1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org> 4 * Copyright (C) 2019-2020 Intel Corporation 5 */ 6#include <linux/netdevice.h> 7#include <linux/types.h> 8#include <linux/skbuff.h> 9#include <linux/debugfs.h> 10#include <linux/random.h> 11#include <linux/moduleparam.h> 12#include <linux/ieee80211.h> 13#include <net/mac80211.h> 14#include "rate.h" 15#include "sta_info.h" 16#include "rc80211_minstrel.h" 17#include "rc80211_minstrel_ht.h" 18 19#define AVG_AMPDU_SIZE 16 20#define AVG_PKT_SIZE 1200 21 22#define SAMPLE_SWITCH_THR 100 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 .bw = _ht40, \ 65 .flags = \ 66 IEEE80211_TX_RC_MCS | \ 67 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 68 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 69 .duration = { \ 70 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s, \ 71 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \ 72 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \ 73 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \ 74 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \ 75 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \ 76 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \ 77 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \ 78 } \ 79} 80 81#define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \ 82 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26)) 83 84#define MCS_GROUP(_streams, _sgi, _ht40) \ 85 __MCS_GROUP(_streams, _sgi, _ht40, \ 86 MCS_GROUP_SHIFT(_streams, _sgi, _ht40)) 87 88#define VHT_GROUP_IDX(_streams, _sgi, _bw) \ 89 (MINSTREL_VHT_GROUP_0 + \ 90 MINSTREL_MAX_STREAMS * 2 * (_bw) + \ 91 MINSTREL_MAX_STREAMS * (_sgi) + \ 92 (_streams) - 1) 93 94#define BW2VBPS(_bw, r3, r2, r1) \ 95 (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) 96 97#define __VHT_GROUP(_streams, _sgi, _bw, _s) \ 98 [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ 99 .streams = _streams, \ 100 .shift = _s, \ 101 .bw = _bw, \ 102 .flags = \ 103 IEEE80211_TX_RC_VHT_MCS | \ 104 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ 105 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ 106 _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ 107 .duration = { \ 108 MCS_DURATION(_streams, _sgi, \ 109 BW2VBPS(_bw, 117, 54, 26)) >> _s, \ 110 MCS_DURATION(_streams, _sgi, \ 111 BW2VBPS(_bw, 234, 108, 52)) >> _s, \ 112 MCS_DURATION(_streams, _sgi, \ 113 BW2VBPS(_bw, 351, 162, 78)) >> _s, \ 114 MCS_DURATION(_streams, _sgi, \ 115 BW2VBPS(_bw, 468, 216, 104)) >> _s, \ 116 MCS_DURATION(_streams, _sgi, \ 117 BW2VBPS(_bw, 702, 324, 156)) >> _s, \ 118 MCS_DURATION(_streams, _sgi, \ 119 BW2VBPS(_bw, 936, 432, 208)) >> _s, \ 120 MCS_DURATION(_streams, _sgi, \ 121 BW2VBPS(_bw, 1053, 486, 234)) >> _s, \ 122 MCS_DURATION(_streams, _sgi, \ 123 BW2VBPS(_bw, 1170, 540, 260)) >> _s, \ 124 MCS_DURATION(_streams, _sgi, \ 125 BW2VBPS(_bw, 1404, 648, 312)) >> _s, \ 126 MCS_DURATION(_streams, _sgi, \ 127 BW2VBPS(_bw, 1560, 720, 346)) >> _s \ 128 } \ 129} 130 131#define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \ 132 GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \ 133 BW2VBPS(_bw, 117, 54, 26))) 134 135#define VHT_GROUP(_streams, _sgi, _bw) \ 136 __VHT_GROUP(_streams, _sgi, _bw, \ 137 VHT_GROUP_SHIFT(_streams, _sgi, _bw)) 138 139#define CCK_DURATION(_bitrate, _short, _len) \ 140 (1000 * (10 /* SIFS */ + \ 141 (_short ? 72 + 24 : 144 + 48) + \ 142 (8 * (_len + 4) * 10) / (_bitrate))) 143 144#define CCK_ACK_DURATION(_bitrate, _short) \ 145 (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ 146 CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) 147 148#define CCK_DURATION_LIST(_short, _s) \ 149 CCK_ACK_DURATION(10, _short) >> _s, \ 150 CCK_ACK_DURATION(20, _short) >> _s, \ 151 CCK_ACK_DURATION(55, _short) >> _s, \ 152 CCK_ACK_DURATION(110, _short) >> _s 153 154#define __CCK_GROUP(_s) \ 155 [MINSTREL_CCK_GROUP] = { \ 156 .streams = 1, \ 157 .flags = 0, \ 158 .shift = _s, \ 159 .duration = { \ 160 CCK_DURATION_LIST(false, _s), \ 161 CCK_DURATION_LIST(true, _s) \ 162 } \ 163 } 164 165#define CCK_GROUP_SHIFT \ 166 GROUP_SHIFT(CCK_ACK_DURATION(10, false)) 167 168#define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) 169 170 171static bool minstrel_vht_only = true; 172module_param(minstrel_vht_only, bool, 0644); 173MODULE_PARM_DESC(minstrel_vht_only, 174 "Use only VHT rates when VHT is supported by sta."); 175 176/* 177 * To enable sufficiently targeted rate sampling, MCS rates are divided into 178 * groups, based on the number of streams and flags (HT40, SGI) that they 179 * use. 180 * 181 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 182 * BW -> SGI -> #streams 183 */ 184const struct mcs_group minstrel_mcs_groups[] = { 185 MCS_GROUP(1, 0, BW_20), 186 MCS_GROUP(2, 0, BW_20), 187 MCS_GROUP(3, 0, BW_20), 188 MCS_GROUP(4, 0, BW_20), 189 190 MCS_GROUP(1, 1, BW_20), 191 MCS_GROUP(2, 1, BW_20), 192 MCS_GROUP(3, 1, BW_20), 193 MCS_GROUP(4, 1, BW_20), 194 195 MCS_GROUP(1, 0, BW_40), 196 MCS_GROUP(2, 0, BW_40), 197 MCS_GROUP(3, 0, BW_40), 198 MCS_GROUP(4, 0, BW_40), 199 200 MCS_GROUP(1, 1, BW_40), 201 MCS_GROUP(2, 1, BW_40), 202 MCS_GROUP(3, 1, BW_40), 203 MCS_GROUP(4, 1, BW_40), 204 205 CCK_GROUP, 206 207 VHT_GROUP(1, 0, BW_20), 208 VHT_GROUP(2, 0, BW_20), 209 VHT_GROUP(3, 0, BW_20), 210 VHT_GROUP(4, 0, BW_20), 211 212 VHT_GROUP(1, 1, BW_20), 213 VHT_GROUP(2, 1, BW_20), 214 VHT_GROUP(3, 1, BW_20), 215 VHT_GROUP(4, 1, BW_20), 216 217 VHT_GROUP(1, 0, BW_40), 218 VHT_GROUP(2, 0, BW_40), 219 VHT_GROUP(3, 0, BW_40), 220 VHT_GROUP(4, 0, BW_40), 221 222 VHT_GROUP(1, 1, BW_40), 223 VHT_GROUP(2, 1, BW_40), 224 VHT_GROUP(3, 1, BW_40), 225 VHT_GROUP(4, 1, BW_40), 226 227 VHT_GROUP(1, 0, BW_80), 228 VHT_GROUP(2, 0, BW_80), 229 VHT_GROUP(3, 0, BW_80), 230 VHT_GROUP(4, 0, BW_80), 231 232 VHT_GROUP(1, 1, BW_80), 233 VHT_GROUP(2, 1, BW_80), 234 VHT_GROUP(3, 1, BW_80), 235 VHT_GROUP(4, 1, BW_80), 236}; 237 238static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 239 240static void 241minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 242 243/* 244 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 245 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 246 * 247 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 248 */ 249static u16 250minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 