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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 | { | |
162 | if (unlikely(mrs->attempts > 0)) { | |
163 | mrs->sample_skipped = 0; | |
164 | mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); | |
5f919abc | 165 | if (unlikely(!mrs->att_hist)) { |
9134073b | 166 | mrs->prob_ewma = mrs->cur_prob; |
5f919abc TH |
167 | } else { |
168 | /* update exponential weighted moving variance */ | |
169 | mrs->prob_ewmsd = minstrel_ewmsd(mrs->prob_ewmsd, | |
170 | mrs->cur_prob, | |
171 | mrs->prob_ewma, | |
172 | EWMA_LEVEL); | |
173 | ||
174 | /*update exponential weighted moving avarage */ | |
9134073b | 175 | mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, |
5f919abc TH |
176 | mrs->cur_prob, |
177 | EWMA_LEVEL); | |
178 | } | |
f62838bc TH |
179 | mrs->att_hist += mrs->attempts; |
180 | mrs->succ_hist += mrs->success; | |
181 | } else { | |
182 | mrs->sample_skipped++; | |
183 | } | |
184 | ||
185 | mrs->last_success = mrs->success; | |
186 | mrs->last_attempts = mrs->attempts; | |
187 | mrs->success = 0; | |
188 | mrs->attempts = 0; | |
189 | } | |
190 | ||
cccf129f FF |
191 | static void |
192 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
193 | { | |
2ff2b690 TH |
194 | u8 tmp_tp_rate[MAX_THR_RATES]; |
195 | u8 tmp_prob_rate = 0; | |
6a27b2c4 | 196 | int i, tmp_cur_tp, tmp_prob_tp; |
cccf129f | 197 | |
f359d3fe | 198 | for (i = 0; i < MAX_THR_RATES; i++) |
2ff2b690 TH |
199 | tmp_tp_rate[i] = 0; |
200 | ||
cccf129f FF |
201 | for (i = 0; i < mi->n_rates; i++) { |
202 | struct minstrel_rate *mr = &mi->r[i]; | |
ca12c0c8 | 203 | struct minstrel_rate_stats *mrs = &mi->r[i].stats; |
50e55a8e | 204 | struct minstrel_rate_stats *tmp_mrs = &mi->r[tmp_prob_rate].stats; |
cccf129f | 205 | |
5f919abc | 206 | /* Update statistics of success probability per rate */ |
f62838bc | 207 | minstrel_calc_rate_stats(mrs); |
cccf129f FF |
208 | |
209 | /* Sample less often below the 10% chance of success. | |
210 | * Sample less often above the 95% chance of success. */ | |
9134073b TH |
211 | if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || |
212 | mrs->prob_ewma < MINSTREL_FRAC(10, 100)) { | |
ca12c0c8 | 213 | mr->adjusted_retry_count = mrs->retry_count >> 1; |
cccf129f FF |
214 | if (mr->adjusted_retry_count > 2) |
215 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 216 | mr->sample_limit = 4; |
cccf129f | 217 | } else { |
f4a8cd94 | 218 | mr->sample_limit = -1; |
ca12c0c8 | 219 | mr->adjusted_retry_count = mrs->retry_count; |
cccf129f FF |
220 | } |
221 | if (!mr->adjusted_retry_count) | |
222 | mr->adjusted_retry_count = 2; | |
cccf129f | 223 | |
2ff2b690 TH |
224 | minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate); |
225 | ||
226 | /* To determine the most robust rate (max_prob_rate) used at | |
227 | * 3rd mmr stage we distinct between two cases: | |
228 | * (1) if any success probabilitiy >= 95%, out of those rates | |
229 | * choose the maximum throughput rate as max_prob_rate | |
230 | * (2) if all success probabilities < 95%, the rate with | |
d070f913 | 231 | * highest success probability is chosen as max_prob_rate */ |
9134073b | 232 | if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) { |
50e55a8e TH |
