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mac80211: unify Minstrel & Minstrel-HTs calculation of rate statistics
[deliverable/linux.git] / net / mac80211 / rc80211_minstrel_ht.c
CommitLineData
ec8aa669 1/*
a0497f9f 2 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
ec8aa669
FF		 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>
9208247d 13#include <linux/moduleparam.h>
ec8aa669
FF		 14#include <linux/ieee80211.h>
15#include <net/mac80211.h>
16#include "rate.h"
17#include "rc80211_minstrel.h"
18#include "rc80211_minstrel_ht.h"
19
d66c2582 20#define AVG_AMPDU_SIZE 16
ec8aa669 21#define AVG_PKT_SIZE 1200
ec8aa669
FF		 22
23/* Number of bits for an average sized packet */
d66c2582 24#define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
ec8aa669
FF		 25
26/* Number of symbols for a packet with (bps) bits per symbol */
00591cea 27#define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
ec8aa669 28
ed97a13c 29/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
ec8aa669
FF		 30#define MCS_SYMBOL_TIME(sgi, syms) \
31 (sgi ? \
ed97a13c
FF		 32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
33 ((syms) * 1000) << 2 /* syms * 4 us */ \
ec8aa669
FF		 34 )
35
36/* Transmit duration for the raw data part of an average sized packet */
d66c2582
FF		 37#define MCS_DURATION(streams, sgi, bps) \
38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
ec8aa669 39
8a0ee4fe
KB		 40#define BW_20 0
41#define BW_40 1
9208247d 42#define BW_80 2
8a0ee4fe 43
a5f69d94
HS		 44/*
45 * Define group sort order: HT40 -> SGI -> #streams
46 */
47#define GROUP_IDX(_streams, _sgi, _ht40) \
8a0ee4fe 48 MINSTREL_HT_GROUP_0 + \
a5f69d94 49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
8a0ee4fe 50 MINSTREL_MAX_STREAMS * _sgi + \
a5f69d94
HS		 51 _streams - 1
52
ec8aa669 53/* MCS rate information for an MCS group */
a5f69d94
HS		 54#define MCS_GROUP(_streams, _sgi, _ht40) \
55 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
ec8aa669
FF		 56 .streams = _streams, \
57 .flags = \
3ec373c4 58 IEEE80211_TX_RC_MCS | \
ec8aa669
FF		 59 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
60 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
61 .duration = { \
62 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
63 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
64 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
65 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
70 } \
71}
72
9208247d
KB		 73#define VHT_GROUP_IDX(_streams, _sgi, _bw) \
74 (MINSTREL_VHT_GROUP_0 + \
75 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
76 MINSTREL_MAX_STREAMS * (_sgi) + \
77 (_streams) - 1)
78
79#define BW2VBPS(_bw, r3, r2, r1) \
80 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
81
82#define VHT_GROUP(_streams, _sgi, _bw) \
83 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
84 .streams = _streams, \
85 .flags = \
86 IEEE80211_TX_RC_VHT_MCS | \
87 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
88 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
89 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
90 .duration = { \
91 MCS_DURATION(_streams, _sgi, \
92 BW2VBPS(_bw, 117, 54, 26)), \
93 MCS_DURATION(_streams, _sgi, \
94 BW2VBPS(_bw, 234, 108, 52)), \
95 MCS_DURATION(_streams, _sgi, \
96 BW2VBPS(_bw, 351, 162, 78)), \
97 MCS_DURATION(_streams, _sgi, \
98 BW2VBPS(_bw, 468, 216, 104)), \
99 MCS_DURATION(_streams, _sgi, \
100 BW2VBPS(_bw, 702, 324, 156)), \
101 MCS_DURATION(_streams, _sgi, \
102 BW2VBPS(_bw, 936, 432, 208)), \
103 MCS_DURATION(_streams, _sgi, \
104 BW2VBPS(_bw, 1053, 486, 234)), \
105 MCS_DURATION(_streams, _sgi, \
106 BW2VBPS(_bw, 1170, 540, 260)), \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 1404, 648, 312)), \
109 MCS_DURATION(_streams, _sgi, \
110 BW2VBPS(_bw, 1560, 720, 346)) \
111 } \
112}
113
a0497f9f 114#define CCK_DURATION(_bitrate, _short, _len) \
ed97a13c 115 (1000 * (10 /* SIFS */ + \
f359d3fe 116 (_short ? 72 + 24 : 144 + 48) + \
ed97a13c 117 (8 * (_len + 4) * 10) / (_bitrate)))
a0497f9f
FF		 118
119#define CCK_ACK_DURATION(_bitrate, _short) \
120 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
121 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
122
123#define CCK_DURATION_LIST(_short) \
124 CCK_ACK_DURATION(10, _short), \
125 CCK_ACK_DURATION(20, _short), \
126 CCK_ACK_DURATION(55, _short), \
127 CCK_ACK_DURATION(110, _short)
128
8a0ee4fe
KB		 129#define CCK_GROUP \
130 [MINSTREL_CCK_GROUP] = { \
131 .streams = 0, \
3ec373c4 132 .flags = 0, \
8a0ee4fe
KB		 133 .duration = { \
134 CCK_DURATION_LIST(false), \
135 CCK_DURATION_LIST(true) \
136 } \
a0497f9f
FF		 137 }
138
9208247d
KB		 139#ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
140static bool minstrel_vht_only = true;
141module_param(minstrel_vht_only, bool, 0644);
142MODULE_PARM_DESC(minstrel_vht_only,
143 "Use only VHT rates when VHT is supported by sta.");
144#endif
145
ec8aa669
FF		 146/*
147 * To enable sufficiently targeted rate sampling, MCS rates are divided into
148 * groups, based on the number of streams and flags (HT40, SGI) that they
149 * use.
