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crypto: s5p-sss - Use AES_BLOCK_SIZE define instead of number
[linux/fpc-iii.git] / net / mac80211 / rc80211_minstrel_ht.c
blobf466ec37d161faf3aeaaf84fdf2f6b95788fb4ca
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 /*
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 minstrel_mcs_groups[group].shift;
316
317 /*
318 * For the throughput calculation, limit the probability value to 90% to
319 * account for collision related packet error rate fluctuation
320 * (prob is scaled - see MINSTREL_FRAC above)
321 */
322 if (prob_ewma > MINSTREL_FRAC(90, 100))
323 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
324 / nsecs));
325 else
326 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
327 }
328
329 /*
330 * Find & sort topmost throughput rates
331 *
332 * If multiple rates provide equal throughput the sorting is based on their
333 * current success probability. Higher success probability is preferred among
334 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
335 */
336 static void
337 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
338 u16 *tp_list)
339 {
340 int cur_group, cur_idx, cur_tp_avg, cur_prob;
341 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
342 int j = MAX_THR_RATES;
343
344 cur_group = index / MCS_GROUP_RATES;
345 cur_idx = index % MCS_GROUP_RATES;
346 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
347 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
348
349 do {
350 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
351 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
352 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
353 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
354 tmp_prob);
355 if (cur_tp_avg < tmp_tp_avg ||
356 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
357 break;
358 j--;
359 } while (j > 0);
360
361 if (j < MAX_THR_RATES - 1) {
362 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
363 (MAX_THR_RATES - (j + 1))));
364 }
365 if (j < MAX_THR_RATES)
366 tp_list[j] = index;
367 }
368
369 /*
370 * Find and set the topmost probability rate per sta and per group
371 */
372 static void
373 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
374 {
375 struct minstrel_mcs_group_data *mg;
376 struct minstrel_rate_stats *mrs;
377 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
378 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
379 int max_gpr_group, max_gpr_idx;
380 int max_gpr_tp_avg, max_gpr_prob;
381
382 cur_group = index / MCS_GROUP_RATES;
383 cur_idx = index % MCS_GROUP_RATES;
384 mg = &mi->groups[index / MCS_GROUP_RATES];
385 mrs = &mg->rates[index % MCS_GROUP_RATES];
386
387 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
388 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
389 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
390 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
391
392 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
393 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
394 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
395 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
396 (max_tp_group != MINSTREL_CCK_GROUP))
397 return;
398
399 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
400 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
401 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
402
403 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
404 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
405 mrs->prob_ewma);
406 if (cur_tp_avg > tmp_tp_avg)
407 mi->max_prob_rate = index;
408
409 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
410 max_gpr_idx,
411 max_gpr_prob);
412 if (cur_tp_avg > max_gpr_tp_avg)
413 mg->max_group_prob_rate = index;
414 } else {
415 if (mrs->prob_ewma > tmp_prob)
416 mi->max_prob_rate = index;
417 if (mrs->prob_ewma > max_gpr_prob)
418 mg->max_group_prob_rate = index;
419 }
420 }
421
422
423 /*
424 * Assign new rate set per sta and use CCK rates only if the fastest
425 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
426 * rate sets where MCS and CCK rates are mixed, because CCK rates can
427 * not use aggregation.
428 */
429 static void
430 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
431 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
432 u16 tmp_cck_tp_rate[MAX_THR_RATES])
433 {
434 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
435 int i;
436
437 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
438 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
439 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
440 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
441
442 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
443 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
444 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
445 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
446
447 if (tmp_cck_tp > tmp_mcs_tp) {
448 for(i = 0; i < MAX_THR_RATES; i++) {
449 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
450 tmp_mcs_tp_rate);
451 }
452 }
453
454 }
455
456 /*
457 * Try to increase robustness of max_prob rate by decrease number of
458 * streams if possible.
