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/limits.h>
11 #include <linux/random.h>
12 #include <linux/moduleparam.h>
13 #include <linux/ieee80211.h>
14 #include <linux/minmax.h>
15 #include <net/mac80211.h>
16 #include "rate.h"
17 #include "sta_info.h"
18 #include "rc80211_minstrel_ht.h"
19
20 #define AVG_AMPDU_SIZE 16
21 #define AVG_PKT_SIZE 1200
22
23 /* Number of bits for an average sized packet */
24 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
25
26 /* Number of symbols for a packet with (bps) bits per symbol */
27 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
28
29 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
30 #define MCS_SYMBOL_TIME(sgi, syms) \
31 (sgi ? \
32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
33 ((syms) * 1000) << 2 /* syms * 4 us */ \
34 )
35
36 /* Transmit duration for the raw data part of an average sized packet */
37 #define MCS_DURATION(streams, sgi, bps) \
38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
39
40 #define BW_20 0
41 #define BW_40 1
42 #define BW_80 2
43
44 /*
45 * Define group sort order: HT40 -> SGI -> #streams
46 */
47 #define GROUP_IDX(_streams, _sgi, _ht40) \
48 MINSTREL_HT_GROUP_0 + \
49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
50 MINSTREL_MAX_STREAMS * _sgi + \
51 _streams - 1
52
53 #define _MAX(a, b) (((a)>(b))?(a):(b))
54
55 #define GROUP_SHIFT(duration) \
56 _MAX(0, 16 - __builtin_clz(duration))
57
58 /* MCS rate information for an MCS group */
59 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
60 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
61 .streams = _streams, \
62 .shift = _s, \
63 .bw = _ht40, \
64 .flags = \
65 IEEE80211_TX_RC_MCS | \
66 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
67 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
68 .duration = { \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
72 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
73 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
74 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
75 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
76 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
77 } \
78 }
79
80 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
81 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
82
83 #define MCS_GROUP(_streams, _sgi, _ht40) \
84 __MCS_GROUP(_streams, _sgi, _ht40, \
85 MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
86
87 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
88 (MINSTREL_VHT_GROUP_0 + \
89 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
90 MINSTREL_MAX_STREAMS * (_sgi) + \
91 (_streams) - 1)
92
93 #define BW2VBPS(_bw, r3, r2, r1) \
94 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
95
96 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \
97 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
98 .streams = _streams, \
99 .shift = _s, \
100 .bw = _bw, \
101 .flags = \
102 IEEE80211_TX_RC_VHT_MCS | \
103 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
104 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
105 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
106 .duration = { \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
109 MCS_DURATION(_streams, _sgi, \
110 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
111 MCS_DURATION(_streams, _sgi, \
112 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
113 MCS_DURATION(_streams, _sgi, \
114 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
115 MCS_DURATION(_streams, _sgi, \
116 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
117 MCS_DURATION(_streams, _sgi, \
118 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
119 MCS_DURATION(_streams, _sgi, \
120 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
121 MCS_DURATION(_streams, _sgi, \
122 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
123 MCS_DURATION(_streams, _sgi, \
124 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
125 MCS_DURATION(_streams, _sgi, \
126 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
127 } \
128 }
129
130 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
131 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
132 BW2VBPS(_bw, 117, 54, 26)))
133
134 #define VHT_GROUP(_streams, _sgi, _bw) \
135 __VHT_GROUP(_streams, _sgi, _bw, \
136 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
137
138 #define CCK_DURATION(_bitrate, _short) \
139 (1000 * (10 /* SIFS */ + \
140 (_short ? 72 + 24 : 144 + 48) + \
141 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
142
143 #define CCK_DURATION_LIST(_short, _s) \
144 CCK_DURATION(10, _short) >> _s, \
145 CCK_DURATION(20, _short) >> _s, \
146 CCK_DURATION(55, _short) >> _s, \
147 CCK_DURATION(110, _short) >> _s
148
149 #define __CCK_GROUP(_s) \
150 [MINSTREL_CCK_GROUP] = { \
151 .streams = 1, \
152 .flags = 0, \
153 .shift = _s, \
154 .duration = { \
155 CCK_DURATION_LIST(false, _s), \
156 CCK_DURATION_LIST(true, _s) \
157 } \
158 }
159
160 #define CCK_GROUP_SHIFT \
161 GROUP_SHIFT(CCK_DURATION(10, false))
162
163 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
164
165 #define OFDM_DURATION(_bitrate) \
166 (1000 * (16 /* SIFS + signal ext */ + \
167 16 /* T_PREAMBLE */ + \
168 4 /* T_SIGNAL */ + \
169 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) / \
170 ((_bitrate) * 4)))))
171
172 #define OFDM_DURATION_LIST(_s) \
173 OFDM_DURATION(60) >> _s, \
174 OFDM_DURATION(90) >> _s, \
175 OFDM_DURATION(120) >> _s, \
176 OFDM_DURATION(180) >> _s, \
177 OFDM_DURATION(240) >> _s, \
178 OFDM_DURATION(360) >> _s, \
179 OFDM_DURATION(480) >> _s, \
180 OFDM_DURATION(540) >> _s
181
182 #define __OFDM_GROUP(_s) \
183 [MINSTREL_OFDM_GROUP] = { \
184 .streams = 1, \
185 .flags = 0, \
186 .shift = _s, \
187 .duration = { \
188 OFDM_DURATION_LIST(_s), \
189 } \
190 }
191
192 #define OFDM_GROUP_SHIFT \
193 GROUP_SHIFT(OFDM_DURATION(60))
194
195 #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
196
197
198 static bool minstrel_vht_only = true;
199 module_param(minstrel_vht_only, bool, 0644);
200 MODULE_PARM_DESC(minstrel_vht_only,
201 "Use only VHT rates when VHT is supported by sta.");
202
203 /*
204 * To enable sufficiently targeted rate sampling, MCS rates are divided into
205 * groups, based on the number of streams and flags (HT40, SGI) that they
206 * use.
