// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2010-2013 Felix Fietkau * Copyright (C) 2019-2020 Intel Corporation */ #include #include #include #include #include #include #include #include #include "rate.h" #include "sta_info.h" #include "rc80211_minstrel_ht.h" #define AVG_AMPDU_SIZE 16 #define AVG_PKT_SIZE 1200 #define SAMPLE_SWITCH_THR 100 /* 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 #define _MAX(a, b) (((a)>(b))?(a):(b)) #define GROUP_SHIFT(duration) \ _MAX(0, 16 - __builtin_clz(duration)) /* MCS rate information for an MCS group */ #define __MCS_GROUP(_streams, _sgi, _ht40, _s) \ [GROUP_IDX(_streams, _sgi, _ht40)] = { \ .streams = _streams, \ .shift = _s, \ .bw = _ht40, \ .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) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 108 : 52) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 162 : 78) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 216 : 104) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 324 : 156) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 432 : 208) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 486 : 234) >> _s, \ MCS_DURATION(_streams, _sgi, _ht40 ? 540 : 260) >> _s \ } \ } #define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \ GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26)) #define MCS_GROUP(_streams, _sgi, _ht40) \ __MCS_GROUP(_streams, _sgi, _ht40, \ MCS_GROUP_SHIFT(_streams, _sgi, _ht40)) #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, _s) \ [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \ .streams = _streams, \ .shift = _s, \ .bw = _bw, \ .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)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 234, 108, 52)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 351, 162, 78)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 468, 216, 104)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 702, 324, 156)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 936, 432, 208)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1053, 486, 234)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1170, 540, 260)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1404, 648, 312)) >> _s, \ MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 1560, 720, 346)) >> _s \ } \ } #define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \ GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \ BW2VBPS(_bw, 117, 54, 26))) #define VHT_GROUP(_streams, _sgi, _bw) \ __VHT_GROUP(_streams, _sgi, _bw, \ VHT_GROUP_SHIFT(_streams, _sgi, _bw)) #define CCK_DURATION(_bitrate, _short) \ (1000 * (10 /* SIFS */ + \ (_short ? 72 + 24 : 144 + 48) + \ (8 * (AVG_PKT_SIZE + 4) * 10) / (_bitrate))) #define CCK_DURATION_LIST(_short, _s) \ CCK_DURATION(10, _short) >> _s, \ CCK_DURATION(20, _short) >> _s, \ CCK_DURATION(55, _short) >> _s, \ CCK_DURATION(110, _short) >> _s #define __CCK_GROUP(_s) \ [MINSTREL_CCK_GROUP] = { \ .streams = 1, \ .flags = 0, \ .shift = _s, \ .duration = { \ CCK_DURATION_LIST(false, _s), \ CCK_DURATION_LIST(true, _s) \ } \ } #define CCK_GROUP_SHIFT \ GROUP_SHIFT(CCK_DURATION(10, false)) #define CCK_GROUP __CCK_GROUP(CCK_GROUP_SHIFT) #define OFDM_DURATION(_bitrate) \ (1000 * (16 /* SIFS + signal ext */ + \ 16 /* T_PREAMBLE */ + \ 4 /* T_SIGNAL */ + \ 4 * (((16 + 80 * (AVG_PKT_SIZE + 4) + 6) / \ ((_bitrate) * 4))))) #define OFDM_DURATION_LIST(_s) \ OFDM_DURATION(60) >> _s, \ OFDM_DURATION(90) >> _s, \ OFDM_DURATION(120) >> _s, \ OFDM_DURATION(180) >> _s, \ OFDM_DURATION(240) >> _s, \ OFDM_DURATION(360) >> _s, \ OFDM_DURATION(480) >> _s, \ OFDM_DURATION(540) >> _s #define __OFDM_GROUP(_s) \ [MINSTREL_OFDM_GROUP] = { \ .streams = 1, \ .flags = 0, \ .shift = _s, \ .duration = { \ OFDM_DURATION_LIST(_s), \ } \ } #define OFDM_GROUP_SHIFT \ GROUP_SHIFT(OFDM_DURATION(60)) #define OFDM_GROUP __OFDM_GROUP(OFDM_GROUP_SHIFT) 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."); /* * 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(4, 0, BW_20), MCS_GROUP(1, 