233 | tmp_cur_tp = minstrel_get_tp_avg(mr, mrs->prob_ewma); |
234 | tmp_prob_tp = minstrel_get_tp_avg(&mi->r[tmp_prob_rate], | |
235 | tmp_mrs->prob_ewma); | |
6a27b2c4 | 236 | if (tmp_cur_tp >= tmp_prob_tp) |
2ff2b690 TH |
237 | tmp_prob_rate = i; |
238 | } else { | |
50e55a8e | 239 | if (mrs->prob_ewma >= tmp_mrs->prob_ewma) |
2ff2b690 | 240 | tmp_prob_rate = i; |
cccf129f FF |
241 | } |
242 | } | |
243 | ||
2ff2b690 TH |
244 | /* Assign the new rate set */ |
245 | memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate)); | |
246 | mi->max_prob_rate = tmp_prob_rate; | |
8f157611 | 247 | |
45966aeb LB |
248 | #ifdef CONFIG_MAC80211_DEBUGFS |
249 | /* use fixed index if set */ | |
250 | if (mp->fixed_rate_idx != -1) { | |
251 | mi->max_tp_rate[0] = mp->fixed_rate_idx; | |
252 | mi->max_tp_rate[1] = mp->fixed_rate_idx; | |
253 | mi->max_prob_rate = mp->fixed_rate_idx; | |
254 | } | |
255 | #endif | |
256 | ||
8f157611 | 257 | /* Reset update timer */ |
9134073b | 258 | mi->last_stats_update = jiffies; |
06d961a8 FF |
259 | |
260 | minstrel_update_rates(mp, mi); | |
cccf129f FF |
261 | } |
262 | ||
263 | static void | |
264 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
f359d3fe | 265 | struct ieee80211_sta *sta, void *priv_sta, |
fb7acfb8 | 266 | struct ieee80211_tx_info *info) |
cccf129f | 267 | { |
8acbcddb | 268 | struct minstrel_priv *mp = priv; |
cccf129f | 269 | struct minstrel_sta_info *mi = priv_sta; |
e6a9854b JB |
270 | struct ieee80211_tx_rate *ar = info->status.rates; |
271 | int i, ndx; | |
272 | int success; | |
cccf129f | 273 | |
e6a9854b | 274 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 275 | |
e6a9854b JB |
276 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
277 | if (ar[i].idx < 0) | |
cccf129f FF |
278 | break; |
279 | ||
e6a9854b | 280 | ndx = rix_to_ndx(mi, ar[i].idx); |
3938b45c LC |
281 | if (ndx < 0) |
282 | continue; | |
283 | ||
ca12c0c8 | 284 | mi->r[ndx].stats.attempts += ar[i].count; |
cccf129f | 285 | |
bfc32e6a | 286 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
ca12c0c8 | 287 | mi->r[ndx].stats.success += success; |
cccf129f FF |
288 | } |
289 | ||
290 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
ca12c0c8 | 291 | mi->sample_packets++; |
cccf129f FF |
292 | |
293 | if (mi->sample_deferred > 0) | |
294 | mi->sample_deferred--; | |
8acbcddb | 295 | |
9134073b | 296 | if (time_after(jiffies, mi->last_stats_update + |
8acbcddb JB |
297 | (mp->update_interval * HZ) / 1000)) |
298 | minstrel_update_stats(mp, mi); | |
cccf129f FF |
299 | } |
300 | ||
301 | ||
302 | static inline unsigned int | |
303 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
f359d3fe | 304 | struct ieee80211_tx_info *info) |
cccf129f | 305 | { |
8d819a92 | 306 | u8 retry = mr->adjusted_retry_count; |
cccf129f | 307 | |
991fec09 | 308 | if (info->control.use_rts) |
8d819a92 | 309 | retry = max_t(u8, 2, min(mr->stats.retry_count_rtscts, retry)); |
991fec09 | 310 | else if (info->control.use_cts_prot) |
8d819a92 | 311 | retry = max_t(u8, 2, min(mr->retry_count_cts, retry)); |
cccf129f FF |
312 | return retry; |
313 | } | |
314 | ||
315 | ||
316 | static int | |
317 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
318 | { | |
319 | unsigned int sample_ndx; | |
8f157611 TH |
320 | sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); |
