Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * Based on minstrel.c: |
| 9 | * Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz> |
| 10 | * Sponsored by Indranet Technologies Ltd |
| 11 | * |
| 12 | * Based on sample.c: |
| 13 | * Copyright (c) 2005 John Bicket |
| 14 | * All rights reserved. |
| 15 | * |
| 16 | * Redistribution and use in source and binary forms, with or without |
| 17 | * modification, are permitted provided that the following conditions |
| 18 | * are met: |
| 19 | * 1. Redistributions of source code must retain the above copyright |
| 20 | * notice, this list of conditions and the following disclaimer, |
| 21 | * without modification. |
| 22 | * 2. Redistributions in binary form must reproduce at minimum a disclaimer |
| 23 | * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any |
| 24 | * redistribution must be conditioned upon including a substantially |
| 25 | * similar Disclaimer requirement for further binary redistribution. |
| 26 | * 3. Neither the names of the above-listed copyright holders nor the names |
| 27 | * of any contributors may be used to endorse or promote products derived |
| 28 | * from this software without specific prior written permission. |
| 29 | * |
| 30 | * Alternatively, this software may be distributed under the terms of the |
| 31 | * GNU General Public License ("GPL") version 2 as published by the Free |
| 32 | * Software Foundation. |
| 33 | * |
| 34 | * NO WARRANTY |
| 35 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 36 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 37 | * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY |
| 38 | * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL |
| 39 | * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, |
| 40 | * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 41 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 42 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER |
| 43 | * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 44 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| 45 | * THE POSSIBILITY OF SUCH DAMAGES. |
| 46 | */ |
| 47 | #include <linux/netdevice.h> |
| 48 | #include <linux/types.h> |
| 49 | #include <linux/skbuff.h> |
| 50 | #include <linux/debugfs.h> |
| 51 | #include <linux/random.h> |
| 52 | #include <linux/ieee80211.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 53 | #include <linux/slab.h> |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 54 | #include <net/mac80211.h> |
| 55 | #include "rate.h" |
| 56 | #include "rc80211_minstrel.h" |
| 57 | |
| 58 | #define SAMPLE_COLUMNS 10 |
| 59 | #define SAMPLE_TBL(_mi, _idx, _col) \ |
| 60 | _mi->sample_table[(_idx * SAMPLE_COLUMNS) + _col] |
| 61 | |
| 62 | /* convert mac80211 rate index to local array index */ |
| 63 | static inline int |
| 64 | rix_to_ndx(struct minstrel_sta_info *mi, int rix) |
| 65 | { |
| 66 | int i = rix; |
| 67 | for (i = rix; i >= 0; i--) |
| 68 | if (mi->r[i].rix == rix) |
| 69 | break; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 70 | return i; |
| 71 | } |
| 72 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 73 | static void |
| 74 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) |
| 75 | { |
| 76 | u32 max_tp = 0, index_max_tp = 0, index_max_tp2 = 0; |
| 77 | u32 max_prob = 0, index_max_prob = 0; |
| 78 | u32 usecs; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 79 | int i; |
| 80 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 81 | for (i = 0; i < mi->n_rates; i++) { |
| 82 | struct minstrel_rate *mr = &mi->r[i]; |
| 83 | |
| 84 | usecs = mr->perfect_tx_time; |
| 85 | if (!usecs) |
| 86 | usecs = 1000000; |
| 87 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 88 | if (mr->attempts) { |
Thomas Huehn | c8ca8c2 | 2013-03-04 23:30:02 +0100 | [diff] [blame] | 89 | mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 90 | mr->succ_hist += mr->success; |
| 91 | mr->att_hist += mr->attempts; |
Thomas Huehn | a512d4b | 2013-03-04 23:30:01 +0100 | [diff] [blame] | 92 | mr->probability = minstrel_ewma(mr->probability, |