1, BW_20), MCS_GROUP(2, 1, BW_20), MCS_GROUP(3, 1, BW_20), MCS_GROUP(4, 1, BW_20), MCS_GROUP(1, 0, BW_40), MCS_GROUP(2, 0, BW_40), MCS_GROUP(3, 0, BW_40), MCS_GROUP(4, 0, BW_40), MCS_GROUP(1, 1, BW_40), MCS_GROUP(2, 1, BW_40), MCS_GROUP(3, 1, BW_40), MCS_GROUP(4, 1, BW_40), CCK_GROUP, OFDM_GROUP, VHT_GROUP(1, 0, BW_20), VHT_GROUP(2, 0, BW_20), VHT_GROUP(3, 0, BW_20), VHT_GROUP(4, 0, BW_20), VHT_GROUP(1, 1, BW_20), VHT_GROUP(2, 1, BW_20), VHT_GROUP(3, 1, BW_20), VHT_GROUP(4, 1, BW_20), VHT_GROUP(1, 0, BW_40), VHT_GROUP(2, 0, BW_40), VHT_GROUP(3, 0, BW_40), VHT_GROUP(4, 0, BW_40), VHT_GROUP(1, 1, BW_40), VHT_GROUP(2, 1, BW_40), VHT_GROUP(3, 1, BW_40), VHT_GROUP(4, 1, BW_40), VHT_GROUP(1, 0, BW_80), VHT_GROUP(2, 0, BW_80), VHT_GROUP(3, 0, BW_80), VHT_GROUP(4, 0, BW_80), VHT_GROUP(1, 1, BW_80), VHT_GROUP(2, 1, BW_80), VHT_GROUP(3, 1, BW_80), VHT_GROUP(4, 1, BW_80), }; const s16 minstrel_cck_bitrates[4] = { 10, 20, 55, 110 }; const s16 minstrel_ofdm_bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 }; 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; } static bool minstrel_ht_is_legacy_group(int group) { return group == MINSTREL_CCK_GROUP || group == MINSTREL_OFDM_GROUP; } /* * 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; goto out; } if (rate->flags & IEEE80211_TX_RC_VHT_MCS) { group = minstrel_vht_get_group_idx(rate); idx = ieee80211_rate_get_vht_mcs(rate); goto out; } group = MINSTREL_CCK_GROUP; for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) { if (rate->idx != mp->cck_rates[idx]) continue; /* short preamble */ if ((mi->supported[group] & BIT(idx + 4)) && (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)) idx += 4; goto out; } group = MINSTREL_OFDM_GROUP; for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++) if (rate->idx == mp->ofdm_rates[mi->band][idx]) goto out; idx = 0; out: 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]; } static unsigned int minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) { if (!mi->avg_ampdu_len) return AVG_AMPDU_SIZE; return MINSTREL_TRUNC(mi->avg_ampdu_len); } /* * 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_avg) { unsigned int nsecs = 0, overhead = mi->overhead; unsigned int ampdu_len = 1; /* do not account throughput if sucess prob is below 10% */ if (prob_avg < MINSTREL_FRAC(10, 100)) return 0; if (minstrel_ht_is_legacy_group(group)) overhead = mi->overhead_legacy; else ampdu_len = minstrel_ht_avg_ampdu_len(mi); nsecs = 1000 * overhead / ampdu_len; nsecs += minstrel_mcs_groups[group].duration[rate] << minstrel_mcs_groups[group].shift; /* * 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_avg > MINSTREL_FRAC(90, 100)) return MINSTREL_TRUNC(100000 * ((MINSTREL_FRAC(90, 100) * 1000) / nsecs)); else return MINSTREL_TRUNC(100000 * ((prob_avg * 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_avg; 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_avg; 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_avg; 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 (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES) && !minstrel_ht_is_legacy_group(max_tp_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_avg; if (mrs->prob_avg > MINSTREL_FRAC(75, 100)) { cur_tp_avg = minstrel_ht_get_tp_avg(mi, cur_group, cur_idx, mrs->prob_avg); 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_avg > tmp_prob) mi->max_prob_rate = index; if (mrs->prob_avg > 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_legacy_tp_rate[MAX_THR_RATES]) { unsigned int tmp_group, tmp_idx, tmp_cck_tp, tmp_mcs_tp, tmp_prob; int i; tmp_group = tmp_legacy_tp_rate[0] / MCS_GROUP_RATES; tmp_idx = tmp_legacy_tp_rate[0] % MCS_GROUP_RATES; tmp_prob = mi->groups[tmp_group].rates[tmp_idx].prob_avg; 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_avg; 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_legacy_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; if (!mi->sta->ht_cap.ht_supported) return; 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_avg; 