1 /* 2 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License version 2 as 6 * published by the Free Software Foundation. 7 */ 8 #include <linux/netdevice.h> 9 #include <linux/types.h> 10 #include <linux/skbuff.h> 11 #include <linux/debugfs.h> 12 #include <linux/random.h> 13 #include <linux/moduleparam.h> 14 #include <linux/ieee80211.h> 15 #include <net/mac80211.h> 16 #include "rate.h" 17 #include "rc80211_minstrel.h" 18 #include "rc80211_minstrel_ht.h" 19 20 #define AVG_PKT_SIZE 1200 21 22 /* Number of bits for an average sized packet */ 23 #define MCS_NBITS (AVG_PKT_SIZE << 3) 24 25 /* Number of symbols for a packet with (bps) bits per symbol */ 26 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) 27 28 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ 29 #define MCS_SYMBOL_TIME(sgi, syms) \ 30 (sgi ? \ 31 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ 32 ((syms) * 1000) << 2 /* syms * 4 us */ \ 33 ) 34 35 /* Transmit duration for the raw data part of an average sized packet */ 36 #define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) 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 /* MCS rate information for an MCS group */ 52 #define MCS_GROUP(_streams, _sgi, _ht40) \ 53 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 54 .streams = _streams, \ 55 .flags = \ 56 IEEE80211_TX_RC_MCS | \ 57 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 58 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 59 .duration = { \ 60 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \ 61 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \ 62 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \ 63 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \ 64 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \ 65 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \ 66 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \ 67 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \ 68 } \ 69 } 70 71 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 72 (MINSTREL_VHT_GROUP_0 + \ 73 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 74 MINSTREL_MAX_STREAMS * (_sgi) + \ 75 (_streams) - 1) 76 77 #define BW2VBPS(_bw, r3, r2, r1) \ 78 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 79 80 #define VHT_GROUP(_streams, _sgi, _bw) \ 81 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 82 .streams = _streams, \ 83 .flags = \ 84 IEEE80211_TX_RC_VHT_MCS | \ 85 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 86 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 87 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 88 .duration = { \ 89 MCS_DURATION(_streams, _sgi, \ 90 BW2VBPS(_bw, 117, 54, 26)), \ 91 MCS_DURATION(_streams, _sgi, \ 92 BW2VBPS(_bw, 234, 108, 52)), \ 93 MCS_DURATION(_streams, _sgi, \ 94 BW2VBPS(_bw, 351, 162, 78)), \ 95 MCS_DURATION(_streams, _sgi, \ 96 BW2VBPS(_bw, 468, 216, 104)), \ 97 MCS_DURATION(_streams, _sgi, \ 98 BW2VBPS(_bw, 702, 324, 156)), \ 99 MCS_DURATION(_streams, _sgi, \ 100 BW2VBPS(_bw, 936, 432, 208)), \ 101 MCS_DURATION(_streams, _sgi, \ 102 BW2VBPS(_bw, 1053, 486, 234)), \ 103 MCS_DURATION(_streams, _sgi, \ 104 BW2VBPS(_bw, 1170, 540, 260)), \ 105 MCS_DURATION(_streams, _sgi, \ 106 BW2VBPS(_bw, 1404, 648, 312)), \ 107 MCS_DURATION(_streams, _sgi, \ 108 BW2VBPS(_bw, 1560, 720, 346)) \ 109 } \ 110 } 111 112 #define CCK_DURATION(_bitrate, _short, _len) \ 113 (1000 * (10 /* SIFS */ + \ 114 (_short ? 72 + 24 : 144 + 48) + \ 115 (8 * (_len + 4) * 10) / (_bitrate))) 116 117 #define CCK_ACK_DURATION(_bitrate, _short) \ 118 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 119 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 120 121 #define CCK_DURATION_LIST(_short) \ 122 CCK_ACK_DURATION(10, _short), \ 123 CCK_ACK_DURATION(20, _short), \ 124 CCK_ACK_DURATION(55, _short), \ 125 CCK_ACK_DURATION(110, _short) 126 127 #define CCK_GROUP \ 128 [MINSTREL_CCK_GROUP] = { \ 129 .streams = 0, \ 130 .flags = 0, \ 131 .duration = { \ 132 CCK_DURATION_LIST(false), \ 133 CCK_DURATION_LIST(true) \ 134 } \ 135 } 136 137 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 138 static bool minstrel_vht_only = true; 139 module_param(minstrel_vht_only, bool, 0644); 140 MODULE_PARM_DESC(minstrel_vht_only, 141 "Use only VHT rates when VHT is supported by sta."); 142 #endif 143 144 /* 145 * To enable sufficiently targeted rate sampling, MCS rates are divided into 146 * groups, based on the number of streams and flags (HT40, SGI) that they 147 * use. 148 * 149 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 150 * BW -> SGI -> #streams 151 */ 152 const struct mcs_group minstrel_mcs_groups[] = { 153 MCS_GROUP(1, 0, BW_20), 154 MCS_GROUP(2, 0, BW_20), 155 #if MINSTREL_MAX_STREAMS >= 3 156 MCS_GROUP(3, 0, BW_20), 157 #endif 158 159 MCS_GROUP(1, 1, BW_20), 160 MCS_GROUP(2, 1, BW_20), 161 #if MINSTREL_MAX_STREAMS >= 3 162 MCS_GROUP(3, 1, BW_20), 163 #endif 164 