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Merge branch 'fixes-base' into fixes
[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 * Return current throughput based on the average A-MPDU length, taking into
318 * account the expected number of retransmissions and their expected length
319 */
320 int
321 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
322 int prob_ewma)
323 {
324 unsigned int nsecs = 0;
325
326 /* do not account throughput if sucess prob is below 10% */
327 if (prob_ewma < MINSTREL_FRAC(10, 100))
328 return 0;
329
330 if (group != MINSTREL_CCK_GROUP)
331 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
332
333 nsecs += minstrel_mcs_groups[group].duration[rate];
334
335 /*
336 * For the throughput calculation, limit the probability value to 90% to
337 * account for collision related packet error rate fluctuation
338 * (prob is scaled - see MINSTREL_FRAC above)
339 */
340 if (prob_ewma > MINSTREL_FRAC(90, 100))
341 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
342 / nsecs));
343 else
344 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
345 }
346
347 /*
348 * Find & sort topmost throughput rates
349 *
350 * If multiple rates provide equal throughput the sorting is based on their
351 * current success probability. Higher success probability is preferred among
352 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
353 */
354 static void
355 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
356 u16 *tp_list)
357 {
358 int cur_group, cur_idx, cur_tp_avg, cur_prob;
359 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
360 int j = MAX_THR_RATES;
361
362 cur_group = index / MCS_GROUP_RATES;
363 cur_idx = index % MCS_GROUP_RATES;
364 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
365 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
366
367 do {
368 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
369 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
370 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
371 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
372 tmp_prob);
373 if (cur_tp_avg < tmp_tp_avg ||
374 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
375 break;
376 j--;
377 } while (j > 0);
378
379 if (j < MAX_THR_RATES - 1) {
380 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
381 (MAX_THR_RATES - (j + 1))));
382 }
383 if (j < MAX_THR_RATES)
384 tp_list[j] = index;
385 }
386
387 /*
388 * Find and set the topmost probability rate per sta and per group
389 */
390 static void
391 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
392 {
393 struct minstrel_mcs_group_data *mg;
394 struct minstrel_rate_stats *mrs;
395 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
396 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
397 int max_gpr_group, max_gpr_idx;
398 int max_gpr_tp_avg, max_gpr_prob;
399
400 cur_group = index / MCS_GROUP_RATES;
401 cur_idx = index % MCS_GROUP_RATES;
402 mg = &mi->groups[index / MCS_GROUP_RATES];
403 mrs = &mg->rates[index % MCS_GROUP_RATES];
404
405 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
406 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
407 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
408 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
409
410 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
411 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
412 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
413 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
414 (max_tp_group != MINSTREL_CCK_GROUP))
415 return;
416
417 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
418 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
419 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
420
421 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
422 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
423 mrs->prob_ewma);
424 if (cur_tp_avg > tmp_tp_avg)
425 mi->max_prob_rate = index;
426
427 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
428 max_gpr_idx,
429 max_gpr_prob);
430 if (cur_tp_avg > max_gpr_tp_avg)
431 mg->max_group_prob_rate = index;
432 } else {
433 if (mrs->prob_ewma > tmp_prob)
434 mi->max_prob_rate = index;
435 if (mrs->prob_ewma > max_gpr_prob)
436 mg->max_group_prob_rate = index;
437 }
438 }
439
440
441 /*
442 * Assign new rate set per sta and use CCK rates only if the fastest
443 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
444 * rate sets where MCS and CCK rates are mixed, because CCK rates can
445 * not use aggregation.
446 */
447 static void
448 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
449 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
450 u16 tmp_cck_tp_rate[MAX_THR_RATES])
451 {
452 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
453 int i;
454
455 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
456 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
457 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
458 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
459
460 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
461 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
462 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
463 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
464
465 if (tmp_cck_tp > tmp_mcs_tp) {
466 for(i = 0; i < MAX_THR_RATES; i++) {
467 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
468 tmp_mcs_tp_rate);
469 }
470 }
471
472 }
473
474 /*
475 * Try to increase robustness of max_prob rate by decrease number of
476 * streams if possible.
