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_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) \ 139 (1000 * (10 /* SIFS */ + \ 140 (_short ? 72 + 24 : 144 + 48) + \ 141 (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate))) 142 143 #define CCK_DURATION_LIST(_short, _s) \ 144 CCK_DURATION(10, _short) >> _s, \ 145 CCK_DURATION(20, _short) >> _s, \ 146 CCK_DURATION(55, _short) >> _s, \ 147 CCK_DURATION(110, _short) >> _s 148 149 #define __CCK_GROUP(_s) \ 150 [MINSTREL_CCK_GROUP] = { \ 151 .streams = 1, \ 152 .flags = 0, \ 153 .shift = _s, \ 154 .duration = { \ 155 CCK_DURATION_LIST(false, _s), \ 156 CCK_DURATION_LIST(true, _s) \ 157 } \ 158 } 159 160 #define CCK_GROUP_SHIFT \ 161 GROUP_SHIFT(CCK_DURATION(10, false)) 162 163 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) 164 165 #define OFDM_DURATION(_bitrate) \ 166 (1000 * (16 /* SIFS + signal ext */ + \ 167 16 /* T_PREAMBLE */ + \ 168 4 /* T_SIGNAL */ + \ 169 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) / \ 170 ((_bitrate) * 4))))) 171 172 #define OFDM_DURATION_LIST(_s) \ 173 OFDM_DURATION(60) >> _s, \ 174 OFDM_DURATION(90) >> _s, \ 175 OFDM_DURATION(120) >> _s, \ 176 OFDM_DURATION(180) >> _s, \ 177 OFDM_DURATION(240) >> _s, \ 178 OFDM_DURATION(360) >> _s, \ 179 OFDM_DURATION(480) >> _s, \ 180 OFDM_DURATION(540) >> _s 181 182 #define __OFDM_GROUP(_s) \ 183 [MINSTREL_OFDM_GROUP] = { \ 184 .streams = 1, \ 185 .flags = 0, \ 186 .shift = _s, \ 187 .duration = { \ 188 OFDM_DURATION_LIST(_s), \ 189 } \ 190 } 191 192 #define OFDM_GROUP_SHIFT \ 193 GROUP_SHIFT(OFDM_DURATION(60)) 194 195 #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT) 196 197 198 static bool minstrel_vht_only = true; 199 module_param(minstrel_vht_only, bool, 0644); 200 MODULE_PARM_DESC(minstrel_vht_only, 201 "Use only VHT rates when VHT is supported by sta."); 202 203 /* 204 * To enable sufficiently targeted rate sampling, MCS rates are divided into 205 * groups, based on the number of streams and flags (HT40, SGI) that they 206 * use. 207 * 208 * Sortorder has to be fixed for GROUP_IDX macro to be applicable: 209 * BW -> SGI -> #streams 210 */ 211 const struct mcs_group minstrel_mcs_groups[] = { 212 MCS_GROUP(1, 0, BW_20), 213 MCS_GROUP(2, 0, BW_20), 214 MCS_GROUP(3, 0, BW_20), 215 MCS_GROUP(4, 0, BW_20), 216 217 MCS_GROUP(1, 1, BW_20), 218 MCS_GROUP(2, 1, BW_20), 219 MCS_GROUP(3, 1, BW_20), 220 MCS_GROUP(4, 1, BW_20), 221 222 MCS_GROUP(1, 0, BW_40), 223 MCS_GROUP(2, 0, BW_40), 224 MCS_GROUP(3, 0, BW_40), 225 MCS_GROUP(4, 0, BW_40), 226 227 MCS_GROUP(1, 1, BW_40), 228 MCS_GROUP(2, 1, BW_40), 229 MCS_GROUP(3, 1, BW_40), 230 MCS_GROUP(4, 1, BW_40), 231 232 CCK_GROUP, 233 OFDM_GROUP, 234 235 VHT_GROUP(1, 0, BW_20), 236 VHT_GROUP(2, 0, BW_20), 237 VHT_GROUP(3, 0, BW_20), 238 VHT_GROUP(4, 0, BW_20), 239 240 VHT_GROUP(1, 1, BW_20), 241 VHT_GROUP(2, 1, BW_20), 242 VHT_GROUP(3, 1, BW_20), 243 VHT_GROUP(4, 1, BW_20), 244 245 VHT_GROUP(1, 0, BW_40), 246 VHT_GROUP(2, 0, BW_40), 247 VHT_GROUP(3, 0, BW_40), 248 VHT_GROUP(4, 0, BW_40), 249 250 VHT_GROUP(1, 1, BW_40), 251 VHT_GROUP(2, 1, BW_40), 252 VHT_GROUP(3, 1, BW_40), 253 VHT_GROUP(4, 1, BW_40), 254 255 VHT_GROUP(1, 0, BW_80), 256 VHT_GROUP(2, 0, BW_80), 257 VHT_GROUP(3, 0, BW_80), 258 VHT_GROUP(4, 0, BW_80), 259 260 VHT_GROUP(1, 1, BW_80), 261 VHT_GROUP(2, 1, BW_80), 262 VHT_GROUP(3, 1, BW_80), 263 VHT_GROUP(4, 1, BW_80), 264 }; 265 266 const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 }; 267 const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 }; 268 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; 269 270 static void 271 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); 272 273 /* 274 * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) 275 * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 276 * 277 * Returns the valid mcs map for struct minstrel_mcs_group_data.supported 278 */ 279 static u16 280 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) 281 { 282 u16 mask = 0; 283 284 if (bw == BW_20) { 285 if (nss != 3 && nss != 6) 286 mask = BIT(9); 287 } else if (bw == BW_80) { 288 if (nss == 3 || nss == 7) 289 mask = BIT(6); 290 else if (nss == 6) 291 mask = BIT(9); 292 } else { 293 WARN_ON(bw != BW_40); 294 } 295 296 switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { 297 case IEEE80211_VHT_MCS_SUPPORT_0_7: 298 mask |= 0x300; 299 break; 300 case IEEE80211_VHT_MCS_SUPPORT_0_8: 301 mask |= 0x200; 302 break; 303 case IEEE80211_VHT_MCS_SUPPORT_0_9: 304 break; 305 default: 306 mask = 0x3ff; 307 } 308 309 return 0x3ff & ~mask; 310 } 311 312 static bool 313 minstrel_ht_is_legacy_group(int group) 314 { 315 return group == MINSTREL_CCK_GROUP || 316 group == MINSTREL_OFDM_GROUP; 317 } 318 319 /* 320 * Look up an MCS group index based on mac80211 rate information 321 */ 322 static int 323 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate) 324 { 325 return GROUP_IDX((rate->idx / 8) + 1, 326 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 327 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); 328 } 329 330 static int 331 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) 332 { 333 return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), 334 !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), 335 !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 336 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); 337 } 338 339 static struct minstrel_rate_stats * 340 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 341 struct ieee80211_tx_rate *rate) 342 { 343 int group, idx; 344 345 if (rate->flags & IEEE80211_TX_RC_MCS) { 346 group = minstrel_ht_get_group_idx(rate); 347 idx = rate->idx % 8; 348 goto out; 349 } 350 351 if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { 352 group = minstrel_vht_get_group_idx(rate); 353 idx = ieee80211_rate_get_vht_mcs(rate); 354 goto out; 355 } 356 357 group = MINSTREL_CCK_GROUP; 358 for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) { 359 if (rate->idx != mp->cck_rates[idx]) 360 continue; 361 362 /* short preamble */ 363 if ((mi->supported[group] & BIT(idx + 4)) && 364 (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) 365 idx += 4; 366 goto out; 367 } 368 369 group = MINSTREL_OFDM_GROUP; 370 for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++) 371 if (rate->idx == mp->ofdm_rates[mi->band][idx]) 372 goto out; 373 374 idx = 0; 375 out: 376 return &mi->groups[group].rates[idx]; 377 } 378 379 static inline struct minstrel_rate_stats * 380 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) 381 { 382 return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; 383 } 384 385 static inline