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 static unsigned int 298 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 299 { 300 if (!mi->avg_ampdu_len) 301 return AVG_AMPDU_SIZE; 302 303 return MINSTREL_TRUNC(mi->avg_ampdu_len); 304 } 305 306 /* 307 * Return current throughput based on the average A-MPDU length, taking into 308 * account the expected number of retransmissions and their expected length 309 */ 310 int 311 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 312 int prob_ewma) 313 { 314 unsigned int nsecs = 0; 315 316 /* do not account throughput if sucess prob is below 10% */ 317 if (prob_ewma < MINSTREL_FRAC(10, 100)) 318 return 0; 319 320 if (group != MINSTREL_CCK_GROUP) 321 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi); 322 323 nsecs += minstrel_mcs_groups[group].duration[rate] << 324 minstrel_mcs_groups[group].shift; 325 326 /* 327 * For the throughput calculation, limit the probability value to 90% to 328 * account for collision related packet error rate fluctuation 329 * (prob is scaled - see MINSTREL_FRAC above) 330 */ 331 if (prob_ewma > MINSTREL_FRAC(90, 100)) 332 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 333 / nsecs)); 334 else 335 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); 336 } 337 338 /* 339 * Find & sort topmost throughput rates 340 * 341 * If multiple rates provide equal throughput the sorting is based on their 342 * current success probability. Higher success probability is preferred among 343 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 344 */ 345 static void 346 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 347 u16 *tp_list) 348 { 349 int cur_group, cur_idx, cur_tp_avg, cur_prob; 350 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 351 int j = MAX_THR_RATES; 352 353 cur_group = index / MCS_GROUP_RATES; 354 cur_idx = index % MCS_GROUP_RATES; 355 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; 356 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 357 358 do { 359 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 360 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 361 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 362 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 363 tmp_prob); 364 if (cur_tp_avg < tmp_tp_avg || 365 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 366 break; 367 j--; 368 } while (j > 0); 369 370 if (j < MAX_THR_RATES - 1) { 371 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 372 (MAX_THR_RATES - (j + 1)))); 373 } 374 if (j < MAX_THR_RATES) 375 tp_list[j] = index; 376 } 377 378 /* 379 * Find and set the topmost probability rate per sta and per group 380 */ 381 static void 382 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 383 { 384 struct minstrel_mcs_group_data *mg; 385 struct minstrel_rate_stats *mrs; 386 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 387 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 388 int max_gpr_group, max_gpr_idx; 389 int max_gpr_tp_avg, max_gpr_prob; 390 391 cur_group = index / MCS_GROUP_RATES; 392 cur_idx = index % MCS_GROUP_RATES; 393 mg = &mi->groups[index / MCS_GROUP_RATES]; 394 mrs = &mg->rates[index % MCS_GROUP_RATES]; 395 396 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 397 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 398 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 399 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 400 401 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 402 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 403 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 404 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 405 (max_tp_group != MINSTREL_CCK_GROUP)) 406 return; 407 408 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 409 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 410 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; 411 412 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { 413 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 414 mrs->prob_ewma); 415 if (cur_tp_avg > tmp_tp_avg) 416 mi->max_prob_rate = index; 417 418 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 419 max_gpr_idx, 420 max_gpr_prob); 421 if (cur_tp_avg > max_gpr_tp_avg) 422 mg->max_group_prob_rate = index; 423 } else { 424 if (mrs->prob_ewma > tmp_prob) 425 mi->max_prob_rate = index; 426 if (mrs->prob_ewma > max_gpr_prob) 427 mg->max_group_prob_rate = index; 428 } 429 } 430 431 432 /* 433 * Assign new rate set per sta and use CCK rates only if the fastest 434 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 435 * rate sets where MCS and CCK rates are mixed, because CCK rates can 436 * not use aggregation. 