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Merge tag 'sound-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai...
[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 inline int
887 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
888 {
889 int group = rate / MCS_GROUP_RATES;
890 rate %= MCS_GROUP_RATES;
891 return mi->groups[group].rates[rate].prob_ewma;
892 }
893
894 static int
895 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
896 {
897 int group = mi->max_prob_rate / MCS_GROUP_RATES;
898 const struct mcs_group *g = &minstrel_mcs_groups[group];
899 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
900
901 /* Disable A-MSDU if max_prob_rate is bad */
902 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
903 return 1;
904
905 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
906 if (g->duration[rate] > MCS_DURATION(1, 0, 52))
907 return 500;
908
909 /*
910 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
911 * data packet size
912 */
913 if (g->duration[rate] > MCS_DURATION(1, 0, 104))
914 return 1600;
915
916 /*
917 * If the rate is slower than single-stream MCS7, or if the max throughput
918 * rate success probability is less than 75%, limit A-MSDU to twice the usual
919 * data packet size
920 */
921 if (g->duration[rate] > MCS_DURATION(1, 0, 260) ||
922 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
923 MINSTREL_FRAC(75, 100)))
924 return 3200;
925
926 /*
927 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
928 * Since aggregation sessions are started/stopped without txq flush, use
929 * the limit here to avoid the complexity of having to de-aggregate
930 * packets in the queue.
931 */
932 if (!mi->sta->vht_cap.vht_supported)
933 return IEEE80211_MAX_MPDU_LEN_HT_BA;
934
935 /* unlimited */
936 return 0;
937 }
938
939 static void
940 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
941 {
942 struct ieee80211_sta_rates *rates;
943 int i = 0;
944
945 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
946 if (!rates)
947 return;
948
949 /* Start with max_tp_rate[0] */
950 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
951
952 if (mp->hw->max_rates >= 3) {
953 /* At least 3 tx rates supported, use max_tp_rate[1] next */
954 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
955 }
956
957 if (mp->hw->max_rates >= 2) {
958 /*
959 * At least 2 tx rates supported, use max_prob_rate next */
960 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
961 }
962
963 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
964 rates->rate[i].idx = -1;
965 rate_control_set_rates(mp->hw, mi->sta, rates);
966 }
967
968 static inline int
969 minstrel_get_duration(int index)
970 {
971 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
972 return group->duration[index % MCS_GROUP_RATES];
973 }
974
975 static int
976 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
977 {
978 struct minstrel_rate_stats *mrs;
979 struct minstrel_mcs_group_data *mg;
980 unsigned int sample_dur, sample_group, cur_max_tp_streams;
981 int tp_rate1, tp_rate2;
982 int sample_idx = 0;
983
984 if (mi->sample_wait > 0) {
985 mi->sample_wait--;
986 return -1;
987 }
988
989 if (!mi->sample_tries)
990 return -1;
991
992 sample_group = mi->sample_group;
993 mg = &mi->groups[sample_group];
994 sample_idx = sample_table[mg->column][mg->index];
995 minstrel_set_next_sample_idx(mi);
996
997 if (!(mg->supported & BIT(sample_idx)))
998 return -1;
999
1000 mrs = &mg->rates[sample_idx];
1001 sample_idx += sample_group * MCS_GROUP_RATES;
1002
1003 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1004 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1005 minstrel_get_duration(mi->max_tp_rate[1])) {
1006 tp_rate1 = mi->max_tp_rate[1];
1007 tp_rate2 = mi->max_tp_rate[0];
1008 } else {
1009 tp_rate1 = mi->max_tp_rate[0];
1010 tp_rate2 = mi->max_tp_rate[1];
1011 }
1012
1013 /*
1014 * Sampling might add some overhead (RTS, no aggregation)
1015 * to the frame. Hence, don't use sampling for the highest currently
1016 * used highest throughput or probability rate.
1017 */
1018 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1019 return -1;
1020
1021 /*
1022 * Do not sample if the probability is already higher than 95%
1023 * to avoid wasting airtime.
1024 */
1025 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100))
1026 return -1;
1027
1028 /*
1029 * Make sure that lower rates get sampled only occasionally,
1030 * if the link is working perfectly.
