?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
mac80211: pull mgmt frame rx into rx handler
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / net / mac80211 / rc80211_minstrel_ht.c
blobc23f08251da460f9525d536d7c43346503e9e983
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 }
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
261 /* try to sample up to half of the availble rates during each interval */
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;
278 }
279
280 mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
281 if (cur_tp < mr->cur_tp) {
282 mi->max_tp_rate = mg->max_tp_rate;
283 cur_tp = mr->cur_tp;
284 }
285
286 mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
287 if (cur_tp2 < mr->cur_tp) {
288 mi->max_tp_rate2 = mg->max_tp_rate2;
289 cur_tp2 = mr->cur_tp;
290 }
291 }
292
293 mi->stats_update = jiffies;
294 }
295
296 static bool
297 minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
298 {
299 if (!rate->count)
300 return false;
301
302 if (rate->idx < 0)
303 return false;
304
305 return !!(rate->flags & IEEE80211_TX_RC_MCS);
306 }
307
308 static void
309 minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
310 {
311 struct minstrel_mcs_group_data *mg;
312
313 for (;;) {
314 mi->sample_group++;
315 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
316 mg = &mi->groups[mi->sample_group];
317
318 if (!mg->supported)
319 continue;
320
321 if (++mg->index >= MCS_GROUP_RATES) {
322 mg->index = 0;
323 if (++mg->column >= ARRAY_SIZE(sample_table))
324 mg->column = 0;
325 }
326 break;
327 }
328 }
329
330 static void
331 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, bool primary)
332 {
333 int group, orig_group;
334
335 orig_group = group = *idx / MCS_GROUP_RATES;
336 while (group > 0) {
337 group--;
338
339 if (!mi->groups[group].supported)
340 continue;
341
342 if (minstrel_mcs_groups[group].streams >
343 minstrel_mcs_groups[orig_group].streams)
344 continue;
345
346 if (primary)
347 *idx = mi->groups[group].max_tp_rate;
348 else
349 *idx = mi->groups[group].max_tp_rate2;
350 break;
351 }
352 }
353
354 static void
355 minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
356 {
357 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
358 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
359 u16 tid;
360
361 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
362 return;
363
364 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
365 return;
366
367 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
368 if (likely(sta->ampdu_mlme.tid_state_tx[tid] != HT_AGG_STATE_IDLE))
369 return;
370
371 ieee80211_start_tx_ba_session(pubsta, tid);
372 }
373
374 static void
375 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
376 struct ieee80211_sta *sta, void *priv_sta,
377 struct sk_buff *skb)
378 {
379 struct minstrel_ht_sta_priv *msp = priv_sta;
380 struct minstrel_ht_sta *mi = &msp->ht;
381 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
382 struct ieee80211_tx_rate *ar = info->status.rates;
383 struct minstrel_rate_stats *rate, *rate2;
384 struct minstrel_priv *mp = priv;
385 bool last = false;
386 int group;
387 int i = 0;
388
389 if (!msp->is_ht)
390 return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
391
392 /* This packet was aggregated but doesn't carry status info */
393 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
394 !(info->flags & IEEE80211_TX_STAT_AMPDU))
395 return;
396
397 if (!info->status.ampdu_len) {
398 info->status.ampdu_ack_len = 1;
399 info->status.ampdu_len = 1;
400 }
401
402 mi->ampdu_packets++;
403 mi->ampdu_len += info->status.ampdu_len;
404
405 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
406 mi->sample_wait = 4 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
407 mi->sample_tries = 3;
408 mi->sample_count--;
409 }
410
411 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) {
412 mi->sample_packets += info->status.ampdu_len;
413 minstrel_next_sample_idx(mi);
414 }
415
416 for (i = 0; !last; i++) {
417 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
418 !minstrel_ht_txstat_valid(&ar[i + 1]);
419
420 if (!minstrel_ht_txstat_valid(&ar[i]))
421 break;
422
423 group = minstrel_ht_get_group_idx(&ar[i]);
424 rate = &mi->groups[group].rates[ar[i].idx % 8];
425
426 if (last && (info->flags & IEEE80211_TX_STAT_ACK))
427 rate->success += info->status.ampdu_ack_len;
428
429 rate->attempts += ar[i].count * info->status.ampdu_len;
430 }
431
432 /*
433 * check for sudden death of spatial multiplexing,
434 * downgrade to a lower number of streams if necessary.
