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Merge tag 'pinctrl-v4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw...
[mirror_ubuntu-artful-kernel.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 "sta_info.h"
18 #include "rc80211_minstrel.h"
19 #include "rc80211_minstrel_ht.h"
20
21 #define AVG_AMPDU_SIZE 16
22 #define AVG_PKT_SIZE 1200
23
24 /* Number of bits for an average sized packet */
25 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
26
27 /* Number of symbols for a packet with (bps) bits per symbol */
28 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
29
30 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
31 #define MCS_SYMBOL_TIME(sgi, syms) \
32 (sgi ? \
33 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
34 ((syms) * 1000) << 2 /* syms * 4 us */ \
35 )
36
37 /* Transmit duration for the raw data part of an average sized packet */
38 #define MCS_DURATION(streams, sgi, bps) \
39 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
40
41 #define BW_20 0
42 #define BW_40 1
43 #define BW_80 2
44
45 /*
46 * Define group sort order: HT40 -> SGI -> #streams
47 */
48 #define GROUP_IDX(_streams, _sgi, _ht40) \
49 MINSTREL_HT_GROUP_0 + \
50 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
51 MINSTREL_MAX_STREAMS * _sgi + \
52 _streams - 1
53
54 /* MCS rate information for an MCS group */
55 #define MCS_GROUP(_streams, _sgi, _ht40) \
56 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
57 .streams = _streams, \
58 .flags = \
59 IEEE80211_TX_RC_MCS | \
60 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
61 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
62 .duration = { \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
71 } \
72 }
73
74 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
75 (MINSTREL_VHT_GROUP_0 + \
76 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
77 MINSTREL_MAX_STREAMS * (_sgi) + \
78 (_streams) - 1)
79
80 #define BW2VBPS(_bw, r3, r2, r1) \
81 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
82
83 #define VHT_GROUP(_streams, _sgi, _bw) \
84 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
85 .streams = _streams, \
86 .flags = \
87 IEEE80211_TX_RC_VHT_MCS | \
88 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
89 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
90 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
91 .duration = { \
92 MCS_DURATION(_streams, _sgi, \
93 BW2VBPS(_bw, 117, 54, 26)), \
94 MCS_DURATION(_streams, _sgi, \
95 BW2VBPS(_bw, 234, 108, 52)), \
96 MCS_DURATION(_streams, _sgi, \
97 BW2VBPS(_bw, 351, 162, 78)), \
98 MCS_DURATION(_streams, _sgi, \
99 BW2VBPS(_bw, 468, 216, 104)), \
100 MCS_DURATION(_streams, _sgi, \
101 BW2VBPS(_bw, 702, 324, 156)), \
102 MCS_DURATION(_streams, _sgi, \
103 BW2VBPS(_bw, 936, 432, 208)), \
104 MCS_DURATION(_streams, _sgi, \
105 BW2VBPS(_bw, 1053, 486, 234)), \
106 MCS_DURATION(_streams, _sgi, \
107 BW2VBPS(_bw, 1170, 540, 260)), \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 1404, 648, 312)), \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 1560, 720, 346)) \
112 } \
113 }
114
115 #define CCK_DURATION(_bitrate, _short, _len) \
116 (1000 * (10 /* SIFS */ + \
117 (_short ? 72 + 24 : 144 + 48) + \
118 (8 * (_len + 4) * 10) / (_bitrate)))
119
120 #define CCK_ACK_DURATION(_bitrate, _short) \
121 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
122 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
123
124 #define CCK_DURATION_LIST(_short) \
125 CCK_ACK_DURATION(10, _short), \
126 CCK_ACK_DURATION(20, _short), \
127 CCK_ACK_DURATION(55, _short), \
128 CCK_ACK_DURATION(110, _short)
129
130 #define CCK_GROUP \
131 [MINSTREL_CCK_GROUP] = { \
132 .streams = 0, \
133 .flags = 0, \
134 .duration = { \
135 CCK_DURATION_LIST(false), \
136 CCK_DURATION_LIST(true) \
137 } \
138 }
139
140 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
141 static bool minstrel_vht_only = true;
142 module_param(minstrel_vht_only, bool, 0644);
143 MODULE_PARM_DESC(minstrel_vht_only,
144 "Use only VHT rates when VHT is supported by sta.");
145 #endif
146
147 /*
148 * To enable sufficiently targeted rate sampling, MCS rates are divided into
149 * groups, based on the number of streams and flags (HT40, SGI) that they
150 * use.