207 *
208 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
209 * BW -> SGI -> #streams
210 */
211 const struct mcs_group minstrel_mcs_groups[] = {
212 MCS_GROUP(1, 0, BW_20),
213 MCS_GROUP(2, 0, BW_20),
214 MCS_GROUP(3, 0, BW_20),
215 MCS_GROUP(4, 0, BW_20),
216
217 MCS_GROUP(1, 1, BW_20),
218 MCS_GROUP(2, 1, BW_20),
219 MCS_GROUP(3, 1, BW_20),
220 MCS_GROUP(4, 1, BW_20),
221
222 MCS_GROUP(1, 0, BW_40),
223 MCS_GROUP(2, 0, BW_40),
224 MCS_GROUP(3, 0, BW_40),
225 MCS_GROUP(4, 0, BW_40),
226
227 MCS_GROUP(1, 1, BW_40),
228 MCS_GROUP(2, 1, BW_40),
229 MCS_GROUP(3, 1, BW_40),
230 MCS_GROUP(4, 1, BW_40),
231
232 CCK_GROUP,
233 OFDM_GROUP,
234
235 VHT_GROUP(1, 0, BW_20),
236 VHT_GROUP(2, 0, BW_20),
237 VHT_GROUP(3, 0, BW_20),
238 VHT_GROUP(4, 0, BW_20),
239
240 VHT_GROUP(1, 1, BW_20),
241 VHT_GROUP(2, 1, BW_20),
242 VHT_GROUP(3, 1, BW_20),
243 VHT_GROUP(4, 1, BW_20),
244
245 VHT_GROUP(1, 0, BW_40),
246 VHT_GROUP(2, 0, BW_40),
247 VHT_GROUP(3, 0, BW_40),
248 VHT_GROUP(4, 0, BW_40),
249
250 VHT_GROUP(1, 1, BW_40),
251 VHT_GROUP(2, 1, BW_40),
252 VHT_GROUP(3, 1, BW_40),
253 VHT_GROUP(4, 1, BW_40),
254
255 VHT_GROUP(1, 0, BW_80),
256 VHT_GROUP(2, 0, BW_80),
257 VHT_GROUP(3, 0, BW_80),
258 VHT_GROUP(4, 0, BW_80),
259
260 VHT_GROUP(1, 1, BW_80),
261 VHT_GROUP(2, 1, BW_80),
262 VHT_GROUP(3, 1, BW_80),
263 VHT_GROUP(4, 1, BW_80),
264 };
265
266 const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
267 const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
268 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
269 static const u8 minstrel_sample_seq[] = {
270 MINSTREL_SAMPLE_TYPE_INC,
271 MINSTREL_SAMPLE_TYPE_JUMP,
272 MINSTREL_SAMPLE_TYPE_INC,
273 MINSTREL_SAMPLE_TYPE_JUMP,
274 MINSTREL_SAMPLE_TYPE_INC,
275 MINSTREL_SAMPLE_TYPE_SLOW,
276 };
277
278 static void
279 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
280
281 /*
282 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
283 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
284 *
285 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
286 */
287 static u16
minstrel_get_valid_vht_rates(int bw,int nss,__le16 mcs_map)288 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
289 {
290 u16 mask = 0;
291
292 if (bw == BW_20) {
293 if (nss != 3 && nss != 6)
294 mask = BIT(9);
295 } else if (bw == BW_80) {
296 if (nss == 3 || nss == 7)
297 mask = BIT(6);
298 else if (nss == 6)
299 mask = BIT(9);
300 } else {
301 WARN_ON(bw != BW_40);
302 }
303
304 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
305 case IEEE80211_VHT_MCS_SUPPORT_0_7:
306 mask |= 0x300;
307 break;
308 case IEEE80211_VHT_MCS_SUPPORT_0_8:
309 mask |= 0x200;
310 break;
311 case IEEE80211_VHT_MCS_SUPPORT_0_9:
312 break;
313 default:
314 mask = 0x3ff;
315 }
316
317 return 0x3ff & ~mask;
318 }
319
320 static bool
minstrel_ht_is_legacy_group(int group)321 minstrel_ht_is_legacy_group(int group)
322 {
323 return group == MINSTREL_CCK_GROUP ||
324 group == MINSTREL_OFDM_GROUP;
325 }
326
327 /*
328 * Look up an MCS group index based on mac80211 rate information
329 */
330 static int
minstrel_ht_get_group_idx(struct ieee80211_tx_rate * rate)331 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
332 {
333 return GROUP_IDX((rate->idx / 8) + 1,
334 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
335 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
336 }
337
338 /*
339 * Look up an MCS group index based on new cfg80211 rate_info.
340 */
341 static int
minstrel_ht_ri_get_group_idx(struct rate_info * rate)342 minstrel_ht_ri_get_group_idx(struct rate_info *rate)
343 {
344 return GROUP_IDX((rate->mcs / 8) + 1,
345 !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
346 !!(rate->bw & RATE_INFO_BW_40));
347 }
348
349 static int
minstrel_vht_get_group_idx(struct ieee80211_tx_rate * rate)350 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
351 {
352 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
353 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
354 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
355 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
356 }
357
358 /*
359 * Look up an MCS group index based on new cfg80211 rate_info.
360 */
361 static int
minstrel_vht_ri_get_group_idx(struct rate_info * rate)362 minstrel_vht_ri_get_group_idx(struct rate_info *rate)
363 {
364 return VHT_GROUP_IDX(rate->nss,
365 !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
366 !!(rate->bw & RATE_INFO_BW_40) +
367 2*!!(rate->bw & RATE_INFO_BW_80));
368 }
369
370 static struct minstrel_rate_stats *
minstrel_ht_get_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_tx_rate * rate)371 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
372 struct ieee80211_tx_rate *rate)
373 {
374 int group, idx;
375
376 if (rate->flags & IEEE80211_TX_RC_MCS) {
377 group = minstrel_ht_get_group_idx(rate);
378 idx = rate->idx % 8;
379 goto out;
380 }
381
382 if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
383 group = minstrel_vht_get_group_idx(rate);
384 idx = ieee80211_rate_get_vht_mcs(rate);
385 goto out;
386 }
387
388 group = MINSTREL_CCK_GROUP;
389 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
390 if (!(mi->supported[group] & BIT(idx)))
391 continue;
392
393 if (rate->idx != mp->cck_rates[idx])
394 continue;
395
396 /* short preamble */
397 if ((mi->supported[group] & BIT(idx + 4)) &&
398 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
399 idx += 4;
400 goto out;
401 }
402
403 group = MINSTREL_OFDM_GROUP;
404 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
405 if (rate->idx == mp->ofdm_rates[mi->band][idx])
406 goto out;
407
408 idx = 0;
409 out:
410 return &mi->groups[group].rates[idx];
411 }
412
413 /*
414 * Get the minstrel rate statistics for specified STA and rate info.
415 */
416 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)417 minstrel_ht_ri_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
418 struct ieee80211_rate_status *rate_status)
419 {
420 int group, idx;
421 struct rate_info *rate = &rate_status->rate_idx;
422
423 if (rate->flags & RATE_INFO_FLAGS_MCS) {
424 group = minstrel_ht_ri_get_group_idx(rate);
425 idx = rate->mcs % 8;
426 goto out;
427 }
428
429 if (rate->flags & RATE_INFO_FLAGS_VHT_MCS) {
430 group = minstrel_vht_ri_get_group_idx(rate);
431 idx = rate->mcs;
432 goto out;
433 }
434
435 group = MINSTREL_CCK_GROUP;
436 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
437 if (rate->legacy != minstrel_cck_bitrates[ mp->cck_rates[idx] ])
438 continue;
439
440 /* short preamble */
441 if ((mi->supported[group] & BIT(idx + 4)) &&
442 mi->use_short_preamble)
443 idx += 4;
444 goto out;
445 }
446
447 group = MINSTREL_OFDM_GROUP;
448 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
449 if (rate->legacy == minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][idx] ])
450 goto out;
451
452 idx = 0;
453 out:
454 return &mi->groups[group].rates[idx];
455 }
456
457 static inline struct minstrel_rate_stats *
minstrel_get_ratestats(struct minstrel_ht_sta * mi,int index)458 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
459 {
460 return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
461 }
462
minstrel_get_duration(int index)463 static inline int minstrel_get_duration(int index)
464 {
465 const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
466 unsigned int duration = group->duration[MI_RATE_IDX(index)];
467
468 return duration << group->shift;
469 }
470
471 static unsigned int
minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta * mi)472 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
473 {
474 int duration;
475
476 if (mi->avg_ampdu_len)
477 return MINSTREL_TRUNC(mi->avg_ampdu_len);
478
479 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
480 return 1;
481
482 duration = minstrel_get_duration(mi->max_tp_rate[0]);
483
484 if (duration > 400 * 1000)
485 return 2;
486
487 if (duration > 250 * 1000)
488 return 4;
489
490 if (duration > 150 * 1000)
491 return 8;
492
493 return 16;
494 }
495
496 /*
497 * Return current throughput based on the average A-MPDU length, taking into
498 * account the expected number of retransmissions and their expected length
499 */
500 int
minstrel_ht_get_tp_avg(struct minstrel_ht_sta * mi,int group,int rate,int prob_avg)501 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
502 int prob_avg)
503 {
504 unsigned int nsecs = 0, overhead = mi->overhead;
505 unsigned int ampdu_len = 1;
506
507 /* do not account throughput if success prob is below 10% */
508 if (prob_avg < MINSTREL_FRAC(10, 100))
509 return 0;
510
511 if (minstrel_ht_is_legacy_group(group))
512 overhead = mi->overhead_legacy;
513 else
514 ampdu_len = minstrel_ht_avg_ampdu_len(mi);
515
516 nsecs = 1000 * overhead / ampdu_len;
517 nsecs += minstrel_mcs_groups[group].duration[rate] <<
518 minstrel_mcs_groups[group].shift;
519
520 /*
521 * For the throughput calculation, limit the probability value to 90% to
