diff options
Diffstat (limited to 'net/mac80211/rc80211_minstrel_ht.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel_ht.c | 2061 |
1 files changed, 2061 insertions, 0 deletions
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c new file mode 100644 index 000000000..3d91b98db --- /dev/null +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -0,0 +1,2061 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010-2013 Felix Fietkau <nbd@openwrt.org> + * Copyright (C) 2019-2022 Intel Corporation + */ +#include <linux/netdevice.h> +#include <linux/types.h> +#include <linux/skbuff.h> +#include <linux/debugfs.h> +#include <linux/random.h> +#include <linux/moduleparam.h> +#include <linux/ieee80211.h> +#include <linux/minmax.h> +#include <net/mac80211.h> +#include "rate.h" +#include "sta_info.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 + +#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 const u8 minstrel_sample_seq[] = { + MINSTREL_SAMPLE_TYPE_INC, + MINSTREL_SAMPLE_TYPE_JUMP, + MINSTREL_SAMPLE_TYPE_INC, + MINSTREL_SAMPLE_TYPE_JUMP, + MINSTREL_SAMPLE_TYPE_INC, + MINSTREL_SAMPLE_TYPE_SLOW, +}; + +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)); +} + +/* + * Look up an MCS group index based on new cfg80211 rate_info. + */ +static int +minstrel_ht_ri_get_group_idx(struct rate_info *rate) +{ + return GROUP_IDX((rate->mcs / 8) + 1, + !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI), + !!(rate->bw & RATE_INFO_BW_40)); +} + +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)); +} + +/* + * Look up an MCS group index based on new cfg80211 rate_info. + */ +static int +minstrel_vht_ri_get_group_idx(struct rate_info *rate) +{ + return VHT_GROUP_IDX(rate->nss, + !!(rate->flags & RATE_INFO_FLAGS_SHORT_GI), + !!(rate->bw & RATE_INFO_BW_40) + + 2*!!(rate->bw & RATE_INFO_BW_80)); +} + +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 (!(mi->supported[group] & BIT(idx))) + continue; + + 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]; +} + +/* + * Get the minstrel rate statistics for specified STA and rate info. + */ +static struct minstrel_rate_stats * +minstrel_ht_ri_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, + struct ieee80211_rate_status *rate_status) +{ + int group, idx; + struct rate_info *rate = &rate_status->rate_idx; + + if (rate->flags & RATE_INFO_FLAGS_MCS) { + group = minstrel_ht_ri_get_group_idx(rate); + idx = rate->mcs % 8; + goto out; + } + + if (rate->flags & RATE_INFO_FLAGS_VHT_MCS) { + group = minstrel_vht_ri_get_group_idx(rate); + idx = rate->mcs; + goto out; + } + + group = MINSTREL_CCK_GROUP; + for (idx = 0; idx < ARRAY_SIZE(mp->cck_rates); idx++) { + if (rate->legacy != minstrel_cck_bitrates[ mp->cck_rates[idx] ]) + continue; + + /* short preamble */ + if ((mi->supported[group] & BIT(idx + 4)) && + mi->use_short_preamble) + idx += 4; + goto out; + } + + group = MINSTREL_OFDM_GROUP; + for (idx = 0; idx < ARRAY_SIZE(mp->ofdm_rates[0]); idx++) + if (rate->legacy == minstrel_ofdm_bitrates[ 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[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)]; +} + +static inline int minstrel_get_duration(int index) +{ + const struct mcs_group *group = &minstrel_mcs_groups[MI_RATE_GROUP(index)]; + unsigned int duration = group->duration[MI_RATE_IDX(index)]; + + return duration << group->shift; +} + +static unsigned int +minstrel_ht_avg_ampdu_len(struct minstrel_ht_sta *mi) +{ + int duration; + + if (mi->avg_ampdu_len) + return MINSTREL_TRUNC(mi->avg_ampdu_len); + + if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_tp_rate[0]))) + return 1; + + duration = minstrel_get_duration(mi->max_tp_rate[0]); + + if (duration > 400 * 1000) + return 2; + + if (duration > 250 * 1000) + return 4; + + if (duration > 150 * 1000) + return 8; + + return 16; +} + +/* + * 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 success 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)) + prob_avg = MINSTREL_FRAC(90, 100); + + return MINSTREL_TRUNC(100 * ((prob_avg * 1000000) / 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 = MI_RATE_GROUP(index); + cur_idx = MI_RATE_IDX(index); + 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 = MI_RATE_GROUP(tp_list[j - 1]); + tmp_idx = MI_RATE_IDX(tp_list[j - 1]); + 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 *dest, 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, max_tp_idx, max_tp_prob; + int cur_tp_avg, cur_group, cur_idx; + int max_gpr_group, max_gpr_idx; + int max_gpr_tp_avg, max_gpr_prob; + + cur_group = MI_RATE_GROUP(index); + cur_idx = MI_RATE_IDX(index); + mg = &mi->groups[cur_group]; + mrs = &mg->rates[cur_idx]; + + tmp_group = MI_RATE_GROUP(*dest); + tmp_idx = MI_RATE_IDX(*dest); + 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_RATE_GROUP(mi->max_tp_rate[0]); + max_tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]); + max_tp_prob = mi->groups[max_tp_group].rates[max_tp_idx].prob_avg; + + if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) && + !minstrel_ht_is_legacy_group(max_tp_group)) + return; + + /* skip rates faster than max tp rate with lower prob */ + if (minstrel_get_duration(mi->max_tp_rate[0]) > minstrel_get_duration(index) && + mrs->prob_avg < max_tp_prob) + return; + + max_gpr_group = MI_RATE_GROUP(mg->max_group_prob_rate); + max_gpr_idx = MI_RATE_IDX(mg->max_group_prob_rate); + 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) + *dest = 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) + *dest = 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 = MI_RATE_GROUP(tmp_legacy_tp_rate[0]); + tmp_idx = MI_RATE_IDX(tmp_legacy_tp_rate[0]); + 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 = MI_RATE_GROUP(tmp_mcs_tp_rate[0]); + tmp_idx = MI_RATE_IDX(tmp_mcs_tp_rate[0]); + 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->deflink.ht_cap.ht_supported) + return; + + group = MI_RATE_GROUP(mi->max_tp_rate[0]); + tmp_max_streams = minstrel_mcs_groups[group].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 = MI_RATE_IDX(mg->max_group_prob_rate); + 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 u16 +__minstrel_ht_get_sample_rate(struct minstrel_ht_sta *mi, + enum minstrel_sample_type type) +{ + u16 *rates = mi->sample[type].sample_rates; + u16 cur; + int i; + + for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) { + if (!rates[i]) + continue; + + cur = rates[i]; + rates[i] = 0; + return cur; + } + + return 0; +} + +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)) { + cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); + minstrel_filter_avg_add(&mrs->prob_avg, + &mrs->prob_avg_1, cur_prob); + mrs->att_hist += mrs->attempts; + mrs->succ_hist += mrs->success; + } + + mrs->last_success = mrs->success; + mrs->last_attempts = mrs->attempts; + mrs->success = 0; + mrs->attempts = 0; +} + +static bool +minstrel_ht_find_sample_rate(struct minstrel_ht_sta *mi, int type, int idx) +{ + int i; + + for (i = 0; i < MINSTREL_SAMPLE_RATES; i++) { + u16 cur = mi->sample[type].sample_rates[i]; + + if (cur == idx) + return true; + + if (!cur) + break; + } + + return false; +} + +static int +minstrel_ht_move_sample_rates(struct minstrel_ht_sta *mi, int type, + u32 fast_rate_dur, u32 slow_rate_dur) +{ + u16 *rates = mi->sample[type].sample_rates; + int i, j; + + for (i = 0, j = 0; i < MINSTREL_SAMPLE_RATES; i++) { + u32 duration; + bool valid = false; + u16 cur; + + cur = rates[i]; + if (!cur) + continue; + + duration = minstrel_get_duration(cur); + switch (type) { + case MINSTREL_SAMPLE_TYPE_SLOW: + valid = duration > fast_rate_dur && + duration < slow_rate_dur; + break; + case MINSTREL_SAMPLE_TYPE_INC: + case MINSTREL_SAMPLE_TYPE_JUMP: + valid = duration < fast_rate_dur; + break; + default: + valid = false; + break; + } + + if (!valid) { + rates[i] = 0; + continue; + } + + if (i == j) + continue; + + rates[j++] = cur; + rates[i] = 0; + } + + return j; +} + +static int +minstrel_ht_group_min_rate_offset(struct minstrel_ht_sta *mi, int group, + u32 max_duration) +{ + u16 supported = mi->supported[group]; + int i; + + for (i = 0; i < MCS_GROUP_RATES && supported; i++, supported >>= 1) { + if (!