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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> | |
53 | #include <net/mac80211.h> | |
54 | #include "rate.h" | |
55 | #include "rc80211_minstrel.h" | |
56 | ||
57 | #define SAMPLE_COLUMNS 10 | |
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; | |
69 | WARN_ON(mi->r[i].rix != rix); | |
70 | return i; | |
71 | } | |
72 | ||
73 | static inline bool | |
74 | use_low_rate(struct sk_buff *skb) | |
75 | { | |
76 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
77 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
78 | u16 fc; | |
79 | ||
80 | fc = le16_to_cpu(hdr->frame_control); | |
81 | ||
82 | return ((info->flags & IEEE80211_TX_CTL_NO_ACK) || | |
83 | (fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA || | |
84 | is_multicast_ether_addr(hdr->addr1)); | |
85 | } | |
86 | ||
87 | ||
88 | static void | |
89 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
90 | { | |
91 | u32 max_tp = 0, index_max_tp = 0, index_max_tp2 = 0; | |
92 | u32 max_prob = 0, index_max_prob = 0; | |
93 | u32 usecs; | |
94 | u32 p; | |
95 | int i; | |
96 | ||
97 | mi->stats_update = jiffies; | |
98 | for (i = 0; i < mi->n_rates; i++) { | |
99 | struct minstrel_rate *mr = &mi->r[i]; | |
100 | ||
101 | usecs = mr->perfect_tx_time; | |
102 | if (!usecs) | |
103 | usecs = 1000000; | |
104 | ||
105 | /* To avoid rounding issues, probabilities scale from 0 (0%) | |
106 | * to 18000 (100%) */ | |
107 | if (mr->attempts) { | |
108 | p = (mr->success * 18000) / mr->attempts; | |
109 | mr->succ_hist += mr->success; | |
110 | mr->att_hist += mr->attempts; | |
111 | mr->cur_prob = p; | |
112 | p = ((p * (100 - mp->ewma_level)) + (mr->probability * | |
113 | mp->ewma_level)) / 100; | |
114 | mr->probability = p; | |
115 | mr->cur_tp = p * (1000000 / usecs); | |
116 | } | |
117 | ||
118 | mr->last_success = mr->success; | |
119 | mr->last_attempts = mr->attempts; | |
120 | mr->success = 0; | |
121 | mr->attempts = 0; | |
122 | ||
123 | /* Sample less often below the 10% chance of success. | |
124 | * Sample less often above the 95% chance of success. */ | |
125 | if ((mr->probability > 17100) || (mr->probability < 1800)) { | |
126 | mr->adjusted_retry_count = mr->retry_count >> 1; | |
127 | if (mr->adjusted_retry_count > 2) | |
128 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 129 | mr->sample_limit = 4; |
cccf129f | 130 | } else { |
f4a8cd94 | 131 | mr->sample_limit = -1; |
cccf129f FF |
132 | mr->adjusted_retry_count = mr->retry_count; |
133 | } | |
134 | if (!mr->adjusted_retry_count) | |
135 | mr->adjusted_retry_count = 2; | |
136 | } | |
137 | ||
138 | for (i = 0; i < mi->n_rates; i++) { | |
139 | struct minstrel_rate *mr = &mi->r[i]; | |
140 | if (max_tp < mr->cur_tp) { | |
141 | index_max_tp = i; | |
142 | max_tp = mr->cur_tp; | |
143 | } | |
144 | if (max_prob < mr->probability) { | |
145 | index_max_prob = i; | |
146 | max_prob = mr->probability; | |
147 | } | |
148 | } | |
149 | ||
150 | max_tp = 0; | |
151 | for (i = 0; i < mi->n_rates; i++) { | |
152 | struct minstrel_rate *mr = &mi->r[i]; | |
153 | ||
154 | if (i == index_max_tp) | |
155 | continue; | |
156 | ||
157 | if (max_tp < mr->cur_tp) { | |
158 | index_max_tp2 = i; | |
159 | max_tp = mr->cur_tp; | |
160 | } | |
161 | } | |
162 | mi->max_tp_rate = index_max_tp; | |
163 | mi->max_tp_rate2 = index_max_tp2; | |
164 | mi->max_prob_rate = index_max_prob; | |
165 | } | |
166 | ||
167 | static void | |
168 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
169 | struct ieee80211_sta *sta, void *priv_sta, | |
170 | struct sk_buff *skb) | |
171 | { | |
172 | struct minstrel_sta_info *mi = priv_sta; | |
