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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
[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 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
418 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
419 mrs->prob_ewma);
420 if (cur_tp_avg > tmp_tp_avg)
421 mi->max_prob_rate = index;
422
423 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
424 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
425 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
426 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
427 max_gpr_idx,
428 max_gpr_prob);
429 if (cur_tp_avg > max_gpr_tp_avg)
430 mg->max_group_prob_rate = index;
431 } else {
432 if (mrs->prob_ewma > tmp_prob)
433 mi->max_prob_rate = index;
434 if (mrs->prob_ewma > mg->rates[mg->max_group_prob_rate].prob_ewma)
435 mg->max_group_prob_rate = index;
436 }
437 }
438
439
440 /*
441 * Assign new rate set per sta and use CCK rates only if the fastest
442 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
443 * rate sets where MCS and CCK rates are mixed, because CCK rates can
444 * not use aggregation.
445 */
446 static void
447 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
448 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
449 u16 tmp_cck_tp_rate[MAX_THR_RATES])
450 {
451 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
452 int i;
453
454 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
455 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
456 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
457 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
458
459 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
460 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
461 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
462 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
463
464 if (tmp_cck_tp > tmp_mcs_tp) {
465 for(i = 0; i < MAX_THR_RATES; i++) {
466 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
467 tmp_mcs_tp_rate);
468 }
469 }
470
471 }
472
473 /*
474 * Try to increase robustness of max_prob rate by decrease number of
475 * streams if possible.
476 */
477 static inline void
478 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
479 {
480 struct minstrel_mcs_group_data *mg;
481 int tmp_max_streams, group, tmp_idx, tmp_prob;
482 int tmp_tp = 0;
483
484 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
485 MCS_GROUP_RATES].streams;
486 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
487 mg = &mi->groups[group];
488 if (!mg->supported || group == MINSTREL_CCK_GROUP)
489 continue;
490
491 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
492 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
493
494 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
495 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
496 mi->max_prob_rate = mg->max_group_prob_rate;
497 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
498 tmp_idx,
499 tmp_prob);
500 }
501 }
502 }
503
504 /*
505 * Update rate statistics and select new primary rates
506 *
507 * Rules for rate selection:
508 * - max_prob_rate must use only one stream, as a tradeoff between delivery
509 * probability and throughput during strong fluctuations
510 * - as long as the max prob rate has a probability of more than 75%, pick
511 * higher throughput rates, even if the probablity is a bit lower
512 */
513 static void
514 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
515 {
516 struct minstrel_mcs_group_data *mg;
517 struct minstrel_rate_stats *mrs;
518 int group, i, j, cur_prob;
519 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
520 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
521
522 if (mi->ampdu_packets > 0) {
523 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
524 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
525 mi->ampdu_len = 0;
526 mi->ampdu_packets = 0;
527 }
528
529 mi->sample_slow = 0;
530 mi->sample_count = 0;
531
532 /* Initialize global rate indexes */
533 for(j = 0; j < MAX_THR_RATES; j++){
534 tmp_mcs_tp_rate[j] = 0;
535 tmp_cck_tp_rate[j] = 0;
536 }
537
538 /* Find best rate sets within all MCS groups*/
539 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
540
541 mg = &mi->groups[group];
542 if (!mg->supported)
543 continue;
544
545 mi->sample_count++;
546
547 /* (re)Initialize group rate indexes */
548 for(j = 0; j < MAX_THR_RATES; j++)
549 tmp_group_tp_rate[j] = group;
550
551 for (i = 0; i < MCS_GROUP_RATES; i++) {
552 if (!(mg->supported & BIT(i)))
553 continue;
554
555 index = MCS_GROUP_RATES * group + i;
556
557 mrs = &mg->rates[i];
558 mrs->retry_updated = false;
559 minstrel_calc_rate_stats(mrs);
560 cur_prob = mrs->prob_ewma;
561
562 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
563 continue;
564
565 /* Find max throughput rate set */
566 if (group != MINSTREL_CCK_GROUP) {
567 minstrel_ht_sort_best_tp_rates(mi, index,
568 tmp_mcs_tp_rate);
569 } else if (group == MINSTREL_CCK_GROUP) {