437 */ 438 static void 439 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 440 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 441 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 442 { 443 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 444 int i; 445 446 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 447 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 448 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 449 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 450 451 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 452 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 453 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 454 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 455 456 if (tmp_cck_tp > tmp_mcs_tp) { 457 for(i = 0; i < MAX_THR_RATES; i++) { 458 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 459 tmp_mcs_tp_rate); 460 } 461 } 462 463 } 464 465 /* 466 * Try to increase robustness of max_prob rate by decrease number of 467 * streams if possible. 468 */ 469 static inline void 470 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 471 { 472 struct minstrel_mcs_group_data *mg; 473 int tmp_max_streams, group, tmp_idx, tmp_prob; 474 int tmp_tp = 0; 475 476 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 477 MCS_GROUP_RATES].streams; 478 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 479 mg = &mi->groups[group]; 480 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 481 continue; 482 483 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 484 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; 485 486 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 487 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 488 mi->max_prob_rate = mg->max_group_prob_rate; 489 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 490 tmp_idx, 491 tmp_prob); 492 } 493 } 494 } 495 496 /* 497 * Update rate statistics and select new primary rates 498 * 499 * Rules for rate selection: 500 * - max_prob_rate must use only one stream, as a tradeoff between delivery 501 * probability and throughput during strong fluctuations 502 * - as long as the max prob rate has a probability of more than 75%, pick 503 * higher throughput rates, even if the probablity is a bit lower 504 */ 505 static void 506 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 507 { 508 struct minstrel_mcs_group_data *mg; 509 struct minstrel_rate_stats *mrs; 510 int group, i, j, cur_prob; 511 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 512 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 513 514 if (mi->ampdu_packets > 0) { 515 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 516 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 517 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 518 EWMA_LEVEL); 519 else 520 mi->avg_ampdu_len = 0; 521 mi->ampdu_len = 0; 522 mi->ampdu_packets = 0; 523 } 524 525 mi->sample_slow = 0; 526 mi->sample_count = 0; 527 528 /* Initialize global rate indexes */ 529 for(j = 0; j < MAX_THR_RATES; j++){ 530 tmp_mcs_tp_rate[j] = 0; 531 tmp_cck_tp_rate[j] = 0; 532 } 533 534 /* Find best rate sets within all MCS groups*/ 535 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 536 537 mg = &mi->groups[group]; 538 if (!mi->supported[group]) 539 continue; 540 541 mi->sample_count++; 542 543 /* (re)Initialize group rate indexes */ 544 for(j = 0; j < MAX_THR_RATES; j++) 545 tmp_group_tp_rate[j] = group; 546 547 for (i = 0; i < MCS_GROUP_RATES; i++) { 548 if (!