?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge tag 'nfsd-5.2-2' of git://linux-nfs.org/~bfields/linux
[linux-2.6/linux-2.6-arm.git] / net / mac80211 / rc80211_minstrel_ht.c
blob298a1acb3ce5c0b480192fee64b02755d7452e29
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 /* Number of bits for an average sized packet */
22 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
23
24 /* Number of symbols for a packet with (bps) bits per symbol */
25 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
26
27 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
28 #define MCS_SYMBOL_TIME(sgi, syms) \
29 (sgi ? \
30 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \
31 ((syms) * 1000) << 2 /* syms * 4 us */ \
32 )
33
34 /* Transmit duration for the raw data part of an average sized packet */
35 #define MCS_DURATION(streams, sgi, bps) \
36 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
37
38 #define BW_20 0
39 #define BW_40 1
40 #define BW_80 2
41
42 /*
43 * Define group sort order: HT40 -> SGI -> #streams
44 */
45 #define GROUP_IDX(_streams, _sgi, _ht40) \
46 MINSTREL_HT_GROUP_0 + \
47 MINSTREL_MAX_STREAMS * 2 * _ht40 + \
48 MINSTREL_MAX_STREAMS * _sgi + \
49 _streams - 1
50
51 #define _MAX(a, b) (((a)>(b))?(a):(b))
52
53 #define GROUP_SHIFT(duration) \
54 _MAX(0, 16 - __builtin_clz(duration))
55
56 /* MCS rate information for an MCS group */
57 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
58 [GROUP_IDX(_streams, _sgi, _ht40)] = { \
59 .streams = _streams, \
60 .shift = _s, \
61 .flags = \
62 IEEE80211_TX_RC_MCS | \
63 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
64 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
65 .duration = { \
66 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \
67 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \
68 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \
69 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \
70 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \
71 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \
72 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \
73 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \
74 } \
75 }
76
77 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
78 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
79
80 #define MCS_GROUP(_streams, _sgi, _ht40) \
81 __MCS_GROUP(_streams, _sgi, _ht40, \
82 MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
83
84 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \
85 (MINSTREL_VHT_GROUP_0 + \
86 MINSTREL_MAX_STREAMS * 2 * (_bw) + \
87 MINSTREL_MAX_STREAMS * (_sgi) + \
88 (_streams) - 1)
89
90 #define BW2VBPS(_bw, r3, r2, r1) \
91 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
92
93 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \
94 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
95 .streams = _streams, \
96 .shift = _s, \
97 .flags = \
98 IEEE80211_TX_RC_VHT_MCS | \
99 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
100 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \
101 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
102 .duration = { \
103 MCS_DURATION(_streams, _sgi, \
104 BW2VBPS(_bw, 117, 54, 26)) >> _s, \
105 MCS_DURATION(_streams, _sgi, \
106 BW2VBPS(_bw, 234, 108, 52)) >> _s, \
107 MCS_DURATION(_streams, _sgi, \
108 BW2VBPS(_bw, 351, 162, 78)) >> _s, \
109 MCS_DURATION(_streams, _sgi, \
110 BW2VBPS(_bw, 468, 216, 104)) >> _s, \
111 MCS_DURATION(_streams, _sgi, \
112 BW2VBPS(_bw, 702, 324, 156)) >> _s, \
113 MCS_DURATION(_streams, _sgi, \
114 BW2VBPS(_bw, 936, 432, 208)) >> _s, \
115 MCS_DURATION(_streams, _sgi, \
116 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \
117 MCS_DURATION(_streams, _sgi, \
118 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \
119 MCS_DURATION(_streams, _sgi, \
120 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \
121 MCS_DURATION(_streams, _sgi, \
122 BW2VBPS(_bw, 1560, 720, 346)) >> _s \
123 } \
124 }
125
126 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
127 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
128 BW2VBPS(_bw, 117, 54, 26)))
129
130 #define VHT_GROUP(_streams, _sgi, _bw) \
131 __VHT_GROUP(_streams, _sgi, _bw, \
132 VHT_GROUP_SHIFT(_streams, _sgi, _bw))
133
134 #define CCK_DURATION(_bitrate, _short, _len) \
135 (1000 * (10 /* SIFS */ + \
136 (_short ? 72 + 24 : 144 + 48) + \
137 (8 * (_len + 4) * 10) / (_bitrate)))
138
139 #define CCK_ACK_DURATION(_bitrate, _short) \
140 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \
141 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE))
142
143 #define CCK_DURATION_LIST(_short, _s) \
144 CCK_ACK_DURATION(10, _short) >> _s, \
145 CCK_ACK_DURATION(20, _short) >> _s, \
146 CCK_ACK_DURATION(55, _short) >> _s, \
147 CCK_ACK_DURATION(110, _short) >> _s
148
149 #define __CCK_GROUP(_s) \
150 [MINSTREL_CCK_GROUP] = { \
151 .streams = 1, \
152 .flags = 0, \
153 .shift = _s, \
154 .duration = { \
155 CCK_DURATION_LIST(false, _s), \
156 CCK_DURATION_LIST(true, _s) \
157 } \
158 }
159
160 #define CCK_GROUP_SHIFT \
161 GROUP_SHIFT(CCK_ACK_DURATION(10, false))
162
163 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
164
165
166 static bool minstrel_vht_only = true;
167 module_param(minstrel_vht_only, bool, 0644);
168 MODULE_PARM_DESC(minstrel_vht_only,
169 "Use only VHT rates when VHT is supported by sta.");
170
171 /*
172 * To enable sufficiently targeted rate sampling, MCS rates are divided into
173 * groups, based on the number of streams and flags (HT40, SGI) that they
174 * use.