477 */
478 static inline void
479 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
480 {
481 struct minstrel_mcs_group_data *mg;
482 int tmp_max_streams, group, tmp_idx, tmp_prob;
483 int tmp_tp = 0;
484
485 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
486 MCS_GROUP_RATES].streams;
487 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
488 mg = &mi->groups[group];
489 if (!mg->supported || group == MINSTREL_CCK_GROUP)
490 continue;
491
492 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
493 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
494
495 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
496 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
497 mi->max_prob_rate = mg->max_group_prob_rate;
498 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
499 tmp_idx,
500 tmp_prob);
501 }
502 }
503 }
504
505 /*
506 * Update rate statistics and select new primary rates
507 *
508 * Rules for rate selection:
509 * - max_prob_rate must use only one stream, as a tradeoff between delivery
510 * probability and throughput during strong fluctuations
511 * - as long as the max prob rate has a probability of more than 75%, pick
512 * higher throughput rates, even if the probablity is a bit lower
513 */
514 static void
515 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
516 {
517 struct minstrel_mcs_group_data *mg;
518 struct minstrel_rate_stats *mrs;
519 int group, i, j, cur_prob;
520 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
521 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
522
523 if (mi->ampdu_packets > 0) {
524 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
525 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
526 mi->ampdu_len = 0;
527 mi->ampdu_packets = 0;
528 }
529
530 mi->sample_slow = 0;
531 mi->sample_count = 0;
532
533 /* Initialize global rate indexes */
534 for(j = 0; j < MAX_THR_RATES; j++){
535 tmp_mcs_tp_rate[j] = 0;
536 tmp_cck_tp_rate[j] = 0;
537 }
538
539 /* Find best rate sets within all MCS groups*/
540 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
541
542 mg = &mi->groups[group];
543 if (!mg->supported)
544 continue;
545
546 mi->sample_count++;
547
548 /* (re)Initialize group rate indexes */
549 for(j = 0; j < MAX_THR_RATES; j++)
550 tmp_group_tp_rate[j] = group;
551
552 for (i = 0; i < MCS_GROUP_RATES; i++) {
553 if (!(mg->supported & BIT(i)))
554 continue;
555
556 index = MCS_GROUP_RATES * group + i;
557
558 mrs = &mg->rates[i];
559 mrs->retry_updated = false;
560 minstrel_calc_rate_stats(mrs);
561 cur_prob = mrs->prob_ewma;
562
563 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
564 continue;
565
566 /* Find max throughput rate set */
567 if (group != MINSTREL_CCK_GROUP) {
568 minstrel_ht_sort_best_tp_rates(mi, index,
569 tmp_mcs_tp_rate);
570 } else if (group == MINSTREL_CCK_GROUP) {
571 minstrel_ht_sort_best_tp_rates(mi, index,
572 tmp_cck_tp_rate);
573 }
574
575 /* Find max throughput rate set within a group */
576 minstrel_ht_sort_best_tp_rates(mi, index,
577 tmp_group_tp_rate);
578
579 /* Find max probability rate per group and global */
580 minstrel_ht_set_best_prob_rate(mi, index);
581 }
582
583 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
584 sizeof(mg->max_group_tp_rate));
585 }
586
587 /* Assign new rate set per sta */
588 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
589 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
590
591 /* Try to increase robustness of max_prob_rate*/
592 minstrel_ht_prob_rate_reduce_streams(mi);
593
594 /* try to sample all available rates during each interval */
595 mi->sample_count *= 8;
596
597 #ifdef CONFIG_MAC80211_DEBUGFS
598 /* use fixed index if set */
599 if (mp->fixed_rate_idx != -1) {
600 for (i = 0; i < 4; i++)
601 mi->max_tp_rate[i] = mp->fixed_rate_idx;
602 mi->max_prob_rate = mp->fixed_rate_idx;
603 }
604 #endif
605
606 /* Reset update timer */
