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Merge tag 'linux-kselftest-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel...
[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_PKT_SIZE 1200
21
22 /* Number of bits for an average sized packet */
23 #define MCS_NBITS (AVG_PKT_SIZE << 3)
24
25 /* Number of symbols for a packet with (bps) bits per symbol */
26 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
27
28 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
29 #define MCS_SYMBOL_TIME(sgi, syms) \
30 (sgi ? \
31 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
32 ((syms) * 1000) << 2 /* syms * 4 us */ \
33 )
34
35 /* Transmit duration for the raw data part of an average sized packet */
36 #define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
37
38 #define BW_20 0
39 #define BW_40 1
40 #define BW_80 2
41
42 /*
43 * Define group sort order: HT40 -> SGI -> #streams
44 */
45 #define GROUP_IDX(_streams, _sgi, _ht40) \
46 MINSTREL_HT_GROUP_0 + \
47 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
48 MINSTREL_MAX_STREAMS * _sgi + \
49 _streams - 1
50
51 /* MCS rate information for an MCS group */
52 #define MCS_GROUP(_streams, _sgi, _ht40) \
53 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
54 .streams = _streams, \
55 .flags = \
56 IEEE80211_TX_RC_MCS | \
57 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
58 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
59 .duration = { \
60 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
61 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
62 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
68 } \
69 }
70
71 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
72 (MINSTREL_VHT_GROUP_0 + \
73 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
74 MINSTREL_MAX_STREAMS * (_sgi) + \
75 (_streams) - 1)
76
77 #define BW2VBPS(_bw, r3, r2, r1) \
78 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
79
80 #define VHT_GROUP(_streams, _sgi, _bw) \
81 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
82 .streams = _streams, \
83 .flags = \
84 IEEE80211_TX_RC_VHT_MCS | \
85 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
86 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
87 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
88 .duration = { \
89 MCS_DURATION(_streams, _sgi, \
90 BW2VBPS(_bw, 117, 54, 26)), \
91 MCS_DURATION(_streams, _sgi, \
92 BW2VBPS(_bw, 234, 108, 52)), \
93 MCS_DURATION(_streams, _sgi, \
94 BW2VBPS(_bw, 351, 162, 78)), \
95 MCS_DURATION(_streams, _sgi, \
96 BW2VBPS(_bw, 468, 216, 104)), \
97 MCS_DURATION(_streams, _sgi, \
98 BW2VBPS(_bw, 702, 324, 156)), \
99 MCS_DURATION(_streams, _sgi, \
100 BW2VBPS(_bw, 936, 432, 208)), \
101 MCS_DURATION(_streams, _sgi, \
102 BW2VBPS(_bw, 1053, 486, 234)), \
103 MCS_DURATION(_streams, _sgi, \
104 BW2VBPS(_bw, 1170, 540, 260)), \
105 MCS_DURATION(_streams, _sgi, \
106 BW2VBPS(_bw, 1404, 648, 312)), \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 1560, 720, 346)) \
109 } \
110 }
111
112 #define CCK_DURATION(_bitrate, _short, _len) \
113 (1000 * (10 /* SIFS */ + \
114 (_short ? 72 + 24 : 144 + 48) + \
115 (8 * (_len + 4) * 10) / (_bitrate)))
116
117 #define CCK_ACK_DURATION(_bitrate, _short) \
118 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
119 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
120
121 #define CCK_DURATION_LIST(_short) \
122 CCK_ACK_DURATION(10, _short), \
123 CCK_ACK_DURATION(20, _short), \
124 CCK_ACK_DURATION(55, _short), \
125 CCK_ACK_DURATION(110, _short)
126
127 #define CCK_GROUP \
128 [MINSTREL_CCK_GROUP] = { \
129 .streams = 0, \
130 .flags = 0, \
131 .duration = { \
132 CCK_DURATION_LIST(false), \
133 CCK_DURATION_LIST(true) \
134 } \
135 }
136
137 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
138 static bool minstrel_vht_only = true;
139 module_param(minstrel_vht_only, bool, 0644);
140 MODULE_PARM_DESC(minstrel_vht_only,
141 "Use only VHT rates when VHT is supported by sta.");
142 #endif
143
144 /*
145 * To enable sufficiently targeted rate sampling, MCS rates are divided into
146 * groups, based on the number of streams and flags (HT40, SGI) that they
147 * use.
