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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) || | |
4edf040a | 83 | (fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA); |
cccf129f FF |
84 | } |
85 | ||
86 | ||
87 | static void | |
88 | minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi) | |
89 | { | |
90 | u32 max_tp = 0, index_max_tp = 0, index_max_tp2 = 0; | |
91 | u32 max_prob = 0, index_max_prob = 0; | |
92 | u32 usecs; | |
93 | u32 p; | |
94 | int i; | |
95 | ||
96 | mi->stats_update = jiffies; | |
97 | for (i = 0; i < mi->n_rates; i++) { | |
98 | struct minstrel_rate *mr = &mi->r[i]; | |
99 | ||
100 | usecs = mr->perfect_tx_time; | |
101 | if (!usecs) | |
102 | usecs = 1000000; | |
103 | ||
104 | /* To avoid rounding issues, probabilities scale from 0 (0%) | |
105 | * to 18000 (100%) */ | |
106 | if (mr->attempts) { | |
107 | p = (mr->success * 18000) / mr->attempts; | |
108 | mr->succ_hist += mr->success; | |
109 | mr->att_hist += mr->attempts; | |
110 | mr->cur_prob = p; | |
111 | p = ((p * (100 - mp->ewma_level)) + (mr->probability * | |
112 | mp->ewma_level)) / 100; | |
113 | mr->probability = p; | |
114 | mr->cur_tp = p * (1000000 / usecs); | |
115 | } | |
116 | ||
117 | mr->last_success = mr->success; | |
118 | mr->last_attempts = mr->attempts; | |
119 | mr->success = 0; | |
120 | mr->attempts = 0; | |
121 | ||
122 | /* Sample less often below the 10% chance of success. | |
123 | * Sample less often above the 95% chance of success. */ | |
124 | if ((mr->probability > 17100) || (mr->probability < 1800)) { | |
125 | mr->adjusted_retry_count = mr->retry_count >> 1; | |
126 | if (mr->adjusted_retry_count > 2) | |
127 | mr->adjusted_retry_count = 2; | |
f4a8cd94 | 128 | mr->sample_limit = 4; |
cccf129f | 129 | } else { |
f4a8cd94 | 130 | mr->sample_limit = -1; |
cccf129f FF |
131 | mr->adjusted_retry_count = mr->retry_count; |
132 | } | |
133 | if (!mr->adjusted_retry_count) | |
134 | mr->adjusted_retry_count = 2; | |
135 | } | |
136 | ||
137 | for (i = 0; i < mi->n_rates; i++) { | |
138 | struct minstrel_rate *mr = &mi->r[i]; | |
139 | if (max_tp < mr->cur_tp) { | |
140 | index_max_tp = i; | |
141 | max_tp = mr->cur_tp; | |
142 | } | |
143 | if (max_prob < mr->probability) { | |
144 | index_max_prob = i; | |
145 | max_prob = mr->probability; | |
146 | } | |
147 | } | |
148 | ||
149 | max_tp = 0; | |
150 | for (i = 0; i < mi->n_rates; i++) { | |
151 | struct minstrel_rate *mr = &mi->r[i]; | |
152 | ||
153 | if (i == index_max_tp) | |
154 | continue; | |
155 | ||
156 | if (max_tp < mr->cur_tp) { | |
157 | index_max_tp2 = i; | |
158 | max_tp = mr->cur_tp; | |
159 | } | |
160 | } | |
161 | mi->max_tp_rate = index_max_tp; | |
162 | mi->max_tp_rate2 = index_max_tp2; | |
163 | mi->max_prob_rate = index_max_prob; | |
164 | } | |
165 | ||
166 | static void | |
167 | minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband, | |
168 | struct ieee80211_sta *sta, void *priv_sta, | |
169 | struct sk_buff *skb) | |
170 | { | |
