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cccf129f FF |
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> | |
5a0e3ad6 | 53 | #include <linux/slab.h> |
cccf129f FF |
54 | #include <net/mac80211.h> |
55 | #include "rate.h" | |
56 | #include "rc80211_minstrel.h" | |
57 | ||
cccf129f FF |
58 | #define SAMPLE_TBL(_mi, _idx, _col) \ |
59 | _mi->sample_table[(_idx * SAMPLE_COLUMNS) + _col] | |
60 | ||
61 | /* convert mac80211 rate index to local array index */ | |
62 | static inline int | |
63 | rix_to_ndx(struct minstrel_sta_info *mi, int rix) | |
64 | { | |
65 | int i = rix; | |
66 | for (i = rix; i >= 0; i--) | |
67 | if (mi->r[i].rix == rix) | |
68 | break; | |
cccf129f FF |
69 | return i; |
70 | } | |
71 | ||
6a27b2c4 | 72 | /* return current EMWA throughput */ |
50e55a8e | 73 | int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma) |
6a27b2c4 TH |
74 | { |
75 | int usecs; | |
76 | ||
77 | usecs = mr->perfect_tx_time; | |
78 | if (!usecs) | |
79 | usecs = 1000000; | |
80 | ||
81 | /* reset thr. below 10% success */ | |
82 | if (mr->stats.prob_ewma < MINSTREL_FRAC(10, 100)) | |
83 | return 0; | |
50e55a8e TH |
84 | |
85 | if (prob_ewma > MINSTREL_FRAC(90, 100)) | |
86 | return MINSTREL_TRUNC(100000 * (MINSTREL_FRAC(90, 100) / usecs)); | |
6a27b2c4 | 87 | else |
50e55a8e | 88 | return MINSTREL_TRUNC(100000 * (prob_ewma / usecs)); |
6a27b2c4 TH |
89 | } |
90 | ||
2ff2b690 TH |
91 | /* find & sort topmost throughput rates */ |
92 | static inline void | |
93 | minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) | |
94 | { | |
f5eeb5fa AS |
95 | int j; |
96 | struct minstrel_rate_stats *tmp_mrs; | |
50e55a8e | 97 | struct minstrel_rate_stats *cur_mrs = &mi->r[i].stats; |
2ff2b690 | 98 | |
f5eeb5fa | 99 | for (j = MAX_THR_RATES; j > 0; --j) { |
50e55a8e | 100 | tmp_mrs = &mi->r[tp_list[j - 1]].stats; |
f5eeb5fa AS |
101 | if (minstrel_get_tp_avg(&mi->r[i], cur_mrs->prob_ewma) <= |
102 | minstrel_get_tp_avg(&mi->r[tp_list[j - 1]], tmp_mrs->prob_ewma)) | |
103 | break; | |
50e55a8e | 104 | } |
6a27b2c4 | 105 | |
2ff2b690 TH |
106 | if (j < MAX_THR_RATES - 1) |
107 | memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1)); | |
108 | if (j < MAX_THR_RATES) | |
109 | tp_list[j] = i; | |
110 | } | |
111 | ||
06d961a8 FF |
112 | static void |
113 | minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl, | |
114 | int offset, int idx) | |
115 | { | |
116 | struct minstrel_rate *r = &mi->r[idx]; | |
117 | ||
118 | ratetbl->rate[offset].idx = r->rix; | |
119 | ratetbl->rate[offset].count = r->adjusted_retry_count; | |
120 | ratetbl->rate[offset].count_cts = r->retry_count_cts; | |
ca12c0c8 | 121 | ratetbl->rate[offset].count_rts = r->stats.retry_count_rtscts; |
06d961a8 FF |
122 | } |
123 | ||
124 | static void | |
125 | minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
126 | { | |
127 | struct ieee80211_sta_rates *ratetbl; | |
128 | int i = 0; | |
129 | ||
130 | ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC); | |
131 | if (!ratetbl) | |
132 | return; | |
133 | ||
134 | /* Start with max_tp_rate */ | |
135 | minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]); | |
136 | ||
137 | if (mp->hw->max_rates >= 3) { | |
138 | /* At least 3 tx rates supported, use max_tp_rate2 next */ | |
139 | minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]); | |
140 | } | |
141 | ||
142 | if (mp->hw->max_rates >= 2) { | |
