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 #define SAMPLE_SWITCH_THR 100 22 23 /* Number of bits for an average sized packet */ 24 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) 25 26 /* Number of symbols for a packet with (bps) bits per symbol */ 27 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) 28 29 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ 30 #define MCS_SYMBOL_TIME(sgi, syms) \ 31 (sgi ? \ 32 ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ 33 ((syms) * 1000) << 2 /* syms * 4 us */ \ 34 ) 35 36 /* Transmit duration for the raw data part of an average sized packet */ 37 #define MCS_DURATION(streams, sgi, bps) \ 38 (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE) 39 40 #define BW_20 0 41 #define BW_40 1 42 #define BW_80 2 43 44 /* 45 * Define group sort order: HT40 -> SGI -> #streams 46 */ 47 #define GROUP_IDX(_streams, _sgi, _ht40) \ 48 MINSTREL_HT_GROUP_0 + \ 49 MINSTREL_MAX_STREAMS * 2 * _ht40 + \ 50 MINSTREL_MAX_STREAMS * _sgi + \ 51 _streams - 1 52 53 #define _MAX(a, b) (((a)>(b))?(a):(b)) 54 55 #define GROUP_SHIFT(duration) \ 56 _MAX(0, 16 - __builtin_clz(duration)) 57 58 /* MCS rate information for an MCS group */ 59 #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \ 60 [GROUP_IDX(_streams, _sgi, _ht40)] = { \ 61 .streams = _streams, \ 62 .shift = _s, \ 63 .bw = _ht40, \ 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 .bw = _bw, \ 101 .flags = \ 102 IEEE80211_TX_RC_VHT_MCS | \ 103 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 104 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 105 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 106 .duration = { \ 107 MCS_DURATION(_streams, _sgi, \ 108 BW2VBPS(_bw, 117, 54, 26)) >> _s, \ 109 MCS_DURATION(_streams, _sgi, \ 110 BW2VBPS(_bw, 234, 108, 52)) >> _s, \ 111 MCS_DURATION(_streams, _sgi, \ 112 BW2VBPS(_bw, 351, 162, 78)) >> _s, \ 113 MCS_DURATION(_streams, _sgi, \ 114 BW2VBPS(_bw, 468, 216, 104)) >> _s, \ 115 MCS_DURATION(_streams, _sgi, \ 116 BW2VBPS(_bw, 702, 324, 156)) >> _s, \ 117 MCS_DURATION(_streams, _sgi, \ 118 BW2VBPS(_bw, 936, 432, 208)) >> _s, \ 119 MCS_DURATION(_streams, _sgi, \ 120 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \ 121 MCS_DURATION(_streams, _sgi, \ 122 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \ 123 MCS_DURATION(_streams, _sgi, \ 124 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \ 125 MCS_DURATION(_streams, _sgi, \ 126 BW2VBPS(_bw, 1560, 720, 346)) >> _s \ 127 } \ 128 } 129 130 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \ 131 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \ 132 BW2VBPS(_bw, 117, 54, 26))) 133 134 #define VHT_GROUP(_streams, _sgi, _bw) \ 135 __VHT_GROUP(_streams, _sgi, _bw, \ 136 VHT_GROUP_SHIFT(_streams, _sgi, _bw)) 137 138 #define CCK_DURATION(_bitrate, _short, _len) \ 139 (1000 * (10 /* SIFS */ + \ 140 (_short ? 72 + 24 : 144 + 48) + \ 141 (8 * (_len + 4) * 10) / (_bitrate))) 142 143 #define CCK_ACK_DURATION(_bitrate, _short) \ 144 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 145 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 146 147 #define CCK_DURATION_LIST(_short, _s) \ 148 CCK_ACK_DURATION(10, _short) >> _s, \ 149 CCK_ACK_DURATION(20, _short) >> _s, \ 150 CCK_ACK_DURATION(55, _short) >> _s, \ 151 CCK_ACK_DURATION(110, _short) >> _s 152 153 #define __CCK_GROUP(_s) \ 154 [MINSTREL_CCK_GROUP] = { \ 155 .streams = 1, \ 156 .flags = 0, \ 157 .shift = _s, \ 158 .duration = { \ 159 CCK_DURATION_LIST(false, _s), \ 160 CCK_DURATION_LIST(true, _s) \ 161 } \ 162 } 163 164 #define CCK_GROUP_SHIFT \ 165 GROUP_SHIFT(CCK_ACK_DURATION(10, false)) 166 167 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) 168 169 170 static bool minstrel_vht_only = true; 171 module_param(minstrel_vht_only, bool, 0644); 172 MODULE_PARM_DESC(minstrel_vht_only, 173 "Use only VHT rates when VHT is supported by sta."); 174 175 /* 176 * To enable sufficiently targeted rate sampling, MCS rates are divided into 177 * groups, based on the number of streams and flags (HT40, SGI) that they 178 * use. 179 * 180 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 181 * BW -> SGI -> #streams 182 */ 183 const struct mcs_group minstrel_mcs_groups[] = { 184 MCS_GROUP(1, 0, BW_20), 185 MCS_GROUP(2, 0, BW_20), 186 MCS_GROUP(3, 0, BW_20), 187 MCS_GROUP(4, 0, BW_20), 188 189 MCS_GROUP(1, 1, BW_20), 190 MCS_GROUP(2, 1, BW_20), 191 MCS_GROUP(3, 1, BW_20), 192 MCS_GROUP(4, 1, BW_20), 193 194 MCS_GROUP(1, 0, BW_40), 195 MCS_GROUP(2, 0, BW_40), 196 MCS_GROUP(3, 0, BW_40), 197 MCS_GROUP(4, 0, BW_40), 198 199 MCS_GROUP(1, 1, BW_40), 200 MCS_GROUP(2, 1, BW_40), 201 MCS_GROUP(3, 1, BW_40), 202 MCS_GROUP(4, 1, BW_40), 203 204 CCK_GROUP, 205 206 VHT_GROUP(1, 0, BW_20), 207 VHT_GROUP(2, 0, BW_20), 208 VHT_GROUP(3, 0, BW_20), 209 VHT_GROUP(4, 0, BW_20), 210 211 VHT_GROUP(1, 1, BW_20), 212 VHT_GROUP(2, 1, BW_20), 213 VHT_GROUP(3, 1, BW_20), 214 VHT_GROUP(4, 1, BW_20), 215 216 VHT_GROUP(1, 0, BW_40), 217 VHT_GROUP(2, 0, BW_40), 218 VHT_GROUP(3, 0, BW_40), 219 VHT_GROUP(4, 0, BW_40), 220 221 VHT_GROUP(1, 1, BW_40), 222 VHT_GROUP(2, 1, BW_40), 223 VHT_GROUP(3, 1, BW_40), 224 VHT_GROUP(4, 1, BW_40), 225 226 VHT_GROUP(1, 0, BW_80), 227 VHT_GROUP(2, 0, BW_80), 228 VHT_GROUP(3, 0, BW_80), 229 VHT_GROUP(4, 0, BW_80), 230 231 VHT_GROUP(1, 1, BW_80), 232 VHT_GROUP(2, 1, BW_80), 233 VHT_GROUP(3, 1, BW_80), 234 VHT_GROUP(4, 1, BW_80), 235 }; 236 237 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 238 239 static void 240 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 241 242 /* 243 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 244 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 245 * 246 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 247 */ 248 static u16 249 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 250 { 251 u16 mask = 0; 252 253 if (bw == BW_20) { 254 if (nss != 3 && nss != 6) 255 mask = BIT(9); 256 } else if (bw == BW_80) { 257 if (nss == 3 || nss == 7) 258 mask = BIT(6); 259 else if (nss == 6) 260 mask = BIT(9); 261 } else { 262 WARN_ON(bw != BW_40); 263 } 264 265 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 266 case IEEE80211_VHT_MCS_SUPPORT_0_7: 267 mask |= 0x300; 268 break; 269 case IEEE80211_VHT_MCS_SUPPORT_0_8: 