522 * account for collision related packet error rate fluctuation
523 * (prob is scaled - see MINSTREL_FRAC above)
524 */
525 if (prob_avg > MINSTREL_FRAC(90, 100))
526 prob_avg = MINSTREL_FRAC(90, 100);
527
528 return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
529 }
530
531 /*
532 * Find & sort topmost throughput rates
533 *
534 * If multiple rates provide equal throughput the sorting is based on their
535 * current success probability. Higher success probability is preferred among
536 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
537 */
538 static void
minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta * mi,u16 index,u16 * tp_list)539 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
540 u16 *tp_list)
541 {
542 int cur_group, cur_idx, cur_tp_avg, cur_prob;
543 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
544 int j = MAX_THR_RATES;
545
546 cur_group = MI_RATE_GROUP(index);
547 cur_idx = MI_RATE_IDX(index);
548 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
549 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
550
551 do {
552 tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
553 tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
554 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
555 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
556 tmp_prob);
557 if (cur_tp_avg < tmp_tp_avg ||
558 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
559 break;
560 j--;
561 } while (j > 0);
562
563 if (j < MAX_THR_RATES - 1) {
564 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
565 (MAX_THR_RATES - (j + 1))));
566 }
567 if (j < MAX_THR_RATES)
568 tp_list[j] = index;
569 }
570
571 /*
572 * Find and set the topmost probability rate per sta and per group
573 */
574 static void
minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta * mi,u16 * dest,u16 index)575 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
576 {
577 struct minstrel_mcs_group_data *mg;
578 struct minstrel_rate_stats *mrs;
579 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
580 int max_tp_group, max_tp_idx, max_tp_prob;
581 int cur_tp_avg, cur_group, cur_idx;
582 int max_gpr_group, max_gpr_idx;
583 int max_gpr_tp_avg, max_gpr_prob;
584
585 cur_group = MI_RATE_GROUP(index);
586 cur_idx = MI_RATE_IDX(index);
587 mg = &mi->groups[cur_group];
588 mrs = &mg->rates[cur_idx];
589
590 tmp_group = MI_RATE_GROUP(*dest);
591 tmp_idx = MI_RATE_IDX(*dest);
592 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
593 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
594
595 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
596 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
597 max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
598 max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
599 max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
600
601 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
602 !minstrel_ht_is_legacy_group(max_tp_group))
603 return;
604
605 /* skip rates faster than max tp rate with lower prob */
606 if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
607 mrs->prob_avg < max_tp_prob)
608 return;
609
610 max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
611 max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
612 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
613
614 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
615 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
616 mrs->prob_avg);
617 if (cur_tp_avg > tmp_tp_avg)
618 *dest = index;
619
620 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
621 max_gpr_idx,
622 max_gpr_prob);
623 if (cur_tp_avg > max_gpr_tp_avg)
624 mg->max_group_prob_rate = index;
625 } else {
626 if (mrs->prob_avg > tmp_prob)
627 *dest = index;
628 if (mrs->prob_avg > max_gpr_prob)
629 mg->max_group_prob_rate = index;
630 }
631 }
632
633
634 /*
635 * Assign new rate set per sta and use CCK rates only if the fastest
636 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
637 * rate sets where MCS and CCK rates are mixed, because CCK rates can
638 * not use aggregation.
639 */
640 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])641 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
642 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
643 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
644 {
645 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
646 int i;
647
648 tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
649 tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
650 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
651 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
652
653 tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
654 tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
655 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
656 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
657
658 if (tmp_cck_tp > tmp_mcs_tp) {
659 for(i = 0; i < MAX_THR_RATES; i++) {
660 minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
661 tmp_mcs_tp_rate);
662 }
663 }
664
665 }
666
667 /*
668 * Try to increase robustness of max_prob rate by decrease number of
669 * streams if possible.
670 */
671 static inline void
minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta * mi)672 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
673 {
674 struct minstrel_mcs_group_data *mg;
675 int tmp_max_streams, group, tmp_idx, tmp_prob;
676 int tmp_tp = 0;
677
678 if (!mi->sta->deflink.ht_cap.ht_supported)
679 return;
680
681 group = MI_RATE_GROUP(mi->max_tp_rate[0]);
682 tmp_max_streams = minstrel_mcs_groups[group].streams;
683 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
684 mg = &mi->groups[group];
685 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
686 continue;
687
688 tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
689 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
690
691 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
692 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
693 mi->max_prob_rate = mg->max_group_prob_rate;
694 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
695 tmp_idx,
696 tmp_prob);
697 }
698 }
699 }
700
701 static u16
__minstrel_ht_get_sample_rate(struct minstrel_ht_sta * mi,enum minstrel_sample_type type)702 __minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
703 enum minstrel_sample_type type)
704 {
705 u16 *rates = mi->sample[type].sample_rates;
706 u16 cur;
707 int i;
708
709 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
710 if (!rates[i])
711 continue;
712
713 cur = rates[i];
714 rates[i] = 0;
715 return cur;
716 }
717
718 return 0;
719 }
720
721 static inline int
minstrel_ewma(int old,int new,int weight)722 minstrel_ewma(int old, int new, int weight)
723 {
724 int diff, incr;
725
726 diff = new - old;
727 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
728
729 return old + incr;
730 }
731
minstrel_filter_avg_add(u16 * prev_1,u16 * prev_2,s32 in)732 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
733 {
734 s32 out_1 = *prev_1;
735 s32 out_2 = *prev_2;
736 s32 val;
737
738 if (!in)
739 in += 1;
740
741 if (!out_1) {
742 val = out_1 = in;
743 goto out;
744 }
745
746 val = MINSTREL_AVG_COEFF1 * in;
747 val += MINSTREL_AVG_COEFF2 * out_1;
748 val += MINSTREL_AVG_COEFF3 * out_2;
749 val >>= MINSTREL_SCALE;
750
751 if (val > 1 << MINSTREL_SCALE)
752 val = 1 << MINSTREL_SCALE;
753 if (val < 0)
754 val = 1;
755
756 out:
757 *prev_2 = out_1;
758 *prev_1 = val;
759
760 return val;
761 }
762
763 /*
764 * Recalculate statistics and counters of a given rate
765 */
766 static void
minstrel_ht_calc_rate_stats(struct minstrel_priv * mp,struct minstrel_rate_stats * mrs)767 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
768 struct minstrel_rate_stats *mrs)
769 {
770 unsigned int cur_prob;
771
772 if (unlikely(mrs->attempts > 0)) {
773 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
774 minstrel_filter_avg_add(&mrs->prob_avg,
775 &mrs->prob_avg_1, cur_prob);
776 mrs->att_hist += mrs->attempts;
777 mrs->succ_hist += mrs->success;
778 }
779
780 mrs->last_success = mrs->success;
781 mrs->last_attempts = mrs->attempts;
782 mrs->success = 0;
783 mrs->attempts = 0;
784 }
785
786 static bool
minstrel_ht_find_sample_rate(struct minstrel_ht_sta * mi,int type,int idx)787 minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
788 {
789 int i;
790
791 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
792 u16 cur = mi->sample[type].sample_rates[i];
793
794 if (cur == idx)
795 return true;
796
797 if (!cur)
798 break;
799 }
800
801 return false;
802 }
803
804 static int
minstrel_ht_move_sample_rates(struct minstrel_ht_sta * mi,int type,u32 fast_rate_dur,u32 slow_rate_dur)805 minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
806 u32 fast_rate_dur, u32 slow_rate_dur)
807 {
808 u16 *rates = mi->sample[type].sample_rates;
