1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2019-2022 Intel Corporation
5 */
6 #include <linux/netdevice.h>
7 #include <linux/types.h>
8 #include <linux/skbuff.h>
9 #include <linux/debugfs.h>
10 #include <linux/random.h>
11 #include <linux/moduleparam.h>
12 #include <linux/ieee80211.h>
13 #include <linux/minmax.h>
14 #include <net/mac80211.h>
15 #include "rate.h"
16 #include "sta_info.h"
17 #include "rc80211_minstrel_ht.h"
18
19 #define AVG_AMPDU_SIZE 16
20 #define AVG_PKT_SIZE 1200
21
22 /* Number of bits for an average sized packet */
23 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
24
25 /* Number of symbols for a packet with (bps) bits per symbol */
26 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
27
28 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
29 #define MCS_SYMBOL_TIME(sgi, syms) \
30 (sgi ? \
31 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
32 ((syms) * 1000) << 2 /* syms * 4 us */ \
33 )
34
35 /* Transmit duration for the raw data part of an average sized packet */
36 #define MCS_DURATION(streams, sgi, bps) \
37 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
38
39 #define BW_20 0
40 #define BW_40 1
41 #define BW_80 2
42
43 /*
44 * Define group sort order: HT40 -> SGI -> #streams
45 */
46 #define GROUP_IDX(_streams, _sgi, _ht40) \
47 MINSTREL_HT_GROUP_0 + \
48 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
49 MINSTREL_MAX_STREAMS * _sgi + \
50 _streams - 1
51
52 #define _MAX(a, b) (((a)>(b))?(a):(b))
53
54 #define GROUP_SHIFT(duration) \
55 _MAX(0, 16 - __builtin_clz(duration))
56
57 /* MCS rate information for an MCS group */
58 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
59 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
60 .streams = _streams, \
61 .shift = _s, \
62 .bw = _ht40, \
63 .flags = \
64 IEEE80211_TX_RC_MCS | \
65 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
66 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
67 .duration = { \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
72 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
73 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
74 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
75 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
76 } \
77 }
78
79 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
80 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
81
82 #define MCS_GROUP(_streams, _sgi, _ht40) \
83 __MCS_GROUP(_streams, _sgi, _ht40, \
84 MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
85
86 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
87 (MINSTREL_VHT_GROUP_0 + \
88 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
89 MINSTREL_MAX_STREAMS * (_sgi) + \
90 (_streams) - 1)
91
92 #define BW2VBPS(_bw, r3, r2, r1) \
93 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
94
95 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \
96 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
97 .streams = _streams, \
98 .shift = _s, \
99 .bw = _bw, \
100 .flags = \
101 IEEE80211_TX_RC_VHT_MCS | \
102 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
103 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
104 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
105 .duration = { \
106 MCS_DURATION(_streams, _sgi, \
107 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
112 MCS_DURATION(_streams, _sgi, \
113 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
114 MCS_DURATION(_streams, _sgi, \
115 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
116 MCS_DURATION(_streams, _sgi, \
117 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
118 MCS_DURATION(_streams, _sgi, \
119 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
120 MCS_DURATION(_streams, _sgi, \
121 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
122 MCS_DURATION(_streams, _sgi, \
123 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
124 MCS_DURATION(_streams, _sgi, \
125 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
126 } \
127 }
128
129 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
130 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
131 BW2VBPS(_bw, 117, 54, 26)))
132
133 #define VHT_GROUP(_streams, _sgi, _bw) \
134 __VHT_GROUP(_streams, _sgi, _bw, \
135 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
136
137 #define CCK_DURATION(_bitrate, _short) \
138 (1000 * (10 /* SIFS */ + \
139 (_short ? 72 + 24 : 144 + 48) + \
140 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
141
142 #define CCK_DURATION_LIST(_short, _s) \
143 CCK_DURATION(10, _short) >> _s, \
144 CCK_DURATION(20, _short) >> _s, \
145 CCK_DURATION(55, _short) >> _s, \
146 CCK_DURATION(110, _short) >> _s
147
148 #define __CCK_GROUP(_s) \
149 [MINSTREL_CCK_GROUP] = { \
150 .streams = 1, \
151 .flags = 0, \
152 .shift = _s, \
153 .duration = { \
154 CCK_DURATION_LIST(false, _s), \
155 CCK_DURATION_LIST(true, _s) \
156 } \
157 }
158
159 #define CCK_GROUP_SHIFT \
160 GROUP_SHIFT(CCK_DURATION(10, false))
161
162 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
163
164 #define OFDM_DURATION(_bitrate) \
165 (1000 * (16 /* SIFS + signal ext */ + \
166 16 /* T_PREAMBLE */ + \
167 4 /* T_SIGNAL */ + \
168 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) / \
169 ((_bitrate) * 4)))))
170
171 #define OFDM_DURATION_LIST(_s) \
172 OFDM_DURATION(60) >> _s, \
173 OFDM_DURATION(90) >> _s, \
174 OFDM_DURATION(120) >> _s, \
175 OFDM_DURATION(180) >> _s, \
176 OFDM_DURATION(240) >> _s, \
177 OFDM_DURATION(360) >> _s, \
178 OFDM_DURATION(480) >> _s, \
179 OFDM_DURATION(540) >> _s
180
181 #define __OFDM_GROUP(_s) \
182 [MINSTREL_OFDM_GROUP] = { \
183 .streams = 1, \
184 .flags = 0, \
185 .shift = _s, \
186 .duration = { \
187 OFDM_DURATION_LIST(_s), \
188 } \
189 }
190
191 #define OFDM_GROUP_SHIFT \
192 GROUP_SHIFT(OFDM_DURATION(60))
193
194 #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
195
196
197 static bool minstrel_vht_only = true;
198 module_param(minstrel_vht_only, bool, 0644);
199 MODULE_PARM_DESC(minstrel_vht_only,
200 "Use only VHT rates when VHT is supported by sta.");
201
202 /*
203 * To enable sufficiently targeted rate sampling, MCS rates are divided into
204 * groups, based on the number of streams and flags (HT40, SGI) that they
205 * use.
