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Merge branch 'for-davem' into for-next
[deliverable/linux.git] / net / mac80211 / rc80211_minstrel_ht.c
1 /*
2 * Copyright (C) 2010-2013 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/moduleparam.h>
14 #include <linux/ieee80211.h>
15 #include <net/mac80211.h>
16 #include "rate.h"
17 #include "rc80211_minstrel.h"
18 #include "rc80211_minstrel_ht.h"
19
20 #define AVG_AMPDU_SIZE 16
21 #define AVG_PKT_SIZE 1200
22
23 /* Number of bits for an average sized packet */
24 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
25
26 /* Number of symbols for a packet with (bps) bits per symbol */
27 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
28
29 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
30 #define MCS_SYMBOL_TIME(sgi, syms) \
31 (sgi ? \
32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
33 ((syms) * 1000) << 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) \
38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
39
40 #define BW_20 0
41 #define BW_40 1
42 #define BW_80 2
43
44 /*
45 * Define group sort order: HT40 -> SGI -> #streams
46 */
47 #define GROUP_IDX(_streams, _sgi, _ht40) \
48 MINSTREL_HT_GROUP_0 + \
49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
50 MINSTREL_MAX_STREAMS * _sgi + \
51 _streams - 1
52
53 /* MCS rate information for an MCS group */
54 #define MCS_GROUP(_streams, _sgi, _ht40) \
55 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
56 .streams = _streams, \
57 .flags = \
58 IEEE80211_TX_RC_MCS | \
59 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
60 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
61 .duration = { \
62 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
70 } \
71 }
72
73 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
74 (MINSTREL_VHT_GROUP_0 + \
75 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
76 MINSTREL_MAX_STREAMS * (_sgi) + \
77 (_streams) - 1)
78
79 #define BW2VBPS(_bw, r3, r2, r1) \
80 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
81
82 #define VHT_GROUP(_streams, _sgi, _bw) \
83 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
84 .streams = _streams, \
85 .flags = \
86 IEEE80211_TX_RC_VHT_MCS | \
87 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
88 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
89 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
90 .duration = { \
91 MCS_DURATION(_streams, _sgi, \
92 BW2VBPS(_bw, 117, 54, 26)), \
93 MCS_DURATION(_streams, _sgi, \
94 BW2VBPS(_bw, 234, 108, 52)), \
95 MCS_DURATION(_streams, _sgi, \
96 BW2VBPS(_bw, 351, 162, 78)), \
97 MCS_DURATION(_streams, _sgi, \
98 BW2VBPS(_bw, 468, 216, 104)), \
99 MCS_DURATION(_streams, _sgi, \
100 BW2VBPS(_bw, 702, 324, 156)), \
101 MCS_DURATION(_streams, _sgi, \
102 BW2VBPS(_bw, 936, 432, 208)), \
103 MCS_DURATION(_streams, _sgi, \
104 BW2VBPS(_bw, 1053, 486, 234)), \
105 MCS_DURATION(_streams, _sgi, \
106 BW2VBPS(_bw, 1170, 540, 260)), \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 1404, 648, 312)), \
109 MCS_DURATION(_streams, _sgi, \
110 BW2VBPS(_bw, 1560, 720, 346)) \
111 } \
112 }
113
114 #define CCK_DURATION(_bitrate, _short, _len) \
115 (1000 * (10 /* SIFS */ + \
116 (_short ? 72 + 24 : 144 + 48) + \
117 (8 * (_len + 4) * 10) / (_bitrate)))
118
119 #define CCK_ACK_DURATION(_bitrate, _short) \
120 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
121 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
122
123 #define CCK_DURATION_LIST(_short) \
124 CCK_ACK_DURATION(10, _short), \
125 CCK_ACK_DURATION(20, _short), \
126 CCK_ACK_DURATION(55, _short), \
127 CCK_ACK_DURATION(110, _short)
128
129 #define CCK_GROUP \
130 [MINSTREL_CCK_GROUP] = { \
131 .streams = 0, \
132 .flags = 0, \
133 .duration = { \
134 CCK_DURATION_LIST(false), \
135 CCK_DURATION_LIST(true) \
136 } \
137 }
138
139 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
140 static bool minstrel_vht_only = true;
141 module_param(minstrel_vht_only, bool, 0644);
142 MODULE_PARM_DESC(minstrel_vht_only,
143 "Use only VHT rates when VHT is supported by sta.");
144 #endif
145
146 /*
147 * To enable sufficiently targeted rate sampling, MCS rates are divided into
148 * groups, based on the number of streams and flags (HT40, SGI) that they
149 * use.