321 | mi->sample_row++; | |
f744bf81 | 322 | if ((int) mi->sample_row >= mi->n_rates) { |
8f157611 | 323 | mi->sample_row = 0; |
cccf129f FF |
324 | mi->sample_column++; |
325 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
326 | mi->sample_column = 0; | |
327 | } | |
328 | return sample_ndx; | |
329 | } | |
330 | ||
2df78167 | 331 | static void |
e6a9854b JB |
332 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
333 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 334 | { |
e6a9854b | 335 | struct sk_buff *skb = txrc->skb; |
cccf129f FF |
336 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
337 | struct minstrel_sta_info *mi = priv_sta; | |
338 | struct minstrel_priv *mp = priv; | |
06d961a8 FF |
339 | struct ieee80211_tx_rate *rate = &info->control.rates[0]; |
340 | struct minstrel_rate *msr, *mr; | |
341 | unsigned int ndx; | |
8f157611 | 342 | bool mrr_capable; |
5c9fc93b | 343 | bool prev_sample; |
06d961a8 | 344 | int delta; |
8f157611 | 345 | int sampling_ratio; |
cccf129f | 346 | |
8f157611 | 347 | /* management/no-ack frames do not use rate control */ |
4c6d4f5c | 348 | if (rate_control_send_low(sta, priv_sta, txrc)) |
cccf129f | 349 | return; |
cccf129f | 350 | |
8f157611 TH |
351 | /* check multi-rate-retry capabilities & adjust lookaround_rate */ |
352 | mrr_capable = mp->has_mrr && | |
353 | !txrc->rts && | |
354 | !txrc->bss_conf->use_cts_prot; | |
355 | if (mrr_capable) | |
356 | sampling_ratio = mp->lookaround_rate_mrr; | |
357 | else | |
358 | sampling_ratio = mp->lookaround_rate; | |
cccf129f | 359 | |
8f157611 | 360 | /* increase sum packet counter */ |
ca12c0c8 | 361 | mi->total_packets++; |
8f157611 | 362 | |
45966aeb LB |
363 | #ifdef CONFIG_MAC80211_DEBUGFS |
364 | if (mp->fixed_rate_idx != -1) | |
365 | return; | |
366 | #endif | |
367 | ||
ca12c0c8 TH |
368 | delta = (mi->total_packets * sampling_ratio / 100) - |
369 | (mi->sample_packets + mi->sample_deferred / 2); | |
cccf129f | 370 | |
06d961a8 | 371 | /* delta < 0: no sampling required */ |
5c9fc93b | 372 | prev_sample = mi->prev_sample; |
06d961a8 FF |
373 | mi->prev_sample = false; |
374 | if (delta < 0 || (!mrr_capable && prev_sample)) | |
375 | return; | |
cccf129f | 376 | |
ca12c0c8 | 377 | if (mi->total_packets >= 10000) { |
06d961a8 | 378 | mi->sample_deferred = 0; |
ca12c0c8 TH |
379 | mi->sample_packets = 0; |
380 | mi->total_packets = 0; | |
06d961a8 FF |
381 | } else if (delta > mi->n_rates * 2) { |
382 | /* With multi-rate retry, not every planned sample | |
383 | * attempt actually gets used, due to the way the retry | |
384 | * chain is set up - [max_tp,sample,prob,lowest] for | |
385 | * sample_rate < max_tp. | |
386 | * | |
387 | * If there's too much sampling backlog and the link | |
388 | * starts getting worse, minstrel would start bursting | |
389 | * out lots of sampling frames, which would result | |
390 | * in a large throughput loss. */ | |
ca12c0c8 | 391 | mi->sample_packets += (delta - mi->n_rates * 2); |
06d961a8 FF |
392 | } |
393 | ||
394 | /* get next random rate sample */ | |
395 | ndx = minstrel_get_next_sample(mi); | |
396 | msr = &mi->r[ndx]; | |
397 | mr = &mi->r[mi->max_tp_rate[0]]; | |
398 | ||
399 | /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) | |