143 | /* At least 2 tx rates supported, use max_prob_rate next */ | |
144 | minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate); | |
145 | } | |
146 | ||
147 | /* Use lowest rate last */ | |
148 | ratetbl->rate[i].idx = mi->lowest_rix; | |
149 | ratetbl->rate[i].count = mp->max_retry; | |
150 | ratetbl->rate[i].count_cts = mp->max_retry; | |
151 | ratetbl->rate[i].count_rts = mp->max_retry; | |
152 | ||
153 | rate_control_set_rates(mp->hw, mi->sta, ratetbl); | |
154 | } | |
155 | ||
f62838bc | 156 | /* |
5f919abc | 157 | * Recalculate statistics and counters of a given rate |
f62838bc TH |
158 | */ |
159 | void | |
160 | minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) | |
161 | { | |
1109dc39 FF |
162 | unsigned int cur_prob; |
163 | ||
f62838bc TH |
164 | if (unlikely(mrs->attempts > 0)) { |
165 | mrs->sample_skipped = 0; | |
1109dc39 | 166 | cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); |
5f919abc | 167 | if (unlikely(!mrs->att_hist)) { |
1109dc39 | 168 | mrs->prob_ewma = cur_prob; |
5f919abc TH |
169 | } else { |
170 | /* update exponential weighted moving variance */ | |
4f0bc9c6 FF |
171 | mrs->prob_ewmv = minstrel_ewmv(mrs->prob_ewmv, |
172 | cur_prob, | |
173 | mrs->prob_ewma, | |
174 | EWMA_LEVEL); | |
5f919abc TH |
175 | |
176 | /*update exponential weighted moving avarage */ | |
9134073b | 177 | mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, |
1109dc39 | 178 | cur_prob, |
5f919abc TH |
179 | EWMA_LEVEL); |
180 | } | |
f62838bc TH |
181 | mrs->att_hist += mrs->attempts; |
182 | mrs->succ_hist += mrs->success; | |
183 | } else { | |
184 | mrs->sample_skipped++; | |
185 | } | |
186 | ||
187 | mrs->last_success = mrs->success; | |
188 | mrs->last_attempts = mrs->attempts; | |
189 | mrs->success = 0; | |
190 | mrs->attempts = 0; | |
191 | } | |
192 | ||
cccf129f FF |
193 | static void |
194 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
195 | { | |
2ff2b690 TH |
196 | u8 tmp_tp_rate[MAX_THR_RATES]; |
197 | u8 tmp_prob_rate = 0; | |
6a27b2c4 | 198 | int i, tmp_cur_tp, tmp_prob_tp; |
cccf129f | 199 | |
f359d3fe | 200 | for (i = 0; i < MAX_THR_RATES; i++) |
2ff2b690 TH |
201 | tmp_tp_rate[i] = 0; |
202 | ||
cccf129f FF |
203 | for (i = 0; i < mi->n_rates; i++) { |
204 | struct minstrel_rate *mr = &mi->r[i]; | |
ca12c0c8 | 205 | struct minstrel_rate_stats *mrs = &mi->r[i].stats; |
50e55a8e | 206 | struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; |
cccf129f | 207 | |
5f919abc | 208 | /* Update statistics of success probability per rate */ |
f62838bc | 209 | minstrel_calc_rate_stats(mrs); |
cccf129f FF |
210 | |
211 | /* Sample less often below the 10% chance of success. | |
212 | * Sample less often above the 95% chance of success. */ | |
9134073b TH |
213 | if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || |
214 | mrs->prob_ewma < MINSTREL_FRAC(10, 100)) { | |
ca12c0c8 | 215 | mr->adjusted_retry_count = mrs->retry_count >> 1; |
cccf129f FF |
216 | if (mr->adjusted_retry_count > 2) |
217 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 218 | mr->sample_limit = 4; |
cccf129f | 219 | } else { |
f4a8cd94 | 220 | mr->sample_limit = -1; |
ca12c0c8 | 221 | mr->adjusted_retry_count = mrs->retry_count; |
cccf129f FF |
222 | } |
223 | if (!mr->adjusted_retry_count) | |
224 | mr->adjusted_retry_count = 2; | |
cccf129f | 225 | |
2ff2b690 TH |
226 | minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate); |
