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