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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 | ||
2ff2b690 TH |
72 | /* find & sort topmost throughput rates */ |
73 | static inline void | |
74 | minstrel_sort_best_tp_rates(struct minstrel_sta_info *mi, int i, u8 *tp_list) | |
75 | { | |
76 | int j = MAX_THR_RATES; | |
77 | ||
ca12c0c8 | 78 | while (j > 0 && mi->r[i].stats.cur_tp > mi->r[tp_list[j - 1]].stats.cur_tp) |
2ff2b690 TH |
79 | j--; |
80 | if (j < MAX_THR_RATES - 1) | |
81 | memmove(&tp_list[j + 1], &tp_list[j], MAX_THR_RATES - (j + 1)); | |
82 | if (j < MAX_THR_RATES) | |
83 | tp_list[j] = i; | |
84 | } | |
85 | ||
06d961a8 FF |
86 | static void |
87 | minstrel_set_rate(struct minstrel_sta_info *mi, struct ieee80211_sta_rates *ratetbl, | |
88 | int offset, int idx) | |
89 | { | |
90 | struct minstrel_rate *r = &mi->r[idx]; | |
91 | ||
92 | ratetbl->rate[offset].idx = r->rix; | |
93 | ratetbl->rate[offset].count = r->adjusted_retry_count; | |
94 | ratetbl->rate[offset].count_cts = r->retry_count_cts; | |
ca12c0c8 | 95 | ratetbl->rate[offset].count_rts = r->stats.retry_count_rtscts; |
06d961a8 FF |
96 | } |
97 | ||
98 | static void | |
99 | minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
100 | { | |
101 | struct ieee80211_sta_rates *ratetbl; | |
102 | int i = 0; | |
103 | ||
104 | ratetbl = kzalloc(sizeof(*ratetbl), GFP_ATOMIC); | |
105 | if (!ratetbl) | |
106 | return; | |
107 | ||
108 | /* Start with max_tp_rate */ | |
109 | minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[0]); | |
110 | ||
111 | if (mp->hw->max_rates >= 3) { | |
112 | /* At least 3 tx rates supported, use max_tp_rate2 next */ | |
113 | minstrel_set_rate(mi, ratetbl, i++, mi->max_tp_rate[1]); | |
114 | } | |
115 | ||
116 | if (mp->hw->max_rates >= 2) { | |
117 | /* At least 2 tx rates supported, use max_prob_rate next */ | |
118 | minstrel_set_rate(mi, ratetbl, i++, mi->max_prob_rate); | |
119 | } | |
120 | ||
121 | /* Use lowest rate last */ | |
122 | ratetbl->rate[i].idx = mi->lowest_rix; | |
123 | ratetbl->rate[i].count = mp->max_retry; | |
124 | ratetbl->rate[i].count_cts = mp->max_retry; | |
125 | ratetbl->rate[i].count_rts = mp->max_retry; | |
126 | ||
127 | rate_control_set_rates(mp->hw, mi->sta, ratetbl); | |
128 | } | |
129 | ||
f62838bc TH |
130 | /* |
131 | * Recalculate success probabilities and counters for a given rate using EWMA | |
132 | */ | |
133 | void | |
134 | minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs) | |
135 | { | |
136 | if (unlikely(mrs->attempts > 0)) { | |
137 | mrs->sample_skipped = 0; | |
138 | mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts); | |
139 | if (unlikely(!mrs->att_hist)) | |
9134073b | 140 | mrs->prob_ewma = mrs->cur_prob; |
f62838bc | 141 | else |
9134073b | 142 | mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma, |
f62838bc TH |
143 | mrs->cur_prob, EWMA_LEVEL); |
144 | mrs->att_hist += mrs->attempts; | |
145 | mrs->succ_hist += mrs->success; | |
146 | } else { | |
147 | mrs->sample_skipped++; | |
148 | } | |
149 | ||
150 | mrs->last_success = mrs->success; | |
151 | mrs->last_attempts = mrs->attempts; | |
152 | mrs->success = 0; | |
153 | mrs->attempts = 0; | |
154 | } | |
155 | ||
cccf129f FF |
156 | static void |
157 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
158 | { | |
2ff2b690 TH |
159 | u8 tmp_tp_rate[MAX_THR_RATES]; |
160 | u8 tmp_prob_rate = 0; | |
cccf129f | 161 | u32 usecs; |
cccf129f FF |
162 | int i; |
163 | ||
f359d3fe | 164 | for (i = 0; i < MAX_THR_RATES; i++) |
2ff2b690 TH |
165 | tmp_tp_rate[i] = 0; |
