1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org> 4 */ 5 #include <linux/netdevice.h> 6 #include <linux/types.h> 7 #include <linux/skbuff.h> 8 #include <linux/debugfs.h> 9 #include <linux/random.h> 10 #include <linux/moduleparam.h> 11 #include <linux/ieee80211.h> 12 #include <net/mac80211.h> 13 #include "rate.h" 14 #include "sta_info.h" 15 #include "rc80211_minstrel.h" 16 #include "rc80211_minstrel_ht.h" 17 18 #define AVG_AMPDU_SIZE 16 19 #define AVG_PKT_SIZE 1200 20 21 /* Number of bits for an average sized packet */ 22 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) 23 24 /* Number of symbols for a packet with (bps) bits per symbol */ 25 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) 26 27 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ 28 #define MCS_SYMBOL_TIME(sgi, syms) \ 29 (sgi ? \ 30 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ 31 ((syms) * 1000) << 2 /* syms * 4 us */ \ 32 ) 33 34 /* Transmit duration for the raw data part of an average sized packet */ 35 #define MCS_DURATION(streams, sgi, bps) \ 36 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE) 37 38 #define BW_20 0 39 #define BW_40 1 40 #define BW_80 2 41 42 /* 43 * Define group sort order: HT40 -> SGI -> #streams 44 */ 45 #define GROUP_IDX(_streams, _sgi, _ht40) \ 46 MINSTREL_HT_GROUP_0 + \ 47 MINSTREL_MAX_STREAMS * 2 * _ht40 + \ 48 MINSTREL_MAX_STREAMS * _sgi + \ 49 _streams - 1 50 51 #define _MAX(a, b) (((a)>(b))?(a):(b)) 52 53 #define GROUP_SHIFT(duration) \ 54 _MAX(0, 16 - __builtin_clz(duration)) 55 56 /* MCS rate information for an MCS group */ 57 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \ 58 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 59 .streams = _streams, \ 60 .shift = _s, \ 61 .flags = \ 62 IEEE80211_TX_RC_MCS | \ 63 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 64 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 65 .duration = { \ 66 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \ 67 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \ 68 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \ 69 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \ 70 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \ 71 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \ 72 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \ 73 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \ 74 } \ 75 } 76 77 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \ 78 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26)) 79 80 #define MCS_GROUP(_streams, _sgi, _ht40) \ 81 __MCS_GROUP(_streams, _sgi, _ht40, \ 82 MCS_GROUP_SHIFT(_streams, _sgi, _ht40)) 83 84 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 85 (MINSTREL_VHT_GROUP_0 + \ 86 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 87 MINSTREL_MAX_STREAMS * (_sgi) + \ 88 (_streams) - 1) 89 90 #define BW2VBPS(_bw, r3, r2, r1) \ 91 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 92 93 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \ 94 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 95 .streams = _streams, \ 96 .shift = _s, \ 97 .flags = \ 98 IEEE80211_TX_RC_VHT_MCS | \ 99 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 100 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 101 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 102 .duration = { \ 103 MCS_DURATION(_streams, _sgi, \ 104 BW2VBPS(_bw, 117, 54, 26)) >> _s, \ 105 MCS_DURATION(_streams, _sgi, \ 106 BW2VBPS(_bw, 234, 108, 52)) >> _s, \ 107 MCS_DURATION(_streams, _sgi, \ 108 BW2VBPS(_bw, 351, 162, 78)) >> _s, \ 109 MCS_DURATION(_streams, _sgi, \ 110 BW2VBPS(_bw, 468, 216, 104)) >> _s, \ 111 MCS_DURATION(_streams, _sgi, \ 112 BW2VBPS(_bw, 702, 324, 156)) >> _s, \ 113 MCS_DURATION(_streams, _sgi, \ 114 BW2VBPS(_bw, 936, 432, 208)) >> _s, \ 115 MCS_DURATION(_streams, _sgi, \ 116 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \ 117 MCS_DURATION(_streams, _sgi, \ 118 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \ 119 MCS_DURATION(_streams, _sgi, \ 120 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \ 121 MCS_DURATION(_streams, _sgi, \ 122 BW2VBPS(_bw, 1560, 720, 346)) >> _s \ 123 } \ 124 } 125 126 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \ 127 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \ 128 BW2VBPS(_bw, 117, 54, 26))) 129 130 #define VHT_GROUP(_streams, _sgi, _bw) \ 131 __VHT_GROUP(_streams, _sgi, _bw, \ 132 VHT_GROUP_SHIFT(_streams, _sgi, _bw)) 133 134 #define CCK_DURATION(_bitrate, _short, _len) \ 135 (1000 * (10 /* SIFS */ + \ 136 (_short ? 72 + 24 : 144 + 48) + \ 137 (8 * (_len + 4) * 10) / (_bitrate))) 138 139 #define CCK_ACK_DURATION(_bitrate, _short) \ 140 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 141 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 142 143 #define CCK_DURATION_LIST(_short, _s) \ 144 CCK_ACK_DURATION(10, _short) >> _s, \ 145 CCK_ACK_DURATION(20, _short) >> _s, \ 146 CCK_ACK_DURATION(55, _short) >> _s, \ 147 CCK_ACK_DURATION(110, _short) >> _s 148 149 #define __CCK_GROUP(_s) \ 150 [MINSTREL_CCK_GROUP] = { \ 151 .streams = 1, \ 152 .flags = 0, \ 153 .shift = _s, \ 154 .duration = { \ 155 CCK_DURATION_LIST(false, _s), \ 156 CCK_DURATION_LIST(true, _s) \ 157 } \ 158 } 159 160 #define CCK_GROUP_SHIFT \ 161 GROUP_SHIFT(CCK_ACK_DURATION(10, false)) 162 163 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) 164 165 166 static bool minstrel_vht_only = true; 167 module_param(minstrel_vht_only, bool, 0644); 168 MODULE_PARM_DESC(minstrel_vht_only, 169 "Use only VHT rates when VHT is supported by sta."); 170 171 /* 172 * To enable sufficiently targeted rate sampling, MCS rates are divided into 173 * groups, based on the number of