570 minstrel_ht_sort_best_tp_rates(mi, index,
571 tmp_cck_tp_rate);
572 }
573
574 /* Find max throughput rate set within a group */
575 minstrel_ht_sort_best_tp_rates(mi, index,
576 tmp_group_tp_rate);
577
578 /* Find max probability rate per group and global */
579 minstrel_ht_set_best_prob_rate(mi, index);
580 }
581
582 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
583 sizeof(mg->max_group_tp_rate));
584 }
585
586 /* Assign new rate set per sta */
587 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
588 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
589
590 /* Try to increase robustness of max_prob_rate*/
591 minstrel_ht_prob_rate_reduce_streams(mi);
592
593 /* try to sample all available rates during each interval */
594 mi->sample_count *= 8;
595
596 #ifdef CONFIG_MAC80211_DEBUGFS
597 /* use fixed index if set */
598 if (mp->fixed_rate_idx != -1) {
599 for (i = 0; i < 4; i++)
600 mi->max_tp_rate[i] = mp->fixed_rate_idx;
601 mi->max_prob_rate = mp->fixed_rate_idx;
602 }
603 #endif
604
605 /* Reset update timer */
606 mi->last_stats_update = jiffies;
607 }
608
609 static bool
610 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
611 {
612 if (rate->idx < 0)
613 return false;
614
615 if (!rate->count)
616 return false;
617
618 if (rate->flags & IEEE80211_TX_RC_MCS ||
619 rate->flags & IEEE80211_TX_RC_VHT_MCS)
620 return true;
621
622 return rate->idx == mp->cck_rates[0] ||
623 rate->idx == mp->cck_rates[1] ||
624 rate->idx == mp->cck_rates[2] ||
625 rate->idx == mp->cck_rates[3];
626 }
627
628 static void
629 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
630 {
631 struct minstrel_mcs_group_data *mg;
632
633 for (;;) {
634 mi->sample_group++;
635 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
636 mg = &mi->groups[mi->sample_group];
637
638 if (!mg->supported)
639 continue;
640
641 if (++mg->index >= MCS_GROUP_RATES) {
642 mg->index = 0;
643 if (++mg->column >= ARRAY_SIZE(sample_table))
644 mg->column = 0;
645 }
646 break;
647 }
648 }
649
650 static void
651 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
652 {
653 int group, orig_group;
654
655 orig_group = group = *idx / MCS_GROUP_RATES;
656 while (group > 0) {
657 group--;
658
659 if (!mi->groups[group].supported)
660 continue;
661
662 if (minstrel_mcs_groups[group].streams >
663 minstrel_mcs_groups[orig_group].streams)
664 continue;
665
666 if (primary)
667 *idx = mi->groups[group].max_group_tp_rate[0];
668 else
669 *idx = mi->groups[group].max_group_tp_rate[1];
670 break;
671 }
672 }
673
674 static void
675 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
676 {
677 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
678 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
679 u16 tid;
680
681 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
682 return;
683
684 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
685 return;
686
687 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
688 return;
689
690 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
691 if (likely(sta->ampdu_mlme.tid_tx[tid]))
692 return;
693
694 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
695 }
696
697 static void
698 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
699 struct ieee80211_sta *sta, void *priv_sta,
700 struct ieee80211_tx_info *info)
701 {
702 struct minstrel_ht_sta_priv *msp = priv_sta;
703 struct minstrel_ht_sta *mi = &msp->ht;
704 struct ieee80211_tx_rate *ar = info->status.rates;
705 struct minstrel_rate_stats *rate, *rate2;
706 struct minstrel_priv *mp = priv;
707 bool last, update = false;
708 int i;
709
710 if (!msp->is_ht)
711 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
712 &msp->legacy, info);
713
714 /* This packet was aggregated but doesn't carry status info */
715 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
716 !(info->flags & IEEE80211_TX_STAT_AMPDU))
717 return;
718
719 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
720 info->status.ampdu_ack_len =
721 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
722 info->status.ampdu_len = 1;
723 }
724
725 mi->ampdu_packets++;
726 mi->ampdu_len += info->status.ampdu_len;
727
728 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
729 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
730 mi->sample_tries = 1;
731 mi->sample_count--;
732 }
733
734 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
735 mi->sample_packets += info->status.ampdu_len;
736
737 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
738 for (i = 0; !last; i++) {
739 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
740 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
741
742 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
743
744 if (last)
745 rate->success += info->status.ampdu_ack_len;
746
747 rate->attempts += ar[i].count * info->status.ampdu_len;
748 }
749
750 /*
751 * check for sudden death of spatial multiplexing,
752 * downgrade to a lower number of streams if necessary.