int minstrel_get_duration(int index) 386 { 387 const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; 388 unsigned int duration = group->duration[index % MCS_GROUP_RATES]; 389 390 return duration << group->shift; 391 } 392 393 static unsigned int 394 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) 395 { 396 int duration; 397 398 if (mi->avg_ampdu_len) 399 return MINSTREL_TRUNC(mi->avg_ampdu_len); 400 401 if (minstrel_ht_is_legacy_group(mi->max_tp_rate[0] / MCS_GROUP_RATES)) 402 return 1; 403 404 duration = minstrel_get_duration(mi->max_tp_rate[0]); 405 406 if (duration > 400 * 1000) 407 return 2; 408 409 if (duration > 250 * 1000) 410 return 4; 411 412 if (duration > 150 * 1000) 413 return 8; 414 415 return 16; 416 } 417 418 /* 419 * Return current throughput based on the average A-MPDU length, taking into 420 * account the expected number of retransmissions and their expected length 421 */ 422 int 423 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, 424 int prob_avg) 425 { 426 unsigned int nsecs = 0, overhead = mi->overhead; 427 unsigned int ampdu_len = 1; 428 429 /* do not account throughput if sucess prob is below 10% */ 430 if (prob_avg < MINSTREL_FRAC(10, 100)) 431 return 0; 432 433 if (minstrel_ht_is_legacy_group(group)) 434 overhead = mi->overhead_legacy; 435 else 436 ampdu_len = minstrel_ht_avg_ampdu_len(mi); 437 438 nsecs = 1000 * overhead / ampdu_len; 439 nsecs += minstrel_mcs_groups[group].duration[rate] << 440 minstrel_mcs_groups[group].shift; 441 442 /* 443 * For the throughput calculation, limit the probability value to 90% to 444 * account for collision related packet error rate fluctuation 445 * (prob is scaled - see MINSTREL_FRAC above) 446 */ 447 if (prob_avg > MINSTREL_FRAC(90, 100)) 448 prob_avg = MINSTREL_FRAC(90, 100); 449 450 return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs)); 451 } 452 453 /* 454 * Find & sort topmost throughput rates 455 * 456 * If multiple rates provide equal throughput the sorting is based on their 457 * current success probability. Higher success probability is preferred among 458 * MCS groups, CCK rates do not provide aggregation and are therefore at last. 459 */ 460 static void 461 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, 462 u16 *tp_list) 463 { 464 int cur_group, cur_idx, cur_tp_avg, cur_prob; 465 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 466 int j = MAX_THR_RATES; 467 468 cur_group = index / MCS_GROUP_RATES; 469 cur_idx = index % MCS_GROUP_RATES; 470 cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg; 471 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); 472 473 do { 474 tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; 475 tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; 476 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 477 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, 478 tmp_prob); 479 if (cur_tp_avg < tmp_tp_avg || 480 (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) 481 break; 482 j--; 483 } while (j > 0); 484 485 if (j < MAX_THR_RATES - 1) { 486 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * 487 (MAX_THR_RATES - (j + 1)))); 488 } 489 if (j < MAX_THR_RATES) 490 tp_list[j] = index; 491 } 492 493 /* 494 * Find and set the topmost probability rate per sta and per group 495 */ 496 static void 497 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index) 498 { 499 struct minstrel_mcs_group_data *mg; 500 struct minstrel_rate_stats *mrs; 501 int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; 502 int max_tp_group, max_tp_idx, max_tp_prob; 503 int cur_tp_avg, cur_group, cur_idx; 504 int max_gpr_group, max_gpr_idx; 505 int max_gpr_tp_avg, max_gpr_prob; 506 507 cur_group = index / MCS_GROUP_RATES; 508 cur_idx = index % MCS_GROUP_RATES; 509 mg = &mi->groups[index / MCS_GROUP_RATES]; 510 mrs = &mg->rates[index % MCS_GROUP_RATES]; 511 512 tmp_group = *dest / MCS_GROUP_RATES; 513 tmp_idx = *dest % MCS_GROUP_RATES; 514 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 515 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 516 517 /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from 518 * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ 519 max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; 520 max_tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; 521 max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg; 522 523 if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES) && 524 !minstrel_ht_is_legacy_group(max_tp_group)) 525 return; 526 527 /* skip rates faster than max tp rate with lower prob */ 528 if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) && 529 mrs->prob_avg < max_tp_prob) 530 return; 531 532 max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; 533 max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 534 max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg; 535 536 if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) { 537 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, 538 mrs->prob_avg); 539 if (cur_tp_avg > tmp_tp_avg) 540 *dest = index; 541 542 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, 543 max_gpr_idx, 544 max_gpr_prob); 545 if (cur_tp_avg > max_gpr_tp_avg) 546 mg->max_group_prob_rate = index; 547 } else { 548 if (mrs->prob_avg > tmp_prob) 549 *dest = index; 550 if (mrs->prob_avg > max_gpr_prob) 551 mg->max_group_prob_rate = index; 552 } 553 } 554 555 556 /* 557 * Assign new rate set per sta and use CCK rates only if the fastest 558 * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted 559 * rate sets where MCS and CCK rates are mixed, because CCK rates can 560 * not use aggregation. 561 */ 562 static void 563 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, 564 u16 tmp_mcs_tp_rate[MAX_THR_RATES], 565 u16 tmp_legacy_tp_rate[MAX_THR_RATES]) 566 { 567 unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; 568 int i; 569 570 tmp_group = tmp_legacy_tp_rate[0] / MCS_GROUP_RATES; 571 tmp_idx = tmp_legacy_tp_rate[0] % MCS_GROUP_RATES; 572 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 573 tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 574 575 tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; 576 tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; 577 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 578 tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); 579 580 if (tmp_cck_tp > tmp_mcs_tp) { 581 for(i = 0; i < MAX_THR_RATES; i++) { 582 minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i], 583 tmp_mcs_tp_rate); 584 } 585 } 586 587 } 588 589 /* 590 * Try to increase robustness of max_prob rate by decrease number of 591 * streams if possible. 