(mi->supported[group] & BIT(i))) 549 continue; 550 551 index = MCS_GROUP_RATES * group + i; 552 553 mrs = &mg->rates[i]; 554 mrs->retry_updated = false; 555 minstrel_calc_rate_stats(mrs); 556 cur_prob = mrs->prob_ewma; 557 558 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 559 continue; 560 561 /* Find max throughput rate set */ 562 if (group != MINSTREL_CCK_GROUP) { 563 minstrel_ht_sort_best_tp_rates(mi, index, 564 tmp_mcs_tp_rate); 565 } else if (group == MINSTREL_CCK_GROUP) { 566 minstrel_ht_sort_best_tp_rates(mi, index, 567 tmp_cck_tp_rate); 568 } 569 570 /* Find max throughput rate set within a group */ 571 minstrel_ht_sort_best_tp_rates(mi, index, 572 tmp_group_tp_rate); 573 574 /* Find max probability rate per group and global */ 575 minstrel_ht_set_best_prob_rate(mi, index); 576 } 577 578 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 579 sizeof(mg->max_group_tp_rate)); 580 } 581 582 /* Assign new rate set per sta */ 583 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 584 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 585 586 /* Try to increase robustness of max_prob_rate*/ 587 minstrel_ht_prob_rate_reduce_streams(mi); 588 589 /* try to sample all available rates during each interval */ 590 mi->sample_count *= 8; 591 592 #ifdef CONFIG_MAC80211_DEBUGFS 593 /* use fixed index if set */ 594 if (mp->fixed_rate_idx != -1) { 595 for (i = 0; i < 4; i++) 596 mi->max_tp_rate[i] = mp->fixed_rate_idx; 597 mi->max_prob_rate = mp->fixed_rate_idx; 598 } 599 #endif 600 601 /* Reset update timer */ 602 mi->last_stats_update = jiffies; 603 } 604 605 static bool 606 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 607 { 608 if (rate->idx < 0) 609 return false; 610 611 if (!rate->count) 612 return false; 613 614 if (rate->flags & IEEE80211_TX_RC_MCS || 615 rate->flags & IEEE80211_TX_RC_VHT_MCS) 616 return true; 617 618 return rate->idx == mp->cck_rates[0] || 619 rate->idx == mp->cck_rates[1] || 620 rate->idx == mp->cck_rates[2] || 621 rate->idx == mp->cck_rates[3]; 622 } 623 624 static void 625 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 626 { 627 struct minstrel_mcs_group_data *mg; 628 629 for (;;) { 630 mi->sample_group++; 631 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 632 mg = &mi->groups[mi->sample_group]; 633 634 if (!mi->supported[mi->sample_group]) 635 continue; 636 637 if (++mg->index >= MCS_GROUP_RATES) { 638 mg->index = 0; 639 if (++mg->column >= ARRAY_SIZE(sample_table)) 640 mg->column = 0; 641 } 642 break; 643 } 644 } 645 646 static void 647 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 648 { 649 int group, orig_group; 650 651 orig_group = group = *idx / MCS_GROUP_RATES; 652 while (group > 0) { 653 group--; 654 655 if (!mi->supported[group]) 656 continue; 657 658 if (minstrel_mcs_groups[group].streams > 659 minstrel_mcs_groups[orig_group].streams) 660 continue; 661 662 if (primary) 663 *idx = mi->groups[group].max_group_tp_rate[0]; 664 else 665 *idx = mi->groups[group].max_group_tp_rate[1]; 666 break; 667 } 668 } 669 670 static void 671 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 672 { 673 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 674 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 675 u16 tid; 676 677 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 678 return; 679 680 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 681 return; 682 683 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 684 return; 685 686 tid = ieee80211_get_tid(hdr); 687 if (likely(sta->ampdu_mlme.tid_tx[tid])) 688 return; 689 690 ieee80211_start_tx_ba_session(pubsta, tid, 0); 691 } 692 693 static void 694 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 695 void *priv_sta, struct ieee80211_tx_status *st) 696 { 697 struct ieee80211_tx_info *info = st->info; 698 struct minstrel_ht_sta_priv *msp = priv_sta; 699 struct minstrel_ht_sta *mi = &msp->ht; 700 struct ieee80211_tx_rate *ar = info->status.rates; 701 struct minstrel_rate_stats *rate, *rate2; 702 struct minstrel_priv *mp = priv; 703 bool last, update = false; 704 int i; 705 706 if (!msp->is_ht) 707 return mac80211_minstrel.tx_status_ext(priv, sband, 708 &msp->legacy, st); 709 710 /* This packet was aggregated but doesn't carry status info */ 711 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 712 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 713 return; 714 715 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 716 info->status.ampdu_ack_len = 717 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 718 info->status.ampdu_len = 1; 719 } 720 721 mi->ampdu_packets++; 722 mi->ampdu_len += info->status.ampdu_len; 723 724 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 725 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 726 727 mi->sample_wait = 16 + 2 * avg_ampdu_len; 728 mi->sample_tries = 1; 729 