--- /dev/null
+--- a/net/mac80211/Makefile
++++ b/net/mac80211/Makefile
+@@ -47,8 +47,8 @@ CFLAGS_driver-trace.o := -I$(src)
+ rc80211_pid-y := rc80211_pid_algo.o
+ rc80211_pid-$(CONFIG_MAC80211_DEBUGFS) += rc80211_pid_debugfs.o
+
+-rc80211_minstrel-y := rc80211_minstrel.o
+-rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o
++rc80211_minstrel-y := rc80211_minstrel.o rc80211_minstrel_ht.o
++rc80211_minstrel-$(CONFIG_MAC80211_DEBUGFS) += rc80211_minstrel_debugfs.o rc80211_minstrel_ht_debugfs.o
+
+ mac80211-$(CONFIG_MAC80211_RC_PID) += $(rc80211_pid-y)
+ mac80211-$(CONFIG_MAC80211_RC_MINSTREL) += $(rc80211_minstrel-y)
+--- a/net/mac80211/main.c
++++ b/net/mac80211/main.c
+@@ -710,6 +710,10 @@ static int __init ieee80211_init(void)
+ if (ret)
+ return ret;
+
++ ret = rc80211_minstrel_ht_init();
++ if (ret)
++ goto err_minstrel;
++
+ ret = rc80211_pid_init();
+ if (ret)
+ goto err_pid;
+@@ -722,6 +726,8 @@ static int __init ieee80211_init(void)
+ err_netdev:
+ rc80211_pid_exit();
+ err_pid:
++ rc80211_minstrel_ht_exit();
++ err_minstrel:
+ rc80211_minstrel_exit();
+
+ return ret;
+@@ -730,6 +736,7 @@ static int __init ieee80211_init(void)
+ static void __exit ieee80211_exit(void)
+ {
+ rc80211_pid_exit();
++ rc80211_minstrel_ht_exit();
+ rc80211_minstrel_exit();
+
+ /*
+--- a/net/mac80211/rate.h
++++ b/net/mac80211/rate.h
+@@ -136,6 +136,8 @@ static inline void rc80211_pid_exit(void
+ #ifdef CONFIG_MAC80211_RC_MINSTREL
+ extern int rc80211_minstrel_init(void);
+ extern void rc80211_minstrel_exit(void);
++extern int rc80211_minstrel_ht_init(void);
++extern void rc80211_minstrel_ht_exit(void);
+ #else
+ static inline int rc80211_minstrel_init(void)
+ {
+@@ -144,6 +146,13 @@ static inline int rc80211_minstrel_init(
+ static inline void rc80211_minstrel_exit(void)
+ {
+ }
++static inline int rc80211_minstrel_ht_init(void)
++{
++ return 0;
++}
++static inline void rc80211_minstrel_ht_exit(void)
++{
++}
+ #endif
+
+
+--- /dev/null
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -0,0 +1,803 @@
++/*
++ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++#include <linux/netdevice.h>
++#include <linux/types.h>
++#include <linux/skbuff.h>
++#include <linux/debugfs.h>
++#include <linux/random.h>
++#include <linux/ieee80211.h>
++#include <net/mac80211.h>
++#include "rate.h"
++#include "rc80211_minstrel.h"
++#include "rc80211_minstrel_ht.h"
++
++#define AVG_PKT_SIZE 1200
++#define SAMPLE_COLUMNS 10
++#define EWMA_LEVEL 75
++
++/* Number of bits for an average sized packet */
++#define MCS_NBITS (AVG_PKT_SIZE << 3)
++
++/* Number of symbols for a packet with (bps) bits per symbol */
++#define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
++
++/* Transmission time for a packet containing (syms) symbols */
++#define MCS_SYMBOL_TIME(sgi, syms) \
++ (sgi ? \
++ ((syms) * 18 + 4) / 5 : /* syms * 3.6 us */ \
++ (syms) << 2 /* syms * 4 us */ \
++ )
++
++/* Transmit duration for the raw data part of an average sized packet */
++#define MCS_DURATION(streams, sgi, bps) MCS_SYMBOL_TIME(sgi, MCS_NSYMS((streams) * (bps)))
++
++/* MCS rate information for an MCS group */
++#define MCS_GROUP(_streams, _sgi, _ht40) { \
++ .streams = _streams, \
++ .flags = \
++ (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \
++ (_ht40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \
++ .duration = { \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234), \
++ MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) \
++ } \
++}
++
++#define MINSTREL_INTFL_SAMPLE_SLOT0 BIT(30)
++#define MINSTREL_INTFL_SAMPLE_SLOT1 BIT(31)
++
++/*
++ * To enable sufficiently targeted rate sampling, MCS rates are divided into
++ * groups, based on the number of streams and flags (HT40, SGI) that they
++ * use.
