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Linux 5.1.15
[linux/fpc-iii.git] / net / mac80211 / rc80211_minstrel_ht.c
blobccaf951e4e3122c1291f88f12dded5341f712b09
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, _s) \
56 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
57 .streams = _streams, \
58 .shift = _s, \
59 .flags = \
60 IEEE80211_TX_RC_MCS | \
61 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
62 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
63 .duration = { \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
72 } \
73 }
74
75 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
76 (MINSTREL_VHT_GROUP_0 + \
77 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
78 MINSTREL_MAX_STREAMS * (_sgi) + \
79 (_streams) - 1)
80
81 #define BW2VBPS(_bw, r3, r2, r1) \
82 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
83
84 #define VHT_GROUP(_streams, _sgi, _bw, _s) \
85 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
86 .streams = _streams, \
87 .shift = _s, \
88 .flags = \
89 IEEE80211_TX_RC_VHT_MCS | \
90 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
91 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
92 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
93 .duration = { \
94 MCS_DURATION(_streams, _sgi, \
95 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
96 MCS_DURATION(_streams, _sgi, \
97 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
98 MCS_DURATION(_streams, _sgi, \
99 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
100 MCS_DURATION(_streams, _sgi, \
101 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
102 MCS_DURATION(_streams, _sgi, \
103 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
104 MCS_DURATION(_streams, _sgi, \
105 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
106 MCS_DURATION(_streams, _sgi, \
107 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
112 MCS_DURATION(_streams, _sgi, \
113 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
114 } \
115 }
116
117 #define CCK_DURATION(_bitrate, _short, _len) \
118 (1000 * (10 /* SIFS */ + \
119 (_short ? 72 + 24 : 144 + 48) + \
120 (8 * (_len + 4) * 10) / (_bitrate)))
121
122 #define CCK_ACK_DURATION(_bitrate, _short) \
123 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
124 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
125
126 #define CCK_DURATION_LIST(_short, _s) \
127 CCK_ACK_DURATION(10, _short) >> _s, \
128 CCK_ACK_DURATION(20, _short) >> _s, \
129 CCK_ACK_DURATION(55, _short) >> _s, \
130 CCK_ACK_DURATION(110, _short) >> _s
131
132 #define CCK_GROUP(_s) \
133 [MINSTREL_CCK_GROUP] = { \
134 .streams = 1, \
135 .flags = 0, \
136 .shift = _s, \
137 .duration = { \
138 CCK_DURATION_LIST(false, _s), \
139 CCK_DURATION_LIST(true, _s) \
140 } \
141 }
142
143 static bool minstrel_vht_only = true;
144 module_param(minstrel_vht_only, bool, 0644);
145 MODULE_PARM_DESC(minstrel_vht_only,
146 "Use only VHT rates when VHT is supported by sta.");
147
148 /*
149 * To enable sufficiently targeted rate sampling, MCS rates are divided into
150 * groups, based on the number of streams and flags (HT40, SGI) that they
151 * use.
152 *
153 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
154 * BW -> SGI -> #streams
155 */
156 const struct mcs_group minstrel_mcs_groups[] = {
157 MCS_GROUP(1, 0, BW_20, 5),
158 MCS_GROUP(2, 0, BW_20, 4),
159 MCS_GROUP(3, 0, BW_20, 4),
160
161 MCS_GROUP(1, 1, BW_20, 5),
162 MCS_GROUP(2, 1, BW_20, 4),
163 MCS_GROUP(3, 1, BW_20, 4),
164
165 MCS_GROUP(1, 0, BW_40, 4),
166 MCS_GROUP(2, 0, BW_40, 4),
167 MCS_GROUP(3, 0, BW_40, 4),
168
169 MCS_GROUP(1, 1, BW_40, 4),
170 MCS_GROUP(2, 1, BW_40, 4),
171 MCS_GROUP(3, 1, BW_40, 4),
172
173 CCK_GROUP(8),
174
175 VHT_GROUP(1, 0, BW_20, 5),
176 VHT_GROUP(2, 0, BW_20, 4),
177 VHT_GROUP(3, 0, BW_20, 4),
178
179 VHT_GROUP(1, 1, BW_20, 5),
180 VHT_GROUP(2, 1, BW_20, 4),
181 VHT_GROUP(3, 1, BW_20, 4),
182
183 VHT_GROUP(1, 0, BW_40, 4),
184 VHT_GROUP(2, 0, BW_40, 4),
185 VHT_GROUP(3, 0, BW_40, 4),
186
187 VHT_GROUP(1, 1, BW_40, 4),
188 VHT_GROUP(2, 1, BW_40, 4),
189 VHT_GROUP(3, 1, BW_40, 4),
190
191 VHT_GROUP(1, 0, BW_80, 4),
192 VHT_GROUP(2, 0, BW_80, 4),
193 VHT_GROUP(3, 0, BW_80, 4),
194
195 VHT_GROUP(1, 1, BW_80, 4),
196 VHT_GROUP(2, 1, BW_80, 4),
197 VHT_GROUP(3, 1, BW_80, 4),
198 };
199
200 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
201
202 static void
203 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
204
205 /*
206 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
207 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
208 *
209 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
210 */
211 static u16
212 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
213 {
214 u16 mask = 0;
215
216 if (bw == BW_20) {
217 if (nss != 3 && nss != 6)
218 mask = BIT(9);
219 } else if (bw == BW_80) {
220 if (nss == 3 || nss == 7)
221 mask = BIT(6);
222 else if (nss == 6)
223 mask = BIT(9);
224 } else {
225 WARN_ON(bw != BW_40);
226 }
227
228 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
229 case IEEE80211_VHT_MCS_SUPPORT_0_7:
230 mask |= 0x300;
231 break;
232 case IEEE80211_VHT_MCS_SUPPORT_0_8:
233 mask |= 0x200;
234 break;
235 case IEEE80211_VHT_MCS_SUPPORT_0_9:
236 break;
237 default:
238 mask = 0x3ff;
239 }
240
241 return 0x3ff & ~mask;
242 }
243
244 /*
245 * Look up an MCS group index based on mac80211 rate information
246 */
247 static int
248 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
249 {
250 return GROUP_IDX((rate->idx / 8) + 1,
251 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
252 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
253 }
254
255 static int
