From: Felix Fietkau Date: Thu, 21 Jan 2021 18:29:30 +0100 Subject: [PATCH] mac80211: minstrel_ht: use bitfields to encode rate indexes Get rid of a lot of divisions and modulo operations Reduces code size and improves performance Signed-off-by: Felix Fietkau --- --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -379,14 +379,14 @@ out: static inline struct minstrel_rate_stats * minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index) { - return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES]; + return &mi->groups[MI_RATE_GROUP(index)].rates[MI_RATE_IDX(index)]; } -static inline int -minstrel_get_duration(int index) +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]; + 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; } @@ -398,7 +398,7 @@ minstrel_ht_avg_ampdu_len(struct minstre if (mi->avg_ampdu_len) return MINSTREL_TRUNC(mi->avg_ampdu_len); - if (minstrel_ht_is_legacy_group(mi->max_tp_rate[0] / MCS_GROUP_RATES)) + 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]); @@ -465,14 +465,14 @@ minstrel_ht_sort_best_tp_rates(struct mi 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_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 = tp_list[j - 1] / MCS_GROUP_RATES; - tmp_idx = tp_list[j - 1] % MCS_GROUP_RATES; + 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); @@ -504,23 +504,23 @@ minstrel_ht_set_best_prob_rate(struct mi 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]; + cur_group = MI_RATE_GROUP(index); + cur_idx = MI_RATE_IDX(index); + mg = &mi->groups[cur_group]; + mrs = &mg->rates[cur_idx]; - tmp_group = *dest / MCS_GROUP_RATES; - tmp_idx = *dest % MCS_GROUP_RATES; + 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->max_tp_rate[0] / MCS_GROUP_RATES; - max_tp_idx = mi->max_tp_rate[0] % MCS_GROUP_RATES; + 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(index / MCS_GROUP_RATES) && + if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index)) && !minstrel_ht_is_legacy_group(max_tp_group)) return; @@ -529,8 +529,8 @@ minstrel_ht_set_best_prob_rate(struct mi mrs->prob_avg < max_tp_prob) 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_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)) { @@ -567,13 +567,13 @@ minstrel_ht_assign_best_tp_rates(struct 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_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 = tmp_mcs_tp_rate[0] / MCS_GROUP_RATES; - tmp_idx = tmp_mcs_tp_rate[0] % MCS_GROUP_RATES; + 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); @@ -600,14 +600,14 @@ minstrel_ht_prob_rate_reduce_streams(str if (!mi->sta->ht_cap.ht_supported) return; - tmp_max_streams = minstrel_mcs_groups[mi->max_tp_rate[0] / - MCS_GROUP_RATES].streams; + 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 = mg->max_group_prob_rate % MCS_GROUP_RATES; + 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) && @@ -644,8 +644,8 @@ minstrel_ht_find_probe_rates(struct mins 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; + tp_group = &minstrel_mcs_groups[MI_RATE_GROUP(mi->max_tp_rate[0])]; + tp_idx = MI_RATE_IDX(mi->max_tp_rate[0]); max_dur = minstrel_get_duration(mi->max_tp_rate[0]); if (faster_rate) @@ -670,7 +670,7 @@ minstrel_ht_find_probe_rates(struct mins if ((group->duration[i] << group->shift) > max_dur) continue; - idx = g * MCS_GROUP_RATES + i; + idx = MI_RATE(g, i); if (idx == mi->max_tp_rate[0]) continue; @@ -712,10 +712,10 @@ minstrel_ht_rate_sample_switch(struct mi /* 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; + int g_idx = MI_RATE_GROUP(mi->max_tp_rate[0]); u16 supported = mi->supported[g_idx]; - supported >>= mi->max_tp_rate[0] % MCS_GROUP_RATES; + supported >>= MI_RATE_IDX(mi->max_tp_rate[0]); for (i = 0; supported; supported >>= 1, i++) { if (!