net/mac80211/rc80211_minstrel_ht.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org>
   4  * Copyright (C) 2019-2022 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 <linux/minmax.h>
  14 #include <net/mac80211.h>
  15 #include "rate.h"
  16 #include "sta_info.h"
  17 #include "rc80211_minstrel_ht.h"
  18
  19 #define AVG_AMPDU_SIZE  16
  20 #define AVG_PKT_SIZE    1200
  21
  22 /* Number of bits for an average sized packet */
  23 #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3)
  24
  25 /* Number of symbols for a packet with (bps) bits per symbol */
  26 #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps))
  27
  28 /* Transmission time (nanoseconds) for a packet containing (syms) symbols */
  29 #define MCS_SYMBOL_TIME(sgi, syms)                                      \
  30         (sgi ?                                                          \
  31           ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */             \
  32           ((syms) * 1000) << 2          /* syms * 4 us */               \
  33         )
  34
  35 /* Transmit duration for the raw data part of an average sized packet */
  36 #define MCS_DURATION(streams, sgi, bps) \
  37         (MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps))) / AVG_AMPDU_SIZE)
  38
  39 #define BW_20                   0
  40 #define BW_40                   1
  41 #define BW_80                   2
  42
  43 /*
  44  * Define group sort order: HT40 -> SGI -> #streams
  45  */
  46 #define GROUP_IDX(_streams, _sgi, _ht40)        \
  47         MINSTREL_HT_GROUP_0 +                   \
  48         MINSTREL_MAX_STREAMS * 2 * _ht40 +      \
  49         MINSTREL_MAX_STREAMS * _sgi +   \
  50         _streams - 1
  51
  52 #define _MAX(a, b) (((a)>(b))?(a):(b))
  53
  54 #define GROUP_SHIFT(duration)                                           \
  55         _MAX(0, 16 - __builtin_clz(duration))
  56
  57 /* MCS rate information for an MCS group */
  58 #define __MCS_GROUP(_streams, _sgi, _ht40, _s)                          \
  59         [GROUP_IDX(_streams, _sgi, _ht40)] = {                          \
  60         .streams = _streams,                                            \
  61         .shift = _s,                                                    \
  62         .bw = _ht40,                                                    \
  63         .flags =                                                        \
  64                 IEEE80211_TX_RC_MCS |                                   \
  65                 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |                 \
  66                 (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),             \
  67         .duration = {                                                   \
  68                 MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26) >> _s,    \
  69                 MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s,   \
  70                 MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s,   \
  71                 MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s,  \
  72                 MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s,  \
  73                 MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s,  \
  74                 MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s,  \
  75                 MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s   \
  76         }                                                               \
  77 }
  78
  79 #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40)                          \
  80         GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
  81
  82 #define MCS_GROUP(_streams, _sgi, _ht40)                                \
  83         __MCS_GROUP(_streams, _sgi, _ht40,                              \
  84                     MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
  85
  86 #define VHT_GROUP_IDX(_streams, _sgi, _bw)                              \
  87         (MINSTREL_VHT_GROUP_0 +                                         \
  88          MINSTREL_MAX_STREAMS * 2 * (_bw) +                             \
  89          MINSTREL_MAX_STREAMS * (_sgi) +                                \
  90          (_streams) - 1)
  91
  92 #define BW2VBPS(_bw, r3, r2, r1)                                        \
  93         (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
  94
  95 #define __VHT_GROUP(_streams, _sgi, _bw, _s)                            \
  96         [VHT_GROUP_IDX(_streams, _sgi, _bw)] = {                        \
  97         .streams = _streams,                                            \
  98         .shift = _s,                                                    \
  99         .bw = _bw,                                                      \
 100         .flags =                                                        \
 101                 IEEE80211_TX_RC_VHT_MCS |                               \
 102                 (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) |                 \
 103                 (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH :          \
 104                  _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0),      \
 105         .duration = {                                                   \
 106                 MCS_DURATION(_streams, _sgi,                            \
 107                              BW2VBPS(_bw,  117,  54,  26)) >> _s,       \
 108                 MCS_DURATION(_streams, _sgi,                            \
 109                              BW2VBPS(_bw,  234, 108,  52)) >> _s,       \
 110                 MCS_DURATION(_streams, _sgi,                            \
 111                              BW2VBPS(_bw,  351, 162,  78)) >> _s,       \
 112                 MCS_DURATION(_streams, _sgi,                            \
 113                              BW2VBPS(_bw,  468, 216, 104)) >> _s,       \
 114                 MCS_DURATION(_streams, _sgi,                            \
 115                              BW2VBPS(_bw,  702, 324, 156)) >> _s,       \
 116                 MCS_DURATION(_streams, _sgi,                            \
 117                              BW2VBPS(_bw,  936, 432, 208)) >> _s,       \
 118                 MCS_DURATION(_streams, _sgi,                            \
 119                              BW2VBPS(_bw, 1053, 486, 234)) >> _s,       \
 120                 MCS_DURATION(_streams, _sgi,                            \
 121                              BW2VBPS(_bw, 1170, 540, 260)) >> _s,       \
 122                 MCS_DURATION(_streams, _sgi,                            \
 123                              BW2VBPS(_bw, 1404, 648, 312)) >> _s,       \
 124                 MCS_DURATION(_streams, _sgi,                            \
 125                              BW2VBPS(_bw, 1560, 720, 346)) >> _s        \
 126         }                                                               \
 127 }
 128
 129 #define VHT_GROUP_SHIFT(_streams, _sgi, _bw)                            \
 130         GROUP_SHIFT(MCS_DURATION(_streams, _sgi,                        \
 131                                  BW2VBPS(_bw,  117,  54,  26)))
 132
 133 #define VHT_GROUP(_streams, _sgi, _bw)                                  \
 134         __VHT_GROUP(_streams, _sgi, _bw,                                \
 135                     VHT_GROUP_SHIFT(_streams, _sgi, _bw))
 136
 137 #define CCK_DURATION(_bitrate, _short)                  \
 138         (1000 * (10 /* SIFS */ +                        \
 139          (_short ? 72 + 24 : 144 + 48) +                \
 140          (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate)))
 141
 142 #define CCK_DURATION_LIST(_short, _s)                   \
 143         CCK_DURATION(10, _short) >> _s,                 \
 144         CCK_DURATION(20, _short) >> _s,                 \
 145         CCK_DURATION(55, _short) >> _s,                 \
 146         CCK_DURATION(110, _short) >> _s
 147
 148 #define __CCK_GROUP(_s)                                 \
 149         [MINSTREL_CCK_GROUP] = {                        \
 150                 .streams = 1,                           \
 151                 .flags = 0,                             \
 152                 .shift = _s,                            \
 153                 .duration = {                           \
 154                         CCK_DURATION_LIST(false, _s),   \
 155                         CCK_DURATION_LIST(true, _s)     \
 156                 }                                       \
 157         }
 158
 159 #define CCK_GROUP_SHIFT                                 \
 160         GROUP_SHIFT(CCK_DURATION(10, false))
 161
 162 #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT)
 163
 164 #define OFDM_DURATION(_bitrate)                         \
 165         (1000 * (16 /* SIFS + signal ext */ +           \
 166          16 /* T_PREAMBLE */ +                          \
 167          4 /* T_SIGNAL */ +                             \
 168          4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) /     \
 169               ((_bitrate) * 4)))))
 170
 171 #define OFDM_DURATION_LIST(_s)                          \
 172         OFDM_DURATION(60) >> _s,                        \
 173         OFDM_DURATION(90) >> _s,                        \
 174         OFDM_DURATION(120) >> _s,                       \
 175         OFDM_DURATION(180) >> _s,                       \
 176         OFDM_DURATION(240) >> _s,                       \
 177         OFDM_DURATION(360) >> _s,                       \
 178         OFDM_DURATION(480) >> _s,                       \
 179         OFDM_DURATION(540) >> _s
 180
 181 #define __OFDM_GROUP(_s)                                \
 182         [MINSTREL_OFDM_GROUP] = {                       \
 183                 .streams = 1,                           \
 184                 .flags = 0,                             \
 185                 .shift = _s,                            \
 186                 .duration = {                           \
 187                         OFDM_DURATION_LIST(_s),         \
 188                 }                                       \
 189         }
 190
 191 #define OFDM_GROUP_SHIFT                                \
 192         GROUP_SHIFT(OFDM_DURATION(60))
 193
 194 #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT)
 195
 196
 197 static bool minstrel_vht_only = true;
 198 module_param(minstrel_vht_only, bool, 0644);
 199 MODULE_PARM_DESC(minstrel_vht_only,
 200                  "Use only VHT rates when VHT is supported by sta.");
 201
 202 /*
 203  * To enable sufficiently targeted rate sampling, MCS rates are divided into
 204  * groups, based on the number of streams and flags (HT40, SGI) that they
 205  * use.