++ */
++const struct mcs_group minstrel_mcs_groups[] = {
++ MCS_GROUP(1, 0, 0),
++ MCS_GROUP(2, 0, 0),
++#if MINSTREL_MAX_STREAMS >= 3
++ MCS_GROUP(3, 0, 0),
++#endif
++
++ MCS_GROUP(1, 1, 0),
++ MCS_GROUP(2, 1, 0),
++#if MINSTREL_MAX_STREAMS >= 3
++ MCS_GROUP(3, 1, 0),
++#endif
++
++ MCS_GROUP(1, 0, 1),
++ MCS_GROUP(2, 0, 1),
++#if MINSTREL_MAX_STREAMS >= 3
++ MCS_GROUP(3, 0, 1),
++#endif
++
++ MCS_GROUP(1, 1, 1),
++ MCS_GROUP(2, 1, 1),
++#if MINSTREL_MAX_STREAMS >= 3
++ MCS_GROUP(3, 1, 1),
++#endif
++};
++
++static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES];
++
++/*
++ * Perform EWMA (Exponentially Weighted Moving Average) calculation
++ */
++static int
++minstrel_ewma(int old, int new, int weight)
++{
++ return (new * (100 - weight) + old * weight) / 100;
++}
++
++/*
++ * Look up an MCS group index based on mac80211 rate information
++ */
++static int
++minstrel_ht_get_group_idx(struct ieee80211_tx_rate *rate)
++{
++ int streams = (rate->idx / MCS_GROUP_RATES) + 1;
++ u32 flags = IEEE80211_TX_RC_SHORT_GI | IEEE80211_TX_RC_40_MHZ_WIDTH;
++ int i;
++
++ for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) {
++ if (minstrel_mcs_groups[i].streams != streams)
++ continue;
++ if (minstrel_mcs_groups[i].flags != (rate->flags & flags))
++ continue;
++
++ return i;
++ }
++
++ WARN_ON(1);
++ return 0;
++}
++
++static inline struct minstrel_rate_stats *
++minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
++{
++ return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
++}
++
++
++/*
++ * Recalculate success probabilities and counters for a rate using EWMA
++ */
++static void
++minstrel_calc_rate_ewma(struct minstrel_priv *mp, struct minstrel_rate_stats *mr)
++{
++ if (mr->attempts) {
++ mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
++ if (!mr->att_hist)
++ mr->probability = mr->cur_prob;
++ else
++ mr->probability = minstrel_ewma(mr->probability,
++ mr->cur_prob, EWMA_LEVEL);
++ mr->att_hist += mr->attempts;
++ mr->succ_hist += mr->success;
++ }
++ mr->last_success = mr->success;
++ mr->last_attempts = mr->attempts;
++ mr->success = 0;
++ mr->attempts = 0;
++}
++
++/*
++ * Calculate throughput based on the average A-MPDU length, taking into account
++ * the expected number of retransmissions and their expected length
++ */
++static void
++minstrel_ht_calc_tp(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++ int group, int rate)
++{
++ struct minstrel_rate_stats *mr;
++ unsigned int usecs;
++
++ mr = &mi->groups[group].rates[rate];
++
++ if (mr->probability < MINSTREL_FRAC(1, 10)) {
++ mr->cur_tp = 0;
++ return;
++ }
++
++ usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
++ usecs += minstrel_mcs_groups[group].duration[rate];
++ mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
++}
++
++/*
++ * Update rate statistics and select new primary rates
++ *
++ * Rules for rate selection:
++ * - max_prob_rate must use only one stream, as a tradeoff between delivery
++ * probability and throughput during strong fluctuations
++ * - as long as the max prob rate has a probability of more than 3/4, pick
++ * higher throughput rates, even if the probablity is a bit lower
++ */
++static void
++minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
++{
++ struct minstrel_mcs_group_data *mg;
++ struct minstrel_rate_stats *mr;
++ int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
++ int group, i, index;
++
++ mi->max_tp_rate = 0;
++ mi->max_tp_rate2 = 0;
++ mi->max_prob_rate = 0;
++
++ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
++ cur_prob = 0;
++ cur_prob_tp = 0;
++ cur_tp = 0;
++ cur_tp2 = 0;
++
++ mg = &mi->groups[group];
++ if (!mg->supported)
++ continue;
++
++ mg->max_tp_rate = 0;
++ mg->max_tp_rate2 = 0;
