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 #define _MAX(a, b) (((a)>(b))?(a):(b)) 55 56 #define GROUP_SHIFT(duration) \ 57 _MAX(0, 16 - __builtin_clz(duration)) 58 59 /* MCS rate information for an MCS group */ 60 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \ 61 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 62 .streams = _streams, \ 63 .shift = _s, \ 64 .flags = \ 65 IEEE80211_TX_RC_MCS | \ 66 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 67 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 68 .duration = { \ 69 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \ 70 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \ 71 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \ 72 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \ 73 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \ 74 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \ 75 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \ 76 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \ 77 } \ 78 } 79 80 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \ 81 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26)) 82 83 #define MCS_GROUP(_streams, _sgi, _ht40) \ 84 __MCS_GROUP(_streams, _sgi, _ht40, \ 85 MCS_GROUP_SHIFT(_streams, _sgi, _ht40)) 86 87 #define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 88 (MINSTREL_VHT_GROUP_0 + \ 89 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 90 MINSTREL_MAX_STREAMS * (_sgi) + \ 91 (_streams) - 1) 92 93 #define BW2VBPS(_bw, r3, r2, r1) \ 94 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 95 96 #define __VHT_GROUP(_streams, _sgi, _bw, _s) \ 97 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 98 .streams = _streams, \ 99 .shift = _s, \ 100 .flags = \ 101 IEEE80211_TX_RC_VHT_MCS | \ 102 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 103 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 104 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 105 .duration = { \ 106 MCS_DURATION(_streams, _sgi, \ 107 BW2VBPS(_bw, 117, 54, 26)) >> _s, \ 108 MCS_DURATION(_streams, _sgi, \ 109 BW2VBPS(_bw, 234, 108, 52)) >> _s, \ 110 MCS_DURATION(_streams, _sgi, \ 111 BW2VBPS(_bw, 351, 162, 78)) >> _s, \ 112 MCS_DURATION(_streams, _sgi, \ 113 BW2VBPS(_bw, 468, 216, 104)) >> _s, \ 114 MCS_DURATION(_streams, _sgi, \ 115 BW2VBPS(_bw, 702, 324, 156)) >> _s, \ 116 MCS_DURATION(_streams, _sgi, \ 117 BW2VBPS(_bw, 936, 432, 208)) >> _s, \ 118 MCS_DURATION(_streams, _sgi, \ 119 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \ 120 MCS_DURATION(_streams, _sgi, \ 121 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \ 122 MCS_DURATION(_streams, _sgi, \ 123 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \ 124 MCS_DURATION(_streams, _sgi, \ 125 BW2VBPS(_bw, 1560, 720, 346)) >> _s \ 126 } \ 127 } 128 129 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \ 130 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \ 131 BW2VBPS(_bw, 117, 54, 26))) 132 133 #define VHT_GROUP(_streams, _sgi, _bw) \ 134 __VHT_GROUP(_streams, _sgi, _bw, \ 135 VHT_GROUP_SHIFT(_streams, _sgi, _bw)) 136 137 #define CCK_DURATION(_bitrate, _short, _len) \ 138 (1000 * (10 /* SIFS */ + \ 139 (_short ? 72 + 24 : 144 + 48) + \ 140 (8 * (_len + 4) * 10) / (_bitrate))) 141 142 #define CCK_ACK_DURATION(_bitrate, _short) \ 143 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 144 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 145 146 #define CCK_DURATION_LIST(_short, _s) \ 147 CCK_ACK_DURATION(10, _short) >> _s, \ 148 CCK_ACK_DURATION(20, _short) >> _s, \ 149 CCK_ACK_DURATION(55, _short) >> _s, \ 150 CCK_ACK_DURATION(110, _short) >> _s 151 152 #define __CCK_GROUP(_s) \ 153 [MINSTREL_CCK_GROUP] = { \ 154 .streams = 1, \ 155 .flags = 0, \ 156 .shift = _s, \ 157 .duration = { \ 158 CCK_DURATION_LIST(false, _s), \ 159 CCK_DURATION_LIST(true, _s) \ 160 } \ 161 } 162 163 #define CCK_GROUP_SHIFT \ 164 GROUP_SHIFT(CCK_ACK_DURATION(10, false)) 165 166 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) 167 168 169 static bool minstrel_vht_only = true; 170 module_param(minstrel_vht_only, bool, 0644); 171 MODULE_PARM_DESC(minstrel_vht_only, 172 "Use only VHT rates when VHT is supported by sta."); 173 174 /* 175 * To enable sufficiently targeted rate sampling, MCS rates are divided into 176 * groups, based on the number of streams and flags (HT40, SGI) that they 177 * use. 178 * 179 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 180 * BW -> SGI -> #streams 181 */ 182 const struct mcs_group minstrel_mcs_groups[] = { 183 MCS_GROUP(1, 0, BW_20), 184 MCS_GROUP(2, 0, BW_20), 185 MCS_GROUP(3, 0, BW_20), 186 MCS_GROUP(4, 0, BW_20), 187 188 MCS_GROUP(1, 1, BW_20), 189 MCS_GROUP(2, 1, BW_20), 190 MCS_GROUP(3, 1, BW_20), 191 MCS_GROUP(4, 1, BW_20), 192 193 MCS_GROUP(1, 0, BW_40), 194 MCS_GROUP(2, 0, BW_40), 195 MCS_GROUP(3, 0, BW_40), 196 MCS_GROUP(4, 0, BW_40), 197 198 MCS_GROUP(1, 1, BW_40), 199 MCS_GROUP(2, 1, BW_40), 200 MCS_GROUP(3, 1, BW_40), 201 MCS_GROUP(4, 1, BW_40), 202 203 CCK_GROUP, 204 205 VHT_GROUP(1, 0, BW_20), 206 VHT_GROUP(2, 0, BW_20), 207 VHT_GROUP(3, 0, BW_20), 208 VHT_GROUP(4, 0, BW_20), 209 210 VHT_GROUP(1, 1, BW_20), 211 VHT_GROUP(2, 1, BW_20), 212 VHT_GROUP(3, 1, BW_20), 213 VHT_GROUP(4, 1, BW_20), 214 215 VHT_GROUP(1, 0, BW_40), 216 VHT_GROUP(2, 0, BW_40), 217 VHT_GROUP(3, 0, BW_40), 218 VHT_GROUP(4, 0, BW_40), 219 220 VHT_GROUP(1, 1, BW_40), 221 VHT_GROUP(2, 1, BW_40), 222 VHT_GROUP(3, 1, BW_40), 223 VHT_GROUP(4, 1, BW_40), 224 225 VHT_GROUP(1, 0, BW_80), 226 VHT_GROUP(2, 0, BW_80), 