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Merge existing fixes from regulator/for-5.14
[mirror_ubuntu-jammy-kernel.git] / net / mac80211 / rc80211_minstrel_ht.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2019-2020 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 <net/mac80211.h>
14 #include "rate.h"
15 #include "sta_info.h"
16 #include "rc80211_minstrel_ht.h"
17
18 #define AVG_AMPDU_SIZE 16
19 #define AVG_PKT_SIZE 1200
20
21 #define SAMPLE_SWITCH_THR 100
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
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
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
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 static int
339 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
340 {
341 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
342 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
343 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
344 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
345 }
346
347 static struct minstrel_rate_stats *
348 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
349 struct ieee80211_tx_rate *rate)
350 {
351 int group, idx;
352
353 if (rate->flags & IEEE80211_TX_RC_MCS) {
354 group = minstrel_ht_get_group_idx(rate);
355 idx = rate->idx % 8;
356 goto out;
357 }
358
359 if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
360 group = minstrel_vht_get_group_idx(rate);
361 idx = ieee80211_rate_get_vht_mcs(rate);
362 goto out;
363 }
364
365 group = MINSTREL_CCK_GROUP;
366 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
367 if (rate->idx != mp->cck_rates[idx])
368 continue;
369
370 /* short preamble */
371 if ((mi->supported[group] & BIT(idx + 4)) &&
372 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
373 idx += 4;
374 goto out;
375 }
376
377 group = MINSTREL_OFDM_GROUP;
378 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
379 if (rate->idx == mp->ofdm_rates[mi->band][idx])
380 goto out;
381
382 idx = 0;
383 out:
384 return &mi->groups[group].rates[idx];
385 }
386
387 static inline struct minstrel_rate_stats *
388 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
389 {
390 return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
391 }
392
393 static inline int minstrel_get_duration(int index)
394 {
395 const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
396 unsigned int duration = group->duration[MI_RATE_IDX(index)];
397
398 return duration << group->shift;
399 }
400
401 static unsigned int
402 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
403 {
404 int duration;
405
406 if (mi->avg_ampdu_len)
407 return MINSTREL_TRUNC(mi->avg_ampdu_len);
408
409 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
410 return 1;
411
412 duration = minstrel_get_duration(mi->max_tp_rate[0]);
413
414 if (duration > 400 * 1000)
415 return 2;
416
417 if (duration > 250 * 1000)
418 return 4;
419
420 if (duration > 150 * 1000)
421 return 8;
422
423 return 16;
424 }
425
426 /*
427 * Return current throughput based on the average A-MPDU length, taking into
428 * account the expected number of retransmissions and their expected length
429 */
430 int
431 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
432 int prob_avg)
433 {
434 unsigned int nsecs = 0, overhead = mi->overhead;
435 unsigned int ampdu_len = 1;
436
437 /* do not account throughput if success prob is below 10% */
438 if (prob_avg < MINSTREL_FRAC(10, 100))
439 return 0;
440
441 if (minstrel_ht_is_legacy_group(group))
442 overhead = mi->overhead_legacy;
443 else
444 ampdu_len = minstrel_ht_avg_ampdu_len(mi);
445
446 nsecs = 1000 * overhead / ampdu_len;
447 nsecs += minstrel_mcs_groups[group].duration[rate] <<
448 minstrel_mcs_groups[group].shift;
449
450 /*
451 * For the throughput calculation, limit the probability value to 90% to
452 * account for collision related packet error rate fluctuation
453 * (prob is scaled - see MINSTREL_FRAC above)
454 */
455 if (prob_avg > MINSTREL_FRAC(90, 100))
456 prob_avg = MINSTREL_FRAC(90, 100);
457
458 return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
459 }
460
461 /*
462 * Find & sort topmost throughput rates
463 *
464 * If multiple rates provide equal throughput the sorting is based on their
465 * current success probability. Higher success probability is preferred among
466 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
467 */
468 static void
469 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
470 u16 *tp_list)
471 {
472 int cur_group, cur_idx, cur_tp_avg, cur_prob;
473 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
474 int j = MAX_THR_RATES;
475
476 cur_group = MI_RATE_GROUP(index);
477 cur_idx = MI_RATE_IDX(index);
478 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
479 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
480
481 do {
482 tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
483 tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
484 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
485 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
486 tmp_prob);
487 if (cur_tp_avg < tmp_tp_avg ||
488 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
489 break;
490 j--;
491 } while (j > 0);
492
493 if (j < MAX_THR_RATES - 1) {
494 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
495 (MAX_THR_RATES - (j + 1))));
496 }
497 if (j < MAX_THR_RATES)
498 tp_list[j] = index;
499 }
500
501 /*
502 * Find and set the topmost probability rate per sta and per group
503 */
504 static void
505 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
506 {
507 struct minstrel_mcs_group_data *mg;
508 struct minstrel_rate_stats *mrs;
509 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
510 int max_tp_group, max_tp_idx, max_tp_prob;
511 int cur_tp_avg, cur_group, cur_idx;
512 int max_gpr_group, max_gpr_idx;
513 int max_gpr_tp_avg, max_gpr_prob;
514
515 cur_group = MI_RATE_GROUP(index);
516 cur_idx = MI_RATE_IDX(index);
517 mg = &mi->groups[cur_group];
518 mrs = &mg->rates[cur_idx];
519
520 tmp_group = MI_RATE_GROUP(*dest);
521 tmp_idx = MI_RATE_IDX(*dest);
522 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
523 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
524
525 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
526 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
527 max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
528 max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
529 max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
530
531 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
532 !minstrel_ht_is_legacy_group(max_tp_group))
533 return;
534
535 /* skip rates faster than max tp rate with lower prob */
536 if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
537 mrs->prob_avg < max_tp_prob)
538 return;
539
540 max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
541 max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
542 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
543
544 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
545 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
546 mrs->prob_avg);
547 if (cur_tp_avg > tmp_tp_avg)
548 *dest = index;
549
550 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
551 max_gpr_idx,
552 max_gpr_prob);
553 if (cur_tp_avg > max_gpr_tp_avg)
554 mg->max_group_prob_rate = index;
555 } else {
556 if (mrs->prob_avg > tmp_prob)
557 *dest = index;
558 if (mrs->prob_avg > max_gpr_prob)
559 mg->max_group_prob_rate = index;
560 }
561 }
562
563
564 /*
565 * Assign new rate set per sta and use CCK rates only if the fastest
566 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
567 * rate sets where MCS and CCK rates are mixed, because CCK rates can
568 * not use aggregation.
