?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
WIP FPC-III support
[linux/fpc-iii.git] / net / mac80211 / rc80211_minstrel_ht.c
blobb11a2af55b06a0fd0712ecd0072339280e1e0e91
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.h"
17 #include "rc80211_minstrel_ht.h"
18
19 #define AVG_AMPDU_SIZE 16
20 #define AVG_PKT_SIZE 1200
21
22 #define SAMPLE_SWITCH_THR 100
23
24 /* Number of bits for an average sized packet */
25 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
26
27 /* Number of symbols for a packet with (bps) bits per symbol */
28 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
29
30 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
31 #define MCS_SYMBOL_TIME(sgi, syms) \
32 (sgi ? \
33 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
34 ((syms) * 1000) << 2 /* syms * 4 us */ \
35 )
36
37 /* Transmit duration for the raw data part of an average sized packet */
38 #define MCS_DURATION(streams, sgi, bps) \
39 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
40
41 #define BW_20 0
42 #define BW_40 1
43 #define BW_80 2
44
45 /*
46 * Define group sort order: HT40 -> SGI -> #streams
47 */
48 #define GROUP_IDX(_streams, _sgi, _ht40) \
49 MINSTREL_HT_GROUP_0 + \
50 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
51 MINSTREL_MAX_STREAMS * _sgi + \
52 _streams - 1
53
54 #define _MAX(a, b) (((a)>(b))?(a):(b))
55
56 #define GROUP_SHIFT(duration) \
57 _MAX(0, 16 - __builtin_clz(duration))
58
59 /* MCS rate information for an MCS group */
60 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
61 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
62 .streams = _streams, \
63 .shift = _s, \
64 .bw = _ht40, \
65 .flags = \
66 IEEE80211_TX_RC_MCS | \
67 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
68 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
69 .duration = { \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
72 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
73 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
74 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
75 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
76 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
77 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
78 } \
79 }
80
81 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
82 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
83
84 #define MCS_GROUP(_streams, _sgi, _ht40) \
85 __MCS_GROUP(_streams, _sgi, _ht40, \
86 MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
87
88 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
89 (MINSTREL_VHT_GROUP_0 + \
90 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
91 MINSTREL_MAX_STREAMS * (_sgi) + \
92 (_streams) - 1)
93
94 #define BW2VBPS(_bw, r3, r2, r1) \
95 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
96
97 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \
98 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
99 .streams = _streams, \
100 .shift = _s, \
101 .bw = _bw, \
102 .flags = \
103 IEEE80211_TX_RC_VHT_MCS | \
104 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
105 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
106 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
107 .duration = { \
108 MCS_DURATION(_streams, _sgi, \
109 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
110 MCS_DURATION(_streams, _sgi, \
111 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
112 MCS_DURATION(_streams, _sgi, \
113 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
114 MCS_DURATION(_streams, _sgi, \
115 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
116 MCS_DURATION(_streams, _sgi, \
117 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
118 MCS_DURATION(_streams, _sgi, \
119 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
120 MCS_DURATION(_streams, _sgi, \
121 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
122 MCS_DURATION(_streams, _sgi, \
123 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
124 MCS_DURATION(_streams, _sgi, \
125 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
126 MCS_DURATION(_streams, _sgi, \
127 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
128 } \
129 }
130
131 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
132 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
133 BW2VBPS(_bw, 117, 54, 26)))
134
135 #define VHT_GROUP(_streams, _sgi, _bw) \
136 __VHT_GROUP(_streams, _sgi, _bw, \
137 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
138
139 #define CCK_DURATION(_bitrate, _short, _len) \
140 (1000 * (10 /* SIFS */ + \
141 (_short ? 72 + 24 : 144 + 48) + \
142 (8 * (_len + 4) * 10) / (_bitrate)))
143
144 #define CCK_ACK_DURATION(_bitrate, _short) \
145 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
146 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
147
148 #define CCK_DURATION_LIST(_short, _s) \
149 CCK_ACK_DURATION(10, _short) >> _s, \
150 CCK_ACK_DURATION(20, _short) >> _s, \
151 CCK_ACK_DURATION(55, _short) >> _s, \
152 CCK_ACK_DURATION(110, _short) >> _s
153
154 #define __CCK_GROUP(_s) \
155 [MINSTREL_CCK_GROUP] = { \
156 .streams = 1, \
157 .flags = 0, \
158 .shift = _s, \
159 .duration = { \
160 CCK_DURATION_LIST(false, _s), \
161 CCK_DURATION_LIST(true, _s) \
162 } \
163 }
164
165 #define CCK_GROUP_SHIFT \
166 GROUP_SHIFT(CCK_ACK_DURATION(10, false))
167
168 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
169
170
171 static bool minstrel_vht_only = true;
172 module_param(minstrel_vht_only, bool, 0644);
173 MODULE_PARM_DESC(minstrel_vht_only,
174 "Use only VHT rates when VHT is supported by sta.");
175
176 /*
177 * To enable sufficiently targeted rate sampling, MCS rates are divided into
178 * groups, based on the number of streams and flags (HT40, SGI) that they
179 * use.
