minstrel_priv *mp = priv;
688 struct minstrel_ht_sta_priv *msp = priv_sta;
689 struct minstrel_ht_sta *mi = &msp->ht;
690 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
691 struct ieee80211_local *local = hw_to_local(mp->hw);
692 u16 sta_cap = sta->ht_cap.cap;
693 int n_supported = 0;
694 int ack_dur;
695 int stbc;
696 int i;
697
698 /* fall back to the old minstrel for legacy stations */
699 if (!sta->ht_cap.ht_supported)
700 goto use_legacy;
701
702 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
703 MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
704
705 msp->is_ht = true;
706 memset(mi, 0, sizeof(*mi));
707 mi->stats_update = jiffies;
708
709 ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
710 mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
711 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
712
713 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
714
715 /* When using MRR, sample more on the first attempt, without delay */
716 if (mp->has_mrr) {
717 mi->sample_count = 16;
718 mi->sample_wait = 0;
719 } else {
720 mi->sample_count = 8;
721 mi->sample_wait = 8;
722 }
723 mi->sample_tries = 4;
724
725 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
726 IEEE80211_HT_CAP_RX_STBC_SHIFT;
727 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
728
729 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
730 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
731
732 if (oper_chan_type != NL80211_CHAN_HT40MINUS &&
733 oper_chan_type != NL80211_CHAN_HT40PLUS)
734 sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
735
736 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
737 u16 req = 0;
738
739 mi->groups[i].supported = 0;
740 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
741 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
742 req |= IEEE80211_HT_CAP_SGI_40;
743 else
744 req |= IEEE80211_HT_CAP_SGI_20;
745 }
746
747 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
748 req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
749
750 if ((sta_cap & req) != req)
751 continue;
752
753 mi->groups[i].supported =
754 mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
755
756 if (mi->groups[i].supported)
757 n_supported++;
758 }
759
760 if (!n_supported)
761 goto use_legacy;
762
763 return;
764
765 use_legacy:
766 msp->is_ht = false;
767 memset(&msp->legacy, 0, sizeof(msp->legacy));
768 msp->legacy.r = msp->ratelist;
769 msp->legacy.sample_table = msp->sample_table;
770 return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
771 }
772
773 static void
774 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
775 struct ieee80211_sta *sta, void *priv_sta)
776 {
777 struct minstrel_priv *mp = priv;
778
779 minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type);
780 }
781
782 static void
783 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
784 struct ieee80211_sta *sta, void *priv_sta,
785 u32 changed, enum nl80211_channel_type oper_chan_type)
786 {
787 minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type);
788 }
789
790 static void *
791 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
792 {
793 struct ieee80211_supported_band *sband;
794 struct minstrel_ht_sta_priv *msp;
795 struct minstrel_priv *mp = priv;
796 struct ieee80211_hw *hw = mp->hw;
797 int max_rates = 0;
798 int i;
799
800 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
801 sband = hw->wiphy->bands[i];
802 if (sband && sband->n_bitrates > max_rates)
803 max_rates = sband->n_bitrates;
804 }
805
806 msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
807 if (!msp)
808 return NULL;
809
810 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
811 if (!msp->ratelist)
812 goto error;
813
814 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
815 if (!msp->sample_table)
816 goto error1;
817
818 return msp;
819
820 error1:
821 kfree(msp->ratelist);
822 error:
823 kfree(msp);
824 return NULL;
825 }
826
827 static void
828 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
829 {
830 struct minstrel_ht_sta_priv *msp = priv_sta;
831
832 kfree(msp->sample_table);
833 kfree(msp->ratelist);
834 kfree(msp);
835 }
836
837 static void *
838 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
839 {
840 return mac80211_minstrel.alloc(hw, debugfsdir);
841 }
842
843 static void
844 minstrel_ht_free(void *priv)
845 {
846 mac80211_minstrel.free(priv);
847 }
848
849 static struct rate_control_ops mac80211_minstrel_ht = {
850 .name = "minstrel_ht",
851 .tx_status = minstrel_ht_tx_status,
852 .get_rate = minstrel_ht_get_rate,
853 .rate_init = minstrel_ht_rate_init,
854 .rate_update = minstrel_ht_rate_update,
855 .alloc_sta = minstrel_ht_alloc_sta,
856 .free_sta = minstrel_ht_free_sta,
857 .alloc = minstrel_ht_alloc,
858 .free = minstrel_ht_free,
859 #ifdef CONFIG_MAC80211_DEBUGFS
860 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
861 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
862 #endif
863 };
864
865
866 static void
867 init_sample_table(void)
868 {
869 int col, i, new_idx;
870 u8 rnd[MCS_GROUP_RATES];
871
872 memset(sample_table, 0xff, sizeof(sample_table));
873 for (col = 0; col < SAMPLE_COLUMNS; col++) {
874 for (i = 0; i < MCS_GROUP_RATES; i++) {
875 get_random_bytes(rnd, sizeof(rnd));
876 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
877
878 while (sample_table[col][new_idx] != 0xff)
879 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
880
881 sample_table[col][new_idx] = i;
882 }
883 }
884 }
885
886 int __init
887 rc80211_minstrel_ht_init(void)
888 {
889 init_sample_table();
890 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
891 }
892
893 void
894 rc80211_minstrel_ht_exit(void)
895 {
896 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
897 }
Linux with added FPC-III support