569 */
570 static void
571 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
572 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
573 u16 tmp_legacy_tp_rate[MAX_THR_RATES])
574 {
575 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
576 int i;
577
578 tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
579 tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
580 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
581 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
582
583 tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
584 tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
585 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
586 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
587
588 if (tmp_cck_tp > tmp_mcs_tp) {
589 for(i = 0; i < MAX_THR_RATES; i++) {
590 minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
591 tmp_mcs_tp_rate);
592 }
593 }
594
595 }
596
597 /*
598 * Try to increase robustness of max_prob rate by decrease number of
599 * streams if possible.
600 */
601 static inline void
602 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
603 {
604 struct minstrel_mcs_group_data *mg;
605 int tmp_max_streams, group, tmp_idx, tmp_prob;
606 int tmp_tp = 0;
607
608 if (!mi->sta->ht_cap.ht_supported)
609 return;
610
611 group = MI_RATE_GROUP(mi->max_tp_rate[0]);
612 tmp_max_streams = minstrel_mcs_groups[group].streams;
613 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
614 mg = &mi->groups[group];
615 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
616 continue;
617
618 tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
619 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
620
621 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
622 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
623 mi->max_prob_rate = mg->max_group_prob_rate;
624 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
625 tmp_idx,
626 tmp_prob);
627 }
628 }
629 }
630
631 static u16
632 __minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
633 enum minstrel_sample_type type)
634 {
635 u16 *rates = mi->sample[type].sample_rates;
636 u16 cur;
637 int i;
638
639 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
640 if (!rates[i])
641 continue;
642
643 cur = rates[i];
644 rates[i] = 0;
645 return cur;
646 }
647
648 return 0;
649 }
650
651 static inline int
652 minstrel_ewma(int old, int new, int weight)
653 {
654 int diff, incr;
655
656 diff = new - old;
657 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
658
659 return old + incr;
660 }
661
662 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
663 {
664 s32 out_1 = *prev_1;
665 s32 out_2 = *prev_2;
666 s32 val;
667
668 if (!in)
669 in += 1;
670
671 if (!out_1) {
672 val = out_1 = in;
673 goto out;
674 }
675
676 val = MINSTREL_AVG_COEFF1 * in;
677 val += MINSTREL_AVG_COEFF2 * out_1;
678 val += MINSTREL_AVG_COEFF3 * out_2;
679 val >>= MINSTREL_SCALE;
680
681 if (val > 1 << MINSTREL_SCALE)
682 val = 1 << MINSTREL_SCALE;
683 if (val < 0)
684 val = 1;
685
686 out:
687 *prev_2 = out_1;
688 *prev_1 = val;
689
690 return val;
691 }
692
693 /*
694 * Recalculate statistics and counters of a given rate
695 */
696 static void
697 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
698 struct minstrel_rate_stats *mrs)
699 {
700 unsigned int cur_prob;
701
702 if (unlikely(mrs->attempts > 0)) {
703 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
704 minstrel_filter_avg_add(&mrs->prob_avg,
705 &mrs->prob_avg_1, cur_prob);
706 mrs->att_hist += mrs->attempts;
707 mrs->succ_hist += mrs->success;
708 }
709
710 mrs->last_success = mrs->success;
711 mrs->last_attempts = mrs->attempts;
712 mrs->success = 0;
713 mrs->attempts = 0;
714 }
715
716 static bool
717 minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
718 {
719 int i;
720
721 for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
722 u16 cur = mi->sample[type].sample_rates[i];
723
724 if (cur == idx)
725 return true;
726
727 if (!cur)
728 break;
729 }
730
731 return false;
732 }
733
734 static int
735 minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
736 u32 fast_rate_dur, u32 slow_rate_dur)
737 {
738 u16 *rates = mi->sample[type].sample_rates;
739 int i, j;
740
741 for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
742 u32 duration;
743 bool valid = false;
744 u16 cur;
745
746 cur = rates[i];
747 if (!cur)
748 continue;
749
750 duration = minstrel_get_duration(cur);
751 switch (type) {
752 case MINSTREL_SAMPLE_TYPE_SLOW:
753 valid = duration > fast_rate_dur &&
754 duration < slow_rate_dur;
755 break;
756 case MINSTREL_SAMPLE_TYPE_INC:
757 case MINSTREL_SAMPLE_TYPE_JUMP:
758 valid = duration < fast_rate_dur;
759 break;
760 default:
761 valid = false;
762 break;
763 }
764
765 if (!valid) {
766 rates[i] = 0;
767 continue;
768 }
769
770 if (i == j)
771 continue;
772
773 rates[j++] = cur;
774 rates[i] = 0;
775 }
776
777 return j;
778 }
779
780 static int
781 minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
782 u32 max_duration)
783 {
784 u16 supported = mi->supported[group];
785 int i;
786
787 for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
788 if (!(supported & BIT(0)))
789 continue;
790
791 if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
792 continue;
793
794 return i;
795 }
796
797 return -1;
798 }
799
800 /*
801 * Incremental update rates:
802 * Flip through groups and pick the first group rate that is faster than the
803 * highest currently selected rate
804 */
805 static u16
