1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
4 */
5 #include <linux/netdevice.h>
6 #include <linux/types.h>
7 #include <linux/skbuff.h>
8 #include <linux/debugfs.h>
9 #include <linux/random.h>
10 #include <linux/moduleparam.h>
11 #include <linux/ieee80211.h>
12 #include <net/mac80211.h>
13 #include "rate.h"
14 #include "sta_info.h"
15 #include "rc80211_minstrel.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, _len) \
139 (1000 * (10 /* SIFS */ + \
140 (_short ? 72 + 24 : 144 + 48) + \
141 (8 * (_len + 4) * 10) / (_bitrate)))
142
143 #define CCK_ACK_DURATION(_bitrate, _short) \
144 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
145 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
146
147 #define CCK_DURATION_LIST(_short, _s) \
148 CCK_ACK_DURATION(10, _short) >> _s, \
149 CCK_ACK_DURATION(20, _short) >> _s, \
150 CCK_ACK_DURATION(55, _short) >> _s, \
151 CCK_ACK_DURATION(110, _short) >> _s
152
153 #define __CCK_GROUP(_s) \
154 [MINSTREL_CCK_GROUP] = { \
155 .streams = 1, \
156 .flags = 0, \
157 .shift = _s, \
158 .duration = { \
159 CCK_DURATION_LIST(false, _s), \
160 CCK_DURATION_LIST(true, _s) \
161 } \
162 }
163
164 #define CCK_GROUP_SHIFT \
165 GROUP_SHIFT(CCK_ACK_DURATION(10, false))
166
167 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
168
169
170 static bool minstrel_vht_only = true;
171 module_param(minstrel_vht_only, bool, 0644);
172 MODULE_PARM_DESC(minstrel_vht_only,
173 "Use only VHT rates when VHT is supported by sta.");
174
175 /*
176 * To enable sufficiently targeted rate sampling, MCS rates are divided into
177 * groups, based on the number of streams and flags (HT40, SGI) that they
178 * use.
179 *
180 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
181 * BW -> SGI -> #streams
182 */
183 const struct mcs_group minstrel_mcs_groups[] = {
184 MCS_GROUP(1, 0, BW_20),
185 MCS_GROUP(2, 0, BW_20),
186 MCS_GROUP(3, 0, BW_20),
187 MCS_GROUP(4, 0, BW_20),
188
189 MCS_GROUP(1, 1, BW_20),
190 MCS_GROUP(2, 1, BW_20),
191 MCS_GROUP(3, 1, BW_20),
192 MCS_GROUP(4, 1, BW_20),
193
194 MCS_GROUP(1, 0, BW_40),
195 MCS_GROUP(2, 0, BW_40),
196 MCS_GROUP(3, 0, BW_40),
197 MCS_GROUP(4, 0, BW_40),
198
199 MCS_GROUP(1, 1, BW_40),
200 MCS_GROUP(2, 1, BW_40),
201 MCS_GROUP(3, 1, BW_40),
202 MCS_GROUP(4, 1, BW_40),
203
204 CCK_GROUP,
205
206 VHT_GROUP(1, 0, BW_20),
207 VHT_GROUP(2, 0, BW_20),
208 VHT_GROUP(3, 0, BW_20),
209 VHT_GROUP(4, 0, BW_20),
210
211 VHT_GROUP(1, 1, BW_20),
212 VHT_GROUP(2, 1, BW_20),
213 VHT_GROUP(3, 1, BW_20),
214 VHT_GROUP(4, 1, BW_20),
215
216 VHT_GROUP(1, 0, BW_40),
217 VHT_GROUP(2, 0, BW_40),
218 VHT_GROUP(3, 0, BW_40),
219 VHT_GROUP(4, 0, BW_40),
220
221 VHT_GROUP(1, 1, BW_40),
222 VHT_GROUP(2, 1, BW_40),
223 VHT_GROUP(3, 1, BW_40),
224 VHT_GROUP(4, 1, BW_40),
225
226 VHT_GROUP(1, 0, BW_80),
227 VHT_GROUP(2, 0, BW_80),
228 VHT_GROUP(3, 0, BW_80),
229 VHT_GROUP(4, 0, BW_80),
230
231 VHT_GROUP(1, 1, BW_80),
232 VHT_GROUP(2, 1, BW_80),
233 VHT_GROUP(3, 1, BW_80),
234 VHT_GROUP(4, 1, BW_80),
235 };
236
237 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
238
239 static void
240 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
241
242 /*
243 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
244 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
245 *
246 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
247 */
248 static u16
minstrel_get_valid_vht_rates(int bw,int nss,__le16 mcs_map)249 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
250 {
251 u16 mask = 0;
252
253 if (bw == BW_20) {
254 if (nss != 3 && nss != 6)
255 mask = BIT(9);
256 } else if (bw == BW_80) {
257 if (nss == 3 || nss == 7)
258 mask = BIT(6);
259 else if (nss == 6)
260 mask = BIT(9);
261 } else {
262 WARN_ON(bw != BW_40);
263 }
264
265 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
266 case IEEE80211_VHT_MCS_SUPPORT_0_7:
267 mask |= 0x300;
268 break;
269 case IEEE80211_VHT_MCS_SUPPORT_0_8:
270 mask |= 0x200;
271 break;
272 case IEEE80211_VHT_MCS_SUPPORT_0_9:
273 break;
274 default:
275 mask = 0x3ff;
276 }
277
278 return 0x3ff & ~mask;
279 }
280
281 /*
282 * Look up an MCS group index based on mac80211 rate information
283 */
284 static int
minstrel_ht_get_group_idx(struct ieee80211_tx_rate * rate)285 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
286 {
287 return GROUP_IDX((rate->idx / 8) + 1,
288 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
289 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
290 }
291
292 static int
minstrel_vht_get_group_idx(struct ieee80211_tx_rate * rate)293 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
294 {
295 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
296 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
297 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
298 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
299 }
300
301 static struct minstrel_rate_stats *
minstrel_ht_get_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_tx_rate * rate)302 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
303 struct ieee80211_tx_rate *rate)
304 {
305 int group, idx;
306
307 if (rate->flags & IEEE80211_TX_RC_MCS) {
308 group = minstrel_ht_get_group_idx(rate);
309 idx = rate->idx % 8;
310 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
311 group = minstrel_vht_get_group_idx(rate);
312 idx = ieee80211_rate_get_vht_mcs(rate);
313 } else {
314 group = MINSTREL_CCK_GROUP;
315
316 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
317 if (rate->idx == mp->cck_rates[idx])
318 break;
319
320 /* short preamble */
321 if ((mi->supported[group] & BIT(idx + 4)) &&
322 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
323 idx += 4;
324 }
325 return &mi->groups[group].rates[idx];
326 }
327
328 static inline struct minstrel_rate_stats *
minstrel_get_ratestats(struct minstrel_ht_sta * mi,int index)329 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
330 {
331 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
332 }
333
334 static unsigned int
minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta * mi)335 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
336 {
337 if (!mi->avg_ampdu_len)
338 return AVG_AMPDU_SIZE;
339
340 return MINSTREL_TRUNC(mi->avg_ampdu_len);
341 }
342
343 /*
344 * Return current throughput based on the average A-MPDU length, taking into
345 * account the expected number of retransmissions and their expected length
346 */
347 int
minstrel_ht_get_tp_avg(struct minstrel_ht_sta * mi,int group,int rate,int prob_ewma)348 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
349 int prob_ewma)
350 {
351 unsigned int nsecs = 0;
352
353 /* do not account throughput if sucess prob is below 10% */
354 if (prob_ewma < MINSTREL_FRAC(10, 100))
355 return 0;
356
357 if (group != MINSTREL_CCK_GROUP)
358 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
359
360 nsecs += minstrel_mcs_groups[group].duration[rate] <<
361 minstrel_mcs_groups[group].shift;
362
363 /*
364 * For the throughput calculation, limit the probability value to 90% to
365 * account for collision related packet error rate fluctuation
366 * (prob is scaled - see MINSTREL_FRAC above)
367 */
368 if (prob_ewma > MINSTREL_FRAC(90, 100))
369 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
370 / nsecs));
371 else
372 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
373 }
374
375 /*
376 * Find & sort topmost throughput rates
377 *
378 * If multiple rates provide equal throughput the sorting is based on their
379 * current success probability. Higher success probability is preferred among
380 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
381 */
382 static void
minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta * mi,u16 index,u16 * tp_list)383 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
384 u16 *tp_list)
385 {
386 int cur_group, cur_idx, cur_tp_avg, cur_prob;
387 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
388 int j = MAX_THR_RATES;
389
390 cur_group = index / MCS_GROUP_RATES;
391 cur_idx = index % MCS_GROUP_RATES;
392 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
393 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
394
395 do {
396 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
397 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
398 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
399 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
400 tmp_prob);
401 if (cur_tp_avg < tmp_tp_avg ||
402 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
403 break;
404 j--;
405 } while (j > 0);
406
407 if (j < MAX_THR_RATES - 1) {
408 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
409 (MAX_THR_RATES - (j + 1))));
410 }
411 if (j < MAX_THR_RATES)
412 tp_list[j] = index;
413 }
414
415 /*
416 * Find and set the topmost probability rate per sta and per group
417 */
418 static void
minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta * mi,u16 index)419 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
420 {
421 struct minstrel_mcs_group_data *mg;
422 struct minstrel_rate_stats *mrs;
423 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
424 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
425 int max_gpr_group, max_gpr_idx;
426 int max_gpr_tp_avg, max_gpr_prob;
427
428 cur_group = index / MCS_GROUP_RATES;
429 cur_idx = index % MCS_GROUP_RATES;
430 mg = &mi->groups[index / MCS_GROUP_RATES];
431 mrs = &mg->rates[index % MCS_GROUP_RATES];
432
433 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
434 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
435 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
436 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
437
438 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
439 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
440 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
441 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
442 (max_tp_group != MINSTREL_CCK_GROUP))
443 return;
444
445 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
446 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
447 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
448
449 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
450 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
451 mrs->prob_ewma);
452 if (cur_tp_avg > tmp_tp_avg)
453 mi->max_prob_rate = index;
454
455 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
456 max_gpr_idx,
457 max_gpr_prob);
458 if (cur_tp_avg > max_gpr_tp_avg)
459 mg->max_group_prob_rate = index;
460 } else {
461 if (mrs->prob_ewma > tmp_prob)
462 mi->max_prob_rate = index;
463 if (mrs->prob_ewma > max_gpr_prob)
464 mg->max_group_prob_rate = index;
465 }
466 }
467
468
469 /*
470 * Assign new rate set per sta and use CCK rates only if the fastest
471 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
472 * rate sets where MCS and CCK rates are mixed, because CCK rates can
473 * not use aggregation.
474 */
475 static void
minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta * mi,u16 tmp_mcs_tp_rate[MAX_THR_RATES],u16 tmp_cck_tp_rate[MAX_THR_RATES])476 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
477 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
478 u16 tmp_cck_tp_rate[MAX_THR_RATES])
479 {
480 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
481 int i;
482
483 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
484 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
485 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
486 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
487
488 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
489 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
490 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
491 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
492
493 if (tmp_cck_tp_rate && tmp_cck_tp > tmp_mcs_tp) {
494 for(i = 0; i < MAX_THR_RATES; i++) {
495 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
496 tmp_mcs_tp_rate);
497 }
498 }
499
500 }
501
502 /*
503 * Try to increase robustness of max_prob rate by decrease number of
504 * streams if possible.