148 *
149 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
150 * BW -> SGI -> #streams
151 */
152 const struct mcs_group minstrel_mcs_groups[] = {
153 MCS_GROUP(1, 0, BW_20),
154 MCS_GROUP(2, 0, BW_20),
155 #if MINSTREL_MAX_STREAMS >= 3
156 MCS_GROUP(3, 0, BW_20),
157 #endif
158
159 MCS_GROUP(1, 1, BW_20),
160 MCS_GROUP(2, 1, BW_20),
161 #if MINSTREL_MAX_STREAMS >= 3
162 MCS_GROUP(3, 1, BW_20),
163 #endif
164
165 MCS_GROUP(1, 0, BW_40),
166 MCS_GROUP(2, 0, BW_40),
167 #if MINSTREL_MAX_STREAMS >= 3
168 MCS_GROUP(3, 0, BW_40),
169 #endif
170
171 MCS_GROUP(1, 1, BW_40),
172 MCS_GROUP(2, 1, BW_40),
173 #if MINSTREL_MAX_STREAMS >= 3
174 MCS_GROUP(3, 1, BW_40),
175 #endif
176
177 CCK_GROUP,
178
179 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
180 VHT_GROUP(1, 0, BW_20),
181 VHT_GROUP(2, 0, BW_20),
182 #if MINSTREL_MAX_STREAMS >= 3
183 VHT_GROUP(3, 0, BW_20),
184 #endif
185
186 VHT_GROUP(1, 1, BW_20),
187 VHT_GROUP(2, 1, BW_20),
188 #if MINSTREL_MAX_STREAMS >= 3
189 VHT_GROUP(3, 1, BW_20),
190 #endif
191
192 VHT_GROUP(1, 0, BW_40),
193 VHT_GROUP(2, 0, BW_40),
194 #if MINSTREL_MAX_STREAMS >= 3
195 VHT_GROUP(3, 0, BW_40),
196 #endif
197
198 VHT_GROUP(1, 1, BW_40),
199 VHT_GROUP(2, 1, BW_40),
200 #if MINSTREL_MAX_STREAMS >= 3
201 VHT_GROUP(3, 1, BW_40),
202 #endif
203
204 VHT_GROUP(1, 0, BW_80),
205 VHT_GROUP(2, 0, BW_80),
206 #if MINSTREL_MAX_STREAMS >= 3
207 VHT_GROUP(3, 0, BW_80),
208 #endif
209
210 VHT_GROUP(1, 1, BW_80),
211 VHT_GROUP(2, 1, BW_80),
212 #if MINSTREL_MAX_STREAMS >= 3
213 VHT_GROUP(3, 1, BW_80),
214 #endif
215 #endif
216 };
217
218 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
219
220 static void
221 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
222
223 /*
224 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
225 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
226 *
227 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
228 */
229 static u16
230 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
231 {
232 u16 mask = 0;
233
234 if (bw == BW_20) {
235 if (nss != 3 && nss != 6)
236 mask = BIT(9);
237 } else if (bw == BW_80) {
238 if (nss == 3 || nss == 7)
239 mask = BIT(6);
240 else if (nss == 6)
241 mask = BIT(9);
242 } else {
243 WARN_ON(bw != BW_40);
244 }
245
246 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
247 case IEEE80211_VHT_MCS_SUPPORT_0_7:
248 mask |= 0x300;
249 break;
250 case IEEE80211_VHT_MCS_SUPPORT_0_8:
251 mask |= 0x200;
252 break;
253 case IEEE80211_VHT_MCS_SUPPORT_0_9:
254 break;
255 default:
256 mask = 0x3ff;
257 }
258
259 return 0x3ff & ~mask;
260 }
261
262 /*
263 * Look up an MCS group index based on mac80211 rate information
264 */
265 static int
266 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
267 {
268 return GROUP_IDX((rate->idx / 8) + 1,
269 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
270 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
271 }
272
273 static int
274 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
275 {
276 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
277 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
278 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
279 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
280 }
281
282 static struct minstrel_rate_stats *
283 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
284 struct ieee80211_tx_rate *rate)
285 {
286 int group, idx;
287
288 if (rate->flags & IEEE80211_TX_RC_MCS) {
289 group = minstrel_ht_get_group_idx(rate);
290 idx = rate->idx % 8;
291 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
292 group = minstrel_vht_get_group_idx(rate);
293 idx = ieee80211_rate_get_vht_mcs(rate);
294 } else {
295 group = MINSTREL_CCK_GROUP;
296
297 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
298 if (rate->idx == mp->cck_rates[idx])
299 break;
300
301 /* short preamble */
302 if (!(mi->groups[group].supported & BIT(idx)))
303 idx += 4;
304 }
305 return &mi->groups[group].rates[idx];
306 }
307
308 static inline struct minstrel_rate_stats *
309 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
310 {
311 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
312 }
313
314
315 /*
316 * Recalculate success probabilities and counters for a rate using EWMA
317 */
318 static void
319 minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
320 {
321 if (unlikely(mr->attempts > 0)) {
322 mr->sample_skipped = 0;
323 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
324 if (!mr->att_hist)
325 mr->probability = mr->cur_prob;
326 else
327 mr->probability = minstrel_ewma(mr->probability,
328 mr->cur_prob, EWMA_LEVEL);
329 mr->att_hist += mr->attempts;
330 mr->succ_hist += mr->success;
331 } else {
332 mr->sample_skipped++;
333 }
334 mr->last_success = mr->success;
335 mr->last_attempts = mr->attempts;
336 mr->success = 0;
337 mr->attempts = 0;