806 minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
807 {
808 u8 type = MINSTREL_SAMPLE_TYPE_INC;
809 int i, index = 0;
810 u8 group;
811
812 group = mi->sample[type].sample_group;
813 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
814 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
815
816 index = minstrel_ht_group_min_rate_offset(mi, group,
817 fast_rate_dur);
818 if (index < 0)
819 continue;
820
821 index = MI_RATE(group, index & 0xf);
822 if (!minstrel_ht_find_sample_rate(mi, type, index))
823 goto out;
824 }
825 index = 0;
826
827 out:
828 mi->sample[type].sample_group = group;
829
830 return index;
831 }
832
833 static int
834 minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
835 u16 supported, int offset)
836 {
837 struct minstrel_mcs_group_data *mg = &mi->groups[group];
838 u16 idx;
839 int i;
840
841 for (i = 0; i < MCS_GROUP_RATES; i++) {
842 idx = sample_table[mg->column][mg->index];
843 if (++mg->index >= MCS_GROUP_RATES) {
844 mg->index = 0;
845 if (++mg->column >= ARRAY_SIZE(sample_table))
846 mg->column = 0;
847 }
848
849 if (idx < offset)
850 continue;
851
852 if (!(supported & BIT(idx)))
853 continue;
854
855 return MI_RATE(group, idx);
856 }
857
858 return -1;
859 }
860
861 /*
862 * Jump rates:
863 * Sample random rates, use those that are faster than the highest
864 * currently selected rate. Rates between the fastest and the slowest
865 * get sorted into the slow sample bucket, but only if it has room
866 */
867 static u16
868 minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
869 u32 slow_rate_dur, int *slow_rate_ofs)
870 {
871 struct minstrel_rate_stats *mrs;
872 u32 max_duration = slow_rate_dur;
873 int i, index, offset;
874 u16 *slow_rates;
875 u16 supported;
876 u32 duration;
877 u8 group;
878
879 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
880 max_duration = fast_rate_dur;
881
882 slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
883 group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
884 for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
885 u8 type;
886
887 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
888
889 supported = mi->supported[group];
890 if (!supported)
891 continue;
892
893 offset = minstrel_ht_group_min_rate_offset(mi, group,
894 max_duration);
895 if (offset < 0)
896 continue;
897
898 index = minstrel_ht_next_group_sample_rate(mi, group, supported,
899 offset);
900 if (index < 0)
901 continue;
902
903 duration = minstrel_get_duration(index);
904 if (duration < fast_rate_dur)
905 type = MINSTREL_SAMPLE_TYPE_JUMP;
906 else
907 type = MINSTREL_SAMPLE_TYPE_SLOW;
908
909 if (minstrel_ht_find_sample_rate(mi, type, index))
910 continue;
911
912 if (type == MINSTREL_SAMPLE_TYPE_JUMP)
913 goto found;
914
915 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
916 continue;
917
918 if (duration >= slow_rate_dur)
919 continue;
920
921 /* skip slow rates with high success probability */
922 mrs = minstrel_get_ratestats(mi, index);
923 if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
924 continue;
925
926 slow_rates[(*slow_rate_ofs)++] = index;
927 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
928 max_duration = fast_rate_dur;
929 }
930 index = 0;
931
932 found:
933 mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
934
935 return index;
936 }
937
938 static void
939 minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
940 {
941 u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
942 u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
943 u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
944 u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
945 u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
946 u16 *rates;
947 int i, j;
948
949 rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
950 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
951 fast_rate_dur, slow_rate_dur);
952 while (i < MINSTREL_SAMPLE_RATES) {
953 rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
954 if (!rates[i])
955 break;
956
957 i++;
958 }
959
960 rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
961 i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
962 fast_rate_dur, slow_rate_dur);
963 j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
964 fast_rate_dur, slow_rate_dur);
965 while (i < MINSTREL_SAMPLE_RATES) {
966 rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
967 slow_rate_dur, &j);
968 if (!rates[i])
969 break;
970
971 i++;
972 }
973
974 for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
975 memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
976 sizeof(mi->sample[i].cur_sample_rates));
977 }
978
979
980 /*
981 * Update rate statistics and select new primary rates
982 *
983 * Rules for rate selection:
984 * - max_prob_rate must use only one stream, as a tradeoff between delivery
985 * probability and throughput during strong fluctuations
986 * - as long as the max prob rate has a probability of more than 75%, pick
987 * higher throughput rates, even if the probablity is a bit lower
988 */
989 static void
990 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
991 {
992 struct minstrel_mcs_group_data *mg;
993 struct minstrel_rate_stats *mrs;
994 int group, i, j, cur_prob;
995 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
996 u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
997 u16 index;
998 bool ht_supported = mi->sta->ht_cap.ht_supported;
999
1000 if (mi->ampdu_packets > 0) {