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); } } } static inline int minstrel_get_duration(int index) { const struct mcs_group *group = &minstrel_mcs_groups[index / MCS_GROUP_RATES]; unsigned int duration = group->duration[index % MCS_GROUP_RATES]; return duration << group->shift; } static bool minstrel_ht_probe_group(struct minstrel_ht_sta *mi, const struct mcs_group *tp_group, int tp_idx, const struct mcs_group *group) { if (group->bw < tp_group->bw) return false; if (group->streams == tp_group->streams) return true; if (tp_idx < 4 && group->streams == tp_group->streams - 1) return true; return group->streams == tp_group->streams + 1; } static void minstrel_ht_find_probe_rates(struct minstrel_ht_sta *mi, u16 *rates, int *n_rates, bool faster_rate) { const struct mcs_group *group, *tp_group; int i, g, max_dur; int tp_idx; tp_group = &minstrel_mcs_groups[mi->max_tp_rate[0] / MCS_GROUP_RATES]; tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; max_dur = minstrel_get_duration(mi->max_tp_rate[0]); if (faster_rate) max_dur -= max_dur / 16; for (g = 0; g < MINSTREL_GROUPS_NB; g++) { u16 supported = mi->supported[g]; if (!supported) continue; group = &minstrel_mcs_groups[g]; if (!minstrel_ht_probe_group(mi, tp_group, tp_idx, group)) continue; for (i = 0; supported; supported >>= 1, i++) { int idx; if (!(supported & 1)) continue; if ((group->duration[i] << group->shift) > max_dur) continue; idx = g * MCS_GROUP_RATES + i; if (idx == mi->max_tp_rate[0]) continue; rates[(*n_rates)++] = idx; break; } } } static void minstrel_ht_rate_sample_switch(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { struct minstrel_rate_stats *mrs; u16 rates[MINSTREL_GROUPS_NB]; int n_rates = 0; int probe_rate = 0; bool faster_rate; int i; u8 random; /* * Use rate switching instead of probing packets for devices with * little control over retry fallback behavior */ if (mp->hw->max_rates > 1) return; /* * If the current EWMA prob is >75%, look for a rate that's 6.25% * faster than the max tp rate. * If that fails, look again for a rate that is at least as fast */ mrs = minstrel_get_ratestats(mi, mi->max_tp_rate[0]); faster_rate = mrs->prob_avg > MINSTREL_FRAC(75, 100); minstrel_ht_find_probe_rates(mi, rates, &n_rates, faster_rate); if (!n_rates && faster_rate) minstrel_ht_find_probe_rates(mi, rates, &n_rates, false); /* If no suitable rate was found, try to pick the next one in the group */ if (!n_rates) { int g_idx = mi->max_tp_rate[0] / MCS_GROUP_RATES; u16 supported = mi->supported[g_idx]; supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; for (i = 0; supported; supported >>= 1, i++) { if (!(supported & 1)) continue; probe_rate = mi->max_tp_rate[0] + i; goto out; } return; } i = 0; if (n_rates > 1) { random = prandom_u32(); i = random % n_rates; } probe_rate = rates[i]; out: mi->sample_rate = probe_rate; mi->sample_mode = MINSTREL_SAMPLE_ACTIVE; } static inline int minstrel_ewma(int old, int new, int weight) { int diff, incr; diff = new - old; incr = (EWMA_DIV - weight) * diff / EWMA_DIV; return old + incr; } static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in) { s32 out_1 = *prev_1; s32 out_2 = *prev_2; s32 val; if (!in) in += 1; if (!out_1) { val = out_1 = in; goto out; } val = MINSTREL_AVG_COEFF1 * in; val += MINSTREL_AVG_COEFF2 * out_1; val += MINSTREL_AVG_COEFF3 * out_2; val >>= MINSTREL_SCALE; if (val > 1 << MINSTREL_SCALE) val = 1 << MINSTREL_SCALE; if (val < 0) val = 1; out: *prev_2 = out_1; *prev_1 = val; return val; } /* * Recalculate statistics and counters of a given rate */ static void minstrel_ht_calc_rate_stats(struct minstrel_priv *mp, struct minstrel_rate_stats *mrs) { unsigned int cur_prob; if (unlikely(mrs->attempts > 0)) { mrs->sample_skipped = 0; cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); if (mp->new_avg) { minstrel_filter_avg_add(&mrs->prob_avg, &mrs->prob_avg_1, cur_prob); } else if (unlikely(!mrs->att_hist)) { mrs->prob_avg = cur_prob; } else { /*update exponential weighted moving avarage */ mrs->prob_avg = minstrel_ewma(mrs->prob_avg, cur_prob, EWMA_LEVEL); } mrs->att_hist += mrs->attempts; mrs->succ_hist += mrs->success; } else { mrs->sample_skipped++; } mrs->last_success = mrs->success; mrs->last_attempts = mrs->attempts; mrs->success = 0; mrs->attempts = 0; } /* * 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, bool sample) { 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_legacy_tp_rate[MAX_THR_RATES], index; bool ht_supported = mi->sta->ht_cap.ht_supported; mi->sample_mode = MINSTREL_SAMPLE_IDLE; if (sample) { mi->total_packets_cur = mi->total_packets - mi->total_packets_last; mi->total_packets_last = mi->total_packets; } if (!mp->sample_switch) sample = false; if (mi->total_packets_cur < SAMPLE_SWITCH_THR && mp->sample_switch != 1) sample = false; if (mi->ampdu_packets > 0) { if (!ieee80211_hw_check(mp->hw, TX_STATUS_NO_AMPDU_LEN)) mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len, MINSTREL_FRAC(mi->ampdu_len, mi->ampdu_packets), EWMA_LEVEL); else mi->avg_ampdu_len = 0; mi->ampdu_len = 0; mi->ampdu_packets = 0; } mi->sample_slow = 0; mi->sample_count = 0; memset(tmp_mcs_tp_rate, 0, sizeof(tmp_mcs_tp_rate)); memset(tmp_legacy_tp_rate, 0, sizeof(tmp_legacy_tp_rate)); if (mi->supported[MINSTREL_CCK_GROUP]) for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++) tmp_legacy_tp_rate[j] = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; else if (mi->supported[MINSTREL_OFDM_GROUP]) for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++) tmp_legacy_tp_rate[j] = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES; if (mi->supported[MINSTREL_VHT_GROUP_0]) index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES; else if (ht_supported) index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES; else if (mi->supported[MINSTREL_CCK_GROUP]) index = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; else index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES; for (j = 0; j < ARRAY_SIZE(tmp_mcs_tp_rate); j++) tmp_mcs_tp_rate[j] = index; /* Find best rate sets within all MCS groups*/ for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { u16 *tp_rate = tmp_mcs_tp_rate; 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] = MCS_GROUP_RATES * group; if (group == MINSTREL_CCK_GROUP && ht_supported) tp_rate = tmp_legacy_tp_rate; 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_ht_calc_rate_stats(mp, mrs); cur_prob = mrs->prob_avg; if (minstrel_ht_get_tp_avg(mi, group, i, cur_prob) == 0) continue; /* Find max throughput rate set */ minstrel_ht_sort_best_tp_rates(mi, index, 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_legacy_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; if (mp->new_avg) mi->sample_count /= 2; if (sample) minstrel_ht_rate_sample_switch(mp, mi); #ifdef CONFIG_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; mi->sample_mode = MINSTREL_SAMPLE_IDLE; } #endif /* Reset update timer */ mi->last_stats_update = jiffies; } static bool minstrel_ht_txstat_valid(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, struct ieee80211_tx_rate *rate) { int i; 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; for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) if (rate->idx == mp->cck_rates[i]) return true; for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) if (rate->idx == mp->ofdm_rates[mi->band][i]) return true; return false; } 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_tid(hdr); 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 *mi = priv_sta; struct ieee80211_tx_rate *ar = info->status.rates; struct minstrel_rate_stats *rate, *rate2, *rate_sample = NULL; struct minstrel_priv *mp = priv; u32 update_interval = mp->update_interval / 2; bool last, update = false; bool sample_status = false; int i; /* 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) { int avg_ampdu_len = minstrel_ht_avg_ampdu_len(mi); mi->sample_wait = 16 + 2 * 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; if (mi->sample_mode != MINSTREL_SAMPLE_IDLE) rate_sample = minstrel_get_ratestats(mi, mi->sample_rate); last = !minstrel_ht_txstat_valid(mp, mi, &ar[0]); for (i = 0; !last; i++) { last = (i == IEEE80211_TX_MAX_RATES - 1) || !minstrel_ht_txstat_valid(mp, mi, &ar[i + 1]); rate = minstrel_ht_get_stats(mp, mi, &ar[i]); if (rate == rate_sample) sample_status = true; if (last) rate->success += info->status.ampdu_ack_len; rate->attempts += ar[i].count * info->status.ampdu_len; } switch (mi->sample_mode) { case MINSTREL_SAMPLE_IDLE: if (mp->new_avg && (mp->hw->max_rates > 1 || mi->total_packets_cur < SAMPLE_SWITCH_THR)) update_interval /= 2; break; case MINSTREL_SAMPLE_ACTIVE: if (!sample_status) break; mi->sample_mode = MINSTREL_SAMPLE_PENDING; update = true; break; case MINSTREL_SAMPLE_PENDING: if (sample_status) break; update = true; minstrel_ht_update_stats(mp, mi, false); break; } if (mp->hw->max_rates > 1) { /* * 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 && rate->success < rate->attempts / 4) { 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 && rate2->success < rate2->attempts / 4) { minstrel_downgrade_rate(mi, &mi->max_tp_rate[1], false); update = true; } } if (time_after(jiffies, mi->last_stats_update + update_interval)) { update = true; minstrel_ht_update_stats(mp, mi, true); } 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; 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_ht_avg_ampdu_len(mi); unsigned int overhead = 0, overhead_rtscts = 0; mrs = minstrel_get_ratestats(mi, index); if (mrs->prob_avg < 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; tx_time_data = minstrel_get_duration(index) * 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 (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES)) { overhead = mi->overhead_legacy; overhead_rtscts = mi->overhead_legacy_rtscts; } else { 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) { int group_idx = index / MCS_GROUP_RATES; const struct mcs_group *group = &minstrel_mcs_groups[group_idx]; 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_avg < 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; } index %= MCS_GROUP_RATES; if (group_idx == MINSTREL_CCK_GROUP) idx = mp->cck_rates[index % ARRAY_SIZE(mp->cck_rates)]; else if (group_idx == MINSTREL_OFDM_GROUP) idx = mp->ofdm_rates[mi->band][index % ARRAY_SIZE(mp->ofdm_rates[0])]; else if (flags & IEEE80211_TX_RC_VHT_MCS) idx = ((group->streams - 1) << 4) | (index & 0xF); else idx = index + (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_avg(struct minstrel_ht_sta *mi, int rate) { int group = rate / MCS_GROUP_RATES; rate %= MCS_GROUP_RATES; return mi->groups[group].rates[rate].prob_avg; } 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; unsigned int duration; /* Disable A-MSDU if max_prob_rate is bad */ if (mi->groups[group].rates[rate].prob_avg < MINSTREL_FRAC(50, 100)) return 1; duration = g->duration[rate]; duration <<= g->shift; /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ if (duration > 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 (duration > 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 (duration > MCS_DURATION(1, 0, 260) || (minstrel_ht_get_prob_avg(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; u16 first_rate = mi->max_tp_rate[0]; int i = 0; if (mi->sample_mode == MINSTREL_SAMPLE_ACTIVE) first_rate = mi->sample_rate; rates = kzalloc(sizeof(*rates), GFP_ATOMIC); if (!rates) return; /* Start with max_tp_rate[0] */ minstrel_ht_set_rate(mp, mi, rates, i++, first_rate); 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) { 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 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 (mp->hw->max_rates == 1 && mp->sample_switch && (mi->total_packets_cur >= SAMPLE_SWITCH_THR || mp->sample_switch == 1)) return -1; 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%, * or if the rate is 3 times slower than the current max probability * rate, to avoid wasting airtime. */ sample_dur = minstrel_get_duration(sample_idx); if (mrs->prob_avg > MINSTREL_FRAC(95, 100) || minstrel_get_duration(mi->max_prob_rate) * 