180 *
181 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
182 * BW -> SGI -> #streams
183 */
184 const struct mcs_group minstrel_mcs_groups[] = {
185 MCS_GROUP(1, 0, BW_20),
186 MCS_GROUP(2, 0, BW_20),
187 MCS_GROUP(3, 0, BW_20),
188 MCS_GROUP(4, 0, BW_20),
189
190 MCS_GROUP(1, 1, BW_20),
191 MCS_GROUP(2, 1, BW_20),
192 MCS_GROUP(3, 1, BW_20),
193 MCS_GROUP(4, 1, BW_20),
194
195 MCS_GROUP(1, 0, BW_40),
196 MCS_GROUP(2, 0, BW_40),
197 MCS_GROUP(3, 0, BW_40),
198 MCS_GROUP(4, 0, BW_40),
199
200 MCS_GROUP(1, 1, BW_40),
201 MCS_GROUP(2, 1, BW_40),
202 MCS_GROUP(3, 1, BW_40),
203 MCS_GROUP(4, 1, BW_40),
204
205 CCK_GROUP,
206
207 VHT_GROUP(1, 0, BW_20),
208 VHT_GROUP(2, 0, BW_20),
209 VHT_GROUP(3, 0, BW_20),
210 VHT_GROUP(4, 0, BW_20),
211
212 VHT_GROUP(1, 1, BW_20),
213 VHT_GROUP(2, 1, BW_20),
214 VHT_GROUP(3, 1, BW_20),
215 VHT_GROUP(4, 1, BW_20),
216
217 VHT_GROUP(1, 0, BW_40),
218 VHT_GROUP(2, 0, BW_40),
219 VHT_GROUP(3, 0, BW_40),
220 VHT_GROUP(4, 0, BW_40),
221
222 VHT_GROUP(1, 1, BW_40),
223 VHT_GROUP(2, 1, BW_40),
224 VHT_GROUP(3, 1, BW_40),
225 VHT_GROUP(4, 1, BW_40),
226
227 VHT_GROUP(1, 0, BW_80),
228 VHT_GROUP(2, 0, BW_80),
229 VHT_GROUP(3, 0, BW_80),
230 VHT_GROUP(4, 0, BW_80),
231
232 VHT_GROUP(1, 1, BW_80),
233 VHT_GROUP(2, 1, BW_80),
234 VHT_GROUP(3, 1, BW_80),
235 VHT_GROUP(4, 1, BW_80),
236 };
237
238 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
239
240 static void
241 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
242
243 /*
244 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
245 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
246 *
247 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
248 */
249 static u16
250 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
251 {
252 u16 mask = 0;
253
254 if (bw == BW_20) {
255 if (nss != 3 && nss != 6)
256 mask = BIT(9);
257 } else if (bw == BW_80) {
258 if (nss == 3 || nss == 7)
259 mask = BIT(6);
260 else if (nss == 6)
261 mask = BIT(9);
262 } else {
263 WARN_ON(bw != BW_40);
264 }
265
266 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
267 case IEEE80211_VHT_MCS_SUPPORT_0_7:
268 mask |= 0x300;
269 break;
270 case IEEE80211_VHT_MCS_SUPPORT_0_8:
271 mask |= 0x200;
272 break;
273 case IEEE80211_VHT_MCS_SUPPORT_0_9:
274 break;
275 default:
276 mask = 0x3ff;
277 }
278
279 return 0x3ff & ~mask;
280 }
281
282 /*
283 * Look up an MCS group index based on mac80211 rate information
284 */
285 static int
286 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
287 {
288 return GROUP_IDX((rate->idx / 8) + 1,
289 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
290 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
291 }
292
293 static int
294 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
295 {
296 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
297 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
298 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
299 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
300 }
301
302 static struct minstrel_rate_stats *
303 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
304 struct ieee80211_tx_rate *rate)
305 {
306 int group, idx;
307
308 if (rate->flags & IEEE80211_TX_RC_MCS) {
309 group = minstrel_ht_get_group_idx(rate);
310 idx = rate->idx % 8;
311 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
312 group = minstrel_vht_get_group_idx(rate);
313 idx = ieee80211_rate_get_vht_mcs(rate);
314 } else {
315 group = MINSTREL_CCK_GROUP;
316
317 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
318 if (rate->idx == mp->cck_rates[idx])
319 break;
320
321 /* short preamble */
322 if ((mi->supported[group] & BIT(idx + 4)) &&
323 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
324 idx += 4;
325 }
326 return &mi->groups[group].rates[idx];
327 }
328
329 static inline struct minstrel_rate_stats *
330 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
331 {
332 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
333 }
334
335 static unsigned int
336 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
337 {
338 if (!mi->avg_ampdu_len)
339 return AVG_AMPDU_SIZE;
340
341 return MINSTREL_TRUNC(mi->avg_ampdu_len);
342 }
343
344 /*
345 * Return current throughput based on the average A-MPDU length, taking into
346 * account the expected number of retransmissions and their expected length
347 */
348 int
349 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
350 int prob_avg)
351 {
352 unsigned int nsecs = 0;
353
354 /* do not account throughput if sucess prob is below 10% */
355 if (prob_avg < MINSTREL_FRAC(10, 100))
356 return 0;
357
358 if (group != MINSTREL_CCK_GROUP)
359 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
360
361 nsecs += minstrel_mcs_groups[group].duration[rate] <<
362 minstrel_mcs_groups[group].shift;
363
364 /*
365 * For the throughput calculation, limit the probability value to 90% to
366 * account for collision related packet error rate fluctuation
367 * (prob is scaled - see MINSTREL_FRAC above)
368 */
369 if (prob_avg > MINSTREL_FRAC(90, 100))
370 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
371 / nsecs));
372 else
373 return MINSTREL_TRUNC(100000 * ((prob_avg * 1000) / nsecs));
374 }
375
376 /*
377 * Find & sort topmost throughput rates
378 *
379 * If multiple rates provide equal throughput the sorting is based on their
380 * current success probability. Higher success probability is preferred among
381 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
382 */
383 static void
384 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
385 u16 *tp_list)
386 {
387 int cur_group, cur_idx, cur_tp_avg, cur_prob;
388 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
389 int j = MAX_THR_RATES;
390
391 cur_group = index / MCS_GROUP_RATES;
392 cur_idx = index % MCS_GROUP_RATES;
393 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
394 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
395
396 do {
397 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
398 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
399 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
400 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
401 tmp_prob);
402 if (cur_tp_avg < tmp_tp_avg ||
403 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
404 break;
405 j--;
406 } while (j > 0);
407
408 if (j < MAX_THR_RATES - 1) {
409 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
410 (MAX_THR_RATES - (j + 1))));
411 }
412 if (j < MAX_THR_RATES)
413 tp_list[j] = index;
414 }
415
416 /*
417 * Find and set the topmost probability rate per sta and per group
418 */
419 static void
420 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
421 {
422 struct minstrel_mcs_group_data *mg;
423 struct minstrel_rate_stats *mrs;
424 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
425 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
426 int max_gpr_group, max_gpr_idx;
427 int max_gpr_tp_avg, max_gpr_prob;
428
429 cur_group = index / MCS_GROUP_RATES;
430 cur_idx = index % MCS_GROUP_RATES;
431 mg = &mi->groups[index / MCS_GROUP_RATES];
432 mrs = &mg->rates[index % MCS_GROUP_RATES];
433
434 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
435 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
436 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
437 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
438
439 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
440 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
441 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
442 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
443 (max_tp_group != MINSTREL_CCK_GROUP))
444 return;
445
446 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
447 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
448 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
449
450 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
451 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
452 mrs->prob_avg);
453 if (cur_tp_avg > tmp_tp_avg)
454 mi->max_prob_rate = index;
455
456 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
457 max_gpr_idx,
458 max_gpr_prob);
459 if (cur_tp_avg > max_gpr_tp_avg)
460 mg->max_group_prob_rate = index;
461 } else {
462 if (mrs->prob_avg > tmp_prob)
463 mi->max_prob_rate = index;
464 if (mrs->prob_avg > max_gpr_prob)
465 mg->max_group_prob_rate = index;
466 }
467 }
468
469
470 /*
471 * Assign new rate set per sta and use CCK rates only if the fastest
472 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
473 * rate sets where MCS and CCK rates are mixed, because CCK rates can
474 * not use aggregation.