227 | ||
228 | /* To determine the most robust rate (max_prob_rate) used at | |
229 | * 3rd mmr stage we distinct between two cases: | |
230 | * (1) if any success probabilitiy >= 95%, out of those rates | |
231 | * choose the maximum throughput rate as max_prob_rate | |
232 | * (2) if all success probabilities < 95%, the rate with | |
d070f913 | 233 | * highest success probability is chosen as max_prob_rate */ |
9134073b | 234 | if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) { |
50e55a8e TH |
235 | tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma); |
236 | tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate], | |
237 | tmp_mrs->prob_ewma); | |
6a27b2c4 | 238 | if (tmp_cur_tp >= tmp_prob_tp) |
2ff2b690 TH |
239 | tmp_prob_rate = i; |
240 | } else { | |
50e55a8e | 241 | if (mrs->prob_ewma >= tmp_mrs->prob_ewma) |
2ff2b690 | 242 | tmp_prob_rate = i; |
cccf129f FF |
243 | } |
244 | } | |
245 | ||
2ff2b690 TH |
246 | /* Assign the new rate set */ |
247 | memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate)); | |
248 | mi->max_prob_rate = tmp_prob_rate; | |
8f157611 | 249 | |
45966aeb LB |
250 | #ifdef CONFIG_MAC80211_DEBUGFS |
251 | /* use fixed index if set */ | |
252 | if (mp->fixed_rate_idx != -1) { | |
253 | mi->max_tp_rate[0] = mp->fixed_rate_idx; | |
254 | mi->max_tp_rate[1] = mp->fixed_rate_idx; | |
255 | mi->max_prob_rate = mp->fixed_rate_idx; | |
256 | } | |
257 | #endif | |
258 | ||
8f157611 | 259 | /* Reset update timer */ |
9134073b | 260 | mi->last_stats_update = jiffies; |
06d961a8 FF |
261 | |
262 | minstrel_update_rates(mp, mi); | |
cccf129f FF |
263 | } |
264 | ||
265 | static void | |
266 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
18fb84d9 | 267 | void *priv_sta, struct ieee80211_tx_status *st) |
cccf129f | 268 | { |
18fb84d9 | 269 | struct ieee80211_tx_info *info = st->info; |
8acbcddb | 270 | struct minstrel_priv *mp = priv; |
cccf129f | 271 | struct minstrel_sta_info *mi = priv_sta; |
e6a9854b JB |
272 | struct ieee80211_tx_rate *ar = info->status.rates; |
273 | int i, ndx; | |
274 | int success; | |
cccf129f | 275 | |
e6a9854b | 276 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 277 | |
e6a9854b JB |
278 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
279 | if (ar[i].idx < 0) | |
cccf129f FF |
280 | break; |
281 | ||
e6a9854b | 282 | ndx = rix_to_ndx(mi, ar[i].idx); |
3938b45c LC |
283 | if (ndx < 0) |
284 | continue; | |
285 | ||
ca12c0c8 | 286 | mi->r[ndx].stats.attempts += ar[i].count; |
cccf129f | 287 | |
bfc32e6a | 288 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
ca12c0c8 | 289 | mi->r[ndx].stats.success += success; |
cccf129f FF |
290 | } |
291 | ||
292 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
ca12c0c8 | 293 | mi->sample_packets++; |
cccf129f FF |
294 | |
295 | if (mi->sample_deferred > 0) | |
296 | mi->sample_deferred--; | |
8acbcddb | 297 | |
9134073b | 298 | if (time_after(jiffies, mi->last_stats_update + |
8acbcddb JB |
299 | (mp->update_interval * HZ) / 1000)) |
300 | minstrel_update_stats(mp, mi); | |
cccf129f FF |
301 | } |
302 | ||
303 | ||
304 | static inline unsigned int | |
305 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
f359d3fe | 306 | struct ieee80211_tx_info *info) |
cccf129f | 307 | { |
8d819a92 | 308 | u8 retry = mr->adjusted_retry_count; |
cccf129f | 309 | |
991fec09 | 310 | if (info->control.use_rts) |