459 */
460 static inline void
461 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
462 {
463 struct minstrel_mcs_group_data *mg;
464 int tmp_max_streams, group, tmp_idx, tmp_prob;
465 int tmp_tp = 0;
466
467 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
468 MCS_GROUP_RATES].streams;
469 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
470 mg = &mi->groups[group];
471 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
472 continue;
473
474 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
475 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
476
477 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
478 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
479 mi->max_prob_rate = mg->max_group_prob_rate;
480 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
481 tmp_idx,
482 tmp_prob);
483 }
484 }
485 }
486
487 /*
488 * Update rate statistics and select new primary rates
489 *
490 * Rules for rate selection:
491 * - max_prob_rate must use only one stream, as a tradeoff between delivery
492 * probability and throughput during strong fluctuations
493 * - as long as the max prob rate has a probability of more than 75%, pick
494 * higher throughput rates, even if the probablity is a bit lower
495 */
496 static void
497 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
498 {
499 struct minstrel_mcs_group_data *mg;
500 struct minstrel_rate_stats *mrs;
501 int group, i, j, cur_prob;
502 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
503 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
504
505 if (mi->ampdu_packets > 0) {
506 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
507 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
508 mi->ampdu_len = 0;
509 mi->ampdu_packets = 0;
510 }
511
512 mi->sample_slow = 0;
513 mi->sample_count = 0;
514
515 /* Initialize global rate indexes */
516 for(j = 0; j < MAX_THR_RATES; j++){
517 tmp_mcs_tp_rate[j] = 0;
518 tmp_cck_tp_rate[j] = 0;
519 }
520
521 /* Find best rate sets within all MCS groups*/
522 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
523
524 mg = &mi->groups[group];
525 if (!mi->supported[group])
526 continue;
527
528 mi->sample_count++;
529
530 /* (re)Initialize group rate indexes */
531 for(j = 0; j < MAX_THR_RATES; j++)
532 tmp_group_tp_rate[j] = group;
533
534 for (i = 0; i < MCS_GROUP_RATES; i++) {
535 if (!(mi->supported[group] & BIT(i)))
536 continue;
537
538 index = MCS_GROUP_RATES * group + i;
539
540 mrs = &mg->rates[i];
541 mrs->retry_updated = false;
542 minstrel_calc_rate_stats(mrs);
543 cur_prob = mrs->prob_ewma;
544
545 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
546 continue;
547
548 /* Find max throughput rate set */
549 if (group != MINSTREL_CCK_GROUP) {
550 minstrel_ht_sort_best_tp_rates(mi, index,
551 tmp_mcs_tp_rate);
552 } else if (group == MINSTREL_CCK_GROUP) {
553 minstrel_ht_sort_best_tp_rates(mi, index,
554 tmp_cck_tp_rate);
555 }
556
557 /* Find max throughput rate set within a group */
558 minstrel_ht_sort_best_tp_rates(mi, index,
559 tmp_group_tp_rate);
560
561 /* Find max probability rate per group and global */
562 minstrel_ht_set_best_prob_rate(mi, index);
563 }
564
565 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
566 sizeof(mg->max_group_tp_rate));
567 }
568
569 /* Assign new rate set per sta */
570 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
571 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
572
573 /* Try to increase robustness of max_prob_rate*/
574 minstrel_ht_prob_rate_reduce_streams(mi);
575
576 /* try to sample all available rates during each interval */
577 mi->sample_count *= 8;
578
579 #ifdef CONFIG_MAC80211_DEBUGFS
580 /* use fixed index if set */
581 if (mp->fixed_rate_idx != -1) {
582 for (i = 0; i < 4; i++)
583 mi->max_tp_rate[i] = mp->fixed_rate_idx;
584 mi->max_prob_rate = mp->fixed_rate_idx;
585 }
586 #endif
587
588 /* Reset update timer */
