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- /*
- * 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)))
- /*
- * Define group sort order: HT40 -> SGI -> #streams
- */
- #define GROUP_IDX(_streams, _sgi, _ht40) \
- MINSTREL_MAX_STREAMS * 2 * _ht40 + \
- MINSTREL_MAX_STREAMS * _sgi + \
- _streams - 1
- /* MCS rate information for an MCS group */
- #define MCS_GROUP(_streams, _sgi, _ht40) \
- [GROUP_IDX(_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) \
- } \
- }
- /*
- * 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.
- *
- * Sortorder has to be fixed for GROUP_IDX macro to be applicable:
- * HT40 -> SGI -> #streams
- */
- 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)
- {
- return GROUP_IDX((rate->idx / MCS_GROUP_RATES) + 1,
- !!(rate->flags & IEEE80211_TX_RC_SHORT_GI),
- !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH));
- }
- 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_rate_stats *mr)
- {
- if (unlikely(mr->attempts > 0)) {
- mr->sample_skipped = 0;
- 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;
- } else {
- mr->sample_skipped++;
- }
- 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_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;
- if (mi->ampdu_packets > 0) {
- mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
- MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL);
- mi->ampdu_len = 0;
- mi->ampdu_packets = 0;
- }
- mi->sample_slow = 0;
- mi->sample_count = 0;
- 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;
- mi->sample_count++;
- 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(mr);
- minstrel_ht_calc_tp(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;
- cur_prob_tp = mr->cur_tp;
- }
- 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;
- }
- }
- }
- /* try to sample up to half of the available rates during each interval */
- mi->sample_count *= 4;
- 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;
- cur_prob_tp = mr->cur_tp;
- }
- mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
- if (cur_tp < mr->cur_tp) {
- mi->max_tp_rate2 = mi->max_tp_rate;
- cur_tp2 = 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->idx < 0)
- return false;
- if (!rate->count)
- 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, unsigned int *idx,
- bool primary)
- {
- 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;
- if (primary)
- *idx = mi->groups[group].max_tp_rate;
- else
- *idx = mi->groups[group].max_tp_rate2;
- break;
- }
- }
- static void
- minstrel_aggr_check(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_tx[tid]))
- return;
- if (skb_get_queue_mapping(skb) == IEEE80211_AC_VO)
- return;
- ieee80211_start_tx_ba_session(pubsta, tid, 5000);
- }
- 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->flags & IEEE80211_TX_STAT_AMPDU)) {
- info->status.ampdu_ack_len =
- (info->flags & IEEE80211_TX_STAT_ACK ? 1 : 0);
- info->status.ampdu_len = 1;
- }
- mi->ampdu_packets++;
- mi->ampdu_len += info->status.ampdu_len;
- if (!mi->sample_wait && !mi->sample_tries && mi->sample_count > 0) {
- mi->sample_wait = 16 + 2 * MINSTREL_TRUNC(mi->avg_ampdu_len);
- mi->sample_tries = 2;
- mi->sample_count--;
- }
- if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE)
- mi->sample_packets += info->status.ampdu_len;
- 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;
- group = minstrel_ht_get_group_idx(&ar[i]);
- rate = &mi->groups[group].rates[ar[i].idx % 8];
- if (last)
- rate->success += info->status.ampdu_ack_len;
- rate->attempts += ar[i].count * info->status.ampdu_len;
- }
- /*
- * 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 (rate->attempts > 30 &&
- MINSTREL_FRAC(rate->success, rate->attempts) <
- MINSTREL_FRAC(20, 100))
- minstrel_downgrade_rate(mi, &mi->max_tp_rate, true);
- rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate2);
- if (rate2->attempts > 30 &&
- MINSTREL_FRAC(rate2->success, rate2->attempts) <
- MINSTREL_FRAC(20, 100))
- minstrel_downgrade_rate(mi, &mi->max_tp_rate2, false);
- if (time_after(jiffies, mi->stats_update + (mp->update_interval / 2 * HZ) / 1000)) {
- minstrel_ht_update_stats(mp, mi);
- if (!(info->flags & IEEE80211_TX_CTL_AMPDU))
- minstrel_aggr_check(sta, skb);
- }
- }
- 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 ctime = 0;
- 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;
- /* Contention time for first 2 tries */
- ctime = (t_slot * cw) >> 1;
- cw = min((cw << 1) | 1, mp->cw_max);
- ctime += (t_slot * cw) >> 1;
- cw = min((cw << 1) | 1, mp->cw_max);
- /* Total TX time for data and Contention after first 2 tries */
- tx_time = ctime + 2 * (mi->overhead + tx_time_data);
- tx_time_rtscts = ctime + 2 * (mi->overhead_rtscts + tx_time_data);
- /* See how many more tries we can fit inside segment size */
- do {
- /* Contention time for this try */
- ctime = (t_slot * cw) >> 1;
- cw = min((cw << 1) | 1, mp->cw_max);
- /* Total TX time after this try */
- tx_time += ctime + mi->overhead + tx_time_data;
- tx_time_rtscts += ctime + mi->overhead_rtscts + tx_time_data;
- 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,
- 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 (sample)
- rate->count = 1;
- else if (mr->probability < MINSTREL_FRAC(20, 100))
- rate->count = 2;
- else if (rtscts)
- rate->count = mr->retry_count_rtscts;
- else
- rate->count = mr->retry_count;
- rate->flags = IEEE80211_TX_RC_MCS | group->flags;
- if (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)
- {
- struct minstrel_rate_stats *mr;
- struct minstrel_mcs_group_data *mg;
- int sample_idx = 0;
- if (mi->sample_wait > 0) {
- mi->sample_wait--;
- return -1;
- }
- if (!mi->sample_tries)
- return -1;
- mi->sample_tries--;
- 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;
- minstrel_next_sample_idx(mi);
- /*
- * Sampling might add some overhead (RTS, no aggregation)
- * to the frame. Hence, don't use sampling for the currently
- * used max TP rate.