151 *
152 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
153 * BW -> SGI -> #streams
154 */
155 const struct mcs_group minstrel_mcs_groups[] = {
156 MCS_GROUP(1, 0, BW_20),
157 MCS_GROUP(2, 0, BW_20),
158 MCS_GROUP(3, 0, BW_20),
159
160 MCS_GROUP(1, 1, BW_20),
161 MCS_GROUP(2, 1, BW_20),
162 MCS_GROUP(3, 1, BW_20),
163
164 MCS_GROUP(1, 0, BW_40),
165 MCS_GROUP(2, 0, BW_40),
166 MCS_GROUP(3, 0, BW_40),
167
168 MCS_GROUP(1, 1, BW_40),
169 MCS_GROUP(2, 1, BW_40),
170 MCS_GROUP(3, 1, BW_40),
171
172 CCK_GROUP,
173
174 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
175 VHT_GROUP(1, 0, BW_20),
176 VHT_GROUP(2, 0, BW_20),
177 VHT_GROUP(3, 0, BW_20),
178
179 VHT_GROUP(1, 1, BW_20),
180 VHT_GROUP(2, 1, BW_20),
181 VHT_GROUP(3, 1, BW_20),
182
183 VHT_GROUP(1, 0, BW_40),
184 VHT_GROUP(2, 0, BW_40),
185 VHT_GROUP(3, 0, BW_40),
186
187 VHT_GROUP(1, 1, BW_40),
188 VHT_GROUP(2, 1, BW_40),
189 VHT_GROUP(3, 1, BW_40),
190
191 VHT_GROUP(1, 0, BW_80),
192 VHT_GROUP(2, 0, BW_80),
193 VHT_GROUP(3, 0, BW_80),
194
195 VHT_GROUP(1, 1, BW_80),
196 VHT_GROUP(2, 1, BW_80),
197 VHT_GROUP(3, 1, BW_80),
198 #endif
199 };
200
201 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
202
203 static void
204 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
205
206 /*
207 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
208 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
209 *
210 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
211 */
212 static u16
213 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
214 {
215 u16 mask = 0;
216
217 if (bw == BW_20) {
218 if (nss != 3 && nss != 6)
219 mask = BIT(9);
220 } else if (bw == BW_80) {
221 if (nss == 3 || nss == 7)
222 mask = BIT(6);
223 else if (nss == 6)
224 mask = BIT(9);
225 } else {
226 WARN_ON(bw != BW_40);
227 }
228
229 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
230 case IEEE80211_VHT_MCS_SUPPORT_0_7:
231 mask |= 0x300;
232 break;
233 case IEEE80211_VHT_MCS_SUPPORT_0_8:
234 mask |= 0x200;
235 break;
236 case IEEE80211_VHT_MCS_SUPPORT_0_9:
237 break;
238 default:
239 mask = 0x3ff;
240 }
241
242 return 0x3ff & ~mask;
243 }
244
245 /*
246 * Look up an MCS group index based on mac80211 rate information
247 */
248 static int
249 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
250 {
251 return GROUP_IDX((rate->idx / 8) + 1,
252 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
253 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
254 }
255
256 static int
257 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
258 {
259 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
260 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
261 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
262 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
263 }
264
265 static struct minstrel_rate_stats *
266 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
267 struct ieee80211_tx_rate *rate)
268 {
269 int group, idx;
270
271 if (rate->flags & IEEE80211_TX_RC_MCS) {
272 group = minstrel_ht_get_group_idx(rate);
273 idx = rate->idx % 8;
274 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
275 group = minstrel_vht_get_group_idx(rate);
276 idx = ieee80211_rate_get_vht_mcs(rate);
277 } else {
278 group = MINSTREL_CCK_GROUP;
279
280 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
281 if (rate->idx == mp->cck_rates[idx])
282 break;
283
284 /* short preamble */
285 if (!(mi->supported[group] & BIT(idx)))
286 idx += 4;
287 }
288 return &mi->groups[group].rates[idx];
289 }
290
291 static inline struct minstrel_rate_stats *
292 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
293 {
294 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
295 }
296
297 /*
298 * Return current throughput based on the average A-MPDU length, taking into
299 * account the expected number of retransmissions and their expected length
300 */
301 int
302 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
303 int prob_ewma)
304 {
305 unsigned int nsecs = 0;
306
307 /* do not account throughput if sucess prob is below 10% */
308 if (prob_ewma < MINSTREL_FRAC(10, 100))
309 return 0;
310
311 if (group != MINSTREL_CCK_GROUP)
312 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
313
314 nsecs += minstrel_mcs_groups[group].duration[rate];
315
316 /*
317 * For the throughput calculation, limit the probability value to 90% to
318 * account for collision related packet error rate fluctuation
319 * (prob is scaled - see MINSTREL_FRAC above)
320 */
321 if (prob_ewma > MINSTREL_FRAC(90, 100))
322 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
323 / nsecs));
324 else
325 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
326 }
327
328 /*
329 * Find & sort topmost throughput rates
330 *
331 * If multiple rates provide equal throughput the sorting is based on their
332 * current success probability. Higher success probability is preferred among
333 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
334 */
335 static void
336 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
337 u16 *tp_list)
338 {
339 int cur_group, cur_idx, cur_tp_avg, cur_prob;
340 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
341 int j = MAX_THR_RATES;
342
343 cur_group = index / MCS_GROUP_RATES;
344 cur_idx = index % MCS_GROUP_RATES;
345 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
346 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
347
348 do {
349 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
350 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
351 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
352 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
353 tmp_prob);