251{ 252 u16 mask = 0; 253 254 if (bw == BW_20) { 255 if (nss != 3 && nss != 6) 256 mask = BIT(9); 257 } else if (bw == BW_80) { 258 if (nss == 3 || nss == 7) 259 mask = BIT(6); 260 else if (nss == 6) 261 mask = BIT(9); 262 } else { 263 WARN_ON(bw != BW_40); 264 } 265 266 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 267 case IEEE80211_VHT_MCS_SUPPORT_0_7: 268 mask |= 0x300; 269 break; 270 case IEEE80211_VHT_MCS_SUPPORT_0_8: 271 mask |= 0x200; 272 break; 273 case IEEE80211_VHT_MCS_SUPPORT_0_9: 274 break; 275 default: 276 mask = 0x3ff; 277 } 278 279 return 0x3ff & ~mask; 280} 281 282/* 283 * Look up an MCS group index based on mac80211 rate information 284 */ 285static int 286minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 287{ 288 return GROUP_IDX((rate->idx / 8) + 1, 289 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 290 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 291} 292 293static int 294minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 295{ 296 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 297 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 298 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 299 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 300} 301 302static struct minstrel_rate_stats * 303minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 304 struct ieee80211_tx_rate *rate) 305{ 306 int group, idx; 307 308 if (rate->flags & IEEE80211_TX_RC_MCS) { 309 group = minstrel_ht_get_group_idx(rate); 310 idx = rate->idx % 8; 311 } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 312 group = minstrel_vht_get_group_idx(rate); 313 idx = ieee80211_rate_get_vht_mcs(rate); 314 } else { 315 group = MINSTREL_CCK_GROUP; 316 317 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) 318 if (rate->idx == mp->cck_rates[idx]) 319 break; 320 321 /* short preamble */ 322 if ((mi->supported[group] & BIT(idx + 4)) && 323 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) 324 idx += 4; 325 } 326 return &mi->groups[group].rates[idx]; 327} 328 329static inline struct minstrel_rate_stats * 330minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 331{ 332 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 333} 334 335static unsigned int 336minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 337{ 338 if (!mi->avg_ampdu_len) 339 return AVG_AMPDU_SIZE; 340 341 return MINSTREL_TRUNC(mi->avg_ampdu_len); 342} 343 344/* 345 * Return current throughput based on the average A-MPDU length, taking into 346 * account the expected number of retransmissions and their expected length 347 */ 348int 349minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 350 int prob_avg) 351{ 352 unsigned int nsecs = 0; 353 354 /* do not account throughput if sucess prob is below 10% */ 355 if (prob_avg < MINSTREL_FRAC(10, 100)) 356 return 0; 357 358 if (group != MINSTREL_CCK_GROUP) 359 nsecs = 1000 * mi->overhead / minstrel_ht_avg_ampdu_len(mi); 360 361 nsecs += minstrel_mcs_groups[group].duration[rate] << 362 minstrel_mcs_groups[group].shift; 363 364 /* 365 * For the throughput calculation, limit the probability value to 90% to 366 * account for collision related packet error rate fluctuation 367 * (prob is scaled - see MINSTREL_FRAC above) 368 */ 369 if (prob_avg > MINSTREL_FRAC(90, 100)) 370 return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) 371 / nsecs)); 372 else 373 return MINSTREL_TRUNC(100000 * ((prob_avg * 1000) / nsecs)); 374} 375 376/* 377 * Find & sort topmost throughput rates 378 * 379 * If multiple rates provide equal throughput the sorting is based on their 380 * current success probability. Higher success probability is preferred among 381 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 382 */ 383static void 384minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 385 u16 *tp_list) 386{ 387 int cur_group, cur_idx, cur_tp_avg, cur_prob; 388 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 389 int j = MAX_THR_RATES; 390 391 cur_group = index / MCS_GROUP_RATES; 392 cur_idx = index % MCS_GROUP_RATES; 393 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg; 394 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 395 396 do { 397 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 398 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 399 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 400 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 401 tmp_prob); 402 if (cur_tp_avg < tmp_tp_avg || 403 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 404 break; 405 j--; 406 } while (j > 0); 407 408 if (j < MAX_THR_RATES - 1) { 409 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 410 (MAX_THR_RATES - (j + 1)))); 411 } 412 if (j < MAX_THR_RATES) 413 tp_list[j] = index; 414} 415 416/* 417 * Find and set the topmost probability rate per sta and per group 418 */ 419static void 420minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) 421{ 422 struct minstrel_mcs_group_data *mg; 423 struct minstrel_rate_stats *mrs; 424 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 425 int max_tp_group, cur_tp_avg, cur_group, cur_idx; 426 int max_gpr_group, max_gpr_idx; 427 int max_gpr_tp_avg, max_gpr_prob; 428 429 cur_group = index / MCS_GROUP_RATES; 430 cur_idx = index % MCS_GROUP_RATES; 431 mg = &mi->groups[index / MCS_GROUP_RATES]; 432 mrs = &mg->rates[index % MCS_GROUP_RATES]; 433 434 tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; 435 tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; 436 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 437 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 438 439 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 440 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 441 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 442 if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && 443 (max_tp_group != MINSTREL_CCK_GROUP)) 444 return; 445 446 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 447 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 448 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg; 449 450 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) { 451 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 452 mrs->prob_avg); 453 if (cur_tp_avg > tmp_tp_avg) 454 mi->max_prob_rate = index; 455 456 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 457 max_gpr_idx, 458 max_gpr_prob); 459 if (cur_tp_avg > max_gpr_tp_avg) 460 mg->max_group_prob_rate = index; 461 } else { 462 if (mrs->prob_avg > tmp_prob) 463 mi->max_prob_rate = index; 464 if (mrs->prob_avg > max_gpr_prob) 465 mg->max_group_prob_rate = index; 466 } 467} 468 469 470/* 471 * Assign new rate set per sta and use CCK rates only if the fastest 472 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 473 * rate sets where MCS and CCK rates are mixed, because CCK rates can 474 * not use aggregation. 