streams and flags (HT40, SGI) that they 174 * use. 175 * 176 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 177 * BW -> SGI -> #streams 178 */ 179 const struct mcs_group minstrel_mcs_groups[] = { 180 MCS_GROUP(1, 0, BW_20), 181 MCS_GROUP(2, 0, BW_20), 182 MCS_GROUP(3, 0, BW_20), 183 MCS_GROUP(4, 0, BW_20), 184 185 MCS_GROUP(1, 1, BW_20), 186 MCS_GROUP(2, 1, BW_20), 187 MCS_GROUP(3, 1, BW_20), 188 MCS_GROUP(4, 1, BW_20), 189 190 MCS_GROUP(1, 0, BW_40), 191 MCS_GROUP(2, 0, BW_40), 192 MCS_GROUP(3, 0, BW_40), 193 MCS_GROUP(4, 0, BW_40), 194 195 MCS_GROUP(1, 1, BW_40), 196 MCS_GROUP(2, 1, BW_40), 197 MCS_GROUP(3, 1, BW_40), 198 MCS_GROUP(4, 1, BW_40), 199 200 CCK_GROUP, 201 202 VHT_GROUP(1, 0, BW_20), 203 VHT_GROUP(2, 0, BW_20), 204 VHT_GROUP(3, 0, BW_20), 205 VHT_GROUP(4, 0, BW_20), 206 207 VHT_GROUP(1, 1, BW_20), 208 VHT_GROUP(2, 1, BW_20), 209 VHT_GROUP(3, 1, BW_20), 210 VHT_GROUP(4, 1, BW_20), 211 212 VHT_GROUP(1, 0, BW_40), 213 VHT_GROUP(2, 0, BW_40), 214 VHT_GROUP(3, 0, BW_40), 215 VHT_GROUP(4, 0, BW_40), 216 217 VHT_GROUP(1, 1, BW_40), 218 VHT_GROUP(2, 1, BW_40), 219 VHT_GROUP(3, 1, BW_40), 220 VHT_GROUP(4, 1, BW_40), 221 222 VHT_GROUP(1, 0, BW_80), 223 VHT_GROUP(2, 0, BW_80), 224 VHT_GROUP(3, 0, BW_80), 225 VHT_GROUP(4, 0, BW_80), 226 227 VHT_GROUP(1, 1, BW_80), 228 VHT_GROUP(2, 1, BW_80), 229 VHT_GROUP(3, 1, BW_80), 230 VHT_GROUP(4, 1, BW_80), 231 }; 232 233 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 234 235 static void 236 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 237 238 /* 239 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 240 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 241 * 242 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 243 */ 244 static u16 245 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 246 { 247 u16 mask = 0; 248 249 if (bw == BW_20) { 250 if (nss != 3 && nss != 6) 251 mask = BIT(9); 252 } else if (bw == BW_80) { 253 if (nss == 3 || nss == 7) 254 mask = BIT(6); 255 else if (nss == 6) 256 mask = BIT(9); 257 } else { 258 WARN_ON(bw != BW_40); 259 } 260 261 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 262 case IEEE80211_VHT_MCS_SUPPORT_0_7: 263 mask |= 0x300; 264 break; 265 case IEEE80211_VHT_MCS_SUPPORT_0_8: 266 mask |= 0x200; 267 break; 268 case IEEE80211_VHT_MCS_SUPPORT_0_9: 269 break; 270 default: 271 mask = 0x3ff; 272 } 273 274 return 0x3ff & ~mask; 275 } 276 277 /* 278 * Look up an MCS group index based on mac80211 rate information 279 */ 280 static int 281 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 282 { 283 return GROUP_IDX((rate->idx / 8) + 1, 284 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 285 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 286 } 287 288 static int 289 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 290 { 291 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 292 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 293 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 294 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 295 } 296 297 static struct minstrel_rate_stats * 298 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 299 struct ieee80211_tx_rate *rate) 300 { 301 int group, idx; 302 303 if (rate->flags & IEEE80211_TX_RC_MCS) { 304 group = minstrel_ht_get_group_idx(rate); 305 idx = rate->idx % 8; 306 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 307 group = minstrel_vht_get_group_idx(rate); 308 idx = ieee80211_rate_get_vht_mcs(rate); 309 } else { 310 group = MINSTREL_CCK_GROUP; 311 312 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 313 if (rate->idx == mp->cck_rates[idx]) 314 break; 315 316 /* short preamble */ 317 if ((mi->supported[group] & BIT(idx + 4)) && 318 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) 319 idx += 4; 320 } 321 return &mi->groups[group].rates[idx]; 322 } 323 324 static inline struct minstrel_rate_stats * 325 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 326 { 327 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 328 } 329 330 static unsigned int 331 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 332 { 333 if (!mi->avg_ampdu_len) 334 return AVG_AMPDU_SIZE; 335 336 return MINSTREL_TRUNC(mi->avg_ampdu_len); 337 } 338 339 /* 340 * Return current throughput based on the average A-MPDU length, taking into 341 * account the expected number of retransmissions and their expected length 342 */ 343 int 344 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 345 int prob_ewma) 346 { 347 unsigned int nsecs = 0; 348 349 /* do not account throughput if sucess prob is below 10% */ 350 if (prob_ewma < MINSTREL_FRAC(10, 100)) 351 return 0; 352 353 if (group != MINSTREL_CCK_GROUP) 354 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi); 355 356 nsecs += minstrel_mcs_groups[group].duration[rate] << 357 minstrel_mcs_groups[group].shift; 358 359 /* 360 * For the throughput calculation, limit the probability value to 90% to 361 * account for collision related packet error rate fluctuation 362 * (prob is scaled - see MINSTREL_FRAC above) 363 */ 364 if (prob_ewma > MINSTREL_FRAC(90, 100)) 365 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 366 / nsecs)); 367 else 368 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); 369 } 370 371 /* 372 * Find & sort topmost throughput rates 373 * 374 * If multiple rates provide equal throughput the sorting is based on their 375 * current success probability. Higher success probability is preferred among 376 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 377 */ 378 static void 379 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 380 u16 *tp_list) 381 { 382 int cur_group, cur_idx, cur_tp_avg, cur_prob; 383 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 