171 | struct minstrel_sta_info *mi = priv_sta; | |
172 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
e6a9854b JB |
173 | struct ieee80211_tx_rate *ar = info->status.rates; |
174 | int i, ndx; | |
175 | int success; | |
cccf129f | 176 | |
e6a9854b | 177 | success = !!(info->flags & IEEE80211_TX_STAT_ACK); |
cccf129f | 178 | |
e6a9854b JB |
179 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
180 | if (ar[i].idx < 0) | |
cccf129f FF |
181 | break; |
182 | ||
e6a9854b JB |
183 | ndx = rix_to_ndx(mi, ar[i].idx); |
184 | mi->r[ndx].attempts += ar[i].count; | |
cccf129f | 185 | |
e6a9854b | 186 | if ((i != IEEE80211_TX_MAX_RATES - 1) && (ar[i + 1].idx < 0)) |
cccf129f FF |
187 | mi->r[ndx].success += success; |
188 | } | |
189 | ||
190 | if ((info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE) && (i >= 0)) | |
191 | mi->sample_count++; | |
192 | ||
193 | if (mi->sample_deferred > 0) | |
194 | mi->sample_deferred--; | |
195 | } | |
196 | ||
197 | ||
198 | static inline unsigned int | |
199 | minstrel_get_retry_count(struct minstrel_rate *mr, | |
200 | struct ieee80211_tx_info *info) | |
201 | { | |
202 | unsigned int retry = mr->adjusted_retry_count; | |
203 | ||
e6a9854b | 204 | if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) |
cccf129f | 205 | retry = max(2U, min(mr->retry_count_rtscts, retry)); |
e6a9854b | 206 | else if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_CTS_PROTECT) |
cccf129f FF |
207 | retry = max(2U, min(mr->retry_count_cts, retry)); |
208 | return retry; | |
209 | } | |
210 | ||
211 | ||
212 | static int | |
213 | minstrel_get_next_sample(struct minstrel_sta_info *mi) | |
214 | { | |
215 | unsigned int sample_ndx; | |
216 | sample_ndx = SAMPLE_TBL(mi, mi->sample_idx, mi->sample_column); | |
217 | mi->sample_idx++; | |
5ee58d7e | 218 | if ((int) mi->sample_idx > (mi->n_rates - 2)) { |
cccf129f FF |
219 | mi->sample_idx = 0; |
220 | mi->sample_column++; | |
221 | if (mi->sample_column >= SAMPLE_COLUMNS) | |
222 | mi->sample_column = 0; | |
223 | } | |
224 | return sample_ndx; | |
225 | } | |
226 | ||
2df78167 | 227 | static void |
e6a9854b JB |
228 | minstrel_get_rate(void *priv, struct ieee80211_sta *sta, |
229 | void *priv_sta, struct ieee80211_tx_rate_control *txrc) | |
cccf129f | 230 | { |
e6a9854b JB |
231 | struct sk_buff *skb = txrc->skb; |
232 | struct ieee80211_supported_band *sband = txrc->sband; | |
cccf129f FF |
233 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); |
234 | struct minstrel_sta_info *mi = priv_sta; | |
235 | struct minstrel_priv *mp = priv; | |
e6a9854b | 236 | struct ieee80211_tx_rate *ar = info->control.rates; |
cccf129f FF |
237 | unsigned int ndx, sample_ndx = 0; |
238 | bool mrr; | |
239 | bool sample_slower = false; | |
240 | bool sample = false; | |
241 | int i, delta; | |
242 | int mrr_ndx[3]; | |
243 | int sample_rate; | |
244 | ||
245 | if (!sta || !mi || use_low_rate(skb)) { | |
e6a9854b | 246 | ar[0].idx = rate_lowest_index(sband, sta); |
4edf040a GS |
247 | if (info->flags & IEEE80211_TX_CTL_NO_ACK) |