809 int i, j;
810
811 for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
812 u32 duration;
813 bool valid = false;
814 u16 cur;
815
816 cur = rates[i];
817 if (!cur)
818 continue;
819
820 duration = minstrel_get_duration(cur);
821 switch (type) {
822 case MINSTREL_SAMPLE_TYPE_SLOW:
823 valid = duration > fast_rate_dur &&
824 duration < slow_rate_dur;
825 break;
826 case MINSTREL_SAMPLE_TYPE_INC:
827 case MINSTREL_SAMPLE_TYPE_JUMP:
828 valid = duration < fast_rate_dur;
829 break;
830 default:
831 valid = false;
832 break;
833 }
834
835 if (!valid) {
836 rates[i] = 0;
837 continue;
838 }
839
840 if (i == j)
841 continue;
842
843 rates[j++] = cur;
844 rates[i] = 0;
845 }
846
847 return j;
848 }
849
850 static int
minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta * mi,int group,u32 max_duration)851 minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
852 u32 max_duration)
853 {
854 u16 supported = mi->supported[group];
855 int i;
856
857 for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
858 if (!(supported & BIT(0)))
859 continue;
860
861 if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
862 continue;
863
864 return i;
865 }
866
867 return -1;
868 }
869
870 /*
871 * Incremental update rates:
872 * Flip through groups and pick the first group rate that is faster than the
873 * highest currently selected rate
874 */
875 static u16
minstrel_ht_next_inc_rate(struct minstrel_ht_sta * mi,u32 fast_rate_dur)876 minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
877 {
878 u8 type = MINSTREL_SAMPLE_TYPE_INC;
879 int i, index = 0;
880 u8 group;
881
882 group = mi->sample[type].sample_group;
883 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
884 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
885
886 index = minstrel_ht_group_min_rate_offset(mi, group,
887 fast_rate_dur);
888 if (index < 0)
889 continue;
890
891 index = MI_RATE(group, index & 0xf);
892 if (!minstrel_ht_find_sample_rate(mi, type, index))
893 goto out;
894 }
895 index = 0;
896
897 out:
898 mi->sample[type].sample_group = group;
899
900 return index;
901 }
902
903 static int
minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta * mi,int group,u16 supported,int offset)904 minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
905 u16 supported, int offset)
906 {
907 struct minstrel_mcs_group_data *mg = &mi->groups[group];
908 u16 idx;
909 int i;
910
911 for (i = 0; i < MCS_GROUP_RATES; i++) {
912 idx = sample_table[mg->column][mg->index];
913 if (++mg->index >= MCS_GROUP_RATES) {
914 mg->index = 0;
915 if (++mg->column >= ARRAY_SIZE(sample_table))
916 mg->column = 0;
917 }
918
919 if (idx < offset)
920 continue;
921
922 if (!(supported & BIT(idx)))
923 continue;
924
925 return MI_RATE(group, idx);
926 }
927
928 return -1;
929 }
930
931 /*
932 * Jump rates:
933 * Sample random rates, use those that are faster than the highest
934 * currently selected rate. Rates between the fastest and the slowest
935 * get sorted into the slow sample bucket, but only if it has room
936 */
937 static u16
minstrel_ht_next_jump_rate(struct minstrel_ht_sta * mi,u32 fast_rate_dur,u32 slow_rate_dur,int * slow_rate_ofs)938 minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
939 u32 slow_rate_dur, int *slow_rate_ofs)
940 {
941 struct minstrel_rate_stats *mrs;
942 u32 max_duration = slow_rate_dur;
943 int i, index, offset;
944 u16 *slow_rates;
945 u16 supported;
946 u32 duration;
947 u8 group;
948
949 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
950 max_duration = fast_rate_dur;
951
952 slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
953 group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
954 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
955 u8 type;
956
957 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
958
959 supported = mi->supported[group];
960 if (!supported)
961 continue;
962
963 offset = minstrel_ht_group_min_rate_offset(mi, group,
964 max_duration);
965 if (offset < 0)
966 continue;
967
968 index = minstrel_ht_next_group_sample_rate(mi, group, supported,
969 offset);
970 if (index < 0)
971 continue;
972
973 duration = minstrel_get_duration(index);
974 if (duration < fast_rate_dur)
975 type = MINSTREL_SAMPLE_TYPE_JUMP;
976 else
977 type = MINSTREL_SAMPLE_TYPE_SLOW;
978
979 if (minstrel_ht_find_sample_rate(mi, type, index))
980 continue;
981
982 if (type == MINSTREL_SAMPLE_TYPE_JUMP)
983 goto found;
984
985 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
986 continue;
987
988 if (duration >= slow_rate_dur)
989 continue;
990
991 /* skip slow rates with high success probability */
992 mrs = minstrel_get_ratestats(mi, index);
993 if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
994 continue;
995
996 slow_rates[(*slow_rate_ofs)++] = index;
997 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
998 max_duration = fast_rate_dur;
999 }
1000 index = 0;
1001
1002 found:
1003 mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
1004
1005 return index;
1006 }
1007
1008 static void
minstrel_ht_refill_sample_rates(struct minstrel_ht_sta * mi)1009 minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
1010 {
1011 u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
1012 u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
1013 u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
1014 u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
1015 u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
1016 u16 *rates;
1017 int i, j;
1018
1019 rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
1020 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
1021 fast_rate_dur, slow_rate_dur);
1022 while (i < MINSTREL_SAMPLE_RATES) {
1023 rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
1024 if (!rates[i])
1025 break;
1026
1027 i++;
1028 }
1029
1030 rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
1031 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
1032 fast_rate_dur, slow_rate_dur);
1033 j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
1034 fast_rate_dur, slow_rate_dur);
1035 while (i < MINSTREL_SAMPLE_RATES) {
1036 rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
1037 slow_rate_dur, &j);
1038 if (!rates[i])
1039 break;
1040
1041 i++;
1042 }
1043
1044 for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
1045 memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
1046 sizeof(mi->sample[i].cur_sample_rates));
1047 }
1048
1049
1050 /*
1051 * Update rate statistics and select new primary rates
1052 *
1053 * Rules for rate selection:
1054 * - max_prob_rate must use only one stream, as a tradeoff between delivery
1055 * probability and throughput during strong fluctuations
1056 * - as long as the max prob rate has a probability of more than 75%, pick
1057 * higher throughput rates, even if the probability is a bit lower
1058 */
1059 static void
minstrel_ht_update_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1060 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1061 {
1062 struct minstrel_mcs_group_data *mg;
1063 struct minstrel_rate_stats *mrs;
1064 int group, i, j, cur_prob;
1065 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
1066 u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
1067 u16 index;
1068 bool ht_supported = mi->sta->deflink.ht_cap.ht_supported;
1069
1070 if (mi->ampdu_packets > 0) {
1071 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1072 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1073 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1074 EWMA_LEVEL);
1075 else
1076 mi->avg_ampdu_len = 0;
1077 mi->ampdu_len = 0;
1078 mi->ampdu_packets = 0;
1079 }
1080
1081 if (mi->supported[MINSTREL_CCK_GROUP])
1082 group = MINSTREL_CCK_GROUP;
1083 else if (mi->supported[MINSTREL_OFDM_GROUP])
1084 group = MINSTREL_OFDM_GROUP;
1085 else
1086 group = 0;
1087
1088 index = MI_RATE(group, 0);
1089 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1090 tmp_legacy_tp_rate[j] = index;
1091
1092 if (mi->supported[MINSTREL_VHT_GROUP_0])
1093 group = MINSTREL_VHT_GROUP_0;
1094 else if (ht_supported)
1095 group = MINSTREL_HT_GROUP_0;
1096 else if (mi->supported[MINSTREL_CCK_GROUP])
1097 group = MINSTREL_CCK_GROUP;
1098 else
1099 group = MINSTREL_OFDM_GROUP;
1100
1101 index = MI_RATE(group, 0);
1102 tmp_max_prob_rate = index;
1103 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1104 tmp_mcs_tp_rate[j] = index;
1105
1106 /* Find best rate sets within all MCS groups*/
1107 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1108 u16 *tp_rate = tmp_mcs_tp_rate;
1109 u16 last_prob = 0;
1110
1111 mg = &mi->groups[group];
1112 if (!mi->supported[group])
1113 continue;
1114
1115 /* (re)Initialize group rate indexes */
1116 for(j = 0; j < MAX_THR_RATES; j++)
1117 tmp_group_tp_rate[j] = MI_RATE(group, 0);
1118
1119 if (group == MINSTREL_CCK_GROUP && ht_supported)
1120 tp_rate = tmp_legacy_tp_rate;
1121