256 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
257 {
258 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
259 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
260 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
261 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
262 }
263
264 static struct minstrel_rate_stats *
265 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
266 struct ieee80211_tx_rate *rate)
267 {
268 int group, idx;
269
270 if (rate->flags & IEEE80211_TX_RC_MCS) {
271 group = minstrel_ht_get_group_idx(rate);
272 idx = rate->idx % 8;
273 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
274 group = minstrel_vht_get_group_idx(rate);
275 idx = ieee80211_rate_get_vht_mcs(rate);
276 } else {
277 group = MINSTREL_CCK_GROUP;
278
279 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
280 if (rate->idx == mp->cck_rates[idx])
281 break;
282
283 /* short preamble */
284 if ((mi->supported[group] & BIT(idx + 4)) &&
285 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
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 static unsigned int
298 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
299 {
300 if (!mi->avg_ampdu_len)
301 return AVG_AMPDU_SIZE;
302
303 return MINSTREL_TRUNC(mi->avg_ampdu_len);
304 }
305
306 /*
307 * Return current throughput based on the average A-MPDU length, taking into
308 * account the expected number of retransmissions and their expected length
309 */
310 int
311 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
312 int prob_ewma)
313 {
314 unsigned int nsecs = 0;
315
316 /* do not account throughput if sucess prob is below 10% */
317 if (prob_ewma < MINSTREL_FRAC(10, 100))
318 return 0;
319
320 if (group != MINSTREL_CCK_GROUP)
321 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
322
323 nsecs += minstrel_mcs_groups[group].duration[rate] <<
324 minstrel_mcs_groups[group].shift;
325
326 /*
327 * For the throughput calculation, limit the probability value to 90% to
328 * account for collision related packet error rate fluctuation
329 * (prob is scaled - see MINSTREL_FRAC above)
330 */
331 if (prob_ewma > MINSTREL_FRAC(90, 100))
332 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
333 / nsecs));
334 else
335 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
336 }
337
338 /*
339 * Find & sort topmost throughput rates
340 *
341 * If multiple rates provide equal throughput the sorting is based on their
342 * current success probability. Higher success probability is preferred among
343 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
344 */
345 static void
346 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
347 u16 *tp_list)
348 {
349 int cur_group, cur_idx, cur_tp_avg, cur_prob;
350 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
351 int j = MAX_THR_RATES;
352
353 cur_group = index / MCS_GROUP_RATES;
354 cur_idx = index % MCS_GROUP_RATES;
355 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
356 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
357
358 do {
359 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
360 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
361 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
362 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
363 tmp_prob);
364 if (cur_tp_avg < tmp_tp_avg ||
365 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
366 break;
367 j--;
368 } while (j > 0);
369
370 if (j < MAX_THR_RATES - 1) {
371 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
372 (MAX_THR_RATES - (j + 1))));
373 }
374 if (j < MAX_THR_RATES)
375 tp_list[j] = index;
376 }
377
378 /*
379 * Find and set the topmost probability rate per sta and per group
380 */
381 static void
382 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
383 {
384 struct minstrel_mcs_group_data *mg;
385 struct minstrel_rate_stats *mrs;
386 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
387 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
388 int max_gpr_group, max_gpr_idx;
389 int max_gpr_tp_avg, max_gpr_prob;
390
391 cur_group = index / MCS_GROUP_RATES;
392 cur_idx = index % MCS_GROUP_RATES;
393 mg = &mi->groups[index / MCS_GROUP_RATES];
394 mrs = &mg->rates[index % MCS_GROUP_RATES];
395
396 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
397 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
398 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
399 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
400
401 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
402 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
403 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
404 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
405 (max_tp_group != MINSTREL_CCK_GROUP))
406 return;
407
408 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
409 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
410 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
411
412 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
413 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
414 mrs->prob_ewma);
415 if (cur_tp_avg > tmp_tp_avg)
416 mi->max_prob_rate = index;
417
418 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
419 max_gpr_idx,
420 max_gpr_prob);
421 if (cur_tp_avg > max_gpr_tp_avg)
422 mg->max_group_prob_rate = index;
423 } else {
424 if (mrs->prob_ewma > tmp_prob)
425 mi->max_prob_rate = index;
426 if (mrs->prob_ewma > max_gpr_prob)
427 mg->max_group_prob_rate = index;
428 }
429 }
430
431
432 /*
433 * Assign new rate set per sta and use CCK rates only if the fastest
434 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
435 * rate sets where MCS and CCK rates are mixed, because CCK rates can
436 * not use aggregation.