435 */
436 rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
437 if (rate->attempts > 30 &&
438 MINSTREL_FRAC(rate->success, rate->attempts) <
439 MINSTREL_FRAC(20, 100))
440 minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
441
442 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
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_rate2, false);
447
448 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
449 minstrel_ht_update_stats(mp, mi);
450 minstrel_aggr_check(mp, sta, skb);
451 }
452 }
453
454 static void
455 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
456 int index)
457 {
458 struct minstrel_rate_stats *mr;
459 const struct mcs_group *group;
460 unsigned int tx_time, tx_time_rtscts, tx_time_data;
461 unsigned int cw = mp->cw_min;
462 unsigned int t_slot = 9; /* FIXME */
463 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
464
465 mr = minstrel_get_ratestats(mi, index);
466 if (mr->probability < MINSTREL_FRAC(1, 10)) {
467 mr->retry_count = 1;
468 mr->retry_count_rtscts = 1;
469 return;
470 }
471
472 mr->retry_count = 2;
473 mr->retry_count_rtscts = 2;
474 mr->retry_updated = true;
475
476 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
477 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
478 tx_time = 2 * (t_slot + mi->overhead + tx_time_data);
479 tx_time_rtscts = 2 * (t_slot + mi->overhead_rtscts + tx_time_data);
480 do {
481 cw = (cw << 1) | 1;
482 cw = min(cw, mp->cw_max);
483 tx_time += cw + t_slot + mi->overhead;
484 tx_time_rtscts += cw + t_slot + mi->overhead_rtscts;
485 if (tx_time_rtscts < mp->segment_size)
486 mr->retry_count_rtscts++;
487 } while ((tx_time < mp->segment_size) &&
488 (++mr->retry_count < mp->max_retry));
489 }
490
491
492 static void
493 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
494 struct ieee80211_tx_rate *rate, int index,
495 struct ieee80211_tx_rate_control *txrc,
496 bool sample, bool rtscts)
497 {
498 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
499 struct minstrel_rate_stats *mr;
500
501 mr = minstrel_get_ratestats(mi, index);
502 if (!mr->retry_updated)
503 minstrel_calc_retransmit(mp, mi, index);
504
505 if (mr->probability < MINSTREL_FRAC(20, 100))
506 rate->count = 2;
507 else if (rtscts)
508 rate->count = mr->retry_count_rtscts;
509 else
510 rate->count = mr->retry_count;
511
512 rate->flags = IEEE80211_TX_RC_MCS | group->flags;
513 if (txrc->short_preamble)
514 rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
515 if (txrc->rts || rtscts)
516 rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
517 rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
518 }
519
520 static inline int
521 minstrel_get_duration(int index)
522 {
523 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
524 return group->duration[index % MCS_GROUP_RATES];
525 }
526
527 static int
528 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
529 {
530 struct minstrel_rate_stats *mr;
531 struct minstrel_mcs_group_data *mg;
532 int sample_idx = 0;
533
534 if (mi->sample_wait > 0) {
535 mi->sample_wait--;
536 return -1;
537 }
538
539 if (!mi->sample_tries)
540 return -1;
541
542 mi->sample_tries--;
543 mg = &mi->groups[mi->sample_group];
544 sample_idx = sample_table[mg->column][mg->index];
545 mr = &mg->rates[sample_idx];
546 sample_idx += mi->sample_group * MCS_GROUP_RATES;
547
548 /*
549 * When not using MRR, do not sample if the probability is already
550 * higher than 95% to avoid wasting airtime
551 */
552 if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
553 goto next;
554
555 /*
556 * Make sure that lower rates get sampled only occasionally,
557 * if the link is working perfectly.
558 */
559 if (minstrel_get_duration(sample_idx) >
560 minstrel_get_duration(mi->max_tp_rate)) {
561 if (mr->sample_skipped < 10)
562 goto next;
563
564 if (mi->sample_slow++ > 2)
565 goto next;
566 }
567
568 return sample_idx;
569
570 next:
571 minstrel_next_sample_idx(mi);
572 return -1;
573 }
574
575 static void
576 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
577 struct ieee80211_tx_rate_control *txrc)
578 {
579 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
580 struct ieee80211_tx_rate *ar = info->status.rates;
581 struct minstrel_ht_sta_priv *msp = priv_sta;
582 struct minstrel_ht_sta *mi = &msp->ht;
583 struct minstrel_priv *mp = priv;
584 int sample_idx;
585
586 if (rate_control_send_low(sta, priv_sta, txrc))
587 return;
588
589 if (!msp->is_ht)
590 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
591
592 info->flags |= mi->tx_flags;
593 sample_idx = minstrel_get_sample_rate(mp, mi);
594 if (sample_idx >= 0) {
595 minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
596 txrc, true, false);
597 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
598 txrc, false, true);
599 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
600 } else {
601 minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
602 txrc, false, false);
603 minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
604 txrc, false, true);
605 }
606 minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate, txrc, false, true);
607
608 ar[3].count = 0;
609 ar[3].idx = -1;
610
611 mi->total_packets++;
612
613 /* wraparound */
614 if (mi->total_packets == ~0) {
615 mi->total_packets = 0;
616 mi->sample_packets = 0;
617 }
618 }
619
620 static void
621 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
622 struct ieee80211_sta *sta, void *priv_sta,
623 enum nl80211_channel_type oper_chan_type)
624 {
625 struct minstrel_priv *mp = priv;
626 struct minstrel_ht_sta_priv *msp = priv_sta;