607 mi->last_stats_update = jiffies;
608 }
609
610 static bool
611 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
612 {
613 if (rate->idx < 0)
614 return false;
615
616 if (!rate->count)
617 return false;
618
619 if (rate->flags & IEEE80211_TX_RC_MCS ||
620 rate->flags & IEEE80211_TX_RC_VHT_MCS)
621 return true;
622
623 return rate->idx == mp->cck_rates[0] ||
624 rate->idx == mp->cck_rates[1] ||
625 rate->idx == mp->cck_rates[2] ||
626 rate->idx == mp->cck_rates[3];
627 }
628
629 static void
630 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
631 {
632 struct minstrel_mcs_group_data *mg;
633
634 for (;;) {
635 mi->sample_group++;
636 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
637 mg = &mi->groups[mi->sample_group];
638
639 if (!mg->supported)
640 continue;
641
642 if (++mg->index >= MCS_GROUP_RATES) {
643 mg->index = 0;
644 if (++mg->column >= ARRAY_SIZE(sample_table))
645 mg->column = 0;
646 }
647 break;
648 }
649 }
650
651 static void
652 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
653 {
654 int group, orig_group;
655
656 orig_group = group = *idx / MCS_GROUP_RATES;
657 while (group > 0) {
658 group--;
659
660 if (!mi->groups[group].supported)
661 continue;
662
663 if (minstrel_mcs_groups[group].streams >
664 minstrel_mcs_groups[orig_group].streams)
665 continue;
666
667 if (primary)
668 *idx = mi->groups[group].max_group_tp_rate[0];
669 else
670 *idx = mi->groups[group].max_group_tp_rate[1];
671 break;
672 }
673 }
674
675 static void
676 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
677 {
678 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
679 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
680 u16 tid;
681
682 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
683 return;
684
685 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
686 return;
687
688 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
689 return;
690
691 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
692 if (likely(sta->ampdu_mlme.tid_tx[tid]))
693 return;
694
695 ieee80211_start_tx_ba_session(pubsta, tid, 0);
696 }
697
698 static void
699 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
700 struct ieee80211_sta *sta, void *priv_sta,
701 struct ieee80211_tx_info *info)
702 {
703 struct minstrel_ht_sta_priv *msp = priv_sta;
704 struct minstrel_ht_sta *mi = &msp->ht;
705 struct ieee80211_tx_rate *ar = info->status.rates;
706 struct minstrel_rate_stats *rate, *rate2;
707 struct minstrel_priv *mp = priv;
708 bool last, update = false;
709 int i;
710
711 if (!msp->is_ht)
712 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
713 &msp->legacy, info);
714
715 /* This packet was aggregated but doesn't carry status info */
716 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
717 !(info->flags & IEEE80211_TX_STAT_AMPDU))
718 return;
719
720 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
721 info->status.ampdu_ack_len =
722 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
723 info->status.ampdu_len = 1;
724 }
725
726 mi->ampdu_packets++;
727 mi->ampdu_len += info->status.ampdu_len;
728
729 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
730 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
731 mi->sample_tries = 1;
732 mi->sample_count--;
733 }
734
735 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
736 mi->sample_packets += info->status.ampdu_len;
737
738 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
739 for (i = 0; !last; i++) {
740 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
741 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
742
743 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
744
745 if (last)
746 rate->success += info->status.ampdu_ack_len;
747
748 rate->attempts += ar[i].count * info->status.ampdu_len;
749 }
750
751 /*
752 * check for sudden death of spatial multiplexing,
753 * downgrade to a lower number of streams if necessary.