166 | ||
cccf129f FF |
167 | for (i = 0; i < mi->n_rates; i++) { |
168 | struct minstrel_rate *mr = &mi->r[i]; | |
ca12c0c8 | 169 | struct minstrel_rate_stats *mrs = &mi->r[i].stats; |
cccf129f FF |
170 | |
171 | usecs = mr->perfect_tx_time; | |
172 | if (!usecs) | |
173 | usecs = 1000000; | |
174 | ||
f62838bc TH |
175 | /* Update success probabilities per rate */ |
176 | minstrel_calc_rate_stats(mrs); | |
cccf129f | 177 | |
db8c5ee6 | 178 | /* Update throughput per rate, reset thr. below 10% success */ |
9134073b | 179 | if (mrs->prob_ewma < MINSTREL_FRAC(10, 100)) |
ca12c0c8 | 180 | mrs->cur_tp = 0; |
db8c5ee6 | 181 | else |
9134073b | 182 | mrs->cur_tp = mrs->prob_ewma * (1000000 / usecs); |
db8c5ee6 | 183 | |
cccf129f FF |
184 | /* Sample less often below the 10% chance of success. |
185 | * Sample less often above the 95% chance of success. */ | |
9134073b TH |
186 | if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) || |
187 | mrs->prob_ewma < MINSTREL_FRAC(10, 100)) { | |
ca12c0c8 | 188 | mr->adjusted_retry_count = mrs->retry_count >> 1; |
cccf129f FF |
189 | if (mr->adjusted_retry_count > 2) |
190 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 191 | mr->sample_limit = 4; |
cccf129f | 192 | } else { |
f4a8cd94 | 193 | mr->sample_limit = -1; |
ca12c0c8 | 194 | mr->adjusted_retry_count = mrs->retry_count; |
cccf129f FF |
195 | } |
196 | if (!mr->adjusted_retry_count) | |
197 | mr->adjusted_retry_count = 2; | |
cccf129f | 198 | |
2ff2b690 TH |
199 | minstrel_sort_best_tp_rates(mi, i, tmp_tp_rate); |
200 | ||
201 | /* To determine the most robust rate (max_prob_rate) used at | |
202 | * 3rd mmr stage we distinct between two cases: | |
203 | * (1) if any success probabilitiy >= 95%, out of those rates | |
204 | * choose the maximum throughput rate as max_prob_rate | |
205 | * (2) if all success probabilities < 95%, the rate with | |
d070f913 | 206 | * highest success probability is chosen as max_prob_rate */ |
9134073b | 207 | if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) { |
ca12c0c8 | 208 | if (mrs->cur_tp >= mi->r[tmp_prob_rate].stats.cur_tp) |
2ff2b690 TH |
209 | tmp_prob_rate = i; |
210 | } else { | |
9134073b | 211 | if (mrs->prob_ewma >= mi->r[tmp_prob_rate].stats.prob_ewma) |
2ff2b690 | 212 | tmp_prob_rate = i; |
cccf129f FF |
213 | } |
214 | } | |
215 | ||
2ff2b690 TH |
216 | /* Assign the new rate set */ |
217 | memcpy(mi->max_tp_rate, tmp_tp_rate, sizeof(mi->max_tp_rate)); | |
218 | mi->max_prob_rate = tmp_prob_rate; | |
8f157611 | 219 | |
45966aeb LB |
220 | #ifdef CONFIG_MAC80211_DEBUGFS |
221 | /* use fixed index if set */ | |
222 | if (mp->fixed_rate_idx != -1) { | |
223 | mi->max_tp_rate[0] = mp->fixed_rate_idx; | |
224 | mi->max_tp_rate[1] = mp->fixed_rate_idx; | |
225 | mi->max_prob_rate = mp->fixed_rate_idx; | |
226 | } | |
227 | #endif | |
228 | ||
8f157611 | 229 | /* Reset update timer */ |
9134073b | 230 | mi->last_stats_update = jiffies; |
06d961a8 FF |
231 | |
232 | minstrel_update_rates(mp, mi); | |
cccf129f FF |
233 | } |
234 | ||
235 | static void | |
236 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
f359d3fe | 237 | struct ieee80211_sta *sta, void *priv_sta, |
fb7acfb8 | 238 | struct ieee80211_tx_info *info) |
cccf129f | 239 | { |
8acbcddb | 240 | struct minstrel_priv *mp = priv; |
cccf129f | 241 | struct minstrel_sta_info *mi = priv_sta; |
e6a9854b JB |
242 | struct ieee80211_tx_rate *ar = info->status.rates; |
243 | int i, ndx; | |
244 | int success; | |
cccf129f | 245 | |
e6a9854b | 246 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 247 | |
