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>
13 #include <linux/slab.h>
14 #include <linux/module.h>
16 #include "ieee80211_i.h"
19 struct rate_control_alg
{
20 struct list_head list
;
21 struct rate_control_ops
*ops
;
24 static LIST_HEAD(rate_ctrl_algs
);
25 static DEFINE_MUTEX(rate_ctrl_mutex
);
27 static char *ieee80211_default_rc_algo
= CONFIG_MAC80211_RC_DEFAULT
;
28 module_param(ieee80211_default_rc_algo
, charp
, 0644);
29 MODULE_PARM_DESC(ieee80211_default_rc_algo
,
30 "Default rate control algorithm for mac80211 to use");
32 int ieee80211_rate_control_register(struct rate_control_ops
*ops
)
34 struct rate_control_alg
*alg
;
39 mutex_lock(&rate_ctrl_mutex
);
40 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
41 if (!strcmp(alg
->ops
->name
, ops
->name
)) {
42 /* don't register an algorithm twice */
44 mutex_unlock(&rate_ctrl_mutex
);
49 alg
= kzalloc(sizeof(*alg
), GFP_KERNEL
);
51 mutex_unlock(&rate_ctrl_mutex
);
56 list_add_tail(&alg
->list
, &rate_ctrl_algs
);
57 mutex_unlock(&rate_ctrl_mutex
);
61 EXPORT_SYMBOL(ieee80211_rate_control_register
);
63 void ieee80211_rate_control_unregister(struct rate_control_ops
*ops
)
65 struct rate_control_alg
*alg
;
67 mutex_lock(&rate_ctrl_mutex
);
68 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
69 if (alg
->ops
== ops
) {
75 mutex_unlock(&rate_ctrl_mutex
);
77 EXPORT_SYMBOL(ieee80211_rate_control_unregister
);
79 static struct rate_control_ops
*
80 ieee80211_try_rate_control_ops_get(const char *name
)
82 struct rate_control_alg
*alg
;
83 struct rate_control_ops
*ops
= NULL
;
88 mutex_lock(&rate_ctrl_mutex
);
89 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
90 if (!strcmp(alg
->ops
->name
, name
))
91 if (try_module_get(alg
->ops
->module
)) {
96 mutex_unlock(&rate_ctrl_mutex
);
100 /* Get the rate control algorithm. */
101 static struct rate_control_ops
*
102 ieee80211_rate_control_ops_get(const char *name
)
104 struct rate_control_ops
*ops
;
105 const char *alg_name
;
107 kparam_block_sysfs_write(ieee80211_default_rc_algo
);
109 alg_name
= ieee80211_default_rc_algo
;
113 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
115 request_module("rc80211_%s", alg_name
);
116 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
119 /* try default if specific alg requested but not found */
120 ops
= ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo
);
122 /* try built-in one if specific alg requested but not found */
123 if (!ops
&& strlen(CONFIG_MAC80211_RC_DEFAULT
))
124 ops
= ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT
);
125 kparam_unblock_sysfs_write(ieee80211_default_rc_algo
);
130 static void ieee80211_rate_control_ops_put(struct rate_control_ops
*ops
)
132 module_put(ops
->module
);
135 #ifdef CONFIG_MAC80211_DEBUGFS
136 static ssize_t
rcname_read(struct file
*file
, char __user
*userbuf
,
137 size_t count
, loff_t
*ppos
)
139 struct rate_control_ref
*ref
= file
->private_data
;
140 int len
= strlen(ref
->ops
->name
);
142 return simple_read_from_buffer(userbuf
, count
, ppos
,
143 ref
->ops
->name
, len
);
146 static const struct file_operations rcname_ops
= {
148 .open
= mac80211_open_file_generic
,
149 .llseek
= default_llseek
,
153 static struct rate_control_ref
*rate_control_alloc(const char *name
,
154 struct ieee80211_local
*local
)
156 struct dentry
*debugfsdir
= NULL
;
157 struct rate_control_ref
*ref
;
159 ref
= kmalloc(sizeof(struct rate_control_ref
), GFP_KERNEL
);
163 ref
->ops
= ieee80211_rate_control_ops_get(name
);
167 #ifdef CONFIG_MAC80211_DEBUGFS
168 debugfsdir
= debugfs_create_dir("rc", local
->hw
.wiphy
->debugfsdir
);
169 local
->debugfs
.rcdir
= debugfsdir
;
170 debugfs_create_file("name", 0400, debugfsdir
, ref
, &rcname_ops
);
173 ref
->priv
= ref
->ops
->alloc(&local
->hw
, debugfsdir
);
179 ieee80211_rate_control_ops_put(ref
->ops
);
186 static void rate_control_free(struct rate_control_ref
*ctrl_ref
)
188 ctrl_ref
->ops
->free(ctrl_ref
->priv
);
190 #ifdef CONFIG_MAC80211_DEBUGFS
191 debugfs_remove_recursive(ctrl_ref
->local
->debugfs
.rcdir
);
192 ctrl_ref
->local
->debugfs
.rcdir
= NULL
;
195 ieee80211_rate_control_ops_put(ctrl_ref
->ops
);
199 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control
*txrc
)
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
);
206 fc
= hdr
->frame_control
;
208 return (info
->flags
& (IEEE80211_TX_CTL_NO_ACK
|
209 IEEE80211_TX_CTL_USE_MINRATE
)) ||
210 !ieee80211_is_data(fc
);
213 static void rc_send_low_broadcast(s8
*idx
, u32 basic_rates
,
214 struct ieee80211_supported_band
*sband
)
218 if (basic_rates
== 0)
219 return; /* assume basic rates unknown and accept rate */
222 if (basic_rates
& (1 << *idx
))
223 return; /* selected rate is a basic rate */
225 for (i
= *idx
+ 1; i
<= sband
->n_bitrates
; i
++) {
226 if (basic_rates
& (1 << i
)) {
232 /* could not find a basic rate; use original selection */
236 rate_lowest_non_cck_index(struct ieee80211_supported_band
*sband
,
237 struct ieee80211_sta
*sta
)
241 for (i
= 0; i
< sband
->n_bitrates
; i
++) {
242 struct ieee80211_rate
*srate
= &sband
->bitrates
[i
];
243 if ((srate
->bitrate
== 10) || (srate
->bitrate
== 20) ||
244 (srate
->bitrate
== 55) || (srate
->bitrate
== 110))
247 if (rate_supported(sta
, sband
->band
, i
))
251 /* No matching rate found */
256 bool rate_control_send_low(struct ieee80211_sta
*sta
,
258 struct ieee80211_tx_rate_control
*txrc
)
260 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
261 struct ieee80211_supported_band
*sband
= txrc
->sband
;
264 if (!sta
|| !priv_sta
|| rc_no_data_or_no_ack_use_min(txrc
)) {
265 if ((sband
->band
!= IEEE80211_BAND_2GHZ
) ||
266 !(info
->flags
& IEEE80211_TX_CTL_NO_CCK_RATE
))
267 info
->control
.rates
[0].idx
=
268 rate_lowest_index(txrc
->sband
, sta
);
270 info
->control
.rates
[0].idx
=
271 rate_lowest_non_cck_index(txrc
->sband
, sta
);
272 info
->control
.rates
[0].count
=
273 (info
->flags
& IEEE80211_TX_CTL_NO_ACK
) ?