592 */ 593 static inline void 594 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) 595 { 596 struct minstrel_mcs_group_data *mg; 597 int tmp_max_streams, group, tmp_idx, tmp_prob; 598 int tmp_tp = 0; 599 600 if (!mi->sta->ht_cap.ht_supported) 601 return; 602 603 tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / 604 MCS_GROUP_RATES].streams; 605 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 606 mg = &mi->groups[group]; 607 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) 608 continue; 609 610 tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; 611 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg; 612 613 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && 614 (minstrel_mcs_groups[group].streams < tmp_max_streams)) { 615 mi->max_prob_rate = mg->max_group_prob_rate; 616 tmp_tp = minstrel_ht_get_tp_avg(mi, group, 617 tmp_idx, 618 tmp_prob); 619 } 620 } 621 } 622 623 static bool 624 minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group, 625 int tp_idx, const struct mcs_group *group) 626 { 627 if (group->bw < tp_group->bw) 628 return false; 629 630 if (group->streams == tp_group->streams) 631 return true; 632 633 if (tp_idx < 4 && group->streams == tp_group->streams - 1) 634 return true; 635 636 return group->streams == tp_group->streams + 1; 637 } 638 639 static void 640 minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates, 641 bool faster_rate) 642 { 643 const struct mcs_group *group, *tp_group; 644 int i, g, max_dur; 645 int tp_idx; 646 647 tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES]; 648 tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; 649 650 max_dur = minstrel_get_duration(mi->max_tp_rate[0]); 651 if (faster_rate) 652 max_dur -= max_dur / 16; 653 654 for (g = 0; g < MINSTREL_GROUPS_NB; g++) { 655 u16 supported = mi->supported[g]; 656 657 if (!supported) 658 continue; 659 660 group = &minstrel_mcs_groups[g]; 661 if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group)) 662 continue; 663 664 for (i = 0; supported; supported >>= 1, i++) { 665 int idx; 666 667 if (!(supported & 1)) 668 continue; 669 670 if ((group->duration[i] << group->shift) > max_dur) 671 continue; 672 673 idx = g * MCS_GROUP_RATES + i; 674 if (idx == mi->max_tp_rate[0]) 675 continue; 676 677 rates[(*n_rates)++] = idx; 678 break; 679 } 680 } 681 } 682 683 static void 684 minstrel_ht_rate_sample_switch(struct minstrel_priv *mp, 685 struct minstrel_ht_sta *mi) 686 { 687 struct minstrel_rate_stats *mrs; 688 u16 rates[MINSTREL_GROUPS_NB]; 689 int n_rates = 0; 690 int probe_rate = 0; 691 bool faster_rate; 692 int i; 693 u8 random; 694 695 /* 696 * Use rate switching instead of probing packets for devices with 697 * little control over retry fallback behavior 698 */ 699 if (mp->hw->max_rates > 1) 700 return; 701 702 /* 703 * If the current EWMA prob is >75%, look for a rate that's 6.25% 704 * faster than the max tp rate. 705 * If that fails, look again for a rate that is at least as fast 706 */ 707 mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 708 faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100); 709 minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate); 710 if (!n_rates && faster_rate) 711 minstrel_ht_find_probe_rates(mi, rates, &n_rates, false); 712 713 /* If no suitable rate was found, try to pick the next one in the group */ 714 if (!n_rates) { 715 int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES; 716 u16 supported = mi->supported[g_idx]; 717 718 supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; 719 for (i = 0; supported; supported >>= 1, i++) { 720 if (!(supported & 1)) 721 continue; 722 723 probe_rate = mi->max_tp_rate[0] + i; 724 goto out; 725 } 726 727 return; 728 } 729 730 i = 0; 731 if (n_rates > 1) { 732 random = prandom_u32(); 733 i = random % n_rates; 734 } 735 probe_rate = rates[i]; 736 737 out: 738 mi->sample_rate = probe_rate; 739 mi->sample_mode = MINSTREL_SAMPLE_ACTIVE; 740 } 741 742 static inline int 743 minstrel_ewma(int old, int new, int weight) 744 { 745 int diff, incr; 746 747 diff = new - old; 748 incr = (EWMA_DIV - weight) * diff / EWMA_DIV; 749 750 return old + incr; 751 } 752 753 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in) 754 { 755 s32 out_1 = *prev_1; 756 s32 out_2 = *prev_2; 757 s32 val; 758 759 if (!in) 760 in += 1; 761 762 if (!out_1) { 763 val = out_1 = in; 764 goto out; 765 } 766 767 val = MINSTREL_AVG_COEFF1 * in; 768 val += MINSTREL_AVG_COEFF2 * out_1; 769 val += MINSTREL_AVG_COEFF3 * out_2; 770 val >>= MINSTREL_SCALE; 771 772 if (val > 1 << MINSTREL_SCALE) 773 val = 1 << MINSTREL_SCALE; 774 if (val < 0) 775 val = 1; 776 777 out: 778 *prev_2 = out_1; 779 *prev_1 = val; 780 781 return val; 782 } 783 784 /* 785 * Recalculate statistics and counters of a given rate 786 */ 787 static void 788 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp, 789 struct minstrel_rate_stats *mrs) 790 { 791 unsigned int cur_prob; 792 793 if (unlikely(mrs->attempts > 0)) { 794 mrs->sample_skipped = 0; 795 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); 796 minstrel_filter_avg_add(&mrs->prob_avg, 797 &mrs->prob_avg_1, cur_prob); 798 mrs->att_hist += mrs->attempts; 799 mrs->succ_hist += mrs->success; 800 } else { 801 mrs->sample_skipped++; 802 } 803 804 mrs->last_success = mrs->success; 805 mrs->last_attempts = mrs->attempts; 806 mrs->success = 0; 807 mrs->attempts = 0; 808 } 809 810 /* 811 * Update rate statistics and select new primary rates 812 * 813 * Rules for rate selection: 814 * - max_prob_rate must use only one stream, as a tradeoff between delivery 815 * probability and throughput during strong fluctuations 816 * - as long as the max prob rate has a probability of more than 75%, pick 817 * higher throughput rates, even if the probablity is a bit lower 818 */ 819 static void 820 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 821 bool sample) 822 { 823 struct minstrel_mcs_group_data *mg; 824 struct minstrel_rate_stats *mrs; 825 int group, i, j, cur_prob; 826 u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; 827 u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate; 828 u16 index; 829 bool ht_supported = mi->sta->ht_cap.ht_supported; 830 831 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 832 833 if (sample) { 834 mi->total_packets_cur = mi->total_packets - 835 mi->total_packets_last; 836 mi->total_packets_last = mi->total_packets; 837 } 838 if (!mp->sample_switch) 839 sample = false; 840 if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1) 841 sample = false; 842 843 if (mi->ampdu_packets > 0) { 844 