 206  *
 207  * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
 208  * BW -> SGI -> #streams
 209  */
 210 const struct mcs_group minstrel_mcs_groups[] = {
 211         MCS_GROUP(1, 0, BW_20),
 212         MCS_GROUP(2, 0, BW_20),
 213         MCS_GROUP(3, 0, BW_20),
 214         MCS_GROUP(4, 0, BW_20),
 215
 216         MCS_GROUP(1, 1, BW_20),
 217         MCS_GROUP(2, 1, BW_20),
 218         MCS_GROUP(3, 1, BW_20),
 219         MCS_GROUP(4, 1, BW_20),
 220
 221         MCS_GROUP(1, 0, BW_40),
 222         MCS_GROUP(2, 0, BW_40),
 223         MCS_GROUP(3, 0, BW_40),
 224         MCS_GROUP(4, 0, BW_40),
 225
 226         MCS_GROUP(1, 1, BW_40),
 227         MCS_GROUP(2, 1, BW_40),
 228         MCS_GROUP(3, 1, BW_40),
 229         MCS_GROUP(4, 1, BW_40),
 230
 231         CCK_GROUP,
 232         OFDM_GROUP,
 233
 234         VHT_GROUP(1, 0, BW_20),
 235         VHT_GROUP(2, 0, BW_20),
 236         VHT_GROUP(3, 0, BW_20),
 237         VHT_GROUP(4, 0, BW_20),
 238
 239         VHT_GROUP(1, 1, BW_20),
 240         VHT_GROUP(2, 1, BW_20),
 241         VHT_GROUP(3, 1, BW_20),
 242         VHT_GROUP(4, 1, BW_20),
 243
 244         VHT_GROUP(1, 0, BW_40),
 245         VHT_GROUP(2, 0, BW_40),
 246         VHT_GROUP(3, 0, BW_40),
 247         VHT_GROUP(4, 0, BW_40),
 248
 249         VHT_GROUP(1, 1, BW_40),
 250         VHT_GROUP(2, 1, BW_40),
 251         VHT_GROUP(3, 1, BW_40),
 252         VHT_GROUP(4, 1, BW_40),
 253
 254         VHT_GROUP(1, 0, BW_80),
 255         VHT_GROUP(2, 0, BW_80),
 256         VHT_GROUP(3, 0, BW_80),
 257         VHT_GROUP(4, 0, BW_80),
 258
 259         VHT_GROUP(1, 1, BW_80),
 260         VHT_GROUP(2, 1, BW_80),
 261         VHT_GROUP(3, 1, BW_80),
 262         VHT_GROUP(4, 1, BW_80),
 263 };
 264
 265 const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 };
 266 const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
 267 static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly;
 268 static const u8 minstrel_sample_seq[] = {
 269         MINSTREL_SAMPLE_TYPE_INC,
 270         MINSTREL_SAMPLE_TYPE_JUMP,
 271         MINSTREL_SAMPLE_TYPE_INC,
 272         MINSTREL_SAMPLE_TYPE_JUMP,
 273         MINSTREL_SAMPLE_TYPE_INC,
 274         MINSTREL_SAMPLE_TYPE_SLOW,
 275 };
 276
 277 static void
 278 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi);
 279
 280 /*
 281  * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer)
 282  * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1
 283  *
 284  * Returns the valid mcs map for struct minstrel_mcs_group_data.supported
 285  */
 286 static u16
 287 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map)
 288 {
 289         u16 mask = 0;
 290
 291         if (bw == BW_20) {
 292                 if (nss != 3 && nss != 6)
 293                         mask = BIT(9);
 294         } else if (bw == BW_80) {
 295                 if (nss == 3 || nss == 7)
 296                         mask = BIT(6);
 297                 else if (nss == 6)
 298                         mask = BIT(9);
 299         } else {
 300                 WARN_ON(bw != BW_40);
 301         }
 302
 303         switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) {
 304         case IEEE80211_VHT_MCS_SUPPORT_0_7:
 305                 mask |= 0x300;
 306                 break;
 307         case IEEE80211_VHT_MCS_SUPPORT_0_8:
 308                 mask |= 0x200;
 309                 break;
 310         case IEEE80211_VHT_MCS_SUPPORT_0_9:
 311                 break;
 312         default:
 313                 mask = 0x3ff;
 314         }
 315
 316         return 0x3ff & ~mask;
 317 }
 318
 319 static bool
 320 minstrel_ht_is_legacy_group(int group)
 321 {
 322         return group == MINSTREL_CCK_GROUP ||
 323                group == MINSTREL_OFDM_GROUP;
 324 }
 325
 326 /*
 327  * Look up an MCS group index based on mac80211 rate information
 328  */
 329 static int
 330 minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
 331 {
 332         return GROUP_IDX((rate->idx / 8) + 1,
 333                          !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
 334                          !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
 335 }
 336
 337 /*
 338  * Look up an MCS group index based on new cfg80211 rate_info.
 339  */
 340 static int
 341 minstrel_ht_ri_get_group_idx(struct rate_info *rate)
 342 {
 343         return GROUP_IDX((rate->mcs / 8) + 1,
 344                          !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
 345                          !!(rate->bw & RATE_INFO_BW_40));
 346 }
 347
 348 static int
 349 minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate)
 350 {
 351         return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate),
 352                              !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
 353                              !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) +
 354                              2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH));
 355 }
 356
 357 /*
 358  * Look up an MCS group index based on new cfg80211 rate_info.
 359  */
 360 static int
 361 minstrel_vht_ri_get_group_idx(struct rate_info *rate)
 362 {
 363         return VHT_GROUP_IDX(rate->nss,
 364                              !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI),
 365                              !!(rate->bw & RATE_INFO_BW_40) +
 366                              2*!!(rate->bw & RATE_INFO_BW_80));
 367 }
 368
 369 static struct minstrel_rate_stats *
 370 minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 371                       struct ieee80211_tx_rate *rate)
 372 {
 373         int group, idx;
 374
 375         if (rate->flags & IEEE80211_TX_RC_MCS) {
 376                 group = minstrel_ht_get_group_idx(rate);
 377                 idx = rate->idx % 8;
 378                 goto out;
 379         }
 380
 381         if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
 382                 group = minstrel_vht_get_group_idx(rate);
 383                 idx = ieee80211_rate_get_vht_mcs(rate);
 384                 goto out;
 385         }
 386
 387         group = MINSTREL_CCK_GROUP;
 388         for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
 389                 if (!(mi->supported[group] & BIT(idx)))
 390                         continue;
 391
 392                 if (rate->idx != mp->cck_rates[idx])
 393                         continue;
 394
 395                 /* short preamble */
 396                 if ((mi->supported[group] & BIT(idx + 4)) &&
 397                     (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE))
 398                         idx += 4;
 399                 goto out;
 400         }
 401
 402         group = MINSTREL_OFDM_GROUP;
 403         for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
 404                 if (rate->idx == mp->ofdm_rates[mi->band][idx])
 405                         goto out;
 406
 407         idx = 0;
 408 out:
 409         return &mi->groups[group].rates[idx];
 410 }
 411
 412 /*
 413  * Get the minstrel rate statistics for specified STA and rate info.