227 VHT_GROUP(3, 0, BW_80), 228 VHT_GROUP(4, 0, BW_80), 229 230 VHT_GROUP(1, 1, BW_80), 231 VHT_GROUP(2, 1, BW_80), 232 VHT_GROUP(3, 1, BW_80), 233 VHT_GROUP(4, 1, BW_80), 234 }; 235 236 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 237 238 static void 239 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 240 241 /* 242 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 243 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 244 * 245 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 246 */ 247 static u16 248 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 249 { 250 u16 mask = 0; 251 252 if (bw == BW_20) { 253 if (nss != 3 && nss != 6) 254 mask = BIT(9); 255 } else if (bw == BW_80) { 256 if (nss == 3 || nss == 7) 257 mask = BIT(6); 258 else if (nss == 6) 259 mask = BIT(9); 260 } else { 261 WARN_ON(bw != BW_40); 262 } 263 264 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 265 case IEEE80211_VHT_MCS_SUPPORT_0_7: 266 mask |= 0x300; 267 break; 268 case IEEE80211_VHT_MCS_SUPPORT_0_8: 269 mask |= 0x200; 270 break; 271 case IEEE80211_VHT_MCS_SUPPORT_0_9: 272 break; 273 default: 274 mask = 0x3ff; 275 } 276 277 return 0x3ff & ~mask; 278 } 279 280 /* 281 * Look up an MCS group index based on mac80211 rate information 282 */ 283 static int 284 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 285 { 286 return GROUP_IDX((rate->idx / 8) + 1, 287 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 288 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 289 } 290 291 static int 292 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 293 { 294 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 295 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 296 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 297 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 298 } 299 300 static struct minstrel_rate_stats * 301 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 302 struct ieee80211_tx_rate *rate) 303 { 304 int group, idx; 305 306 if (rate->flags & IEEE80211_TX_RC_MCS) { 307 group = minstrel_ht_get_group_idx(rate); 308 idx = rate->idx % 8; 309 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 310 group = minstrel_vht_get_group_idx(rate); 311 idx = ieee80211_rate_get_vht_mcs(rate); 312 } else { 313 group = MINSTREL_CCK_GROUP; 314 315 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 316 if (rate->idx == mp->cck_rates[idx]) 317 break; 318 319 /* short preamble */ 320 if ((mi->supported[group] & BIT(idx + 4)) && 321 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) 322 idx += 4; 323 } 324 return &mi->groups[group].rates[idx]; 325 } 326 327 static inline struct minstrel_rate_stats * 328 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 329 { 330 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 331 } 332 333 static unsigned int 334 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 335 { 336 if (!mi->avg_ampdu_len) 337 return AVG_AMPDU_SIZE; 338 339 return MINSTREL_TRUNC(mi->avg_ampdu_len); 340 } 341 342 /* 343 * Return current throughput based on the average A-MPDU length, taking into 344 * account the expected number of retransmissions and their expected length 345 */ 346 int 347 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 348 int prob_ewma) 349 { 350 unsigned int nsecs = 0; 351 352 /* do not account throughput if sucess prob is below 10% */ 353 if (prob_ewma < MINSTREL_FRAC(10, 100)) 354 return 0; 355 356 if (group != MINSTREL_CCK_GROUP) 357 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi); 358 359 nsecs += minstrel_mcs_groups[group].duration[rate] << 360 minstrel_mcs_groups[group].shift; 361 362 /* 363 * For the throughput calculation, limit the probability value to 90% to 364 * account for collision related packet error rate fluctuation 365 * (prob is scaled - see MINSTREL_FRAC above) 366 */ 367 if (prob_ewma > MINSTREL_FRAC(90, 100)) 368 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 369 / nsecs)); 370 else 371 return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); 372 } 373 374 /* 375 * Find & sort topmost throughput rates 376 * 377 * If multiple rates provide equal throughput the sorting is based on their 378 * current success probability. Higher success probability is preferred among 379 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 380 */ 381 static void 382 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 383 u16 *tp_list) 384 { 385 int cur_group, cur_idx, cur_tp_avg, cur_prob; 386 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 387 int j = MAX_THR_RATES; 388 389 cur_group = index / MCS_GROUP_RATES; 390 cur_idx = index % MCS_GROUP_RATES; 391 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; 392 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 393 394 do { 395 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 396 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 397 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 398 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 399 tmp_prob); 400 if (cur_tp_avg < tmp_tp_avg || 401 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 402 break; 403 j--; 404 } while (j > 0); 405 406 if (j < MAX_THR_RATES - 1) { 407 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 408 (MAX_THR_RATES - (j + 1)))); 409 } 410 if (j < MAX_THR_RATES) 411 tp_list[j] = index; 412 } 413 414 /* 415 * Find and set the topmost probability rate per sta and per group 416 */ 417 static void 418 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 419 { 420 struct minstrel_mcs_group_data *mg; 421 struct minstrel_rate_stats *mrs; 422 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 423 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 424 int max_gpr_group, max_gpr_idx; 425 int max_gpr_tp_avg, max_gpr_prob; 426 427 cur_group = index / MCS_GROUP_RATES; 428 cur_idx = index % MCS_GROUP_RATES; 429 mg = &mi->groups[index / MCS_GROUP_RATES]; 430 mrs = &mg->rates[index % MCS_GROUP_RATES]; 431 432 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 433 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 434 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 435 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 436 437 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 438 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 439 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 440 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 441 (max_tp_group != MINSTREL_CCK_GROUP)) 442 return; 443 444 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 445 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 446 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; 447 448 if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { 449 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 450 mrs->prob_ewma); 451 if (cur_tp_avg > tmp_tp_avg) 452 mi->max_prob_rate = index; 453 454 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 455 max_gpr_idx, 456 max_gpr_prob); 457 if (cur_tp_avg > max_gpr_tp_avg) 458 mg->max_group_prob_rate = index; 459 } else { 460 if (mrs->prob_ewma > tmp_prob) 461 mi->max_prob_rate = index; 462 if (mrs->prob_ewma > max_gpr_prob) 463 mg->max_group_prob_rate = index; 464 } 465 } 466 467 468 /* 469 * Assign new rate set per sta and use CCK rates only if the fastest 470 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 471 * rate sets where MCS and CCK rates are mixed, because CCK rates can 472 * not use aggregation. 473 */ 474 static void 475 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 476 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 477 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 478 { 479 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 480 int i; 481 482 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 483 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 484 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 485 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 486 487 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 488 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 489 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; 490 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 491 492 if (tmp_cck_tp > tmp_mcs_tp) { 493 for(i = 0; i < MAX_THR_RATES; i++) { 494 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 495 tmp_mcs_tp_rate); 496 } 497 } 498 499 } 500 501 /* 502 * Try to increase robustness of max_prob rate by decrease number of 503 * streams if possible. 504 */ 505 static inline void 506 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 507 { 508 struct minstrel_mcs_group_data *mg; 509 int tmp_max_streams, group, tmp_idx, tmp_prob; 510 int tmp_tp = 0; 511 512 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 513 MCS_GROUP_RATES].streams; 514 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 515 mg = &mi->groups[group]; 516 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 517 continue; 518 519 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 520 tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; 521 522 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 523 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 524 mi->max_prob_rate = mg->max_group_prob_rate; 525 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 526 tmp_idx, 527 tmp_prob); 528 } 529 } 530 } 531 532 /* 533 * Update rate statistics and select new primary rates 534 * 535 * Rules for rate selection: 536 * - max_prob_rate must use only one stream, as a tradeoff between delivery 537 * probability and throughput during strong fluctuations 538 * - as long as the max prob rate has a probability of more than 75%, pick 539 * higher throughput rates, even if the probablity is a bit lower 540 */ 541 static void 542 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 543 { 544 struct minstrel_mcs_group_data *mg; 545 struct minstrel_rate_stats *mrs; 546 int group, i, j, cur_prob; 547 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 548 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 549 550 if (mi->ampdu_packets > 0) { 551 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 552 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 553 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 554 EWMA_LEVEL); 555 else 556 mi->avg_ampdu_len = 0; 557 mi->ampdu_len = 0; 558 mi->ampdu_packets = 0; 559 } 560 561 mi->sample_slow = 0; 562 mi->sample_count = 0; 563 564 /* Initialize global rate indexes */ 565 for(j = 0; j < MAX_THR_RATES; j++){ 566 tmp_mcs_tp_rate[j] = 0; 567 tmp_cck_tp_rate[j] = 0; 568 } 569 570 /* Find best rate sets within all MCS groups*/ 571 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 572 573 mg = &mi->groups[group]; 574 if (!mi->supported[group]) 575 continue; 576 577 mi->sample_count++; 578 579 /* (re)Initialize group rate indexes */ 580 for(j = 0; j < MAX_THR_RATES; j++) 581 tmp_group_tp_rate[j] = group; 582 583 for (i = 0; i < MCS_GROUP_RATES; i++) { 584 if (!