206 *
207 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
208 * BW -> SGI -> #streams
209 */
210 const struct mcs_group minstrel_mcs_groups[] = {
211 MCS_GROUP(1, 0, BW_20),
212 MCS_GROUP(2, 0, BW_20),
213 MCS_GROUP(3, 0, BW_20),
214 MCS_GROUP(4, 0, BW_20),
215
216 MCS_GROUP(1, 1, BW_20),
217 MCS_GROUP(2, 1, BW_20),
218 MCS_GROUP(3, 1, BW_20),
219 MCS_GROUP(4, 1, BW_20),
220
221 MCS_GROUP(1, 0, BW_40),
222 MCS_GROUP(2, 0, BW_40),
223 MCS_GROUP(3, 0, BW_40),
224 MCS_GROUP(4, 0, BW_40),
225
226 MCS_GROUP(1, 1, BW_40),
227 MCS_GROUP(2, 1, BW_40),
228 MCS_GROUP(3, 1, BW_40),
229 MCS_GROUP(4, 1, BW_40),
230
231 CCK_GROUP,
232 OFDM_GROUP,
233
234 VHT_GROUP(1, 0, BW_20),
235 VHT_GROUP(2, 0, BW_20),
236 VHT_GROUP(3, 0, BW_20),
237 VHT_GROUP(4, 0, BW_20),
238
239 VHT_GROUP(1, 1, BW_20),
240 VHT_GROUP(2, 1, BW_20),
241 VHT_GROUP(3, 1, BW_20),
242 VHT_GROUP(4, 1, BW_20),
243
244 VHT_GROUP(1, 0, BW_40),
245 VHT_GROUP(2, 0, BW_40),
246 VHT_GROUP(3, 0, BW_40),
247 VHT_GROUP(4, 0, BW_40),
248
249 VHT_GROUP(1, 1, BW_40),
250 VHT_GROUP(2, 1, BW_40),
251 VHT_GROUP(3, 1, BW_40),
252 VHT_GROUP(4, 1, BW_40),
253
254 VHT_GROUP(1, 0, BW_80),
255 VHT_GROUP(2, 0, BW_80),
256 VHT_GROUP(3, 0, BW_80),
257 VHT_GROUP(4, 0, BW_80),
258
259 VHT_GROUP(1, 1, BW_80),
260 VHT_GROUP(2, 1, BW_80),
261 VHT_GROUP(3, 1, BW_80),
262 VHT_GROUP(4, 1, BW_80),
263 };
264
265 const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
266 const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
267 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
268 static const u8 minstrel_sample_seq[] = {
269 MINSTREL_SAMPLE_TYPE_INC,
270 MINSTREL_SAMPLE_TYPE_JUMP,
271 MINSTREL_SAMPLE_TYPE_INC,
272 MINSTREL_SAMPLE_TYPE_JUMP,
273 MINSTREL_SAMPLE_TYPE_INC,
274 MINSTREL_SAMPLE_TYPE_SLOW,
275 };
276
277 static void
278 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
279
280 /*
281 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
282 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
283 *
284 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
285 */
286 static u16
minstrel_get_valid_vht_rates(int bw,int nss,__le16 mcs_map)287 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
288 {
289 u16 mask = 0;
290
291 if (bw == BW_20) {
292 if (nss != 3 && nss != 6)
293 mask = BIT(9);
294 } else if (bw == BW_80) {
295 if (nss == 3 || nss == 7)
296 mask = BIT(6);
297 else if (nss == 6)
298 mask = BIT(9);
299 } else {
300 WARN_ON(bw != BW_40);
301 }
302
303 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
304 case IEEE80211_VHT_MCS_SUPPORT_0_7:
305 mask |= 0x300;
306 break;
307 case IEEE80211_VHT_MCS_SUPPORT_0_8:
308 mask |= 0x200;
309 break;
310 case IEEE80211_VHT_MCS_SUPPORT_0_9:
311 break;
312 default:
313 mask = 0x3ff;
314 }
315
316 return 0x3ff & ~mask;
317 }
318
319 static bool
minstrel_ht_is_legacy_group(int group)320 minstrel_ht_is_legacy_group(int group)
321 {
322 return group == MINSTREL_CCK_GROUP ||
323 group == MINSTREL_OFDM_GROUP;
324 }
325
326 /*
327 * Look up an MCS group index based on mac80211 rate information
328 */
329 static int
minstrel_ht_get_group_idx(struct ieee80211_tx_rate * rate)330 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
331 {
332 return GROUP_IDX((rate->idx / 8) + 1,
333 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
334 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
335 }
336
337 /*
338 * Look up an MCS group index based on new cfg80211 rate_info.
339 */
340 static int
minstrel_ht_ri_get_group_idx(struct rate_info * rate)341 minstrel_ht_ri_get_group_idx(struct rate_info *rate)
342 {
343 return GROUP_IDX((rate->mcs / 8) + 1,
344 !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
345 !!(rate->bw & RATE_INFO_BW_40));
346 }
347
348 static int
minstrel_vht_get_group_idx(struct ieee80211_tx_rate * rate)349 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
350 {
351 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
352 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
353 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
354 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
355 }
356
357 /*
358 * Look up an MCS group index based on new cfg80211 rate_info.
359 */
360 static int
minstrel_vht_ri_get_group_idx(struct rate_info * rate)361 minstrel_vht_ri_get_group_idx(struct rate_info *rate)
362 {
363 return VHT_GROUP_IDX(rate->nss,
364 !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
365 !!(rate->bw & RATE_INFO_BW_40) +
366 2*!!(rate->bw & RATE_INFO_BW_80));
367 }
368
369 static struct minstrel_rate_stats *
minstrel_ht_get_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_tx_rate * rate)370 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
371 struct ieee80211_tx_rate *rate)
372 {
373 int group, idx;
374
375 if (rate->flags & IEEE80211_TX_RC_MCS) {
376 group = minstrel_ht_get_group_idx(rate);
377 idx = rate->idx % 8;
378 goto out;
379 }
380
381 if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
382 group = minstrel_vht_get_group_idx(rate);
383 idx = ieee80211_rate_get_vht_mcs(rate);
384 goto out;
385 }
386
387 group = MINSTREL_CCK_GROUP;
388 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
389 if (!(mi->supported[group] & BIT(idx)))
390 continue;
391
392 if (rate->idx != mp->cck_rates[idx])
393 continue;
394
395 /* short preamble */
396 if ((mi->supported[group] & BIT(idx + 4)) &&
397 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
398 idx += 4;
399 goto out;
400 }
401
402 group = MINSTREL_OFDM_GROUP;
403 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
404 if (rate->idx == mp->ofdm_rates[mi->band][idx])
405 goto out;
406
407 idx = 0;
408 out:
409 return &mi->groups[group].rates[idx];
410 }
411
412 /*
413 * Get the minstrel rate statistics for specified STA and rate info.
414 */
415 static struct minstrel_rate_stats *
minstrel_ht_ri_get_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_rate_status * rate_status)416 minstrel_ht_ri_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
417 struct ieee80211_rate_status *rate_status)
418 {
419 int group, idx;
420 struct rate_info *rate = &rate_status->rate_idx;
421
422 if (rate->flags & RATE_INFO_FLAGS_MCS) {
423 group = minstrel_ht_ri_get_group_idx(rate);
424 idx = rate->mcs % 8;
425 goto out;
426 }
427
428 if (rate->flags & RATE_INFO_FLAGS_VHT_MCS) {
429 group = minstrel_vht_ri_get_group_idx(rate);
430 idx = rate->mcs;
431 goto out;
432 }
433
434 group = MINSTREL_CCK_GROUP;
435 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
436 if (rate->legacy != minstrel_cck_bitrates[ mp->cck_rates[idx] ])
437 continue;
438
439 /* short preamble */
440 if ((mi->supported[group] & BIT(idx + 4)) &&
441 mi->use_short_preamble)
442 idx += 4;
443 goto out;
444 }
445
446 group = MINSTREL_OFDM_GROUP;
447 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
448 if (rate->legacy == minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][idx] ])
449 goto out;
450
451 idx = 0;
452 out:
453 return &mi->groups[group].rates[idx];
454 }
455
456 static inline struct minstrel_rate_stats *
minstrel_get_ratestats(struct minstrel_ht_sta * mi,int index)457 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
458 {
459 return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
460 }
461
minstrel_get_duration(int index)462 static inline int minstrel_get_duration(int index)
463 {
464 const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
465 unsigned int duration = group->duration[MI_RATE_IDX(index)];
466
467 return duration << group->shift;
468 }
469
470 static unsigned int
minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta * mi)471 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
472 {
473 int duration;
474
475 if (mi->avg_ampdu_len)
476 return MINSTREL_TRUNC(mi->avg_ampdu_len);
477
478 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
479 return 1;
480
481 duration = minstrel_get_duration(mi->max_tp_rate[0]);
482
483 if (duration > 400 * 1000)
484 return 2;
485
486 if (duration > 250 * 1000)
487 return 4;
488
489 if (duration > 150 * 1000)
490 return 8;
491
492 return 16;
493 }
494
495 /*
496 * Return current throughput based on the average A-MPDU length, taking into
497 * account the expected number of retransmissions and their expected length
498 */
499 int
minstrel_ht_get_tp_avg(struct minstrel_ht_sta * mi,int group,int rate,int prob_avg)500 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
501 int prob_avg)
502 {
503 unsigned int nsecs = 0, overhead = mi->overhead;
