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