589 mi->last_stats_update = jiffies;
590 }
591
592 static bool
593 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
594 {
595 if (rate->idx < 0)
596 return false;
597
598 if (!rate->count)
599 return false;
600
601 if (rate->flags & IEEE80211_TX_RC_MCS ||
602 rate->flags & IEEE80211_TX_RC_VHT_MCS)
603 return true;
604
605 return rate->idx == mp->cck_rates[0] ||
606 rate->idx == mp->cck_rates[1] ||
607 rate->idx == mp->cck_rates[2] ||
608 rate->idx == mp->cck_rates[3];
609 }
610
611 static void
612 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
613 {
614 struct minstrel_mcs_group_data *mg;
615
616 for (;;) {
617 mi->sample_group++;
618 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
619 mg = &mi->groups[mi->sample_group];
620
621 if (!mi->supported[mi->sample_group])
622 continue;
623
624 if (++mg->index >= MCS_GROUP_RATES) {
625 mg->index = 0;
626 if (++mg->column >= ARRAY_SIZE(sample_table))
627 mg->column = 0;
628 }
629 break;
630 }
631 }
632
633 static void
634 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
635 {
636 int group, orig_group;
637
638 orig_group = group = *idx / MCS_GROUP_RATES;
639 while (group > 0) {
640 group--;
641
642 if (!mi->supported[group])
643 continue;
644
645 if (minstrel_mcs_groups[group].streams >
646 minstrel_mcs_groups[orig_group].streams)
647 continue;
648
649 if (primary)
650 *idx = mi->groups[group].max_group_tp_rate[0];
651 else
652 *idx = mi->groups[group].max_group_tp_rate[1];
653 break;
654 }
655 }
656
657 static void
658 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
659 {
660 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
661 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
662 u16 tid;
663
664 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
665 return;
666
667 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
668 return;
669
670 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
671 return;
672
673 tid = ieee80211_get_tid(hdr);
674 if (likely(sta->ampdu_mlme.tid_tx[tid]))
675 return;
676
677 ieee80211_start_tx_ba_session(pubsta, tid, 0);
678 }
679
680 static void
681 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
682 void *priv_sta, struct ieee80211_tx_status *st)
683 {
684 struct ieee80211_tx_info *info = st->info;
685 struct minstrel_ht_sta_priv *msp = priv_sta;
686 struct minstrel_ht_sta *mi = &msp->ht;
687 struct ieee80211_tx_rate *ar = info->status.rates;
688 struct minstrel_rate_stats *rate, *rate2;
689 struct minstrel_priv *mp = priv;
690 bool last, update = false;
691 int i;
692
693 if (!msp->is_ht)
694 return mac80211_minstrel.tx_status_ext(priv, sband,
695 &msp->legacy, st);
696
697 /* This packet was aggregated but doesn't carry status info */
698 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
699 !(info->flags & IEEE80211_TX_STAT_AMPDU))
700 return;
701
702 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
703 info->status.ampdu_ack_len =
704 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
705 info->status.ampdu_len = 1;
706 }
707
708 mi->ampdu_packets++;
709 mi->ampdu_len += info->status.ampdu_len;
710
711 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
712 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
713 mi->sample_tries = 1;
714 mi->sample_count--;
715 }
716
717 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
718 mi->sample_packets += info->status.ampdu_len;
719
720 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
721 for (i = 0; !last; i++) {
722 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
723 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
724
725 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
726
727 if (last)
728 rate->success += info->status.ampdu_ack_len;
729
730 rate->attempts += ar[i].count * info->status.ampdu_len;
731 }
732
733 /*
734 * check for sudden death of spatial multiplexing,
735 * downgrade to a lower number of streams if necessary.