e6a9854b JB |
248 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
249 | if (ar[i].idx < 0) | |
cccf129f FF |
250 | break; |
251 | ||
e6a9854b | 252 | ndx = rix_to_ndx(mi, ar[i].idx); |
3938b45c LC |
253 | if (ndx < 0) |
254 | continue; | |
255 | ||
ca12c0c8 | 256 | mi->r[ndx].stats.attempts += ar[i].count; |
cccf129f | 257 | |
bfc32e6a | 258 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
ca12c0c8 | 259 | mi->r[ndx].stats.success += success; |
cccf129f FF |
260 | } |
261 | ||
262 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
ca12c0c8 | 263 | mi->sample_packets++; |
cccf129f FF |
264 | |
265 | if (mi->sample_deferred > 0) | |
266 | mi->sample_deferred--; | |
8acbcddb | 267 | |
9134073b | 268 | if (time_after(jiffies, mi->last_stats_update + |
8acbcddb JB |
269 | (mp->update_interval * HZ) / 1000)) |
270 | minstrel_update_stats(mp, mi); | |
cccf129f FF |
271 | } |
272 | ||
273 | ||
274 | static inline unsigned int | |
275 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
f359d3fe | 276 | struct ieee80211_tx_info *info) |
cccf129f | 277 | { |
8d819a92 | 278 | u8 retry = mr->adjusted_retry_count; |
cccf129f | 279 | |
991fec09 | 280 | if (info->control.use_rts) |
8d819a92 | 281 | retry = max_t(u8, 2, min(mr->stats.retry_count_rtscts, retry)); |
991fec09 | 282 | else if (info->control.use_cts_prot) |
8d819a92 | 283 | retry = max_t(u8, 2, min(mr->retry_count_cts, retry)); |
cccf129f FF |
284 | return retry; |
285 | } | |
286 | ||
287 | ||
288 | static int | |
289 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
290 | { | |
291 | unsigned int sample_ndx; | |
8f157611 TH |
292 | sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); |
293 | mi->sample_row++; | |
f744bf81 | 294 | if ((int) mi->sample_row >= mi->n_rates) { |
8f157611 | 295 | mi->sample_row = 0; |
cccf129f FF |
296 | mi->sample_column++; |
297 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
298 | mi->sample_column = 0; | |
299 | } | |
300 | return sample_ndx; | |
301 | } | |
302 | ||
2df78167 | 303 | static void |
e6a9854b JB |
304 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
305 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 306 | { |
e6a9854b | 307 | struct sk_buff *skb = txrc->skb; |
cccf129f FF |
308 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
309 | struct minstrel_sta_info *mi = priv_sta; | |
310 | struct minstrel_priv *mp = priv; | |
06d961a8 FF |
311 | struct ieee80211_tx_rate *rate = &info->control.rates[0]; |
312 | struct minstrel_rate *msr, *mr; | |
313 | unsigned int ndx; | |
8f157611 | 314 | bool mrr_capable; |
5c9fc93b | 315 | bool prev_sample; |
06d961a8 | 316 | int delta; |
8f157611 | 317 | int sampling_ratio; |
cccf129f | 318 | |
8f157611 | 319 | /* management/no-ack frames do not use rate control */ |
4c6d4f5c | 320 | if (rate_control_send_low(sta, priv_sta, txrc)) |
cccf129f | 321 | return; |
cccf129f | 322 | |
8f157611 TH |
323 | /* check multi-rate-retry capabilities & adjust lookaround_rate */ |
324 | mrr_capable = mp->has_mrr && | |
325 | !txrc->rts && | |
326 | !txrc->bss_conf->use_cts_prot; | |
327 | if (mrr_capable) | |
328 | sampling_ratio = mp->lookaround_rate_mrr; | |
329 | else | |
330 | sampling_ratio = mp->lookaround_rate; | |
cccf129f | 331 | |
8f157611 | 332 | /* increase sum packet counter */ |
ca12c0c8 | 333 | mi->total_packets++; |
8f157611 | 334 | |
45966aeb LB |
335 | #ifdef CONFIG_MAC80211_DEBUGFS |
336 | if (mp->fixed_rate_idx != -1) | |
337 | return; | |
338 | #endif | |
339 | ||
ca12c0c8 TH |
