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ad018375 MN |
1 | /* |
2 | * Copyright 2002-2005, Instant802 Networks, Inc. | |
3 | * Copyright 2005, Devicescape Software, Inc. | |
4 | * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de> | |
90d501d6 | 5 | * Copyright 2007, Stefano Brivio <stefano.brivio@polimi.it> |
ad018375 MN |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/netdevice.h> | |
13 | #include <linux/types.h> | |
14 | #include <linux/skbuff.h> | |
4b475898 | 15 | #include <linux/debugfs.h> |
ad018375 MN |
16 | #include <net/mac80211.h> |
17 | #include "ieee80211_rate.h" | |
18 | ||
12446c67 MN |
19 | #include "rc80211_pid.h" |
20 | ||
ad018375 MN |
21 | |
22 | /* This is an implementation of a TX rate control algorithm that uses a PID | |
23 | * controller. Given a target failed frames rate, the controller decides about | |
24 | * TX rate changes to meet the target failed frames rate. | |
25 | * | |
26 | * The controller basically computes the following: | |
27 | * | |
1dc4d1e6 | 28 | * adj = CP * err + CI * err_avg + CD * (err - last_err) * (1 + sharpening) |
ad018375 MN |
29 | * |
30 | * where | |
31 | * adj adjustment value that is used to switch TX rate (see below) | |
32 | * err current error: target vs. current failed frames percentage | |
33 | * last_err last error | |
34 | * err_avg average (i.e. poor man's integral) of recent errors | |
1dc4d1e6 SB |
35 | * sharpening non-zero when fast response is needed (i.e. right after |
36 | * association or no frames sent for a long time), heading | |
37 | * to zero over time | |
ad018375 MN |
38 | * CP Proportional coefficient |
39 | * CI Integral coefficient | |
40 | * CD Derivative coefficient | |
41 | * | |
42 | * CP, CI, CD are subject to careful tuning. | |
43 | * | |
44 | * The integral component uses a exponential moving average approach instead of | |
45 | * an actual sliding window. The advantage is that we don't need to keep an | |
46 | * array of the last N error values and computation is easier. | |
47 | * | |
90d501d6 SB |
48 | * Once we have the adj value, we map it to a rate by means of a learning |
49 | * algorithm. This algorithm keeps the state of the percentual failed frames | |
50 | * difference between rates. The behaviour of the lowest available rate is kept | |
51 | * as a reference value, and every time we switch between two rates, we compute | |
52 | * the difference between the failed frames each rate exhibited. By doing so, | |
53 | * we compare behaviours which different rates exhibited in adjacent timeslices, | |
54 | * thus the comparison is minimally affected by external conditions. This | |
55 | * difference gets propagated to the whole set of measurements, so that the | |
56 | * reference is always the same. Periodically, we normalize this set so that | |
57 | * recent events weigh the most. By comparing the adj value with this set, we | |
58 | * avoid pejorative switches to lower rates and allow for switches to higher | |
59 | * rates if they behaved well. | |