338 }
339
340 /*
341 * Calculate throughput based on the average A-MPDU length, taking into account
342 * the expected number of retransmissions and their expected length
343 */
344 static void
345 minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
346 {
347 struct minstrel_rate_stats *mr;
348 unsigned int nsecs = 0;
349 unsigned int tp;
350 unsigned int prob;
351
352 mr = &mi->groups[group].rates[rate];
353 prob = mr->probability;
354
355 if (prob < MINSTREL_FRAC(1, 10)) {
356 mr->cur_tp = 0;
357 return;
358 }
359
360 /*
361 * For the throughput calculation, limit the probability value to 90% to
362 * account for collision related packet error rate fluctuation
363 */
364 if (prob > MINSTREL_FRAC(9, 10))
365 prob = MINSTREL_FRAC(9, 10);
366
367 if (group != MINSTREL_CCK_GROUP)
368 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
369
370 nsecs += minstrel_mcs_groups[group].duration[rate];
371
372 /* prob is scaled - see MINSTREL_FRAC above */
373 tp = 1000000 * ((prob * 1000) / nsecs);
374 mr->cur_tp = MINSTREL_TRUNC(tp);
375 }
376
377 /*
378 * Find & sort topmost throughput rates
379 *
380 * If multiple rates provide equal throughput the sorting is based on their
381 * current success probability. Higher success probability is preferred among
382 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
383 */
384 static void
385 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
386 u16 *tp_list)
387 {
388 int cur_group, cur_idx, cur_thr, cur_prob;
389 int tmp_group, tmp_idx, tmp_thr, tmp_prob;
390 int j = MAX_THR_RATES;
391
392 cur_group = index / MCS_GROUP_RATES;
393 cur_idx = index % MCS_GROUP_RATES;
394 cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
395 cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
396
397 do {
398 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
399 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
400 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
401 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
402 if (cur_thr < tmp_thr ||
403 (cur_thr == tmp_thr && cur_prob <= tmp_prob))
404 break;
405 j--;
406 } while (j > 0);
407
408 if (j < MAX_THR_RATES - 1) {
409 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
410 (MAX_THR_RATES - (j + 1))));
411 }
412 if (j < MAX_THR_RATES)
413 tp_list[j] = index;
414 }
415
416 /*
417 * Find and set the topmost probability rate per sta and per group
418 */
419 static void
420 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
421 {
422 struct minstrel_mcs_group_data *mg;
423 struct minstrel_rate_stats *mr;
424 int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group;
425
426 mg = &mi->groups[index / MCS_GROUP_RATES];
427 mr = &mg->rates[index % MCS_GROUP_RATES];
428
429 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
430 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
431 tmp_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
432 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
433
434 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
435 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
436 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
437 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
438 (max_tp_group != MINSTREL_CCK_GROUP))
439 return;
440
441 if (mr->probability > MINSTREL_FRAC(75, 100)) {
442 if (mr->cur_tp > tmp_tp)
443 mi->max_prob_rate = index;
444 if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp)
445 mg->max_group_prob_rate = index;
446 } else {
447 if (mr->probability > tmp_prob)
448 mi->max_prob_rate = index;
449 if (mr->probability > mg->rates[mg->max_group_prob_rate].probability)
450 mg->max_group_prob_rate = index;
451 }
452 }
453
454
455 /*
456 * Assign new rate set per sta and use CCK rates only if the fastest
457 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
458 * rate sets where MCS and CCK rates are mixed, because CCK rates can
459 * not use aggregation.
460 */
461 static void
462 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
463 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
464 u16 tmp_cck_tp_rate[MAX_THR_RATES])
465 {
466 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
467 int i;
468
469 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
470 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
471 tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
472
473 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
474 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
475 tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
476
477 if (tmp_cck_tp > tmp_mcs_tp) {
478 for(i = 0; i < MAX_THR_RATES; i++) {
479 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
480 tmp_mcs_tp_rate);
481 }
482 }
483
484 }
485
486 /*
487 * Try to increase robustness of max_prob rate by decrease number of
488 * streams if possible.