475 */ 476static void 477minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 478 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 479 u16 tmp_cck_tp_rate[MAX_THR_RATES]) 480{ 481 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 482 int i; 483 484 tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; 485 tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; 486 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 487 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 488 489 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 490 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 491 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 492 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 493 494 if (tmp_cck_tp > tmp_mcs_tp) { 495 for(i = 0; i < MAX_THR_RATES; i++) { 496 minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], 497 tmp_mcs_tp_rate); 498 } 499 } 500 501} 502 503/* 504 * Try to increase robustness of max_prob rate by decrease number of 505 * streams if possible. 506 */ 507static inline void 508minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 509{ 510 struct minstrel_mcs_group_data *mg; 511 int tmp_max_streams, group, tmp_idx, tmp_prob; 512 int tmp_tp = 0; 513 514 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 515 MCS_GROUP_RATES].streams; 516 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 517 mg = &mi->groups[group]; 518 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 519 continue; 520 521 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 522 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg; 523 524 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 525 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 526 mi->max_prob_rate = mg->max_group_prob_rate; 527 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 528 tmp_idx, 529 tmp_prob); 530 } 531 } 532} 533 534static inline int 535minstrel_get_duration(int index) 536{ 537 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 538 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 539 return duration << group->shift; 540} 541 542static bool 543minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group, 544 int tp_idx, const struct mcs_group *group) 545{ 546 if (group->bw < tp_group->bw) 547 return false; 548 549 if (group->streams == tp_group->streams) 550 return true; 551 552 if (tp_idx < 4 && group->streams == tp_group->streams - 1) 553 return true; 554 555 return group->streams == tp_group->streams + 1; 556} 557 558static void 559minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates, 560 bool faster_rate) 561{ 562 const struct mcs_group *group, *tp_group; 563 int i, g, max_dur; 564 int tp_idx; 565 566 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES]; 567 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; 568 569 max_dur = minstrel_get_duration(mi->max_tp_rate[0]); 570 if (faster_rate) 571 max_dur -= max_dur / 16; 572 573 for (g = 0; g < MINSTREL_GROUPS_NB; g++) { 574 u16 supported = mi->supported[g]; 575 576 if (!supported) 577 continue; 578 579 group = &minstrel_mcs_groups[g]; 580 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group)) 581 continue; 582 583 for (i = 0; supported; supported >>= 1, i++) { 584 int idx; 585 586 if (!(supported & 1)) 587 continue; 588 589 if ((group->duration[i] << group->shift) > max_dur) 590 continue; 591 592 idx = g * MCS_GROUP_RATES + i; 593 if (idx == mi->max_tp_rate[0]) 594 continue; 595 596 rates[(*n_rates)++] = idx; 597 break; 598 } 599 } 600} 601 602static void 603minstrel_ht_rate_sample_switch(struct minstrel_priv *mp, 604 struct minstrel_ht_sta *mi) 605{ 606 struct minstrel_rate_stats *mrs; 607 u16 rates[MINSTREL_GROUPS_NB]; 608 int n_rates = 0; 609 int probe_rate = 0; 610 bool faster_rate; 611 int i; 612 u8 random; 613 614 /* 615 * Use rate switching instead of probing packets for devices with 616 * little control over retry fallback behavior 617 */ 618 if (mp->hw->max_rates > 1) 619 return; 620 621 /* 622 * If the current EWMA prob is >75%, look for a rate that's 6.25% 623 * faster than the max tp rate. 624 * If that fails, look again for a rate that is at least as fast 625 */ 626 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 627 faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100); 628 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate); 629 if (!n_rates && faster_rate) 630 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false); 631 632 /* If no suitable rate was found, try to pick the next one in the group */ 633 if (!n_rates) { 634 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES; 635 u16 supported = mi->supported[g_idx]; 636 637 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; 638 for (i = 0; supported; supported >>= 1, i++) { 639 if (!(supported & 1)) 640 continue; 641 642 probe_rate = mi->max_tp_rate[0] + i; 643 goto out; 644 } 645 646 return; 647 } 648 649 i = 0; 650 if (n_rates > 1) { 651 random = prandom_u32(); 652 i = random % n_rates; 653 } 654 probe_rate = rates[i]; 655 656out: 657 mi->sample_rate = probe_rate; 658 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE; 659} 660 661/* 662 * Update rate statistics and select new primary rates 663 * 664 * Rules for rate selection: 665 * - max_prob_rate must use only one stream, as a tradeoff between delivery 666 * probability and throughput during strong fluctuations 667 * - as long as the max prob rate has a probability of more than 75%, pick 668 * higher throughput rates, even if the probablity is a bit lower 669 */ 670static void 671minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 672 bool sample) 673{ 674 struct minstrel_mcs_group_data *mg; 675 struct minstrel_rate_stats *mrs; 676 int group, i, j, cur_prob; 677 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 