3 < sample_dur) return -1; /* * For devices with no configurable multi-rate retry, skip sampling * below the per-group max throughput rate, and only use one sampling * attempt per rate */ if (mp->hw->max_rates == 1 && (minstrel_get_duration(mg->max_group_tp_rate[0]) < sample_dur || mrs->attempts)) return -1; /* Skip already sampled slow rates */ if (sample_dur >= minstrel_get_duration(tp_rate1) && mrs->attempts) 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; 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 *mi = priv_sta; struct minstrel_priv *mp = priv; int sample_idx; if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && !minstrel_ht_is_legacy_group(mi->max_prob_rate / MCS_GROUP_RATES)) minstrel_aggr_check(sta, txrc->skb); info->flags |= mi->tx_flags; #ifdef CONFIG_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]; sample_idx %= MCS_GROUP_RATES; if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP] && (sample_idx >= 4) != txrc->short_preamble) return; info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; rate->count = 1; if (sample_group == &minstrel_mcs_groups[MINSTREL_CCK_GROUP]) { int idx = sample_idx % ARRAY_SIZE(mp->cck_rates); rate->idx = mp->cck_rates[idx]; } else if (sample_group == &minstrel_mcs_groups[MINSTREL_OFDM_GROUP]) { int idx = sample_idx % ARRAY_SIZE(mp->ofdm_rates[0]); rate->idx = mp->ofdm_rates[mi->band][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 + (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 (sta->ht_cap.ht_supported && !ieee80211_hw_check(mp->hw, SUPPORTS_HT_CCK_RATES)) return; for (i = 0; i < 4; i++) { if (mp->cck_rates[i] == 0xff || !rate_supported(sta, sband->band, mp->cck_rates[i])) continue; mi->supported[MINSTREL_CCK_GROUP] |= BIT(i); if (sband->bitrates[i].flags & IEEE80211_RATE_SHORT_PREAMBLE) mi->supported[MINSTREL_CCK_GROUP] |= BIT(i + 4); } } static void minstrel_ht_update_ofdm(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, struct ieee80211_supported_band *sband, struct ieee80211_sta *sta) { const u8 *rates; int i; if (sta->ht_cap.ht_supported) return; rates = mp->ofdm_rates[sband->band]; for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates[0]); i++) { if (rates[i] == 0xff || !rate_supported(sta, sband->band, rates[i])) continue; mi->supported[MINSTREL_OFDM_GROUP] |= BIT(i); } } 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 *mi = priv_sta; struct ieee80211_mcs_info *mcs = &sta->ht_cap.mcs; u16 ht_cap = sta->ht_cap.cap; struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; const struct ieee80211_rate *ctl_rate; bool ldpc, erp; int use_vht; int n_supported = 0; int ack_dur; int stbc; int i; BUILD_BUG_ON(ARRAY_SIZE(minstrel_mcs_groups) != MINSTREL_GROUPS_NB); if (vht_cap->vht_supported) use_vht = vht_cap->vht_mcs.tx_mcs_map != cpu_to_le16(~0); else use_vht = 0; memset(mi, 0, sizeof(*mi)); mi->sta = sta; mi->band = sband->band; 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; ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)]; erp = ctl_rate->flags & IEEE80211_RATE_ERP_G; ack_dur = ieee80211_frame_duration(sband->band, 10, ctl_rate->bitrate, erp, 1, ieee80211_chandef_get_shift(chandef)); mi->overhead_legacy = ack_dur; mi->overhead_legacy_rtscts = mi->overhead_legacy + 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; if (!use_vht) { stbc = (ht_cap & IEEE80211_HT_CAP_RX_STBC) >> IEEE80211_HT_CAP_RX_STBC_SHIFT; ldpc = ht_cap & IEEE80211_HT_CAP_LDPC_CODING; } else { stbc = (vht_cap->cap & IEEE80211_VHT_CAP_RXSTBC_MASK) >> IEEE80211_VHT_CAP_RXSTBC_SHIFT; ldpc = vht_cap->cap & IEEE80211_VHT_CAP_RXLDPC; } mi->tx_flags |= stbc << IEEE80211_TX_CTL_STBC_SHIFT; if (ldpc) 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 (minstrel_ht_is_legacy_group(i)) continue; if (gflags & IEEE80211_TX_RC_SHORT_GI) { if (gflags & IEEE80211_TX_RC_40_MHZ_WIDTH) { if (!(ht_cap & IEEE80211_HT_CAP_SGI_40)) continue; } else { if (!