| 93 | mr->cur_prob, |
| 94 | EWMA_LEVEL); |
| 95 | mr->cur_tp = mr->probability * (1000000 / usecs); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | mr->last_success = mr->success; |
| 99 | mr->last_attempts = mr->attempts; |
| 100 | mr->success = 0; |
| 101 | mr->attempts = 0; |
| 102 | |
| 103 | /* Sample less often below the 10% chance of success. |
| 104 | * Sample less often above the 95% chance of success. */ |
Thomas Huehn | c8ca8c2 | 2013-03-04 23:30:02 +0100 | [diff] [blame] | 105 | if (mr->probability > MINSTREL_FRAC(95, 100) || |
| 106 | mr->probability < MINSTREL_FRAC(10, 100)) { |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 107 | mr->adjusted_retry_count = mr->retry_count >> 1; |
| 108 | if (mr->adjusted_retry_count > 2) |
| 109 | mr->adjusted_retry_count = 2; |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 110 | mr->sample_limit = 4; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 111 | } else { |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 112 | mr->sample_limit = -1; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 113 | mr->adjusted_retry_count = mr->retry_count; |
| 114 | } |
| 115 | if (!mr->adjusted_retry_count) |
| 116 | mr->adjusted_retry_count = 2; |
| 117 | } |
| 118 | |
| 119 | for (i = 0; i < mi->n_rates; i++) { |
| 120 | struct minstrel_rate *mr = &mi->r[i]; |
| 121 | if (max_tp < mr->cur_tp) { |
| 122 | index_max_tp = i; |
| 123 | max_tp = mr->cur_tp; |
| 124 | } |
| 125 | if (max_prob < mr->probability) { |
| 126 | index_max_prob = i; |
| 127 | max_prob = mr->probability; |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | max_tp = 0; |
| 132 | for (i = 0; i < mi->n_rates; i++) { |
| 133 | struct minstrel_rate *mr = &mi->r[i]; |
| 134 | |
| 135 | if (i == index_max_tp) |
| 136 | continue; |
| 137 | |
| 138 | if (max_tp < mr->cur_tp) { |
| 139 | index_max_tp2 = i; |
| 140 | max_tp = mr->cur_tp; |
| 141 | } |
| 142 | } |
| 143 | mi->max_tp_rate = index_max_tp; |
| 144 | mi->max_tp_rate2 = index_max_tp2; |
| 145 | mi->max_prob_rate = index_max_prob; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 146 | |
| 147 | /* Reset update timer */ |
| 148 | mi->stats_update = jiffies; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 149 | } |
| 150 | |
| 151 | static void |
| 152 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, |
| 153 | struct ieee80211_sta *sta, void *priv_sta, |
| 154 | struct sk_buff *skb) |
| 155 | { |
Johannes Berg | 8acbcdd | 2012-11-15 18:27:56 +0100 | [diff] [blame] | 156 | struct minstrel_priv *mp = priv; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 157 | struct minstrel_sta_info *mi = priv_sta; |
| 158 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 159 | struct ieee80211_tx_rate *ar = info->status.rates; |
| 160 | int i, ndx; |
| 161 | int success; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 162 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 163 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 164 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 165 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
| 166 | if (ar[i].idx < 0) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 167 | break; |
| 168 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 169 | ndx = rix_to_ndx(mi, ar[i].idx); |
Luciano Coelho | 3938b45 | 2009-07-03 08:25:08 +0300 | [diff] [blame] | 170 | if (ndx < 0) |
| 171 | continue; |
| 172 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 173 | mi->r[ndx].attempts += ar[i].count; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 174 | |
Javier Cardona | bfc32e6 | 2009-08-17 17:15:55 -0700 | [diff] [blame] | 175 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 176 | mi->r[ndx].success += success; |
| 177 | } |
| 178 | |
| 179 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) |
| 180 | mi->sample_count++; |
| 181 | |
| 182 | if (mi->sample_deferred > 0) |
| 183 | mi->sample_deferred--; |
Johannes Berg | 8acbcdd | 2012-11-15 18:27:56 +0100 | [diff] [blame] | 184 | |