437 */
438 static void
439 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
440 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
441 u16 tmp_cck_tp_rate[MAX_THR_RATES])
442 {
443 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
444 int i;
445
446 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
447 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
448 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
449 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
450
451 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
452 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
453 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
454 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
455
456 if (tmp_cck_tp > tmp_mcs_tp) {
457 for(i = 0; i < MAX_THR_RATES; i++) {
458 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
459 tmp_mcs_tp_rate);
460 }
461 }
462
463 }
464
465 /*
466 * Try to increase robustness of max_prob rate by decrease number of
467 * streams if possible.
468 */
469 static inline void
470 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
471 {
472 struct minstrel_mcs_group_data *mg;
473 int tmp_max_streams, group, tmp_idx, tmp_prob;
474 int tmp_tp = 0;
475
476 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
477 MCS_GROUP_RATES].streams;
478 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
479 mg = &mi->groups[group];
480 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
481 continue;
482
483 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
484 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
485
486 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
487 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
488 mi->max_prob_rate = mg->max_group_prob_rate;
489 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
490 tmp_idx,
491 tmp_prob);
492 }
493 }
494 }
495
496 /*
497 * Update rate statistics and select new primary rates
498 *
499 * Rules for rate selection:
500 * - max_prob_rate must use only one stream, as a tradeoff between delivery
501 * probability and throughput during strong fluctuations
502 * - as long as the max prob rate has a probability of more than 75%, pick
503 * higher throughput rates, even if the probablity is a bit lower
504 */
505 static void
506 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
507 {
508 struct minstrel_mcs_group_data *mg;
509 struct minstrel_rate_stats *mrs;
510 int group, i, j, cur_prob;
511 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
512 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
513
514 if (mi->ampdu_packets > 0) {
515 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
516 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
517 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
518 EWMA_LEVEL);
519 else
520 mi->avg_ampdu_len = 0;
521 mi->ampdu_len = 0;
522 mi->ampdu_packets = 0;
523 }
524
525 mi->sample_slow = 0;
526 mi->sample_count = 0;
527
528 /* Initialize global rate indexes */
529 for(j = 0; j < MAX_THR_RATES; j++){
530 tmp_mcs_tp_rate[j] = 0;
531 tmp_cck_tp_rate[j] = 0;
532 }
533
534 /* Find best rate sets within all MCS groups*/
535 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
536
537 mg = &mi->groups[group];
538 if (!mi->supported[group])
539 continue;
540
541 mi->sample_count++;
542
543 /* (re)Initialize group rate indexes */
544 for(j = 0; j < MAX_THR_RATES; j++)
545 tmp_group_tp_rate[j] = group;
546
547 for (i = 0; i < MCS_GROUP_RATES; i++) {
548 if (!(mi->supported[group] & BIT(i)))
549 continue;
550
551 index = MCS_GROUP_RATES * group + i;
552
553 mrs = &mg->rates[i];
554 mrs->retry_updated = false;
555 minstrel_calc_rate_stats(mrs);
556 cur_prob = mrs->prob_ewma;
557
558 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
559 continue;
560
561 /* Find max throughput rate set */
562 if (group != MINSTREL_CCK_GROUP) {
563 minstrel_ht_sort_best_tp_rates(mi, index,
564 tmp_mcs_tp_rate);
565 } else if (group == MINSTREL_CCK_GROUP) {
566 minstrel_ht_sort_best_tp_rates(mi, index,
567 tmp_cck_tp_rate);
568 }
569
570 /* Find max throughput rate set within a group */
571 minstrel_ht_sort_best_tp_rates(mi, index,
572 tmp_group_tp_rate);
573
574 /* Find max probability rate per group and global */
575 minstrel_ht_set_best_prob_rate(mi, index);
576 }
577
578 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
579 sizeof(mg->max_group_tp_rate));
580 }
581
582 /* Assign new rate set per sta */
583 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