505 */
506 static inline void
minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta * mi)507 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
508 {
509 struct minstrel_mcs_group_data *mg;
510 int tmp_max_streams, group, tmp_idx, tmp_prob;
511 int tmp_tp = 0;
512
513 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
514 MCS_GROUP_RATES].streams;
515 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
516 mg = &mi->groups[group];
517 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
518 continue;
519
520 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
521 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
522
523 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
524 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
525 mi->max_prob_rate = mg->max_group_prob_rate;
526 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
527 tmp_idx,
528 tmp_prob);
529 }
530 }
531 }
532
533 static inline int
minstrel_get_duration(int index)534 minstrel_get_duration(int index)
535 {
536 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
537 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
538 return duration << group->shift;
539 }
540
541 static bool
minstrel_ht_probe_group(struct minstrel_ht_sta * mi,const struct mcs_group * tp_group,int tp_idx,const struct mcs_group * group)542 minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group,
543 int tp_idx, const struct mcs_group *group)
544 {
545 if (group->bw < tp_group->bw)
546 return false;
547
548 if (group->streams == tp_group->streams)
549 return true;
550
551 if (tp_idx < 4 && group->streams == tp_group->streams - 1)
552 return true;
553
554 return group->streams == tp_group->streams + 1;
555 }
556
557 static void
minstrel_ht_find_probe_rates(struct minstrel_ht_sta * mi,u16 * rates,int * n_rates,bool faster_rate)558 minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates,
559 bool faster_rate)
560 {
561 const struct mcs_group *group, *tp_group;
562 int i, g, max_dur;
563 int tp_idx;
564
565 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES];
566 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES;
567
568 max_dur = minstrel_get_duration(mi->max_tp_rate[0]);
569 if (faster_rate)
570 max_dur -= max_dur / 16;
571
572 for (g = 0; g < MINSTREL_GROUPS_NB; g++) {
573 u16 supported = mi->supported[g];
574
575 if (!supported)
576 continue;
577
578 group = &minstrel_mcs_groups[g];
579 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group))
580 continue;
581
582 for (i = 0; supported; supported >>= 1, i++) {
583 int idx;
584
585 if (!(supported & 1))
586 continue;
587
588 if ((group->duration[i] << group->shift) > max_dur)
589 continue;
590
591 idx = g * MCS_GROUP_RATES + i;
592 if (idx == mi->max_tp_rate[0])
593 continue;
594
595 rates[(*n_rates)++] = idx;
596 break;
597 }
598 }
599 }
600
601 static void
minstrel_ht_rate_sample_switch(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)602 minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
603 struct minstrel_ht_sta *mi)
604 {
605 struct minstrel_rate_stats *mrs;
606 u16 rates[MINSTREL_GROUPS_NB];
607 int n_rates = 0;
608 int probe_rate = 0;
609 bool faster_rate;
610 int i;
611 u8 random;
612
613 /*
614 * Use rate switching instead of probing packets for devices with
615 * little control over retry fallback behavior
616 */
617 if (mp->hw->max_rates > 1)
618 return;
619
620 /*
621 * If the current EWMA prob is >75%, look for a rate that's 6.25%
622 * faster than the max tp rate.
623 * If that fails, look again for a rate that is at least as fast
624 */
625 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
626 faster_rate = mrs->prob_ewma > MINSTREL_FRAC(75, 100);
627 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
628 if (!n_rates && faster_rate)
629 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
630
631 /* If no suitable rate was found, try to pick the next one in the group */
632 if (!n_rates) {
633 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES;
634 u16 supported = mi->supported[g_idx];
635
636 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES;
637 for (i = 0; supported; supported >>= 1, i++) {
638 if (!(supported & 1))
639 continue;
640
641 probe_rate = mi->max_tp_rate[0] + i;
642 goto out;
643 }
644
645 return;
646 }
647
648 i = 0;
649 if (n_rates > 1) {
650 random = prandom_u32();
651 i = random % n_rates;
652 }
653 probe_rate = rates[i];
654
655 out:
656 mi->sample_rate = probe_rate;
657 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE;
658 }
659
660 /*
661 * Update rate statistics and select new primary rates
662 *
663 * Rules for rate selection:
664 * - max_prob_rate must use only one stream, as a tradeoff between delivery
665 * probability and throughput during strong fluctuations
666 * - as long as the max prob rate has a probability of more than 75%, pick
667 * higher throughput rates, even if the probablity is a bit lower
668 */
669 static void
minstrel_ht_update_stats(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,bool sample)670 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
671 bool sample)
672 {
673 struct minstrel_mcs_group_data *mg;
674 struct minstrel_rate_stats *mrs;
675 int group, i, j, cur_prob;
676 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
677 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
678
679 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
680
681 if (sample) {
682 mi->total_packets_cur = mi->total_packets -
683 mi->total_packets_last;
684 mi->total_packets_last = mi->total_packets;
685 }
686 if (!mp->sample_switch)
687 sample = false;
688 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1)
689 sample = false;
690
691 if (mi->ampdu_packets > 0) {
692 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
693 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
694 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
695 EWMA_LEVEL);
696 else
697 mi->avg_ampdu_len = 0;
698 mi->ampdu_len = 0;
699 mi->ampdu_packets = 0;
700 }
701
702 mi->sample_slow = 0;
703 mi->sample_count = 0;
704
705 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate));
706 memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate));
707 if (mi->supported[MINSTREL_CCK_GROUP])
708 for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++)
709 tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
710
711 if (mi->supported[MINSTREL_VHT_GROUP_0])
712 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES;
713 else
714 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES;
715
716 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
717 tmp_mcs_tp_rate[j] = index;
718
719 /* Find best rate sets within all MCS groups*/
720 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
721
722 mg = &mi->groups[group];
723 if (!mi->supported[group])
724 continue;
725
726 mi->sample_count++;
727