1001 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1002 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1003 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1004 EWMA_LEVEL);
1005 else
1006 mi->avg_ampdu_len = 0;
1007 mi->ampdu_len = 0;
1008 mi->ampdu_packets = 0;
1009 }
1010
1011 if (mi->supported[MINSTREL_CCK_GROUP])
1012 group = MINSTREL_CCK_GROUP;
1013 else if (mi->supported[MINSTREL_OFDM_GROUP])
1014 group = MINSTREL_OFDM_GROUP;
1015 else
1016 group = 0;
1017
1018 index = MI_RATE(group, 0);
1019 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1020 tmp_legacy_tp_rate[j] = index;
1021
1022 if (mi->supported[MINSTREL_VHT_GROUP_0])
1023 group = MINSTREL_VHT_GROUP_0;
1024 else if (ht_supported)
1025 group = MINSTREL_HT_GROUP_0;
1026 else if (mi->supported[MINSTREL_CCK_GROUP])
1027 group = MINSTREL_CCK_GROUP;
1028 else
1029 group = MINSTREL_OFDM_GROUP;
1030
1031 index = MI_RATE(group, 0);
1032 tmp_max_prob_rate = index;
1033 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1034 tmp_mcs_tp_rate[j] = index;
1035
1036 /* Find best rate sets within all MCS groups*/
1037 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1038 u16 *tp_rate = tmp_mcs_tp_rate;
1039 u16 last_prob = 0;
1040
1041 mg = &mi->groups[group];
1042 if (!mi->supported[group])
1043 continue;
1044
1045 /* (re)Initialize group rate indexes */
1046 for(j = 0; j < MAX_THR_RATES; j++)
1047 tmp_group_tp_rate[j] = MI_RATE(group, 0);
1048
1049 if (group == MINSTREL_CCK_GROUP && ht_supported)
1050 tp_rate = tmp_legacy_tp_rate;
1051
1052 for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1053 if (!(mi->supported[group] & BIT(i)))
1054 continue;
1055
1056 index = MI_RATE(group, i);
1057
1058 mrs = &mg->rates[i];
1059 mrs->retry_updated = false;
1060 minstrel_ht_calc_rate_stats(mp, mrs);
1061
1062 if (mrs->att_hist)
1063 last_prob = max(last_prob, mrs->prob_avg);
1064 else
1065 mrs->prob_avg = max(last_prob, mrs->prob_avg);
1066 cur_prob = mrs->prob_avg;
1067
1068 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1069 continue;
1070
1071 /* Find max throughput rate set */
1072 minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
1073
1074 /* Find max throughput rate set within a group */
1075 minstrel_ht_sort_best_tp_rates(mi, index,
1076 tmp_group_tp_rate);
1077 }
1078
1079 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1080 sizeof(mg->max_group_tp_rate));
1081 }
1082
1083 /* Assign new rate set per sta */
1084 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1085 tmp_legacy_tp_rate);
1086 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1087
1088 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1089 if (!mi->supported[group])
1090 continue;
1091
1092 mg = &mi->groups[group];
1093 mg->max_group_prob_rate = MI_RATE(group, 0);
1094
1095 for (i = 0; i < MCS_GROUP_RATES; i++) {
1096 if (!(mi->supported[group] & BIT(i)))
1097 continue;
1098
1099 index = MI_RATE(group, i);
1100
1101 /* Find max probability rate per group and global */
1102 minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1103 index);
1104 }
1105 }
1106
1107 mi->max_prob_rate = tmp_max_prob_rate;
1108
1109 /* Try to increase robustness of max_prob_rate*/
1110 minstrel_ht_prob_rate_reduce_streams(mi);
1111 minstrel_ht_refill_sample_rates(mi);
1112
1113 #ifdef CONFIG_MAC80211_DEBUGFS
1114 /* use fixed index if set */
1115 if (mp->fixed_rate_idx != -1) {
1116 for (i = 0; i < 4; i++)
1117 mi->max_tp_rate[i] = mp->fixed_rate_idx;
1118 mi->max_prob_rate = mp->fixed_rate_idx;
1119 }
1120 #endif
1121
1122 /* Reset update timer */
1123 mi->last_stats_update = jiffies;
1124 mi->sample_time = jiffies;
1125 }
1126
1127 static bool
1128 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1129 struct ieee80211_tx_rate *rate)
1130 {
1131 int i;
1132
1133 if (rate->idx < 0)
1134 return false;
1135
1136 if (!rate->count)
1137 return false;
1138
1139 if (rate->flags & IEEE80211_TX_RC_MCS ||
1140 rate->flags & IEEE80211_TX_RC_VHT_MCS)
1141 return true;
1142
1143 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1144 if (rate->idx == mp->cck_rates[i])
1145 return true;
1146
1147 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1148 if (rate->idx == mp->ofdm_rates[mi->band][i])
1149 return true;
1150
1151 return false;
1152 }
1153
1154 static void
1155 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1156 {
1157 int group, orig_group;
1158
1159 orig_group = group = MI_RATE_GROUP(*idx);
1160 while (group > 0) {
1161 group--;
1162
1163 if (!mi->supported[group])
1164 continue;
1165
1166 if (minstrel_mcs_groups[group].streams >
1167 minstrel_mcs_groups[orig_group].streams)
1168 continue;
1169
1170 if (primary)
1171 *idx = mi->groups[group].max_group_tp_rate[0];
1172 else
1173 *idx = mi->groups[group].max_group_tp_rate[1];
1174 break;
1175 }
1176 }
1177
1178 static void
1179 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1180 void *priv_sta, struct ieee80211_tx_status *st)
1181 {
1182 struct ieee80211_tx_info *info = st->info;
1183 struct minstrel_ht_sta *mi = priv_sta;
1184 struct ieee80211_tx_rate *ar = info->status.rates;
1185 struct minstrel_rate_stats *rate, *rate2;
1186 struct minstrel_priv *mp = priv;
1187 u32 update_interval = mp->update_interval;
1188 bool last, update = false;
1189 int i;
1190
1191 /* Ignore packet that was sent with noAck flag */
1192 if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1193 return;
1194
1195 /* This packet was aggregated but doesn't carry status info */
1196 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1197 !(info->flags & IEEE80211_TX_STAT_AMPDU))