175 *
176 * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
177 * BW -> SGI -> #streams
178 */
179 const struct mcs_group minstrel_mcs_groups[] = {
180 MCS_GROUP(1, 0, BW_20),
181 MCS_GROUP(2, 0, BW_20),
182 MCS_GROUP(3, 0, BW_20),
183 MCS_GROUP(4, 0, BW_20),
184
185 MCS_GROUP(1, 1, BW_20),
186 MCS_GROUP(2, 1, BW_20),
187 MCS_GROUP(3, 1, BW_20),
188 MCS_GROUP(4, 1, BW_20),
189
190 MCS_GROUP(1, 0, BW_40),
191 MCS_GROUP(2, 0, BW_40),
192 MCS_GROUP(3, 0, BW_40),
193 MCS_GROUP(4, 0, BW_40),
194
195 MCS_GROUP(1, 1, BW_40),
196 MCS_GROUP(2, 1, BW_40),
197 MCS_GROUP(3, 1, BW_40),
198 MCS_GROUP(4, 1, BW_40),
199
200 CCK_GROUP,
201
202 VHT_GROUP(1, 0, BW_20),
203 VHT_GROUP(2, 0, BW_20),
204 VHT_GROUP(3, 0, BW_20),
205 VHT_GROUP(4, 0, BW_20),
206
207 VHT_GROUP(1, 1, BW_20),
208 VHT_GROUP(2, 1, BW_20),
209 VHT_GROUP(3, 1, BW_20),
210 VHT_GROUP(4, 1, BW_20),
211
212 VHT_GROUP(1, 0, BW_40),
213 VHT_GROUP(2, 0, BW_40),
214 VHT_GROUP(3, 0, BW_40),
215 VHT_GROUP(4, 0, BW_40),
216
217 VHT_GROUP(1, 1, BW_40),
218 VHT_GROUP(2, 1, BW_40),
219 VHT_GROUP(3, 1, BW_40),
220 VHT_GROUP(4, 1, BW_40),
221
222 VHT_GROUP(1, 0, BW_80),
223 VHT_GROUP(2, 0, BW_80),
224 VHT_GROUP(3, 0, BW_80),
225 VHT_GROUP(4, 0, BW_80),
226
227 VHT_GROUP(1, 1, BW_80),
228 VHT_GROUP(2, 1, BW_80),
229 VHT_GROUP(3, 1, BW_80),
230 VHT_GROUP(4, 1, BW_80),
231 };
232
233 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
234
235 static void
236 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
237
238 /*
239 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
240 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
241 *
242 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
243 */
244 static u16
245 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
246 {
247 u16 mask = 0;
248
249 if (bw == BW_20) {
250 if (nss != 3 && nss != 6)
251 mask = BIT(9);
252 } else if (bw == BW_80) {
253 if (nss == 3 || nss == 7)
254 mask = BIT(6);
255 else if (nss == 6)
256 mask = BIT(9);
257 } else {
258 WARN_ON(bw != BW_40);
259 }
260
261 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
262 case IEEE80211_VHT_MCS_SUPPORT_0_7:
263 mask |= 0x300;
264 break;
265 case IEEE80211_VHT_MCS_SUPPORT_0_8:
266 mask |= 0x200;
267 break;
268 case IEEE80211_VHT_MCS_SUPPORT_0_9:
269 break;
270 default:
271 mask = 0x3ff;
272 }
273
274 return 0x3ff & ~mask;
275 }
276
277 /*
278 * Look up an MCS group index based on mac80211 rate information
279 */
280 static int
281 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
282 {
283 return GROUP_IDX((rate->idx / 8) + 1,
284 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
285 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
286 }
287
288 static int
289 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
290 {
291 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
292 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
293 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
294 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
295 }
296
297 static struct minstrel_rate_stats *
298 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
299 struct ieee80211_tx_rate *rate)
300 {
301 int group, idx;
302
303 if (rate->flags & IEEE80211_TX_RC_MCS) {
304 group = minstrel_ht_get_group_idx(rate);
305 idx = rate->idx % 8;
306 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
307 group = minstrel_vht_get_group_idx(rate);
308 idx = ieee80211_rate_get_vht_mcs(rate);
309 } else {
310 group = MINSTREL_CCK_GROUP;
311
312 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++)
313 if (rate->idx == mp->cck_rates[idx])
314 break;
315
316 /* short preamble */
317 if ((mi->supported[group] & BIT(idx + 4)) &&
318 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
319 idx += 4;
320 }
321 return &mi->groups[group].rates[idx];
322 }
323
324 static inline struct minstrel_rate_stats *
325 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
326 {
327 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
328 }
329
330 static unsigned int
331 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
332 {
333 if (!mi->avg_ampdu_len)
334 return AVG_AMPDU_SIZE;
335
336 return MINSTREL_TRUNC(mi->avg_ampdu_len);
337 }
338
339 /*
340 * Return current throughput based on the average A-MPDU length, taking into
341 * account the expected number of retransmissions and their expected length
342 */
343 int
344 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
345 int prob_ewma)
346 {
347 unsigned int nsecs = 0;
348
349 /* do not account throughput if sucess prob is below 10% */
350 if (prob_ewma < MINSTREL_FRAC(10, 100))
351 return 0;
352
353 if (group != MINSTREL_CCK_GROUP)
354 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi);
355
356 nsecs += minstrel_mcs_groups[group].duration[rate] <<
357 minstrel_mcs_groups[group].shift;
358
359 /*
360 * For the throughput calculation, limit the probability value to 90% to
361 * account for collision related packet error rate fluctuation
362 * (prob is scaled - see MINSTREL_FRAC above)
363 */
364 if (prob_ewma > MINSTREL_FRAC(90, 100))
365 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000)
366 / nsecs));
367 else
368 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs));
369 }
370
371 /*
372 * Find & sort topmost throughput rates
373 *
374 * If multiple rates provide equal throughput the sorting is based on their
375 * current success probability. Higher success probability is preferred among
376 * MCS groups, CCK rates do not provide aggregation and are therefore at last.
