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 "sta_info.h" 18 #include "rc80211_minstrel.h" 19 #include "rc80211_minstrel_ht.h" 20 21 #define AVG_AMPDU_SIZE 16 22 #define AVG_PKT_SIZE 1200 23 24 /* Number of bits for an average sized packet */ 25 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) 26 27 /* Number of symbols for a packet with (bps) bits per symbol */ 28 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) 29 30 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ 31 #define MCS_SYMBOL_TIME(sgi, syms) \ 32 (sgi ? \ 33 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ 34 ((syms) * 1000) << 2 /* syms * 4 us */ \ 35 ) 36 37 /* Transmit duration for the raw data part of an average sized packet */ 38 #define MCS_DURATION(streams, sgi, bps) \ 39 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE) 40 41 #define BW_20 0 42 #define BW_40 1 43 #define BW_80 2 44 45 /* 46 * Define group sort order: HT40 -> SGI -> #streams 47 */ 48 #define GROUP_IDX(_streams, _sgi, _ht40) \ 49 MINSTREL_HT_GROUP_0 + \ 50 MINSTREL_MAX_STREAMS * 2 * _ht40 + \ 51 MINSTREL_MAX_STREAMS * _sgi + \ 52 _streams - 1 53 54 /* MCS rate information for an MCS group */ 55 #define MCS_GROUP(_streams, _sgi, _ht40) \ 56 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 57 .streams = _streams, \ 58 .flags = \ 59 IEEE80211_TX_RC_MCS | \ 60 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 61 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 62 .duration = { \ 63 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \ 64 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \ 65 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \ 66 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \ 67 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \ 68 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \ 69 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \ 70 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \ 71 } \ 72 } 73 74 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 75 (MINSTREL_VHT_GROUP_0 + \ 76 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 77 MINSTREL_MAX_STREAMS * (_sgi) + \ 78 (_streams) - 1) 79 80 #define BW2VBPS(_bw, r3, r2, r1) \ 81 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 82 83 #define VHT_GROUP(_streams, _sgi, _bw) \ 84 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 85 .streams = _streams, \ 86 .flags = \ 87 IEEE80211_TX_RC_VHT_MCS | \ 88 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 89 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 90 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 91 .duration = { \ 92 MCS_DURATION(_streams, _sgi, \ 93 BW2VBPS(_bw, 117, 54, 26)), \ 94 MCS_DURATION(_streams, _sgi, \ 95 BW2VBPS(_bw, 234, 108, 52)), \ 96 MCS_DURATION(_streams, _sgi, \ 97 BW2VBPS(_bw, 351, 162, 78)), \ 98 MCS_DURATION(_streams, _sgi, \ 99 BW2VBPS(_bw, 468, 216, 104)), \ 100 MCS_DURATION(_streams, _sgi, \ 101 BW2VBPS(_bw, 702, 324, 156)), \ 102 MCS_DURATION(_streams, _sgi, \ 103 BW2VBPS(_bw, 936, 432, 208)), \ 104 MCS_DURATION(_streams, _sgi, \ 105 BW2VBPS(_bw, 1053, 486, 234)), \ 106 MCS_DURATION(_streams, _sgi, \ 107 BW2VBPS(_bw, 1170, 540, 260)), \ 108 MCS_DURATION(_streams, _sgi, \ 109 BW2VBPS(_bw, 1404, 648, 312)), \ 110 MCS_DURATION(_streams, _sgi, \ 111 BW2VBPS(_bw, 1560, 720, 346)) \ 112 } \ 113 } 114 115 #define CCK_DURATION(_bitrate, _short, _len) \ 116 (1000 * (10 /* SIFS */ + \ 117 (_short ? 72 + 24 : 144 + 48) + \ 118 (8 * (_len + 4) * 10) / (_bitrate))) 119 120 #define CCK_ACK_DURATION(_bitrate, _short) \ 121 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 122 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 123 124 #define CCK_DURATION_LIST(_short) \ 125 CCK_ACK_DURATION(10, _short), \ 126 CCK_ACK_DURATION(20, _short), \ 127 CCK_ACK_DURATION(55, _short), \ 128 CCK_ACK_DURATION(110, _short) 129 130 #define CCK_GROUP \ 131 [MINSTREL_CCK_GROUP] = { \ 132 .streams = 0, \ 133 .flags = 0, \ 134 .duration = { \ 135 CCK_DURATION_LIST(false), \ 136 CCK_DURATION_LIST(true) \ 137 } \ 138 } 139 140 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 141 static bool minstrel_vht_only = true; 142 module_param(minstrel_vht_only, bool, 0644); 143 MODULE_PARM_DESC(minstrel_vht_only, 144 "Use only VHT rates when VHT is supported by sta."); 145 #endif 146 147 /* 148 * To enable sufficiently targeted rate sampling, MCS rates are divided into 149 * groups, based on the number of streams and flags (HT40, SGI) that they 150 * use. 151 * 152 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 153 * BW -> SGI -> #streams 154 */ 155 const struct mcs_group minstrel_mcs_groups[] = { 156 MCS_GROUP(1, 0, BW_20), 157 MCS_GROUP(2, 0, BW_20), 158 MCS_GROUP(3, 0, BW_20), 159 160 MCS_GROUP(1, 1, BW_20), 161 MCS_GROUP(2, 1, BW_20), 162 MCS_GROUP(3, 1, BW_20), 163 164 MCS_GROUP(1, 0, BW_40), 165 MCS_GROUP(2, 0, BW_40), 166 MCS_GROUP(3, 0, BW_40), 167 168 MCS_GROUP(1, 1, BW_40), 169 MCS_GROUP(2, 1, BW_40), 170 MCS_GROUP(3, 1, BW_40), 171 172 CCK_GROUP, 173 174 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 175 VHT_GROUP(1, 0, BW_20), 176 VHT_GROUP(2, 0, BW_20), 177 VHT_GROUP(3, 0, BW_20), 178 179 VHT_GROUP(1, 1, BW_20), 180 VHT_GROUP(2, 1, BW_20), 