a5f69d94
HS		 150 *
151 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
8a0ee4fe 152 * BW -> SGI -> #streams
ec8aa669
FF		 153 */
154const struct mcs_group minstrel_mcs_groups[] = {
8a0ee4fe
KB		 155 MCS_GROUP(1, 0, BW_20),
156 MCS_GROUP(2, 0, BW_20),
ec8aa669 157#if MINSTREL_MAX_STREAMS >= 3
8a0ee4fe 158 MCS_GROUP(3, 0, BW_20),
ec8aa669
FF		 159#endif
160
8a0ee4fe
KB		 161 MCS_GROUP(1, 1, BW_20),
162 MCS_GROUP(2, 1, BW_20),
ec8aa669 163#if MINSTREL_MAX_STREAMS >= 3
8a0ee4fe 164 MCS_GROUP(3, 1, BW_20),
ec8aa669
FF		 165#endif
166
8a0ee4fe
KB		 167 MCS_GROUP(1, 0, BW_40),
168 MCS_GROUP(2, 0, BW_40),
ec8aa669 169#if MINSTREL_MAX_STREAMS >= 3
8a0ee4fe 170 MCS_GROUP(3, 0, BW_40),
ec8aa669
FF		 171#endif
172
8a0ee4fe
KB		 173 MCS_GROUP(1, 1, BW_40),
174 MCS_GROUP(2, 1, BW_40),
ec8aa669 175#if MINSTREL_MAX_STREAMS >= 3
8a0ee4fe 176 MCS_GROUP(3, 1, BW_40),
ec8aa669 177#endif
a0497f9f 178
9208247d
KB		 179 CCK_GROUP,
180
181#ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
182 VHT_GROUP(1, 0, BW_20),
183 VHT_GROUP(2, 0, BW_20),
184#if MINSTREL_MAX_STREAMS >= 3
185 VHT_GROUP(3, 0, BW_20),
186#endif
187
188 VHT_GROUP(1, 1, BW_20),
189 VHT_GROUP(2, 1, BW_20),
190#if MINSTREL_MAX_STREAMS >= 3
191 VHT_GROUP(3, 1, BW_20),
192#endif
ec8aa669 193
9208247d
KB		 194 VHT_GROUP(1, 0, BW_40),
195 VHT_GROUP(2, 0, BW_40),
196#if MINSTREL_MAX_STREAMS >= 3
197 VHT_GROUP(3, 0, BW_40),
198#endif
199
200 VHT_GROUP(1, 1, BW_40),
201 VHT_GROUP(2, 1, BW_40),
202#if MINSTREL_MAX_STREAMS >= 3
203 VHT_GROUP(3, 1, BW_40),
204#endif
205
206 VHT_GROUP(1, 0, BW_80),
207 VHT_GROUP(2, 0, BW_80),
208#if MINSTREL_MAX_STREAMS >= 3
209 VHT_GROUP(3, 0, BW_80),
210#endif
211
212 VHT_GROUP(1, 1, BW_80),
213 VHT_GROUP(2, 1, BW_80),
214#if MINSTREL_MAX_STREAMS >= 3
215 VHT_GROUP(3, 1, BW_80),
216#endif
217#endif
218};
a0497f9f 219
f6e1a73b 220static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
ec8aa669 221
a8566662
FF		 222static void
223minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
224
9208247d
KB		 225/*
226 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
227 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
228 *
229 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
230 */
231static u16
232minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
233{
234 u16 mask = 0;
235
236 if (bw == BW_20) {
237 if (nss != 3 && nss != 6)
238 mask = BIT(9);
239 } else if (bw == BW_80) {
240 if (nss == 3 || nss == 7)
241 mask = BIT(6);
242 else if (nss == 6)
243 mask = BIT(9);
244 } else {
245 WARN_ON(bw != BW_40);
246 }
247
248 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
249 case IEEE80211_VHT_MCS_SUPPORT_0_7:
250 mask |= 0x300;
251 break;
252 case IEEE80211_VHT_MCS_SUPPORT_0_8:
253 mask |= 0x200;
254 break;
255 case IEEE80211_VHT_MCS_SUPPORT_0_9:
256 break;
257 default:
258 mask = 0x3ff;
259 }
260
261 return 0x3ff & ~mask;
262}
263
ec8aa669
FF		 264/*
265 * Look up an MCS group index based on mac80211 rate information
266 */
267static int
268minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
269{
cc61d8df 270 return GROUP_IDX((rate->idx / 8) + 1,
a5f69d94
HS		 271 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
272 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
ec8aa669
FF		 273}
274
9208247d
KB		 275static int
276minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
277{
278 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
279 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
280 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
281 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
282}
283
a0497f9f
FF		 284static struct minstrel_rate_stats *
285minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
286 struct ieee80211_tx_rate *rate)
287{
288 int group, idx;
289
290 if (rate->flags & IEEE80211_TX_RC_MCS) {
291 group = minstrel_ht_get_group_idx(rate);
7a5e3fa2 292 idx = rate->idx % 8;
9208247d
KB		 293 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
294 group = minstrel_vht_get_group_idx(rate);
295 idx = ieee80211_rate_get_vht_mcs(rate);
a0497f9f
FF		 296 } else {
297 group = MINSTREL_CCK_GROUP;
298
299 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
300 if (rate->idx == mp->cck_rates[idx])
301 break;
302
303 /* short preamble */
304 if (!(mi->groups[group].supported & BIT(idx)))
305 idx += 4;
306 }
307 return &mi->groups[group].rates[idx];
308}
309
ec8aa669
FF		 310static inline struct minstrel_rate_stats *
311minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
312{
313 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
314}
315
ec8aa669
FF		 316/*
317 * Calculate throughput based on the average A-MPDU length, taking into account
318 * the expected number of retransmissions and their expected length
319 */
320static void
6048d763 321minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
ec8aa669
FF		 322{