475 */
476 static void
477 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
478 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
479 u16 tmp_cck_tp_rate[MAX_THR_RATES])
480 {
481 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
482 int i;
483
484 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
485 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
486 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
487 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
488
489 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
490 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
491 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
492 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
493
494 if (tmp_cck_tp > tmp_mcs_tp) {
495 for(i = 0; i < MAX_THR_RATES; i++) {
496 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
497 tmp_mcs_tp_rate);
498 }
499 }
500
501 }
502
503 /*
504 * Try to increase robustness of max_prob rate by decrease number of
505 * streams if possible.
506 */
507 static inline void
508 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
509 {
510 struct minstrel_mcs_group_data *mg;
511 int tmp_max_streams, group, tmp_idx, tmp_prob;
512 int tmp_tp = 0;
513
514 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
515 MCS_GROUP_RATES].streams;
516 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
517 mg = &mi->groups[group];
518 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
519 continue;
520
521 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
522 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
523
524 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
525 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
526 mi->max_prob_rate = mg->max_group_prob_rate;
527 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
528 tmp_idx,
529 tmp_prob);
530 }
531 }
532 }
533
534 static inline int
535 minstrel_get_duration(int index)
536 {
537 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
538 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
539 return duration << group->shift;
540 }
541
542 static bool
543 minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group,
544 int tp_idx, const struct mcs_group *group)
545 {
546 if (group->bw < tp_group->bw)
547 return false;
548
549 if (group->streams == tp_group->streams)
550 return true;
551
552 if (tp_idx < 4 && group->streams == tp_group->streams - 1)
553 return true;
554
555 return group->streams == tp_group->streams + 1;
556 }
557
558 static void
559 minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates,
560 bool faster_rate)
561 {
562 const struct mcs_group *group, *tp_group;
563 int i, g, max_dur;
564 int tp_idx;
565
566 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES];
567 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES;
568
569 max_dur = minstrel_get_duration(mi->max_tp_rate[0]);
570 if (faster_rate)
571 max_dur -= max_dur / 16;
572
573 for (g = 0; g < MINSTREL_GROUPS_NB; g++) {
574 u16 supported = mi->supported[g];
575
576 if (!supported)
577 continue;
578
579 group = &minstrel_mcs_groups[g];
580 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group))
581 continue;
582
583 for (i = 0; supported; supported >>= 1, i++) {
584 int idx;
585
586 if (!(supported & 1))
587 continue;
588
589 if ((group->duration[i] << group->shift) > max_dur)
590 continue;
591
592 idx = g * MCS_GROUP_RATES + i;
593 if (idx == mi->max_tp_rate[0])
594 continue;
595
596 rates[(*n_rates)++] = idx;
597 break;
598 }
599 }
600 }
601
602 static void
603 minstrel_ht_rate_sample_switch(struct minstrel_priv *mp,
604 struct minstrel_ht_sta *mi)
605 {
606 struct minstrel_rate_stats *mrs;
607 u16 rates[MINSTREL_GROUPS_NB];
608 int n_rates = 0;
609 int probe_rate = 0;
610 bool faster_rate;
611 int i;
612 u8 random;
613
614 /*
615 * Use rate switching instead of probing packets for devices with
616 * little control over retry fallback behavior
617 */
618 if (mp->hw->max_rates > 1)
619 return;
620
621 /*
622 * If the current EWMA prob is >75%, look for a rate that's 6.25%
623 * faster than the max tp rate.