340 | delta = (mi->total_packets * sampling_ratio / 100) - |
341 | (mi->sample_packets + mi->sample_deferred / 2); | |
cccf129f | 342 | |
06d961a8 | 343 | /* delta < 0: no sampling required */ |
5c9fc93b | 344 | prev_sample = mi->prev_sample; |
06d961a8 FF |
345 | mi->prev_sample = false; |
346 | if (delta < 0 || (!mrr_capable && prev_sample)) | |
347 | return; | |
cccf129f | 348 | |
ca12c0c8 | 349 | if (mi->total_packets >= 10000) { |
06d961a8 | 350 | mi->sample_deferred = 0; |
ca12c0c8 TH |
351 | mi->sample_packets = 0; |
352 | mi->total_packets = 0; | |
06d961a8 FF |
353 | } else if (delta > mi->n_rates * 2) { |
354 | /* With multi-rate retry, not every planned sample | |
355 | * attempt actually gets used, due to the way the retry | |
356 | * chain is set up - [max_tp,sample,prob,lowest] for | |
357 | * sample_rate < max_tp. | |
358 | * | |
359 | * If there's too much sampling backlog and the link | |
360 | * starts getting worse, minstrel would start bursting | |
361 | * out lots of sampling frames, which would result | |
362 | * in a large throughput loss. */ | |
ca12c0c8 | 363 | mi->sample_packets += (delta - mi->n_rates * 2); |
06d961a8 FF |
364 | } |
365 | ||
366 | /* get next random rate sample */ | |
367 | ndx = minstrel_get_next_sample(mi); | |
368 | msr = &mi->r[ndx]; | |
369 | mr = &mi->r[mi->max_tp_rate[0]]; | |
370 | ||
371 | /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) | |
372 | * rate sampling method should be used. | |
373 | * Respect such rates that are not sampled for 20 interations. | |
374 | */ | |
375 | if (mrr_capable && | |
376 | msr->perfect_tx_time > mr->perfect_tx_time && | |
ca12c0c8 | 377 | msr->stats.sample_skipped < 20) { |
06d961a8 FF |
378 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark |
379 | * packets that have the sampling rate deferred to the | |
380 | * second MRR stage. Increase the sample counter only | |
381 | * if the deferred sample rate was actually used. | |
382 | * Use the sample_deferred counter to make sure that | |
383 | * the sampling is not done in large bursts */ | |
384 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
385 | rate++; | |
386 | mi->sample_deferred++; | |
387 | } else { | |
17dce158 | 388 | if (!msr->sample_limit) |
06d961a8 FF |
389 | return; |
390 | ||
ca12c0c8 | 391 | mi->sample_packets++; |
06d961a8 FF |
392 | if (msr->sample_limit > 0) |
393 | msr->sample_limit--; | |
cccf129f | 394 | } |
f4a8cd94 FF |
395 | |
396 | /* If we're not using MRR and the sampling rate already | |
397 | * has a probability of >95%, we shouldn't be attempting | |
398 | * to use it, as this only wastes precious airtime */ | |
06d961a8 | 399 | if (!mrr_capable && |
9134073b | 400 | (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100))) |
cccf129f | 401 | return; |
cccf129f | 402 | |
06d961a8 | 403 | mi->prev_sample = true; |
8f157611 | 404 | |
06d961a8 FF |
405 | rate->idx = mi->r[ndx].rix; |
406 | rate->count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f FF |
407 | } |
408 | ||
409 | ||
410 | static void | |
4ee73f33 MK |
411 | calc_rate_durations(enum ieee80211_band band, |
412 | struct minstrel_rate *d, | |
438b61b7 SW |
413 | struct ieee80211_rate *rate, |
414 | struct cfg80211_chan_def *chandef) | |
cccf129f FF |
415 | { |
416 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
438b61b7 | 417 | int shift = ieee80211_chandef_get_shift(chandef); |
cccf129f | 418 | |
4ee73f33 | 419 | d->perfect_tx_time = ieee80211_frame_duration(band, 1200, |
438b61b7 SW |
420 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
421 | shift); | |