mi->sample_count--; 730 } 731 732 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 733 mi->sample_packets += info->status.ampdu_len; 734 735 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 736 for (i = 0; !last; i++) { 737 last = (i == IEEE80211_TX_MAX_RATES - 1) || 738 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 739 740 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 741 742 if (last) 743 rate->success += info->status.ampdu_ack_len; 744 745 rate->attempts += ar[i].count * info->status.ampdu_len; 746 } 747 748 /* 749 * check for sudden death of spatial multiplexing, 750 * downgrade to a lower number of streams if necessary. 751 */ 752 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 753 if (rate->attempts > 30 && 754 MINSTREL_FRAC(rate->success, rate->attempts) < 755 MINSTREL_FRAC(20, 100)) { 756 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 757 update = true; 758 } 759 760 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 761 if (rate2->attempts > 30 && 762 MINSTREL_FRAC(rate2->success, rate2->attempts) < 763 MINSTREL_FRAC(20, 100)) { 764 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 765 update = true; 766 } 767 768 if (time_after(jiffies, mi->last_stats_update + 769 (mp->update_interval / 2 * HZ) / 1000)) { 770 update = true; 771 minstrel_ht_update_stats(mp, mi); 772 } 773 774 if (update) 775 minstrel_ht_update_rates(mp, mi); 776 } 777 778 static inline int 779 minstrel_get_duration(int index) 780 { 781 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 782 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 783 return duration << group->shift; 784 } 785 786 static void 787 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 788 int index) 789 { 790 struct minstrel_rate_stats *mrs; 791 unsigned int tx_time, tx_time_rtscts, tx_time_data; 792 unsigned int cw = mp->cw_min; 793 unsigned int ctime = 0; 794 unsigned int t_slot = 9; /* FIXME */ 795 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 796 unsigned int overhead = 0, overhead_rtscts = 0; 797 798 mrs = minstrel_get_ratestats(mi, index); 799 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { 800 mrs->retry_count = 1; 801 mrs->retry_count_rtscts = 1; 802 return; 803 } 804 805 mrs->retry_count = 2; 806 mrs->retry_count_rtscts = 2; 807 mrs->retry_updated = true; 808 809 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 810 811 /* Contention time for first 2 tries */ 812 ctime = (t_slot * cw) >> 1; 813 cw = min((cw << 1) | 1, mp->cw_max); 814 ctime += (t_slot * cw) >> 1; 815 cw = min((cw << 1) | 1, mp->cw_max); 816 817 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 818 overhead = mi->overhead; 819 overhead_rtscts = mi->overhead_rtscts; 820 } 821 822 /* Total TX time for data and Contention after first 2 tries */ 823 tx_time = ctime + 2 * (overhead + tx_time_data); 824 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 825 826 /* See how many more tries we can fit inside segment size */ 827 do { 828 /* Contention time for this try */ 829 ctime = (t_slot * cw) >> 1; 830 cw = min((cw << 1) | 1, mp->cw_max); 831 832 /* Total TX time after this try */ 833 tx_time += ctime + overhead + tx_time_data; 834 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 835 836 if (tx_time_rtscts < mp->segment_size) 837 mrs->retry_count_rtscts++; 838 } while ((tx_time < mp->segment_size) && 839 (++mrs->retry_count < mp->max_retry)); 840 } 841 842 843 static void 844 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 845 struct ieee80211_sta_rates *ratetbl, int offset, int index) 846 { 847 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 848 struct minstrel_rate_stats *mrs; 849 u8 idx; 850 u16 flags = group->flags; 851 852 mrs = minstrel_get_ratestats(mi, index); 853 if (!mrs->retry_updated) 854 minstrel_calc_retransmit(mp, mi, index); 855 856 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 857 ratetbl->rate[offset].count = 2; 858 ratetbl->rate[offset].count_rts = 2; 859 ratetbl->rate[offset].count_cts = 2; 860 } else { 861 ratetbl->rate[offset].count = mrs->retry_count; 862 ratetbl->rate[offset].count_cts = mrs->retry_count; 863 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 864 } 865 866 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 867 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 868 else if (flags & IEEE80211_TX_RC_VHT_MCS) 