8d819a92 | 311 | retry = max_t(u8, 2, min(mr->stats.retry_count_rtscts, retry)); |
991fec09 | 312 | else if (info->control.use_cts_prot) |
8d819a92 | 313 | retry = max_t(u8, 2, min(mr->retry_count_cts, retry)); |
cccf129f FF |
314 | return retry; |
315 | } | |
316 | ||
317 | ||
318 | static int | |
319 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
320 | { | |
321 | unsigned int sample_ndx; | |
8f157611 TH |
322 | sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); |
323 | mi->sample_row++; | |
f744bf81 | 324 | if ((int) mi->sample_row >= mi->n_rates) { |
8f157611 | 325 | mi->sample_row = 0; |
cccf129f FF |
326 | mi->sample_column++; |
327 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
328 | mi->sample_column = 0; | |
329 | } | |
330 | return sample_ndx; | |
331 | } | |
332 | ||
2df78167 | 333 | static void |
e6a9854b JB |
334 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
335 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 336 | { |
e6a9854b | 337 | struct sk_buff *skb = txrc->skb; |
cccf129f FF |
338 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
339 | struct minstrel_sta_info *mi = priv_sta; | |
340 | struct minstrel_priv *mp = priv; | |
06d961a8 FF |
341 | struct ieee80211_tx_rate *rate = &info->control.rates[0]; |
342 | struct minstrel_rate *msr, *mr; | |
343 | unsigned int ndx; | |
8f157611 | 344 | bool mrr_capable; |
5c9fc93b | 345 | bool prev_sample; |
06d961a8 | 346 | int delta; |
8f157611 | 347 | int sampling_ratio; |
cccf129f | 348 | |
8f157611 | 349 | /* management/no-ack frames do not use rate control */ |
4c6d4f5c | 350 | if (rate_control_send_low(sta, priv_sta, txrc)) |
cccf129f | 351 | return; |
cccf129f | 352 | |
8f157611 TH |
353 | /* check multi-rate-retry capabilities & adjust lookaround_rate */ |
354 | mrr_capable = mp->has_mrr && | |
355 | !txrc->rts && | |
356 | !txrc->bss_conf->use_cts_prot; | |
357 | if (mrr_capable) | |
358 | sampling_ratio = mp->lookaround_rate_mrr; | |
359 | else | |
360 | sampling_ratio = mp->lookaround_rate; | |
cccf129f | 361 | |
8f157611 | 362 | /* increase sum packet counter */ |
ca12c0c8 | 363 | mi->total_packets++; |
8f157611 | 364 | |
45966aeb LB |
365 | #ifdef CONFIG_MAC80211_DEBUGFS |
366 | if (mp->fixed_rate_idx != -1) | |
367 | return; | |
368 | #endif | |
369 | ||
38252e9e TH |
370 | /* Don't use EAPOL frames for sampling on non-mrr hw */ |
371 | if (mp->hw->max_rates == 1 && | |
372 | (info->control.flags & IEEE80211_TX_CTRL_PORT_CTRL_PROTO)) | |
373 | return; | |
374 | ||
ca12c0c8 TH |
375 | delta = (mi->total_packets * sampling_ratio / 100) - |
376 | (mi->sample_packets + mi->sample_deferred / 2); | |
cccf129f | 377 | |
06d961a8 | 378 | /* delta < 0: no sampling required */ |
5c9fc93b | 379 | prev_sample = mi->prev_sample; |
06d961a8 FF |
380 | mi->prev_sample = false; |
381 | if (delta < 0 || (!mrr_capable && prev_sample)) | |
382 | return; | |
cccf129f | 383 | |
ca12c0c8 | 384 | if (mi->total_packets >= 10000) { |
06d961a8 | 385 | mi->sample_deferred = 0; |
ca12c0c8 TH |
386 | mi->sample_packets = 0; |
387 | mi->total_packets = 0; | |
06d961a8 FF |
388 | } else if (delta > mi->n_rates * 2) { |
389 | /* With multi-rate retry, not every planned sample | |
390 | * attempt actually gets used, due to the way the retry | |
391 | * chain is set up - [max_tp,sample,prob,lowest] for | |
392 | * sample_rate < max_tp. | |
393 | * | |
394 | * If there's too much sampling backlog and the link | |