270 mask |= 0x200; 271 break; 272 case IEEE80211_VHT_MCS_SUPPORT_0_9: 273 break; 274 default: 275 mask = 0x3ff; 276 } 277 278 return 0x3ff & ~mask; 279 } 280 281 /* 282 * Look up an MCS group index based on mac80211 rate information 283 */ 284 static int 285 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 286 { 287 return GROUP_IDX((rate->idx / 8) + 1, 288 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 289 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 290 } 291 292 static int 293 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 294 { 295 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 296 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 297 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 298 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 299 } 300 301 static struct minstrel_rate_stats * 302 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 303 struct ieee80211_tx_rate *rate) 304 { 305 int group, idx; 306 307 if (rate->flags & IEEE80211_TX_RC_MCS) { 308 group = minstrel_ht_get_group_idx(rate); 309 idx = rate->idx % 8; 310 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 311 group = minstrel_vht_get_group_idx(rate); 312 idx = ieee80211_rate_get_vht_mcs(rate); 313 } else { 314 group = MINSTREL_CCK_GROUP; 315 316 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 317 if (rate->idx == mp->cck_rates[idx]) 318 break; 319 320 /* short preamble */ 321 if ((mi->supported[group] & BIT(idx + 4)) && 322 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) 323 idx += 4; 324 } 325 return &mi->groups[group].rates[idx]; 326 } 327 328 static inline struct minstrel_rate_stats * 329 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 330 { 331 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 332 } 333 334 static unsigned int 335 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 336 { 337 if (!mi->avg_ampdu_len) 338 return AVG_AMPDU_SIZE; 339 340 return MINSTREL_TRUNC(mi->avg_ampdu_len); 341 } 342 343 /* 344 * Return current throughput based on the average A-MPDU length, taking into 345 * account the expected number of retransmissions and their expected length 346 */ 347 int 348 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 349 int prob_avg) 350 { 351 unsigned int nsecs = 0; 352 353 /* do not account throughput if sucess prob is below 10% */ 354 if (prob_avg < MINSTREL_FRAC(10, 100)) 355 return 0; 356 357 if (group != MINSTREL_CCK_GROUP) 358 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi); 359 360 nsecs += minstrel_mcs_groups[group].duration[rate] << 361 minstrel_mcs_groups[group].shift; 362 363 /* 364 * For the throughput calculation, limit the probability value to 90% to 365 * account for collision related packet error rate fluctuation 366 * (prob is scaled - see MINSTREL_FRAC above) 367 */ 368 if (prob_avg > MINSTREL_FRAC(90, 100)) 369 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 370 / nsecs)); 371 else 372 return MINSTREL_TRUNC(100000 * ((prob_avg * 1000) / nsecs)); 373 } 374 375 /* 376 * Find & sort topmost throughput rates 377 * 378 * If multiple rates provide equal throughput the sorting is based on their 379 * current success probability. Higher success probability is preferred among 380 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 381 */ 382 static void 383 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 384 u16 *tp_list) 385 { 386 int cur_group, cur_idx, cur_tp_avg, cur_prob; 387 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 388 int j = MAX_THR_RATES; 389 390 cur_group = index / MCS_GROUP_RATES; 391 cur_idx = index % MCS_GROUP_RATES; 392 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg; 393 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 394 395 do { 396 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 397 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 398 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 399 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 400 tmp_prob); 401 if (cur_tp_avg < tmp_tp_avg || 402 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 403 break; 404 j--; 405 } while (j > 0); 406 407 if (j < MAX_THR_RATES - 1) { 408 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 409 (MAX_THR_RATES - (j + 1)))); 410 } 411 if (j < MAX_THR_RATES) 412 tp_list[j] = index; 413 } 414 415 /* 416 * Find and set the topmost probability rate per sta and per group 417 */ 418 static void 419 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 420 { 421 struct minstrel_mcs_group_data *mg; 422 struct minstrel_rate_stats *mrs; 423 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 424 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 425 int max_gpr_group, max_gpr_idx; 426 int max_gpr_tp_avg, max_gpr_prob; 427 428 cur_group = index / MCS_GROUP_RATES; 429 cur_idx = index % MCS_GROUP_RATES; 430 mg = &mi->groups[index / MCS_GROUP_RATES]; 431 mrs = &mg->rates[index % MCS_GROUP_RATES]; 432 433 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 434 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 435 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 436 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 437 438 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 439 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 440 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 441 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 442 (max_tp_group != MINSTREL_CCK_GROUP)) 443 return; 444 445 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 446 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 447 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg; 448 449 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) { 450 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 451 mrs->prob_avg); 452 if (cur_tp_avg > tmp_tp_avg) 453 mi->max_prob_rate = index; 454 455 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 456 max_gpr_idx, 457 max_gpr_prob); 458 if (cur_tp_avg > max_gpr_tp_avg) 459 mg->max_group_prob_rate = index; 460 } else { 461 if (mrs->prob_avg > tmp_prob) 462 mi->max_prob_rate = index; 463 if (mrs->prob_avg > max_gpr_prob) 464 mg->max_group_prob_rate = index; 465 } 466 } 467 468 469 /* 470 * Assign new rate set per sta and use CCK rates only if the fastest 471 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 472 * rate sets where MCS and CCK rates are mixed, because CCK rates can 473 * not use aggregation. 