400 | * rate sampling method should be used. | |
401 | * Respect such rates that are not sampled for 20 interations. | |
402 | */ | |
403 | if (mrr_capable && | |
404 | msr->perfect_tx_time > mr->perfect_tx_time && | |
ca12c0c8 | 405 | msr->stats.sample_skipped < 20) { |
06d961a8 FF |
406 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark |
407 | * packets that have the sampling rate deferred to the | |
408 | * second MRR stage. Increase the sample counter only | |
409 | * if the deferred sample rate was actually used. | |
410 | * Use the sample_deferred counter to make sure that | |
411 | * the sampling is not done in large bursts */ | |
412 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
413 | rate++; | |
414 | mi->sample_deferred++; | |
415 | } else { | |
17dce158 | 416 | if (!msr->sample_limit) |
06d961a8 FF |
417 | return; |
418 | ||
ca12c0c8 | 419 | mi->sample_packets++; |
06d961a8 FF |
420 | if (msr->sample_limit > 0) |
421 | msr->sample_limit--; | |
cccf129f | 422 | } |
f4a8cd94 FF |
423 | |
424 | /* If we're not using MRR and the sampling rate already | |
425 | * has a probability of >95%, we shouldn't be attempting | |
426 | * to use it, as this only wastes precious airtime */ | |
06d961a8 | 427 | if (!mrr_capable && |
9134073b | 428 | (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100))) |
cccf129f | 429 | return; |
cccf129f | 430 | |
06d961a8 | 431 | mi->prev_sample = true; |
8f157611 | 432 | |
06d961a8 FF |
433 | rate->idx = mi->r[ndx].rix; |
434 | rate->count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f FF |
435 | } |
436 | ||
437 | ||
438 | static void | |
57fbcce3 | 439 | calc_rate_durations(enum nl80211_band band, |
4ee73f33 | 440 | struct minstrel_rate *d, |
438b61b7 SW |
441 | struct ieee80211_rate *rate, |
442 | struct cfg80211_chan_def *chandef) | |
cccf129f FF |
443 | { |
444 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
438b61b7 | 445 | int shift = ieee80211_chandef_get_shift(chandef); |
cccf129f | 446 | |
4ee73f33 | 447 | d->perfect_tx_time = ieee80211_frame_duration(band, 1200, |
438b61b7 SW |
448 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
449 | shift); | |
4ee73f33 | 450 | d->ack_time = ieee80211_frame_duration(band, 10, |
438b61b7 SW |
451 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
452 | shift); | |
cccf129f FF |
453 | } |
454 | ||
455 | static void | |
456 | init_sample_table(struct minstrel_sta_info *mi) | |
457 | { | |
458 | unsigned int i, col, new_idx; | |
cccf129f FF |
459 | u8 rnd[8]; |
460 | ||
461 | mi->sample_column = 0; | |
8f157611 | 462 | mi->sample_row = 0; |
f744bf81 | 463 | memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); |
cccf129f FF |
464 | |
465 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
f7d8ad81 | 466 | prandom_bytes(rnd, sizeof(rnd)); |
f744bf81 | 467 | for (i = 0; i < mi->n_rates; i++) { |
f744bf81 | 468 | new_idx = (i + rnd[i & 7]) % mi->n_rates; |
f744bf81 TH |
469 | while (SAMPLE_TBL(mi, new_idx, col) != 0xff) |
470 | new_idx = (new_idx + 1) % mi->n_rates; | |
cccf129f | 471 | |
f744bf81 | 472 | SAMPLE_TBL(mi, new_idx, col) = i; |
cccf129f FF |
473 | } |
474 | } | |
475 | } | |
476 | ||
477 | static void | |
478 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
3de805cf SW |
479 | struct cfg80211_chan_def *chandef, |