395 | * starts getting worse, minstrel would start bursting | |
396 | * out lots of sampling frames, which would result | |
397 | * in a large throughput loss. */ | |
ca12c0c8 | 398 | mi->sample_packets += (delta - mi->n_rates * 2); |
06d961a8 FF |
399 | } |
400 | ||
401 | /* get next random rate sample */ | |
402 | ndx = minstrel_get_next_sample(mi); | |
403 | msr = &mi->r[ndx]; | |
404 | mr = &mi->r[mi->max_tp_rate[0]]; | |
405 | ||
406 | /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) | |
407 | * rate sampling method should be used. | |
408 | * Respect such rates that are not sampled for 20 interations. | |
409 | */ | |
410 | if (mrr_capable && | |
411 | msr->perfect_tx_time > mr->perfect_tx_time && | |
ca12c0c8 | 412 | msr->stats.sample_skipped < 20) { |
06d961a8 FF |
413 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark |
414 | * packets that have the sampling rate deferred to the | |
415 | * second MRR stage. Increase the sample counter only | |
416 | * if the deferred sample rate was actually used. | |
417 | * Use the sample_deferred counter to make sure that | |
418 | * the sampling is not done in large bursts */ | |
419 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
420 | rate++; | |
421 | mi->sample_deferred++; | |
422 | } else { | |
17dce158 | 423 | if (!msr->sample_limit) |
06d961a8 FF |
424 | return; |
425 | ||
ca12c0c8 | 426 | mi->sample_packets++; |
06d961a8 FF |
427 | if (msr->sample_limit > 0) |
428 | msr->sample_limit--; | |
cccf129f | 429 | } |
f4a8cd94 FF |
430 | |
431 | /* If we're not using MRR and the sampling rate already | |
432 | * has a probability of >95%, we shouldn't be attempting | |
433 | * to use it, as this only wastes precious airtime */ | |
06d961a8 | 434 | if (!mrr_capable && |
9134073b | 435 | (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100))) |
cccf129f | 436 | return; |
cccf129f | 437 | |
06d961a8 | 438 | mi->prev_sample = true; |
8f157611 | 439 | |
06d961a8 FF |
440 | rate->idx = mi->r[ndx].rix; |
441 | rate->count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f FF |
442 | } |
443 | ||
444 | ||
445 | static void | |
57fbcce3 | 446 | calc_rate_durations(enum nl80211_band band, |
4ee73f33 | 447 | struct minstrel_rate *d, |
438b61b7 SW |
448 | struct ieee80211_rate *rate, |
449 | struct cfg80211_chan_def *chandef) | |
cccf129f FF |
450 | { |
451 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
438b61b7 | 452 | int shift = ieee80211_chandef_get_shift(chandef); |
cccf129f | 453 | |
4ee73f33 | 454 | d->perfect_tx_time = ieee80211_frame_duration(band, 1200, |
438b61b7 SW |
455 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
456 | shift); | |
4ee73f33 | 457 | d->ack_time = ieee80211_frame_duration(band, 10, |
438b61b7 SW |
458 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
459 | shift); | |
cccf129f FF |
460 | } |
461 | ||
462 | static void | |
463 | init_sample_table(struct minstrel_sta_info *mi) | |
464 | { | |
465 | unsigned int i, col, new_idx; | |
cccf129f FF |
466 | u8 rnd[8]; |
467 | ||
468 | mi->sample_column = 0; | |
8f157611 | 469 | mi->sample_row = 0; |
f744bf81 | 470 | memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); |
cccf129f FF |
471 | |
472 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
f7d8ad81 | 473 | prandom_bytes(rnd, sizeof(rnd)); |
f744bf81 | 474 | for (i = 0; i < mi->n_rates; i++) { |
f744bf81 | 475 | new_idx = (i + rnd[i & 7]) % mi->n_rates; |