181 VHT_GROUP(3, 1, BW_20), 182 183 VHT_GROUP(1, 0, BW_40), 184 VHT_GROUP(2, 0, BW_40), 185 VHT_GROUP(3, 0, BW_40), 186 187 VHT_GROUP(1, 1, BW_40), 188 VHT_GROUP(2, 1, BW_40), 189 VHT_GROUP(3, 1, BW_40), 190 191 VHT_GROUP(1, 0, BW_80), 192 VHT_GROUP(2, 0, BW_80), 193 VHT_GROUP(3, 0, BW_80), 194 195 VHT_GROUP(1, 1, BW_80), 196 VHT_GROUP(2, 1, BW_80), 197 VHT_GROUP(3, 1, BW_80), 198 #endif 199 }; 200 201 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 202 203 static void 204 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 205 206 /* 207 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 208 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 209 * 210 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 211 */ 212 static u16 213 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 214 { 215 u16 mask = 0; 216 217 if (bw == BW_20) { 218 if (nss != 3 && nss != 6) 219 mask = BIT(9); 220 } else if (bw == BW_80) { 221 if (nss == 3 || nss == 7) 222 mask = BIT(6); 223 else if (nss == 6) 224 mask = BIT(9); 225 } else { 226 WARN_ON(bw != BW_40); 227 } 228 229 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 230 case IEEE80211_VHT_MCS_SUPPORT_0_7: 231 mask |= 0x300; 232 break; 233 case IEEE80211_VHT_MCS_SUPPORT_0_8: 234 mask |= 0x200; 235 break; 236 case IEEE80211_VHT_MCS_SUPPORT_0_9: 237 break; 238 default: 239 mask = 0x3ff; 240 } 241 242 return 0x3ff & ~mask; 243 } 244 245 /* 246 * Look up an MCS group index based on mac80211 rate information 247 */ 248 static int 249 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 250 { 251 return GROUP_IDX((rate->idx / 8) + 1, 252 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 253 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 254 } 255 256 static int 257 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 258 { 259 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 260 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 261 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 262 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 263 } 264 265 static struct minstrel_rate_stats * 266 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 267 struct ieee80211_tx_rate *rate) 268 { 269 int group, idx; 270 271 if (rate->flags & IEEE80211_TX_RC_MCS) { 272 group = minstrel_ht_get_group_idx(rate); 273 idx = rate->idx % 8; 274 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 275 group = minstrel_vht_get_group_idx(rate); 276 idx = ieee80211_rate_get_vht_mcs(rate); 277 } else { 278 group = MINSTREL_CCK_GROUP; 279 280 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 281 if (rate->idx == mp->cck_rates[idx]) 282 break; 283 284 /* short preamble */ 285 if (!(mi->supported[group] & BIT(idx))) 286 idx += 4; 287 } 288 return &mi->groups[group].rates[idx]; 289 } 290 291 static inline struct minstrel_rate_stats * 292 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 293 { 294 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 295 } 296 297 /* 298 * Return current throughput based on the average A-MPDU length, taking into 299 * account the expected number of retransmissions and their expected length 300 */ 301 int 302 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 303 int prob_ewma) 304 { 305 unsigned int nsecs = 0; 306 307 /* do not account throughput if sucess prob is below 10% */ 308 if (prob_ewma < MINSTREL_FRAC(10, 100)) 309 return 0; 310 311 if (group != MINSTREL_CCK_GROUP) 312 nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); 313 314 nsecs += minstrel_mcs_groups[group].duration[rate]; 315 316 /* 317 * For the throughput calculation, limit the probability value to 90% to 318 * account for collision related packet error rate fluctuation 319 * (prob is scaled - see MINSTREL_FRAC above) 320 */ 321 if (prob_ewma > MINSTREL_FRAC(90, 100)) 322 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 323 / nsecs)); 324 else 325 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); 326 } 327 328 /* 329 * Find & sort topmost throughput rates 330 * 331 * If multiple rates provide equal throughput the sorting is based on their 332 * current success probability. Higher success probability is preferred among 333 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 334 */ 335 static void 336 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 337 u16 *tp_list) 338 { 339 int cur_group, cur_idx, cur_tp_avg, cur_prob; 340 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 341 int j = MAX_THR_RATES; 342 343 cur_group = index / MCS_GROUP_RATES; 344 cur_idx = index % MCS_GROUP_RATES; 345 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; 346 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 347 348 do { 349 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 350 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 351 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 352 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 353 tmp_prob); 354 if (cur_tp_avg < tmp_tp_avg || 355 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 356 break; 357 j--; 358 } while (j > 0); 359 360 if (j < MAX_THR_RATES - 1) { 361 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 362 (MAX_THR_RATES - (j + 1)))); 363 } 364 if (j < MAX_THR_RATES) 