150 *
151 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
152 * BW -> SGI -> #streams
153 */
154 const struct mcs_group minstrel_mcs_groups[] = {
155 MCS_GROUP(1, 0, BW_20),
156 MCS_GROUP(2, 0, BW_20),
157 #if MINSTREL_MAX_STREAMS >= 3
158 MCS_GROUP(3, 0, BW_20),
159 #endif
160
161 MCS_GROUP(1, 1, BW_20),
162 MCS_GROUP(2, 1, BW_20),
163 #if MINSTREL_MAX_STREAMS >= 3
164 MCS_GROUP(3, 1, BW_20),
165 #endif
166
167 MCS_GROUP(1, 0, BW_40),
168 MCS_GROUP(2, 0, BW_40),
169 #if MINSTREL_MAX_STREAMS >= 3
170 MCS_GROUP(3, 0, BW_40),
171 #endif
172
173 MCS_GROUP(1, 1, BW_40),
174 MCS_GROUP(2, 1, BW_40),
175 #if MINSTREL_MAX_STREAMS >= 3
176 MCS_GROUP(3, 1, BW_40),
177 #endif
178
179 CCK_GROUP,
180
181 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
182 VHT_GROUP(1, 0, BW_20),
183 VHT_GROUP(2, 0, BW_20),
184 #if MINSTREL_MAX_STREAMS >= 3
185 VHT_GROUP(3, 0, BW_20),
186 #endif
187
188 VHT_GROUP(1, 1, BW_20),
189 VHT_GROUP(2, 1, BW_20),
190 #if MINSTREL_MAX_STREAMS >= 3
191 VHT_GROUP(3, 1, BW_20),
192 #endif
193
194 VHT_GROUP(1, 0, BW_40),
195 VHT_GROUP(2, 0, BW_40),
196 #if MINSTREL_MAX_STREAMS >= 3
197 VHT_GROUP(3, 0, BW_40),
198 #endif
199
200 VHT_GROUP(1, 1, BW_40),
201 VHT_GROUP(2, 1, BW_40),
202 #if MINSTREL_MAX_STREAMS >= 3
203 VHT_GROUP(3, 1, BW_40),
204 #endif
205
206 VHT_GROUP(1, 0, BW_80),
207 VHT_GROUP(2, 0, BW_80),
208 #if MINSTREL_MAX_STREAMS >= 3
209 VHT_GROUP(3, 0, BW_80),
210 #endif
211
212 VHT_GROUP(1, 1, BW_80),
213 VHT_GROUP(2, 1, BW_80),
214 #if MINSTREL_MAX_STREAMS >= 3
215 VHT_GROUP(3, 1, BW_80),
216 #endif
217 #endif
218 };
219
220 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
221
222 static void
223 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
224
225 /*
226 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
227 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
228 *
229 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
230 */
231 static u16
232 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
233 {
234 u16 mask = 0;
235
236 if (bw == BW_20) {
237 if (nss != 3 && nss != 6)
238 mask = BIT(9);
239 } else if (bw == BW_80) {
240 if (nss == 3 || nss == 7)
241 mask = BIT(6);
242 else if (nss == 6)
243 mask = BIT(9);
244 } else {
245 WARN_ON(bw != BW_40);
246 }
247
248 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
249 case IEEE80211_VHT_MCS_SUPPORT_0_7:
250 mask |= 0x300;
251 break;
252 case IEEE80211_VHT_MCS_SUPPORT_0_8:
253 mask |= 0x200;
254 break;
255 case IEEE80211_VHT_MCS_SUPPORT_0_9:
256 break;
257 default:
258 mask = 0x3ff;
259 }
260
261 return 0x3ff & ~mask;
262 }
263
264 /*
265 * Look up an MCS group index based on mac80211 rate information
266 */
267 static int
268 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
269 {
270 return GROUP_IDX((rate->idx / 8) + 1,
271 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
272 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
273 }
274
275 static int
276 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
277 {
278 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
279 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
280 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
281 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
282 }
283
284 static struct minstrel_rate_stats *
285 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
286 struct ieee80211_tx_rate *rate)
287 {
288 int group, idx;
289
290 if (rate->flags & IEEE80211_TX_RC_MCS) {
291 group = minstrel_ht_get_group_idx(rate);
292 idx = rate->idx % 8;
293 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
294 group = minstrel_vht_get_group_idx(rate);
295 idx = ieee80211_rate_get_vht_mcs(rate);
296 } else {
297 group = MINSTREL_CCK_GROUP;
298
299 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
300 if (rate->idx == mp->cck_rates[idx])
301 break;
302
303 /* short preamble */
304 if (!(mi->groups[group].supported & BIT(idx)))
305 idx += 4;
306 }
307 return &mi->groups[group].rates[idx];
308 }
309
310 static inline struct minstrel_rate_stats *
311 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
312 {
313 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
314 }
315
316
317 /*
318 * Recalculate success probabilities and counters for a rate using EWMA
319 */
320 static void
321 minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
322 {
323 if (unlikely(mr->attempts > 0)) {
324 mr->sample_skipped = 0;
325 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
326 if (!mr->att_hist)
327 mr->probability = mr->cur_prob;
328 else
329 mr->probability = minstrel_ewma(mr->probability,
330 mr->cur_prob, EWMA_LEVEL);
331 mr->att_hist += mr->attempts;
332 mr->succ_hist += mr->success;
333 } else {
334 mr->sample_skipped++;
335 }
336 mr->last_success = mr->success;
337 mr->last_attempts = mr->attempts;
338 mr->success = 0;
339 mr->attempts = 0;