584 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
585
586 /* Try to increase robustness of max_prob_rate*/
587 minstrel_ht_prob_rate_reduce_streams(mi);
588
589 /* try to sample all available rates during each interval */
590 mi->sample_count *= 8;
591
592 #ifdef CONFIG_MAC80211_DEBUGFS
593 /* use fixed index if set */
594 if (mp->fixed_rate_idx != -1) {
595 for (i = 0; i < 4; i++)
596 mi->max_tp_rate[i] = mp->fixed_rate_idx;
597 mi->max_prob_rate = mp->fixed_rate_idx;
598 }
599 #endif
600
601 /* Reset update timer */
602 mi->last_stats_update = jiffies;
603 }
604
605 static bool
606 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
607 {
608 if (rate->idx < 0)
609 return false;
610
611 if (!rate->count)
612 return false;
613
614 if (rate->flags & IEEE80211_TX_RC_MCS ||
615 rate->flags & IEEE80211_TX_RC_VHT_MCS)
616 return true;
617
618 return rate->idx == mp->cck_rates[0] ||
619 rate->idx == mp->cck_rates[1] ||
620 rate->idx == mp->cck_rates[2] ||
621 rate->idx == mp->cck_rates[3];
622 }
623
624 static void
625 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
626 {
627 struct minstrel_mcs_group_data *mg;
628
629 for (;;) {
630 mi->sample_group++;
631 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
632 mg = &mi->groups[mi->sample_group];
633
634 if (!mi->supported[mi->sample_group])
635 continue;
636
637 if (++mg->index >= MCS_GROUP_RATES) {
638 mg->index = 0;
639 if (++mg->column >= ARRAY_SIZE(sample_table))
640 mg->column = 0;
641 }
642 break;
643 }
644 }
645
646 static void
647 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
648 {
649 int group, orig_group;
650
651 orig_group = group = *idx / MCS_GROUP_RATES;
652 while (group > 0) {
653 group--;
654
655 if (!mi->supported[group])
656 continue;
657
658 if (minstrel_mcs_groups[group].streams >
659 minstrel_mcs_groups[orig_group].streams)
660 continue;
661
662 if (primary)
663 *idx = mi->groups[group].max_group_tp_rate[0];
664 else
665 *idx = mi->groups[group].max_group_tp_rate[1];
666 break;
667 }
668 }
669
670 static void
671 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
672 {
673 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
674 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
675 u16 tid;
676
677 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
678 return;
679
680 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
681 return;
682
683 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
684 return;
685
686 tid = ieee80211_get_tid(hdr);
687 if (likely(sta->ampdu_mlme.tid_tx[tid]))
688 return;
689
690 ieee80211_start_tx_ba_session(pubsta, tid, 0);
691 }
692
693 static void
694 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
695 void *priv_sta, struct ieee80211_tx_status *st)
696 {
697 struct ieee80211_tx_info *info = st->info;
698 struct minstrel_ht_sta_priv *msp = priv_sta;
699 struct minstrel_ht_sta *mi = &msp->ht;
700 struct ieee80211_tx_rate *ar = info->status.rates;
701 struct minstrel_rate_stats *rate, *rate2;
702 struct minstrel_priv *mp = priv;
703 bool last, update = false;
704 int i;
705
706 if (!msp->is_ht)
707 return mac80211_minstrel.tx_status_ext(priv, sband,
708 &msp->legacy, st);
709
710 /* This packet was aggregated but doesn't carry status info */
711 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
712 !(info->flags & IEEE80211_TX_STAT_AMPDU))
713 return;
714
715 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
716 info->status.ampdu_ack_len =
717 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
718 info->status.ampdu_len = 1;
719 }
720
721 mi->ampdu_packets++;
722 mi->ampdu_len += info->status.ampdu_len;
723
724 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
725 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
726
727 mi->sample_wait = 16 + 2 * avg_ampdu_len;
728 mi->sample_tries = 1;
729 mi->sample_count--;
730 }
731
732 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
733 mi->sample_packets += info->status.ampdu_len;
734
735 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
736 for (i = 0; !last; i++) {
737 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
738 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
739
740 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
741
742 if (last)
743 rate->success += info->status.ampdu_ack_len;
744
745 rate->attempts += ar[i].count * info->status.ampdu_len;
746 }
747
748 /*
749 * check for sudden death of spatial multiplexing,
750 * downgrade to a lower number of streams if necessary.