274 1 : txrc
->hw
->max_rate_tries
;
275 if (!sta
&& txrc
->bss
) {
276 mcast_rate
= txrc
->bss_conf
->mcast_rate
[sband
->band
];
277 if (mcast_rate
> 0) {
278 info
->control
.rates
[0].idx
= mcast_rate
- 1;
282 rc_send_low_broadcast(&info
->control
.rates
[0].idx
,
283 txrc
->bss_conf
->basic_rates
,
290 EXPORT_SYMBOL(rate_control_send_low
);
292 static void rate_idx_match_mask(struct ieee80211_tx_rate
*rate
,
293 int n_bitrates
, u32 mask
)
297 /* See whether the selected rate or anything below it is allowed. */
298 for (j
= rate
->idx
; j
>= 0; j
--) {
299 if (mask
& (1 << j
)) {
300 /* Okay, found a suitable rate. Use it. */
306 /* Try to find a higher rate that would be allowed */
307 for (j
= rate
->idx
+ 1; j
< n_bitrates
; j
++) {
308 if (mask
& (1 << j
)) {
309 /* Okay, found a suitable rate. Use it. */
316 * Uh.. No suitable rate exists. This should not really happen with
317 * sane TX rate mask configurations. However, should someone manage to
318 * configure supported rates and TX rate mask in incompatible way,
319 * allow the frame to be transmitted with whatever the rate control
324 void rate_control_get_rate(struct ieee80211_sub_if_data
*sdata
,
325 struct sta_info
*sta
,
326 struct ieee80211_tx_rate_control
*txrc
)
328 struct rate_control_ref
*ref
= sdata
->local
->rate_ctrl
;
329 void *priv_sta
= NULL
;
330 struct ieee80211_sta
*ista
= NULL
;
331 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
337 priv_sta
= sta
->rate_ctrl_priv
;
340 for (i
= 0; i
< IEEE80211_TX_MAX_RATES
; i
++) {
341 info
->control
.rates
[i
].idx
= -1;
342 info
->control
.rates
[i
].flags
= 0;
343 info
->control
.rates
[i
].count
= 1;
346 if (sdata
->local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
)
349 ref
->ops
->get_rate(ref
->priv
, ista
, priv_sta
, txrc
);
352 * Try to enforce the rateidx mask the user wanted. skip this if the
353 * default mask (allow all rates) is used to save some processing for
356 mask
= sdata
->rc_rateidx_mask
[info
->band
];
357 if (mask
!= (1 << txrc
->sband
->n_bitrates
) - 1) {
359 /* Filter out rates that the STA does not support */
360 mask
&= sta
->sta
.supp_rates
[info
->band
];
363 * Make sure the rate index selected for each TX rate is
364 * included in the configured mask and change the rate indexes
367 for (i
= 0; i
< IEEE80211_TX_MAX_RATES
; i
++) {
368 /* Skip invalid rates */
369 if (info
->control
.rates
[i
].idx
< 0)
371 /* Rate masking supports only legacy rates for now */
372 if (info
->control
.rates
[i
].flags
& IEEE80211_TX_RC_MCS
)
374 rate_idx_match_mask(&info
->control
.rates
[i
],
375 txrc
->sband
->n_bitrates
, mask
);
379 BUG_ON(info
->control
.rates
[0].idx
< 0);
382 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local
*local
,
385 struct rate_control_ref
*ref
;
389 if (local
->open_count
)
392 if (local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
) {
393 if (WARN_ON(!local
->ops
->set_rts_threshold
))
398 ref
= rate_control_alloc(name
, local
);
400 wiphy_warn(local
->hw
.wiphy
,
401 "Failed to select rate control algorithm\n");
405 WARN_ON(local
->rate_ctrl
);
406 local
->rate_ctrl
= ref
;
408 wiphy_debug(local
->hw
.wiphy
, "Selected rate control algorithm '%s'\n",
414 void rate_control_deinitialize(struct ieee80211_local
*local
)
416 struct rate_control_ref
*ref
;
418 ref
= local
->rate_ctrl
;
423 local
->rate_ctrl
= NULL
;
424 rate_control_free(ref
);