diff options
Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 574 |
1 files changed, 0 insertions, 574 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c deleted file mode 100644 index b13b1da19386..000000000000 --- a/net/mac80211/rc80211_minstrel.c +++ /dev/null @@ -1,574 +0,0 @@ -/* - * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - * - * Based on minstrel.c: - * Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz> - * Sponsored by Indranet Technologies Ltd - * - * Based on sample.c: - * Copyright (c) 2005 John Bicket - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer, - * without modification. - * 2. Redistributions in binary form must reproduce at minimum a disclaimer - * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any - * redistribution must be conditioned upon including a substantially - * similar Disclaimer requirement for further binary redistribution. - * 3. Neither the names of the above-listed copyright holders nor the names - * of any contributors may be used to endorse or promote products derived - * from this software without specific prior written permission. - * - * Alternatively, this software may be distributed under the terms of the - * GNU General Public License ("GPL") version 2 as published by the Free - * Software Foundation. - * - * NO WARRANTY - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY - * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL - * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, - * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER - * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF - * THE POSSIBILITY OF SUCH DAMAGES. - */ -#include <linux/netdevice.h> -#include <linux/types.h> -#include <linux/skbuff.h> -#include <linux/debugfs.h> -#include <linux/random.h> -#include <linux/ieee80211.h> -#include <linux/slab.h> -#include <net/mac80211.h> -#include "rate.h" -#include "rc80211_minstrel.h" - -#define SAMPLE_TBL(_mi, _idx, _col) \ - _mi->sample_table[(_idx * SAMPLE_COLUMNS) + _col] - -/* convert mac80211 rate index to local array index */ -static inline int -rix_to_ndx(struct minstrel_sta_info *mi, int rix) -{ - int i = rix; - for (i = rix; i >= 0; i--) - if (mi->r[i].rix == rix) - break; - return i; -} - -/* return current EMWA throughput */ -int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_avg) -{ - int usecs; - - usecs = mr->perfect_tx_time; - if (!usecs) - usecs = 1000000; - - /* reset thr. below 10% success */ - if (mr->stats.prob_avg < MINSTREL_FRAC(10, 100)) - return 0; - - if (prob_avg > MINSTREL_FRAC(90, 100)) - return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs)); - else - return MINSTREL_TRUNC(100000 * (prob_avg / usecs)); -} - -/* find & sort topmost throughput rates */ -static inline void -minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) -{ - int j; - struct minstrel_rate_stats *tmp_mrs; - struct minstrel_rate_stats *cur_mrs = &mi->r[i].stats; - - for (j = MAX_THR_RATES; j > 0; --j) { - tmp_mrs = &mi->r[tp_list[j - 1]].stats; - if (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_avg) <= - minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_avg)) - break; - } - - if (j < MAX_THR_RATES - 1) - memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1)); - if (j < MAX_THR_RATES) - tp_list[j] = i; -} - -static void -minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl, - int offset, int idx) -{ - struct minstrel_rate *r = &mi->r[idx]; - - ratetbl->rate[offset].idx = r->rix; - ratetbl->rate[offset].count = r->adjusted_retry_count; - ratetbl->rate[offset].count_cts = r->retry_count_cts; - ratetbl->rate[offset].count_rts = r->stats.retry_count_rtscts; -} - -static void -minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) -{ - struct ieee80211_sta_rates *ratetbl; - int i = 0; - - ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC); - if (!ratetbl) - return; - - /* Start with max_tp_rate */ - minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]); - - if (mp->hw->max_rates >= 3) { - /* At least 3 tx rates supported, use max_tp_rate2 next */ - minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]); - } - - if (mp->hw->max_rates >= 2) { - /* At least 2 tx rates supported, use max_prob_rate next */ - minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate); - } - - /* Use lowest rate last */ - ratetbl->rate[i].idx = mi->lowest_rix; - ratetbl->rate[i].count = mp->max_retry; - ratetbl->rate[i].count_cts = mp->max_retry; - ratetbl->rate[i].count_rts = mp->max_retry; - - rate_control_set_rates(mp->hw, mi->sta, ratetbl); -} - -/* -* Recalculate statistics and counters of a given rate -*/ -void -minstrel_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; -} - -static void -minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) -{ - u8 tmp_tp_rate[MAX_THR_RATES]; - u8 tmp_prob_rate = 0; - int i, tmp_cur_tp, tmp_prob_tp; - - for (i = 0; i < MAX_THR_RATES; i++) - tmp_tp_rate[i] = 0; - - for (i = 0; i < mi->n_rates; i++) { - struct minstrel_rate *mr = &mi->r[i]; - struct minstrel_rate_stats *mrs = &mi->r[i].stats; - struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; - - /* Update statistics of success probability per rate */ - minstrel_calc_rate_stats(mp, mrs); - - /* Sample less often below the 10% chance of success. - * Sample less often above the 95% chance of success. */ - if (mrs->prob_avg > MINSTREL_FRAC(95, 100) || - mrs->prob_avg < MINSTREL_FRAC(10, 100)) { - mr->adjusted_retry_count = mrs->retry_count >> 1; - if (mr->adjusted_retry_count > 2) - mr->adjusted_retry_count = 2; - mr->sample_limit = 4; - } else { - mr->sample_limit = -1; - mr->adjusted_retry_count = mrs->retry_count; - } - if (!mr->adjusted_retry_count) - mr->adjusted_retry_count = 2; - - minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate); - - /* To determine the most robust rate (max_prob_rate) used at - * 3rd mmr stage we distinct between two cases: - * (1) if any success probabilitiy >= 95%, out of those rates - * choose the maximum throughput rate as max_prob_rate - * (2) if all success probabilities < 95%, the rate with - * highest success probability is chosen as max_prob_rate */ - if (mrs->prob_avg >= MINSTREL_FRAC(95, 100)) { - tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_avg); - tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate], - tmp_mrs->prob_avg); - if (tmp_cur_tp >= tmp_prob_tp) - tmp_prob_rate = i; - } else { - if (mrs->prob_avg >= tmp_mrs->prob_avg) - tmp_prob_rate = i; - } - } - - /* Assign the new rate set */ - memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate)); - mi->max_prob_rate = tmp_prob_rate; - -#ifdef CONFIG_MAC80211_DEBUGFS - /* use fixed index if set */ - if (mp->fixed_rate_idx != -1) { - mi->max_tp_rate[0] = mp->fixed_rate_idx; - mi->max_tp_rate[1] = mp->fixed_rate_idx; - mi->max_prob_rate = mp->fixed_rate_idx; - } -#endif - - /* Reset update timer */ - mi->last_stats_update = jiffies; - - minstrel_update_rates(mp, mi); -} - -static void -minstrel_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_priv *mp = priv; - struct minstrel_sta_info *mi = priv_sta; - struct ieee80211_tx_rate *ar = info->status.rates; - int i, ndx; - int success; - - success = !!(info->flags & IEEE80211_TX_STAT_ACK); - - for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { - if (ar[i].idx < 0 || !ar[i].count) - break; - - ndx = rix_to_ndx(mi, ar[i].idx); - if (ndx < 0) - continue; - - mi->r[ndx].stats.attempts += ar[i].count; - - if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) - mi->r[ndx].stats.success += success; - } - - if (time_after(jiffies, mi->last_stats_update + - mp->update_interval / (mp->new_avg ? 