(mi->supported[group] & BIT(i))) 585 continue; 586 587 index = MCS_GROUP_RATES * group + i; 588 589 mrs = &mg->rates[i]; 590 mrs->retry_updated = false; 591 minstrel_calc_rate_stats(mrs); 592 cur_prob = mrs->prob_ewma; 593 594 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 595 continue; 596 597 /* Find max throughput rate set */ 598 if (group != MINSTREL_CCK_GROUP) { 599 minstrel_ht_sort_best_tp_rates(mi, index, 600 tmp_mcs_tp_rate); 601 } else if (group == MINSTREL_CCK_GROUP) { 602 minstrel_ht_sort_best_tp_rates(mi, index, 603 tmp_cck_tp_rate); 604 } 605 606 /* Find max throughput rate set within a group */ 607 minstrel_ht_sort_best_tp_rates(mi, index, 608 tmp_group_tp_rate); 609 610 /* Find max probability rate per group and global */ 611 minstrel_ht_set_best_prob_rate(mi, index); 612 } 613 614 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 615 sizeof(mg->max_group_tp_rate)); 616 } 617 618 /* Assign new rate set per sta */ 619 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 620 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 621 622 /* Try to increase robustness of max_prob_rate*/ 623 minstrel_ht_prob_rate_reduce_streams(mi); 624 625 /* try to sample all available rates during each interval */ 626 mi->sample_count *= 8; 627 628 #ifdef CONFIG_MAC80211_DEBUGFS 629 /* use fixed index if set */ 630 if (mp->fixed_rate_idx != -1) { 631 for (i = 0; i < 4; i++) 632 mi->max_tp_rate[i] = mp->fixed_rate_idx; 633 mi->max_prob_rate = mp->fixed_rate_idx; 634 } 635 #endif 636 637 /* Reset update timer */ 638 mi->last_stats_update = jiffies; 639 } 640 641 static bool 642 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 643 { 644 if (rate->idx < 0) 645 return false; 646 647 if (!rate->count) 648 return false; 649 650 if (rate->flags & IEEE80211_TX_RC_MCS || 651 rate->flags & IEEE80211_TX_RC_VHT_MCS) 652 return true; 653 654 return rate->idx == mp->cck_rates[0] || 655 rate->idx == mp->cck_rates[1] || 656 rate->idx == mp->cck_rates[2] || 657 rate->idx == mp->cck_rates[3]; 658 } 659 660 static void 661 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 662 { 663 struct minstrel_mcs_group_data *mg; 664 665 for (;;) { 666 mi->sample_group++; 667 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 668 mg = &mi->groups[mi->sample_group]; 669 670 if (!mi->supported[mi->sample_group]) 671 continue; 672 673 if (++mg->index >= MCS_GROUP_RATES) { 674 mg->index = 0; 675 if (++mg->column >= ARRAY_SIZE(sample_table)) 676 mg->column = 0; 677 } 678 break; 679 } 680 } 681 682 static void 683 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 684 { 685 int group, orig_group; 686 687 orig_group = group = *idx / MCS_GROUP_RATES; 688 while (group > 0) { 689 group--; 690 691 if (!mi->supported[group]) 692 continue; 693 694 if (minstrel_mcs_groups[group].streams > 695 minstrel_mcs_groups[orig_group].streams) 696 continue; 697 698 if (primary) 699 *idx = mi->groups[group].max_group_tp_rate[0]; 700 else 701 *idx = mi->groups[group].max_group_tp_rate[1]; 702 break; 703 } 704 } 705 706 static void 707 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 708 { 709 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 710 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 711 u16 tid; 712 713 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 714 return; 715 716 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 717 return; 718 719 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 720 return; 721 722 tid = ieee80211_get_tid(hdr); 723 if (likely(sta->ampdu_mlme.tid_tx[tid])) 724 return; 725 726 ieee80211_start_tx_ba_session(pubsta, tid, 0); 727 } 728 729 static void 730 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 731 void *priv_sta, struct ieee80211_tx_status *st) 732 { 733 struct ieee80211_tx_info *info = st->info; 734 struct minstrel_ht_sta_priv *msp = priv_sta; 735 struct minstrel_ht_sta *mi = &msp->ht; 736 struct ieee80211_tx_rate *ar = info->status.rates; 737 struct minstrel_rate_stats *rate, *rate2; 738 struct minstrel_priv *mp = priv; 739 bool last, update = false; 740 int i; 741 742 if (!msp->is_ht) 743 return mac80211_minstrel.tx_status_ext(priv, sband, 744 &msp->legacy, st); 745 746 /* This packet was aggregated but doesn't carry status info */ 747 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 748 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 749 return; 750 751 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 752 info->status.ampdu_ack_len = 753 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 754 info->status.ampdu_len = 1; 755 } 756 757 mi->ampdu_packets++; 758 mi->ampdu_len += info->status.ampdu_len; 759 760 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 761 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 762 763 mi->sample_wait = 16 + 2 * avg_ampdu_len; 764 mi->sample_tries = 1; 765 mi->sample_count--; 766 } 767 768 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 769 mi->sample_packets += info->status.ampdu_len; 770 771 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 772 for (i = 0; !last; i++) { 773 last = (i == IEEE80211_TX_MAX_RATES - 1) || 774 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 775 776 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 777 778 if (last) 779 rate->success += info->status.ampdu_ack_len; 780 781 rate->attempts += ar[i].count * info->status.ampdu_len; 782 } 783 784 /* 785 * check for sudden death of spatial multiplexing, 786 * downgrade to a lower number of streams if necessary. 