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f0706e82 JB |
1 | /* |
2 | * Copyright 2002-2005, Instant802 Networks, Inc. | |
3 | * Copyright 2005-2006, Devicescape Software, Inc. | |
4 | * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | */ | |
10 | ||
11 | #include <linux/kernel.h> | |
ff688089 | 12 | #include <linux/rtnetlink.h> |
2c8dccc7 | 13 | #include "rate.h" |
f0706e82 | 14 | #include "ieee80211_i.h" |
4b7679a5 | 15 | #include "debugfs.h" |
f0706e82 JB |
16 | |
17 | struct rate_control_alg { | |
18 | struct list_head list; | |
19 | struct rate_control_ops *ops; | |
20 | }; | |
21 | ||
22 | static LIST_HEAD(rate_ctrl_algs); | |
23 | static DEFINE_MUTEX(rate_ctrl_mutex); | |
24 | ||
c21b39ac SB |
25 | static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; |
26 | module_param(ieee80211_default_rc_algo, charp, 0644); | |
27 | MODULE_PARM_DESC(ieee80211_default_rc_algo, | |
28 | "Default rate control algorithm for mac80211 to use"); | |
29 | ||
f0706e82 JB |
30 | int ieee80211_rate_control_register(struct rate_control_ops *ops) |
31 | { | |
32 | struct rate_control_alg *alg; | |
33 | ||
ac71c691 JB |
34 | if (!ops->name) |
35 | return -EINVAL; | |
36 | ||
999acd9c JB |
37 | mutex_lock(&rate_ctrl_mutex); |
38 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
39 | if (!strcmp(alg->ops->name, ops->name)) { | |
40 | /* don't register an algorithm twice */ | |
41 | WARN_ON(1); | |
b808ab16 | 42 | mutex_unlock(&rate_ctrl_mutex); |
999acd9c JB |
43 | return -EALREADY; |
44 | } | |
45 | } | |
46 | ||
dd00cc48 | 47 | alg = kzalloc(sizeof(*alg), GFP_KERNEL); |
f0706e82 | 48 | if (alg == NULL) { |
999acd9c | 49 | mutex_unlock(&rate_ctrl_mutex); |
f0706e82 JB |
50 | return -ENOMEM; |
51 | } | |
f0706e82 JB |
52 | alg->ops = ops; |
53 | ||
f0706e82 JB |
54 | list_add_tail(&alg->list, &rate_ctrl_algs); |
55 | mutex_unlock(&rate_ctrl_mutex); | |
56 | ||
57 | return 0; | |
58 | } | |
59 | EXPORT_SYMBOL(ieee80211_rate_control_register); | |
60 | ||
61 | void ieee80211_rate_control_unregister(struct rate_control_ops *ops) | |
62 | { | |
63 | struct rate_control_alg *alg; | |
64 | ||
65 | mutex_lock(&rate_ctrl_mutex); | |
66 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
67 | if (alg->ops == ops) { | |
68 | list_del(&alg->list); | |
20880e89 | 69 | kfree(alg); |
f0706e82 JB |
70 | break; |
71 | } | |
72 | } | |
73 | mutex_unlock(&rate_ctrl_mutex); | |
f0706e82 JB |
74 | } |
75 | EXPORT_SYMBOL(ieee80211_rate_control_unregister); | |
76 | ||
77 | static struct rate_control_ops * | |
78 | ieee80211_try_rate_control_ops_get(const char *name) | |
79 | { | |
80 | struct rate_control_alg *alg; | |
81 | struct rate_control_ops *ops = NULL; | |
82 | ||
ac71c691 JB |
83 | if (!name) |
84 | return NULL; | |
85 | ||
f0706e82 JB |
86 | mutex_lock(&rate_ctrl_mutex); |
87 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
ac71c691 | 88 | if (!strcmp(alg->ops->name, name)) |
f0706e82 JB |
89 | if (try_module_get(alg->ops->module)) { |
90 | ops = alg->ops; | |
91 | break; | |
92 | } | |
93 | } | |
94 | mutex_unlock(&rate_ctrl_mutex); | |
95 | return ops; | |
96 | } | |
97 | ||
c21b39ac | 98 | /* Get the rate control algorithm. */ |
f0706e82 JB |
99 | static struct rate_control_ops * |
100 | ieee80211_rate_control_ops_get(const char *name) | |
101 | { | |
102 | struct rate_control_ops *ops; | |
c21b39ac | 103 | const char *alg_name; |
f0706e82 | 104 | |
ac71c691 | 105 | if (!name) |