678 u16 tmp_cck_tp_rate[MAX_THR_RATES], index; 679 680 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 681 682 if (sample) { 683 mi->total_packets_cur = mi->total_packets - 684 mi->total_packets_last; 685 mi->total_packets_last = mi->total_packets; 686 } 687 if (!mp->sample_switch) 688 sample = false; 689 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1) 690 sample = false; 691 692 if (mi->ampdu_packets > 0) { 693 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 694 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 695 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 696 EWMA_LEVEL); 697 else 698 mi->avg_ampdu_len = 0; 699 mi->ampdu_len = 0; 700 mi->ampdu_packets = 0; 701 } 702 703 mi->sample_slow = 0; 704 mi->sample_count = 0; 705 706 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate)); 707 memset(tmp_cck_tp_rate, 0, sizeof(tmp_cck_tp_rate)); 708 if (mi->supported[MINSTREL_CCK_GROUP]) 709 for (j = 0; j < ARRAY_SIZE(tmp_cck_tp_rate); j++) 710 tmp_cck_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; 711 712 if (mi->supported[MINSTREL_VHT_GROUP_0]) 713 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES; 714 else 715 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES; 716 717 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++) 718 tmp_mcs_tp_rate[j] = index; 719 720 /* Find best rate sets within all MCS groups*/ 721 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 722 723 mg = &mi->groups[group]; 724 if (!mi->supported[group]) 725 continue; 726 727 mi->sample_count++; 728 729 /* (re)Initialize group rate indexes */ 730 for(j = 0; j < MAX_THR_RATES; j++) 731 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group; 732 733 for (i = 0; i < MCS_GROUP_RATES; i++) { 734 if (!(mi->supported[group] & BIT(i))) 735 continue; 736 737 index = MCS_GROUP_RATES * group + i; 738 739 mrs = &mg->rates[i]; 740 mrs->retry_updated = false; 741 minstrel_calc_rate_stats(mp, mrs); 742 cur_prob = mrs->prob_avg; 743 744 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 745 continue; 746 747 /* Find max throughput rate set */ 748 if (group != MINSTREL_CCK_GROUP) { 749 minstrel_ht_sort_best_tp_rates(mi, index, 750 tmp_mcs_tp_rate); 751 } else if (group == MINSTREL_CCK_GROUP) { 752 minstrel_ht_sort_best_tp_rates(mi, index, 753 tmp_cck_tp_rate); 754 } 755 756 /* Find max throughput rate set within a group */ 757 minstrel_ht_sort_best_tp_rates(mi, index, 758 tmp_group_tp_rate); 759 760 /* Find max probability rate per group and global */ 761 minstrel_ht_set_best_prob_rate(mi, index); 762 } 763 764 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 765 sizeof(mg->max_group_tp_rate)); 766 } 767 768 /* Assign new rate set per sta */ 769 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); 770 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 771 772 /* Try to increase robustness of max_prob_rate*/ 773 minstrel_ht_prob_rate_reduce_streams(mi); 774 775 /* try to sample all available rates during each interval */ 776 mi->sample_count *= 8; 777 if (mp->new_avg) 778 mi->sample_count /= 2; 779 780 if (sample) 781 minstrel_ht_rate_sample_switch(mp, mi); 782 783#ifdef CONFIG_MAC80211_DEBUGFS 784 /* use fixed index if set */ 785 if (mp->fixed_rate_idx != -1) { 786 for (i = 0; i < 4; i++) 787 mi->max_tp_rate[i] = mp->fixed_rate_idx; 788 mi->max_prob_rate = mp->fixed_rate_idx; 789 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 790 } 791#endif 792 793 /* Reset update timer */ 794 mi->last_stats_update = jiffies; 795} 796 797static bool 798minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) 799{ 800 if (rate->idx < 0) 801 return false; 802 803 if (!rate->count) 804 return false; 805 806 if (rate->flags & IEEE80211_TX_RC_MCS || 807 rate->flags & IEEE80211_TX_RC_VHT_MCS) 808 return true; 809 810 return rate->idx == mp->cck_rates[0] || 811 rate->idx == mp->cck_rates[1] || 812 rate->idx == mp->cck_rates[2] || 813 rate->idx == mp->cck_rates[3]; 814} 815 816static void 817minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 818{ 819 struct minstrel_mcs_group_data *mg; 820 821 for (;;) { 822 mi->sample_group++; 823 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 824 mg = &mi->groups[mi->sample_group]; 825 826 if (!mi->supported[mi->sample_group]) 827 continue; 828 829 if (++mg->index >= MCS_GROUP_RATES) { 830 mg->index = 0; 831 if (++mg->column >= ARRAY_SIZE(sample_table)) 832 mg->column = 0; 833 } 834 break; 835 } 836} 837 838static void 839minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 840{ 841 int group, orig_group; 842 843 orig_group = group = *idx / MCS_GROUP_RATES; 844 while (group > 0) { 845 group--; 846 847 if (!mi->supported[group]) 848 continue; 849 850 if (minstrel_mcs_groups[group].streams > 851 minstrel_mcs_groups[orig_group].streams) 852 continue; 853 854 if (primary) 855 *idx = mi->groups[group].max_group_tp_rate[0]; 856 else 857 *idx = mi->groups[group].max_group_tp_rate[1]; 858 break; 859 } 860} 861 862static void 863minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 864{ 865 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 866 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 867 u16 tid; 868 869 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 870 return; 871 872 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 873 return; 874 875 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 876 return; 877 878 tid = ieee80211_get_tid(hdr); 879 if (likely(sta->ampdu_mlme.tid_tx[tid])) 880 return; 881 882 ieee80211_start_tx_ba_session(pubsta, tid, 0); 883} 884 885static void 886minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 887 void *priv_sta, struct ieee80211_tx_status *st) 888{ 889 struct ieee80211_tx_info *info = st->info; 890 struct minstrel_ht_sta_priv *msp = priv_sta; 891 struct minstrel_ht_sta *mi = &msp->ht; 892 struct ieee80211_tx_rate *ar = info->status.rates; 893 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; 894 struct minstrel_priv *mp = priv; 895 u32 update_interval = mp->update_interval / 2; 896 bool last, update = false; 897 bool sample_status = false; 898 int i; 899 900 if (!msp->is_ht) 901 return mac80211_minstrel.tx_status_ext(priv, sband, 902 &msp->legacy, st); 903 904 905 /* This packet was aggregated but doesn't carry status info */ 906 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 