753 */
754 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
755 if (rate->attempts > 30 &&
756 MINSTREL_FRAC(rate->success, rate->attempts) <
757 MINSTREL_FRAC(20, 100)) {
758 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
759 update = true;
760 }
761
762 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
763 if (rate2->attempts > 30 &&
764 MINSTREL_FRAC(rate2->success, rate2->attempts) <
765 MINSTREL_FRAC(20, 100)) {
766 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
767 update = true;
768 }
769
770 if (time_after(jiffies, mi->last_stats_update +
771 (mp->update_interval / 2 * HZ) / 1000)) {
772 update = true;
773 minstrel_ht_update_stats(mp, mi);
774 }
775
776 if (update)
777 minstrel_ht_update_rates(mp, mi);
778 }
779
780 static void
781 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
782 int index)
783 {
784 struct minstrel_rate_stats *mrs;
785 const struct mcs_group *group;
786 unsigned int tx_time, tx_time_rtscts, tx_time_data;
787 unsigned int cw = mp->cw_min;
788 unsigned int ctime = 0;
789 unsigned int t_slot = 9; /* FIXME */
790 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
791 unsigned int overhead = 0, overhead_rtscts = 0;
792
793 mrs = minstrel_get_ratestats(mi, index);
794 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
795 mrs->retry_count = 1;
796 mrs->retry_count_rtscts = 1;
797 return;
798 }
799
800 mrs->retry_count = 2;
801 mrs->retry_count_rtscts = 2;
802 mrs->retry_updated = true;
803
804 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
805 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
806
807 /* Contention time for first 2 tries */
808 ctime = (t_slot * cw) >> 1;
809 cw = min((cw << 1) | 1, mp->cw_max);
810 ctime += (t_slot * cw) >> 1;
811 cw = min((cw << 1) | 1, mp->cw_max);
812
813 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
814 overhead = mi->overhead;
815 overhead_rtscts = mi->overhead_rtscts;
816 }
817
818 /* Total TX time for data and Contention after first 2 tries */
819 tx_time = ctime + 2 * (overhead + tx_time_data);
820 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
821
822 /* See how many more tries we can fit inside segment size */
823 do {
824 /* Contention time for this try */
825 ctime = (t_slot * cw) >> 1;
826 cw = min((cw << 1) | 1, mp->cw_max);
827
828 /* Total TX time after this try */
829 tx_time += ctime + overhead + tx_time_data;
830 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
831
832 if (tx_time_rtscts < mp->segment_size)
833 mrs->retry_count_rtscts++;
834 } while ((tx_time < mp->segment_size) &&
835 (++mrs->retry_count < mp->max_retry));
836 }
837
838
839 static void
840 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
841 struct ieee80211_sta_rates *ratetbl, int offset, int index)
842 {
843 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
844 struct minstrel_rate_stats *mrs;
845 u8 idx;
846 u16 flags = group->flags;
847
848 mrs = minstrel_get_ratestats(mi, index);
849 if (!mrs->retry_updated)
850 minstrel_calc_retransmit(mp, mi, index);
851
852 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
853 ratetbl->rate[offset].count = 2;
854 ratetbl->rate[offset].count_rts = 2;
855 ratetbl->rate[offset].count_cts = 2;
856 } else {
857 ratetbl->rate[offset].count = mrs->retry_count;
858 ratetbl->rate[offset].count_cts = mrs->retry_count;
859 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
860 }
861
862 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
863 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
864 else if (flags & IEEE80211_TX_RC_VHT_MCS)
865 idx = ((group->streams - 1) << 4) |
866 ((index % MCS_GROUP_RATES) & 0xF);
867 else
868 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
869
870 /* enable RTS/CTS if needed:
871 * - if station is in dynamic SMPS (and streams > 1)
872 * - for fallback rates, to increase chances of getting through
873 */
874 if (offset > 0 &&
875 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
876 group->streams > 1)) {
877 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
878 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
879 }
880
881 ratetbl->rate[offset].idx = idx;
882 ratetbl->rate[offset].flags = flags;
883 }
884
885 static void
886 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
887 {
888 struct ieee80211_sta_rates *rates;
889 int i = 0;
890
891 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
892 if (!rates)
893 return;
894
895 /* Start with max_tp_rate[0] */
896 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
897
898 if (mp->hw->max_rates >= 3) {
899 /* At least 3 tx rates supported, use max_tp_rate[1] next */
900 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