751 */
752 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
753 if (rate->attempts > 30 &&
754 MINSTREL_FRAC(rate->success, rate->attempts) <
755 MINSTREL_FRAC(20, 100)) {
756 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
757 update = true;
758 }
759
760 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
761 if (rate2->attempts > 30 &&
762 MINSTREL_FRAC(rate2->success, rate2->attempts) <
763 MINSTREL_FRAC(20, 100)) {
764 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
765 update = true;
766 }
767
768 if (time_after(jiffies, mi->last_stats_update +
769 (mp->update_interval / 2 * HZ) / 1000)) {
770 update = true;
771 minstrel_ht_update_stats(mp, mi);
772 }
773
774 if (update)
775 minstrel_ht_update_rates(mp, mi);
776 }
777
778 static inline int
779 minstrel_get_duration(int index)
780 {
781 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
782 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
783 return duration << group->shift;
784 }
785
786 static void
787 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
788 int index)
789 {
790 struct minstrel_rate_stats *mrs;
791 unsigned int tx_time, tx_time_rtscts, tx_time_data;
792 unsigned int cw = mp->cw_min;
793 unsigned int ctime = 0;
794 unsigned int t_slot = 9; /* FIXME */
795 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
796 unsigned int overhead = 0, overhead_rtscts = 0;
797
798 mrs = minstrel_get_ratestats(mi, index);
799 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
800 mrs->retry_count = 1;
801 mrs->retry_count_rtscts = 1;
802 return;
803 }
804
805 mrs->retry_count = 2;
806 mrs->retry_count_rtscts = 2;
807 mrs->retry_updated = true;
808
809 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
810
811 /* Contention time for first 2 tries */
812 ctime = (t_slot * cw) >> 1;
813 cw = min((cw << 1) | 1, mp->cw_max);
814 ctime += (t_slot * cw) >> 1;
815 cw = min((cw << 1) | 1, mp->cw_max);
816
817 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
818 overhead = mi->overhead;
819 overhead_rtscts = mi->overhead_rtscts;
820 }
821
822 /* Total TX time for data and Contention after first 2 tries */
823 tx_time = ctime + 2 * (overhead + tx_time_data);
824 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
825
826 /* See how many more tries we can fit inside segment size */
827 do {
828 /* Contention time for this try */
829 ctime = (t_slot * cw) >> 1;
830 cw = min((cw << 1) | 1, mp->cw_max);
831
832 /* Total TX time after this try */
833 tx_time += ctime + overhead + tx_time_data;
834 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
835
836 if (tx_time_rtscts < mp->segment_size)
837 mrs->retry_count_rtscts++;
838 } while ((tx_time < mp->segment_size) &&
839 (++mrs->retry_count < mp->max_retry));
840 }
841
842
843 static void
844 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
845 struct ieee80211_sta_rates *ratetbl, int offset, int index)
846 {
847 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
848 struct minstrel_rate_stats *mrs;
849 u8 idx;
850 u16 flags = group->flags;
851
852 mrs = minstrel_get_ratestats(mi, index);
853 if (!mrs->retry_updated)
854 minstrel_calc_retransmit(mp, mi, index);
855
856 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
857 ratetbl->rate[offset].count = 2;
858 ratetbl->rate[offset].count_rts = 2;
859 ratetbl->rate[offset].count_cts = 2;
860 } else {
861 ratetbl->rate[offset].count = mrs->retry_count;
862 ratetbl->rate[offset].count_cts = mrs->retry_count;
863 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
864 }
865
866 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
867 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
868 else if (flags & IEEE80211_TX_RC_VHT_MCS)
869 idx = ((group->streams - 1) << 4) |
870 ((index % MCS_GROUP_RATES) & 0xF);
871 else
872 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
873
874 /* enable RTS/CTS if needed:
875 * - if station is in dynamic SMPS (and streams > 1)
876 * - for fallback rates, to increase chances of getting through
877 */
878 if (offset > 0 ||
879 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
880 group->streams > 1)) {
881 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
882 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
883 }
884
885 ratetbl->rate[offset].idx = idx;
886 ratetbl->rate[offset].flags = flags;
887 }
888
889 static inline int
890 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
891 {
892 int group = rate / MCS_GROUP_RATES;
893 rate %= MCS_GROUP_RATES;
894 return mi->groups[group].rates[rate].prob_ewma;
895 }
896
897 static int
898 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
899 {
900 int group = mi->max_prob_rate / MCS_GROUP_RATES;
901 const struct mcs_group *g = &minstrel_mcs_groups[group];
902 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
903 unsigned int duration;
904
905 /* Disable A-MSDU if max_prob_rate is bad */
906 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
907 return 1;
908
909 duration = g->duration[rate];
910 duration <<= g->shift;
911
912 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
913 if (duration > MCS_DURATION(1, 0, 52))
914 return 500;
915
916 /*
917 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
918 * data packet size
919 */
920 if (duration > MCS_DURATION(1, 0, 104))
921 return 1600;
922
923 /*
924 * If the rate is slower than single-stream MCS7, or if the max throughput
925 * rate success probability is less than 75%, limit A-MSDU to twice the usual
926 * data packet size
927 */
928 if (duration > MCS_DURATION(1, 0, 260) ||
929 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
930 MINSTREL_FRAC(75, 100)))
931 return 3200;
932
933 /*
934 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
935 * Since aggregation sessions are started/stopped without txq flush, use
936 * the limit here to avoid the complexity of having to de-aggregate
937 * packets in the queue.