 414  */
 415 static struct minstrel_rate_stats *
 416 minstrel_ht_ri_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
 417                           struct ieee80211_rate_status *rate_status)
 418 {
 419         int group, idx;
 420         struct rate_info *rate = &rate_status->rate_idx;
 421
 422         if (rate->flags & RATE_INFO_FLAGS_MCS) {
 423                 group = minstrel_ht_ri_get_group_idx(rate);
 424                 idx = rate->mcs % 8;
 425                 goto out;
 426         }
 427
 428         if (rate->flags & RATE_INFO_FLAGS_VHT_MCS) {
 429                 group = minstrel_vht_ri_get_group_idx(rate);
 430                 idx = rate->mcs;
 431                 goto out;
 432         }
 433
 434         group = MINSTREL_CCK_GROUP;
 435         for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) {
 436                 if (rate->legacy != minstrel_cck_bitrates[ mp->cck_rates[idx] ])
 437                         continue;
 438
 439                 /* short preamble */
 440                 if ((mi->supported[group] & BIT(idx + 4)) &&
 441                                                         mi->use_short_preamble)
 442                         idx += 4;
 443                 goto out;
 444         }
 445
 446         group = MINSTREL_OFDM_GROUP;
 447         for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++)
 448                 if (rate->legacy == minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][idx] ])
 449                         goto out;
 450
 451         idx = 0;
 452 out:
 453         return &mi->groups[group].rates[idx];
 454 }
 455
 456 static inline struct minstrel_rate_stats *
 457 minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
 458 {
 459         return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)];
 460 }
 461
 462 static inline int minstrel_get_duration(int index)
 463 {
 464         const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)];
 465         unsigned int duration = group->duration[MI_RATE_IDX(index)];
 466
 467         return duration << group->shift;
 468 }
 469
 470 static unsigned int
 471 minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi)
 472 {
 473         int duration;
 474
 475         if (mi->avg_ampdu_len)
 476                 return MINSTREL_TRUNC(mi->avg_ampdu_len);
 477
 478         if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0])))
 479                 return 1;
 480
 481         duration = minstrel_get_duration(mi->max_tp_rate[0]);
 482
 483         if (duration > 400 * 1000)
 484                 return 2;
 485
 486         if (duration > 250 * 1000)
 487                 return 4;
 488
 489         if (duration > 150 * 1000)
 490                 return 8;
 491
 492         return 16;
 493 }
 494
 495 /*
 496  * Return current throughput based on the average A-MPDU length, taking into
 497  * account the expected number of retransmissions and their expected length
 498  */
 499 int
 500 minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate,
 501                        int prob_avg)
 502 {
 503         unsigned int nsecs = 0, overhead = mi->overhead;
 504         unsigned int ampdu_len = 1;
 505
 506         /* do not account throughput if success prob is below 10% */
 507         if (prob_avg < MINSTREL_FRAC(10, 100))
 508                 return 0;
 509
 510         if (minstrel_ht_is_legacy_group(group))
 511                 overhead = mi->overhead_legacy;
 512         else
 513                 ampdu_len = minstrel_ht_avg_ampdu_len(mi);
 514
 515         nsecs = 1000 * overhead / ampdu_len;
 516         nsecs += minstrel_mcs_groups[group].duration[rate] <<
 517                  minstrel_mcs_groups[group].shift;
 518
 519         /*
 520          * For the throughput calculation, limit the probability value to 90% to
 521          * account for collision related packet error rate fluctuation
 522          * (prob is scaled - see MINSTREL_FRAC above)
 523          */
 524         if (prob_avg > MINSTREL_FRAC(90, 100))
 525                 prob_avg = MINSTREL_FRAC(90, 100);
 526
 527         return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / nsecs));
 528 }
 529
 530 /*
 531  * Find & sort topmost throughput rates
 532  *
 533  * If multiple rates provide equal throughput the sorting is based on their
 534  * current success probability. Higher success probability is preferred among
 535  * MCS groups, CCK rates do not provide aggregation and are therefore at last.
 536  */
 537 static void
 538 minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index,
 539                                u16 *tp_list)
 540 {
 541         int cur_group, cur_idx, cur_tp_avg, cur_prob;
 542         int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
 543         int j = MAX_THR_RATES;
 544
 545         cur_group = MI_RATE_GROUP(index);
 546         cur_idx = MI_RATE_IDX(index);
 547         cur_prob = mi->groups[cur_group].rates[cur_idx].prob_avg;
 548         cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob);
 549
 550         do {
 551                 tmp_group = MI_RATE_GROUP(tp_list[j - 1]);
 552                 tmp_idx = MI_RATE_IDX(tp_list[j - 1]);
 553                 tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 554                 tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx,
 555                                                     tmp_prob);
 556                 if (cur_tp_avg < tmp_tp_avg ||
 557                     (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob))
 558                         break;
 559                 j--;
 560         } while (j > 0);
 561
 562         if (j < MAX_THR_RATES - 1) {
 563                 memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) *
 564                        (MAX_THR_RATES - (j + 1))));
 565         }
 566         if (j < MAX_THR_RATES)
 567                 tp_list[j] = index;
 568 }
 569
 570 /*
 571  * Find and set the topmost probability rate per sta and per group
 572  */
 573 static void
 574 minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 *dest, u16 index)
 575 {
 576         struct minstrel_mcs_group_data *mg;
 577         struct minstrel_rate_stats *mrs;
 578         int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob;
 579         int max_tp_group, max_tp_idx, max_tp_prob;
 580         int cur_tp_avg, cur_group, cur_idx;
 581         int max_gpr_group, max_gpr_idx;
 582         int max_gpr_tp_avg, max_gpr_prob;
 583
 584         cur_group = MI_RATE_GROUP(index);
 585         cur_idx = MI_RATE_IDX(index);
 586         mg = &mi->groups[cur_group];
 587         mrs = &mg->rates[cur_idx];
 588
 589         tmp_group = MI_RATE_GROUP(*dest);
 590         tmp_idx = MI_RATE_IDX(*dest);
 591         tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 592         tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 593
 594         /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from
 595          * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */
 596         max_tp_group = MI_RATE_GROUP(mi->max_tp_rate[0]);
 597         max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]);
 598         max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg;
 599
 600         if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) &&
 601             !minstrel_ht_is_legacy_group(max_tp_group))
 602                 return;
 603
 604         /* skip rates faster than max tp rate with lower prob */
 605         if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) &&
 606             mrs->prob_avg < max_tp_prob)
 607                 return;
 608
 609         max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate);
 610         max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate);
 611         max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_avg;
 612
 613         if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) {
 614                 cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx,
 615                                                     mrs->prob_avg);
 616                 if (cur_tp_avg > tmp_tp_avg)
 617                         *dest = index;
 618
 619                 max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group,
 620                                                         max_gpr_idx,
 621                                                         max_gpr_prob);
 622                 if (cur_tp_avg > max_gpr_tp_avg)
 623                         mg->max_group_prob_rate = index;
 624         } else {
 625                 if (mrs->prob_avg > tmp_prob)
 626                         *dest = index;
 627                 if (mrs->prob_avg > max_gpr_prob)
 628                         mg->max_group_prob_rate = index;
 629         }
 630 }
 631
 632
 633 /*
 634  * Assign new rate set per sta and use CCK rates only if the fastest
 635  * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted
 636  * rate sets where MCS and CCK rates are mixed, because CCK rates can
 637  * not use aggregation.
 638  */
 639 static void
 640 minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi,
 641                                  u16 tmp_mcs_tp_rate[MAX_THR_RATES],
 642                                  u16 tmp_legacy_tp_rate[MAX_THR_RATES])
 643 {
 644         unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob;
 645         int i;
 646
 647         tmp_group = MI_RATE_GROUP(tmp_legacy_tp_rate[0]);
 648         tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]);
 649         tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 650         tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 651
 652         tmp_group = MI_RATE_GROUP(tmp_mcs_tp_rate[0]);
 653         tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]);
 654         tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg;
 655         tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob);
 656
 657         if (tmp_cck_tp > tmp_mcs_tp) {
 658                 for(i = 0; i < MAX_THR_RATES; i++) {
 659                         minstrel_ht_sort_best_tp_rates(mi, tmp_legacy_tp_rate[i],
 660                                                        tmp_mcs_tp_rate);
 661                 }
 662         }
 663
 664 }
 665
 666 /*
 667  * Try to increase robustness of max_prob rate by decrease number of
 668  * streams if possible.