365 tp_list[j] = index; 366 } 367 368 /* 369 * Find and set the topmost probability rate per sta and per group 370 */ 371 static void 372 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 373 { 374 struct minstrel_mcs_group_data *mg; 375 struct minstrel_rate_stats *mrs; 376 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 377 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 378 int max_gpr_group, max_gpr_idx; 379 int max_gpr_tp_avg, max_gpr_prob; 380 381 cur_group = index / MCS_GROUP_RATES; 382 cur_idx = index % MCS_GROUP_RATES; 383 mg = &mi->groups[index / MCS_GROUP_RATES]; 384 mrs = &mg->rates[index % MCS_GROUP_RATES]; 385 386 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 387 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 388 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 389 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 390 391 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 392 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 393 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 394 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 395 (max_tp_group != MINSTREL_CCK_GROUP)) 396 return; 397 398 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 399 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 400 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; 401 402 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { 403 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 404 mrs->prob_ewma); 405 if (cur_tp_avg > tmp_tp_avg) 406 mi->max_prob_rate = index; 407 408 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 409 max_gpr_idx, 410 max_gpr_prob); 411 if (cur_tp_avg > max_gpr_tp_avg) 412 mg->max_group_prob_rate = index; 413 } else { 414 if (mrs->prob_ewma > tmp_prob) 415 mi->max_prob_rate = index; 416 if (mrs->prob_ewma > max_gpr_prob) 417 mg->max_group_prob_rate = index; 418 } 419 } 420 421 422 /* 423 * Assign new rate set per sta and use CCK rates only if the fastest 424 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 425 * rate sets where MCS and CCK rates are mixed, because CCK rates can 426 * not use aggregation. 427 */ 428 static void 429 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 430 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 431 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 432 { 433 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 434 int i; 435 436 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 437 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 438 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 439 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 440 441 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 442 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 443 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 444 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 445 446 if (tmp_cck_tp > tmp_mcs_tp) { 447 for(i = 0; i < MAX_THR_RATES; i++) { 448 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 449 tmp_mcs_tp_rate); 450 } 451 } 452 453 } 454 455 /* 456 * Try to increase robustness of max_prob rate by decrease number of 457 * streams if possible. 458 */ 459 static inline void 460 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 461 { 462 struct minstrel_mcs_group_data *mg; 463 int tmp_max_streams, group, tmp_idx, tmp_prob; 464 int tmp_tp = 0; 465 466 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 467 MCS_GROUP_RATES].streams; 468 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 469 mg = &mi->groups[group]; 470 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 471 continue; 472 473 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 474 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; 475 476 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 477 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 478 mi->max_prob_rate = mg->max_group_prob_rate; 479 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 480 tmp_idx, 481 tmp_prob); 482 } 483 } 484 } 485 486 /* 487 * Update rate statistics and select new primary rates 488 * 489 * Rules for rate selection: 490 * - max_prob_rate must use only one stream, as a tradeoff between delivery 491 * probability and throughput during strong fluctuations 492 * - as long as the max prob rate has a probability of more than 75%, pick 493 * higher throughput rates, even if the probablity is a bit lower 494 */ 495 static void 496 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 497 { 498 struct minstrel_mcs_group_data *mg; 499 struct minstrel_rate_stats *mrs; 500 int group, i, j, cur_prob; 501 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 502 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 503 504 if (mi->ampdu_packets > 0) { 505 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 506 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL); 507 mi->ampdu_len = 0; 508 mi->ampdu_packets = 0; 509 } 510 511 mi->sample_slow = 0; 512 mi->sample_count = 0; 513 514 /* Initialize global rate indexes */ 515 for(j = 0; j < MAX_THR_RATES; j++){ 516 tmp_mcs_tp_rate[j] = 0; 517 tmp_cck_tp_rate[j] = 0; 518 } 519 520 /* Find best rate sets within all MCS groups*/ 521 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 522 523 mg = &mi->groups[group]; 524 if (!mi->supported[group]) 525 continue; 526 527 mi->sample_count++; 528 529 /* (re)Initialize group rate indexes */ 530 for(j = 0; j < MAX_THR_RATES; j++) 531 tmp_group_tp_rate[j] = group; 532 533 for (i = 0; i < MCS_GROUP_RATES; i++) { 534 if (!