736 */
737 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
738 if (rate->attempts > 30 &&
739 MINSTREL_FRAC(rate->success, rate->attempts) <
740 MINSTREL_FRAC(20, 100)) {
741 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
742 update = true;
743 }
744
745 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
746 if (rate2->attempts > 30 &&
747 MINSTREL_FRAC(rate2->success, rate2->attempts) <
748 MINSTREL_FRAC(20, 100)) {
749 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
750 update = true;
751 }
752
753 if (time_after(jiffies, mi->last_stats_update +
754 (mp->update_interval / 2 * HZ) / 1000)) {
755 update = true;
756 minstrel_ht_update_stats(mp, mi);
757 }
758
759 if (update)
760 minstrel_ht_update_rates(mp, mi);
761 }
762
763 static inline int
764 minstrel_get_duration(int index)
765 {
766 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
767 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
768 return duration << group->shift;
769 }
770
771 static void
772 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
773 int index)
774 {
775 struct minstrel_rate_stats *mrs;
776 unsigned int tx_time, tx_time_rtscts, tx_time_data;
777 unsigned int cw = mp->cw_min;
778 unsigned int ctime = 0;
779 unsigned int t_slot = 9; /* FIXME */
780 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
781 unsigned int overhead = 0, overhead_rtscts = 0;
782
783 mrs = minstrel_get_ratestats(mi, index);
784 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
785 mrs->retry_count = 1;
786 mrs->retry_count_rtscts = 1;
787 return;
788 }
789
790 mrs->retry_count = 2;
791 mrs->retry_count_rtscts = 2;
792 mrs->retry_updated = true;
793
794 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
795
796 /* Contention time for first 2 tries */
797 ctime = (t_slot * cw) >> 1;
798 cw = min((cw << 1) | 1, mp->cw_max);
799 ctime += (t_slot * cw) >> 1;
800 cw = min((cw << 1) | 1, mp->cw_max);
801
802 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
803 overhead = mi->overhead;
804 overhead_rtscts = mi->overhead_rtscts;
805 }
806
807 /* Total TX time for data and Contention after first 2 tries */
808 tx_time = ctime + 2 * (overhead + tx_time_data);
809 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
810
811 /* See how many more tries we can fit inside segment size */
812 do {
813 /* Contention time for this try */
814 ctime = (t_slot * cw) >> 1;
815 cw = min((cw << 1) | 1, mp->cw_max);
816
817 /* Total TX time after this try */
818 tx_time += ctime + overhead + tx_time_data;
819 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
820
821 if (tx_time_rtscts < mp->segment_size)
822 mrs->retry_count_rtscts++;
823 } while ((tx_time < mp->segment_size) &&
824 (++mrs->retry_count < mp->max_retry));
825 }
826
827
828 static void
829 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
830 struct ieee80211_sta_rates *ratetbl, int offset, int index)
831 {
832 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
833 struct minstrel_rate_stats *mrs;
834 u8 idx;
835 u16 flags = group->flags;
836
837 mrs = minstrel_get_ratestats(mi, index);
838 if (!mrs->retry_updated)
839 minstrel_calc_retransmit(mp, mi, index);
840
841 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
842 ratetbl->rate[offset].count = 2;
843 ratetbl->rate[offset].count_rts = 2;
844 ratetbl->rate[offset].count_cts = 2;
845 } else {
846 ratetbl->rate[offset].count = mrs->retry_count;
847 ratetbl->rate[offset].count_cts = mrs->retry_count;
848 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
849 }
850
851 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
852 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
853 else if (flags & IEEE80211_TX_RC_VHT_MCS)
854 idx = ((group->streams - 1) << 4) |
855 ((index % MCS_GROUP_RATES) & 0xF);
856 else
857 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
858
859 /* enable RTS/CTS if needed:
860 * - if station is in dynamic SMPS (and streams > 1)
861 * - for fallback rates, to increase chances of getting through
862 */
863 if (offset > 0 ||
864 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
865 group->streams > 1)) {
866 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
867 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
868 }
869
870 ratetbl->rate[offset].idx = idx;
871 ratetbl->rate[offset].flags = flags;
872 }
873
874 static inline int
875 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
876 {
877 int group = rate / MCS_GROUP_RATES;
878 rate %= MCS_GROUP_RATES;
879 return mi->groups[group].rates[rate].prob_ewma;
880 }
881
882 static int
883 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
884 {
885 int group = mi->max_prob_rate / MCS_GROUP_RATES;
886 const struct mcs_group *g = &minstrel_mcs_groups[group];
887 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
888 unsigned int duration;
889
890 /* Disable A-MSDU if max_prob_rate is bad */
891 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
892 return 1;
893
894 duration = g->duration[rate];
895 duration <<= g->shift;
896
897 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
898 if (duration > MCS_DURATION(1, 0, 52))
899 return 500;
900
901 /*
902 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
903 * data packet size
904 */
905 if (duration > MCS_DURATION(1, 0, 104))
906 return 1600;
907
908 /*
909 * If the rate is slower than single-stream MCS7, or if the max throughput
910 * rate success probability is less than 75%, limit A-MSDU to twice the usual
911 * data packet size
912 */
913 if (duration > MCS_DURATION(1, 0, 260) ||
914 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
915 MINSTREL_FRAC(75, 100)))
916 return 3200;
917
918 /*
919 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
920 * Since aggregation sessions are started/stopped without txq flush, use
921 * the limit here to avoid the complexity of having to de-aggregate
922 * packets in the queue.