 669  */
 670 static inline void
 671 minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi)
 672 {
 673         struct minstrel_mcs_group_data *mg;
 674         int tmp_max_streams, group, tmp_idx, tmp_prob;
 675         int tmp_tp = 0;
 676
 677         if (!mi->sta->deflink.ht_cap.ht_supported)
 678                 return;
 679
 680         group = MI_RATE_GROUP(mi->max_tp_rate[0]);
 681         tmp_max_streams = minstrel_mcs_groups[group].streams;
 682         for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
 683                 mg = &mi->groups[group];
 684                 if (!mi->supported[group] || group == MINSTREL_CCK_GROUP)
 685                         continue;
 686
 687                 tmp_idx = MI_RATE_IDX(mg->max_group_prob_rate);
 688                 tmp_prob = mi->groups[group].rates[tmp_idx].prob_avg;
 689
 690                 if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) &&
 691                    (minstrel_mcs_groups[group].streams < tmp_max_streams)) {
 692                                 mi->max_prob_rate = mg->max_group_prob_rate;
 693                                 tmp_tp = minstrel_ht_get_tp_avg(mi, group,
 694                                                                 tmp_idx,
 695                                                                 tmp_prob);
 696                 }
 697         }
 698 }
 699
 700 static u16
 701 __minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi,
 702                               enum minstrel_sample_type type)
 703 {
 704         u16 *rates = mi->sample[type].sample_rates;
 705         u16 cur;
 706         int i;
 707
 708         for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 709                 if (!rates[i])
 710                         continue;
 711
 712                 cur = rates[i];
 713                 rates[i] = 0;
 714                 return cur;
 715         }
 716
 717         return 0;
 718 }
 719
 720 static inline int
 721 minstrel_ewma(int old, int new, int weight)
 722 {
 723         int diff, incr;
 724
 725         diff = new - old;
 726         incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
 727
 728         return old + incr;
 729 }
 730
 731 static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
 732 {
 733         s32 out_1 = *prev_1;
 734         s32 out_2 = *prev_2;
 735         s32 val;
 736
 737         if (!in)
 738                 in += 1;
 739
 740         if (!out_1) {
 741                 val = out_1 = in;
 742                 goto out;
 743         }
 744
 745         val = MINSTREL_AVG_COEFF1 * in;
 746         val += MINSTREL_AVG_COEFF2 * out_1;
 747         val += MINSTREL_AVG_COEFF3 * out_2;
 748         val >>= MINSTREL_SCALE;
 749
 750         if (val > 1 << MINSTREL_SCALE)
 751                 val = 1 << MINSTREL_SCALE;
 752         if (val < 0)
 753                 val = 1;
 754
 755 out:
 756         *prev_2 = out_1;
 757         *prev_1 = val;
 758
 759         return val;
 760 }
 761
 762 /*
 763 * Recalculate statistics and counters of a given rate
 764 */
 765 static void
 766 minstrel_ht_calc_rate_stats(struct minstrel_priv *mp,
 767                             struct minstrel_rate_stats *mrs)
 768 {
 769         unsigned int cur_prob;
 770
 771         if (unlikely(mrs->attempts > 0)) {
 772                 cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
 773                 minstrel_filter_avg_add(&mrs->prob_avg,
 774                                         &mrs->prob_avg_1, cur_prob);
 775                 mrs->att_hist += mrs->attempts;
 776                 mrs->succ_hist += mrs->success;
 777         }
 778
 779         mrs->last_success = mrs->success;
 780         mrs->last_attempts = mrs->attempts;
 781         mrs->success = 0;
 782         mrs->attempts = 0;
 783 }
 784
 785 static bool
 786 minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx)
 787 {
 788         int i;
 789
 790         for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 791                 u16 cur = mi->sample[type].sample_rates[i];
 792
 793                 if (cur == idx)
 794                         return true;
 795
 796                 if (!cur)
 797                         break;
 798         }
 799
 800         return false;
 801 }
 802
 803 static int
 804 minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type,
 805                               u32 fast_rate_dur, u32 slow_rate_dur)
 806 {
 807         u16 *rates = mi->sample[type].sample_rates;
 808         int i, j;
 809
 810         for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) {
 811                 u32 duration;
 812                 bool valid = false;
 813                 u16 cur;
 814
 815                 cur = rates[i];
 816                 if (!cur)
 817                         continue;
 818
 819                 duration = minstrel_get_duration(cur);
 820                 switch (type) {
 821                 case MINSTREL_SAMPLE_TYPE_SLOW:
 822                         valid = duration > fast_rate_dur &&
 823                                 duration < slow_rate_dur;
 824                         break;
 825                 case MINSTREL_SAMPLE_TYPE_INC:
 826                 case MINSTREL_SAMPLE_TYPE_JUMP:
 827                         valid = duration < fast_rate_dur;
 828                         break;
 829                 default:
 830                         valid = false;
 831                         break;
 832                 }
 833
 834                 if (!valid) {
 835                         rates[i] = 0;
 836                         continue;
 837                 }
 838
 839                 if (i == j)
 840                         continue;
 841
 842                 rates[j++] = cur;
 843                 rates[i] = 0;
 844         }
 845
 846         return j;
 847 }
 848
 849 static int
 850 minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group,
 851                                   u32 max_duration)
 852 {
 853         u16 supported = mi->supported[group];
 854         int i;
 855
 856         for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) {
 857                 if (!(supported & BIT(0)))
 858                         continue;
 859
 860                 if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration)
 861                         continue;
 862
 863                 return i;
 864         }
 865
 866         return -1;
 867 }
 868
 869 /*
 870  * Incremental update rates:
 871  * Flip through groups and pick the first group rate that is faster than the
 872  * highest currently selected rate
 873  */
 874 static u16
 875 minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur)
 876 {
 877         u8 type = MINSTREL_SAMPLE_TYPE_INC;
 878         int i, index = 0;
 879         u8 group;
 880
 881         group = mi->sample[type].sample_group;
 882         for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
 883                 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
 884
 885                 index = minstrel_ht_group_min_rate_offset(mi, group,
 886                                                           fast_rate_dur);
 887                 if (index < 0)
 888                         continue;
 889
 890                 index = MI_RATE(group, index & 0xf);
 891                 if (!minstrel_ht_find_sample_rate(mi, type, index))
 892                         goto out;
 893         }
 894         index = 0;
 895
 896 out:
 897         mi->sample[type].sample_group = group;
 898
 899         return index;
 900 }
 901
 902 static int
 903 minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group,
 904                                    u16 supported, int offset)
 905 {
 906         struct minstrel_mcs_group_data *mg = &mi->groups[group];
 907         u16 idx;
 908         int i;
 909
 910         for (i = 0; i < MCS_GROUP_RATES; i++) {
 911                 idx = sample_table[mg->column][mg->index];
 912                 if (++mg->index >= MCS_GROUP_RATES) {
 913                         mg->index = 0;
 914                         if (++mg->column >= ARRAY_SIZE(sample_table))
 915                                 mg->column = 0;
 916                 }
 917
 918                 if (idx < offset)
 919                         continue;
 920
 921                 if (!(supported & BIT(idx)))
 922                         continue;
 923
 924                 return MI_RATE(group, idx);
 925         }
 926
 927         return -1;
 928 }
 929
 930 /*
 931  * Jump rates:
 932  * Sample random rates, use those that are faster than the highest
 933  * currently selected rate. Rates between the fastest and the slowest
 934  * get sorted into the slow sample bucket, but only if it has room
 935  */
 936 static u16
 937 minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur,
 938                            u32 slow_rate_dur, int *slow_rate_ofs)
 939 {
 940         struct minstrel_rate_stats *mrs;
 941         u32 max_duration = slow_rate_dur;
 942         int i, index, offset;
 943         u16 *slow_rates;
 944         u16 supported;
 945         u32 duration;
 946         u8 group;
 947
 948         if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 949                 max_duration = fast_rate_dur;
 950
 951         slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates;
 952         group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group;
 953         for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
 954                 u8 type;
 955
 956                 group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups);
 957
 958                 supported = mi->supported[group];
 959                 if (!supported)
 960                         continue;
 961
 962                 offset = minstrel_ht_group_min_rate_offset(mi, group,
 963                                                            max_duration);
 964                 if (offset < 0)
 965                         continue;
 966
 967                 index = minstrel_ht_next_group_sample_rate(mi, group, supported,
 968                                                            offset);
 969                 if (index < 0)
 970                         continue;
 971
 972                 duration = minstrel_get_duration(index);
 973                 if (duration < fast_rate_dur)
