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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> |
5a0e3ad6 | 13 | #include <linux/slab.h> |
2c8dccc7 | 14 | #include "rate.h" |
f0706e82 | 15 | #include "ieee80211_i.h" |
4b7679a5 | 16 | #include "debugfs.h" |
f0706e82 JB |
17 | |
18 | struct rate_control_alg { | |
19 | struct list_head list; | |
20 | struct rate_control_ops *ops; | |
21 | }; | |
22 | ||
23 | static LIST_HEAD(rate_ctrl_algs); | |
24 | static DEFINE_MUTEX(rate_ctrl_mutex); | |
25 | ||
c21b39ac SB |
26 | static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT; |
27 | module_param(ieee80211_default_rc_algo, charp, 0644); | |
28 | MODULE_PARM_DESC(ieee80211_default_rc_algo, | |
29 | "Default rate control algorithm for mac80211 to use"); | |
30 | ||
f0706e82 JB |
31 | int ieee80211_rate_control_register(struct rate_control_ops *ops) |
32 | { | |
33 | struct rate_control_alg *alg; | |
34 | ||
ac71c691 JB |
35 | if (!ops->name) |
36 | return -EINVAL; | |
37 | ||
999acd9c JB |
38 | mutex_lock(&rate_ctrl_mutex); |
39 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
40 | if (!strcmp(alg->ops->name, ops->name)) { | |
41 | /* don't register an algorithm twice */ | |
42 | WARN_ON(1); | |
b808ab16 | 43 | mutex_unlock(&rate_ctrl_mutex); |
999acd9c JB |
44 | return -EALREADY; |
45 | } | |
46 | } | |
47 | ||
dd00cc48 | 48 | alg = kzalloc(sizeof(*alg), GFP_KERNEL); |
f0706e82 | 49 | if (alg == NULL) { |
999acd9c | 50 | mutex_unlock(&rate_ctrl_mutex); |
f0706e82 JB |
51 | return -ENOMEM; |
52 | } | |
f0706e82 JB |
53 | alg->ops = ops; |
54 | ||
f0706e82 JB |
55 | list_add_tail(&alg->list, &rate_ctrl_algs); |
56 | mutex_unlock(&rate_ctrl_mutex); | |
57 | ||
58 | return 0; | |
59 | } | |
60 | EXPORT_SYMBOL(ieee80211_rate_control_register); | |
61 | ||
62 | void ieee80211_rate_control_unregister(struct rate_control_ops *ops) | |
63 | { | |
64 | struct rate_control_alg *alg; | |
65 | ||
66 | mutex_lock(&rate_ctrl_mutex); | |
67 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
68 | if (alg->ops == ops) { | |
69 | list_del(&alg->list); | |
20880e89 | 70 | kfree(alg); |
f0706e82 JB |
71 | break; |
72 | } | |
73 | } | |
74 | mutex_unlock(&rate_ctrl_mutex); | |
f0706e82 JB |
75 | } |
76 | EXPORT_SYMBOL(ieee80211_rate_control_unregister); | |
77 | ||
78 | static struct rate_control_ops * | |
79 | ieee80211_try_rate_control_ops_get(const char *name) | |
80 | { | |
81 | struct rate_control_alg *alg; | |
82 | struct rate_control_ops *ops = NULL; | |
83 | ||
ac71c691 JB |
84 | if (!name) |
85 | return NULL; | |
86 | ||
f0706e82 JB |
87 | mutex_lock(&rate_ctrl_mutex); |
88 | list_for_each_entry(alg, &rate_ctrl_algs, list) { | |
ac71c691 | 89 | if (!strcmp(alg->ops->name, name)) |
f0706e82 JB |
90 | if (try_module_get(alg->ops->module)) { |
91 | ops = alg->ops; | |
92 | break; | |
93 | } | |
94 | } | |
95 | mutex_unlock(&rate_ctrl_mutex); | |
96 | return ops; | |
97 | } | |
98 | ||
c21b39ac | 99 | /* Get the rate control algorithm. */ |
f0706e82 JB |
100 | static struct rate_control_ops * |
101 | ieee80211_rate_control_ops_get(const char *name) | |
102 | { | |
103 | struct rate_control_ops *ops; | |
c21b39ac | 104 | const char *alg_name; |
f0706e82 | 105 | |
ac71c691 | 106 | if (!name) |
c21b39ac SB |
107 | alg_name = ieee80211_default_rc_algo; |
108 | else | |
109 | alg_name = name; | |
ac71c691 | 110 | |
c21b39ac | 111 | ops = ieee80211_try_rate_control_ops_get(alg_name); |