923 */
924 if (!mi->sta->vht_cap.vht_supported)
925 return IEEE80211_MAX_MPDU_LEN_HT_BA;
926
927 /* unlimited */
928 return 0;
929 }
930
931 static void
932 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
933 {
934 struct ieee80211_sta_rates *rates;
935 int i = 0;
936
937 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
938 if (!rates)
939 return;
940
941 /* Start with max_tp_rate[0] */
942 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
943
944 if (mp->hw->max_rates >= 3) {
945 /* At least 3 tx rates supported, use max_tp_rate[1] next */
946 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
947 }
948
949 if (mp->hw->max_rates >= 2) {
950 /*
951 * At least 2 tx rates supported, use max_prob_rate next */
952 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
953 }
954
955 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
956 rates->rate[i].idx = -1;
957 rate_control_set_rates(mp->hw, mi->sta, rates);
958 }
959
960 static int
961 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
962 {
963 struct minstrel_rate_stats *mrs;
964 struct minstrel_mcs_group_data *mg;
965 unsigned int sample_dur, sample_group, cur_max_tp_streams;
966 int tp_rate1, tp_rate2;
967 int sample_idx = 0;
968
969 if (mi->sample_wait > 0) {
970 mi->sample_wait--;
971 return -1;
972 }
973
974 if (!mi->sample_tries)
975 return -1;
976
977 sample_group = mi->sample_group;
978 mg = &mi->groups[sample_group];
979 sample_idx = sample_table[mg->column][mg->index];
980 minstrel_set_next_sample_idx(mi);
981
982 if (!(mi->supported[sample_group] & BIT(sample_idx)))
983 return -1;
984
985 mrs = &mg->rates[sample_idx];
986 sample_idx += sample_group * MCS_GROUP_RATES;
987
988 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
989 if (minstrel_get_duration(mi->max_tp_rate[0]) >
990 minstrel_get_duration(mi->max_tp_rate[1])) {
991 tp_rate1 = mi->max_tp_rate[1];
992 tp_rate2 = mi->max_tp_rate[0];
993 } else {
994 tp_rate1 = mi->max_tp_rate[0];
995 tp_rate2 = mi->max_tp_rate[1];
996 }
997
998 /*
999 * Sampling might add some overhead (RTS, no aggregation)
1000 * to the frame. Hence, don't use sampling for the highest currently
1001 * used highest throughput or probability rate.
1002 */
1003 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1004 return -1;
1005
1006 /*
1007 * Do not sample if the probability is already higher than 95%,
1008 * or if the rate is 3 times slower than the current max probability
1009 * rate, to avoid wasting airtime.
1010 */
1011 sample_dur = minstrel_get_duration(sample_idx);
1012 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
1013 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1014 return -1;
1015
1016 /*
1017 * Make sure that lower rates get sampled only occasionally,
1018 * if the link is working perfectly.
