New: mac80211 stack from the wireless-dev tree
[openwrt/openwrt.git] / package / mac80211 / src / mac80211 / ieee80211_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 "ieee80211_rate.h"
13 #include "ieee80211_i.h"
14
15 struct rate_control_alg {
16 struct list_head list;
17 struct rate_control_ops *ops;
18 };
19
20 static LIST_HEAD(rate_ctrl_algs);
21 static DEFINE_MUTEX(rate_ctrl_mutex);
22
23 int ieee80211_rate_control_register(struct rate_control_ops *ops)
24 {
25 struct rate_control_alg *alg;
26
27 alg = kmalloc(sizeof(*alg), GFP_KERNEL);
28 if (alg == NULL) {
29 return -ENOMEM;
30 }
31 memset(alg, 0, sizeof(*alg));
32 alg->ops = ops;
33
34 mutex_lock(&rate_ctrl_mutex);
35 list_add_tail(&alg->list, &rate_ctrl_algs);
36 mutex_unlock(&rate_ctrl_mutex);
37
38 return 0;
39 }
40 EXPORT_SYMBOL(ieee80211_rate_control_register);
41
42 void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
43 {
44 struct rate_control_alg *alg;
45
46 mutex_lock(&rate_ctrl_mutex);
47 list_for_each_entry(alg, &rate_ctrl_algs, list) {
48 if (alg->ops == ops) {
49 list_del(&alg->list);
50 break;
51 }
52 }
53 mutex_unlock(&rate_ctrl_mutex);
54 kfree(alg);
55 }
56 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
57
58 static struct rate_control_ops *
59 ieee80211_try_rate_control_ops_get(const char *name)
60 {
61 struct rate_control_alg *alg;
62 struct rate_control_ops *ops = NULL;
63
64 mutex_lock(&rate_ctrl_mutex);
65 list_for_each_entry(alg, &rate_ctrl_algs, list) {
66 if (!name || !strcmp(alg->ops->name, name))
67 if (try_module_get(alg->ops->module)) {
68 ops = alg->ops;
69 break;
70 }
71 }
72 mutex_unlock(&rate_ctrl_mutex);
73 return ops;
74 }
75
76 /* Get the rate control algorithm. If `name' is NULL, get the first
77 * available algorithm. */
78 static struct rate_control_ops *
79 ieee80211_rate_control_ops_get(const char *name)
80 {
81 struct rate_control_ops *ops;
82
83 ops = ieee80211_try_rate_control_ops_get(name);
84 if (!ops) {
85 request_module("rc80211_%s", name ? name : "default");
86 ops = ieee80211_try_rate_control_ops_get(name);
87 }
88 return ops;
89 }
90
91 static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
92 {
93 module_put(ops->module);
94 }
95
96 struct rate_control_ref *rate_control_alloc(const char *name,
97 struct ieee80211_local *local)
98 {
99 struct rate_control_ref *ref;
100
101 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
102 if (!ref)
103 goto fail_ref;
104 kref_init(&ref->kref);
105 ref->ops = ieee80211_rate_control_ops_get(name);
106 if (!ref->ops)
107 goto fail_ops;
108 ref->priv = ref->ops->alloc(local);
109 if (!ref->priv)
110 goto fail_priv;
111 return ref;
112
113 fail_priv:
114 ieee80211_rate_control_ops_put(ref->ops);
115 fail_ops:
116 kfree(ref);
117 fail_ref:
118 return NULL;
119 }
120
121 static void rate_control_release(struct kref *kref)
122 {
123 struct rate_control_ref *ctrl_ref;
124
125 ctrl_ref = container_of(kref, struct rate_control_ref, kref);
126 ctrl_ref->ops->free(ctrl_ref->priv);
127 ieee80211_rate_control_ops_put(ctrl_ref->ops);
128 kfree(ctrl_ref);
129 }
130
131 struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
132 {
133 kref_get(&ref->kref);
134 return ref;
135 }
136
137 void rate_control_put(struct rate_control_ref *ref)
138 {
139 kref_put(&ref->kref, rate_control_release);
140 }