489 */
490 static inline void
491 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
492 {
493 struct minstrel_mcs_group_data *mg;
494 struct minstrel_rate_stats *mr;
495 int tmp_max_streams, group;
496 int tmp_tp = 0;
497
498 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
499 MCS_GROUP_RATES].streams;
500 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
501 mg = &mi->groups[group];
502 if (!mg->supported || group == MINSTREL_CCK_GROUP)
503 continue;
504 mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate);
505 if (tmp_tp < mr->cur_tp &&
506 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
507 mi->max_prob_rate = mg->max_group_prob_rate;
508 tmp_tp = mr->cur_tp;
509 }
510 }
511 }
512
513 /*
514 * Update rate statistics and select new primary rates
515 *
516 * Rules for rate selection:
517 * - max_prob_rate must use only one stream, as a tradeoff between delivery
518 * probability and throughput during strong fluctuations
519 * - as long as the max prob rate has a probability of more than 75%, pick
520 * higher throughput rates, even if the probablity is a bit lower
521 */
522 static void
523 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
524 {
525 struct minstrel_mcs_group_data *mg;
526 struct minstrel_rate_stats *mr;
527 int group, i, j;
528 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
529 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
530
531 if (mi->ampdu_packets > 0) {
532 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
533 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
534 mi->ampdu_len = 0;
535 mi->ampdu_packets = 0;
536 }
537
538 mi->sample_slow = 0;
539 mi->sample_count = 0;
540
541 /* Initialize global rate indexes */
542 for(j = 0; j < MAX_THR_RATES; j++){
543 tmp_mcs_tp_rate[j] = 0;
544 tmp_cck_tp_rate[j] = 0;
545 }
546
547 /* Find best rate sets within all MCS groups*/
548 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
549
550 mg = &mi->groups[group];
551 if (!mg->supported)
552 continue;
553
554 mi->sample_count++;
555
556 /* (re)Initialize group rate indexes */
557 for(j = 0; j < MAX_THR_RATES; j++)
558 tmp_group_tp_rate[j] = group;
559
560 for (i = 0; i < MCS_GROUP_RATES; i++) {
561 if (!(mg->supported & BIT(i)))
562 continue;
563
564 index = MCS_GROUP_RATES * group + i;
565
566 mr = &mg->rates[i];
567 mr->retry_updated = false;
568 minstrel_calc_rate_ewma(mr);
569 minstrel_ht_calc_tp(mi, group, i);
570
571 if (!mr->cur_tp)
572 continue;
573
574 /* Find max throughput rate set */
575 if (group != MINSTREL_CCK_GROUP) {
576 minstrel_ht_sort_best_tp_rates(mi, index,
577 tmp_mcs_tp_rate);
578 } else if (group == MINSTREL_CCK_GROUP) {
579 minstrel_ht_sort_best_tp_rates(mi, index,
580 tmp_cck_tp_rate);
581 }
582
583 /* Find max throughput rate set within a group */
584 minstrel_ht_sort_best_tp_rates(mi, index,
585 tmp_group_tp_rate);
586
587 /* Find max probability rate per group and global */
588 minstrel_ht_set_best_prob_rate(mi, index);
589 }
590
591 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
592 sizeof(mg->max_group_tp_rate));
593 }
594
595 /* Assign new rate set per sta */
596 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
597 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
598
599 /* Try to increase robustness of max_prob_rate*/
600 minstrel_ht_prob_rate_reduce_streams(mi);
601
602 /* try to sample all available rates during each interval */
603 mi->sample_count *= 8;
604
605 #ifdef CONFIG_MAC80211_DEBUGFS
606 /* use fixed index if set */
607 if (mp->fixed_rate_idx != -1) {
608 for (i = 0; i < 4; i++)
609 mi->max_tp_rate[i] = mp->fixed_rate_idx;
610 mi->max_prob_rate = mp->fixed_rate_idx;
611 }
612 #endif
613
614 /* Reset update timer */
615 mi->stats_update = jiffies;
616 }
617
618 static bool
619 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
620 {
621 if (rate->idx < 0)
622 return false;
623
624 if (!rate->count)
625 return false;
626
627 if (rate->flags & IEEE80211_TX_RC_MCS ||
628 rate->flags & IEEE80211_TX_RC_VHT_MCS)
629 return true;
630
631 return rate->idx == mp->cck_rates[0] ||
632 rate->idx == mp->cck_rates[1] ||
633 rate->idx == mp->cck_rates[2] ||
634 rate->idx == mp->cck_rates[3];
635 }
636
637 static void
638 minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
639 {
640 struct minstrel_mcs_group_data *mg;
641
642 for (;;) {
643 mi->sample_group++;
644 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
645 mg = &mi->groups[mi->sample_group];
646
647 if (!mg->supported)
648 continue;
649
650 if (++mg->index >= MCS_GROUP_RATES) {
651 mg->index = 0;