480 | struct ieee80211_sta *sta, void *priv_sta) | |
cccf129f FF |
481 | { |
482 | struct minstrel_sta_info *mi = priv_sta; | |
483 | struct minstrel_priv *mp = priv; | |
d57854bb | 484 | struct ieee80211_rate *ctl_rate; |
cccf129f FF |
485 | unsigned int i, n = 0; |
486 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
438b61b7 | 487 | u32 rate_flags; |
cccf129f | 488 | |
06d961a8 | 489 | mi->sta = sta; |
cccf129f | 490 | mi->lowest_rix = rate_lowest_index(sband, sta); |
d57854bb | 491 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
4ee73f33 MK |
492 | mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, |
493 | ctl_rate->bitrate, | |
438b61b7 SW |
494 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1, |
495 | ieee80211_chandef_get_shift(chandef)); | |
cccf129f | 496 | |
438b61b7 | 497 | rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
06d961a8 FF |
498 | memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate)); |
499 | mi->max_prob_rate = 0; | |
500 | ||
cccf129f FF |
501 | for (i = 0; i < sband->n_bitrates; i++) { |
502 | struct minstrel_rate *mr = &mi->r[n]; | |
ca12c0c8 | 503 | struct minstrel_rate_stats *mrs = &mi->r[n].stats; |
cccf129f FF |
504 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; |
505 | unsigned int tx_time_single; | |
506 | unsigned int cw = mp->cw_min; | |
438b61b7 | 507 | int shift; |
cccf129f FF |
508 | |
509 | if (!rate_supported(sta, sband->band, i)) | |
510 | continue; | |
438b61b7 SW |
511 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
512 | continue; | |
513 | ||
cccf129f FF |
514 | n++; |
515 | memset(mr, 0, sizeof(*mr)); | |
ca12c0c8 | 516 | memset(mrs, 0, sizeof(*mrs)); |
cccf129f FF |
517 | |
518 | mr->rix = i; | |
438b61b7 SW |
519 | shift = ieee80211_chandef_get_shift(chandef); |
520 | mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate, | |
521 | (1 << shift) * 5); | |
522 | calc_rate_durations(sband->band, mr, &sband->bitrates[i], | |
523 | chandef); | |
cccf129f FF |
524 | |
525 | /* calculate maximum number of retransmissions before | |
526 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 527 | mr->sample_limit = -1; |
ca12c0c8 | 528 | mrs->retry_count = 1; |
cccf129f | 529 | mr->retry_count_cts = 1; |
ca12c0c8 | 530 | mrs->retry_count_rtscts = 1; |
cccf129f FF |
531 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; |
532 | do { | |
533 | /* add one retransmission */ | |
534 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
535 | ||
536 | /* contention window */ | |
8fddddff DH |
537 | tx_time_single += (t_slot * cw) >> 1; |
538 | cw = min((cw << 1) | 1, mp->cw_max); | |
cccf129f FF |
539 | |
540 | tx_time += tx_time_single; | |
541 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
542 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
543 | if ((tx_time_cts < mp->segment_size) && | |
544 | (mr->retry_count_cts < mp->max_retry)) | |
545 | mr->retry_count_cts++; | |
546 | if ((tx_time_rtscts < mp->segment_size) && | |
ca12c0c8 TH |
547 | (mrs->retry_count_rtscts < mp->max_retry)) |
548 | mrs->retry_count_rtscts++; | |
cccf129f | 549 | } while ((tx_time < mp->segment_size) && |
ca12c0c8 TH |
550 | (++mr->stats.retry_count < mp->max_retry)); |
551 | mr->adjusted_retry_count = mrs->retry_count; | |