173 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
e6a9854b JB |
174 | struct ieee80211_tx_rate *ar = info->status.rates; |
175 | int i, ndx; | |
176 | int success; | |
cccf129f | 177 | |
e6a9854b | 178 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 179 | |
e6a9854b JB |
180 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
181 | if (ar[i].idx < 0) | |
cccf129f FF |
182 | break; |
183 | ||
e6a9854b JB |
184 | ndx = rix_to_ndx(mi, ar[i].idx); |
185 | mi->r[ndx].attempts += ar[i].count; | |
cccf129f | 186 | |
e6a9854b | 187 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
cccf129f FF |
188 | mi->r[ndx].success += success; |
189 | } | |
190 | ||
191 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
192 | mi->sample_count++; | |
193 | ||
194 | if (mi->sample_deferred > 0) | |
195 | mi->sample_deferred--; | |
196 | } | |
197 | ||
198 | ||
199 | static inline unsigned int | |
200 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
201 | struct ieee80211_tx_info *info) | |
202 | { | |
203 | unsigned int retry = mr->adjusted_retry_count; | |
204 | ||
e6a9854b | 205 | if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) |
cccf129f | 206 | retry = max(2U, min(mr->retry_count_rtscts, retry)); |
e6a9854b | 207 | else if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) |
cccf129f FF |
208 | retry = max(2U, min(mr->retry_count_cts, retry)); |
209 | return retry; | |
210 | } | |
211 | ||
212 | ||
213 | static int | |
214 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
215 | { | |
216 | unsigned int sample_ndx; | |
217 | sample_ndx = SAMPLE_TBL(mi, mi->sample_idx, mi->sample_column); | |
218 | mi->sample_idx++; | |
219 | if (mi->sample_idx > (mi->n_rates - 2)) { | |
220 | mi->sample_idx = 0; | |
221 | mi->sample_column++; | |
222 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
223 | mi->sample_column = 0; | |
224 | } | |
225 | return sample_ndx; | |
226 | } | |
227 | ||
2df78167 | 228 | static void |
e6a9854b JB |
229 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
230 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 231 | { |
e6a9854b JB |
232 | struct sk_buff *skb = txrc->skb; |
233 | struct ieee80211_supported_band *sband = txrc->sband; | |
cccf129f FF |
234 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
235 | struct minstrel_sta_info *mi = priv_sta; | |
236 | struct minstrel_priv *mp = priv; | |
e6a9854b | 237 | struct ieee80211_tx_rate *ar = info->control.rates; |
cccf129f FF |
238 | unsigned int ndx, sample_ndx = 0; |
239 | bool mrr; | |
240 | bool sample_slower = false; | |
241 | bool sample = false; | |
242 | int i, delta; | |
243 | int mrr_ndx[3]; | |
244 | int sample_rate; | |
245 | ||
246 | if (!sta || !mi || use_low_rate(skb)) { | |
e6a9854b JB |
247 | ar[0].idx = rate_lowest_index(sband, sta); |
248 | ar[0].count = mp->max_retry; | |
cccf129f FF |
249 | return; |
250 | } | |
251 | ||
e6a9854b | 252 | mrr = mp->has_mrr && !txrc->rts && !txrc->bss_conf->use_cts_prot; |
cccf129f FF |
253 | |
254 | if (time_after(jiffies, mi->stats_update + (mp->update_interval * | |
255 | HZ) / 1000)) | |
256 | minstrel_update_stats(mp, mi); | |
257 | ||
258 | ndx = mi->max_tp_rate; | |
259 | ||
260 | if (mrr) | |
261 | sample_rate = mp->lookaround_rate_mrr; | |
262 | else | |
263 | sample_rate = mp->lookaround_rate; | |
264 | ||
265 | mi->packet_count++; | |
266 | delta = (mi->packet_count * sample_rate / 100) - | |
267 | (mi->sample_count + mi->sample_deferred / 2); | |
268 | ||
269 | /* delta > 0: sampling required */ | |
f4a8cd94 FF |
270 | if ((delta > 0) && (mrr || !mi->prev_sample)) { |
271 | struct minstrel_rate *msr; | |
cccf129f FF |