384 int j = MAX_THR_RATES; 385 386 cur_group = index / MCS_GROUP_RATES; 387 cur_idx = index % MCS_GROUP_RATES; 388 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; 389 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 390 391 do { 392 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 393 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 394 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 395 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 396 tmp_prob); 397 if (cur_tp_avg < tmp_tp_avg || 398 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 399 break; 400 j--; 401 } while (j > 0); 402 403 if (j < MAX_THR_RATES - 1) { 404 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 405 (MAX_THR_RATES - (j + 1)))); 406 } 407 if (j < MAX_THR_RATES) 408 tp_list[j] = index; 409 } 410 411 /* 412 * Find and set the topmost probability rate per sta and per group 413 */ 414 static void 415 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 416 { 417 struct minstrel_mcs_group_data *mg; 418 struct minstrel_rate_stats *mrs; 419 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 420 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 421 int max_gpr_group, max_gpr_idx; 422 int max_gpr_tp_avg, max_gpr_prob; 423 424 cur_group = index / MCS_GROUP_RATES; 425 cur_idx = index % MCS_GROUP_RATES; 426 mg = &mi->groups[index / MCS_GROUP_RATES]; 427 mrs = &mg->rates[index % MCS_GROUP_RATES]; 428 429 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 430 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 431 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 432 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 433 434 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 435 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 436 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 437 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 438 (max_tp_group != MINSTREL_CCK_GROUP)) 439 return; 440 441 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 442 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 443 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; 444 445 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { 446 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 447 mrs->prob_ewma); 448 if (cur_tp_avg > tmp_tp_avg) 449 mi->max_prob_rate = index; 450 451 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 452 max_gpr_idx, 453 max_gpr_prob); 454 if (cur_tp_avg > max_gpr_tp_avg) 455 mg->max_group_prob_rate = index; 456 } else { 457 if (mrs->prob_ewma > tmp_prob) 458 mi->max_prob_rate = index; 459 if (mrs->prob_ewma > max_gpr_prob) 460 mg->max_group_prob_rate = index; 461 } 462 } 463 464 465 /* 466 * Assign new rate set per sta and use CCK rates only if the fastest 467 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 468 * rate sets where MCS and CCK rates are mixed, because CCK rates can 469 * not use aggregation. 470 */ 471 static void 472 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 473 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 474 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 475 { 476 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 477 int i; 478 479 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 480 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 481 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 482 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 483 484 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 485 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 486 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 487 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 488 489 if (tmp_cck_tp > tmp_mcs_tp) { 490 for(i = 0; i < MAX_THR_RATES; i++) { 491 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 492 tmp_mcs_tp_rate); 493 } 494 } 495 496 } 497 498 /* 499 * Try to increase robustness of max_prob rate by decrease number of 500 * streams if possible. 501 */ 502 static inline void 503 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 504 { 505 struct minstrel_mcs_group_data *mg; 506 int tmp_max_streams, group, tmp_idx, tmp_prob; 507 int tmp_tp = 0; 508 509 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 510 MCS_GROUP_RATES].streams; 511 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 512 mg = &mi->groups[group]; 513 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 514 continue; 515 516 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 517 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; 518 519 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 520 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 521 mi->max_prob_rate = mg->max_group_prob_rate; 522 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 523 tmp_idx, 524 tmp_prob); 525 } 526 } 527 } 528 529 /* 530 * Update rate statistics and select new primary rates 531 * 532 * Rules for rate selection: 533 * - max_prob_rate must use only one stream, as a tradeoff between delivery 534 * probability and throughput during strong fluctuations 535 * - as long as the max prob rate has a probability of more than 75%, pick 536 * higher throughput rates, even if the probablity is a bit lower 537 */ 538 static void 539 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 540 { 541 struct minstrel_mcs_group_data *mg; 542 struct minstrel_rate_stats *mrs; 543 int group, i, j, cur_prob; 544 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 545 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 546 547 if (mi->ampdu_packets > 0) { 548 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 549 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 550 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 551 EWMA_LEVEL); 552 else 553 mi->avg_ampdu_len = 0; 554 mi->ampdu_len = 0; 555 mi->ampdu_packets = 0; 556 } 557 558 mi->sample_slow = 0; 559 mi->sample_count = 0; 560 561 /* Initialize global rate indexes */ 562 for(j = 0; j < MAX_THR_RATES; j++){ 563 tmp_mcs_tp_rate[j] = 0; 564 tmp_cck_tp_rate[j] = 0; 565 } 566 567 /* Find best rate sets within all MCS groups*/ 568 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 569 570 mg = &mi->groups[group]; 571 if (!mi->supported[group]) 572 continue; 573 574 mi->sample_count++; 575 576 /* (re)Initialize group rate indexes */ 577 for(j = 0; j < MAX_THR_RATES; j++) 578 tmp_group_tp_rate[j] = group; 579 580 for (i = 0; i < MCS_GROUP_RATES; i++) { 581 if (!