938 */
939 if (!mi->sta->vht_cap.vht_supported)
940 return IEEE80211_MAX_MPDU_LEN_HT_BA;
941
942 /* unlimited */
943 return 0;
944 }
945
946 static void
947 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
948 {
949 struct ieee80211_sta_rates *rates;
950 int i = 0;
951
952 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
953 if (!rates)
954 return;
955
956 /* Start with max_tp_rate[0] */
957 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
958
959 if (mp->hw->max_rates >= 3) {
960 /* At least 3 tx rates supported, use max_tp_rate[1] next */
961 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
962 }
963
964 if (mp->hw->max_rates >= 2) {
965 /*
966 * At least 2 tx rates supported, use max_prob_rate next */
967 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
968 }
969
970 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
971 rates->rate[i].idx = -1;
972 rate_control_set_rates(mp->hw, mi->sta, 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 (!(mi->supported[sample_group] & 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 * or if the rate is 3 times slower than the current max probability
1024 * rate, to avoid wasting airtime.
1025 */
1026 sample_dur = minstrel_get_duration(sample_idx);
1027 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
1028 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1029 return -1;
1030
1031 /*
1032 * Make sure that lower rates get sampled only occasionally,
1033 * if the link is working perfectly.
1034 */
1035
1036 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1037 MCS_GROUP_RATES].streams;
1038 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1039 (cur_max_tp_streams - 1 <
1040 minstrel_mcs_groups[sample_group].streams ||
1041 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1042 if (mrs->sample_skipped < 20)
1043 return -1;
1044
1045 if (mi->sample_slow++ > 2)
1046 return -1;
1047 }
1048 mi->sample_tries--;
1049
1050 return sample_idx;
1051 }
1052
1053 static void
1054 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1055 struct ieee80211_tx_rate_control *txrc)
1056 {
1057 const struct mcs_group *sample_group;
1058 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1059 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1060 struct minstrel_ht_sta_priv *msp = priv_sta;
1061 struct minstrel_ht_sta *mi = &msp->ht;
1062 struct minstrel_priv *mp = priv;
1063 int sample_idx;
1064
1065 if (rate_control_send_low(sta, priv_sta, txrc))
1066 return;
1067
1068 if (!msp->is_ht)
1069 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1070
1071 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1072 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1073 minstrel_aggr_check(sta, txrc->skb);
1074
1075 info->flags |= mi->tx_flags;
1076
1077 #ifdef CONFIG_MAC80211_DEBUGFS
1078 if (mp->fixed_rate_idx != -1)
1079 return;
1080 #endif
1081
1082 /* Don't use EAPOL frames for sampling on non-mrr hw */
1083 if (mp->hw->max_rates == 1 &&
1084 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1085 sample_idx = -1;
1086 else
1087 sample_idx = minstrel_get_sample_rate(mp, mi);
1088
1089 mi->total_packets++;
1090
1091 /* wraparound */
1092 if (mi->total_packets == ~0) {
1093 mi->total_packets = 0;
1094 mi->sample_packets = 0;
1095 }
1096
1097 if (sample_idx < 0)
1098 return;
1099
1100 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1101 sample_idx %= MCS_GROUP_RATES;
1102
1103 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1104 (sample_idx >= 4) != txrc->short_preamble)
1105 return;
1106
1107 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1108 rate->count = 1;
1109
1110 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1111 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1112 rate->idx = mp->cck_rates[idx];
1113 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1114 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1115 sample_group->streams);
1116 } else {
1117 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1118 }
1119
1120 rate->flags = sample_group->flags;
1121 }
1122
1123 static void
1124 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1125 struct ieee80211_supported_band *sband,
1126 struct ieee80211_sta *sta)
1127 {
1128 int i;
1129
1130 if (sband->band != NL80211_BAND_2GHZ)
1131 return;
1132
1133 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1134 return;
1135
1136 mi->cck_supported = 0;
1137 mi->cck_supported_short = 0;
1138 for (i = 0; i < 4; i++) {
1139 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1140 continue;
1141
1142 mi->cck_supported |= BIT(i);
1143 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1144 mi->cck_supported_short |= BIT(i);
1145 }
1146
1147 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1148 }
1149
1150 static void
1151 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1152 struct cfg80211_chan_def *chandef,
1153 struct ieee80211_sta *sta, void *priv_sta)
1154 {
1155 struct minstrel_priv *mp = priv;
1156 struct minstrel_ht_sta_priv *msp = priv_sta;
1157 struct minstrel_ht_sta *mi = &msp->ht;