ad018375 MN |
60 | * |
61 | * Note that for the computations we use a fixed-point representation to avoid | |
62 | * floating point arithmetic. Hence, all values are shifted left by | |
63 | * RC_PID_ARITH_SHIFT. | |
64 | */ | |
65 | ||
ad018375 | 66 | |
90d501d6 SB |
67 | /* Shift the adjustment so that we won't switch to a lower rate if it exhibited |
68 | * a worse failed frames behaviour and we'll choose the highest rate whose | |
69 | * failed frames behaviour is not worse than the one of the original rate | |
70 | * target. While at it, check that the adjustment is within the ranges. Then, | |
71 | * provide the new rate index. */ | |
72 | static int rate_control_pid_shift_adjust(struct rc_pid_rateinfo *r, | |
73 | int adj, int cur, int l) | |
74 | { | |
75 | int i, j, k, tmp; | |
76 | ||
fa44327c SB |
77 | j = r[cur].rev_index; |
78 | i = j + adj; | |
90d501d6 | 79 | |
fa44327c SB |
80 | if (i < 0) |
81 | return r[0].index; | |
82 | if (i >= l - 1) | |
83 | return r[l - 1].index; | |
90d501d6 | 84 | |
fa44327c | 85 | tmp = i; |
90d501d6 SB |
86 | |
87 | if (adj < 0) { | |
fa44327c SB |
88 | for (k = j; k >= i; k--) |
89 | if (r[k].diff <= r[j].diff) | |
90 | tmp = k; | |
91 | } else { | |
92 | for (k = i + 1; k + i < l; k++) | |
93 | if (r[k].diff <= r[i].diff) | |
94 | tmp = k; | |
90d501d6 | 95 | } |
fa44327c SB |
96 | |
97 | return r[tmp].index; | |
90d501d6 | 98 | } |
ad018375 MN |
99 | |
100 | static void rate_control_pid_adjust_rate(struct ieee80211_local *local, | |
90d501d6 SB |
101 | struct sta_info *sta, int adj, |
102 | struct rc_pid_rateinfo *rinfo) | |
ad018375 MN |
103 | { |
104 | struct ieee80211_sub_if_data *sdata; | |
105 | struct ieee80211_hw_mode *mode; | |
90d501d6 | 106 | int newidx; |
ad018375 MN |
107 | int maxrate; |
108 | int back = (adj > 0) ? 1 : -1; | |
109 | ||
110 | sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); | |
111 | if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) { | |
112 | /* forced unicast rate - do not change STA rate */ | |
113 | return; | |
114 | } | |
115 | ||
116 | mode = local->oper_hw_mode; | |
117 | maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1; | |
118 | ||
90d501d6 SB |
119 | newidx = rate_control_pid_shift_adjust(rinfo, adj, sta->txrate, |
120 | mode->num_rates); | |
ad018375 MN |
121 | |
122 | while (newidx != sta->txrate) { | |
123 | if (rate_supported(sta, mode, newidx) && | |
124 | (maxrate < 0 || newidx <= maxrate)) { | |
125 | sta->txrate = newidx; | |
126 | break; | |
127 | } | |
128 | ||
129 | newidx += back; | |
130 | } | |
12446c67 MN |
131 | |
132 | #ifdef CONFIG_MAC80211_DEBUGFS | |
133 | rate_control_pid_event_rate_change( | |
134 | &((struct rc_pid_sta_info *)sta->rate_ctrl_priv)->events, | |
135 | newidx, mode->rates[newidx].rate); | |
136 | #endif | |
ad018375 MN |
137 | } |
138 | ||
90d501d6 | 139 | /* Normalize the failed frames per-rate differences. */ |
1946b74c | 140 | static void rate_control_pid_normalize(struct rc_pid_info *pinfo, int l) |
90d501d6 | 141 | { |
1946b74c MN |