340 }
341
342 /*
343 * Calculate throughput based on the average A-MPDU length, taking into account
344 * the expected number of retransmissions and their expected length
345 */
346 static void
347 minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
348 {
349 struct minstrel_rate_stats *mr;
350 unsigned int nsecs = 0;
351 unsigned int tp;
352 unsigned int prob;
353
354 mr = &mi->groups[group].rates[rate];
355 prob = mr->probability;
356
357 if (prob < MINSTREL_FRAC(1, 10)) {
358 mr->cur_tp = 0;
359 return;
360 }
361
362 /*
363 * For the throughput calculation, limit the probability value to 90% to
364 * account for collision related packet error rate fluctuation
365 */
366 if (prob > MINSTREL_FRAC(9, 10))
367 prob = MINSTREL_FRAC(9, 10);
368
369 if (group != MINSTREL_CCK_GROUP)
370 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
371
372 nsecs += minstrel_mcs_groups[group].duration[rate];
373
374 /* prob is scaled - see MINSTREL_FRAC above */
375 tp = 1000000 * ((prob * 1000) / nsecs);
376 mr->cur_tp = MINSTREL_TRUNC(tp);
377 }
378
379 /*
380 * Find & sort topmost throughput rates
381 *
382 * If multiple rates provide equal throughput the sorting is based on their
383 * current success probability. Higher success probability is preferred among
384 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
385 */
386 static void
387 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
388 u16 *tp_list)
389 {
390 int cur_group, cur_idx, cur_thr, cur_prob;
391 int tmp_group, tmp_idx, tmp_thr, tmp_prob;
392 int j = MAX_THR_RATES;
393
394 cur_group = index / MCS_GROUP_RATES;
395 cur_idx = index % MCS_GROUP_RATES;
396 cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
397 cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
398
399 do {
400 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
401 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
402 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
403 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
404 if (cur_thr < tmp_thr ||
405 (cur_thr == tmp_thr && cur_prob <= tmp_prob))
406 break;
407 j--;
408 } while (j > 0);
409
410 if (j < MAX_THR_RATES - 1) {
411 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
412 (MAX_THR_RATES - (j + 1))));
413 }
414 if (j < MAX_THR_RATES)
415 tp_list[j] = index;
416 }
417
418 /*
419 * Find and set the topmost probability rate per sta and per group
420 */
421 static void
422 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
423 {
424 struct minstrel_mcs_group_data *mg;
425 struct minstrel_rate_stats *mr;
426 int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group;
427
428 mg = &mi->groups[index / MCS_GROUP_RATES];
429 mr = &mg->rates[index % MCS_GROUP_RATES];
430
431 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
432 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
433 tmp_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
434 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
435
436 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
437 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
438 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
439 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
440 (max_tp_group != MINSTREL_CCK_GROUP))
441 return;
442
443 if (mr->probability > MINSTREL_FRAC(75, 100)) {
444 if (mr->cur_tp > tmp_tp)
445 mi->max_prob_rate = index;
446 if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp)
447 mg->max_group_prob_rate = index;
448 } else {
449 if (mr->probability > tmp_prob)
450 mi->max_prob_rate = index;
451 if (mr->probability > mg->rates[mg->max_group_prob_rate].probability)
452 mg->max_group_prob_rate = index;
453 }
454 }
455
456
457 /*
458 * Assign new rate set per sta and use CCK rates only if the fastest
459 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
460 * rate sets where MCS and CCK rates are mixed, because CCK rates can
461 * not use aggregation.
462 */
463 static void
464 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
465 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
466 u16 tmp_cck_tp_rate[MAX_THR_RATES])
467 {
468 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
469 int i;
470
471 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
472 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
473 tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
474
475 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
476 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
477 tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
478
479 if (tmp_cck_tp > tmp_mcs_tp) {
480 for(i = 0; i < MAX_THR_RATES; i++) {
481 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
482 tmp_mcs_tp_rate);
483 }
484 }
485
486 }
487
488 /*
489 * Try to increase robustness of max_prob rate by decrease number of
490 * streams if possible.