624 * If that fails, look again for a rate that is at least as fast
625 */
626 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
627 faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100);
628 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate);
629 if (!n_rates && faster_rate)
630 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false);
631
632 /* If no suitable rate was found, try to pick the next one in the group */
633 if (!n_rates) {
634 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES;
635 u16 supported = mi->supported[g_idx];
636
637 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES;
638 for (i = 0; supported; supported >>= 1, i++) {
639 if (!(supported & 1))
640 continue;
641
642 probe_rate = mi->max_tp_rate[0] + i;
643 goto out;
644 }
645
646 return;
647 }
648
649 i = 0;
650 if (n_rates > 1) {
651 random = prandom_u32();
652 i = random % n_rates;
653 }
654 probe_rate = rates[i];
655
656 out:
657 mi->sample_rate = probe_rate;
658 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE;
659 }
660
661 /*
662 * Update rate statistics and select new primary rates
663 *
664 * Rules for rate selection:
665 * - max_prob_rate must use only one stream, as a tradeoff between delivery
666 * probability and throughput during strong fluctuations
667 * - as long as the max prob rate has a probability of more than 75%, pick
668 * higher throughput rates, even if the probablity is a bit lower
669 */
670 static void
671 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
672 bool sample)
673 {
674 struct minstrel_mcs_group_data *mg;
675 struct minstrel_rate_stats *mrs;
676 int group, i, j, cur_prob;
677 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
678 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
679
680 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
681
682 if (sample) {
683 mi->total_packets_cur = mi->total_packets -
684 mi->total_packets_last;
685 mi->total_packets_last = mi->total_packets;
686 }
687 if (!mp->sample_switch)
688 sample = false;
689 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1)
690 sample = false;
691
692 if (mi->ampdu_packets > 0) {
693 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
694 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
695 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
696 EWMA_LEVEL);
697 else
698 mi->avg_ampdu_len = 0;
699 mi->ampdu_len = 0;
700 mi->ampdu_packets = 0;
701 }
702
703 mi->sample_slow = 0;
704 mi->sample_count = 0;
705
706 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate));
707 memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate));
708 if (mi->supported[MINSTREL_CCK_GROUP])
709 for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++)
710 tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES;
711
712 if (mi->supported[MINSTREL_VHT_GROUP_0])
713 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES;
714 else
715 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES;
716
717 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
718 tmp_mcs_tp_rate[j] = index;
719
720 /* Find best rate sets within all MCS groups*/
721 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
722
723 mg = &mi->groups[group];
724 if (!mi->supported[group])
725 continue;
726
727 mi->sample_count++;
728
729 /* (re)Initialize group rate indexes */
730 for(j = 0; j < MAX_THR_RATES; j++)
731 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group;
732
733 for (i = 0; i < MCS_GROUP_RATES; i++) {
734 if (!(mi->supported[group] & BIT(i)))
735 continue;
736
737 index = MCS_GROUP_RATES * group + i;
738
739 mrs = &mg->rates[i];
740 mrs->retry_updated = false;
741 minstrel_calc_rate_stats(mp, mrs);
742 cur_prob = mrs->prob_avg;
743
744 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
745 continue;
746
747 /* Find max throughput rate set */
748 if (group != MINSTREL_CCK_GROUP) {
749 minstrel_ht_sort_best_tp_rates(mi, index,
750 tmp_mcs_tp_rate);
751 } else if (group == MINSTREL_CCK_GROUP) {
752 minstrel_ht_sort_best_tp_rates(mi, index,
753 tmp_cck_tp_rate);
754 }
755
756 /* Find max throughput rate set within a group */
757 minstrel_ht_sort_best_tp_rates(mi, index,
758 tmp_group_tp_rate);
759
760 /* Find max probability rate per group and global */
761 minstrel_ht_set_best_prob_rate(mi, index);
762 }
763
764 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
765 sizeof(mg->max_group_tp_rate));
766 }
767
768 /* Assign new rate set per sta */
769 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
770 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
771
772 /* Try to increase robustness of max_prob_rate*/
773 minstrel_ht_prob_rate_reduce_streams(mi);
774
775 /* try to sample all available rates during each interval */
776 mi->sample_count *= 8;
777 if (mp->new_avg)
778 mi->sample_count /= 2;
779
780 if (sample)
781 minstrel_ht_rate_sample_switch(mp, mi);
782
783 #ifdef CONFIG_MAC80211_DEBUGFS
784 /* use fixed index if set */
785 if (mp->fixed_rate_idx != -1) {
786 for (i = 0; i < 4; i++)
787 mi->max_tp_rate[i] = mp->fixed_rate_idx;
788 mi->max_prob_rate = mp->fixed_rate_idx;
789 mi->sample_mode = MINSTREL_SAMPLE_IDLE;
790 }
791 #endif
792
793 /* Reset update timer */
794 mi->last_stats_update = jiffies;
795 }
796
797 static bool
798 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
799 {
800 if (rate->idx < 0)
801 return false;
802
803 if (!rate->count)
804 return false;
805
806 if (rate->flags & IEEE80211_TX_RC_MCS ||
807 rate->flags & IEEE80211_TX_RC_VHT_MCS)
808 return true;
809
810 return rate->idx == mp->cck_rates[0] ||
811 rate->idx == mp->cck_rates[1] ||
812 rate->idx == mp->cck_rates[2] ||
813 rate->idx == mp->cck_rates[3];
814 }
815
816 static void
817 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
818 {
819 struct minstrel_mcs_group_data *mg;
820
821 for (;;) {
822 mi->sample_group++;
823 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
824 mg = &mi->groups[mi->sample_group];
825
826 if (!mi->supported[mi->sample_group])
827 continue;
828
829 if (++mg->index >= MCS_GROUP_RATES) {
830 mg->index = 0;
831 if (++mg->column >= ARRAY_SIZE(sample_table))
832 mg->column = 0;
833 }
834 break;
835 }
836 }
837
838 static void
839 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
840 {
841 int group, orig_group;
842
843 orig_group = group = *idx / MCS_GROUP_RATES;
844 while (group > 0) {
845 group--;
846
847 if (!mi->supported[group])
848 continue;
849
850 if (minstrel_mcs_groups[group].streams >
851 minstrel_mcs_groups[orig_group].streams)
852 continue;
853
854 if (primary)
855 *idx = mi->groups[group].max_group_tp_rate[0];
856 else
857 *idx = mi->groups[group].max_group_tp_rate[1];
858 break;
859 }
860 }
861
862 static void
863 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
864 {
865 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
866 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
867 u16 tid;
868
869 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
870 return;
871
872 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
873 return;
874
875 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
876 return;
877
878 tid = ieee80211_get_tid(hdr);
879 if (likely(sta->ampdu_mlme.tid_tx[tid]))
880 return;
881
882 ieee80211_start_tx_ba_session(pubsta, tid, 0);
883 }
884
885 static void
886 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
887 void *priv_sta, struct ieee80211_tx_status *st)
888 {
889 struct ieee80211_tx_info *info = st->info;
890 struct minstrel_ht_sta_priv *msp = priv_sta;
891 struct minstrel_ht_sta *mi = &msp->ht;
892 struct ieee80211_tx_rate *ar = info->status.rates;
893 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL;
894 struct minstrel_priv *mp = priv;
895 u32 update_interval = mp->update_interval / 2;
896 bool last, update = false;
897 bool sample_status = false;
898 int i;
899
900 if (!msp->is_ht)