142 | int i, norm_offset = pinfo->norm_offset; |
143 | struct rc_pid_rateinfo *r = pinfo->rinfo; | |
90d501d6 | 144 | |
1946b74c MN |
145 | if (r[0].diff > norm_offset) |
146 | r[0].diff -= norm_offset; | |
147 | else if (r[0].diff < -norm_offset) | |
148 | r[0].diff += norm_offset; | |
90d501d6 | 149 | for (i = 0; i < l - 1; i++) |
1946b74c MN |
150 | if (r[i + 1].diff > r[i].diff + norm_offset) |
151 | r[i + 1].diff -= norm_offset; | |
90d501d6 | 152 | else if (r[i + 1].diff <= r[i].diff) |
1946b74c | 153 | r[i + 1].diff += norm_offset; |
90d501d6 SB |
154 | } |
155 | ||
ad018375 MN |
156 | static void rate_control_pid_sample(struct rc_pid_info *pinfo, |
157 | struct ieee80211_local *local, | |
158 | struct sta_info *sta) | |
159 | { | |
160 | struct rc_pid_sta_info *spinfo = sta->rate_ctrl_priv; | |
90d501d6 SB |
161 | struct rc_pid_rateinfo *rinfo = pinfo->rinfo; |
162 | struct ieee80211_hw_mode *mode; | |
ad018375 MN |
163 | u32 pf; |
164 | s32 err_avg; | |
1946b74c MN |
165 | u32 err_prop; |
166 | u32 err_int; | |
167 | u32 err_der; | |
90d501d6 | 168 | int adj, i, j, tmp; |
1946b74c | 169 | unsigned long period; |
ad018375 | 170 | |
90d501d6 | 171 | mode = local->oper_hw_mode; |
ad018375 | 172 | spinfo = sta->rate_ctrl_priv; |
1dc4d1e6 SB |
173 | |
174 | /* In case nothing happened during the previous control interval, turn | |
175 | * the sharpening factor on. */ | |
1946b74c MN |
176 | period = (HZ * pinfo->sampling_period + 500) / 1000; |
177 | if (!period) | |
178 | period = 1; | |
179 | if (jiffies - spinfo->last_sample > 2 * period) | |
180 | spinfo->sharp_cnt = pinfo->sharpen_duration; | |
1dc4d1e6 | 181 | |
ad018375 MN |
182 | spinfo->last_sample = jiffies; |
183 | ||
1dc4d1e6 | 184 | /* This should never happen, but in case, we assume the old sample is |
ad018375 | 185 | * still a good measurement and copy it. */ |
1dc4d1e6 | 186 | if (unlikely(spinfo->tx_num_xmit == 0)) |
ad018375 MN |
187 | pf = spinfo->last_pf; |
188 | else { | |
189 | pf = spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit; | |
190 | pf <<= RC_PID_ARITH_SHIFT; | |
ad018375 MN |
191 | } |
192 | ||
1dc4d1e6 SB |
193 | spinfo->tx_num_xmit = 0; |
194 | spinfo->tx_num_failed = 0; | |
195 | ||
90d501d6 SB |
196 | /* If we just switched rate, update the rate behaviour info. */ |
197 | if (pinfo->oldrate != sta->txrate) { | |
198 | ||
199 | i = rinfo[pinfo->oldrate].rev_index; | |
200 | j = rinfo[sta->txrate].rev_index; | |
201 | ||
202 | tmp = (pf - spinfo->last_pf); | |
203 | tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT); | |
204 | ||
205 | rinfo[j].diff = rinfo[i].diff + tmp; | |
206 | pinfo->oldrate = sta->txrate; | |
207 | } | |
1946b74c | 208 | rate_control_pid_normalize(pinfo, mode->num_rates); |
90d501d6 | 209 | |
ad018375 | 210 | /* Compute the proportional, integral and derivative errors. */ |
426706c0 | 211 | err_prop = (pinfo->target << RC_PID_ARITH_SHIFT) - pf; |
ad018375 | 212 | |
1946b74c | 213 | err_avg = spinfo->err_avg_sc >> pinfo->smoothing_shift; |