++ mg->max_prob_rate = 0;
++
++ for (i = 0; i < MCS_GROUP_RATES; i++) {
++ if (!(mg->supported & BIT(i)))
++ continue;
++
++ mr = &mg->rates[i];
++ mr->retry_updated = false;
++ index = MCS_GROUP_RATES * group + i;
++ minstrel_calc_rate_ewma(mp, mr);
++ minstrel_ht_calc_tp(mp, mi, group, i);
++
++ if (!mr->cur_tp)
++ continue;
++
++ /* ignore the lowest rate of each single-stream group */
++ if (!i && minstrel_mcs_groups[group].streams == 1)
++ continue;
++
++ if ((mr->cur_tp > cur_prob_tp && mr->probability >
++ MINSTREL_FRAC(3, 4)) || mr->probability > cur_prob) {
++ mg->max_prob_rate = index;
++ cur_prob = mr->probability;
++ }
++
++ if (mr->cur_tp > cur_tp) {
++ swap(index, mg->max_tp_rate);
++ cur_tp = mr->cur_tp;
++ mr = minstrel_get_ratestats(mi, index);
++ }
++
++ if (index == mg->max_tp_rate)
++ continue;
++
++ if (mr->cur_tp > cur_tp2) {
++ mg->max_tp_rate2 = index;
++ cur_tp2 = mr->cur_tp;
++ }
++ }
++ }
++
++ cur_prob = 0;
++ cur_prob_tp = 0;
++ cur_tp = 0;
++ cur_tp2 = 0;
++ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
++ mg = &mi->groups[group];
++ if (!mg->supported)
++ continue;
++
++ mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
++ if (cur_prob_tp < mr->cur_tp &&
++ minstrel_mcs_groups[group].streams == 1) {
++ mi->max_prob_rate = mg->max_prob_rate;
++ cur_prob = mr->cur_prob;
++ }
++
++ mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
++ if (cur_tp < mr->cur_tp) {
++ mi->max_tp_rate = mg->max_tp_rate;
++ cur_tp = mr->cur_tp;
++ }
++
++ mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
++ if (cur_tp2 < mr->cur_tp) {
++ mi->max_tp_rate2 = mg->max_tp_rate2;
++ cur_tp2 = mr->cur_tp;
++ }
++ }
++
++ mi->stats_update = jiffies;
++}
++
++static bool
++minstrel_ht_txstat_valid(struct ieee80211_tx_rate *rate)
++{
++ if (!rate->count)
++ return false;
++
++ if (rate->idx < 0)
++ return false;
++
++ return !!(rate->flags & IEEE80211_TX_RC_MCS);
++}
++
++static void
++minstrel_next_sample_idx(struct minstrel_ht_sta *mi)
++{
++ struct minstrel_mcs_group_data *mg;
++
++ for (;;) {
++ mi->sample_group++;
++ mi->sample_group %= ARRAY_SIZE(minstrel_mcs_groups);
++ mg = &mi->groups[mi->sample_group];
++
++ if (!mg->supported)
++ continue;
++
++ if (++mg->index > MCS_GROUP_RATES) {
++ mg->index = 0;
++ if (++mg->column > ARRAY_SIZE(sample_table))
++ mg->column = 0;
++ }
++ break;
++ }
++}
++
++static void
++minstrel_downgrade_rate(struct minstrel_ht_sta *mi, int *idx, int type)
++{
++ int group, orig_group;
++
++ orig_group = group = *idx / MCS_GROUP_RATES;
++ while (group > 0) {
++ group--;
++
++ if (!mi->groups[group].supported)
++ continue;
++
++ if (minstrel_mcs_groups[group].streams >=
++ minstrel_mcs_groups[orig_group].streams)
++ continue;
++
++ switch(type) {
++ case 0:
++ *idx = mi->groups[group].max_tp_rate;
++ break;
++ case 1:
++ *idx = mi->groups[group].max_tp_rate2;
++ break;
++ }
++ break;
++ }
++}
++
++
++static void
++minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband,
++ struct ieee80211_sta *sta, void *priv_sta,
++ struct sk_buff *skb)
++{
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++ struct minstrel_ht_sta *mi = &msp->ht;
++ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
++ struct ieee80211_tx_rate *ar = info->status.rates;
++ struct minstrel_rate_stats *rate, *rate2;
++ struct minstrel_priv *mp = priv;
++ bool last = false;
++ int group;
++ int i = 0;
++
++ if (!msp->is_ht)
++ return mac80211_minstrel.tx_status(priv, sband, sta, &msp->legacy, skb);
++
++ /* This packet was aggregated but doesn't carry status info */
++ if ((info->flags & IEEE80211_TX_CTL_AMPDU) &&
++ !(info->flags & IEEE80211_TX_STAT_AMPDU))
++ return;
++
++ if (!info->status.ampdu_len) {
