blob: 33f76993da081fcd73c10cad2bf1328c46d83299 [file] [log] [blame]
Jiri Bencf0706e82007-05-05 11:45:53 -07001/*
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>
Johannes Bergff688082007-07-27 15:43:23 +020012#include <linux/rtnetlink.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/slab.h>
Johannes Berg2c8dccc2008-04-08 15:14:40 -040014#include "rate.h"
Jiri Bencf0706e82007-05-05 11:45:53 -070015#include "ieee80211_i.h"
Johannes Berg4b7679a2008-09-18 18:14:18 +020016#include "debugfs.h"
Jiri Bencf0706e82007-05-05 11:45:53 -070017
18struct rate_control_alg {
19 struct list_head list;
20 struct rate_control_ops *ops;
21};
22
23static LIST_HEAD(rate_ctrl_algs);
24static DEFINE_MUTEX(rate_ctrl_mutex);
25
Stefano Brivioc21b39a2007-12-19 01:26:16 +010026static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
27module_param(ieee80211_default_rc_algo, charp, 0644);
28MODULE_PARM_DESC(ieee80211_default_rc_algo,
29 "Default rate control algorithm for mac80211 to use");
30
Jiri Bencf0706e82007-05-05 11:45:53 -070031int ieee80211_rate_control_register(struct rate_control_ops *ops)
32{
33 struct rate_control_alg *alg;
34
Johannes Bergac71c692007-10-28 14:17:44 +010035 if (!ops->name)
36 return -EINVAL;
37
Johannes Berg999acd92007-10-28 14:49:33 +010038 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);
Cyrill Gorcunovb808ab12007-12-13 15:52:11 -080043 mutex_unlock(&rate_ctrl_mutex);
Johannes Berg999acd92007-10-28 14:49:33 +010044 return -EALREADY;
45 }
46 }
47
Yoann Padioleaudd00cc42007-07-19 01:49:03 -070048 alg = kzalloc(sizeof(*alg), GFP_KERNEL);
Jiri Bencf0706e82007-05-05 11:45:53 -070049 if (alg == NULL) {
Johannes Berg999acd92007-10-28 14:49:33 +010050 mutex_unlock(&rate_ctrl_mutex);
Jiri Bencf0706e82007-05-05 11:45:53 -070051 return -ENOMEM;
52 }
Jiri Bencf0706e82007-05-05 11:45:53 -070053 alg->ops = ops;
54
Jiri Bencf0706e82007-05-05 11:45:53 -070055 list_add_tail(&alg->list, &rate_ctrl_algs);
56 mutex_unlock(&rate_ctrl_mutex);
57
58 return 0;
59}
60EXPORT_SYMBOL(ieee80211_rate_control_register);
61
62void 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);
Cyrill Gorcunov20880e82007-12-13 16:17:03 -080070 kfree(alg);
Jiri Bencf0706e82007-05-05 11:45:53 -070071 break;
72 }
73 }
74 mutex_unlock(&rate_ctrl_mutex);
Jiri Bencf0706e82007-05-05 11:45:53 -070075}
76EXPORT_SYMBOL(ieee80211_rate_control_unregister);
77
78static struct rate_control_ops *
79ieee80211_try_rate_control_ops_get(const char *name)
80{
81 struct rate_control_alg *alg;
82 struct rate_control_ops *ops = NULL;
83
Johannes Bergac71c692007-10-28 14:17:44 +010084 if (!name)
85 return NULL;
86
Jiri Bencf0706e82007-05-05 11:45:53 -070087 mutex_lock(&rate_ctrl_mutex);
88 list_for_each_entry(alg, &rate_ctrl_algs, list) {
Johannes Bergac71c692007-10-28 14:17:44 +010089 if (!strcmp(alg->ops->name, name))
Jiri Bencf0706e82007-05-05 11:45:53 -070090 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
Stefano Brivioc21b39a2007-12-19 01:26:16 +010099/* Get the rate control algorithm. */
Jiri Bencf0706e82007-05-05 11:45:53 -0700100static struct rate_control_ops *
101ieee80211_rate_control_ops_get(const char *name)
102{
103 struct rate_control_ops *ops;
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100104 const char *alg_name;
Jiri Bencf0706e82007-05-05 11:45:53 -0700105
Rusty Russelld6d1b652010-08-11 23:04:27 -0600106 kparam_block_sysfs_write(ieee80211_default_rc_algo);
Johannes Bergac71c692007-10-28 14:17:44 +0100107 if (!name)
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100108 alg_name = ieee80211_default_rc_algo;
109 else
110 alg_name = name;
Johannes Bergac71c692007-10-28 14:17:44 +0100111
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100112 ops = ieee80211_try_rate_control_ops_get(alg_name);
Jiri Bencf0706e82007-05-05 11:45:53 -0700113 if (!ops) {
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100114 request_module("rc80211_%s", alg_name);