 974                         type = MINSTREL_SAMPLE_TYPE_JUMP;
 975                 else
 976                         type = MINSTREL_SAMPLE_TYPE_SLOW;
 977
 978                 if (minstrel_ht_find_sample_rate(mi, type, index))
 979                         continue;
 980
 981                 if (type == MINSTREL_SAMPLE_TYPE_JUMP)
 982                         goto found;
 983
 984                 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 985                         continue;
 986
 987                 if (duration >= slow_rate_dur)
 988                         continue;
 989
 990                 /* skip slow rates with high success probability */
 991                 mrs = minstrel_get_ratestats(mi, index);
 992                 if (mrs->prob_avg > MINSTREL_FRAC(95, 100))
 993                         continue;
 994
 995                 slow_rates[(*slow_rate_ofs)++] = index;
 996                 if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES)
 997                         max_duration = fast_rate_dur;
 998         }
 999         index = 0;
1000
1001 found:
1002         mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group;
1003
1004         return index;
1005 }
1006
1007 static void
1008 minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi)
1009 {
1010         u32 prob_dur = minstrel_get_duration(mi->max_prob_rate);
1011         u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]);
1012         u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]);
1013         u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur);
1014         u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur);
1015         u16 *rates;
1016         int i, j;
1017
1018         rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates;
1019         i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC,
1020                                           fast_rate_dur, slow_rate_dur);
1021         while (i < MINSTREL_SAMPLE_RATES) {
1022                 rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur);
1023                 if (!rates[i])
1024                         break;
1025
1026                 i++;
1027         }
1028
1029         rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates;
1030         i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP,
1031                                           fast_rate_dur, slow_rate_dur);
1032         j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW,
1033                                           fast_rate_dur, slow_rate_dur);
1034         while (i < MINSTREL_SAMPLE_RATES) {
1035                 rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur,
1036                                                       slow_rate_dur, &j);
1037                 if (!rates[i])
1038                         break;
1039
1040                 i++;
1041         }
1042
1043         for (i = 0; i < ARRAY_SIZE(mi->sample); i++)
1044                 memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates,
1045                        sizeof(mi->sample[i].cur_sample_rates));
1046 }
1047
1048
1049 /*
1050  * Update rate statistics and select new primary rates
1051  *
1052  * Rules for rate selection:
1053  *  - max_prob_rate must use only one stream, as a tradeoff between delivery
1054  *    probability and throughput during strong fluctuations
1055  *  - as long as the max prob rate has a probability of more than 75%, pick
1056  *    higher throughput rates, even if the probablity is a bit lower
1057  */
1058 static void
1059 minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1060 {
1061         struct minstrel_mcs_group_data *mg;
1062         struct minstrel_rate_stats *mrs;
1063         int group, i, j, cur_prob;
1064         u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES];
1065         u16 tmp_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate;
1066         u16 index;
1067         bool ht_supported = mi->sta->deflink.ht_cap.ht_supported;
1068
1069         if (mi->ampdu_packets > 0) {
1070                 if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN))
1071                         mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
1072                                 MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets),
1073                                               EWMA_LEVEL);
1074                 else
1075                         mi->avg_ampdu_len = 0;
1076                 mi->ampdu_len = 0;
1077                 mi->ampdu_packets = 0;
1078         }
1079
1080         if (mi->supported[MINSTREL_CCK_GROUP])
1081                 group = MINSTREL_CCK_GROUP;
1082         else if (mi->supported[MINSTREL_OFDM_GROUP])
1083                 group = MINSTREL_OFDM_GROUP;
1084         else
1085                 group = 0;
1086
1087         index = MI_RATE(group, 0);
1088         for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++)
1089                 tmp_legacy_tp_rate[j] = index;
1090
1091         if (mi->supported[MINSTREL_VHT_GROUP_0])
1092                 group = MINSTREL_VHT_GROUP_0;
1093         else if (ht_supported)
1094                 group = MINSTREL_HT_GROUP_0;
1095         else if (mi->supported[MINSTREL_CCK_GROUP])
1096                 group = MINSTREL_CCK_GROUP;
1097         else
1098                 group = MINSTREL_OFDM_GROUP;
1099
1100         index = MI_RATE(group, 0);
1101         tmp_max_prob_rate = index;
1102         for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++)
1103                 tmp_mcs_tp_rate[j] = index;
1104
1105         /* Find best rate sets within all MCS groups*/
1106         for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1107                 u16 *tp_rate = tmp_mcs_tp_rate;
1108                 u16 last_prob = 0;
1109
1110                 mg = &mi->groups[group];
1111                 if (!mi->supported[group])
1112                         continue;
1113
1114                 /* (re)Initialize group rate indexes */
1115                 for(j = 0; j < MAX_THR_RATES; j++)
1116                         tmp_group_tp_rate[j] = MI_RATE(group, 0);
1117
1118                 if (group == MINSTREL_CCK_GROUP && ht_supported)
1119                         tp_rate = tmp_legacy_tp_rate;
1120
1121                 for (i = MCS_GROUP_RATES - 1; i >= 0; i--) {
1122                         if (!(mi->supported[group] & BIT(i)))
1123                                 continue;
1124
1125                         index = MI_RATE(group, i);
1126
1127                         mrs = &mg->rates[i];
1128                         mrs->retry_updated = false;
1129                         minstrel_ht_calc_rate_stats(mp, mrs);
1130
1131                         if (mrs->att_hist)
1132                                 last_prob = max(last_prob, mrs->prob_avg);
1133                         else
1134                                 mrs->prob_avg = max(last_prob, mrs->prob_avg);
1135                         cur_prob = mrs->prob_avg;
1136
1137                         if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0)
1138                                 continue;
1139
1140                         /* Find max throughput rate set */
1141                         minstrel_ht_sort_best_tp_rates(mi, index, tp_rate);
1142
1143                         /* Find max throughput rate set within a group */
1144                         minstrel_ht_sort_best_tp_rates(mi, index,
1145                                                        tmp_group_tp_rate);
1146                 }
1147
1148                 memcpy(mg->max_group_tp_rate, tmp_group_tp_rate,
1149                        sizeof(mg->max_group_tp_rate));
1150         }
1151
1152         /* Assign new rate set per sta */
1153         minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate,
1154                                          tmp_legacy_tp_rate);
1155         memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate));
1156
1157         for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
1158                 if (!mi->supported[group])
1159                         continue;
1160
1161                 mg = &mi->groups[group];
1162                 mg->max_group_prob_rate = MI_RATE(group, 0);
1163
1164                 for (i = 0; i < MCS_GROUP_RATES; i++) {
1165                         if (!(mi->supported[group] & BIT(i)))
1166                                 continue;
1167
1168                         index = MI_RATE(group, i);
1169
1170                         /* Find max probability rate per group and global */
1171                         minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate,
1172                                                        index);
1173                 }
1174         }
1175
1176         mi->max_prob_rate = tmp_max_prob_rate;
1177
1178         /* Try to increase robustness of max_prob_rate*/
1179         minstrel_ht_prob_rate_reduce_streams(mi);
1180         minstrel_ht_refill_sample_rates(mi);
1181
1182 #ifdef CONFIG_MAC80211_DEBUGFS
1183         /* use fixed index if set */
1184         if (mp->fixed_rate_idx != -1) {
1185                 for (i = 0; i < 4; i++)
1186                         mi->max_tp_rate[i] = mp->fixed_rate_idx;
1187                 mi->max_prob_rate = mp->fixed_rate_idx;
1188         }
1189 #endif
1190
1191         /* Reset update timer */
1192         mi->last_stats_update = jiffies;
1193         mi->sample_time = jiffies;
1194 }
1195
1196 static bool
1197 minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1198                          struct ieee80211_tx_rate *rate)
1199 {
1200         int i;
1201
1202         if (rate->idx < 0)
1203                 return false;
1204
1205         if (!rate->count)
1206                 return false;
1207
1208         if (rate->flags & IEEE80211_TX_RC_MCS ||
1209             rate->flags & IEEE80211_TX_RC_VHT_MCS)
1210                 return true;
1211
1212         for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++)
1213                 if (rate->idx == mp->cck_rates[i])
1214                         return true;
1215
1216         for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++)
1217                 if (rate->idx == mp->ofdm_rates[mi->band][i])
1218                         return true;
1219
1220         return false;
1221 }
1222
1223 /*
1224  * Check whether rate_status contains valid information.