c21b39ac SB |
106 | alg_name = ieee80211_default_rc_algo; |
107 | else | |
108 | alg_name = name; | |
ac71c691 | 109 | |
c21b39ac | 110 | ops = ieee80211_try_rate_control_ops_get(alg_name); |
f0706e82 | 111 | if (!ops) { |
c21b39ac SB |
112 | request_module("rc80211_%s", alg_name); |
113 | ops = ieee80211_try_rate_control_ops_get(alg_name); | |
f0706e82 | 114 | } |
c21b39ac SB |
115 | if (!ops && name) |
116 | /* try default if specific alg requested but not found */ | |
117 | ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); | |
118 | ||
4b475898 JB |
119 | /* try built-in one if specific alg requested but not found */ |
120 | if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) | |
121 | ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); | |
122 | ||
f0706e82 JB |
123 | return ops; |
124 | } | |
125 | ||
126 | static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) | |
127 | { | |
128 | module_put(ops->module); | |
129 | } | |
130 | ||
4b7679a5 JB |
131 | #ifdef CONFIG_MAC80211_DEBUGFS |
132 | static ssize_t rcname_read(struct file *file, char __user *userbuf, | |
133 | size_t count, loff_t *ppos) | |
134 | { | |
135 | struct rate_control_ref *ref = file->private_data; | |
136 | int len = strlen(ref->ops->name); | |
137 | ||
138 | return simple_read_from_buffer(userbuf, count, ppos, | |
139 | ref->ops->name, len); | |
140 | } | |
141 | ||
142 | static const struct file_operations rcname_ops = { | |
143 | .read = rcname_read, | |
144 | .open = mac80211_open_file_generic, | |
145 | }; | |
146 | #endif | |
147 | ||
f0706e82 JB |
148 | struct rate_control_ref *rate_control_alloc(const char *name, |
149 | struct ieee80211_local *local) | |
150 | { | |
4b7679a5 | 151 | struct dentry *debugfsdir = NULL; |
f0706e82 JB |
152 | struct rate_control_ref *ref; |
153 | ||
154 | ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); | |
155 | if (!ref) | |
156 | goto fail_ref; | |
157 | kref_init(&ref->kref); | |
4b7679a5 | 158 | ref->local = local; |
f0706e82 JB |
159 | ref->ops = ieee80211_rate_control_ops_get(name); |
160 | if (!ref->ops) | |
161 | goto fail_ops; | |
4b7679a5 JB |
162 | |
163 | #ifdef CONFIG_MAC80211_DEBUGFS | |
164 | debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); | |
165 | local->debugfs.rcdir = debugfsdir; | |
7bcfaf2f | 166 | debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); |
4b7679a5 JB |
167 | #endif |
168 | ||
169 | ref->priv = ref->ops->alloc(&local->hw, debugfsdir); | |
f0706e82 JB |
170 | if (!ref->priv) |
171 | goto fail_priv; | |
172 | return ref; | |
173 | ||
174 | fail_priv: | |
175 | ieee80211_rate_control_ops_put(ref->ops); | |
176 | fail_ops: | |
177 | kfree(ref); | |
178 | fail_ref: | |
179 | return NULL; | |
180 | } | |
181 | ||
182 | static void rate_control_release(struct kref *kref) | |
183 | { | |
184 | struct rate_control_ref *ctrl_ref; | |
185 | ||
186 | ctrl_ref = container_of(kref, struct rate_control_ref, kref); | |
187 | ctrl_ref->ops->free(ctrl_ref->priv); | |
4b7679a5 JB |
188 | |
189 | #ifdef CONFIG_MAC80211_DEBUGFS | |
7bcfaf2f | 190 | debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); |
4b7679a5 JB |
191 | ctrl_ref->local->debugfs.rcdir = NULL; |
192 | #endif | |
193 | ||
f0706e82 JB |
194 | ieee80211_rate_control_ops_put(ctrl_ref->ops); |
195 | kfree(ctrl_ref); | |
196 | } | |
197 | ||
4c6d4f5c LR |
198 | static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc) |
199 | { | |