901 return mac80211_minstrel.tx_status_ext(priv, sband,
902 &msp->legacy, st);
903
904
905 /* This packet was aggregated but doesn't carry status info */
906 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
907 !(info->flags & IEEE80211_TX_STAT_AMPDU))
908 return;
909
910 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
911 info->status.ampdu_ack_len =
912 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
913 info->status.ampdu_len = 1;
914 }
915
916 mi->ampdu_packets++;
917 mi->ampdu_len += info->status.ampdu_len;
918
919 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
920 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
921
922 mi->sample_wait = 16 + 2 * avg_ampdu_len;
923 mi->sample_tries = 1;
924 mi->sample_count--;
925 }
926
927 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
928 mi->sample_packets += info->status.ampdu_len;
929
930 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE)
931 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate);
932
933 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
934 for (i = 0; !last; i++) {
935 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
936 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
937
938 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
939 if (rate == rate_sample)
940 sample_status = true;
941
942 if (last)
943 rate->success += info->status.ampdu_ack_len;
944
945 rate->attempts += ar[i].count * info->status.ampdu_len;
946 }
947
948 switch (mi->sample_mode) {
949 case MINSTREL_SAMPLE_IDLE:
950 if (mp->new_avg &&
951 (mp->hw->max_rates > 1 ||
952 mi->total_packets_cur < SAMPLE_SWITCH_THR))
953 update_interval /= 2;
954 break;
955
956 case MINSTREL_SAMPLE_ACTIVE:
957 if (!sample_status)
958 break;
959
960 mi->sample_mode = MINSTREL_SAMPLE_PENDING;
961 update = true;
962 break;
963
964 case MINSTREL_SAMPLE_PENDING:
965 if (sample_status)
966 break;
967
968 update = true;
969 minstrel_ht_update_stats(mp, mi, false);
970 break;
971 }
972
973
974 if (mp->hw->max_rates > 1) {
975 /*
976 * check for sudden death of spatial multiplexing,
977 * downgrade to a lower number of streams if necessary.
978 */
979 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
980 if (rate->attempts > 30 &&
981 rate->success < rate->attempts / 4) {
982 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
983 update = true;
984 }
985
986 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
987 if (rate2->attempts > 30 &&
988 rate2->success < rate2->attempts / 4) {
989 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
990 update = true;
991 }
992 }
993
994 if (time_after(jiffies, mi->last_stats_update + update_interval)) {
995 update = true;
996 minstrel_ht_update_stats(mp, mi, true);
997 }
998
999 if (update)
1000 minstrel_ht_update_rates(mp, mi);
1001 }
1002
1003 static void
1004 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1005 int index)
1006 {
1007 struct minstrel_rate_stats *mrs;
1008 unsigned int tx_time, tx_time_rtscts, tx_time_data;
1009 unsigned int cw = mp->cw_min;
1010 unsigned int ctime = 0;
1011 unsigned int t_slot = 9; /* FIXME */
1012 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1013 unsigned int overhead = 0, overhead_rtscts = 0;
1014
1015 mrs = minstrel_get_ratestats(mi, index);
1016 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1017 mrs->retry_count = 1;
1018 mrs->retry_count_rtscts = 1;
1019 return;
1020 }
1021
1022 mrs->retry_count = 2;
1023 mrs->retry_count_rtscts = 2;
1024 mrs->retry_updated = true;
1025
1026 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1027
1028 /* Contention time for first 2 tries */
1029 ctime = (t_slot * cw) >> 1;
1030 cw = min((cw << 1) | 1, mp->cw_max);
1031 ctime += (t_slot * cw) >> 1;
1032 cw = min((cw << 1) | 1, mp->cw_max);
1033
1034 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
1035 overhead = mi->overhead;
1036 overhead_rtscts = mi->overhead_rtscts;
1037 }
1038
1039 /* Total TX time for data and Contention after first 2 tries */
1040 tx_time = ctime + 2 * (overhead + tx_time_data);
1041 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1042
1043 /* See how many more tries we can fit inside segment size */
1044 do {
1045 /* Contention time for this try */
1046 ctime = (t_slot * cw) >> 1;
1047 cw = min((cw << 1) | 1, mp->cw_max);
1048
1049 /* Total TX time after this try */
1050 tx_time += ctime + overhead + tx_time_data;
1051 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1052
1053 if (tx_time_rtscts < mp->segment_size)
1054 mrs->retry_count_rtscts++;
1055 } while ((tx_time < mp->segment_size) &&
1056 (++mrs->retry_count < mp->max_retry));
1057 }
1058
1059
1060 static void
1061 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1062 struct ieee80211_sta_rates *ratetbl, int offset, int index)
1063 {
1064 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
1065 struct minstrel_rate_stats *mrs;
1066 u8 idx;
1067 u16 flags = group->flags;
1068
1069 mrs = minstrel_get_ratestats(mi, index);
1070 if (!mrs->retry_updated)
1071 minstrel_calc_retransmit(mp, mi, index);
1072
1073 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1074 ratetbl->rate[offset].count = 2;
1075 ratetbl->rate[offset].count_rts = 2;
1076 ratetbl->rate[offset].count_cts = 2;
1077 } else {
1078 ratetbl->rate[offset].count = mrs->retry_count;
1079 ratetbl->rate[offset].count_cts = mrs->retry_count;
1080 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1081 }
1082
1083 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
1084 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1085 else if (flags & IEEE80211_TX_RC_VHT_MCS)
1086 idx = ((group->streams - 1) << 4) |
1087 ((index % MCS_GROUP_RATES) & 0xF);
1088 else
1089 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
1090
1091 /* enable RTS/CTS if needed:
1092 * - if station is in dynamic SMPS (and streams > 1)
1093 * - for fallback rates, to increase chances of getting through
1094 */
1095 if (offset > 0 ||
1096 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
1097 group->streams > 1)) {
1098 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1099 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1100 }
1101
1102 ratetbl->rate[offset].idx = idx;
1103 ratetbl->rate[offset].flags = flags;
1104 }
1105
1106 static inline int
1107 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1108 {
1109 int group = rate / MCS_GROUP_RATES;
1110 rate %= MCS_GROUP_RATES;
1111 return mi->groups[group].rates[rate].prob_avg;
1112 }
1113
1114 static int
1115 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1116 {
1117 int group = mi->max_prob_rate / MCS_GROUP_RATES;
1118 const struct mcs_group *g = &minstrel_mcs_groups[group];
1119 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
1120 unsigned int duration;
1121
1122 /* Disable A-MSDU if max_prob_rate is bad */
1123 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1124 return 1;
1125
1126 duration = g->duration[rate];
1127 duration <<= g->shift;
1128
1129 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1130 if (duration > MCS_DURATION(1, 0, 52))
1131 return 500;
1132
1133 /*
1134 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1135 * data packet size
1136 */
1137 if (duration > MCS_DURATION(1, 0, 104))
1138 return 1600;
1139
1140 /*
1141 * If the rate is slower than single-stream MCS7, or if the max throughput
1142 * rate success probability is less than 75%, limit A-MSDU to twice the usual
1143 * data packet size
1144 */
1145 if (duration > MCS_DURATION(1, 0, 260) ||
1146 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1147 MINSTREL_FRAC(75, 100)))
1148 return 3200;
1149
1150 /*
1151 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1152 * Since aggregation sessions are started/stopped without txq flush, use
1153 * the limit here to avoid the complexity of having to de-aggregate
1154 * packets in the queue.