1158 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1159 u16 ht_cap = sta->ht_cap.cap;
1160 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1161 int use_vht;
1162 int n_supported = 0;
1163 int ack_dur;
1164 int stbc;
1165 int i;
1166 bool ldpc;
1167
1168 /* fall back to the old minstrel for legacy stations */
1169 if (!sta->ht_cap.ht_supported)
1170 goto use_legacy;
1171
1172 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1173
1174 if (vht_cap->vht_supported)
1175 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1176 else
1177 use_vht = 0;
1178
1179 msp->is_ht = true;
1180 memset(mi, 0, sizeof(*mi));
1181
1182 mi->sta = sta;
1183 mi->last_stats_update = jiffies;
1184
1185 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1186 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1187 mi->overhead += ack_dur;
1188 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1189
1190 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1191
1192 /* When using MRR, sample more on the first attempt, without delay */
1193 if (mp->has_mrr) {
1194 mi->sample_count = 16;
1195 mi->sample_wait = 0;
1196 } else {
1197 mi->sample_count = 8;
1198 mi->sample_wait = 8;
1199 }
1200 mi->sample_tries = 4;
1201
1202 if (!use_vht) {
1203 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1204 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1205
1206 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1207 } else {
1208 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1209 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1210
1211 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1212 }
1213
1214 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1215 if (ldpc)
1216 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1217
1218 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1219 u32 gflags = minstrel_mcs_groups[i].flags;
1220 int bw, nss;
1221
1222 mi->supported[i] = 0;
1223 if (i == MINSTREL_CCK_GROUP) {
1224 minstrel_ht_update_cck(mp, mi, sband, sta);
1225 continue;
1226 }
1227
1228 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1229 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1230 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1231 continue;
1232 } else {
1233 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1234 continue;
1235 }
1236 }
1237
1238 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1239 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1240 continue;
1241
1242 nss = minstrel_mcs_groups[i].streams;
1243
1244 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1245 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1246 continue;
1247
1248 /* HT rate */
1249 if (gflags & IEEE80211_TX_RC_MCS) {
1250 if (use_vht && minstrel_vht_only)
1251 continue;
1252
1253 mi->supported[i] = mcs->rx_mask[nss - 1];
1254 if (mi->supported[i])
1255 n_supported++;
1256 continue;
1257 }
1258
1259 /* VHT rate */
1260 if (!vht_cap->vht_supported ||
1261 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1262 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1263 continue;
1264
1265 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1266 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1267 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1268 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1269 continue;
1270 }
1271 }
1272
1273 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1274 bw = BW_40;
1275 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1276 bw = BW_80;
1277 else
1278 bw = BW_20;
1279
1280 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1281 vht_cap->vht_mcs.tx_mcs_map);
1282
1283 if (mi->supported[i])
1284 n_supported++;
1285 }
1286
1287 if (!n_supported)
1288 goto use_legacy;
1289
1290 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1291
1292 /* create an initial rate table with the lowest supported rates */
1293 minstrel_ht_update_stats(mp, mi);
1294 minstrel_ht_update_rates(mp, mi);
1295
1296 return;
1297
1298 use_legacy:
1299 msp->is_ht = false;
1300 memset(&msp->legacy, 0, sizeof(msp->legacy));
1301 msp->legacy.r = msp->ratelist;
1302 msp->legacy.sample_table = msp->sample_table;
1303 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1304 &msp->legacy);
1305 }
1306
1307 static void
1308 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1309 struct cfg80211_chan_def *chandef,
1310 struct ieee80211_sta *sta, void *priv_sta)
1311 {
1312 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1313 }
1314
1315 static void
1316 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1317 struct cfg80211_chan_def *chandef,
1318 struct ieee80211_sta *sta, void *priv_sta,
1319 u32 changed)
1320 {
1321 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1322 }
1323
1324 static void *
1325 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1326 {
1327 struct ieee80211_supported_band *sband;
1328 struct minstrel_ht_sta_priv *msp;
1329 struct minstrel_priv *mp = priv;
1330 struct ieee80211_hw *hw = mp->hw;
1331 int max_rates = 0;
1332 int i;
1333
1334 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1335 sband = hw->wiphy->bands[i];