f744bf81 TH |
476 | while (SAMPLE_TBL(mi, new_idx, col) != 0xff) |
477 | new_idx = (new_idx + 1) % mi->n_rates; | |
cccf129f | 478 | |
f744bf81 | 479 | SAMPLE_TBL(mi, new_idx, col) = i; |
cccf129f FF |
480 | } |
481 | } | |
482 | } | |
483 | ||
484 | static void | |
485 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
3de805cf SW |
486 | struct cfg80211_chan_def *chandef, |
487 | struct ieee80211_sta *sta, void *priv_sta) | |
cccf129f FF |
488 | { |
489 | struct minstrel_sta_info *mi = priv_sta; | |
490 | struct minstrel_priv *mp = priv; | |
d57854bb | 491 | struct ieee80211_rate *ctl_rate; |
cccf129f FF |
492 | unsigned int i, n = 0; |
493 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
438b61b7 | 494 | u32 rate_flags; |
cccf129f | 495 | |
06d961a8 | 496 | mi->sta = sta; |
cccf129f | 497 | mi->lowest_rix = rate_lowest_index(sband, sta); |
d57854bb | 498 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
4ee73f33 MK |
499 | mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, |
500 | ctl_rate->bitrate, | |
438b61b7 SW |
501 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1, |
502 | ieee80211_chandef_get_shift(chandef)); | |
cccf129f | 503 | |
438b61b7 | 504 | rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
06d961a8 FF |
505 | memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate)); |
506 | mi->max_prob_rate = 0; | |
507 | ||
cccf129f FF |
508 | for (i = 0; i < sband->n_bitrates; i++) { |
509 | struct minstrel_rate *mr = &mi->r[n]; | |
ca12c0c8 | 510 | struct minstrel_rate_stats *mrs = &mi->r[n].stats; |
cccf129f FF |
511 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; |
512 | unsigned int tx_time_single; | |
513 | unsigned int cw = mp->cw_min; | |
438b61b7 | 514 | int shift; |
cccf129f FF |
515 | |
516 | if (!rate_supported(sta, sband->band, i)) | |
517 | continue; | |
438b61b7 SW |
518 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
519 | continue; | |
520 | ||
cccf129f FF |
521 | n++; |
522 | memset(mr, 0, sizeof(*mr)); | |
ca12c0c8 | 523 | memset(mrs, 0, sizeof(*mrs)); |
cccf129f FF |
524 | |
525 | mr->rix = i; | |
438b61b7 SW |
526 | shift = ieee80211_chandef_get_shift(chandef); |
527 | mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate, | |
528 | (1 << shift) * 5); | |
529 | calc_rate_durations(sband->band, mr, &sband->bitrates[i], | |
530 | chandef); | |
cccf129f FF |
531 | |
532 | /* calculate maximum number of retransmissions before | |
533 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 534 | mr->sample_limit = -1; |
ca12c0c8 | 535 | mrs->retry_count = 1; |
cccf129f | 536 | mr->retry_count_cts = 1; |
ca12c0c8 | 537 | mrs->retry_count_rtscts = 1; |
cccf129f FF |
538 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; |
539 | do { | |
540 | /* add one retransmission */ | |
541 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
542 | ||
543 | /* contention window */ | |
8fddddff DH |
544 | tx_time_single += (t_slot * cw) >> 1; |
545 | cw = min((cw << 1) | 1, mp->cw_max); | |
cccf129f FF |
546 | |
547 | tx_time += tx_time_single; | |
548 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
549 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
550 | if ((tx_time_cts < mp->segment_size) && | |
551 | (mr->retry_count_cts < mp->max_retry)) | |
552 | mr->retry_count_cts++; | |
553 | if ((tx_time_rtscts < mp->segment_size) && | |
ca12c0c8 TH |