754 */
755 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
756 if (rate->attempts > 30 &&
757 MINSTREL_FRAC(rate->success, rate->attempts) <
758 MINSTREL_FRAC(20, 100)) {
759 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
760 update = true;
761 }
762
763 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
764 if (rate2->attempts > 30 &&
765 MINSTREL_FRAC(rate2->success, rate2->attempts) <
766 MINSTREL_FRAC(20, 100)) {
767 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
768 update = true;
769 }
770
771 if (time_after(jiffies, mi->last_stats_update +
772 (mp->update_interval / 2 * HZ) / 1000)) {
773 update = true;
774 minstrel_ht_update_stats(mp, mi);
775 }
776
777 if (update)
778 minstrel_ht_update_rates(mp, mi);
779 }
780
781 static void
782 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
783 int index)
784 {
785 struct minstrel_rate_stats *mrs;
786 const struct mcs_group *group;
787 unsigned int tx_time, tx_time_rtscts, tx_time_data;
788 unsigned int cw = mp->cw_min;
789 unsigned int ctime = 0;
790 unsigned int t_slot = 9; /* FIXME */
791 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
792 unsigned int overhead = 0, overhead_rtscts = 0;
793
794 mrs = minstrel_get_ratestats(mi, index);
795 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
796 mrs->retry_count = 1;
797 mrs->retry_count_rtscts = 1;
798 return;
799 }
800
801 mrs->retry_count = 2;
802 mrs->retry_count_rtscts = 2;
803 mrs->retry_updated = true;
804
805 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
806 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
807
808 /* Contention time for first 2 tries */
809 ctime = (t_slot * cw) >> 1;
810 cw = min((cw << 1) | 1, mp->cw_max);
811 ctime += (t_slot * cw) >> 1;
812 cw = min((cw << 1) | 1, mp->cw_max);
813
814 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
815 overhead = mi->overhead;
816 overhead_rtscts = mi->overhead_rtscts;
817 }
818
819 /* Total TX time for data and Contention after first 2 tries */
820 tx_time = ctime + 2 * (overhead + tx_time_data);
821 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
822
823 /* See how many more tries we can fit inside segment size */
824 do {
825 /* Contention time for this try */
826 ctime = (t_slot * cw) >> 1;
827 cw = min((cw << 1) | 1, mp->cw_max);
828
829 /* Total TX time after this try */
830 tx_time += ctime + overhead + tx_time_data;
831 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
832
833 if (tx_time_rtscts < mp->segment_size)
834 mrs->retry_count_rtscts++;
835 } while ((tx_time < mp->segment_size) &&
836 (++mrs->retry_count < mp->max_retry));
837 }
838
839
840 static void
841 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
842 struct ieee80211_sta_rates *ratetbl, int offset, int index)
843 {
844 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
845 struct minstrel_rate_stats *mrs;
846 u8 idx;
847 u16 flags = group->flags;
848
849 mrs = minstrel_get_ratestats(mi, index);
850 if (!mrs->retry_updated)
851 minstrel_calc_retransmit(mp, mi, index);
852
853 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
854 ratetbl->rate[offset].count = 2;
855 ratetbl->rate[offset].count_rts = 2;
856 ratetbl->rate[offset].count_cts = 2;
857 } else {
858 ratetbl->rate[offset].count = mrs->retry_count;
859 ratetbl->rate[offset].count_cts = mrs->retry_count;
860 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
861 }
862
863 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
864 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
865 else if (flags & IEEE80211_TX_RC_VHT_MCS)
866 idx = ((group->streams - 1) << 4) |
867 ((index % MCS_GROUP_RATES) & 0xF);
868 else
869 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
870
871 /* enable RTS/CTS if needed:
872 * - if station is in dynamic SMPS (and streams > 1)
873 * - for fallback rates, to increase chances of getting through
874 */
875 if (offset > 0 ||
876 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
877 group->streams > 1)) {
878 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
879 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
880 }
881
882 ratetbl->rate[offset].idx = idx;
883 ratetbl->rate[offset].flags = flags;
884 }
885
886 static void
887 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
888 {
889 struct ieee80211_sta_rates *rates;
890 int i = 0;
891
892 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
893 if (!rates)
894 return;
895
896 /* Start with max_tp_rate[0] */
897 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
898
899 if (mp->hw->max_rates >= 3) {
900 /* At least 3 tx rates supported, use max_tp_rate[1] next */
901 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
902 }
903
904 if (mp->hw->max_rates >= 2) {
905 /*
906 * At least 2 tx rates supported, use max_prob_rate next */
907 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
908 }
909
910 rates->rate[i].idx = -1;
911 rate_control_set_rates(mp->hw, mi->sta, rates);
912 }
913
914 static inline int
915 minstrel_get_duration(int index)
916 {
917 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
918 return group->duration[index % MCS_GROUP_RATES];
919 }
920
921 static int
922 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
923 {
924 struct minstrel_rate_stats *mrs;
925 struct minstrel_mcs_group_data *mg;
926 unsigned int sample_dur, sample_group, cur_max_tp_streams;
927 int sample_idx = 0;
928
929 if (mi->sample_wait > 0) {
930 mi->sample_wait--;
931 return -1;
932 }
933
934 if (!mi->sample_tries)
935 return -1;
936
937 sample_group = mi->sample_group;
938 mg = &mi->groups[sample_group];
939 sample_idx = sample_table[mg->column][mg->index];
940 minstrel_set_next_sample_idx(mi);
941
942 if (!(mg->supported & BIT(sample_idx)))
943 return -1;
944
945 mrs = &mg->rates[sample_idx];
946 sample_idx += sample_group * MCS_GROUP_RATES;
947
948 /*
949 * Sampling might add some overhead (RTS, no aggregation)
950 * to the frame. Hence, don't use sampling for the currently
951 * used rates.