(mi->supported[group] & BIT(i))) 582 continue; 583 584 index = MCS_GROUP_RATES * group + i; 585 586 mrs = &mg->rates[i]; 587 mrs->retry_updated = false; 588 minstrel_calc_rate_stats(mrs); 589 cur_prob = mrs->prob_ewma; 590 591 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 592 continue; 593 594 /* Find max throughput rate set */ 595 if (group != MINSTREL_CCK_GROUP) { 596 minstrel_ht_sort_best_tp_rates(mi, index, 597 tmp_mcs_tp_rate); 598 } else if (group == MINSTREL_CCK_GROUP) { 599 minstrel_ht_sort_best_tp_rates(mi, index, 600 tmp_cck_tp_rate); 601 } 602 603 /* Find max throughput rate set within a group */ 604 minstrel_ht_sort_best_tp_rates(mi, index, 605 tmp_group_tp_rate); 606 607 /* Find max probability rate per group and global */ 608 minstrel_ht_set_best_prob_rate(mi, index); 609 } 610 611 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 612 sizeof(mg->max_group_tp_rate)); 613 } 614 615 /* Assign new rate set per sta */ 616 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 617 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 618 619 /* Try to increase robustness of max_prob_rate*/ 620 minstrel_ht_prob_rate_reduce_streams(mi); 621 622 /* try to sample all available rates during each interval */ 623 mi->sample_count *= 8; 624 625 #ifdef CONFIG_MAC80211_DEBUGFS 626 /* use fixed index if set */ 627 if (mp->fixed_rate_idx != -1) { 628 for (i = 0; i < 4; i++) 629 mi->max_tp_rate[i] = mp->fixed_rate_idx; 630 mi->max_prob_rate = mp->fixed_rate_idx; 631 } 632 #endif 633 634 /* Reset update timer */ 635 mi->last_stats_update = jiffies; 636 } 637 638 static bool 639 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 640 { 641 if (rate->idx < 0) 642 return false; 643 644 if (!rate->count) 645 return false; 646 647 if (rate->flags & IEEE80211_TX_RC_MCS || 648 rate->flags & IEEE80211_TX_RC_VHT_MCS) 649 return true; 650 651 return rate->idx == mp->cck_rates[0] || 652 rate->idx == mp->cck_rates[1] || 653 rate->idx == mp->cck_rates[2] || 654 rate->idx == mp->cck_rates[3]; 655 } 656 657 static void 658 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 659 { 660 struct minstrel_mcs_group_data *mg; 661 662 for (;;) { 663 mi->sample_group++; 664 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 665 mg = &mi->groups[mi->sample_group]; 666 667 if (!mi->supported[mi->sample_group]) 668 continue; 669 670 if (++mg->index >= MCS_GROUP_RATES) { 671 mg->index = 0; 672 if (++mg->column >= ARRAY_SIZE(sample_table)) 673 mg->column = 0; 674 } 675 break; 676 } 677 } 678 679 static void 680 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 681 { 682 int group, orig_group; 683 684 orig_group = group = *idx / MCS_GROUP_RATES; 685 while (group > 0) { 686 group--; 687 688 if (!mi->supported[group]) 689 continue; 690 691 if (minstrel_mcs_groups[group].streams > 692 minstrel_mcs_groups[orig_group].streams) 693 continue; 694 695 if (primary) 696 *idx = mi->groups[group].max_group_tp_rate[0]; 697 else 698 *idx = mi->groups[group].max_group_tp_rate[1]; 699 break; 700 } 701 } 702 703 static void 704 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 705 { 706 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 707 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 708 u16 tid; 709 710 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 711 return; 712 713 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 714 return; 715 716 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 717 return; 718 719 tid = ieee80211_get_tid(hdr); 720 if (likely(sta->ampdu_mlme.tid_tx[tid])) 721 return; 722 723 ieee80211_start_tx_ba_session(pubsta, tid, 0); 724 } 725 726 static void 727 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 728 void *priv_sta, struct ieee80211_tx_status *st) 729 { 730 struct ieee80211_tx_info *info = st->info; 731 struct minstrel_ht_sta_priv *msp = priv_sta; 732 struct minstrel_ht_sta *mi = &msp->ht; 733 struct ieee80211_tx_rate *ar = info->status.rates; 734 struct minstrel_rate_stats *rate, *rate2; 735 struct minstrel_priv *mp = priv; 736 bool last, update = false; 737 int i; 738 739 if (!msp->is_ht) 740 return mac80211_minstrel.tx_status_ext(priv, sband, 741 &msp->legacy, st); 742 743 /* This packet was aggregated but doesn't carry status info */ 744 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 745 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 746 return; 747 748 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 749 info->status.ampdu_ack_len = 750 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 751 info->status.ampdu_len = 1; 752 } 753 754 mi->ampdu_packets++; 755 mi->ampdu_len += info->status.ampdu_len; 756 757 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 758 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 759 760 mi->sample_wait = 16 + 2 * avg_ampdu_len; 761 mi->sample_tries = 1; 762 mi->sample_count--; 763 } 764 765 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 766 mi->sample_packets += info->status.ampdu_len; 767 768 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 769 for (i = 0; !last; i++) { 770 last = (i == IEEE80211_TX_MAX_RATES - 1) || 771 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 772 773 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 774 775 if (last) 776 rate->success += info->status.ampdu_ack_len; 777 778 rate->attempts += ar[i].count * info->status.ampdu_len; 779 } 780 781 /* 782 * check for sudden death of spatial multiplexing, 783 * downgrade to a lower number of streams if necessary. 