4ee73f33 | 422 | d->ack_time = ieee80211_frame_duration(band, 10, |
438b61b7 SW |
423 | DIV_ROUND_UP(rate->bitrate, 1 << shift), erp, 1, |
424 | shift); | |
cccf129f FF |
425 | } |
426 | ||
427 | static void | |
428 | init_sample_table(struct minstrel_sta_info *mi) | |
429 | { | |
430 | unsigned int i, col, new_idx; | |
cccf129f FF |
431 | u8 rnd[8]; |
432 | ||
433 | mi->sample_column = 0; | |
8f157611 | 434 | mi->sample_row = 0; |
f744bf81 | 435 | memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); |
cccf129f FF |
436 | |
437 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
f7d8ad81 | 438 | prandom_bytes(rnd, sizeof(rnd)); |
f744bf81 | 439 | for (i = 0; i < mi->n_rates; i++) { |
f744bf81 | 440 | new_idx = (i + rnd[i & 7]) % mi->n_rates; |
f744bf81 TH |
441 | while (SAMPLE_TBL(mi, new_idx, col) != 0xff) |
442 | new_idx = (new_idx + 1) % mi->n_rates; | |
cccf129f | 443 | |
f744bf81 | 444 | SAMPLE_TBL(mi, new_idx, col) = i; |
cccf129f FF |
445 | } |
446 | } | |
447 | } | |
448 | ||
449 | static void | |
450 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
3de805cf SW |
451 | struct cfg80211_chan_def *chandef, |
452 | struct ieee80211_sta *sta, void *priv_sta) | |
cccf129f FF |
453 | { |
454 | struct minstrel_sta_info *mi = priv_sta; | |
455 | struct minstrel_priv *mp = priv; | |
d57854bb | 456 | struct ieee80211_rate *ctl_rate; |
cccf129f FF |
457 | unsigned int i, n = 0; |
458 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
438b61b7 | 459 | u32 rate_flags; |
cccf129f | 460 | |
06d961a8 | 461 | mi->sta = sta; |
cccf129f | 462 | mi->lowest_rix = rate_lowest_index(sband, sta); |
d57854bb | 463 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
4ee73f33 MK |
464 | mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, |
465 | ctl_rate->bitrate, | |
438b61b7 SW |
466 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1, |
467 | ieee80211_chandef_get_shift(chandef)); | |
cccf129f | 468 | |
438b61b7 | 469 | rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
06d961a8 FF |
470 | memset(mi->max_tp_rate, 0, sizeof(mi->max_tp_rate)); |
471 | mi->max_prob_rate = 0; | |
472 | ||
cccf129f FF |
473 | for (i = 0; i < sband->n_bitrates; i++) { |
474 | struct minstrel_rate *mr = &mi->r[n]; | |
ca12c0c8 | 475 | struct minstrel_rate_stats *mrs = &mi->r[n].stats; |
cccf129f FF |
476 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; |
477 | unsigned int tx_time_single; | |
478 | unsigned int cw = mp->cw_min; | |
438b61b7 | 479 | int shift; |
cccf129f FF |
480 | |
481 | if (!rate_supported(sta, sband->band, i)) | |
482 | continue; | |
438b61b7 SW |
483 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
484 | continue; | |
485 | ||
cccf129f FF |
486 | n++; |
487 | memset(mr, 0, sizeof(*mr)); | |
ca12c0c8 | 488 | memset(mrs, 0, sizeof(*mrs)); |
cccf129f FF |
489 | |
490 | mr->rix = i; | |
438b61b7 SW |
491 | shift = ieee80211_chandef_get_shift(chandef); |
492 | mr->bitrate = DIV_ROUND_UP(sband->bitrates[i].bitrate, | |
493 | (1 << shift) * 5); | |
494 | calc_rate_durations(sband->band, mr, &sband->bitrates[i], | |
495 | chandef); | |
cccf129f FF |
496 | |
497 | /* calculate maximum number of retransmissions before | |
498 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 499 | mr->sample_limit = -1; |
ca12c0c8 | 500 | mrs->retry_count = 1; |
cccf129f | 501 | mr->retry_count_cts = 1; |
ca12c0c8 | 502 | mrs->retry_count_rtscts = 1; |
cccf129f FF |
503 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; |
504 | do { | |
505 | /* add one retransmission */ | |
506 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