787 */ 788 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 789 if (rate->attempts > 30 && 790 MINSTREL_FRAC(rate->success, rate->attempts) < 791 MINSTREL_FRAC(20, 100)) { 792 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 793 update = true; 794 } 795 796 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 797 if (rate2->attempts > 30 && 798 MINSTREL_FRAC(rate2->success, rate2->attempts) < 799 MINSTREL_FRAC(20, 100)) { 800 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 801 update = true; 802 } 803 804 if (time_after(jiffies, mi->last_stats_update + 805 (mp->update_interval / 2 * HZ) / 1000)) { 806 update = true; 807 minstrel_ht_update_stats(mp, mi); 808 } 809 810 if (update) 811 minstrel_ht_update_rates(mp, mi); 812 } 813 814 static inline int 815 minstrel_get_duration(int index) 816 { 817 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 818 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 819 return duration << group->shift; 820 } 821 822 static void 823 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 824 int index) 825 { 826 struct minstrel_rate_stats *mrs; 827 unsigned int tx_time, tx_time_rtscts, tx_time_data; 828 unsigned int cw = mp->cw_min; 829 unsigned int ctime = 0; 830 unsigned int t_slot = 9; /* FIXME */ 831 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 832 unsigned int overhead = 0, overhead_rtscts = 0; 833 834 mrs = minstrel_get_ratestats(mi, index); 835 if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { 836 mrs->retry_count = 1; 837 mrs->retry_count_rtscts = 1; 838 return; 839 } 840 841 mrs->retry_count = 2; 842 mrs->retry_count_rtscts = 2; 843 mrs->retry_updated = true; 844 845 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 846 847 /* Contention time for first 2 tries */ 848 ctime = (t_slot * cw) >> 1; 849 cw = min((cw << 1) | 1, mp->cw_max); 850 ctime += (t_slot * cw) >> 1; 851 cw = min((cw << 1) | 1, mp->cw_max); 852 853 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 854 overhead = mi->overhead; 855 overhead_rtscts = mi->overhead_rtscts; 856 } 857 858 /* Total TX time for data and Contention after first 2 tries */ 859 tx_time = ctime + 2 * (overhead + tx_time_data); 860 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 861 862 /* See how many more tries we can fit inside segment size */ 863 do { 864 /* Contention time for this try */ 865 ctime = (t_slot * cw) >> 1; 866 cw = min((cw << 1) | 1, mp->cw_max); 867 868 /* Total TX time after this try */ 869 tx_time += ctime + overhead + tx_time_data; 870 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 871 872 if (tx_time_rtscts < mp->segment_size) 873 mrs->retry_count_rtscts++; 874 } while ((tx_time < mp->segment_size) && 875 (++mrs->retry_count < mp->max_retry)); 876 } 877 878 879 static void 880 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 881 struct ieee80211_sta_rates *ratetbl, int offset, int index) 882 { 883 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 884 struct minstrel_rate_stats *mrs; 885 u8 idx; 886 u16 flags = group->flags; 887 888 mrs = minstrel_get_ratestats(mi, index); 889 if (!mrs->retry_updated) 890 minstrel_calc_retransmit(mp, mi, index); 891 892 if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 893 ratetbl->rate[offset].count = 2; 894 ratetbl->rate[offset].count_rts = 2; 895 ratetbl->rate[offset].count_cts = 2; 896 } else { 897 ratetbl->rate[offset].count = mrs->retry_count; 898 ratetbl->rate[offset].count_cts = mrs->retry_count; 899 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 900 } 901 902 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 903 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 904 else if (flags & IEEE80211_TX_RC_VHT_MCS) 905 idx = ((group->streams - 1) << 4) | 906 ((index % MCS_GROUP_RATES) & 0xF); 907 else 908 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 909 910 /* enable RTS/CTS if needed: 911 * - if station is in dynamic SMPS (and streams > 1) 912 * - for fallback rates, to increase chances of getting through 913 */ 914 if (offset > 0 || 915 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 916 group->streams > 1)) { 917 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 918 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 919 } 920 921 ratetbl->rate[offset].idx = idx; 922 ratetbl->rate[offset].flags = flags; 923 } 924 925 static inline int 926 minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) 927 { 928 int group = rate / MCS_GROUP_RATES; 929 rate %= MCS_GROUP_RATES; 930 return mi->groups[group].rates[rate].prob_ewma; 931 } 932 933 static int 934 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 935 { 936 int group = mi->max_prob_rate / MCS_GROUP_RATES; 937 const struct mcs_group *g = &minstrel_mcs_groups[group]; 938 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 939 unsigned int duration; 940 941 /* Disable A-MSDU if max_prob_rate is bad */ 942 if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) 943 return 1; 944 945 duration = g->duration[rate]; 946 duration <<= g->shift; 947 948 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 949 if (duration > MCS_DURATION(1, 0, 52)) 950 return 500; 951 952 /* 953 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 954 * data packet size 955 */ 956 if (duration > MCS_DURATION(1, 0, 104)) 957 return 1600; 958 959 /* 960 * If the rate is slower than single-stream MCS7, or if the max throughput 961 * rate success probability is less than 75%, limit A-MSDU to twice the usual 962 * data packet size 963 */ 964 if (duration > MCS_DURATION(1, 0, 260) || 965 (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < 966 MINSTREL_FRAC(75, 100))) 967 return 3200; 968 969 /* 970 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 971 * Since aggregation sessions are started/stopped without txq flush, use 972 * the limit here to avoid the complexity of having to de-aggregate 973 * packets in the queue. 