474 */ 475 static void 476 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 477 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 478 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 479 { 480 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 481 int i; 482 483 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 484 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 485 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 486 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 487 488 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 489 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 490 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 491 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 492 493 if (tmp_cck_tp_rate && tmp_cck_tp > tmp_mcs_tp) { 494 for(i = 0; i < MAX_THR_RATES; i++) { 495 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 496 tmp_mcs_tp_rate); 497 } 498 } 499 500 } 501 502 /* 503 * Try to increase robustness of max_prob rate by decrease number of 504 * streams if possible. 505 */ 506 static inline void 507 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 508 { 509 struct minstrel_mcs_group_data *mg; 510 int tmp_max_streams, group, tmp_idx, tmp_prob; 511 int tmp_tp = 0; 512 513 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 514 MCS_GROUP_RATES].streams; 515 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 516 mg = &mi->groups[group]; 517 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 518 continue; 519 520 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 521 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg; 522 523 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 524 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 525 mi->max_prob_rate = mg->max_group_prob_rate; 526 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 527 tmp_idx, 528 tmp_prob); 529 } 530 } 531 } 532 533 static inline int 534 minstrel_get_duration(int index) 535 { 536 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 537 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 538 return duration << group->shift; 539 } 540 541 static bool 542 minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group, 543 int tp_idx, const struct mcs_group *group) 544 { 545 if (group->bw < tp_group->bw) 546 return false; 547 548 if (group->streams == tp_group->streams) 549 return true; 550 551 if (tp_idx < 4 && group->streams == tp_group->streams - 1) 552 return true; 553 554 return group->streams == tp_group->streams + 1; 555 } 556 557 static void 558 minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates, 559 bool faster_rate) 560 { 561 const struct mcs_group *group, *tp_group; 562 int i, g, max_dur; 563 int tp_idx; 564 565 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES]; 566 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; 567 568 max_dur = minstrel_get_duration(mi->max_tp_rate[0]); 569 if (faster_rate) 570 max_dur -= max_dur / 16; 571 572 for (g = 0; g < MINSTREL_GROUPS_NB; g++) { 573 u16 supported = mi->supported[g]; 574 575 if (!supported) 576 continue; 577 578 group = &minstrel_mcs_groups[g]; 579 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group)) 580 continue; 581 582 for (i = 0; supported; supported >>= 1, i++) { 583 int idx; 584 585 if (!(supported & 1)) 586 continue; 587 588 if ((group->duration[i] << group->shift) > max_dur) 589 continue; 590 591 idx = g * MCS_GROUP_RATES + i; 592 if (idx == mi->max_tp_rate[0]) 593 continue; 594 595 rates[(*n_rates)++] = idx; 596 break; 597 } 598 } 599 } 600 601 static void 602 minstrel_ht_rate_sample_switch(struct minstrel_priv *mp, 603 struct minstrel_ht_sta *mi) 604 { 605 struct minstrel_rate_stats *mrs; 606 u16 rates[MINSTREL_GROUPS_NB]; 607 int n_rates = 0; 608 int probe_rate = 0; 609 bool faster_rate; 610 int i; 611 u8 random; 612 613 /* 614 * Use rate switching instead of probing packets for devices with 615 * little control over retry fallback behavior 616 */ 617 if (mp->hw->max_rates > 1) 618 return; 619 620 /* 621 * If the current EWMA prob is >75%, look for a rate that's 6.25% 622 * faster than the max tp rate. 623 * If that fails, look again for a rate that is at least as fast 624 */ 625 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 626 faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100); 627 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate); 628 if (!n_rates && faster_rate) 629 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false); 630 631 /* If no suitable rate was found, try to pick the next one in the group */ 632 if (!n_rates) { 633 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES; 634 u16 supported = mi->supported[g_idx]; 635 636 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; 637 for (i = 0; supported; supported >>= 1, i++) { 638 if (!(supported & 1)) 639 continue; 640 641 probe_rate = mi->max_tp_rate[0] + i; 642 goto out; 643 } 644 645 return; 646 } 647 648 i = 0; 649 if (n_rates > 1) { 650 random = prandom_u32(); 651 i = random % n_rates; 652 } 653 probe_rate = rates[i]; 654 655 out: 656 mi->sample_rate = probe_rate; 657 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE; 658 } 659 660 /* 661 * Update rate statistics and select new primary rates 662 * 663 * Rules for rate selection: 664 * - max_prob_rate must use only one stream, as a tradeoff between delivery 665 * probability and throughput during strong fluctuations 666 * - as long as the max prob rate has a probability of more than 75%, pick 667 * higher throughput rates, even if the probablity is a bit lower 668 */ 669 static void 670 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 671 bool sample) 672 { 673 struct minstrel_mcs_group_data *mg; 674 struct minstrel_rate_stats *mrs; 675 int group, i, j, cur_prob; 676 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 677 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 678 679 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 680 681 if (sample) { 682 mi->total_packets_cur = mi->total_packets - 683 mi->total_packets_last; 