2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
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.
11 #include <linux/kernel.h>
12 #include <linux/rtnetlink.h>
14 #include "ieee80211_i.h"
17 struct rate_control_alg
{
18 struct list_head list
;
19 struct rate_control_ops
*ops
;
22 static LIST_HEAD(rate_ctrl_algs
);
23 static DEFINE_MUTEX(rate_ctrl_mutex
);
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");
30 int ieee80211_rate_control_register(struct rate_control_ops
*ops
)
32 struct rate_control_alg
*alg
;
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 */
42 mutex_unlock(&rate_ctrl_mutex
);
47 alg
= kzalloc(sizeof(*alg
), GFP_KERNEL
);
49 mutex_unlock(&rate_ctrl_mutex
);
54 list_add_tail(&alg
->list
, &rate_ctrl_algs
);
55 mutex_unlock(&rate_ctrl_mutex
);
59 EXPORT_SYMBOL(ieee80211_rate_control_register
);
61 void ieee80211_rate_control_unregister(struct rate_control_ops
*ops
)
63 struct rate_control_alg
*alg
;
65 mutex_lock(&rate_ctrl_mutex
);
66 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
67 if (alg
->ops
== ops
) {
73 mutex_unlock(&rate_ctrl_mutex
);
75 EXPORT_SYMBOL(ieee80211_rate_control_unregister
);
77 static struct rate_control_ops
*
78 ieee80211_try_rate_control_ops_get(const char *name
)
80 struct rate_control_alg
*alg
;
81 struct rate_control_ops
*ops
= NULL
;
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
)) {
94 mutex_unlock(&rate_ctrl_mutex
);
98 /* Get the rate control algorithm. */
99 static struct rate_control_ops
*
100 ieee80211_rate_control_ops_get(const char *name
)
102 struct rate_control_ops
*ops
;
103 const char *alg_name
;
106 alg_name
= ieee80211_default_rc_algo
;
110 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
112 request_module("rc80211_%s", alg_name
);
113 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
116 /* try default if specific alg requested but not found */
117 ops
= ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo
);
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
);
126 static void ieee80211_rate_control_ops_put(struct rate_control_ops
*ops
)
128 module_put(ops
->module
);
131 #ifdef CONFIG_MAC80211_DEBUGFS
132 static ssize_t
rcname_read(struct file
*file
, char __user
*userbuf
,
133 size_t count
, loff_t
*ppos
)
135 struct rate_control_ref
*ref
= file
->private_data
;
136 int len
= strlen(ref
->ops
->name
);
138 return simple_read_from_buffer(userbuf
, count
, ppos
,
139 ref
->ops
->name
, len
);
142 static const struct file_operations rcname_ops
= {
144 .open
= mac80211_open_file_generic
,
148 static struct rate_control_ref
*rate_control_alloc(const char *name
,
149 struct ieee80211_local
*local
)
151 struct dentry
*debugfsdir
= NULL
;
152 struct rate_control_ref
*ref
;
154 ref
= kmalloc(sizeof(struct rate_control_ref
), GFP_KERNEL
);
157 kref_init(&ref
->kref
);
159 ref
->ops
= ieee80211_rate_control_ops_get(name
);
163 #ifdef CONFIG_MAC80211_DEBUGFS
164 debugfsdir
= debugfs_create_dir("rc", local
->hw
.wiphy
->debugfsdir
);
165 local
->debugfs
.rcdir
= debugfsdir
;
166 debugfs_create_file("name", 0400, debugfsdir
, ref
, &rcname_ops
);
169 ref
->priv
= ref
->ops
->alloc(&local
->hw
, debugfsdir
);
175 ieee80211_rate_control_ops_put(ref
->ops
);
182 static void rate_control_release(struct kref
*kref
)
184 struct rate_control_ref
*ctrl_ref
;
186 ctrl_ref
= container_of(kref
, struct rate_control_ref
, kref
);
187 ctrl_ref
->ops
->free(ctrl_ref
->priv
);
189 #ifdef CONFIG_MAC80211_DEBUGFS
190 debugfs_remove_recursive(ctrl_ref
->local
->debugfs
.rcdir
);
191 ctrl_ref
->local
->debugfs
.rcdir
= NULL
;
194 ieee80211_rate_control_ops_put(ctrl_ref
->ops
);