1198 return;
1199
1200 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1201 info->status.ampdu_ack_len =
1202 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1203 info->status.ampdu_len = 1;
1204 }
1205
1206 /* wraparound */
1207 if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1208 mi->total_packets = 0;
1209 mi->sample_packets = 0;
1210 }
1211
1212 mi->total_packets += info->status.ampdu_len;
1213 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1214 mi->sample_packets += info->status.ampdu_len;
1215
1216 mi->ampdu_packets++;
1217 mi->ampdu_len += info->status.ampdu_len;
1218
1219 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1220 for (i = 0; !last; i++) {
1221 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1222 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1223
1224 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1225 if (last)
1226 rate->success += info->status.ampdu_ack_len;
1227
1228 rate->attempts += ar[i].count * info->status.ampdu_len;
1229 }
1230
1231 if (mp->hw->max_rates > 1) {
1232 /*
1233 * check for sudden death of spatial multiplexing,
1234 * downgrade to a lower number of streams if necessary.
1235 */
1236 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1237 if (rate->attempts > 30 &&
1238 rate->success < rate->attempts / 4) {
1239 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1240 update = true;
1241 }
1242
1243 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1244 if (rate2->attempts > 30 &&
1245 rate2->success < rate2->attempts / 4) {
1246 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1247 update = true;
1248 }
1249 }
1250
1251 if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1252 update = true;
1253 minstrel_ht_update_stats(mp, mi);
1254 }
1255
1256 if (update)
1257 minstrel_ht_update_rates(mp, mi);
1258 }
1259
1260 static void
1261 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1262 int index)
1263 {
1264 struct minstrel_rate_stats *mrs;
1265 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1266 unsigned int cw = mp->cw_min;
1267 unsigned int ctime = 0;
1268 unsigned int t_slot = 9; /* FIXME */
1269 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1270 unsigned int overhead = 0, overhead_rtscts = 0;
1271
1272 mrs = minstrel_get_ratestats(mi, index);
1273 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1274 mrs->retry_count = 1;
1275 mrs->retry_count_rtscts = 1;
1276 return;
1277 }
1278
1279 mrs->retry_count = 2;
1280 mrs->retry_count_rtscts = 2;
1281 mrs->retry_updated = true;
1282
1283 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1284
1285 /* Contention time for first 2 tries */
1286 ctime = (t_slot * cw) >> 1;
1287 cw = min((cw << 1) | 1, mp->cw_max);
1288 ctime += (t_slot * cw) >> 1;
1289 cw = min((cw << 1) | 1, mp->cw_max);
1290
1291 if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1292 overhead = mi->overhead_legacy;
1293 overhead_rtscts = mi->overhead_legacy_rtscts;
1294 } else {
1295 overhead = mi->overhead;
1296 overhead_rtscts = mi->overhead_rtscts;
1297 }
1298
1299 /* Total TX time for data and Contention after first 2 tries */
1300 tx_time = ctime + 2 * (overhead + tx_time_data);
1301 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1302
1303 /* See how many more tries we can fit inside segment size */
1304 do {
1305 /* Contention time for this try */
1306 ctime = (t_slot * cw) >> 1;
1307 cw = min((cw << 1) | 1, mp->cw_max);
1308
1309 /* Total TX time after this try */
1310 tx_time += ctime + overhead + tx_time_data;
1311 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1312
1313 if (tx_time_rtscts < mp->segment_size)
1314 mrs->retry_count_rtscts++;
1315 } while ((tx_time < mp->segment_size) &&
1316 (++mrs->retry_count < mp->max_retry));
1317 }
1318
1319
1320 static void
1321 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1322 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1323 {
1324 int group_idx = MI_RATE_GROUP(index);
1325 const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1326 struct minstrel_rate_stats *mrs;
1327 u8 idx;
1328 u16 flags = group->flags;
1329
1330 mrs = minstrel_get_ratestats(mi, index);
1331 if (!mrs->retry_updated)
1332 minstrel_calc_retransmit(mp, mi, index);
1333
1334 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1335 ratetbl->rate[offset].count = 2;
1336 ratetbl->rate[offset].count_rts = 2;
1337 ratetbl->rate[offset].count_cts = 2;
1338 } else {
1339 ratetbl->rate[offset].count = mrs->retry_count;
1340 ratetbl->rate[offset].count_cts = mrs->retry_count;
1341 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1342 }
1343
1344 index = MI_RATE_IDX(index);
1345 if (group_idx == MINSTREL_CCK_GROUP)
1346 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1347 else if (group_idx == MINSTREL_OFDM_GROUP)
1348 idx = mp->ofdm_rates[mi->band][index %
1349 ARRAY_SIZE(mp->ofdm_rates[0])];
1350 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1351 idx = ((group->streams - 1) << 4) |
1352 (index & 0xF);
1353 else
1354 idx = index + (group->streams - 1) * 8;
1355
1356 /* enable RTS/CTS if needed:
1357 * - if station is in dynamic SMPS (and streams > 1)
1358 * - for fallback rates, to increase chances of getting through
1359 */
1360 if (offset > 0 ||
1361 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
1362 group->streams > 1)) {
1363 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1364 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1365 }
1366
1367 ratetbl->rate[offset].idx = idx;