- */
- if (sample_idx == mi->max_tp_rate)
- return -1;
- /*
- * 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;
- /*
- * Make sure that lower rates get sampled only occasionally,
- * if the link is working perfectly.
- */
- if (minstrel_get_duration(sample_idx) >
- minstrel_get_duration(mi->max_tp_rate)) {
- if (mr->sample_skipped < 20)
- return -1;
- if (mi->sample_slow++ > 2)
- return -1;
- }
- return sample_idx;
- }
- 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;
- int sample_idx;
- bool sample = false;
- if (rate_control_send_low(sta, priv_sta, txrc))
- return;
- if (!msp->is_ht)
- return mac80211_minstrel.get_rate(priv, sta, &msp->legacy, txrc);
- info->flags |= mi->tx_flags;
- /* Don't use EAPOL frames for sampling on non-mrr hw */
- if (mp->hw->max_rates == 1 &&
- txrc->skb->protocol == cpu_to_be16(ETH_P_PAE))
- sample_idx = -1;
- else
- sample_idx = minstrel_get_sample_rate(mp, mi);
- #ifdef CONFIG_MAC80211_DEBUGFS
- /* use fixed index if set */
- if (mp->fixed_rate_idx != -1)
- sample_idx = mp->fixed_rate_idx;
- #endif
- if (sample_idx >= 0) {
- sample = true;
- minstrel_ht_set_rate(mp, mi, &ar[0], sample_idx,
- true, false);
- info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE;
- } else {
- minstrel_ht_set_rate(mp, mi, &ar[0], mi->max_tp_rate,
- false, false);
- }
- if (mp->hw->max_rates >= 3) {
- /*
- * At least 3 tx rates supported, use
- * sample_rate -> max_tp_rate -> max_prob_rate for sampling and
- * max_tp_rate -> max_tp_rate2 -> max_prob_rate by default.
- */
- if (sample_idx >= 0)
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate,
- false, false);
- else
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_tp_rate2,
- false, true);
- minstrel_ht_set_rate(mp, mi, &ar[2], mi->max_prob_rate,
- false, !sample);
- ar[3].count = 0;
- ar[3].idx = -1;
- } else if (mp->hw->max_rates == 2) {
- /*
- * Only 2 tx rates supported, use
- * sample_rate -> max_prob_rate for sampling and
- * max_tp_rate -> max_prob_rate by default.
- */
- minstrel_ht_set_rate(mp, mi, &ar[1], mi->max_prob_rate,
- false, !sample);
- ar[2].count = 0;
- ar[2].idx = -1;
- } else {
- /* Not using MRR, only use the first rate */
- ar[1].count = 0;
- ar[1].idx = -1;
- }
- mi->total_packets++;
- /* wraparound */
- if (mi->total_packets == ~0) {
- mi->total_packets = 0;
- mi->sample_packets = 0;
- }
- }
- static void
- minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband,
- struct ieee80211_sta *sta, void *priv_sta,
- enum nl80211_channel_type oper_chan_type)
- {
- 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);
- u16 sta_cap = sta->ht_cap.cap;
- int n_supported = 0;
- int ack_dur;
- int stbc;
- int i;
- unsigned int smps;
- /* fall back to the old minstrel for legacy stations */
- if (!sta->ht_cap.ht_supported)
- goto use_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);
- /* When using MRR, sample more on the first attempt, without delay */
- if (mp->has_mrr) {
- mi->sample_count = 16;
- mi->sample_wait = 0;
- } else {
- mi->sample_count = 8;
- mi->sample_wait = 8;
- }
- mi->sample_tries = 4;
- stbc = (sta_cap & IEEE80211_HT_CAP_RX_STBC) >>
- IEEE80211_HT_CAP_RX_STBC_SHIFT;
- mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT;
- if (sta_cap & IEEE80211_HT_CAP_LDPC_CODING)
- mi->tx_flags |= IEEE80211_TX_CTL_LDPC;
- if (oper_chan_type != NL80211_CHAN_HT40MINUS &&
- oper_chan_type != NL80211_CHAN_HT40PLUS)
- sta_cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
- smps = (sta_cap & IEEE80211_HT_CAP_SM_PS) >>
- IEEE80211_HT_CAP_SM_PS_SHIFT;
- for (i = 0; i < ARRAY_SIZE(mi->groups); i++) {
- u16 req = 0;
- mi->groups[i].supported = 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_cap & req) != req)
- continue;
- /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */
- if (smps == WLAN_HT_CAP_SM_PS_STATIC &&
- minstrel_mcs_groups[i].streams > 1)
- continue;
- mi->groups[i].supported =
- mcs->rx_mask[minstrel_mcs_groups[i].streams - 1];
- if (mi->groups[i].supported)
- n_supported++;
- }
- if (!n_supported)
- goto use_legacy;
- return;
- use_legacy:
- 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);
- }
- 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;
- minstrel_ht_update_caps(priv, sband, sta, priv_sta, mp->hw->conf.channel_type);
- }
- static void
- minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband,
- struct ieee80211_sta *sta, void *priv_sta,
- u32 changed, enum nl80211_channel_type oper_chan_type)
- {
- minstrel_ht_update_caps(priv, sband, sta, priv_sta, oper_chan_type);
- }
- 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->ratelist);
- 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,
- .rate_update = minstrel_ht_rate_update,
- .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);
- }
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