507 | ||
508 | /* contention window */ | |
8fddddff DH |
509 | tx_time_single += (t_slot * cw) >> 1; |
510 | cw = min((cw << 1) | 1, mp->cw_max); | |
cccf129f FF |
511 | |
512 | tx_time += tx_time_single; | |
513 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
514 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
515 | if ((tx_time_cts < mp->segment_size) && | |
516 | (mr->retry_count_cts < mp->max_retry)) | |
517 | mr->retry_count_cts++; | |
518 | if ((tx_time_rtscts < mp->segment_size) && | |
ca12c0c8 TH |
519 | (mrs->retry_count_rtscts < mp->max_retry)) |
520 | mrs->retry_count_rtscts++; | |
cccf129f | 521 | } while ((tx_time < mp->segment_size) && |
ca12c0c8 TH |
522 | (++mr->stats.retry_count < mp->max_retry)); |
523 | mr->adjusted_retry_count = mrs->retry_count; | |
991fec09 | 524 | if (!(sband->bitrates[i].flags & IEEE80211_RATE_ERP_G)) |
ca12c0c8 | 525 | mr->retry_count_cts = mrs->retry_count; |
cccf129f FF |
526 | } |
527 | ||
528 | for (i = n; i < sband->n_bitrates; i++) { | |
529 | struct minstrel_rate *mr = &mi->r[i]; | |
530 | mr->rix = -1; | |
531 | } | |
532 | ||
533 | mi->n_rates = n; | |
9134073b | 534 | mi->last_stats_update = jiffies; |
cccf129f FF |
535 | |
536 | init_sample_table(mi); | |
06d961a8 | 537 | minstrel_update_rates(mp, mi); |
cccf129f FF |
538 | } |
539 | ||
540 | static void * | |
541 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
542 | { | |
543 | struct ieee80211_supported_band *sband; | |
544 | struct minstrel_sta_info *mi; | |
545 | struct minstrel_priv *mp = priv; | |
546 | struct ieee80211_hw *hw = mp->hw; | |
547 | int max_rates = 0; | |
548 | int i; | |
549 | ||
550 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
551 | if (!mi) | |
552 | return NULL; | |
553 | ||
554 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { | |
8e532175 | 555 | sband = hw->wiphy->bands[i]; |
621ad7c9 | 556 | if (sband && sband->n_bitrates > max_rates) |
cccf129f FF |
557 | max_rates = sband->n_bitrates; |
558 | } | |
559 | ||
560 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
561 | if (!mi->r) | |
562 | goto error; | |
563 | ||
564 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
565 | if (!mi->sample_table) | |
566 | goto error1; | |
567 | ||
9134073b | 568 | mi->last_stats_update = jiffies; |
cccf129f FF |
569 | return mi; |
570 | ||
571 | error1: | |
572 | kfree(mi->r); | |
573 | error: | |
574 | kfree(mi); | |
575 | return NULL; | |
576 | } | |
577 | ||
578 | static void | |
579 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
580 | { | |
581 | struct minstrel_sta_info *mi = priv_sta; | |
582 | ||
583 | kfree(mi->sample_table); | |
584 | kfree(mi->r); | |
585 | kfree(mi); | |
586 | } | |
587 | ||
a0497f9f FF |
588 | static void |
589 | minstrel_init_cck_rates(struct minstrel_priv *mp) | |
590 | { | |
591 | static const int bitrates[4] = { 10, 20, 55, 110 }; | |
592 | struct ieee80211_supported_band *sband; | |
438b61b7 | 593 | u32 rate_flags = ieee80211_chandef_rate_flags(&mp->hw->conf.chandef); |
a0497f9f FF |
594 | int i, j; |
595 | ||
596 | sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ]; | |
597 | if (!sband) | |
598 | return; | |
599 | ||
600 | for (i = 0, j = 0; i < sband->n_bitrates; i++) { | |
601 | struct ieee80211_rate *rate = &sband->bitrates[i]; | |
602 | ||
603 | if (rate->flags & IEEE80211_RATE_ERP_G) | |
604 | continue; | |
605 | ||
438b61b7 SW |
606 | if ((rate_flags & sband->bitrates[i].flags) != rate_flags) |
607 | continue; | |
608 | ||
a0497f9f FF |
609 | for (j = 0; j < ARRAY_SIZE(bitrates); j++) { |