354 if (cur_tp_avg < tmp_tp_avg ||
355 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
356 break;
357 j--;
358 } while (j > 0);
359
360 if (j < MAX_THR_RATES - 1) {
361 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
362 (MAX_THR_RATES - (j + 1))));
363 }
364 if (j < MAX_THR_RATES)
365 tp_list[j] = index;
366 }
367
368 /*
369 * Find and set the topmost probability rate per sta and per group
370 */
371 static void
372 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
373 {
374 struct minstrel_mcs_group_data *mg;
375 struct minstrel_rate_stats *mrs;
376 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
377 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
378 int max_gpr_group, max_gpr_idx;
379 int max_gpr_tp_avg, max_gpr_prob;
380
381 cur_group = index / MCS_GROUP_RATES;
382 cur_idx = index % MCS_GROUP_RATES;
383 mg = &mi->groups[index / MCS_GROUP_RATES];
384 mrs = &mg->rates[index % MCS_GROUP_RATES];
385
386 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
387 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
388 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
389 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
390
391 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
392 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
393 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
394 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
395 (max_tp_group != MINSTREL_CCK_GROUP))
396 return;
397
398 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
399 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
400 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
401
402 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
403 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
404 mrs->prob_ewma);
405 if (cur_tp_avg > tmp_tp_avg)
406 mi->max_prob_rate = index;
407
408 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
409 max_gpr_idx,
410 max_gpr_prob);
411 if (cur_tp_avg > max_gpr_tp_avg)
412 mg->max_group_prob_rate = index;
413 } else {
414 if (mrs->prob_ewma > tmp_prob)
415 mi->max_prob_rate = index;
416 if (mrs->prob_ewma > max_gpr_prob)
417 mg->max_group_prob_rate = index;
418 }
419 }
420
421
422 /*
423 * Assign new rate set per sta and use CCK rates only if the fastest
424 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
425 * rate sets where MCS and CCK rates are mixed, because CCK rates can
426 * not use aggregation.
427 */
428 static void
429 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
430 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
431 u16 tmp_cck_tp_rate[MAX_THR_RATES])
432 {
433 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
434 int i;
435
436 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
437 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
438 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
439 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
440
441 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
442 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
443 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
444 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
445
446 if (tmp_cck_tp > tmp_mcs_tp) {
447 for(i = 0; i < MAX_THR_RATES; i++) {
448 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
449 tmp_mcs_tp_rate);
450 }
451 }
452
453 }
454
455 /*
456 * Try to increase robustness of max_prob rate by decrease number of
457 * streams if possible.
458 */
459 static inline void
460 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
461 {
462 struct minstrel_mcs_group_data *mg;
463 int tmp_max_streams, group, tmp_idx, tmp_prob;
464 int tmp_tp = 0;
465
466 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
467 MCS_GROUP_RATES].streams;
468 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
469 mg = &mi->groups[group];
470 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
471 continue;
472
473 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
474 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
475
476 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
477 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
478 mi->max_prob_rate = mg->max_group_prob_rate;
479 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
480 tmp_idx,
481 tmp_prob);
482 }
483 }
484 }
485
486 /*
487 * Update rate statistics and select new primary rates
488 *
489 * Rules for rate selection:
490 * - max_prob_rate must use only one stream, as a tradeoff between delivery
491 * probability and throughput during strong fluctuations
492 * - as long as the max prob rate has a probability of more than 75%, pick
493 * higher throughput rates, even if the probablity is a bit lower
494 */
495 static void
496 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
497 {
498 struct minstrel_mcs_group_data *mg;
499 struct minstrel_rate_stats *mrs;
500 int group, i, j, cur_prob;
501 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
502 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
503
504 if (mi->ampdu_packets > 0) {
505 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
506 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
507 mi->ampdu_len = 0;
508 mi->ampdu_packets = 0;
509 }
510
511 mi->sample_slow = 0;
512 mi->sample_count = 0;
513
514 /* Initialize global rate indexes */
515 for(j = 0; j < MAX_THR_RATES; j++){
516 tmp_mcs_tp_rate[j] = 0;
517 tmp_cck_tp_rate[j] = 0;
518 }
519
520 /* Find best rate sets within all MCS groups*/
521 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
522
523 mg = &mi->groups[group];
524 if (!mi->supported[group])
525 continue;
526
527 mi->sample_count++;
528