1336 if (sband && sband->n_bitrates > max_rates)
1337 max_rates = sband->n_bitrates;
1338 }
1339
1340 msp = kzalloc(sizeof(*msp), gfp);
1341 if (!msp)
1342 return NULL;
1343
1344 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1345 if (!msp->ratelist)
1346 goto error;
1347
1348 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1349 if (!msp->sample_table)
1350 goto error1;
1351
1352 return msp;
1353
1354 error1:
1355 kfree(msp->ratelist);
1356 error:
1357 kfree(msp);
1358 return NULL;
1359 }
1360
1361 static void
1362 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1363 {
1364 struct minstrel_ht_sta_priv *msp = priv_sta;
1365
1366 kfree(msp->sample_table);
1367 kfree(msp->ratelist);
1368 kfree(msp);
1369 }
1370
1371 static void
1372 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1373 {
1374 static const int bitrates[4] = { 10, 20, 55, 110 };
1375 struct ieee80211_supported_band *sband;
1376 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1377 int i, j;
1378
1379 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1380 if (!sband)
1381 return;
1382
1383 for (i = 0; i < sband->n_bitrates; i++) {
1384 struct ieee80211_rate *rate = &sband->bitrates[i];
1385
1386 if (rate->flags & IEEE80211_RATE_ERP_G)
1387 continue;
1388
1389 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1390 continue;
1391
1392 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1393 if (rate->bitrate != bitrates[j])
1394 continue;
1395
1396 mp->cck_rates[j] = i;
1397 break;
1398 }
1399 }
1400 }
1401
1402 static void *
1403 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1404 {
1405 struct minstrel_priv *mp;
1406
1407 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1408 if (!mp)
1409 return NULL;
1410
1411 /* contention window settings
1412 * Just an approximation. Using the per-queue values would complicate
1413 * the calculations and is probably unnecessary */
1414 mp->cw_min = 15;
1415 mp->cw_max = 1023;
1416
1417 /* number of packets (in %) to use for sampling other rates
1418 * sample less often for non-mrr packets, because the overhead
1419 * is much higher than with mrr */
1420 mp->lookaround_rate = 5;
1421 mp->lookaround_rate_mrr = 10;
1422
1423 /* maximum time that the hw is allowed to stay in one MRR segment */
1424 mp->segment_size = 6000;
1425
1426 if (hw->max_rate_tries > 0)
1427 mp->max_retry = hw->max_rate_tries;
1428 else
1429 /* safe default, does not necessarily have to match hw properties */
1430 mp->max_retry = 7;
1431
1432 if (hw->max_rates >= 4)
1433 mp->has_mrr = true;
1434
1435 mp->hw = hw;
1436 mp->update_interval = 100;
1437
1438 #ifdef CONFIG_MAC80211_DEBUGFS
1439 mp->fixed_rate_idx = (u32) -1;
1440 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1441 &mp->fixed_rate_idx);
1442 #endif
1443
1444 minstrel_ht_init_cck_rates(mp);
1445
1446 return mp;
1447 }
1448
1449 static void
1450 minstrel_ht_free(void *priv)
1451 {
1452 kfree(priv);
1453 }
1454
1455 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1456 {
1457 struct minstrel_ht_sta_priv *msp = priv_sta;
1458 struct minstrel_ht_sta *mi = &msp->ht;
1459 int i, j, prob, tp_avg;
1460
1461 if (!msp->is_ht)
1462 return mac80211_minstrel.get_expected_throughput(priv_sta);
1463
1464 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1465 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1466 prob = mi->groups[i].rates[j].prob_ewma;
1467
1468 /* convert tp_avg from pkt per second in kbps */
1469 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1470 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1471
1472 return tp_avg;
1473 }
1474
1475 static const struct rate_control_ops mac80211_minstrel_ht = {
1476 .name = "minstrel_ht",
1477 .tx_status_ext = minstrel_ht_tx_status,
1478 .get_rate = minstrel_ht_get_rate,
1479 .rate_init = minstrel_ht_rate_init,
1480 .rate_update = minstrel_ht_rate_update,
1481 .alloc_sta = minstrel_ht_alloc_sta,
1482 .free_sta = minstrel_ht_free_sta,
1483 .alloc = minstrel_ht_alloc,
1484 .free = minstrel_ht_free,
1485 #ifdef CONFIG_MAC80211_DEBUGFS
1486 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1487 #endif
1488 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1489 };
1490
1491
1492 static void __init init_sample_table(void)
1493 {
1494 int col, i, new_idx;
1495 u8 rnd[MCS_GROUP_RATES];
1496
1497 memset(sample_table, 0xff, sizeof(sample_table));
1498 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1499 prandom_bytes(rnd, sizeof(rnd));
1500 for (i = 0; i < MCS_GROUP_RATES; i++) {
1501 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1502 while (sample_table[col][new_idx] != 0xff)
1503 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1504
1505 sample_table[col][new_idx] = i;
1506 }
1507 }
1508 }
1509
1510 int __init
1511 rc80211_minstrel_init(void)
1512 {
1513 init_sample_table();
1514 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1515 }
1516
1517 void
1518 rc80211_minstrel_exit(void)
1519 {
1520 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1521 }
Linux with added FPC-III support