554 | (mrs->retry_count_rtscts < mp->max_retry)) |
555 | mrs->retry_count_rtscts++; | |
cccf129f | 556 | } while ((tx_time < mp->segment_size) && |
ca12c0c8 TH |
557 | (++mr->stats.retry_count < mp->max_retry)); |
558 | mr->adjusted_retry_count = mrs->retry_count; | |
991fec09 | 559 | if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) |
ca12c0c8 | 560 | mr->retry_count_cts = mrs->retry_count; |
cccf129f FF |
561 | } |
562 | ||
563 | for (i = n; i < sband->n_bitrates; i++) { | |
564 | struct minstrel_rate *mr = &mi->r[i]; | |
565 | mr->rix = -1; | |
566 | } | |
567 | ||
568 | mi->n_rates = n; | |
9134073b | 569 | mi->last_stats_update = jiffies; |
cccf129f FF |
570 | |
571 | init_sample_table(mi); | |
06d961a8 | 572 | minstrel_update_rates(mp, mi); |
cccf129f FF |
573 | } |
574 | ||
575 | static void * | |
576 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
577 | { | |
578 | struct ieee80211_supported_band *sband; | |
579 | struct minstrel_sta_info *mi; | |
580 | struct minstrel_priv *mp = priv; | |
581 | struct ieee80211_hw *hw = mp->hw; | |
582 | int max_rates = 0; | |
583 | int i; | |
584 | ||
585 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
586 | if (!mi) | |
587 | return NULL; | |
588 | ||
57fbcce3 | 589 | for (i = 0; i < NUM_NL80211_BANDS; i++) { |
8e532175 | 590 | sband = hw->wiphy->bands[i]; |
621ad7c9 | 591 | if (sband && sband->n_bitrates > max_rates) |
cccf129f FF |
592 | max_rates = sband->n_bitrates; |
593 | } | |
594 | ||
595 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
596 | if (!mi->r) | |
597 | goto error; | |
598 | ||
599 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
600 | if (!mi->sample_table) | |
601 | goto error1; | |
602 | ||
9134073b | 603 | mi->last_stats_update = jiffies; |
cccf129f FF |
604 | return mi; |
605 | ||
606 | error1: | |
607 | kfree(mi->r); | |
608 | error: | |
609 | kfree(mi); | |
610 | return NULL; | |
611 | } | |
612 | ||
613 | static void | |
614 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
615 | { | |
616 | struct minstrel_sta_info *mi = priv_sta; | |
617 | ||
618 | kfree(mi->sample_table); | |
619 | kfree(mi->r); | |
620 | kfree(mi); | |
621 | } | |
622 | ||
a0497f9f FF |
623 | static void |
624 | minstrel_init_cck_rates(struct minstrel_priv *mp) | |
625 | { | |
626 | static const int bitrates[4] = { 10, 20, 55, 110 }; | |
627 | struct ieee80211_supported_band *sband; | |
438b61b7 | 628 | u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
a0497f9f FF |
629 | int i, j; |
630 | ||
57fbcce3 | 631 | sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; |
a0497f9f FF |
632 | if (!sband) |
633 | return; | |
634 | ||
635 | for (i = 0, j = 0; i < sband->n_bitrates; i++) { | |
636 | struct ieee80211_rate *rate = &sband->bitrates[i]; | |
637 | ||
638 | if (rate->flags & IEEE80211_RATE_ERP_G) | |
639 | continue; | |
640 | ||
438b61b7 SW |
641 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
642 | continue; | |
643 | ||
a0497f9f FF |
644 | for (j = 0; j < ARRAY_SIZE(bitrates); j++) { |
645 | if (rate->bitrate != bitrates[j]) | |
646 | continue; | |
647 | ||
648 | mp->cck_rates[j] = i; | |
649 | break; | |
650 | } | |
651 | } | |
652 | } | |
653 | ||
cccf129f FF |
654 | static void * |
655 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
656 | { | |
657 | struct minstrel_priv *mp; | |
658 | ||
659 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
660 | if (!mp) | |