491 */
492 static inline void
493 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
494 {
495 struct minstrel_mcs_group_data *mg;
496 struct minstrel_rate_stats *mr;
497 int tmp_max_streams, group;
498 int tmp_tp = 0;
499
500 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
501 MCS_GROUP_RATES].streams;
502 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
503 mg = &mi->groups[group];
504 if (!mg->supported || group == MINSTREL_CCK_GROUP)
505 continue;
506 mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate);
507 if (tmp_tp < mr->cur_tp &&
508 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
509 mi->max_prob_rate = mg->max_group_prob_rate;
510 tmp_tp = mr->cur_tp;
511 }
512 }
513 }
514
515 /*
516 * Update rate statistics and select new primary rates
517 *
518 * Rules for rate selection:
519 * - max_prob_rate must use only one stream, as a tradeoff between delivery
520 * probability and throughput during strong fluctuations
521 * - as long as the max prob rate has a probability of more than 75%, pick
522 * higher throughput rates, even if the probablity is a bit lower
523 */
524 static void
525 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
526 {
527 struct minstrel_mcs_group_data *mg;
528 struct minstrel_rate_stats *mr;
529 int group, i, j;
530 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
531 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
532
533 if (mi->ampdu_packets > 0) {
534 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
535 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
536 mi->ampdu_len = 0;
537 mi->ampdu_packets = 0;
538 }
539
540 mi->sample_slow = 0;
541 mi->sample_count = 0;
542
543 /* Initialize global rate indexes */
544 for(j = 0; j < MAX_THR_RATES; j++){
545 tmp_mcs_tp_rate[j] = 0;
546 tmp_cck_tp_rate[j] = 0;
547 }
548
549 /* Find best rate sets within all MCS groups*/
550 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
551
552 mg = &mi->groups[group];
553 if (!mg->supported)
554 continue;
555
556 mi->sample_count++;
557
558 /* (re)Initialize group rate indexes */
559 for(j = 0; j < MAX_THR_RATES; j++)
560 tmp_group_tp_rate[j] = group;
561
562 for (i = 0; i < MCS_GROUP_RATES; i++) {
563 if (!(mg->supported & BIT(i)))
564 continue;
565
566 index = MCS_GROUP_RATES * group + i;
567
568 mr = &mg->rates[i];
569 mr->retry_updated = false;
570 minstrel_calc_rate_ewma(mr);
571 minstrel_ht_calc_tp(mi, group, i);
572
573 if (!mr->cur_tp)
574 continue;
575
576 /* Find max throughput rate set */
577 if (group != MINSTREL_CCK_GROUP) {
578 minstrel_ht_sort_best_tp_rates(mi, index,
579 tmp_mcs_tp_rate);
580 } else if (group == MINSTREL_CCK_GROUP) {
581 minstrel_ht_sort_best_tp_rates(mi, index,
582 tmp_cck_tp_rate);
583 }
584
585 /* Find max throughput rate set within a group */
586 minstrel_ht_sort_best_tp_rates(mi, index,
587 tmp_group_tp_rate);
588
589 /* Find max probability rate per group and global */
590 minstrel_ht_set_best_prob_rate(mi, index);
591 }
592
593 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
594 sizeof(mg->max_group_tp_rate));
595 }
596
597 /* Assign new rate set per sta */
598 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
599 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
600
601 /* Try to increase robustness of max_prob_rate*/
602 minstrel_ht_prob_rate_reduce_streams(mi);
603
604 /* try to sample all available rates during each interval */
605 mi->sample_count *= 8;
606
607 #ifdef CONFIG_MAC80211_DEBUGFS
608 /* use fixed index if set */
609 if (mp->fixed_rate_idx != -1) {
610 for (i = 0; i < 4; i++)
611 mi->max_tp_rate[i] = mp->fixed_rate_idx;
612 mi->max_prob_rate = mp->fixed_rate_idx;
613 }
614 #endif
615
616 /* Reset update timer */
617 mi->stats_update = jiffies;
618 }
619
620 static bool
621 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
622 {
623 if (rate->idx < 0)
624 return false;
625
626 if (!rate->count)
627 return false;
628
629 if (rate->flags & IEEE80211_TX_RC_MCS ||
630 rate->flags & IEEE80211_TX_RC_VHT_MCS)
631 return true;
632
633 return rate->idx == mp->cck_rates[0] ||
634 rate->idx == mp->cck_rates[1] ||
635 rate->idx == mp->cck_rates[2] ||
636 rate->idx == mp->cck_rates[3];
637 }
638
639 static void
640 minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
641 {
642 struct minstrel_mcs_group_data *mg;
643
644 for (;;) {
645 mi->sample_group++;
646 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
647 mg = &mi->groups[mi->sample_group];
648
649 if (!mg->supported)
650 continue;
651
652 if (++mg->index >= MCS_GROUP_RATES) {
653 mg->index = 0;