f0706e82 | 112 | if (!ops) { |
c21b39ac SB |
113 | request_module("rc80211_%s", alg_name); |
114 | ops = ieee80211_try_rate_control_ops_get(alg_name); | |
f0706e82 | 115 | } |
c21b39ac SB |
116 | if (!ops && name) |
117 | /* try default if specific alg requested but not found */ | |
118 | ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo); | |
119 | ||
4b475898 JB |
120 | /* try built-in one if specific alg requested but not found */ |
121 | if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT)) | |
122 | ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT); | |
123 | ||
f0706e82 JB |
124 | return ops; |
125 | } | |
126 | ||
127 | static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops) | |
128 | { | |
129 | module_put(ops->module); | |
130 | } | |
131 | ||
4b7679a5 JB |
132 | #ifdef CONFIG_MAC80211_DEBUGFS |
133 | static ssize_t rcname_read(struct file *file, char __user *userbuf, | |
134 | size_t count, loff_t *ppos) | |
135 | { | |
136 | struct rate_control_ref *ref = file->private_data; | |
137 | int len = strlen(ref->ops->name); | |
138 | ||
139 | return simple_read_from_buffer(userbuf, count, ppos, | |
140 | ref->ops->name, len); | |
141 | } | |
142 | ||
143 | static const struct file_operations rcname_ops = { | |
144 | .read = rcname_read, | |
145 | .open = mac80211_open_file_generic, | |
146 | }; | |
147 | #endif | |
148 | ||
209c671d | 149 | static struct rate_control_ref *rate_control_alloc(const char *name, |
f0706e82 JB |
150 | struct ieee80211_local *local) |
151 | { | |
4b7679a5 | 152 | struct dentry *debugfsdir = NULL; |
f0706e82 JB |
153 | struct rate_control_ref *ref; |
154 | ||
155 | ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL); | |
156 | if (!ref) | |
157 | goto fail_ref; | |
158 | kref_init(&ref->kref); | |
4b7679a5 | 159 | ref->local = local; |
f0706e82 JB |
160 | ref->ops = ieee80211_rate_control_ops_get(name); |
161 | if (!ref->ops) | |
162 | goto fail_ops; | |
4b7679a5 JB |
163 | |
164 | #ifdef CONFIG_MAC80211_DEBUGFS | |
165 | debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir); | |
166 | local->debugfs.rcdir = debugfsdir; | |
7bcfaf2f | 167 | debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops); |
4b7679a5 JB |
168 | #endif |
169 | ||
170 | ref->priv = ref->ops->alloc(&local->hw, debugfsdir); | |
f0706e82 JB |
171 | if (!ref->priv) |
172 | goto fail_priv; | |
173 | return ref; | |
174 | ||
175 | fail_priv: | |
176 | ieee80211_rate_control_ops_put(ref->ops); | |
177 | fail_ops: | |
178 | kfree(ref); | |
179 | fail_ref: | |
180 | return NULL; | |
181 | } | |
182 | ||
183 | static void rate_control_release(struct kref *kref) | |
184 | { | |
185 | struct rate_control_ref *ctrl_ref; | |
186 | ||
187 | ctrl_ref = container_of(kref, struct rate_control_ref, kref); | |
188 | ctrl_ref->ops->free(ctrl_ref->priv); | |
4b7679a5 JB |
189 | |
190 | #ifdef CONFIG_MAC80211_DEBUGFS | |
7bcfaf2f | 191 | debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir); |
4b7679a5 JB |
192 | ctrl_ref->local->debugfs.rcdir = NULL; |
193 | #endif | |
194 | ||
f0706e82 JB |
195 | ieee80211_rate_control_ops_put(ctrl_ref->ops); |
196 | kfree(ctrl_ref); | |
197 | } | |
198 | ||
4c6d4f5c LR |
199 | static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc) |
200 | { | |
201 | struct sk_buff *skb = txrc->skb; | |
202 | struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; | |
203 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); | |