901 }
902
903 if (mp->hw->max_rates >= 2) {
904 /*
905 * At least 2 tx rates supported, use max_prob_rate next */
906 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
907 }
908
909 rates->rate[i].idx = -1;
910 rate_control_set_rates(mp->hw, mi->sta, rates);
911 }
912
913 static inline int
914 minstrel_get_duration(int index)
915 {
916 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
917 return group->duration[index % MCS_GROUP_RATES];
918 }
919
920 static int
921 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
922 {
923 struct minstrel_rate_stats *mrs;
924 struct minstrel_mcs_group_data *mg;
925 unsigned int sample_dur, sample_group, cur_max_tp_streams;
926 int sample_idx = 0;
927
928 if (mi->sample_wait > 0) {
929 mi->sample_wait--;
930 return -1;
931 }
932
933 if (!mi->sample_tries)
934 return -1;
935
936 sample_group = mi->sample_group;
937 mg = &mi->groups[sample_group];
938 sample_idx = sample_table[mg->column][mg->index];
939 minstrel_set_next_sample_idx(mi);
940
941 if (!(mg->supported & BIT(sample_idx)))
942 return -1;
943
944 mrs = &mg->rates[sample_idx];
945 sample_idx += sample_group * MCS_GROUP_RATES;
946
947 /*
948 * Sampling might add some overhead (RTS, no aggregation)
949 * to the frame. Hence, don't use sampling for the currently
950 * used rates.
951 */
952 if (sample_idx == mi->max_tp_rate[0] ||
953 sample_idx == mi->max_tp_rate[1] ||
954 sample_idx == mi->max_prob_rate)
955 return -1;
956
957 /*
958 * Do not sample if the probability is already higher than 95%
959 * to avoid wasting airtime.
960 */
961 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100))
962 return -1;
963
964 /*
965 * Make sure that lower rates get sampled only occasionally,
966 * if the link is working perfectly.
967 */
968
969 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
970 MCS_GROUP_RATES].streams;
971 sample_dur = minstrel_get_duration(sample_idx);
972 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
973 (cur_max_tp_streams - 1 <
974 minstrel_mcs_groups[sample_group].streams ||
975 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
976 if (mrs->sample_skipped < 20)
977 return -1;
978
979 if (mi->sample_slow++ > 2)
980 return -1;
981 }
982 mi->sample_tries--;
983
984 return sample_idx;
985 }
986
987 static void
988 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
989 struct minstrel_ht_sta *mi, bool val)
990 {
991 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
992
993 if (!supported || !mi->cck_supported_short)
994 return;
995
996 if (supported & (mi->cck_supported_short << (val * 4)))
997 return;
998
999 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1000 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1001 }
1002
1003 static void
1004 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1005 struct ieee80211_tx_rate_control *txrc)
1006 {
1007 const struct mcs_group *sample_group;
1008 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1009 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1010 struct minstrel_ht_sta_priv *msp = priv_sta;
1011 struct minstrel_ht_sta *mi = &msp->ht;
1012 struct minstrel_priv *mp = priv;
1013 int sample_idx;
1014
1015 if (rate_control_send_low(sta, priv_sta, txrc))
1016 return;
1017
1018 if (!msp->is_ht)
1019 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1020
1021 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1022 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1023 minstrel_aggr_check(sta, txrc->skb);
1024
1025 info->flags |= mi->tx_flags;
1026 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1027
1028 #ifdef CONFIG_MAC80211_DEBUGFS
1029 if (mp->fixed_rate_idx != -1)
1030 return;
1031 #endif
1032
1033 /* Don't use EAPOL frames for sampling on non-mrr hw */
1034 if (mp->hw->max_rates == 1 &&
1035 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1036 sample_idx = -1;
1037 else
1038 sample_idx = minstrel_get_sample_rate(mp, mi);
1039
1040 mi->total_packets++;
1041
1042 /* wraparound */
1043 if (mi->total_packets == ~0) {
1044 mi->total_packets = 0;
1045 mi->sample_packets = 0;
1046 }
1047
1048 if (sample_idx < 0)
1049 return;
1050
1051 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1052 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1053 rate->count = 1;
1054
1055 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1056 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1057 rate->idx = mp->cck_rates[idx];
1058 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1059 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1060 sample_group->streams);
1061 } else {
1062 rate->idx = sample_idx % MCS_GROUP_RATES +