165 MCS_GROUP(1, 0, BW_40), 166 MCS_GROUP(2, 0, BW_40), 167 #if MINSTREL_MAX_STREAMS >= 3 168 MCS_GROUP(3, 0, BW_40), 169 #endif 170 171 MCS_GROUP(1, 1, BW_40), 172 MCS_GROUP(2, 1, BW_40), 173 #if MINSTREL_MAX_STREAMS >= 3 174 MCS_GROUP(3, 1, BW_40), 175 #endif 176 177 CCK_GROUP, 178 179 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 180 VHT_GROUP(1, 0, BW_20), 181 VHT_GROUP(2, 0, BW_20), 182 #if MINSTREL_MAX_STREAMS >= 3 183 VHT_GROUP(3, 0, BW_20), 184 #endif 185 186 VHT_GROUP(1, 1, BW_20), 187 VHT_GROUP(2, 1, BW_20), 188 #if MINSTREL_MAX_STREAMS >= 3 189 VHT_GROUP(3, 1, BW_20), 190 #endif 191 192 VHT_GROUP(1, 0, BW_40), 193 VHT_GROUP(2, 0, BW_40), 194 #if MINSTREL_MAX_STREAMS >= 3 195 VHT_GROUP(3, 0, BW_40), 196 #endif 197 198 VHT_GROUP(1, 1, BW_40), 199 VHT_GROUP(2, 1, BW_40), 200 #if MINSTREL_MAX_STREAMS >= 3 201 VHT_GROUP(3, 1, BW_40), 202 #endif 203 204 VHT_GROUP(1, 0, BW_80), 205 VHT_GROUP(2, 0, BW_80), 206 #if MINSTREL_MAX_STREAMS >= 3 207 VHT_GROUP(3, 0, BW_80), 208 #endif 209 210 VHT_GROUP(1, 1, BW_80), 211 VHT_GROUP(2, 1, BW_80), 212 #if MINSTREL_MAX_STREAMS >= 3 213 VHT_GROUP(3, 1, BW_80), 214 #endif 215 #endif 216 }; 217 218 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 219 220 static void 221 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 222 223 /* 224 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 225 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 226 * 227 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 228 */ 229 static u16 230 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 231 { 232 u16 mask = 0; 233 234 if (bw == BW_20) { 235 if (nss != 3 && nss != 6) 236 mask = BIT(9); 237 } else if (bw == BW_80) { 238 if (nss == 3 || nss == 7) 239 mask = BIT(6); 240 else if (nss == 6) 241 mask = BIT(9); 242 } else { 243 WARN_ON(bw != BW_40); 244 } 245 246 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 247 case IEEE80211_VHT_MCS_SUPPORT_0_7: 248 mask |= 0x300; 249 break; 250 case IEEE80211_VHT_MCS_SUPPORT_0_8: 251 mask |= 0x200; 252 break; 253 case IEEE80211_VHT_MCS_SUPPORT_0_9: 254 break; 255 default: 256 mask = 0x3ff; 257 } 258 259 return 0x3ff & ~mask; 260 } 261 262 /* 263 * Look up an MCS group index based on mac80211 rate information 264 */ 265 static int 266 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 267 { 268 return GROUP_IDX((rate->idx / 8) + 1, 269 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 270 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 271 } 272 273 static int 274 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 275 { 276 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 277 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 278 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 279 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 280 } 281 282 static struct minstrel_rate_stats * 283 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 284 struct ieee80211_tx_rate *rate) 285 { 286 int group, idx; 287 288 if (rate->flags & IEEE80211_TX_RC_MCS) { 289 group = minstrel_ht_get_group_idx(rate); 290 idx = rate->idx % 8; 291 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 292 group = minstrel_vht_get_group_idx(rate); 293 idx = ieee80211_rate_get_vht_mcs(rate); 294 } else { 295 group = MINSTREL_CCK_GROUP; 296 297 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 298 if (rate->idx == mp->cck_rates[idx]) 299 break; 300 301 /* short preamble */ 302 if (!(mi->groups[group].supported & BIT(idx))) 303 idx += 4; 304 } 305 return &mi->groups[group].rates[idx]; 306 } 307 308 static inline struct minstrel_rate_stats * 309 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 310 { 311 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 312 } 313 314 315 /* 316 * Recalculate success probabilities and counters for a rate using EWMA 317 */ 318 static void 319 minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr) 320 { 321 if (unlikely(mr->attempts > 0)) { 322 mr->sample_skipped = 0; 323 mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); 324 if (!mr->att_hist) 325 mr->probability = mr->cur_prob; 326 else 327 mr->probability = minstrel_ewma(mr->probability, 328 mr->cur_prob, EWMA_LEVEL); 329 mr->att_hist += mr->attempts; 330 mr->succ_hist += mr->success; 331 } else { 332 mr->sample_skipped++; 333 } 334 mr->last_success = mr->success; 335 mr->last_attempts = mr->attempts; 336 mr->success = 0; 337 mr->attempts = 0; 338 } 339 340 /* 341 * Calculate throughput based on the average A-MPDU length, taking into account 342 * the expected number of retransmissions and their expected length 343 */ 344 static void 345 minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate) 346 { 347 struct minstrel_rate_stats *mr; 348 unsigned int nsecs = 0; 349 unsigned int tp; 350 unsigned int prob; 351 352 mr = &mi->groups[group].rates[rate]; 353 prob = mr->probability; 354 355 if (prob < MINSTREL_FRAC(1, 10)) { 356 