529 /* (re)Initialize group rate indexes */
530 for(j = 0; j < MAX_THR_RATES; j++)
531 tmp_group_tp_rate[j] = group;
532
533 for (i = 0; i < MCS_GROUP_RATES; i++) {
534 if (!(mi->supported[group] & BIT(i)))
535 continue;
536
537 index = MCS_GROUP_RATES * group + i;
538
539 mrs = &mg->rates[i];
540 mrs->retry_updated = false;
541 minstrel_calc_rate_stats(mrs);
542 cur_prob = mrs->prob_ewma;
543
544 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
545 continue;
546
547 /* Find max throughput rate set */
548 if (group != MINSTREL_CCK_GROUP) {
549 minstrel_ht_sort_best_tp_rates(mi, index,
550 tmp_mcs_tp_rate);
551 } else if (group == MINSTREL_CCK_GROUP) {
552 minstrel_ht_sort_best_tp_rates(mi, index,
553 tmp_cck_tp_rate);
554 }
555
556 /* Find max throughput rate set within a group */
557 minstrel_ht_sort_best_tp_rates(mi, index,
558 tmp_group_tp_rate);
559
560 /* Find max probability rate per group and global */
561 minstrel_ht_set_best_prob_rate(mi, index);
562 }
563
564 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
565 sizeof(mg->max_group_tp_rate));
566 }
567
568 /* Assign new rate set per sta */
569 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
570 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
571
572 /* Try to increase robustness of max_prob_rate*/
573 minstrel_ht_prob_rate_reduce_streams(mi);
574
575 /* try to sample all available rates during each interval */
576 mi->sample_count *= 8;
577
578 #ifdef CONFIG_MAC80211_DEBUGFS
579 /* use fixed index if set */
580 if (mp->fixed_rate_idx != -1) {
581 for (i = 0; i < 4; i++)
582 mi->max_tp_rate[i] = mp->fixed_rate_idx;
583 mi->max_prob_rate = mp->fixed_rate_idx;
584 }
585 #endif
586
587 /* Reset update timer */
588 mi->last_stats_update = jiffies;
589 }
590
591 static bool
592 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
593 {
594 if (rate->idx < 0)
595 return false;
596
597 if (!rate->count)
598 return false;
599
600 if (rate->flags & IEEE80211_TX_RC_MCS ||
601 rate->flags & IEEE80211_TX_RC_VHT_MCS)
602 return true;
603
604 return rate->idx == mp->cck_rates[0] ||
605 rate->idx == mp->cck_rates[1] ||
606 rate->idx == mp->cck_rates[2] ||
607 rate->idx == mp->cck_rates[3];
608 }
609
610 static void
611 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
612 {
613 struct minstrel_mcs_group_data *mg;
614
615 for (;;) {
616 mi->sample_group++;
617 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
618 mg = &mi->groups[mi->sample_group];
619
620 if (!mi->supported[mi->sample_group])
621 continue;
622
623 if (++mg->index >= MCS_GROUP_RATES) {
624 mg->index = 0;
625 if (++mg->column >= ARRAY_SIZE(sample_table))
626 mg->column = 0;
627 }
628 break;
629 }
630 }
631
632 static void
633 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
634 {
635 int group, orig_group;
636
637 orig_group = group = *idx / MCS_GROUP_RATES;
638 while (group > 0) {
639 group--;
640
641 if (!mi->supported[group])
642 continue;
643
644 if (minstrel_mcs_groups[group].streams >
645 minstrel_mcs_groups[orig_group].streams)
646 continue;
647
648 if (primary)
649 *idx = mi->groups[group].max_group_tp_rate[0];
650 else
651 *idx = mi->groups[group].max_group_tp_rate[1];
652 break;
653 }
654 }
655
656 static void
657 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
658 {
659 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
660 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
661 u16 tid;
662
663 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
664 return;
665
666 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
667 return;
668
669 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
670 return;
671
672 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
673 if (likely(sta->ampdu_mlme.tid_tx[tid]))
674 return;
675
676 ieee80211_start_tx_ba_session(pubsta, tid, 0);
677 }
678
679 static void
680 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
681 void *priv_sta, struct ieee80211_tx_status *st)
682 {
683 struct ieee80211_tx_info *info = st->info;
684 struct minstrel_ht_sta_priv *msp = priv_sta;
685 struct minstrel_ht_sta *mi = &msp->ht;
686 struct ieee80211_tx_rate *ar = info->status.rates;
687 struct minstrel_rate_stats *rate, *rate2;
688 struct minstrel_priv *mp = priv;
689 bool last, update = false;
690 int i;
691
692 if (!msp->is_ht)
693 return mac80211_minstrel.tx_status_ext(priv, sband,
694 &msp->legacy, st);
695
696 /* This packet was aggregated but doesn't carry status info */
697 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
698 !(info->flags & IEEE80211_TX_STAT_AMPDU))
699 return;
700
701 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
702 info->status.ampdu_ack_len =
703 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
704 info->status.ampdu_len = 1;
705 }
706
707 mi->ampdu_packets++;
708 mi->ampdu_len += info->status.ampdu_len;
709
710 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
711 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
712 mi->sample_tries = 1;
713 mi->sample_count--;
714 }
715
716 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
717 mi->sample_packets += info->status.ampdu_len;
718
719 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
720 for (i = 0; !last; i++) {
721 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
722 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
723
724 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
725
726 if (last)
727 rate->success += info->status.ampdu_ack_len;
728
729 rate->attempts += ar[i].count * info->status.ampdu_len;
730 }
731
732 /*
733 * check for sudden death of spatial multiplexing,
734 * downgrade to a lower number of streams if necessary.