684 mi->total_packets_last = mi->total_packets; 685 } 686 if (!mp->sample_switch) 687 sample = false; 688 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1) 689 sample = false; 690 691 if (mi->ampdu_packets > 0) { 692 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 693 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 694 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 695 EWMA_LEVEL); 696 else 697 mi->avg_ampdu_len = 0; 698 mi->ampdu_len = 0; 699 mi->ampdu_packets = 0; 700 } 701 702 mi->sample_slow = 0; 703 mi->sample_count = 0; 704 705 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate)); 706 memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate)); 707 if (mi->supported[MINSTREL_CCK_GROUP]) 708 for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++) 709 tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; 710 711 if (mi->supported[MINSTREL_VHT_GROUP_0]) 712 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES; 713 else 714 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES; 715 716 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++) 717 tmp_mcs_tp_rate[j] = index; 718 719 /* Find best rate sets within all MCS groups*/ 720 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 721 722 mg = &mi->groups[group]; 723 if (!mi->supported[group]) 724 continue; 725 726 mi->sample_count++; 727 728 /* (re)Initialize group rate indexes */ 729 for(j = 0; j < MAX_THR_RATES; j++) 730 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group; 731 732 for (i = 0; i < MCS_GROUP_RATES; i++) { 733 if (!(mi->supported[group] & BIT(i))) 734 continue; 735 736 index = MCS_GROUP_RATES * group + i; 737 738 mrs = &mg->rates[i]; 739 mrs->retry_updated = false; 740 minstrel_calc_rate_stats(mp, mrs); 741 cur_prob = mrs->prob_avg; 742 743 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 744 continue; 745 746 /* Find max throughput rate set */ 747 if (group != MINSTREL_CCK_GROUP) { 748 minstrel_ht_sort_best_tp_rates(mi, index, 749 tmp_mcs_tp_rate); 750 } else if (group == MINSTREL_CCK_GROUP) { 751 minstrel_ht_sort_best_tp_rates(mi, index, 752 tmp_cck_tp_rate); 753 } 754 755 /* Find max throughput rate set within a group */ 756 minstrel_ht_sort_best_tp_rates(mi, index, 757 tmp_group_tp_rate); 758 759 /* Find max probability rate per group and global */ 760 minstrel_ht_set_best_prob_rate(mi, index); 761 } 762 763 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 764 sizeof(mg->max_group_tp_rate)); 765 } 766 767 /* Assign new rate set per sta */ 768 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 769 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 770 771 /* Try to increase robustness of max_prob_rate*/ 772 minstrel_ht_prob_rate_reduce_streams(mi); 773 774 /* try to sample all available rates during each interval */ 775 mi->sample_count *= 8; 776 if (mp->new_avg) 777 mi->sample_count /= 2; 778 779 if (sample) 780 minstrel_ht_rate_sample_switch(mp, mi); 781 782 #ifdef CONFIG_MAC80211_DEBUGFS 783 /* use fixed index if set */ 784 if (mp->fixed_rate_idx != -1) { 785 for (i = 0; i < 4; i++) 786 mi->max_tp_rate[i] = mp->fixed_rate_idx; 787 mi->max_prob_rate = mp->fixed_rate_idx; 788 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 789 } 790 #endif 791 792 /* Reset update timer */ 793 mi->last_stats_update = jiffies; 794 } 795 796 static bool 797 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 798 { 799 if (rate->idx < 0) 800 return false; 801 802 if (!rate->count) 803 return false; 804 805 if (rate->flags & IEEE80211_TX_RC_MCS || 806 rate->flags & IEEE80211_TX_RC_VHT_MCS) 807 return true; 808 809 return rate->idx == mp->cck_rates[0] || 810 rate->idx == mp->cck_rates[1] || 811 rate->idx == mp->cck_rates[2] || 812 rate->idx == mp->cck_rates[3]; 813 } 814 815 static void 816 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 817 { 818 struct minstrel_mcs_group_data *mg; 819 820 for (;;) { 821 mi->sample_group++; 822 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 823 mg = &mi->groups[mi->sample_group]; 824 825 if (!mi->supported[mi->sample_group]) 826 continue; 827 828 if (++mg->index >= MCS_GROUP_RATES) { 829 mg->index = 0; 830 if (++mg->column >= ARRAY_SIZE(sample_table)) 831 mg->column = 0; 832 } 833 break; 834 } 835 } 836 837 static void 838 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 839 { 840 int group, orig_group; 841 842 orig_group = group = *idx / MCS_GROUP_RATES; 843 while (group > 0) { 844 group--; 845 846 if (!mi->supported[group]) 847 continue; 848 849 if (minstrel_mcs_groups[group].streams > 850 minstrel_mcs_groups[orig_group].streams) 851 continue; 852 853 if (primary) 854 *idx = mi->groups[group].max_group_tp_rate[0]; 855 else 856 *idx = mi->groups[group].max_group_tp_rate[1]; 857 break; 858 } 859 } 860 861 static void 862 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 863 { 864 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 865 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 866 u16 tid; 867 868 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 869 return; 870 871 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 872 return; 873 874 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 875 return; 876 877 tid = ieee80211_get_tid(hdr); 878 if (likely(sta->ampdu_mlme.tid_tx[tid])) 879 return; 880 881 ieee80211_start_tx_ba_session(pubsta, tid, 0); 882 } 883 884 static void 885 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 886 void *priv_sta, struct ieee80211_tx_status *st) 887 { 888 struct ieee80211_tx_info *info = st->info; 889 struct minstrel_ht_sta_priv *msp = priv_sta; 890 struct minstrel_ht_sta *mi = &msp->ht; 891 struct ieee80211_tx_rate *ar = info->status.rates; 892 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; 893 struct minstrel_priv *mp = priv; 894 u32 update_interval = mp->update_interval / 2; 895 bool last, update = false; 896 bool sample_status = false; 897 int i; 898 899 if (!msp->is_ht) 900 return mac80211_minstrel.tx_status_ext(priv, sband, 901 &msp->legacy, st); 902 903 904 /* This packet was aggregated but doesn't carry status info */ 905 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 906 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 907 return; 908 909 