| 185 | if (time_after(jiffies, mi->stats_update + |
| 186 | (mp->update_interval * HZ) / 1000)) |
| 187 | minstrel_update_stats(mp, mi); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 188 | } |
| 189 | |
| 190 | |
| 191 | static inline unsigned int |
| 192 | minstrel_get_retry_count(struct minstrel_rate *mr, |
| 193 | struct ieee80211_tx_info *info) |
| 194 | { |
| 195 | unsigned int retry = mr->adjusted_retry_count; |
| 196 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 197 | if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 198 | retry = max(2U, min(mr->retry_count_rtscts, retry)); |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 199 | else if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 200 | retry = max(2U, min(mr->retry_count_cts, retry)); |
| 201 | return retry; |
| 202 | } |
| 203 | |
| 204 | |
| 205 | static int |
| 206 | minstrel_get_next_sample(struct minstrel_sta_info *mi) |
| 207 | { |
| 208 | unsigned int sample_ndx; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 209 | sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); |
| 210 | mi->sample_row++; |
| 211 | if ((int) mi->sample_row > (mi->n_rates - 2)) { |
| 212 | mi->sample_row = 0; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 213 | mi->sample_column++; |
| 214 | if (mi->sample_column >= SAMPLE_COLUMNS) |
| 215 | mi->sample_column = 0; |
| 216 | } |
| 217 | return sample_ndx; |
| 218 | } |
| 219 | |
Johannes Berg | 2df7816 | 2008-10-28 16:49:41 +0100 | [diff] [blame] | 220 | static void |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 221 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
| 222 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 223 | { |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 224 | struct sk_buff *skb = txrc->skb; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 225 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
| 226 | struct minstrel_sta_info *mi = priv_sta; |
| 227 | struct minstrel_priv *mp = priv; |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 228 | struct ieee80211_tx_rate *ar = info->control.rates; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 229 | unsigned int ndx, sample_ndx = 0; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 230 | bool mrr_capable; |
| 231 | bool indirect_rate_sampling = false; |
| 232 | bool rate_sampling = false; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 233 | int i, delta; |
| 234 | int mrr_ndx[3]; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 235 | int sampling_ratio; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 236 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 237 | /* management/no-ack frames do not use rate control */ |
Luis R. Rodriguez | 4c6d4f5 | 2009-07-16 10:05:41 -0700 | [diff] [blame] | 238 | if (rate_control_send_low(sta, priv_sta, txrc)) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 239 | return; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 240 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 241 | /* check multi-rate-retry capabilities & adjust lookaround_rate */ |
| 242 | mrr_capable = mp->has_mrr && |
| 243 | !txrc->rts && |
| 244 | !txrc->bss_conf->use_cts_prot; |
| 245 | if (mrr_capable) |
| 246 | sampling_ratio = mp->lookaround_rate_mrr; |
| 247 | else |
| 248 | sampling_ratio = mp->lookaround_rate; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 249 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 250 | /* init rateindex [ndx] with max throughput rate */ |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 251 | ndx = mi->max_tp_rate; |
| 252 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 253 | /* increase sum packet counter */ |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 254 | mi->packet_count++; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 255 | |
| 256 | delta = (mi->packet_count * sampling_ratio / 100) - |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 257 | (mi->sample_count + mi->sample_deferred / 2); |
| 258 | |