323 struct minstrel_rate_stats *mr;
ed97a13c
FF		 324 unsigned int nsecs = 0;
325 unsigned int tp;
3e8b1eb2 326 unsigned int prob;
ec8aa669
FF		 327
328 mr = &mi->groups[group].rates[rate];
3e8b1eb2 329 prob = mr->probability;
ec8aa669 330
3e8b1eb2 331 if (prob < MINSTREL_FRAC(1, 10)) {
ec8aa669
FF		 332 mr->cur_tp = 0;
333 return;
334 }
335
3e8b1eb2
FF		 336 /*
337 * For the throughput calculation, limit the probability value to 90% to
338 * account for collision related packet error rate fluctuation
339 */
340 if (prob > MINSTREL_FRAC(9, 10))
341 prob = MINSTREL_FRAC(9, 10);
342
a0497f9f 343 if (group != MINSTREL_CCK_GROUP)
ed97a13c 344 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
a0497f9f 345
ed97a13c 346 nsecs += minstrel_mcs_groups[group].duration[rate];
ed97a13c 347
00591cea
JB		 348 /* prob is scaled - see MINSTREL_FRAC above */
349 tp = 1000000 * ((prob * 1000) / nsecs);
ed97a13c 350 mr->cur_tp = MINSTREL_TRUNC(tp);
ec8aa669
FF		 351}
352
5935839a
TH		 353/*
354 * Find & sort topmost throughput rates
355 *
356 * If multiple rates provide equal throughput the sorting is based on their
357 * current success probability. Higher success probability is preferred among
358 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
359 */
360static void
d4d141ca
KB		 361minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
362 u16 *tp_list)
5935839a
TH		 363{
364 int cur_group, cur_idx, cur_thr, cur_prob;
365 int tmp_group, tmp_idx, tmp_thr, tmp_prob;
366 int j = MAX_THR_RATES;
367
368 cur_group = index / MCS_GROUP_RATES;
369 cur_idx = index % MCS_GROUP_RATES;
370 cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp;
371 cur_prob = mi->groups[cur_group].rates[cur_idx].probability;
372
280ba51d 373 do {
5935839a
TH		 374 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
375 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
376 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
377 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
280ba51d
FF		 378 if (cur_thr < tmp_thr ||
379 (cur_thr == tmp_thr && cur_prob <= tmp_prob))
380 break;
381 j--;
382 } while (j > 0);
5935839a
TH		 383
384 if (j < MAX_THR_RATES - 1) {
385 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
386 (MAX_THR_RATES - (j + 1))));
387 }
388 if (j < MAX_THR_RATES)
389 tp_list[j] = index;
390}
391
392/*
393 * Find and set the topmost probability rate per sta and per group
394 */
395static void
d4d141ca 396minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
5935839a
TH		 397{
398 struct minstrel_mcs_group_data *mg;
399 struct minstrel_rate_stats *mr;
400 int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group;
401
402 mg = &mi->groups[index / MCS_GROUP_RATES];
403 mr = &mg->rates[index % MCS_GROUP_RATES];
404
405 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
406 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
407 tmp_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
408 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability;
409
410 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
411 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
412 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
413 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
414 (max_tp_group != MINSTREL_CCK_GROUP))
415 return;
416
417 if (mr->probability > MINSTREL_FRAC(75, 100)) {
418 if (mr->cur_tp > tmp_tp)
419 mi->max_prob_rate = index;
420 if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp)
421 mg->max_group_prob_rate = index;
422 } else {
423 if (mr->probability > tmp_prob)
424 mi->max_prob_rate = index;
425 if (mr->probability > mg->rates[mg->max_group_prob_rate].probability)
426 mg->max_group_prob_rate = index;
427 }
428}
429
430
431/*
432 * Assign new rate set per sta and use CCK rates only if the fastest
433 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
434 * rate sets where MCS and CCK rates are mixed, because CCK rates can
435 * not use aggregation.
436 */
437static void
438minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
d4d141ca
KB		 439 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
440 u16 tmp_cck_tp_rate[MAX_THR_RATES])
5935839a
TH		 441{
442 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp;
443 int i;
444
445 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
446 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
447 tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
448
449 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
450 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
451 tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp;
452
453 if (tmp_cck_tp > tmp_mcs_tp) {
454 for(i = 0; i < MAX_THR_RATES; i++) {
455 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
456 tmp_mcs_tp_rate);
457 }
458 }
459
460}
461
462/*
463 * Try to increase robustness of max_prob rate by decrease number of
464 * streams if possible.