ad018375 | 214 | spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop; |
1946b74c | 215 | err_int = spinfo->err_avg_sc >> pinfo->smoothing_shift; |
ad018375 | 216 | |
1946b74c MN |
217 | err_der = (pf - spinfo->last_pf) * |
218 | (1 + pinfo->sharpen_factor * spinfo->sharp_cnt); | |
ad018375 | 219 | spinfo->last_pf = pf; |
1dc4d1e6 SB |
220 | if (spinfo->sharp_cnt) |
221 | spinfo->sharp_cnt--; | |
ad018375 | 222 | |
12446c67 MN |
223 | #ifdef CONFIG_MAC80211_DEBUGFS |
224 | rate_control_pid_event_pf_sample(&spinfo->events, pf, err_prop, err_int, | |
225 | err_der); | |
226 | #endif | |
227 | ||
ad018375 MN |
228 | /* Compute the controller output. */ |
229 | adj = (err_prop * pinfo->coeff_p + err_int * pinfo->coeff_i | |
230 | + err_der * pinfo->coeff_d); | |
90d501d6 | 231 | adj = RC_PID_DO_ARITH_RIGHT_SHIFT(adj, 2 * RC_PID_ARITH_SHIFT); |
ad018375 MN |
232 | |
233 | /* Change rate. */ | |
234 | if (adj) | |
90d501d6 | 235 | rate_control_pid_adjust_rate(local, sta, adj, rinfo); |
ad018375 MN |
236 | } |
237 | ||
238 | static void rate_control_pid_tx_status(void *priv, struct net_device *dev, | |
239 | struct sk_buff *skb, | |
240 | struct ieee80211_tx_status *status) | |
241 | { | |
242 | struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); | |
243 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
244 | struct rc_pid_info *pinfo = priv; | |
245 | struct sta_info *sta; | |
246 | struct rc_pid_sta_info *spinfo; | |
1946b74c | 247 | unsigned long period; |
ad018375 MN |
248 | |
249 | sta = sta_info_get(local, hdr->addr1); | |
250 | ||
251 | if (!sta) | |
252 | return; | |
253 | ||
254 | /* Ignore all frames that were sent with a different rate than the rate | |
255 | * we currently advise mac80211 to use. */ | |
256 | if (status->control.rate != &local->oper_hw_mode->rates[sta->txrate]) | |
13e05aa6 | 257 | goto ignore; |
ad018375 MN |
258 | |
259 | spinfo = sta->rate_ctrl_priv; | |
260 | spinfo->tx_num_xmit++; | |
261 | ||
12446c67 MN |
262 | #ifdef CONFIG_MAC80211_DEBUGFS |
263 | rate_control_pid_event_tx_status(&spinfo->events, status); | |
264 | #endif | |
265 | ||
ad018375 MN |
266 | /* We count frames that totally failed to be transmitted as two bad |
267 | * frames, those that made it out but had some retries as one good and | |
268 | * one bad frame. */ | |
269 | if (status->excessive_retries) { | |
270 | spinfo->tx_num_failed += 2; | |
271 | spinfo->tx_num_xmit++; | |
272 | } else if (status->retry_count) { | |
273 | spinfo->tx_num_failed++; | |
274 | spinfo->tx_num_xmit++; | |
275 | } | |
276 | ||
277 | if (status->excessive_retries) { | |
278 | sta->tx_retry_failed++; | |
279 | sta->tx_num_consecutive_failures++; | |
280 | sta->tx_num_mpdu_fail++; | |
281 | } else { | |
282 | sta->last_ack_rssi[0] = sta->last_ack_rssi[1]; | |
283 | sta->last_ack_rssi[1] = sta->last_ack_rssi[2]; | |
284 | sta->last_ack_rssi[2] = status->ack_signal; | |
285 | sta->tx_num_consecutive_failures = 0; | |
286 | sta->tx_num_mpdu_ok++; | |
287 | } | |
288 | sta->tx_retry_count += status->retry_count; | |