654 if (++mg->column >= ARRAY_SIZE(sample_table))
655 mg->column = 0;
656 }
657 break;
658 }
659 }
660
661 static void
662 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
663 {
664 int group, orig_group;
665
666 orig_group = group = *idx / MCS_GROUP_RATES;
667 while (group > 0) {
668 group--;
669
670 if (!mi->groups[group].supported)
671 continue;
672
673 if (minstrel_mcs_groups[group].streams >
674 minstrel_mcs_groups[orig_group].streams)
675 continue;
676
677 if (primary)
678 *idx = mi->groups[group].max_group_tp_rate[0];
679 else
680 *idx = mi->groups[group].max_group_tp_rate[1];
681 break;
682 }
683 }
684
685 static void
686 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
687 {
688 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
689 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
690 u16 tid;
691
692 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
693 return;
694
695 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
696 return;
697
698 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
699 return;
700
701 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
702 if (likely(sta->ampdu_mlme.tid_tx[tid]))
703 return;
704
705 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
706 }
707
708 static void
709 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
710 struct ieee80211_sta *sta, void *priv_sta,
711 struct ieee80211_tx_info *info)
712 {
713 struct minstrel_ht_sta_priv *msp = priv_sta;
714 struct minstrel_ht_sta *mi = &msp->ht;
715 struct ieee80211_tx_rate *ar = info->status.rates;
716 struct minstrel_rate_stats *rate, *rate2;
717 struct minstrel_priv *mp = priv;
718 bool last, update = false;
719 int i;
720
721 if (!msp->is_ht)
722 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
723 &msp->legacy, info);
724
725 /* This packet was aggregated but doesn't carry status info */
726 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
727 !(info->flags & IEEE80211_TX_STAT_AMPDU))
728 return;
729
730 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
731 info->status.ampdu_ack_len =
732 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
733 info->status.ampdu_len = 1;
734 }
735
736 mi->ampdu_packets++;
737 mi->ampdu_len += info->status.ampdu_len;
738
739 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
740 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
741 mi->sample_tries = 1;
742 mi->sample_count--;
743 }
744
745 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
746 mi->sample_packets += info->status.ampdu_len;
747
748 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
749 for (i = 0; !last; i++) {
750 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
751 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
752
753 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
754
755 if (last)
756 rate->success += info->status.ampdu_ack_len;
757
758 rate->attempts += ar[i].count * info->status.ampdu_len;
759 }
760
761 /*
762 * check for sudden death of spatial multiplexing,
763 * downgrade to a lower number of streams if necessary.
764 */
765 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
766 if (rate->attempts > 30 &&
767 MINSTREL_FRAC(rate->success, rate->attempts) <
768 MINSTREL_FRAC(20, 100)) {
769 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
770 update = true;
771 }
772
773 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
774 if (rate2->attempts > 30 &&
775 MINSTREL_FRAC(rate2->success, rate2->attempts) <
776 MINSTREL_FRAC(20, 100)) {
777 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
778 update = true;
779 }
780
781 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
782 update = true;
783 minstrel_ht_update_stats(mp, mi);
784 }
785
786 if (update)
787 minstrel_ht_update_rates(mp, mi);
788 }
789
790 static void
791 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
792 int index)
793 {
794 struct minstrel_rate_stats *mr;
795 const struct mcs_group *group;
796 unsigned int tx_time, tx_time_rtscts, tx_time_data;
797 unsigned int cw = mp->cw_min;
798 unsigned int ctime = 0;
799 unsigned int t_slot = 9; /* FIXME */
800 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
801 unsigned int overhead = 0, overhead_rtscts = 0;
802
803 mr = minstrel_get_ratestats(mi, index);
804 if (mr->probability < MINSTREL_FRAC(1, 10)) {
805 mr->retry_count = 1;
806 mr->retry_count_rtscts = 1;
807 return;
808 }
809
810 mr->retry_count = 2;
811 mr->retry_count_rtscts = 2;
812 mr->retry_updated = true;
813
814 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
815 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
