| /* |
| * 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_ewma) |
| { |
| int usecs; |
| |
| usecs = mr->perfect_tx_time; |
| if (!usecs) |
| usecs = 1000000; |
| |
| /* reset thr. below 10% success */ |
| if (mr->stats.prob_ewma < MINSTREL_FRAC(10, 100)) |
| return 0; |
| |
| if (prob_ewma > MINSTREL_FRAC(90, 100)) |
| return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs)); |
| else |
| return MINSTREL_TRUNC(100000 * (prob_ewma / 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_ewma) <= |
| minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma)) |
| 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_rate_stats *mrs) |
| { |
| if (unlikely(mrs->attempts > 0)) { |
| mrs->sample_skipped = 0; |
| mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); |
| if (unlikely(!mrs->att_hist)) { |
| mrs->prob_ewma = mrs->cur_prob; |
| } else { |
| /* update exponential weighted moving variance */ |
| mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd, |
| mrs->cur_prob, |
| mrs->prob_ewma, |
| EWMA_LEVEL); |
| |
| /*update exponential weighted moving avarage */ |
| mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, |
| mrs->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(mrs); |
| |
| /* Sample less often below the 10% chance of success. |
| * Sample less often above the 95% chance of success. */ |
| if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || |
| mrs->prob_ewma < 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_ewma >= MINSTREL_FRAC(95, 100)) { |
| tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma); |
| tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate], |
| tmp_mrs->prob_ewma); |
| if (tmp_cur_tp >= tmp_prob_tp) |
| tmp_prob_rate = i; |
| } else { |
| if (mrs->prob_ewma >= tmp_mrs->prob_ewma) |
| 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 CPTCFG_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, |
| struct ieee80211_sta *sta, void *priv_sta, |
| struct ieee80211_tx_info *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) |
| 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 ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) |
| mi->sample_packets++; |
| |
| if (mi->sample_deferred > 0) |
| mi->sample_deferred--; |
| |
| if (time_after(jiffies, mi->last_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) |
| { |
| 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; |
| |
| /* 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->total_packets++; |
| |
| #ifdef CPTCFG_MAC80211_DEBUGFS |
| if (mp->fixed_rate_idx != -1) |
| return; |
| #endif |
| |
| delta = (mi->total_packets * sampling_ratio / 100) - |
| (mi->sample_packets + mi->sample_deferred / 2); |
| |
| /* 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_deferred = 0; |
| 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 (mrr_capable && |
| msr->perfect_tx_time > mr->perfect_tx_time && |
| msr->stats.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) |
| 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_ewma > 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, |
| 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 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->last_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; |
| u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
| 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; |
| |
| if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
| 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 CPTCFG_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 CPTCFG_MAC80211_DEBUGFS |
| debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); |
| #endif |
| kfree(priv); |
| } |
| |
| 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_ewma); |
| tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; |
| |
| return tmp_cur_tp; |
| } |
| |
| const struct rate_control_ops mac80211_minstrel = { |
| .name = "minstrel", |
| .tx_status_noskb = 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 CPTCFG_MAC80211_DEBUGFS |
| .add_sta_debugfs = minstrel_add_sta_debugfs, |
| .remove_sta_debugfs = minstrel_remove_sta_debugfs, |
| #endif |
| .get_expected_throughput = minstrel_get_expected_throughput, |
| }; |
| |
| int __init |
| rc80211_minstrel_init(void) |
| { |
| return ieee80211_rate_control_register(&mac80211_minstrel); |
| } |
| |
| void |
| rc80211_minstrel_exit(void) |
| { |
| ieee80211_rate_control_unregister(&mac80211_minstrel); |
| } |
| |