mr->cur_tp = 0; 357 return; 358 } 359 360 /* 361 * For the throughput calculation, limit the probability value to 90% to 362 * account for collision related packet error rate fluctuation 363 */ 364 if (prob > MINSTREL_FRAC(9, 10)) 365 prob = MINSTREL_FRAC(9, 10); 366 367 if (group != MINSTREL_CCK_GROUP) 368 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); 369 370 nsecs += minstrel_mcs_groups[group].duration[rate]; 371 372 /* prob is scaled - see MINSTREL_FRAC above */ 373 tp = 1000000 * ((prob * 1000) / nsecs); 374 mr->cur_tp = MINSTREL_TRUNC(tp); 375 } 376 377 /* 378 * Find & sort topmost throughput rates 379 * 380 * If multiple rates provide equal throughput the sorting is based on their 381 * current success probability. Higher success probability is preferred among 382 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 383 */ 384 static void 385 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 386 u16 *tp_list) 387 { 388 int cur_group, cur_idx, cur_thr, cur_prob; 389 int tmp_group, tmp_idx, tmp_thr, tmp_prob; 390 int j = MAX_THR_RATES; 391 392 cur_group = index / MCS_GROUP_RATES; 393 cur_idx = index % MCS_GROUP_RATES; 394 cur_thr = mi->groups[cur_group].rates[cur_idx].cur_tp; 395 cur_prob = mi->groups[cur_group].rates[cur_idx].probability; 396 397 do { 398 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 399 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 400 tmp_thr = mi->groups[tmp_group].rates[tmp_idx].cur_tp; 401 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability; 402 if (cur_thr < tmp_thr || 403 (cur_thr == tmp_thr && 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 *mr; 424 int tmp_group, tmp_idx, tmp_tp, tmp_prob, max_tp_group; 425 426 mg = &mi->groups[index / MCS_GROUP_RATES]; 427 mr = &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_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp; 432 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].probability; 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 if (mr->probability > MINSTREL_FRAC(75, 100)) { 442 if (mr->cur_tp > tmp_tp) 443 mi->max_prob_rate = index; 444 if (mr->cur_tp > mg->rates[mg->max_group_prob_rate].cur_tp) 445 mg->max_group_prob_rate = index; 446 } else { 447 if (mr->probability > tmp_prob) 448 mi->max_prob_rate = index; 449 if (mr->probability > mg->rates[mg->max_group_prob_rate].probability) 450 mg->max_group_prob_rate = index; 451 } 452 } 453 454 455 /* 456 * Assign new rate set per sta and use CCK rates only if the fastest 457 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 458 * rate sets where MCS and CCK rates are mixed, because CCK rates can 459 * not use aggregation. 460 */ 461 static void 462 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 463 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 464 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 465 { 466 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp; 467 int i; 468 469 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 470 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 471 tmp_cck_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp; 472 473 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 474 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 475 tmp_mcs_tp = mi->groups[tmp_group].rates[tmp_idx].cur_tp; 476 477 if (tmp_cck_tp > tmp_mcs_tp) { 478 for(i = 0; i < MAX_THR_RATES; i++) { 479 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 480 tmp_mcs_tp_rate); 481 } 482 } 483 484 } 485 486 /* 487 * Try to increase robustness of max_prob rate by decrease number of 488 * streams if possible. 489 */ 490 static inline void 491 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 492 { 493 struct minstrel_mcs_group_data *mg; 494 struct minstrel_rate_stats *mr; 495 int tmp_max_streams, group; 496 int tmp_tp = 0; 497 498 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 499 MCS_GROUP_RATES].streams; 500 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 501 mg = &mi->groups[group]; 502 if (!mg->supported || group == MINSTREL_CCK_GROUP) 503 continue; 504 mr = minstrel_get_ratestats(mi, mg->max_group_prob_rate); 505 if (tmp_tp < mr->cur_tp && 506 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 507 mi->max_prob_rate = mg->max_group_prob_rate; 508 tmp_tp = mr->cur_tp; 509 } 510 } 511 } 512 513 /* 514 * Update rate statistics and select new primary rates 515 * 516 * Rules for rate selection: 517 * - max_prob_rate must use only one stream, as a tradeoff between delivery 518 * probability and throughput during strong fluctuations 519 * - as long as the max prob rate has a probability of more than 75%, pick 520 * higher throughput rates, even if the probablity is a bit lower 521 */ 522 static void 523 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 524 { 525 struct minstrel_mcs_group_data *mg; 526 struct minstrel_rate_stats *mr; 527 int group, i, j; 528 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 529 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 530 531 if (mi->ampdu_packets > 0) { 532 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 533 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL); 534 mi->ampdu_len = 0; 535 mi->ampdu_packets = 0; 536 } 537 538 mi->sample_slow = 0; 539 mi->sample_count = 0; 540 541 /* Initialize global rate indexes */ 542 for(j = 0; j < MAX_THR_RATES; j++){ 543 tmp_mcs_tp_rate[j] = 0; 544 tmp_cck_tp_rate[j] = 0; 545 } 546 547 /* Find best rate sets within all MCS groups*/ 548 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 549 550 mg = &mi->groups[group]; 551 if (!mg->supported) 552 continue; 553 554 mi->sample_count++; 555 556 /* (re)Initialize group rate indexes */ 557 for(j = 0; j < MAX_THR_RATES; j++) 558 tmp_group_tp_rate[j] = group; 559 560 for (i = 0; i < MCS_GROUP_RATES; i++) { 561 if (!(mg->supported & BIT(i))) 562 continue; 563 564 index = MCS_GROUP_RATES * group + i; 565 566 mr = &mg->rates[i]; 567 mr->retry_updated = false; 568 minstrel_calc_rate_ewma(mr); 569 minstrel_ht_calc_tp(mi, group, i); 570 571 if (!mr->cur_tp) 572 continue; 573 574 /* Find max throughput rate set */ 575 if (group != MINSTREL_CCK_GROUP) { 576 minstrel_ht_sort_best_tp_rates(mi, index, 577 tmp_mcs_tp_rate); 578 } else if (group == MINSTREL_CCK_GROUP) { 579 minstrel_ht_sort_best_tp_rates(mi, index, 580 tmp_cck_tp_rate); 581 } 582 583 /* Find max throughput rate set within a group */ 584 minstrel_ht_sort_best_tp_rates(mi, index, 585 tmp_group_tp_rate); 586 587 /* Find max probability rate per group and global */ 588 minstrel_ht_set_best_prob_rate(mi, index); 589 } 590 591 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 592 sizeof(mg->max_group_tp_rate)); 593 } 594 595 /* Assign new rate set per sta */ 596 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 597 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 598 599 /* Try to increase robustness of max_prob_rate*/ 600 minstrel_ht_prob_rate_reduce_streams(mi); 601 602 /* try to sample all available rates during each interval */ 603 mi->sample_count *= 8; 604 605 #ifdef CONFIG_MAC80211_DEBUGFS 606 /* use fixed index if set */ 607 if (mp->fixed_rate_idx != -1) { 608 for (i = 0; i < 4; i++) 609 mi->max_tp_rate[i] = mp->fixed_rate_idx; 610 mi->max_prob_rate = mp->fixed_rate_idx; 611 } 612 #endif 613 614 /* Reset update timer */ 615 mi->stats_update = jiffies; 616 } 617 618 static bool 619 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 620 { 621 if (rate->idx < 0) 622 return false; 623 624 if (!rate->count) 625 return false; 626 627 if (rate->flags & IEEE80211_TX_RC_MCS || 628 rate->flags & IEEE80211_TX_RC_VHT_MCS) 629 return true; 630 631 return rate->idx == mp->cck_rates[0] || 632 rate->idx == mp->cck_rates[1] || 633 rate->idx == mp->cck_rates[2] || 634 rate->idx == mp->cck_rates[3]; 635 } 636 637 static void 638 minstrel_next_sample_idx(struct minstrel_ht_sta *mi) 639 { 640 struct minstrel_mcs_group_data *mg; 641 642 for (;;) { 643 mi->sample_group++; 644 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 645 mg = &mi->groups[mi->sample_group]; 646 647 if (!mg->supported) 648 continue; 649 650 if (++mg->index >= MCS_GROUP_RATES) { 651 mg->index = 0; 652 if (++mg->column >= ARRAY_SIZE(sample_table)) 653 mg->column = 0; 654 } 655 break; 656 } 657 } 658 659 static void 660 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 661 { 662 int group, orig_group; 663 664 orig_group = group = *idx / MCS_GROUP_RATES; 665 while (group > 0) { 666 group--; 667 668 if (!mi->groups[group].supported) 669 continue; 670 671 if (minstrel_mcs_groups[group].streams > 672 minstrel_mcs_groups[orig_group].streams) 673 continue; 674 675 if (primary) 676 *idx = mi->groups[group].max_group_tp_rate[0]; 677 else 678 *idx = mi->groups[group].max_group_tp_rate[1]; 679 break; 680 } 681 } 682 683 static void 684 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 685 { 686 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 687 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 688 u16 tid; 689 690 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 691 return; 692 693 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 694 return; 695 696 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 697 return; 698 699 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 700 if (likely(sta->ampdu_mlme.tid_tx[tid])) 701 return; 702 703 ieee80211_start_tx_ba_session(pubsta, tid, 5000); 704 } 705 706 static void 707 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 708 struct ieee80211_sta *sta, void *priv_sta, 709 struct ieee80211_tx_info *info) 710 { 711 struct minstrel_ht_sta_priv *msp = priv_sta; 712 struct minstrel_ht_sta *mi = &msp->ht; 713 struct ieee80211_tx_rate *ar = info->status.rates; 714 struct minstrel_rate_stats *rate, *rate2; 715 struct minstrel_priv *mp = priv; 716 bool last, update = false; 717 int i; 718 719 if (!msp->is_ht) 720 return mac80211_minstrel.tx_status_noskb(priv, sband, sta, 721 &msp->legacy, info); 722 723 /* This packet was aggregated but doesn't carry status info */ 724 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 725 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 726 return; 727 728 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 729 info->status.ampdu_ack_len = 730 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 731 info->status.ampdu_len = 1; 732 } 733 734 mi->ampdu_packets++; 735 mi->ampdu_len += info->status.ampdu_len; 736 737 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 738 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len); 739 mi->sample_tries = 1; 740 mi->sample_count--; 741 } 742 743 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 744 mi->sample_packets += info->status.ampdu_len; 745 746 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 747 for (i = 0; !last; i++) { 748 last = (i == IEEE80211_TX_MAX_RATES - 1) || 749 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 750 751 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 752 753 if (last) 754 rate->success += info->status.ampdu_ack_len; 755 756 rate->attempts += ar[i].count * info->status.ampdu_len; 757 } 758 759 /* 760 * check for sudden death of spatial multiplexing, 761 * downgrade to a lower number of streams if necessary. 762 */ 763 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 764 if (rate->attempts > 30 && 765 MINSTREL_FRAC(rate->success, rate->attempts) < 766 MINSTREL_FRAC(20, 100)) { 767 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 768 update = true; 769 } 770 771 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 772 if (rate2->attempts > 30 && 773 MINSTREL_FRAC(rate2->success, rate2->attempts) < 774 MINSTREL_FRAC(20, 100)) { 775 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 776 update = true; 777 } 778 779 if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) { 780 update = true; 781 minstrel_ht_update_stats(mp, mi); 782 } 783 784 if (update) 785 minstrel_ht_update_rates(mp, mi); 786 } 787 788 static void 789 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 790 int index) 791 { 792 struct minstrel_rate_stats *mr; 793 const struct mcs_group *group; 794 unsigned int tx_time, tx_time_rtscts, tx_time_data; 795 unsigned int cw = mp->cw_min; 796 unsigned int ctime = 0; 797 unsigned int t_slot = 9; /* FIXME */ 798 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len); 799 unsigned int overhead = 0, overhead_rtscts = 0; 800 801 mr = minstrel_get_ratestats(mi, index); 802 if (mr->probability < MINSTREL_FRAC(1, 10)) { 803 mr->retry_count = 1; 804 mr->retry_count_rtscts = 1; 805 return; 806 } 807 808 mr->retry_count = 2; 809 mr->retry_count_rtscts = 2; 810 mr->retry_updated = true; 811 812 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 813 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000; 814 815 /* Contention time for first 2 tries */ 816 ctime = (t_slot * cw) >> 1; 817 cw = min((cw << 1) | 1, mp->cw_max); 818 ctime += (t_slot * cw) >> 1; 819 cw = min((cw << 1) | 1, mp->cw_max); 820 821 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 822 overhead = mi->overhead; 823 overhead_rtscts = mi->overhead_rtscts; 824 } 825 826 /* Total TX time for data and Contention after first 2 tries */ 827 tx_time = ctime + 2 * (overhead + tx_time_data); 828 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 829 830 /* See how many more tries we can fit inside segment size */ 831 do { 832 /* Contention time for this try */ 833 ctime = (t_slot * cw) >> 1; 834 cw = min((cw << 1) | 1, mp->cw_max); 835 836 /* Total TX time after this try */ 837 tx_time += ctime + overhead + tx_time_data; 838 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 839 840 if (tx_time_rtscts < mp->segment_size) 841 mr->retry_count_rtscts++; 842 } while ((tx_time < mp->segment_size) && 843 (++mr->retry_count < mp->max_retry)); 844 } 845 846 847 static void 848 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 849 struct ieee80211_sta_rates *ratetbl, int offset, int index) 850 { 851 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 852 struct minstrel_rate_stats *mr; 853 u8 idx; 854 u16 flags = group->flags; 855 856 mr = minstrel_get_ratestats(mi, index); 857 if (!mr->retry_updated) 858 minstrel_calc_retransmit(mp, mi, index); 859 860 if (mr->probability < MINSTREL_FRAC(20, 100) || !mr->retry_count) { 861 ratetbl->rate[offset].count = 2; 862 ratetbl->rate[offset].count_rts = 2; 863 ratetbl->rate[offset].count_cts = 2; 864 } else { 865 ratetbl->rate[offset].count = mr->retry_count; 866 ratetbl->rate[offset].count_cts = mr->retry_count; 867 ratetbl->rate[offset].count_rts = mr->retry_count_rtscts; 868 } 869 870 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 871 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 872 else if (flags & IEEE80211_TX_RC_VHT_MCS) 873 idx = ((group->streams - 1) << 4) | 874 ((index % MCS_GROUP_RATES) & 0xF); 875 else 876 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 877 878 if (offset > 0) { 879 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 880 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 881 } 882 883 ratetbl->rate[offset].idx = idx; 884 ratetbl->rate[offset].flags = flags; 885 } 886 887 static void 888 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 889 { 890 struct ieee80211_sta_rates *rates; 891 int i = 0; 892 893 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 894 if (!rates) 895 return; 896 897 /* Start with max_tp_rate[0] */ 898 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 899 900 if (mp->hw->max_rates >= 3) { 901 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 902 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 903 } 904 905 if (mp->hw->max_rates >= 2) { 906 /* 907 * At least 2 tx rates supported, use max_prob_rate next */ 908 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 909 } 910 911 rates->rate[i].idx = -1; 912 rate_control_set_rates(mp->hw, mi->sta, rates); 913 } 914 915 static inline int 916 minstrel_get_duration(int index) 917 { 918 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 919 return group->duration[index % MCS_GROUP_RATES]; 920 } 921 922 static int 923 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 924 { 925 struct minstrel_rate_stats *mr; 926 struct minstrel_mcs_group_data *mg; 927 unsigned int sample_dur, sample_group, cur_max_tp_streams; 928 int sample_idx = 0; 929 930 if (mi->sample_wait > 0) { 931 mi->sample_wait--; 932 return -1; 933 } 934 935 if (!mi->sample_tries) 936 return -1; 937 938 sample_group = mi->sample_group; 939 mg = &mi->groups[sample_group]; 940 sample_idx = sample_table[mg->column][mg->index]; 941 minstrel_next_sample_idx(mi); 942 943 if (!(mg->supported & BIT(sample_idx))) 944 return -1; 945 946 mr = &mg->rates[sample_idx]; 947 sample_idx += sample_group * MCS_GROUP_RATES; 948 949 /* 950 * Sampling might add some overhead (RTS, no aggregation) 951 * to the frame. Hence, don't use sampling for the currently 952 * used rates. 953 */ 954 if (sample_idx == mi->max_tp_rate[0] || 955 sample_idx == mi->max_tp_rate[1] || 956 sample_idx == mi->max_prob_rate) 957 return -1; 958 959 /* 960 * Do not sample if the probability is already higher than 95% 961 * to avoid wasting airtime. 962 */ 963 if (mr->probability > MINSTREL_FRAC(95, 100)) 964 return -1; 965 966 /* 967 * Make sure that lower rates get sampled only occasionally, 968 * if the link is working perfectly. 969 */ 970 971 cur_max_tp_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 972 MCS_GROUP_RATES].streams; 973 sample_dur = minstrel_get_duration(sample_idx); 974 if (sample_dur >= minstrel_get_duration(mi->max_tp_rate[1]) && 975 (cur_max_tp_streams - 1 < 976 minstrel_mcs_groups[sample_group].streams || 977 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 978 if (mr->sample_skipped < 20) 979 return -1; 980 981 if (mi->sample_slow++ > 2) 982 return -1; 983 } 984 mi->sample_tries--; 985 986 return sample_idx; 987 } 988 989 static void 990 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp, 991 struct minstrel_ht_sta *mi, bool val) 992 { 993 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported; 994 995 if (!supported || !mi->cck_supported_short) 996 return; 997 998 if (supported & (mi->cck_supported_short << (val * 4))) 999 return; 1000 1001 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4); 1002 mi->groups[MINSTREL_CCK_GROUP].supported = supported; 1003 } 1004 1005 static void 1006 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1007 struct ieee80211_tx_rate_control *txrc) 1008 { 1009 const struct mcs_group *sample_group; 1010 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1011 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1012 struct minstrel_ht_sta_priv *msp = priv_sta; 1013 struct minstrel_ht_sta *mi = &msp->ht; 1014 struct minstrel_priv *mp = priv; 1015 int sample_idx; 1016 1017 if (rate_control_send_low(sta, priv_sta, txrc)) 1018 return; 1019 1020 if (!msp->is_ht) 1021 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1022 1023 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1024 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1025 minstrel_aggr_check(sta, txrc->skb); 1026 1027 info->flags |= mi->tx_flags; 1028 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble); 1029 1030 #ifdef CONFIG_MAC80211_DEBUGFS 1031 if (mp->fixed_rate_idx != -1) 1032 return; 1033 #endif 1034 1035 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1036 if (mp->hw->max_rates == 1 && 1037 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1038 sample_idx = -1; 1039 else 1040 sample_idx = minstrel_get_sample_rate(mp, mi); 1041 1042 mi->total_packets++; 1043 1044 /* wraparound */ 1045 if (mi->total_packets == ~0) { 1046 mi->total_packets = 0; 1047 mi->sample_packets = 0; 1048 } 1049 1050 if (sample_idx < 0) 1051 return; 1052 1053 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1054 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1055 rate->count = 1; 1056 1057 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { 1058 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1059 rate->idx = mp->cck_rates[idx]; 1060 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1061 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1062 sample_group->streams); 1063 } else { 1064 rate->idx = sample_idx % MCS_GROUP_RATES + 1065 (sample_group->streams - 1) * 8; 1066 } 1067 1068 rate->flags = sample_group->flags; 1069 } 1070 1071 static void 1072 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1073 struct ieee80211_supported_band *sband, 1074 struct ieee80211_sta *sta) 1075 { 1076 int i; 1077 1078 if (sband->band != IEEE80211_BAND_2GHZ) 1079 return; 1080 1081 if (!(mp->hw->flags & IEEE80211_HW_SUPPORTS_HT_CCK_RATES)) 1082 return; 1083 1084 mi->cck_supported = 0; 1085 mi->cck_supported_short = 0; 1086 for (i = 0; i < 4; i++) { 1087 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1088 continue; 1089 1090 mi->cck_supported |= BIT(i); 1091 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1092 mi->cck_supported_short |= BIT(i); 1093 } 1094 1095 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported; 1096 } 1097 1098 static void 1099 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1100 struct cfg80211_chan_def *chandef, 1101 struct ieee80211_sta *sta, void *priv_sta) 1102 { 1103 struct minstrel_priv *mp = priv; 1104 struct minstrel_ht_sta_priv *msp = priv_sta; 1105 struct minstrel_ht_sta *mi = &msp->ht; 1106 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1107 u16 sta_cap = sta->ht_cap.cap; 1108 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1109 int use_vht; 1110 int n_supported = 0; 1111 int ack_dur; 1112 int stbc; 1113 int i; 1114 1115 /* fall back to the old minstrel for legacy stations */ 1116 if (!sta->ht_cap.ht_supported) 1117 goto use_legacy; 1118 1119 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1120 1121 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1122 if (vht_cap->vht_supported) 1123 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1124 else 1125 #endif 1126 use_vht = 0; 1127 1128 msp->is_ht = true; 1129 memset(mi, 0, sizeof(*mi)); 1130 1131 mi->sta = sta; 1132 mi->stats_update = jiffies; 1133 1134 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1135 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1136 mi->overhead += ack_dur; 1137 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1138 1139 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1140 1141 /* When using MRR, sample more on the first attempt, without delay */ 1142 if (mp->has_mrr) { 1143 mi->sample_count = 16; 1144 mi->sample_wait = 0; 1145 } else { 1146 mi->sample_count = 8; 1147 mi->sample_wait = 8; 1148 } 1149 mi->sample_tries = 4; 1150 1151 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */ 1152 if (!use_vht) { 1153 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >> 1154 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1155 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1156 1157 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING) 1158 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1159 } 1160 1161 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1162 u32 gflags = minstrel_mcs_groups[i].flags; 1163 int bw, nss; 1164 1165 mi->groups[i].supported = 0; 1166 if (i == MINSTREL_CCK_GROUP) { 1167 minstrel_ht_update_cck(mp, mi, sband, sta); 1168 continue; 1169 } 1170 1171 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1172 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1173 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40)) 1174 continue; 1175 } else { 1176 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20)) 1177 continue; 1178 } 1179 } 1180 1181 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1182 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1183 continue; 1184 1185 nss = minstrel_mcs_groups[i].streams; 1186 1187 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1188 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1189 continue; 1190 1191 /* HT rate */ 1192 if (gflags & IEEE80211_TX_RC_MCS) { 1193 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1194 if (use_vht && minstrel_vht_only) 1195 continue; 1196 #endif 1197 mi->groups[i].supported = mcs->rx_mask[nss - 1]; 1198 if (mi->groups[i].supported) 1199 n_supported++; 1200 continue; 1201 } 1202 1203 /* VHT rate */ 1204 if (!vht_cap->vht_supported || 1205 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1206 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1207 continue; 1208 1209 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1210 