1019 */
1020
1021 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1022 MCS_GROUP_RATES].streams;
1023 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1024 (cur_max_tp_streams - 1 <
1025 minstrel_mcs_groups[sample_group].streams ||
1026 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1027 if (mrs->sample_skipped < 20)
1028 return -1;
1029
1030 if (mi->sample_slow++ > 2)
1031 return -1;
1032 }
1033 mi->sample_tries--;
1034
1035 return sample_idx;
1036 }
1037
1038 static void
1039 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1040 struct ieee80211_tx_rate_control *txrc)
1041 {
1042 const struct mcs_group *sample_group;
1043 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1044 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1045 struct minstrel_ht_sta_priv *msp = priv_sta;
1046 struct minstrel_ht_sta *mi = &msp->ht;
1047 struct minstrel_priv *mp = priv;
1048 int sample_idx;
1049
1050 if (rate_control_send_low(sta, priv_sta, txrc))
1051 return;
1052
1053 if (!msp->is_ht)
1054 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1055
1056 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1057 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1058 minstrel_aggr_check(sta, txrc->skb);
1059
1060 info->flags |= mi->tx_flags;
1061
1062 #ifdef CONFIG_MAC80211_DEBUGFS
1063 if (mp->fixed_rate_idx != -1)
1064 return;
1065 #endif
1066
1067 /* Don't use EAPOL frames for sampling on non-mrr hw */
1068 if (mp->hw->max_rates == 1 &&
1069 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1070 sample_idx = -1;
1071 else
1072 sample_idx = minstrel_get_sample_rate(mp, mi);
1073
1074 mi->total_packets++;
1075
1076 /* wraparound */
1077 if (mi->total_packets == ~0) {
1078 mi->total_packets = 0;
1079 mi->sample_packets = 0;
1080 }
1081
1082 if (sample_idx < 0)
1083 return;
1084
1085 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1086 sample_idx %= MCS_GROUP_RATES;
1087
1088 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1089 (sample_idx >= 4) != txrc->short_preamble)
1090 return;
1091
1092 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1093 rate->count = 1;
1094
1095 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1096 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1097 rate->idx = mp->cck_rates[idx];
1098 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1099 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1100 sample_group->streams);
1101 } else {
1102 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1103 }
1104
1105 rate->flags = sample_group->flags;
1106 }
1107
1108 static void
1109 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1110 struct ieee80211_supported_band *sband,
1111 struct ieee80211_sta *sta)
1112 {
1113 int i;
1114
1115 if (sband->band != NL80211_BAND_2GHZ)
1116 return;
1117
1118 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1119 return;
1120
1121 mi->cck_supported = 0;
1122 mi->cck_supported_short = 0;
1123 for (i = 0; i < 4; i++) {
1124 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1125 continue;
1126
1127 mi->cck_supported |= BIT(i);
1128 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1129 mi->cck_supported_short |= BIT(i);
1130 }
1131
1132 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1133 }
1134
1135 static void
1136 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1137 struct cfg80211_chan_def *chandef,
1138 struct ieee80211_sta *sta, void *priv_sta)
1139 {
1140 struct minstrel_priv *mp = priv;
1141 struct minstrel_ht_sta_priv *msp = priv_sta;
1142 struct minstrel_ht_sta *mi = &msp->ht;
1143 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1144 u16 ht_cap = sta->ht_cap.cap;
1145 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1146 int use_vht;
1147 int n_supported = 0;
1148 int ack_dur;
1149 int stbc;
1150 int i;
1151 bool ldpc;
1152
1153 /* fall back to the old minstrel for legacy stations */
1154 if (!sta->ht_cap.ht_supported)
1155 goto use_legacy;
1156
1157 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1158
1159 if (vht_cap->vht_supported)
1160 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1161 else
1162 use_vht = 0;
1163
1164 msp->is_ht = true;
1165 memset(mi, 0, sizeof(*mi));
1166
1167 mi->sta = sta;
1168 mi->last_stats_update = jiffies;
1169
1170 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1171 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1172 mi->overhead += ack_dur;
1173 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1174
1175 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1176
