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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 | ||
cccf129f FF |
72 | static void |
73 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
74 | { | |
75 | u32 max_tp = 0, index_max_tp = 0, index_max_tp2 = 0; | |
76 | u32 max_prob = 0, index_max_prob = 0; | |
77 | u32 usecs; | |
cccf129f FF |
78 | int i; |
79 | ||
cccf129f FF |
80 | for (i = 0; i < mi->n_rates; i++) { |
81 | struct minstrel_rate *mr = &mi->r[i]; | |
82 | ||
83 | usecs = mr->perfect_tx_time; | |
84 | if (!usecs) | |
85 | usecs = 1000000; | |
86 | ||
1e9c27df TH |
87 | if (unlikely(mr->attempts > 0)) { |
88 | mr->sample_skipped = 0; | |
c8ca8c2f | 89 | mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts); |
cccf129f FF |
90 | mr->succ_hist += mr->success; |
91 | mr->att_hist += mr->attempts; | |
a512d4b5 TH |
92 | mr->probability = minstrel_ewma(mr->probability, |
93 | mr->cur_prob, | |
94 | EWMA_LEVEL); | |
1e9c27df TH |
95 | } else |
96 | mr->sample_skipped++; | |
cccf129f FF |
97 | |
98 | mr->last_success = mr->success; | |
99 | mr->last_attempts = mr->attempts; | |
100 | mr->success = 0; | |
101 | mr->attempts = 0; | |
102 | ||
db8c5ee6 TH |
103 | /* Update throughput per rate, reset thr. below 10% success */ |
104 | if (mr->probability < MINSTREL_FRAC(10, 100)) | |
105 | mr->cur_tp = 0; | |
106 | else | |
107 | mr->cur_tp = mr->probability * (1000000 / usecs); | |
108 | ||
cccf129f FF |
109 | /* Sample less often below the 10% chance of success. |
110 | * Sample less often above the 95% chance of success. */ | |
c8ca8c2f TH |
111 | if (mr->probability > MINSTREL_FRAC(95, 100) || |
112 | mr->probability < MINSTREL_FRAC(10, 100)) { | |
cccf129f FF |
113 | mr->adjusted_retry_count = mr->retry_count >> 1; |
114 | if (mr->adjusted_retry_count > 2) | |
115 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 116 | mr->sample_limit = 4; |
cccf129f | 117 | } else { |
f4a8cd94 | 118 | mr->sample_limit = -1; |
cccf129f FF |
119 | mr->adjusted_retry_count = mr->retry_count; |
120 | } | |
121 | if (!mr->adjusted_retry_count) | |
122 | mr->adjusted_retry_count = 2; | |
123 | } | |
124 | ||
125 | for (i = 0; i < mi->n_rates; i++) { | |
126 | struct minstrel_rate *mr = &mi->r[i]; | |
127 | if (max_tp < mr->cur_tp) { | |
128 | index_max_tp = i; | |
129 | max_tp = mr->cur_tp; | |
130 | } | |
131 | if (max_prob < mr->probability) { | |
132 | index_max_prob = i; | |
133 | max_prob = mr->probability; | |
134 | } | |
135 | } | |
136 | ||
137 | max_tp = 0; | |
138 | for (i = 0; i < mi->n_rates; i++) { | |
139 | struct minstrel_rate *mr = &mi->r[i]; | |
140 | ||
141 | if (i == index_max_tp) | |
142 | continue; | |
143 | ||
144 | if (max_tp < mr->cur_tp) { | |
145 | index_max_tp2 = i; | |
146 | max_tp = mr->cur_tp; | |
147 | } | |
148 | } | |
149 | mi->max_tp_rate = index_max_tp; | |
150 | mi->max_tp_rate2 = index_max_tp2; | |
151 | mi->max_prob_rate = index_max_prob; | |
8f157611 TH |
152 | |
153 | /* Reset update timer */ | |
154 | mi->stats_update = jiffies; | |
cccf129f FF |
155 | } |
156 | ||
157 | static void | |
158 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
159 | struct ieee80211_sta *sta, void *priv_sta, | |
160 | struct sk_buff *skb) | |
161 | { | |
8acbcddb | 162 | struct minstrel_priv *mp = priv; |
cccf129f FF |
163 | struct minstrel_sta_info *mi = priv_sta; |
164 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