504 unsigned int ampdu_len = 1;
505
506 /* do not account throughput if success prob is below 10% */
507 if (prob_avg < MINSTREL_FRAC(10, 100))
508 return 0;
509
510 if (minstrel_ht_is_legacy_group(group))
511 overhead = mi->overhead_legacy;
512 else
513 ampdu_len = minstrel_ht_avg_ampdu_len(mi);
514
515 nsecs = 1000 * overhead / ampdu_len;
516 nsecs += minstrel_mcs_groups[group].duration[rate] <<
517 minstrel_mcs_groups[group].shift;
518
519 /*
520 * For the throughput calculation, limit the probability value to 90% to
521 * account for collision related packet error rate fluctuation
522 * (prob is scaled - see MINSTREL_FRAC above)
523 */
524 if (prob_avg > MINSTREL_FRAC(90, 100))
525 prob_avg = MINSTREL_FRAC(90, 100);
526
527 return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
528 }
529
530 /*
531 * Find & sort topmost throughput rates
532 *
533 * If multiple rates provide equal throughput the sorting is based on their
534 * current success probability. Higher success probability is preferred among
535 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
536 */
537 static void
minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta * mi,u16 index,u16 * tp_list)538 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
539 u16 *tp_list)
540 {
541 int cur_group, cur_idx, cur_tp_avg, cur_prob;
542 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
543 int j = MAX_THR_RATES;
544
545 cur_group = MI_RATE_GROUP(index);
546 cur_idx = MI_RATE_IDX(index);
547 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
548 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
549
550 do {
551 tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
552 tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
553 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
554 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
555 tmp_prob);
556 if (cur_tp_avg < tmp_tp_avg ||
557 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
558 break;
559 j--;
560 } while (j > 0);
561
562 if (j < MAX_THR_RATES - 1) {
563 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
564 (MAX_THR_RATES - (j + 1))));
565 }
566 if (j < MAX_THR_RATES)
567 tp_list[j] = index;
568 }
569
570 /*
571 * Find and set the topmost probability rate per sta and per group
572 */
573 static void
minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta * mi,u16 * dest,u16 index)574 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
575 {
576 struct minstrel_mcs_group_data *mg;
577 struct minstrel_rate_stats *mrs;
578 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
579 int max_tp_group, max_tp_idx, max_tp_prob;
580 int cur_tp_avg, cur_group, cur_idx;
581 int max_gpr_group, max_gpr_idx;
582 int max_gpr_tp_avg, max_gpr_prob;
583
584 cur_group = MI_RATE_GROUP(index);
585 cur_idx = MI_RATE_IDX(index);
586 mg = &mi->groups[cur_group];
587 mrs = &mg->rates[cur_idx];
588
589 tmp_group = MI_RATE_GROUP(*dest);
590 tmp_idx = MI_RATE_IDX(*dest);
591 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
592 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
593
594 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
595 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
596 max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
597 max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
598 max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
599
600 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
601 !minstrel_ht_is_legacy_group(max_tp_group))
602 return;
603
604 /* skip rates faster than max tp rate with lower prob */
605 if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
606 mrs->prob_avg < max_tp_prob)
607 return;
608
609 max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
610 max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
611 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
612
613 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
614 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
615 mrs->prob_avg);
616 if (cur_tp_avg > tmp_tp_avg)
617 *dest = index;
618
619 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
620 max_gpr_idx,
621 max_gpr_prob);
622 if (cur_tp_avg > max_gpr_tp_avg)
623 mg->max_group_prob_rate = index;
624 } else {
625 if (mrs->prob_avg > tmp_prob)
626 *dest = index;
627 if (mrs->prob_avg > max_gpr_prob)
628 mg->max_group_prob_rate = index;
629 }
630 }
631
632
633 /*
634 * Assign new rate set per sta and use CCK rates only if the fastest
635 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
636 * rate sets where MCS and CCK rates are mixed, because CCK rates can
637 * not use aggregation.
638 */
639 static void
minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta * mi,u16 tmp_mcs_tp_rate[MAX_THR_RATES],u16 tmp_legacy_tp_rate[MAX_THR_RATES])640 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
641 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
642 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
643 {
644 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
645 int i;
646
647 tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
648 tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
649 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
650 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
651
652 tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
653 tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
654 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
655 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
656
657 if (tmp_cck_tp > tmp_mcs_tp) {
658 for(i = 0; i < MAX_THR_RATES; i++) {
659 minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
660 tmp_mcs_tp_rate);
661 }
662 }
663
664 }
665
666 /*
667 * Try to increase robustness of max_prob rate by decrease number of
668 * streams if possible.
669 */
670 static inline void
minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta * mi)671 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
672 {
673 struct minstrel_mcs_group_data *mg;
674 int tmp_max_streams, group, tmp_idx, tmp_prob;
675 int tmp_tp = 0;
676
677 if (!mi->sta->deflink.ht_cap.ht_supported)
678 return;
679
680 group = MI_RATE_GROUP(mi->max_tp_rate[0]);
681 tmp_max_streams = minstrel_mcs_groups[group].streams;
682 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
683 mg = &mi->groups[group];
684 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
685 continue;
686
687 tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
688 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
689
690 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
691 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
692 mi->max_prob_rate = mg->max_group_prob_rate;
693 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
694 tmp_idx,
695 tmp_prob);
696 }
697 }
698 }
699
700 static u16
__minstrel_ht_get_sample_rate(struct minstrel_ht_sta * mi,enum minstrel_sample_type type)701 __minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
702 enum minstrel_sample_type type)
703 {
704 u16 *rates = mi->sample[type].sample_rates;
705 u16 cur;
706 int i;
707
708 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
709 if (!rates[i])
710 continue;
711
712 cur = rates[i];
713 rates[i] = 0;
714 return cur;
715 }
716
717 return 0;
718 }
719
720 static inline int
minstrel_ewma(int old,int new,int weight)721 minstrel_ewma(int old, int new, int weight)
722 {
723 int diff, incr;
724
725 diff = new - old;
726 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
727
728 return old + incr;
729 }
730
minstrel_filter_avg_add(u16 * prev_1,u16 * prev_2,s32 in)731 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
732 {
733 s32 out_1 = *prev_1;
734 s32 out_2 = *prev_2;
735 s32 val;
736
737 if (!in)
738 in += 1;
739
740 if (!out_1) {
741 val = out_1 = in;
742 goto out;
743 }
744
745 val = MINSTREL_AVG_COEFF1 * in;
746 val += MINSTREL_AVG_COEFF2 * out_1;
747 val += MINSTREL_AVG_COEFF3 * out_2;
748 val >>= MINSTREL_SCALE;
749
750 if (val > 1 << MINSTREL_SCALE)
751 val = 1 << MINSTREL_SCALE;
752 if (val < 0)
753 val = 1;
754
755 out:
756 *prev_2 = out_1;
757 *prev_1 = val;
758
759 return val;
760 }
761
762 /*
763 * Recalculate statistics and counters of a given rate
764 */
765 static void
minstrel_ht_calc_rate_stats(struct minstrel_priv * mp,struct minstrel_rate_stats * mrs)766 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
767 struct minstrel_rate_stats *mrs)
768 {
769 unsigned int cur_prob;
770
771 if (unlikely(mrs->attempts > 0)) {