952 */
953 if (sample_idx == mi->max_tp_rate[0] ||
954 sample_idx == mi->max_tp_rate[1] ||
955 sample_idx == mi->max_prob_rate)
956 return -1;
957
958 /*
959 * Do not sample if the probability is already higher than 95%
960 * to avoid wasting airtime.
961 */
962 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100))
963 return -1;
964
965 /*
966 * Make sure that lower rates get sampled only occasionally,
967 * if the link is working perfectly.
968 */
969
970 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
971 MCS_GROUP_RATES].streams;
972 sample_dur = minstrel_get_duration(sample_idx);
973 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
974 (cur_max_tp_streams - 1 <
975 minstrel_mcs_groups[sample_group].streams ||
976 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
977 if (mrs->sample_skipped < 20)
978 return -1;
979
980 if (mi->sample_slow++ > 2)
981 return -1;
982 }
983 mi->sample_tries--;
984
985 return sample_idx;
986 }
987
988 static void
989 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
990 struct minstrel_ht_sta *mi, bool val)
991 {
992 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
993
994 if (!supported || !mi->cck_supported_short)
995 return;
996
997 if (supported & (mi->cck_supported_short << (val * 4)))
998 return;
999
1000 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1001 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1002 }
1003
1004 static void
1005 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1006 struct ieee80211_tx_rate_control *txrc)
1007 {
1008 const struct mcs_group *sample_group;
1009 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1010 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1011 struct minstrel_ht_sta_priv *msp = priv_sta;
1012 struct minstrel_ht_sta *mi = &msp->ht;
1013 struct minstrel_priv *mp = priv;
1014 int sample_idx;
1015
1016 if (rate_control_send_low(sta, priv_sta, txrc))
1017 return;
1018
1019 if (!msp->is_ht)
1020 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1021
1022 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1023 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1024 minstrel_aggr_check(sta, txrc->skb);
1025
1026 info->flags |= mi->tx_flags;
1027 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1028
1029 #ifdef CONFIG_MAC80211_DEBUGFS
1030 if (mp->fixed_rate_idx != -1)
1031 return;
1032 #endif
1033
1034 /* Don't use EAPOL frames for sampling on non-mrr hw */
1035 if (mp->hw->max_rates == 1 &&
1036 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1037 sample_idx = -1;
1038 else
1039 sample_idx = minstrel_get_sample_rate(mp, mi);
1040
1041 mi->total_packets++;
1042
1043 /* wraparound */
1044 if (mi->total_packets == ~0) {
1045 mi->total_packets = 0;
1046 mi->sample_packets = 0;
1047 }
1048
1049 if (sample_idx < 0)
1050 return;
1051
1052 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1053 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1054 rate->count = 1;
1055
1056 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1057 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1058 rate->idx = mp->cck_rates[idx];
1059 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1060 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1061 sample_group->streams);
1062 } else {
1063 rate->idx = sample_idx % MCS_GROUP_RATES +
1064 (sample_group->streams - 1) * 8;
1065 }
1066
1067 rate->flags = sample_group->flags;
1068 }
1069
1070 static void
1071 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1072 struct ieee80211_supported_band *sband,
1073 struct ieee80211_sta *sta)
1074 {
1075 int i;
1076
1077 if (sband->band != IEEE80211_BAND_2GHZ)
1078 return;
1079
1080 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1081 return;
1082
1083 mi->cck_supported = 0;
1084 mi->cck_supported_short = 0;
1085 for (i = 0; i < 4; i++) {
1086 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1087 continue;
1088
1089 mi->cck_supported |= BIT(i);
1090 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1091 mi->cck_supported_short |= BIT(i);
1092 }
1093
1094 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1095 }
1096
1097 static void
1098 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1099 struct cfg80211_chan_def *chandef,
