diff options
Diffstat (limited to 'net/mac80211/rc80211_minstrel.c')
| -rw-r--r-- | net/mac80211/rc80211_minstrel.c | 653 |
1 files changed, 0 insertions, 653 deletions
diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c deleted file mode 100644 index ac7ef5414bde..000000000000 --- a/net/mac80211/rc80211_minstrel.c +++ /dev/null @@ -1,653 +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; -} - -/* 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 = MAX_THR_RATES; - - while (j > 0 && mi->r[i].cur_tp > mi->r[tp_list[j - 1]].cur_tp) - j--; - 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->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); -} - -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; - u32 usecs; - int i; - - 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]; - - usecs = mr->perfect_tx_time; - if (!usecs) - usecs = 1000000; - - if (unlikely(mr->attempts > 0)) { - mr->sample_skipped = 0; - mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); - mr->succ_hist += mr->success; - mr->att_hist += mr->attempts; - mr->probability = minstrel_ewma(mr->probability, - mr->cur_prob, - EWMA_LEVEL); - } else - mr->sample_skipped++; - - mr->last_success = mr->success; - mr->last_attempts = mr->attempts; - mr->success = 0; - mr->attempts = 0; - - /* Update throughput per rate, reset thr. below 10% success */ - if (mr->probability < MINSTREL_FRAC(10, 100)) - mr->cur_tp = 0; - else - mr->cur_tp = mr->probability * (1000000 / usecs); - - /* Sample less often below the 10% chance of success. - * Sample less often above the 95% chance of success. */ - if (mr->probability > MINSTREL_FRAC(95, 100) || - mr->probability < MINSTREL_FRAC(10, 100)) { - mr->adjusted_retry_count = mr->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 = mr->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 choosen as max_prob_rate */ - if (mr->probability >= MINSTREL_FRAC(95,100)) { - if (mr->cur_tp >= mi->r[tmp_prob_rate].cur_tp) - tmp_prob_rate = i; - } else { - if (mr->probability >= mi->r[tmp_prob_rate].probability) - 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; - - /* Reset update timer */ - mi->stats_update = jiffies; - - minstrel_update_rates(mp, mi); -} - -static void -minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, - struct ieee80211_sta *sta, void *priv_sta, - struct sk_buff *skb) -{ - struct minstrel_priv *mp = priv; - struct minstrel_sta_info *mi = priv_sta; - struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); - 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) - break; - - ndx = rix_to_ndx(mi, ar[i].idx); - if (ndx < 0) - continue; - - mi->r[ndx].attempts += ar[i].count; - - if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) - mi->r[ndx].success += success; - } - - if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) - mi->sample_count++; - - if (mi->sample_deferred > 0) - mi->sample_deferred--; - - if (time_after(jiffies, mi->stats_update + - (mp->update_interval * HZ) / 1000)) - minstrel_update_stats(mp, mi); -} - - -static inline unsigned int -minstrel_get_retry_count(struct minstrel_rate *mr, - struct ieee80211_tx_info *info) -{ - unsigned int retry = mr->adjusted_retry_count; - - if (info->control.use_rts) - retry = max(2U, min(mr->retry_count_rtscts, retry)); - else if (info->control.use_cts_prot) - retry = max(2U, 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 = mi->prev_sample; - int delta; - int sampling_ratio; - - /* management/no-ack frames do not use rate control */ - if (rate_control_send_low(sta, priv_sta, txrc)) - return; - - /* 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->packet_count++; - - delta = (mi->packet_count * sampling_ratio / 100) - - (mi->sample_count + mi->sample_deferred / 2); - - /* delta < 0: no sampling required */ - mi->prev_sample = false; - if (delta < 0 || (!mrr_capable && prev_sample)) - return; - - if (mi->packet_count >= 10000) { - mi->sample_deferred = 0; - mi->sample_count = 0; - mi->packet_count = 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_count += (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 (mrr_capable && - msr->perfect_tx_time > mr->perfect_tx_time && - msr->sample_skipped < 20) { - /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark - * packets that have the sampling rate deferred to the - * second MRR stage. Increase the sample counter only - * if the deferred sample rate was actually used. - * Use the sample_deferred counter to make sure that - * the sampling is not done in large bursts */ - info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; - rate++; - mi->sample_deferred++; - } else { - if (!msr->sample_limit != 0) - return; - - mi->sample_count++; - 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].probability > 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); -} - - -static