610 | if (rate->bitrate != bitrates[j]) | |
611 | continue; | |
612 | ||
613 | mp->cck_rates[j] = i; | |
614 | break; | |
615 | } | |
616 | } | |
617 | } | |
618 | ||
cccf129f FF |
619 | static void * |
620 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
621 | { | |
622 | struct minstrel_priv *mp; | |
623 | ||
624 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
625 | if (!mp) | |
626 | return NULL; | |
627 | ||
628 | /* contention window settings | |
629 | * Just an approximation. Using the per-queue values would complicate | |
630 | * the calculations and is probably unnecessary */ | |
631 | mp->cw_min = 15; | |
632 | mp->cw_max = 1023; | |
633 | ||
634 | /* number of packets (in %) to use for sampling other rates | |
635 | * sample less often for non-mrr packets, because the overhead | |
636 | * is much higher than with mrr */ | |
637 | mp->lookaround_rate = 5; | |
638 | mp->lookaround_rate_mrr = 10; | |
639 | ||
cccf129f FF |
640 | /* maximum time that the hw is allowed to stay in one MRR segment */ |
641 | mp->segment_size = 6000; | |
642 | ||
e6a9854b JB |
643 | if (hw->max_rate_tries > 0) |
644 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
645 | else |
646 | /* safe default, does not necessarily have to match hw properties */ | |
647 | mp->max_retry = 7; | |
648 | ||
e6a9854b | 649 | if (hw->max_rates >= 4) |
cccf129f FF |
650 | mp->has_mrr = true; |
651 | ||
652 | mp->hw = hw; | |
653 | mp->update_interval = 100; | |
654 | ||
24f7580e ZK |
655 | #ifdef CONFIG_MAC80211_DEBUGFS |
656 | mp->fixed_rate_idx = (u32) -1; | |
657 | mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", | |
658 | S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); | |
659 | #endif | |
660 | ||
a0497f9f FF |
661 | minstrel_init_cck_rates(mp); |
662 | ||
cccf129f FF |
663 | return mp; |
664 | } | |
665 | ||
666 | static void | |
667 | minstrel_free(void *priv) | |
668 | { | |
24f7580e ZK |
669 | #ifdef CONFIG_MAC80211_DEBUGFS |
670 | debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); | |
671 | #endif | |
cccf129f FF |
672 | kfree(priv); |
673 | } | |
674 | ||
cca674d4 AQ |
675 | static u32 minstrel_get_expected_throughput(void *priv_sta) |
676 | { | |
677 | struct minstrel_sta_info *mi = priv_sta; | |
678 | int idx = mi->max_tp_rate[0]; | |
679 | ||
680 | /* convert pkt per sec in kbps (1200 is the average pkt size used for | |
681 | * computing cur_tp | |
682 | */ | |
ca12c0c8 | 683 | return MINSTREL_TRUNC(mi->r[idx].stats.cur_tp) * 1200 * 8 / 1024; |
cca674d4 AQ |
684 | } |
685 | ||
631ad703 | 686 | const struct rate_control_ops mac80211_minstrel = { |
cccf129f | 687 | .name = "minstrel", |
fb7acfb8 | 688 | .tx_status_noskb = minstrel_tx_status, |
cccf129f FF |
689 | .get_rate = minstrel_get_rate, |
690 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
691 | .alloc = minstrel_alloc, |
692 | .free = minstrel_free, | |
693 | .alloc_sta = minstrel_alloc_sta, | |
694 | .free_sta = minstrel_free_sta, | |
695 | #ifdef CONFIG_MAC80211_DEBUGFS | |
696 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
697 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
698 | #endif | |
cca674d4 | 699 | .get_expected_throughput = minstrel_get_expected_throughput, |
cccf129f FF |
700 | }; |
701 | ||
702 | int __init | |
703 | rc80211_minstrel_init(void) | |
704 | { | |
705 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
706 | } | |
707 | ||
708 | void | |
709 | rc80211_minstrel_exit(void) | |
710 | { | |
711 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
712 | } | |
713 |