465 */
466static inline void
467minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
468{
469 struct minstrel_mcs_group_data *mg;
470 struct minstrel_rate_stats *mr;
471 int tmp_max_streams, group;
472 int tmp_tp = 0;
473
474 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
475 MCS_GROUP_RATES].streams;
476 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
477 mg = &mi->groups[group];
478 if (!mg->supported || group == MINSTREL_CCK_GROUP)
479 continue;
480 mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate);
481 if (tmp_tp < mr->cur_tp &&
482 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
483 mi->max_prob_rate = mg->max_group_prob_rate;
484 tmp_tp = mr->cur_tp;
485 }
486 }
487}
488
ec8aa669
FF		 489/*
490 * Update rate statistics and select new primary rates
491 *
492 * Rules for rate selection:
493 * - max_prob_rate must use only one stream, as a tradeoff between delivery
494 * probability and throughput during strong fluctuations
5935839a 495 * - as long as the max prob rate has a probability of more than 75%, pick
ec8aa669
FF		 496 * higher throughput rates, even if the probablity is a bit lower
497 */
498static void
499minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
500{
501 struct minstrel_mcs_group_data *mg;
502 struct minstrel_rate_stats *mr;
5935839a 503 int group, i, j;
d4d141ca
KB		 504 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
505 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
ec8aa669
FF		 506
507 if (mi->ampdu_packets > 0) {
508 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
509 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
510 mi->ampdu_len = 0;
511 mi->ampdu_packets = 0;
512 }
513
514 mi->sample_slow = 0;
515 mi->sample_count = 0;
ec8aa669 516
5935839a
TH		 517 /* Initialize global rate indexes */
518 for(j = 0; j < MAX_THR_RATES; j++){
519 tmp_mcs_tp_rate[j] = 0;
520 tmp_cck_tp_rate[j] = 0;
521 }
c2eb5b0f 522
5935839a
TH		 523 /* Find best rate sets within all MCS groups*/
524 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
ec8aa669
FF		 525
526 mg = &mi->groups[group];
527 if (!mg->supported)
528 continue;
529
ec8aa669
FF		 530 mi->sample_count++;
531
5935839a
TH		 532 /* (re)Initialize group rate indexes */
533 for(j = 0; j < MAX_THR_RATES; j++)
534 tmp_group_tp_rate[j] = group;
535
ec8aa669
FF		 536 for (i = 0; i < MCS_GROUP_RATES; i++) {
537 if (!(mg->supported & BIT(i)))
538 continue;
539
351df099
KB		 540 index = MCS_GROUP_RATES * group + i;
541
ec8aa669
FF		 542 mr = &mg->rates[i];
543 mr->retry_updated = false;
f62838bc 544 minstrel_calc_rate_stats(mr);
6048d763 545 minstrel_ht_calc_tp(mi, group, i);
ec8aa669
FF		 546
547 if (!mr->cur_tp)
548 continue;
549
5935839a
TH		 550 /* Find max throughput rate set */
551 if (group != MINSTREL_CCK_GROUP) {
552 minstrel_ht_sort_best_tp_rates(mi, index,
553 tmp_mcs_tp_rate);
554 } else if (group == MINSTREL_CCK_GROUP) {
555 minstrel_ht_sort_best_tp_rates(mi, index,
556 tmp_cck_tp_rate);
ec8aa669 557 }
ec8aa669 558
5935839a
TH		 559 /* Find max throughput rate set within a group */
560 minstrel_ht_sort_best_tp_rates(mi, index,
561 tmp_group_tp_rate);
ec8aa669 562
5935839a
TH		 563 /* Find max probability rate per group and global */
564 minstrel_ht_set_best_prob_rate(mi, index);
ec8aa669
FF		 565 }
566
5935839a
TH		 567 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
568 sizeof(mg->max_group_tp_rate));
ec8aa669
FF		 569 }
570
5935839a
TH		 571 /* Assign new rate set per sta */
572 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
573 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
a299c6d5 574
5935839a
TH		 575 /* Try to increase robustness of max_prob_rate*/
576 minstrel_ht_prob_rate_reduce_streams(mi);
577
578 /* try to sample all available rates during each interval */
579 mi->sample_count *= 8;
a299c6d5 580
37feb7e2
LB		 581#ifdef CONFIG_MAC80211_DEBUGFS
582 /* use fixed index if set */
583 if (mp->fixed_rate_idx != -1) {
5935839a
TH		 584 for (i = 0; i < 4; i++)
585 mi->max_tp_rate[i] = mp->fixed_rate_idx;
37feb7e2
LB		 586 mi->max_prob_rate = mp->fixed_rate_idx;
587 }
588#endif
a299c6d5 589
5935839a 590 /* Reset update timer */
ec8aa669
FF		 591 mi->stats_update = jiffies;
592}
593
594static bool
a0497f9f 595minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
ec8aa669 596{
b79296be 597 if (rate->idx < 0)
ec8aa669
FF		 598 return false;
599
b79296be 600 if (!rate->count)
ec8aa669
FF		 601 return false;
602
9208247d
KB		 603 if (rate->flags & IEEE80211_TX_RC_MCS ||
604 rate->flags & IEEE80211_TX_RC_VHT_MCS)
a0497f9f
FF		 605 return true;
606
607 return rate->idx == mp->cck_rates[0] ||
608 rate->idx == mp->cck_rates[1] ||
609 rate->idx == mp->cck_rates[2] ||
610 rate->idx == mp->cck_rates[3];
ec8aa669
FF		 611}
612
613static void
614minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
615{
616 struct minstrel_mcs_group_data *mg;
617
618 for (;;) {
619 mi->sample_group++;
620 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
621 mg = &mi->groups[mi->sample_group];
622
623 if (!mg->supported)
624 continue;
625
626 if (++mg->index >= MCS_GROUP_RATES) {
627 mg->index = 0;
628 if (++mg->column >= ARRAY_SIZE(sample_table))
629 mg->column = 0;
630 }
631 break;
632 }
633}
634
635static void
d4d141ca 636minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
ec8aa669
FF		 637{
638 int group, orig_group;
639
640 orig_group = group = *idx / MCS_GROUP_RATES;
641 while (group > 0) {
642 group--;
643
644 if (!mi->groups[group].supported)
645 continue;
646
647 if (minstrel_mcs_groups[group].streams >
648 minstrel_mcs_groups[orig_group].streams)
649 continue;
650
651 if (primary)
5935839a 652 *idx = mi->groups[group].max_group_tp_rate[0];
ec8aa669 653 else
5935839a 654 *idx = mi->groups[group].max_group_tp_rate[1];
ec8aa669
FF		 655 break;
656 }
657}