735 */
736 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
737 if (rate->attempts > 30 &&
738 MINSTREL_FRAC(rate->success, rate->attempts) <
739 MINSTREL_FRAC(20, 100)) {
740 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
741 update = true;
742 }
743
744 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
745 if (rate2->attempts > 30 &&
746 MINSTREL_FRAC(rate2->success, rate2->attempts) <
747 MINSTREL_FRAC(20, 100)) {
748 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
749 update = true;
750 }
751
752 if (time_after(jiffies, mi->last_stats_update +
753 (mp->update_interval / 2 * HZ) / 1000)) {
754 update = true;
755 minstrel_ht_update_stats(mp, mi);
756 }
757
758 if (update)
759 minstrel_ht_update_rates(mp, mi);
760 }
761
762 static void
763 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
764 int index)
765 {
766 struct minstrel_rate_stats *mrs;
767 const struct mcs_group *group;
768 unsigned int tx_time, tx_time_rtscts, tx_time_data;
769 unsigned int cw = mp->cw_min;
770 unsigned int ctime = 0;
771 unsigned int t_slot = 9; /* FIXME */
772 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
773 unsigned int overhead = 0, overhead_rtscts = 0;
774
775 mrs = minstrel_get_ratestats(mi, index);
776 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
777 mrs->retry_count = 1;
778 mrs->retry_count_rtscts = 1;
779 return;
780 }
781
782 mrs->retry_count = 2;
783 mrs->retry_count_rtscts = 2;
784 mrs->retry_updated = true;
785
786 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
787 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
788
789 /* Contention time for first 2 tries */
790 ctime = (t_slot * cw) >> 1;
791 cw = min((cw << 1) | 1, mp->cw_max);
792 ctime += (t_slot * cw) >> 1;
793 cw = min((cw << 1) | 1, mp->cw_max);
794
795 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
796 overhead = mi->overhead;
797 overhead_rtscts = mi->overhead_rtscts;
798 }
799
800 /* Total TX time for data and Contention after first 2 tries */
801 tx_time = ctime + 2 * (overhead + tx_time_data);
802 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
803
804 /* See how many more tries we can fit inside segment size */
805 do {
806 /* Contention time for this try */
807 ctime = (t_slot * cw) >> 1;
808 cw = min((cw << 1) | 1, mp->cw_max);
809
810 /* Total TX time after this try */
811 tx_time += ctime + overhead + tx_time_data;
812 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
813
814 if (tx_time_rtscts < mp->segment_size)
815 mrs->retry_count_rtscts++;
816 } while ((tx_time < mp->segment_size) &&
817 (++mrs->retry_count < mp->max_retry));
818 }
819
820
821 static void
822 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
823 struct ieee80211_sta_rates *ratetbl, int offset, int index)
824 {
825 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
826 struct minstrel_rate_stats *mrs;
827 u8 idx;
828 u16 flags = group->flags;
829
830 mrs = minstrel_get_ratestats(mi, index);
831 if (!mrs->retry_updated)
832 minstrel_calc_retransmit(mp, mi, index);
833
834 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
835 ratetbl->rate[offset].count = 2;
836 ratetbl->rate[offset].count_rts = 2;
837 ratetbl->rate[offset].count_cts = 2;
838 } else {
839 ratetbl->rate[offset].count = mrs->retry_count;
840 ratetbl->rate[offset].count_cts = mrs->retry_count;
841 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
842 }
843
844 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
845 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
846 else if (flags & IEEE80211_TX_RC_VHT_MCS)
847 idx = ((group->streams - 1) << 4) |
848 ((index % MCS_GROUP_RATES) & 0xF);
849 else
850 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
851
852 /* enable RTS/CTS if needed:
853 * - if station is in dynamic SMPS (and streams > 1)
854 * - for fallback rates, to increase chances of getting through
855 */
856 if (offset > 0 ||
857 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
858 group->streams > 1)) {
859 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
860 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
861 }
862
863 ratetbl->rate[offset].idx = idx;
864 ratetbl->rate[offset].flags = flags;
865 }
866
867 static inline int
868 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
869 {
870 int group = rate / MCS_GROUP_RATES;
871 rate %= MCS_GROUP_RATES;
872 return mi->groups[group].rates[rate].prob_ewma;
873 }
874
875 static int
876 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
877 {
878 int group = mi->max_prob_rate / MCS_GROUP_RATES;
879 const struct mcs_group *g = &minstrel_mcs_groups[group];
880 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
881
882 /* Disable A-MSDU if max_prob_rate is bad */
883 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
884 return 1;
885
886 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
887 if (g->duration[rate] > MCS_DURATION(1, 0, 52))
888 return 500;
889
890 /*
891 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
892 * data packet size
893 */
894 if (g->duration[rate] > MCS_DURATION(1, 0, 104))
895 return 1600;
896
897 /*
898 * If the rate is slower than single-stream MCS7, or if the max throughput
899 * rate success probability is less than 75%, limit A-MSDU to twice the usual
900 * data packet size
901 */
902 if (g->duration[rate] > MCS_DURATION(1, 0, 260) ||
903 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
904 MINSTREL_FRAC(75, 100)))
905 return 3200;
906
907 /*
908 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
909 * Since aggregation sessions are started/stopped without txq flush, use
910 * the limit here to avoid the complexity of having to de-aggregate
911 * packets in the queue.