974 */ 975 if (!mi->sta->vht_cap.vht_supported) 976 return IEEE80211_MAX_MPDU_LEN_HT_BA; 977 978 /* unlimited */ 979 return 0; 980 } 981 982 static void 983 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 984 { 985 struct ieee80211_sta_rates *rates; 986 int i = 0; 987 988 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 989 if (!rates) 990 return; 991 992 /* Start with max_tp_rate[0] */ 993 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); 994 995 if (mp->hw->max_rates >= 3) { 996 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 997 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 998 } 999 1000 if (mp->hw->max_rates >= 2) { 1001 /* 1002 * At least 2 tx rates supported, use max_prob_rate next */ 1003 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 1004 } 1005 1006 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 1007 rates->rate[i].idx = -1; 1008 rate_control_set_rates(mp->hw, mi->sta, rates); 1009 } 1010 1011 static int 1012 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1013 { 1014 struct minstrel_rate_stats *mrs; 1015 struct minstrel_mcs_group_data *mg; 1016 unsigned int sample_dur, sample_group, cur_max_tp_streams; 1017 int tp_rate1, tp_rate2; 1018 int sample_idx = 0; 1019 1020 if (mi->sample_wait > 0) { 1021 mi->sample_wait--; 1022 return -1; 1023 } 1024 1025 if (!mi->sample_tries) 1026 return -1; 1027 1028 sample_group = mi->sample_group; 1029 mg = &mi->groups[sample_group]; 1030 sample_idx = sample_table[mg->column][mg->index]; 1031 minstrel_set_next_sample_idx(mi); 1032 1033 if (!(mi->supported[sample_group] & BIT(sample_idx))) 1034 return -1; 1035 1036 mrs = &mg->rates[sample_idx]; 1037 sample_idx += sample_group * MCS_GROUP_RATES; 1038 1039 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 1040 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1041 minstrel_get_duration(mi->max_tp_rate[1])) { 1042 tp_rate1 = mi->max_tp_rate[1]; 1043 tp_rate2 = mi->max_tp_rate[0]; 1044 } else { 1045 tp_rate1 = mi->max_tp_rate[0]; 1046 tp_rate2 = mi->max_tp_rate[1]; 1047 } 1048 1049 /* 1050 * Sampling might add some overhead (RTS, no aggregation) 1051 * to the frame. Hence, don't use sampling for the highest currently 1052 * used highest throughput or probability rate. 1053 */ 1054 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1055 return -1; 1056 1057 /* 1058 * Do not sample if the probability is already higher than 95%, 1059 * or if the rate is 3 times slower than the current max probability 1060 * rate, to avoid wasting airtime. 1061 */ 1062 sample_dur = minstrel_get_duration(sample_idx); 1063 if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || 1064 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1065 return -1; 1066 1067 /* 1068 * Make sure that lower rates get sampled only occasionally, 1069 * if the link is working perfectly. 1070 */ 1071 1072 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1073 MCS_GROUP_RATES].streams; 1074 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1075 (cur_max_tp_streams - 1 < 1076 minstrel_mcs_groups[sample_group].streams || 1077 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1078 if (mrs->sample_skipped < 20) 1079 return -1; 1080 1081 if (mi->sample_slow++ > 2) 1082 return -1; 1083 } 1084 mi->sample_tries--; 1085 1086 return sample_idx; 1087 } 1088 1089 static void 1090 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1091 struct ieee80211_tx_rate_control *txrc) 1092 { 1093 const struct mcs_group *sample_group; 1094 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1095 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1096 struct minstrel_ht_sta_priv *msp = priv_sta; 1097 struct minstrel_ht_sta *mi = &msp->ht; 1098 struct minstrel_priv *mp = priv; 1099 int sample_idx; 1100 1101 if (!msp->is_ht) 1102 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1103 1104 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1105 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1106 minstrel_aggr_check(sta, txrc->skb); 1107 1108 info->flags |= mi->tx_flags; 1109 1110 #ifdef CONFIG_MAC80211_DEBUGFS 1111 if (mp->fixed_rate_idx != -1) 1112 return; 1113 #endif 1114 1115 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1116 if (mp->hw->max_rates == 1 && 1117 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1118 sample_idx = -1; 1119 else 1120 sample_idx = minstrel_get_sample_rate(mp, mi); 1121 1122 mi->total_packets++; 1123 1124 /* wraparound */ 1125 if (mi->total_packets == ~0) { 1126 mi->total_packets = 0; 1127 mi->sample_packets = 0; 1128 } 1129 1130 if (sample_idx < 0) 1131 return; 1132 1133 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1134 sample_idx %= MCS_GROUP_RATES; 1135 1136 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1137 (sample_idx >= 4) != txrc->short_preamble) 1138 return; 1139 1140 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1141 rate->count = 1; 1142 1143 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1144 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1145 rate->idx = mp->cck_rates[idx]; 1146 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1147 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1148 sample_group->streams); 1149 } else { 1150 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1151 } 1152 1153 rate->flags = sample_group->flags; 1154 } 1155 1156 static void 1157 