728 /* (re)Initialize group rate indexes */
729 for(j = 0; j < MAX_THR_RATES; j++)
730 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
731
732 for (i = 0; i < MCS_GROUP_RATES; i++) {
733 if (!(mi->supported[group] & BIT(i)))
734 continue;
735
736 index = MCS_GROUP_RATES * group + i;
737
738 mrs = &mg->rates[i];
739 mrs->retry_updated = false;
740 minstrel_calc_rate_stats(mrs);
741 cur_prob = mrs->prob_ewma;
742
743 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
744 continue;
745
746 /* Find max throughput rate set */
747 if (group != MINSTREL_CCK_GROUP) {
748 minstrel_ht_sort_best_tp_rates(mi, index,
749 tmp_mcs_tp_rate);
750 } else if (group == MINSTREL_CCK_GROUP) {
751 minstrel_ht_sort_best_tp_rates(mi, index,
752 tmp_cck_tp_rate);
753 }
754
755 /* Find max throughput rate set within a group */
756 minstrel_ht_sort_best_tp_rates(mi, index,
757 tmp_group_tp_rate);
758
759 /* Find max probability rate per group and global */
760 minstrel_ht_set_best_prob_rate(mi, index);
761 }
762
763 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
764 sizeof(mg->max_group_tp_rate));
765 }
766
767 /* Assign new rate set per sta */
768 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
769 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
770
771 /* Try to increase robustness of max_prob_rate*/
772 minstrel_ht_prob_rate_reduce_streams(mi);
773
774 /* try to sample all available rates during each interval */
775 mi->sample_count *= 8;
776
777 if (sample)
778 minstrel_ht_rate_sample_switch(mp, mi);
779
780 #ifdef CONFIG_MAC80211_DEBUGFS
781 /* use fixed index if set */
782 if (mp->fixed_rate_idx != -1) {
783 for (i = 0; i < 4; i++)
784 mi->max_tp_rate[i] = mp->fixed_rate_idx;
785 mi->max_prob_rate = mp->fixed_rate_idx;
786 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
787 }
788 #endif
789
790 /* Reset update timer */
791 mi->last_stats_update = jiffies;
792 }
793
794 static bool
minstrel_ht_txstat_valid(struct minstrel_priv * mp,struct ieee80211_tx_rate * rate)795 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
796 {
797 if (rate->idx < 0)
798 return false;
799
800 if (!rate->count)
801 return false;
802
803 if (rate->flags & IEEE80211_TX_RC_MCS ||
804 rate->flags & IEEE80211_TX_RC_VHT_MCS)
805 return true;
806
807 return rate->idx == mp->cck_rates[0] ||
808 rate->idx == mp->cck_rates[1] ||
809 rate->idx == mp->cck_rates[2] ||
810 rate->idx == mp->cck_rates[3];
811 }
812
813 static void
minstrel_set_next_sample_idx(struct minstrel_ht_sta * mi)814 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
815 {
816 struct minstrel_mcs_group_data *mg;
817
818 for (;;) {
819 mi->sample_group++;
820 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
821 mg = &mi->groups[mi->sample_group];
822
823 if (!mi->supported[mi->sample_group])
824 continue;
825
826 if (++mg->index >= MCS_GROUP_RATES) {
827 mg->index = 0;
828 if (++mg->column >= ARRAY_SIZE(sample_table))
829 mg->column = 0;
830 }
831 break;
832 }
833 }
834
835 static void
minstrel_downgrade_rate(struct minstrel_ht_sta * mi,u16 * idx,bool primary)836 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
837 {
838 int group, orig_group;
839
840 orig_group = group = *idx / MCS_GROUP_RATES;
841 while (group > 0) {
842 group--;
843
844 if (!mi->supported[group])
845 continue;
846
847 if (minstrel_mcs_groups[group].streams >
848 minstrel_mcs_groups[orig_group].streams)
849 continue;
850
851 if (primary)
852 *idx = mi->groups[group].max_group_tp_rate[0];
853 else
854 *idx = mi->groups[group].max_group_tp_rate[1];
855 break;
856 }
857 }
858
859 static void
minstrel_aggr_check(struct ieee80211_sta * pubsta,struct sk_buff * skb)860 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
861 {
862 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
863 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
864 u16 tid;
865
866 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
867 return;
868
869 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
870 return;
871
872 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
873 return;
874
875 tid = ieee80211_get_tid(hdr);
876 if (likely(sta->ampdu_mlme.tid_tx[tid]))
877 return;
878
879 ieee80211_start_tx_ba_session(pubsta, tid, 0);
880 }
881
882 static void
minstrel_ht_tx_status(void * priv,struct ieee80211_supported_band * sband,void * priv_sta,struct ieee80211_tx_status * st)883 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
884 void *priv_sta, struct ieee80211_tx_status *st)
885 {
886 struct ieee80211_tx_info *info = st->info;
887 struct minstrel_ht_sta_priv *msp = priv_sta;
888 struct minstrel_ht_sta *mi = &msp->ht;
889 struct ieee80211_tx_rate *ar = info->status.rates;
890 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL;
891 struct minstrel_priv *mp = priv;
892 bool last, update = false;
893 bool sample_status = false;
894 int i;
895
896 if (!msp->is_ht)
897 return mac80211_minstrel.tx_status_ext(priv, sband,
898 &msp->legacy, st);
899
900
901 /* This packet was aggregated but doesn't carry status info */
902 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
903 !(info->flags & IEEE80211_TX_STAT_AMPDU))
904 return;
905
906 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
907 info->status.ampdu_ack_len =
908 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
909 info->status.ampdu_len = 1;
910 }
911
912 mi->ampdu_packets++;
913 mi->ampdu_len += info->status.ampdu_len;
914
915 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
916 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
917
918 mi->sample_wait = 16 + 2 * avg_ampdu_len;
919 mi->sample_tries = 1;
920 mi->sample_count--;
921 }
922
923 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
924 mi->sample_packets += info->status.ampdu_len;
925
926 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
927 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
928
929 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
930 for (i = 0; !last; i++) {
931 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
932 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
933
934 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
935 if (rate == rate_sample)
936 sample_status = true;
937
938 if (last)
939 rate->success += info->status.ampdu_ack_len;
940
941 rate->attempts += ar[i].count * info->status.ampdu_len;
942 }
943
944 switch (mi->sample_mode) {
945 case MINSTREL_SAMPLE_IDLE:
946 break;
947
948 case MINSTREL_SAMPLE_ACTIVE:
949 if (!sample_status)
950 break;
951
952 mi->sample_mode = MINSTREL_SAMPLE_PENDING;
953 update = true;
954 break;
955
956 case MINSTREL_SAMPLE_PENDING:
957 if (sample_status)
958 break;
959
960 update = true;
961 minstrel_ht_update_stats(mp, mi, false);
962 break;
963 }
964
965
966 if (mp->hw->max_rates > 1) {
967 /*
968 * check for sudden death of spatial multiplexing,
969 * downgrade to a lower number of streams if necessary.