(supported & BIT(0))) + continue; + + if (minstrel_get_duration(MI_RATE(group, i)) >= max_duration) + continue; + + return i; + } + + return -1; +} + +/* + * Incremental update rates: + * Flip through groups and pick the first group rate that is faster than the + * highest currently selected rate + */ +static u16 +minstrel_ht_next_inc_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur) +{ + u8 type = MINSTREL_SAMPLE_TYPE_INC; + int i, index = 0; + u8 group; + + group = mi->sample[type].sample_group; + for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) { + group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups); + + index = minstrel_ht_group_min_rate_offset(mi, group, + fast_rate_dur); + if (index < 0) + continue; + + index = MI_RATE(group, index & 0xf); + if (!minstrel_ht_find_sample_rate(mi, type, index)) + goto out; + } + index = 0; + +out: + mi->sample[type].sample_group = group; + + return index; +} + +static int +minstrel_ht_next_group_sample_rate(struct minstrel_ht_sta *mi, int group, + u16 supported, int offset) +{ + struct minstrel_mcs_group_data *mg = &mi->groups[group]; + u16 idx; + int i; + + for (i = 0; i < MCS_GROUP_RATES; i++) { + idx = sample_table[mg->column][mg->index]; + if (++mg->index >= MCS_GROUP_RATES) { + mg->index = 0; + if (++mg->column >= ARRAY_SIZE(sample_table)) + mg->column = 0; + } + + if (idx < offset) + continue; + + if (!(supported & BIT(idx))) + continue; + + return MI_RATE(group, idx); + } + + return -1; +} + +/* + * Jump rates: + * Sample random rates, use those that are faster than the highest + * currently selected rate. Rates between the fastest and the slowest + * get sorted into the slow sample bucket, but only if it has room + */ +static u16 +minstrel_ht_next_jump_rate(struct minstrel_ht_sta *mi, u32 fast_rate_dur, + u32 slow_rate_dur, int *slow_rate_ofs) +{ + struct minstrel_rate_stats *mrs; + u32 max_duration = slow_rate_dur; + int i, index, offset; + u16 *slow_rates; + u16 supported; + u32 duration; + u8 group; + + if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES) + max_duration = fast_rate_dur; + + slow_rates = mi->sample[MINSTREL_SAMPLE_TYPE_SLOW].sample_rates; + group = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group; + for (i = 0; i < ARRAY_SIZE(minstrel_mcs_groups); i++) { + u8 type; + + group = (group + 1) % ARRAY_SIZE(minstrel_mcs_groups); + + supported = mi->supported[group]; + if (!supported) + continue; + + offset = minstrel_ht_group_min_rate_offset(mi, group, + max_duration); + if (offset < 0) + continue; + + index = minstrel_ht_next_group_sample_rate(mi, group, supported, + offset); + if (index < 0) + continue; + + duration = minstrel_get_duration(index); + if (duration < fast_rate_dur) + type = MINSTREL_SAMPLE_TYPE_JUMP; + else + type = MINSTREL_SAMPLE_TYPE_SLOW; + + if (minstrel_ht_find_sample_rate(mi, type, index)) + continue; + + if (type == MINSTREL_SAMPLE_TYPE_JUMP) + goto found; + + if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES) + continue; + + if (duration >= slow_rate_dur) + continue; + + /* skip slow rates with high success probability */ + mrs = minstrel_get_ratestats(mi, index); + if (mrs->prob_avg > MINSTREL_FRAC(95, 100)) + continue; + + slow_rates[(*slow_rate_ofs)++] = index; + if (*slow_rate_ofs >= MINSTREL_SAMPLE_RATES) + max_duration = fast_rate_dur; + } + index = 0; + +found: + mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_group = group; + + return index; +} + +static void +minstrel_ht_refill_sample_rates(struct minstrel_ht_sta *mi) +{ + u32 prob_dur = minstrel_get_duration(mi->max_prob_rate); + u32 tp_dur = minstrel_get_duration(mi->max_tp_rate[0]); + u32 tp2_dur = minstrel_get_duration(mi->max_tp_rate[1]); + u32 fast_rate_dur = min(min(tp_dur, tp2_dur), prob_dur); + u32 slow_rate_dur = max(max(tp_dur, tp2_dur), prob_dur); + u16 *rates; + int i, j; + + rates = mi->sample[MINSTREL_SAMPLE_TYPE_INC].sample_rates; + i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_INC, + fast_rate_dur, slow_rate_dur); + while (i < MINSTREL_SAMPLE_RATES) { + rates[i] = minstrel_ht_next_inc_rate(mi, tp_dur); + if (!rates[i]) + break; + + i++; + } + + rates = mi->sample[MINSTREL_SAMPLE_TYPE_JUMP].sample_rates; + i = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_JUMP, + fast_rate_dur, slow_rate_dur); + j = minstrel_ht_move_sample_rates(mi, MINSTREL_SAMPLE_TYPE_SLOW, + fast_rate_dur, slow_rate_dur); + while (i < MINSTREL_SAMPLE_RATES) { + rates[i] = minstrel_ht_next_jump_rate(mi, fast_rate_dur, + slow_rate_dur, &j); + if (!rates[i]) + break; + + i++; + } + + for (i = 0; i < ARRAY_SIZE(mi->sample); i++) + memcpy(mi->sample[i].cur_sample_rates, mi->sample[i].sample_rates, + sizeof(mi->sample[i].cur_sample_rates)); +} + + +/* + * 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_legacy_tp_rate[MAX_THR_RATES], tmp_max_prob_rate; + u16 