248 | ar[0].count = 1; | |
249 | else | |
250 | ar[0].count = mp->max_retry; | |
cccf129f FF |
251 | return; |
252 | } | |
253 | ||
e6a9854b | 254 | mrr = mp->has_mrr && !txrc->rts && !txrc->bss_conf->use_cts_prot; |
cccf129f FF |
255 | |
256 | if (time_after(jiffies, mi->stats_update + (mp->update_interval * | |
257 | HZ) / 1000)) | |
258 | minstrel_update_stats(mp, mi); | |
259 | ||
260 | ndx = mi->max_tp_rate; | |
261 | ||
262 | if (mrr) | |
263 | sample_rate = mp->lookaround_rate_mrr; | |
264 | else | |
265 | sample_rate = mp->lookaround_rate; | |
266 | ||
267 | mi->packet_count++; | |
268 | delta = (mi->packet_count * sample_rate / 100) - | |
269 | (mi->sample_count + mi->sample_deferred / 2); | |
270 | ||
271 | /* delta > 0: sampling required */ | |
f4a8cd94 FF |
272 | if ((delta > 0) && (mrr || !mi->prev_sample)) { |
273 | struct minstrel_rate *msr; | |
cccf129f FF |
274 | if (mi->packet_count >= 10000) { |
275 | mi->sample_deferred = 0; | |
276 | mi->sample_count = 0; | |
277 | mi->packet_count = 0; | |
278 | } else if (delta > mi->n_rates * 2) { | |
279 | /* With multi-rate retry, not every planned sample | |
280 | * attempt actually gets used, due to the way the retry | |
281 | * chain is set up - [max_tp,sample,prob,lowest] for | |
282 | * sample_rate < max_tp. | |
283 | * | |
284 | * If there's too much sampling backlog and the link | |
285 | * starts getting worse, minstrel would start bursting | |
286 | * out lots of sampling frames, which would result | |
287 | * in a large throughput loss. */ | |
288 | mi->sample_count += (delta - mi->n_rates * 2); | |
289 | } | |
290 | ||
291 | sample_ndx = minstrel_get_next_sample(mi); | |
f4a8cd94 | 292 | msr = &mi->r[sample_ndx]; |
cccf129f | 293 | sample = true; |
f4a8cd94 | 294 | sample_slower = mrr && (msr->perfect_tx_time > |
cccf129f FF |
295 | mi->r[ndx].perfect_tx_time); |
296 | ||
297 | if (!sample_slower) { | |
f4a8cd94 FF |
298 | if (msr->sample_limit != 0) { |
299 | ndx = sample_ndx; | |
300 | mi->sample_count++; | |
301 | if (msr->sample_limit > 0) | |
302 | msr->sample_limit--; | |
303 | } else { | |
304 | sample = false; | |
305 | } | |
cccf129f FF |
306 | } else { |
307 | /* Only use IEEE80211_TX_CTL_RATE_CTRL_PROBE to mark | |
308 | * packets that have the sampling rate deferred to the | |
309 | * second MRR stage. Increase the sample counter only | |
310 | * if the deferred sample rate was actually used. | |
311 | * Use the sample_deferred counter to make sure that | |
312 | * the sampling is not done in large bursts */ | |
313 | info->flags |= IEEE80211_TX_CTL_RATE_CTRL_PROBE; | |
314 | mi->sample_deferred++; | |
315 | } | |
316 | } | |
f4a8cd94 FF |
317 | mi->prev_sample = sample; |
318 | ||
319 | /* If we're not using MRR and the sampling rate already | |
320 | * has a probability of >95%, we shouldn't be attempting | |
321 | * to use it, as this only wastes precious airtime */ | |
322 | if (!mrr && sample && (mi->r[ndx].probability > 17100)) | |
323 | ndx = mi->max_tp_rate; | |
324 | ||
e6a9854b JB |