784 */ 785 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 786 if (rate->attempts > 30 && 787 MINSTREL_FRAC(rate->success, rate->attempts) < 788 MINSTREL_FRAC(20, 100)) { 789 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 790 update = true; 791 } 792 793 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 794 if (rate2->attempts > 30 && 795 MINSTREL_FRAC(rate2->success, rate2->attempts) < 796 MINSTREL_FRAC(20, 100)) { 797 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 798 update = true; 799 } 800 801 if (time_after(jiffies, mi->last_stats_update + 802 (mp->update_interval / 2 * HZ) / 1000)) { 803 update = true; 804 minstrel_ht_update_stats(mp, mi); 805 } 806 807 if (update) 808 minstrel_ht_update_rates(mp, mi); 809 } 810 811 static inline int 812 minstrel_get_duration(int index) 813 { 814 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 815 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 816 return duration << group->shift; 817 } 818 819 static void 820 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 821 int index) 822 { 823 struct minstrel_rate_stats *mrs; 824 unsigned int tx_time, tx_time_rtscts, tx_time_data; 825 unsigned int cw = mp->cw_min; 826 unsigned int ctime = 0; 827 unsigned int t_slot = 9; /* FIXME */ 828 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 829 unsigned int overhead = 0, overhead_rtscts = 0; 830 831 mrs = minstrel_get_ratestats(mi, index); 832 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { 833 mrs->retry_count = 1; 834 mrs->retry_count_rtscts = 1; 835 return; 836 } 837 838 mrs->retry_count = 2; 839 mrs->retry_count_rtscts = 2; 840 mrs->retry_updated = true; 841 842 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 843 844 /* Contention time for first 2 tries */ 845 ctime = (t_slot * cw) >> 1; 846 cw = min((cw << 1) | 1, mp->cw_max); 847 ctime += (t_slot * cw) >> 1; 848 cw = min((cw << 1) | 1, mp->cw_max); 849 850 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 851 overhead = mi->overhead; 852 overhead_rtscts = mi->overhead_rtscts; 853 } 854 855 /* Total TX time for data and Contention after first 2 tries */ 856 tx_time = ctime + 2 * (overhead + tx_time_data); 857 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 858 859 /* See how many more tries we can fit inside segment size */ 860 do { 861 /* Contention time for this try */ 862 ctime = (t_slot * cw) >> 1; 863 cw = min((cw << 1) | 1, mp->cw_max); 864 865 /* Total TX time after this try */ 866 tx_time += ctime + overhead + tx_time_data; 867 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 868 869 if (tx_time_rtscts < mp->segment_size) 870 mrs->retry_count_rtscts++; 871 } while ((tx_time < mp->segment_size) && 872 (++mrs->retry_count < mp->max_retry)); 873 } 874 875 876 static void 877 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 878 struct ieee80211_sta_rates *ratetbl, int offset, int index) 879 { 880 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 881 struct minstrel_rate_stats *mrs; 882 u8 idx; 883 u16 flags = group->flags; 884 885 mrs = minstrel_get_ratestats(mi, index); 886 if (!mrs->retry_updated) 887 minstrel_calc_retransmit(mp, mi, index); 888 889 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 890 ratetbl->rate[offset].count = 2; 891 ratetbl->rate[offset].count_rts = 2; 892 ratetbl->rate[offset].count_cts = 2; 893 } else { 894 ratetbl->rate[offset].count = mrs->retry_count; 895 ratetbl->rate[offset].count_cts = mrs->retry_count; 896 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 897 } 898 899 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 900 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 901 else if (flags & IEEE80211_TX_RC_VHT_MCS) 902 idx = ((group->streams - 1) << 4) | 903 ((index % MCS_GROUP_RATES) & 0xF); 904 else 905 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 906 907 /* enable RTS/CTS if needed: 908 * - if station is in dynamic SMPS (and streams > 1) 909 * - for fallback rates, to increase chances of getting through 910 */ 911 if (offset > 0 || 912 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 913 group->streams > 1)) { 914 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 915 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 916 } 917 918 ratetbl->rate[offset].idx = idx; 919 ratetbl->rate[offset].flags = flags; 920 } 921 922 static inline int 923 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) 924 { 925 int group = rate / MCS_GROUP_RATES; 926 rate %= MCS_GROUP_RATES; 927 return mi->groups[group].rates[rate].prob_ewma; 928 } 929 930 static int 931 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 932 { 933 int group = mi->max_prob_rate / MCS_GROUP_RATES; 934 const struct mcs_group *g = &minstrel_mcs_groups[group]; 935 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 936 unsigned int duration; 937 938 /* Disable A-MSDU if max_prob_rate is bad */ 939 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) 940 return 1; 941 942 duration = g->duration[rate]; 943 duration <<= g->shift; 944 945 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 946 if (duration > MCS_DURATION(1, 0, 52)) 947 return 500; 948 949 /* 950 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 951 * data packet size 952 */ 953 if (duration > MCS_DURATION(1, 0, 104)) 954 return 1600; 955 956 /* 957 * If the rate is slower than single-stream MCS7, or if the max throughput 958 * rate success probability is less than 75%, limit A-MSDU to twice the usual 959 * data packet size 960 */ 961 if (duration > MCS_DURATION(1, 0, 260) || 962 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < 963 MINSTREL_FRAC(75, 100))) 964 return 3200; 965 966 /* 967 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 968 * Since aggregation sessions are started/stopped without txq flush, use 969 * the limit here to avoid the complexity of having to de-aggregate 970 * packets in the queue. 