1122 for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1123 if (!(mi->supported[group] & BIT(i)))
1124 continue;
1125
1126 index = MI_RATE(group, i);
1127
1128 mrs = &mg->rates[i];
1129 mrs->retry_updated = false;
1130 minstrel_ht_calc_rate_stats(mp, mrs);
1131
1132 if (mrs->att_hist)
1133 last_prob = max(last_prob, mrs->prob_avg);
1134 else
1135 mrs->prob_avg = max(last_prob, mrs->prob_avg);
1136 cur_prob = mrs->prob_avg;
1137
1138 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1139 continue;
1140
1141 /* Find max throughput rate set */
1142 minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
1143
1144 /* Find max throughput rate set within a group */
1145 minstrel_ht_sort_best_tp_rates(mi, index,
1146 tmp_group_tp_rate);
1147 }
1148
1149 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1150 sizeof(mg->max_group_tp_rate));
1151 }
1152
1153 /* Assign new rate set per sta */
1154 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1155 tmp_legacy_tp_rate);
1156 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1157
1158 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1159 if (!mi->supported[group])
1160 continue;
1161
1162 mg = &mi->groups[group];
1163 mg->max_group_prob_rate = MI_RATE(group, 0);
1164
1165 for (i = 0; i < MCS_GROUP_RATES; i++) {
1166 if (!(mi->supported[group] & BIT(i)))
1167 continue;
1168
1169 index = MI_RATE(group, i);
1170
1171 /* Find max probability rate per group and global */
1172 minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1173 index);
1174 }
1175 }
1176
1177 mi->max_prob_rate = tmp_max_prob_rate;
1178
1179 /* Try to increase robustness of max_prob_rate*/
1180 minstrel_ht_prob_rate_reduce_streams(mi);
1181 minstrel_ht_refill_sample_rates(mi);
1182
1183 #ifdef CONFIG_MAC80211_DEBUGFS
1184 /* use fixed index if set */
1185 if (mp->fixed_rate_idx != -1) {
1186 for (i = 0; i < 4; i++)
1187 mi->max_tp_rate[i] = mp->fixed_rate_idx;
1188 mi->max_prob_rate = mp->fixed_rate_idx;
1189 }
1190 #endif
1191
1192 /* Reset update timer */
1193 mi->last_stats_update = jiffies;
1194 mi->sample_time = jiffies;
1195 }
1196
1197 /*
1198 * Check whether an HT/VHT rate from a TX status entry maps to an entry
1199 * in the minstrel_ht rate tables. Values that cannot be represented
1200 * there must not be used for indexing mi->groups[] and the MCS groups.
1201 */
1202 static bool
minstrel_ht_txstat_rate_valid(struct ieee80211_tx_rate * rate)1203 minstrel_ht_txstat_rate_valid(struct ieee80211_tx_rate *rate)
1204 {
1205 unsigned int bw;
1206
1207 if (!(rate->flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS)))
1208 return true;
1209
1210 if (rate->flags & IEEE80211_TX_RC_MCS) {
1211 /* minstrel_ht supports up to MINSTREL_MAX_STREAMS streams */
1212 return rate->idx < MINSTREL_MAX_STREAMS * 8;
1213 }
1214
1215 /* minstrel_ht has no VHT groups for 160 MHz and wider */
1216 bw = !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
1217 2 * !!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH);
1218 if ((rate->flags & IEEE80211_TX_RC_160_MHZ_WIDTH) || bw > BW_80)
1219 return false;
1220
1221 return ieee80211_rate_get_vht_nss(rate) <= MINSTREL_MAX_STREAMS &&
1222 ieee80211_rate_get_vht_mcs(rate) < MCS_GROUP_RATES;
1223 }
1224
1225 static bool
minstrel_ht_ri_txstat_rate_valid(struct rate_info * rate)1226 minstrel_ht_ri_txstat_rate_valid(struct rate_info *rate)
1227 {
1228 if (!(rate->flags & (RATE_INFO_FLAGS_MCS | RATE_INFO_FLAGS_VHT_MCS)))
1229 return true;
1230
1231 if (rate->flags & RATE_INFO_FLAGS_MCS) {
1232 /* minstrel_ht supports up to MINSTREL_MAX_STREAMS streams */
1233 return rate->mcs < MINSTREL_MAX_STREAMS * 8;
1234 }
1235
1236 /* minstrel_ht has VHT groups only for 20/40/80 MHz */
1237 if (rate->bw != RATE_INFO_BW_20 && rate->bw != RATE_INFO_BW_40 &&
1238 rate->bw != RATE_INFO_BW_80)
1239 return false;
1240
1241 return rate->nss <= MINSTREL_MAX_STREAMS &&
1242 rate->mcs < MCS_GROUP_RATES;
1243 }
1244
1245 static bool
minstrel_ht_txstat_valid(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_tx_rate * rate)1246 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1247 struct ieee80211_tx_rate *rate)
1248 {
1249 int i;
1250
1251 if (rate->idx < 0)
1252 return false;
1253
1254 if (!rate->count)
1255 return false;
1256
1257 if (rate->flags & (IEEE80211_TX_RC_MCS | IEEE80211_TX_RC_VHT_MCS))
1258 return minstrel_ht_txstat_rate_valid(rate);
1259
1260 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1261 if (rate->idx == mp->cck_rates[i])
1262 return true;
1263
1264 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1265 if (rate->idx == mp->ofdm_rates[mi->band][i])
1266 return true;
1267
1268 return false;
1269 }
1270
1271 /*
1272 * Check whether rate_status contains valid information.
1273 */
1274 static bool
minstrel_ht_ri_txstat_valid(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_rate_status * rate_status)1275 minstrel_ht_ri_txstat_valid(struct minstrel_priv *mp,
1276 struct minstrel_ht_sta *mi,
1277 struct ieee80211_rate_status *rate_status)
1278 {
1279 int i;
1280
1281 if (!rate_status)
1282 return false;
1283 if (!rate_status->try_count)
1284 return false;
1285
1286 if (rate_status->rate_idx.flags &
1287 (RATE_INFO_FLAGS_MCS | RATE_INFO_FLAGS_VHT_MCS))
1288 return minstrel_ht_ri_txstat_rate_valid(&rate_status->rate_idx);
1289
1290 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) {
1291 if (rate_status->rate_idx.legacy ==
1292 minstrel_cck_bitrates[ mp->cck_rates[i] ])
1293 return true;
1294 }
1295
1296 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates); i++) {
1297 if (rate_status->rate_idx.legacy ==
1298 minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][i] ])
1299 return true;
1300 }
1301
1302 return false;
1303 }
1304
1305 static void
minstrel_downgrade_rate(struct minstrel_ht_sta * mi,u16 * idx,bool primary)1306 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1307 {
1308 int group, orig_group;
1309
1310 orig_group = group = MI_RATE_GROUP(*idx);
1311 while (group > 0) {
1312 group--;
1313
1314 if (!mi->supported[group])
1315 continue;
1316
1317 if (minstrel_mcs_groups[group].streams >
1318 minstrel_mcs_groups[orig_group].streams)
1319 continue;
1320
1321 if (primary)
1322 *idx = mi->groups[group].max_group_tp_rate[0];
1323 else
1324 *idx = mi->groups[group].max_group_tp_rate[1];
1325 break;
1326 }
1327 }
1328
1329 static void
minstrel_ht_tx_status(void * priv,struct ieee80211_supported_band * sband,void * priv_sta,struct ieee80211_tx_status * st)1330 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1331 void *priv_sta, struct ieee80211_tx_status *st)
1332 {
1333 struct ieee80211_tx_info *info = st->info;
1334 struct minstrel_ht_sta *mi = priv_sta;
1335 struct ieee80211_tx_rate *ar = info->status.rates;
1336 struct minstrel_rate_stats *rate, *rate2;
1337 struct minstrel_priv *mp = priv;
1338 u32 update_interval = mp->update_interval;
1339 bool last, update = false;
1340 int i;
1341
1342 /* Ignore packet that was sent with noAck flag */
1343 if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1344 return;
1345
1346 /* This packet was aggregated but doesn't carry status info */
1347 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1348 !(info->flags & IEEE80211_TX_STAT_AMPDU))
1349 return;
1350
1351 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1352 info->status.ampdu_ack_len =
1353 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1354 info->status.ampdu_len = 1;
1355 }
1356
1357 /* wraparound */
1358 if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1359 mi->total_packets = 0;
1360 mi->sample_packets = 0;
1361 }
1362
1363 mi->total_packets += info->status.ampdu_len;
1364 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1365 mi->sample_packets += info->status.ampdu_len;
1366
1367 mi->ampdu_packets++;
1368 mi->ampdu_len += info->status.ampdu_len;
1369
1370 if (st->rates && st->n_rates) {
1371 last = !minstrel_ht_ri_txstat_valid(mp, mi, &(st->rates[0]));
1372 for (i = 0; !last; i++) {
1373 last = (i == st->n_rates - 1) ||
1374 !minstrel_ht_ri_txstat_valid(mp, mi,
1375 &(st->rates[i + 1]));
1376
1377 rate = minstrel_ht_ri_get_stats(mp, mi,
1378 &(st->rates[i]));
1379
1380 if (last)
1381 rate->success += info->status.ampdu_ack_len;
1382
1383 rate->attempts += st->rates[i].try_count *
1384 info->status.ampdu_len;
1385 }
1386 } else {
1387 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1388 for (i = 0; !last; i++) {
1389 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1390 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1391
1392 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1393 if (last)
1394 rate->success += info->status.ampdu_ack_len;
1395
1396 rate->attempts += ar[i].count * info->status.ampdu_len;
1397 }
1398 }
1399
1400 if (mp->hw->max_rates > 1) {
1401 /*
1402 * check for sudden death of spatial multiplexing,
1403 * downgrade to a lower number of streams if necessary.