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 910 info->status.ampdu_ack_len = 911 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 912 info->status.ampdu_len = 1; 913 } 914 915 mi->ampdu_packets++; 916 mi->ampdu_len += info->status.ampdu_len; 917 918 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 919 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 920 921 mi->sample_wait = 16 + 2 * avg_ampdu_len; 922 mi->sample_tries = 1; 923 mi->sample_count--; 924 } 925 926 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 927 mi->sample_packets += info->status.ampdu_len; 928 929 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE) 930 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate); 931 932 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 933 for (i = 0; !last; i++) { 934 last = (i == IEEE80211_TX_MAX_RATES - 1) || 935 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 936 937 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 938 if (rate == rate_sample) 939 sample_status = true; 940 941 if (last) 942 rate->success += info->status.ampdu_ack_len; 943 944 rate->attempts += ar[i].count * info->status.ampdu_len; 945 } 946 947 switch (mi->sample_mode) { 948 case MINSTREL_SAMPLE_IDLE: 949 if (mp->new_avg && 950 (mp->hw->max_rates > 1 || 951 mi->total_packets_cur < SAMPLE_SWITCH_THR)) 952 update_interval /= 2; 953 break; 954 955 case MINSTREL_SAMPLE_ACTIVE: 956 if (!sample_status) 957 break; 958 959 mi->sample_mode = MINSTREL_SAMPLE_PENDING; 960 update = true; 961 break; 962 963 case MINSTREL_SAMPLE_PENDING: 964 if (sample_status) 965 break; 966 967 update = true; 968 minstrel_ht_update_stats(mp, mi, false); 969 break; 970 } 971 972 973 if (mp->hw->max_rates > 1) { 974 /* 975 * check for sudden death of spatial multiplexing, 976 * downgrade to a lower number of streams if necessary. 977 */ 978 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 979 if (rate->attempts > 30 && 980 rate->success < rate->attempts / 4) { 981 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 982 update = true; 983 } 984 985 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 986 if (rate2->attempts > 30 && 987 rate2->success < rate2->attempts / 4) { 988 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 989 update = true; 990 } 991 } 992 993 if (time_after(jiffies, mi->last_stats_update + update_interval)) { 994 update = true; 995 minstrel_ht_update_stats(mp, mi, true); 996 } 997 998 if (update) 999 minstrel_ht_update_rates(mp, mi); 1000 } 1001 1002 static void 1003 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1004 int index) 1005 { 1006 struct minstrel_rate_stats *mrs; 1007 unsigned int tx_time, tx_time_rtscts, tx_time_data; 1008 unsigned int cw = mp->cw_min; 1009 unsigned int ctime = 0; 1010 unsigned int t_slot = 9; /* FIXME */ 1011 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 1012 unsigned int overhead = 0, overhead_rtscts = 0; 1013 1014 mrs = minstrel_get_ratestats(mi, index); 1015 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) { 1016 mrs->retry_count = 1; 1017 mrs->retry_count_rtscts = 1; 1018 return; 1019 } 1020 1021 mrs->retry_count = 2; 1022 mrs->retry_count_rtscts = 2; 1023 mrs->retry_updated = true; 1024 1025 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 1026 1027 /* Contention time for first 2 tries */ 1028 ctime = (t_slot * cw) >> 1; 1029 cw = min((cw << 1) | 1, mp->cw_max); 1030 ctime += (t_slot * cw) >> 1; 1031 cw = min((cw << 1) | 1, mp->cw_max); 1032 1033 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 1034 overhead = mi->overhead; 1035 overhead_rtscts = mi->overhead_rtscts; 1036 } 1037 1038 /* Total TX time for data and Contention after first 2 tries */ 1039 tx_time = ctime + 2 * (overhead + tx_time_data); 1040 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 1041 1042 /* See how many more tries we can fit inside segment size */ 1043 do { 1044 /* Contention time for this try */ 1045 ctime = (t_slot * cw) >> 1; 1046 cw = min((cw << 1) | 1, mp->cw_max); 1047 1048 /* Total TX time after this try */ 1049 tx_time += ctime + overhead + tx_time_data; 1050 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 1051 1052 if (tx_time_rtscts < mp->segment_size) 1053 mrs->retry_count_rtscts++; 1054 } while ((tx_time < mp->segment_size) && 1055 (++mrs->retry_count < mp->max_retry)); 1056 } 1057 1058 1059 static void 1060 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1061 struct ieee80211_sta_rates *ratetbl, int offset, int index) 1062 { 1063 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 1064 struct minstrel_rate_stats *mrs; 1065 u8 idx; 1066 u16 flags = group->flags; 1067 1068 mrs = minstrel_get_ratestats(mi, index); 1069 if (!mrs->retry_updated) 1070 minstrel_calc_retransmit(mp, mi, index); 1071 1072 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 1073 ratetbl->rate[offset].count = 2; 1074 ratetbl->rate[offset].count_rts = 2; 1075 ratetbl->rate[offset].count_cts = 2; 1076 } else { 1077 ratetbl->rate[offset].count = mrs->retry_count; 1078 ratetbl->rate[offset].count_cts = mrs->retry_count; 1079 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 1080 } 1081 1082 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 1083 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 1084 else if (flags & IEEE80211_TX_RC_VHT_MCS) 1085 idx = ((group->streams - 1) << 4) | 1086 ((index % MCS_GROUP_RATES) & 0xF); 1087 else 1088 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 1089 1090 /* enable RTS/CTS if needed: 1091 * - if station is in dynamic SMPS (and streams > 1) 1092 * - for fallback rates, to increase chances of getting through 1093 */ 1094 if (offset > 0 || 1095 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 1096 group->streams > 1)) { 1097 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 1098 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 1099 } 1100 1101 ratetbl->rate[offset].idx = idx; 1102 ratetbl->rate[offset].flags = flags; 1103 } 1104 1105 static inline int 1106 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate) 1107 { 1108 int group = rate / MCS_GROUP_RATES; 1109 rate %= MCS_GROUP_RATES; 1110 return mi->groups[group].rates[rate].prob_avg; 1111 } 1112 1113 static int 1114 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 