e6a9854b JB |
165 | struct ieee80211_tx_rate *ar = info->status.rates; |
166 | int i, ndx; | |
167 | int success; | |
cccf129f | 168 | |
e6a9854b | 169 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 170 | |
e6a9854b JB |
171 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
172 | if (ar[i].idx < 0) | |
cccf129f FF |
173 | break; |
174 | ||
e6a9854b | 175 | ndx = rix_to_ndx(mi, ar[i].idx); |
3938b45c LC |
176 | if (ndx < 0) |
177 | continue; | |
178 | ||
e6a9854b | 179 | mi->r[ndx].attempts += ar[i].count; |
cccf129f | 180 | |
bfc32e6a | 181 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
cccf129f FF |
182 | mi->r[ndx].success += success; |
183 | } | |
184 | ||
185 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
186 | mi->sample_count++; | |
187 | ||
188 | if (mi->sample_deferred > 0) | |
189 | mi->sample_deferred--; | |
8acbcddb JB |
190 | |
191 | if (time_after(jiffies, mi->stats_update + | |
192 | (mp->update_interval * HZ) / 1000)) | |
193 | minstrel_update_stats(mp, mi); | |
cccf129f FF |
194 | } |
195 | ||
196 | ||
197 | static inline unsigned int | |
198 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
199 | struct ieee80211_tx_info *info) | |
200 | { | |
201 | unsigned int retry = mr->adjusted_retry_count; | |
202 | ||
e6a9854b | 203 | if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) |
cccf129f | 204 | retry = max(2U, min(mr->retry_count_rtscts, retry)); |
e6a9854b | 205 | else if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) |
cccf129f FF |
206 | retry = max(2U, min(mr->retry_count_cts, retry)); |
207 | return retry; | |
208 | } | |
209 | ||
210 | ||
211 | static int | |
212 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
213 | { | |
214 | unsigned int sample_ndx; | |
8f157611 TH |
215 | sample_ndx = SAMPLE_TBL(mi, mi->sample_row, mi->sample_column); |
216 | mi->sample_row++; | |
f744bf81 | 217 | if ((int) mi->sample_row >= mi->n_rates) { |
8f157611 | 218 | mi->sample_row = 0; |
cccf129f FF |
219 | mi->sample_column++; |
220 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
221 | mi->sample_column = 0; | |
222 | } | |
223 | return sample_ndx; | |
224 | } | |
225 | ||
2df78167 | 226 | static void |
e6a9854b JB |
227 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
228 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 229 | { |
e6a9854b | 230 | struct sk_buff *skb = txrc->skb; |
cccf129f FF |
231 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
232 | struct minstrel_sta_info *mi = priv_sta; | |
233 | struct minstrel_priv *mp = priv; | |
e6a9854b | 234 | struct ieee80211_tx_rate *ar = info->control.rates; |
cccf129f | 235 | unsigned int ndx, sample_ndx = 0; |
8f157611 TH |
236 | bool mrr_capable; |
237 | bool indirect_rate_sampling = false; | |
238 | bool rate_sampling = false; | |
cccf129f FF |
239 | int i, delta; |
240 | int mrr_ndx[3]; | |
8f157611 | 241 | int sampling_ratio; |
cccf129f | 242 | |
8f157611 | 243 | /* management/no-ack frames do not use rate control */ |
4c6d4f5c | 244 | if (rate_control_send_low(sta, priv_sta, txrc)) |
cccf129f | 245 | return; |
cccf129f | 246 | |
8f157611 TH |
247 | /* check multi-rate-retry capabilities & adjust lookaround_rate */ |
248 | mrr_capable = mp->has_mrr && | |
249 | !txrc->rts && | |
250 | !txrc->bss_conf->use_cts_prot; | |
251 | if (mrr_capable) | |
252 | sampling_ratio = mp->lookaround_rate_mrr; | |
