/* * Copyright (C) 2010-2013 Felix Fietkau * * 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 #include #include #include #include #include #include #include #include "rate.h" #include "sta_info.h" #include "rc80211_minstrel.h" #include "rc80211_minstrel_ht.h" #define AVG_AMPDU_SIZE 16 #define AVG_PKT_SIZE 1200 /* Number of bits for an average sized packet */ #define MCS_NBITS ((AVG_PKT_SIZE * AVG_AMPDU_SIZE) << 3) /* Number of symbols for a packet with (bps) bits per symbol */ #define MCS_NSYMS(bps) DIV_ROUND_UP(MCS_NBITS, (bps)) /* Transmission time (nanoseconds) for a packet containing (syms) symbols */ #define MCS_SYMBOL_TIME(sgi, syms) \ (sgi ? \ ((syms) * 18000 + 4000) / 5 : /* syms * 3.6 us */ \ ((syms) * 1000) << 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))) / AVG_AMPDU_SIZE) #define BW_20 0 #define BW_40 1 #define BW_80 2 /* * Define group sort order: HT40 -> SGI -> #streams */ #define GROUP_IDX(_streams, _sgi, _ht40) \ MINSTREL_HT_GROUP_0 + \ 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 = \ IEEE80211_TX_RC_MCS | \ (_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 VHT_GROUP_IDX(_streams, _sgi, _bw) \ (MINSTREL_VHT_GROUP_0 + \ MINSTREL_MAX_STREAMS * 2 * (_bw) + \ MINSTREL_MAX_STREAMS * (_sgi) + \ (_streams) - 1) #define BW2VBPS(_bw, r3, r2, r1) \ (_bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1) #define VHT_GROUP(_streams, _sgi, _bw) \ [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ .streams = _streams, \ .flags = \ IEEE80211_TX_RC_VHT_MCS | \ (_sgi ? IEEE80211_TX_RC_SHORT_GI : 0) | \ (_bw == BW_80 ? IEEE80211_TX_RC_80_MHZ_WIDTH : \ _bw == BW_40 ? IEEE80211_TX_RC_40_MHZ_WIDTH : 0), \ .duration = { \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 117, 54, 26)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 234, 108, 52)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 351, 162, 78)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 468, 216, 104)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 702, 324, 156)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 936, 432, 208)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1053, 486, 234)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1170, 540, 260)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1404, 648, 312)), \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1560, 720, 346)) \ } \ } #define CCK_DURATION(_bitrate, _short, _len) \ (1000 * (10 /* SIFS */ + \ (_short ? 72 + 24 : 144 + 48) + \ (8 * (_len + 4) * 10) / (_bitrate))) #define CCK_ACK_DURATION(_bitrate, _short) \ (CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) + \ CCK_DURATION(_bitrate, _short, AVG_PKT_SIZE)) #define CCK_DURATION_LIST(_short) \ CCK_ACK_DURATION(10, _short), \ CCK_ACK_DURATION(20, _short), \ CCK_ACK_DURATION(55, _short), \ CCK_ACK_DURATION(110, _short) #define CCK_GROUP \ [MINSTREL_CCK_GROUP] = { \ .streams = 0, \ .flags = 0, \ .duration = { \ CCK_DURATION_LIST(false), \ CCK_DURATION_LIST(true) \ } \ } #ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT static bool minstrel_vht_only = true; module_param(minstrel_vht_only, bool, 0644); MODULE_PARM_DESC(minstrel_vht_only, "Use only VHT rates when VHT is supported by sta."); #endif /* * 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: * BW -> SGI -> #streams */ const struct mcs_group minstrel_mcs_groups[] = { MCS_GROUP(1, 0, BW_20), MCS_GROUP(2, 0, BW_20), MCS_GROUP(3, 0, BW_20), MCS_GROUP(1, 1, BW_20), MCS_GROUP(2, 1, BW_20), MCS_GROUP(3, 1, BW_20), MCS_GROUP(1, 0, BW_40), MCS_GROUP(2, 0, BW_40), MCS_GROUP(3, 0, BW_40), MCS_GROUP(1, 1, BW_40), MCS_GROUP(2, 1, BW_40), MCS_GROUP(3, 1, BW_40), CCK_GROUP, #ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT VHT_GROUP(1, 0, BW_20), VHT_GROUP(2, 