198 static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control
*txrc
)
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
);
205 fc
= hdr
->frame_control
;
207 return ((info
->flags
& IEEE80211_TX_CTL_NO_ACK
) || !ieee80211_is_data(fc
));
210 static void rc_send_low_broadcast(s8
*idx
, u32 basic_rates
, u8 max_rate_idx
)
214 if (basic_rates
== 0)
215 return; /* assume basic rates unknown and accept rate */
218 if (basic_rates
& (1 << *idx
))
219 return; /* selected rate is a basic rate */
221 for (i
= *idx
+ 1; i
<= max_rate_idx
; i
++) {
222 if (basic_rates
& (1 << i
)) {
228 /* could not find a basic rate; use original selection */
231 bool rate_control_send_low(struct ieee80211_sta
*sta
,
233 struct ieee80211_tx_rate_control
*txrc
)
235 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
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
;
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
);
250 EXPORT_SYMBOL(rate_control_send_low
);
252 static void rate_idx_match_mask(struct ieee80211_tx_rate
*rate
,
253 int n_bitrates
, u32 mask
)
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. */
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. */
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
284 void rate_control_get_rate(struct ieee80211_sub_if_data
*sdata
,
285 struct sta_info
*sta
,
286 struct ieee80211_tx_rate_control
*txrc
)
288 struct rate_control_ref
*ref
= sdata
->local
->rate_ctrl
;
289 void *priv_sta
= NULL
;
290 struct ieee80211_sta
*ista
= NULL
;
291 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
297 priv_sta
= sta
->rate_ctrl_priv
;
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;
306 if (sdata
->local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
)
309 ref
->ops
->get_rate(ref
->priv
, ista
, priv_sta
, txrc
);
312 * Try to enforce the rateidx mask the user wanted. skip this if the
313 * default mask (allow all rates) is used to save some processing for
316 mask
= sdata
->rc_rateidx_mask
[info
->band
];
317 if (mask
!= (1 << txrc
->sband
->n_bitrates
) - 1) {
319 /* Filter out rates that the STA does not support */
320 mask
&= sta
->sta
.supp_rates
[info
->band
];
323 * Make sure the rate index selected for each TX rate is
324 * included in the configured mask and change the rate indexes
327 for (i
= 0; i
< IEEE80211_TX_MAX_RATES
; i
++) {
328 /* Rate masking supports only legacy rates for now */
329 if (info
->control
.rates
[i
].flags
& IEEE80211_TX_RC_MCS
)
331 rate_idx_match_mask(&info
->control
.rates
[i
],
332 txrc
->sband
->n_bitrates
, mask
);
336 BUG_ON(info
->control
.rates
[0].idx
< 0);
339 struct rate_control_ref
*rate_control_get(struct rate_control_ref
*ref
)
341 kref_get(&ref
->kref
);
345 void rate_control_put(struct rate_control_ref
*ref
)
347 kref_put(&ref
->kref
, rate_control_release
);
350 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local
*local
,
353 struct rate_control_ref
*ref
, *old
;
357 if (local
->open_count
)
360 if (local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
) {
361 if (WARN_ON(!local
->ops
->set_rts_threshold
))
366 ref
= rate_control_alloc(name
, local
);
368 printk(KERN_WARNING
"%s: Failed to select rate control "
369 "algorithm\n", wiphy_name(local
->hw
.wiphy
));
373 old
= local
->rate_ctrl
;
374 local
->rate_ctrl
= ref
;
376 rate_control_put(old
);
377 sta_info_flush(local
, NULL
);
380 printk(KERN_DEBUG
"%s: Selected rate control "
381 "algorithm '%s'\n", wiphy_name(local
->hw
.wiphy
),
387 void rate_control_deinitialize(struct ieee80211_local
*local
)
389 struct rate_control_ref
*ref
;
391 ref
= local
->rate_ctrl
;
396 local
->rate_ctrl
= NULL
;
397 rate_control_put(ref
);