772 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
773 minstrel_filter_avg_add(&mrs->prob_avg,
774 &mrs->prob_avg_1, cur_prob);
775 mrs->att_hist += mrs->attempts;
776 mrs->succ_hist += mrs->success;
777 }
778
779 mrs->last_success = mrs->success;
780 mrs->last_attempts = mrs->attempts;
781 mrs->success = 0;
782 mrs->attempts = 0;
783 }
784
785 static bool
minstrel_ht_find_sample_rate(struct minstrel_ht_sta * mi,int type,int idx)786 minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
787 {
788 int i;
789
790 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
791 u16 cur = mi->sample[type].sample_rates[i];
792
793 if (cur == idx)
794 return true;
795
796 if (!cur)
797 break;
798 }
799
800 return false;
801 }
802
803 static int
minstrel_ht_move_sample_rates(struct minstrel_ht_sta * mi,int type,u32 fast_rate_dur,u32 slow_rate_dur)804 minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
805 u32 fast_rate_dur, u32 slow_rate_dur)
806 {
807 u16 *rates = mi->sample[type].sample_rates;
808 int i, j;
809
810 for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
811 u32 duration;
812 bool valid = false;
813 u16 cur;
814
815 cur = rates[i];
816 if (!cur)
817 continue;
818
819 duration = minstrel_get_duration(cur);
820 switch (type) {
821 case MINSTREL_SAMPLE_TYPE_SLOW:
822 valid = duration > fast_rate_dur &&
823 duration < slow_rate_dur;
824 break;
825 case MINSTREL_SAMPLE_TYPE_INC:
826 case MINSTREL_SAMPLE_TYPE_JUMP:
827 valid = duration < fast_rate_dur;
828 break;
829 default:
830 valid = false;
831 break;
832 }
833
834 if (!valid) {
835 rates[i] = 0;
836 continue;
837 }
838
839 if (i == j)
840 continue;
841
842 rates[j++] = cur;
843 rates[i] = 0;
844 }
845
846 return j;
847 }
848
849 static int
minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta * mi,int group,u32 max_duration)850 minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
851 u32 max_duration)
852 {
853 u16 supported = mi->supported[group];
854 int i;
855
856 for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
857 if (!(supported & BIT(0)))
858 continue;
859
860 if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
861 continue;
862
863 return i;
864 }
865
866 return -1;
867 }
868
869 /*
870 * Incremental update rates:
871 * Flip through groups and pick the first group rate that is faster than the
872 * highest currently selected rate
873 */
874 static u16
minstrel_ht_next_inc_rate(struct minstrel_ht_sta * mi,u32 fast_rate_dur)875 minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
876 {
877 u8 type = MINSTREL_SAMPLE_TYPE_INC;
878 int i, index = 0;
879 u8 group;
880
881 group = mi->sample[type].sample_group;
882 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
883 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
884
885 index = minstrel_ht_group_min_rate_offset(mi, group,
886 fast_rate_dur);
887 if (index < 0)
888 continue;
889
890 index = MI_RATE(group, index & 0xf);
891 if (!minstrel_ht_find_sample_rate(mi, type, index))
892 goto out;
893 }
894 index = 0;
895
896 out:
897 mi->sample[type].sample_group = group;
898
899 return index;
900 }
901
902 static int
minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta * mi,int group,u16 supported,int offset)903 minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
904 u16 supported, int offset)
905 {
906 struct minstrel_mcs_group_data *mg = &mi->groups[group];
907 u16 idx;
908 int i;
909
910 for (i = 0; i < MCS_GROUP_RATES; i++) {
911 idx = sample_table[mg->column][mg->index];
912 if (++mg->index >= MCS_GROUP_RATES) {
913 mg->index = 0;
914 if (++mg->column >= ARRAY_SIZE(sample_table))
915 mg->column = 0;
916 }
917
918 if (idx < offset)
919 continue;
920
921 if (!(supported & BIT(idx)))
922 continue;
923
924 return MI_RATE(group, idx);
925 }
926
927 return -1;
928 }
929
930 /*
931 * Jump rates:
932 * Sample random rates, use those that are faster than the highest
933 * currently selected rate. Rates between the fastest and the slowest
934 * get sorted into the slow sample bucket, but only if it has room
935 */
936 static u16
minstrel_ht_next_jump_rate(struct minstrel_ht_sta * mi,u32 fast_rate_dur,u32 slow_rate_dur,int * slow_rate_ofs)937 minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
938 u32 slow_rate_dur, int *slow_rate_ofs)
939 {
940 struct minstrel_rate_stats *mrs;
941 u32 max_duration = slow_rate_dur;
942 int i, index, offset;
943 u16 *slow_rates;
944 u16 supported;
945 u32 duration;
946 u8 group;
947
948 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
949 max_duration = fast_rate_dur;
950
951 slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
952 group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
953 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
954 u8 type;
955
956 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
957
958 supported = mi->supported[group];
959 if (!supported)
960 continue;
961
962 offset = minstrel_ht_group_min_rate_offset(mi, group,
963 max_duration);
964 if (offset < 0)
965 continue;
966
967 index = minstrel_ht_next_group_sample_rate(mi, group, supported,
968 offset);
969 if (index < 0)
970 continue;
971
972 duration = minstrel_get_duration(index);
973 if (duration < fast_rate_dur)
974 type = MINSTREL_SAMPLE_TYPE_JUMP;
975 else
976 type = MINSTREL_SAMPLE_TYPE_SLOW;
977
978 if (minstrel_ht_find_sample_rate(mi, type, index))
979 continue;
980
981 if (type == MINSTREL_SAMPLE_TYPE_JUMP)
982 goto found;
983
984 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
985 continue;
986
987 if (duration >= slow_rate_dur)
988 continue;
989
990 /* skip slow rates with high success probability */
991 mrs = minstrel_get_ratestats(mi, index);
992 if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
993 continue;
994
995 slow_rates[(*slow_rate_ofs)++] = index;
996 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
997 max_duration = fast_rate_dur;
998 }
999 index = 0;
1000
1001 found:
1002 mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
1003
1004 return index;
1005 }
1006
1007 static void
minstrel_ht_refill_sample_rates(struct minstrel_ht_sta * mi)1008 minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
1009 {
1010 u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
1011 u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
1012 u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
1013 u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
1014 u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
1015 u16 *rates;
1016 int i, j;
1017
1018 rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
1019 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
1020 fast_rate_dur, slow_rate_dur);
1021 while (i < MINSTREL_SAMPLE_RATES) {
1022 rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
1023 if (!rates[i])
1024 break;
1025
1026 i++;
1027 }
1028
1029 rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
1030 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
1031 fast_rate_dur, slow_rate_dur);
1032 j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
1033 fast_rate_dur, slow_rate_dur);
1034 while (i < MINSTREL_SAMPLE_RATES) {
1035 rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
1036 slow_rate_dur, &j);
1037 if (!rates[i])
1038 break;
1039
1040 i++;
1041 }
1042
1043 for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
1044 memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
1045 sizeof(mi->sample[i].cur_sample_rates));
1046 }
1047
1048
1049 /*
1050 * Update rate statistics and select new primary rates
1051 *
1052 * Rules for rate selection:
1053 * - max_prob_rate must use only one stream, as a tradeoff between delivery
1054 * probability and throughput during strong fluctuations
1055 * - as long as the max prob rate has a probability of more than 75%, pick
1056 * higher throughput rates, even if the probablity is a bit lower
1057 */
1058 static void
minstrel_ht_update_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1059 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1060 {
1061 struct minstrel_mcs_group_data *mg;
1062 struct minstrel_rate_stats *mrs;
1063 int group, i, j, cur_prob;
1064 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
1065 u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
1066 u16 index;
1067 bool ht_supported = mi->sta->deflink.ht_cap.ht_supported;
1068
1069 if (mi->ampdu_packets > 0) {
1070 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1071 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1072 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1073 EWMA_LEVEL);