272 | if (mi->packet_count >= 10000) { |
273 | mi->sample_deferred = 0; | |
274 | mi->sample_count = 0; | |
275 | mi->packet_count = 0; | |
276 | } else if (delta > mi->n_rates * 2) { | |
277 | /* With multi-rate retry, not every planned sample | |
278 | * attempt actually gets used, due to the way the retry | |
279 | * chain is set up - [max_tp,sample,prob,lowest] for | |
280 | * sample_rate < max_tp. | |
281 | * | |
282 | * If there's too much sampling backlog and the link | |
283 | * starts getting worse, minstrel would start bursting | |
284 | * out lots of sampling frames, which would result | |
285 | * in a large throughput loss. */ | |
286 | mi->sample_count += (delta - mi->n_rates * 2); | |
287 | } | |
288 | ||
289 | sample_ndx = minstrel_get_next_sample(mi); | |
f4a8cd94 | 290 | msr = &mi->r[sample_ndx]; |
cccf129f | 291 | sample = true; |
f4a8cd94 | 292 | sample_slower = mrr && (msr->perfect_tx_time > |
cccf129f FF |
293 | mi->r[ndx].perfect_tx_time); |
294 | ||
295 | if (!sample_slower) { | |
f4a8cd94 FF |
296 | if (msr->sample_limit != 0) { |
297 | ndx = sample_ndx; | |
298 | mi->sample_count++; | |
299 | if (msr->sample_limit > 0) | |
300 | msr->sample_limit--; | |
301 | } else { | |
302 | sample = false; | |
303 | } | |
cccf129f FF |
304 | } else { |
305 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark | |
306 | * packets that have the sampling rate deferred to the | |
307 | * second MRR stage. Increase the sample counter only | |
308 | * if the deferred sample rate was actually used. | |
309 | * Use the sample_deferred counter to make sure that | |
310 | * the sampling is not done in large bursts */ | |
311 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
312 | mi->sample_deferred++; | |
313 | } | |
314 | } | |
f4a8cd94 FF |
315 | mi->prev_sample = sample; |
316 | ||
317 | /* If we're not using MRR and the sampling rate already | |
318 | * has a probability of >95%, we shouldn't be attempting | |
319 | * to use it, as this only wastes precious airtime */ | |
320 | if (!mrr && sample && (mi->r[ndx].probability > 17100)) | |
321 | ndx = mi->max_tp_rate; | |
322 | ||
e6a9854b JB |
323 | ar[0].idx = mi->r[ndx].rix; |
324 | ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f FF |
325 | |
326 | if (!mrr) { | |
f4a8cd94 FF |
327 | if (!sample) |
328 | ar[0].count = mp->max_retry; | |
e6a9854b JB |
329 | ar[1].idx = mi->lowest_rix; |
330 | ar[1].count = mp->max_retry; | |
cccf129f FF |
331 | return; |
332 | } | |
333 | ||
334 | /* MRR setup */ | |
335 | if (sample) { | |
336 | if (sample_slower) | |
337 | mrr_ndx[0] = sample_ndx; | |
338 | else | |
339 | mrr_ndx[0] = mi->max_tp_rate; | |
340 | } else { | |
341 | mrr_ndx[0] = mi->max_tp_rate2; | |
342 | } | |
343 | mrr_ndx[1] = mi->max_prob_rate; | |
344 | mrr_ndx[2] = 0; | |
e6a9854b JB |
345 | for (i = 1; i < 4; i++) { |
346 | ar[i].idx = mi->r[mrr_ndx[i - 1]].rix; | |
347 | ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count; | |
cccf129f FF |
348 | } |
349 | } | |
350 | ||
351 | ||
352 | static void | |
353 | calc_rate_durations(struct minstrel_sta_info *mi, struct ieee80211_local *local, | |
354 | struct minstrel_rate *d, struct ieee80211_rate *rate) | |
355 | { | |
356 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
357 | ||
358 | d->perfect_tx_time = ieee80211_frame_duration(local, 1200, | |
359 | rate->bitrate, erp, 1); | |
360 | d->ack_time = ieee80211_frame_duration(local, 10, | |
361 | rate->bitrate, erp, 1); | |
362 | } | |
363 | ||
364 | static void | |
365 | init_sample_table(struct minstrel_sta_info *mi) | |
366 | { | |
367 | unsigned int i, col, new_idx; | |
368 | unsigned int n_srates = mi->n_rates - 1; | |
369 | u8 rnd[8]; | |