| 259 | /* delta > 0: sampling required */ |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 260 | if ((delta > 0) && (mrr_capable || !mi->prev_sample)) { |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 261 | struct minstrel_rate *msr; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 262 | if (mi->packet_count >= 10000) { |
| 263 | mi->sample_deferred = 0; |
| 264 | mi->sample_count = 0; |
| 265 | mi->packet_count = 0; |
| 266 | } else if (delta > mi->n_rates * 2) { |
| 267 | /* With multi-rate retry, not every planned sample |
| 268 | * attempt actually gets used, due to the way the retry |
| 269 | * chain is set up - [max_tp,sample,prob,lowest] for |
| 270 | * sample_rate < max_tp. |
| 271 | * |
| 272 | * If there's too much sampling backlog and the link |
| 273 | * starts getting worse, minstrel would start bursting |
| 274 | * out lots of sampling frames, which would result |
| 275 | * in a large throughput loss. */ |
| 276 | mi->sample_count += (delta - mi->n_rates * 2); |
| 277 | } |
| 278 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 279 | /* get next random rate sample */ |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 280 | sample_ndx = minstrel_get_next_sample(mi); |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 281 | msr = &mi->r[sample_ndx]; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 282 | rate_sampling = true; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 283 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 284 | /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) |
| 285 | * rate sampling method should be used */ |
| 286 | if (mrr_capable && |
| 287 | msr->perfect_tx_time > mi->r[ndx].perfect_tx_time) |
| 288 | indirect_rate_sampling = true; |
| 289 | |
| 290 | if (!indirect_rate_sampling) { |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 291 | if (msr->sample_limit != 0) { |
| 292 | ndx = sample_ndx; |
| 293 | mi->sample_count++; |
| 294 | if (msr->sample_limit > 0) |
| 295 | msr->sample_limit--; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 296 | } else |
| 297 | rate_sampling = false; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 298 | } else { |
| 299 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark |
| 300 | * packets that have the sampling rate deferred to the |
| 301 | * second MRR stage. Increase the sample counter only |
| 302 | * if the deferred sample rate was actually used. |
| 303 | * Use the sample_deferred counter to make sure that |
| 304 | * the sampling is not done in large bursts */ |
| 305 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; |
| 306 | mi->sample_deferred++; |
| 307 | } |
| 308 | } |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 309 | mi->prev_sample = rate_sampling; |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 310 | |
| 311 | /* If we're not using MRR and the sampling rate already |
| 312 | * has a probability of >95%, we shouldn't be attempting |
| 313 | * to use it, as this only wastes precious airtime */ |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 314 | if (!mrr_capable && rate_sampling && |
| 315 | (mi->r[ndx].probability > MINSTREL_FRAC(95, 100))) |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 316 | ndx = mi->max_tp_rate; |
| 317 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 318 | /* mrr setup for 1st stage */ |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 319 | ar[0].idx = mi->r[ndx].rix; |
| 320 | ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 321 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 322 | /* non mrr setup for 2nd stage */ |
| 323 | if (!mrr_capable) { |
| 324 | if (!rate_sampling) |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 325 | ar[0].count = mp->max_retry; |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 326 | ar[1].idx = mi->lowest_rix; |
| 327 | ar[1].count = mp->max_retry; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 328 | return; |
| 329 | } |
| 330 | |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 331 | /* mrr setup for 2nd stage */ |