1100 struct ieee80211_sta *sta, void *priv_sta)
1101 {
1102 struct minstrel_priv *mp = priv;
1103 struct minstrel_ht_sta_priv *msp = priv_sta;
1104 struct minstrel_ht_sta *mi = &msp->ht;
1105 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1106 u16 sta_cap = sta->ht_cap.cap;
1107 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1108 int use_vht;
1109 int n_supported = 0;
1110 int ack_dur;
1111 int stbc;
1112 int i;
1113
1114 /* fall back to the old minstrel for legacy stations */
1115 if (!sta->ht_cap.ht_supported)
1116 goto use_legacy;
1117
1118 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1119
1120 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1121 if (vht_cap->vht_supported)
1122 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1123 else
1124 #endif
1125 use_vht = 0;
1126
1127 msp->is_ht = true;
1128 memset(mi, 0, sizeof(*mi));
1129
1130 mi->sta = sta;
1131 mi->last_stats_update = jiffies;
1132
1133 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1134 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1135 mi->overhead += ack_dur;
1136 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1137
1138 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1139
1140 /* When using MRR, sample more on the first attempt, without delay */
1141 if (mp->has_mrr) {
1142 mi->sample_count = 16;
1143 mi->sample_wait = 0;
1144 } else {
1145 mi->sample_count = 8;
1146 mi->sample_wait = 8;
1147 }
1148 mi->sample_tries = 4;
1149
1150 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1151 if (!use_vht) {
1152 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1153 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1154 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1155
1156 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1157 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1158 }
1159
1160 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1161 u32 gflags = minstrel_mcs_groups[i].flags;
1162 int bw, nss;
1163
1164 mi->groups[i].supported = 0;
1165 if (i == MINSTREL_CCK_GROUP) {
1166 minstrel_ht_update_cck(mp, mi, sband, sta);
1167 continue;
1168 }
1169
1170 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1171 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1172 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1173 continue;
1174 } else {
1175 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1176 continue;
1177 }
1178 }
1179
1180 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1181 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1182 continue;
1183
1184 nss = minstrel_mcs_groups[i].streams;
1185
1186 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1187 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1188 continue;
1189
1190 /* HT rate */
1191 if (gflags & IEEE80211_TX_RC_MCS) {
1192 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1193 if (use_vht && minstrel_vht_only)
1194 continue;
1195 #endif
1196 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1197 if (mi->groups[i].supported)
1198 n_supported++;
1199 continue;
1200 }
1201
1202 /* VHT rate */
1203 if (!vht_cap->vht_supported ||
1204 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1205 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1206 continue;
1207
1208 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1209 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1210 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1211 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1212 continue;
1213 }
1214 }
1215
1216 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1217 bw = BW_40;
1218 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1219 bw = BW_80;
1220 else
1221 bw = BW_20;
1222
1223 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1224 vht_cap->vht_mcs.tx_mcs_map);
1225
1226 if (mi->groups[i].supported)
1227 n_supported++;
1228 }
1229
1230 if (!n_supported)
1231 goto use_legacy;
1232
1233 /* create an initial rate table with the lowest supported rates */
1234 minstrel_ht_update_stats(mp, mi);
1235 minstrel_ht_update_rates(mp, mi);
1236
1237 return;
1238
1239 use_legacy:
1240 msp->is_ht = false;
1241 memset(&msp->legacy, 0, sizeof(msp->legacy));
1242 msp->legacy.r = msp->ratelist;