652 if (++mg->column >= ARRAY_SIZE(sample_table))
653 mg->column = 0;
654 }
655 break;
656 }
657 }
658
659 static void
660 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
661 {
662 int group, orig_group;
663
664 orig_group = group = *idx / MCS_GROUP_RATES;
665 while (group > 0) {
666 group--;
667
668 if (!mi->groups[group].supported)
669 continue;
670
671 if (minstrel_mcs_groups[group].streams >
672 minstrel_mcs_groups[orig_group].streams)
673 continue;
674
675 if (primary)
676 *idx = mi->groups[group].max_group_tp_rate[0];
677 else
678 *idx = mi->groups[group].max_group_tp_rate[1];
679 break;
680 }
681 }
682
683 static void
684 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
685 {
686 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
687 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
688 u16 tid;
689
690 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
691 return;
692
693 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
694 return;
695
696 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
697 return;
698
699 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
700 if (likely(sta->ampdu_mlme.tid_tx[tid]))
701 return;
702
703 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
704 }
705
706 static void
707 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
708 struct ieee80211_sta *sta, void *priv_sta,
709 struct ieee80211_tx_info *info)
710 {
711 struct minstrel_ht_sta_priv *msp = priv_sta;
712 struct minstrel_ht_sta *mi = &msp->ht;
713 struct ieee80211_tx_rate *ar = info->status.rates;
714 struct minstrel_rate_stats *rate, *rate2;
715 struct minstrel_priv *mp = priv;
716 bool last, update = false;
717 int i;
718
719 if (!msp->is_ht)
720 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
721 &msp->legacy, info);
722
723 /* This packet was aggregated but doesn't carry status info */
724 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
725 !(info->flags & IEEE80211_TX_STAT_AMPDU))
726 return;
727
728 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
729 info->status.ampdu_ack_len =
730 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
731 info->status.ampdu_len = 1;
732 }
733
734 mi->ampdu_packets++;
735 mi->ampdu_len += info->status.ampdu_len;
736
737 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
738 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
739 mi->sample_tries = 1;
740 mi->sample_count--;
741 }
742
743 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
744 mi->sample_packets += info->status.ampdu_len;
745
746 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
747 for (i = 0; !last; i++) {
748 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
749 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
750
751 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
752
753 if (last)
754 rate->success += info->status.ampdu_ack_len;
755
756 rate->attempts += ar[i].count * info->status.ampdu_len;
757 }
758
759 /*
760 * check for sudden death of spatial multiplexing,
761 * downgrade to a lower number of streams if necessary.
762 */
763 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
764 if (rate->attempts > 30 &&
765 MINSTREL_FRAC(rate->success, rate->attempts) <
766 MINSTREL_FRAC(20, 100)) {
767 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
768 update = true;
769 }
770
771 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
772 if (rate2->attempts > 30 &&
773 MINSTREL_FRAC(rate2->success, rate2->attempts) <
774 MINSTREL_FRAC(20, 100)) {
775 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
776 update = true;
777 }
778
779 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
780 update = true;
781 minstrel_ht_update_stats(mp, mi);
782 }
783
784 if (update)
785 minstrel_ht_update_rates(mp, mi);
786 }
787
788 static void
789 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
790 int index)
791 {
792 struct minstrel_rate_stats *mr;
793 const struct mcs_group *group;
794 unsigned int tx_time, tx_time_rtscts, tx_time_data;
795 unsigned int cw = mp->cw_min;
796 unsigned int ctime = 0;
797 unsigned int t_slot = 9; /* FIXME */
798 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
799 unsigned int overhead = 0, overhead_rtscts = 0;
800
801 mr = minstrel_get_ratestats(mi, index);
802 if (mr->probability < MINSTREL_FRAC(1, 10)) {
803 mr->retry_count = 1;
804 mr->retry_count_rtscts = 1;
805 return;
806 }
807
808 mr->retry_count = 2;
809 mr->retry_count_rtscts = 2;
810 mr->retry_updated = true;
811
812 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
813 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