970 */
971 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
972 if (rate->attempts > 30 &&
973 MINSTREL_FRAC(rate->success, rate->attempts) <
974 MINSTREL_FRAC(20, 100)) {
975 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
976 update = true;
977 }
978
979 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
980 if (rate2->attempts > 30 &&
981 MINSTREL_FRAC(rate2->success, rate2->attempts) <
982 MINSTREL_FRAC(20, 100)) {
983 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
984 update = true;
985 }
986 }
987
988 if (time_after(jiffies, mi->last_stats_update +
989 (mp->update_interval / 2 * HZ) / 1000)) {
990 update = true;
991 minstrel_ht_update_stats(mp, mi, true);
992 }
993
994 if (update)
995 minstrel_ht_update_rates(mp, mi);
996 }
997
998 static void
minstrel_calc_retransmit(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,int index)999 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1000 int index)
1001 {
1002 struct minstrel_rate_stats *mrs;
1003 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1004 unsigned int cw = mp->cw_min;
1005 unsigned int ctime = 0;
1006 unsigned int t_slot = 9; /* FIXME */
1007 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1008 unsigned int overhead = 0, overhead_rtscts = 0;
1009
1010 mrs = minstrel_get_ratestats(mi, index);
1011 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
1012 mrs->retry_count = 1;
1013 mrs->retry_count_rtscts = 1;
1014 return;
1015 }
1016
1017 mrs->retry_count = 2;
1018 mrs->retry_count_rtscts = 2;
1019 mrs->retry_updated = true;
1020
1021 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1022
1023 /* Contention time for first 2 tries */
1024 ctime = (t_slot * cw) >> 1;
1025 cw = min((cw << 1) | 1, mp->cw_max);
1026 ctime += (t_slot * cw) >> 1;
1027 cw = min((cw << 1) | 1, mp->cw_max);
1028
1029 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
1030 overhead = mi->overhead;
1031 overhead_rtscts = mi->overhead_rtscts;
1032 }
1033
1034 /* Total TX time for data and Contention after first 2 tries */
1035 tx_time = ctime + 2 * (overhead + tx_time_data);
1036 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1037
1038 /* See how many more tries we can fit inside segment size */
1039 do {
1040 /* Contention time for this try */
1041 ctime = (t_slot * cw) >> 1;
1042 cw = min((cw << 1) | 1, mp->cw_max);
1043
1044 /* Total TX time after this try */
1045 tx_time += ctime + overhead + tx_time_data;
1046 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1047
1048 if (tx_time_rtscts < mp->segment_size)
1049 mrs->retry_count_rtscts++;
1050 } while ((tx_time < mp->segment_size) &&
1051 (++mrs->retry_count < mp->max_retry));
1052 }
1053
1054
1055 static void
minstrel_ht_set_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_sta_rates * ratetbl,int offset,int index)1056 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1057 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1058 {
1059 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
1060 struct minstrel_rate_stats *mrs;
1061 u8 idx;
1062 u16 flags = group->flags;
1063
1064 mrs = minstrel_get_ratestats(mi, index);
1065 if (!mrs->retry_updated)
1066 minstrel_calc_retransmit(mp, mi, index);
1067
1068 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1069 ratetbl->rate[offset].count = 2;
1070 ratetbl->rate[offset].count_rts = 2;
1071 ratetbl->rate[offset].count_cts = 2;
1072 } else {
1073 ratetbl->rate[offset].count = mrs->retry_count;
1074 ratetbl->rate[offset].count_cts = mrs->retry_count;
1075 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1076 }
1077
1078 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
1079 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1080 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1081 idx = ((group->streams - 1) << 4) |
1082 ((index % MCS_GROUP_RATES) & 0xF);
1083 else
1084 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
1085
1086 /* enable RTS/CTS if needed:
1087 * - if station is in dynamic SMPS (and streams > 1)
1088 * - for fallback rates, to increase chances of getting through
1089 */
1090 if (offset > 0 ||
1091 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
1092 group->streams > 1)) {
1093 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1094 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1095 }
1096
1097 ratetbl->rate[offset].idx = idx;
1098 ratetbl->rate[offset].flags = flags;
1099 }
1100
1101 static inline int
minstrel_ht_get_prob_ewma(struct minstrel_ht_sta * mi,int rate)1102 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
1103 {
1104 int group = rate / MCS_GROUP_RATES;
1105 rate %= MCS_GROUP_RATES;
1106 return mi->groups[group].rates[rate].prob_ewma;
1107 }
1108
1109 static int
minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta * mi)1110 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1111 {
1112 int group = mi->max_prob_rate / MCS_GROUP_RATES;
1113 const struct mcs_group *g = &minstrel_mcs_groups[group];
1114 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
1115 unsigned int duration;
1116
1117 /* Disable A-MSDU if max_prob_rate is bad */
1118 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
1119 return 1;
1120
1121 duration = g->duration[rate];
1122 duration <<= g->shift;
1123
1124 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1125 if (duration > MCS_DURATION(1, 0, 52))
1126 return 500;
1127
1128 /*
1129 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1130 * data packet size
1131 */
1132 if (duration > MCS_DURATION(1, 0, 104))
1133 return 1600;
1134
1135 /*
1136 * If the rate is slower than single-stream MCS7, or if the max throughput
1137 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1138 * data packet size
1139 */
1140 if (duration > MCS_DURATION(1, 0, 260) ||
1141 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
1142 MINSTREL_FRAC(75, 100)))
1143 return 3200;
1144
1145 /*
1146 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1147 * Since aggregation sessions are started/stopped without txq flush, use
1148 * the limit here to avoid the complexity of having to de-aggregate
1149 * packets in the queue.