115 ops = ieee80211_try_rate_control_ops_get(alg_name);
Jiri Bencf0706e82007-05-05 11:45:53 -0700116 }
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100117 if (!ops && name)
118 /* try default if specific alg requested but not found */
119 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
120
Johannes Berg4b475892008-01-02 15:17:03 +0100121 /* try built-in one if specific alg requested but not found */
122 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
123 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
Rusty Russelld6d1b652010-08-11 23:04:27 -0600124 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
Johannes Berg4b475892008-01-02 15:17:03 +0100125
Jiri Bencf0706e82007-05-05 11:45:53 -0700126 return ops;
127}
128
129static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
130{
131 module_put(ops->module);
132}
133
Johannes Berg4b7679a2008-09-18 18:14:18 +0200134#ifdef CONFIG_MAC80211_DEBUGFS
135static ssize_t rcname_read(struct file *file, char __user *userbuf,
136 size_t count, loff_t *ppos)
137{
138 struct rate_control_ref *ref = file->private_data;
139 int len = strlen(ref->ops->name);
140
141 return simple_read_from_buffer(userbuf, count, ppos,
142 ref->ops->name, len);
143}
144
145static const struct file_operations rcname_ops = {
146 .read = rcname_read,
147 .open = mac80211_open_file_generic,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200148 .llseek = default_llseek,
Johannes Berg4b7679a2008-09-18 18:14:18 +0200149};
150#endif
151
Andres Salomon209c6712010-02-07 21:47:50 -0500152static struct rate_control_ref *rate_control_alloc(const char *name,
Jiri Bencf0706e82007-05-05 11:45:53 -0700153 struct ieee80211_local *local)
154{
Johannes Berg4b7679a2008-09-18 18:14:18 +0200155 struct dentry *debugfsdir = NULL;
Jiri Bencf0706e82007-05-05 11:45:53 -0700156 struct rate_control_ref *ref;
157
158 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
159 if (!ref)
160 goto fail_ref;
161 kref_init(&ref->kref);
Johannes Berg4b7679a2008-09-18 18:14:18 +0200162 ref->local = local;
Jiri Bencf0706e82007-05-05 11:45:53 -0700163 ref->ops = ieee80211_rate_control_ops_get(name);
164 if (!ref->ops)
165 goto fail_ops;
Johannes Berg4b7679a2008-09-18 18:14:18 +0200166
167#ifdef CONFIG_MAC80211_DEBUGFS
168 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
169 local->debugfs.rcdir = debugfsdir;
Johannes Berg7bcfaf22009-10-27 12:59:03 +0100170 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
Johannes Berg4b7679a2008-09-18 18:14:18 +0200171#endif
172
173 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
Jiri Bencf0706e82007-05-05 11:45:53 -0700174 if (!ref->priv)
175 goto fail_priv;
176 return ref;
177
178fail_priv:
179 ieee80211_rate_control_ops_put(ref->ops);
180fail_ops:
181 kfree(ref);
182fail_ref:
183 return NULL;
184}
185
186static void rate_control_release(struct kref *kref)
187{
188 struct rate_control_ref *ctrl_ref;
189
190 ctrl_ref = container_of(kref, struct rate_control_ref, kref);
191 ctrl_ref->ops->free(ctrl_ref->priv);
Johannes Berg4b7679a2008-09-18 18:14:18 +0200192
193#ifdef CONFIG_MAC80211_DEBUGFS
Johannes Berg7bcfaf22009-10-27 12:59:03 +0100194 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
Johannes Berg4b7679a2008-09-18 18:14:18 +0200195 ctrl_ref->local->debugfs.rcdir = NULL;
196#endif
197
Jiri Bencf0706e82007-05-05 11:45:53 -0700198 ieee80211_rate_control_ops_put(ctrl_ref->ops);
199 kfree(ctrl_ref);
200}
201
Luis R. Rodriguez4c6d4f52009-07-16 10:05:41 -0700202static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc)
203{
204 struct sk_buff *skb = txrc->skb;
205 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
206 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
207 __le16 fc;
208
209 fc = hdr->frame_control;
210
Eric Dumazeta02cec22010-09-22 20:43:57 +0000211 return (info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc);
Luis R. Rodriguez4c6d4f52009-07-16 10:05:41 -0700212}
213