814
815 /* Contention time for first 2 tries */
816 ctime = (t_slot * cw) >> 1;
817 cw = min((cw << 1) | 1, mp->cw_max);
818 ctime += (t_slot * cw) >> 1;
819 cw = min((cw << 1) | 1, mp->cw_max);
820
821 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
822 overhead = mi->overhead;
823 overhead_rtscts = mi->overhead_rtscts;
824 }
825
826 /* Total TX time for data and Contention after first 2 tries */
827 tx_time = ctime + 2 * (overhead + tx_time_data);
828 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
829
830 /* See how many more tries we can fit inside segment size */
831 do {
832 /* Contention time for this try */
833 ctime = (t_slot * cw) >> 1;
834 cw = min((cw << 1) | 1, mp->cw_max);
835
836 /* Total TX time after this try */
837 tx_time += ctime + overhead + tx_time_data;
838 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
839
840 if (tx_time_rtscts < mp->segment_size)
841 mr->retry_count_rtscts++;
842 } while ((tx_time < mp->segment_size) &&
843 (++mr->retry_count < mp->max_retry));
844 }
845
846
847 static void
848 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
849 struct ieee80211_sta_rates *ratetbl, int offset, int index)
850 {
851 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
852 struct minstrel_rate_stats *mr;
853 u8 idx;
854 u16 flags = group->flags;
855
856 mr = minstrel_get_ratestats(mi, index);
857 if (!mr->retry_updated)
858 minstrel_calc_retransmit(mp, mi, index);
859
860 if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
861 ratetbl->rate[offset].count = 2;
862 ratetbl->rate[offset].count_rts = 2;
863 ratetbl->rate[offset].count_cts = 2;
864 } else {
865 ratetbl->rate[offset].count = mr->retry_count;
866 ratetbl->rate[offset].count_cts = mr->retry_count;
867 ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
868 }
869
870 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
871 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
872 else if (flags & IEEE80211_TX_RC_VHT_MCS)
873 idx = ((group->streams - 1) << 4) |
874 ((index % MCS_GROUP_RATES) & 0xF);
875 else
876 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
877
878 if (offset > 0) {
879 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
880 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
881 }
882
883 ratetbl->rate[offset].idx = idx;
884 ratetbl->rate[offset].flags = flags;
885 }
886
887 static void
888 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
889 {
890 struct ieee80211_sta_rates *rates;
891 int i = 0;
892
893 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
894 if (!rates)
895 return;
896
897 /* Start with max_tp_rate[0] */
898 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
899
900 if (mp->hw->max_rates >= 3) {
901 /* At least 3 tx rates supported, use max_tp_rate[1] next */
902 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
903 }
904
905 if (mp->hw->max_rates >= 2) {
906 /*
907 * At least 2 tx rates supported, use max_prob_rate next */
908 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
909 }
910
911 rates->rate[i].idx = -1;
912 rate_control_set_rates(mp->hw, mi->sta, rates);
913 }
914
915 static inline int
916 minstrel_get_duration(int index)
917 {
918 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
919 return group->duration[index % MCS_GROUP_RATES];
920 }
921
922 static int
923 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
924 {
925 struct minstrel_rate_stats *mr;
926 struct minstrel_mcs_group_data *mg;
927 unsigned int sample_dur, sample_group, cur_max_tp_streams;
928 int sample_idx = 0;
929
930 if (mi->sample_wait > 0) {
931 mi->sample_wait--;
932 return -1;
933 }
934
935 if (!mi->sample_tries)
936 return -1;
937
938 sample_group = mi->sample_group;
939 mg = &mi->groups[sample_group];
940 sample_idx = sample_table[mg->column][mg->index];
941 minstrel_next_sample_idx(mi);
942
943 if (!(mg->supported & BIT(sample_idx)))
944 return -1;
945
946 mr = &mg->rates[sample_idx];
947 sample_idx += sample_group * MCS_GROUP_RATES;
948
949 /*
950 * Sampling might add some overhead (RTS, no aggregation)
951 * to the frame. Hence, don't use sampling for the currently
952 * used rates.
953 */
954 if (sample_idx == mi->max_tp_rate[0] ||
955 sample_idx == mi->max_tp_rate[1] ||
956 sample_idx == mi->max_prob_rate)
957 return -1;
958
959 /*
960 * Do not sample if the probability is already higher than 95%
961 * to avoid wasting airtime.
962 */
963 if (mr->probability > MINSTREL_FRAC(95, 100))
964 return -1;
965
966 /*
967 * Make sure that lower rates get sampled only occasionally,
968 * if the link is working perfectly.