204 | __le16 fc; | |
205 | ||
206 | fc = hdr->frame_control; | |
207 | ||
208 | return ((info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc)); | |
209 | } | |
210 | ||
e00cfce0 JM |
211 | static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx) |
212 | { | |
213 | u8 i; | |
214 | ||
215 | if (basic_rates == 0) | |
216 | return; /* assume basic rates unknown and accept rate */ | |
217 | if (*idx < 0) | |
218 | return; | |
219 | if (basic_rates & (1 << *idx)) | |
220 | return; /* selected rate is a basic rate */ | |
221 | ||
222 | for (i = *idx + 1; i <= max_rate_idx; i++) { | |
223 | if (basic_rates & (1 << i)) { | |
224 | *idx = i; | |
225 | return; | |
226 | } | |
227 | } | |
228 | ||
229 | /* could not find a basic rate; use original selection */ | |
230 | } | |
231 | ||
4c6d4f5c LR |
232 | bool rate_control_send_low(struct ieee80211_sta *sta, |
233 | void *priv_sta, | |
234 | struct ieee80211_tx_rate_control *txrc) | |
235 | { | |
236 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); | |
237 | ||
238 | if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) { | |
239 | info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta); | |
240 | info->control.rates[0].count = | |
241 | (info->flags & IEEE80211_TX_CTL_NO_ACK) ? | |
242 | 1 : txrc->hw->max_rate_tries; | |
e00cfce0 JM |
243 | if (!sta && txrc->ap) |
244 | rc_send_low_broadcast(&info->control.rates[0].idx, | |
245 | txrc->bss_conf->basic_rates, | |
246 | txrc->sband->n_bitrates); | |
4c6d4f5c LR |
247 | return true; |
248 | } | |
249 | return false; | |
250 | } | |
251 | EXPORT_SYMBOL(rate_control_send_low); | |
252 | ||
37eb0b16 JM |
253 | static void rate_idx_match_mask(struct ieee80211_tx_rate *rate, |
254 | int n_bitrates, u32 mask) | |
255 | { | |
256 | int j; | |
257 | ||
258 | /* See whether the selected rate or anything below it is allowed. */ | |
259 | for (j = rate->idx; j >= 0; j--) { | |
260 | if (mask & (1 << j)) { | |
261 | /* Okay, found a suitable rate. Use it. */ | |
262 | rate->idx = j; | |
263 | return; | |
264 | } | |
265 | } | |
266 | ||
267 | /* Try to find a higher rate that would be allowed */ | |
268 | for (j = rate->idx + 1; j < n_bitrates; j++) { | |
269 | if (mask & (1 << j)) { | |
270 | /* Okay, found a suitable rate. Use it. */ | |
271 | rate->idx = j; | |
272 | return; | |
273 | } | |
274 | } | |
275 | ||
276 | /* | |
277 | * Uh.. No suitable rate exists. This should not really happen with | |
278 | * sane TX rate mask configurations. However, should someone manage to | |
279 | * configure supported rates and TX rate mask in incompatible way, | |
280 | * allow the frame to be transmitted with whatever the rate control | |
281 | * selected. | |
282 | */ | |
283 | } | |
284 | ||
4b7679a5 | 285 | void rate_control_get_rate(struct ieee80211_sub_if_data *sdata, |
e6a9854b JB |
286 | struct sta_info *sta, |
287 | struct ieee80211_tx_rate_control *txrc) | |
1abbe498 | 288 | { |
4b7679a5 JB |
289 | struct rate_control_ref *ref = sdata->local->rate_ctrl; |
290 | void *priv_sta = NULL; | |
291 | struct ieee80211_sta *ista = NULL; | |
e6a9854b | 292 | struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb); |
1abbe498 | 293 | int i; |
37eb0b16 | 294 | u32 mask; |
1abbe498 | 295 | |
4b7679a5 JB |
296 | if (sta) { |
297 | ista = &sta->sta; | |
298 | priv_sta = sta->rate_ctrl_priv; | |
299 | } | |
300 | ||
e6a9854b JB |
301 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