index; + bool ht_supported = mi->sta->deflink.ht_cap.ht_supported; + + 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; + } + + if (mi->supported[MINSTREL_CCK_GROUP]) + group = MINSTREL_CCK_GROUP; + else if (mi->supported[MINSTREL_OFDM_GROUP]) + group = MINSTREL_OFDM_GROUP; + else + group = 0; + + index = MI_RATE(group, 0); + for (j = 0; j < ARRAY_SIZE(tmp_legacy_tp_rate); j++) + tmp_legacy_tp_rate[j] = index; + + if (mi->supported[MINSTREL_VHT_GROUP_0]) + group = MINSTREL_VHT_GROUP_0; + else if (ht_supported) + group = MINSTREL_HT_GROUP_0; + else if (mi->supported[MINSTREL_CCK_GROUP]) + group = MINSTREL_CCK_GROUP; + else + group = MINSTREL_OFDM_GROUP; + + index = MI_RATE(group, 0); + tmp_max_prob_rate = index; + 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; + u16 last_prob = 0; + + mg = &mi->groups[group]; + if (!mi->supported[group]) + continue; + + /* (re)Initialize group rate indexes */ + for(j = 0; j < MAX_THR_RATES; j++) + tmp_group_tp_rate[j] = MI_RATE(group, 0); + + if (group == MINSTREL_CCK_GROUP && ht_supported) + tp_rate = tmp_legacy_tp_rate; + + for (i = MCS_GROUP_RATES - 1; i >= 0; i--) { + if (!(mi->supported[group] & BIT(i))) + continue; + + index = MI_RATE(group, i); + + mrs = &mg->rates[i]; + mrs->retry_updated = false; + minstrel_ht_calc_rate_stats(mp, mrs); + + if (mrs->att_hist) + last_prob = max(last_prob, mrs->prob_avg); + else + mrs->prob_avg = max(last_prob, mrs->prob_avg); + 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); + } + + 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)); + + for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) { + if (!mi->supported[group]) + continue; + + mg = &mi->groups[group]; + mg->max_group_prob_rate = MI_RATE(group, 0); + + for (i = 0; i < MCS_GROUP_RATES; i++) { + if (!(mi->supported[group] & BIT(i))) + continue; + + index = MI_RATE(group, i); + + /* Find max probability rate per group and global */ + minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate, + index); + } + } + + mi->max_prob_rate = tmp_max_prob_rate; + + /* Try to increase robustness of max_prob_rate*/ + minstrel_ht_prob_rate_reduce_streams(mi); + minstrel_ht_refill_sample_rates(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; + } +#endif + + /* Reset update timer */ + mi->last_stats_update = jiffies; + mi->sample_time = 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; +} + +/* + * Check whether rate_status contains valid information. + */ +static bool +minstrel_ht_ri_txstat_valid(struct minstrel_priv *mp, + struct minstrel_ht_sta *mi, + struct ieee80211_rate_status *rate_status) +{ + int i; + + if (!rate_status) + return false; + if (!rate_status->try_count) + return false; + + if (rate_status->rate_idx.flags & RATE_INFO_FLAGS_MCS || + rate_status->rate_idx.flags & RATE_INFO_FLAGS_VHT_MCS) + return true; + + for (i = 0; i < ARRAY_SIZE(mp->cck_rates); i++) { + if (rate_status->rate_idx.legacy == + minstrel_cck_bitrates[ mp->cck_rates[i] ]) + return true; + } + + for (i = 0; i < ARRAY_SIZE(mp->ofdm_rates); i++) { + if (rate_status->rate_idx.legacy == + minstrel_ofdm_bitrates[ mp->ofdm_rates[mi->band][i] ]) + return true; + } + + return false; +} + +static void +minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) +{ + int group, orig_group; + + orig_group = group = MI_RATE_GROUP(*idx); + 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_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; + struct minstrel_priv *mp = priv; + u32 update_interval = mp->update_interval; + bool last, update = false; + int i; + + /* Ignore packet that was sent with noAck flag */ + if (info->flags & IEEE80211_TX_CTL_NO_ACK) + return; + + /* 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; + } + + /* wraparound */ + if (mi->total_packets >= ~0 - info->status.ampdu_len) { + mi->total_packets = 0; + mi->sample_packets = 0; + } + + mi->total_packets += info->status.ampdu_len; + if (info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) + mi->sample_packets += info->status.ampdu_len; + + mi->ampdu_packets++; + mi->ampdu_len += info->status.ampdu_len; + + if (st->rates && st->n_rates) { + last = !minstrel_ht_ri_txstat_valid(mp, mi, &(st->rates[0])); + for (i = 0; !last; i++) { + last = (i == st->n_rates - 