| 332 | if (rate_sampling) { |
| 333 | if (indirect_rate_sampling) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 334 | mrr_ndx[0] = sample_ndx; |
| 335 | else |
| 336 | mrr_ndx[0] = mi->max_tp_rate; |
| 337 | } else { |
| 338 | mrr_ndx[0] = mi->max_tp_rate2; |
| 339 | } |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 340 | |
| 341 | /* mrr setup for 3rd & 4th stage */ |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 342 | mrr_ndx[1] = mi->max_prob_rate; |
| 343 | mrr_ndx[2] = 0; |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 344 | for (i = 1; i < 4; i++) { |
| 345 | ar[i].idx = mi->r[mrr_ndx[i - 1]].rix; |
| 346 | ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 347 | } |
| 348 | } |
| 349 | |
| 350 | |
| 351 | static void |
Michal Kazior | 4ee73f3 | 2012-04-11 08:47:56 +0200 | [diff] [blame] | 352 | calc_rate_durations(enum ieee80211_band band, |
| 353 | struct minstrel_rate *d, |
Patrick Kelle | 868a5f7 | 2011-11-10 15:13:11 +0100 | [diff] [blame] | 354 | struct ieee80211_rate *rate) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 355 | { |
| 356 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); |
| 357 | |
Michal Kazior | 4ee73f3 | 2012-04-11 08:47:56 +0200 | [diff] [blame] | 358 | d->perfect_tx_time = ieee80211_frame_duration(band, 1200, |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 359 | rate->bitrate, erp, 1); |
Michal Kazior | 4ee73f3 | 2012-04-11 08:47:56 +0200 | [diff] [blame] | 360 | d->ack_time = ieee80211_frame_duration(band, 10, |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 361 | rate->bitrate, erp, 1); |
| 362 | } |
| 363 | |
| 364 | static void |
| 365 | init_sample_table(struct minstrel_sta_info *mi) |
| 366 | { |
| 367 | unsigned int i, col, new_idx; |
| 368 | unsigned int n_srates = mi->n_rates - 1; |
| 369 | u8 rnd[8]; |
| 370 | |
| 371 | mi->sample_column = 0; |
Thomas Huehn | 8f15761 | 2013-03-04 23:30:03 +0100 | [diff] [blame^] | 372 | mi->sample_row = 0; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 373 | memset(mi->sample_table, 0, SAMPLE_COLUMNS * mi->n_rates); |
| 374 | |
| 375 | for (col = 0; col < SAMPLE_COLUMNS; col++) { |
| 376 | for (i = 0; i < n_srates; i++) { |
| 377 | get_random_bytes(rnd, sizeof(rnd)); |
| 378 | new_idx = (i + rnd[i & 7]) % n_srates; |
| 379 | |
| 380 | while (SAMPLE_TBL(mi, new_idx, col) != 0) |
| 381 | new_idx = (new_idx + 1) % n_srates; |
| 382 | |
| 383 | /* Don't sample the slowest rate (i.e. slowest base |
| 384 | * rate). We must presume that the slowest rate works |
| 385 | * fine, or else other management frames will also be |
| 386 | * failing and the link will break */ |
| 387 | SAMPLE_TBL(mi, new_idx, col) = i + 1; |
| 388 | } |
| 389 | } |
| 390 | } |
| 391 | |
| 392 | static void |
| 393 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, |
| 394 | struct ieee80211_sta *sta, void *priv_sta) |
| 395 | { |
| 396 | struct minstrel_sta_info *mi = priv_sta; |
| 397 | struct minstrel_priv *mp = priv; |
Christian Lamparter | d57854b | 2008-12-22 15:35:31 +0100 | [diff] [blame] | 398 | struct ieee80211_rate *ctl_rate; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 399 | unsigned int i, n = 0; |
| 400 | unsigned int t_slot = 9; /* FIXME: get real slot time */ |
| 401 | |
| 402 | mi->lowest_rix = rate_lowest_index(sband, sta); |
Christian Lamparter | d57854b | 2008-12-22 15:35:31 +0100 | [diff] [blame] | 403 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
Michal Kazior | 4ee73f3 | 2012-04-11 08:47:56 +0200 | [diff] [blame] | 404 | mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, |
| 405 | ctl_rate->bitrate, |
Christian Lamparter | d57854b | 2008-12-22 15:35:31 +0100 | [diff] [blame] | 406 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 407 | |
| 408 | for (i = 0; i < sband->n_bitrates; i++) { |
| 409 | struct minstrel_rate *mr = &mi->r[n]; |
| 410 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; |
| 411 | unsigned int tx_time_single; |
| 412 | unsigned int cw = mp->cw_min; |
| 413 | |