869 idx = ((group->streams - 1) << 4) | 870 ((index % MCS_GROUP_RATES) & 0xF); 871 else 872 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 873 874 /* enable RTS/CTS if needed: 875 * - if station is in dynamic SMPS (and streams > 1) 876 * - for fallback rates, to increase chances of getting through 877 */ 878 if (offset > 0 || 879 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 880 group->streams > 1)) { 881 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 882 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 883 } 884 885 ratetbl->rate[offset].idx = idx; 886 ratetbl->rate[offset].flags = flags; 887 } 888 889 static inline int 890 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) 891 { 892 int group = rate / MCS_GROUP_RATES; 893 rate %= MCS_GROUP_RATES; 894 return mi->groups[group].rates[rate].prob_ewma; 895 } 896 897 static int 898 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 899 { 900 int group = mi->max_prob_rate / MCS_GROUP_RATES; 901 const struct mcs_group *g = &minstrel_mcs_groups[group]; 902 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 903 unsigned int duration; 904 905 /* Disable A-MSDU if max_prob_rate is bad */ 906 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) 907 return 1; 908 909 duration = g->duration[rate]; 910 duration <<= g->shift; 911 912 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 913 if (duration > MCS_DURATION(1, 0, 52)) 914 return 500; 915 916 /* 917 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 918 * data packet size 919 */ 920 if (duration > MCS_DURATION(1, 0, 104)) 921 return 1600; 922 923 /* 924 * If the rate is slower than single-stream MCS7, or if the max throughput 925 * rate success probability is less than 75%, limit A-MSDU to twice the usual 926 * data packet size 927 */ 928 if (duration > MCS_DURATION(1, 0, 260) || 929 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < 930 MINSTREL_FRAC(75, 100))) 931 return 3200; 932 933 /* 934 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 935 * Since aggregation sessions are started/stopped without txq flush, use 936 * the limit here to avoid the complexity of having to de-aggregate 937 * packets in the queue. 938 */ 939 if (!mi->sta->vht_cap.vht_supported) 940 return IEEE80211_MAX_MPDU_LEN_HT_BA; 941 942 /* unlimited */ 943 return 0; 944 } 945 946 static void 947 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 948 { 949 struct ieee80211_sta_rates *rates; 950 int i = 0; 951 952 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 953 if (!rates) 954 return; 955 956 /* Start with max_tp_rate[0] */ 957 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 958 959 if (mp->hw->max_rates >= 3) { 960 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 961 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 962 } 963 964 if (mp->hw->max_rates >= 2) { 965 /* 966 * At least 2 tx rates supported, use max_prob_rate next */ 967 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 968 } 969 970 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 971 rates->rate[i].idx = -1; 972 rate_control_set_rates(mp->hw, mi->sta, 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 (!(mi->supported[sample_group] & 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 * or if the rate is 3 times slower than the current max probability 1024 * rate, to avoid wasting airtime. 1025 */ 1026 sample_dur = minstrel_get_duration(sample_idx); 1027 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || 1028 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1029 return -1; 1030 1031 /* 1032 * Make sure that lower rates get sampled only occasionally, 1033 * if the link is working perfectly. 1034 */ 1035 1036 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1037 MCS_GROUP_RATES].streams; 1038 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1039 (cur_max_tp_streams - 1 < 1040 minstrel_mcs_groups[sample_group].streams || 1041 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1042 if (mrs->sample_skipped < 20) 1043 return -1; 1044 1045 if (mi->sample_slow++ > 2) 1046 return -1; 1047 } 1048 mi->sample_tries--; 1049 1050 return sample_idx; 1051 } 1052 1053 static void 1054 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1055 struct ieee80211_tx_rate_control *txrc) 1056 { 1057 const struct mcs_group *sample_group; 1058 