971 */ 972 if (!mi->sta->vht_cap.vht_supported) 973 return IEEE80211_MAX_MPDU_LEN_HT_BA; 974 975 /* unlimited */ 976 return 0; 977 } 978 979 static void 980 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 981 { 982 struct ieee80211_sta_rates *rates; 983 int i = 0; 984 985 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 986 if (!rates) 987 return; 988 989 /* Start with max_tp_rate[0] */ 990 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 991 992 if (mp->hw->max_rates >= 3) { 993 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 994 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 995 } 996 997 if (mp->hw->max_rates >= 2) { 998 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 999 } 1000 1001 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 1002 rates->rate[i].idx = -1; 1003 rate_control_set_rates(mp->hw, mi->sta, rates); 1004 } 1005 1006 static int 1007 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1008 { 1009 struct minstrel_rate_stats *mrs; 1010 struct minstrel_mcs_group_data *mg; 1011 unsigned int sample_dur, sample_group, cur_max_tp_streams; 1012 int tp_rate1, tp_rate2; 1013 int sample_idx = 0; 1014 1015 if (mi->sample_wait > 0) { 1016 mi->sample_wait--; 1017 return -1; 1018 } 1019 1020 if (!mi->sample_tries) 1021 return -1; 1022 1023 sample_group = mi->sample_group; 1024 mg = &mi->groups[sample_group]; 1025 sample_idx = sample_table[mg->column][mg->index]; 1026 minstrel_set_next_sample_idx(mi); 1027 1028 if (!(mi->supported[sample_group] & BIT(sample_idx))) 1029 return -1; 1030 1031 mrs = &mg->rates[sample_idx]; 1032 sample_idx += sample_group * MCS_GROUP_RATES; 1033 1034 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 1035 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1036 minstrel_get_duration(mi->max_tp_rate[1])) { 1037 tp_rate1 = mi->max_tp_rate[1]; 1038 tp_rate2 = mi->max_tp_rate[0]; 1039 } else { 1040 tp_rate1 = mi->max_tp_rate[0]; 1041 tp_rate2 = mi->max_tp_rate[1]; 1042 } 1043 1044 /* 1045 * Sampling might add some overhead (RTS, no aggregation) 1046 * to the frame. Hence, don't use sampling for the highest currently 1047 * used highest throughput or probability rate. 1048 */ 1049 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1050 return -1; 1051 1052 /* 1053 * Do not sample if the probability is already higher than 95%, 1054 * or if the rate is 3 times slower than the current max probability 1055 * rate, to avoid wasting airtime. 1056 */ 1057 sample_dur = minstrel_get_duration(sample_idx); 1058 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || 1059 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1060 return -1; 1061 1062 /* 1063 * Make sure that lower rates get sampled only occasionally, 1064 * if the link is working perfectly. 1065 */ 1066 1067 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1068 MCS_GROUP_RATES].streams; 1069 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1070 (cur_max_tp_streams - 1 < 1071 minstrel_mcs_groups[sample_group].streams || 1072 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1073 if (mrs->sample_skipped < 20) 1074 return -1; 1075 1076 if (mi->sample_slow++ > 2) 1077 return -1; 1078 } 1079 mi->sample_tries--; 1080 1081 return sample_idx; 1082 } 1083 1084 static void 1085 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1086 struct ieee80211_tx_rate_control *txrc) 1087 { 1088 const struct mcs_group *sample_group; 1089 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1090 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1091 struct minstrel_ht_sta_priv *msp = priv_sta; 1092 struct minstrel_ht_sta *mi = &msp->ht; 1093 struct minstrel_priv *mp = priv; 1094 int sample_idx; 1095 1096 if (!msp->is_ht) 1097 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1098 1099 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1100 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1101 minstrel_aggr_check(sta, txrc->skb); 1102 1103 info->flags |= mi->tx_flags; 1104 1105 #ifdef CONFIG_MAC80211_DEBUGFS 1106 if (mp->fixed_rate_idx != -1) 1107 return; 1108 #endif 1109 1110 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1111 if (mp->hw->max_rates == 1 && 1112 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1113 sample_idx = -1; 1114 else 1115 sample_idx = minstrel_get_sample_rate(mp, mi); 1116 1117 mi->total_packets++; 1118 1119 /* wraparound */ 1120 if (mi->total_packets == ~0) { 1121 mi->total_packets = 0; 1122 mi->sample_packets = 0; 1123 } 1124 1125 if (sample_idx < 0) 1126 return; 1127 1128 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1129 sample_idx %= MCS_GROUP_RATES; 1130 1131 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1132 (sample_idx >= 4) != txrc->short_preamble) 1133 return; 1134 1135 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1136 rate->count = 1; 1137 1138 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1139 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1140 rate->idx = mp->cck_rates[idx]; 1141 