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1158 struct ieee80211_supported_band *sband, 1159 struct ieee80211_sta *sta) 1160 { 1161 int i; 1162 1163 if (sband->band != NL80211_BAND_2GHZ) 1164 return; 1165 1166 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1167 return; 1168 1169 mi->cck_supported = 0; 1170 mi->cck_supported_short = 0; 1171 for (i = 0; i < 4; i++) { 1172 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1173 continue; 1174 1175 mi->cck_supported |= BIT(i); 1176 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1177 mi->cck_supported_short |= BIT(i); 1178 } 1179 1180 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1181 } 1182 1183 static void 1184 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1185 struct cfg80211_chan_def *chandef, 1186 struct ieee80211_sta *sta, void *priv_sta) 1187 { 1188 struct minstrel_priv *mp = priv; 1189 struct minstrel_ht_sta_priv *msp = priv_sta; 1190 struct minstrel_ht_sta *mi = &msp->ht; 1191 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1192 u16 ht_cap = sta->ht_cap.cap; 1193 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1194 int use_vht; 1195 int n_supported = 0; 1196 int ack_dur; 1197 int stbc; 1198 int i; 1199 bool ldpc; 1200 1201 /* fall back to the old minstrel for legacy stations */ 1202 if (!sta->ht_cap.ht_supported) 1203 goto use_legacy; 1204 1205 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1206 1207 if (vht_cap->vht_supported) 1208 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1209 else 1210 use_vht = 0; 1211 1212 msp->is_ht = true; 1213 memset(mi, 0, sizeof(*mi)); 1214 1215 mi->sta = sta; 1216 mi->last_stats_update = jiffies; 1217 1218 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1219 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1220 mi->overhead += ack_dur; 1221 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1222 1223 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1224 1225 /* When using MRR, sample more on the first attempt, without delay */ 1226 if (mp->has_mrr) { 1227 mi->sample_count = 16; 1228 mi->sample_wait = 0; 1229 } else { 1230 mi->sample_count = 8; 1231 mi->sample_wait = 8; 1232 } 1233 mi->sample_tries = 4; 1234 1235 if (!use_vht) { 1236 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1237 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1238 1239 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1240 } else { 1241 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1242 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1243 1244 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1245 } 1246 1247 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1248 if (ldpc) 1249 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1250 1251 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1252 u32 gflags = minstrel_mcs_groups[i].flags; 1253 int bw, nss; 1254 1255 mi->supported[i] = 0; 1256 if (i == MINSTREL_CCK_GROUP) { 1257 minstrel_ht_update_cck(mp, mi, sband, sta); 1258 continue; 1259 } 1260 1261 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1262 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1263 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1264 continue; 1265 } else { 1266 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1267 continue; 1268 } 1269 } 1270 1271 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1272 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1273 continue; 1274 1275 nss = minstrel_mcs_groups[i].streams; 1276 1277 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1278 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1279 continue; 1280 1281 /* HT rate */ 1282 if (gflags & IEEE80211_TX_RC_MCS) { 1283 if (use_vht && minstrel_vht_only) 1284 continue; 1285 1286 mi->supported[i] = mcs->rx_mask[nss - 1]; 1287 if (mi->supported[i]) 1288 n_supported++; 1289 continue; 1290 } 1291 1292 /* VHT rate */ 1293 if (!vht_cap->vht_supported || 1294 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1295 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1296 continue; 1297 1298 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1299 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1300 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1301 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1302 continue; 1303 } 1304 } 1305 1306 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1307 bw = BW_40; 1308 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1309 bw = BW_80; 1310 else 1311 bw = BW_20; 1312 1313 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1314 vht_cap->vht_mcs.tx_mcs_map); 1315 1316 if (mi->supported[i]) 1317 n_supported++; 1318 } 1319 1320 if (!n_supported) 1321 goto use_legacy; 1322 1323 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; 1324 1325 /* create an initial rate table with the lowest supported rates */ 1326 minstrel_ht_update_stats(mp, mi); 1327 minstrel_ht_update_rates(mp, mi); 1328 1329 return; 1330 1331 use_legacy: 1332 msp->is_ht = false; 1333 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1334 msp->legacy.r = msp->ratelist; 1335 msp->legacy.sample_table = msp->sample_table; 1336 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1337 &msp->legacy); 1338 } 1339 1340 static void 1341 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1342 struct cfg80211_chan_def *chandef, 1343 struct ieee80211_sta *sta, void *priv_sta) 1344 { 1345 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1346 } 1347 1348 static void 1349 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1350 struct