0, BW_20), VHT_GROUP(3, 0, BW_20), VHT_GROUP(1, 1, BW_20), VHT_GROUP(2, 1, BW_20), VHT_GROUP(3, 1, BW_20), VHT_GROUP(1, 0, BW_40), VHT_GROUP(2, 0, BW_40), VHT_GROUP(3, 0, BW_40), VHT_GROUP(1, 1, BW_40), VHT_GROUP(2, 1, BW_40), VHT_GROUP(3, 1, BW_40), VHT_GROUP(1, 0, BW_80), VHT_GROUP(2, 0, BW_80), VHT_GROUP(3, 0, BW_80), VHT_GROUP(1, 1, BW_80), VHT_GROUP(2, 1, BW_80), VHT_GROUP(3, 1, BW_80), #endif }; static u8 sample_table[SAMPLE_COLUMNS][MCS_GROUP_RATES] __read_mostly; static void minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi); /* * Some VHT MCSes are invalid (when Ndbps / Nes is not an integer) * e.g for MCS9@20MHzx1Nss: Ndbps=8x52*(5/6) Nes=1 * * Returns the valid mcs map for struct minstrel_mcs_group_data.supported */ static u16 minstrel_get_valid_vht_rates(int bw, int nss, __le16 mcs_map) { u16 mask = 0; if (bw == BW_20) { if (nss != 3 && nss != 6) mask = BIT(9); } else if (bw == BW_80) { if (nss == 3 || nss == 7) mask = BIT(6); else if (nss == 6) mask = BIT(9); } else { WARN_ON(bw != BW_40); } switch ((le16_to_cpu(mcs_map) >> (2 * (nss - 1))) & 3) { case IEEE80211_VHT_MCS_SUPPORT_0_7: mask |= 0x300; break; case IEEE80211_VHT_MCS_SUPPORT_0_8: mask |= 0x200; break; case IEEE80211_VHT_MCS_SUPPORT_0_9: break; default: mask = 0x3ff; } return 0x3ff & ~mask; } /* * 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 / 8) + 1, !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)); } static int minstrel_vht_get_group_idx(struct ieee80211_tx_rate *rate) { return VHT_GROUP_IDX(ieee80211_rate_get_vht_nss(rate), !!(rate->flags & IEEE80211_TX_RC_SHORT_GI), !!(rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) + 2*!!(rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)); } static struct minstrel_rate_stats * minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, struct ieee80211_tx_rate *rate) { int group, idx; if (rate->flags & IEEE80211_TX_RC_MCS) { group = minstrel_ht_get_group_idx(rate); idx = rate->idx % 8; } else if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { group = minstrel_vht_get_group_idx(rate); idx = ieee80211_rate_get_vht_mcs(rate); } else { group = MINSTREL_CCK_GROUP; for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) if (rate->idx == mp->cck_rates[idx]) break; /* short preamble */ if (!(mi->supported[group] & BIT(idx))) idx += 4; } return &mi->groups[group].rates[idx]; } 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]; } /* * Return current throughput based on the average A-MPDU length, taking into * account the expected number of retransmissions and their expected length */ int minstrel_ht_get_tp_avg(struct minstrel_ht_sta *mi, int group, int rate, int prob_ewma) { unsigned int nsecs = 0; /* do not account throughput if sucess prob is below 10% */ if (prob_ewma < MINSTREL_FRAC(10, 100)) return 0; if (group != MINSTREL_CCK_GROUP) nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len); nsecs += minstrel_mcs_groups[group].duration[rate]; /* * For the throughput calculation, limit the probability value to 90% to * account for collision related packet error rate fluctuation * (prob is scaled - see MINSTREL_FRAC above) */ if (prob_ewma > MINSTREL_FRAC(90, 100)) return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) / nsecs)); else return MINSTREL_TRUNC(100000 * ((prob_ewma * 1000) / nsecs)); } /* * Find & sort topmost throughput rates * * If multiple rates provide equal throughput the sorting is based on their * current success probability. Higher success probability is preferred among * MCS groups, CCK rates do not provide aggregation and are therefore at last. */ static void minstrel_ht_sort_best_tp_rates(struct minstrel_ht_sta *mi, u16 index, u16 *tp_list) { int cur_group, cur_idx, cur_tp_avg, cur_prob; int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; int