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1142 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1143 sample_group->streams); 1144 } else { 1145 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1146 } 1147 1148 rate->flags = sample_group->flags; 1149 } 1150 1151 static void 1152 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1153 struct ieee80211_supported_band *sband, 1154 struct ieee80211_sta *sta) 1155 { 1156 int i; 1157 1158 if (sband->band != NL80211_BAND_2GHZ) 1159 return; 1160 1161 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1162 return; 1163 1164 mi->cck_supported = 0; 1165 mi->cck_supported_short = 0; 1166 for (i = 0; i < 4; i++) { 1167 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1168 continue; 1169 1170 mi->cck_supported |= BIT(i); 1171 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1172 mi->cck_supported_short |= BIT(i); 1173 } 1174 1175 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1176 } 1177 1178 static void 1179 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1180 struct cfg80211_chan_def *chandef, 1181 struct ieee80211_sta *sta, void *priv_sta) 1182 { 1183 struct minstrel_priv *mp = priv; 1184 struct minstrel_ht_sta_priv *msp = priv_sta; 1185 struct minstrel_ht_sta *mi = &msp->ht; 1186 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1187 u16 ht_cap = sta->ht_cap.cap; 1188 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1189 int use_vht; 1190 int n_supported = 0; 1191 int ack_dur; 1192 int stbc; 1193 int i; 1194 bool ldpc; 1195 1196 /* fall back to the old minstrel for legacy stations */ 1197 if (!sta->ht_cap.ht_supported) 1198 goto use_legacy; 1199 1200 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1201 1202 if (vht_cap->vht_supported) 1203 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1204 else 1205 use_vht = 0; 1206 1207 msp->is_ht = true; 1208 memset(mi, 0, sizeof(*mi)); 1209 1210 mi->sta = sta; 1211 mi->last_stats_update = jiffies; 1212 1213 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1214 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1215 mi->overhead += ack_dur; 1216 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1217 1218 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1219 1220 /* When using MRR, sample more on the first attempt, without delay */ 1221 if (mp->has_mrr) { 1222 mi->sample_count = 16; 1223 mi->sample_wait = 0; 1224 } else { 1225 mi->sample_count = 8; 1226 mi->sample_wait = 8; 1227 } 1228 mi->sample_tries = 4; 1229 1230 if (!use_vht) { 1231 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1232 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1233 1234 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1235 } else { 1236 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1237 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1238 1239 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1240 } 1241 1242 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1243 if (ldpc) 1244 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1245 1246 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1247 u32 gflags = minstrel_mcs_groups[i].flags; 1248 int bw, nss; 1249 1250 mi->supported[i] = 0; 1251 if (i == MINSTREL_CCK_GROUP) { 1252 minstrel_ht_update_cck(mp, mi, sband, sta); 1253 continue; 1254 } 1255 1256 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1257 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1258 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1259 continue; 1260 } else { 1261 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1262 continue; 1263 } 1264 } 1265 1266 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1267 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1268 continue; 1269 1270 nss = minstrel_mcs_groups[i].streams; 1271 1272 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1273 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1274 continue; 1275 1276 /* HT rate */ 1277 if (gflags & IEEE80211_TX_RC_MCS) { 1278 if (use_vht && minstrel_vht_only) 1279 continue; 1280 1281 mi->supported[i] = mcs->rx_mask[nss - 1]; 1282 if (mi->supported[i]) 1283 n_supported++; 1284 continue; 1285 } 1286 1287 /* VHT rate */ 1288 if (!vht_cap->vht_supported || 1289 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1290 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1291 continue; 1292 1293 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1294 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1295 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1296 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1297 continue; 1298 } 1299 } 1300 1301 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1302 bw = BW_40; 1303 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1304 bw = BW_80; 1305 else 1306 bw = BW_20; 1307 1308 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1309 vht_cap->vht_mcs.tx_mcs_map); 1310 1311 if (mi->supported[i]) 1312 n_supported++; 1313 } 1314 1315 if (!n_supported) 1316 goto use_legacy; 1317 1318 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; 1319 1320 /* create an initial rate table with the lowest supported rates */ 1321 minstrel_ht_update_stats(mp, mi); 1322 minstrel_ht_update_rates(mp, mi); 1323 1324 return; 1325 1326 use_legacy: 1327 msp->is_ht = false; 1328 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1329 msp->legacy.r = msp->ratelist; 1330 msp->legacy.sample_table = msp->sample_table; 1331 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1332 &msp->legacy); 1333 } 1334 1335 static void 1336 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1337 struct cfg80211_chan_def *chandef, 1338 struct ieee80211_sta *sta, void *priv_sta) 1339 { 1340 