289 | sta->tx_num_mpdu_fail += status->retry_count; | |
290 | ||
291 | /* Update PID controller state. */ | |
1946b74c MN |
292 | period = (HZ * pinfo->sampling_period + 500) / 1000; |
293 | if (!period) | |
294 | period = 1; | |
295 | if (time_after(jiffies, spinfo->last_sample + period)) | |
ad018375 MN |
296 | rate_control_pid_sample(pinfo, local, sta); |
297 | ||
13e05aa6 | 298 | ignore: |
ad018375 MN |
299 | sta_info_put(sta); |
300 | } | |
301 | ||
302 | static void rate_control_pid_get_rate(void *priv, struct net_device *dev, | |
303 | struct ieee80211_hw_mode *mode, | |
304 | struct sk_buff *skb, | |
305 | struct rate_selection *sel) | |
306 | { | |
307 | struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr); | |
308 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
309 | struct sta_info *sta; | |
310 | int rateidx; | |
311 | ||
312 | sta = sta_info_get(local, hdr->addr1); | |
313 | ||
314 | if (!sta) { | |
315 | sel->rate = rate_lowest(local, mode, NULL); | |
316 | sta_info_put(sta); | |
317 | return; | |
318 | } | |
319 | ||
320 | rateidx = sta->txrate; | |
321 | ||
322 | if (rateidx >= mode->num_rates) | |
323 | rateidx = mode->num_rates - 1; | |
324 | ||
325 | sta_info_put(sta); | |
326 | ||
327 | sel->rate = &mode->rates[rateidx]; | |
12446c67 MN |
328 | |
329 | #ifdef CONFIG_MAC80211_DEBUGFS | |
330 | rate_control_pid_event_tx_rate( | |
331 | &((struct rc_pid_sta_info *) sta->rate_ctrl_priv)->events, | |
332 | rateidx, mode->rates[rateidx].rate); | |
333 | #endif | |
ad018375 MN |
334 | } |
335 | ||
336 | static void rate_control_pid_rate_init(void *priv, void *priv_sta, | |
337 | struct ieee80211_local *local, | |
338 | struct sta_info *sta) | |
339 | { | |
340 | /* TODO: This routine should consider using RSSI from previous packets | |
341 | * as we need to have IEEE 802.1X auth succeed immediately after assoc.. | |
342 | * Until that method is implemented, we will use the lowest supported | |
343 | * rate as a workaround. */ | |
344 | sta->txrate = rate_lowest_index(local, local->oper_hw_mode, sta); | |
345 | } | |
346 | ||
347 | static void *rate_control_pid_alloc(struct ieee80211_local *local) | |
348 | { | |
349 | struct rc_pid_info *pinfo; | |
90d501d6 SB |
350 | struct rc_pid_rateinfo *rinfo; |
351 | struct ieee80211_hw_mode *mode; | |
352 | int i, j, tmp; | |
353 | bool s; | |
1946b74c MN |
354 | #ifdef CONFIG_MAC80211_DEBUGFS |
355 | struct rc_pid_debugfs_entries *de; | |
356 | #endif | |
ad018375 MN |
357 | |
358 | pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC); | |
90d501d6 SB |
359 | if (!pinfo) |
360 | return NULL; | |
361 | ||
362 | /* We can safely assume that oper_hw_mode won't change unless we get | |
363 | * reinitialized. */ | |
364 | mode = local->oper_hw_mode; | |
365 | rinfo = kmalloc(sizeof(*rinfo) * mode->num_rates, GFP_ATOMIC); | |
366 | if (!rinfo) { | |
367 | kfree(pinfo); | |
368 | return NULL; | |
369 | } | |
370 | ||
371 | /* Sort the rates. This is optimized for the most common case (i.e. | |