1031 */
1032
1033 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1034 MCS_GROUP_RATES].streams;
1035 sample_dur = minstrel_get_duration(sample_idx);
1036 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1037 (cur_max_tp_streams - 1 <
1038 minstrel_mcs_groups[sample_group].streams ||
1039 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1040 if (mrs->sample_skipped < 20)
1041 return -1;
1042
1043 if (mi->sample_slow++ > 2)
1044 return -1;
1045 }
1046 mi->sample_tries--;
1047
1048 return sample_idx;
1049 }
1050
1051 static void
1052 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
1053 struct minstrel_ht_sta *mi, bool val)
1054 {
1055 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
1056
1057 if (!supported || !mi->cck_supported_short)
1058 return;
1059
1060 if (supported & (mi->cck_supported_short << (val * 4)))
1061 return;
1062
1063 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1064 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1065 }
1066
1067 static void
1068 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1069 struct ieee80211_tx_rate_control *txrc)
1070 {
1071 const struct mcs_group *sample_group;
1072 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1073 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1074 struct minstrel_ht_sta_priv *msp = priv_sta;
1075 struct minstrel_ht_sta *mi = &msp->ht;
1076 struct minstrel_priv *mp = priv;
1077 int sample_idx;
1078
1079 if (rate_control_send_low(sta, priv_sta, txrc))
1080 return;
1081
1082 if (!msp->is_ht)
1083 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1084
1085 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1086 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1087 minstrel_aggr_check(sta, txrc->skb);
1088
1089 info->flags |= mi->tx_flags;
1090 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1091
1092 #ifdef CONFIG_MAC80211_DEBUGFS
1093 if (mp->fixed_rate_idx != -1)
1094 return;
1095 #endif
1096
1097 /* Don't use EAPOL frames for sampling on non-mrr hw */
1098 if (mp->hw->max_rates == 1 &&
1099 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1100 sample_idx = -1;
1101 else
1102 sample_idx = minstrel_get_sample_rate(mp, mi);
1103
1104 mi->total_packets++;
1105
1106 /* wraparound */
1107 if (mi->total_packets == ~0) {
1108 mi->total_packets = 0;
1109 mi->sample_packets = 0;
1110 }
1111
1112 if (sample_idx < 0)
1113 return;
1114
1115 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1116 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1117 rate->count = 1;
1118
1119 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1120 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1121 rate->idx = mp->cck_rates[idx];
1122 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1123 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1124 sample_group->streams);
1125 } else {
1126 rate->idx = sample_idx % MCS_GROUP_RATES +
1127 (sample_group->streams - 1) * 8;
1128 }
1129
1130 rate->flags = sample_group->flags;
1131 }
1132
1133 static void
1134 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1135 struct ieee80211_supported_band *sband,
1136 struct ieee80211_sta *sta)
1137 {
1138 int i;
1139
1140 if (sband->band != NL80211_BAND_2GHZ)
1141 return;
1142
1143 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1144 return;
1145
1146 mi->cck_supported = 0;
1147 mi->cck_supported_short = 0;
1148 for (i = 0; i < 4; i++) {
1149 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1150 continue;
1151
1152 mi->cck_supported |= BIT(i);
1153 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1154 mi->cck_supported_short |= BIT(i);
1155 }
1156
1157 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1158 }
1159
1160 static void
1161 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1162 struct cfg80211_chan_def *chandef,
1163 struct ieee80211_sta *sta, void *priv_sta)
1164 {
1165 struct minstrel_priv *mp = priv;
1166 struct minstrel_ht_sta_priv *msp = priv_sta;
1167 struct minstrel_ht_sta *mi = &msp->ht;
1168 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1169 u16 sta_cap = sta->ht_cap.cap;
1170 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1171 int use_vht;
1172 int n_supported = 0;
1173 int ack_dur;
1174 int stbc;
1175 int i;
1176
1177 /* fall back to the old minstrel for legacy stations */
1178 if (!sta->ht_cap.ht_supported)
1179 goto use_legacy;
1180
1181 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1182
1183 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1184 if (vht_cap->vht_supported)
1185 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1186 else
1187 #endif
1188 use_vht = 0;
1189
1190 msp->is_ht = true;
1191 memset(mi, 0, sizeof(*mi));
1192
1193 mi->sta = sta;
1194 mi->last_stats_update = jiffies;
1195
1196 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1197 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1198 mi->overhead += ack_dur;
1199 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1200
1201 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1202
1203 /* When using MRR, sample more on the first attempt, without delay */
1204 if (mp->has_mrr) {
1205 mi->sample_count = 16;
1206 mi->sample_wait = 0;
1207 } else {
1208 mi->sample_count = 8;
1209 mi->sample_wait = 8;
1210 }
1211 mi->sample_tries = 4;
1212
1213 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1214 if (!use_vht) {
1215 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1216 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1217 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1218
1219 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1220 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1221 }
1222
1223 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1224 u32 gflags = minstrel_mcs_groups[i].flags;
1225 int bw, nss;
1226
1227 mi->groups[i].supported = 0;
1228 if (i == MINSTREL_CCK_GROUP) {
1229 minstrel_ht_update_cck(mp, mi, sband, sta);
1230 continue;
1231 }
1232
1233 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1234 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1235 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1236 continue;