1115 { 1116 int group = mi->max_prob_rate / MCS_GROUP_RATES; 1117 const struct mcs_group *g = &minstrel_mcs_groups[group]; 1118 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 1119 unsigned int duration; 1120 1121 /* Disable A-MSDU if max_prob_rate is bad */ 1122 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100)) 1123 return 1; 1124 1125 duration = g->duration[rate]; 1126 duration <<= g->shift; 1127 1128 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 1129 if (duration > MCS_DURATION(1, 0, 52)) 1130 return 500; 1131 1132 /* 1133 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 1134 * data packet size 1135 */ 1136 if (duration > MCS_DURATION(1, 0, 104)) 1137 return 1600; 1138 1139 /* 1140 * If the rate is slower than single-stream MCS7, or if the max throughput 1141 * rate success probability is less than 75%, limit A-MSDU to twice the usual 1142 * data packet size 1143 */ 1144 if (duration > MCS_DURATION(1, 0, 260) || 1145 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) < 1146 MINSTREL_FRAC(75, 100))) 1147 return 3200; 1148 1149 /* 1150 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 1151 * Since aggregation sessions are started/stopped without txq flush, use 1152 * the limit here to avoid the complexity of having to de-aggregate 1153 * packets in the queue. 1154 */ 1155 if (!mi->sta->vht_cap.vht_supported) 1156 return IEEE80211_MAX_MPDU_LEN_HT_BA; 1157 1158 /* unlimited */ 1159 return 0; 1160 } 1161 1162 static void 1163 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1164 { 1165 struct ieee80211_sta_rates *rates; 1166 u16 first_rate = mi->max_tp_rate[0]; 1167 int i = 0; 1168 1169 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE) 1170 first_rate = mi->sample_rate; 1171 1172 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 1173 if (!rates) 1174 return; 1175 1176 /* Start with max_tp_rate[0] */ 1177 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate); 1178 1179 if (mp->hw->max_rates >= 3) { 1180 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 1181 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 1182 } 1183 1184 if (mp->hw->max_rates >= 2) { 1185 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 1186 } 1187 1188 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 1189 rates->rate[i].idx = -1; 1190 rate_control_set_rates(mp->hw, mi->sta, rates); 1191 } 1192 1193 static int 1194 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1195 { 1196 struct minstrel_rate_stats *mrs; 1197 struct minstrel_mcs_group_data *mg; 1198 unsigned int sample_dur, sample_group, cur_max_tp_streams; 1199 int tp_rate1, tp_rate2; 1200 int sample_idx = 0; 1201 1202 if (mp->hw->max_rates == 1 && mp->sample_switch && 1203 (mi->total_packets_cur >= SAMPLE_SWITCH_THR || 1204 mp->sample_switch == 1)) 1205 return -1; 1206 1207 if (mi->sample_wait > 0) { 1208 mi->sample_wait--; 1209 return -1; 1210 } 1211 1212 if (!mi->sample_tries) 1213 return -1; 1214 1215 sample_group = mi->sample_group; 1216 mg = &mi->groups[sample_group]; 1217 sample_idx = sample_table[mg->column][mg->index]; 1218 minstrel_set_next_sample_idx(mi); 1219 1220 if (!(mi->supported[sample_group] & BIT(sample_idx))) 1221 return -1; 1222 1223 mrs = &mg->rates[sample_idx]; 1224 sample_idx += sample_group * MCS_GROUP_RATES; 1225 1226 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 1227 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1228 minstrel_get_duration(mi->max_tp_rate[1])) { 1229 tp_rate1 = mi->max_tp_rate[1]; 1230 tp_rate2 = mi->max_tp_rate[0]; 1231 } else { 1232 tp_rate1 = mi->max_tp_rate[0]; 1233 tp_rate2 = mi->max_tp_rate[1]; 1234 } 1235 1236 /* 1237 * Sampling might add some overhead (RTS, no aggregation) 1238 * to the frame. Hence, don't use sampling for the highest currently 1239 * used highest throughput or probability rate. 1240 */ 1241 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1242 return -1; 1243 1244 /* 1245 * Do not sample if the probability is already higher than 95%, 1246 * or if the rate is 3 times slower than the current max probability 1247 * rate, to avoid wasting airtime. 1248 */ 1249 sample_dur = minstrel_get_duration(sample_idx); 1250 if (mrs->prob_avg > MINSTREL_FRAC(95, 100) || 1251 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1252 return -1; 1253 1254 1255 /* 1256 * For devices with no configurable multi-rate retry, skip sampling 1257 * below the per-group max throughput rate, and only use one sampling 1258 * attempt per rate 1259 */ 1260 if (mp->hw->max_rates == 1 && 1261 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur || 1262 mrs->attempts)) 1263 return -1; 1264 1265 /* Skip already sampled slow rates */ 1266 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts) 1267 return -1; 1268 1269 /* 1270 * Make sure that lower rates get sampled only occasionally, 1271 * if the link is working perfectly. 1272 */ 1273 1274 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1275 MCS_GROUP_RATES].streams; 1276 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1277 (cur_max_tp_streams - 1 < 1278 minstrel_mcs_groups[sample_group].streams || 1279 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1280 if (mrs->sample_skipped < 20) 1281 return -1; 1282 1283 if (mi->sample_slow++ > 2) 1284 return -1; 1285 } 1286 mi->sample_tries--; 1287 1288 return sample_idx; 1289 } 1290 1291 static void 1292 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1293 struct ieee80211_tx_rate_control *txrc) 1294 { 1295 const struct mcs_group *sample_group; 1296 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1297 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1298 struct minstrel_ht_sta_priv *msp = priv_sta; 1299 struct minstrel_ht_sta *mi = &msp->ht; 1300 struct minstrel_priv *mp = priv; 1301 int sample_idx; 1302 1303 if (!msp->is_ht) 1304 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1305 1306 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1307 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1308 minstrel_aggr_check(sta, txrc->skb); 1309 1310 info->flags |= mi->tx_flags; 1311 1312 #ifdef CONFIG_MAC80211_DEBUGFS 1313 if (mp->fixed_rate_idx != -1) 1314 return; 1315 #endif 1316 1317 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1318 if (mp->hw->max_rates == 1 && 1319 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1320 sample_idx = -1; 1321 else 1322 sample_idx = minstrel_get_sample_rate(mp, mi); 1323 1324 mi->total_packets++; 1325 1326 /* wraparound */ 1327 if (mi->total_packets == ~0) { 1328 mi->total_packets = 0; 1329 mi->sample_packets = 0; 1330 } 1331 1332 if (sample_idx < 0) 1333 return; 1334 1335 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1336 sample_idx %= MCS_GROUP_RATES; 1337 1338 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1339 (sample_idx >= 4) != txrc->short_preamble) 1340 return; 1341 1342 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1343 rate->count = 1; 1344 1345 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1346 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1347 rate->idx = mp->cck_rates[idx]; 1348 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1349 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1350 sample_group->streams); 1351 } else { 1352 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1353 } 1354 1355 rate->flags = sample_group->flags; 1356 } 1357 1358 static void 1359 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1360 struct ieee80211_supported_band *sband, 1361 struct ieee80211_sta *sta) 1362 { 1363 int i; 1364 1365 if (sband->band != NL80211_BAND_2GHZ) 1366 return; 1367 1368 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1369 return; 1370 1371 mi->cck_supported = 0; 1372 mi->cck_supported_short = 0; 1373 for (i = 0; i < 4; i++) { 1374 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1375 continue; 1376 1377 mi->cck_supported |= BIT(i); 1378 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1379 mi->cck_supported_short |= BIT(i); 1380 } 1381 1382 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1383 } 1384 1385 static void 1386 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1387 struct cfg80211_chan_def *chandef, 1388 struct ieee80211_sta *sta, void *priv_sta) 1389 { 1390 struct minstrel_priv *mp = priv; 1391 struct minstrel_ht_sta_priv *msp = priv_sta; 1392 struct minstrel_ht_sta *mi = &msp->ht; 1393 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1394 u16 ht_cap = sta->ht_cap.cap; 1395 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1396 int use_vht; 1397 int n_supported = 0; 1398 int ack_dur; 1399 int stbc; 1400 int i; 1401 bool ldpc; 1402 1403 /* fall back to the old minstrel for legacy stations */ 1404 if (!sta->ht_cap.ht_supported) 1405 goto use_legacy; 1406 1407 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1408 1409 if (vht_cap->vht_supported) 1410 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1411 else 1412 use_vht = 0; 1413 1414 msp->is_ht = true; 1415 memset(mi, 0, sizeof(*mi)); 1416 1417 mi->sta = sta; 1418 mi->last_stats_update = jiffies; 1419 1420 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1421 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1422 mi->overhead += ack_dur; 1423 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1424 1425 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1426 1427 /* When using MRR, sample more on the first attempt, without delay */ 1428 if (mp->has_mrr) { 1429 mi->sample_count = 16; 1430 mi->sample_wait = 0; 1431 } else { 1432 mi->sample_count = 8; 1433 mi->sample_wait = 8; 1434 } 1435 mi->sample_tries = 4; 1436 1437 if (!use_vht) { 1438 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1439 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1440 1441 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1442 } else { 1443 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1444 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1445 1446 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1447 } 1448 1449 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1450 if (ldpc) 1451 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1452 1453 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1454 u32 gflags = minstrel_mcs_groups[i].flags; 1455 int bw, nss; 1456 1457 mi->supported[i] = 0; 1458 if (i == MINSTREL_CCK_GROUP) { 1459 minstrel_ht_update_cck(mp, mi, sband, sta); 1460 continue; 1461 } 1462 1463 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1464 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1465 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1466 continue; 1467 } else { 1468 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1469 continue; 1470 } 1471 } 1472 1473 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1474 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1475 continue; 1476 1477 nss = minstrel_mcs_groups[i].streams; 1478 1479 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1480 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1481 continue; 1482 1483 /* HT rate */ 1484 if (gflags & IEEE80211_TX_RC_MCS) { 1485 if (use_vht && minstrel_vht_only) 1486 continue; 1487 1488 mi->supported[i] = mcs->rx_mask[nss - 1]; 1489 if (mi->supported[i]) 1490 n_supported++; 1491 continue; 1492 } 1493 1494 /* VHT rate */ 1495 if (!vht_cap->vht_supported || 1496 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1497 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1498 continue; 1499 1500 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1501 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1502 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1503 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1504 continue; 1505 } 1506 } 1507 1508 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1509 bw = BW_40; 1510 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1511 bw = BW_80; 1512 else 1513 bw = BW_20; 1514 1515 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1516 vht_cap->vht_mcs.tx_mcs_map); 1517 1518 if (mi->supported[i]) 1519 n_supported++; 1520 } 1521 1522 if (!n_supported) 1523 goto use_legacy; 1524 1525 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; 1526 1527 /* create an initial rate table with the lowest supported rates */ 1528 minstrel_ht_update_stats(mp, mi, true); 1529 minstrel_ht_update_rates(mp, mi); 1530 1531 return; 1532 1533 use_legacy: 1534 msp->is_ht = false; 1535 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1536 msp->legacy.r = msp->ratelist; 1537 