200 | struct sk_buff *skb = txrc->skb; | |
201 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
202 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
203 | __le16 fc; | |
204 | ||
205 | fc = hdr->frame_control; | |
206 | ||
207 | return ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc)); | |
208 | } | |
209 | ||
e00cfce0 JM |
210 | static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx) |
211 | { | |
212 | u8 i; | |
213 | ||
214 | if (basic_rates == 0) | |
215 | return; /* assume basic rates unknown and accept rate */ | |
216 | if (*idx < 0) | |
217 | return; | |
218 | if (basic_rates & (1 << *idx)) | |
219 | return; /* selected rate is a basic rate */ | |
220 | ||
221 | for (i = *idx + 1; i <= max_rate_idx; i++) { | |
222 | if (basic_rates & (1 << i)) { | |
223 | *idx = i; | |
224 | return; | |
225 | } | |
226 | } | |
227 | ||
228 | /* could not find a basic rate; use original selection */ | |
229 | } | |
230 | ||
4c6d4f5c LR |
231 | bool rate_control_send_low(struct ieee80211_sta *sta, |
232 | void *priv_sta, | |
233 | struct ieee80211_tx_rate_control *txrc) | |
234 | { | |
235 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); | |
236 | ||
237 | if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) { | |
238 | info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta); | |
239 | info->control.rates[0].count = | |
240 | (info->flags & IEEE80211_TX_CTL_NO_ACK) ? | |
241 | 1 : txrc->hw->max_rate_tries; | |
e00cfce0 JM |
242 | if (!sta && txrc->ap) |
243 | rc_send_low_broadcast(&info->control.rates[0].idx, | |
244 | txrc->bss_conf->basic_rates, | |
245 | txrc->sband->n_bitrates); | |
4c6d4f5c LR |
246 | return true; |
247 | } | |
248 | return false; | |
249 | } | |
250 | EXPORT_SYMBOL(rate_control_send_low); | |
251 | ||
37eb0b16 JM |
252 | static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, |
253 | int n_bitrates, u32 mask) | |
254 | { | |
255 | int j; | |
256 | ||
257 | /* See whether the selected rate or anything below it is allowed. */ | |
258 | for (j = rate->idx; j >= 0; j--) { | |
259 | if (mask & (1 << j)) { | |
260 | /* Okay, found a suitable rate. Use it. */ | |
261 | rate->idx = j; | |
262 | return; | |
263 | } | |
264 | } | |
265 | ||
266 | /* Try to find a higher rate that would be allowed */ | |
267 | for (j = rate->idx + 1; j < n_bitrates; j++) { | |
268 | if (mask & (1 << j)) { | |
269 | /* Okay, found a suitable rate. Use it. */ | |
270 | rate->idx = j; | |
271 | return; | |
272 | } | |
273 | } | |
274 | ||
275 | /* | |
276 | * Uh.. No suitable rate exists. This should not really happen with | |
277 | * sane TX rate mask configurations. However, should someone manage to | |
278 | * configure supported rates and TX rate mask in incompatible way, | |
279 | * allow the frame to be transmitted with whatever the rate control | |
280 | * selected. | |
281 | */ | |
282 | } | |
283 | ||
4b7679a5 | 284 | void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, |
e6a9854b JB |
285 | struct sta_info *sta, |
286 | struct ieee80211_tx_rate_control *txrc) | |
1abbe498 | 287 | { |
4b7679a5 JB |
288 | struct rate_control_ref *ref = sdata->local->rate_ctrl; |
289 | void *priv_sta = NULL; | |
290 | struct ieee80211_sta *ista = NULL; | |
e6a9854b | 291 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
1abbe498 | 292 | int i; |
37eb0b16 | 293 | u32 mask; |
1abbe498 | 294 | |
4b7679a5 JB |
295 | if (sta) { |
296 | ista = &sta->sta; | |