912 */
913 if (!mi->sta->vht_cap.vht_supported)
914 return IEEE80211_MAX_MPDU_LEN_HT_BA;
915
916 /* unlimited */
917 return 0;
918 }
919
920 static void
921 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
922 {
923 struct ieee80211_sta_rates *rates;
924 int i = 0;
925
926 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
927 if (!rates)
928 return;
929
930 /* Start with max_tp_rate[0] */
931 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
932
933 if (mp->hw->max_rates >= 3) {
934 /* At least 3 tx rates supported, use max_tp_rate[1] next */
935 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
936 }
937
938 if (mp->hw->max_rates >= 2) {
939 /*
940 * At least 2 tx rates supported, use max_prob_rate next */
941 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
942 }
943
944 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
945 rates->rate[i].idx = -1;
946 rate_control_set_rates(mp->hw, mi->sta, rates);
947 }
948
949 static inline int
950 minstrel_get_duration(int index)
951 {
952 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
953 return group->duration[index % MCS_GROUP_RATES];
954 }
955
956 static int
957 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
958 {
959 struct minstrel_rate_stats *mrs;
960 struct minstrel_mcs_group_data *mg;
961 unsigned int sample_dur, sample_group, cur_max_tp_streams;
962 int tp_rate1, tp_rate2;
963 int sample_idx = 0;
964
965 if (mi->sample_wait > 0) {
966 mi->sample_wait--;
967 return -1;
968 }
969
970 if (!mi->sample_tries)
971 return -1;
972
973 sample_group = mi->sample_group;
974 mg = &mi->groups[sample_group];
975 sample_idx = sample_table[mg->column][mg->index];
976 minstrel_set_next_sample_idx(mi);
977
978 if (!(mi->supported[sample_group] & BIT(sample_idx)))
979 return -1;
980
981 mrs = &mg->rates[sample_idx];
982 sample_idx += sample_group * MCS_GROUP_RATES;
983
984 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
985 if (minstrel_get_duration(mi->max_tp_rate[0]) >
986 minstrel_get_duration(mi->max_tp_rate[1])) {
987 tp_rate1 = mi->max_tp_rate[1];
988 tp_rate2 = mi->max_tp_rate[0];
989 } else {
990 tp_rate1 = mi->max_tp_rate[0];
991 tp_rate2 = mi->max_tp_rate[1];
992 }
993
994 /*
995 * Sampling might add some overhead (RTS, no aggregation)
996 * to the frame. Hence, don't use sampling for the highest currently
997 * used highest throughput or probability rate.
998 */
999 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1000 return -1;
1001
1002 /*
1003 * Do not sample if the probability is already higher than 95%
1004 * to avoid wasting airtime.
1005 */
1006 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100))
1007 return -1;
1008
1009 /*
1010 * Make sure that lower rates get sampled only occasionally,
1011 * if the link is working perfectly.