1225  */
1226 static bool
1227 minstrel_ht_ri_txstat_valid(struct minstrel_priv *mp,
1228                             struct minstrel_ht_sta *mi,
1229                             struct ieee80211_rate_status *rate_status)
1230 {
1231         int i;
1232
1233         if (!rate_status)
1234                 return false;
1235         if (!rate_status->try_count)
1236                 return false;
1237
1238         if (rate_status->rate_idx.flags & RATE_INFO_FLAGS_MCS ||
1239             rate_status->rate_idx.flags & RATE_INFO_FLAGS_VHT_MCS)
1240                 return true;
1241
1242         for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) {
1243                 if (rate_status->rate_idx.legacy ==
1244                     minstrel_cck_bitrates[ mp->cck_rates[i] ])
1245                         return true;
1246         }
1247
1248         for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates); i++) {
1249                 if (rate_status->rate_idx.legacy ==
1250                     minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][i] ])
1251                         return true;
1252         }
1253
1254         return false;
1255 }
1256
1257 static void
1258 minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary)
1259 {
1260         int group, orig_group;
1261
1262         orig_group = group = MI_RATE_GROUP(*idx);
1263         while (group > 0) {
1264                 group--;
1265
1266                 if (!mi->supported[group])
1267                         continue;
1268
1269                 if (minstrel_mcs_groups[group].streams >
1270                     minstrel_mcs_groups[orig_group].streams)
1271                         continue;
1272
1273                 if (primary)
1274                         *idx = mi->groups[group].max_group_tp_rate[0];
1275                 else
1276                         *idx = mi->groups[group].max_group_tp_rate[1];
1277                 break;
1278         }
1279 }
1280
1281 static void
1282 minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
1283                       void *priv_sta, struct ieee80211_tx_status *st)
1284 {
1285         struct ieee80211_tx_info *info = st->info;
1286         struct minstrel_ht_sta *mi = priv_sta;
1287         struct ieee80211_tx_rate *ar = info->status.rates;
1288         struct minstrel_rate_stats *rate, *rate2;
1289         struct minstrel_priv *mp = priv;
1290         u32 update_interval = mp->update_interval;
1291         bool last, update = false;
1292         int i;
1293
1294         /* Ignore packet that was sent with noAck flag */
1295         if (info->flags & IEEE80211_TX_CTL_NO_ACK)
1296                 return;
1297
1298         /* This packet was aggregated but doesn't carry status info */
1299         if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
1300             !(info->flags & IEEE80211_TX_STAT_AMPDU))
1301                 return;
1302
1303         if (!(info->flags & IEEE80211_TX_STAT_AMPDU)) {
1304                 info->status.ampdu_ack_len =
1305                         (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
1306                 info->status.ampdu_len = 1;
1307         }
1308
1309         /* wraparound */
1310         if (mi->total_packets >= ~0 - info->status.ampdu_len) {
1311                 mi->total_packets = 0;
1312                 mi->sample_packets = 0;
1313         }
1314
1315         mi->total_packets += info->status.ampdu_len;
1316         if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
1317                 mi->sample_packets += info->status.ampdu_len;
1318
1319         mi->ampdu_packets++;
1320         mi->ampdu_len += info->status.ampdu_len;
1321
1322         if (st->rates && st->n_rates) {
1323                 last = !minstrel_ht_ri_txstat_valid(mp, mi, &(st->rates[0]));
1324                 for (i = 0; !last; i++) {
1325                         last = (i == st->n_rates - 1) ||
1326                                 !minstrel_ht_ri_txstat_valid(mp, mi,
1327                                                         &(st->rates[i + 1]));
1328
1329                         rate = minstrel_ht_ri_get_stats(mp, mi,
1330                                                         &(st->rates[i]));
1331
1332                         if (last)
1333                                 rate->success += info->status.ampdu_ack_len;
1334
1335                         rate->attempts += st->rates[i].try_count *
1336                                           info->status.ampdu_len;
1337                 }
1338         } else {
1339                 last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]);
1340                 for (i = 0; !last; i++) {
1341                         last = (i == IEEE80211_TX_MAX_RATES - 1) ||
1342                                 !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]);
1343
1344                         rate = minstrel_ht_get_stats(mp, mi, &ar[i]);
1345                         if (last)
1346                                 rate->success += info->status.ampdu_ack_len;
1347
1348                         rate->attempts += ar[i].count * info->status.ampdu_len;
1349                 }
1350         }
1351
1352         if (mp->hw->max_rates > 1) {
1353                 /*
1354                  * check for sudden death of spatial multiplexing,
1355                  * downgrade to a lower number of streams if necessary.
1356                  */
1357                 rate = minstrel_get_ratestats(mi, mi->max_tp_rate[0]);
1358                 if (rate->attempts > 30 &&
1359                     rate->success < rate->attempts / 4) {
1360                         minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true);
1361                         update = true;
1362                 }
1363
1364                 rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]);
1365                 if (rate2->attempts > 30 &&
1366                     rate2->success < rate2->attempts / 4) {
1367                         minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false);
1368                         update = true;
1369                 }
1370         }
1371
1372         if (time_after(jiffies, mi->last_stats_update + update_interval)) {
1373                 update = true;
1374                 minstrel_ht_update_stats(mp, mi);
1375         }
1376
1377         if (update)
1378                 minstrel_ht_update_rates(mp, mi);
1379 }
1380
1381 static void
1382 minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1383                          int index)
1384 {
1385         struct minstrel_rate_stats *mrs;
1386         unsigned int tx_time, tx_time_rtscts, tx_time_data;
1387         unsigned int cw = mp->cw_min;
1388         unsigned int ctime = 0;
1389         unsigned int t_slot = 9; /* FIXME */
1390         unsigned int ampdu_len = minstrel_ht_avg_ampdu_len(mi);
1391         unsigned int overhead = 0, overhead_rtscts = 0;
1392
1393         mrs = minstrel_get_ratestats(mi, index);
1394         if (mrs->prob_avg < MINSTREL_FRAC(1, 10)) {
1395                 mrs->retry_count = 1;
1396                 mrs->retry_count_rtscts = 1;
1397                 return;
1398         }
1399
1400         mrs->retry_count = 2;
1401         mrs->retry_count_rtscts = 2;
1402         mrs->retry_updated = true;
1403
1404         tx_time_data = minstrel_get_duration(index) * ampdu_len / 1000;
1405
1406         /* Contention time for first 2 tries */
1407         ctime = (t_slot * cw) >> 1;
1408         cw = min((cw << 1) | 1, mp->cw_max);
1409         ctime += (t_slot * cw) >> 1;
1410         cw = min((cw << 1) | 1, mp->cw_max);
1411
1412         if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) {
1413                 overhead = mi->overhead_legacy;
1414                 overhead_rtscts = mi->overhead_legacy_rtscts;
1415         } else {
1416                 overhead = mi->overhead;
1417                 overhead_rtscts = mi->overhead_rtscts;
1418         }
1419
1420         /* Total TX time for data and Contention after first 2 tries */
1421         tx_time = ctime + 2 * (overhead + tx_time_data);
1422         tx_time_rtscts = ctime + 2 * (overhead_rtscts + tx_time_data);
1423
1424         /* See how many more tries we can fit inside segment size */
1425         do {
1426                 /* Contention time for this try */
1427                 ctime = (t_slot * cw) >> 1;
1428                 cw = min((cw << 1) | 1, mp->cw_max);
1429
1430                 /* Total TX time after this try */
1431                 tx_time += ctime + overhead + tx_time_data;
1432                 tx_time_rtscts += ctime + overhead_rtscts + tx_time_data;
1433
1434                 if (tx_time_rtscts < mp->segment_size)
1435                         mrs->retry_count_rtscts++;
1436         } while ((tx_time < mp->segment_size) &&
1437                  (++mrs->retry_count < mp->max_retry));
1438 }
1439
1440
1441 static void
1442 minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1443                      struct ieee80211_sta_rates *ratetbl, int offset, int index)
1444 {
1445         int group_idx = MI_RATE_GROUP(index);
1446         const struct mcs_group *group = &minstrel_mcs_groups[group_idx];
1447         struct minstrel_rate_stats *mrs;
1448         u8 idx;
1449         u16 flags = group->flags;
1450
1451         mrs = minstrel_get_ratestats(mi, index);
1452         if (!mrs->retry_updated)
1453                 minstrel_calc_retransmit(mp, mi, index);
1454
1455         if (mrs->prob_avg < MINSTREL_FRAC(20, 100) || !mrs->retry_count) {
1456                 ratetbl->rate[offset].count = 2;
1457                 ratetbl->rate[offset].count_rts = 2;
1458                 ratetbl->rate[offset].count_cts = 2;
1459         } else {
1460                 ratetbl->rate[offset].count = mrs->retry_count;
1461                 ratetbl->rate[offset].count_cts = mrs->retry_count;
1462                 ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts;
1463         }
1464
1465         index = MI_RATE_IDX(index);
1466         if (group_idx == MINSTREL_CCK_GROUP)
1467                 idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)];
1468         else if (group_idx == MINSTREL_OFDM_GROUP)
1469                 idx = mp->ofdm_rates[mi->band][index %
1470                                                ARRAY_SIZE(mp->ofdm_rates[0])];
1471         else if (flags & IEEE80211_TX_RC_VHT_MCS)
1472                 idx = ((group->streams - 1) << 4) |
1473                       (index & 0xF);
1474         else
1475                 idx = index + (group->streams - 1) * 8;
1476
1477         /* enable RTS/CTS if needed:
1478          *  - if station is in dynamic SMPS (and streams > 1)
1479          *  - for fallback rates, to increase chances of getting through
1480          */
1481         if (offset > 0 ||
1482             (mi->sta->deflink.smps_mode == IEEE80211_SMPS_DYNAMIC &&
1483              group->streams > 1)) {
1484                 ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts;
1485                 flags |= IEEE80211_TX_RC_USE_RTS_CTS;
1486         }
1487
1488         ratetbl->rate[offset].idx = idx;
1489         ratetbl->rate[offset].flags = flags;
1490 }
1491
1492 static inline int
1493 minstrel_ht_get_prob_avg(struct minstrel_ht_sta *mi, int rate)
1494 {
1495         int group = MI_RATE_GROUP(rate);
1496         rate = MI_RATE_IDX(rate);
1497         return mi->groups[group].rates[rate].prob_avg;
1498 }
1499
1500 static int
1501 minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi)
1502 {
1503         int group = MI_RATE_GROUP(mi->max_prob_rate);
1504         const struct mcs_group *g = &minstrel_mcs_groups[group];
1505         int rate = MI_RATE_IDX(mi->max_prob_rate);
1506         unsigned int duration;
1507
1508         /* Disable A-MSDU if max_prob_rate is bad */
1509         if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100))
1510                 return 1;
1511
1512         duration = g->duration[rate];
1513         duration <<= g->shift;
1514
1515         /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */
1516         if (duration > MCS_DURATION(1, 0, 52))
1517                 return 500;
1518
1519         /*
1520          * If the rate is slower than single-stream MCS4, limit A-MSDU to usual
1521          * data packet size
1522          */
1523         if (duration > MCS_DURATION(1, 0, 104))
1524                 return 1600;
1525
1526         /*
1527          * If the rate is slower than single-stream MCS7, or if the max throughput
1528          * rate success probability is less than 75%, limit A-MSDU to twice the usual
1529          * data packet size
1530          */
1531         if (duration > MCS_DURATION(1, 0, 260) ||
1532             (minstrel_ht_get_prob_avg(mi, mi->max_tp_rate[0]) <
1533              MINSTREL_FRAC(75, 100)))
1534                 return 3200;
1535
1536         /*
1537          * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes.