++ info->status.ampdu_ack_len = 1;
++ info->status.ampdu_len = 1;
++ }
++
++ mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
++ MINSTREL_FRAC(info->status.ampdu_len, 1), 90);
++
++ for (i = 0; !last; i++) {
++ last = (i == IEEE80211_TX_MAX_RATES - 1) ||
++ !minstrel_ht_txstat_valid(&ar[i + 1]);
++
++ if (!minstrel_ht_txstat_valid(&ar[i]))
++ break;
++
++ if ((i == 0 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT0)) ||
++ (i == 1 && (info->flags & MINSTREL_INTFL_SAMPLE_SLOT1))) {
++ if (mi->sample_pending > 0)
++ mi->sample_pending--;
++ mi->sample_packets++;
++ minstrel_next_sample_idx(mi);
++ }
++
++ group = minstrel_ht_get_group_idx(&ar[i]);
++ rate = &mi->groups[group].rates[ar[i].idx % 8];
++
++ if (last && (info->flags & IEEE80211_TX_STAT_ACK) &&
++ info->status.ampdu_len == info->status.ampdu_ack_len)
++ rate->success++;
++
++ rate->attempts += ar[i].count;
++ }
++
++
++ /*
++ * check for sudden death of spatial multiplexing,
++ * downgrade to a lower number of streams if necessary.
++ */
++ rate = minstrel_get_ratestats(mi, mi->max_tp_rate);
++ if (MINSTREL_FRAC(rate->success, rate->attempts) <
++ MINSTREL_FRAC(20, 100) && rate->attempts > 15)
++ minstrel_downgrade_rate(mi, &mi->max_tp_rate, 0);
++
++ rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
++ if (MINSTREL_FRAC(rate->success, rate->attempts) <
++ MINSTREL_FRAC(20, 100) && rate->attempts > 15)
++ minstrel_downgrade_rate(mi, &mi->max_tp_rate2, 1);
++
++ if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000))
++ minstrel_ht_update_stats(mp, mi);
++}
++
++static void
++minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++ int index)
++{
++ struct minstrel_rate_stats *mr;
++ const struct mcs_group *group;
++ unsigned int tx_time, tx_time_rtscts, tx_time_data;
++ unsigned int cw = mp->cw_min;
++ unsigned int t_slot = 9; /* FIXME */
++ unsigned int ampdu_len = MINSTREL_TRUNC(mi->avg_ampdu_len);
++
++ mr = minstrel_get_ratestats(mi, index);
++ if (mr->probability < MINSTREL_FRAC(1, 10)) {
++ mr->retry_count = 1;
++ mr->retry_count_rtscts = 1;
++ return;
++ }
++
++ mr->retry_count = 2;
++ mr->retry_count_rtscts = 2;
++ mr->retry_updated = true;
++
++ group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
++ tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
++ tx_time = 2 * (t_slot + mi->overhead + tx_time_data);
++ tx_time_rtscts = 2 * (t_slot + mi->overhead_rtscts + tx_time_data);
++ do {
++ cw = (cw << 1) | 1;
++ cw = min(cw, mp->cw_max);
++ tx_time += cw + t_slot + mi->overhead;
++ tx_time_rtscts += cw + t_slot + mi->overhead_rtscts;
++ if (tx_time_rtscts < mp->segment_size)
++ mr->retry_count_rtscts++;
++ } while ((tx_time < mp->segment_size) &&
++ (++mr->retry_count < mp->max_retry));
++}
++
++
++static void
++minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++ struct ieee80211_tx_rate *rate, int index,
++ struct ieee80211_tx_rate_control *txrc,
++ bool sample, bool rtscts)
++{
++ const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
++ struct minstrel_rate_stats *mr;
++
++ mr = minstrel_get_ratestats(mi, index);
++ if (!mr->retry_updated)
++ minstrel_calc_retransmit(mp, mi, index);
++
++ if (rtscts)
++ rate->count = mr->retry_count_rtscts;
++ else
++ rate->count = mr->retry_count;
++
++ rate->flags = IEEE80211_TX_RC_MCS | group->flags;
++ if (txrc->short_preamble)
++ rate->flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
++ if (txrc->rts || rtscts)
++ rate->flags |= IEEE80211_TX_RC_USE_RTS_CTS;
++ rate->idx = index % MCS_GROUP_RATES + (group->streams - 1) * MCS_GROUP_RATES;
++}
++
++static inline int
++minstrel_get_duration(int index)
++{
++ const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
++ return group->duration[index % MCS_GROUP_RATES];