1150 */
1151 if (!mi->sta->vht_cap.vht_supported)
1152 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1153
1154 /* unlimited */
1155 return 0;
1156 }
1157
1158 static void
minstrel_ht_update_rates(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1159 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1160 {
1161 struct ieee80211_sta_rates *rates;
1162 u16 first_rate = mi->max_tp_rate[0];
1163 int i = 0;
1164
1165 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE)
1166 first_rate = mi->sample_rate;
1167
1168 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1169 if (!rates)
1170 return;
1171
1172 /* Start with max_tp_rate[0] */
1173 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate);
1174
1175 if (mp->hw->max_rates >= 3) {
1176 /* At least 3 tx rates supported, use max_tp_rate[1] next */
1177 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1178 }
1179
1180 if (mp->hw->max_rates >= 2) {
1181 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1182 }
1183
1184 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1185 rates->rate[i].idx = -1;
1186 rate_control_set_rates(mp->hw, mi->sta, rates);
1187 }
1188
1189 static int
minstrel_get_sample_rate(struct minstrel_priv * mp,struct minstrel_ht_sta * mi)1190 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1191 {
1192 struct minstrel_rate_stats *mrs;
1193 struct minstrel_mcs_group_data *mg;
1194 unsigned int sample_dur, sample_group, cur_max_tp_streams;
1195 int tp_rate1, tp_rate2;
1196 int sample_idx = 0;
1197
1198 if (mp->hw->max_rates == 1 && mp->sample_switch &&
1199 (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
1200 mp->sample_switch == 1))
1201 return -1;
1202
1203 if (mi->sample_wait > 0) {
1204 mi->sample_wait--;
1205 return -1;
1206 }
1207
1208 if (!mi->sample_tries)
1209 return -1;
1210
1211 sample_group = mi->sample_group;
1212 mg = &mi->groups[sample_group];
1213 sample_idx = sample_table[mg->column][mg->index];
1214 minstrel_set_next_sample_idx(mi);
1215
1216 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1217 return -1;
1218
1219 mrs = &mg->rates[sample_idx];
1220 sample_idx += sample_group * MCS_GROUP_RATES;
1221
1222 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1223 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1224 minstrel_get_duration(mi->max_tp_rate[1])) {
1225 tp_rate1 = mi->max_tp_rate[1];
1226 tp_rate2 = mi->max_tp_rate[0];
1227 } else {
1228 tp_rate1 = mi->max_tp_rate[0];
1229 tp_rate2 = mi->max_tp_rate[1];
1230 }
1231
1232 /*
1233 * Sampling might add some overhead (RTS, no aggregation)
1234 * to the frame. Hence, don't use sampling for the highest currently
1235 * used highest throughput or probability rate.
1236 */
1237 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1238 return -1;
1239
1240 /*
1241 * Do not sample if the probability is already higher than 95%,
1242 * or if the rate is 3 times slower than the current max probability
1243 * rate, to avoid wasting airtime.
1244 */
1245 sample_dur = minstrel_get_duration(sample_idx);
1246 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
1247 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1248 return -1;
1249
1250
1251 /*
1252 * For devices with no configurable multi-rate retry, skip sampling
1253 * below the per-group max throughput rate, and only use one sampling
1254 * attempt per rate
1255 */
1256 if (mp->hw->max_rates == 1 &&
1257 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur ||
1258 mrs->attempts))
1259 return -1;
1260
1261 /* Skip already sampled slow rates */
1262 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts)
1263 return -1;
1264
1265 /*
1266 * Make sure that lower rates get sampled only occasionally,
1267 * if the link is working perfectly.