816
817 /* Contention time for first 2 tries */
818 ctime = (t_slot * cw) >> 1;
819 cw = min((cw << 1) | 1, mp->cw_max);
820 ctime += (t_slot * cw) >> 1;
821 cw = min((cw << 1) | 1, mp->cw_max);
822
823 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
824 overhead = mi->overhead;
825 overhead_rtscts = mi->overhead_rtscts;
826 }
827
828 /* Total TX time for data and Contention after first 2 tries */
829 tx_time = ctime + 2 * (overhead + tx_time_data);
830 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
831
832 /* See how many more tries we can fit inside segment size */
833 do {
834 /* Contention time for this try */
835 ctime = (t_slot * cw) >> 1;
836 cw = min((cw << 1) | 1, mp->cw_max);
837
838 /* Total TX time after this try */
839 tx_time += ctime + overhead + tx_time_data;
840 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
841
842 if (tx_time_rtscts < mp->segment_size)
843 mr->retry_count_rtscts++;
844 } while ((tx_time < mp->segment_size) &&
845 (++mr->retry_count < mp->max_retry));
846 }
847
848
849 static void
850 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
851 struct ieee80211_sta_rates *ratetbl, int offset, int index)
852 {
853 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
854 struct minstrel_rate_stats *mr;
855 u8 idx;
856 u16 flags = group->flags;
857
858 mr = minstrel_get_ratestats(mi, index);
859 if (!mr->retry_updated)
860 minstrel_calc_retransmit(mp, mi, index);
861
862 if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
863 ratetbl->rate[offset].count = 2;
864 ratetbl->rate[offset].count_rts = 2;
865 ratetbl->rate[offset].count_cts = 2;
866 } else {
867 ratetbl->rate[offset].count = mr->retry_count;
868 ratetbl->rate[offset].count_cts = mr->retry_count;
869 ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
870 }
871
872 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
873 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
874 else if (flags & IEEE80211_TX_RC_VHT_MCS)
875 idx = ((group->streams - 1) << 4) |
876 ((index % MCS_GROUP_RATES) & 0xF);
877 else
878 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
879
880 if (offset > 0) {
881 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
882 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
883 }
884
885 ratetbl->rate[offset].idx = idx;
886 ratetbl->rate[offset].flags = flags;
887 }
888
889 static void
890 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
891 {
892 struct ieee80211_sta_rates *rates;
893 int i = 0;
894
895 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
896 if (!rates)
897 return;
898
899 /* Start with max_tp_rate[0] */
900 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
901
902 if (mp->hw->max_rates >= 3) {
903 /* At least 3 tx rates supported, use max_tp_rate[1] next */
904 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
905 }
906
907 if (mp->hw->max_rates >= 2) {
908 /*
909 * At least 2 tx rates supported, use max_prob_rate next */
910 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
911 }
912
913 rates->rate[i].idx = -1;
914 rate_control_set_rates(mp->hw, mi->sta, rates);
915 }
916
917 static inline int
918 minstrel_get_duration(int index)
919 {
920 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
921 return group->duration[index % MCS_GROUP_RATES];
922 }
923
924 static int
925 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
926 {
927 struct minstrel_rate_stats *mr;
928 struct minstrel_mcs_group_data *mg;
929 unsigned int sample_dur, sample_group, cur_max_tp_streams;
930 int sample_idx = 0;
931
932 if (mi->sample_wait > 0) {
933 mi->sample_wait--;
934 return -1;
935 }
936
937 if (!mi->sample_tries)
938 return -1;
939
940 sample_group = mi->sample_group;
941 mg = &mi->groups[sample_group];
942 sample_idx = sample_table[mg->column][mg->index];
943 minstrel_next_sample_idx(mi);
944
945 if (!(mg->supported & BIT(sample_idx)))
946 return -1;
947
948 mr = &mg->rates[sample_idx];
949 sample_idx += sample_group * MCS_GROUP_RATES;
950
951 /*
952 * Sampling might add some overhead (RTS, no aggregation)
953 * to the frame. Hence, don't use sampling for the currently
954 * used rates.
955 */
956 if (sample_idx == mi->max_tp_rate[0] ||
957 sample_idx == mi->max_tp_rate[1] ||
958 sample_idx == mi->max_prob_rate)
959 return -1;
960
961 /*
962 * Do not sample if the probability is already higher than 95%
963 * to avoid wasting airtime.
964 */
965 if (mr->probability > MINSTREL_FRAC(95, 100))
966 return -1;
967
968 /*
969 * Make sure that lower rates get sampled only occasionally,
970 * if the link is working perfectly.