(mi->supported[group] & BIT(i))) 535 continue; 536 537 index = MCS_GROUP_RATES * group + i; 538 539 mrs = &mg->rates[i]; 540 mrs->retry_updated = false; 541 minstrel_calc_rate_stats(mrs); 542 cur_prob = mrs->prob_ewma; 543 544 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 545 continue; 546 547 /* Find max throughput rate set */ 548 if (group != MINSTREL_CCK_GROUP) { 549 minstrel_ht_sort_best_tp_rates(mi, index, 550 tmp_mcs_tp_rate); 551 } else if (group == MINSTREL_CCK_GROUP) { 552 minstrel_ht_sort_best_tp_rates(mi, index, 553 tmp_cck_tp_rate); 554 } 555 556 /* Find max throughput rate set within a group */ 557 minstrel_ht_sort_best_tp_rates(mi, index, 558 tmp_group_tp_rate); 559 560 /* Find max probability rate per group and global */ 561 minstrel_ht_set_best_prob_rate(mi, index); 562 } 563 564 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 565 sizeof(mg->max_group_tp_rate)); 566 } 567 568 /* Assign new rate set per sta */ 569 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 570 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 571 572 /* Try to increase robustness of max_prob_rate*/ 573 minstrel_ht_prob_rate_reduce_streams(mi); 574 575 /* try to sample all available rates during each interval */ 576 mi->sample_count *= 8; 577 578 #ifdef CONFIG_MAC80211_DEBUGFS 579 /* use fixed index if set */ 580 if (mp->fixed_rate_idx != -1) { 581 for (i = 0; i < 4; i++) 582 mi->max_tp_rate[i] = mp->fixed_rate_idx; 583 mi->max_prob_rate = mp->fixed_rate_idx; 584 } 585 #endif 586 587 /* Reset update timer */ 588 mi->last_stats_update = jiffies; 589 } 590 591 static bool 592 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 593 { 594 if (rate->idx < 0) 595 return false; 596 597 if (!rate->count) 598 return false; 599 600 if (rate->flags & IEEE80211_TX_RC_MCS || 601 rate->flags & IEEE80211_TX_RC_VHT_MCS) 602 return true; 603 604 return rate->idx == mp->cck_rates[0] || 605 rate->idx == mp->cck_rates[1] || 606 rate->idx == mp->cck_rates[2] || 607 rate->idx == mp->cck_rates[3]; 608 } 609 610 static void 611 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 612 { 613 struct minstrel_mcs_group_data *mg; 614 615 for (;;) { 616 mi->sample_group++; 617 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 618 mg = &mi->groups[mi->sample_group]; 619 620 if (!mi->supported[mi->sample_group]) 621 continue; 622 623 if (++mg->index >= MCS_GROUP_RATES) { 624 mg->index = 0; 625 if (++mg->column >= ARRAY_SIZE(sample_table)) 626 mg->column = 0; 627 } 628 break; 629 } 630 } 631 632 static void 633 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 634 { 635 int group, orig_group; 636 637 orig_group = group = *idx / MCS_GROUP_RATES; 638 while (group > 0) { 639 group--; 640 641 if (!mi->supported[group]) 642 continue; 643 644 if (minstrel_mcs_groups[group].streams > 645 minstrel_mcs_groups[orig_group].streams) 646 continue; 647 648 if (primary) 649 *idx = mi->groups[group].max_group_tp_rate[0]; 650 else 651 *idx = mi->groups[group].max_group_tp_rate[1]; 652 break; 653 } 654 } 655 656 static void 657 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 658 { 659 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 660 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 661 u16 tid; 662 663 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 664 return; 665 666 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 667 return; 668 669 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 670 return; 671 672 tid = ieee80211_get_tid(hdr); 673 if (likely(sta->ampdu_mlme.tid_tx[tid])) 674 return; 675 676 ieee80211_start_tx_ba_session(pubsta, tid, 0); 677 } 678 679 static void 680 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 681 void *priv_sta, struct ieee80211_tx_status *st) 682 { 683 struct ieee80211_tx_info *info = st->info; 684 struct minstrel_ht_sta_priv *msp = priv_sta; 685 struct minstrel_ht_sta *mi = &msp->ht; 686 struct ieee80211_tx_rate *ar = info->status.rates; 687 struct minstrel_rate_stats *rate, *rate2; 688 struct minstrel_priv *mp = priv; 689 bool last, update = false; 690 int i; 691 692 if (!msp->is_ht) 693 return mac80211_minstrel.tx_status_ext(priv, sband, 694 &msp->legacy, st); 695 696 /* This packet was aggregated but doesn't carry status info */ 697 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 698 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 699 return; 700 701 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 702 info->status.ampdu_ack_len = 703 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 704 info->status.ampdu_len = 1; 705 } 706 707 mi->ampdu_packets++; 708 mi->ampdu_len += info->status.ampdu_len; 709 710 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 711 mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len); 712 mi->sample_tries = 1; 713 mi->sample_count--; 714 } 715 716 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 717 mi->sample_packets += info->status.ampdu_len; 718 719 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 720 for (i = 0; !last; i++) { 721 last = (i == IEEE80211_TX_MAX_RATES - 1) || 722 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 723 724 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 725 726 if (last) 727 rate->success += info->status.ampdu_ack_len; 728 729 rate->attempts += ar[i].count * info->status.ampdu_len; 730 } 731 732 /* 733 * check for sudden death of spatial multiplexing, 734 * downgrade to a lower number of streams if necessary. 