253 | else | |
254 | sampling_ratio = mp->lookaround_rate; | |
cccf129f | 255 | |
8f157611 | 256 | /* init rateindex [ndx] with max throughput rate */ |
cccf129f FF |
257 | ndx = mi->max_tp_rate; |
258 | ||
8f157611 | 259 | /* increase sum packet counter */ |
cccf129f | 260 | mi->packet_count++; |
8f157611 TH |
261 | |
262 | delta = (mi->packet_count * sampling_ratio / 100) - | |
cccf129f FF |
263 | (mi->sample_count + mi->sample_deferred / 2); |
264 | ||
265 | /* delta > 0: sampling required */ | |
8f157611 | 266 | if ((delta > 0) && (mrr_capable || !mi->prev_sample)) { |
f4a8cd94 | 267 | struct minstrel_rate *msr; |
cccf129f FF |
268 | if (mi->packet_count >= 10000) { |
269 | mi->sample_deferred = 0; | |
270 | mi->sample_count = 0; | |
271 | mi->packet_count = 0; | |
272 | } else if (delta > mi->n_rates * 2) { | |
273 | /* With multi-rate retry, not every planned sample | |
274 | * attempt actually gets used, due to the way the retry | |
275 | * chain is set up - [max_tp,sample,prob,lowest] for | |
276 | * sample_rate < max_tp. | |
277 | * | |
278 | * If there's too much sampling backlog and the link | |
279 | * starts getting worse, minstrel would start bursting | |
280 | * out lots of sampling frames, which would result | |
281 | * in a large throughput loss. */ | |
282 | mi->sample_count += (delta - mi->n_rates * 2); | |
283 | } | |
284 | ||
8f157611 | 285 | /* get next random rate sample */ |
cccf129f | 286 | sample_ndx = minstrel_get_next_sample(mi); |
f4a8cd94 | 287 | msr = &mi->r[sample_ndx]; |
8f157611 | 288 | rate_sampling = true; |
cccf129f | 289 | |
8f157611 | 290 | /* Decide if direct ( 1st mrr stage) or indirect (2nd mrr stage) |
1e9c27df TH |
291 | * rate sampling method should be used. |
292 | * Respect such rates that are not sampled for 20 interations. | |
293 | */ | |
8f157611 | 294 | if (mrr_capable && |
1e9c27df TH |
295 | msr->perfect_tx_time > mi->r[ndx].perfect_tx_time && |
296 | msr->sample_skipped < 20) | |
8f157611 TH |
297 | indirect_rate_sampling = true; |
298 | ||
299 | if (!indirect_rate_sampling) { | |
f4a8cd94 FF |
300 | if (msr->sample_limit != 0) { |
301 | ndx = sample_ndx; | |
302 | mi->sample_count++; | |
303 | if (msr->sample_limit > 0) | |
304 | msr->sample_limit--; | |
8f157611 TH |
305 | } else |
306 | rate_sampling = false; | |
cccf129f FF |
307 | } else { |
308 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark | |
309 | * packets that have the sampling rate deferred to the | |
310 | * second MRR stage. Increase the sample counter only | |
311 | * if the deferred sample rate was actually used. | |
312 | * Use the sample_deferred counter to make sure that | |
313 | * the sampling is not done in large bursts */ | |
314 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
315 | mi->sample_deferred++; | |
316 | } | |
317 | } | |
8f157611 | 318 | mi->prev_sample = rate_sampling; |
f4a8cd94 FF |
319 | |
320 | /* If we're not using MRR and the sampling rate already | |
321 | * has a probability of >95%, we shouldn't be attempting | |
322 | * to use it, as this only wastes precious airtime */ | |
8f157611 TH |
323 | if (!mrr_capable && rate_sampling && |
324 | (mi->r[ndx].probability > MINSTREL_FRAC(95, 100))) | |
f4a8cd94 FF |
325 | ndx = mi->max_tp_rate; |
326 | ||
8f157611 | 327 | /* mrr setup for 1st stage */ |
e6a9854b JB |
328 | ar[0].idx = mi->r[ndx].rix; |