302 | info->control.rates[i].idx = -1; | |
303 | info->control.rates[i].flags = 0; | |
304 | info->control.rates[i].count = 1; | |
305 | } | |
306 | ||
5affcd6b JO |
307 | if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) |
308 | return; | |
309 | ||
37eb0b16 | 310 | ref->ops->get_rate(ref->priv, ista, priv_sta, txrc); |
e6a9854b JB |
311 | |
312 | /* | |
37eb0b16 JM |
313 | * Try to enforce the rateidx mask the user wanted. skip this if the |
314 | * default mask (allow all rates) is used to save some processing for | |
315 | * the common case. | |
e6a9854b | 316 | */ |
37eb0b16 JM |
317 | mask = sdata->rc_rateidx_mask[info->band]; |
318 | if (mask != (1 << txrc->sband->n_bitrates) - 1) { | |
319 | if (sta) { | |
320 | /* Filter out rates that the STA does not support */ | |
321 | mask &= sta->sta.supp_rates[info->band]; | |
322 | } | |
323 | /* | |
324 | * Make sure the rate index selected for each TX rate is | |
325 | * included in the configured mask and change the rate indexes | |
326 | * if needed. | |
327 | */ | |
e6a9854b | 328 | for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) { |
37eb0b16 | 329 | /* Rate masking supports only legacy rates for now */ |
e6a9854b JB |
330 | if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) |
331 | continue; | |
37eb0b16 JM |
332 | rate_idx_match_mask(&info->control.rates[i], |
333 | txrc->sband->n_bitrates, mask); | |
334 | } | |
1abbe498 | 335 | } |
e6a9854b JB |
336 | |
337 | BUG_ON(info->control.rates[0].idx < 0); | |
1abbe498 MN |
338 | } |
339 | ||
f0706e82 JB |
340 | struct rate_control_ref *rate_control_get(struct rate_control_ref *ref) |
341 | { | |
342 | kref_get(&ref->kref); | |
343 | return ref; | |
344 | } | |
345 | ||
346 | void rate_control_put(struct rate_control_ref *ref) | |
347 | { | |
348 | kref_put(&ref->kref, rate_control_release); | |
349 | } | |
ff688089 JB |
350 | |
351 | int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local, | |
352 | const char *name) | |
353 | { | |
354 | struct rate_control_ref *ref, *old; | |
355 | ||
356 | ASSERT_RTNL(); | |
af65cd96 | 357 | |
3b8d81e0 | 358 | if (local->open_count) |
ff688089 JB |
359 | return -EBUSY; |
360 | ||
af65cd96 JB |
361 | if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) { |
362 | if (WARN_ON(!local->ops->set_rts_threshold)) | |
363 | return -EINVAL; | |
364 | return 0; | |
365 | } | |
366 | ||
ff688089 JB |
367 | ref = rate_control_alloc(name, local); |
368 | if (!ref) { | |
369 | printk(KERN_WARNING "%s: Failed to select rate control " | |
dd1cd4c6 | 370 | "algorithm\n", wiphy_name(local->hw.wiphy)); |
ff688089 JB |
371 | return -ENOENT; |
372 | } | |
373 | ||
374 | old = local->rate_ctrl; | |
375 | local->rate_ctrl = ref; | |
376 | if (old) { | |
377 | rate_control_put(old); | |
378 | sta_info_flush(local, NULL); | |
379 | } | |
380 | ||
381 | printk(KERN_DEBUG "%s: Selected rate control " | |
dd1cd4c6 | 382 | "algorithm '%s'\n", wiphy_name(local->hw.wiphy), |
ff688089 JB |
383 | ref->ops->name); |
384 | ||
ff688089 JB |
385 | return 0; |
386 | } | |
387 | ||
388 | void rate_control_deinitialize(struct ieee80211_local *local) | |
389 | { | |
390 | struct rate_control_ref *ref; | |
391 | ||
392 | ref = local->rate_ctrl; | |
af65cd96 JB |
393 | |
394 | if (!ref) | |
395 | return; | |
396 | ||
ff688089 JB |
397 | local->rate_ctrl = NULL; |
398 | rate_control_put(ref); | |
399 | } | |
c21b39ac | 400 |