370 | ||
371 | mi->sample_column = 0; | |
372 | mi->sample_idx = 0; | |
373 | memset(mi->sample_table, 0, SAMPLE_COLUMNS * mi->n_rates); | |
374 | ||
375 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
376 | for (i = 0; i < n_srates; i++) { | |
377 | get_random_bytes(rnd, sizeof(rnd)); | |
378 | new_idx = (i + rnd[i & 7]) % n_srates; | |
379 | ||
380 | while (SAMPLE_TBL(mi, new_idx, col) != 0) | |
381 | new_idx = (new_idx + 1) % n_srates; | |
382 | ||
383 | /* Don't sample the slowest rate (i.e. slowest base | |
384 | * rate). We must presume that the slowest rate works | |
385 | * fine, or else other management frames will also be | |
386 | * failing and the link will break */ | |
387 | SAMPLE_TBL(mi, new_idx, col) = i + 1; | |
388 | } | |
389 | } | |
390 | } | |
391 | ||
392 | static void | |
393 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
394 | struct ieee80211_sta *sta, void *priv_sta) | |
395 | { | |
396 | struct minstrel_sta_info *mi = priv_sta; | |
397 | struct minstrel_priv *mp = priv; | |
d57854bb CL |
398 | struct ieee80211_local *local = hw_to_local(mp->hw); |
399 | struct ieee80211_rate *ctl_rate; | |
cccf129f FF |
400 | unsigned int i, n = 0; |
401 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
402 | ||
403 | mi->lowest_rix = rate_lowest_index(sband, sta); | |
d57854bb CL |
404 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
405 | mi->sp_ack_dur = ieee80211_frame_duration(local, 10, ctl_rate->bitrate, | |
406 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1); | |
cccf129f FF |
407 | |
408 | for (i = 0; i < sband->n_bitrates; i++) { | |
409 | struct minstrel_rate *mr = &mi->r[n]; | |
410 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; | |
411 | unsigned int tx_time_single; | |
412 | unsigned int cw = mp->cw_min; | |
413 | ||
414 | if (!rate_supported(sta, sband->band, i)) | |
415 | continue; | |
416 | n++; | |
417 | memset(mr, 0, sizeof(*mr)); | |
418 | ||
419 | mr->rix = i; | |
420 | mr->bitrate = sband->bitrates[i].bitrate / 5; | |
d57854bb | 421 | calc_rate_durations(mi, local, mr, |
cccf129f FF |
422 | &sband->bitrates[i]); |
423 | ||
424 | /* calculate maximum number of retransmissions before | |
425 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 426 | mr->sample_limit = -1; |
cccf129f FF |
427 | mr->retry_count = 1; |
428 | mr->retry_count_cts = 1; | |
429 | mr->retry_count_rtscts = 1; | |
430 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; | |
431 | do { | |
432 | /* add one retransmission */ | |
433 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
434 | ||
435 | /* contention window */ | |
436 | tx_time_single += t_slot + min(cw, mp->cw_max); | |
437 | cw = (cw + 1) << 1; | |
438 | ||
439 | tx_time += tx_time_single; | |
440 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
441 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
442 | if ((tx_time_cts < mp->segment_size) && | |
443 | (mr->retry_count_cts < mp->max_retry)) | |
444 | mr->retry_count_cts++; | |
445 | if ((tx_time_rtscts < mp->segment_size) && | |
446 | (mr->retry_count_rtscts < mp->max_retry)) | |
447 | mr->retry_count_rtscts++; | |
448 | } while ((tx_time < mp->segment_size) && | |
449 | (++mr->retry_count < mp->max_retry)); | |
450 | mr->adjusted_retry_count = mr->retry_count; | |
451 | } | |
452 | ||
453 | for (i = n; i < sband->n_bitrates; i++) { | |
454 | struct minstrel_rate *mr = &mi->r[i]; | |
455 | mr->rix = -1; | |
456 | } | |
457 | ||
458 | mi->n_rates = n; | |
459 | mi->stats_update = jiffies; | |
460 | ||
461 | init_sample_table(mi); | |
462 | } | |
463 | ||
464 | static void * | |
465 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