j = MAX_THR_RATES; cur_group = index / MCS_GROUP_RATES; cur_idx = index % MCS_GROUP_RATES; cur_prob = mi->groups[cur_group].rates[cur_idx].prob_ewma; cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, cur_prob); do { tmp_group = tp_list[j - 1] / MCS_GROUP_RATES; tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); if (cur_tp_avg < tmp_tp_avg || (cur_tp_avg == tmp_tp_avg && cur_prob <= tmp_prob)) break; j--; } while (j > 0); if (j < MAX_THR_RATES - 1) { memmove(&tp_list[j + 1], &tp_list[j], (sizeof(*tp_list) * (MAX_THR_RATES - (j + 1)))); } if (j < MAX_THR_RATES) tp_list[j] = index; } /* * Find and set the topmost probability rate per sta and per group */ static void minstrel_ht_set_best_prob_rate(struct minstrel_ht_sta *mi, u16 index) { struct minstrel_mcs_group_data *mg; struct minstrel_rate_stats *mrs; int tmp_group, tmp_idx, tmp_tp_avg, tmp_prob; int max_tp_group, cur_tp_avg, cur_group, cur_idx; int max_gpr_group, max_gpr_idx; int max_gpr_tp_avg, max_gpr_prob; cur_group = index / MCS_GROUP_RATES; cur_idx = index % MCS_GROUP_RATES; mg = &mi->groups[index / MCS_GROUP_RATES]; mrs = &mg->rates[index % MCS_GROUP_RATES]; tmp_group = mi->max_prob_rate / MCS_GROUP_RATES; tmp_idx = mi->max_prob_rate % MCS_GROUP_RATES; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; tmp_tp_avg = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); /* if max_tp_rate[0] is from MCS_GROUP max_prob_rate get selected from * MCS_GROUP as well as CCK_GROUP rates do not allow aggregation */ max_tp_group = mi->max_tp_rate[0] / MCS_GROUP_RATES; if((index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) && (max_tp_group != MINSTREL_CCK_GROUP)) return; max_gpr_group = mg->max_group_prob_rate / MCS_GROUP_RATES; max_gpr_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; max_gpr_prob = mi->groups[max_gpr_group].rates[max_gpr_idx].prob_ewma; if (mrs->prob_ewma > MINSTREL_FRAC(75, 100)) { cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, mrs->prob_ewma); if (cur_tp_avg > tmp_tp_avg) mi->max_prob_rate = index; max_gpr_tp_avg = minstrel_ht_get_tp_avg(mi, max_gpr_group, max_gpr_idx, max_gpr_prob); if (cur_tp_avg > max_gpr_tp_avg) mg->max_group_prob_rate = index; } else { if (mrs->prob_ewma > tmp_prob) mi->max_prob_rate = index; if (mrs->prob_ewma > max_gpr_prob) mg->max_group_prob_rate = index; } } /* * Assign new rate set per sta and use CCK rates only if the fastest * rate (max_tp_rate[0]) is from CCK group. This prohibits such sorted * rate sets where MCS and CCK rates are mixed, because CCK rates can * not use aggregation. */ static void minstrel_ht_assign_best_tp_rates(struct minstrel_ht_sta *mi, u16 tmp_mcs_tp_rate[MAX_THR_RATES], u16 tmp_cck_tp_rate[MAX_THR_RATES]) { unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; int i; tmp_group = tmp_cck_tp_rate[0] / MCS_GROUP_RATES; tmp_idx = tmp_cck_tp_rate[0] % MCS_GROUP_RATES; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; tmp_cck_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); tmp_group = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_ewma; tmp_mcs_tp = minstrel_ht_get_tp_avg(mi, tmp_group, tmp_idx, tmp_prob); if (tmp_cck_tp > tmp_mcs_tp) { for(i = 0; i < MAX_THR_RATES; i++) { minstrel_ht_sort_best_tp_rates(mi, tmp_cck_tp_rate[i], tmp_mcs_tp_rate); } } } /* * Try to increase robustness of max_prob rate by decrease number of * streams if possible. */ static inline void minstrel_ht_prob_rate_reduce_streams(struct minstrel_ht_sta *mi) { struct minstrel_mcs_group_data *mg; int tmp_max_streams, group, tmp_idx, tmp_prob; int tmp_tp = 0; tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES].streams; for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { mg = &mi->groups[group]; if (!mi->supported[group] || group == MINSTREL_CCK_GROUP) continue; tmp_idx = mg->max_group_prob_rate % MCS_GROUP_RATES; tmp_prob = mi->groups[group].rates[tmp_idx].prob_ewma; if (tmp_tp < minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob) && (minstrel_mcs_groups[group].streams < tmp_max_streams)) { mi->max_prob_rate = mg->max_group_prob_rate; tmp_tp = minstrel_ht_get_tp_avg(mi, group, tmp_idx, tmp_prob); } } } /* * 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 75%, 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 *mrs; int group, i, j, cur_prob; u16 tmp_mcs_tp_rate[MAX_THR_RATES], tmp_group_tp_rate[MAX_THR_RATES]; u16 tmp_cck_tp_rate[MAX_THR_RATES], 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; /* Initialize global rate indexes */ for(j = 0; j < MAX_THR_RATES; j++){ tmp_mcs_tp_rate[j] = 0; tmp_cck_tp_rate[j] = 0; } /* Find best rate sets within all MCS groups*/ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { mg = &mi->groups[group]; if (!mi->supported[group]) continue; mi->sample_count++; /* (re)Initialize group rate indexes */ for(j = 0; j < MAX_THR_RATES; j++) tmp_group_tp_rate[j] = group; for (i = 0; i < MCS_GROUP_RATES; i++) { if (!(mi->supported[group] & BIT(i))) continue; index = MCS_GROUP_RATES * group + i; mrs = &mg->rates[i]; mrs->retry_updated = false; minstrel_calc_rate_stats(mrs); cur_prob = mrs->prob_ewma; if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) continue; /* Find max throughput rate set */ if (group != MINSTREL_CCK_GROUP) { minstrel_ht_sort_best_tp_rates(mi, index, tmp_mcs_tp_rate); } else if (group == MINSTREL_CCK_GROUP) { minstrel_ht_sort_best_tp_rates(mi, index, tmp_cck_tp_rate); } /* Find max throughput rate set within a group */ minstrel_ht_sort_best_tp_rates(mi, index, tmp_group_tp_rate); /* Find max probability rate per group and global */ minstrel_ht_set_best_prob_rate(mi, index); } memcpy(mg->max_group_tp_rate, tmp_group_tp_rate, sizeof(mg->max_group_tp_rate)); } /* Assign new rate set per sta */ minstrel_ht_assign_best_tp_rates(mi, tmp_mcs_tp_rate, tmp_cck_tp_rate); memcpy(mi->max_tp_rate, tmp_mcs_tp_rate, sizeof(mi->max_tp_rate)); /* Try to increase robustness of max_prob_rate*/ minstrel_ht_prob_rate_reduce_streams(mi); /* try to sample all available rates during each interval */ mi->sample_count *= 8; #ifdef CPTCFG_MAC80211_DEBUGFS /* use fixed index if set */ if (mp->fixed_rate_idx != -1) { for (i = 0; i < 4; i++) mi->max_tp_rate[i] = mp->fixed_rate_idx; mi->max_prob_rate = mp->fixed_rate_idx; } #endif /* Reset update timer */ mi->last_stats_update = jiffies; } static bool minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct ieee80211_tx_rate *rate) { if (rate->idx < 0) return false; if (!rate->count) return false; if (rate->flags & IEEE80211_TX_RC_MCS || rate->flags & IEEE80211_TX_RC_VHT_MCS) return true; return rate->idx == mp->cck_rates[0] || rate->idx == mp->cck_rates[1] || rate->idx == mp->cck_rates[2] || rate->idx == mp->cck_rates[3]; } static void minstrel_set_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 (!mi->supported[mi->sample_group]) 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, u16 *idx, bool primary) { int group, orig_group; orig_group = group = *idx / MCS_GROUP_RATES; while (group > 0) { group--; if (!mi->supported[group]) continue; if (minstrel_mcs_groups[group].streams > minstrel_mcs_groups[orig_group].streams) continue; if (primary) *idx = mi->groups[group].max_group_tp_rate[0]; else *idx = mi->groups[group].max_group_tp_rate[1]; 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 (skb_get_queue_mapping(skb) == IEEE80211_AC_VO) return; 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; ieee80211_start_tx_ba_session(pubsta, tid, 0); } static void minstrel_ht_tx_status(void *priv, struct ieee80211_supported_band *sband, void *priv_sta, struct ieee80211_tx_status *st) { struct ieee80211_tx_info *info = st->info; struct minstrel_ht_sta_priv *msp = priv_sta; struct minstrel_ht_sta *mi = &msp->ht; struct ieee80211_tx_rate *ar = info->status.rates; struct minstrel_rate_stats *rate, *rate2; struct minstrel_priv *mp = priv; bool last, update = false; int i; if (!msp->is_ht) return mac80211_minstrel.tx_status_ext(priv, sband, &msp->legacy, st); /* 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 = 1; mi->sample_count--; } if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) mi->sample_packets += info->status.ampdu_len; last = !minstrel_ht_txstat_valid(mp, &ar[0]); for (i = 0; !last; i++) { last = (i == IEEE80211_TX_MAX_RATES - 1) || !minstrel_ht_txstat_valid(mp, &ar[i + 1]); rate = minstrel_ht_get_stats(mp, mi, &ar[i]); 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[0]); if (rate->attempts > 30 && MINSTREL_FRAC(rate->success, rate->attempts) < MINSTREL_FRAC(20, 100)) { minstrel_downgrade_rate(mi, &mi->max_tp_rate[0], true); update = true; } rate2 = minstrel_get_ratestats(mi, mi->max_tp_rate[1]); if (rate2->attempts > 30 && MINSTREL_FRAC(rate2->success, rate2->attempts) < MINSTREL_FRAC(20, 100)) { minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); update = true; } if (time_after(jiffies, mi->last_stats_update + (mp->update_interval / 2 * HZ) / 1000)) { update = true; minstrel_ht_update_stats(mp, mi); } if (update) minstrel_ht_update_rates(mp, mi); } static void minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, int index) { struct minstrel_rate_stats *mrs; 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); unsigned int overhead = 0, overhead_rtscts = 0; mrs = minstrel_get_ratestats(mi, index); if (mrs->prob_ewma < MINSTREL_FRAC(1, 10)) { mrs->retry_count = 1; mrs->retry_count_rtscts = 1; return; } mrs->retry_count = 2; mrs->retry_count_rtscts = 2; mrs->retry_updated = true; group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000; /* 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); if (index / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) { overhead = mi->overhead; overhead_rtscts = mi->overhead_rtscts; } /* Total TX time for data and Contention after first 2 tries */ tx_time = ctime + 2 * (overhead + tx_time_data); tx_time_rtscts = ctime + 2 * (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 + overhead + tx_time_data; tx_time_rtscts += ctime + overhead_rtscts + tx_time_data; if (tx_time_rtscts < mp->segment_size) mrs->retry_count_rtscts++; } while ((tx_time < mp->segment_size) && (++mrs->retry_count < mp->max_retry)); } static void minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, struct ieee80211_sta_rates *ratetbl, int offset, int index) { const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; struct minstrel_rate_stats *mrs; u8 idx; u16 flags = group->flags; mrs = minstrel_get_ratestats(mi, index); if (!mrs->retry_updated) minstrel_calc_retransmit(mp, mi, index); if (mrs->prob_ewma < MINSTREL_FRAC(20, 100) || !mrs->retry_count) { ratetbl->rate[offset].count = 2; ratetbl->rate[offset].count_rts = 2; ratetbl->rate[offset].count_cts = 2; } else { ratetbl->rate[offset].count = mrs->retry_count; ratetbl->rate[offset].count_cts = mrs->retry_count; ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; } if (index / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; else if (flags & IEEE80211_TX_RC_VHT_MCS) idx = ((group->streams - 1) << 4) | ((index % MCS_GROUP_RATES) & 0xF); else idx = index % MCS_GROUP_RATES + (group->streams - 1) * 8; /* enable RTS/CTS if needed: * - if station is in dynamic SMPS (and streams > 1) * - for fallback rates, to increase chances of getting through */ if (offset > 0 || (mi->sta->smps_mode == IEEE80211_SMPS_DYNAMIC && group->streams > 1)) { ratetbl->rate[offset].count = ratetbl->rate[offset].count_rts; flags |= IEEE80211_TX_RC_USE_RTS_CTS; } ratetbl->rate[offset].idx = idx; ratetbl->rate[offset].flags = flags; } static inline int minstrel_ht_get_prob_ewma(struct minstrel_ht_sta *mi, int rate) { int group = rate / MCS_GROUP_RATES; rate %= MCS_GROUP_RATES; return mi->groups[group].rates[rate].prob_ewma; } static int minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) { int group = mi->max_prob_rate / MCS_GROUP_RATES; const struct mcs_group *g = &minstrel_mcs_groups[group]; int rate = mi->max_prob_rate % MCS_GROUP_RATES; /* Disable A-MSDU if max_prob_rate is bad */ if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) return 1; /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ if (g->duration[rate] > MCS_DURATION(1, 0, 52)) return 500; /* * If the rate is slower than single-stream MCS4, limit A-MSDU to usual * data packet size */ if (g->duration[rate] > MCS_DURATION(1, 0, 104)) return 1600; /* * If the rate is slower than single-stream MCS7, or if the max throughput * rate success probability is less than 75%, limit A-MSDU to twice the usual * data packet size */ if (g->duration[rate] > MCS_DURATION(1, 0, 260) || (minstrel_ht_get_prob_ewma(mi, mi->max_tp_rate[0]) < MINSTREL_FRAC(75, 100))) return 3200; /* * HT A-MPDU limits maximum MPDU size under BA agreement to 4095 bytes. * Since aggregation sessions are started/stopped without txq flush, use * the limit here to avoid the complexity of having to de-aggregate * packets in the queue. */ if (!mi->sta->vht_cap.vht_supported) return IEEE80211_MAX_MPDU_LEN_HT_BA; /* unlimited */ return 0; } static void minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { struct ieee80211_sta_rates *rates; int i = 0; rates = kzalloc(sizeof(*rates), GFP_ATOMIC); if (!rates) return; /* Start with max_tp_rate[0] */ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[0]); if (mp->hw->max_rates >= 3) { /* At least 3 tx rates supported, use max_tp_rate[1] next */ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_tp_rate[1]); } if (mp->hw->max_rates >= 2) { /* * At least 2 tx rates supported, use max_prob_rate next */ minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); } mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); rates->rate[i].idx = -1; rate_control_set_rates(mp->hw, mi->sta, 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 *mrs; struct minstrel_mcs_group_data *mg; unsigned int sample_dur, sample_group, cur_max_tp_streams; int tp_rate1, tp_rate2; int sample_idx = 0; if (mi->sample_wait > 0) { mi->sample_wait--; return -1; } if (!mi->sample_tries) return -1; sample_group = mi->sample_group; mg = &mi->groups[sample_group]; sample_idx = sample_table[mg->column][mg->index]; minstrel_set_next_sample_idx(mi); if (!(mi->supported[sample_group] & BIT(sample_idx))) return -1; mrs = &mg->rates[sample_idx]; sample_idx += sample_group * MCS_GROUP_RATES; /* Set tp_rate1, tp_rate2 to the highest / second highest max_tp_rate */ if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(mi->max_tp_rate[1])) { tp_rate1 = mi->max_tp_rate[1]; tp_rate2 = mi->max_tp_rate[0]; } else { tp_rate1 = mi->max_tp_rate[0]; tp_rate2 = mi->max_tp_rate[1]; } /* * Sampling might add some overhead (RTS, no aggregation) * to the frame. Hence, don't use sampling for the highest currently * used highest throughput or probability rate. */ if (sample_idx == mi->max_tp_rate[0] || sample_idx == mi->max_prob_rate) return -1; /* * Do not sample if the probability is already higher than 95% * to avoid wasting airtime. */ if (mrs->prob_ewma > MINSTREL_FRAC(95, 100)) return -1; /* * Make sure that lower rates get sampled