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) 845 mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, 846 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), 847 EWMA_LEVEL); 848 else 849 mi->avg_ampdu_len = 0; 850 mi->ampdu_len = 0; 851 mi->ampdu_packets = 0; 852 } 853 854 mi->sample_slow = 0; 855 mi->sample_count = 0; 856 857 memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate)); 858 memset(tmp_legacy_tp_rate, 0, sizeof(tmp_legacy_tp_rate)); 859 if (mi->supported[MINSTREL_CCK_GROUP]) 860 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++) 861 tmp_legacy_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; 862 else if (mi->supported[MINSTREL_OFDM_GROUP]) 863 for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++) 864 tmp_legacy_tp_rate[j] = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES; 865 866 if (mi->supported[MINSTREL_VHT_GROUP_0]) 867 index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES; 868 else if (ht_supported) 869 index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES; 870 else if (mi->supported[MINSTREL_CCK_GROUP]) 871 index = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; 872 else 873 index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES; 874 875 tmp_max_prob_rate = index; 876 for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++) 877 tmp_mcs_tp_rate[j] = index; 878 879 /* Find best rate sets within all MCS groups*/ 880 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 881 u16 *tp_rate = tmp_mcs_tp_rate; 882 883 mg = &mi->groups[group]; 884 if (!mi->supported[group]) 885 continue; 886 887 mi->sample_count++; 888 889 /* (re)Initialize group rate indexes */ 890 for(j = 0; j < MAX_THR_RATES; j++) 891 tmp_group_tp_rate[j] = MCS_GROUP_RATES * group; 892 893 if (group == MINSTREL_CCK_GROUP && ht_supported) 894 tp_rate = tmp_legacy_tp_rate; 895 896 for (i = 0; i < MCS_GROUP_RATES; i++) { 897 if (!(mi->supported[group] & BIT(i))) 898 continue; 899 900 index = MCS_GROUP_RATES * group + i; 901 902 mrs = &mg->rates[i]; 903 mrs->retry_updated = false; 904 minstrel_ht_calc_rate_stats(mp, mrs); 905 cur_prob = mrs->prob_avg; 906 907 if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) 908 continue; 909 910 /* Find max throughput rate set */ 911 minstrel_ht_sort_best_tp_rates(mi, index, tp_rate); 912 913 /* Find max throughput rate set within a group */ 914 minstrel_ht_sort_best_tp_rates(mi, index, 915 tmp_group_tp_rate); 916 } 917 918 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, 919 sizeof(mg->max_group_tp_rate)); 920 } 921 922 /* Assign new rate set per sta */ 923 minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, 924 tmp_legacy_tp_rate); 925 memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); 926 927 for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { 928 if (!mi->supported[group]) 929 continue; 930 931 mg = &mi->groups[group]; 932 mg->max_group_prob_rate = MCS_GROUP_RATES * group; 933 934 for (i = 0; i < MCS_GROUP_RATES; i++) { 935 if (!(mi->supported[group] & BIT(i))) 936 continue; 937 938 index = MCS_GROUP_RATES * group + i; 939 940 /* Find max probability rate per group and global */ 941 minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate, 942 index); 943 } 944 } 945 946 mi->max_prob_rate = tmp_max_prob_rate; 947 948 /* Try to increase robustness of max_prob_rate*/ 949 minstrel_ht_prob_rate_reduce_streams(mi); 950 951 /* try to sample half of all available rates during each interval */ 952 mi->sample_count *= 4; 953 954 if (sample) 955 minstrel_ht_rate_sample_switch(mp, mi); 956 957 #ifdef CONFIG_MAC80211_DEBUGFS 958 /* use fixed index if set */ 959 if (mp->fixed_rate_idx != -1) { 960 for (i = 0; i < 4; i++) 961 mi->max_tp_rate[i] = mp->fixed_rate_idx; 962 mi->max_prob_rate = mp->fixed_rate_idx; 963 mi->sample_mode = MINSTREL_SAMPLE_IDLE; 964 } 965 #endif 966 967 /* Reset update timer */ 968 mi->last_stats_update = jiffies; 969 } 970 971 static bool 972 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 973 struct ieee80211_tx_rate *rate) 974 { 975 int i; 976 977 if (rate->idx < 0) 978 return false; 979 980 if (!rate->count) 981 return false; 982 983 if (rate->flags & IEEE80211_TX_RC_MCS || 984 rate->flags & IEEE80211_TX_RC_VHT_MCS) 985 return true; 986 987 for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) 988 if (rate->idx == mp->cck_rates[i]) 989 return true; 990 991 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) 992 if (rate->idx == mp->ofdm_rates[mi->band][i]) 993 return true; 994 995 return false; 996 } 997 998 static void 999 minstrel_set_next_sample_idx(struct minstrel_ht_sta *mi) 1000 { 1001 struct minstrel_mcs_group_data *mg; 1002 1003 for (;;) { 1004 mi->sample_group++; 1005 mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups); 1006 mg = &mi->groups[mi->sample_group]; 1007 1008 if (!mi->supported[mi->sample_group]) 1009 continue; 1010 1011 if (++mg->index >= MCS_GROUP_RATES) { 1012 mg->index = 0; 1013 if (++mg->column >= ARRAY_SIZE(sample_table)) 1014 mg->column = 0; 1015 } 1016 break; 1017 } 1018 } 1019 1020 static void 1021 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 1022 { 1023 int group, orig_group; 1024 1025 orig_group = group = *idx / MCS_GROUP_RATES; 1026 while (group > 0) { 1027 group--; 1028 1029 if (!mi->supported[group]) 1030 continue; 1031 1032 if (minstrel_mcs_groups[group].streams > 1033 minstrel_mcs_groups[orig_group].streams) 1034 continue; 1035 1036 if (primary) 1037 *idx = mi->groups[group].max_group_tp_rate[0]; 1038 else 1039 *idx = mi->groups[group].max_group_tp_rate[1]; 1040 break; 1041 } 1042 } 1043 1044 static void 1045 minstrel_aggr_check(struct ieee80211_sta *pubsta, struct sk_buff *skb) 1046 { 1047 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; 1048 struct sta_info *sta = container_of(pubsta, struct sta_info, sta); 1049 u16 tid; 1050 1051 if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) 1052 return; 1053 1054 if (unlikely(!ieee80211_is_data_qos(hdr->frame_control))) 1055 return; 1056 1057 if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE))) 1058 return; 1059 1060 tid = ieee80211_get_tid(hdr); 1061 if (likely(sta->ampdu_mlme.tid_tx[tid])) 1062 return; 1063 1064 ieee80211_start_tx_ba_session(pubsta, tid, 0); 1065 } 1066 1067 static void 1068 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, 1069 void *priv_sta, struct ieee80211_tx_status *st) 1070 { 1071 struct ieee80211_tx_info *info = st->info; 1072 struct minstrel_ht_sta *mi = priv_sta; 1073 struct ieee80211_tx_rate *ar = info->status.rates; 1074 struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; 1075 struct minstrel_priv *mp = priv; 1076 u32 update_interval = mp->update_interval; 1077 bool last, update = false; 1078 bool sample_status = false; 1079 int i; 1080 1081 /* This packet was aggregated but doesn't carry status info */ 1082 if ((info->flags & IEEE80211_TX_CTL_AMPDU) && 1083 !