void -calc_rate_durations(enum ieee80211_band band, - struct minstrel_rate *d, - struct ieee80211_rate *rate) -{ - int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); - - d->perfect_tx_time = ieee80211_frame_duration(band, 1200, - rate->bitrate, erp, 1); - d->ack_time = ieee80211_frame_duration(band, 10, - rate->bitrate, erp, 1); -} - -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++) { - for (i = 0; i < mi->n_rates; i++) { - get_random_bytes(rnd, sizeof(rnd)); - 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 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 */ - - 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); - - 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]; - unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; - unsigned int tx_time_single; - unsigned int cw = mp->cw_min; - - if (!rate_supported(sta, sband->band, i)) - continue; - n++; - memset(mr, 0, sizeof(*mr)); - - mr->rix = i; - mr->bitrate = sband->bitrates[i].bitrate / 5; - calc_rate_durations(sband->band, mr, &sband->bitrates[i]); - - /* calculate maximum number of retransmissions before - * fallback (based on maximum segment size) */ - mr->sample_limit = -1; - mr->retry_count = 1; - mr->retry_count_cts = 1; - mr->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) && - (mr->retry_count_rtscts < mp->max_retry)) - mr->retry_count_rtscts++; - } while ((tx_time < mp->segment_size) && - (++mr->retry_count < mp->max_retry)); - mr->adjusted_retry_count = mr->retry_count; - if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) - mr->retry_count_cts = mr->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->stats_update = jiffies; - - init_sample_table(mi); - minstrel_update_rates(mp, mi); -} - -static void * -minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) -{ - struct ieee80211_supported_band *sband; - struct minstrel_sta_info *mi; - struct minstrel_priv *mp = priv; - struct ieee80211_hw *hw = mp->hw; - int max_rates = 0; - int i; - - mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); - if (!mi) - return NULL; - - for (i = 0; i < IEEE80211_NUM_BANDS; i++) { - sband = hw->wiphy->bands[i]; - if (sband && sband->n_bitrates > max_rates) - max_rates = sband->n_bitrates; - } - - mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); - if (!mi->r) - goto error; - - mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); - if (!mi->sample_table) - goto error1; - - mi->stats_update = jiffies; - return mi; - -error1: - kfree(mi->r); -error: - kfree(mi); - return NULL; -} - -static void -minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) -{ - struct minstrel_sta_info *mi = priv_sta; - - kfree(mi->sample_table); - kfree(mi->r); - kfree(mi); -} - -static void -minstrel_init_cck_rates(struct minstrel_priv *mp) -{ - static const int bitrates[4] = { 10, 20, 55, 110 }; - struct ieee80211_supported_band *sband; - int i, j; - - sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ]; - if (!sband) - return; - - for (i = 0, j = 0; i < sband->n_bitrates; i++) { - struct ieee80211_rate *rate = &sband->bitrates[i]; - - if (rate->flags & IEEE80211_RATE_ERP_G) - continue; - - for (j = 0; j < ARRAY_SIZE(bitrates); j++) { - if (rate->bitrate != bitrates[j]) - continue; - - mp->cck_rates[j] = i; - break; - } - } -} - -static void * -minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) -{ - struct minstrel_priv *mp; - - 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; - - /* number of packets (in %) to use for sampling other rates - * sample less often for non-mrr packets, because the overhead - * is much higher than with mrr */ - mp->lookaround_rate = 5; - mp->lookaround_rate_mrr = 10; - - /* 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 = 100; - -#ifdef CONFIG_MAC80211_DEBUGFS - mp->fixed_rate_idx = (u32) -1; - mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", - S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); -#endif - - minstrel_init_cck_rates(mp); - - return mp; -} - -static void -minstrel_free(void *priv) -{ -#ifdef CONFIG_MAC80211_DEBUGFS - debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); -#endif - kfree(priv); -} - -struct rate_control_ops mac80211_minstrel = { - .name = "minstrel", - .tx_status = minstrel_tx_status, - .get_rate = minstrel_get_rate, - .rate_init = minstrel_rate_init, - .alloc = minstrel_alloc, - .free = minstrel_free, - .alloc_sta = minstrel_alloc_sta, - .free_sta = minstrel_free_sta, -#ifdef CONFIG_MAC80211_DEBUGFS - .add_sta_debugfs = minstrel_add_sta_debugfs, - .remove_sta_debugfs = minstrel_remove_sta_debugfs, -#endif -}; - -int __init -rc80211_minstrel_init(void) -{ - return ieee80211_rate_control_register(&mac80211_minstrel); -} - -void -rc80211_minstrel_exit(void) -{ - ieee80211_rate_control_unregister(&mac80211_minstrel); -} - |