907 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 908 return; 909 910 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 911 info->status.ampdu_ack_len = 912 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 913 info->status.ampdu_len = 1; 914 } 915 916 mi->ampdu_packets++; 917 mi->ampdu_len += info->status.ampdu_len; 918 919 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 920 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 921 922 mi->sample_wait = 16 + 2 * avg_ampdu_len; 923 mi->sample_tries = 1; 924 mi->sample_count--; 925 } 926 927 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 928 mi->sample_packets += info->status.ampdu_len; 929 930 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE) 931 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate); 932 933 last = !minstrel_ht_txstat_valid(mp, &ar[0]); 934 for (i = 0; !last; i++) { 935 last = (i == IEEE80211_TX_MAX_RATES - 1) || 936 !minstrel_ht_txstat_valid(mp, &ar[i + 1]); 937 938 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 939 if (rate == rate_sample) 940 sample_status = true; 941 942 if (last) 943 rate->success += info->status.ampdu_ack_len; 944 945 rate->attempts += ar[i].count * info->status.ampdu_len; 946 } 947 948 switch (mi->sample_mode) { 949 case MINSTREL_SAMPLE_IDLE: 950 if (mp->new_avg && 951 (mp->hw->max_rates > 1 || 952 mi->total_packets_cur < SAMPLE_SWITCH_THR)) 953 update_interval /= 2; 954 break; 955 956 case MINSTREL_SAMPLE_ACTIVE: 957 if (!sample_status) 958 break; 959 960 mi->sample_mode = MINSTREL_SAMPLE_PENDING; 961 update = true; 962 break; 963 964 case MINSTREL_SAMPLE_PENDING: 965 if (sample_status) 966 break; 967 968 update = true; 969 minstrel_ht_update_stats(mp, mi, false); 970 break; 971 } 972 973 974 if (mp->hw->max_rates > 1) { 975 /* 976 * check for sudden death of spatial multiplexing, 977 * downgrade to a lower number of streams if necessary. 978 */ 979 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 980 if (rate->attempts > 30 && 981 rate->success < rate->attempts / 4) { 982 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 983 update = true; 984 } 985 986 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 987 if (rate2->attempts > 30 && 988 rate2->success < rate2->attempts / 4) { 989 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 990 update = true; 991 } 992 } 993 994 if (time_after(jiffies, mi->last_stats_update + update_interval)) { 995 update = true; 996 minstrel_ht_update_stats(mp, mi, true); 997 } 998 999 if (update) 1000 minstrel_ht_update_rates(mp, mi); 1001} 1002 1003static void 1004minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1005 int index) 1006{ 1007 struct minstrel_rate_stats *mrs; 1008 unsigned int tx_time, tx_time_rtscts, tx_time_data; 1009 unsigned int cw = mp->cw_min; 1010 unsigned int ctime = 0; 1011 unsigned int t_slot = 9; /* FIXME */ 1012 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 1013 unsigned int overhead = 0, overhead_rtscts = 0; 1014 1015 mrs = minstrel_get_ratestats(mi, index); 1016 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) { 1017 mrs->retry_count = 1; 1018 mrs->retry_count_rtscts = 1; 1019 return; 1020 } 1021 1022 mrs->retry_count = 2; 1023 mrs->retry_count_rtscts = 2; 1024 mrs->retry_updated = true; 1025 1026 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 1027 1028 /* Contention time for first 2 tries */ 1029 ctime = (t_slot * cw) >> 1; 1030 cw = min((cw << 1) | 1, mp->cw_max); 1031 ctime += (t_slot * cw) >> 1; 1032 cw = min((cw << 1) | 1, mp->cw_max); 1033 1034 if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { 1035 overhead = mi->overhead; 1036 overhead_rtscts = mi->overhead_rtscts; 1037 } 1038 1039 /* Total TX time for data and Contention after first 2 tries */ 1040 tx_time = ctime + 2 * (overhead + tx_time_data); 1041 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 1042 1043 /* See how many more tries we can fit inside segment size */ 1044 do { 1045 /* Contention time for this try */ 1046 ctime = (t_slot * cw) >> 1; 1047 cw = min((cw << 1) | 1, mp->cw_max); 1048 1049 /* Total TX time after this try */ 1050 tx_time += ctime + overhead + tx_time_data; 1051 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 1052 1053 if (tx_time_rtscts < mp->segment_size) 1054 mrs->retry_count_rtscts++; 1055 } while ((tx_time < mp->segment_size) && 1056 (++mrs->retry_count < mp->max_retry)); 1057} 1058 1059 1060static void 1061minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1062 struct ieee80211_sta_rates *ratetbl, int offset, int index) 1063{ 1064 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 1065 struct minstrel_rate_stats *mrs; 1066 u8 idx; 1067 u16 flags = group->flags; 1068 1069 mrs = minstrel_get_ratestats(mi, index); 1070 if (!mrs->retry_updated) 1071 minstrel_calc_retransmit(mp, mi, index); 1072 1073 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 1074 ratetbl->rate[offset].count = 2; 1075 ratetbl->rate[offset].count_rts = 2; 1076 ratetbl->rate[offset].count_cts = 2; 1077 } else { 1078 ratetbl->rate[offset].count = mrs->retry_count; 1079 ratetbl->rate[offset].count_cts = mrs->retry_count; 1080 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 1081 } 1082 1083 if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) 1084 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 1085 else if (flags & IEEE80211_TX_RC_VHT_MCS) 1086 idx = ((group->streams - 1) << 4) | 1087 ((index % MCS_GROUP_RATES) & 0xF); 1088 else 1089 idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; 1090 1091 /* enable RTS/CTS if needed: 1092 * - if station is in dynamic SMPS (and streams > 1) 1093 * - for fallback rates, to increase chances of getting through 1094 */ 1095 if (offset > 0 || 1096 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 1097 group->streams > 1)) { 1098 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 1099 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 1100 } 1101 1102 ratetbl->rate[offset].idx = idx; 1103 ratetbl->rate[offset].flags = flags; 1104} 1105 1106static inline int 1107minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate) 1108{ 1109 int group = rate / MCS_GROUP_RATES; 1110 rate %= MCS_GROUP_RATES; 1111 return mi->groups[group].rates[rate].prob_avg; 1112} 1113 1114static int 