++}
++
++static int
++minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi,
++ bool *defer)
++{
++ struct minstrel_rate_stats *mr;
++ struct minstrel_mcs_group_data *mg;
++ int sample_idx = 0;
++ int sample_rate;
++ int delta;
++
++ if (mp->has_mrr)
++ sample_rate = mp->lookaround_rate_mrr;
++ else
++ sample_rate = mp->lookaround_rate;
++
++ delta = (mi->total_packets * sample_rate) / 100 - mi->sample_packets;
++ delta -= mi->sample_pending / 2;
++
++ if (delta <= 0)
++ return -1;
++
++ delta -= 16;
++ if (delta > 1) {
++ /* With multi-rate retry, not every planned sample
++ * attempt actually gets used, due to the way the retry
++ * chain is set up - [max_tp,sample,prob,lowest] for
++ * sample_rate < max_tp.
++ *
++ * If there's too much sampling backlog and the link
++ * starts getting worse, minstrel would start bursting
++ * out lots of sampling frames, which would result
++ * in a large throughput loss.
++ */
++ mi->sample_packets += delta - 1;
++ }
++
++ mg = &mi->groups[mi->sample_group];
++ sample_idx = sample_table[mg->column][mg->index];
++ mr = &mg->rates[sample_idx];
++ sample_idx += mi->sample_group * MCS_GROUP_RATES;
++
++ /*
++ * When not using MRR, do not sample if the probability is already
++ * higher than 95% to avoid wasting airtime
++ */
++ if (!mp->has_mrr && (mr->probability > MINSTREL_FRAC(95, 100)))
++ return -1;
++
++ if (minstrel_get_duration(sample_idx) >
++ minstrel_get_duration(mi->max_tp_rate)) {
++ /*
++ * Make sure that lower rates get sampled occasionally, even
++ * if the link is working perfectly. Some drivers such as ath9k
++ * severely limit aggregation size if the MRR chain contains low
++ * rates
++ *
++ * If the lower rate has already been tried a few times, there's
++ * no point in forcing it to be sampled again, so skip to the
++ * next sampling index after applying this one in the tx control
++ */
++ if (mr->att_hist > 15) {
++ *defer = true;
++ minstrel_next_sample_idx(mi);
++ }
++ }
++
++ return sample_idx;
++}
++
++static void
++minstrel_aggr_check(struct minstrel_priv *mp, struct ieee80211_sta *pubsta, struct sk_buff *skb)
++{
++ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
++ struct sta_info *sta = container_of(pubsta, struct sta_info, sta);
++ u16 tid;
++
++ if (unlikely(!ieee80211_is_data_qos(hdr->frame_control)))
++ return;
++
++ if (unlikely(skb->protocol == cpu_to_be16(ETH_P_PAE)))
++ return;
++
++ tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
++ if (likely(sta->ampdu_mlme.tid_state_tx[tid] != HT_AGG_STATE_IDLE))
++ return;
++
++ ieee80211_start_tx_ba_session(pubsta, tid);
++}
++
++static void
++minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
++ struct ieee80211_tx_rate_control *txrc)
++{
++ struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
++ struct ieee80211_tx_rate *ar = info->status.rates;
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++ struct minstrel_ht_sta *mi = &msp->ht;
++ struct minstrel_priv *mp = priv;
++ bool sample_defer = false;
++ int sample_idx;
++
++ if (rate_control_send_low(sta, priv_sta, txrc))
++ return;
++
++ if (!msp->is_ht)
++ return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
++
++ minstrel_aggr_check(mp, sta, txrc->skb);
++
++ sample_idx = minstrel_get_sample_rate(mp, mi, &sample_defer);
++ if (sample_idx >= 0) {
++ if (sample_defer) {
++ minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
++ txrc, false, false);
++ minstrel_ht_set_rate(mp, mi, &ar[1], sample_idx,
++ txrc, true, true);
++ info->flags |= MINSTREL_INTFL_SAMPLE_SLOT1;
++ } else {
++ minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
++ txrc, true, false);
++ minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