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1341 } 1342 1343 static void 1344 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1345 struct cfg80211_chan_def *chandef, 1346 struct ieee80211_sta *sta, void *priv_sta, 1347 u32 changed) 1348 { 1349 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1350 } 1351 1352 static void * 1353 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1354 { 1355 struct ieee80211_supported_band *sband; 1356 struct minstrel_ht_sta_priv *msp; 1357 struct minstrel_priv *mp = priv; 1358 struct ieee80211_hw *hw = mp->hw; 1359 int max_rates = 0; 1360 int i; 1361 1362 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1363 sband = hw->wiphy->bands[i]; 1364 if (sband && sband->n_bitrates > max_rates) 1365 max_rates = sband->n_bitrates; 1366 } 1367 1368 msp = kzalloc(sizeof(*msp), gfp); 1369 if (!msp) 1370 return NULL; 1371 1372 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1373 if (!msp->ratelist) 1374 goto error; 1375 1376 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1377 if (!msp->sample_table) 1378 goto error1; 1379 1380 return msp; 1381 1382 error1: 1383 kfree(msp->ratelist); 1384 error: 1385 kfree(msp); 1386 return NULL; 1387 } 1388 1389 static void 1390 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1391 { 1392 struct minstrel_ht_sta_priv *msp = priv_sta; 1393 1394 kfree(msp->sample_table); 1395 kfree(msp->ratelist); 1396 kfree(msp); 1397 } 1398 1399 static void 1400 minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1401 { 1402 static const int bitrates[4] = { 10, 20, 55, 110 }; 1403 struct ieee80211_supported_band *sband; 1404 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1405 int i, j; 1406 1407 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1408 if (!sband) 1409 return; 1410 1411 for (i = 0; i < sband->n_bitrates; i++) { 1412 struct ieee80211_rate *rate = &sband->bitrates[i]; 1413 1414 if (rate->flags & IEEE80211_RATE_ERP_G) 1415 continue; 1416 1417 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1418 continue; 1419 1420 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 1421 if (rate->bitrate != bitrates[j]) 1422 continue; 1423 1424 mp->cck_rates[j] = i; 1425 break; 1426 } 1427 } 1428 } 1429 1430 static void * 1431 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1432 { 1433 struct minstrel_priv *mp; 1434 1435 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1436 if (!mp) 1437 return NULL; 1438 1439 /* contention window settings 1440 * Just an approximation. Using the per-queue values would complicate 1441 * the calculations and is probably unnecessary */ 1442 mp->cw_min = 15; 1443 mp->cw_max = 1023; 1444 1445 /* number of packets (in %) to use for sampling other rates 1446 * sample less often for non-mrr packets, because the overhead 1447 * is much higher than with mrr */ 1448 mp->lookaround_rate = 5; 1449 mp->lookaround_rate_mrr = 10; 1450 1451 /* maximum time that the hw is allowed to stay in one MRR segment */ 1452 mp->segment_size = 6000; 1453 1454 if (hw->max_rate_tries > 0) 1455 mp->max_retry = hw->max_rate_tries; 1456 else 1457 /* safe default, does not necessarily have to match hw properties */ 1458 mp->max_retry = 7; 1459 1460 if (hw->max_rates >= 4) 1461 mp->has_mrr = true; 1462 1463 mp->hw = hw; 1464 mp->update_interval = 100; 1465 1466 #ifdef CONFIG_MAC80211_DEBUGFS 1467 mp->fixed_rate_idx = (u32) -1; 1468 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1469 &mp->fixed_rate_idx); 1470 #endif 1471 1472 minstrel_ht_init_cck_rates(mp); 1473 1474 return mp; 1475 } 1476 1477 static void 1478 minstrel_ht_free(void *priv) 1479 { 1480 kfree(priv); 1481 } 1482 1483 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1484 { 1485 struct minstrel_ht_sta_priv *msp = priv_sta; 1486 struct minstrel_ht_sta *mi = &msp->ht; 1487 int i, j, prob, tp_avg; 1488 1489 if (!msp->is_ht) 1490 return mac80211_minstrel.get_expected_throughput(priv_sta); 1491 1492 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1493 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1494 prob = mi->groups[i].rates[j].prob_ewma; 1495 1496 /* convert tp_avg from pkt per second in kbps */ 1497 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1498 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1499 1500 return tp_avg; 1501 } 1502 1503 static const struct rate_control_ops mac80211_minstrel_ht = { 1504 .name = "minstrel_ht", 1505 .tx_status_ext = minstrel_ht_tx_status, 1506 .get_rate = minstrel_ht_get_rate, 1507 .rate_init = minstrel_ht_rate_init, 1508 .rate_update = minstrel_ht_rate_update, 1509 .alloc_sta = minstrel_ht_alloc_sta, 1510 .free_sta = minstrel_ht_free_sta, 1511 .alloc = minstrel_ht_alloc, 1512 .free = minstrel_ht_free, 1513 #ifdef CONFIG_MAC80211_DEBUGFS 1514 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1515 #endif 1516 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1517 }; 1518 1519 1520 static void __init init_sample_table(void) 1521 { 1522 int col, i, new_idx; 1523 u8 rnd[MCS_GROUP_RATES]; 1524 1525 memset(sample_table, 0xff, sizeof(sample_table)); 1526 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1527 prandom_bytes(rnd, sizeof(rnd)); 1528 for (i = 0; i < MCS_GROUP_RATES; i++) { 1529 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1530 while (sample_table[col][new_idx] != 0xff) 1531 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1532 1533 sample_table[col][new_idx] = i; 1534 } 1535 } 1536 } 1537 1538 int __init 1539 rc80211_minstrel_init(void) 1540 { 1541 init_sample_table(); 1542 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1543 } 1544 1545 void 1546 rc80211_minstrel_exit(void) 1547 { 1548 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1549 } 1550