1012 */
1013
1014 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1015 MCS_GROUP_RATES].streams;
1016 sample_dur = minstrel_get_duration(sample_idx);
1017 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1018 (cur_max_tp_streams - 1 <
1019 minstrel_mcs_groups[sample_group].streams ||
1020 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1021 if (mrs->sample_skipped < 20)
1022 return -1;
1023
1024 if (mi->sample_slow++ > 2)
1025 return -1;
1026 }
1027 mi->sample_tries--;
1028
1029 return sample_idx;
1030 }
1031
1032 static void
1033 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1034 struct ieee80211_tx_rate_control *txrc)
1035 {
1036 const struct mcs_group *sample_group;
1037 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1038 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1039 struct minstrel_ht_sta_priv *msp = priv_sta;
1040 struct minstrel_ht_sta *mi = &msp->ht;
1041 struct minstrel_priv *mp = priv;
1042 int sample_idx;
1043
1044 if (rate_control_send_low(sta, priv_sta, txrc))
1045 return;
1046
1047 if (!msp->is_ht)
1048 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1049
1050 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1051 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1052 minstrel_aggr_check(sta, txrc->skb);
1053
1054 info->flags |= mi->tx_flags;
1055
1056 #ifdef CONFIG_MAC80211_DEBUGFS
1057 if (mp->fixed_rate_idx != -1)
1058 return;
1059 #endif
1060
1061 /* Don't use EAPOL frames for sampling on non-mrr hw */
1062 if (mp->hw->max_rates == 1 &&
1063 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1064 sample_idx = -1;
1065 else
1066 sample_idx = minstrel_get_sample_rate(mp, mi);
1067
1068 mi->total_packets++;
1069
1070 /* wraparound */
1071 if (mi->total_packets == ~0) {
1072 mi->total_packets = 0;
1073 mi->sample_packets = 0;
1074 }
1075
1076 if (sample_idx < 0)
1077 return;
1078
1079 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1080 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1081 rate->count = 1;
1082
1083 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1084 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1085 rate->idx = mp->cck_rates[idx];
1086 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1087 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1088 sample_group->streams);
1089 } else {
1090 rate->idx = sample_idx % MCS_GROUP_RATES +
1091 (sample_group->streams - 1) * 8;
1092 }
1093
1094 rate->flags = sample_group->flags;
1095 }
1096
1097 static void
1098 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1099 struct ieee80211_supported_band *sband,
1100 struct ieee80211_sta *sta)
1101 {
1102 int i;
1103
1104 if (sband->band != NL80211_BAND_2GHZ)
1105 return;
1106
1107 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1108 return;
1109
1110 mi->cck_supported = 0;
1111 mi->cck_supported_short = 0;
1112 for (i = 0; i < 4; i++) {
1113 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1114 continue;
1115
1116 mi->cck_supported |= BIT(i);
1117 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1118 mi->cck_supported_short |= BIT(i);
1119 }
1120
1121 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1122 }
1123
1124 static void
1125 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1126 struct cfg80211_chan_def *chandef,
1127 struct ieee80211_sta *sta, void *priv_sta)
1128 {
1129 struct minstrel_priv *mp = priv;
1130 struct minstrel_ht_sta_priv *msp = priv_sta;
1131 struct minstrel_ht_sta *mi = &msp->ht;
1132 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1133 u16 sta_cap = sta->ht_cap.cap;
1134 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1135 struct sta_info *sinfo = container_of(sta, struct sta_info, sta);
1136 int use_vht;
1137 int n_supported = 0;
1138 int ack_dur;
1139 int stbc;
1140 int i;
1141
1142 /* fall back to the old minstrel for legacy stations */
1143 if (!sta->ht_cap.ht_supported)
1144 goto use_legacy;
1145
1146 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1147
1148 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1149 if (vht_cap->vht_supported)
1150 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1151 else
1152 #endif
1153 use_vht = 0;
1154
1155 msp->is_ht = true;
1156 memset(mi, 0, sizeof(*mi));
1157
1158 mi->sta = sta;
1159 mi->last_stats_update = jiffies;
1160
1161 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1162 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1163 mi->overhead += ack_dur;
1164 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1165
1166 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1167
1168 /* When using MRR, sample more on the first attempt, without delay */
1169 if (mp->has_mrr) {
1170 mi->sample_count = 16;
1171 mi->sample_wait = 0;
1172 } else {
1173 mi->sample_count = 8;
1174 mi->sample_wait = 8;
1175 }
1176 mi->sample_tries = 4;
1177
1178 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1179 if (!use_vht) {
1180 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1181 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1182 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1183
1184 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1185 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1186 }
1187
1188 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1189 u32 gflags = minstrel_mcs_groups[i].flags;
1190 int bw, nss;
1191
1192 mi->supported[i] = 0;
1193 if (i == MINSTREL_CCK_GROUP) {
1194 minstrel_ht_update_cck(mp, mi, sband, sta);
1195 continue;
1196 }
1197
1198 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1199 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1200 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1201 continue;
1202 } else {
1203 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1204 continue;
1205 }
1206 }
1207
1208 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1209 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1210 continue;
1211