1368 ratetbl->rate[offset].flags = flags;
1369 }
1370
1371 static inline int
1372 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1373 {
1374 int group = MI_RATE_GROUP(rate);
1375 rate = MI_RATE_IDX(rate);
1376 return mi->groups[group].rates[rate].prob_avg;
1377 }
1378
1379 static int
1380 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1381 {
1382 int group = MI_RATE_GROUP(mi->max_prob_rate);
1383 const struct mcs_group *g = &minstrel_mcs_groups[group];
1384 int rate = MI_RATE_IDX(mi->max_prob_rate);
1385 unsigned int duration;
1386
1387 /* Disable A-MSDU if max_prob_rate is bad */
1388 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1389 return 1;
1390
1391 duration = g->duration[rate];
1392 duration <<= g->shift;
1393
1394 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1395 if (duration > MCS_DURATION(1, 0, 52))
1396 return 500;
1397
1398 /*
1399 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1400 * data packet size
1401 */
1402 if (duration > MCS_DURATION(1, 0, 104))
1403 return 1600;
1404
1405 /*
1406 * If the rate is slower than single-stream MCS7, or if the max throughput
1407 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1408 * data packet size
1409 */
1410 if (duration > MCS_DURATION(1, 0, 260) ||
1411 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1412 MINSTREL_FRAC(75, 100)))
1413 return 3200;
1414
1415 /*
1416 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1417 * Since aggregation sessions are started/stopped without txq flush, use
1418 * the limit here to avoid the complexity of having to de-aggregate
1419 * packets in the queue.
1420 */
1421 if (!mi->sta->vht_cap.vht_supported)
1422 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1423
1424 /* unlimited */
1425 return 0;
1426 }
1427
1428 static void
1429 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1430 {
1431 struct ieee80211_sta_rates *rates;
1432 int i = 0;
1433
1434 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1435 if (!rates)
1436 return;
1437
1438 /* Start with max_tp_rate[0] */
1439 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1440
1441 if (mp->hw->max_rates >= 3) {
1442 /* At least 3 tx rates supported, use max_tp_rate[1] next */
1443 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1444 }
1445
1446 if (mp->hw->max_rates >= 2) {
1447 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1448 }
1449
1450 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1451 rates->rate[i].idx = -1;
1452 rate_control_set_rates(mp->hw, mi->sta, rates);
1453 }
1454
1455 static u16
1456 minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1457 {
1458 u8 seq;
1459
1460 if (mp->hw->max_rates > 1) {
1461 seq = mi->sample_seq;
1462 mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1463 seq = minstrel_sample_seq[seq];
1464 } else {
1465 seq = MINSTREL_SAMPLE_TYPE_INC;
1466 }
1467
1468 return __minstrel_ht_get_sample_rate(mi, seq);
1469 }
1470
1471 static void
1472 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1473 struct ieee80211_tx_rate_control *txrc)
1474 {
1475 const struct mcs_group *sample_group;
1476 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1477 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1478 struct minstrel_ht_sta *mi = priv_sta;
1479 struct minstrel_priv *mp = priv;
1480 u16 sample_idx;
1481
1482 info->flags |= mi->tx_flags;
1483
1484 #ifdef CONFIG_MAC80211_DEBUGFS
1485 if (mp->fixed_rate_idx != -1)
1486 return;
1487 #endif
1488
1489 /* Don't use EAPOL frames for sampling on non-mrr hw */
1490 if (mp->hw->max_rates == 1 &&
1491 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1492 return;
1493
1494 if (time_is_after_jiffies(mi->sample_time))
1495 return;
1496
1497 mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1498 sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1499 if (!sample_idx)
1500 return;
1501
1502 sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1503 sample_idx = MI_RATE_IDX(sample_idx);
1504
1505 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1506 (sample_idx >= 4) != txrc->short_preamble)
1507 return;
1508
1509 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1510 rate->count = 1;
1511
1512 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1513 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1514 rate->idx = mp->cck_rates[idx];
1515 } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1516 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1517 rate->idx = mp->ofdm_rates[mi->band][idx];
1518 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1519 ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1520 sample_group->streams);
1521 } else {
1522 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1523 }
1524
1525 rate->flags = sample_group->flags;
1526 }
1527
1528 static void
1529 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1530 struct ieee80211_supported_band *sband,
1531 struct ieee80211_sta *sta)
1532 {
1533 int i;
1534
1535 if (sband->band != NL80211_BAND_2GHZ)
1536 return;
1537
1538 if (sta->ht_cap.ht_supported &&
1539 !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1540 return;
1541
1542 for (i = 0; i < 4; i++) {
1543 if (mp->cck_rates[i] == 0xff ||
1544 !rate_supported(sta, sband->band, mp->cck_rates[i]))
1545 continue;
1546
1547 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1548 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1549 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1550 }
1551 }
1552
1553 static void