cfg80211_chan_def *chandef, 1351 struct ieee80211_sta *sta, void *priv_sta, 1352 u32 changed) 1353 { 1354 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1355 } 1356 1357 static void * 1358 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1359 { 1360 struct ieee80211_supported_band *sband; 1361 struct minstrel_ht_sta_priv *msp; 1362 struct minstrel_priv *mp = priv; 1363 struct ieee80211_hw *hw = mp->hw; 1364 int max_rates = 0; 1365 int i; 1366 1367 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1368 sband = hw->wiphy->bands[i]; 1369 if (sband && sband->n_bitrates > max_rates) 1370 max_rates = sband->n_bitrates; 1371 } 1372 1373 msp = kzalloc(sizeof(*msp), gfp); 1374 if (!msp) 1375 return NULL; 1376 1377 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1378 if (!msp->ratelist) 1379 goto error; 1380 1381 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1382 if (!msp->sample_table) 1383 goto error1; 1384 1385 return msp; 1386 1387 error1: 1388 kfree(msp->ratelist); 1389 error: 1390 kfree(msp); 1391 return NULL; 1392 } 1393 1394 static void 1395 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1396 { 1397 struct minstrel_ht_sta_priv *msp = priv_sta; 1398 1399 kfree(msp->sample_table); 1400 kfree(msp->ratelist); 1401 kfree(msp); 1402 } 1403 1404 static void 1405 minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1406 { 1407 static const int bitrates[4] = { 10, 20, 55, 110 }; 1408 struct ieee80211_supported_band *sband; 1409 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1410 int i, j; 1411 1412 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1413 if (!sband) 1414 return; 1415 1416 for (i = 0; i < sband->n_bitrates; i++) { 1417 struct ieee80211_rate *rate = &sband->bitrates[i]; 1418 1419 if (rate->flags & IEEE80211_RATE_ERP_G) 1420 continue; 1421 1422 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1423 continue; 1424 1425 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 1426 if (rate->bitrate != bitrates[j]) 1427 continue; 1428 1429 mp->cck_rates[j] = i; 1430 break; 1431 } 1432 } 1433 } 1434 1435 static void * 1436 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1437 { 1438 struct minstrel_priv *mp; 1439 1440 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1441 if (!mp) 1442 return NULL; 1443 1444 /* contention window settings 1445 * Just an approximation. Using the per-queue values would complicate 1446 * the calculations and is probably unnecessary */ 1447 mp->cw_min = 15; 1448 mp->cw_max = 1023; 1449 1450 /* number of packets (in %) to use for sampling other rates 1451 * sample less often for non-mrr packets, because the overhead 1452 * is much higher than with mrr */ 1453 mp->lookaround_rate = 5; 1454 mp->lookaround_rate_mrr = 10; 1455 1456 /* maximum time that the hw is allowed to stay in one MRR segment */ 1457 mp->segment_size = 6000; 1458 1459 if (hw->max_rate_tries > 0) 1460 mp->max_retry = hw->max_rate_tries; 1461 else 1462 /* safe default, does not necessarily have to match hw properties */ 1463 mp->max_retry = 7; 1464 1465 if (hw->max_rates >= 4) 1466 mp->has_mrr = true; 1467 1468 mp->hw = hw; 1469 mp->update_interval = 100; 1470 1471 #ifdef CONFIG_MAC80211_DEBUGFS 1472 mp->fixed_rate_idx = (u32) -1; 1473 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1474 &mp->fixed_rate_idx); 1475 #endif 1476 1477 minstrel_ht_init_cck_rates(mp); 1478 1479 return mp; 1480 } 1481 1482 static void 1483 minstrel_ht_free(void *priv) 1484 { 1485 kfree(priv); 1486 } 1487 1488 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1489 { 1490 struct minstrel_ht_sta_priv *msp = priv_sta; 1491 struct minstrel_ht_sta *mi = &msp->ht; 1492 int i, j, prob, tp_avg; 1493 1494 if (!msp->is_ht) 1495 return mac80211_minstrel.get_expected_throughput(priv_sta); 1496 1497 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1498 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1499 prob = mi->groups[i].rates[j].prob_ewma; 1500 1501 /* convert tp_avg from pkt per second in kbps */ 1502 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1503 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1504 1505 return tp_avg; 1506 } 1507 1508 static const struct rate_control_ops mac80211_minstrel_ht = { 1509 .name = "minstrel_ht", 1510 .tx_status_ext = minstrel_ht_tx_status, 1511 .get_rate = minstrel_ht_get_rate, 1512 .rate_init = minstrel_ht_rate_init, 1513 .rate_update = minstrel_ht_rate_update, 1514 .alloc_sta = minstrel_ht_alloc_sta, 1515 .free_sta = minstrel_ht_free_sta, 1516 .alloc = minstrel_ht_alloc, 1517 .free = minstrel_ht_free, 1518 #ifdef CONFIG_MAC80211_DEBUGFS 1519 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1520 #endif 1521 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1522 }; 1523 1524 1525 static void __init init_sample_table(void) 1526 { 1527 int col, i, new_idx; 1528 u8 rnd[MCS_GROUP_RATES]; 1529 1530 memset(sample_table, 0xff, sizeof(sample_table)); 1531 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1532 prandom_bytes(rnd, sizeof(rnd)); 1533 for (i = 0; i < MCS_GROUP_RATES; i++) { 1534 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1535 while (sample_table[col][new_idx] != 0xff) 1536 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1537 1538 sample_table[col][new_idx] = i; 1539 } 1540 } 1541 } 1542 1543 int __init 1544 rc80211_minstrel_init(void) 1545 { 1546 init_sample_table(); 1547 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1548 } 1549 1550 void 1551 rc80211_minstrel_exit(void) 1552 { 1553 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1554 } 1555