991fec09 | 552 | if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) |
ca12c0c8 | 553 | mr->retry_count_cts = mrs->retry_count; |
cccf129f FF |
554 | } |
555 | ||
556 | for (i = n; i < sband->n_bitrates; i++) { | |
557 | struct minstrel_rate *mr = &mi->r[i]; | |
558 | mr->rix = -1; | |
559 | } | |
560 | ||
561 | mi->n_rates = n; | |
9134073b | 562 | mi->last_stats_update = jiffies; |
cccf129f FF |
563 | |
564 | init_sample_table(mi); | |
06d961a8 | 565 | minstrel_update_rates(mp, mi); |
cccf129f FF |
566 | } |
567 | ||
568 | static void * | |
569 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
570 | { | |
571 | struct ieee80211_supported_band *sband; | |
572 | struct minstrel_sta_info *mi; | |
573 | struct minstrel_priv *mp = priv; | |
574 | struct ieee80211_hw *hw = mp->hw; | |
575 | int max_rates = 0; | |
576 | int i; | |
577 | ||
578 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
579 | if (!mi) | |
580 | return NULL; | |
581 | ||
57fbcce3 | 582 | for (i = 0; i < NUM_NL80211_BANDS; i++) { |
8e532175 | 583 | sband = hw->wiphy->bands[i]; |
621ad7c9 | 584 | if (sband && sband->n_bitrates > max_rates) |
cccf129f FF |
585 | max_rates = sband->n_bitrates; |
586 | } | |
587 | ||
588 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
589 | if (!mi->r) | |
590 | goto error; | |
591 | ||
592 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
593 | if (!mi->sample_table) | |
594 | goto error1; | |
595 | ||
9134073b | 596 | mi->last_stats_update = jiffies; |
cccf129f FF |
597 | return mi; |
598 | ||
599 | error1: | |
600 | kfree(mi->r); | |
601 | error: | |
602 | kfree(mi); | |
603 | return NULL; | |
604 | } | |
605 | ||
606 | static void | |
607 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
608 | { | |
609 | struct minstrel_sta_info *mi = priv_sta; | |
610 | ||
611 | kfree(mi->sample_table); | |
612 | kfree(mi->r); | |
613 | kfree(mi); | |
614 | } | |
615 | ||
a0497f9f FF |
616 | static void |
617 | minstrel_init_cck_rates(struct minstrel_priv *mp) | |
618 | { | |
619 | static const int bitrates[4] = { 10, 20, 55, 110 }; | |
620 | struct ieee80211_supported_band *sband; | |
438b61b7 | 621 | u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
a0497f9f FF |
622 | int i, j; |
623 | ||
57fbcce3 | 624 | sband = mp->hw->wiphy->bands[NL80211_BAND_2GHZ]; |
a0497f9f FF |
625 | if (!sband) |
626 | return; | |
627 | ||
628 | for (i = 0, j = 0; i < sband->n_bitrates; i++) { | |
629 | struct ieee80211_rate *rate = &sband->bitrates[i]; | |
630 | ||
631 | if (rate->flags & IEEE80211_RATE_ERP_G) | |
632 | continue; | |
633 | ||
438b61b7 SW |
634 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
635 | continue; | |
636 | ||
a0497f9f FF |
637 | for (j = 0; j < ARRAY_SIZE(bitrates); j++) { |
638 | if (rate->bitrate != bitrates[j]) | |
639 | continue; | |
640 | ||
641 | mp->cck_rates[j] = i; | |
642 | break; | |
643 | } | |
644 | } | |
645 | } | |
646 | ||
cccf129f FF |
647 | static void * |
648 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
649 | { | |
650 | struct minstrel_priv *mp; | |
651 | ||
652 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
653 | if (!mp) | |
654 | return NULL; | |
655 | ||
656 | /* contention window settings | |
657 | * Just an approximation. Using the per-queue values would complicate | |