(supported & 1)) continue; @@ -856,22 +856,26 @@ minstrel_ht_update_stats(struct minstrel 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; + group = MINSTREL_CCK_GROUP; 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; + group = MINSTREL_OFDM_GROUP; + + 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]) - index = MINSTREL_VHT_GROUP_0 * MCS_GROUP_RATES; + group = MINSTREL_VHT_GROUP_0; else if (ht_supported) - index = MINSTREL_HT_GROUP_0 * MCS_GROUP_RATES; + group = MINSTREL_HT_GROUP_0; else if (mi->supported[MINSTREL_CCK_GROUP]) - index = MINSTREL_CCK_GROUP * MCS_GROUP_RATES; + group = MINSTREL_CCK_GROUP; else - index = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES; + 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; @@ -888,7 +892,7 @@ minstrel_ht_update_stats(struct minstrel /* (re)Initialize group rate indexes */ for(j = 0; j < MAX_THR_RATES; j++) - tmp_group_tp_rate[j] = MCS_GROUP_RATES * group; + tmp_group_tp_rate[j] = MI_RATE(group, 0); if (group == MINSTREL_CCK_GROUP && ht_supported) tp_rate = tmp_legacy_tp_rate; @@ -897,7 +901,7 @@ minstrel_ht_update_stats(struct minstrel if (!(mi->supported[group] & BIT(i))) continue; - index = MCS_GROUP_RATES * group + i; + index = MI_RATE(group, i); mrs = &mg->rates[i]; mrs->retry_updated = false; @@ -929,13 +933,13 @@ minstrel_ht_update_stats(struct minstrel continue; mg = &mi->groups[group]; - mg->max_group_prob_rate = MCS_GROUP_RATES * 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 = MCS_GROUP_RATES * group + i; + index = MI_RATE(group, i); /* Find max probability rate per group and global */ minstrel_ht_set_best_prob_rate(mi, &tmp_max_prob_rate, @@ -1022,7 +1026,7 @@ minstrel_downgrade_rate(struct minstrel_ { int group, orig_group; - orig_group = group = *idx / MCS_GROUP_RATES; + orig_group = group = MI_RATE_GROUP(*idx); while (group > 0) { group--; @@ -1206,7 +1210,7 @@ minstrel_calc_retransmit(struct minstrel ctime += (t_slot * cw) >> 1; cw = min((cw << 1) | 1, mp->cw_max); - if (minstrel_ht_is_legacy_group(index / MCS_GROUP_RATES)) { + if (minstrel_ht_is_legacy_group(MI_RATE_GROUP(index))) { overhead = mi->overhead_legacy; overhead_rtscts = mi->overhead_legacy_rtscts; } else { @@ -1239,7 +1243,7 @@ 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; + int group_idx = MI_RATE_GROUP(index); const struct mcs_group *group = &minstrel_mcs_groups[group_idx]; struct minstrel_rate_stats *mrs; u8 idx; @@ -1259,7 +1263,7 @@ minstrel_ht_set_rate(struct minstrel_pri ratetbl->rate[offset].count_rts = mrs->retry_count_rtscts; } - index %= MCS_GROUP_RATES; + 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) @@ -1289,17 +1293,17 @@ minstrel_ht_set_rate(struct minstrel_pri 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; + 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->max_prob_rate / MCS_GROUP_RATES; + int