1155 */
1156 if (!mi->sta->vht_cap.vht_supported)
1157 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1158
1159 /* unlimited */
1160 return 0;
1161 }
1162
1163 static void
1164 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1165 {
1166 struct ieee80211_sta_rates *rates;
1167 u16 first_rate = mi->max_tp_rate[0];
1168 int i = 0;
1169
1170 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE)
1171 first_rate = mi->sample_rate;
1172
1173 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1174 if (!rates)
1175 return;
1176
1177 /* Start with max_tp_rate[0] */
1178 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate);
1179
1180 if (mp->hw->max_rates >= 3) {
1181 /* At least 3 tx rates supported, use max_tp_rate[1] next */
1182 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
1183 }
1184
1185 if (mp->hw->max_rates >= 2) {
1186 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1187 }
1188
1189 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1190 rates->rate[i].idx = -1;
1191 rate_control_set_rates(mp->hw, mi->sta, rates);
1192 }
1193
1194 static int
1195 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1196 {
1197 struct minstrel_rate_stats *mrs;
1198 struct minstrel_mcs_group_data *mg;
1199 unsigned int sample_dur, sample_group, cur_max_tp_streams;
1200 int tp_rate1, tp_rate2;
1201 int sample_idx = 0;
1202
1203 if (mp->hw->max_rates == 1 && mp->sample_switch &&
1204 (mi->total_packets_cur >= SAMPLE_SWITCH_THR ||
1205 mp->sample_switch == 1))
1206 return -1;
1207
1208 if (mi->sample_wait > 0) {
1209 mi->sample_wait--;
1210 return -1;
1211 }
1212
1213 if (!mi->sample_tries)
1214 return -1;
1215
1216 sample_group = mi->sample_group;
1217 mg = &mi->groups[sample_group];
1218 sample_idx = sample_table[mg->column][mg->index];
1219 minstrel_set_next_sample_idx(mi);
1220
1221 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1222 return -1;
1223
1224 mrs = &mg->rates[sample_idx];
1225 sample_idx += sample_group * MCS_GROUP_RATES;
1226
1227 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1228 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1229 minstrel_get_duration(mi->max_tp_rate[1])) {
1230 tp_rate1 = mi->max_tp_rate[1];
1231 tp_rate2 = mi->max_tp_rate[0];
1232 } else {
1233 tp_rate1 = mi->max_tp_rate[0];
1234 tp_rate2 = mi->max_tp_rate[1];
1235 }
1236
1237 /*
1238 * Sampling might add some overhead (RTS, no aggregation)
1239 * to the frame. Hence, don't use sampling for the highest currently
1240 * used highest throughput or probability rate.
1241 */
1242 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1243 return -1;
1244
1245 /*
1246 * Do not sample if the probability is already higher than 95%,
1247 * or if the rate is 3 times slower than the current max probability
1248 * rate, to avoid wasting airtime.
1249 */
1250 sample_dur = minstrel_get_duration(sample_idx);
1251 if (mrs->prob_avg > MINSTREL_FRAC(95, 100) ||
1252 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1253 return -1;
1254
1255
1256 /*
1257 * For devices with no configurable multi-rate retry, skip sampling
1258 * below the per-group max throughput rate, and only use one sampling
1259 * attempt per rate
1260 */
1261 if (mp->hw->max_rates == 1 &&
1262 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur ||
1263 mrs->attempts))
1264 return -1;
1265
1266 /* Skip already sampled slow rates */
1267 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts)
1268 return -1;
1269
1270 /*
1271 * Make sure that lower rates get sampled only occasionally,
1272 * if the link is working perfectly.