658
659static void
6048d763 660minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
ec8aa669
FF		 661{
662 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
663 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
664 u16 tid;
665
75769c80
FF		 666 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
667 return;
668
ec8aa669
FF		 669 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
670 return;
671
e133fae2 672 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
ec8aa669
FF		 673 return;
674
675 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
a622ab72 676 if (likely(sta->ampdu_mlme.tid_tx[tid]))
ec8aa669
FF		 677 return;
678
bd2ce6e4 679 ieee80211_start_tx_ba_session(pubsta, tid, 5000);
ec8aa669
FF		 680}
681
682static void
683minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
684 struct ieee80211_sta *sta, void *priv_sta,
63558a65 685 struct ieee80211_tx_info *info)
ec8aa669
FF		 686{
687 struct minstrel_ht_sta_priv *msp = priv_sta;
688 struct minstrel_ht_sta *mi = &msp->ht;
ec8aa669
FF		 689 struct ieee80211_tx_rate *ar = info->status.rates;
690 struct minstrel_rate_stats *rate, *rate2;
691 struct minstrel_priv *mp = priv;
a8566662 692 bool last, update = false;
a544ab7f 693 int i;
ec8aa669
FF		 694
695 if (!msp->is_ht)
63558a65
FF		 696 return mac80211_minstrel.tx_status_noskb(priv, sband, sta,
697 &msp->legacy, info);
ec8aa669
FF		 698
699 /* This packet was aggregated but doesn't carry status info */
700 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
701 !(info->flags & IEEE80211_TX_STAT_AMPDU))
702 return;
703
15d46f38
BS		 704 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
705 info->status.ampdu_ack_len =
706 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
ec8aa669
FF		 707 info->status.ampdu_len = 1;
708 }
709
710 mi->ampdu_packets++;
711 mi->ampdu_len += info->status.ampdu_len;
712
713 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
c7317e41 714 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
52c00a37 715 mi->sample_tries = 1;
ec8aa669
FF		 716 mi->sample_count--;
717 }
718
8d5eab5a 719 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
ec8aa669 720 mi->sample_packets += info->status.ampdu_len;
ec8aa669 721
a0497f9f 722 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
ec8aa669
FF		 723 for (i = 0; !last; i++) {
724 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
a0497f9f 725 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
ec8aa669 726
a0497f9f 727 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
ec8aa669 728
15d46f38 729 if (last)
ec8aa669
FF		 730 rate->success += info->status.ampdu_ack_len;
731
732 rate->attempts += ar[i].count * info->status.ampdu_len;
733 }
734
735 /*
736 * check for sudden death of spatial multiplexing,
737 * downgrade to a lower number of streams if necessary.
738 */
5935839a 739 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
ec8aa669
FF		 740 if (rate->attempts > 30 &&
741 MINSTREL_FRAC(rate->success, rate->attempts) <
a8566662 742 MINSTREL_FRAC(20, 100)) {
5935839a 743 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
a8566662
FF		 744 update = true;
745 }
ec8aa669 746
5935839a 747 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
ecc3d5ae
ML		 748 if (rate2->attempts > 30 &&
749 MINSTREL_FRAC(rate2->success, rate2->attempts) <
a8566662 750 MINSTREL_FRAC(20, 100)) {
5935839a 751 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
a8566662
FF		 752 update = true;
753 }
ec8aa669
FF		 754
755 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
a8566662 756 update = true;
ec8aa669 757 minstrel_ht_update_stats(mp, mi);
ec8aa669 758 }
a8566662
FF		 759
760 if (update)
761 minstrel_ht_update_rates(mp, mi);
ec8aa669
FF		 762}
763
764static void
765minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
766 int index)
767{
768 struct minstrel_rate_stats *mr;
769 const struct mcs_group *group;
770 unsigned int tx_time, tx_time_rtscts, tx_time_data;
771 unsigned int cw = mp->cw_min;
8fddddff 772 unsigned int ctime = 0;
ec8aa669
FF		 773 unsigned int t_slot = 9; /* FIXME */
774 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
a0497f9f 775 unsigned int overhead = 0, overhead_rtscts = 0;
ec8aa669
FF		 776
777 mr = minstrel_get_ratestats(mi, index);
778 if (mr->probability < MINSTREL_FRAC(1, 10)) {
779 mr->retry_count = 1;
780 mr->retry_count_rtscts = 1;
781 return;
782 }
783
784 mr->retry_count = 2;
785 mr->retry_count_rtscts = 2;
786 mr->retry_updated = true;
787
788 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
ed97a13c 789 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
8fddddff
DH		 790
791 /* Contention time for first 2 tries */
792 ctime = (t_slot * cw) >> 1;
793 cw = min((cw << 1) | 1, mp->cw_max);
794 ctime += (t_slot * cw) >> 1;
795 cw = min((cw << 1) | 1, mp->cw_max);
796
a0497f9f
FF		 797 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
798 overhead = mi->overhead;
799 overhead_rtscts = mi->overhead_rtscts;
800 }
801
8fddddff 802 /* Total TX time for data and Contention after first 2 tries */
a0497f9f
FF		 803 tx_time = ctime + 2 * (overhead + tx_time_data);
804 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
8fddddff
DH		 805
806 /* See how many more tries we can fit inside segment size */
ec8aa669 807 do {
8fddddff
DH		 808 /* Contention time for this try */
809 ctime = (t_slot * cw) >> 1;
810 cw = min((cw << 1) | 1, mp->cw_max);
811
812 /* Total TX time after this try */
a0497f9f
FF		 813 tx_time += ctime + overhead + tx_time_data;
814 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
8fddddff 815
ec8aa669
FF		 816 if (tx_time_rtscts < mp->segment_size)
817 mr->retry_count_rtscts++;
818 } while ((tx_time < mp->segment_size) &&
819 (++mr->retry_count < mp->max_retry));
820}
821
822
823static void
824minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