1115minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 1116{ 1117 int group = mi->max_prob_rate / MCS_GROUP_RATES; 1118 const struct mcs_group *g = &minstrel_mcs_groups[group]; 1119 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 1120 unsigned int duration; 1121 1122 /* Disable A-MSDU if max_prob_rate is bad */ 1123 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100)) 1124 return 1; 1125 1126 duration = g->duration[rate]; 1127 duration <<= g->shift; 1128 1129 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 1130 if (duration > MCS_DURATION(1, 0, 52)) 1131 return 500; 1132 1133 /* 1134 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 1135 * data packet size 1136 */ 1137 if (duration > MCS_DURATION(1, 0, 104)) 1138 return 1600; 1139 1140 /* 1141 * If the rate is slower than single-stream MCS7, or if the max throughput 1142 * rate success probability is less than 75%, limit A-MSDU to twice the usual 1143 * data packet size 1144 */ 1145 if (duration > MCS_DURATION(1, 0, 260) || 1146 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) < 1147 MINSTREL_FRAC(75, 100))) 1148 return 3200; 1149 1150 /* 1151 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 1152 * Since aggregation sessions are started/stopped without txq flush, use 1153 * the limit here to avoid the complexity of having to de-aggregate 1154 * packets in the queue. 1155 */ 1156 if (!mi->sta->vht_cap.vht_supported) 1157 return IEEE80211_MAX_MPDU_LEN_HT_BA; 1158 1159 /* unlimited */ 1160 return 0; 1161} 1162 1163static void 1164minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1165{ 1166 struct ieee80211_sta_rates *rates; 1167 u16 first_rate = mi->max_tp_rate[0]; 1168 int i = 0; 1169 1170 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE) 1171 first_rate = mi->sample_rate; 1172 1173 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 1174 if (!rates) 1175 return; 1176 1177 /* Start with max_tp_rate[0] */ 1178 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate); 1179 1180 if (mp->hw->max_rates >= 3) { 1181 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 1182 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 1183 } 1184 1185 if (mp->hw->max_rates >= 2) { 1186 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 1187 } 1188 1189 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 1190 rates->rate[i].idx = -1; 1191 rate_control_set_rates(mp->hw, mi->sta, rates); 1192} 1193 1194static int 1195minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1196{ 1197 struct minstrel_rate_stats *mrs; 1198 struct minstrel_mcs_group_data *mg; 1199 unsigned int sample_dur, sample_group, cur_max_tp_streams; 1200 int tp_rate1, tp_rate2; 1201 int sample_idx = 0; 1202 1203 if (mp->hw->max_rates == 1 && mp->sample_switch && 1204 (mi->total_packets_cur >= SAMPLE_SWITCH_THR || 1205 mp->sample_switch == 1)) 1206 return -1; 1207 1208 if (mi->sample_wait > 0) { 1209 mi->sample_wait--; 1210 return -1; 1211 } 1212 1213 if (!mi->sample_tries) 1214 return -1; 1215 1216 sample_group = mi->sample_group; 1217 mg = &mi->groups[sample_group]; 1218 sample_idx = sample_table[mg->column][mg->index]; 1219 minstrel_set_next_sample_idx(mi); 1220 1221 if (!(mi->supported[sample_group] & BIT(sample_idx))) 1222 return -1; 1223 1224 mrs = &mg->rates[sample_idx]; 1225 sample_idx += sample_group * MCS_GROUP_RATES; 1226 1227 /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ 1228 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1229 minstrel_get_duration(mi->max_tp_rate[1])) { 1230 tp_rate1 = mi->max_tp_rate[1]; 1231 tp_rate2 = mi->max_tp_rate[0]; 1232 } else { 1233 tp_rate1 = mi->max_tp_rate[0]; 1234 tp_rate2 = mi->max_tp_rate[1]; 1235 } 1236 1237 /* 1238 * Sampling might add some overhead (RTS, no aggregation) 1239 * to the frame. Hence, don't use sampling for the highest currently 1240 * used highest throughput or probability rate. 1241 */ 1242 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1243 return -1; 1244 1245 /* 1246 * Do not sample if the probability is already higher than 95%, 1247 * or if the rate is 3 times slower than the current max probability 1248 * rate, to avoid wasting airtime. 1249 */ 1250 sample_dur = minstrel_get_duration(sample_idx); 1251 if (mrs->prob_avg > MINSTREL_FRAC(95, 100) || 1252 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1253 return -1; 1254 1255 1256 /* 1257 * For devices with no configurable multi-rate retry, skip sampling 1258 * below the per-group max throughput rate, and only use one sampling 1259 * attempt per rate 1260 */ 1261 if (mp->hw->max_rates == 1 && 1262 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur || 1263 mrs->attempts)) 1264 return -1; 1265 1266 /* Skip already sampled slow rates */ 1267 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts) 1268 return -1; 1269 1270 /* 1271 * Make sure that lower rates get sampled only occasionally, 1272 * if the link is working perfectly. 1273 */ 1274 1275 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1276 MCS_GROUP_RATES].streams; 1277 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1278 (cur_max_tp_streams - 1 < 1279 minstrel_mcs_groups[sample_group].streams || 1280 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1281 if (mrs->sample_skipped < 20) 1282 return -1; 1283 1284 if (mi->sample_slow++ > 2) 1285 return -1; 1286 } 1287 mi->sample_tries--; 1288 1289 return sample_idx; 1290} 1291 1292static void 1293minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1294 struct ieee80211_tx_rate_control *txrc) 1295{ 1296 const struct mcs_group *sample_group; 1297 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1298 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1299 struct minstrel_ht_sta_priv *msp = priv_sta; 1300 struct minstrel_ht_sta *mi = &msp->ht; 1301 struct minstrel_priv *mp = priv; 1302 int sample_idx; 1303 1304 if (!msp->is_ht) 1305 return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc); 1306 1307 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1308 mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) 1309 minstrel_aggr_check(sta, txrc->skb); 1310 1311 info->flags |= mi->tx_flags; 1312 1313#ifdef CONFIG_MAC80211_DEBUGFS 1314 if (mp->fixed_rate_idx != -1) 1315 return; 1316#endif 1317 1318 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1319 if (mp->hw->max_rates == 1 && 1320 