only occasionally, * if the link is working perfectly. */ cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / MCS_GROUP_RATES].streams; sample_dur = minstrel_get_duration(sample_idx); if (sample_dur >= minstrel_get_duration(tp_rate2) && (cur_max_tp_streams - 1 < minstrel_mcs_groups[sample_group].streams || sample_dur >= minstrel_get_duration(mi->max_prob_rate))) { if (mrs->sample_skipped < 20) return -1; if (mi->sample_slow++ > 2) return -1; } mi->sample_tries--; return sample_idx; } static void minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, struct ieee80211_tx_rate_control *txrc) { const struct mcs_group *sample_group; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); struct ieee80211_tx_rate *rate = &info->status.rates[0]; struct minstrel_ht_sta_priv *msp = priv_sta; struct minstrel_ht_sta *mi = &msp->ht; struct minstrel_priv *mp = priv; 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); if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && mi->max_prob_rate / MCS_GROUP_RATES != MINSTREL_CCK_GROUP) minstrel_aggr_check(sta, txrc->skb); info->flags |= mi->tx_flags; #ifdef CPTCFG_MAC80211_DEBUGFS if (mp->fixed_rate_idx != -1) return; #endif /* Don't use EAPOL frames for sampling on non-mrr hw */ if (mp->hw->max_rates == 1 && (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) sample_idx = -1; else sample_idx = minstrel_get_sample_rate(mp, mi); mi->total_packets++; /* wraparound */ if (mi->total_packets == ~0) { mi->total_packets = 0; mi->sample_packets = 0; } if (sample_idx < 0) return; sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; rate->count = 1; if (sample_idx / MCS_GROUP_RATES == MINSTREL_CCK_GROUP) { int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); rate->idx = mp->cck_rates[idx]; } else if (sample_group->flags & IEEE80211_TX_RC_VHT_MCS) { ieee80211_rate_set_vht(rate, sample_idx % MCS_GROUP_RATES, sample_group->streams); } else { rate->idx = sample_idx % MCS_GROUP_RATES + (sample_group->streams - 1) * 8; } rate->flags = sample_group->flags; } static void minstrel_ht_update_cck(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, struct ieee80211_supported_band *sband, struct ieee80211_sta *sta) { int i; if (sband->band != NL80211_BAND_2GHZ) return; if (!ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) return; mi->cck_supported = 0; mi->cck_supported_short = 0; for (i = 0; i < 4; i++) { if (!rate_supported(sta, sband->band, mp->cck_rates[i])) continue; mi->cck_supported |= BIT(i); if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) mi->cck_supported_short |= BIT(i); } mi->supported[MINSTREL_CCK_GROUP] = mi->cck_supported; } static void minstrel_ht_update_caps(void *priv, struct ieee80211_supported_band *sband, struct cfg80211_chan_def *chandef, 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; u16 sta_cap = sta->ht_cap.cap; struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; struct sta_info *sinfo = container_of(sta, struct sta_info, sta); int use_vht; int n_supported = 0; int ack_dur; int stbc; int i; /* 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_GROUPS_NB); #ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT if (vht_cap->vht_supported) use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); else #endif use_vht = 0; msp->is_ht = true; memset(mi, 0, sizeof(*mi)); mi->sta = sta; mi->last_stats_update = jiffies; ack_dur = ieee80211_frame_duration(sband->band, 10, 60, 1, 1, 0); mi->overhead = ieee80211_frame_duration(sband->band, 0, 60, 1, 1, 0); mi->overhead += 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; /* TODO tx_flags for vht - ATM the RC API is not fine-grained enough */ if (!use_vht) { 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; } for (i = 0; i < ARRAY_SIZE(mi->groups); i++) { u32 gflags = minstrel_mcs_groups[i].flags; int bw, nss; mi->supported[i] = 0; if (i == MINSTREL_CCK_GROUP) { minstrel_ht_update_cck(mp, mi, sband, sta); continue; } if (gflags & IEEE80211_TX_RC_SHORT_GI) { if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { if (!