(info->flags & IEEE80211_TX_STAT_AMPDU)) 1084 return; 1085 1086 if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) { 1087 info->status.ampdu_ack_len = 1088 (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0); 1089 info->status.ampdu_len = 1; 1090 } 1091 1092 mi->ampdu_packets++; 1093 mi->ampdu_len += info->status.ampdu_len; 1094 1095 if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) { 1096 int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); 1097 1098 mi->sample_wait = 16 + 2 * avg_ampdu_len; 1099 mi->sample_tries = 1; 1100 mi->sample_count--; 1101 } 1102 1103 if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) 1104 mi->sample_packets += info->status.ampdu_len; 1105 1106 if (mi->sample_mode != MINSTREL_SAMPLE_IDLE) 1107 rate_sample = minstrel_get_ratestats(mi, mi->sample_rate); 1108 1109 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]); 1110 for (i = 0; !last; i++) { 1111 last = (i == IEEE80211_TX_MAX_RATES - 1) || 1112 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]); 1113 1114 rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 1115 if (rate == rate_sample) 1116 sample_status = true; 1117 1118 if (last) 1119 rate->success += info->status.ampdu_ack_len; 1120 1121 rate->attempts += ar[i].count * info->status.ampdu_len; 1122 } 1123 1124 switch (mi->sample_mode) { 1125 case MINSTREL_SAMPLE_IDLE: 1126 if (mp->hw->max_rates > 1 || 1127 mi->total_packets_cur < SAMPLE_SWITCH_THR) 1128 update_interval /= 2; 1129 break; 1130 1131 case MINSTREL_SAMPLE_ACTIVE: 1132 if (!sample_status) 1133 break; 1134 1135 mi->sample_mode = MINSTREL_SAMPLE_PENDING; 1136 update = true; 1137 break; 1138 1139 case MINSTREL_SAMPLE_PENDING: 1140 if (sample_status) 1141 break; 1142 1143 update = true; 1144 minstrel_ht_update_stats(mp, mi, false); 1145 break; 1146 } 1147 1148 1149 if (mp->hw->max_rates > 1) { 1150 /* 1151 * check for sudden death of spatial multiplexing, 1152 * downgrade to a lower number of streams if necessary. 1153 */ 1154 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); 1155 if (rate->attempts > 30 && 1156 rate->success < rate->attempts / 4) { 1157 minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); 1158 update = true; 1159 } 1160 1161 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); 1162 if (rate2->attempts > 30 && 1163 rate2->success < rate2->attempts / 4) { 1164 minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); 1165 update = true; 1166 } 1167 } 1168 1169 if (time_after(jiffies, mi->last_stats_update + update_interval)) { 1170 update = true; 1171 minstrel_ht_update_stats(mp, mi, true); 1172 } 1173 1174 if (update) 1175 minstrel_ht_update_rates(mp, mi); 1176 } 1177 1178 static void 1179 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1180 int index) 1181 { 1182 struct minstrel_rate_stats *mrs; 1183 unsigned int tx_time, tx_time_rtscts, tx_time_data; 1184 unsigned int cw = mp->cw_min; 1185 unsigned int ctime = 0; 1186 unsigned int t_slot = 9; /* FIXME */ 1187 unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi); 1188 unsigned int overhead = 0, overhead_rtscts = 0; 1189 1190 mrs = minstrel_get_ratestats(mi, index); 1191 if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) { 1192 mrs->retry_count = 1; 1193 mrs->retry_count_rtscts = 1; 1194 return; 1195 } 1196 1197 mrs->retry_count = 2; 1198 mrs->retry_count_rtscts = 2; 1199 mrs->retry_updated = true; 1200 1201 tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000; 1202 1203 /* Contention time for first 2 tries */ 1204 ctime = (t_slot * cw) >> 1; 1205 cw = min((cw << 1) | 1, mp->cw_max); 1206 ctime += (t_slot * cw) >> 1; 1207 cw = min((cw << 1) | 1, mp->cw_max); 1208 1209 if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES)) { 1210 overhead = mi->overhead_legacy; 1211 overhead_rtscts = mi->overhead_legacy_rtscts; 1212 } else { 1213 overhead = mi->overhead; 1214 overhead_rtscts = mi->overhead_rtscts; 1215 } 1216 1217 /* Total TX time for data and Contention after first 2 tries */ 1218 tx_time = ctime + 2 * (overhead + tx_time_data); 1219 tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data); 1220 1221 /* See how many more tries we can fit inside segment size */ 1222 do { 1223 /* Contention time for this try */ 1224 ctime = (t_slot * cw) >> 1; 1225 cw = min((cw << 1) | 1, mp->cw_max); 1226 1227 /* Total TX time after this try */ 1228 tx_time += ctime + overhead + tx_time_data; 1229 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; 1230 1231 if (tx_time_rtscts < mp->segment_size) 1232 mrs->retry_count_rtscts++; 1233 } while ((tx_time < mp->segment_size) && 1234 (++mrs->retry_count < mp->max_retry)); 1235 } 1236 1237 1238 static void 1239 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1240 struct ieee80211_sta_rates *ratetbl, int offset, int index) 1241 { 1242 int group_idx = index / MCS_GROUP_RATES; 1243 const struct mcs_group *group = &minstrel_mcs_groups[group_idx]; 1244 struct minstrel_rate_stats *mrs; 1245 u8 idx; 1246 u16 flags = group->flags; 1247 1248 mrs = minstrel_get_ratestats(mi, index); 1249 if (!mrs->retry_updated) 1250 minstrel_calc_retransmit(mp, mi, index); 1251 1252 if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { 1253 ratetbl->rate[offset].count = 2; 1254 ratetbl->rate[offset].count_rts = 2; 1255 ratetbl->rate[offset].count_cts = 2; 1256 } else { 1257 ratetbl->rate[offset].count = mrs->retry_count; 1258 ratetbl->rate[offset].count_cts = mrs->retry_count; 1259 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; 1260 } 1261 1262 index %= MCS_GROUP_RATES; 1263 if (group_idx == MINSTREL_CCK_GROUP) 1264 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; 1265 else if (group_idx == MINSTREL_OFDM_GROUP) 1266 idx = mp->ofdm_rates[mi->band][index % 1267 ARRAY_SIZE(mp->ofdm_rates[0])]; 1268 else if (flags & IEEE80211_TX_RC_VHT_MCS) 1269 idx = ((group->streams - 1) << 4) | 1270 (index & 0xF); 1271 else 1272 idx = index + (group->streams - 1) * 8; 1273 1274 /* enable RTS/CTS if needed: 1275 * - if station is in dynamic SMPS (and streams > 1) 1276 * - for fallback rates, to increase chances of getting through 1277 */ 1278 if (offset > 0 || 1279 (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && 1280 group->streams > 1)) { 1281 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; 1282 flags |= IEEE80211_TX_RC_USE_RTS_CTS; 1283 } 1284 1285 ratetbl->rate[offset].idx = idx; 1286 ratetbl->rate[offset].flags = flags; 1287 } 1288 1289 static inline int 1290 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate) 1291 { 1292 int group = rate / MCS_GROUP_RATES; 1293 rate %= MCS_GROUP_RATES; 1294 return mi->groups[group].rates[rate].prob_avg; 1295 } 1296 1297 static int 1298 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) 1299 { 1300 int group = mi->max_prob_rate / MCS_GROUP_RATES; 1301 const struct mcs_group *g = &minstrel_mcs_groups[group]; 1302 int rate = mi->max_prob_rate % MCS_GROUP_RATES; 1303 unsigned int duration; 1304 1305 /* Disable A-MSDU if max_prob_rate is bad */ 1306 if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100)) 1307 return 1; 1308 1309 duration = g->duration[rate]; 1310 duration <<= g->shift; 1311 1312 /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ 1313 if (duration > MCS_DURATION(1, 0, 52)) 1314 return 500; 1315 1316 /* 1317 * If the rate is slower than single-stream MCS4, limit A-MSDU to usual 1318 * data packet size 1319 */ 1320 if (duration > MCS_DURATION(1, 0, 104)) 1321 return 1600; 1322 1323 /* 1324 * If the rate is slower than single-stream MCS7, or if the max throughput 1325 * rate success probability is less than 75%, limit A-MSDU to twice the usual 1326 * data packet size 1327 */ 1328 if (duration > MCS_DURATION(1, 0, 260) || 1329 (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) < 1330 MINSTREL_FRAC(75, 100))) 1331 return 3200; 1332 1333 /* 1334 * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. 1335 * Since aggregation sessions are started/stopped without txq flush, use 1336 * the limit here to avoid the complexity of having to de-aggregate 1337 * packets in the queue. 1338 */ 1339 if (!mi->sta->vht_cap.vht_supported) 1340 return IEEE80211_MAX_MPDU_LEN_HT_BA; 1341 1342 /* unlimited */ 1343 return 0; 1344 } 1345 1346 static void 1347 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1348 { 1349 struct ieee80211_sta_rates *rates; 1350 u16 first_rate = mi->max_tp_rate[0]; 1351 int i = 0; 1352 1353 if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE) 1354 first_rate = mi->sample_rate; 1355 1356 rates = kzalloc(sizeof(*rates), GFP_ATOMIC); 1357 if (!rates) 1358 return; 1359 1360 /* Start with max_tp_rate[0] */ 1361 minstrel_ht_set_rate(mp, mi, rates, i++, first_rate); 1362 1363 if (mp->hw->max_rates >= 3) { 1364 /* At least 3 tx rates supported, use max_tp_rate[1] next */ 1365 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); 1366 } 1367 1368 if (mp->hw->max_rates >= 2) { 1369 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); 1370 } 1371 1372 mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); 1373 rates->rate[i].idx = -1; 1374 rate_control_set_rates(mp->hw, mi->sta, rates); 1375 } 1376 1377 static int 1378 minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 1379 { 1380 struct minstrel_rate_stats *mrs; 1381 struct minstrel_mcs_group_data *mg; 1382 unsigned int sample_dur, sample_group, cur_max_tp_streams; 1383 int tp_rate1, tp_rate2; 1384 int sample_idx = 0; 1385 1386 if (mp->hw->max_rates == 1 && mp->sample_switch && 1387 (mi->total_packets_cur >= SAMPLE_SWITCH_THR || 1388 mp->sample_switch == 1)) 1389 return -1; 1390 1391 if (mi->sample_wait > 0) { 1392 mi->sample_wait--; 1393 return -1; 1394 } 1395 1396 if (!mi->sample_tries) 1397 return -1; 1398 1399 sample_group = mi->sample_group; 1400 mg = &mi->groups[sample_group]; 1401 sample_idx = sample_table[mg->column][mg->index]; 1402 minstrel_set_next_sample_idx(mi); 1403 1404 if (!(mi->supported[sample_group] & BIT(sample_idx))) 1405 return -1; 1406 1407 mrs = &mg->rates[sample_idx]; 1408 sample_idx += sample_group * MCS_GROUP_RATES; 1409 1410 tp_rate1 = mi->max_tp_rate[0]; 1411 1412 /* Set tp_rate2 to the second highest max_tp_rate */ 1413 if (minstrel_get_duration(mi->max_tp_rate[0]) > 1414 minstrel_get_duration(mi->max_tp_rate[1])) { 1415 tp_rate2 = mi->max_tp_rate[0]; 1416 } else { 1417 tp_rate2 = mi->max_tp_rate[1]; 1418 } 1419 1420 /* 1421 * Sampling might add some overhead (RTS, no aggregation) 1422 * to the frame. Hence, don't use sampling for the highest currently 1423 * used highest throughput or probability rate. 1424 */ 1425 if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) 1426 return -1; 1427 1428 /* 1429 * Do not sample if the probability is already higher than 95%, 1430 * or if the rate is 3 times slower than the current max probability 1431 * rate, to avoid wasting airtime. 1432 */ 1433 sample_dur = minstrel_get_duration(sample_idx); 1434 if (mrs->prob_avg > MINSTREL_FRAC(95, 100) || 1435 minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) 1436 return -1; 1437 1438 1439 /* 1440 * For devices with no configurable multi-rate retry, skip sampling 1441 * below the per-group max throughput rate, and only use one sampling 1442 * attempt per rate 1443 */ 1444 if (mp->hw->max_rates == 1 && 1445 (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur || 1446 mrs->attempts)) 1447 return -1; 1448 1449 /* Skip already sampled slow rates */ 1450 if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts) 1451 return -1; 1452 1453 /* 1454 * Make sure that lower rates get sampled only occasionally, 1455 * if the link is working perfectly. 1456 */ 1457 1458 cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / 1459 MCS_GROUP_RATES].streams; 1460 if (sample_dur >= minstrel_get_duration(tp_rate2) && 1461 (cur_max_tp_streams - 1 < 1462 minstrel_mcs_groups[sample_group].streams || 1463 sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { 1464 if (mrs->sample_skipped < 20) 1465 return -1; 1466 1467 if (mi->sample_slow++ > 2) 1468 return -1; 1469 } 1470 mi->sample_tries--; 1471 1472 return sample_idx; 1473 } 1474 1475 static void 1476 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 1477 struct ieee80211_tx_rate_control *txrc) 1478 { 1479 const struct mcs_group *sample_group; 1480 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); 1481 struct ieee80211_tx_rate *rate = &info->status.rates[0]; 1482 struct minstrel_ht_sta *mi = priv_sta; 1483 struct minstrel_priv *mp = priv; 1484 int sample_idx; 1485 1486 if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && 1487 !minstrel_ht_is_legacy_group(mi->max_prob_rate / MCS_GROUP_RATES)) 1488 minstrel_aggr_check(sta, txrc->skb); 1489 1490 info->flags |= mi->tx_flags; 1491 1492 #ifdef CONFIG_MAC80211_DEBUGFS 1493 if (mp->fixed_rate_idx != -1) 1494 return; 1495 #endif 1496 1497 /* Don't use EAPOL frames for sampling on non-mrr hw */ 1498 if (mp->hw->max_rates == 1 && 1499 (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) 1500 sample_idx = -1; 1501 else 1502 sample_idx = minstrel_get_sample_rate(mp, mi); 