Jouni Malinene00cfce2009-12-29 12:59:19 +0200214static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
215{
216 u8 i;
217
218 if (basic_rates == 0)
219 return; /* assume basic rates unknown and accept rate */
220 if (*idx < 0)
221 return;
222 if (basic_rates & (1 << *idx))
223 return; /* selected rate is a basic rate */
224
225 for (i = *idx + 1; i <= max_rate_idx; i++) {
226 if (basic_rates & (1 << i)) {
227 *idx = i;
228 return;
229 }
230 }
231
232 /* could not find a basic rate; use original selection */
233}
234
Luis R. Rodriguez4c6d4f52009-07-16 10:05:41 -0700235bool rate_control_send_low(struct ieee80211_sta *sta,
236 void *priv_sta,
237 struct ieee80211_tx_rate_control *txrc)
238{
239 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
240
241 if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
242 info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
243 info->control.rates[0].count =
244 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
245 1 : txrc->hw->max_rate_tries;
Jouni Malinene00cfce2009-12-29 12:59:19 +0200246 if (!sta && txrc->ap)
247 rc_send_low_broadcast(&info->control.rates[0].idx,
248 txrc->bss_conf->basic_rates,
249 txrc->sband->n_bitrates);
Luis R. Rodriguez4c6d4f52009-07-16 10:05:41 -0700250 return true;
251 }
252 return false;
253}
254EXPORT_SYMBOL(rate_control_send_low);
255
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200256static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
257 int n_bitrates, u32 mask)
258{
259 int j;
260
261 /* See whether the selected rate or anything below it is allowed. */
262 for (j = rate->idx; j >= 0; j--) {
263 if (mask & (1 << j)) {
264 /* Okay, found a suitable rate. Use it. */
265 rate->idx = j;
266 return;
267 }
268 }
269
270 /* Try to find a higher rate that would be allowed */
271 for (j = rate->idx + 1; j < n_bitrates; j++) {
272 if (mask & (1 << j)) {
273 /* Okay, found a suitable rate. Use it. */
274 rate->idx = j;
275 return;
276 }
277 }
278
279 /*
280 * Uh.. No suitable rate exists. This should not really happen with
281 * sane TX rate mask configurations. However, should someone manage to
282 * configure supported rates and TX rate mask in incompatible way,
283 * allow the frame to be transmitted with whatever the rate control
284 * selected.
285 */
286}
287
Johannes Berg4b7679a2008-09-18 18:14:18 +0200288void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
Johannes Berge6a98542008-10-21 12:40:02 +0200289 struct sta_info *sta,
290 struct ieee80211_tx_rate_control *txrc)
Mattias Nissler1abbe492007-12-20 13:50:07 +0100291{
Johannes Berg4b7679a2008-09-18 18:14:18 +0200292 struct rate_control_ref *ref = sdata->local->rate_ctrl;
293 void *priv_sta = NULL;
294 struct ieee80211_sta *ista = NULL;
Johannes Berge6a98542008-10-21 12:40:02 +0200295 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
Mattias Nissler1abbe492007-12-20 13:50:07 +0100296 int i;
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200297 u32 mask;
Mattias Nissler1abbe492007-12-20 13:50:07 +0100298
Johannes Berg4b7679a2008-09-18 18:14:18 +0200299 if (sta) {
300 ista = &sta->sta;
301 priv_sta = sta->rate_ctrl_priv;
302 }
303
Johannes Berge6a98542008-10-21 12:40:02 +0200304 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
305 info->control.rates[i].idx = -1;
306 info->control.rates[i].flags = 0;
307 info->control.rates[i].count = 1;
Mattias Nissler1abbe492007-12-20 13:50:07 +0100308 }
Johannes Berge6a98542008-10-21 12:40:02 +0200309
Juuso Oikarinen5affcd62010-02-12 10:05:45 +0200310 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
311 return;
312
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200313 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
Johannes Berge6a98542008-10-21 12:40:02 +0200314
315 /*
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200316 * Try to enforce the rateidx mask the user wanted. skip this if the
317 * default mask (allow all rates) is used to save some processing for
318 * the common case.