329 | ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f | 330 | |
8f157611 TH |
331 | /* non mrr setup for 2nd stage */ |
332 | if (!mrr_capable) { | |
333 | if (!rate_sampling) | |
f4a8cd94 | 334 | ar[0].count = mp->max_retry; |
e6a9854b JB |
335 | ar[1].idx = mi->lowest_rix; |
336 | ar[1].count = mp->max_retry; | |
cccf129f FF |
337 | return; |
338 | } | |
339 | ||
8f157611 TH |
340 | /* mrr setup for 2nd stage */ |
341 | if (rate_sampling) { | |
342 | if (indirect_rate_sampling) | |
cccf129f FF |
343 | mrr_ndx[0] = sample_ndx; |
344 | else | |
345 | mrr_ndx[0] = mi->max_tp_rate; | |
346 | } else { | |
347 | mrr_ndx[0] = mi->max_tp_rate2; | |
348 | } | |
8f157611 TH |
349 | |
350 | /* mrr setup for 3rd & 4th stage */ | |
cccf129f FF |
351 | mrr_ndx[1] = mi->max_prob_rate; |
352 | mrr_ndx[2] = 0; | |
e6a9854b JB |
353 | for (i = 1; i < 4; i++) { |
354 | ar[i].idx = mi->r[mrr_ndx[i - 1]].rix; | |
355 | ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count; | |
cccf129f FF |
356 | } |
357 | } | |
358 | ||
359 | ||
360 | static void | |
4ee73f33 MK |
361 | calc_rate_durations(enum ieee80211_band band, |
362 | struct minstrel_rate *d, | |
868a5f71 | 363 | struct ieee80211_rate *rate) |
cccf129f FF |
364 | { |
365 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
366 | ||
4ee73f33 | 367 | d->perfect_tx_time = ieee80211_frame_duration(band, 1200, |
cccf129f | 368 | rate->bitrate, erp, 1); |
4ee73f33 | 369 | d->ack_time = ieee80211_frame_duration(band, 10, |
cccf129f FF |
370 | rate->bitrate, erp, 1); |
371 | } | |
372 | ||
373 | static void | |
374 | init_sample_table(struct minstrel_sta_info *mi) | |
375 | { | |
376 | unsigned int i, col, new_idx; | |
cccf129f FF |
377 | u8 rnd[8]; |
378 | ||
379 | mi->sample_column = 0; | |
8f157611 | 380 | mi->sample_row = 0; |
f744bf81 | 381 | memset(mi->sample_table, 0xff, SAMPLE_COLUMNS * mi->n_rates); |
cccf129f FF |
382 | |
383 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
f744bf81 | 384 | for (i = 0; i < mi->n_rates; i++) { |
cccf129f | 385 | get_random_bytes(rnd, sizeof(rnd)); |
f744bf81 | 386 | new_idx = (i + rnd[i & 7]) % mi->n_rates; |
cccf129f | 387 | |
f744bf81 TH |
388 | while (SAMPLE_TBL(mi, new_idx, col) != 0xff) |
389 | new_idx = (new_idx + 1) % mi->n_rates; | |
cccf129f | 390 | |
f744bf81 | 391 | SAMPLE_TBL(mi, new_idx, col) = i; |
cccf129f FF |
392 | } |
393 | } | |
394 | } | |
395 | ||
396 | static void | |
397 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
398 | struct ieee80211_sta *sta, void *priv_sta) | |
399 | { | |
400 | struct minstrel_sta_info *mi = priv_sta; | |
401 | struct minstrel_priv *mp = priv; | |
d57854bb | 402 | struct ieee80211_rate *ctl_rate; |
cccf129f FF |
403 | unsigned int i, n = 0; |
404 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
405 | ||
406 | mi->lowest_rix = rate_lowest_index(sband, sta); | |
d57854bb | 407 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
4ee73f33 MK |
408 | mi->sp_ack_dur = ieee80211_frame_duration(sband->band, 10, |
409 | ctl_rate->bitrate, | |
d57854bb | 410 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1); |
cccf129f FF |
411 | |
412 | for (i = 0; i < sband->n_bitrates; i++) { | |
413 | struct minstrel_rate *mr = &mi->r[n]; | |
414 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; | |
415 | unsigned int tx_time_single; | |
416 | unsigned int cw = mp->cw_min; | |
417 | ||