735 */ 736 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 737 if (rate->attempts > 30 && 738 MINSTREL_FRAC(rate->success, rate->attempts) < 739 MINSTREL_FRAC(20, 100)) { 740 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 741 update = true; 742 } 743 744 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 745 if (rate2->attempts > 30 && 746 MINSTREL_FRAC(rate2->success, rate2->attempts) < 747 MINSTREL_FRAC(20, 100)) { 748 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 749 update = true; 750 } 751 752 if (time_after(jiffies, mi->last_stats_update + 753 (mp->update_interval / 2 * HZ) / 1000)) { 754 update = true; 755 minstrel_ht_update_stats(mp, mi); 756 } 757 758 if (update) 759 minstrel_ht_update_rates(mp, mi); 760 } 761 762 static void 763 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 764 int index) 765 { 766 struct minstrel_rate_stats *mrs; 767 const struct mcs_group *group; 768 unsigned int tx_time, tx_time_rtscts, tx_time_data; 769 unsigned int cw = mp->cw_min; 770 unsigned int ctime = 0; 771 unsigned int t_slot = 9; /* FIXME */ 772 unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len); 773 unsigned int overhead = 0, overhead_rtscts = 0; 774 775 mrs = minstrel_get_ratestats(mi, index); 776 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { 777 mrs->retry_count = 1; 778 mrs->retry_count_rtscts = 1; 779 return; 780 } 781 782 mrs->retry_count = 2; 783 mrs->retry_count_rtscts = 2; 784 mrs->retry_updated = true; 785 786 group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 787 tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000; 788 789 /* Contention time for first 2 tries */ 790 ctime = (t_slot * cw) >> 1; 791 cw = min((cw << 1) | 1, mp->cw_max); 792 ctime += (t_slot * cw) >> 1; 793 cw = min((cw << 1) | 1, mp->cw_max); 794 795 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 796 overhead = mi->overhead; 797 overhead_rtscts = mi->overhead_rtscts; 798 } 799 800 /* Total TX time for data and Contention after first 2 tries */ 801 tx_time = ctime + 2 * (overhead + tx_time_data); 802 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 803 804 /* See how many more tries we can fit inside segment size */ 805 do { 806 /* Contention time for this try */ 807 ctime = (t_slot * cw) >> 1; 808 cw = min((cw << 1) | 1, mp->cw_max); 809 810 /* Total TX time after this try */ 811 tx_time += ctime + overhead + tx_time_data; 812 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 813 814 if (tx_time_rtscts < mp->segment_size) 815 mrs->retry_count_rtscts++; 816 } while ((tx_time < mp->segment_size) && 817 (++mrs->retry_count < mp->max_retry)); 818 } 819 820 821 static void 822 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 823 struct ieee80211_sta_rates *ratetbl, int offset, int index) 824 { 825 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 826 struct minstrel_rate_stats *mrs; 827 u8 idx; 828 u16 flags = group->flags; 829 830 mrs = minstrel_get_ratestats(mi, index); 831 if (!mrs->retry_updated) 832 minstrel_calc_retransmit(mp, mi, index); 833 834 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 835 ratetbl->rate[offset].count = 2; 836 ratetbl->rate[offset].count_rts = 2; 837 ratetbl->rate[offset].count_cts = 2; 838 } else { 839 ratetbl->rate[offset].count = mrs->retry_count; 840 ratetbl->rate[offset].count_cts = mrs->retry_count; 841 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 842 } 843 844 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 845 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 846 else if (flags & IEEE80211_TX_RC_VHT_MCS) 847 idx = ((group->streams - 1) << 4) | 848 ((index % MCS_GROUP_RATES) & 0xF); 849 else 850 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 851 852 /* enable RTS/CTS if needed: 853 * - if station is in dynamic SMPS (and streams > 1) 854 * - for fallback rates, to increase chances of getting through 855 */ 856 if (offset > 0 || 857 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 858 group->streams > 1)) { 859 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 860 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 861 } 862 863 ratetbl->rate[offset].idx = idx; 864 ratetbl->rate[offset].flags = flags; 865 } 866 867 static inline int 868 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) 869 { 870 int group = rate / MCS_GROUP_RATES; 871 rate %= MCS_GROUP_RATES; 872 return mi->groups[group].rates[rate].prob_ewma; 873 } 874 875 static int 876 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 877 { 878 int group = mi->max_prob_rate / MCS_GROUP_RATES; 879 const struct mcs_group *g = &minstrel_mcs_groups[group]; 880 