1177 /* When using MRR, sample more on the first attempt, without delay */
1178 if (mp->has_mrr) {
1179 mi->sample_count = 16;
1180 mi->sample_wait = 0;
1181 } else {
1182 mi->sample_count = 8;
1183 mi->sample_wait = 8;
1184 }
1185 mi->sample_tries = 4;
1186
1187 if (!use_vht) {
1188 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1189 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1190
1191 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1192 } else {
1193 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1194 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1195
1196 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1197 }
1198
1199 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1200 if (ldpc)
1201 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1202
1203 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1204 u32 gflags = minstrel_mcs_groups[i].flags;
1205 int bw, nss;
1206
1207 mi->supported[i] = 0;
1208 if (i == MINSTREL_CCK_GROUP) {
1209 minstrel_ht_update_cck(mp, mi, sband, sta);
1210 continue;
1211 }
1212
1213 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1214 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1215 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1216 continue;
1217 } else {
1218 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1219 continue;
1220 }
1221 }
1222
1223 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1224 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1225 continue;
1226
1227 nss = minstrel_mcs_groups[i].streams;
1228
1229 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1230 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1231 continue;
1232
1233 /* HT rate */
1234 if (gflags & IEEE80211_TX_RC_MCS) {
1235 if (use_vht && minstrel_vht_only)
1236 continue;
1237
1238 mi->supported[i] = mcs->rx_mask[nss - 1];
1239 if (mi->supported[i])
1240 n_supported++;
1241 continue;
1242 }
1243
1244 /* VHT rate */
1245 if (!vht_cap->vht_supported ||
1246 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1247 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1248 continue;
1249
1250 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1251 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1252 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1253 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1254 continue;
1255 }
1256 }
1257
1258 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1259 bw = BW_40;
1260 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1261 bw = BW_80;
1262 else
1263 bw = BW_20;
1264
1265 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1266 vht_cap->vht_mcs.tx_mcs_map);
1267
1268 if (mi->supported[i])
1269 n_supported++;
1270 }
1271
1272 if (!n_supported)
1273 goto use_legacy;
1274
1275 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1276
1277 /* create an initial rate table with the lowest supported rates */
1278 minstrel_ht_update_stats(mp, mi);
1279 minstrel_ht_update_rates(mp, mi);
1280
1281 return;
1282
1283 use_legacy:
1284 msp->is_ht = false;
1285 memset(&msp->legacy, 0, sizeof(msp->legacy));
1286 msp->legacy.r = msp->ratelist;
1287 msp->legacy.sample_table = msp->sample_table;
1288 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1289 &msp->legacy);
1290 }
1291
1292 static void
1293 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1294 struct cfg80211_chan_def *chandef,
1295 struct ieee80211_sta *sta, void *priv_sta)
1296 {
1297 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1298 }
1299
1300 static void
1301 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1302 struct cfg80211_chan_def *chandef,
1303 struct ieee80211_sta *sta, void *priv_sta,
1304 u32 changed)
1305 {
1306 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1307 }
1308
1309 static void *
1310 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1311 {
1312 struct ieee80211_supported_band *sband;
1313 struct minstrel_ht_sta_priv *msp;
1314 struct minstrel_priv *mp = priv;
1315 struct ieee80211_hw *hw = mp->hw;
1316 int max_rates = 0;
1317 int i;
1318
1319 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1320 sband = hw->wiphy->bands[i];
1321 if (sband && sband->n_bitrates > max_rates)
1322 max_rates = sband->n_bitrates;
1323 }
1324
1325 msp = kzalloc(sizeof(*msp), gfp);
1326 if (!msp)
1327 return NULL;
1328
1329 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1330 if (!msp->ratelist)
1331 goto error;
1332
1333 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1334 if (!msp->sample_table)
1335 goto error1;
1336
1337 return msp;
1338
1339 error1:
1340 kfree(msp->ratelist);