| 414 | if (!rate_supported(sta, sband->band, i)) |
| 415 | continue; |
| 416 | n++; |
| 417 | memset(mr, 0, sizeof(*mr)); |
| 418 | |
| 419 | mr->rix = i; |
| 420 | mr->bitrate = sband->bitrates[i].bitrate / 5; |
Michal Kazior | 4ee73f3 | 2012-04-11 08:47:56 +0200 | [diff] [blame] | 421 | calc_rate_durations(sband->band, mr, &sband->bitrates[i]); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 422 | |
| 423 | /* calculate maximum number of retransmissions before |
| 424 | * fallback (based on maximum segment size) */ |
Felix Fietkau | f4a8cd9 | 2008-10-15 19:13:59 +0200 | [diff] [blame] | 425 | mr->sample_limit = -1; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 426 | mr->retry_count = 1; |
| 427 | mr->retry_count_cts = 1; |
| 428 | mr->retry_count_rtscts = 1; |
| 429 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; |
| 430 | do { |
| 431 | /* add one retransmission */ |
| 432 | tx_time_single = mr->ack_time + mr->perfect_tx_time; |
| 433 | |
| 434 | /* contention window */ |
Daniel Halperin | 8fddddf | 2011-05-10 19:00:45 -0700 | [diff] [blame] | 435 | tx_time_single += (t_slot * cw) >> 1; |
| 436 | cw = min((cw << 1) | 1, mp->cw_max); |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 437 | |
| 438 | tx_time += tx_time_single; |
| 439 | tx_time_cts += tx_time_single + mi->sp_ack_dur; |
| 440 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; |
| 441 | if ((tx_time_cts < mp->segment_size) && |
| 442 | (mr->retry_count_cts < mp->max_retry)) |
| 443 | mr->retry_count_cts++; |
| 444 | if ((tx_time_rtscts < mp->segment_size) && |
| 445 | (mr->retry_count_rtscts < mp->max_retry)) |
| 446 | mr->retry_count_rtscts++; |
| 447 | } while ((tx_time < mp->segment_size) && |
| 448 | (++mr->retry_count < mp->max_retry)); |
| 449 | mr->adjusted_retry_count = mr->retry_count; |
| 450 | } |
| 451 | |
| 452 | for (i = n; i < sband->n_bitrates; i++) { |
| 453 | struct minstrel_rate *mr = &mi->r[i]; |
| 454 | mr->rix = -1; |
| 455 | } |
| 456 | |
| 457 | mi->n_rates = n; |
| 458 | mi->stats_update = jiffies; |
| 459 | |
| 460 | init_sample_table(mi); |
| 461 | } |
| 462 | |
| 463 | static void * |
| 464 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) |
| 465 | { |
| 466 | struct ieee80211_supported_band *sband; |
| 467 | struct minstrel_sta_info *mi; |
| 468 | struct minstrel_priv *mp = priv; |
| 469 | struct ieee80211_hw *hw = mp->hw; |
| 470 | int max_rates = 0; |
| 471 | int i; |
| 472 | |
| 473 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); |
| 474 | if (!mi) |
| 475 | return NULL; |
| 476 | |
| 477 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { |
Jiri Slaby | 8e53217 | 2009-05-04 18:04:55 +0200 | [diff] [blame] | 478 | sband = hw->wiphy->bands[i]; |
John W. Linville | 621ad7c | 2009-05-05 15:18:26 -0400 | [diff] [blame] | 479 | if (sband && sband->n_bitrates > max_rates) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 480 | max_rates = sband->n_bitrates; |
| 481 | } |
| 482 | |
| 483 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); |
| 484 | if (!mi->r) |
| 485 | goto error; |
| 486 | |
| 487 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); |
| 488 | if (!mi->sample_table) |
| 489 | goto error1; |
| 490 | |
| 491 | mi->stats_update = jiffies; |
| 492 | return mi; |
| 493 | |
| 494 | error1: |
| 495 | kfree(mi->r); |
| 496 | error: |
| 497 | kfree(mi); |
| 498 | return NULL; |
| 499 | } |
| 500 | |
| 501 | static void |
| 502 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) |
| 503 | { |
| 504 | struct minstrel_sta_info *mi = priv_sta; |
| 505 | |
| 506 | kfree(mi->sample_table); |
| 507 | kfree(mi->r); |
| 508 | kfree(mi); |
| 509 | } |
| 510 | |
Felix Fietkau | a0497f9 | 2013-02-13 10:51:08 +0100 | [diff] [blame] | 511 | static void |
| 512 | minstrel_init_cck_rates(struct minstrel_priv *mp) |
| 513 | { |
| 514 | static const int bitrates[4] = { 10, 20, 55, 110 }; |
| 515 | struct ieee80211_supported_band *sband; |
| 516 | int i, j; |
| 517 | |
| 518 | sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ]; |
| 519 | if (!sband) |
| 520 | return; |
| 521 | |
| 522 | for (i = 0, j = 0; i < sband->n_bitrates; i++) { |
| 523 | struct ieee80211_rate *rate = &sband->bitrates[i]; |
| 524 | |
| 525 | if (rate->flags & IEEE80211_RATE_ERP_G) |
| 526 | continue; |
| 527 | |
| 528 | for (j = 0; j < ARRAY_SIZE(bitrates); j++) { |
| 529 | if (rate->bitrate != bitrates[j]) |
| 530 | continue; |
| 531 | |
| 532 | mp->cck_rates[j] = i; |
| 533 | break; |
| 534 | } |
| 535 | } |
| 536 | } |
| 537 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 538 | static void * |
| 539 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) |
| 540 | { |
| 541 | struct minstrel_priv *mp; |
| 542 | |
| 543 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); |
| 544 | if (!mp) |
| 545 | return NULL; |
| 546 | |
| 547 | /* contention window settings |
| 548 | * Just an approximation. Using the per-queue values would complicate |
| 549 | * the calculations and is probably unnecessary */ |
| 550 | mp->cw_min = 15; |
| 551 | mp->cw_max = 1023; |
| 552 | |
| 553 | /* number of packets (in %) to use for sampling other rates |
| 554 | * sample less often for non-mrr packets, because the overhead |
| 555 | * is much higher than with mrr */ |
| 556 | mp->lookaround_rate = 5; |
| 557 | mp->lookaround_rate_mrr = 10; |
| 558 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 559 | /* maximum time that the hw is allowed to stay in one MRR segment */ |
| 560 | mp->segment_size = 6000; |
| 561 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 562 | if (hw->max_rate_tries > 0) |
| 563 | mp->max_retry = hw->max_rate_tries; |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 564 | else |
| 565 | /* safe default, does not necessarily have to match hw properties */ |
| 566 | mp->max_retry = 7; |
| 567 | |
Johannes Berg | e6a9854 | 2008-10-21 12:40:02 +0200 | [diff] [blame] | 568 | if (hw->max_rates >= 4) |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 569 | mp->has_mrr = true; |
| 570 | |
| 571 | mp->hw = hw; |
| 572 | mp->update_interval = 100; |
| 573 | |
Zefir Kurtisi | 24f7580 | 2011-05-20 20:29:17 +0200 | [diff] [blame] | 574 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 575 | mp->fixed_rate_idx = (u32) -1; |
| 576 | mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", |
| 577 | S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); |
| 578 | #endif |
| 579 | |
Felix Fietkau | a0497f9 | 2013-02-13 10:51:08 +0100 | [diff] [blame] | 580 | minstrel_init_cck_rates(mp); |
| 581 | |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 582 | return mp; |
| 583 | } |
| 584 | |
| 585 | static void |
| 586 | minstrel_free(void *priv) |
| 587 | { |
Zefir Kurtisi | 24f7580 | 2011-05-20 20:29:17 +0200 | [diff] [blame] | 588 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 589 | debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); |
| 590 | #endif |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 591 | kfree(priv); |
| 592 | } |
| 593 | |
Felix Fietkau | eae4475 | 2010-03-01 22:21:40 +0100 | [diff] [blame] | 594 | struct rate_control_ops mac80211_minstrel = { |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 595 | .name = "minstrel", |
| 596 | .tx_status = minstrel_tx_status, |
| 597 | .get_rate = minstrel_get_rate, |
| 598 | .rate_init = minstrel_rate_init, |
Felix Fietkau | cccf129 | 2008-10-05 18:07:45 +0200 | [diff] [blame] | 599 | .alloc = minstrel_alloc, |
| 600 | .free = minstrel_free, |
| 601 | .alloc_sta = minstrel_alloc_sta, |
| 602 | .free_sta = minstrel_free_sta, |
| 603 | #ifdef CONFIG_MAC80211_DEBUGFS |
| 604 | .add_sta_debugfs = minstrel_add_sta_debugfs, |
| 605 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, |
| 606 | #endif |
| 607 | }; |
| 608 | |
| 609 | int __init |
| 610 | rc80211_minstrel_init(void) |
| 611 | { |
| 612 | return ieee80211_rate_control_register(&mac80211_minstrel); |
| 613 | } |
| 614 | |
| 615 | void |
| 616 | rc80211_minstrel_exit(void) |
| 617 | { |
| 618 | ieee80211_rate_control_unregister(&mac80211_minstrel); |
| 619 | } |
| 620 | |