1538          * Since aggregation sessions are started/stopped without txq flush, use
1539          * the limit here to avoid the complexity of having to de-aggregate
1540          * packets in the queue.
1541          */
1542         if (!mi->sta->deflink.vht_cap.vht_supported)
1543                 return IEEE80211_MAX_MPDU_LEN_HT_BA;
1544
1545         /* unlimited */
1546         return 0;
1547 }
1548
1549 static void
1550 minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1551 {
1552         struct ieee80211_sta_rates *rates;
1553         int i = 0;
1554         int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
1555
1556         rates = kzalloc(sizeof(*rates), GFP_ATOMIC);
1557         if (!rates)
1558                 return;
1559
1560         /* Start with max_tp_rate[0] */
1561         minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]);
1562
1563         /* Fill up remaining, keep one entry for max_probe_rate */
1564         for (; i < (max_rates - 1); i++)
1565                 minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]);
1566
1567         if (i < max_rates)
1568                 minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate);
1569
1570         if (i < IEEE80211_TX_RATE_TABLE_SIZE)
1571                 rates->rate[i].idx = -1;
1572
1573         mi->sta->deflink.agg.max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi);
1574         ieee80211_sta_recalc_aggregates(mi->sta);
1575         rate_control_set_rates(mp->hw, mi->sta, rates);
1576 }
1577
1578 static u16
1579 minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
1580 {
1581         u8 seq;
1582
1583         if (mp->hw->max_rates > 1) {
1584                 seq = mi->sample_seq;
1585                 mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq);
1586                 seq = minstrel_sample_seq[seq];
1587         } else {
1588                 seq = MINSTREL_SAMPLE_TYPE_INC;
1589         }
1590
1591         return __minstrel_ht_get_sample_rate(mi, seq);
1592 }
1593
1594 static void
1595 minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
1596                      struct ieee80211_tx_rate_control *txrc)
1597 {
1598         const struct mcs_group *sample_group;
1599         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1600         struct ieee80211_tx_rate *rate = &info->status.rates[0];
1601         struct minstrel_ht_sta *mi = priv_sta;
1602         struct minstrel_priv *mp = priv;
1603         u16 sample_idx;
1604
1605         info->flags |= mi->tx_flags;
1606
1607 #ifdef CONFIG_MAC80211_DEBUGFS
1608         if (mp->fixed_rate_idx != -1)
1609                 return;
1610 #endif
1611
1612         /* Don't use EAPOL frames for sampling on non-mrr hw */
1613         if (mp->hw->max_rates == 1 &&
1614             (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO))
1615                 return;
1616
1617         if (time_is_after_jiffies(mi->sample_time))
1618                 return;
1619
1620         mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL;
1621         sample_idx = minstrel_ht_get_sample_rate(mp, mi);
1622         if (!sample_idx)
1623                 return;
1624
1625         sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)];
1626         sample_idx = MI_RATE_IDX(sample_idx);
1627
1628         if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] &&
1629             (sample_idx >= 4) != txrc->short_preamble)
1630                 return;
1631
1632         info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
1633         rate->count = 1;
1634
1635         if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) {
1636                 int idx = sample_idx % ARRAY_SIZE(mp->cck_rates);
1637                 rate->idx = mp->cck_rates[idx];
1638         } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) {
1639                 int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]);
1640                 rate->idx = mp->ofdm_rates[mi->band][idx];
1641         } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) {
1642                 ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx),
1643                                        sample_group->streams);
1644         } else {
1645                 rate->idx = sample_idx + (sample_group->streams - 1) * 8;
1646         }
1647
1648         rate->flags = sample_group->flags;
1649 }
1650
1651 static void
1652 minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1653                        struct ieee80211_supported_band *sband,
1654                        struct ieee80211_sta *sta)
1655 {
1656         int i;
1657
1658         if (sband->band != NL80211_BAND_2GHZ)
1659                 return;
1660
1661         if (sta->deflink.ht_cap.ht_supported &&
1662             !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES))
1663                 return;
1664
1665         for (i = 0; i < 4; i++) {
1666                 if (mp->cck_rates[i] == 0xff ||
1667                     !rate_supported(sta, sband->band, mp->cck_rates[i]))
1668                         continue;
1669
1670                 mi->supported[MINSTREL_CCK_GROUP] |= BIT(i);
1671                 if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE)
1672                         mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4);
1673         }
1674 }
1675
1676 static void
1677 minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
1678                         struct ieee80211_supported_band *sband,
1679                         struct ieee80211_sta *sta)
1680 {
1681         const u8 *rates;
1682         int i;
1683
1684         if (sta->deflink.ht_cap.ht_supported)
1685                 return;
1686
1687         rates = mp->ofdm_rates[sband->band];
1688         for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) {
1689                 if (rates[i] == 0xff ||
1690                     !rate_supported(sta, sband->band, rates[i]))
1691                         continue;
1692
1693                 mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i);
1694         }
1695 }
1696
1697 static void
1698 minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
1699                         struct cfg80211_chan_def *chandef,
1700                         struct ieee80211_sta *sta, void *priv_sta)
1701 {
1702         struct minstrel_priv *mp = priv;
1703         struct minstrel_ht_sta *mi = priv_sta;
1704         struct ieee80211_mcs_info *mcs = &sta->deflink.ht_cap.mcs;
1705         u16 ht_cap = sta->deflink.ht_cap.cap;
1706         struct ieee80211_sta_vht_cap *vht_cap = &sta->deflink.vht_cap;
1707         const struct ieee80211_rate *ctl_rate;
1708         struct sta_info *sta_info;
1709         bool ldpc, erp;
1710         int use_vht;
1711         int n_supported = 0;
1712         int ack_dur;
1713         int stbc;
1714         int i;
1715
1716         BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB);
1717
1718         if (vht_cap->vht_supported)
1719                 use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0);
1720         else
1721                 use_vht = 0;
1722
1723         memset(mi, 0, sizeof(*mi));
1724
1725         mi->sta = sta;
1726         mi->band = sband->band;
1727         mi->last_stats_update = jiffies;
1728
1729         ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0);
1730         mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0);
1731         mi->overhead += ack_dur;
1732         mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
1733
1734         ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];
1735         erp = ctl_rate->flags & IEEE80211_RATE_ERP_G;
1736         ack_dur = ieee80211_frame_duration(sband->band, 10,
1737                                            ctl_rate->bitrate, erp, 1,
1738                                            ieee80211_chandef_get_shift(chandef));
1739         mi->overhead_legacy = ack_dur;
1740         mi->overhead_legacy_rtscts = mi->overhead_legacy + 2 * ack_dur;
1741
1742         mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
1743
1744         if (!use_vht) {
1745                 stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >>
1746                         IEEE80211_HT_CAP_RX_STBC_SHIFT;
1747
1748                 ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING;
1749         } else {
1750                 stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >>
1751                         IEEE80211_VHT_CAP_RXSTBC_SHIFT;
1752
1753                 ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC;
1754         }
1755
1756         mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
1757         if (ldpc)
1758                 mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
1759
1760         for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
1761                 u32 gflags = minstrel_mcs_groups[i].flags;
1762                 int bw, nss;
1763
1764                 mi->supported[i] = 0;
1765                 if (minstrel_ht_is_legacy_group(i))
1766                         continue;
1767
1768                 if (gflags & IEEE80211_TX_RC_SHORT_GI) {
1769                         if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
1770                                 if (!(ht_cap & IEEE80211_HT_CAP_SGI_40))
1771                                         continue;
1772                         } else {
1773                                 if (!(ht_cap & IEEE80211_HT_CAP_SGI_20))
1774                                         continue;
1775                         }
1776                 }
1777
1778                 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH &&
1779                     sta->deflink.bandwidth < IEEE80211_STA_RX_BW_40)
1780                         continue;
1781
1782                 nss = minstrel_mcs_groups[i].streams;
1783
1784                 /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
1785                 if (sta->deflink.smps_mode == IEEE80211_SMPS_STATIC && nss > 1)
1786                         continue;
1787
1788                 /* HT rate */
1789                 if (gflags & IEEE80211_TX_RC_MCS) {