377 */
378 static void
379 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
380 u16 *tp_list)
381 {
382 int cur_group, cur_idx, cur_tp_avg, cur_prob;
383 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
384 int j = MAX_THR_RATES;
385
386 cur_group = index / MCS_GROUP_RATES;
387 cur_idx = index % MCS_GROUP_RATES;
388 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma;
389 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
390
391 do {
392 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES;
393 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES;
394 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
395 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
396 tmp_prob);
397 if (cur_tp_avg < tmp_tp_avg ||
398 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
399 break;
400 j--;
401 } while (j > 0);
402
403 if (j < MAX_THR_RATES - 1) {
404 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
405 (MAX_THR_RATES - (j + 1))));
406 }
407 if (j < MAX_THR_RATES)
408 tp_list[j] = index;
409 }
410
411 /*
412 * Find and set the topmost probability rate per sta and per group
413 */
414 static void
415 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index)
416 {
417 struct minstrel_mcs_group_data *mg;
418 struct minstrel_rate_stats *mrs;
419 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
420 int max_tp_group, cur_tp_avg, cur_group, cur_idx;
421 int max_gpr_group, max_gpr_idx;
422 int max_gpr_tp_avg, max_gpr_prob;
423
424 cur_group = index / MCS_GROUP_RATES;
425 cur_idx = index % MCS_GROUP_RATES;
426 mg = &mi->groups[index / MCS_GROUP_RATES];
427 mrs = &mg->rates[index % MCS_GROUP_RATES];
428
429 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES;
430 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES;
431 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
432 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
433
434 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
435 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
436 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES;
437 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) &&
438 (max_tp_group != MINSTREL_CCK_GROUP))
439 return;
440
441 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES;
442 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
443 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma;
444
445 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) {
446 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
447 mrs->prob_ewma);
448 if (cur_tp_avg > tmp_tp_avg)
449 mi->max_prob_rate = index;
450
451 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
452 max_gpr_idx,
453 max_gpr_prob);
454 if (cur_tp_avg > max_gpr_tp_avg)
455 mg->max_group_prob_rate = index;
456 } else {
457 if (mrs->prob_ewma > tmp_prob)
458 mi->max_prob_rate = index;
459 if (mrs->prob_ewma > max_gpr_prob)
460 mg->max_group_prob_rate = index;
461 }
462 }
463
464
465 /*
466 * Assign new rate set per sta and use CCK rates only if the fastest
467 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
468 * rate sets where MCS and CCK rates are mixed, because CCK rates can
469 * not use aggregation.
470 */
471 static void
472 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
473 u16 tmp_mcs_tp_rate[MAX_THR_RATES],
474 u16 tmp_cck_tp_rate[MAX_THR_RATES])
475 {
476 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
477 int i;
478
479 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES;
480 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES;
481 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
482 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
483
484 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES;
485 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES;
486 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma;
487 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
488
489 if (tmp_cck_tp > tmp_mcs_tp) {
490 for(i = 0; i < MAX_THR_RATES; i++) {
491 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i],
492 tmp_mcs_tp_rate);
493 }
494 }
495
496 }
497
498 /*
499 * Try to increase robustness of max_prob rate by decrease number of
500 * streams if possible.
501 */
502 static inline void
503 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
504 {
505 struct minstrel_mcs_group_data *mg;
506 int tmp_max_streams, group, tmp_idx, tmp_prob;
507 int tmp_tp = 0;
508
509 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] /
510 MCS_GROUP_RATES].streams;
511 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
512 mg = &mi->groups[group];
513 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
514 continue;
515
516 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES;
517 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma;
518
519 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
520 (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
521 mi->max_prob_rate = mg->max_group_prob_rate;
522 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
523 tmp_idx,
524 tmp_prob);
525 }
526 }
527 }
528
529 /*
530 * Update rate statistics and select new primary rates
531 *
532 * Rules for rate selection:
533 * - max_prob_rate must use only one stream, as a tradeoff between delivery
534 * probability and throughput during strong fluctuations
535 * - as long as the max prob rate has a probability of more than 75%, pick
536 * higher throughput rates, even if the probablity is a bit lower
537 */
538 static void
539 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
540 {
541 struct minstrel_mcs_group_data *mg;
542 struct minstrel_rate_stats *mrs;
543 int group, i, j, cur_prob;
544 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
545 u16 tmp_cck_tp_rate[MAX_THR_RATES], index;
546
547 if (mi->ampdu_packets > 0) {
548 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
549 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
550 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
551 EWMA_LEVEL);
552 else
553 mi->avg_ampdu_len = 0;
554 mi->ampdu_len = 0;
555 mi->ampdu_packets = 0;
556 }
557
558 mi->sample_slow = 0;