1554 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1555 struct ieee80211_supported_band *sband,
1556 struct ieee80211_sta *sta)
1557 {
1558 const u8 *rates;
1559 int i;
1560
1561 if (sta->ht_cap.ht_supported)
1562 return;
1563
1564 rates = mp->ofdm_rates[sband->band];
1565 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1566 if (rates[i] == 0xff ||
1567 !rate_supported(sta, sband->band, rates[i]))
1568 continue;
1569
1570 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1571 }
1572 }
1573
1574 static void
1575 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1576 struct cfg80211_chan_def *chandef,
1577 struct ieee80211_sta *sta, void *priv_sta)
1578 {
1579 struct minstrel_priv *mp = priv;
1580 struct minstrel_ht_sta *mi = priv_sta;
1581 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1582 u16 ht_cap = sta->ht_cap.cap;
1583 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1584 const struct ieee80211_rate *ctl_rate;
1585 bool ldpc, erp;
1586 int use_vht;
1587 int n_supported = 0;
1588 int ack_dur;
1589 int stbc;
1590 int i;
1591
1592 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1593
1594 if (vht_cap->vht_supported)
1595 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1596 else
1597 use_vht = 0;
1598
1599 memset(mi, 0, sizeof(*mi));
1600
1601 mi->sta = sta;
1602 mi->band = sband->band;
1603 mi->last_stats_update = jiffies;
1604
1605 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1606 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1607 mi->overhead += ack_dur;
1608 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1609
1610 ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1611 erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1612 ack_dur = ieee80211_frame_duration(sband->band, 10,
1613 ctl_rate->bitrate, erp, 1,
1614 ieee80211_chandef_get_shift(chandef));
1615 mi->overhead_legacy = ack_dur;
1616 mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1617
1618 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1619
1620 if (!use_vht) {
1621 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1622 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1623
1624 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1625 } else {
1626 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1627 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1628
1629 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1630 }
1631
1632 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1633 if (ldpc)
1634 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1635
1636 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1637 u32 gflags = minstrel_mcs_groups[i].flags;
1638 int bw, nss;
1639
1640 mi->supported[i] = 0;
1641 if (minstrel_ht_is_legacy_group(i))
1642 continue;
1643
1644 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1645 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1646 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1647 continue;
1648 } else {
1649 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1650 continue;
1651 }
1652 }
1653
1654 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1655 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1656 continue;
1657
1658 nss = minstrel_mcs_groups[i].streams;
1659
1660 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1661 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1662 continue;
1663
1664 /* HT rate */
1665 if (gflags & IEEE80211_TX_RC_MCS) {
1666 if (use_vht && minstrel_vht_only)
1667 continue;
1668
1669 mi->supported[i] = mcs->rx_mask[nss - 1];
1670 if (mi->supported[i])
1671 n_supported++;
1672 continue;
1673 }
1674
1675 /* VHT rate */
1676 if (!vht_cap->vht_supported ||
1677 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1678 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1679 continue;
1680
1681 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1682 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1683 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1684 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1685 continue;
1686 }
1687 }
1688
1689 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1690 bw = BW_40;
1691 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1692 bw = BW_80;
1693 else
1694 bw = BW_20;
1695
1696 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1697 vht_cap->vht_mcs.tx_mcs_map);
1698
1699 if (mi->supported[i])
1700 n_supported++;
1701 }
1702
1703 minstrel_ht_update_cck(mp, mi, sband, sta);
1704 minstrel_ht_update_ofdm(mp, mi, sband, sta);
1705
1706 /* create an initial rate table with the lowest supported rates */
1707 minstrel_ht_update_stats(mp, mi);
1708 minstrel_ht_update_rates(mp, mi);
1709 }
1710
1711 static void
1712 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1713 struct cfg80211_chan_def *chandef,
1714 struct ieee80211_sta *sta, void *priv_sta)
1715 {
1716 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1717 }
1718
1719 static void
1720 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1721 struct cfg80211_chan_def *chandef,
1722 struct ieee80211_sta *sta, void *priv_sta,
1723 u32 changed)
1724 {
1725 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1726 }
1727
1728 static void *
1729 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1730 {
1731 struct ieee80211_supported_band *sband;
1732 struct minstrel_ht_sta *mi;
1733 struct minstrel_priv *mp = priv;
1734 struct ieee80211_hw *hw = mp->hw;
1735 int max_rates = 0;
1736 int i;
1737
1738 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1739 sband = hw->wiphy->bands[i];