1503 1504 mi->total_packets++; 1505 1506 /* wraparound */ 1507 if (mi->total_packets == ~0) { 1508 mi->total_packets = 0; 1509 mi->sample_packets = 0; 1510 } 1511 1512 if (sample_idx < 0) 1513 return; 1514 1515 sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; 1516 sample_idx %= MCS_GROUP_RATES; 1517 1518 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && 1519 (sample_idx >= 4) != txrc->short_preamble) 1520 return; 1521 1522 info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; 1523 rate->count = 1; 1524 1525 if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { 1526 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); 1527 rate->idx = mp->cck_rates[idx]; 1528 } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) { 1529 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]); 1530 rate->idx = mp->ofdm_rates[mi->band][idx]; 1531 } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { 1532 ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, 1533 sample_group->streams); 1534 } else { 1535 rate->idx = sample_idx + (sample_group->streams - 1) * 8; 1536 } 1537 1538 rate->flags = sample_group->flags; 1539 } 1540 1541 static void 1542 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1543 struct ieee80211_supported_band *sband, 1544 struct ieee80211_sta *sta) 1545 { 1546 int i; 1547 1548 if (sband->band != NL80211_BAND_2GHZ) 1549 return; 1550 1551 if (sta->ht_cap.ht_supported && 1552 !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) 1553 return; 1554 1555 for (i = 0; i < 4; i++) { 1556 if (mp->cck_rates[i] == 0xff || 1557 !rate_supported(sta, sband->band, mp->cck_rates[i])) 1558 continue; 1559 1560 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i); 1561 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) 1562 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4); 1563 } 1564 } 1565 1566 static void 1567 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 1568 struct ieee80211_supported_band *sband, 1569 struct ieee80211_sta *sta) 1570 { 1571 const u8 *rates; 1572 int i; 1573 1574 if (sta->ht_cap.ht_supported) 1575 return; 1576 1577 rates = mp->ofdm_rates[sband->band]; 1578 for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) { 1579 if (rates[i] == 0xff || 1580 !rate_supported(sta, sband->band, rates[i])) 1581 continue; 1582 1583 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i); 1584 } 1585 } 1586 1587 static void 1588 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, 1589 struct cfg80211_chan_def *chandef, 1590 struct ieee80211_sta *sta, void *priv_sta) 1591 { 1592 struct minstrel_priv *mp = priv; 1593 struct minstrel_ht_sta *mi = priv_sta; 1594 struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; 1595 u16 ht_cap = sta->ht_cap.cap; 1596 struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; 1597 const struct ieee80211_rate *ctl_rate; 1598 bool ldpc, erp; 1599 int use_vht; 1600 int n_supported = 0; 1601 int ack_dur; 1602 int stbc; 1603 int i; 1604 1605 BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); 1606 1607 if (vht_cap->vht_supported) 1608 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); 1609 else 1610 use_vht = 0; 1611 1612 memset(mi, 0, sizeof(*mi)); 1613 1614 mi->sta = sta; 1615 mi->band = sband->band; 1616 mi->last_stats_update = jiffies; 1617 1618 ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); 1619 mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); 1620 mi->overhead += ack_dur; 1621 mi->overhead_rtscts = mi->overhead + 2 * ack_dur; 1622 1623 ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)]; 1624 erp = ctl_rate->flags & IEEE80211_RATE_ERP_G; 1625 ack_dur = ieee80211_frame_duration(sband->band, 10, 1626 ctl_rate->bitrate, erp, 1, 1627 ieee80211_chandef_get_shift(chandef)); 1628 mi->overhead_legacy = ack_dur; 1629 mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur; 1630 1631 mi->avg_ampdu_len = MINSTREL_FRAC(1, 1); 1632 1633 /* When using MRR, sample more on the first attempt, without delay */ 1634 if (mp->has_mrr) { 1635 mi->sample_count = 16; 1636 mi->sample_wait = 0; 1637 } else { 1638 mi->sample_count = 8; 1639 mi->sample_wait = 8; 1640 } 1641 mi->sample_tries = 4; 1642 1643 if (!use_vht) { 1644 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> 1645 IEEE80211_HT_CAP_RX_STBC_SHIFT; 1646 1647 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; 1648 } else { 1649 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> 1650 IEEE80211_VHT_CAP_RXSTBC_SHIFT; 1651 1652 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; 1653 } 1654 1655 mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; 1656 if (ldpc) 1657 mi->tx_flags |= IEEE80211_TX_CTL_LDPC; 1658 1659 for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { 1660 u32 gflags = minstrel_mcs_groups[i].flags; 1661 int bw, nss; 1662 1663 mi->supported[i] = 0; 1664 if (minstrel_ht_is_legacy_group(i)) 1665 continue; 1666 1667 if (gflags & IEEE80211_TX_RC_SHORT_GI) { 1668 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { 1669 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) 1670 continue; 1671 } else { 1672 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20)) 1673 continue; 1674 } 1675 } 1676 1677 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && 1678 sta->bandwidth < IEEE80211_STA_RX_BW_40) 1679 continue; 1680 1681 nss = minstrel_mcs_groups[i].streams; 1682 1683 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ 1684 if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) 1685 continue; 1686 1687 /* HT rate */ 1688 if (gflags & IEEE80211_TX_RC_MCS) { 1689 if (use_vht && minstrel_vht_only) 1690 continue; 1691 1692 mi->supported[i] = mcs->rx_mask[nss - 1]; 1693 if (mi->supported[i]) 1694 n_supported++; 1695 continue; 1696 } 1697 1698 /* VHT rate */ 1699 if (!vht_cap->vht_supported || 1700 WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || 1701 WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) 1702 continue; 1703 1704 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { 1705 if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || 1706 ((gflags & IEEE80211_TX_RC_SHORT_GI) && 1707 !