559 mi->sample_count = 0;
560
561 /* Initialize global rate indexes */
562 for(j = 0; j < MAX_THR_RATES; j++){
563 tmp_mcs_tp_rate[j] = 0;
564 tmp_cck_tp_rate[j] = 0;
565 }
566
567 /* Find best rate sets within all MCS groups*/
568 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
569
570 mg = &mi->groups[group];
571 if (!mi->supported[group])
572 continue;
573
574 mi->sample_count++;
575
576 /* (re)Initialize group rate indexes */
577 for(j = 0; j < MAX_THR_RATES; j++)
578 tmp_group_tp_rate[j] = group;
579
580 for (i = 0; i < MCS_GROUP_RATES; i++) {
581 if (!(mi->supported[group] & BIT(i)))
582 continue;
583
584 index = MCS_GROUP_RATES * group + i;
585
586 mrs = &mg->rates[i];
587 mrs->retry_updated = false;
588 minstrel_calc_rate_stats(mrs);
589 cur_prob = mrs->prob_ewma;
590
591 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
592 continue;
593
594 /* Find max throughput rate set */
595 if (group != MINSTREL_CCK_GROUP) {
596 minstrel_ht_sort_best_tp_rates(mi, index,
597 tmp_mcs_tp_rate);
598 } else if (group == MINSTREL_CCK_GROUP) {
599 minstrel_ht_sort_best_tp_rates(mi, index,
600 tmp_cck_tp_rate);
601 }
602
603 /* Find max throughput rate set within a group */
604 minstrel_ht_sort_best_tp_rates(mi, index,
605 tmp_group_tp_rate);
606
607 /* Find max probability rate per group and global */
608 minstrel_ht_set_best_prob_rate(mi, index);
609 }
610
611 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
612 sizeof(mg->max_group_tp_rate));
613 }
614
615 /* Assign new rate set per sta */
616 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate);
617 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
618
619 /* Try to increase robustness of max_prob_rate*/
620 minstrel_ht_prob_rate_reduce_streams(mi);
621
622 /* try to sample all available rates during each interval */
623 mi->sample_count *= 8;
624
625 #ifdef CONFIG_MAC80211_DEBUGFS
626 /* use fixed index if set */
627 if (mp->fixed_rate_idx != -1) {
628 for (i = 0; i < 4; i++)
629 mi->max_tp_rate[i] = mp->fixed_rate_idx;
630 mi->max_prob_rate = mp->fixed_rate_idx;
631 }
632 #endif
633
634 /* Reset update timer */
635 mi->last_stats_update = jiffies;
636 }
637
638 static bool
639 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate)
640 {
641 if (rate->idx < 0)
642 return false;
643
644 if (!rate->count)
645 return false;
646
647 if (rate->flags & IEEE80211_TX_RC_MCS ||
648 rate->flags & IEEE80211_TX_RC_VHT_MCS)
649 return true;
650
651 return rate->idx == mp->cck_rates[0] ||
652 rate->idx == mp->cck_rates[1] ||
653 rate->idx == mp->cck_rates[2] ||
654 rate->idx == mp->cck_rates[3];
655 }
656
657 static void
658 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi)
659 {
660 struct minstrel_mcs_group_data *mg;
661
662 for (;;) {
663 mi->sample_group++;
664 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
665 mg = &mi->groups[mi->sample_group];
666
667 if (!mi->supported[mi->sample_group])
668 continue;
669
670 if (++mg->index >= MCS_GROUP_RATES) {
671 mg->index = 0;
672 if (++mg->column >= ARRAY_SIZE(sample_table))
673 mg->column = 0;
674 }
675 break;
676 }
677 }
678
679 static void
680 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
681 {
682 int group, orig_group;
683
684 orig_group = group = *idx / MCS_GROUP_RATES;
685 while (group > 0) {
686 group--;
687
688 if (!mi->supported[group])
689 continue;
690
691 if (minstrel_mcs_groups[group].streams >
692 minstrel_mcs_groups[orig_group].streams)
693 continue;
694
695 if (primary)
696 *idx = mi->groups[group].max_group_tp_rate[0];
697 else
698 *idx = mi->groups[group].max_group_tp_rate[1];
699 break;
700 }
701 }
702
703 static void
704 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb)
705 {
706 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
707 struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
708 u16 tid;
709
710 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
711 return;
712
713 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
714 return;
715
716 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
717 return;
718
719 tid = ieee80211_get_tid(hdr);
720 if (likely(sta->ampdu_mlme.tid_tx[tid]))
721 return;
722
723 ieee80211_start_tx_ba_session(pubsta, tid, 0);
724 }
725
726 static void
727 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
728 void *priv_sta, struct ieee80211_tx_status *st)
729 {
730 struct ieee80211_tx_info *info = st->info;
731 struct minstrel_ht_sta_priv *msp = priv_sta;
732 struct minstrel_ht_sta *mi = &msp->ht;
733 struct ieee80211_tx_rate *ar = info->status.rates;
734 struct minstrel_rate_stats *rate, *rate2;
735 struct minstrel_priv *mp = priv;
736 bool last, update = false;
737 int i;
738
739 if (!msp->is_ht)
740 return mac80211_minstrel.tx_status_ext(priv, sband,
741 &msp->legacy, st);
742
743 /* This packet was aggregated but doesn't carry status info */
744 if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
745 !(info->flags & IEEE80211_TX_STAT_AMPDU))
746 return;
747
748 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
749 info->status.ampdu_ack_len =
750 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
751 info->status.ampdu_len = 1;
752 }
753
754 mi->ampdu_packets++;
755 mi->ampdu_len += info->status.ampdu_len;
756
757 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
758 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi);
759
760 mi->sample_wait = 16 + 2 * avg_ampdu_len;
761 mi->sample_tries = 1;
762 mi->sample_count--;
763 }
764
765 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
766 mi->sample_packets += info->status.ampdu_len;
767
768 last = !minstrel_ht_txstat_valid(mp, &ar[0]);
769 for (i = 0; !last; i++) {
770 last = (i == IEEE80211_TX_MAX_RATES - 1) ||
771 !minstrel_ht_txstat_valid(mp, &ar[i + 1]);
772
773 rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
774
775 if (last)
776 rate->success += info->status.ampdu_ack_len;
777
778 rate->attempts += ar[i].count * info->status.ampdu_len;
779 }
780
781 /*
782 * check for sudden death of spatial multiplexing,
783 * downgrade to a lower number of streams if necessary.