1740 if (sband && sband->n_bitrates > max_rates)
1741 max_rates = sband->n_bitrates;
1742 }
1743
1744 return kzalloc(sizeof(*mi), gfp);
1745 }
1746
1747 static void
1748 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1749 {
1750 kfree(priv_sta);
1751 }
1752
1753 static void
1754 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1755 const s16 *bitrates, int n_rates, u32 rate_flags)
1756 {
1757 int i, j;
1758
1759 for (i = 0; i < sband->n_bitrates; i++) {
1760 struct ieee80211_rate *rate = &sband->bitrates[i];
1761
1762 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1763 continue;
1764
1765 for (j = 0; j < n_rates; j++) {
1766 if (rate->bitrate != bitrates[j])
1767 continue;
1768
1769 dest[j] = i;
1770 break;
1771 }
1772 }
1773 }
1774
1775 static void
1776 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1777 {
1778 static const s16 bitrates[4] = { 10, 20, 55, 110 };
1779 struct ieee80211_supported_band *sband;
1780 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1781
1782 memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1783 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1784 if (!sband)
1785 return;
1786
1787 BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1788 minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1789 minstrel_cck_bitrates,
1790 ARRAY_SIZE(minstrel_cck_bitrates),
1791 rate_flags);
1792 }
1793
1794 static void
1795 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1796 {
1797 static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1798 struct ieee80211_supported_band *sband;
1799 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1800
1801 memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1802 sband = mp->hw->wiphy->bands[band];
1803 if (!sband)
1804 return;
1805
1806 BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1807 minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1808 minstrel_ofdm_bitrates,
1809 ARRAY_SIZE(minstrel_ofdm_bitrates),
1810 rate_flags);
1811 }
1812
1813 static void *
1814 minstrel_ht_alloc(struct ieee80211_hw *hw)
1815 {
1816 struct minstrel_priv *mp;
1817 int i;
1818
1819 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1820 if (!mp)
1821 return NULL;
1822
1823 /* contention window settings
1824 * Just an approximation. Using the per-queue values would complicate
1825 * the calculations and is probably unnecessary */
1826 mp->cw_min = 15;
1827 mp->cw_max = 1023;
1828
1829 /* maximum time that the hw is allowed to stay in one MRR segment */
1830 mp->segment_size = 6000;
1831
1832 if (hw->max_rate_tries > 0)
1833 mp->max_retry = hw->max_rate_tries;
1834 else
1835 /* safe default, does not necessarily have to match hw properties */
1836 mp->max_retry = 7;
1837
1838 if (hw->max_rates >= 4)
1839 mp->has_mrr = true;
1840
1841 mp->hw = hw;
1842 mp->update_interval = HZ / 20;
1843
1844 minstrel_ht_init_cck_rates(mp);
1845 for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1846 minstrel_ht_init_ofdm_rates(mp, i);
1847
1848 return mp;
1849 }
1850
1851 #ifdef CONFIG_MAC80211_DEBUGFS
1852 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1853 struct dentry *debugfsdir)
1854 {
1855 struct minstrel_priv *mp = priv;
1856
1857 mp->fixed_rate_idx = (u32) -1;
1858 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1859 &mp->fixed_rate_idx);
1860 }
1861 #endif
1862
1863 static void
1864 minstrel_ht_free(void *priv)
1865 {
1866 kfree(priv);
1867 }
1868
1869 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1870 {
1871 struct minstrel_ht_sta *mi = priv_sta;
1872 int i, j, prob, tp_avg;
1873
1874 i = MI_RATE_GROUP(mi->max_tp_rate[0]);
1875 j = MI_RATE_IDX(mi->max_tp_rate[0]);
1876 prob = mi->groups[i].rates[j].prob_avg;
1877
1878 /* convert tp_avg from pkt per second in kbps */
1879 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1880 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1881
1882 return tp_avg;
1883 }
1884
1885 static const struct rate_control_ops mac80211_minstrel_ht = {
1886 .name = "minstrel_ht",
1887 .capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
1888 .tx_status_ext = minstrel_ht_tx_status,
1889 .get_rate = minstrel_ht_get_rate,
1890 .rate_init = minstrel_ht_rate_init,
1891 .rate_update = minstrel_ht_rate_update,
1892 .alloc_sta = minstrel_ht_alloc_sta,
1893 .free_sta = minstrel_ht_free_sta,
1894 .alloc = minstrel_ht_alloc,
1895 .free = minstrel_ht_free,
1896 #ifdef CONFIG_MAC80211_DEBUGFS
1897 .add_debugfs = minstrel_ht_add_debugfs,
1898 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1899 #endif
1900 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1901 };
1902
1903
1904 static void __init init_sample_table(void)
1905 {
1906 int col, i, new_idx;
1907 u8 rnd[MCS_GROUP_RATES];
1908
1909 memset(sample_table, 0xff, sizeof(sample_table));
1910 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1911 prandom_bytes(rnd, sizeof(rnd));
1912 for (i = 0; i < MCS_GROUP_RATES; i++) {
1913 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1914 while (sample_table[col][new_idx] != 0xff)
1915 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1916
1917 sample_table[col][new_idx] = i;
1918 }
1919 }
1920 }
1921
1922 int __init
1923 rc80211_minstrel_init(void)
1924 {
1925 init_sample_table();
1926 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1927 }
1928
1929 void
1930 rc80211_minstrel_exit(void)
1931 {
1932 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1933 }
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