325 | ar[0].idx = mi->r[ndx].rix; |
326 | ar[0].count = minstrel_get_retry_count(&mi->r[ndx], info); | |
cccf129f FF |
327 | |
328 | if (!mrr) { | |
f4a8cd94 FF |
329 | if (!sample) |
330 | ar[0].count = mp->max_retry; | |
e6a9854b JB |
331 | ar[1].idx = mi->lowest_rix; |
332 | ar[1].count = mp->max_retry; | |
cccf129f FF |
333 | return; |
334 | } | |
335 | ||
336 | /* MRR setup */ | |
337 | if (sample) { | |
338 | if (sample_slower) | |
339 | mrr_ndx[0] = sample_ndx; | |
340 | else | |
341 | mrr_ndx[0] = mi->max_tp_rate; | |
342 | } else { | |
343 | mrr_ndx[0] = mi->max_tp_rate2; | |
344 | } | |
345 | mrr_ndx[1] = mi->max_prob_rate; | |
346 | mrr_ndx[2] = 0; | |
e6a9854b JB |
347 | for (i = 1; i < 4; i++) { |
348 | ar[i].idx = mi->r[mrr_ndx[i - 1]].rix; | |
349 | ar[i].count = mi->r[mrr_ndx[i - 1]].adjusted_retry_count; | |
cccf129f FF |
350 | } |
351 | } | |
352 | ||
353 | ||
354 | static void | |
355 | calc_rate_durations(struct minstrel_sta_info *mi, struct ieee80211_local *local, | |
356 | struct minstrel_rate *d, struct ieee80211_rate *rate) | |
357 | { | |
358 | int erp = !!(rate->flags & IEEE80211_RATE_ERP_G); | |
359 | ||
360 | d->perfect_tx_time = ieee80211_frame_duration(local, 1200, | |
361 | rate->bitrate, erp, 1); | |
362 | d->ack_time = ieee80211_frame_duration(local, 10, | |
363 | rate->bitrate, erp, 1); | |
364 | } | |
365 | ||
366 | static void | |
367 | init_sample_table(struct minstrel_sta_info *mi) | |
368 | { | |
369 | unsigned int i, col, new_idx; | |
370 | unsigned int n_srates = mi->n_rates - 1; | |
371 | u8 rnd[8]; | |
372 | ||
373 | mi->sample_column = 0; | |
374 | mi->sample_idx = 0; | |
375 | memset(mi->sample_table, 0, SAMPLE_COLUMNS * mi->n_rates); | |
376 | ||
377 | for (col = 0; col < SAMPLE_COLUMNS; col++) { | |
378 | for (i = 0; i < n_srates; i++) { | |
379 | get_random_bytes(rnd, sizeof(rnd)); | |
380 | new_idx = (i + rnd[i & 7]) % n_srates; | |
381 | ||
382 | while (SAMPLE_TBL(mi, new_idx, col) != 0) | |
383 | new_idx = (new_idx + 1) % n_srates; | |
384 | ||
385 | /* Don't sample the slowest rate (i.e. slowest base | |
386 | * rate). We must presume that the slowest rate works | |
387 | * fine, or else other management frames will also be | |
388 | * failing and the link will break */ | |
389 | SAMPLE_TBL(mi, new_idx, col) = i + 1; | |
390 | } | |
391 | } | |
392 | } | |
393 | ||
394 | static void | |
395 | minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband, | |
396 | struct ieee80211_sta *sta, void *priv_sta) | |
397 | { | |
398 | struct minstrel_sta_info *mi = priv_sta; | |
399 | struct minstrel_priv *mp = priv; | |
d57854bb CL |
400 | struct ieee80211_local *local = hw_to_local(mp->hw); |
401 | struct ieee80211_rate *ctl_rate; | |
cccf129f FF |
402 | unsigned int i, n = 0; |
403 | unsigned int t_slot = 9; /* FIXME: get real slot time */ | |
404 | ||
405 | mi->lowest_rix = rate_lowest_index(sband, sta); | |
d57854bb CL |
406 | ctl_rate = &sband->bitrates[mi->lowest_rix]; |
407 | mi->sp_ack_dur = ieee80211_frame_duration(local, 10, ctl_rate->bitrate, | |