784 */
785 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
786 if (rate->attempts > 30 &&
787 MINSTREL_FRAC(rate->success, rate->attempts) <
788 MINSTREL_FRAC(20, 100)) {
789 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
790 update = true;
791 }
792
793 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
794 if (rate2->attempts > 30 &&
795 MINSTREL_FRAC(rate2->success, rate2->attempts) <
796 MINSTREL_FRAC(20, 100)) {
797 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
798 update = true;
799 }
800
801 if (time_after(jiffies, mi->last_stats_update +
802 (mp->update_interval / 2 * HZ) / 1000)) {
803 update = true;
804 minstrel_ht_update_stats(mp, mi);
805 }
806
807 if (update)
808 minstrel_ht_update_rates(mp, mi);
809 }
810
811 static inline int
812 minstrel_get_duration(int index)
813 {
814 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
815 unsigned int duration = group->duration[index % MCS_GROUP_RATES];
816 return duration << group->shift;
817 }
818
819 static void
820 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
821 int index)
822 {
823 struct minstrel_rate_stats *mrs;
824 unsigned int tx_time, tx_time_rtscts, tx_time_data;
825 unsigned int cw = mp->cw_min;
826 unsigned int ctime = 0;
827 unsigned int t_slot = 9; /* FIXME */
828 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
829 unsigned int overhead = 0, overhead_rtscts = 0;
830
831 mrs = minstrel_get_ratestats(mi, index);
832 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) {
833 mrs->retry_count = 1;
834 mrs->retry_count_rtscts = 1;
835 return;
836 }
837
838 mrs->retry_count = 2;
839 mrs->retry_count_rtscts = 2;
840 mrs->retry_updated = true;
841
842 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
843
844 /* Contention time for first 2 tries */
845 ctime = (t_slot * cw) >> 1;
846 cw = min((cw << 1) | 1, mp->cw_max);
847 ctime += (t_slot * cw) >> 1;
848 cw = min((cw << 1) | 1, mp->cw_max);
849
850 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) {
851 overhead = mi->overhead;
852 overhead_rtscts = mi->overhead_rtscts;
853 }
854
855 /* Total TX time for data and Contention after first 2 tries */
856 tx_time = ctime + 2 * (overhead + tx_time_data);
857 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
858
859 /* See how many more tries we can fit inside segment size */
860 do {
861 /* Contention time for this try */
862 ctime = (t_slot * cw) >> 1;
863 cw = min((cw << 1) | 1, mp->cw_max);
864
865 /* Total TX time after this try */
866 tx_time += ctime + overhead + tx_time_data;
867 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
868
869 if (tx_time_rtscts < mp->segment_size)
870 mrs->retry_count_rtscts++;
871 } while ((tx_time < mp->segment_size) &&
872 (++mrs->retry_count < mp->max_retry));
873 }
874
875
876 static void
877 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
878 struct ieee80211_sta_rates *ratetbl, int offset, int index)
879 {
880 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
881 struct minstrel_rate_stats *mrs;
882 u8 idx;
883 u16 flags = group->flags;
884
885 mrs = minstrel_get_ratestats(mi, index);
886 if (!mrs->retry_updated)
887 minstrel_calc_retransmit(mp, mi, index);
888
889 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
890 ratetbl->rate[offset].count = 2;
891 ratetbl->rate[offset].count_rts = 2;
892 ratetbl->rate[offset].count_cts = 2;
893 } else {
894 ratetbl->rate[offset].count = mrs->retry_count;
895 ratetbl->rate[offset].count_cts = mrs->retry_count;
896 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
897 }
898
899 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP)
900 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
901 else if (flags & IEEE80211_TX_RC_VHT_MCS)
902 idx = ((group->streams - 1) << 4) |
903 ((index % MCS_GROUP_RATES) & 0xF);
904 else
905 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8;
906
907 /* enable RTS/CTS if needed:
908 * - if station is in dynamic SMPS (and streams > 1)
909 * - for fallback rates, to increase chances of getting through
910 */
911 if (offset > 0 ||
912 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC &&
913 group->streams > 1)) {
914 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
915 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
916 }
917
918 ratetbl->rate[offset].idx = idx;
919 ratetbl->rate[offset].flags = flags;
920 }
921
922 static inline int
923 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate)
924 {
925 int group = rate / MCS_GROUP_RATES;
926 rate %= MCS_GROUP_RATES;
927 return mi->groups[group].rates[rate].prob_ewma;
928 }
929
930 static int
931 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
932 {
933 int group = mi->max_prob_rate / MCS_GROUP_RATES;
934 const struct mcs_group *g = &minstrel_mcs_groups[group];
935 int rate = mi->max_prob_rate % MCS_GROUP_RATES;
936 unsigned int duration;
937
938 /* Disable A-MSDU if max_prob_rate is bad */
939 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100))
940 return 1;
941
942 duration = g->duration[rate];
943 duration <<= g->shift;
944
945 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
946 if (duration > MCS_DURATION(1, 0, 52))
947 return 500;
948
949 /*
950 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
951 * data packet size
952 */
953 if (duration > MCS_DURATION(1, 0, 104))
954 return 1600;
955
956 /*
957 * If the rate is slower than single-stream MCS7, or if the max throughput
958 * rate success probability is less than 75%, limit A-MSDU to twice the usual
959 * data packet size
960 */
961 if (duration > MCS_DURATION(1, 0, 260) ||
962 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) <
963 MINSTREL_FRAC(75, 100)))
964 return 3200;
965
966 /*
967 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
968 * Since aggregation sessions are started/stopped without txq flush, use
969 * the limit here to avoid the complexity of having to de-aggregate
970 * packets in the queue.