661 | return NULL; | |
662 | ||
663 | /* contention window settings | |
664 | * Just an approximation. Using the per-queue values would complicate | |
665 | * the calculations and is probably unnecessary */ | |
666 | mp->cw_min = 15; | |
667 | mp->cw_max = 1023; | |
668 | ||
669 | /* number of packets (in %) to use for sampling other rates | |
670 | * sample less often for non-mrr packets, because the overhead | |
671 | * is much higher than with mrr */ | |
672 | mp->lookaround_rate = 5; | |
673 | mp->lookaround_rate_mrr = 10; | |
674 | ||
cccf129f FF |
675 | /* maximum time that the hw is allowed to stay in one MRR segment */ |
676 | mp->segment_size = 6000; | |
677 | ||
e6a9854b JB |
678 | if (hw->max_rate_tries > 0) |
679 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
680 | else |
681 | /* safe default, does not necessarily have to match hw properties */ | |
682 | mp->max_retry = 7; | |
683 | ||
e6a9854b | 684 | if (hw->max_rates >= 4) |
cccf129f FF |
685 | mp->has_mrr = true; |
686 | ||
687 | mp->hw = hw; | |
688 | mp->update_interval = 100; | |
689 | ||
24f7580e ZK |
690 | #ifdef CONFIG_MAC80211_DEBUGFS |
691 | mp->fixed_rate_idx = (u32) -1; | |
692 | mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", | |
693 | S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); | |
694 | #endif | |
695 | ||
a0497f9f FF |
696 | minstrel_init_cck_rates(mp); |
697 | ||
cccf129f FF |
698 | return mp; |
699 | } | |
700 | ||
701 | static void | |
702 | minstrel_free(void *priv) | |
703 | { | |
24f7580e ZK |
704 | #ifdef CONFIG_MAC80211_DEBUGFS |
705 | debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); | |
706 | #endif | |
cccf129f FF |
707 | kfree(priv); |
708 | } | |
709 | ||
cca674d4 AQ |
710 | static u32 minstrel_get_expected_throughput(void *priv_sta) |
711 | { | |
712 | struct minstrel_sta_info *mi = priv_sta; | |
50e55a8e | 713 | struct minstrel_rate_stats *tmp_mrs; |
cca674d4 | 714 | int idx = mi->max_tp_rate[0]; |
6a27b2c4 | 715 | int tmp_cur_tp; |
cca674d4 AQ |
716 | |
717 | /* convert pkt per sec in kbps (1200 is the average pkt size used for | |
718 | * computing cur_tp | |
719 | */ | |
50e55a8e | 720 | tmp_mrs = &mi->r[idx].stats; |
212c5a5e | 721 | tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma) * 10; |
6a27b2c4 TH |
722 | tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; |
723 | ||
724 | return tmp_cur_tp; | |
cca674d4 AQ |
725 | } |
726 | ||
631ad703 | 727 | const struct rate_control_ops mac80211_minstrel = { |
cccf129f | 728 | .name = "minstrel", |
18fb84d9 | 729 | .tx_status_ext = minstrel_tx_status, |
cccf129f FF |
730 | .get_rate = minstrel_get_rate, |
731 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
732 | .alloc = minstrel_alloc, |
733 | .free = minstrel_free, | |
734 | .alloc_sta = minstrel_alloc_sta, | |
735 | .free_sta = minstrel_free_sta, | |
736 | #ifdef CONFIG_MAC80211_DEBUGFS | |
737 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
738 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
739 | #endif | |
cca674d4 | 740 | .get_expected_throughput = minstrel_get_expected_throughput, |
cccf129f FF |
741 | }; |
742 | ||
743 | int __init | |
744 | rc80211_minstrel_init(void) | |
745 | { | |
746 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
747 | } | |
748 | ||
749 | void | |
750 | rc80211_minstrel_exit(void) | |
751 | { | |
752 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
753 | } | |
754 |