1) || + !minstrel_ht_ri_txstat_valid(mp, mi, + &(st->rates[i + 1])); + + rate = minstrel_ht_ri_get_stats(mp, mi, + &(st->rates[i])); + + if (last) + rate->success += info->status.ampdu_ack_len; + + rate->attempts += st->rates[i].try_count * + info->status.ampdu_len; + } + } else { + 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 (last) + rate->success += info->status.ampdu_ack_len; + + rate->attempts += ar[i].count * info->status.ampdu_len; + } + } + + 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); + } + + 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(MI_RATE_GROUP(index))) { + 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 = MI_RATE_GROUP(index); + 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 = MI_RATE_IDX(index); + 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->deflink.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 = MI_RATE_GROUP(rate); + rate = MI_RATE_IDX(rate); + return mi->groups[group].rates[rate].prob_avg; +} + +static int +minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) +{ + int group = MI_RATE_GROUP(mi->max_prob_rate); + const struct mcs_group *g = &minstrel_mcs_groups[group]; + int rate = MI_RATE_IDX(mi->max_prob_rate); + 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->deflink.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; + int max_rates = min_t(int, mp->hw->max_rates, IEEE80211_TX_RATE_TABLE_SIZE); + + 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]); + + /* Fill up remaining, keep one entry for max_probe_rate */ + for (; i < (max_rates - 1); i++) + minstrel_ht_set_rate(mp, mi, rates, i, mi->max_tp_rate[i]); + + if (i < max_rates) + minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); + + if (i < IEEE80211_TX_RATE_TABLE_SIZE) + rates->rate[i].idx = -1; + + mi->sta->deflink.agg.max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); + ieee80211_sta_recalc_aggregates(mi->sta); + rate_control_set_rates(mp->hw, mi->sta, rates); +} + +static u16 +minstrel_ht_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) +{ + u8 seq; + + if (mp->hw->max_rates > 1) { + seq = mi->sample_seq; + mi->sample_seq = (seq + 1) % ARRAY_SIZE(minstrel_sample_seq); + seq = minstrel_sample_seq[seq]; + } else { + seq = MINSTREL_SAMPLE_TYPE_INC; + } + + return __minstrel_ht_get_sample_rate(mi, seq); +} + +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; + u16 sample_idx; + + 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)) + return; + + if (time_is_after_jiffies(mi->sample_time)) + return; + + mi->sample_time = jiffies + MINSTREL_SAMPLE_INTERVAL; + sample_idx = minstrel_ht_get_sample_rate(mp, mi); + if (!sample_idx) + return; + + sample_group = &minstrel_mcs_groups[MI_RATE_GROUP(sample_idx)]; + sample_idx = MI_RATE_IDX(sample_idx); + + 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, MI_RATE_IDX(sample_idx), + 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->deflink.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->deflink.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->deflink.ht_cap.mcs; + u16 ht_cap = sta->deflink.ht_cap.cap; + struct ieee80211_sta_vht_cap *vht_cap = &sta->deflink.vht_cap; + const struct ieee80211_rate *ctl_rate; + struct sta_info *sta_info; + 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); + + 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->deflink.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->deflink.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->deflink.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++; + } + + sta_info = container_of(sta, struct sta_info, sta); + mi->use_short_preamble = test_sta_flag(sta_info, WLAN_STA_SHORT_PREAMBLE) && + sta_info->sdata->vif.bss_conf.use_short_preamble; + + 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); + 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; + + /* 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 / 20; + + 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); +} +#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_RATE_GROUP(mi->max_tp_rate[0]); + j = MI_RATE_IDX(mi->max_tp_rate[0]); + 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", + .capa = RATE_CTRL_CAPA_AMPDU_TRIGGER, + .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++) { + get_random_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); +} |