418 | if (!rate_supported(sta, sband->band, i)) | |
419 | continue; | |
420 | n++; | |
421 | memset(mr, 0, sizeof(*mr)); | |
422 | ||
423 | mr->rix = i; | |
424 | mr->bitrate = sband->bitrates[i].bitrate / 5; | |
4ee73f33 | 425 | calc_rate_durations(sband->band, mr, &sband->bitrates[i]); |
cccf129f FF |
426 | |
427 | /* calculate maximum number of retransmissions before | |
428 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 429 | mr->sample_limit = -1; |
cccf129f FF |
430 | mr->retry_count = 1; |
431 | mr->retry_count_cts = 1; | |
432 | mr->retry_count_rtscts = 1; | |
433 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; | |
434 | do { | |
435 | /* add one retransmission */ | |
436 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
437 | ||
438 | /* contention window */ | |
8fddddff DH |
439 | tx_time_single += (t_slot * cw) >> 1; |
440 | cw = min((cw << 1) | 1, mp->cw_max); | |
cccf129f FF |
441 | |
442 | tx_time += tx_time_single; | |
443 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
444 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
445 | if ((tx_time_cts < mp->segment_size) && | |
446 | (mr->retry_count_cts < mp->max_retry)) | |
447 | mr->retry_count_cts++; | |
448 | if ((tx_time_rtscts < mp->segment_size) && | |
449 | (mr->retry_count_rtscts < mp->max_retry)) | |
450 | mr->retry_count_rtscts++; | |
451 | } while ((tx_time < mp->segment_size) && | |
452 | (++mr->retry_count < mp->max_retry)); | |
453 | mr->adjusted_retry_count = mr->retry_count; | |
454 | } | |
455 | ||
456 | for (i = n; i < sband->n_bitrates; i++) { | |
457 | struct minstrel_rate *mr = &mi->r[i]; | |
458 | mr->rix = -1; | |
459 | } | |
460 | ||
461 | mi->n_rates = n; | |
462 | mi->stats_update = jiffies; | |
463 | ||
464 | init_sample_table(mi); | |
465 | } | |
466 | ||
467 | static void * | |
468 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
469 | { | |
470 | struct ieee80211_supported_band *sband; | |
471 | struct minstrel_sta_info *mi; | |
472 | struct minstrel_priv *mp = priv; | |
473 | struct ieee80211_hw *hw = mp->hw; | |
474 | int max_rates = 0; | |
475 | int i; | |
476 | ||
477 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
478 | if (!mi) | |
479 | return NULL; | |
480 | ||
481 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { | |
8e532175 | 482 | sband = hw->wiphy->bands[i]; |
621ad7c9 | 483 | if (sband && sband->n_bitrates > max_rates) |
cccf129f FF |
484 | max_rates = sband->n_bitrates; |
485 | } | |
486 | ||
487 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
488 | if (!mi->r) | |
489 | goto error; | |
490 | ||
491 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
492 | if (!mi->sample_table) | |
493 | goto error1; | |
494 | ||
495 | mi->stats_update = jiffies; | |
496 | return mi; | |
497 | ||
498 | error1: | |
499 | kfree(mi->r); | |
500 | error: | |
501 | kfree(mi); | |
502 | return NULL; | |
503 | } | |
504 | ||
505 | static void | |
506 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
507 | { | |
508 | struct minstrel_sta_info *mi = priv_sta; | |
509 | ||
510 | kfree(mi->sample_table); | |
511 | kfree(mi->r); | |
512 | kfree(mi); | |
513 | } | |
514 | ||
a0497f9f FF |
515 | static void |
516 | minstrel_init_cck_rates(struct minstrel_priv *mp) | |
517 | { | |
518 | static const int bitrates[4] = { 10, 20, 55, 110 }; | |
519 | struct ieee80211_supported_band *sband; | |