1212 nss = minstrel_mcs_groups[i].streams;
1213
1214 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1215 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1216 continue;
1217
1218 /* HT rate */
1219 if (gflags & IEEE80211_TX_RC_MCS) {
1220 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1221 if (use_vht && minstrel_vht_only)
1222 continue;
1223 #endif
1224 mi->supported[i] = mcs->rx_mask[nss - 1];
1225 if (mi->supported[i])
1226 n_supported++;
1227 continue;
1228 }
1229
1230 /* VHT rate */
1231 if (!vht_cap->vht_supported ||
1232 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1233 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1234 continue;
1235
1236 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1237 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1238 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1239 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1240 continue;
1241 }
1242 }
1243
1244 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1245 bw = BW_40;
1246 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1247 bw = BW_80;
1248 else
1249 bw = BW_20;
1250
1251 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1252 vht_cap->vht_mcs.tx_mcs_map);
1253
1254 if (mi->supported[i])
1255 n_supported++;
1256 }
1257
1258 if (!n_supported)
1259 goto use_legacy;
1260
1261 if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE))
1262 mi->cck_supported_short |= mi->cck_supported_short << 4;
1263
1264 /* create an initial rate table with the lowest supported rates */
1265 minstrel_ht_update_stats(mp, mi);
1266 minstrel_ht_update_rates(mp, mi);
1267
1268 return;
1269
1270 use_legacy:
1271 msp->is_ht = false;
1272 memset(&msp->legacy, 0, sizeof(msp->legacy));
1273 msp->legacy.r = msp->ratelist;
1274 msp->legacy.sample_table = msp->sample_table;
1275 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1276 &msp->legacy);
1277 }
1278
1279 static void
1280 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1281 struct cfg80211_chan_def *chandef,
1282 struct ieee80211_sta *sta, void *priv_sta)
1283 {
1284 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1285 }
1286
1287 static void
1288 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1289 struct cfg80211_chan_def *chandef,
1290 struct ieee80211_sta *sta, void *priv_sta,
1291 u32 changed)
1292 {
1293 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1294 }
1295
1296 static void *
1297 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1298 {
1299 struct ieee80211_supported_band *sband;
1300 struct minstrel_ht_sta_priv *msp;
1301 struct minstrel_priv *mp = priv;
1302 struct ieee80211_hw *hw = mp->hw;
1303 int max_rates = 0;
1304 int i;
1305
1306 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1307 sband = hw->wiphy->bands[i];
1308 if (sband && sband->n_bitrates > max_rates)
1309 max_rates = sband->n_bitrates;
1310 }
1311
1312 msp = kzalloc(sizeof(*msp), gfp);
1313 if (!msp)
1314 return NULL;
1315
1316 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1317 if (!msp->ratelist)
1318 goto error;
1319
1320 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1321 if (!msp->sample_table)
1322 goto error1;
1323
1324 return msp;
1325
1326 error1:
1327 kfree(msp->ratelist);
1328 error:
1329 kfree(msp);
1330 return NULL;
1331 }
1332
1333 static void
1334 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1335 {
1336 struct minstrel_ht_sta_priv *msp = priv_sta;
1337
1338 kfree(msp->sample_table);
1339 kfree(msp->ratelist);
1340 kfree(msp);
1341 }
1342
1343 static void *
1344 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1345 {
1346 return mac80211_minstrel.alloc(hw, debugfsdir);
1347 }
1348
1349 static void
1350 minstrel_ht_free(void *priv)
1351 {
1352 mac80211_minstrel.free(priv);
1353 }
1354
1355 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1356 {
1357 struct minstrel_ht_sta_priv *msp = priv_sta;
1358 struct minstrel_ht_sta *mi = &msp->ht;
1359 int i, j, prob, tp_avg;
1360
1361 if (!msp->is_ht)
1362 return mac80211_minstrel.get_expected_throughput(priv_sta);
1363
1364 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1365 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1366 prob = mi->groups[i].rates[j].prob_ewma;
1367
1368 /* convert tp_avg from pkt per second in kbps */
1369 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1370 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1371
1372 return tp_avg;
1373 }
1374
1375 static const struct rate_control_ops mac80211_minstrel_ht = {
1376 .name = "minstrel_ht",
1377 .tx_status_ext = minstrel_ht_tx_status,
1378 .get_rate = minstrel_ht_get_rate,
1379 .rate_init = minstrel_ht_rate_init,
1380 .rate_update = minstrel_ht_rate_update,
1381 .alloc_sta = minstrel_ht_alloc_sta,
1382 .free_sta = minstrel_ht_free_sta,
1383 .alloc = minstrel_ht_alloc,
1384 .free = minstrel_ht_free,
1385 #ifdef CONFIG_MAC80211_DEBUGFS
1386 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1387 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1388 #endif
1389 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1390 };
1391
1392
1393 static void __init init_sample_table(void)
1394 {
1395 int col, i, new_idx;
1396 u8 rnd[MCS_GROUP_RATES];
1397
1398 memset(sample_table, 0xff, sizeof(sample_table));
1399 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1400 prandom_bytes(rnd, sizeof(rnd));
1401 for (i = 0; i < MCS_GROUP_RATES; i++) {
1402 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1403 while (sample_table[col][new_idx] != 0xff)
1404 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1405
1406 sample_table[col][new_idx] = i;
1407 }
1408 }
1409 }
1410
1411 int __init
1412 rc80211_minstrel_ht_init(void)
1413 {
1414 init_sample_table();
1415 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1416 }
1417
1418 void
1419 rc80211_minstrel_ht_exit(void)
1420 {
1421 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1422 }
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