372 | * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed | |
373 | * mapping too. */ | |
374 | for (i = 0; i < mode->num_rates; i++) { | |
375 | rinfo[i].index = i; | |
376 | rinfo[i].rev_index = i; | |
1946b74c | 377 | if (pinfo->fast_start) |
90d501d6 SB |
378 | rinfo[i].diff = 0; |
379 | else | |
1946b74c | 380 | rinfo[i].diff = i * pinfo->norm_offset; |
90d501d6 SB |
381 | } |
382 | for (i = 1; i < mode->num_rates; i++) { | |
383 | s = 0; | |
384 | for (j = 0; j < mode->num_rates - i; j++) | |
385 | if (unlikely(mode->rates[rinfo[j].index].rate > | |
386 | mode->rates[rinfo[j + 1].index].rate)) { | |
387 | tmp = rinfo[j].index; | |
388 | rinfo[j].index = rinfo[j + 1].index; | |
389 | rinfo[j + 1].index = tmp; | |
390 | rinfo[rinfo[j].index].rev_index = j; | |
391 | rinfo[rinfo[j + 1].index].rev_index = j + 1; | |
392 | s = 1; | |
393 | } | |
394 | if (!s) | |
395 | break; | |
396 | } | |
ad018375 MN |
397 | |
398 | pinfo->target = RC_PID_TARGET_PF; | |
1946b74c | 399 | pinfo->sampling_period = RC_PID_INTERVAL; |
ad018375 MN |
400 | pinfo->coeff_p = RC_PID_COEFF_P; |
401 | pinfo->coeff_i = RC_PID_COEFF_I; | |
402 | pinfo->coeff_d = RC_PID_COEFF_D; | |
1946b74c MN |
403 | pinfo->smoothing_shift = RC_PID_SMOOTHING_SHIFT; |
404 | pinfo->sharpen_factor = RC_PID_SHARPENING_FACTOR; | |
405 | pinfo->sharpen_duration = RC_PID_SHARPENING_DURATION; | |
406 | pinfo->norm_offset = RC_PID_NORM_OFFSET; | |
407 | pinfo->fast_start = RC_PID_FAST_START; | |
90d501d6 SB |
408 | pinfo->rinfo = rinfo; |
409 | pinfo->oldrate = 0; | |
ad018375 | 410 | |
1946b74c MN |
411 | #ifdef CONFIG_MAC80211_DEBUGFS |
412 | de = &pinfo->dentries; | |
413 | de->dir = debugfs_create_dir("rc80211_pid", | |
414 | local->hw.wiphy->debugfsdir); | |
415 | de->target = debugfs_create_u32("target_pf", S_IRUSR | S_IWUSR, | |
416 | de->dir, &pinfo->target); | |
417 | de->sampling_period = debugfs_create_u32("sampling_period", | |
418 | S_IRUSR | S_IWUSR, de->dir, | |
419 | &pinfo->sampling_period); | |
420 | de->coeff_p = debugfs_create_u32("coeff_p", S_IRUSR | S_IWUSR, | |
421 | de->dir, &pinfo->coeff_p); | |
422 | de->coeff_i = debugfs_create_u32("coeff_i", S_IRUSR | S_IWUSR, | |
423 | de->dir, &pinfo->coeff_i); | |
424 | de->coeff_d = debugfs_create_u32("coeff_d", S_IRUSR | S_IWUSR, | |
425 | de->dir, &pinfo->coeff_d); | |
426 | de->smoothing_shift = debugfs_create_u32("smoothing_shift", | |
427 | S_IRUSR | S_IWUSR, de->dir, | |
428 | &pinfo->smoothing_shift); | |
429 | de->sharpen_factor = debugfs_create_u32("sharpen_factor", | |
430 | S_IRUSR | S_IWUSR, de->dir, | |
431 | &pinfo->sharpen_factor); | |
432 | de->sharpen_duration = debugfs_create_u32("sharpen_duration", | |
433 | S_IRUSR | S_IWUSR, de->dir, | |
434 | &pinfo->sharpen_duration); | |
435 | de->norm_offset = debugfs_create_u32("norm_offset", | |
436 | S_IRUSR | S_IWUSR, de->dir, | |
437 | &pinfo->norm_offset); | |
438 | de->fast_start = debugfs_create_bool("fast_start", | |
439 | S_IRUSR | S_IWUSR, de->dir, | |
440 | &pinfo->fast_start); | |