627 struct minstrel_ht_sta *mi = &msp->ht;
628 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
629 struct ieee80211_local *local = hw_to_local(mp->hw);
630 u16 sta_cap = sta->ht_cap.cap;
631 int ack_dur;
632 int stbc;
633 int i;
634
635 /* fall back to the old minstrel for legacy stations */
636 if (sta && !sta->ht_cap.ht_supported) {
637 msp->is_ht = false;
638 memset(&msp->legacy, 0, sizeof(msp->legacy));
639 msp->legacy.r = msp->ratelist;
640 msp->legacy.sample_table = msp->sample_table;
641 return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
642 }
643
644 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
645 MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
646
647 msp->is_ht = true;
648 memset(mi, 0, sizeof(*mi));
649 mi->stats_update = jiffies;
650
651 ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
652 mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
653 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
654
655 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
656
657 /* When using MRR, sample more on the first attempt, without delay */
658 if (mp->has_mrr) {
659 mi->sample_count = 16;
660 mi->sample_wait = 0;
661 } else {
662 mi->sample_count = 8;
663 mi->sample_wait = 8;
664 }
665 mi->sample_tries = 4;
666
667 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
668 IEEE80211_HT_CAP_RX_STBC_SHIFT;
669 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
670
671 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
672 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
673
674 if (oper_chan_type != NL80211_CHAN_HT40MINUS &&
675 oper_chan_type != NL80211_CHAN_HT40PLUS)
676 sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
677
678 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
679 u16 req = 0;
680
681 mi->groups[i].supported = 0;
682 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
683 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
684 req |= IEEE80211_HT_CAP_SGI_40;
685 else
686 req |= IEEE80211_HT_CAP_SGI_20;
687 }
688
689 if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
690 req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
691
692 if ((sta_cap & req) != req)
693 continue;
694
695 mi->groups[i].supported =
696 mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
697 }
698 }
699
700 static void
701 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
702 struct ieee80211_sta *sta, void *priv_sta)
703 {
704 struct minstrel_priv *mp = priv;
705
706 minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type);
707 }
708
709 static void
710 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
711 struct ieee80211_sta *sta, void *priv_sta,
712 u32 changed, enum nl80211_channel_type oper_chan_type)
713 {
714 minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type);
715 }
716
717 static void *
718 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
719 {
720 struct ieee80211_supported_band *sband;
721 struct minstrel_ht_sta_priv *msp;
722 struct minstrel_priv *mp = priv;
723 struct ieee80211_hw *hw = mp->hw;
724 int max_rates = 0;
725 int i;
726
727 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
728 sband = hw->wiphy->bands[i];
729 if (sband && sband->n_bitrates > max_rates)
730 max_rates = sband->n_bitrates;
731 }
732
733 msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
734 if (!msp)
735 return NULL;
736
737 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
738 if (!msp->ratelist)
739 goto error;
740
741 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
742 if (!msp->sample_table)
743 goto error1;
744
745 return msp;
746
747 error1:
748 kfree(msp->sample_table);
749 error:
750 kfree(msp);
751 return NULL;
752 }
753
754 static void
755 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
756 {
757 struct minstrel_ht_sta_priv *msp = priv_sta;
758
759 kfree(msp->sample_table);
760 kfree(msp->ratelist);
761 kfree(msp);
762 }
763
764 static void *
765 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
766 {
767 return mac80211_minstrel.alloc(hw, debugfsdir);
768 }
769
770 static void
771 minstrel_ht_free(void *priv)
772 {
773 mac80211_minstrel.free(priv);
774 }
775
776 static struct rate_control_ops mac80211_minstrel_ht = {
777 .name = "minstrel_ht",
778 .tx_status = minstrel_ht_tx_status,
779 .get_rate = minstrel_ht_get_rate,
780 .rate_init = minstrel_ht_rate_init,
781 .rate_update = minstrel_ht_rate_update,
782 .alloc_sta = minstrel_ht_alloc_sta,
783 .free_sta = minstrel_ht_free_sta,
784 .alloc = minstrel_ht_alloc,
785 .free = minstrel_ht_free,
786 #ifdef CONFIG_MAC80211_DEBUGFS
787 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
788 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
789 #endif
790 };
791
792
793 static void
794 init_sample_table(void)
795 {
796 int col, i, new_idx;
797 u8 rnd[MCS_GROUP_RATES];
798
799 memset(sample_table, 0xff, sizeof(sample_table));
800 for (col = 0; col < SAMPLE_COLUMNS; col++) {
801 for (i = 0; i < MCS_GROUP_RATES; i++) {
802 get_random_bytes(rnd, sizeof(rnd));
803 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
804
805 while (sample_table[col][new_idx] != 0xff)
806 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
807
808 sample_table[col][new_idx] = i;
809 }
810 }
811 }
812
813 int __init
814 rc80211_minstrel_ht_init(void)
815 {
816 init_sample_table();
817 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
818 }
819
820 void
821 rc80211_minstrel_ht_exit(void)
822 {
823 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
824 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree