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_AMPDU_SIZE 16 21 #define AVG_PKT_SIZE 1200 22 23 /* Number of bits for an average sized packet */ 24 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) 25 26 /* Number of symbols for a packet with (bps) bits per symbol */ 27 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) 28 29 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ 30 #define MCS_SYMBOL_TIME(sgi, syms) \ 31 (sgi ? \ 32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ 33 ((syms) * 1000) << 2 /* syms * 4 us */ \ 34 ) 35 36 /* Transmit duration for the raw data part of an average sized packet */ 37 #define MCS_DURATION(streams, sgi, bps) \ 38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE) 39 40 #define BW_20 0 41 #define BW_40 1 42 #define BW_80 2 43 44 /* 45 * Define group sort order: HT40 -> SGI -> #streams 46 */ 47 #define GROUP_IDX(_streams, _sgi, _ht40) \ 48 MINSTREL_HT_GROUP_0 + \ 49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \ 50 MINSTREL_MAX_STREAMS * _sgi + \ 51 _streams - 1 52 53 /* MCS rate information for an MCS group */ 54 #define MCS_GROUP(_streams, _sgi, _ht40) \ 55 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 56 .streams = _streams, \ 57 .flags = \ 58 IEEE80211_TX_RC_MCS | \ 59 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 60 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 61 .duration = { \ 62 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \ 63 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \ 64 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \ 65 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \ 66 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \ 67 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \ 68 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \ 69 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \ 70 } \ 71 } 72 73 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 74 (MINSTREL_VHT_GROUP_0 + \ 75 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 76 MINSTREL_MAX_STREAMS * (_sgi) + \ 77 (_streams) - 1) 78 79 #define BW2VBPS(_bw, r3, r2, r1) \ 80 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 81 82 #define VHT_GROUP(_streams, _sgi, _bw) \ 83 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 84 .streams = _streams, \ 85 .flags = \ 86 IEEE80211_TX_RC_VHT_MCS | \ 87 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 88 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 89 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 90 .duration = { \ 91 MCS_DURATION(_streams, _sgi, \ 92 BW2VBPS(_bw, 117, 54, 26)), \ 93 MCS_DURATION(_streams, _sgi, \ 94 BW2VBPS(_bw, 234, 108, 52)), \ 95 MCS_DURATION(_streams, _sgi, \ 96 BW2VBPS(_bw, 351, 162, 78)), \ 97 MCS_DURATION(_streams, _sgi, \ 98 BW2VBPS(_bw, 468, 216, 104)), \ 99 MCS_DURATION(_streams, _sgi, \ 100 BW2VBPS(_bw, 702, 324, 156)), \ 101 MCS_DURATION(_streams, _sgi, \ 102 BW2VBPS(_bw, 936, 432, 208)), \ 103 MCS_DURATION(_streams, _sgi, \ 104 BW2VBPS(_bw, 1053, 486, 234)), \ 105 MCS_DURATION(_streams, _sgi, \ 106 BW2VBPS(_bw, 1170, 540, 260)), \ 107 MCS_DURATION(_streams, _sgi, \ 108 BW2VBPS(_bw, 1404, 648, 312)), \ 109 MCS_DURATION(_streams, _sgi, \ 110 BW2VBPS(_bw, 1560, 720, 346)) \ 111 } \ 112 } 113 114 #define CCK_DURATION(_bitrate, _short, _len) \ 115 (1000 * (10 /* SIFS */ + \ 116 (_short ? 72 + 24 : 144 + 48) + \ 117 (8 * (_len + 4) * 10) / (_bitrate))) 118 119 #define CCK_ACK_DURATION(_bitrate, _short) \ 120 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 121 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 122 123 #define CCK_DURATION_LIST(_short) \ 124 CCK_ACK_DURATION(10, _short), \ 125 CCK_ACK_DURATION(20, _short), \ 126 CCK_ACK_DURATION(55, _short), \ 127 CCK_ACK_DURATION(110, _short) 128 129 #define CCK_GROUP \ 130 [MINSTREL_CCK_GROUP] = { \ 131 .streams = 0, \ 132 .flags = 0, \ 133 .duration = { \ 134 CCK_DURATION_LIST(false), \ 135 CCK_DURATION_LIST(true) \ 136 } \ 137 } 138 139 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 140 static bool minstrel_vht_only = true; 141 module_param(minstrel_vht_only, bool, 0644); 142 MODULE_PARM_DESC(minstrel_vht_only, 143 "Use only VHT rates when VHT is supported by sta."); 144 #endif 145 146 /* 147 * To enable sufficiently targeted rate sampling, MCS rates are divided into 148 * groups, based on the number of streams and flags (HT40, SGI) that they 149 * use. 150 * 151 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 152 * BW -> SGI -> #streams 153 */ 154 const struct mcs_group minstrel_mcs_groups[] = { 155 MCS_GROUP(1, 0, BW_20), 156 MCS_GROUP(2, 0, BW_20), 157 #if MINSTREL_MAX_STREAMS >= 3 158 MCS_GROUP(3, 0, BW_20), 159 #endif 160 161 MCS_GROUP(1, 1, BW_20), 162 MCS_GROUP(2, 1, BW_20), 163 #if MINSTREL_MAX_STREAMS >= 3 164 MCS_GROUP(3, 1, BW_20), 165 #endif 166 167 MCS_GROUP(1, 0, BW_40), 168 MCS_GROUP(2, 0, BW_40), 169 #if MINSTREL_MAX_STREAMS >= 3 170 MCS_GROUP(3, 0, BW_40), 171 #endif 172 173 MCS_GROUP(1, 1, BW_40), 174 MCS_GROUP(2, 1, BW_40), 175 #if MINSTREL_MAX_STREAMS >= 3 176 MCS_GROUP(3, 1, BW_40), 177 #endif 178 179 CCK_GROUP, 180 181 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 182 VHT_GROUP(1, 0, BW_20), 183 VHT_GROUP(2, 0, BW_20), 184 #if MINSTREL_MAX_STREAMS >= 3 185 VHT_GROUP(3, 0, BW_20), 186 #endif 187 188 VHT_GROUP(1, 1, BW_20), 189 VHT_GROUP(2, 1, BW_20), 190 #if MINSTREL_MAX_STREAMS >= 3 191 VHT_GROUP(3, 1, BW_20), 192 #endif 193 194 VHT_GROUP(1, 0, BW_40), 195 VHT_GROUP(2, 0, BW_40), 196 #if MINSTREL_MAX_STREAMS >= 3 197 VHT_GROUP(3, 0, BW_40), 198 #endif 199 200 VHT_GROUP(1, 1, BW_40), 201 VHT_GROUP(2, 1, BW_40), 202 #if MINSTREL_MAX_STREAMS >= 3 203 VHT_GROUP(3, 1, BW_40), 204 #endif 205 206 VHT_GROUP(1, 0, BW_80), 207 VHT_GROUP(2, 0, BW_80), 208 #if MINSTREL_MAX_STREAMS >= 3 209 VHT_GROUP(3, 0, BW_80), 210 #endif 211 212 VHT_GROUP(1, 1, BW_80), 213 VHT_GROUP(2, 1, BW_80), 214 #if MINSTREL_MAX_STREAMS >= 3 215 VHT_GROUP(3, 1, BW_80), 216 #endif 217 #endif 218 }; 219 220 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 221 222 static void 223 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 224 225 /* 226 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 227 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 228 * 229 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 230 */ 231 static u16 232 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 233 { 234 u16 mask = 0; 235 236 if (bw == BW_20) { 237 if (nss != 3 && nss != 6) 238 mask = BIT(9); 239 } else if (bw == BW_80) { 240 if (nss == 3 || nss == 7) 241 mask = BIT(6); 242 else if (nss == 6) 243 mask = BIT(9); 244 } else { 245 WARN_ON(bw != BW_40); 246 } 247 248 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 249 case IEEE80211_VHT_MCS_SUPPORT_0_7: 250 mask |= 0x300; 251 break; 252 case IEEE80211_VHT_MCS_SUPPORT_0_8: 253 mask |= 0x200; 254 break; 255 case IEEE80211_VHT_MCS_SUPPORT_0_9: 256 break; 257 default: 258 mask = 0x3ff; 259 } 260 261 return 0x3ff & ~mask; 262 } 263 264 /* 265 * Look up an MCS group index based on mac80211 rate information 266 */ 267 static int 268 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 269 { 270 return GROUP_IDX((rate->idx / 8) + 1, 271 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 272 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 273 } 274 275 static int 276 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 277 { 278 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 279 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 280 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 281 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 282 } 283 284 static struct minstrel_rate_stats * 285 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 286 struct ieee80211_tx_rate *rate) 287 { 288 int group, idx; 289 290 if (rate->flags & IEEE80211_TX_RC_MCS) { 291 group = minstrel_ht_get_group_idx(rate); 292 idx = rate->idx % 8; 293 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 294 group = minstrel_vht_get_group_idx(rate); 295 idx = ieee80211_rate_get_vht_mcs(rate); 296 } else { 297 group = MINSTREL_CCK_GROUP; 298 299 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 300 if (rate->idx == mp->cck_rates[idx]) 301 break; 302 303 /* short preamble */ 304 if (!(mi->groups[group].supported & BIT(idx))) 305 idx += 4; 306 } 307 return &mi->groups[group].rates[idx]; 308 } 309 310 static inline struct minstrel_rate_stats * 311 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 312 { 313 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 314 } 315 316 /* 317 * Return current throughput based on the average A-MPDU length, taking into 318 * account the expected number of retransmissions and their expected length 319 */ 320 int 321 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 322 int prob_ewma) 323 { 324 unsigned int nsecs = 0; 325 326 /* do not account throughput if sucess prob is below 10% */ 327 if (prob_ewma < MINSTREL_FRAC(10, 100)) 328 return 0; 329 330 if (group != MINSTREL_CCK_GROUP) 331 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); 332 333 nsecs += minstrel_mcs_groups[group].duration[rate]; 334 335 /* 336 * For the throughput calculation, limit the probability value to 90% to 337 * account for collision related packet error rate fluctuation 338 * (prob is scaled - see MINSTREL_FRAC above) 339 */ 340 if (prob_ewma > MINSTREL_FRAC(90, 100)) 341 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 342 / nsecs)); 343 else 344 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); 345 } 346 347 /* 348 * Find & sort topmost throughput rates 349 * 350 * If multiple rates provide equal throughput the sorting is based on their 351 * current success probability. Higher success probability is preferred among 352 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 353 */ 354 static void 355 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 356 u16 *tp_list) 357 { 358 int cur_group, cur_idx, cur_tp_avg, cur_prob; 359 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 360 int j = MAX_THR_RATES; 361 362 cur_group = index / MCS_GROUP_RATES; 363 cur_idx = index % MCS_GROUP_RATES; 364 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; 365 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 366 367 do { 368 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 369 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 370 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 371 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 372 tmp_prob); 373 if (cur_tp_avg < tmp_tp_avg || 374 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 375 break; 376 j--; 377 } while (j > 0); 378 379 if (j < MAX_THR_RATES - 1) { 380 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 381 (MAX_THR_RATES - (j + 1)))); 382 } 383 if (j < MAX_THR_RATES) 384 tp_list[j] = index; 385 } 386 387 /* 388 * Find and set the topmost probability rate per sta and per group 389 */ 390 static void 391 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 392 { 393 struct minstrel_mcs_group_data *mg; 394 struct minstrel_rate_stats *mrs; 395 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 396 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 397 int max_gpr_group, max_gpr_idx; 398 int max_gpr_tp_avg, max_gpr_prob; 399 400 cur_group = index / MCS_GROUP_RATES; 401 cur_idx = index % MCS_GROUP_RATES; 402 mg = &mi->groups[index / MCS_GROUP_RATES]; 403 mrs = &mg->rates[index % MCS_GROUP_RATES]; 404 405 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 406 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 407 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 408 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 409 410 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 411 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 412 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 413 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 414 (max_tp_group != MINSTREL_CCK_GROUP)) 415 return; 416 417 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 418 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 419 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; 420 421 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { 422 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 423 mrs->prob_ewma); 424 if (cur_tp_avg > tmp_tp_avg) 425 mi->max_prob_rate = index; 426 427 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 428 max_gpr_idx, 429 max_gpr_prob); 430 if (cur_tp_avg > max_gpr_tp_avg) 431 mg->max_group_prob_rate = index; 432 } else { 433 if (mrs->prob_ewma > tmp_prob) 434 mi->max_prob_rate = index; 435 if (mrs->prob_ewma > max_gpr_prob) 436 mg->max_group_prob_rate = index; 437 } 438 } 439 440 441 /* 442 * Assign new rate set per sta and use CCK rates only if the fastest 443 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 444 * rate sets where MCS and CCK rates are mixed, because CCK rates can 445 * not use aggregation. 446 */ 447 static void 448 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 449 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 450 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 451 { 452 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 453 int i; 454 455 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 456 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 457 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 458 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 459 460 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 461 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 462 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 463 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 464 465 if (tmp_cck_tp > tmp_mcs_tp) { 466 for(i = 0; i < MAX_THR_RATES; i++) { 467 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 468 tmp_mcs_tp_rate); 469 } 470 } 471 472 } 473 474 /* 475 * Try to increase robustness of max_prob rate by decrease number of 476 * streams if possible. 477 */ 478 static inline void 479 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 480 { 481 struct minstrel_mcs_group_data *mg; 482 int tmp_max_streams, group, tmp_idx, tmp_prob; 483 int tmp_tp = 0; 484 485 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 486 MCS_GROUP_RATES].streams; 487 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 488 mg = &mi->groups[group]; 489 if (!mg->supported || group == MINSTREL_CCK_GROUP) 490 continue; 491 492 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 493 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; 494 495 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 496 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 497 mi->max_prob_rate = mg->max_group_prob_rate; 498 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 499 tmp_idx, 500 tmp_prob); 501 } 502 } 503 } 504 505 /* 506 * Update rate statistics and select new primary rates 507 * 508 * Rules for rate selection: 509 * - max_prob_rate must use only one stream, as a tradeoff between delivery 510 * probability and throughput during strong fluctuations 511 * - as long as the max prob rate has a probability of more than 75%, pick 512 * higher throughput rates, even if the probablity is a bit lower 513 */ 514 static void 515 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 516 { 517 struct minstrel_mcs_group_data *mg; 518 struct minstrel_rate_stats *mrs; 519 int group, i, j, cur_prob; 520 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 521 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 522 523 if (mi->ampdu_packets > 0) { 524 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 525 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL); 526 mi->ampdu_len = 0; 527 mi->ampdu_packets = 0; 528 } 529 530 mi->sample_slow = 0; 531 mi->sample_count = 0; 532 533 /* Initialize global rate indexes */ 534 for(j = 0; j < MAX_THR_RATES; j++){ 535 tmp_mcs_tp_rate[j] = 0; 536 tmp_cck_tp_rate[j] = 0; 537 } 538 539 /* Find best rate sets within all MCS groups*/ 540 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 541 542 mg = &mi->groups[group]; 543 if (!mg->supported) 544 continue; 545 546 mi->sample_count++; 547 548 /* (re)Initialize group rate indexes */ 549 for(j = 0; j < MAX_THR_RATES; j++) 550 tmp_group_tp_rate[j] = group; 551 552 for (i = 0; i < MCS_GROUP_RATES; i++) { 553 if (!(mg->supported & BIT(i))) 554 continue; 555 556 index = MCS_GROUP_RATES * group + i; 557 558 mrs = &mg->rates[i]; 559 mrs->retry_updated = false; 560 minstrel_calc_rate_stats(mrs); 561 cur_prob = mrs->prob_ewma; 562 563 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 564 continue; 565 566 /* Find max throughput rate set */ 567 if (group != MINSTREL_CCK_GROUP) { 568 minstrel_ht_sort_best_tp_rates(mi, index, 569 tmp_mcs_tp_rate); 570 } else if (group == MINSTREL_CCK_GROUP) { 571 minstrel_ht_sort_best_tp_rates(mi, index, 572 tmp_cck_tp_rate); 573 } 574 575 /* Find max throughput rate set within a group */ 576 minstrel_ht_sort_best_tp_rates(mi, index, 577 tmp_group_tp_rate); 578 579 /* Find max probability rate per group and global */ 580 minstrel_ht_set_best_prob_rate(mi, index); 581 } 582 583 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 584 sizeof(mg->max_group_tp_rate)); 585 } 586 587 /* Assign new rate set per sta */ 588 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 589 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 590 591 /* Try to increase robustness of max_prob_rate*/ 592 minstrel_ht_prob_rate_reduce_streams(mi); 593 594 /* try to sample all available rates during each interval */ 595 mi->sample_count *= 8; 596 597 #ifdef CONFIG_MAC80211_DEBUGFS 598 /* use fixed index if set */ 599 if (mp->fixed_rate_idx != -1) { 600 for (i = 0; i < 4; i++) 601 mi->max_tp_rate[i] = mp->fixed_rate_idx; 602 mi->max_prob_rate = mp->fixed_rate_idx; 603 } 604 #endif 605 606 /* Reset update timer */ 607 mi->last_stats_update = jiffies; 608 } 609 610 static bool 611 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 612 { 613 if (rate->idx < 0) 614 return false; 615 616 if (!rate->count) 617 return false; 618 619 if (rate->flags & IEEE80211_TX_RC_MCS || 620 rate->flags & IEEE80211_TX_RC_VHT_MCS) 621 return true; 622 623 return rate->idx == mp->cck_rates[0] || 624 rate->idx == mp->cck_rates[1] || 625 rate->idx == mp->cck_rates[2] || 626 rate->idx == mp->cck_rates[3]; 627 } 628 629 static void 630 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 631 { 632 struct minstrel_mcs_group_data *mg; 633 634 for (;;) { 635 mi->sample_group++; 636 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 637 mg = &mi->groups[mi->sample_group]; 638 639 if (!mg->supported) 640 continue; 641 642 if (++mg->index >= MCS_GROUP_RATES) { 643 mg->index = 0; 644 if (++mg->column >= ARRAY_SIZE(sample_table)) 645 mg->column = 0; 646 } 647 break; 648 } 649 } 650 651 static void 652 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 653 { 654 int group, orig_group; 655 656 orig_group = group = *idx / MCS_GROUP_RATES; 657 while (group > 0) { 658 group--; 659 660 if (!mi->groups[group].supported) 661 continue; 662 663 if (minstrel_mcs_groups[group].streams > 664 minstrel_mcs_groups[orig_group].streams) 665 continue; 666 667 if (primary) 668 *idx = mi->groups[group].max_group_tp_rate[0]; 669 else 670 *idx = mi->groups[group].max_group_tp_rate[1]; 671 break; 672 } 673 } 674 675 static void 676 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 677 { 678 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 679 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 680 u16 tid; 681 682 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 683 return; 684 685 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 686 return; 687 688 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 689 return; 690 691 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK; 692 if (likely(sta->ampdu_mlme.tid_tx[tid])) 693 return; 694 695 ieee80211_start_tx_ba_session(pubsta, tid, 0); 696 } 697 698 static void 699 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 700 struct ieee80211_sta *sta, void *priv_sta, 701 struct ieee80211_tx_info *info) 702 { 703 struct minstrel_ht_sta_priv *msp = priv_sta; 704 struct minstrel_ht_sta *mi = &msp->ht; 705 struct ieee80211_tx_rate *ar = info->status.rates; 706 struct minstrel_rate_stats *rate, *rate2; 707 struct minstrel_priv *mp = priv; 708 bool last, update = false; 709 int i; 710 711 if (!msp->is_ht) 712 return mac80211_minstrel.tx_status_noskb(priv, sband, sta, 713 &msp->legacy, info); 714 715 /* This packet was aggregated but doesn't carry status info */ 716 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 717 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 718 return; 719 720 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 721 info->status.ampdu_ack_len = 722 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 723 info->status.ampdu_len = 1; 724 } 725 726 mi->ampdu_packets++; 727 mi->ampdu_len += info->status.ampdu_len; 728 729 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 730 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len); 731 mi->sample_tries = 1; 732 mi->sample_count--; 733 } 734 735 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 736 mi->sample_packets += info->status.ampdu_len; 737 738 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 739 for (i = 0; !last; i++) { 740 last = (i == IEEE80211_TX_MAX_RATES - 1) || 741 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 742 743 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 744 745 if (last) 746 rate->success += info->status.ampdu_ack_len; 747 748 rate->attempts += ar[i].count * info->status.ampdu_len; 749 } 750 751 /* 752 * check for sudden death of spatial multiplexing, 753 * downgrade to a lower number of streams if necessary. 754 */ 755 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 756 if (rate->attempts > 30 && 757 MINSTREL_FRAC(rate->success, rate->attempts) < 758 MINSTREL_FRAC(20, 100)) { 759 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 760 update = true; 761 } 762 763 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 764 if (rate2->attempts > 30 && 765 MINSTREL_FRAC(rate2->success, rate2->attempts) < 766 MINSTREL_FRAC(20, 100)) { 767 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 768 update = true; 769 } 770 771 if (time_after(jiffies, mi->last_stats_update + 772 (mp->update_interval / 2 * HZ) / 1000)) { 773 update = true; 774 minstrel_ht_update_stats(mp, mi); 775 } 776 777 if (update) 778 minstrel_ht_update_rates(mp, mi); 779 } 780 781 static void 782 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 783 int index) 784 { 785 struct minstrel_rate_stats *mrs; 786 const struct mcs_group *group; 787 unsigned int tx_time, tx_time_rtscts, tx_time_data; 788 unsigned int cw = mp->cw_min; 789 unsigned int ctime = 0; 790 unsigned int t_slot = 9; /* FIXME */ 791 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len); 792 unsigned int overhead = 0, overhead_rtscts = 0; 793 794 mrs = minstrel_get_ratestats(mi, index); 795 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { 796 mrs->retry_count = 1; 797 mrs->retry_count_rtscts = 1; 798 return; 799 } 800 801 mrs->retry_count = 2; 802 mrs->retry_count_rtscts = 2; 803 mrs->retry_updated = true; 804 805 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 806 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000; 807 808 /* Contention time for first 2 tries */ 809 ctime = (t_slot * cw) >> 1; 810 cw = min((cw << 1) | 1, mp->cw_max); 811 ctime += (t_slot * cw) >> 1; 812 cw = min((cw << 1) | 1, mp->cw_max); 813 814 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 815 overhead = mi->overhead; 816 overhead_rtscts = mi->overhead_rtscts; 817 } 818 819 /* Total TX time for data and Contention after first 2 tries */ 820 tx_time = ctime + 2 * (overhead + tx_time_data); 821 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 822 823 /* See how many more tries we can fit inside segment size */ 824 do { 825 /* Contention time for this try */ 826 ctime = (t_slot * cw) >> 1; 827 cw = min((cw << 1) | 1, mp->cw_max); 828 829 /* Total TX time after this try */ 830 tx_time += ctime + overhead + tx_time_data; 831 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 832 833 if (tx_time_rtscts < mp->segment_size) 834 mrs->retry_count_rtscts++; 835 } while ((tx_time < mp->segment_size) && 836 (++mrs->retry_count < mp->max_retry)); 837 } 838 839 840 static void 841 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 842 struct ieee80211_sta_rates *ratetbl, int offset, int index) 843 { 844 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 845 struct minstrel_rate_stats *mrs; 846 u8 idx; 847 u16 flags = group->flags; 848 849 mrs = minstrel_get_ratestats(mi, index); 850 if (!mrs->retry_updated) 851 minstrel_calc_retransmit(mp, mi, index); 852 853 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 854 ratetbl->rate[offset].count = 2; 855 ratetbl->rate[offset].count_rts = 2; 856 ratetbl->rate[offset].count_cts = 2; 857 } else { 858 ratetbl->rate[offset].count = mrs->retry_count; 859 ratetbl->rate[offset].count_cts = mrs->retry_count; 860 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 861 } 862 863 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 864 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 865 else if (flags & IEEE80211_TX_RC_VHT_MCS) 866 idx = ((group->streams - 1) << 4) | 867 ((index % MCS_GROUP_RATES) & 0xF); 868 else 869 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 870 871 /* enable RTS/CTS if needed: 872 * - if station is in dynamic SMPS (and streams > 1) 873 * - for fallback rates, to increase chances of getting through 874 */ 875 if (offset > 0 || 876 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 877 group->streams > 1)) { 878 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 879 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 880 } 881 882 ratetbl->rate[offset].idx = idx; 883 ratetbl->rate[offset].flags = flags; 884 } 885 886 static inline int 887 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) 888 { 889 int group = rate / MCS_GROUP_RATES; 890 rate %= MCS_GROUP_RATES; 891 return mi->groups[group].rates[rate].prob_ewma; 892 } 893 894 static int 895 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 896 { 897 int group = mi->max_prob_rate / MCS_GROUP_RATES; 898 const struct mcs_group *g = &minstrel_mcs_groups[group]; 899 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 900 901 /* Disable A-MSDU if max_prob_rate is bad */ 902 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) 903 return 1; 904 905 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 906 if (g->duration[rate] > MCS_DURATION(1, 0, 52)) 907 return 500; 908 909 /* 910 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 911 * data packet size 912 */ 913 if (g->duration[rate] > MCS_DURATION(1, 0, 104)) 914 return 1600; 915 916 /* 917 * If the rate is slower than single-stream MCS7, or if the max throughput 918 * rate success probability is less than 75%, limit A-MSDU to twice the usual 919 * data packet size 920 */ 921 if (g->duration[rate] > MCS_DURATION(1, 0, 260) || 922 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < 923 MINSTREL_FRAC(75, 100))) 924 return 3200; 925 926 /* 927 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 928 * Since aggregation sessions are started/stopped without txq flush, use 929 * the limit here to avoid the complexity of having to de-aggregate 930 * packets in the queue. 931 */ 932 if (!mi->sta->vht_cap.vht_supported) 933 return IEEE80211_MAX_MPDU_LEN_HT_BA; 934 935 /* unlimited */ 936 return 0; 937 } 938 939 static void 940 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 941 { 942 struct ieee80211_sta_rates *rates; 943 int i = 0; 944 945 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 946 if (!rates) 947 return; 948 949 /* Start with max_tp_rate[0] */ 950 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 951 952 if (mp->hw->max_rates >= 3) { 953 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 954 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 955 } 956 957 if (mp->hw->max_rates >= 2) { 958 /* 959 * At least 2 tx rates supported, use max_prob_rate next */ 960 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 961 } 962 963 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 964 rates->rate[i].idx = -1; 965 rate_control_set_rates(mp->hw, mi->sta, rates); 966 } 967 968 static inline int 969 minstrel_get_duration(int index) 970 { 971 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 972 return group->duration[index % MCS_GROUP_RATES]; 973 } 974 975 static int 976 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 977 { 978 struct minstrel_rate_stats *mrs; 979 struct minstrel_mcs_group_data *mg; 980 unsigned int sample_dur, sample_group, cur_max_tp_streams; 981 int tp_rate1, tp_rate2; 982 int sample_idx = 0; 983 984 if (mi->sample_wait > 0) { 985 mi->sample_wait--; 986 return -1; 987 } 988 989 if (!mi->sample_tries) 990 return -1; 991 992 sample_group = mi->sample_group; 993 mg = &mi->groups[sample_group]; 994 sample_idx = sample_table[mg->column][mg->index]; 995 minstrel_set_next_sample_idx(mi); 996 997 if (!(mg->supported & BIT(sample_idx))) 998 return -1; 999 1000 mrs = &mg->rates[sample_idx]; 1001 sample_idx += sample_group * MCS_GROUP_RATES; 1002 1003 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 1004 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1005 minstrel_get_duration(mi->max_tp_rate[1])) { 1006 tp_rate1 = mi->max_tp_rate[1]; 1007 tp_rate2 = mi->max_tp_rate[0]; 1008 } else { 1009 tp_rate1 = mi->max_tp_rate[0]; 1010 tp_rate2 = mi->max_tp_rate[1]; 1011 } 1012 1013 /* 1014 * Sampling might add some overhead (RTS, no aggregation) 1015 * to the frame. Hence, don't use sampling for the highest currently 1016 * used highest throughput or probability rate. 1017 */ 1018 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1019 return -1; 1020 1021 /* 1022 * Do not sample if the probability is already higher than 95% 1023 * to avoid wasting airtime. 1024 */ 1025 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100)) 1026 return -1; 1027 1028 /* 1029 * Make sure that lower rates get sampled only occasionally, 1030 * if the link is working perfectly. 1031 */ 1032 1033 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1034 MCS_GROUP_RATES].streams; 1035 sample_dur = minstrel_get_duration(sample_idx); 1036 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1037 (cur_max_tp_streams - 1 < 1038 minstrel_mcs_groups[sample_group].streams || 1039 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1040 if (mrs->sample_skipped < 20) 1041 return -1; 1042 1043 if (mi->sample_slow++ > 2) 1044 return -1; 1045 } 1046 mi->sample_tries--; 1047 1048 return sample_idx; 1049 } 1050 1051 static void 1052 minstrel_ht_check_cck_shortpreamble(struct minstrel_priv *mp, 1053 struct minstrel_ht_sta *mi, bool val) 1054 { 1055 u8 supported = mi->groups[MINSTREL_CCK_GROUP].supported; 1056 1057 if (!supported || !mi->cck_supported_short) 1058 return; 1059 1060 if (supported & (mi->cck_supported_short << (val * 4))) 1061 return; 1062 1063 supported ^= mi->cck_supported_short | (mi->cck_supported_short << 4); 1064 mi->groups[MINSTREL_CCK_GROUP].supported = supported; 1065 } 1066 1067 static void 1068 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1069 struct ieee80211_tx_rate_control *txrc) 1070 { 1071 const struct mcs_group *sample_group; 1072 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1073 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1074 struct minstrel_ht_sta_priv *msp = priv_sta; 1075 struct minstrel_ht_sta *mi = &msp->ht; 1076 struct minstrel_priv *mp = priv; 1077 int sample_idx; 1078 1079 if (rate_control_send_low(sta, priv_sta, txrc)) 1080 return; 1081 1082 if (!msp->is_ht) 1083 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1084 1085 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1086 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1087 minstrel_aggr_check(sta, txrc->skb); 1088 1089 info->flags |= mi->tx_flags; 1090 minstrel_ht_check_cck_shortpreamble(mp, mi, txrc->short_preamble); 1091 1092 #ifdef CONFIG_MAC80211_DEBUGFS 1093 if (mp->fixed_rate_idx != -1) 1094 return; 1095 #endif 1096 1097 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1098 if (mp->hw->max_rates == 1 && 1099 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1100 sample_idx = -1; 1101 else 1102 sample_idx = minstrel_get_sample_rate(mp, mi); 1103 1104 mi->total_packets++; 1105 1106 /* wraparound */ 1107 if (mi->total_packets == ~0) { 1108 mi->total_packets = 0; 1109 mi->sample_packets = 0; 1110 } 1111 1112 if (sample_idx < 0) 1113 return; 1114 1115 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1116 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1117 rate->count = 1; 1118 1119 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { 1120 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1121 rate->idx = mp->cck_rates[idx]; 1122 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1123 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1124 sample_group->streams); 1125 } else { 1126 rate->idx = sample_idx % MCS_GROUP_RATES + 1127 (sample_group->streams - 1) * 8; 1128 } 1129 1130 rate->flags = sample_group->flags; 1131 } 1132 1133 static void 1134 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1135 struct ieee80211_supported_band *sband, 1136 struct ieee80211_sta *sta) 1137 { 1138 int i; 1139 1140 if (sband->band != NL80211_BAND_2GHZ) 1141 return; 1142 1143 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1144 return; 1145 1146 mi->cck_supported = 0; 1147 mi->cck_supported_short = 0; 1148 for (i = 0; i < 4; i++) { 1149 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1150 continue; 1151 1152 mi->cck_supported |= BIT(i); 1153 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1154 mi->cck_supported_short |= BIT(i); 1155 } 1156 1157 mi->groups[MINSTREL_CCK_GROUP].supported = mi->cck_supported; 1158 } 1159 1160 static void 1161 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1162 struct cfg80211_chan_def *chandef, 1163 struct ieee80211_sta *sta, void *priv_sta) 1164 { 1165 struct minstrel_priv *mp = priv; 1166 struct minstrel_ht_sta_priv *msp = priv_sta; 1167 struct minstrel_ht_sta *mi = &msp->ht; 1168 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1169 u16 sta_cap = sta->ht_cap.cap; 1170 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1171 int use_vht; 1172 int n_supported = 0; 1173 int ack_dur; 1174 int stbc; 1175 int i; 1176 1177 /* fall back to the old minstrel for legacy stations */ 1178 if (!sta->ht_cap.ht_supported) 1179 goto use_legacy; 1180 1181 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1182 1183 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1184 if (vht_cap->vht_supported) 1185 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1186 else 1187 #endif 1188 use_vht = 0; 1189 1190 msp->is_ht = true; 1191 memset(mi, 0, sizeof(*mi)); 1192 1193 mi->sta = sta; 1194 mi->last_stats_update = jiffies; 1195 1196 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1197 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1198 mi->overhead += ack_dur; 1199 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1200 1201 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1202 1203 /* When using MRR, sample more on the first attempt, without delay */ 1204 if (mp->has_mrr) { 1205 mi->sample_count = 16; 1206 mi->sample_wait = 0; 1207 } else { 1208 mi->sample_count = 8; 1209 mi->sample_wait = 8; 1210 } 1211 mi->sample_tries = 4; 1212 1213 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */ 1214 if (!use_vht) { 1215 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >> 1216 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1217 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1218 1219 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING) 1220 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1221 } 1222 1223 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1224 u32 gflags = minstrel_mcs_groups[i].flags; 1225 int bw, nss; 1226 1227 mi->groups[i].supported = 0; 1228 if (i == MINSTREL_CCK_GROUP) { 1229 minstrel_ht_update_cck(mp, mi, sband, sta); 1230 continue; 1231 } 1232 1233 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1234 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1235 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40)) 1236 continue; 1237 } else { 1238 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20)) 1239 continue; 1240 } 1241 } 1242 1243 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1244 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1245 continue; 1246 1247 nss = minstrel_mcs_groups[i].streams; 1248 1249 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1250 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1251 continue; 1252 1253 /* HT rate */ 1254 if (gflags & IEEE80211_TX_RC_MCS) { 1255 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1256 if (use_vht && minstrel_vht_only) 1257 continue; 1258 #endif 1259 mi->groups[i].supported = mcs->rx_mask[nss - 1]; 1260 if (mi->groups[i].supported) 1261 n_supported++; 1262 continue; 1263 } 1264 1265 /* VHT rate */ 1266 if (!vht_cap->vht_supported || 1267 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1268 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1269 continue; 1270 1271 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1272 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1273 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1274 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1275 continue; 1276 } 1277 } 1278 1279 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1280 bw = BW_40; 1281 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1282 bw = BW_80; 1283 else 1284 bw = BW_20; 1285 1286 mi->groups[i].supported = minstrel_get_valid_vht_rates(bw, nss, 1287 vht_cap->vht_mcs.tx_mcs_map); 1288 1289 if (mi->groups[i].supported) 1290 n_supported++; 1291 } 1292 1293 if (!n_supported) 1294 goto use_legacy; 1295 1296 /* create an initial rate table with the lowest supported rates */ 1297 minstrel_ht_update_stats(mp, mi); 1298 minstrel_ht_update_rates(mp, mi); 1299 1300 return; 1301 1302 use_legacy: 1303 msp->is_ht = false; 1304 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1305 msp->legacy.r = msp->ratelist; 1306 msp->legacy.sample_table = msp->sample_table; 1307 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1308 &msp->legacy); 1309 } 1310 1311 static void 1312 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1313 struct cfg80211_chan_def *chandef, 1314 struct ieee80211_sta *sta, void *priv_sta) 1315 { 1316 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1317 } 1318 1319 static void 1320 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1321 struct cfg80211_chan_def *chandef, 1322 struct ieee80211_sta *sta, void *priv_sta, 1323 u32 changed) 1324 { 1325 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1326 } 1327 1328 static void * 1329 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1330 { 1331 struct ieee80211_supported_band *sband; 1332 struct minstrel_ht_sta_priv *msp; 1333 struct minstrel_priv *mp = priv; 1334 struct ieee80211_hw *hw = mp->hw; 1335 int max_rates = 0; 1336 int i; 1337 1338 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1339 sband = hw->wiphy->bands[i]; 1340 if (sband && sband->n_bitrates > max_rates) 1341 max_rates = sband->n_bitrates; 1342 } 1343 1344 msp = kzalloc(sizeof(*msp), gfp); 1345 if (!msp) 1346 return NULL; 1347 1348 msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); 1349 if (!msp->ratelist) 1350 goto error; 1351 1352 msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); 1353 if (!msp->sample_table) 1354 goto error1; 1355 1356 return msp; 1357 1358 error1: 1359 kfree(msp->ratelist); 1360 error: 1361 kfree(msp); 1362 return NULL; 1363 } 1364 1365 static void 1366 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1367 { 1368 struct minstrel_ht_sta_priv *msp = priv_sta; 1369 1370 kfree(msp->sample_table); 1371 kfree(msp->ratelist); 1372 kfree(msp); 1373 } 1374 1375 static void * 1376 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1377 { 1378 return mac80211_minstrel.alloc(hw, debugfsdir); 1379 } 1380 1381 static void 1382 minstrel_ht_free(void *priv) 1383 { 1384 mac80211_minstrel.free(priv); 1385 } 1386 1387 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1388 { 1389 struct minstrel_ht_sta_priv *msp = priv_sta; 1390 struct minstrel_ht_sta *mi = &msp->ht; 1391 int i, j, prob, tp_avg; 1392 1393 if (!msp->is_ht) 1394 return mac80211_minstrel.get_expected_throughput(priv_sta); 1395 1396 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1397 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1398 prob = mi->groups[i].rates[j].prob_ewma; 1399 1400 /* convert tp_avg from pkt per second in kbps */ 1401 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1402 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1403 1404 return tp_avg; 1405 } 1406 1407 static const struct rate_control_ops mac80211_minstrel_ht = { 1408 .name = "minstrel_ht", 1409 .tx_status_noskb = minstrel_ht_tx_status, 1410 .get_rate = minstrel_ht_get_rate, 1411 .rate_init = minstrel_ht_rate_init, 1412 .rate_update = minstrel_ht_rate_update, 1413 .alloc_sta = minstrel_ht_alloc_sta, 1414 .free_sta = minstrel_ht_free_sta, 1415 .alloc = minstrel_ht_alloc, 1416 .free = minstrel_ht_free, 1417 #ifdef CONFIG_MAC80211_DEBUGFS 1418 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1419 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs, 1420 #endif 1421 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1422 }; 1423 1424 1425 static void __init init_sample_table(void) 1426 { 1427 int col, i, new_idx; 1428 u8 rnd[MCS_GROUP_RATES]; 1429 1430 memset(sample_table, 0xff, sizeof(sample_table)); 1431 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1432 prandom_bytes(rnd, sizeof(rnd)); 1433 for (i = 0; i < MCS_GROUP_RATES; i++) { 1434 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1435 while (sample_table[col][new_idx] != 0xff) 1436 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1437 1438 sample_table[col][new_idx] = i; 1439 } 1440 } 1441 } 1442 1443 int __init 1444 rc80211_minstrel_ht_init(void) 1445 { 1446 init_sample_table(); 1447 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1448 } 1449 1450 void 1451 rc80211_minstrel_ht_exit(void) 1452 { 1453 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1454 } 1455