971 */
972 if (!mi->sta->vht_cap.vht_supported)
973 return IEEE80211_MAX_MPDU_LEN_HT_BA;
974
975 /* unlimited */
976 return 0;
977 }
978
979 static void
980 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
981 {
982 struct ieee80211_sta_rates *rates;
983 int i = 0;
984
985 rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
986 if (!rates)
987 return;
988
989 /* Start with max_tp_rate[0] */
990 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
991
992 if (mp->hw->max_rates >= 3) {
993 /* At least 3 tx rates supported, use max_tp_rate[1] next */
994 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]);
995 }
996
997 if (mp->hw->max_rates >= 2) {
998 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
999 }
1000
1001 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1002 rates->rate[i].idx = -1;
1003 rate_control_set_rates(mp->hw, mi->sta, rates);
1004 }
1005
1006 static int
1007 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1008 {
1009 struct minstrel_rate_stats *mrs;
1010 struct minstrel_mcs_group_data *mg;
1011 unsigned int sample_dur, sample_group, cur_max_tp_streams;
1012 int tp_rate1, tp_rate2;
1013 int sample_idx = 0;
1014
1015 if (mi->sample_wait > 0) {
1016 mi->sample_wait--;
1017 return -1;
1018 }
1019
1020 if (!mi->sample_tries)
1021 return -1;
1022
1023 sample_group = mi->sample_group;
1024 mg = &mi->groups[sample_group];
1025 sample_idx = sample_table[mg->column][mg->index];
1026 minstrel_set_next_sample_idx(mi);
1027
1028 if (!(mi->supported[sample_group] & BIT(sample_idx)))
1029 return -1;
1030
1031 mrs = &mg->rates[sample_idx];
1032 sample_idx += sample_group * MCS_GROUP_RATES;
1033
1034 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */
1035 if (minstrel_get_duration(mi->max_tp_rate[0]) >
1036 minstrel_get_duration(mi->max_tp_rate[1])) {
1037 tp_rate1 = mi->max_tp_rate[1];
1038 tp_rate2 = mi->max_tp_rate[0];
1039 } else {
1040 tp_rate1 = mi->max_tp_rate[0];
1041 tp_rate2 = mi->max_tp_rate[1];
1042 }
1043
1044 /*
1045 * Sampling might add some overhead (RTS, no aggregation)
1046 * to the frame. Hence, don't use sampling for the highest currently
1047 * used highest throughput or probability rate.
1048 */
1049 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate)
1050 return -1;
1051
1052 /*
1053 * Do not sample if the probability is already higher than 95%,
1054 * or if the rate is 3 times slower than the current max probability
1055 * rate, to avoid wasting airtime.
1056 */
1057 sample_dur = minstrel_get_duration(sample_idx);
1058 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
1059 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur)
1060 return -1;
1061
1062 /*
1063 * Make sure that lower rates get sampled only occasionally,
1064 * if the link is working perfectly.
1065 */
1066
1067 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 /
1068 MCS_GROUP_RATES].streams;
1069 if (sample_dur >= minstrel_get_duration(tp_rate2) &&
1070 (cur_max_tp_streams - 1 <
1071 minstrel_mcs_groups[sample_group].streams ||
1072 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) {
1073 if (mrs->sample_skipped < 20)
1074 return -1;
1075
1076 if (mi->sample_slow++ > 2)
1077 return -1;
1078 }
1079 mi->sample_tries--;
1080
1081 return sample_idx;
1082 }
1083
1084 static void
1085 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1086 struct ieee80211_tx_rate_control *txrc)
1087 {
1088 const struct mcs_group *sample_group;
1089 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1090 struct ieee80211_tx_rate *rate = &info->status.rates[0];
1091 struct minstrel_ht_sta_priv *msp = priv_sta;
1092 struct minstrel_ht_sta *mi = &msp->ht;
1093 struct minstrel_priv *mp = priv;
1094 int sample_idx;
1095
1096 if (rate_control_send_low(sta, priv_sta, txrc))
1097 return;
1098
1099 if (!msp->is_ht)
1100 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
1101
1102 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) &&
1103 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP)
1104 minstrel_aggr_check(sta, txrc->skb);
1105
1106 info->flags |= mi->tx_flags;
1107
1108 #ifdef CONFIG_MAC80211_DEBUGFS
1109 if (mp->fixed_rate_idx != -1)
1110 return;
1111 #endif
1112
1113 /* Don't use EAPOL frames for sampling on non-mrr hw */
1114 if (mp->hw->max_rates == 1 &&
1115 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1116 sample_idx = -1;
1117 else
1118 sample_idx = minstrel_get_sample_rate(mp, mi);
1119
1120 mi->total_packets++;
1121
1122 /* wraparound */
1123 if (mi->total_packets == ~0) {
1124 mi->total_packets = 0;
1125 mi->sample_packets = 0;
1126 }
1127
1128 if (sample_idx < 0)
1129 return;
1130
1131 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES];
1132 sample_idx %= MCS_GROUP_RATES;
1133
1134 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1135 (sample_idx >= 4) != txrc->short_preamble)
1136 return;
1137
1138 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1139 rate->count = 1;
1140
1141 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1142 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1143 rate->idx = mp->cck_rates[idx];
1144 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1145 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES,
1146 sample_group->streams);
1147 } else {
1148 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1149 }
1150
1151 rate->flags = sample_group->flags;
1152 }
1153
1154 static void
1155 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1156 struct ieee80211_supported_band *sband,
1157 struct ieee80211_sta *sta)