++ txrc, false, true);
++ info->flags |= MINSTREL_INTFL_SAMPLE_SLOT0;
++ }
++ mi->sample_pending++;
++ } else {
++ minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
++ txrc, false, false);
++ minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
++ txrc, false, true);
++ }
++ minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate, txrc, false, true);
++
++ ar[3].count = 0;
++ ar[3].idx = -1;
++
++ mi->total_packets++;
++
++ /* wraparound */
++ if (mi->total_packets >= 100000) {
++ mi->total_packets = 0;
++ mi->sample_packets = 0;
++ mi->sample_pending = 0;
++ }
++}
++
++
++static void
++minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband,
++ struct ieee80211_sta *sta, void *priv_sta)
++{
++ struct minstrel_priv *mp = priv;
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++ struct minstrel_ht_sta *mi = &msp->ht;
++ struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs;
++ struct ieee80211_local *local = hw_to_local(mp->hw);
++ int tx_streams;
++ int ack_dur;
++ int i;
++
++ /* fall back to the old minstrel for legacy stations */
++ if (sta && !sta->ht_cap.ht_supported) {
++ msp->is_ht = false;
++ memset(&msp->legacy, 0, sizeof(msp->legacy));
++ msp->legacy.r = msp->ratelist;
++ msp->legacy.sample_table = msp->sample_table;
++ return mac80211_minstrel.rate_init(priv, sband, sta, &msp->legacy);
++ }
++
++ BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) !=
++ MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS);
++
++ msp->is_ht = true;
++ memset(mi, 0, sizeof(*mi));
++ mi->stats_update = jiffies;
++
++ ack_dur = ieee80211_frame_duration(local, 10, 60, 1, 1);
++ mi->overhead = ieee80211_frame_duration(local, 0, 60, 1, 1) + ack_dur;
++ mi->overhead_rtscts = mi->overhead + 2 * ack_dur;
++
++ mi->avg_ampdu_len = MINSTREL_FRAC(1, 1);
++ tx_streams = ((mcs->tx_params & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK) >>
++ IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
++
++ for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
++ u16 req = 0;
++
++ if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI) {
++ if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
++ req |= IEEE80211_HT_CAP_SGI_40;
++ else
++ req |= IEEE80211_HT_CAP_SGI_20;
++ }
++
++ if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
++ req |= IEEE80211_HT_CAP_SUP_WIDTH_20_40;
++
++ if ((sta->ht_cap.cap & req) != req)
++ continue;
++
++ mi->groups[i].supported =
++ mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
++ }
++}
++
++static void *
++minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
++{
++ struct ieee80211_supported_band *sband;
++ struct minstrel_ht_sta_priv *msp;
++ struct minstrel_priv *mp = priv;
++ struct ieee80211_hw *hw = mp->hw;
++ int max_rates = 0;
++ int i;
++
++ for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
++ sband = hw->wiphy->bands[i];
++ if (sband && sband->n_bitrates > max_rates)
++ max_rates = sband->n_bitrates;
++ }
++
++ msp = kzalloc(sizeof(struct minstrel_ht_sta), gfp);
++ if (!msp)
++ return NULL;
++
++ msp->ratelist = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp);
++ if (!msp->ratelist)
++ goto error;
++
++ msp->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp);
++ if (!msp->sample_table)
++ goto error1;
++
++ return msp;
++
++error1:
++ kfree(msp->sample_table);
++error:
++ kfree(msp);
++ return NULL;
++}
++
++static void
++minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta)
++{
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++
++ kfree(msp->sample_table);
++ kfree(msp->ratelist);
++ kfree(msp);
++}
++
++static void *
++minstrel_ht_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
++{
++ return mac80211_minstrel.alloc(hw, debugfsdir);
++}