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { 1708 continue; 1709 } 1710 } 1711 1712 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) 1713 bw = BW_40; 1714 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) 1715 bw = BW_80; 1716 else 1717 bw = BW_20; 1718 1719 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, 1720 vht_cap->vht_mcs.tx_mcs_map); 1721 1722 if (mi->supported[i]) 1723 n_supported++; 1724 } 1725 1726 minstrel_ht_update_cck(mp, mi, sband, sta); 1727 minstrel_ht_update_ofdm(mp, mi, sband, sta); 1728 1729 /* create an initial rate table with the lowest supported rates */ 1730 minstrel_ht_update_stats(mp, mi, true); 1731 minstrel_ht_update_rates(mp, mi); 1732 } 1733 1734 static void 1735 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, 1736 struct cfg80211_chan_def *chandef, 1737 struct ieee80211_sta *sta, void *priv_sta) 1738 { 1739 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1740 } 1741 1742 static void 1743 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, 1744 struct cfg80211_chan_def *chandef, 1745 struct ieee80211_sta *sta, void *priv_sta, 1746 u32 changed) 1747 { 1748 minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); 1749 } 1750 1751 static void * 1752 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) 1753 { 1754 struct ieee80211_supported_band *sband; 1755 struct minstrel_ht_sta *mi; 1756 struct minstrel_priv *mp = priv; 1757 struct ieee80211_hw *hw = mp->hw; 1758 int max_rates = 0; 1759 int i; 1760 1761 for (i = 0; i < NUM_NL80211_BANDS; i++) { 1762 sband = hw->wiphy->bands[i]; 1763 if (sband && sband->n_bitrates > max_rates) 1764 max_rates = sband->n_bitrates; 1765 } 1766 1767 return kzalloc(sizeof(*mi), gfp); 1768 } 1769 1770 static void 1771 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) 1772 { 1773 kfree(priv_sta); 1774 } 1775 1776 static void 1777 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband, 1778 const s16 *bitrates, int n_rates, u32 rate_flags) 1779 { 1780 int i, j; 1781 1782 for (i = 0; i < sband->n_bitrates; i++) { 1783 struct ieee80211_rate *rate = &sband->bitrates[i]; 1784 1785 if ((rate_flags & sband->bitrates[i].flags) != rate_flags) 1786 continue; 1787 1788 for (j = 0; j < n_rates; j++) { 1789 if (rate->bitrate != bitrates[j]) 1790 continue; 1791 1792 dest[j] = i; 1793 break; 1794 } 1795 } 1796 } 1797 1798 static void 1799 minstrel_ht_init_cck_rates(struct minstrel_priv *mp) 1800 { 1801 static const s16 bitrates[4] = { 10, 20, 55, 110 }; 1802 struct ieee80211_supported_band *sband; 1803 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1804 1805 memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates)); 1806 sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; 1807 if (!sband) 1808 return; 1809 1810 BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates)); 1811 minstrel_ht_fill_rate_array(mp->cck_rates, sband, 1812 minstrel_cck_bitrates, 1813 ARRAY_SIZE(minstrel_cck_bitrates), 1814 rate_flags); 1815 } 1816 1817 static void 1818 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band) 1819 { 1820 static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 }; 1821 struct ieee80211_supported_band *sband; 1822 u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); 1823 1824 memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band])); 1825 sband = mp->hw->wiphy->bands[band]; 1826 if (!sband) 1827 return; 1828 1829 BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates)); 1830 minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband, 1831 minstrel_ofdm_bitrates, 1832 ARRAY_SIZE(minstrel_ofdm_bitrates), 1833 rate_flags); 1834 } 1835 1836 static void * 1837 minstrel_ht_alloc(struct ieee80211_hw *hw) 1838 { 1839 struct minstrel_priv *mp; 1840 int i; 1841 1842 mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); 1843 if (!mp) 1844 return NULL; 1845 1846 mp->sample_switch = -1; 1847 1848 /* contention window settings 1849 * Just an approximation. Using the per-queue values would complicate 1850 * the calculations and is probably unnecessary */ 1851 mp->cw_min = 15; 1852 mp->cw_max = 1023; 1853 1854 /* maximum time that the hw is allowed to stay in one MRR segment */ 1855 mp->segment_size = 6000; 1856 1857 if (hw->max_rate_tries > 0) 1858 mp->max_retry = hw->max_rate_tries; 1859 else 1860 /* safe default, does not necessarily have to match hw properties */ 1861 mp->max_retry = 7; 1862 1863 if (hw->max_rates >= 4) 1864 mp->has_mrr = true; 1865 1866 mp->hw = hw; 1867 mp->update_interval = HZ / 10; 1868 1869 minstrel_ht_init_cck_rates(mp); 1870 for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++) 1871 minstrel_ht_init_ofdm_rates(mp, i); 1872 1873 return mp; 1874 } 1875 1876 #ifdef CONFIG_MAC80211_DEBUGFS 1877 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv, 1878 struct dentry *debugfsdir) 1879 { 1880 struct minstrel_priv *mp = priv; 1881 1882 mp->fixed_rate_idx = (u32) -1; 1883 debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, 1884 &mp->fixed_rate_idx); 1885 debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, 1886 &mp->sample_switch); 1887 } 1888 #endif 1889 1890 static void 1891 minstrel_ht_free(void *priv) 1892 { 1893 kfree(priv); 1894 } 1895 1896 static u32 minstrel_ht_get_expected_throughput(void *priv_sta) 1897 { 1898 struct minstrel_ht_sta *mi = priv_sta; 1899 int i, j, prob, tp_avg; 1900 1901 i = mi->max_tp_rate[0] / MCS_GROUP_RATES; 1902 j = mi->max_tp_rate[0] % MCS_GROUP_RATES; 1903 prob = mi->groups[i].rates[j].prob_avg; 1904 1905 /* convert tp_avg from pkt per second in kbps */ 1906 tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; 1907 tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; 1908 1909 return tp_avg; 1910 } 1911 1912 static const struct rate_control_ops mac80211_minstrel_ht = { 1913 .name = "minstrel_ht", 1914 .tx_status_ext = minstrel_ht_tx_status, 1915 .get_rate = minstrel_ht_get_rate, 1916 .rate_init = minstrel_ht_rate_init, 1917 .rate_update = minstrel_ht_rate_update, 1918 .alloc_sta = minstrel_ht_alloc_sta, 1919 .free_sta = minstrel_ht_free_sta, 1920 .alloc = minstrel_ht_alloc, 1921 .free = minstrel_ht_free, 1922 #ifdef CONFIG_MAC80211_DEBUGFS 1923 .add_debugfs = minstrel_ht_add_debugfs, 1924 .add_sta_debugfs = minstrel_ht_add_sta_debugfs, 1925 #endif 1926 .get_expected_throughput = minstrel_ht_get_expected_throughput, 1927 }; 1928 1929 1930 static void __init init_sample_table(void) 1931 { 1932 int col, i, new_idx; 1933 u8 rnd[MCS_GROUP_RATES]; 1934 1935 memset(sample_table, 0xff, sizeof(sample_table)); 1936 for (col = 0; col < SAMPLE_COLUMNS; col++) { 1937 prandom_bytes(rnd, sizeof(rnd)); 1938 for (i = 0; i < MCS_GROUP_RATES; i++) { 1939 new_idx = (i + rnd[i]) % MCS_GROUP_RATES; 1940 while (sample_table[col][new_idx] != 0xff) 1941 new_idx = (new_idx + 1) % MCS_GROUP_RATES; 1942 1943 sample_table[col][new_idx] = i; 1944 } 1945 } 1946 } 1947 1948 int __init 1949 rc80211_minstrel_init(void) 1950 { 1951 init_sample_table(); 1952 return ieee80211_rate_control_register(&mac80211_minstrel_ht); 1953 } 1954 1955 void 1956 rc80211_minstrel_exit(void) 1957 { 1958 ieee80211_rate_control_unregister(&mac80211_minstrel_ht); 1959 } 1960