466 | { | |
467 | struct ieee80211_supported_band *sband; | |
468 | struct minstrel_sta_info *mi; | |
469 | struct minstrel_priv *mp = priv; | |
470 | struct ieee80211_hw *hw = mp->hw; | |
471 | int max_rates = 0; | |
472 | int i; | |
473 | ||
474 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
475 | if (!mi) | |
476 | return NULL; | |
477 | ||
478 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { | |
8e532175 | 479 | sband = hw->wiphy->bands[i]; |
cccf129f FF |
480 | if (sband->n_bitrates > max_rates) |
481 | max_rates = sband->n_bitrates; | |
482 | } | |
483 | ||
484 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
485 | if (!mi->r) | |
486 | goto error; | |
487 | ||
488 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
489 | if (!mi->sample_table) | |
490 | goto error1; | |
491 | ||
492 | mi->stats_update = jiffies; | |
493 | return mi; | |
494 | ||
495 | error1: | |
496 | kfree(mi->r); | |
497 | error: | |
498 | kfree(mi); | |
499 | return NULL; | |
500 | } | |
501 | ||
502 | static void | |
503 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
504 | { | |
505 | struct minstrel_sta_info *mi = priv_sta; | |
506 | ||
507 | kfree(mi->sample_table); | |
508 | kfree(mi->r); | |
509 | kfree(mi); | |
510 | } | |
511 | ||
cccf129f FF |
512 | static void * |
513 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
514 | { | |
515 | struct minstrel_priv *mp; | |
516 | ||
517 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
518 | if (!mp) | |
519 | return NULL; | |
520 | ||
521 | /* contention window settings | |
522 | * Just an approximation. Using the per-queue values would complicate | |
523 | * the calculations and is probably unnecessary */ | |
524 | mp->cw_min = 15; | |
525 | mp->cw_max = 1023; | |
526 | ||
527 | /* number of packets (in %) to use for sampling other rates | |
528 | * sample less often for non-mrr packets, because the overhead | |
529 | * is much higher than with mrr */ | |
530 | mp->lookaround_rate = 5; | |
531 | mp->lookaround_rate_mrr = 10; | |
532 | ||
533 | /* moving average weight for EWMA */ | |
534 | mp->ewma_level = 75; | |
535 | ||
536 | /* maximum time that the hw is allowed to stay in one MRR segment */ | |
537 | mp->segment_size = 6000; | |
538 | ||
e6a9854b JB |
539 | if (hw->max_rate_tries > 0) |
540 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
541 | else |
542 | /* safe default, does not necessarily have to match hw properties */ | |
543 | mp->max_retry = 7; | |
544 | ||
e6a9854b | 545 | if (hw->max_rates >= 4) |
cccf129f FF |
546 | mp->has_mrr = true; |
547 | ||
548 | mp->hw = hw; | |
549 | mp->update_interval = 100; | |
550 | ||
551 | return mp; | |
552 | } | |
553 | ||
554 | static void | |
555 | minstrel_free(void *priv) | |
556 | { | |
557 | kfree(priv); | |
558 | } | |
559 | ||
560 | static struct rate_control_ops mac80211_minstrel = { | |
561 | .name = "minstrel", | |
562 | .tx_status = minstrel_tx_status, | |
563 | .get_rate = minstrel_get_rate, | |
564 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
565 | .alloc = minstrel_alloc, |
566 | .free = minstrel_free, | |
567 | .alloc_sta = minstrel_alloc_sta, | |
568 | .free_sta = minstrel_free_sta, | |
569 | #ifdef CONFIG_MAC80211_DEBUGFS | |
570 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
571 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
572 | #endif | |
573 | }; | |
574 | ||
575 | int __init | |
576 | rc80211_minstrel_init(void) | |
577 | { | |
578 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
579 | } | |
580 | ||
581 | void | |
582 | rc80211_minstrel_exit(void) | |
583 | { | |
584 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
585 | } | |
586 |