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 881 882 /* Disable A-MSDU if max_prob_rate is bad */ 883 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) 884 return 1; 885 886 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 887 if (g->duration[rate] > MCS_DURATION(1, 0, 52)) 888 return 500; 889 890 /* 891 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 892 * data packet size 893 */ 894 if (g->duration[rate] > MCS_DURATION(1, 0, 104)) 895 return 1600; 896 897 /* 898 * If the rate is slower than single-stream MCS7, or if the max throughput 899 * rate success probability is less than 75%, limit A-MSDU to twice the usual 900 * data packet size 901 */ 902 if (g->duration[rate] > MCS_DURATION(1, 0, 260) || 903 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < 904 MINSTREL_FRAC(75, 100))) 905 return 3200; 906 907 /* 908 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 909 * Since aggregation sessions are started/stopped without txq flush, use 910 * the limit here to avoid the complexity of having to de-aggregate 911 * packets in the queue. 912 */ 913 if (!mi->sta->vht_cap.vht_supported) 914 return IEEE80211_MAX_MPDU_LEN_HT_BA; 915 916 /* unlimited */ 917 return 0; 918 } 919 920 static void 921 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 922 { 923 struct ieee80211_sta_rates *rates; 924 int i = 0; 925 926 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 927 if (!rates) 928 return; 929 930 /* Start with max_tp_rate[0] */ 931 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 932 933 if (mp->hw->max_rates >= 3) { 934 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 935 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 936 } 937 938 if (mp->hw->max_rates >= 2) { 939 /* 940 * At least 2 tx rates supported, use max_prob_rate next */ 941 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 942 } 943 944 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 945 rates->rate[i].idx = -1; 946 rate_control_set_rates(mp->hw, mi->sta, rates); 947 } 948 949 static inline int 950 minstrel_get_duration(int index) 951 { 952 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 953 return group->duration[index % MCS_GROUP_RATES]; 954 } 955 956 static int 957 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 958 { 959 struct minstrel_rate_stats *mrs; 960 struct minstrel_mcs_group_data *mg; 961 unsigned int sample_dur, sample_group, cur_max_tp_streams; 962 int tp_rate1, tp_rate2; 963 int sample_idx = 0; 964 965 if (mi->sample_wait > 0) { 966 mi->sample_wait--; 967 return -1; 968 } 969 970 if (!mi->sample_tries) 971 return -1; 972 973 sample_group = mi->sample_group; 974 mg = &mi->groups[sample_group]; 975 sample_idx = sample_table[mg->column][mg->index]; 976 minstrel_set_next_sample_idx(mi); 977 978 if (!(mi->supported[sample_group] & BIT(sample_idx))) 979 return -1; 980 981 mrs = &mg->rates[sample_idx]; 982 sample_idx += sample_group * MCS_GROUP_RATES; 983 984 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 985 if (minstrel_get_duration(mi->max_tp_rate[0]) > 986 minstrel_get_duration(mi->max_tp_rate[1])) { 987 tp_rate1 = mi->max_tp_rate[1]; 988 tp_rate2 = mi->max_tp_rate[0]; 989 } else { 990 tp_rate1 = mi->max_tp_rate[0]; 991 tp_rate2 = mi->max_tp_rate[1]; 992 } 993 994 /* 995 * Sampling might add some overhead (RTS, no aggregation) 996 * to the frame. Hence, don't use sampling for the highest currently 997 * used highest throughput or probability rate. 998 */ 999 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1000 return -1; 1001 1002 /* 1003 * Do not sample if the probability is already higher than 95% 1004 * to avoid wasting airtime. 1005 */ 1006 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100)) 1007 return -1; 1008 1009 /* 1010 * Make sure that lower rates get sampled only occasionally, 1011 * if the link is working perfectly. 1012 */ 1013 1014 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1015 MCS_GROUP_RATES].streams; 1016 sample_dur = minstrel_get_duration(sample_idx); 1017 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1018 (cur_max_tp_streams - 1 < 1019 minstrel_mcs_groups[sample_group].streams || 1020 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1021 if (mrs->sample_skipped < 20) 1022 return -1; 1023 1024 if (mi->sample_slow++ > 2) 1025 return -1; 1026 } 1027 mi->sample_tries--; 1028 1029 return sample_idx; 1030 } 1031 1032 static void 1033 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1034 struct ieee80211_tx_rate_control *txrc) 1035 { 1036 const struct mcs_group *sample_group; 1037 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1038 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1039 struct minstrel_ht_sta_priv *msp = priv_sta; 1040 struct minstrel_ht_sta *mi = &msp->ht; 1041 struct minstrel_priv *mp = priv; 1042 int sample_idx; 1043 1044 if (rate_control_send_low(sta, priv_sta, txrc)) 1045 return; 1046 1047 if (!msp->is_ht) 1048 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1049 1050 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1051 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1052 minstrel_aggr_check(sta, txrc->skb); 1053 1054 info->flags |= mi->tx_flags; 1055 1056 #ifdef CONFIG_MAC80211_DEBUGFS 1057 if (mp->fixed_rate_idx != -1) 1058 return; 1059 #endif 1060 1061 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1062 if (mp->hw->max_rates == 1 && 1063 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1064 sample_idx = -1; 1065 else 1066 sample_idx = minstrel_get_sample_rate(mp, mi); 1067 1068 mi->total_packets++; 1069 1070 /* wraparound */ 1071 if (mi->total_packets == ~0) { 1072 mi->total_packets = 0; 1073 mi->sample_packets = 0; 1074 } 1075 1076 if (sample_idx < 0) 1077 return; 1078 1079 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1080 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1081 rate->count = 1; 1082 1083 if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { 1084 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1085 rate->idx = mp->cck_rates[idx]; 1086 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1087 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1088 sample_group->streams); 1089 } else { 1090 rate->idx = sample_idx % MCS_GROUP_RATES + 1091 (sample_group->streams - 1) * 8; 1092 } 1093 1094 rate->flags = sample_group->flags; 1095 } 1096 1097 static void 1098 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1099 struct ieee80211_supported_band *sband, 1100 struct ieee80211_sta *sta) 1101 { 1102 int i; 1103 1104 if (sband->band != NL80211_BAND_2GHZ) 1105 return; 1106 1107 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1108 return; 1109 1110 mi->cck_supported = 0; 1111 mi->cck_supported_short = 0; 1112 for (i = 0; i < 4; i++) { 1113 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1114 continue; 1115 1116 mi->cck_supported |= BIT(i); 1117 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1118 mi->cck_supported_short |= BIT(i); 1119 } 1120 1121 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1122 } 1123 1124 static void 1125 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1126 struct cfg80211_chan_def *chandef, 1127 struct ieee80211_sta *sta, void *priv_sta) 1128 { 1129 struct minstrel_priv *mp = priv; 1130 struct minstrel_ht_sta_priv *msp = priv_sta; 1131 struct minstrel_ht_sta *mi = &msp->ht; 1132 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1133 u16 sta_cap = sta->ht_cap.cap; 1134 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1135 struct sta_info *sinfo = container_of(sta, struct sta_info, sta); 1136 int use_vht; 1137 int n_supported = 0; 1138 int ack_dur; 1139 int stbc; 1140 int i; 1141 1142 /* fall back to the old minstrel for legacy stations */ 1143 if (!sta->ht_cap.ht_supported) 1144 goto use_legacy; 1145 1146 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1147 1148 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1149 if (vht_cap->vht_supported) 1150 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1151 else 1152 #endif 1153 use_vht = 0; 1154 1155 msp->is_ht = true; 1156 memset(mi, 0, sizeof(*mi)); 1157 1158 mi->sta = sta; 1159 mi->last_stats_update = jiffies; 1160 1161 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1162 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1163 mi->overhead += ack_dur; 1164 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1165 1166 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1167 1168 /* When using MRR, sample more on the first attempt, without delay */ 1169 if (mp->has_mrr) { 1170 mi->sample_count = 16; 1171 mi->sample_wait = 0; 1172 } else { 1173 mi->sample_count = 8; 1174 mi->sample_wait = 8; 1175 } 1176 mi->sample_tries = 4; 1177 1178 /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */ 1179 if (!use_vht) { 1180 stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >> 1181 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1182 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1183 1184 if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING) 1185 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1186 } 1187 1188 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1189 u32 gflags = minstrel_mcs_groups[i].flags; 1190 int bw, nss; 1191 1192 mi->supported[i] = 0; 1193 if (i == MINSTREL_CCK_GROUP) { 1194 minstrel_ht_update_cck(mp, mi, sband, sta); 1195 continue; 1196 } 1197 1198 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1199 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1200 if (!(sta_cap & IEEE80211_HT_CAP_SGI_40)) 1201 continue; 1202 } else { 1203 if (!(sta_cap & IEEE80211_HT_CAP_SGI_20)) 1204 continue; 1205 } 1206 } 1207 1208 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1209 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1210 continue; 1211 1212 nss = minstrel_mcs_groups[i].streams; 1213 1214 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1215 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1216 continue; 1217 1218 /* HT rate */ 1219 if (gflags & IEEE80211_TX_RC_MCS) { 1220 #ifdef CONFIG_MAC80211_RC_MINSTREL_VHT 1221 if (use_vht && minstrel_vht_only) 1222 continue; 1223 #endif 1224 mi->supported[i] = mcs->rx_mask[nss - 1]; 1225 if (mi->supported[i]) 1226 n_supported++; 1227 continue; 1228 } 1229 1230 /* VHT rate */ 1231 if (!vht_cap->vht_supported || 1232 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1233 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1234 continue; 1235 1236 