mac80211: rate control status only for controlled packets
[linux-2.6.git] / net / mac80211 / rate.c
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>
12 #include <linux/rtnetlink.h>
13 #include "rate.h"
14 #include "ieee80211_i.h"
15 #include "debugfs.h"
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
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
30 int ieee80211_rate_control_register(struct rate_control_ops *ops)
31 {
32         struct rate_control_alg *alg;
33
34         if (!ops->name)
35                 return -EINVAL;
36
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);
42                         mutex_unlock(&rate_ctrl_mutex);
43                         return -EALREADY;
44                 }
45         }
46
47         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
48         if (alg == NULL) {
49                 mutex_unlock(&rate_ctrl_mutex);
50                 return -ENOMEM;
51         }
52         alg->ops = ops;
53
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);
69                         kfree(alg);
70                         break;
71                 }
72         }
73         mutex_unlock(&rate_ctrl_mutex);
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
83         if (!name)
84                 return NULL;
85
86         mutex_lock(&rate_ctrl_mutex);
87         list_for_each_entry(alg, &rate_ctrl_algs, list) {
88                 if (!strcmp(alg->ops->name, name))
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
98 /* Get the rate control algorithm. */
99 static struct rate_control_ops *
100 ieee80211_rate_control_ops_get(const char *name)
101 {
102         struct rate_control_ops *ops;
103         const char *alg_name;
104
105         if (!name)
106                 alg_name = ieee80211_default_rc_algo;
107         else
108                 alg_name = name;
109
110         ops = ieee80211_try_rate_control_ops_get(alg_name);
111         if (!ops) {
112                 request_module("rc80211_%s", alg_name);
113                 ops = ieee80211_try_rate_control_ops_get(alg_name);
114         }
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
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
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
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
148 struct rate_control_ref *rate_control_alloc(const char *name,
149                                             struct ieee80211_local *local)
150 {
151         struct dentry *debugfsdir = NULL;
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);
158         ref->local = local;
159         ref->ops = ieee80211_rate_control_ops_get(name);
160         if (!ref->ops)
161                 goto fail_ops;
162
163 #ifdef CONFIG_MAC80211_DEBUGFS
164         debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
165         local->debugfs.rcdir = debugfsdir;
166         local->debugfs.rcname = debugfs_create_file("name", 0400, debugfsdir,
167                                                     ref, &rcname_ops);
168 #endif
169
170         ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
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);
189
190 #ifdef CONFIG_MAC80211_DEBUGFS
191         debugfs_remove(ctrl_ref->local->debugfs.rcname);
192         ctrl_ref->local->debugfs.rcname = NULL;
193         debugfs_remove(ctrl_ref->local->debugfs.rcdir);
194         ctrl_ref->local->debugfs.rcdir = NULL;
195 #endif
196
197         ieee80211_rate_control_ops_put(ctrl_ref->ops);
198         kfree(ctrl_ref);
199 }
200
201 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
202                            struct sta_info *sta,
203                            struct ieee80211_tx_rate_control *txrc)
204 {
205         struct rate_control_ref *ref = sdata->local->rate_ctrl;
206         void *priv_sta = NULL;
207         struct ieee80211_sta *ista = NULL;
208         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
209         int i;
210
211         if (sta) {
212                 ista = &sta->sta;
213                 priv_sta = sta->rate_ctrl_priv;
214         }
215
216         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
217                 info->control.rates[i].idx = -1;
218                 info->control.rates[i].flags = 0;
219                 info->control.rates[i].count = 1;
220         }
221
222         if (sta && sdata->force_unicast_rateidx > -1) {
223                 info->control.rates[0].idx = sdata->force_unicast_rateidx;
224         } else {
225                 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
226                 info->flags |= IEEE80211_TX_INTFL_RCALGO;
227         }
228
229         /*
230          * try to enforce the maximum rate the user wanted
231          */
232         if (sdata->max_ratectrl_rateidx > -1)
233                 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
234                         if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
235                                 continue;
236                         info->control.rates[i].idx =
237                                 min_t(s8, info->control.rates[i].idx,
238                                       sdata->max_ratectrl_rateidx);
239         }
240
241         BUG_ON(info->control.rates[0].idx < 0);
242 }
243
244 struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
245 {
246         kref_get(&ref->kref);
247         return ref;
248 }
249
250 void rate_control_put(struct rate_control_ref *ref)
251 {
252         kref_put(&ref->kref, rate_control_release);
253 }
254
255 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
256                                  const char *name)
257 {
258         struct rate_control_ref *ref, *old;
259
260         ASSERT_RTNL();
261         if (local->open_count || netif_running(local->mdev))
262                 return -EBUSY;
263
264         ref = rate_control_alloc(name, local);
265         if (!ref) {
266                 printk(KERN_WARNING "%s: Failed to select rate control "
267                        "algorithm\n", wiphy_name(local->hw.wiphy));
268                 return -ENOENT;
269         }
270
271         old = local->rate_ctrl;
272         local->rate_ctrl = ref;
273         if (old) {
274                 rate_control_put(old);
275                 sta_info_flush(local, NULL);
276         }
277
278         printk(KERN_DEBUG "%s: Selected rate control "
279                "algorithm '%s'\n", wiphy_name(local->hw.wiphy),
280                ref->ops->name);
281
282
283         return 0;
284 }
285
286 void rate_control_deinitialize(struct ieee80211_local *local)
287 {
288         struct rate_control_ref *ref;
289
290         ref = local->rate_ctrl;
291         local->rate_ctrl = NULL;
292         rate_control_put(ref);
293 }
294