408 | !!(ctl_rate->flags & IEEE80211_RATE_ERP_G), 1); | |
cccf129f FF |
409 | |
410 | for (i = 0; i < sband->n_bitrates; i++) { | |
411 | struct minstrel_rate *mr = &mi->r[n]; | |
412 | unsigned int tx_time = 0, tx_time_cts = 0, tx_time_rtscts = 0; | |
413 | unsigned int tx_time_single; | |
414 | unsigned int cw = mp->cw_min; | |
415 | ||
416 | if (!rate_supported(sta, sband->band, i)) | |
417 | continue; | |
418 | n++; | |
419 | memset(mr, 0, sizeof(*mr)); | |
420 | ||
421 | mr->rix = i; | |
422 | mr->bitrate = sband->bitrates[i].bitrate / 5; | |
d57854bb | 423 | calc_rate_durations(mi, local, mr, |
cccf129f FF |
424 | &sband->bitrates[i]); |
425 | ||
426 | /* calculate maximum number of retransmissions before | |
427 | * fallback (based on maximum segment size) */ | |
f4a8cd94 | 428 | mr->sample_limit = -1; |
cccf129f FF |
429 | mr->retry_count = 1; |
430 | mr->retry_count_cts = 1; | |
431 | mr->retry_count_rtscts = 1; | |
432 | tx_time = mr->perfect_tx_time + mi->sp_ack_dur; | |
433 | do { | |
434 | /* add one retransmission */ | |
435 | tx_time_single = mr->ack_time + mr->perfect_tx_time; | |
436 | ||
437 | /* contention window */ | |
438 | tx_time_single += t_slot + min(cw, mp->cw_max); | |
439 | cw = (cw + 1) << 1; | |
440 | ||
441 | tx_time += tx_time_single; | |
442 | tx_time_cts += tx_time_single + mi->sp_ack_dur; | |
443 | tx_time_rtscts += tx_time_single + 2 * mi->sp_ack_dur; | |
444 | if ((tx_time_cts < mp->segment_size) && | |
445 | (mr->retry_count_cts < mp->max_retry)) | |
446 | mr->retry_count_cts++; | |
447 | if ((tx_time_rtscts < mp->segment_size) && | |
448 | (mr->retry_count_rtscts < mp->max_retry)) | |
449 | mr->retry_count_rtscts++; | |
450 | } while ((tx_time < mp->segment_size) && | |
451 | (++mr->retry_count < mp->max_retry)); | |
452 | mr->adjusted_retry_count = mr->retry_count; | |
453 | } | |
454 | ||
455 | for (i = n; i < sband->n_bitrates; i++) { | |
456 | struct minstrel_rate *mr = &mi->r[i]; | |
457 | mr->rix = -1; | |
458 | } | |
459 | ||
460 | mi->n_rates = n; | |
461 | mi->stats_update = jiffies; | |
462 | ||
463 | init_sample_table(mi); | |
464 | } | |
465 | ||
466 | static void * | |
467 | minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp) | |
468 | { | |
469 | struct ieee80211_supported_band *sband; | |
470 | struct minstrel_sta_info *mi; | |
471 | struct minstrel_priv *mp = priv; | |
472 | struct ieee80211_hw *hw = mp->hw; | |
473 | int max_rates = 0; | |
474 | int i; | |
475 | ||
476 | mi = kzalloc(sizeof(struct minstrel_sta_info), gfp); | |
477 | if (!mi) | |
478 | return NULL; | |
479 | ||
480 | for (i = 0; i < IEEE80211_NUM_BANDS; i++) { | |
8e532175 | 481 | sband = hw->wiphy->bands[i]; |
621ad7c9 | 482 | if (sband && sband->n_bitrates > max_rates) |
cccf129f FF |
483 | max_rates = sband->n_bitrates; |
484 | } | |
485 | ||
486 | mi->r = kzalloc(sizeof(struct minstrel_rate) * max_rates, gfp); | |
487 | if (!mi->r) | |
488 | goto error; | |
489 | ||
490 | mi->sample_table = kmalloc(SAMPLE_COLUMNS * max_rates, gfp); | |