(ht_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) { if (use_vht && minstrel_vht_only) continue; 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++; } minstrel_ht_update_cck(mp, mi, sband, sta); minstrel_ht_update_ofdm(mp, mi, sband, sta); /* create an initial rate table with the lowest supported rates */ minstrel_ht_update_stats(mp, mi, true); minstrel_ht_update_rates(mp, mi); } 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 *mi; 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; } return kzalloc(sizeof(*mi), gfp); } static void minstrel_ht_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) { kfree(priv_sta); } static void minstrel_ht_fill_rate_array(u8 *dest, struct ieee80211_supported_band *sband, const s16 *bitrates, int n_rates, u32 rate_flags) { int i, j; for (i = 0; i < sband->n_bitrates; i++) { struct ieee80211_rate *rate = &sband->bitrates[i]; if ((rate_flags & sband->bitrates[i].flags) != rate_flags) continue; for (j = 0; j < n_rates; j++) { if (rate->bitrate != bitrates[j]) continue; dest[j] = i; break; } } } static void minstrel_ht_init_cck_rates(struct minstrel_priv *mp) { static const s16 bitrates[4] = { 10, 20, 55, 110 }; struct ieee80211_supported_band *sband; u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); memset(mp->cck_rates, 0xff, sizeof(mp->cck_rates)); sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; if (!sband) return; BUILD_BUG_ON(ARRAY_SIZE(mp->cck_rates) != ARRAY_SIZE(bitrates)); minstrel_ht_fill_rate_array(mp->cck_rates, sband, minstrel_cck_bitrates, ARRAY_SIZE(minstrel_cck_bitrates), rate_flags); } static void minstrel_ht_init_ofdm_rates(struct minstrel_priv *mp, enum nl80211_band band) { static const s16 bitrates[8] = { 60, 90, 120, 180, 240, 360, 480, 540 }; struct ieee80211_supported_band *sband; u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); memset(mp->ofdm_rates[band], 0xff, sizeof(mp->ofdm_rates[band])); sband = mp->hw->wiphy->bands[band]; if (!sband) return; BUILD_BUG_ON(ARRAY_SIZE(mp->ofdm_rates[band]) != ARRAY_SIZE(bitrates)); minstrel_ht_fill_rate_array(mp->ofdm_rates[band], sband, minstrel_ofdm_bitrates, ARRAY_SIZE(minstrel_ofdm_bitrates), rate_flags); } static void * minstrel_ht_alloc(struct ieee80211_hw *hw) { struct minstrel_priv *mp; int i; mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); if (!mp) return NULL; mp->sample_switch = -1; /* contention window settings * Just an approximation. Using the per-queue values would complicate * the calculations and is probably unnecessary */ mp->cw_min = 15; mp->cw_max = 1023; /* maximum time that the hw is allowed to stay in one MRR segment */ mp->segment_size = 6000; if (hw->max_rate_tries > 0) mp->max_retry = hw->max_rate_tries; else /* safe default, does not necessarily have to match hw properties */ mp->max_retry = 7; if (hw->max_rates >= 4) mp->has_mrr = true; mp->hw = hw; mp->update_interval = HZ / 10; mp->new_avg = true; minstrel_ht_init_cck_rates(mp); for (i = 0; i < ARRAY_SIZE(mp->hw->wiphy->bands); i++) minstrel_ht_init_ofdm_rates(mp, i); return mp; } #ifdef CONFIG_MAC80211_DEBUGFS static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv, struct dentry *debugfsdir) { struct minstrel_priv *mp = priv; mp->fixed_rate_idx = (u32) -1; debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); debugfs_create_u32("sample_switch", S_IRUGO | S_IWUSR, debugfsdir, &mp->sample_switch); debugfs_create_bool("new_avg", S_IRUGO | S_IWUSR, debugfsdir, &mp->new_avg); } #endif static void minstrel_ht_free(void *priv) { kfree(priv); } static u32 minstrel_ht_get_expected_throughput(void *priv_sta) { struct minstrel_ht_sta *mi = priv_sta; int i, j, prob, tp_avg; 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_avg; /* 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 CONFIG_MAC80211_DEBUGFS .add_debugfs = minstrel_ht_add_debugfs, .add_sta_debugfs = minstrel_ht_add_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_init(void) { init_sample_table(); return ieee80211_rate_control_register(&mac80211_minstrel_ht); } void rc80211_minstrel_exit(void) { ieee80211_rate_control_unregister(&mac80211_minstrel_ht); }