1243 msp->legacy.sample_table = msp->sample_table;
1244 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1245 &msp->legacy);
1246 }
1247
1248 static void
1249 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1250 struct cfg80211_chan_def *chandef,
1251 struct ieee80211_sta *sta, void *priv_sta)
1252 {
1253 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1254 }
1255
1256 static void
1257 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1258 struct cfg80211_chan_def *chandef,
1259 struct ieee80211_sta *sta, void *priv_sta,
1260 u32 changed)
1261 {
1262 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1263 }
1264
1265 static void *
1266 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1267 {
1268 struct ieee80211_supported_band *sband;
1269 struct minstrel_ht_sta_priv *msp;
1270 struct minstrel_priv *mp = priv;
1271 struct ieee80211_hw *hw = mp->hw;
1272 int max_rates = 0;
1273 int i;
1274
1275 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1276 sband = hw->wiphy->bands[i];
1277 if (sband && sband->n_bitrates > max_rates)
1278 max_rates = sband->n_bitrates;
1279 }
1280
1281 msp = kzalloc(sizeof(*msp), gfp);
1282 if (!msp)
1283 return NULL;
1284
1285 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1286 if (!msp->ratelist)
1287 goto error;
1288
1289 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1290 if (!msp->sample_table)
1291 goto error1;
1292
1293 return msp;
1294
1295 error1:
1296 kfree(msp->ratelist);
1297 error:
1298 kfree(msp);
1299 return NULL;
1300 }
1301
1302 static void
1303 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1304 {
1305 struct minstrel_ht_sta_priv *msp = priv_sta;
1306
1307 kfree(msp->sample_table);
1308 kfree(msp->ratelist);
1309 kfree(msp);
1310 }
1311
1312 static void *
1313 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1314 {
1315 return mac80211_minstrel.alloc(hw, debugfsdir);
1316 }
1317
1318 static void
1319 minstrel_ht_free(void *priv)
1320 {
1321 mac80211_minstrel.free(priv);
1322 }
1323
1324 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1325 {
1326 struct minstrel_ht_sta_priv *msp = priv_sta;
1327 struct minstrel_ht_sta *mi = &msp->ht;
1328 int i, j, prob, tp_avg;
1329
1330 if (!msp->is_ht)
1331 return mac80211_minstrel.get_expected_throughput(priv_sta);
1332
1333 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1334 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1335 prob = mi->groups[i].rates[j].prob_ewma;
1336
1337 /* convert tp_avg from pkt per second in kbps */
1338 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1339 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1340
1341 return tp_avg;
1342 }
1343
1344 static const struct rate_control_ops mac80211_minstrel_ht = {
1345 .name = "minstrel_ht",
1346 .tx_status_noskb = minstrel_ht_tx_status,
1347 .get_rate = minstrel_ht_get_rate,
1348 .rate_init = minstrel_ht_rate_init,
1349 .rate_update = minstrel_ht_rate_update,
1350 .alloc_sta = minstrel_ht_alloc_sta,
1351 .free_sta = minstrel_ht_free_sta,
1352 .alloc = minstrel_ht_alloc,
1353 .free = minstrel_ht_free,
1354 #ifdef CONFIG_MAC80211_DEBUGFS
1355 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1356 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1357 #endif
1358 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1359 };
1360
1361
1362 static void __init init_sample_table(void)
1363 {
1364 int col, i, new_idx;
1365 u8 rnd[MCS_GROUP_RATES];
1366
1367 memset(sample_table, 0xff, sizeof(sample_table));
1368 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1369 prandom_bytes(rnd, sizeof(rnd));
1370 for (i = 0; i < MCS_GROUP_RATES; i++) {
1371 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1372 while (sample_table[col][new_idx] != 0xff)
1373 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1374
1375 sample_table[col][new_idx] = i;
1376 }
1377 }
1378 }
1379
1380 int __init
1381 rc80211_minstrel_ht_init(void)
1382 {
1383 init_sample_table();
1384 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1385 }
1386
1387 void
1388 rc80211_minstrel_ht_exit(void)
1389 {
1390 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1391 }
Linux kernel - Deliverables
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