1074 else
1075 mi->avg_ampdu_len = 0;
1076 mi->ampdu_len = 0;
1077 mi->ampdu_packets = 0;
1078 }
1079
1080 if (mi->supported[MINSTREL_CCK_GROUP])
1081 group = MINSTREL_CCK_GROUP;
1082 else if (mi->supported[MINSTREL_OFDM_GROUP])
1083 group = MINSTREL_OFDM_GROUP;
1084 else
1085 group = 0;
1086
1087 index = MI_RATE(group, 0);
1088 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1089 tmp_legacy_tp_rate[j] = index;
1090
1091 if (mi->supported[MINSTREL_VHT_GROUP_0])
1092 group = MINSTREL_VHT_GROUP_0;
1093 else if (ht_supported)
1094 group = MINSTREL_HT_GROUP_0;
1095 else if (mi->supported[MINSTREL_CCK_GROUP])
1096 group = MINSTREL_CCK_GROUP;
1097 else
1098 group = MINSTREL_OFDM_GROUP;
1099
1100 index = MI_RATE(group, 0);
1101 tmp_max_prob_rate = index;
1102 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1103 tmp_mcs_tp_rate[j] = index;
1104
1105 /* Find best rate sets within all MCS groups*/
1106 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1107 u16 *tp_rate = tmp_mcs_tp_rate;
1108 u16 last_prob = 0;
1109
1110 mg = &mi->groups[group];
1111 if (!mi->supported[group])
1112 continue;
1113
1114 /* (re)Initialize group rate indexes */
1115 for(j = 0; j < MAX_THR_RATES; j++)
1116 tmp_group_tp_rate[j] = MI_RATE(group, 0);
1117
1118 if (group == MINSTREL_CCK_GROUP && ht_supported)
1119 tp_rate = tmp_legacy_tp_rate;
1120
1121 for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1122 if (!(mi->supported[group] & BIT(i)))
1123 continue;
1124
1125 index = MI_RATE(group, i);
1126
1127 mrs = &mg->rates[i];
1128 mrs->retry_updated = false;
1129 minstrel_ht_calc_rate_stats(mp, mrs);
1130
1131 if (mrs->att_hist)
1132 last_prob = max(last_prob, mrs->prob_avg);
1133 else
1134 mrs->prob_avg = max(last_prob, mrs->prob_avg);
1135 cur_prob = mrs->prob_avg;
1136
1137 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1138 continue;
1139
1140 /* Find max throughput rate set */
1141 minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
1142
1143 /* Find max throughput rate set within a group */
1144 minstrel_ht_sort_best_tp_rates(mi, index,
1145 tmp_group_tp_rate);
1146 }
1147
1148 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1149 sizeof(mg->max_group_tp_rate));
1150 }
1151
1152 /* Assign new rate set per sta */
1153 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1154 tmp_legacy_tp_rate);
1155 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1156
1157 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1158 if (!mi->supported[group])
1159 continue;
1160
1161 mg = &mi->groups[group];
1162 mg->max_group_prob_rate = MI_RATE(group, 0);
1163
1164 for (i = 0; i < MCS_GROUP_RATES; i++) {
1165 if (!(mi->supported[group] & BIT(i)))
1166 continue;
1167
1168 index = MI_RATE(group, i);
1169
1170 /* Find max probability rate per group and global */
1171 minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1172 index);
1173 }
1174 }
1175
1176 mi->max_prob_rate = tmp_max_prob_rate;
1177
1178 /* Try to increase robustness of max_prob_rate*/
1179 minstrel_ht_prob_rate_reduce_streams(mi);
1180 minstrel_ht_refill_sample_rates(mi);
1181
1182 #ifdef CONFIG_MAC80211_DEBUGFS
1183 /* use fixed index if set */
1184 if (mp->fixed_rate_idx != -1) {
1185 for (i = 0; i < 4; i++)
1186 mi->max_tp_rate[i] = mp->fixed_rate_idx;
1187 mi->max_prob_rate = mp->fixed_rate_idx;
1188 }
1189 #endif
1190
1191 /* Reset update timer */
1192 mi->last_stats_update = jiffies;
1193 mi->sample_time = jiffies;
1194 }
1195
1196 static bool
minstrel_ht_txstat_valid(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_tx_rate * rate)1197 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1198 struct ieee80211_tx_rate *rate)
1199 {
1200 int i;
1201
1202 if (rate->idx < 0)
1203 return false;
1204
1205 if (!rate->count)
1206 return false;
1207
1208 if (rate->flags & IEEE80211_TX_RC_MCS ||
1209 rate->flags & IEEE80211_TX_RC_VHT_MCS)
1210 return true;
1211
1212 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1213 if (rate->idx == mp->cck_rates[i])
1214 return true;
1215
1216 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1217 if (rate->idx == mp->ofdm_rates[mi->band][i])
1218 return true;
1219
1220 return false;
1221 }
1222
1223 /*
1224 * Check whether rate_status contains valid information.
1225 */
1226 static bool
minstrel_ht_ri_txstat_valid(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_rate_status * rate_status)1227 minstrel_ht_ri_txstat_valid(struct minstrel_priv *mp,
1228 struct minstrel_ht_sta *mi,
1229 struct ieee80211_rate_status *rate_status)
1230 {
1231 int i;
1232
1233 if (!rate_status)
1234 return false;
1235 if (!rate_status->try_count)
1236 return false;
1237
1238 if (rate_status->rate_idx.flags & RATE_INFO_FLAGS_MCS ||
1239 rate_status->rate_idx.flags & RATE_INFO_FLAGS_VHT_MCS)
1240 return true;
1241
1242 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) {
1243 if (rate_status->rate_idx.legacy ==
1244 minstrel_cck_bitrates[ mp->cck_rates[i] ])
1245 return true;
1246 }
1247
1248 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates); i++) {
1249 if (rate_status->rate_idx.legacy ==
1250 minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][i] ])
1251 return true;
1252 }
1253
1254 return false;
1255 }
1256
1257 static void
minstrel_downgrade_rate(struct minstrel_ht_sta * mi,u16 * idx,bool primary)1258 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1259 {
1260 int group, orig_group;
1261
1262 orig_group = group = MI_RATE_GROUP(*idx);
1263 while (group > 0) {
1264 group--;
1265
1266 if (!mi->supported[group])
1267 continue;
1268
1269 if (minstrel_mcs_groups[group].streams >
1270 minstrel_mcs_groups[orig_group].streams)
1271 continue;
1272
1273 if (primary)
1274 *idx = mi->groups[group].max_group_tp_rate[0];
1275 else
1276 *idx = mi->groups[group].max_group_tp_rate[1];
1277 break;
1278 }
1279 }
1280
1281 static void
minstrel_ht_tx_status(void * priv,struct ieee80211_supported_band * sband,void * priv_sta,struct ieee80211_tx_status * st)1282 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1283 void *priv_sta, struct ieee80211_tx_status *st)
1284 {
1285 struct ieee80211_tx_info *info = st->info;
1286 struct minstrel_ht_sta *mi = priv_sta;
1287 struct ieee80211_tx_rate *ar = info->status.rates;
1288 struct minstrel_rate_stats *rate, *rate2;
1289 struct minstrel_priv *mp = priv;
1290 u32 update_interval = mp->update_interval;
1291 bool last, update = false;
1292 int i;
1293
1294 /* Ignore packet that was sent with noAck flag */
1295 if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1296 return;
1297
1298 /* This packet was aggregated but doesn't carry status info */
1299 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1300 !(info->flags & IEEE80211_TX_STAT_AMPDU))
1301 return;
1302
1303 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1304 info->status.ampdu_ack_len =
1305 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1306 info->status.ampdu_len = 1;
1307 }
1308
1309 /* wraparound */
1310 if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1311 mi->total_packets = 0;
1312 mi->sample_packets = 0;
1313 }
1314
1315 mi->total_packets += info->status.ampdu_len;
1316 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1317 mi->sample_packets += info->status.ampdu_len;
1318
1319 mi->ampdu_packets++;
1320 mi->ampdu_len += info->status.ampdu_len;
1321
1322 if (st->rates && st->n_rates) {
1323 last = !minstrel_ht_ri_txstat_valid(mp, mi, &(st->rates[0]));
1324 for (i = 0; !last; i++) {
1325 last = (i == st->n_rates - 1) ||
1326 !minstrel_ht_ri_txstat_valid(mp, mi,
1327 &(st->rates[i + 1]));
1328
1329 rate = minstrel_ht_ri_get_stats(mp, mi,
1330 &(st->rates[i]));
1331
1332 if (last)
1333 rate->success += info->status.ampdu_ack_len;
1334
1335 rate->attempts += st->rates[i].try_count *
1336 info->status.ampdu_len;
1337 }
1338 } else {
1339 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1340 for (i = 0; !last; i++) {
1341 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1342 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1343
1344 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1345 if (last)
1346 rate->success += info->status.ampdu_ack_len;
1347
1348 rate->attempts += ar[i].count * info->status.ampdu_len;
1349 }
1350 }
1351
1352 if (mp->hw->max_rates > 1) {
1353 /*
1354 * check for sudden death of spatial multiplexing,
1355 * downgrade to a lower number of streams if necessary.