++
++static void
++minstrel_ht_free(void *priv)
++{
++ mac80211_minstrel.free(priv);
++}
++
++static struct rate_control_ops mac80211_minstrel_ht = {
++ .name = "minstrel_ht",
++ .tx_status = minstrel_ht_tx_status,
++ .get_rate = minstrel_ht_get_rate,
++ .rate_init = minstrel_ht_rate_init,
++ .alloc_sta = minstrel_ht_alloc_sta,
++ .free_sta = minstrel_ht_free_sta,
++ .alloc = minstrel_ht_alloc,
++ .free = minstrel_ht_free,
++#ifdef CONFIG_MAC80211_DEBUGFS
++ .add_sta_debugfs = minstrel_ht_add_sta_debugfs,
++ .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
++#endif
++};
++
++
++static void
++init_sample_table(void)
++{
++ int col, i, new_idx;
++ u8 rnd[MCS_GROUP_RATES];
++
++ memset(sample_table, 0xff, sizeof(sample_table));
++ for (col = 0; col < SAMPLE_COLUMNS; col++) {
++ for (i = 0; i < MCS_GROUP_RATES; i++) {
++ get_random_bytes(rnd, sizeof(rnd));
++ new_idx = (i + rnd[i]) % MCS_GROUP_RATES;
++
++ while (sample_table[col][new_idx] != 0xff)
++ new_idx = (new_idx + 1) % MCS_GROUP_RATES;
++
++ sample_table[col][new_idx] = i;
++ }
++ }
++}
++
++int __init
++rc80211_minstrel_ht_init(void)
++{
++ init_sample_table();
++ return ieee80211_rate_control_register(&mac80211_minstrel_ht);
++}
++
++void
++rc80211_minstrel_ht_exit(void)
++{
++ ieee80211_rate_control_unregister(&mac80211_minstrel_ht);
++}
+--- /dev/null
++++ b/net/mac80211/rc80211_minstrel_ht.h
+@@ -0,0 +1,115 @@
++/*
++ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++
++#ifndef __RC_MINSTREL_HT_H
++#define __RC_MINSTREL_HT_H
++
++/*
++ * maximum number of spatial streams to make use of
++ * set this value to 3 once we have drivers that support it
++ */
++#define MINSTREL_MAX_STREAMS 2
++#define MINSTREL_STREAM_GROUPS 4
++
++/* scaled fraction values */
++#define MINSTREL_SCALE 16
++#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
++#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
++
++#define MCS_GROUP_RATES 8
++
++struct mcs_group {
++ u32 flags;
++ unsigned int streams;
++ unsigned int duration[MCS_GROUP_RATES];
++};
++
++struct minstrel_rate_stats {
++ /* current / last sampling period attempts/success counters */
++ unsigned int attempts, last_attempts;
++ unsigned int success, last_success;
++
++ /* total attempts/success counters */
++ u64 att_hist, succ_hist;
++
++ /* current throughput */
++ unsigned int cur_tp;
++
++ /* packet delivery probabilities */
++ unsigned int cur_prob, probability;
++
++ /* maximum retry counts */
++ bool retry_updated;
++ unsigned int retry_count;
++ unsigned int retry_count_rtscts;
++};
++
++struct minstrel_mcs_group_data {
++ u8 index;
++ u8 column;
++
++ /* bitfield of supported MCS rates of this group */
++ u8 supported;
++
++ /* selected primary rates */
++ unsigned int max_tp_rate;
++ unsigned int max_tp_rate2;
++ unsigned int max_prob_rate;
++
++ /* MCS rate statistics */
++ struct minstrel_rate_stats rates[MCS_GROUP_RATES];
++};
++
++struct minstrel_ht_sta {
++ /* ampdu length average (EWMA) */
++ unsigned int avg_ampdu_len;
++
++ /* best throughput rate */
++ unsigned int max_tp_rate;
++
++ /* second best throughput rate */
++ unsigned int max_tp_rate2;
++
++ /* best probability rate */
++ unsigned int max_prob_rate;
++
++ /* time of last status update */
++ unsigned long stats_update;
++
++ /* overhead time in usec for each frame */
++ unsigned int overhead;
++ unsigned int overhead_rtscts;
++
++ unsigned int total_packets;
++ unsigned int sample_packets;
++ unsigned int sample_pending;
++
++ /* current MCS group to be sampled */
++ unsigned int sample_group;
++
++ /* MCS rate group info and statistics */
++ struct minstrel_mcs_group_data groups[MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS];
++};
++