969 */
970
971 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
972 MCS_GROUP_RATES].streams;
973 sample_dur = minstrel_get_duration(sample_idx);
974 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
975 (cur_max_tp_streams - 1 <
976 minstrel_mcs_groups[sample_group].streams ||
977 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
978 if (mr->sample_skipped < 20)
979 return -1;
980
981 if (mi->sample_slow++ > 2)
982 return -1;
983 }
984 mi->sample_tries--;
985
986 return sample_idx;
987 }
988
989 static void
990 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
991 struct minstrel_ht_sta *mi, bool val)
992 {
993 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
994
995 if (!supported || !mi->cck_supported_short)
996 return;
997
998 if (supported & (mi->cck_supported_short << (val * 4)))
999 return;
1000
1001 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
1002 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
1003 }
1004
1005 static void
1006 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1007 struct ieee80211_tx_rate_control *txrc)
1008 {
1009 const struct mcs_group *sample_group;
1010 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1011 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1012 struct minstrel_ht_sta_priv *msp = priv_sta;
1013 struct minstrel_ht_sta *mi = &msp->ht;
1014 struct minstrel_priv *mp = priv;
1015 int sample_idx;
1016
1017 if (rate_control_send_low(sta, priv_sta, txrc))
1018 return;
1019
1020 if (!msp->is_ht)
1021 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1022
1023 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1024 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1025 minstrel_aggr_check(sta, txrc->skb);
1026
1027 info->flags |= mi->tx_flags;
1028 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
1029
1030 #ifdef CONFIG_MAC80211_DEBUGFS
1031 if (mp->fixed_rate_idx != -1)
1032 return;
1033 #endif
1034
1035 /* Don't use EAPOL frames for sampling on non-mrr hw */
1036 if (mp->hw->max_rates == 1 &&
1037 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1038 sample_idx = -1;
1039 else
1040 sample_idx = minstrel_get_sample_rate(mp, mi);
1041
1042 mi->total_packets++;
1043
1044 /* wraparound */
1045 if (mi->total_packets == ~0) {
1046 mi->total_packets = 0;
1047 mi->sample_packets = 0;
1048 }
1049
1050 if (sample_idx < 0)
1051 return;
1052
1053 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1054 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1055 rate->count = 1;
1056
1057 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1058 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1059 rate->idx = mp->cck_rates[idx];
1060 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1061 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1062 sample_group->streams);
1063 } else {
1064 rate->idx = sample_idx % MCS_GROUP_RATES +
1065 (sample_group->streams - 1) * 8;
1066 }
1067
1068 rate->flags = sample_group->flags;
1069 }
1070
1071 static void
1072 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1073 struct ieee80211_supported_band *sband,
1074 struct ieee80211_sta *sta)
1075 {
1076 int i;
1077
1078 if (sband->band != IEEE80211_BAND_2GHZ)
1079 return;
1080
1081 if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES))
1082 return;
1083
1084 mi->cck_supported = 0;
1085 mi->cck_supported_short = 0;
1086 for (i = 0; i < 4; i++) {
1087 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1088 continue;
1089
1090 mi->cck_supported |= BIT(i);
1091 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1092 mi->cck_supported_short |= BIT(i);
1093 }
1094
1095 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1096 }
1097
1098 static void
1099 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1100 struct cfg80211_chan_def *chandef,
1101 struct ieee80211_sta *sta, void *priv_sta)
1102 {
1103 struct minstrel_priv *mp = priv;
1104 struct minstrel_ht_sta_priv *msp = priv_sta;
1105 struct minstrel_ht_sta *mi = &msp->ht;
1106 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1107 u16 sta_cap = sta->ht_cap.cap;
1108 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1109 int use_vht;
1110 int n_supported = 0;
1111 int ack_dur;
1112 int stbc;
1113 int i;
1114
1115 /* fall back to the old minstrel for legacy stations */
1116 if (!sta->ht_cap.ht_supported)
1117 goto use_legacy;
1118
1119 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1120
1121 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1122 if (vht_cap->vht_supported)
1123 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1124 else
1125 #endif
1126 use_vht = 0;
1127
1128 msp->is_ht = true;
1129 memset(mi, 0, sizeof(*mi));
1130
1131 mi->sta = sta;
1132 mi->stats_update = jiffies;
1133
1134 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1135 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1136 mi->overhead += ack_dur;
1137 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1138
1139 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1140
1141 /* When using MRR, sample more on the first attempt, without delay */
1142 if (mp->has_mrr) {
1143 mi->sample_count = 16;
1144 mi->sample_wait = 0;
1145 } else {
1146 mi->sample_count = 8;
1147 mi->sample_wait = 8;
1148 }
1149 mi->sample_tries = 4;
1150
1151 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1152 if (!use_vht) {
1153 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1154 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1155 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1156
1157 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1158 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1159 }
1160
1161 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1162 u32 gflags = minstrel_mcs_groups[i].flags;
1163 int bw, nss;
1164
1165 mi->groups[i].supported = 0;
1166 if (i == MINSTREL_CCK_GROUP) {
1167 minstrel_ht_update_cck(mp, mi, sband, sta);
1168 continue;
1169 }
1170
1171 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1172 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1173 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1174 continue;