441 | #endif | |
442 | ||
ad018375 MN |
443 | return pinfo; |
444 | } | |
445 | ||
446 | static void rate_control_pid_free(void *priv) | |
447 | { | |
448 | struct rc_pid_info *pinfo = priv; | |
1946b74c MN |
449 | #ifdef CONFIG_MAC80211_DEBUGFS |
450 | struct rc_pid_debugfs_entries *de = &pinfo->dentries; | |
451 | ||
452 | debugfs_remove(de->fast_start); | |
453 | debugfs_remove(de->norm_offset); | |
454 | debugfs_remove(de->sharpen_duration); | |
455 | debugfs_remove(de->sharpen_factor); | |
456 | debugfs_remove(de->smoothing_shift); | |
457 | debugfs_remove(de->coeff_d); | |
458 | debugfs_remove(de->coeff_i); | |
459 | debugfs_remove(de->coeff_p); | |
460 | debugfs_remove(de->sampling_period); | |
461 | debugfs_remove(de->target); | |
462 | debugfs_remove(de->dir); | |
463 | #endif | |
464 | ||
90d501d6 | 465 | kfree(pinfo->rinfo); |
ad018375 MN |
466 | kfree(pinfo); |
467 | } | |
468 | ||
469 | static void rate_control_pid_clear(void *priv) | |
470 | { | |
471 | } | |
472 | ||
473 | static void *rate_control_pid_alloc_sta(void *priv, gfp_t gfp) | |
474 | { | |
475 | struct rc_pid_sta_info *spinfo; | |
476 | ||
477 | spinfo = kzalloc(sizeof(*spinfo), gfp); | |
12446c67 MN |
478 | if (spinfo == NULL) |
479 | return NULL; | |
480 | ||
481 | #ifdef CONFIG_MAC80211_DEBUGFS | |
482 | spin_lock_init(&spinfo->events.lock); | |
483 | init_waitqueue_head(&spinfo->events.waitqueue); | |
484 | #endif | |
ad018375 MN |
485 | |
486 | return spinfo; | |
487 | } | |
488 | ||
489 | static void rate_control_pid_free_sta(void *priv, void *priv_sta) | |
490 | { | |
491 | struct rc_pid_sta_info *spinfo = priv_sta; | |
492 | kfree(spinfo); | |
493 | } | |
494 | ||
4b475898 | 495 | static struct rate_control_ops mac80211_rcpid = { |
ad018375 MN |
496 | .name = "pid", |
497 | .tx_status = rate_control_pid_tx_status, | |
498 | .get_rate = rate_control_pid_get_rate, | |
499 | .rate_init = rate_control_pid_rate_init, | |
500 | .clear = rate_control_pid_clear, | |
501 | .alloc = rate_control_pid_alloc, | |
502 | .free = rate_control_pid_free, | |
503 | .alloc_sta = rate_control_pid_alloc_sta, | |
504 | .free_sta = rate_control_pid_free_sta, | |
12446c67 MN |
505 | #ifdef CONFIG_MAC80211_DEBUGFS |
506 | .add_sta_debugfs = rate_control_pid_add_sta_debugfs, | |
507 | .remove_sta_debugfs = rate_control_pid_remove_sta_debugfs, | |
508 | #endif | |
ad018375 | 509 | }; |
4b475898 JB |
510 | |
511 | MODULE_DESCRIPTION("PID controller based rate control algorithm"); | |
512 | MODULE_AUTHOR("Stefano Brivio"); | |
513 | MODULE_AUTHOR("Mattias Nissler"); | |
514 | MODULE_LICENSE("GPL"); | |
515 | ||
516 | int __init rc80211_pid_init(void) | |
517 | { | |
518 | return ieee80211_rate_control_register(&mac80211_rcpid); | |
519 | } | |
520 | ||
521 | void __exit rc80211_pid_exit(void) | |
522 | { | |
523 | ieee80211_rate_control_unregister(&mac80211_rcpid); | |
524 | } | |
525 | ||
526 | #ifdef CONFIG_MAC80211_RC_PID_MODULE | |
527 | module_init(rc80211_pid_init); | |
528 | module_exit(rc80211_pid_exit); | |
529 | #endif |