658 | * the calculations and is probably unnecessary */ | |
659 | mp->cw_min = 15; | |
660 | mp->cw_max = 1023; | |
661 | ||
662 | /* number of packets (in %) to use for sampling other rates | |
663 | * sample less often for non-mrr packets, because the overhead | |
664 | * is much higher than with mrr */ | |
665 | mp->lookaround_rate = 5; | |
666 | mp->lookaround_rate_mrr = 10; | |
667 | ||
cccf129f FF |
668 | /* maximum time that the hw is allowed to stay in one MRR segment */ |
669 | mp->segment_size = 6000; | |
670 | ||
e6a9854b JB |
671 | if (hw->max_rate_tries > 0) |
672 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
673 | else |
674 | /* safe default, does not necessarily have to match hw properties */ | |
675 | mp->max_retry = 7; | |
676 | ||
e6a9854b | 677 | if (hw->max_rates >= 4) |
cccf129f FF |
678 | mp->has_mrr = true; |
679 | ||
680 | mp->hw = hw; | |
681 | mp->update_interval = 100; | |
682 | ||
24f7580e ZK |
683 | #ifdef CONFIG_MAC80211_DEBUGFS |
684 | mp->fixed_rate_idx = (u32) -1; | |
685 | mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", | |
686 | S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); | |
687 | #endif | |
688 | ||
a0497f9f FF |
689 | minstrel_init_cck_rates(mp); |
690 | ||
cccf129f FF |
691 | return mp; |
692 | } | |
693 | ||
694 | static void | |
695 | minstrel_free(void *priv) | |
696 | { | |
24f7580e ZK |
697 | #ifdef CONFIG_MAC80211_DEBUGFS |
698 | debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); | |
699 | #endif | |
cccf129f FF |
700 | kfree(priv); |
701 | } | |
702 | ||
cca674d4 AQ |
703 | static u32 minstrel_get_expected_throughput(void *priv_sta) |
704 | { | |
705 | struct minstrel_sta_info *mi = priv_sta; | |
50e55a8e | 706 | struct minstrel_rate_stats *tmp_mrs; |
cca674d4 | 707 | int idx = mi->max_tp_rate[0]; |
6a27b2c4 | 708 | int tmp_cur_tp; |
cca674d4 AQ |
709 | |
710 | /* convert pkt per sec in kbps (1200 is the average pkt size used for | |
711 | * computing cur_tp | |
712 | */ | |
50e55a8e | 713 | tmp_mrs = &mi->r[idx].stats; |
212c5a5e | 714 | tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma) * 10; |
6a27b2c4 TH |
715 | tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024; |
716 | ||
717 | return tmp_cur_tp; | |
cca674d4 AQ |
718 | } |
719 | ||
631ad703 | 720 | const struct rate_control_ops mac80211_minstrel = { |
cccf129f | 721 | .name = "minstrel", |
fb7acfb8 | 722 | .tx_status_noskb = minstrel_tx_status, |
cccf129f FF |
723 | .get_rate = minstrel_get_rate, |
724 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
725 | .alloc = minstrel_alloc, |
726 | .free = minstrel_free, | |
727 | .alloc_sta = minstrel_alloc_sta, | |
728 | .free_sta = minstrel_free_sta, | |
729 | #ifdef CONFIG_MAC80211_DEBUGFS | |
730 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
731 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
732 | #endif | |
cca674d4 | 733 | .get_expected_throughput = minstrel_get_expected_throughput, |
cccf129f FF |
734 | }; |
735 | ||
736 | int __init | |
737 | rc80211_minstrel_init(void) | |
738 | { | |
739 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
740 | } | |
741 | ||
742 | void | |
743 | rc80211_minstrel_exit(void) | |
744 | { | |
745 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
746 | } | |
747 |