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1321 sample_idx = -1; 1322 else 1323 sample_idx = minstrel_get_sample_rate(mp, mi); 1324 1325 mi->total_packets++; 1326 1327 /* wraparound */ 1328 if (mi->total_packets == ~0) { 1329 mi->total_packets = 0; 1330 mi->sample_packets = 0; 1331 } 1332 1333 if (sample_idx < 0) 1334 return; 1335 1336 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1337 sample_idx %= MCS_GROUP_RATES; 1338 1339 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1340 (sample_idx >= 4) != txrc->short_preamble) 1341 return; 1342 1343 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1344 rate->count = 1; 1345 1346 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1347 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1348 rate->idx = mp->cck_rates[idx]; 1349 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1350 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1351 sample_group->streams); 1352 } else { 1353 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1354 } 1355 1356 rate->flags = sample_group->flags; 1357} 1358 1359static void 1360minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1361 struct ieee80211_supported_band *sband, 1362 struct ieee80211_sta *sta) 1363{ 1364 int i; 1365 1366 if (sband->band != NL80211_BAND_2GHZ) 1367 return; 1368 1369 if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1370 return; 1371 1372 mi->cck_supported = 0; 1373 mi->cck_supported_short = 0; 1374 for (i = 0; i < 4; i++) { 1375 if (!rate_supported(sta, sband->band, mp->cck_rates[i])) 1376 continue; 1377 1378 mi->cck_supported |= BIT(i); 1379 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1380 mi->cck_supported_short |= BIT(i); 1381 } 1382 1383 mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; 1384} 1385 1386static void 1387minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1388 struct cfg80211_chan_def *chandef, 1389 struct ieee80211_sta *sta, void *priv_sta) 1390{ 1391 struct minstrel_priv *mp = priv; 1392 struct minstrel_ht_sta_priv *msp = priv_sta; 1393 struct minstrel_ht_sta *mi = &msp->ht; 1394 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1395 u16 ht_cap = sta->ht_cap.cap; 1396 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1397 int use_vht; 1398 int n_supported = 0; 1399 int ack_dur; 1400 int stbc; 1401 int i; 1402 bool ldpc; 1403 1404 /* fall back to the old minstrel for legacy stations */ 1405 if (!sta->ht_cap.ht_supported) 1406 goto use_legacy; 1407 1408 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1409 1410 if (vht_cap->vht_supported) 1411 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1412 else 1413 use_vht = 0; 1414 1415 msp->is_ht = true; 1416 memset(mi, 0, sizeof(*mi)); 1417 1418 mi->sta = sta; 1419 mi->last_stats_update = jiffies; 1420 1421 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1422 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1423 mi->overhead += ack_dur; 1424 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1425 1426 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1427 1428 /* When using MRR, sample more on the first attempt, without delay */ 1429 if (mp->has_mrr) { 1430 mi->sample_count = 16; 1431 mi->sample_wait = 0; 1432 } else { 1433 mi->sample_count = 8; 1434 mi->sample_wait = 8; 1435 } 1436 mi->sample_tries = 4; 1437 1438 if (!use_vht) { 1439 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1440 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1441 1442 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1443 } else { 1444 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1445 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1446 1447 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1448 } 1449 1450 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1451 if (ldpc) 1452 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1453 1454 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1455 u32 gflags = minstrel_mcs_groups[i].flags; 1456 int bw, nss; 1457 1458 mi->supported[i] = 0; 1459 if (i == MINSTREL_CCK_GROUP) { 1460 minstrel_ht_update_cck(mp, mi, sband, sta); 1461 continue; 1462 } 1463 1464 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1465 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1466 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1467 continue; 1468 } else { 1469 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1470 continue; 1471 } 1472 } 1473 1474 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1475 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1476 continue; 1477 1478 nss = minstrel_mcs_groups[i].streams; 1479 1480 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1481 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1482 continue; 1483 1484 /* HT rate */ 1485 if (gflags & IEEE80211_TX_RC_MCS) { 1486 if (use_vht && minstrel_vht_only) 1487 continue; 1488 1489 mi->supported[i] = mcs->rx_mask[nss - 1]; 1490 if (mi->supported[i]) 1491 n_supported++; 1492 continue; 1493 } 1494 1495 /* VHT rate */ 1496 if (!vht_cap->vht_supported || 1497 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1498 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1499 continue; 1500 1501 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1502 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1503 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1504 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1505 continue; 1506 } 1507 } 1508 1509 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1510 bw = BW_40; 1511 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1512 bw = BW_80; 1513 else 1514 bw = BW_20; 1515 1516 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1517 vht_cap->vht_mcs.tx_mcs_map); 1518 1519 if (mi->supported[i]) 1520 n_supported++; 1521 } 1522 1523 if (!n_supported) 1524 goto use_legacy; 1525 1526 mi->supported[MINSTREL_CCK_GROUP] |= mi->cck_supported_short << 4; 1527 1528 /* create an initial rate table with the lowest supported rates */ 1529 minstrel_ht_update_stats(mp, mi, true); 1530 minstrel_ht_update_rates(mp, mi); 1531 1532 return; 1533 1534use_legacy: 1535 msp->is_ht = false; 1536 memset(&msp->legacy, 0, sizeof(msp->legacy)); 1537 msp->legacy.r = msp->ratelist; 1538 msp->legacy.sample_table = msp->sample_table; 1539 return mac80211_minstrel.rate_init(priv, sband, chandef, sta, 