1063 (sample_group->streams - 1) * 8;
1064 }
1065
1066 rate->flags = sample_group->flags;
1067 }
1068
1069 static void
1070 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1071 struct ieee80211_supported_band *sband,
1072 struct ieee80211_sta *sta)
1073 {
1074 int i;
1075
1076 if (sband->band != IEEE80211_BAND_2GHZ)
1077 return;
1078
1079 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1080 return;
1081
1082 mi->cck_supported = 0;
1083 mi->cck_supported_short = 0;
1084 for (i = 0; i < 4; i++) {
1085 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1086 continue;
1087
1088 mi->cck_supported |= BIT(i);
1089 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1090 mi->cck_supported_short |= BIT(i);
1091 }
1092
1093 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1094 }
1095
1096 static void
1097 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1098 struct cfg80211_chan_def *chandef,
1099 struct ieee80211_sta *sta, void *priv_sta)
1100 {
1101 struct minstrel_priv *mp = priv;
1102 struct minstrel_ht_sta_priv *msp = priv_sta;
1103 struct minstrel_ht_sta *mi = &msp->ht;
1104 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1105 u16 sta_cap = sta->ht_cap.cap;
1106 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1107 int use_vht;
1108 int n_supported = 0;
1109 int ack_dur;
1110 int stbc;
1111 int i;
1112
1113 /* fall back to the old minstrel for legacy stations */
1114 if (!sta->ht_cap.ht_supported)
1115 goto use_legacy;
1116
1117 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1118
1119 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1120 if (vht_cap->vht_supported)
1121 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1122 else
1123 #endif
1124 use_vht = 0;
1125
1126 msp->is_ht = true;
1127 memset(mi, 0, sizeof(*mi));
1128
1129 mi->sta = sta;
1130 mi->last_stats_update = jiffies;
1131
1132 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1133 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1134 mi->overhead += ack_dur;
1135 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1136
1137 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1138
1139 /* When using MRR, sample more on the first attempt, without delay */
1140 if (mp->has_mrr) {
1141 mi->sample_count = 16;
1142 mi->sample_wait = 0;
1143 } else {
1144 mi->sample_count = 8;
1145 mi->sample_wait = 8;
1146 }
1147 mi->sample_tries = 4;
1148
1149 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1150 if (!use_vht) {
1151 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1152 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1153 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1154
1155 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1156 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1157 }
1158
1159 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1160 u32 gflags = minstrel_mcs_groups[i].flags;
1161 int bw, nss;
1162
1163 mi->groups[i].supported = 0;
1164 if (i == MINSTREL_CCK_GROUP) {
1165 minstrel_ht_update_cck(mp, mi, sband, sta);
1166 continue;
1167 }
1168
1169 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1170 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1171 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1172 continue;
1173 } else {
1174 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1175 continue;
1176 }
1177 }
1178
1179 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1180 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1181 continue;
1182
1183 nss = minstrel_mcs_groups[i].streams;
1184
1185 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1186 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1187 continue;
1188
1189 /* HT rate */
1190 if (gflags & IEEE80211_TX_RC_MCS) {
1191 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1192 if (use_vht && minstrel_vht_only)
1193 continue;
1194 #endif
1195 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1196 if (mi->groups[i].supported)
1197 n_supported++;
1198 continue;
1199 }
1200
1201 /* VHT rate */
1202 if (!vht_cap->vht_supported ||
1203 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1204 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1205 continue;
1206
1207 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1208 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1209 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1210 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1211 continue;
1212 }
1213 }
1214
1215 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1216 bw = BW_40;
1217 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1218 bw = BW_80;
1219 else
1220 bw = BW_20;
1221