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1211 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1212 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1213 continue; 1214 } 1215 } 1216 1217 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1218 bw = BW_40; 1219 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1220 bw = BW_80; 1221 else 1222 bw = BW_20; 1223 1224 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss, 1225 vht_cap->vht_mcs.tx_mcs_map); 1226 1227 if (mi->groups[i].supported) 1228 n_supported++; 1229 } 1230 1231 if (!n_supported) 1232 goto use_legacy; 1233 1234 /* create an initial rate table with the lowest supported rates */ 1235 minstrel_ht_update_stats(mp, mi); 1236 minstrel_ht_update_rates(mp, mi); 1237 1238 return; 1239 1240 use_legacy: 1241 msp->is_ht = false; 1242 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1243 msp->legacy.r = msp->ratelist; 1244 msp->legacy.sample_table = msp->sample_table; 1245 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1246 &msp->legacy); 1247 } 1248 1249 static void 1250 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1251 struct cfg80211_chan_def *chandef, 1252 struct ieee80211_sta *sta, void *priv_sta) 1253 { 1254 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1255 } 1256 1257 static void 1258 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1259 struct cfg80211_chan_def *chandef, 1260 struct ieee80211_sta *sta, void *priv_sta, 1261 u32 changed) 1262 { 1263 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1264 } 1265 1266 static void * 1267 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1268 { 1269 struct ieee80211_supported_band *sband; 1270 struct minstrel_ht_sta_priv *msp; 1271 struct minstrel_priv *mp = priv; 1272 struct ieee80211_hw *hw = mp->hw; 1273 int max_rates = 0; 1274 int i; 1275 1276 for (i = 0; i < IEEE80211_NUM_BANDS; i++) { 1277 sband = hw->wiphy->bands[i]; 1278 if (sband && sband->n_bitrates > max_rates) 1279 max_rates = sband->n_bitrates; 1280 } 1281 1282 msp = kzalloc(sizeof(*msp), gfp); 1283 if (!msp) 1284 return NULL; 1285 1286 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); 1287 if (!msp->ratelist) 1288 goto error; 1289 1290 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); 1291 if (!msp->sample_table) 1292 goto error1; 1293 1294 return msp; 1295 1296 error1: 1297 kfree(msp->ratelist); 1298 error: 1299 kfree(msp); 1300 return NULL; 1301 } 1302 1303 static void 1304 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1305 { 1306 struct minstrel_ht_sta_priv *msp = priv_sta; 1307 1308 kfree(msp->sample_table); 1309 kfree(msp->ratelist); 1310 kfree(msp); 1311 } 1312 1313 static void * 1314 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1315 { 1316 return mac80211_minstrel.alloc(hw, debugfsdir); 1317 } 1318 1319 static void 1320 minstrel_ht_free(void *priv) 1321 { 1322 mac80211_minstrel.free(priv); 1323 } 1324 1325 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1326 { 1327 struct minstrel_ht_sta_priv *msp = priv_sta; 1328 struct minstrel_ht_sta *mi = &msp->ht; 1329 int i, j; 1330 1331 if (!msp->is_ht) 1332 return mac80211_minstrel.get_expected_throughput(priv_sta); 1333 1334 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1335 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1336 1337 /* convert cur_tp from pkt per second in kbps */ 1338 return mi->groups[i].rates[j].cur_tp * AVG_PKT_SIZE * 8 / 1024; 1339 } 1340 1341 static const struct rate_control_ops mac80211_minstrel_ht = { 1342 .name = "minstrel_ht", 1343 .tx_status_noskb = minstrel_ht_tx_status, 1344 .get_rate = minstrel_ht_get_rate, 1345 .rate_init = minstrel_ht_rate_init, 1346 .rate_update = minstrel_ht_rate_update, 1347 .alloc_sta = minstrel_ht_alloc_sta, 1348 .free_sta = minstrel_ht_free_sta, 1349 .alloc = minstrel_ht_alloc, 1350 .free = minstrel_ht_free, 1351 #ifdef CONFIG_MAC80211_DEBUGFS 1352 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1353 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs, 1354 #endif 1355 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1356 }; 1357 1358 1359 static void __init init_sample_table(void) 1360 { 1361 int col, i, new_idx; 1362 u8 rnd[MCS_GROUP_RATES]; 1363 1364 memset(sample_table, 0xff, sizeof(sample_table)); 1365 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1366 prandom_bytes(rnd, sizeof(rnd)); 1367 for (i = 0; i < MCS_GROUP_RATES; i++) { 1368 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1369 while (sample_table[col][new_idx] != 0xff) 1370 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1371 1372 sample_table[col][new_idx] = i; 1373 } 1374 } 1375 } 1376 1377 int __init 1378 rc80211_minstrel_ht_init(void) 1379 { 1380 init_sample_table(); 1381 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1382 } 1383 1384 void 1385 rc80211_minstrel_ht_exit(void) 1386 { 1387 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1388 } 1389