group = MI_RATE_GROUP(mi->max_prob_rate); const struct mcs_group *g = &minstrel_mcs_groups[group]; - int rate = mi->max_prob_rate % MCS_GROUP_RATES; + int rate = MI_RATE_IDX(mi->max_prob_rate); unsigned int duration; /* Disable A-MSDU if max_prob_rate is bad */ @@ -1405,7 +1409,7 @@ minstrel_get_sample_rate(struct minstrel return -1; mrs = &mg->rates[sample_idx]; - sample_idx += sample_group * MCS_GROUP_RATES; + sample_idx += MI_RATE(sample_group, 0); tp_rate1 = mi->max_tp_rate[0]; @@ -1455,8 +1459,7 @@ minstrel_get_sample_rate(struct minstrel * if the link is working perfectly. */ - cur_max_tp_streams = minstrel_mcs_groups[tp_rate1 / - MCS_GROUP_RATES].streams; + cur_max_tp_streams = minstrel_mcs_groups[MI_RATE_GROUP(tp_rate1)].streams; if (sample_dur >= minstrel_get_duration(tp_rate2) && (cur_max_tp_streams - 1 < minstrel_mcs_groups[sample_group].streams || @@ -1484,7 +1487,7 @@ minstrel_ht_get_rate(void *priv, struct int sample_idx; if (!(info->flags & IEEE80211_TX_CTL_AMPDU) && - !minstrel_ht_is_legacy_group(mi->max_prob_rate / MCS_GROUP_RATES)) + !minstrel_ht_is_legacy_group(MI_RATE_GROUP(mi->max_prob_rate))) minstrel_aggr_check(sta, txrc->skb); info->flags |= mi->tx_flags; @@ -1512,8 +1515,8 @@ minstrel_ht_get_rate(void *priv, struct if (sample_idx < 0) return; - sample_group = &minstrel_mcs_groups[sample_idx / MCS_GROUP_RATES]; - sample_idx %= MCS_GROUP_RATES; + 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) @@ -1529,7 +1532,7 @@ minstrel_ht_get_rate(void *priv, struct 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, + ieee80211_rate_set_vht(rate, MI_RATE_IDX(sample_idx), sample_group->streams); } else { rate->idx = sample_idx + (sample_group->streams - 1) * 8; @@ -1898,8 +1901,8 @@ static u32 minstrel_ht_get_expected_thro 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; + 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 */ --- a/net/mac80211/rc80211_minstrel_ht.h +++ b/net/mac80211/rc80211_minstrel_ht.h @@ -6,6 +6,8 @@ #ifndef __RC_MINSTREL_HT_H #define __RC_MINSTREL_HT_H +#include + /* number of highest throughput rates to consider*/ #define MAX_THR_RATES 4 #define SAMPLE_COLUMNS 10 /* number of columns in sample table */ @@ -57,6 +59,17 @@ #define MCS_GROUP_RATES 10 +#define MI_RATE_IDX_MASK GENMASK(3, 0) +#define MI_RATE_GROUP_MASK GENMASK(15, 4) + +#define MI_RATE(_group, _idx) \ + (FIELD_PREP(MI_RATE_GROUP_MASK, _group) | \ + FIELD_PREP(MI_RATE_IDX_MASK, _idx)) + +#define MI_RATE_IDX(_rate) FIELD_GET(MI_RATE_IDX_MASK, _rate) +#define MI_RATE_GROUP(_rate) FIELD_GET(MI_RATE_GROUP_MASK, _rate) + + struct minstrel_priv { struct ieee80211_hw *hw; bool has_mrr; --- a/net/mac80211/rc80211_minstrel_ht_debugfs.c +++ b/net/mac80211/rc80211_minstrel_ht_debugfs.c @@ -56,7 +56,7 @@ minstrel_ht_stats_dump(struct minstrel_h for (j = 0; j < MCS_GROUP_RATES; j++) { struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j]; - int idx = i * MCS_GROUP_RATES + j; + int idx = MI_RATE(i, j); unsigned int duration; if (!(mi->supported[i] & BIT(j))) @@ -201,7 +201,7 @@ minstrel_ht_stats_csv_dump(struct minstr for (j = 0; j < MCS_GROUP_RATES; j++) { struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j]; - int idx = i * MCS_GROUP_RATES + j; + int idx = MI_RATE(i, j); unsigned int duration; if (!(mi->supported[i] & BIT(j)))