520 | int i, j; | |
521 | ||
522 | sband = mp->hw->wiphy->bands[IEEE80211_BAND_2GHZ]; | |
523 | if (!sband) | |
524 | return; | |
525 | ||
526 | for (i = 0, j = 0; i < sband->n_bitrates; i++) { | |
527 | struct ieee80211_rate *rate = &sband->bitrates[i]; | |
528 | ||
529 | if (rate->flags & IEEE80211_RATE_ERP_G) | |
530 | continue; | |
531 | ||
532 | for (j = 0; j < ARRAY_SIZE(bitrates); j++) { | |
533 | if (rate->bitrate != bitrates[j]) | |
534 | continue; | |
535 | ||
536 | mp->cck_rates[j] = i; | |
537 | break; | |
538 | } | |
539 | } | |
540 | } | |
541 | ||
cccf129f FF |
542 | static void * |
543 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
544 | { | |
545 | struct minstrel_priv *mp; | |
546 | ||
547 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
548 | if (!mp) | |
549 | return NULL; | |
550 | ||
551 | /* contention window settings | |
552 | * Just an approximation. Using the per-queue values would complicate | |
553 | * the calculations and is probably unnecessary */ | |
554 | mp->cw_min = 15; | |
555 | mp->cw_max = 1023; | |
556 | ||
557 | /* number of packets (in %) to use for sampling other rates | |
558 | * sample less often for non-mrr packets, because the overhead | |
559 | * is much higher than with mrr */ | |
560 | mp->lookaround_rate = 5; | |
561 | mp->lookaround_rate_mrr = 10; | |
562 | ||
cccf129f FF |
563 | /* maximum time that the hw is allowed to stay in one MRR segment */ |
564 | mp->segment_size = 6000; | |
565 | ||
e6a9854b JB |
566 | if (hw->max_rate_tries > 0) |
567 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
568 | else |
569 | /* safe default, does not necessarily have to match hw properties */ | |
570 | mp->max_retry = 7; | |
571 | ||
e6a9854b | 572 | if (hw->max_rates >= 4) |
cccf129f FF |
573 | mp->has_mrr = true; |
574 | ||
575 | mp->hw = hw; | |
576 | mp->update_interval = 100; | |
577 | ||
24f7580e ZK |
578 | #ifdef CONFIG_MAC80211_DEBUGFS |
579 | mp->fixed_rate_idx = (u32) -1; | |
580 | mp->dbg_fixed_rate = debugfs_create_u32("fixed_rate_idx", | |
581 | S_IRUGO | S_IWUGO, debugfsdir, &mp->fixed_rate_idx); | |
582 | #endif | |
583 | ||
a0497f9f FF |
584 | minstrel_init_cck_rates(mp); |
585 | ||
cccf129f FF |
586 | return mp; |
587 | } | |
588 | ||
589 | static void | |
590 | minstrel_free(void *priv) | |
591 | { | |
24f7580e ZK |
592 | #ifdef CONFIG_MAC80211_DEBUGFS |
593 | debugfs_remove(((struct minstrel_priv *)priv)->dbg_fixed_rate); | |
594 | #endif | |
cccf129f FF |
595 | kfree(priv); |
596 | } | |
597 | ||
eae44756 | 598 | struct rate_control_ops mac80211_minstrel = { |
cccf129f FF |
599 | .name = "minstrel", |
600 | .tx_status = minstrel_tx_status, | |
601 | .get_rate = minstrel_get_rate, | |
602 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
603 | .alloc = minstrel_alloc, |
604 | .free = minstrel_free, | |
605 | .alloc_sta = minstrel_alloc_sta, | |
606 | .free_sta = minstrel_free_sta, | |
607 | #ifdef CONFIG_MAC80211_DEBUGFS | |
608 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
609 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
610 | #endif | |
611 | }; | |
612 | ||
613 | int __init | |
614 | rc80211_minstrel_init(void) | |
615 | { | |
616 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
617 | } | |
618 | ||
619 | void | |
620 | rc80211_minstrel_exit(void) | |
621 | { | |
622 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
623 | } | |
624 |