1341 error:
1342 kfree(msp);
1343 return NULL;
1344 }
1345
1346 static void
1347 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1348 {
1349 struct minstrel_ht_sta_priv *msp = priv_sta;
1350
1351 kfree(msp->sample_table);
1352 kfree(msp->ratelist);
1353 kfree(msp);
1354 }
1355
1356 static void
1357 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1358 {
1359 static const int bitrates[4] = { 10, 20, 55, 110 };
1360 struct ieee80211_supported_band *sband;
1361 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1362 int i, j;
1363
1364 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1365 if (!sband)
1366 return;
1367
1368 for (i = 0; i < sband->n_bitrates; i++) {
1369 struct ieee80211_rate *rate = &sband->bitrates[i];
1370
1371 if (rate->flags & IEEE80211_RATE_ERP_G)
1372 continue;
1373
1374 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1375 continue;
1376
1377 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1378 if (rate->bitrate != bitrates[j])
1379 continue;
1380
1381 mp->cck_rates[j] = i;
1382 break;
1383 }
1384 }
1385 }
1386
1387 static void *
1388 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1389 {
1390 struct minstrel_priv *mp;
1391
1392 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1393 if (!mp)
1394 return NULL;
1395
1396 /* contention window settings
1397 * Just an approximation. Using the per-queue values would complicate
1398 * the calculations and is probably unnecessary */
1399 mp->cw_min = 15;
1400 mp->cw_max = 1023;
1401
1402 /* number of packets (in %) to use for sampling other rates
1403 * sample less often for non-mrr packets, because the overhead
1404 * is much higher than with mrr */
1405 mp->lookaround_rate = 5;
1406 mp->lookaround_rate_mrr = 10;
1407
1408 /* maximum time that the hw is allowed to stay in one MRR segment */
1409 mp->segment_size = 6000;
1410
1411 if (hw->max_rate_tries > 0)
1412 mp->max_retry = hw->max_rate_tries;
1413 else
1414 /* safe default, does not necessarily have to match hw properties */
1415 mp->max_retry = 7;
1416
1417 if (hw->max_rates >= 4)
1418 mp->has_mrr = true;
1419
1420 mp->hw = hw;
1421 mp->update_interval = 100;
1422
1423 #ifdef CONFIG_MAC80211_DEBUGFS
1424 mp->fixed_rate_idx = (u32) -1;
1425 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1426 &mp->fixed_rate_idx);
1427 #endif
1428
1429 minstrel_ht_init_cck_rates(mp);
1430
1431 return mp;
1432 }
1433
1434 static void
1435 minstrel_ht_free(void *priv)
1436 {
1437 kfree(priv);
1438 }
1439
1440 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1441 {
1442 struct minstrel_ht_sta_priv *msp = priv_sta;
1443 struct minstrel_ht_sta *mi = &msp->ht;
1444 int i, j, prob, tp_avg;
1445
1446 if (!msp->is_ht)
1447 return mac80211_minstrel.get_expected_throughput(priv_sta);
1448
1449 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1450 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1451 prob = mi->groups[i].rates[j].prob_ewma;
1452
1453 /* convert tp_avg from pkt per second in kbps */
1454 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1455 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1456
1457 return tp_avg;
1458 }
1459
1460 static const struct rate_control_ops mac80211_minstrel_ht = {
1461 .name = "minstrel_ht",
1462 .tx_status_ext = minstrel_ht_tx_status,
1463 .get_rate = minstrel_ht_get_rate,
1464 .rate_init = minstrel_ht_rate_init,
1465 .rate_update = minstrel_ht_rate_update,
1466 .alloc_sta = minstrel_ht_alloc_sta,
1467 .free_sta = minstrel_ht_free_sta,
1468 .alloc = minstrel_ht_alloc,
1469 .free = minstrel_ht_free,
1470 #ifdef CONFIG_MAC80211_DEBUGFS
1471 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1472 #endif
1473 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1474 };
1475
1476
1477 static void __init init_sample_table(void)
1478 {
1479 int col, i, new_idx;
1480 u8 rnd[MCS_GROUP_RATES];
1481
1482 memset(sample_table, 0xff, sizeof(sample_table));
1483 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1484 prandom_bytes(rnd, sizeof(rnd));
1485 for (i = 0; i < MCS_GROUP_RATES; i++) {
1486 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1487 while (sample_table[col][new_idx] != 0xff)
1488 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1489
1490 sample_table[col][new_idx] = i;
1491 }
1492 }
1493 }
1494
1495 int __init
1496 rc80211_minstrel_init(void)
1497 {
1498 init_sample_table();
1499 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1500 }
1501
1502 void
1503 rc80211_minstrel_exit(void)
1504 {
1505 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1506 }
Linux with added FPC-III support