491 | if (!mi->sample_table) | |
492 | goto error1; | |
493 | ||
494 | mi->stats_update = jiffies; | |
495 | return mi; | |
496 | ||
497 | error1: | |
498 | kfree(mi->r); | |
499 | error: | |
500 | kfree(mi); | |
501 | return NULL; | |
502 | } | |
503 | ||
504 | static void | |
505 | minstrel_free_sta(void *priv, struct ieee80211_sta *sta, void *priv_sta) | |
506 | { | |
507 | struct minstrel_sta_info *mi = priv_sta; | |
508 | ||
509 | kfree(mi->sample_table); | |
510 | kfree(mi->r); | |
511 | kfree(mi); | |
512 | } | |
513 | ||
cccf129f FF |
514 | static void * |
515 | minstrel_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir) | |
516 | { | |
517 | struct minstrel_priv *mp; | |
518 | ||
519 | mp = kzalloc(sizeof(struct minstrel_priv), GFP_ATOMIC); | |
520 | if (!mp) | |
521 | return NULL; | |
522 | ||
523 | /* contention window settings | |
524 | * Just an approximation. Using the per-queue values would complicate | |
525 | * the calculations and is probably unnecessary */ | |
526 | mp->cw_min = 15; | |
527 | mp->cw_max = 1023; | |
528 | ||
529 | /* number of packets (in %) to use for sampling other rates | |
530 | * sample less often for non-mrr packets, because the overhead | |
531 | * is much higher than with mrr */ | |
532 | mp->lookaround_rate = 5; | |
533 | mp->lookaround_rate_mrr = 10; | |
534 | ||
535 | /* moving average weight for EWMA */ | |
536 | mp->ewma_level = 75; | |
537 | ||
538 | /* maximum time that the hw is allowed to stay in one MRR segment */ | |
539 | mp->segment_size = 6000; | |
540 | ||
e6a9854b JB |
541 | if (hw->max_rate_tries > 0) |
542 | mp->max_retry = hw->max_rate_tries; | |
cccf129f FF |
543 | else |
544 | /* safe default, does not necessarily have to match hw properties */ | |
545 | mp->max_retry = 7; | |
546 | ||
e6a9854b | 547 | if (hw->max_rates >= 4) |
cccf129f FF |
548 | mp->has_mrr = true; |
549 | ||
550 | mp->hw = hw; | |
551 | mp->update_interval = 100; | |
552 | ||
553 | return mp; | |
554 | } | |
555 | ||
556 | static void | |
557 | minstrel_free(void *priv) | |
558 | { | |
559 | kfree(priv); | |
560 | } | |
561 | ||
562 | static struct rate_control_ops mac80211_minstrel = { | |
563 | .name = "minstrel", | |
564 | .tx_status = minstrel_tx_status, | |
565 | .get_rate = minstrel_get_rate, | |
566 | .rate_init = minstrel_rate_init, | |
cccf129f FF |
567 | .alloc = minstrel_alloc, |
568 | .free = minstrel_free, | |
569 | .alloc_sta = minstrel_alloc_sta, | |
570 | .free_sta = minstrel_free_sta, | |
571 | #ifdef CONFIG_MAC80211_DEBUGFS | |
572 | .add_sta_debugfs = minstrel_add_sta_debugfs, | |
573 | .remove_sta_debugfs = minstrel_remove_sta_debugfs, | |
574 | #endif | |
575 | }; | |
576 | ||
577 | int __init | |
578 | rc80211_minstrel_init(void) | |
579 | { | |
580 | return ieee80211_rate_control_register(&mac80211_minstrel); | |
581 | } | |
582 | ||
583 | void | |
584 | rc80211_minstrel_exit(void) | |
585 | { | |
586 | ieee80211_rate_control_unregister(&mac80211_minstrel); | |
587 | } | |
588 |