1222 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1223 vht_cap->vht_mcs.tx_mcs_map);
1224
1225 if (mi->groups[i].supported)
1226 n_supported++;
1227 }
1228
1229 if (!n_supported)
1230 goto use_legacy;
1231
1232 /* create an initial rate table with the lowest supported rates */
1233 minstrel_ht_update_stats(mp, mi);
1234 minstrel_ht_update_rates(mp, mi);
1235
1236 return;
1237
1238 use_legacy:
1239 msp->is_ht = false;
1240 memset(&msp->legacy, 0, sizeof(msp->legacy));
1241 msp->legacy.r = msp->ratelist;
1242 msp->legacy.sample_table = msp->sample_table;
1243 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1244 &msp->legacy);
1245 }
1246
1247 static void
1248 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1249 struct cfg80211_chan_def *chandef,
1250 struct ieee80211_sta *sta, void *priv_sta)
1251 {
1252 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1253 }
1254
1255 static void
1256 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1257 struct cfg80211_chan_def *chandef,
1258 struct ieee80211_sta *sta, void *priv_sta,
1259 u32 changed)
1260 {
1261 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1262 }
1263
1264 static void *
1265 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1266 {
1267 struct ieee80211_supported_band *sband;
1268 struct minstrel_ht_sta_priv *msp;
1269 struct minstrel_priv *mp = priv;
1270 struct ieee80211_hw *hw = mp->hw;
1271 int max_rates = 0;
1272 int i;
1273
1274 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1275 sband = hw->wiphy->bands[i];
1276 if (sband && sband->n_bitrates > max_rates)
1277 max_rates = sband->n_bitrates;
1278 }
1279
1280 msp = kzalloc(sizeof(*msp), gfp);
1281 if (!msp)
1282 return NULL;
1283
1284 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1285 if (!msp->ratelist)
1286 goto error;
1287
1288 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1289 if (!msp->sample_table)
1290 goto error1;
1291
1292 return msp;
1293
1294 error1:
1295 kfree(msp->ratelist);
1296 error:
1297 kfree(msp);
1298 return NULL;
1299 }
1300
1301 static void
1302 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1303 {
1304 struct minstrel_ht_sta_priv *msp = priv_sta;
1305
1306 kfree(msp->sample_table);
1307 kfree(msp->ratelist);
1308 kfree(msp);
1309 }
1310
1311 static void *
1312 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1313 {
1314 return mac80211_minstrel.alloc(hw, debugfsdir);
1315 }
1316
1317 static void
1318 minstrel_ht_free(void *priv)
1319 {
1320 mac80211_minstrel.free(priv);
1321 }
1322
1323 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1324 {
1325 struct minstrel_ht_sta_priv *msp = priv_sta;
1326 struct minstrel_ht_sta *mi = &msp->ht;
1327 int i, j, prob, tp_avg;
1328
1329 if (!msp->is_ht)
1330 return mac80211_minstrel.get_expected_throughput(priv_sta);
1331
1332 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1333 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1334 prob = mi->groups[i].rates[j].prob_ewma;
1335
1336 /* convert tp_avg from pkt per second in kbps */
1337 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * AVG_PKT_SIZE * 8 / 1024;
1338
1339 return tp_avg;
1340 }
1341
1342 static const struct rate_control_ops mac80211_minstrel_ht = {
1343 .name = "minstrel_ht",
1344 .tx_status_noskb = minstrel_ht_tx_status,
1345 .get_rate = minstrel_ht_get_rate,
1346 .rate_init = minstrel_ht_rate_init,
1347 .rate_update = minstrel_ht_rate_update,
1348 .alloc_sta = minstrel_ht_alloc_sta,
1349 .free_sta = minstrel_ht_free_sta,
1350 .alloc = minstrel_ht_alloc,
1351 .free = minstrel_ht_free,
1352 #ifdef CONFIG_MAC80211_DEBUGFS
1353 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1354 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1355 #endif
1356 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1357 };
1358
1359
1360 static void __init init_sample_table(void)
1361 {
1362 int col, i, new_idx;
1363 u8 rnd[MCS_GROUP_RATES];
1364
1365 memset(sample_table, 0xff, sizeof(sample_table));
1366 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1367 prandom_bytes(rnd, sizeof(rnd));
1368 for (i = 0; i < MCS_GROUP_RATES; i++) {
1369 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1370 while (sample_table[col][new_idx] != 0xff)
1371 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1372
1373 sample_table[col][new_idx] = i;
1374 }
1375 }
1376 }
1377
1378 int __init
1379 rc80211_minstrel_ht_init(void)
1380 {
1381 init_sample_table();
1382 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1383 }
1384
1385 void
1386 rc80211_minstrel_ht_exit(void)
1387 {
1388 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1389 }
Linux kernel - Deliverables
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