a8566662 825 struct ieee80211_sta_rates *ratetbl, int offset, int index)
ec8aa669
FF		 826{
827 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
828 struct minstrel_rate_stats *mr;
a8566662 829 u8 idx;
3ec373c4 830 u16 flags = group->flags;
ec8aa669
FF		 831
832 mr = minstrel_get_ratestats(mi, index);
833 if (!mr->retry_updated)
834 minstrel_calc_retransmit(mp, mi, index);
835
a8566662
FF		 836 if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) {
837 ratetbl->rate[offset].count = 2;
838 ratetbl->rate[offset].count_rts = 2;
839 ratetbl->rate[offset].count_cts = 2;
840 } else {
841 ratetbl->rate[offset].count = mr->retry_count;
842 ratetbl->rate[offset].count_cts = mr->retry_count;
843 ratetbl->rate[offset].count_rts = mr->retry_count_rtscts;
844 }
a0497f9f 845
3ec373c4 846 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
a8566662 847 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
9208247d
KB		 848 else if (flags & IEEE80211_TX_RC_VHT_MCS)
849 idx = ((group->streams - 1) << 4) |
850 ((index % MCS_GROUP_RATES) & 0xF);
3ec373c4 851 else
7a5e3fa2 852 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
a8566662
FF		 853
854 if (offset > 0) {
855 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
856 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
857 }
858
859 ratetbl->rate[offset].idx = idx;
860 ratetbl->rate[offset].flags = flags;
861}
862
863static void
864minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
865{
866 struct ieee80211_sta_rates *rates;
867 int i = 0;
868
869 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
870 if (!rates)
a0497f9f 871 return;
a8566662 872
5935839a
TH		 873 /* Start with max_tp_rate[0] */
874 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
a8566662
FF		 875
876 if (mp->hw->max_rates >= 3) {
5935839a
TH		 877 /* At least 3 tx rates supported, use max_tp_rate[1] next */
878 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
a8566662
FF		 879 }
880
881 if (mp->hw->max_rates >= 2) {
882 /*
883 * At least 2 tx rates supported, use max_prob_rate next */
884 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
a0497f9f
FF		 885 }
886
a8566662
FF		 887 rates->rate[i].idx = -1;
888 rate_control_set_rates(mp->hw, mi->sta, rates);
ec8aa669
FF		 889}
890
891static inline int
892minstrel_get_duration(int index)
893{
894 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
895 return group->duration[index % MCS_GROUP_RATES];
896}
897
898static int
899minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
900{
901 struct minstrel_rate_stats *mr;
902 struct minstrel_mcs_group_data *mg;
5935839a 903 unsigned int sample_dur, sample_group, cur_max_tp_streams;
ec8aa669
FF		 904 int sample_idx = 0;
905
906 if (mi->sample_wait > 0) {
907 mi->sample_wait--;
908 return -1;
909 }
910
911 if (!mi->sample_tries)
912 return -1;
913
f12140c0
KB		 914 sample_group = mi->sample_group;
915 mg = &mi->groups[sample_group];
ec8aa669 916 sample_idx = sample_table[mg->column][mg->index];
f12140c0
KB		 917 minstrel_next_sample_idx(mi);
918
919 if (!(mg->supported & BIT(sample_idx)))
920 return -1;
921
ec8aa669 922 mr = &mg->rates[sample_idx];
965237ab 923 sample_idx += sample_group * MCS_GROUP_RATES;
ec8aa669 924
ba6fa29c
HS		 925 /*
926 * Sampling might add some overhead (RTS, no aggregation)
927 * to the frame. Hence, don't use sampling for the currently
a0ca796c 928 * used rates.
ba6fa29c 929 */
5935839a
TH		 930 if (sample_idx == mi->max_tp_rate[0] ||
931 sample_idx == mi->max_tp_rate[1] ||
a0ca796c 932 sample_idx == mi->max_prob_rate)
ba6fa29c 933 return -1;
a0ca796c 934
ec8aa669 935 /*
bc96f242
FF		 936 * Do not sample if the probability is already higher than 95%
937 * to avoid wasting airtime.
ec8aa669 938 */
bc96f242 939 if (mr->probability > MINSTREL_FRAC(95, 100))
8d5eab5a 940 return -1;
ec8aa669
FF		 941
942 /*
943 * Make sure that lower rates get sampled only occasionally,
944 * if the link is working perfectly.
945 */
5935839a
TH		 946
947 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
948 MCS_GROUP_RATES].streams;
965237ab 949 sample_dur = minstrel_get_duration(sample_idx);
5935839a
TH		 950 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) &&
951 (cur_max_tp_streams - 1 <
965237ab
FF		 952 minstrel_mcs_groups[sample_group].streams ||
953 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
c7317e41 954 if (mr->sample_skipped < 20)
8d5eab5a 955 return -1;
ec8aa669
FF		 956
957 if (mi->sample_slow++ > 2)
8d5eab5a 958 return -1;
ec8aa669 959 }
098b8afb 960 mi->sample_tries--;
ec8aa669
FF		 961
962 return sample_idx;
ec8aa669
FF		 963}
964
a0497f9f
FF		 965static void
966minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp,
967 struct minstrel_ht_sta *mi, bool val)
968{
969 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported;
970
971 if (!supported || !mi->cck_supported_short)
972 return;
973
974 if (supported & (mi->cck_supported_short << (val * 4)))
975 return;
976
977 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4);
978 mi->groups[MINSTREL_CCK_GROUP].supported = supported;
979}
980
ec8aa669
FF		 981static void
982minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
983 struct ieee80211_tx_rate_control *txrc)
984{
a8566662 985 const struct mcs_group *sample_group;
ec8aa669 986 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
a8566662 987 struct ieee80211_tx_rate *rate = &info->status.rates[0];
ec8aa669
FF		 988 struct minstrel_ht_sta_priv *msp = priv_sta;
989 struct minstrel_ht_sta *mi = &msp->ht;
990 struct minstrel_priv *mp = priv;
991 int sample_idx;
992
993 if (rate_control_send_low(sta, priv_sta, txrc))
994 return;
995
996 if (!msp->is_ht)
997 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
998
95943425