1237 } else {
1238 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1239 continue;
1240 }
1241 }
1242
1243 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1244 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1245 continue;
1246
1247 nss = minstrel_mcs_groups[i].streams;
1248
1249 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1250 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1251 continue;
1252
1253 /* HT rate */
1254 if (gflags & IEEE80211_TX_RC_MCS) {
1255 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1256 if (use_vht && minstrel_vht_only)
1257 continue;
1258 #endif
1259 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1260 if (mi->groups[i].supported)
1261 n_supported++;
1262 continue;
1263 }
1264
1265 /* VHT rate */
1266 if (!vht_cap->vht_supported ||
1267 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1268 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1269 continue;
1270
1271 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1272 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1273 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1274 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1275 continue;
1276 }
1277 }
1278
1279 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1280 bw = BW_40;
1281 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1282 bw = BW_80;
1283 else
1284 bw = BW_20;
1285
1286 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1287 vht_cap->vht_mcs.tx_mcs_map);
1288
1289 if (mi->groups[i].supported)
1290 n_supported++;
1291 }
1292
1293 if (!n_supported)
1294 goto use_legacy;
1295
1296 /* create an initial rate table with the lowest supported rates */
1297 minstrel_ht_update_stats(mp, mi);
1298 minstrel_ht_update_rates(mp, mi);
1299
1300 return;
1301
1302 use_legacy:
1303 msp->is_ht = false;
1304 memset(&msp->legacy, 0, sizeof(msp->legacy));
1305 msp->legacy.r = msp->ratelist;
1306 msp->legacy.sample_table = msp->sample_table;
1307 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1308 &msp->legacy);
1309 }
1310
1311 static void
1312 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1313 struct cfg80211_chan_def *chandef,
1314 struct ieee80211_sta *sta, void *priv_sta)
1315 {
1316 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1317 }
1318
1319 static void
1320 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1321 struct cfg80211_chan_def *chandef,
1322 struct ieee80211_sta *sta, void *priv_sta,
1323 u32 changed)
1324 {
1325 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1326 }
1327
1328 static void *
1329 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1330 {
1331 struct ieee80211_supported_band *sband;
1332 struct minstrel_ht_sta_priv *msp;
1333 struct minstrel_priv *mp = priv;
1334 struct ieee80211_hw *hw = mp->hw;
1335 int max_rates = 0;
1336 int i;
1337
1338 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1339 sband = hw->wiphy->bands[i];
1340 if (sband && sband->n_bitrates > max_rates)
1341 max_rates = sband->n_bitrates;
1342 }
1343
1344 msp = kzalloc(sizeof(*msp), gfp);
1345 if (!msp)
1346 return NULL;
1347
1348 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1349 if (!msp->ratelist)
1350 goto error;
1351
1352 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1353 if (!msp->sample_table)
1354 goto error1;
1355
1356 return msp;
1357
1358 error1:
1359 kfree(msp->ratelist);
1360 error:
1361 kfree(msp);
1362 return NULL;
1363 }
1364
1365 static void
1366 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1367 {
1368 struct minstrel_ht_sta_priv *msp = priv_sta;
1369
1370 kfree(msp->sample_table);
1371 kfree(msp->ratelist);
1372 kfree(msp);
1373 }
1374
1375 static void *
1376 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1377 {
1378 return mac80211_minstrel.alloc(hw, debugfsdir);
1379 }
1380
1381 static void
1382 minstrel_ht_free(void *priv)
1383 {
1384 mac80211_minstrel.free(priv);
1385 }
1386
1387 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1388 {
1389 struct minstrel_ht_sta_priv *msp = priv_sta;
1390 struct minstrel_ht_sta *mi = &msp->ht;
1391 int i, j, prob, tp_avg;
1392
1393 if (!msp->is_ht)
1394 return mac80211_minstrel.get_expected_throughput(priv_sta);
1395
1396 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1397 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1398 prob = mi->groups[i].rates[j].prob_ewma;
1399
1400 /* convert tp_avg from pkt per second in kbps */
1401 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1402 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1403
1404 return tp_avg;
1405 }
1406
1407 static const struct rate_control_ops mac80211_minstrel_ht = {
1408 .name = "minstrel_ht",
1409 .tx_status_noskb = minstrel_ht_tx_status,
1410 .get_rate = minstrel_ht_get_rate,
1411 .rate_init = minstrel_ht_rate_init,
1412 .rate_update = minstrel_ht_rate_update,
1413 .alloc_sta = minstrel_ht_alloc_sta,
1414 .free_sta = minstrel_ht_free_sta,
1415 .alloc = minstrel_ht_alloc,
1416 .free = minstrel_ht_free,
1417 #ifdef CONFIG_MAC80211_DEBUGFS
1418 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1419 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1420 #endif
1421 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1422 };
1423
1424
1425 static void __init init_sample_table(void)
1426 {
1427 int col, i, new_idx;
1428 u8 rnd[MCS_GROUP_RATES];
1429
1430 memset(sample_table, 0xff, sizeof(sample_table));
1431 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1432 prandom_bytes(rnd, sizeof(rnd));
1433 for (i = 0; i < MCS_GROUP_RATES; i++) {
1434 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1435 while (sample_table[col][new_idx] != 0xff)
1436 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1437
1438 sample_table[col][new_idx] = i;
1439 }
1440 }
1441 }
1442
1443 int __init
1444 rc80211_minstrel_ht_init(void)
1445 {
1446 init_sample_table();
1447 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1448 }
1449
1450 void
1451 rc80211_minstrel_ht_exit(void)
1452 {
1453 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1454 }
Linux kernel - Deliverables
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