Commit a42fa256 authored by Felix Fietkau's avatar Felix Fietkau Committed by Johannes Berg
Browse files

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: default avatarFelix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210127055735.78599-1-nbd@nbd.name


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 9e6d5126

net/mac80211/rc80211_minstrel_ht.c

+64 −62
Original line number Diff line number Diff line
@@ -379,13 +379,13 @@ minstrel_ht_get_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
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)

{

	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 minstrel_ht_sta *mi) 
	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 minstrel_ht_sta *mi, u16 index, 
	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 minstrel_ht_sta *mi, u16 *dest, u16 index) 
	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 minstrel_ht_sta *mi, u16 *dest, u16 index) 
	    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 minstrel_ht_sta *mi, 
	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(struct minstrel_ht_sta *mi) 
	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 minstrel_ht_sta *mi, u16 *rates, int *n_rate 
	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 minstrel_ht_sta *mi, u16 *rates, int *n_rate 
			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 minstrel_priv *mp, 


	/* 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;
@@ -854,24 +854,27 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
	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;

		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] = MINSTREL_OFDM_GROUP * MCS_GROUP_RATES;

		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 +891,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 


		/* (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 +900,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
			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 +932,13 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
			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 +1025,7 @@ minstrel_downgrade_rate(struct minstrel_ht_sta *mi, u16 *idx, bool primary) 
{

	int group, orig_group;



	orig_group = group = *idx / MCS_GROUP_RATES;

	orig_group = group = MI_RATE_GROUP(*idx);

	while (group > 0) {

		group--;
@@ -1206,7 +1209,7 @@ minstrel_calc_retransmit(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
	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 +1242,7 @@ 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 +1262,7 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
		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 +1292,17 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, 
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 +1408,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 
		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 +1458,7 @@ minstrel_get_sample_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) 
	 * 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 +1486,7 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 
	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 +1514,8 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 
	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 +1531,7 @@ minstrel_ht_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, 
		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 +1900,8 @@ 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;

	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 */

net/mac80211/rc80211_minstrel_ht.h

+13 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#ifndef __RC_MINSTREL_HT_H

#define __RC_MINSTREL_HT_H



#include <linux/bitfield.h>



/* 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;

net/mac80211/rc80211_minstrel_ht_debugfs.c

+2 −2
Original line number Diff line number Diff line
@@ -56,7 +56,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p) 


	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 minstrel_ht_sta *mi, int i, char *p) 


	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)))