1158 {
1159 int i;
1160
1161 if (sband->band != NL80211_BAND_2GHZ)
1162 return;
1163
1164 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1165 return;
1166
1167 mi->cck_supported = 0;
1168 mi->cck_supported_short = 0;
1169 for (i = 0; i < 4; i++) {
1170 if (!rate_supported(sta, sband->band, mp->cck_rates[i]))
1171 continue;
1172
1173 mi->cck_supported |= BIT(i);
1174 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1175 mi->cck_supported_short |= BIT(i);
1176 }
1177
1178 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported;
1179 }
1180
1181 static void
1182 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1183 struct cfg80211_chan_def *chandef,
1184 struct ieee80211_sta *sta, void *priv_sta)
1185 {
1186 struct minstrel_priv *mp = priv;
1187 struct minstrel_ht_sta_priv *msp = priv_sta;
1188 struct minstrel_ht_sta *mi = &msp->ht;
1189 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
1190 u16 ht_cap = sta->ht_cap.cap;
1191 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap;
1192 int use_vht;
1193 int n_supported = 0;
1194 int ack_dur;
1195 int stbc;
1196 int i;
1197 bool ldpc;
1198
1199 /* fall back to the old minstrel for legacy stations */
1200 if (!sta->ht_cap.ht_supported)
1201 goto use_legacy;
1202
1203 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1204
1205 if (vht_cap->vht_supported)
1206 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1207 else
1208 use_vht = 0;
1209
1210 msp->is_ht = true;
1211 memset(mi, 0, sizeof(*mi));
1212
1213 mi->sta = sta;
1214 mi->last_stats_update = jiffies;
1215
1216 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1217 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1218 mi->overhead += ack_dur;
1219 mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1220
1221 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1222
1223 /* When using MRR, sample more on the first attempt, without delay */
1224 if (mp->has_mrr) {
1225 mi->sample_count = 16;
1226 mi->sample_wait = 0;
1227 } else {
1228 mi->sample_count = 8;
1229 mi->sample_wait = 8;
1230 }
1231 mi->sample_tries = 4;
1232
1233 if (!use_vht) {
1234 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1235 IEEE80211_HT_CAP_RX_STBC_SHIFT;
1236
1237 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1238 } else {
1239 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1240 IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1241
1242 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1243 }
1244
1245 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1246 if (ldpc)
1247 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1248
1249 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1250 u32 gflags = minstrel_mcs_groups[i].flags;
1251 int bw, nss;
1252
1253 mi->supported[i] = 0;
1254 if (i == MINSTREL_CCK_GROUP) {
1255 minstrel_ht_update_cck(mp, mi, sband, sta);
1256 continue;
1257 }
1258
1259 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1260 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1261 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1262 continue;
1263 } else {
1264 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1265 continue;
1266 }
1267 }
1268
1269 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1270 sta->bandwidth < IEEE80211_STA_RX_BW_40)
1271 continue;
1272
1273 nss = minstrel_mcs_groups[i].streams;
1274
1275 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1276 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1277 continue;
1278
1279 /* HT rate */
1280 if (gflags & IEEE80211_TX_RC_MCS) {
1281 if (use_vht && minstrel_vht_only)
1282 continue;
1283
1284 mi->supported[i] = mcs->rx_mask[nss - 1];
1285 if (mi->supported[i])
1286 n_supported++;
1287 continue;
1288 }
1289
1290 /* VHT rate */
1291 if (!vht_cap->vht_supported ||
1292 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1293 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1294 continue;
1295
1296 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1297 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 ||
1298 ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1299 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1300 continue;
1301 }
1302 }
1303
1304 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1305 bw = BW_40;
1306 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1307 bw = BW_80;
1308 else
1309 bw = BW_20;
1310
1311 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1312 vht_cap->vht_mcs.tx_mcs_map);
1313
1314 if (mi->supported[i])
1315 n_supported++;
1316 }
1317
1318 if (!n_supported)
1319 goto use_legacy;
1320
1321 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4;
1322
1323 /* create an initial rate table with the lowest supported rates */
1324 minstrel_ht_update_stats(mp, mi);
1325 minstrel_ht_update_rates(mp, mi);
1326
1327 return;
1328
1329 use_legacy:
1330 msp->is_ht = false;
1331 memset(&msp->legacy, 0, sizeof(msp->legacy));
1332 msp->legacy.r = msp->ratelist;
1333 msp->legacy.sample_table = msp->sample_table;
1334 return mac80211_minstrel.rate_init(priv, sband, chandef, sta,
1335 &msp->legacy);
1336 }
1337
1338 static void
1339 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1340 struct cfg80211_chan_def *chandef,
1341 struct ieee80211_sta *sta, void *priv_sta)
1342 {
1343 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1344 }
1345
1346 static void
1347 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1348 struct cfg80211_chan_def *chandef,
1349 struct ieee80211_sta *sta, void *priv_sta,