971 */
972
973 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
974 MCS_GROUP_RATES].streams;
975 sample_dur = minstrel_get_duration(sample_idx);
976 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
977 (cur_max_tp_streams - 1 <
978 minstrel_mcs_groups[sample_group].streams ||
979 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
980 if (mr->sample_skipped < 20)
981 return -1;
982
983 if (mi->sample_slow++ > 2)
984 return -1;
985 }
986 mi->sample_tries--;
987
988 return sample_idx;
989 }
990
991 static void
992 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
993 struct minstrel_ht_sta *mi, bool val)
994 {
995 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
996
997 if (!supported || !mi->cck_supported_short)
998 return;
999
1000 if (supported & (mi->cck_supported_short << (val * 4)))
1001 return;
1002
1003 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1004 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1005 }
1006
1007 static void
1008 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1009 struct ieee80211_tx_rate_control *txrc)
1010 {
1011 const struct mcs_group *sample_group;
1012 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1013 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1014 struct minstrel_ht_sta_priv *msp = priv_sta;
1015 struct minstrel_ht_sta *mi = &msp->ht;
1016 struct minstrel_priv *mp = priv;
1017 int sample_idx;
1018
1019 if (rate_control_send_low(sta, priv_sta, txrc))
1020 return;
1021
1022 if (!msp->is_ht)
1023 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1024
1025 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1026 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1027 minstrel_aggr_check(sta, txrc->skb);
1028
1029 info->flags |= mi->tx_flags;
1030 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1031
1032 #ifdef CONFIG_MAC80211_DEBUGFS
1033 if (mp->fixed_rate_idx != -1)
1034 return;
1035 #endif
1036
1037 /* Don't use EAPOL frames for sampling on non-mrr hw */
1038 if (mp->hw->max_rates == 1 &&
1039 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1040 sample_idx = -1;
1041 else
1042 sample_idx = minstrel_get_sample_rate(mp, mi);
1043
1044 mi->total_packets++;
1045
1046 /* wraparound */
1047 if (mi->total_packets == ~0) {
1048 mi->total_packets = 0;
1049 mi->sample_packets = 0;
1050 }
1051
1052 if (sample_idx < 0)
1053 return;
1054
1055 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1056 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1057 rate->count = 1;
1058
1059 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1060 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1061 rate->idx = mp->cck_rates[idx];
1062 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1063 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1064 sample_group->streams);
1065 } else {
1066 rate->idx = sample_idx % MCS_GROUP_RATES +
1067 (sample_group->streams - 1) * 8;
1068 }
1069
1070 rate->flags = sample_group->flags;
1071 }
1072
1073 static void
1074 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1075 struct ieee80211_supported_band *sband,
1076 struct ieee80211_sta *sta)
1077 {
1078 int i;
1079
1080 if (sband->band != IEEE80211_BAND_2GHZ)
1081 return;
1082
1083 if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES))
1084 return;
1085
1086 mi->cck_supported = 0;
1087 mi->cck_supported_short = 0;
1088 for (i = 0; i < 4; i++) {
1089 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1090 continue;
1091
1092 mi->cck_supported |= BIT(i);
1093 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1094 mi->cck_supported_short |= BIT(i);
1095 }
1096
1097 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1098 }
1099
1100 static void
1101 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1102 struct cfg80211_chan_def *chandef,
1103 struct ieee80211_sta *sta, void *priv_sta)
1104 {
1105 struct minstrel_priv *mp = priv;
1106 struct minstrel_ht_sta_priv *msp = priv_sta;
1107 struct minstrel_ht_sta *mi = &msp->ht;
1108 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1109 u16 sta_cap = sta->ht_cap.cap;
1110 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1111 int use_vht;
1112 int n_supported = 0;
1113 int ack_dur;
1114 int stbc;
1115 int i;
1116
1117 /* fall back to the old minstrel for legacy stations */
1118 if (!sta->ht_cap.ht_supported)
1119 goto use_legacy;
1120
1121 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1122
1123 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1124 if (vht_cap->vht_supported)
1125 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1126 else
1127 #endif
1128 use_vht = 0;
1129
1130 msp->is_ht = true;
1131 memset(mi, 0, sizeof(*mi));
1132
1133 mi->sta = sta;
1134 mi->stats_update = jiffies;
1135
1136 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1137 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1138 mi->overhead += ack_dur;
1139 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1140
1141 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1142
1143 /* When using MRR, sample more on the first attempt, without delay */
1144 if (mp->has_mrr) {
1145 mi->sample_count = 16;
1146 mi->sample_wait = 0;
1147 } else {
1148 mi->sample_count = 8;
1149 mi->sample_wait = 8;
1150 }
1151 mi->sample_tries = 4;
1152
1153 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1154 if (!use_vht) {
1155 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1156 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1157 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1158
1159 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1160 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1161 }
1162
1163 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1164 u32 gflags = minstrel_mcs_groups[i].flags;
1165 int bw, nss;
1166
1167 mi->groups[i].supported = 0;
1168 if (i == MINSTREL_CCK_GROUP) {
1169 minstrel_ht_update_cck(mp, mi, sband, sta);
1170 continue;
1171 }
1172
1173 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1174 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1175 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1176 continue;