1540 &msp->legacy); 1541} 1542 1543static void 1544minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1545 struct cfg80211_chan_def *chandef, 1546 struct ieee80211_sta *sta, void *priv_sta) 1547{ 1548 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1549} 1550 1551static void 1552minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1553 struct cfg80211_chan_def *chandef, 1554 struct ieee80211_sta *sta, void *priv_sta, 1555 u32 changed) 1556{ 1557 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1558} 1559 1560static void * 1561minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1562{ 1563 struct ieee80211_supported_band *sband; 1564 struct minstrel_ht_sta_priv *msp; 1565 struct minstrel_priv *mp = priv; 1566 struct ieee80211_hw *hw = mp->hw; 1567 int max_rates = 0; 1568 int i; 1569 1570 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1571 sband = hw->wiphy->bands[i]; 1572 if (sband && sband->n_bitrates > max_rates) 1573 max_rates = sband->n_bitrates; 1574 } 1575 1576 msp = kzalloc(sizeof(*msp), gfp); 1577 if (!msp) 1578 return NULL; 1579 1580 msp->ratelist = kcalloc(max_rates, sizeof(struct minstrel_rate), gfp); 1581 if (!msp->ratelist) 1582 goto error; 1583 1584 msp->sample_table = kmalloc_array(max_rates, SAMPLE_COLUMNS, gfp); 1585 if (!msp->sample_table) 1586 goto error1; 1587 1588 return msp; 1589 1590error1: 1591 kfree(msp->ratelist); 1592error: 1593 kfree(msp); 1594 return NULL; 1595} 1596 1597static void 1598minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1599{ 1600 struct minstrel_ht_sta_priv *msp = priv_sta; 1601 1602 kfree(msp->sample_table); 1603 kfree(msp->ratelist); 1604 kfree(msp); 1605} 1606 1607static void 1608minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1609{ 1610 static const int bitrates[4] = { 10, 20, 55, 110 }; 1611 struct ieee80211_supported_band *sband; 1612 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1613 int i, j; 1614 1615 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1616 if (!sband) 1617 return; 1618 1619 for (i = 0; i < sband->n_bitrates; i++) { 1620 struct ieee80211_rate *rate = &sband->bitrates[i]; 1621 1622 if (rate->flags & IEEE80211_RATE_ERP_G) 1623 continue; 1624 1625 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1626 continue; 1627 1628 for (j = 0; j < ARRAY_SIZE(bitrates); j++) { 1629 if (rate->bitrate != bitrates[j]) 1630 continue; 1631 1632 mp->cck_rates[j] = i; 1633 break; 1634 } 1635 } 1636} 1637 1638static void * 1639minstrel_ht_alloc(struct ieee80211_hw *hw) 1640{ 1641 struct minstrel_priv *mp; 1642 1643 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1644 if (!mp) 1645 return NULL; 1646 1647 mp->sample_switch = -1; 1648 1649 /* contention window settings 1650 * Just an approximation. Using the per-queue values would complicate 1651 * the calculations and is probably unnecessary */ 1652 mp->cw_min = 15; 1653 mp->cw_max = 1023; 1654 1655 /* number of packets (in %) to use for sampling other rates 1656 * sample less often for non-mrr packets, because the overhead 1657 * is much higher than with mrr */ 1658 mp->lookaround_rate = 5; 1659 mp->lookaround_rate_mrr = 10; 1660 1661 /* maximum time that the hw is allowed to stay in one MRR segment */ 1662 mp->segment_size = 6000; 1663 1664 if (hw->max_rate_tries > 0) 1665 mp->max_retry = hw->max_rate_tries; 1666 else 1667 /* safe default, does not necessarily have to match hw properties */ 1668 mp->max_retry = 7; 1669 1670 if (hw->max_rates >= 4) 1671 mp->has_mrr = true; 1672 1673 mp->hw = hw; 1674 mp->update_interval = HZ / 10; 1675 mp->new_avg = true; 1676 1677 minstrel_ht_init_cck_rates(mp); 1678 1679 return mp; 1680} 1681 1682#ifdef CONFIG_MAC80211_DEBUGFS 1683static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv, 1684 struct dentry *debugfsdir) 1685{ 1686 struct minstrel_priv *mp = priv; 1687 1688 mp->fixed_rate_idx = (u32) -1; 1689 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1690 &mp->fixed_rate_idx); 1691 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, 1692 &mp->sample_switch); 1693 debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir, 1694 &mp->new_avg); 1695} 1696#endif 1697 1698static void 1699minstrel_ht_free(void *priv) 1700{ 1701 kfree(priv); 1702} 1703 1704static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1705{ 1706 struct minstrel_ht_sta_priv *msp = priv_sta; 1707 struct minstrel_ht_sta *mi = &msp->ht; 1708 int i, j, prob, tp_avg; 1709 1710 if (!msp->is_ht) 1711 return mac80211_minstrel.get_expected_throughput(priv_sta); 1712 1713 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1714 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1715 prob = mi->groups[i].rates[j].prob_avg; 1716 1717 /* convert tp_avg from pkt per second in kbps */ 1718 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1719 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1720 1721 return tp_avg; 1722} 1723 1724static const struct rate_control_ops mac80211_minstrel_ht = { 1725 .name = "minstrel_ht", 1726 .tx_status_ext = minstrel_ht_tx_status, 1727 .get_rate = minstrel_ht_get_rate, 1728 .rate_init = minstrel_ht_rate_init, 1729 .rate_update = minstrel_ht_rate_update, 1730 .alloc_sta = minstrel_ht_alloc_sta, 1731 .free_sta = minstrel_ht_free_sta, 1732 .alloc = minstrel_ht_alloc, 1733 .free = minstrel_ht_free, 1734#ifdef CONFIG_MAC80211_DEBUGFS 1735 .add_debugfs = minstrel_ht_add_debugfs, 1736 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1737#endif 1738 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1739}; 1740 1741 1742static void __init init_sample_table(void) 1743{ 1744 int col, i, new_idx; 1745 u8 rnd[MCS_GROUP_RATES]; 1746 1747 memset(sample_table, 0xff, sizeof(sample_table)); 1748 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1749 prandom_bytes(rnd, sizeof(rnd)); 1750 for (i = 0; i < MCS_GROUP_RATES; i++) { 1751 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1752 while (sample_table[col][new_idx] != 0xff) 1753 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1754 1755 sample_table[col][new_idx] = i; 1756 } 1757 } 1758} 1759 1760int __init 1761rc80211_minstrel_init(void) 1762{ 1763 init_sample_table(); 1764 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1765} 1766 1767void 1768rc80211_minstrel_exit(void) 1769{ 1770 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1771} 1772