1268 */
1269
1270 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1271 MCS_GROUP_RATES].streams;
1272 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1273 (cur_max_tp_streams - 1 <
1274 minstrel_mcs_groups[sample_group].streams ||
1275 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1276 if (mrs->sample_skipped < 20)
1277 return -1;
1278
1279 if (mi->sample_slow++ > 2)
1280 return -1;
1281 }
1282 mi->sample_tries--;
1283
1284 return sample_idx;
1285 }
1286
1287 static void
minstrel_ht_get_rate(void * priv,struct ieee80211_sta * sta,void * priv_sta,struct ieee80211_tx_rate_control * txrc)1288 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1289 struct ieee80211_tx_rate_control *txrc)
1290 {
1291 const struct mcs_group *sample_group;
1292 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1293 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1294 struct minstrel_ht_sta_priv *msp = priv_sta;
1295 struct minstrel_ht_sta *mi = &msp->ht;
1296 struct minstrel_priv *mp = priv;
1297 int sample_idx;
1298
1299 if (!msp->is_ht)
1300 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1301
1302 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1303 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1304 minstrel_aggr_check(sta, txrc->skb);
1305
1306 info->flags |= mi->tx_flags;
1307
1308 #ifdef CONFIG_MAC80211_DEBUGFS
1309 if (mp->fixed_rate_idx != -1)
1310 return;
1311 #endif
1312
1313 /* Don't use EAPOL frames for sampling on non-mrr hw */
1314 if (mp->hw->max_rates == 1 &&
1315 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1316 sample_idx = -1;
1317 else
1318 sample_idx = minstrel_get_sample_rate(mp, mi);
1319
1320 mi->total_packets++;
1321
1322 /* wraparound */
1323 if (mi->total_packets == ~0) {
1324 mi->total_packets = 0;
1325 mi->sample_packets = 0;
1326 }
1327
1328 if (sample_idx < 0)
1329 return;
1330
1331 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1332 sample_idx %= MCS_GROUP_RATES;
1333
1334 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1335 (sample_idx >= 4) != txrc->short_preamble)
1336 return;
1337
1338 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1339 rate->count = 1;
1340
1341 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1342 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1343 rate->idx = mp->cck_rates[idx];
1344 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1345 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1346 sample_group->streams);
1347 } else {
1348 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1349 }
1350
1351 rate->flags = sample_group->flags;
1352 }
1353
1354 static void
minstrel_ht_update_cck(struct minstrel_priv * mp,struct minstrel_ht_sta * mi,struct ieee80211_supported_band * sband,struct ieee80211_sta * sta)1355 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1356 struct ieee80211_supported_band *sband,
1357 struct ieee80211_sta *sta)
1358 {
1359 int i;
1360
1361 if (sband->band != NL80211_BAND_2GHZ)
1362 return;
1363
1364 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1365 return;
1366
1367 mi->cck_supported = 0;
1368 mi->cck_supported_short = 0;
1369 for (i = 0; i < 4; i++) {
1370 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1371 continue;
1372
1373 mi->cck_supported |= BIT(i);
1374 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1375 mi->cck_supported_short |= BIT(i);
1376 }
1377
1378 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1379 }
1380
1381 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)1382 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1383 struct cfg80211_chan_def *chandef,
1384 struct ieee80211_sta *sta, void *priv_sta)
1385 {
1386 struct minstrel_priv *mp = priv;
1387 struct minstrel_ht_sta_priv *msp = priv_sta;
1388 struct minstrel_ht_sta *mi = &msp->ht;
1389 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1390 u16 ht_cap = sta->ht_cap.cap;
1391 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1392 int use_vht;
1393 int n_supported = 0;
1394 int ack_dur;
1395 int stbc;
1396 int i;
1397 bool ldpc;
1398
1399 /* fall back to the old minstrel for legacy stations */
1400 if (!sta->ht_cap.ht_supported)
1401 goto use_legacy;
1402
1403 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1404
1405 if (vht_cap->vht_supported)
1406 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1407 else
1408 use_vht = 0;
1409
1410 msp->is_ht = true;
1411 memset(mi, 0, sizeof(*mi));
1412
1413 mi->sta = sta;
1414 mi->last_stats_update = jiffies;
1415
1416 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1417 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1418 mi->overhead += ack_dur;
1419 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1420
1421 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1422
1423 /* When using MRR, sample more on the first attempt, without delay */
1424 if (mp->has_mrr) {
1425 mi->sample_count = 16;
1426 mi->sample_wait = 0;
1427 } else {
1428 mi->sample_count = 8;
1429 mi->sample_wait = 8;
1430 }
1431 mi->sample_tries = 4;
1432
1433 if (!use_vht) {
1434 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1435 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1436
1437 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1438 } else {
1439 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1440 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1441
1442 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1443 }
1444
1445 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1446 if (ldpc)
1447 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1448
1449 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1450 u32 gflags = minstrel_mcs_groups[i].flags;
1451 int bw, nss;
1452
1453 mi->supported[i] = 0;
1454 if (i == MINSTREL_CCK_GROUP) {
1455 minstrel_ht_update_cck(mp, mi, sband, sta);
1456 continue;
1457 }
1458
1459 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1460 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1461 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1462 continue;
1463 } else {
1464 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1465 continue;
1466 }
1467 }
1468
1469 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1470 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1471 continue;
1472
1473 nss = minstrel_mcs_groups[i].streams;
1474
1475 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1476 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1477 continue;
1478
1479 /* HT rate */
1480 if (gflags & IEEE80211_TX_RC_MCS) {
1481 if (use_vht && minstrel_vht_only)
1482 continue;
1483
1484 mi->supported[i] = mcs->rx_mask[nss - 1];
1485 if (mi->supported[i])
1486 n_supported++;
1487 continue;
1488 }
1489
1490 /* VHT rate */
1491 if (!vht_cap->vht_supported ||
1492 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1493 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1494 continue;
1495
1496 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1497 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1498 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1499 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1500 continue;
1501 }
1502 }
1503
1504 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1505 bw = BW_40;
1506 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1507 bw = BW_80;