1177 } else {
1178 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1179 continue;
1180 }
1181 }
1182
1183 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1184 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1185 continue;
1186
1187 nss = minstrel_mcs_groups[i].streams;
1188
1189 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1190 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1191 continue;
1192
1193 /* HT rate */
1194 if (gflags & IEEE80211_TX_RC_MCS) {
1195 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1196 if (use_vht && minstrel_vht_only)
1197 continue;
1198 #endif
1199 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1200 if (mi->groups[i].supported)
1201 n_supported++;
1202 continue;
1203 }
1204
1205 /* VHT rate */
1206 if (!vht_cap->vht_supported ||
1207 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1208 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1209 continue;
1210
1211 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1212 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1213 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1214 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1215 continue;
1216 }
1217 }
1218
1219 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1220 bw = BW_40;
1221 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1222 bw = BW_80;
1223 else
1224 bw = BW_20;
1225
1226 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1227 vht_cap->vht_mcs.tx_mcs_map);
1228
1229 if (mi->groups[i].supported)
1230 n_supported++;
1231 }
1232
1233 if (!n_supported)
1234 goto use_legacy;
1235
1236 /* create an initial rate table with the lowest supported rates */
1237 minstrel_ht_update_stats(mp, mi);
1238 minstrel_ht_update_rates(mp, mi);
1239
1240 return;
1241
1242 use_legacy:
1243 msp->is_ht = false;
1244 memset(&msp->legacy, 0, sizeof(msp->legacy));
1245 msp->legacy.r = msp->ratelist;
1246 msp->legacy.sample_table = msp->sample_table;
1247 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1248 &msp->legacy);
1249 }
1250
1251 static void
1252 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1253 struct cfg80211_chan_def *chandef,
1254 struct ieee80211_sta *sta, void *priv_sta)
1255 {
1256 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1257 }
1258
1259 static void
1260 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1261 struct cfg80211_chan_def *chandef,
1262 struct ieee80211_sta *sta, void *priv_sta,
1263 u32 changed)
1264 {
1265 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1266 }
1267
1268 static void *
1269 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1270 {
1271 struct ieee80211_supported_band *sband;
1272 struct minstrel_ht_sta_priv *msp;
1273 struct minstrel_priv *mp = priv;
1274 struct ieee80211_hw *hw = mp->hw;
1275 int max_rates = 0;
1276 int i;
1277
1278 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1279 sband = hw->wiphy->bands[i];
1280 if (sband && sband->n_bitrates > max_rates)
1281 max_rates = sband->n_bitrates;
1282 }
1283
1284 msp = kzalloc(sizeof(*msp), gfp);
1285 if (!msp)
1286 return NULL;
1287
1288 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1289 if (!msp->ratelist)
1290 goto error;
1291
1292 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1293 if (!msp->sample_table)
1294 goto error1;
1295
1296 return msp;
1297
1298 error1:
1299 kfree(msp->ratelist);
1300 error:
1301 kfree(msp);
1302 return NULL;
1303 }
1304
1305 static void
1306 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1307 {
1308 struct minstrel_ht_sta_priv *msp = priv_sta;
1309
1310 kfree(msp->sample_table);
1311 kfree(msp->ratelist);
1312 kfree(msp);
1313 }
1314
1315 static void *
1316 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1317 {
1318 return mac80211_minstrel.alloc(hw, debugfsdir);
1319 }
1320
1321 static void
1322 minstrel_ht_free(void *priv)
1323 {
1324 mac80211_minstrel.free(priv);
1325 }
1326
1327 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1328 {
1329 struct minstrel_ht_sta_priv *msp = priv_sta;
1330 struct minstrel_ht_sta *mi = &msp->ht;
1331 int i, j;
1332
1333 if (!msp->is_ht)
1334 return mac80211_minstrel.get_expected_throughput(priv_sta);
1335
1336 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1337 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1338
1339 /* convert cur_tp from pkt per second in kbps */
1340 return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
1341 }
1342
1343 static const struct rate_control_ops mac80211_minstrel_ht = {
1344 .name = "minstrel_ht",
1345 .tx_status_noskb = minstrel_ht_tx_status,
1346 .get_rate = minstrel_ht_get_rate,
1347 .rate_init = minstrel_ht_rate_init,
1348 .rate_update = minstrel_ht_rate_update,
1349 .alloc_sta = minstrel_ht_alloc_sta,
1350 .free_sta = minstrel_ht_free_sta,
1351 .alloc = minstrel_ht_alloc,
1352 .free = minstrel_ht_free,
1353 #ifdef CONFIG_MAC80211_DEBUGFS
1354 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1355 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1356 #endif
1357 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1358 };
1359
1360
1361 static void __init init_sample_table(void)
1362 {
1363 int col, i, new_idx;
1364 u8 rnd[MCS_GROUP_RATES];
1365
1366 memset(sample_table, 0xff, sizeof(sample_table));
1367 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1368 prandom_bytes(rnd, sizeof(rnd));
1369 for (i = 0; i < MCS_GROUP_RATES; i++) {
1370 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1371 while (sample_table[col][new_idx] != 0xff)
1372 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1373
1374 sample_table[col][new_idx] = i;
1375 }
1376 }
1377 }
1378
1379 int __init
1380 rc80211_minstrel_ht_init(void)
1381 {
1382 init_sample_table();
1383 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1384 }
1385
1386 void
1387 rc80211_minstrel_ht_exit(void)
1388 {
1389 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1390 }
Linux kernel - Deliverables
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