1273 */
1274
1275 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1276 MCS_GROUP_RATES].streams;
1277 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1278 (cur_max_tp_streams - 1 <
1279 minstrel_mcs_groups[sample_group].streams ||
1280 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1281 if (mrs->sample_skipped < 20)
1282 return -1;
1283
1284 if (mi->sample_slow++ > 2)
1285 return -1;
1286 }
1287 mi->sample_tries--;
1288
1289 return sample_idx;
1290 }
1291
1292 static void
1293 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1294 struct ieee80211_tx_rate_control *txrc)
1295 {
1296 const struct mcs_group *sample_group;
1297 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1298 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1299 struct minstrel_ht_sta_priv *msp = priv_sta;
1300 struct minstrel_ht_sta *mi = &msp->ht;
1301 struct minstrel_priv *mp = priv;
1302 int sample_idx;
1303
1304 if (!msp->is_ht)
1305 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1306
1307 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1308 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1309 minstrel_aggr_check(sta, txrc->skb);
1310
1311 info->flags |= mi->tx_flags;
1312
1313 #ifdef CONFIG_MAC80211_DEBUGFS
1314 if (mp->fixed_rate_idx != -1)
1315 return;
1316 #endif
1317
1318 /* Don't use EAPOL frames for sampling on non-mrr hw */
1319 if (mp->hw->max_rates == 1 &&
1320 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1321 sample_idx = -1;
1322 else
1323 sample_idx = minstrel_get_sample_rate(mp, mi);
1324
1325 mi->total_packets++;
1326
1327 /* wraparound */
1328 if (mi->total_packets == ~0) {
1329 mi->total_packets = 0;
1330 mi->sample_packets = 0;
1331 }
1332
1333 if (sample_idx < 0)
1334 return;
1335
1336 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1337 sample_idx %= MCS_GROUP_RATES;
1338
1339 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1340 (sample_idx >= 4) != txrc->short_preamble)
1341 return;
1342
1343 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1344 rate->count = 1;
1345
1346 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1347 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1348 rate->idx = mp->cck_rates[idx];
1349 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1350 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1351 sample_group->streams);
1352 } else {
1353 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1354 }
1355
1356 rate->flags = sample_group->flags;
1357 }
1358
1359 static void
1360 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1361 struct ieee80211_supported_band *sband,
1362 struct ieee80211_sta *sta)
1363 {
1364 int i;
1365
1366 if (sband->band != NL80211_BAND_2GHZ)
1367 return;
1368
1369 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1370 return;
1371
1372 mi->cck_supported = 0;
1373 mi->cck_supported_short = 0;
1374 for (i = 0; i < 4; i++) {
1375 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1376 continue;
1377
1378 mi->cck_supported |= BIT(i);
1379 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1380 mi->cck_supported_short |= BIT(i);
1381 }
1382
1383 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1384 }
1385
1386 static void
1387 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1388 struct cfg80211_chan_def *chandef,
1389 struct ieee80211_sta *sta, void *priv_sta)
1390 {
1391 struct minstrel_priv *mp = priv;
1392 struct minstrel_ht_sta_priv *msp = priv_sta;
1393 struct minstrel_ht_sta *mi = &msp->ht;
1394 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1395 u16 ht_cap = sta->ht_cap.cap;
1396 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1397 int use_vht;
1398 int n_supported = 0;
1399 int ack_dur;
1400 int stbc;
1401 int i;
1402 bool ldpc;
1403
1404 /* fall back to the old minstrel for legacy stations */
1405 if (!sta->ht_cap.ht_supported)
1406 goto use_legacy;
1407
1408 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1409
1410 if (vht_cap->vht_supported)
1411 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1412 else
1413 use_vht = 0;
1414
1415 msp->is_ht = true;
1416 memset(mi, 0, sizeof(*mi));
1417
1418 mi->sta = sta;
1419 mi->last_stats_update = jiffies;
1420
1421 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1422 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1423 mi->overhead += ack_dur;
1424 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1425
1426 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1427
1428 /* When using MRR, sample more on the first attempt, without delay */
1429 if (mp->has_mrr) {
1430 mi->sample_count = 16;
1431 mi->sample_wait = 0;
1432 } else {
1433 mi->sample_count = 8;
1434 mi->sample_wait = 8;
1435 }
1436 mi->sample_tries = 4;
1437
1438 if (!use_vht) {
1439 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1440 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1441
1442 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1443 } else {
1444 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1445 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1446
1447 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1448 }
1449
1450 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1451 if (ldpc)
1452 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1453
1454 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1455 u32 gflags = minstrel_mcs_groups[i].flags;
1456 int bw, nss;
1457
1458 mi->supported[i] = 0;
1459 if (i == MINSTREL_CCK_GROUP) {
1460 minstrel_ht_update_cck(mp, mi, sband, sta);
1461 continue;
1462 }
1463
1464 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1465 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1466 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1467 continue;
1468 } else {
1469 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1470 continue;
1471 }
1472 }
1473
1474 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1475 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1476 continue;
1477
1478 nss = minstrel_mcs_groups[i].streams;
1479
1480 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1481 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1482 continue;
1483
1484 /* HT rate */
1485 if (gflags & IEEE80211_TX_RC_MCS) {
1486 if (use_vht && minstrel_vht_only)
1487 continue;
1488
1489 mi->supported[i] = mcs->rx_mask[nss - 1];
1490 if (mi->supported[i])
1491 n_supported++;
1492 continue;
1493 }
1494
1495 /* VHT rate */
1496 if (!vht_cap->vht_supported ||
1497 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1498 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1499 continue;
1500
1501 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1502 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1503 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1504 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1505 continue;
1506 }
1507 }
1508
1509 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1510 bw = BW_40;
1511 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1512 bw = BW_80;
1513 else
1514 bw = BW_20;
1515