Johannes Berge6a98542008-10-21 12:40:02 +0200319 */
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200320 mask = sdata->rc_rateidx_mask[info->band];
321 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
322 if (sta) {
323 /* Filter out rates that the STA does not support */
324 mask &= sta->sta.supp_rates[info->band];
325 }
326 /*
327 * Make sure the rate index selected for each TX rate is
328 * included in the configured mask and change the rate indexes
329 * if needed.
330 */
Johannes Berge6a98542008-10-21 12:40:02 +0200331 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
Christian Lamparter5f4e6b22010-10-16 18:49:15 +0200332 /* Skip invalid rates */
333 if (info->control.rates[i].idx < 0)
334 break;
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200335 /* Rate masking supports only legacy rates for now */
Johannes Berge6a98542008-10-21 12:40:02 +0200336 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
337 continue;
Jouni Malinen37eb0b12010-01-06 13:09:08 +0200338 rate_idx_match_mask(&info->control.rates[i],
339 txrc->sband->n_bitrates, mask);
340 }
Johannes Berge6a98542008-10-21 12:40:02 +0200341 }
342
343 BUG_ON(info->control.rates[0].idx < 0);
Mattias Nissler1abbe492007-12-20 13:50:07 +0100344}
345
Jiri Bencf0706e82007-05-05 11:45:53 -0700346struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
347{
348 kref_get(&ref->kref);
349 return ref;
350}
351
352void rate_control_put(struct rate_control_ref *ref)
353{
354 kref_put(&ref->kref, rate_control_release);
355}
Johannes Bergff688082007-07-27 15:43:23 +0200356
357int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
358 const char *name)
359{
360 struct rate_control_ref *ref, *old;
361
362 ASSERT_RTNL();
Johannes Bergaf65cd962009-11-17 18:18:36 +0100363
Johannes Berg3b8d81e02009-06-17 17:43:56 +0200364 if (local->open_count)
Johannes Bergff688082007-07-27 15:43:23 +0200365 return -EBUSY;
366
Johannes Bergaf65cd962009-11-17 18:18:36 +0100367 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
368 if (WARN_ON(!local->ops->set_rts_threshold))
369 return -EINVAL;
370 return 0;
371 }
372
Johannes Bergff688082007-07-27 15:43:23 +0200373 ref = rate_control_alloc(name, local);
374 if (!ref) {
Joe Perches0fb9a9e2010-08-20 16:25:38 -0700375 wiphy_warn(local->hw.wiphy,
376 "Failed to select rate control algorithm\n");
Johannes Bergff688082007-07-27 15:43:23 +0200377 return -ENOENT;
378 }
379
380 old = local->rate_ctrl;
381 local->rate_ctrl = ref;
382 if (old) {
383 rate_control_put(old);
384 sta_info_flush(local, NULL);
385 }
386
Joe Perches0fb9a9e2010-08-20 16:25:38 -0700387 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
388 ref->ops->name);
Johannes Bergff688082007-07-27 15:43:23 +0200389
Johannes Bergff688082007-07-27 15:43:23 +0200390 return 0;
391}
392
393void rate_control_deinitialize(struct ieee80211_local *local)
394{
395 struct rate_control_ref *ref;
396
397 ref = local->rate_ctrl;
Johannes Bergaf65cd962009-11-17 18:18:36 +0100398
399 if (!ref)
400 return;
401
Johannes Bergff688082007-07-27 15:43:23 +0200402 local->rate_ctrl = NULL;
403 rate_control_put(ref);
404}
Stefano Brivioc21b39a2007-12-19 01:26:16 +0100405