2 : 1))) - minstrel_update_stats(mp, mi); -} - - -static inline unsigned int -minstrel_get_retry_count(struct minstrel_rate *mr, - struct ieee80211_tx_info *info) -{ - u8 retry = mr->adjusted_retry_count; - - if (info->control.use_rts) - retry = max_t(u8, 2, min(mr->stats.retry_count_rtscts, retry)); - else if (info->control.use_cts_prot) - retry = max_t(u8, 2, min(mr->retry_count_cts, retry)); - return retry; -} - - -static int -minstrel_get_next_sample(struct minstrel_sta_info *mi) -{ - unsigned int sample_ndx; - sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); - mi->sample_row++; - if ((int) mi->sample_row >= mi->n_rates) { - mi->sample_row = 0; - mi->sample_column++; - if (mi->sample_column >= SAMPLE_COLUMNS) - mi->sample_column = 0; - } - return sample_ndx; -} - -static void -minstrel_get_rate(void *priv, struct ieee80211_sta *sta, - void *priv_sta, struct ieee80211_tx_rate_control *txrc) -{ - struct sk_buff *skb = txrc->skb; - struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); - struct minstrel_sta_info *mi = priv_sta; - struct minstrel_priv *mp = priv; - struct ieee80211_tx_rate *rate = &info->control.rates[0]; - struct minstrel_rate *msr, *mr; - unsigned int ndx; - bool mrr_capable; - bool prev_sample; - int delta; - int sampling_ratio; - - /* check multi-rate-retry capabilities & adjust lookaround_rate */ - mrr_capable = mp->has_mrr && - !txrc->rts && - !txrc->bss_conf->use_cts_prot; - if (mrr_capable) - sampling_ratio = mp->lookaround_rate_mrr; - else - sampling_ratio = mp->lookaround_rate; - - /* increase sum packet counter */ - mi->total_packets++; - -#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; - - delta = (mi->total_packets * sampling_ratio / 100) - - mi->sample_packets; - - /* delta < 0: no sampling required */ - prev_sample = mi->prev_sample; - mi->prev_sample = false; - if (delta < 0 || (!mrr_capable && prev_sample)) - return; - - if (mi->total_packets >= 10000) { - mi->sample_packets = 0; - mi->total_packets = 0; - } else if (delta > mi->n_rates * 2) { - /* With multi-rate retry, not every planned sample - * attempt actually gets used, due to the way the retry - * chain is set up - [max_tp,sample,prob,lowest] for - * sample_rate < max_tp. - * - * If there's too much sampling backlog and the link - * starts getting worse, minstrel would start bursting - * out lots of sampling frames, which would result - * in a large throughput loss. */ - mi->sample_packets += (delta - mi->n_rates * 2); - } - - /* get next random rate sample */ - ndx = minstrel_get_next_sample(mi); - msr = &mi->r[ndx]; - mr = &mi->r[mi->max_tp_rate[0]]; - - /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) - * rate sampling method should be used. - * Respect such rates that are not sampled for 20 interations. - */ - if (msr->perfect_tx_time < mr->perfect_tx_time || - msr->stats.sample_skipped >= 20) { - if (!msr->sample_limit) - return; - - mi->sample_packets++; - if (msr->sample_limit > 0) - msr->sample_limit--; - } - - /* If we're not using MRR and the sampling rate already - * has a probability of >95%, we shouldn't be attempting - * to use it, as this only wastes precious airtime */ - if (!mrr_capable && - (mi->r[ndx].stats.prob_avg > MINSTREL_FRAC(95, 100))) - return; - - mi->prev_sample = true; - - rate->idx = mi->r[ndx].rix; - rate->count = minstrel_get_retry_count(&mi->r[ndx], info); - info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; -} - - -static void -calc_rate_durations(enum nl80211_band band, - struct minstrel_rate *d, - struct ieee80211_rate *rate, - struct cfg80211_chan_def *chandef) -{ - int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); - int shift = ieee80211_chandef_get_shift(chandef); - - d->perfect_tx_time = ieee80211_frame_duration(band, 1200, - DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, - shift); - d->ack_time = ieee80211_frame_duration(band, 10, - DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, - shift); -} - -static void -init_sample_table(struct minstrel_sta_info *mi) -{ - unsigned int i, col, new_idx; - u8 rnd[8]; - - mi->sample_column = 0; - mi->sample_row = 0; - memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); - - for (col = 0; col < SAMPLE_COLUMNS; col++) { - prandom_bytes(rnd, sizeof(rnd)); - for (i = 0; i < mi->n_rates; i++) { - new_idx = (i + rnd[i & 7]) % mi->n_rates; - while (SAMPLE_TBL(mi, new_idx, col) != 0xff) - new_idx = (new_idx + 1) % mi->n_rates; - - SAMPLE_TBL(mi, new_idx, col) = i; - } - } -} - -static void -minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, - struct cfg80211_chan_def *chandef, - struct ieee80211_sta *sta, void *priv_sta) -{ - struct minstrel_sta_info *mi = priv_sta; - struct minstrel_priv *mp = priv; - struct ieee80211_rate *ctl_rate; - unsigned int i, n = 0; - unsigned int t_slot = 9; /* FIXME: get real slot time */ - u32 rate_flags; - - mi->sta = sta; - mi->lowest_rix = rate_lowest_index(sband, sta); - ctl_rate = &sband->bitrates[mi->lowest_rix]; - mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, - ctl_rate->bitrate, - !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1, - ieee80211_chandef_get_shift(chandef)); - - rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); - memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate)); - mi->max_prob_rate = 0; - - for (i = 0; i < sband->n_bitrates; i++) { - struct minstrel_rate *mr = &mi->r[n]; - struct minstrel_rate_stats *mrs = &mi->r[n].stats; - unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; - unsigned int tx_time_single; - unsigned int cw = mp->cw_min; - int shift; - - if (!rate_supported(sta, sband->band, i)) - continue; - if ((rate_flags & sband->bitrates[i].flags) != rate_flags) - continue; - - n++; - memset(mr, 0, sizeof(*mr)); - memset(mrs, 0, sizeof(*mrs)); - - mr->rix = i; - shift = ieee80211_chandef_get_shift(chandef); - mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate, - (1 << shift) * 5); - calc_rate_durations(sband->band, mr, &sband->bitrates[i], - chandef); - - /* calculate maximum number of retransmissions before - * fallback (based on maximum segment size) */ - mr->sample_limit = -1; - mrs->retry_count = 1; - mr->retry_count_cts = 1; - mrs->retry_count_rtscts = 1; - tx_time = mr->perfect_tx_time + mi->sp_ack_dur; - do { - /* add one retransmission */ - tx_time_single = mr->ack_time + mr->perfect_tx_time; - - /* contention window */ - tx_time_single += (t_slot * cw) >> 1; - cw = min((cw << 1) | 1, mp->cw_max); - - tx_time += tx_time_single; - tx_time_cts += tx_time_single + mi->sp_ack_dur; - tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; - if ((tx_time_cts < mp->segment_size) && - (mr->retry_count_cts < mp->max_retry)) - mr->retry_count_cts++; - if ((tx_time_rtscts < mp->segment_size) && - (mrs->retry_count_rtscts < mp->max_retry)) - mrs->retry_count_rtscts++; - } while ((tx_time < mp->segment_size) && - (++mr->stats.retry_count < mp->max_retry)); - mr->adjusted_retry_count = mrs->retry_count; - if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) - mr->retry_count_cts = mrs->retry_count; - } - - for (i = n; i < sband->n_bitrates; i++) { - struct minstrel_rate *mr = &mi->r[i]; - mr->rix = -1; - } - - mi->n_rates = n; - mi->last_stats_update = jiffies; - - init_sample_table(mi); - minstrel_update_rates(mp, mi); -} - -static u32 minstrel_get_expected_throughput(void *priv_sta) -{ - struct minstrel_sta_info *mi = priv_sta; - struct minstrel_rate_stats *tmp_mrs; - int idx = mi->max_tp_rate[0]; - int tmp_cur_tp; - - /* convert pkt per sec in kbps (1200 is the average pkt size used for - * computing cur_tp - */ - tmp_mrs = &mi->r[idx].stats; - tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_avg) * 10; - tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; - - return tmp_cur_tp; -} - -const struct rate_control_ops mac80211_minstrel = { - .tx_status_ext = minstrel_tx_status, - .get_rate = minstrel_get_rate, - .rate_init = minstrel_rate_init, - .get_expected_throughput = minstrel_get_expected_throughput, -}; |