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1059 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1060 struct minstrel_ht_sta_priv *msp = priv_sta; 1061 struct minstrel_ht_sta *mi = &msp->ht; 1062 struct minstrel_priv *mp = priv; 1063 int sample_idx; 1064 1065 if (rate_control_send_low(sta, priv_sta, txrc)) 1066 return; 1067 1068 if (!msp->is_ht) 1069 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1070 1071 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1072 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1073 minstrel_aggr_check(sta, txrc->skb); 1074 1075 info->flags |= mi->tx_flags; 1076 1077 #ifdef CONFIG_MAC80211_DEBUGFS 1078 if (mp->fixed_rate_idx != -1) 1079 return; 1080 #endif 1081 1082 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1083 if (mp->hw->max_rates == 1 && 1084 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1085 sample_idx = -1; 1086 else 1087 sample_idx = minstrel_get_sample_rate(mp, mi); 1088 1089 mi->total_packets++; 1090 1091 /* wraparound */ 1092 if (mi->total_packets == ~0) { 1093 mi->total_packets = 0; 1094 mi->sample_packets = 0; 1095 } 1096 1097 if (sample_idx < 0) 1098 return; 1099 1100 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1101 sample_idx %= MCS_GROUP_RATES; 1102 1103 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1104 (sample_idx >= 4) != txrc->short_preamble) 1105 return; 1106 1107 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1108 rate->count = 1; 1109 1110 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1111 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1112 rate->idx = mp->cck_rates[idx]; 1113 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1114 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1115 sample_group->streams); 1116 } else { 1117 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1118 } 1119 1120 rate->flags = sample_group->flags; 1121 } 1122 1123 static void 1124 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1125 struct ieee80211_supported_band *sband, 1126 struct ieee80211_sta *sta) 1127 { 1128 int i; 1129 1130 if (sband->band != NL80211_BAND_2GHZ) 1131 return; 1132 1133 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1134 return; 1135 1136 mi->cck_supported = 0; 1137 mi->cck_supported_short = 0; 1138 for (i = 0; i < 4; i++) { 1139 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1140 continue; 1141 1142 mi->cck_supported |= BIT(i); 1143 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1144 mi->cck_supported_short |= BIT(i); 1145 } 1146 1147 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1148 } 1149 1150 static void 1151 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1152 struct cfg80211_chan_def *chandef, 1153 struct ieee80211_sta *sta, void *priv_sta) 1154 { 1155 struct minstrel_priv *mp = priv; 1156 struct minstrel_ht_sta_priv *msp = priv_sta; 1157 struct minstrel_ht_sta *mi = &msp->ht; 1158 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1159 u16 ht_cap = sta->ht_cap.cap; 1160 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1161 int use_vht; 1162 int n_supported = 0; 1163 int ack_dur; 1164 int stbc; 1165 int i; 1166 bool ldpc; 1167 1168 /* fall back to the old minstrel for legacy stations */ 1169 if (!sta->ht_cap.ht_supported) 1170 goto use_legacy; 1171 1172 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1173 1174 if (vht_cap->vht_supported) 1175 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1176 else 1177 use_vht = 0; 1178 1179 msp->is_ht = true; 1180 memset(mi, 0, sizeof(*mi)); 1181 1182 mi->sta = sta; 1183 mi->last_stats_update = jiffies; 1184 1185 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1186 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1187 mi->overhead += ack_dur; 1188 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1189 1190 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1191 1192 /* When using MRR, sample more on the first attempt, without delay */ 1193 if (mp->has_mrr) { 1194 mi->sample_count = 16; 1195 mi->sample_wait = 0; 1196 } else { 1197 mi->sample_count = 8; 1198 mi->sample_wait = 8; 1199 } 1200 mi->sample_tries = 4; 1201 1202 if (!use_vht) { 1203 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1204 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1205 1206 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1207 } else { 1208 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1209 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1210 1211 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1212 } 1213 1214 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1215 if (ldpc) 1216 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1217 1218 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1219 u32 gflags = minstrel_mcs_groups[i].flags; 1220 int bw, nss; 1221 1222 mi->supported[i] = 0; 1223 if (i == MINSTREL_CCK_GROUP) { 1224 minstrel_ht_update_cck(mp, mi, sband, sta); 1225 continue; 1226 } 1227 1228 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1229 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1230 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1231 continue; 1232 } else { 1233 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1234 continue; 1235 } 1236 } 1237 1238 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1239 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1240 continue; 1241 1242 nss = minstrel_mcs_groups[i].streams; 1243 1244 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1245 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1246 continue; 1247 1248 /* HT rate */ 1249 if (gflags & IEEE80211_TX_RC_MCS) { 1250 if (use_vht && minstrel_vht_only) 1251 continue; 1252 1253 mi->supported[i] = mcs->rx_mask[nss - 1]; 1254 if (mi->supported[i]) 1255 n_supported++; 1256 continue; 1257 } 1258 1259 /* VHT rate */ 1260 if (!vht_cap->vht_supported || 1261 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1262 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1263 continue; 1264 1265 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1266 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1267 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1268 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1269 continue; 1270 } 1271 } 1272 1273 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1274 bw = BW_40; 1275 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1276 bw = BW_80; 1277 else 1278 bw = BW_20; 1279 1280 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1281 vht_cap->vht_mcs.tx_mcs_map); 1282 1283 if (mi->supported[i]) 1284 n_supported++; 1285 } 1286 1287 if (!n_supported) 1288 goto use_legacy; 1289 1290 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; 1291 1292 /* create an initial rate table with the lowest supported rates */ 1293 minstrel_ht_update_stats(mp, mi); 1294 minstrel_ht_update_rates(mp, mi); 1295 1296 return; 1297 1298 use_legacy: 1299 msp->is_ht = false; 1300 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1301 msp->legacy.r = msp->ratelist; 1302 msp->legacy.sample_table = msp->sample_table; 1303 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1304 &msp->legacy); 1305 } 1306 1307 static void 1308 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1309 struct cfg80211_chan_def *chandef, 1310 struct ieee80211_sta *sta, void *priv_sta) 1311 { 1312 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1313 } 1314 1315 static void 1316 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1317 struct cfg80211_chan_def *chandef, 1318 struct ieee80211_sta *sta, void *priv_sta, 1319 u32 changed) 1320 { 1321 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1322 } 1323 1324 static void * 1325 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1326 { 1327 struct ieee80211_supported_band *sband; 1328 struct minstrel_ht_sta_priv *msp; 1329 struct minstrel_priv *mp = priv; 1330 struct ieee80211_hw *hw = mp->hw; 1331 int max_rates = 0; 1332 int i; 1333 1334 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1335 sband = hw->wiphy->bands[i]; 1336 if (sband && sband->n_bitrates > max_rates) 1337 max_rates = sband->n_bitrates; 1338 } 1339 1340 msp = kzalloc(sizeof(*msp), gfp); 1341 if (!msp) 1342 return NULL; 1343 1344 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1345 if (!msp->ratelist) 1346 goto error; 1347 1348 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1349 if (!msp->sample_table) 1350 goto error1; 1351 1352 return msp; 1353 1354 error1: 1355 kfree(msp->ratelist); 1356 error: 1357 kfree(msp); 1358 return NULL; 1359 } 1360 1361 static void 1362 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1363 { 1364 struct minstrel_ht_sta_priv *msp = priv_sta; 1365 1366 