1404 */
1405 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1406 if (rate->attempts > 30 &&
1407 rate->success < rate->attempts / 4) {
1408 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1409 update = true;
1410 }
1411
1412 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1413 if (rate2->attempts > 30 &&
1414 rate2->success < rate2->attempts / 4) {
1415 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1416 update = true;
1417 }
1418 }
1419
1420 if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1421 update = true;
1422 minstrel_ht_update_stats(mp, mi);
1423 }
1424
1425 if (update)
1426 minstrel_ht_update_rates(mp, mi);
1427 }
1428
1429 static void
minstrel_calc_retransmit(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,int index)1430 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1431 int index)
1432 {
1433 struct minstrel_rate_stats *mrs;
1434 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1435 unsigned int cw = mp->cw_min;
1436 unsigned int ctime = 0;
1437 unsigned int t_slot = 9; /* FIXME */
1438 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1439 unsigned int overhead = 0, overhead_rtscts = 0;
1440
1441 mrs = minstrel_get_ratestats(mi, index);
1442 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1443 mrs->retry_count = 1;
1444 mrs->retry_count_rtscts = 1;
1445 return;
1446 }
1447
1448 mrs->retry_count = 2;
1449 mrs->retry_count_rtscts = 2;
1450 mrs->retry_updated = true;
1451
1452 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1453
1454 /* Contention time for first 2 tries */
1455 ctime = (t_slot * cw) >> 1;
1456 cw = min((cw << 1) | 1, mp->cw_max);
1457 ctime += (t_slot * cw) >> 1;
1458 cw = min((cw << 1) | 1, mp->cw_max);
1459
1460 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1461 overhead = mi->overhead_legacy;
1462 overhead_rtscts = mi->overhead_legacy_rtscts;
1463 } else {
1464 overhead = mi->overhead;
1465 overhead_rtscts = mi->overhead_rtscts;
1466 }
1467
1468 /* Total TX time for data and Contention after first 2 tries */
1469 tx_time = ctime + 2 * (overhead + tx_time_data);
1470 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1471
1472 /* See how many more tries we can fit inside segment size */
1473 do {
1474 /* Contention time for this try */
1475 ctime = (t_slot * cw) >> 1;
1476 cw = min((cw << 1) | 1, mp->cw_max);
1477
1478 /* Total TX time after this try */
1479 tx_time += ctime + overhead + tx_time_data;
1480 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1481
1482 if (tx_time_rtscts < mp->segment_size)
1483 mrs->retry_count_rtscts++;
1484 } while ((tx_time < mp->segment_size) &&
1485 (++mrs->retry_count < mp->max_retry));
1486 }
1487
1488
1489 static void
minstrel_ht_set_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_sta_rates * ratetbl,int offset,int index)1490 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1491 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1492 {
1493 int group_idx = MI_RATE_GROUP(index);
1494 const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1495 struct minstrel_rate_stats *mrs;
1496 u8 idx;
1497 u16 flags = group->flags;
1498
1499 mrs = minstrel_get_ratestats(mi, index);
1500 if (!mrs->retry_updated)
1501 minstrel_calc_retransmit(mp, mi, index);
1502
1503 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1504 ratetbl->rate[offset].count = 2;
1505 ratetbl->rate[offset].count_rts = 2;
1506 ratetbl->rate[offset].count_cts = 2;
1507 } else {
1508 ratetbl->rate[offset].count = mrs->retry_count;
1509 ratetbl->rate[offset].count_cts = mrs->retry_count;
1510 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1511 }
1512
1513 index = MI_RATE_IDX(index);
1514 if (group_idx == MINSTREL_CCK_GROUP)
1515 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1516 else if (group_idx == MINSTREL_OFDM_GROUP)
1517 idx = mp->ofdm_rates[mi->band][index %
1518 ARRAY_SIZE(mp->ofdm_rates[0])];
1519 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1520 idx = ((group->streams - 1) << 4) |
1521 (index & 0xF);
1522 else
1523 idx = index + (group->streams - 1) * 8;
1524
1525 /* enable RTS/CTS if needed:
1526 * - if station is in dynamic SMPS (and streams > 1)
1527 * - for fallback rates, to increase chances of getting through
1528 */
1529 if (offset > 0 ||
1530 (mi->sta->deflink.smps_mode == IEEE80211_SMPS_DYNAMIC &&
1531 group->streams > 1)) {
1532 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1533 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1534 }
1535
1536 ratetbl->rate[offset].idx = idx;
1537 ratetbl->rate[offset].flags = flags;
1538 }
1539
1540 static inline int
minstrel_ht_get_prob_avg(struct minstrel_ht_sta * mi,int rate)1541 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1542 {
1543 int group = MI_RATE_GROUP(rate);
1544 rate = MI_RATE_IDX(rate);
1545 return mi->groups[group].rates[rate].prob_avg;
1546 }
1547
1548 static int
minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta * mi)1549 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1550 {
1551 int group = MI_RATE_GROUP(mi->max_prob_rate);
1552 const struct mcs_group *g = &minstrel_mcs_groups[group];
1553 int rate = MI_RATE_IDX(mi->max_prob_rate);
1554 unsigned int duration;
1555
1556 /* Disable A-MSDU if max_prob_rate is bad */
1557 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1558 return 1;
1559
1560 duration = g->duration[rate];
1561 duration <<= g->shift;
1562
1563 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1564 if (duration > MCS_DURATION(1, 0, 52))
1565 return 500;
1566
1567 /*
1568 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1569 * data packet size
1570 */
1571 if (duration > MCS_DURATION(1, 0, 104))
1572 return 1600;
1573
1574 /*
1575 * If the rate is slower than single-stream MCS7, or if the max throughput
1576 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1577 * data packet size
1578 */
1579 if (duration > MCS_DURATION(1, 0, 260) ||
1580 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1581 MINSTREL_FRAC(75, 100)))
1582 return 3200;
1583
1584 /*
1585 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1586 * Since aggregation sessions are started/stopped without txq flush, use
1587 * the limit here to avoid the complexity of having to de-aggregate
1588 * packets in the queue.