FF		 999 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1000 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1001 minstrel_aggr_check(sta, txrc->skb);
1002
ec8aa669 1003 info->flags |= mi->tx_flags;
a0497f9f 1004 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble);
6de062ce 1005
37feb7e2
LB		 1006#ifdef CONFIG_MAC80211_DEBUGFS
1007 if (mp->fixed_rate_idx != -1)
1008 return;
1009#endif
1010
6de062ce
HS		 1011 /* Don't use EAPOL frames for sampling on non-mrr hw */
1012 if (mp->hw->max_rates == 1 &&
af61a165 1013 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
6de062ce
HS		 1014 sample_idx = -1;
1015 else
1016 sample_idx = minstrel_get_sample_rate(mp, mi);
24f7580e 1017
ec8aa669
FF		 1018 mi->total_packets++;
1019
1020 /* wraparound */
1021 if (mi->total_packets == ~0) {
1022 mi->total_packets = 0;
1023 mi->sample_packets = 0;
1024 }
a8566662
FF		 1025
1026 if (sample_idx < 0)
1027 return;
1028
1029 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1030 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1cd15857
FF		 1031 rate->count = 1;
1032
1033 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) {
1034 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1035 rate->idx = mp->cck_rates[idx];
9208247d
KB		 1036 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1037 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1038 sample_group->streams);
3ec373c4
KB		 1039 } else {
1040 rate->idx = sample_idx % MCS_GROUP_RATES +
1041 (sample_group->streams - 1) * 8;
1cd15857
FF		 1042 }
1043
3ec373c4 1044 rate->flags = sample_group->flags;
ec8aa669
FF		 1045}
1046
a0497f9f
FF		 1047static void
1048minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1049 struct ieee80211_supported_band *sband,
1050 struct ieee80211_sta *sta)
1051{
1052 int i;
1053
1054 if (sband->band != IEEE80211_BAND_2GHZ)
1055 return;
1056
2dfca312
FF		 1057 if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES))
1058 return;
1059
a0497f9f
FF		 1060 mi->cck_supported = 0;
1061 mi->cck_supported_short = 0;
1062 for (i = 0; i < 4; i++) {
1063 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1064 continue;
1065
1066 mi->cck_supported |= BIT(i);
1067 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1068 mi->cck_supported_short |= BIT(i);
1069 }
1070
1071 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported;
1072}
1073
ec8aa669
FF		 1074static void
1075minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
3de805cf 1076 struct cfg80211_chan_def *chandef,
64f68e5d 1077 struct ieee80211_sta *sta, void *priv_sta)
ec8aa669
FF		 1078{
1079 struct minstrel_priv *mp = priv;
1080 struct minstrel_ht_sta_priv *msp = priv_sta;
1081 struct minstrel_ht_sta *mi = &msp->ht;
1082 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
ec8aa669 1083 u16 sta_cap = sta->ht_cap.cap;
9208247d
KB		 1084 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1085 int use_vht;
4dc217df 1086 int n_supported = 0;
ec8aa669
FF		 1087 int ack_dur;
1088 int stbc;
1089 int i;
1090
1091 /* fall back to the old minstrel for legacy stations */
4dc217df
FF		 1092 if (!sta->ht_cap.ht_supported)
1093 goto use_legacy;
ec8aa669 1094
8a0ee4fe 1095 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
ec8aa669 1096
9208247d
KB		 1097#ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
1098 if (vht_cap->vht_supported)
1099 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1100 else
1101#endif
1102 use_vht = 0;
1103
ec8aa669
FF		 1104 msp->is_ht = true;
1105 memset(mi, 0, sizeof(*mi));
a8566662
FF		 1106
1107 mi->sta = sta;
ec8aa669
FF		 1108 mi->stats_update = jiffies;
1109
438b61b7
SW		 1110 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1111 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1112 mi->overhead += ack_dur;
ec8aa669
FF		 1113 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1114
1115 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1116
1117 /* When using MRR, sample more on the first attempt, without delay */
1118 if (mp->has_mrr) {
1119 mi->sample_count = 16;
1120 mi->sample_wait = 0;
1121 } else {
1122 mi->sample_count = 8;
1123 mi->sample_wait = 8;
1124 }
1125 mi->sample_tries = 4;
1126
9208247d
KB		 1127 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */
1128 if (!use_vht) {
1129 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
1130 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1131 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
ec8aa669 1132
9208247d
KB		 1133 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
1134 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1135 }
ec8aa669 1136
ec8aa669 1137 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
3ec373c4 1138 u32 gflags = minstrel_mcs_groups[i].flags;
9208247d 1139 int bw, nss;
3ec373c4 1140
ec8aa669 1141 mi->groups[i].supported = 0;
a0497f9f
FF		 1142 if (i == MINSTREL_CCK_GROUP) {
1143 minstrel_ht_update_cck(mp, mi, sband, sta);
1144 continue;
1145 }
1146
3ec373c4
KB		 1147 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1148 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
e1a0c6b3
JB		 1149 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40))
1150 continue;
1151 } else {
1152 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20))
1153 continue;
1154 }
ec8aa669
FF		 1155 }
1156
3ec373c4 1157 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
e1a0c6b3 1158 sta->bandwidth < IEEE80211_STA_RX_BW_40)
ec8aa669
FF		 1159 continue;
1160
9208247d
KB		 1161 nss = minstrel_mcs_groups[i].streams;
1162
e9219779 1163 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
9208247d
KB		 1164 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1165 continue;
1166
1167 /* HT rate */
1168 if (gflags & IEEE80211_TX_RC_MCS) {
1169#ifdef CONFIG_MAC80211_RC_MINSTREL_VHT
9ffe9044 1170 if (use_vht && minstrel_vht_only)
9208247d
KB		 1171 continue;
1172#endif