297 | priv_sta = sta->rate_ctrl_priv; | |
298 | } | |
299 | ||
e6a9854b JB |
300 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
301 | info->control.rates[i].idx = -1; | |
302 | info->control.rates[i].flags = 0; | |
303 | info->control.rates[i].count = 1; | |
304 | } | |
305 | ||
37eb0b16 | 306 | ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); |
e6a9854b JB |
307 | |
308 | /* | |
37eb0b16 JM |
309 | * Try to enforce the rateidx mask the user wanted. skip this if the |
310 | * default mask (allow all rates) is used to save some processing for | |
311 | * the common case. | |
e6a9854b | 312 | */ |
37eb0b16 JM |
313 | mask = sdata->rc_rateidx_mask[info->band]; |
314 | if (mask != (1 << txrc->sband->n_bitrates) - 1) { | |
315 | if (sta) { | |
316 | /* Filter out rates that the STA does not support */ | |
317 | mask &= sta->sta.supp_rates[info->band]; | |
318 | } | |
319 | /* | |
320 | * Make sure the rate index selected for each TX rate is | |
321 | * included in the configured mask and change the rate indexes | |
322 | * if needed. | |
323 | */ | |
e6a9854b | 324 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
37eb0b16 | 325 | /* Rate masking supports only legacy rates for now */ |
e6a9854b JB |
326 | if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) |
327 | continue; | |
37eb0b16 JM |
328 | rate_idx_match_mask(&info->control.rates[i], |
329 | txrc->sband->n_bitrates, mask); | |
330 | } | |
1abbe498 | 331 | } |
e6a9854b JB |
332 | |
333 | BUG_ON(info->control.rates[0].idx < 0); | |
1abbe498 MN |
334 | } |
335 | ||
f0706e82 JB |
336 | struct rate_control_ref *rate_control_get(struct rate_control_ref *ref) |
337 | { | |
338 | kref_get(&ref->kref); | |
339 | return ref; | |
340 | } | |
341 | ||
342 | void rate_control_put(struct rate_control_ref *ref) | |
343 | { | |
344 | kref_put(&ref->kref, rate_control_release); | |
345 | } | |
ff688089 JB |
346 | |
347 | int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, | |
348 | const char *name) | |
349 | { | |
350 | struct rate_control_ref *ref, *old; | |
351 | ||
352 | ASSERT_RTNL(); | |
af65cd96 | 353 | |
3b8d81e0 | 354 | if (local->open_count) |
ff688089 JB |
355 | return -EBUSY; |
356 | ||
af65cd96 JB |
357 | if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { |
358 | if (WARN_ON(!local->ops->set_rts_threshold)) | |
359 | return -EINVAL; | |
360 | return 0; | |
361 | } | |
362 | ||
ff688089 JB |
363 | ref = rate_control_alloc(name, local); |
364 | if (!ref) { | |
365 | printk(KERN_WARNING "%s: Failed to select rate control " | |
dd1cd4c6 | 366 | "algorithm\n", wiphy_name(local->hw.wiphy)); |
ff688089 JB |
367 | return -ENOENT; |
368 | } | |
369 | ||
370 | old = local->rate_ctrl; | |
371 | local->rate_ctrl = ref; | |
372 | if (old) { | |
373 | rate_control_put(old); | |
374 | sta_info_flush(local, NULL); | |
375 | } | |
376 | ||
377 | printk(KERN_DEBUG "%s: Selected rate control " | |
dd1cd4c6 | 378 | "algorithm '%s'\n", wiphy_name(local->hw.wiphy), |
ff688089 JB |
379 | ref->ops->name); |
380 | ||
ff688089 JB |
381 | return 0; |
382 | } | |
383 | ||
384 | void rate_control_deinitialize(struct ieee80211_local *local) | |
385 | { | |
386 | struct rate_control_ref *ref; | |
387 | ||
388 | ref = local->rate_ctrl; | |
af65cd96 JB |
389 | |
390 | if (!ref) | |
391 | return; | |
392 | ||
ff688089 JB |
393 | local->rate_ctrl = NULL; |
394 | rate_control_put(ref); | |
395 | } | |
c21b39ac | 396 |