msp->legacy.sample_table = msp->sample_table; 1538 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1539 &msp->legacy); 1540 } 1541 1542 static void 1543 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1544 struct cfg80211_chan_def *chandef, 1545 struct ieee80211_sta *sta, void *priv_sta) 1546 { 1547 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1548 } 1549 1550 static void 1551 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1552 struct cfg80211_chan_def *chandef, 1553 struct ieee80211_sta *sta, void *priv_sta, 1554 u32 changed) 1555 { 1556 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1557 } 1558 1559 static void * 1560 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1561 { 1562 struct ieee80211_supported_band *sband; 1563 struct minstrel_ht_sta_priv *msp; 1564 struct minstrel_priv *mp = priv; 1565 struct ieee80211_hw *hw = mp->hw; 1566 int max_rates = 0; 1567 int i; 1568 1569 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1570 sband = hw->wiphy->bands[i]; 1571 if (sband && sband->n_bitrates > max_rates) 1572 max_rates = sband->n_bitrates; 1573 } 1574 1575 msp = kzalloc(sizeof(*msp), gfp); 1576 if (!msp) 1577 return NULL; 1578 1579 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1580 if (!msp->ratelist) 1581 goto error; 1582 1583 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1584 if (!msp->sample_table) 1585 goto error1; 1586 1587 return msp; 1588 1589 error1: 1590 kfree(msp->ratelist); 1591 error: 1592 kfree(msp); 1593 return NULL; 1594 } 1595 1596 static void 1597 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1598 { 1599 struct minstrel_ht_sta_priv *msp = priv_sta; 1600 1601 kfree(msp->sample_table); 1602 kfree(msp->ratelist); 1603 kfree(msp); 1604 } 1605 1606 static void 1607 minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1608 { 1609 static const int bitrates[4] = { 10, 20, 55, 110 }; 1610 struct ieee80211_supported_band *sband; 1611 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1612 int i, j; 1613 1614 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1615 if (!sband) 1616 return; 1617 1618 for (i = 0; i < sband->n_bitrates; i++) { 1619 struct ieee80211_rate *rate = &sband->bitrates[i]; 1620 1621 if (rate->flags & IEEE80211_RATE_ERP_G) 1622 continue; 1623 1624 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1625 continue; 1626 1627 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 1628 if (rate->bitrate != bitrates[j]) 1629 continue; 1630 1631 mp->cck_rates[j] = i; 1632 break; 1633 } 1634 } 1635 } 1636 1637 static void * 1638 minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) 1639 { 1640 struct minstrel_priv *mp; 1641 1642 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1643 if (!mp) 1644 return NULL; 1645 1646 mp->sample_switch = -1; 1647 1648 /* contention window settings 1649 * Just an approximation. Using the per-queue values would complicate 1650 * the calculations and is probably unnecessary */ 1651 mp->cw_min = 15; 1652 mp->cw_max = 1023; 1653 1654 /* number of packets (in %) to use for sampling other rates 1655 * sample less often for non-mrr packets, because the overhead 1656 * is much higher than with mrr */ 1657 mp->lookaround_rate = 5; 1658 mp->lookaround_rate_mrr = 10; 1659 1660 /* maximum time that the hw is allowed to stay in one MRR segment */ 1661 mp->segment_size = 6000; 1662 1663 if (hw->max_rate_tries > 0) 1664 mp->max_retry = hw->max_rate_tries; 1665 else 1666 /* safe default, does not necessarily have to match hw properties */ 1667 mp->max_retry = 7; 1668 1669 if (hw->max_rates >= 4) 1670 mp->has_mrr = true; 1671 1672 mp->hw = hw; 1673 mp->update_interval = HZ / 10; 1674 mp->new_avg = true; 1675 1676 #ifdef CONFIG_MAC80211_DEBUGFS 1677 mp->fixed_rate_idx = (u32) -1; 1678 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1679 &mp->fixed_rate_idx); 1680 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, 1681 &mp->sample_switch); 1682 debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir, 1683 &mp->new_avg); 1684 #endif 1685 1686 minstrel_ht_init_cck_rates(mp); 1687 1688 return mp; 1689 } 1690 1691 static void 1692 minstrel_ht_free(void *priv) 1693 { 1694 kfree(priv); 1695 } 1696 1697 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1698 { 1699 struct minstrel_ht_sta_priv *msp = priv_sta; 1700 struct minstrel_ht_sta *mi = &msp->ht; 1701 int i, j, prob, tp_avg; 1702 1703 if (!msp->is_ht) 1704 return mac80211_minstrel.get_expected_throughput(priv_sta); 1705 1706 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1707 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1708 prob = mi->groups[i].rates[j].prob_avg; 1709 1710 /* convert tp_avg from pkt per second in kbps */ 1711 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1712 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1713 1714 return tp_avg; 1715 } 1716 1717 static const struct rate_control_ops mac80211_minstrel_ht = { 1718 .name = "minstrel_ht", 1719 .tx_status_ext = minstrel_ht_tx_status, 1720 .get_rate = minstrel_ht_get_rate, 1721 .rate_init = minstrel_ht_rate_init, 1722 .rate_update = minstrel_ht_rate_update, 1723 .alloc_sta = minstrel_ht_alloc_sta, 1724 .free_sta = minstrel_ht_free_sta, 1725 .alloc = minstrel_ht_alloc, 1726 .free = minstrel_ht_free, 1727 #ifdef CONFIG_MAC80211_DEBUGFS 1728 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1729 #endif 1730 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1731 }; 1732 1733 1734 static void __init init_sample_table(void) 1735 { 1736 int col, i, new_idx; 1737 u8 rnd[MCS_GROUP_RATES]; 1738 1739 memset(sample_table, 0xff, sizeof(sample_table)); 1740 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1741 prandom_bytes(rnd, sizeof(rnd)); 1742 for (i = 0; i < MCS_GROUP_RATES; i++) { 1743 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1744 while (sample_table[col][new_idx] != 0xff) 1745 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1746 1747 sample_table[col][new_idx] = i; 1748 } 1749 } 1750 } 1751 1752 int __init 1753 rc80211_minstrel_init(void) 1754 { 1755 init_sample_table(); 1756 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1757 } 1758 1759 void 1760 rc80211_minstrel_exit(void) 1761 { 1762 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1763 } 1764