1589 */
1590 if (!mi->sta->deflink.vht_cap.vht_supported)
1591 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1592
1593 /* unlimited */
1594 return 0;
1595 }
1596
1597 static void
minstrel_ht_update_rates(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1598 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1599 {
1600 struct ieee80211_sta_rates *rates;
1601 int i = 0;
1602 int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
1603
1604 rates = kzalloc_obj(*rates, GFP_ATOMIC);
1605 if (!rates)
1606 return;
1607
1608 /* Start with max_tp_rate[0] */
1609 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1610
1611 /* Fill up remaining, keep one entry for max_probe_rate */
1612 for (; i < (max_rates - 1); i++)
1613 minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]);
1614
1615 if (i < max_rates)
1616 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1617
1618 if (i < IEEE80211_TX_RATE_TABLE_SIZE)
1619 rates->rate[i].idx = -1;
1620
1621 mi->sta->deflink.agg.max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1622 ieee80211_sta_recalc_aggregates(mi->sta);
1623 rate_control_set_rates(mp->hw, mi->sta, rates);
1624 }
1625
1626 static u16
minstrel_ht_get_sample_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1627 minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1628 {
1629 u8 seq;
1630
1631 if (mp->hw->max_rates > 1) {
1632 seq = mi->sample_seq;
1633 mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1634 seq = minstrel_sample_seq[seq];
1635 } else {
1636 seq = MINSTREL_SAMPLE_TYPE_INC;
1637 }
1638
1639 return __minstrel_ht_get_sample_rate(mi, seq);
1640 }
1641
1642 static void
minstrel_ht_get_rate(void * priv,struct ieee80211_sta * sta,void * priv_sta,struct ieee80211_tx_rate_control * txrc)1643 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1644 struct ieee80211_tx_rate_control *txrc)
1645 {
1646 const struct mcs_group *sample_group;
1647 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1648 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1649 struct minstrel_ht_sta *mi = priv_sta;
1650 struct minstrel_priv *mp = priv;
1651 u16 sample_idx;
1652
1653 info->flags |= mi->tx_flags;
1654
1655 #ifdef CONFIG_MAC80211_DEBUGFS
1656 if (mp->fixed_rate_idx != -1)
1657 return;
1658 #endif
1659
1660 /* Don't use EAPOL frames for sampling on non-mrr hw */
1661 if (mp->hw->max_rates == 1 &&
1662 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1663 return;
1664
1665 if (time_is_after_jiffies(mi->sample_time))
1666 return;
1667
1668 mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1669 sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1670 if (!sample_idx)
1671 return;
1672
1673 sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1674 sample_idx = MI_RATE_IDX(sample_idx);
1675
1676 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1677 (sample_idx >= 4) != txrc->short_preamble)
1678 return;
1679
1680 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1681 rate->count = 1;
1682
1683 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1684 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1685 rate->idx = mp->cck_rates[idx];
1686 } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1687 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1688 rate->idx = mp->ofdm_rates[mi->band][idx];
1689 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1690 ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1691 sample_group->streams);
1692 } else {
1693 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1694 }
1695
1696 rate->flags = sample_group->flags;
1697 }
1698
1699 static void
minstrel_ht_update_cck(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta)1700 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1701 struct ieee80211_supported_band *sband,
1702 struct ieee80211_sta *sta)
1703 {
1704 int i;
1705
1706 if (sband->band != NL80211_BAND_2GHZ)
1707 return;
1708
1709 if (sta->deflink.ht_cap.ht_supported &&
1710 !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1711 return;
1712
1713 for (i = 0; i < 4; i++) {
1714 if (mp->cck_rates[i] == 0xff ||
1715 !rate_supported(sta, sband->band, mp->cck_rates[i]))
1716 continue;
1717
1718 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1719 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1720 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1721 }
1722 }
1723
1724 static void
minstrel_ht_update_ofdm(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta)1725 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1726 struct ieee80211_supported_band *sband,
1727 struct ieee80211_sta *sta)
1728 {
1729 const u8 *rates;
1730 int i;
1731
1732 if (sta->deflink.ht_cap.ht_supported)
1733 return;
1734
1735 rates = mp->ofdm_rates[sband->band];
1736 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1737 if (rates[i] == 0xff ||
1738 !rate_supported(sta, sband->band, rates[i]))
1739 continue;
1740
1741 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1742 }
1743 }
1744
1745 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)1746 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1747 struct cfg80211_chan_def *chandef,
1748 struct ieee80211_sta *sta, void *priv_sta)
1749 {
1750 struct minstrel_priv *mp = priv;
1751 struct minstrel_ht_sta *mi = priv_sta;
1752 struct ieee80211_mcs_info *mcs = &sta->deflink.ht_cap.mcs;
1753 u16 ht_cap = sta->deflink.ht_cap.cap;
1754 struct ieee80211_sta_vht_cap *vht_cap = &sta->deflink.vht_cap;
1755 const struct ieee80211_rate *ctl_rate;
1756 struct sta_info *sta_info;
1757 bool ldpc, erp;
1758 int use_vht;
1759 int ack_dur;
1760 int stbc;
1761 int i;
1762
1763 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1764
1765 if (vht_cap->vht_supported)
1766 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1767 else
1768 use_vht = 0;
1769
1770 memset(mi, 0, sizeof(*mi));
1771
1772 mi->sta = sta;
1773 mi->band = sband->band;
1774 mi->last_stats_update = jiffies;
1775
1776 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1);
1777 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1);
1778 mi->overhead += ack_dur;
1779 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1780
1781 ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1782 erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1783 ack_dur = ieee80211_frame_duration(sband->band, 10,
1784 ctl_rate->bitrate, erp, 1);
1785 mi->overhead_legacy = ack_dur;
1786 mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1787
1788 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1789
1790 if (!use_vht) {
1791 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1792 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1793
1794 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1795 } else {
1796 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1797 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1798
1799 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1800 }
1801
1802 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1803 if (ldpc)
1804 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1805
1806 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1807 u32 gflags = minstrel_mcs_groups[i].flags;
1808 int bw, nss;
1809
1810 mi->supported[i] = 0;
1811 if (minstrel_ht_is_legacy_group(i))
1812 continue;
1813
1814 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1815 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1816 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1817 continue;
1818 } else {
1819 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1820 continue;
1821 }
1822 }
1823
1824 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1825 sta->deflink.bandwidth < IEEE80211_STA_RX_BW_40)
1826 continue;
1827
1828 nss = minstrel_mcs_groups[i].streams;
1829
1830 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1831 if (sta->deflink.smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1832 continue;
1833
1834 /* HT rate */
1835 if (gflags & IEEE80211_TX_RC_MCS) {
1836 if (use_vht && minstrel_vht_only)
1837 continue;
1838
1839 mi->supported[i] = mcs->rx_mask[nss - 1];
1840 continue;
1841 }
1842
1843 /* VHT rate */
1844 if (!vht_cap->vht_supported ||
1845 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1846 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1847 continue;