1356 */
1357 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1358 if (rate->attempts > 30 &&
1359 rate->success < rate->attempts / 4) {
1360 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1361 update = true;
1362 }
1363
1364 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1365 if (rate2->attempts > 30 &&
1366 rate2->success < rate2->attempts / 4) {
1367 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1368 update = true;
1369 }
1370 }
1371
1372 if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1373 update = true;
1374 minstrel_ht_update_stats(mp, mi);
1375 }
1376
1377 if (update)
1378 minstrel_ht_update_rates(mp, mi);
1379 }
1380
1381 static void
minstrel_calc_retransmit(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,int index)1382 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1383 int index)
1384 {
1385 struct minstrel_rate_stats *mrs;
1386 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1387 unsigned int cw = mp->cw_min;
1388 unsigned int ctime = 0;
1389 unsigned int t_slot = 9; /* FIXME */
1390 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1391 unsigned int overhead = 0, overhead_rtscts = 0;
1392
1393 mrs = minstrel_get_ratestats(mi, index);
1394 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1395 mrs->retry_count = 1;
1396 mrs->retry_count_rtscts = 1;
1397 return;
1398 }
1399
1400 mrs->retry_count = 2;
1401 mrs->retry_count_rtscts = 2;
1402 mrs->retry_updated = true;
1403
1404 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1405
1406 /* Contention time for first 2 tries */
1407 ctime = (t_slot * cw) >> 1;
1408 cw = min((cw << 1) | 1, mp->cw_max);
1409 ctime += (t_slot * cw) >> 1;
1410 cw = min((cw << 1) | 1, mp->cw_max);
1411
1412 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1413 overhead = mi->overhead_legacy;
1414 overhead_rtscts = mi->overhead_legacy_rtscts;
1415 } else {
1416 overhead = mi->overhead;
1417 overhead_rtscts = mi->overhead_rtscts;
1418 }
1419
1420 /* Total TX time for data and Contention after first 2 tries */
1421 tx_time = ctime + 2 * (overhead + tx_time_data);
1422 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1423
1424 /* See how many more tries we can fit inside segment size */
1425 do {
1426 /* Contention time for this try */
1427 ctime = (t_slot * cw) >> 1;
1428 cw = min((cw << 1) | 1, mp->cw_max);
1429
1430 /* Total TX time after this try */
1431 tx_time += ctime + overhead + tx_time_data;
1432 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1433
1434 if (tx_time_rtscts < mp->segment_size)
1435 mrs->retry_count_rtscts++;
1436 } while ((tx_time < mp->segment_size) &&
1437 (++mrs->retry_count < mp->max_retry));
1438 }
1439
1440
1441 static void
minstrel_ht_set_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_sta_rates * ratetbl,int offset,int index)1442 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1443 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1444 {
1445 int group_idx = MI_RATE_GROUP(index);
1446 const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1447 struct minstrel_rate_stats *mrs;
1448 u8 idx;
1449 u16 flags = group->flags;
1450
1451 mrs = minstrel_get_ratestats(mi, index);
1452 if (!mrs->retry_updated)
1453 minstrel_calc_retransmit(mp, mi, index);
1454
1455 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1456 ratetbl->rate[offset].count = 2;
1457 ratetbl->rate[offset].count_rts = 2;
1458 ratetbl->rate[offset].count_cts = 2;
1459 } else {
1460 ratetbl->rate[offset].count = mrs->retry_count;
1461 ratetbl->rate[offset].count_cts = mrs->retry_count;
1462 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1463 }
1464
1465 index = MI_RATE_IDX(index);
1466 if (group_idx == MINSTREL_CCK_GROUP)
1467 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1468 else if (group_idx == MINSTREL_OFDM_GROUP)
1469 idx = mp->ofdm_rates[mi->band][index %
1470 ARRAY_SIZE(mp->ofdm_rates[0])];
1471 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1472 idx = ((group->streams - 1) << 4) |
1473 (index & 0xF);
1474 else
1475 idx = index + (group->streams - 1) * 8;
1476
1477 /* enable RTS/CTS if needed:
1478 * - if station is in dynamic SMPS (and streams > 1)
1479 * - for fallback rates, to increase chances of getting through
1480 */
1481 if (offset > 0 ||
1482 (mi->sta->deflink.smps_mode == IEEE80211_SMPS_DYNAMIC &&
1483 group->streams > 1)) {
1484 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1485 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1486 }
1487
1488 ratetbl->rate[offset].idx = idx;
1489 ratetbl->rate[offset].flags = flags;
1490 }
1491
1492 static inline int
minstrel_ht_get_prob_avg(struct minstrel_ht_sta * mi,int rate)1493 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1494 {
1495 int group = MI_RATE_GROUP(rate);
1496 rate = MI_RATE_IDX(rate);
1497 return mi->groups[group].rates[rate].prob_avg;
1498 }
1499
1500 static int
minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta * mi)1501 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1502 {
1503 int group = MI_RATE_GROUP(mi->max_prob_rate);
1504 const struct mcs_group *g = &minstrel_mcs_groups[group];
1505 int rate = MI_RATE_IDX(mi->max_prob_rate);
1506 unsigned int duration;
1507
1508 /* Disable A-MSDU if max_prob_rate is bad */
1509 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1510 return 1;
1511
1512 duration = g->duration[rate];
1513 duration <<= g->shift;
1514
1515 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1516 if (duration > MCS_DURATION(1, 0, 52))
1517 return 500;
1518
1519 /*
1520 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1521 * data packet size
1522 */
1523 if (duration > MCS_DURATION(1, 0, 104))
1524 return 1600;
1525
1526 /*
1527 * If the rate is slower than single-stream MCS7, or if the max throughput
1528 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1529 * data packet size
1530 */
1531 if (duration > MCS_DURATION(1, 0, 260) ||
1532 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1533 MINSTREL_FRAC(75, 100)))
1534 return 3200;
1535
1536 /*
1537 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1538 * Since aggregation sessions are started/stopped without txq flush, use
1539 * the limit here to avoid the complexity of having to de-aggregate
1540 * packets in the queue.