1516 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1517 vht_cap->vht_mcs.tx_mcs_map);
1518
1519 if (mi->supported[i])
1520 n_supported++;
1521 }
1522
1523 if (!n_supported)
1524 goto use_legacy;
1525
1526 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1527
1528 /* create an initial rate table with the lowest supported rates */
1529 minstrel_ht_update_stats(mp, mi, true);
1530 minstrel_ht_update_rates(mp, mi);
1531
1532 return;
1533
1534 use_legacy:
1535 msp->is_ht = false;
1536 memset(&msp->legacy, 0, sizeof(msp->legacy));
1537 msp->legacy.r = msp->ratelist;
1538 msp->legacy.sample_table = msp->sample_table;
1539 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1540 &msp->legacy);
1541 }
1542
1543 static void
1544 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1545 struct cfg80211_chan_def *chandef,
1546 struct ieee80211_sta *sta, void *priv_sta)
1547 {
1548 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1549 }
1550
1551 static void
1552 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1553 struct cfg80211_chan_def *chandef,
1554 struct ieee80211_sta *sta, void *priv_sta,
1555 u32 changed)
1556 {
1557 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1558 }
1559
1560 static void *
1561 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1562 {
1563 struct ieee80211_supported_band *sband;
1564 struct minstrel_ht_sta_priv *msp;
1565 struct minstrel_priv *mp = priv;
1566 struct ieee80211_hw *hw = mp->hw;
1567 int max_rates = 0;
1568 int i;
1569
1570 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1571 sband = hw->wiphy->bands[i];
1572 if (sband && sband->n_bitrates > max_rates)
1573 max_rates = sband->n_bitrates;
1574 }
1575
1576 msp = kzalloc(sizeof(*msp), gfp);
1577 if (!msp)
1578 return NULL;
1579
1580 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1581 if (!msp->ratelist)
1582 goto error;
1583
1584 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1585 if (!msp->sample_table)
1586 goto error1;
1587
1588 return msp;
1589
1590 error1:
1591 kfree(msp->ratelist);
1592 error:
1593 kfree(msp);
1594 return NULL;
1595 }
1596
1597 static void
1598 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1599 {
1600 struct minstrel_ht_sta_priv *msp = priv_sta;
1601
1602 kfree(msp->sample_table);
1603 kfree(msp->ratelist);
1604 kfree(msp);
1605 }
1606
1607 static void
1608 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1609 {
1610 static const int bitrates[4] = { 10, 20, 55, 110 };
1611 struct ieee80211_supported_band *sband;
1612 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1613 int i, j;
1614
1615 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1616 if (!sband)
1617 return;
1618
1619 for (i = 0; i < sband->n_bitrates; i++) {
1620 struct ieee80211_rate *rate = &sband->bitrates[i];
1621
1622 if (rate->flags & IEEE80211_RATE_ERP_G)
1623 continue;
1624
1625 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1626 continue;
1627
1628 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1629 if (rate->bitrate != bitrates[j])
1630 continue;
1631
1632 mp->cck_rates[j] = i;
1633 break;
1634 }
1635 }
1636 }
1637
1638 static void *
1639 minstrel_ht_alloc(struct ieee80211_hw *hw)
1640 {
1641 struct minstrel_priv *mp;
1642
1643 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1644 if (!mp)
1645 return NULL;
1646
1647 mp->sample_switch = -1;
1648
1649 /* contention window settings
1650 * Just an approximation. Using the per-queue values would complicate
1651 * the calculations and is probably unnecessary */
1652 mp->cw_min = 15;
1653 mp->cw_max = 1023;
1654
1655 /* number of packets (in %) to use for sampling other rates
1656 * sample less often for non-mrr packets, because the overhead
1657 * is much higher than with mrr */
1658 mp->lookaround_rate = 5;
1659 mp->lookaround_rate_mrr = 10;
1660
1661 /* maximum time that the hw is allowed to stay in one MRR segment */
1662 mp->segment_size = 6000;
1663
1664 if (hw->max_rate_tries > 0)
1665 mp->max_retry = hw->max_rate_tries;
1666 else
1667 /* safe default, does not necessarily have to match hw properties */
1668 mp->max_retry = 7;
1669
1670 if (hw->max_rates >= 4)
1671 mp->has_mrr = true;
1672
1673 mp->hw = hw;
1674 mp->update_interval = HZ / 10;
1675 mp->new_avg = true;
1676
1677 minstrel_ht_init_cck_rates(mp);
1678
1679 return mp;
1680 }
1681
1682 #ifdef CONFIG_MAC80211_DEBUGFS
1683 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1684 struct dentry *debugfsdir)
1685 {
1686 struct minstrel_priv *mp = priv;
1687
1688 mp->fixed_rate_idx = (u32) -1;
1689 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1690 &mp->fixed_rate_idx);
1691 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir,
1692 &mp->sample_switch);
1693 debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir,
1694 &mp->new_avg);
1695 }
1696 #endif
1697
1698 static void
1699 minstrel_ht_free(void *priv)
1700 {
1701 kfree(priv);
1702 }
1703
1704 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1705 {
1706 struct minstrel_ht_sta_priv *msp = priv_sta;
1707 struct minstrel_ht_sta *mi = &msp->ht;
1708 int i, j, prob, tp_avg;
1709
1710 if (!msp->is_ht)
1711 return mac80211_minstrel.get_expected_throughput(priv_sta);
1712
1713 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1714 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1715 prob = mi->groups[i].rates[j].prob_avg;
1716
1717 /* convert tp_avg from pkt per second in kbps */
1718 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1719 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1720
1721 return tp_avg;
1722 }
1723
1724 static const struct rate_control_ops mac80211_minstrel_ht = {
1725 .name = "minstrel_ht",
1726 .tx_status_ext = minstrel_ht_tx_status,
1727 .get_rate = minstrel_ht_get_rate,
1728 .rate_init = minstrel_ht_rate_init,
1729 .rate_update = minstrel_ht_rate_update,
1730 .alloc_sta = minstrel_ht_alloc_sta,
1731 .free_sta = minstrel_ht_free_sta,
1732 .alloc = minstrel_ht_alloc,
1733 .free = minstrel_ht_free,
1734 #ifdef CONFIG_MAC80211_DEBUGFS
1735 .add_debugfs = minstrel_ht_add_debugfs,
1736 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1737 #endif
1738 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1739 };
1740
1741
1742 static void __init init_sample_table(void)
1743 {
1744 int col, i, new_idx;
1745 u8 rnd[MCS_GROUP_RATES];
1746
1747 memset(sample_table, 0xff, sizeof(sample_table));
1748 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1749 prandom_bytes(rnd, sizeof(rnd));
1750 for (i = 0; i < MCS_GROUP_RATES; i++) {
1751 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1752 while (sample_table[col][new_idx] != 0xff)
1753 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1754
1755 sample_table[col][new_idx] = i;
1756 }
1757 }
1758 }
1759
1760 int __init
1761 rc80211_minstrel_init(void)
1762 {
1763 init_sample_table();
1764 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1765 }
1766
1767 void
1768 rc80211_minstrel_exit(void)
1769 {
1770 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1771 }
Linux with added FPC-III support