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1237 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1238 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1239 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1240 continue; 1241 } 1242 } 1243 1244 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1245 bw = BW_40; 1246 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1247 bw = BW_80; 1248 else 1249 bw = BW_20; 1250 1251 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1252 vht_cap->vht_mcs.tx_mcs_map); 1253 1254 if (mi->supported[i]) 1255 n_supported++; 1256 } 1257 1258 if (!n_supported) 1259 goto use_legacy; 1260 1261 if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE)) 1262 mi->cck_supported_short |= mi->cck_supported_short << 4; 1263 1264 /* create an initial rate table with the lowest supported rates */ 1265 minstrel_ht_update_stats(mp, mi); 1266 minstrel_ht_update_rates(mp, mi); 1267 1268 return; 1269 1270 use_legacy: 1271 msp->is_ht = false; 1272 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1273 msp->legacy.r = msp->ratelist; 1274 msp->legacy.sample_table = msp->sample_table; 1275 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1276 &msp->legacy); 1277 } 1278 1279 static void 1280 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1281 struct cfg80211_chan_def *chandef, 1282 struct ieee80211_sta *sta, void *priv_sta) 1283 { 1284 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1285 } 1286 1287 static void 1288 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1289 struct cfg80211_chan_def *chandef, 1290 struct ieee80211_sta *sta, void *priv_sta, 1291 u32 changed) 1292 { 1293 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1294 } 1295 1296 static void * 1297 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1298 { 1299 struct ieee80211_supported_band *sband; 1300 struct minstrel_ht_sta_priv *msp; 1301 struct minstrel_priv *mp = priv; 1302 struct ieee80211_hw *hw = mp->hw; 1303 int max_rates = 0; 1304 int i; 1305 1306 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1307 sband = hw->wiphy->bands[i]; 1308 if (sband && sband->n_bitrates > max_rates) 1309 max_rates = sband->n_bitrates; 1310 } 1311 1312 msp = kzalloc(sizeof(*msp), gfp); 1313 if (!msp) 1314 return NULL; 1315 1316 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1317 if (!msp->ratelist) 1318 goto error; 1319 1320 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1321 if (!msp->sample_table) 1322 goto error1; 1323 1324 return msp; 1325 1326 error1: 1327 kfree(msp->ratelist); 1328 error: 1329 kfree(msp); 1330 return NULL; 1331 } 1332 1333 static void 1334 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1335 { 1336 struct minstrel_ht_sta_priv *msp = priv_sta; 1337 1338 kfree(msp->sample_table); 1339 kfree(msp->ratelist); 1340 kfree(msp); 1341 } 1342 1343 static void * 1344 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1345 { 1346 return mac80211_minstrel.alloc(hw, debugfsdir); 1347 } 1348 1349 static void 1350 minstrel_ht_free(void *priv) 1351 { 1352 mac80211_minstrel.free(priv); 1353 } 1354 1355 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1356 { 1357 struct minstrel_ht_sta_priv *msp = priv_sta; 1358 struct minstrel_ht_sta *mi = &msp->ht; 1359 int i, j, prob, tp_avg; 1360 1361 if (!msp->is_ht) 1362 return mac80211_minstrel.get_expected_throughput(priv_sta); 1363 1364 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1365 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1366 prob = mi->groups[i].rates[j].prob_ewma; 1367 1368 /* convert tp_avg from pkt per second in kbps */ 1369 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1370 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1371 1372 return tp_avg; 1373 } 1374 1375 static const struct rate_control_ops mac80211_minstrel_ht = { 1376 .name = "minstrel_ht", 1377 .tx_status_ext = minstrel_ht_tx_status, 1378 .get_rate = minstrel_ht_get_rate, 1379 .rate_init = minstrel_ht_rate_init, 1380 .rate_update = minstrel_ht_rate_update, 1381 .alloc_sta = minstrel_ht_alloc_sta, 1382 .free_sta = minstrel_ht_free_sta, 1383 .alloc = minstrel_ht_alloc, 1384 .free = minstrel_ht_free, 1385 #ifdef CONFIG_MAC80211_DEBUGFS 1386 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1387 .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs, 1388 #endif 1389 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1390 }; 1391 1392 1393 static void __init init_sample_table(void) 1394 { 1395 int col, i, new_idx; 1396 u8 rnd[MCS_GROUP_RATES]; 1397 1398 memset(sample_table, 0xff, sizeof(sample_table)); 1399 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1400 prandom_bytes(rnd, sizeof(rnd)); 1401 for (i = 0; i < MCS_GROUP_RATES; i++) { 1402 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1403 while (sample_table[col][new_idx] != 0xff) 1404 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1405 1406 sample_table[col][new_idx] = i; 1407 } 1408 } 1409 } 1410 1411 int __init 1412 rc80211_minstrel_ht_init(void) 1413 { 1414 init_sample_table(); 1415 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1416 } 1417 1418 void 1419 rc80211_minstrel_ht_exit(void) 1420 { 1421 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1422 } 1423