1350 u32 changed)
1351 {
1352 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1353 }
1354
1355 static void *
1356 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1357 {
1358 struct ieee80211_supported_band *sband;
1359 struct minstrel_ht_sta_priv *msp;
1360 struct minstrel_priv *mp = priv;
1361 struct ieee80211_hw *hw = mp->hw;
1362 int max_rates = 0;
1363 int i;
1364
1365 for (i = 0; i < NUM_NL80211_BANDS; i++) {
1366 sband = hw->wiphy->bands[i];
1367 if (sband && sband->n_bitrates > max_rates)
1368 max_rates = sband->n_bitrates;
1369 }
1370
1371 msp = kzalloc(sizeof(*msp), gfp);
1372 if (!msp)
1373 return NULL;
1374
1375 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp);
1376 if (!msp->ratelist)
1377 goto error;
1378
1379 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp);
1380 if (!msp->sample_table)
1381 goto error1;
1382
1383 return msp;
1384
1385 error1:
1386 kfree(msp->ratelist);
1387 error:
1388 kfree(msp);
1389 return NULL;
1390 }
1391
1392 static void
1393 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1394 {
1395 struct minstrel_ht_sta_priv *msp = priv_sta;
1396
1397 kfree(msp->sample_table);
1398 kfree(msp->ratelist);
1399 kfree(msp);
1400 }
1401
1402 static void
1403 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1404 {
1405 static const int bitrates[4] = { 10, 20, 55, 110 };
1406 struct ieee80211_supported_band *sband;
1407 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1408 int i, j;
1409
1410 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1411 if (!sband)
1412 return;
1413
1414 for (i = 0; i < sband->n_bitrates; i++) {
1415 struct ieee80211_rate *rate = &sband->bitrates[i];
1416
1417 if (rate->flags & IEEE80211_RATE_ERP_G)
1418 continue;
1419
1420 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1421 continue;
1422
1423 for (j = 0; j < ARRAY_SIZE(bitrates); j++) {
1424 if (rate->bitrate != bitrates[j])
1425 continue;
1426
1427 mp->cck_rates[j] = i;
1428 break;
1429 }
1430 }
1431 }
1432
1433 static void *
1434 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
1435 {
1436 struct minstrel_priv *mp;
1437
1438 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1439 if (!mp)
1440 return NULL;
1441
1442 /* contention window settings
1443 * Just an approximation. Using the per-queue values would complicate
1444 * the calculations and is probably unnecessary */
1445 mp->cw_min = 15;
1446 mp->cw_max = 1023;
1447
1448 /* number of packets (in %) to use for sampling other rates
1449 * sample less often for non-mrr packets, because the overhead
1450 * is much higher than with mrr */
1451 mp->lookaround_rate = 5;
1452 mp->lookaround_rate_mrr = 10;
1453
1454 /* maximum time that the hw is allowed to stay in one MRR segment */
1455 mp->segment_size = 6000;
1456
1457 if (hw->max_rate_tries > 0)
1458 mp->max_retry = hw->max_rate_tries;
1459 else
1460 /* safe default, does not necessarily have to match hw properties */
1461 mp->max_retry = 7;
1462
1463 if (hw->max_rates >= 4)
1464 mp->has_mrr = true;
1465
1466 mp->hw = hw;
1467 mp->update_interval = 100;
1468
1469 #ifdef CONFIG_MAC80211_DEBUGFS
1470 mp->fixed_rate_idx = (u32) -1;
1471 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1472 &mp->fixed_rate_idx);
1473 #endif
1474
1475 minstrel_ht_init_cck_rates(mp);
1476
1477 return mp;
1478 }
1479
1480 static void
1481 minstrel_ht_free(void *priv)
1482 {
1483 kfree(priv);
1484 }
1485
1486 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1487 {
1488 struct minstrel_ht_sta_priv *msp = priv_sta;
1489 struct minstrel_ht_sta *mi = &msp->ht;
1490 int i, j, prob, tp_avg;
1491
1492 if (!msp->is_ht)
1493 return mac80211_minstrel.get_expected_throughput(priv_sta);
1494
1495 i = mi->max_tp_rate[0] / MCS_GROUP_RATES;
1496 j = mi->max_tp_rate[0] % MCS_GROUP_RATES;
1497 prob = mi->groups[i].rates[j].prob_ewma;
1498
1499 /* convert tp_avg from pkt per second in kbps */
1500 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
1501 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
1502
1503 return tp_avg;
1504 }
1505
1506 static const struct rate_control_ops mac80211_minstrel_ht = {
1507 .name = "minstrel_ht",
1508 .tx_status_ext = minstrel_ht_tx_status,
1509 .get_rate = minstrel_ht_get_rate,
1510 .rate_init = minstrel_ht_rate_init,
1511 .rate_update = minstrel_ht_rate_update,
1512 .alloc_sta = minstrel_ht_alloc_sta,
1513 .free_sta = minstrel_ht_free_sta,
1514 .alloc = minstrel_ht_alloc,
1515 .free = minstrel_ht_free,
1516 #ifdef CONFIG_MAC80211_DEBUGFS
1517 .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
1518 #endif
1519 .get_expected_throughput = minstrel_ht_get_expected_throughput,
1520 };
1521
1522
1523 static void __init init_sample_table(void)
1524 {
1525 int col, i, new_idx;
1526 u8 rnd[MCS_GROUP_RATES];
1527
1528 memset(sample_table, 0xff, sizeof(sample_table));
1529 for (col = 0; col < SAMPLE_COLUMNS; col++) {
1530 prandom_bytes(rnd, sizeof(rnd));
1531 for (i = 0; i < MCS_GROUP_RATES; i++) {
1532 new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
1533 while (sample_table[col][new_idx] != 0xff)
1534 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
1535
1536 sample_table[col][new_idx] = i;
1537 }
1538 }
1539 }
1540
1541 int __init
1542 rc80211_minstrel_init(void)
1543 {
1544 init_sample_table();
1545 return ieee80211_rate_control_register(&mac80211_minstrel_ht);
1546 }
1547
1548 void
1549 rc80211_minstrel_exit(void)
1550 {
1551 ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
1552 }
Mirror of linux-2.6-arm at arm.linux.org.uk