(sta_cap & IEEE80211_HT_CAP_SGI_40)) continue; } else { if (!(sta_cap & IEEE80211_HT_CAP_SGI_20)) continue; } } if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH && sta->bandwidth < IEEE80211_STA_RX_BW_40) continue; nss = minstrel_mcs_groups[i].streams; /* Mark MCS > 7 as unsupported if STA is in static SMPS mode */ if (sta->smps_mode == IEEE80211_SMPS_STATIC && nss > 1) continue; /* HT rate */ if (gflags & IEEE80211_TX_RC_MCS) { #ifdef CPTCFG_MAC80211_RC_MINSTREL_VHT if (use_vht && minstrel_vht_only) continue; #endif mi->supported[i] = mcs->rx_mask[nss - 1]; if (mi->supported[i]) n_supported++; continue; } /* VHT rate */ if (!vht_cap->vht_supported || WARN_ON(!(gflags & IEEE80211_TX_RC_VHT_MCS)) || WARN_ON(gflags & IEEE80211_TX_RC_160_MHZ_WIDTH)) continue; if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) { if (sta->bandwidth < IEEE80211_STA_RX_BW_80 || ((gflags & IEEE80211_TX_RC_SHORT_GI) && !(vht_cap->cap & IEEE80211_VHT_CAP_SHORT_GI_80))) { continue; } } if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) bw = BW_40; else if (gflags & IEEE80211_TX_RC_80_MHZ_WIDTH) bw = BW_80; else bw = BW_20; mi->supported[i] = minstrel_get_valid_vht_rates(bw, nss, vht_cap->vht_mcs.tx_mcs_map); if (mi->supported[i]) n_supported++; } if (!n_supported) goto use_legacy; if (test_sta_flag(sinfo, WLAN_STA_SHORT_PREAMBLE)) mi->cck_supported_short |= mi->cck_supported_short << 4; /* create an initial rate table with the lowest supported rates */ minstrel_ht_update_stats(mp, mi); minstrel_ht_update_rates(mp, mi); 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, chandef, sta, &msp->legacy); } static void minstrel_ht_rate_init(void *priv, struct ieee80211_supported_band *sband, struct cfg80211_chan_def *chandef, struct ieee80211_sta *sta, void *priv_sta) { minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); } static void minstrel_ht_rate_update(void *priv, struct ieee80211_supported_band *sband, struct cfg80211_chan_def *chandef, struct ieee80211_sta *sta, void *priv_sta, u32 changed) { minstrel_ht_update_caps(priv, sband, chandef, sta, priv_sta); } 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 < NUM_NL80211_BANDS; i++) { sband = hw->wiphy->bands[i]; if (sband && sband->n_bitrates > max_rates) max_rates = sband->n_bitrates; } msp = kzalloc(sizeof(*msp), 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 u32 minstrel_ht_get_expected_throughput(void *priv_sta) { struct minstrel_ht_sta_priv *msp = priv_sta; struct minstrel_ht_sta *mi = &msp->ht; int i, j, prob, tp_avg; if (!msp->is_ht) return mac80211_minstrel.get_expected_throughput(priv_sta); i = mi->max_tp_rate[0] / MCS_GROUP_RATES; j = mi->max_tp_rate[0] % MCS_GROUP_RATES; prob = mi->groups[i].rates[j].prob_ewma; /* convert tp_avg from pkt per second in kbps */ tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10; tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024; return tp_avg; } static const struct rate_control_ops mac80211_minstrel_ht = { .name = "minstrel_ht", .tx_status_ext = 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 CPTCFG_MAC80211_DEBUGFS .add_sta_debugfs = minstrel_ht_add_sta_debugfs, .remove_sta_debugfs = minstrel_ht_remove_sta_debugfs, #endif .get_expected_throughput = minstrel_ht_get_expected_throughput, }; static void __init 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++) { prandom_bytes(rnd, sizeof(rnd)); for (i = 0; i < MCS_GROUP_RATES; i++) { 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); }