++struct minstrel_ht_sta_priv {
++ union {
++ struct minstrel_ht_sta ht;
++ struct minstrel_sta_info legacy;
++ };
++#ifdef CONFIG_MAC80211_DEBUGFS
++ struct dentry *dbg_stats;
++#endif
++ void *ratelist;
++ void *sample_table;
++ bool is_ht;
++};
++
++void minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
++void minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta);
++
++#endif
+--- /dev/null
++++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c
+@@ -0,0 +1,120 @@
++/*
++ * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++#include <linux/netdevice.h>
++#include <linux/types.h>
++#include <linux/skbuff.h>
++#include <linux/debugfs.h>
++#include <linux/ieee80211.h>
++#include <net/mac80211.h>
++#include "rc80211_minstrel.h"
++#include "rc80211_minstrel_ht.h"
++
++extern const struct mcs_group minstrel_mcs_groups[];
++
++static int
++minstrel_ht_stats_open(struct inode *inode, struct file *file)
++{
++ struct minstrel_ht_sta_priv *msp = inode->i_private;
++ struct minstrel_ht_sta *mi = &msp->ht;
++ struct minstrel_debugfs_info *ms;
++ unsigned int i, j, tp, prob, eprob;
++ char *p;
++ int ret;
++
++ if (!msp->is_ht) {
++ inode->i_private = &msp->legacy;
++ ret = minstrel_stats_open(inode, file);
++ inode->i_private = msp;
++ return ret;
++ }
++
++ ms = kmalloc(sizeof(*ms) + 8192, GFP_KERNEL);
++ if (!ms)
++ return -ENOMEM;
++
++ file->private_data = ms;
++ p = ms->buf;
++ p += sprintf(p, "type rate throughput ewma prob this prob "
++ "this succ/attempt success attempts\n");
++ for (i = 0; i < MINSTREL_MAX_STREAMS * MINSTREL_STREAM_GROUPS; i++) {
++ char htmode = '2';
++ char gimode = 'L';
++
++ if (!mi->groups[i].supported)
++ continue;
++
++ if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
++ htmode = '4';
++ if (minstrel_mcs_groups[i].flags & IEEE80211_TX_RC_SHORT_GI)
++ gimode = 'S';
++
++ for (j = 0; j < MCS_GROUP_RATES; j++) {
++ struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
++ int idx = i * MCS_GROUP_RATES + j;
++
++ if (!mi->groups[i].supported & BIT(j))
++ continue;
++
++ p += sprintf(p, "HT%c0/%cGI ", htmode, gimode);
++
++ *(p++) = (idx == mi->max_tp_rate) ? 'T' : ' ';
++ *(p++) = (idx == mi->max_tp_rate2) ? 't' : ' ';
++ *(p++) = (idx == mi->max_prob_rate) ? 'P' : ' ';
++ p += sprintf(p, "MCS%-2u", (minstrel_mcs_groups[i].streams - 1) *
++ MCS_GROUP_RATES + j);
++
++ tp = mr->cur_tp / 10;
++ prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
++ eprob = MINSTREL_TRUNC(mr->probability * 1000);
++
++ p += sprintf(p, " %6u.%1u %6u.%1u %6u.%1u "
++ "%3u(%3u) %8llu %8llu\n",
++ tp / 10, tp % 10,
++ eprob / 10, eprob % 10,
++ prob / 10, prob % 10,
++ mr->last_success,
++ mr->last_attempts,
++ (unsigned long long)mr->succ_hist,
++ (unsigned long long)mr->att_hist);
++ }
++ }
++ p += sprintf(p, "\nTotal packet count:: ideal %d "
++ "lookaround %d\n",
++ max(0, (int) mi->total_packets - (int) mi->sample_packets),
++ mi->sample_packets);
++ p += sprintf(p, "Average A-MPDU length: %d.%d\n",
++ MINSTREL_TRUNC(mi->avg_ampdu_len),
++ MINSTREL_TRUNC(mi->avg_ampdu_len * 10) % 10);
++ ms->len = p - ms->buf;
++
++ return 0;
++}
++
++static const struct file_operations minstrel_ht_stat_fops = {
++ .owner = THIS_MODULE,
++ .open = minstrel_ht_stats_open,
++ .read = minstrel_stats_read,
++ .release = minstrel_stats_release,
++};
++
++void
++minstrel_ht_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
++{
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++
++ msp->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, msp,
++ &minstrel_ht_stat_fops);
++}
++
++void
++minstrel_ht_remove_sta_debugfs(void *priv, void *priv_sta)
++{
++ struct minstrel_ht_sta_priv *msp = priv_sta;
++
++ debugfs_remove(msp->dbg_stats);
++}