1173 mi->groups[i].supported = mcs->rx_mask[nss - 1];
1174 if (mi->groups[i].supported)
1175 n_supported++;
1176 continue;
1177 }
1178
1179 /* VHT rate */
1180 if (!vht_cap->vht_supported ||
1181 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1182 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
e9219779
HS		 1183 continue;
1184
9208247d
KB		 1185 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1186 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1187 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1188 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1189 continue;
1190 }
1191 }
1192
1193 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1194 bw = BW_40;
1195 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1196 bw = BW_80;
1197 else
1198 bw = BW_20;
1199
1200 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss,
1201 vht_cap->vht_mcs.tx_mcs_map);
4dc217df
FF		 1202
1203 if (mi->groups[i].supported)
1204 n_supported++;
ec8aa669 1205 }
4dc217df
FF		 1206
1207 if (!n_supported)
1208 goto use_legacy;
1209
a8566662 1210 /* create an initial rate table with the lowest supported rates */
a3647362 1211 minstrel_ht_update_stats(mp, mi);
a8566662 1212 minstrel_ht_update_rates(mp, mi);
a3647362 1213
4dc217df
FF		 1214 return;
1215
1216use_legacy:
1217 msp->is_ht = false;
1218 memset(&msp->legacy, 0, sizeof(msp->legacy));
1219 msp->legacy.r = msp->ratelist;
1220 msp->legacy.sample_table = msp->sample_table;
3de805cf
SW		 1221 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1222 &msp->legacy);
ec8aa669
FF		 1223}
1224
1225static void
1226minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
3de805cf 1227 struct cfg80211_chan_def *chandef,
ec8aa669
FF		 1228 struct ieee80211_sta *sta, void *priv_sta)
1229{
3de805cf 1230 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
ec8aa669
FF		 1231}
1232
1233static void
1234minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
3de805cf 1235 struct cfg80211_chan_def *chandef,
ec8aa669 1236 struct ieee80211_sta *sta, void *priv_sta,
64f68e5d 1237 u32 changed)
ec8aa669 1238{
3de805cf 1239 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
ec8aa669
FF		 1240}
1241
1242static void *
1243minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1244{
1245 struct ieee80211_supported_band *sband;
1246 struct minstrel_ht_sta_priv *msp;
1247 struct minstrel_priv *mp = priv;
1248 struct ieee80211_hw *hw = mp->hw;
1249 int max_rates = 0;
1250 int i;
1251
1252 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
1253 sband = hw->wiphy->bands[i];
1254 if (sband && sband->n_bitrates > max_rates)
1255 max_rates = sband->n_bitrates;
1256 }
1257
472dd35c 1258 msp = kzalloc(sizeof(*msp), gfp);
ec8aa669
FF		 1259 if (!msp)
1260 return NULL;
1261
1262 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
1263 if (!msp->ratelist)
1264 goto error;
1265
1266 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
1267 if (!msp->sample_table)
1268 goto error1;
1269
1270 return msp;
1271
1272error1:
7e988014 1273 kfree(msp->ratelist);
ec8aa669
FF		 1274error:
1275 kfree(msp);
1276 return NULL;
1277}
1278
1279static void
1280minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1281{
1282 struct minstrel_ht_sta_priv *msp = priv_sta;
1283
1284 kfree(msp->sample_table);
1285 kfree(msp->ratelist);
1286 kfree(msp);
1287}
1288
1289static void *
1290minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1291{
1292 return mac80211_minstrel.alloc(hw, debugfsdir);
1293}
1294
1295static void
1296minstrel_ht_free(void *priv)
1297{
1298 mac80211_minstrel.free(priv);
1299}
1300
cca674d4
AQ		 1301static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1302{
1303 struct minstrel_ht_sta_priv *msp = priv_sta;
1304 struct minstrel_ht_sta *mi = &msp->ht;
1305 int i, j;
1306
1307 if (!msp->is_ht)
1308 return mac80211_minstrel.get_expected_throughput(priv_sta);
1309
5935839a
TH		 1310 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1311 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
cca674d4
AQ		 1312
1313 /* convert cur_tp from pkt per second in kbps */
1314 return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024;
1315}
1316
631ad703 1317static const struct rate_control_ops mac80211_minstrel_ht = {
ec8aa669 1318 .name = "minstrel_ht",
63558a65 1319 .tx_status_noskb = minstrel_ht_tx_status,
ec8aa669
FF		 1320 .get_rate = minstrel_ht_get_rate,
1321 .rate_init = minstrel_ht_rate_init,
1322 .rate_update = minstrel_ht_rate_update,
1323 .alloc_sta = minstrel_ht_alloc_sta,
1324 .free_sta = minstrel_ht_free_sta,
1325 .alloc = minstrel_ht_alloc,
1326 .free = minstrel_ht_free,
1327#ifdef CONFIG_MAC80211_DEBUGFS
1328 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1329 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
1330#endif
cca674d4 1331 .get_expected_throughput = minstrel_ht_get_expected_throughput,
ec8aa669
FF		 1332};
1333
1334
f6e1a73b 1335static void __init init_sample_table(void)
ec8aa669
FF		 1336{
1337 int col, i, new_idx;
1338 u8 rnd[MCS_GROUP_RATES];
1339
1340 memset(sample_table, 0xff, sizeof(sample_table));
1341 for (col = 0; col < SAMPLE_COLUMNS; col++) {
f7d8ad81 1342 prandom_bytes(rnd, sizeof(rnd));
ec8aa669 1343 for (i = 0; i < MCS_GROUP_RATES; i++) {
ec8aa669 1344 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
ec8aa669
FF		 1345 while (sample_table[col][new_idx] != 0xff)
1346 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1347
1348 sample_table[col][new_idx] = i;
1349 }
1350 }
1351}
1352
1353int __init
1354rc80211_minstrel_ht_init(void)
1355{
1356 init_sample_table();
1357 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1358}
1359
1360void
1361rc80211_minstrel_ht_exit(void)
1362{
1363 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1364}
Linux kernel - Deliverables
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