1848
1849 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1850 if (sta->deflink.bandwidth < IEEE80211_STA_RX_BW_80 ||
1851 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1852 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1853 continue;
1854 }
1855 }
1856
1857 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1858 bw = BW_40;
1859 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1860 bw = BW_80;
1861 else
1862 bw = BW_20;
1863
1864 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1865 vht_cap->vht_mcs.tx_mcs_map);
1866 }
1867
1868 sta_info = container_of(sta, struct sta_info, sta);
1869 mi->use_short_preamble = test_sta_flag(sta_info, WLAN_STA_SHORT_PREAMBLE) &&
1870 sta_info->sdata->vif.bss_conf.use_short_preamble;
1871
1872 minstrel_ht_update_cck(mp, mi, sband, sta);
1873 minstrel_ht_update_ofdm(mp, mi, sband, sta);
1874
1875 /* create an initial rate table with the lowest supported rates */
1876 minstrel_ht_update_stats(mp, mi);
1877 minstrel_ht_update_rates(mp, mi);
1878 }
1879
1880 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)1881 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1882 struct cfg80211_chan_def *chandef,
1883 struct ieee80211_sta *sta, void *priv_sta)
1884 {
1885 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1886 }
1887
1888 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)1889 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1890 struct cfg80211_chan_def *chandef,
1891 struct ieee80211_sta *sta, void *priv_sta,
1892 u32 changed)
1893 {
1894 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1895 }
1896
1897 static void *
minstrel_ht_alloc_sta(void * priv,struct ieee80211_sta * sta,gfp_t gfp)1898 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1899 {
1900 return kzalloc_obj(struct minstrel_ht_sta, gfp);
1901 }
1902
1903 static void
minstrel_ht_free_sta(void * priv,struct ieee80211_sta * sta,void * priv_sta)1904 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1905 {
1906 kfree(priv_sta);
1907 }
1908
1909 static void
minstrel_ht_fill_rate_array(u8 * dest,struct ieee80211_supported_band * sband,const s16 * bitrates,int n_rates)1910 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1911 const s16 *bitrates, int n_rates)
1912 {
1913 int i, j;
1914
1915 for (i = 0; i < sband->n_bitrates; i++) {
1916 struct ieee80211_rate *rate = &sband->bitrates[i];
1917
1918 for (j = 0; j < n_rates; j++) {
1919 if (rate->bitrate != bitrates[j])
1920 continue;
1921
1922 dest[j] = i;
1923 break;
1924 }
1925 }
1926 }
1927
1928 static void
minstrel_ht_init_cck_rates(struct minstrel_priv * mp)1929 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1930 {
1931 static const s16 bitrates[4] = { 10, 20, 55, 110 };
1932 struct ieee80211_supported_band *sband;
1933
1934 memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1935 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1936 if (!sband)
1937 return;
1938
1939 BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1940 minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1941 minstrel_cck_bitrates,
1942 ARRAY_SIZE(minstrel_cck_bitrates));
1943 }
1944
1945 static void
minstrel_ht_init_ofdm_rates(struct minstrel_priv * mp,enum nl80211_band band)1946 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1947 {
1948 static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1949 struct ieee80211_supported_band *sband;
1950
1951 memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1952 sband = mp->hw->wiphy->bands[band];
1953 if (!sband)
1954 return;
1955
1956 BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1957 minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1958 minstrel_ofdm_bitrates,
1959 ARRAY_SIZE(minstrel_ofdm_bitrates));
1960 }
1961
1962 static void *
minstrel_ht_alloc(struct ieee80211_hw * hw)1963 minstrel_ht_alloc(struct ieee80211_hw *hw)
1964 {
1965 struct minstrel_priv *mp;
1966 int i;
1967
1968 mp = kzalloc_obj(struct minstrel_priv, GFP_ATOMIC);
1969 if (!mp)
1970 return NULL;
1971
1972 /* contention window settings
1973 * Just an approximation. Using the per-queue values would complicate
1974 * the calculations and is probably unnecessary */
1975 mp->cw_min = 15;
1976 mp->cw_max = 1023;
1977
1978 /* maximum time that the hw is allowed to stay in one MRR segment */
1979 mp->segment_size = 6000;
1980
1981 if (hw->max_rate_tries > 0)
1982 mp->max_retry = hw->max_rate_tries;
1983 else
1984 /* safe default, does not necessarily have to match hw properties */
1985 mp->max_retry = 7;
1986
1987 mp->hw = hw;
1988 mp->update_interval = HZ / 20;
1989
1990 minstrel_ht_init_cck_rates(mp);
1991 for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1992 minstrel_ht_init_ofdm_rates(mp, i);
1993
1994 return mp;
1995 }
1996
1997 #ifdef CONFIG_MAC80211_DEBUGFS
minstrel_ht_fixed_rate_idx_get(void * data,u64 * val)1998 static int minstrel_ht_fixed_rate_idx_get(void *data, u64 *val)
1999 {
2000 *val = *(u32 *)data;
2001 return 0;
2002 }
2003
minstrel_ht_fixed_rate_idx_set(void * data,u64 val)2004 static int minstrel_ht_fixed_rate_idx_set(void *data, u64 val)
2005 {
2006 u32 idx = val;
2007
2008 /* U32_MAX is the default and keeps fixed rate processing disabled */
2009 if (val != U32_MAX &&
2010 (val > U16_MAX ||
2011 MI_RATE_GROUP(idx) >= ARRAY_SIZE(minstrel_mcs_groups) ||
2012 MI_RATE_IDX(idx) >= MCS_GROUP_RATES))
2013 return -EINVAL;
2014
2015 *(u32 *)data = idx;
2016 return 0;
2017 }
2018
2019 DEFINE_DEBUGFS_ATTRIBUTE(minstrel_ht_fixed_rate_idx_fops,
2020 minstrel_ht_fixed_rate_idx_get,
2021 minstrel_ht_fixed_rate_idx_set, "%llu\n");
2022
minstrel_ht_add_debugfs(struct ieee80211_hw * hw,void * priv,struct dentry * debugfsdir)2023 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
2024 struct dentry *debugfsdir)
2025 {
2026 struct minstrel_priv *mp = priv;
2027
2028 mp->fixed_rate_idx = (u32) -1;
2029 debugfs_create_file("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
2030 &mp->fixed_rate_idx, &minstrel_ht_fixed_rate_idx_fops);
2031 }
2032 #endif
2033
2034 static void
minstrel_ht_free(void * priv)2035 minstrel_ht_free(void *priv)
2036 {
2037 kfree(priv);
2038 }
2039
minstrel_ht_get_expected_throughput(void * priv_sta)2040 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
2041 {
2042 struct minstrel_ht_sta *mi = priv_sta;
2043 int i, j, prob, tp_avg;
2044
2045 i = MI_RATE_GROUP(mi->max_tp_rate[0]);
2046 j = MI_RATE_IDX(mi->max_tp_rate[0]);
2047 prob = mi->groups[i].rates[j].prob_avg;
2048
2049 /* convert tp_avg from pkt per second in kbps */
2050 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
2051 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
2052
2053 return tp_avg;
2054 }
2055
2056 static const struct rate_control_ops mac80211_minstrel_ht = {
2057 .name = "minstrel_ht",
2058 .capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
2059 .tx_status_ext = minstrel_ht_tx_status,
2060 .get_rate = minstrel_ht_get_rate,
2061 .rate_init = minstrel_ht_rate_init,
2062 .rate_update = minstrel_ht_rate_update,
2063 .alloc_sta = minstrel_ht_alloc_sta,
2064 .free_sta = minstrel_ht_free_sta,
2065 .alloc = minstrel_ht_alloc,
2066 .free = minstrel_ht_free,
2067 #ifdef CONFIG_MAC80211_DEBUGFS
2068 .add_debugfs = minstrel_ht_add_debugfs,
2069 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
2070 #endif
2071 .get_expected_throughput = minstrel_ht_get_expected_throughput,
2072 };
2073
2074
init_sample_table(void)2075 static void __init init_sample_table(void)
2076 {
2077 int col, i, new_idx;
2078 u8 rnd[MCS_GROUP_RATES];
2079
2080 memset(sample_table, 0xff, sizeof(sample_table));
2081 for (col = 0; col < SAMPLE_COLUMNS; col++) {
2082 get_random_bytes(rnd, sizeof(rnd));
2083 for (i = 0; i < MCS_GROUP_RATES; i++) {
2084 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
2085 while (sample_table[col][new_idx] != 0xff)
2086 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
2087
2088 sample_table[col][new_idx] = i;
2089 }
2090 }
2091 }
2092
2093 int __init
rc80211_minstrel_init(void)2094 rc80211_minstrel_init(void)
2095 {
2096 init_sample_table();
2097 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
2098 }
2099
2100 void
rc80211_minstrel_exit(void)2101 rc80211_minstrel_exit(void)
2102 {
2103 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
2104 }
2105