1175 } else {
1176 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1177 continue;
1178 }
1179 }
1180
1181 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1182 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1183 continue;
1184
1185 nss = minstrel_mcs_groups[i].streams;
1186
1187 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1188 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1189 continue;
1190
1191 /* HT rate */
1192 if (gflags & IEEE80211_TX_RC_MCS) {
1193 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1194 if (use_vht && minstrel_vht_only)
1195 continue;
1196 #endif
1197 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1198 if (mi->groups[i].supported)
1199 n_supported++;
1200 continue;
1201 }
1202
1203 /* VHT rate */
1204 if (!vht_cap->vht_supported ||
1205 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1206 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1207 continue;
1208
1209 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1210 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1211 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1212 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1213 continue;
1214 }
1215 }
1216
1217 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1218 bw = BW_40;
1219 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1220 bw = BW_80;
1221 else
1222 bw = BW_20;
1223
1224 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1225 vht_cap->vht_mcs.tx_mcs_map);
1226
1227 if (mi->groups[i].supported)
1228 n_supported++;
1229 }
1230
1231 if (!n_supported)
1232 goto use_legacy;
1233
1234 /* create an initial rate table with the lowest supported rates */
1235 minstrel_ht_update_stats(mp, mi);
1236 minstrel_ht_update_rates(mp, mi);
1237
1238 return;
1239
1240 use_legacy:
1241 msp->is_ht = false;
1242 memset(&msp->legacy, 0, sizeof(msp->legacy));
1243 msp->legacy.r = msp->ratelist;
1244 msp->legacy.sample_table = msp->sample_table;
1245 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1246 &msp->legacy);
1247 }
1248
1249 static void
1250 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1251 struct cfg80211_chan_def *chandef,
1252 struct ieee80211_sta *sta, void *priv_sta)
1253 {
1254 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1255 }
1256
1257 static void
1258 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1259 struct cfg80211_chan_def *chandef,
1260 struct ieee80211_sta *sta, void *priv_sta,
1261 u32 changed)
1262 {
1263 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1264 }
1265
1266 static void *
1267 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1268 {
1269 struct ieee80211_supported_band *sband;
1270 struct minstrel_ht_sta_priv *msp;
1271 struct minstrel_priv *mp = priv;
1272 struct ieee80211_hw *hw = mp->hw;
1273 int max_rates = 0;
1274 int i;
1275
1276 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1277 sband = hw->wiphy->bands[i];
1278 if (sband && sband->n_bitrates > max_rates)
1279 max_rates = sband->n_bitrates;
1280 }
1281
1282 msp = kzalloc(sizeof(*msp), gfp);
1283 if (!msp)
1284 return NULL;
1285
1286 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1287 if (!msp->ratelist)
1288 goto error;
1289
1290 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1291 if (!msp->sample_table)
1292 goto error1;
1293
1294 return msp;
1295
1296 error1:
1297 kfree(msp->ratelist);
1298 error:
1299 kfree(msp);
1300 return NULL;
1301 }
1302
1303 static void
1304 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1305 {
1306 struct minstrel_ht_sta_priv *msp = priv_sta;
1307
1308 kfree(msp->sample_table);
1309 kfree(msp->ratelist);
1310 kfree(msp);
1311 }
1312
1313 static void *
1314 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1315 {
1316 return mac80211_minstrel.alloc(hw, debugfsdir);
1317 }
1318
1319 static void
1320 minstrel_ht_free(void *priv)
1321 {
1322 mac80211_minstrel.free(priv);
1323 }
1324
1325 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1326 {
1327 struct minstrel_ht_sta_priv *msp = priv_sta;
1328 struct minstrel_ht_sta *mi = &msp->ht;
1329 int i, j;
1330
1331 if (!msp->is_ht)
1332 return mac80211_minstrel.get_expected_throughput(priv_sta);
1333
1334 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1335 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1336
1337 /* convert cur_tp from pkt per second in kbps */
1338 return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
1339 }
1340
1341 static const struct rate_control_ops mac80211_minstrel_ht = {
1342 .name = "minstrel_ht",
1343 .tx_status_noskb = minstrel_ht_tx_status,
1344 .get_rate = minstrel_ht_get_rate,
1345 .rate_init = minstrel_ht_rate_init,
1346 .rate_update = minstrel_ht_rate_update,
1347 .alloc_sta = minstrel_ht_alloc_sta,
1348 .free_sta = minstrel_ht_free_sta,
1349 .alloc = minstrel_ht_alloc,
1350 .free = minstrel_ht_free,
1351 #ifdef CONFIG_MAC80211_DEBUGFS
1352 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1353 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1354 #endif
1355 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1356 };
1357
1358
1359 static void __init init_sample_table(void)
1360 {
1361 int col, i, new_idx;
1362 u8 rnd[MCS_GROUP_RATES];
1363
1364 memset(sample_table, 0xff, sizeof(sample_table));
1365 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1366 prandom_bytes(rnd, sizeof(rnd));
1367 for (i = 0; i < MCS_GROUP_RATES; i++) {
1368 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1369 while (sample_table[col][new_idx] != 0xff)
1370 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1371
1372 sample_table[col][new_idx] = i;
1373 }
1374 }
1375 }
1376
1377 int __init
1378 rc80211_minstrel_ht_init(void)
1379 {
1380 init_sample_table();
1381 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1382 }
1383
1384 void
1385 rc80211_minstrel_ht_exit(void)
1386 {
1387 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1388 }
Linux kernel - Deliverables
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