kfree(msp->sample_table); 1367 kfree(msp->ratelist); 1368 kfree(msp); 1369 } 1370 1371 static void 1372 minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1373 { 1374 static const int bitrates[4] = { 10, 20, 55, 110 }; 1375 struct ieee80211_supported_band *sband; 1376 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1377 int i, j; 1378 1379 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1380 if (!sband) 1381 return; 1382 1383 for (i = 0; i < sband->n_bitrates; i++) { 1384 struct ieee80211_rate *rate = &sband->bitrates[i]; 1385 1386 if (rate->flags & IEEE80211_RATE_ERP_G) 1387 continue; 1388 1389 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1390 continue; 1391 1392 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 1393 if (rate->bitrate != bitrates[j]) 1394 continue; 1395 1396 mp->cck_rates[j] = i; 1397 break; 1398 } 1399 } 1400 } 1401 1402 static void * 1403 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1404 { 1405 struct minstrel_priv *mp; 1406 1407 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1408 if (!mp) 1409 return NULL; 1410 1411 /* contention window settings 1412 * Just an approximation. Using the per-queue values would complicate 1413 * the calculations and is probably unnecessary */ 1414 mp->cw_min = 15; 1415 mp->cw_max = 1023; 1416 1417 /* number of packets (in %) to use for sampling other rates 1418 * sample less often for non-mrr packets, because the overhead 1419 * is much higher than with mrr */ 1420 mp->lookaround_rate = 5; 1421 mp->lookaround_rate_mrr = 10; 1422 1423 /* maximum time that the hw is allowed to stay in one MRR segment */ 1424 mp->segment_size = 6000; 1425 1426 if (hw->max_rate_tries > 0) 1427 mp->max_retry = hw->max_rate_tries; 1428 else 1429 /* safe default, does not necessarily have to match hw properties */ 1430 mp->max_retry = 7; 1431 1432 if (hw->max_rates >= 4) 1433 mp->has_mrr = true; 1434 1435 mp->hw = hw; 1436 mp->update_interval = 100; 1437 1438 #ifdef CONFIG_MAC80211_DEBUGFS 1439 mp->fixed_rate_idx = (u32) -1; 1440 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1441 &mp->fixed_rate_idx); 1442 #endif 1443 1444 minstrel_ht_init_cck_rates(mp); 1445 1446 return mp; 1447 } 1448 1449 static void 1450 minstrel_ht_free(void *priv) 1451 { 1452 kfree(priv); 1453 } 1454 1455 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1456 { 1457 struct minstrel_ht_sta_priv *msp = priv_sta; 1458 struct minstrel_ht_sta *mi = &msp->ht; 1459 int i, j, prob, tp_avg; 1460 1461 if (!msp->is_ht) 1462 return mac80211_minstrel.get_expected_throughput(priv_sta); 1463 1464 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1465 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1466 prob = mi->groups[i].rates[j].prob_ewma; 1467 1468 /* convert tp_avg from pkt per second in kbps */ 1469 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1470 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1471 1472 return tp_avg; 1473 } 1474 1475 static const struct rate_control_ops mac80211_minstrel_ht = { 1476 .name = "minstrel_ht", 1477 .tx_status_ext = minstrel_ht_tx_status, 1478 .get_rate = minstrel_ht_get_rate, 1479 .rate_init = minstrel_ht_rate_init, 1480 .rate_update = minstrel_ht_rate_update, 1481 .alloc_sta = minstrel_ht_alloc_sta, 1482 .free_sta = minstrel_ht_free_sta, 1483 .alloc = minstrel_ht_alloc, 1484 .free = minstrel_ht_free, 1485 #ifdef CONFIG_MAC80211_DEBUGFS 1486 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1487 #endif 1488 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1489 }; 1490 1491 1492 static void __init init_sample_table(void) 1493 { 1494 int col, i, new_idx; 1495 u8 rnd[MCS_GROUP_RATES]; 1496 1497 memset(sample_table, 0xff, sizeof(sample_table)); 1498 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1499 prandom_bytes(rnd, sizeof(rnd)); 1500 for (i = 0; i < MCS_GROUP_RATES; i++) { 1501 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1502 while (sample_table[col][new_idx] != 0xff) 1503 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1504 1505 sample_table[col][new_idx] = i; 1506 } 1507 } 1508 } 1509 1510 int __init 1511 rc80211_minstrel_init(void) 1512 { 1513 init_sample_table(); 1514 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1515 } 1516 1517 void 1518 rc80211_minstrel_exit(void) 1519 { 1520 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1521 } 1522