1508 else
1509 bw = BW_20;
1510
1511 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1512 vht_cap->vht_mcs.tx_mcs_map);
1513
1514 if (mi->supported[i])
1515 n_supported++;
1516 }
1517
1518 if (!n_supported)
1519 goto use_legacy;
1520
1521 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1522
1523 /* create an initial rate table with the lowest supported rates */
1524 minstrel_ht_update_stats(mp, mi, true);
1525 minstrel_ht_update_rates(mp, mi);
1526
1527 return;
1528
1529 use_legacy:
1530 msp->is_ht = false;
1531 memset(&msp->legacy, 0, sizeof(msp->legacy));
1532 msp->legacy.r = msp->ratelist;
1533 msp->legacy.sample_table = msp->sample_table;
1534 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1535 &msp->legacy);
1536 }
1537
1538 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)1539 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1540 struct cfg80211_chan_def *chandef,
1541 struct ieee80211_sta *sta, void *priv_sta)
1542 {
1543 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1544 }
1545
1546 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)1547 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1548 struct cfg80211_chan_def *chandef,
1549 struct ieee80211_sta *sta, void *priv_sta,
1550 u32 changed)
1551 {
1552 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1553 }
1554
1555 static void *
minstrel_ht_alloc_sta(void * priv,struct ieee80211_sta * sta,gfp_t gfp)1556 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1557 {
1558 struct ieee80211_supported_band *sband;
1559 struct minstrel_ht_sta_priv *msp;
1560 struct minstrel_priv *mp = priv;
1561 struct ieee80211_hw *hw = mp->hw;
1562 int max_rates = 0;
1563 int i;
1564
1565 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1566 sband = hw->wiphy->bands[i];
1567 if (sband && sband->n_bitrates > max_rates)
1568 max_rates = sband->n_bitrates;
1569 }
1570
1571 msp = kzalloc(sizeof(*msp), gfp);
1572 if (!msp)
1573 return NULL;
1574
1575 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1576 if (!msp->ratelist)
1577 goto error;
1578
1579 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1580 if (!msp->sample_table)
1581 goto error1;
1582
1583 return msp;
1584
1585 error1:
1586 kfree(msp->ratelist);
1587 error:
1588 kfree(msp);
1589 return NULL;
1590 }
1591
1592 static void
minstrel_ht_free_sta(void * priv,struct ieee80211_sta * sta,void * priv_sta)1593 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1594 {
1595 struct minstrel_ht_sta_priv *msp = priv_sta;
1596
1597 kfree(msp->sample_table);
1598 kfree(msp->ratelist);
1599 kfree(msp);
1600 }
1601
1602 static void
minstrel_ht_init_cck_rates(struct minstrel_priv * mp)1603 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1604 {
1605 static const int bitrates[4] = { 10, 20, 55, 110 };
1606 struct ieee80211_supported_band *sband;
1607 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1608 int i, j;
1609
1610 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1611 if (!sband)
1612 return;
1613
1614 for (i = 0; i < sband->n_bitrates; i++) {
1615 struct ieee80211_rate *rate = &sband->bitrates[i];
1616
1617 if (rate->flags & IEEE80211_RATE_ERP_G)
1618 continue;
1619
1620 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1621 continue;
1622
1623 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1624 if (rate->bitrate != bitrates[j])
1625 continue;
1626
1627 mp->cck_rates[j] = i;
1628 break;
1629 }
1630 }
1631 }
1632
1633 static void *
minstrel_ht_alloc(struct ieee80211_hw * hw,struct dentry * debugfsdir)1634 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1635 {
1636 struct minstrel_priv *mp;
1637
1638 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1639 if (!mp)
1640 return NULL;
1641
1642 mp->sample_switch = -1;
1643
1644 /* contention window settings
1645 * Just an approximation. Using the per-queue values would complicate
1646 * the calculations and is probably unnecessary */
1647 mp->cw_min = 15;
1648 mp->cw_max = 1023;
1649
1650 /* number of packets (in %) to use for sampling other rates
1651 * sample less often for non-mrr packets, because the overhead
1652 * is much higher than with mrr */
1653 mp->lookaround_rate = 5;
1654 mp->lookaround_rate_mrr = 10;
1655
1656 /* maximum time that the hw is allowed to stay in one MRR segment */
1657 mp->segment_size = 6000;
1658
1659 if (hw->max_rate_tries > 0)
1660 mp->max_retry = hw->max_rate_tries;
1661 else
1662 /* safe default, does not necessarily have to match hw properties */
1663 mp->max_retry = 7;
1664
1665 if (hw->max_rates >= 4)
1666 mp->has_mrr = true;
1667
1668 mp->hw = hw;
1669 mp->update_interval = 100;
1670
1671 #ifdef CONFIG_MAC80211_DEBUGFS
1672 mp->fixed_rate_idx = (u32) -1;
1673 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1674 &mp->fixed_rate_idx);
1675 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir,
1676 &mp->sample_switch);
1677 #endif
1678
1679 minstrel_ht_init_cck_rates(mp);
1680
1681 return mp;
1682 }
1683
1684 static void
minstrel_ht_free(void * priv)1685 minstrel_ht_free(void *priv)
1686 {
1687 kfree(priv);
1688 }
1689
minstrel_ht_get_expected_throughput(void * priv_sta)1690 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1691 {
1692 struct minstrel_ht_sta_priv *msp = priv_sta;
1693 struct minstrel_ht_sta *mi = &msp->ht;
1694 int i, j, prob, tp_avg;
1695
1696 if (!msp->is_ht)
1697 return mac80211_minstrel.get_expected_throughput(priv_sta);
1698
1699 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1700 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1701 prob = mi->groups[i].rates[j].prob_ewma;
1702
1703 /* convert tp_avg from pkt per second in kbps */
1704 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1705 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1706
1707 return tp_avg;
1708 }
1709
1710 static const struct rate_control_ops mac80211_minstrel_ht = {
1711 .name = "minstrel_ht",
1712 .tx_status_ext = minstrel_ht_tx_status,
1713 .get_rate = minstrel_ht_get_rate,
1714 .rate_init = minstrel_ht_rate_init,
1715 .rate_update = minstrel_ht_rate_update,
1716 .alloc_sta = minstrel_ht_alloc_sta,
1717 .free_sta = minstrel_ht_free_sta,
1718 .alloc = minstrel_ht_alloc,
1719 .free = minstrel_ht_free,
1720 #ifdef CONFIG_MAC80211_DEBUGFS
1721 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1722 #endif
1723 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1724 };
1725
1726
init_sample_table(void)1727 static void __init init_sample_table(void)
1728 {
1729 int col, i, new_idx;
1730 u8 rnd[MCS_GROUP_RATES];
1731
1732 memset(sample_table, 0xff, sizeof(sample_table));
1733 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1734 prandom_bytes(rnd, sizeof(rnd));
1735 for (i = 0; i < MCS_GROUP_RATES; i++) {
1736 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1737 while (sample_table[col][new_idx] != 0xff)
1738 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1739
1740 sample_table[col][new_idx] = i;
1741 }
1742 }
1743 }
1744
1745 int __init
rc80211_minstrel_init(void)1746 rc80211_minstrel_init(void)
1747 {
1748 init_sample_table();
1749 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1750 }
1751
1752 void
rc80211_minstrel_exit(void)1753 rc80211_minstrel_exit(void)
1754 {
1755 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1756 }
1757