1541 */
1542 if (!mi->sta->deflink.vht_cap.vht_supported)
1543 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1544
1545 /* unlimited */
1546 return 0;
1547 }
1548
1549 static void
minstrel_ht_update_rates(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1550 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1551 {
1552 struct ieee80211_sta_rates *rates;
1553 int i = 0;
1554 int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
1555
1556 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1557 if (!rates)
1558 return;
1559
1560 /* Start with max_tp_rate[0] */
1561 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1562
1563 /* Fill up remaining, keep one entry for max_probe_rate */
1564 for (; i < (max_rates - 1); i++)
1565 minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]);
1566
1567 if (i < max_rates)
1568 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1569
1570 if (i < IEEE80211_TX_RATE_TABLE_SIZE)
1571 rates->rate[i].idx = -1;
1572
1573 mi->sta->deflink.agg.max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1574 ieee80211_sta_recalc_aggregates(mi->sta);
1575 rate_control_set_rates(mp->hw, mi->sta, rates);
1576 }
1577
1578 static u16
minstrel_ht_get_sample_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1579 minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1580 {
1581 u8 seq;
1582
1583 if (mp->hw->max_rates > 1) {
1584 seq = mi->sample_seq;
1585 mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1586 seq = minstrel_sample_seq[seq];
1587 } else {
1588 seq = MINSTREL_SAMPLE_TYPE_INC;
1589 }
1590
1591 return __minstrel_ht_get_sample_rate(mi, seq);
1592 }
1593
1594 static void
minstrel_ht_get_rate(void * priv,struct ieee80211_sta * sta,void * priv_sta,struct ieee80211_tx_rate_control * txrc)1595 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1596 struct ieee80211_tx_rate_control *txrc)
1597 {
1598 const struct mcs_group *sample_group;
1599 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1600 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1601 struct minstrel_ht_sta *mi = priv_sta;
1602 struct minstrel_priv *mp = priv;
1603 u16 sample_idx;
1604
1605 info->flags |= mi->tx_flags;
1606
1607 #ifdef CONFIG_MAC80211_DEBUGFS
1608 if (mp->fixed_rate_idx != -1)
1609 return;
1610 #endif
1611
1612 /* Don't use EAPOL frames for sampling on non-mrr hw */
1613 if (mp->hw->max_rates == 1 &&
1614 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1615 return;
1616
1617 if (time_is_after_jiffies(mi->sample_time))
1618 return;
1619
1620 mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1621 sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1622 if (!sample_idx)
1623 return;
1624
1625 sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1626 sample_idx = MI_RATE_IDX(sample_idx);
1627
1628 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1629 (sample_idx >= 4) != txrc->short_preamble)
1630 return;
1631
1632 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1633 rate->count = 1;
1634
1635 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1636 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1637 rate->idx = mp->cck_rates[idx];
1638 } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1639 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1640 rate->idx = mp->ofdm_rates[mi->band][idx];
1641 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1642 ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1643 sample_group->streams);
1644 } else {
1645 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1646 }
1647
1648 rate->flags = sample_group->flags;
1649 }
1650
1651 static void
minstrel_ht_update_cck(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta)1652 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1653 struct ieee80211_supported_band *sband,
1654 struct ieee80211_sta *sta)
1655 {
1656 int i;
1657
1658 if (sband->band != NL80211_BAND_2GHZ)
1659 return;
1660
1661 if (sta->deflink.ht_cap.ht_supported &&
1662 !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1663 return;
1664
1665 for (i = 0; i < 4; i++) {
1666 if (mp->cck_rates[i] == 0xff ||
1667 !rate_supported(sta, sband->band, mp->cck_rates[i]))
1668 continue;
1669
1670 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1671 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1672 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1673 }
1674 }
1675
1676 static void
minstrel_ht_update_ofdm(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta)1677 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1678 struct ieee80211_supported_band *sband,
1679 struct ieee80211_sta *sta)
1680 {
1681 const u8 *rates;
1682 int i;
1683
1684 if (sta->deflink.ht_cap.ht_supported)
1685 return;
1686
1687 rates = mp->ofdm_rates[sband->band];
1688 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1689 if (rates[i] == 0xff ||
1690 !rate_supported(sta, sband->band, rates[i]))
1691 continue;
1692
1693 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1694 }
1695 }
1696
1697 static void
minstrel_ht_update_caps(void * priv,struct ieee80211_supported_band * sband,struct cfg80211_chan_def * chandef,struct ieee80211_sta * sta,void * priv_sta)1698 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1699 struct cfg80211_chan_def *chandef,
1700 struct ieee80211_sta *sta, void *priv_sta)
1701 {
1702 struct minstrel_priv *mp = priv;
1703 struct minstrel_ht_sta *mi = priv_sta;
1704 struct ieee80211_mcs_info *mcs = &sta->deflink.ht_cap.mcs;
1705 u16 ht_cap = sta->deflink.ht_cap.cap;
1706 struct ieee80211_sta_vht_cap *vht_cap = &sta->deflink.vht_cap;
1707 const struct ieee80211_rate *ctl_rate;
1708 struct sta_info *sta_info;
1709 bool ldpc, erp;
1710 int use_vht;
1711 int n_supported = 0;
1712 int ack_dur;
1713 int stbc;
1714 int i;
1715
1716 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1717
1718 if (vht_cap->vht_supported)
1719 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1720 else
1721 use_vht = 0;
1722
1723 memset(mi, 0, sizeof(*mi));
1724
1725 mi->sta = sta;
1726 mi->band = sband->band;
1727 mi->last_stats_update = jiffies;
1728
1729 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1730 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1731 mi->overhead += ack_dur;
1732 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1733
1734 ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1735 erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1736 ack_dur = ieee80211_frame_duration(sband->band, 10,
1737 ctl_rate->bitrate, erp, 1,
1738 ieee80211_chandef_get_shift(chandef));
1739 mi->overhead_legacy = ack_dur;
1740 mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1741
1742 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1743
1744 if (!use_vht) {
1745 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1746 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1747
1748 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1749 } else {
1750 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1751 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1752
1753 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1754 }
1755
1756 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1757 if (ldpc)
1758 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1759
1760 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1761 u32 gflags = minstrel_mcs_groups[i].flags;
1762 int bw, nss;
1763
1764 mi->supported[i] = 0;
1765 if (minstrel_ht_is_legacy_group(i))
1766 continue;
1767
1768 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1769 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1770 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1771 continue;
1772 } else {
1773 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1774 continue;
1775 }
1776 }
1777
1778 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1779 sta->deflink.bandwidth < IEEE80211_STA_RX_BW_40)
1780 continue;
1781
1782 nss = minstrel_mcs_groups[i].streams;
1783
1784 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1785 if (sta->deflink.smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1786 continue;
1787
1788 /* HT rate */
1789 if (gflags & IEEE80211_TX_RC_MCS) {
1790 if (use_vht && minstrel_vht_only)
1791 continue;
1792
1793 mi->supported[i] = mcs->rx_mask[nss - 1];
1794 if (mi->supported[i])
1795 n_supported++;
1796 continue;
1797 }
1798
1799 /* VHT rate */
1800 if (!vht_cap->vht_supported ||