1790                         if (use_vht && minstrel_vht_only)
1791                                 continue;
1792
1793                         mi->supported[i] = mcs->rx_mask[nss - 1];
1794                         if (mi->supported[i])
1795                                 n_supported++;
1796                         continue;
1797                 }
1798
1799                 /* VHT rate */
1800                 if (!vht_cap->vht_supported ||
1801                     WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) ||
1802                     WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH))
1803                         continue;
1804
1805                 if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) {
1806                         if (sta->deflink.bandwidth < IEEE80211_STA_RX_BW_80 ||
1807                             ((gflags & IEEE80211_TX_RC_SHORT_GI) &&
1808                              !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) {
1809                                 continue;
1810                         }
1811                 }
1812
1813                 if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH)
1814                         bw = BW_40;
1815                 else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH)
1816                         bw = BW_80;
1817                 else
1818                         bw = BW_20;
1819
1820                 mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss,
1821                                 vht_cap->vht_mcs.tx_mcs_map);
1822
1823                 if (mi->supported[i])
1824                         n_supported++;
1825         }
1826
1827         sta_info = container_of(sta, struct sta_info, sta);
1828         mi->use_short_preamble = test_sta_flag(sta_info, WLAN_STA_SHORT_PREAMBLE) &&
1829                                  sta_info->sdata->vif.bss_conf.use_short_preamble;
1830
1831         minstrel_ht_update_cck(mp, mi, sband, sta);
1832         minstrel_ht_update_ofdm(mp, mi, sband, sta);
1833
1834         /* create an initial rate table with the lowest supported rates */
1835         minstrel_ht_update_stats(mp, mi);
1836         minstrel_ht_update_rates(mp, mi);
1837 }
1838
1839 static void
1840 minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
1841                       struct cfg80211_chan_def *chandef,
1842                       struct ieee80211_sta *sta, void *priv_sta)
1843 {
1844         minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1845 }
1846
1847 static void
1848 minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
1849                         struct cfg80211_chan_def *chandef,
1850                         struct ieee80211_sta *sta, void *priv_sta,
1851                         u32 changed)
1852 {
1853         minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta);
1854 }
1855
1856 static void *
1857 minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
1858 {
1859         struct ieee80211_supported_band *sband;
1860         struct minstrel_ht_sta *mi;
1861         struct minstrel_priv *mp = priv;
1862         struct ieee80211_hw *hw = mp->hw;
1863         int max_rates = 0;
1864         int i;
1865
1866         for (i = 0; i < NUM_NL80211_BANDS; i++) {
1867                 sband = hw->wiphy->bands[i];
1868                 if (sband && sband->n_bitrates > max_rates)
1869                         max_rates = sband->n_bitrates;
1870         }
1871
1872         return kzalloc(sizeof(*mi), gfp);
1873 }
1874
1875 static void
1876 minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
1877 {
1878         kfree(priv_sta);
1879 }
1880
1881 static void
1882 minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband,
1883                             const s16 *bitrates, int n_rates, u32 rate_flags)
1884 {
1885         int i, j;
1886
1887         for (i = 0; i < sband->n_bitrates; i++) {
1888                 struct ieee80211_rate *rate = &sband->bitrates[i];
1889
1890                 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
1891                         continue;
1892
1893                 for (j = 0; j < n_rates; j++) {
1894                         if (rate->bitrate != bitrates[j])
1895                                 continue;
1896
1897                         dest[j] = i;
1898                         break;
1899                 }
1900         }
1901 }
1902
1903 static void
1904 minstrel_ht_init_cck_rates(struct minstrel_priv *mp)
1905 {
1906         static const s16 bitrates[4] = { 10, 20, 55, 110 };
1907         struct ieee80211_supported_band *sband;
1908         u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1909
1910         memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates));
1911         sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ];
1912         if (!sband)
1913                 return;
1914
1915         BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates));
1916         minstrel_ht_fill_rate_array(mp->cck_rates, sband,
1917                                     minstrel_cck_bitrates,
1918                                     ARRAY_SIZE(minstrel_cck_bitrates),
1919                                     rate_flags);
1920 }
1921
1922 static void
1923 minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band)
1924 {
1925         static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 };
1926         struct ieee80211_supported_band *sband;
1927         u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef);
1928
1929         memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band]));
1930         sband = mp->hw->wiphy->bands[band];
1931         if (!sband)
1932                 return;
1933
1934         BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates));
1935         minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband,
1936                                     minstrel_ofdm_bitrates,
1937                                     ARRAY_SIZE(minstrel_ofdm_bitrates),
1938                                     rate_flags);
1939 }
1940
1941 static void *
1942 minstrel_ht_alloc(struct ieee80211_hw *hw)
1943 {
1944         struct minstrel_priv *mp;
1945         int i;
1946
1947         mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC);
1948         if (!mp)
1949                 return NULL;
1950
1951         /* contention window settings
1952          * Just an approximation. Using the per-queue values would complicate
1953          * the calculations and is probably unnecessary */
1954         mp->cw_min = 15;
1955         mp->cw_max = 1023;
1956
1957         /* maximum time that the hw is allowed to stay in one MRR segment */
1958         mp->segment_size = 6000;
1959
1960         if (hw->max_rate_tries > 0)
1961                 mp->max_retry = hw->max_rate_tries;
1962         else
1963                 /* safe default, does not necessarily have to match hw properties */
1964                 mp->max_retry = 7;
1965
1966         mp->hw = hw;
1967         mp->update_interval = HZ / 20;
1968
1969         minstrel_ht_init_cck_rates(mp);
1970         for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++)
1971             minstrel_ht_init_ofdm_rates(mp, i);
1972
1973         return mp;
1974 }
1975
1976 #ifdef CONFIG_MAC80211_DEBUGFS
1977 static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv,
1978                                     struct dentry *debugfsdir)
1979 {
1980         struct minstrel_priv *mp = priv;
1981
1982         mp->fixed_rate_idx = (u32) -1;
1983         debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir,
1984                            &mp->fixed_rate_idx);
1985 }
1986 #endif
1987
1988 static void
1989 minstrel_ht_free(void *priv)
1990 {
1991         kfree(priv);
1992 }
1993
1994 static u32 minstrel_ht_get_expected_throughput(void *priv_sta)
1995 {
1996         struct minstrel_ht_sta *mi = priv_sta;
1997         int i, j, prob, tp_avg;
1998
1999         i = MI_RATE_GROUP(mi->max_tp_rate[0]);
2000         j = MI_RATE_IDX(mi->max_tp_rate[0]);
2001         prob = mi->groups[i].rates[j].prob_avg;
2002
2003         /* convert tp_avg from pkt per second in kbps */
2004         tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
2005         tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
2006
2007         return tp_avg;
2008 }
2009
2010 static const struct rate_control_ops mac80211_minstrel_ht = {
2011         .name = "minstrel_ht",
2012         .capa = RATE_CTRL_CAPA_AMPDU_TRIGGER,
2013         .tx_status_ext = minstrel_ht_tx_status,
2014         .get_rate = minstrel_ht_get_rate,
2015         .rate_init = minstrel_ht_rate_init,
2016         .rate_update = minstrel_ht_rate_update,
2017         .alloc_sta = minstrel_ht_alloc_sta,
2018         .free_sta = minstrel_ht_free_sta,
2019         .alloc = minstrel_ht_alloc,
2020         .free = minstrel_ht_free,
2021 #ifdef CONFIG_MAC80211_DEBUGFS
2022         .add_debugfs = minstrel_ht_add_debugfs,
2023         .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
2024 #endif
2025         .get_expected_throughput = minstrel_ht_get_expected_throughput,
2026 };
2027
2028
2029 static void __init init_sample_table(void)
2030 {
2031         int col, i, new_idx;
2032         u8 rnd[MCS_GROUP_RATES];
2033
2034         memset(sample_table, 0xff, sizeof(sample_table));
2035         for (col = 0; col < SAMPLE_COLUMNS; col++) {
2036                 get_random_bytes(rnd, sizeof(rnd));
2037                 for (i = 0; i < MCS_GROUP_RATES; i++) {
2038                         new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
2039                         while (sample_table[col][new_idx] != 0xff)
2040                                 new_idx = (new_idx + 1) % MCS_GROUP_RATES;
2041
2042                         sample_table[col][new_idx] = i;
2043                 }
2044         }
2045 }
2046
2047 int __init
2048 rc80211_minstrel_init(void)
2049 {
2050         init_sample_table();
2051         return ieee80211_rate_control_register(&mac80211_minstrel_ht);
2052 }
2053
2054 void
2055 rc80211_minstrel_exit(void)
2056 {
2057         ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
2058 }