1801 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1802 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1803 continue;
1804
1805 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1806 if (sta->deflink.bandwidth < IEEE80211_STA_RX_BW_80 ||
1807 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1808 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1809 continue;
1810 }
1811 }
1812
1813 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1814 bw = BW_40;
1815 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1816 bw = BW_80;
1817 else
1818 bw = BW_20;
1819
1820 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1821 vht_cap->vht_mcs.tx_mcs_map);
1822
1823 if (mi->supported[i])
1824 n_supported++;
1825 }
1826
1827 sta_info = container_of(sta, struct sta_info, sta);
1828 mi->use_short_preamble = test_sta_flag(sta_info, WLAN_STA_SHORT_PREAMBLE) &&
1829 sta_info->sdata->vif.bss_conf.use_short_preamble;
1830
1831 minstrel_ht_update_cck(mp, mi, sband, sta);
1832 minstrel_ht_update_ofdm(mp, mi, sband, sta);
1833
1834 /* create an initial rate table with the lowest supported rates */
1835 minstrel_ht_update_stats(mp, mi);
1836 minstrel_ht_update_rates(mp, mi);
1837 }
1838
1839 static void
minstrel_ht_rate_init(void * priv,struct ieee80211_supported_band * sband,struct cfg80211_chan_def * chandef,struct ieee80211_sta * sta,void * priv_sta)1840 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1841 struct cfg80211_chan_def *chandef,
1842 struct ieee80211_sta *sta, void *priv_sta)
1843 {
1844 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1845 }
1846
1847 static void
minstrel_ht_rate_update(void * priv,struct ieee80211_supported_band * sband,struct cfg80211_chan_def * chandef,struct ieee80211_sta * sta,void * priv_sta,u32 changed)1848 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1849 struct cfg80211_chan_def *chandef,
1850 struct ieee80211_sta *sta, void *priv_sta,
1851 u32 changed)
1852 {
1853 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1854 }
1855
1856 static void *
minstrel_ht_alloc_sta(void * priv,struct ieee80211_sta * sta,gfp_t gfp)1857 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1858 {
1859 struct ieee80211_supported_band *sband;
1860 struct minstrel_ht_sta *mi;
1861 struct minstrel_priv *mp = priv;
1862 struct ieee80211_hw *hw = mp->hw;
1863 int max_rates = 0;
1864 int i;
1865
1866 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1867 sband = hw->wiphy->bands[i];
1868 if (sband && sband->n_bitrates > max_rates)
1869 max_rates = sband->n_bitrates;
1870 }
1871
1872 return kzalloc(sizeof(*mi), gfp);
1873 }
1874
1875 static void
minstrel_ht_free_sta(void * priv,struct ieee80211_sta * sta,void * priv_sta)1876 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1877 {
1878 kfree(priv_sta);
1879 }
1880
1881 static void
minstrel_ht_fill_rate_array(u8 * dest,struct ieee80211_supported_band * sband,const s16 * bitrates,int n_rates,u32 rate_flags)1882 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1883 const s16 *bitrates, int n_rates, u32 rate_flags)
1884 {
1885 int i, j;
1886
1887 for (i = 0; i < sband->n_bitrates; i++) {
1888 struct ieee80211_rate *rate = &sband->bitrates[i];
1889
1890 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1891 continue;
1892
1893 for (j = 0; j < n_rates; j++) {
1894 if (rate->bitrate != bitrates[j])
1895 continue;
1896
1897 dest[j] = i;
1898 break;
1899 }
1900 }
1901 }
1902
1903 static void
minstrel_ht_init_cck_rates(struct minstrel_priv * mp)1904 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1905 {
1906 static const s16 bitrates[4] = { 10, 20, 55, 110 };
1907 struct ieee80211_supported_band *sband;
1908 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1909
1910 memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1911 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1912 if (!sband)
1913 return;
1914
1915 BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1916 minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1917 minstrel_cck_bitrates,
1918 ARRAY_SIZE(minstrel_cck_bitrates),
1919 rate_flags);
1920 }
1921
1922 static void
minstrel_ht_init_ofdm_rates(struct minstrel_priv * mp,enum nl80211_band band)1923 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1924 {
1925 static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1926 struct ieee80211_supported_band *sband;
1927 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1928
1929 memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1930 sband = mp->hw->wiphy->bands[band];
1931 if (!sband)
1932 return;
1933
1934 BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1935 minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1936 minstrel_ofdm_bitrates,
1937 ARRAY_SIZE(minstrel_ofdm_bitrates),
1938 rate_flags);
1939 }
1940
1941 static void *
minstrel_ht_alloc(struct ieee80211_hw * hw)1942 minstrel_ht_alloc(struct ieee80211_hw *hw)
1943 {
1944 struct minstrel_priv *mp;
1945 int i;
1946
1947 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1948 if (!mp)
1949 return NULL;
1950
1951 /* contention window settings
1952 * Just an approximation. Using the per-queue values would complicate
1953 * the calculations and is probably unnecessary */
1954 mp->cw_min = 15;
1955 mp->cw_max = 1023;
1956
1957 /* maximum time that the hw is allowed to stay in one MRR segment */
1958 mp->segment_size = 6000;
1959
1960 if (hw->max_rate_tries > 0)
1961 mp->max_retry = hw->max_rate_tries;
1962 else
1963 /* safe default, does not necessarily have to match hw properties */
1964 mp->max_retry = 7;
1965
1966 if (hw->max_rates >= 4)
1967 mp->has_mrr = true;
1968
1969 mp->hw = hw;
1970 mp->update_interval = HZ / 20;
1971
1972 minstrel_ht_init_cck_rates(mp);
1973 for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1974 minstrel_ht_init_ofdm_rates(mp, i);
1975
1976 return mp;
1977 }
1978
1979 #ifdef CONFIG_MAC80211_DEBUGFS
minstrel_ht_add_debugfs(struct ieee80211_hw * hw,void * priv,struct dentry * debugfsdir)1980 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1981 struct dentry *debugfsdir)
1982 {
1983 struct minstrel_priv *mp = priv;
1984
1985 mp->fixed_rate_idx = (u32) -1;
1986 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1987 &mp->fixed_rate_idx);
1988 }
1989 #endif
1990
1991 static void
minstrel_ht_free(void * priv)1992 minstrel_ht_free(void *priv)
1993 {
1994 kfree(priv);
1995 }
1996
minstrel_ht_get_expected_throughput(void * priv_sta)1997 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1998 {
1999 struct minstrel_ht_sta *mi = priv_sta;
2000 int i, j, prob, tp_avg;
2001
2002 i = MI_RATE_GROUP(mi->max_tp_rate[0]);
2003 j = MI_RATE_IDX(mi->max_tp_rate[0]);
2004 prob = mi->groups[i].rates[j].prob_avg;
2005
2006 /* convert tp_avg from pkt per second in kbps */
2007 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
2008 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
2009
2010 return tp_avg;
2011 }
2012
2013 static const struct rate_control_ops mac80211_minstrel_ht = {
2014 .name = "minstrel_ht",
2015 .capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
2016 .tx_status_ext = minstrel_ht_tx_status,
2017 .get_rate = minstrel_ht_get_rate,
2018 .rate_init = minstrel_ht_rate_init,
2019 .rate_update = minstrel_ht_rate_update,
2020 .alloc_sta = minstrel_ht_alloc_sta,
2021 .free_sta = minstrel_ht_free_sta,
2022 .alloc = minstrel_ht_alloc,
2023 .free = minstrel_ht_free,
2024 #ifdef CONFIG_MAC80211_DEBUGFS
2025 .add_debugfs = minstrel_ht_add_debugfs,
2026 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
2027 #endif
2028 .get_expected_throughput = minstrel_ht_get_expected_throughput,
2029 };
2030
2031
init_sample_table(void)2032 static void __init init_sample_table(void)
2033 {
2034 int col, i, new_idx;
2035 u8 rnd[MCS_GROUP_RATES];
2036
2037 memset(sample_table, 0xff, sizeof(sample_table));
2038 for (col = 0; col < SAMPLE_COLUMNS; col++) {
2039 get_random_bytes(rnd, sizeof(rnd));
2040 for (i = 0; i < MCS_GROUP_RATES; i++) {
2041 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
2042 while (sample_table[col][new_idx] != 0xff)
2043 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
2044
2045 sample_table[col][new_idx] = i;
2046 }
2047 }
2048 }
2049
2050 int __init
rc80211_minstrel_init(void)2051 rc80211_minstrel_init(void)
2052 {
2053 init_sample_table();
2054 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
2055 }
2056
2057 void
rc80211_minstrel_exit(void)2058 rc80211_minstrel_exit(void)
2059 {
2060 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
2061 }
2062
