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>
15 #include "ieee80211_i.h"
18 struct rate_control_alg {
19 struct list_head list;
20 struct rate_control_ops *ops;
23 static LIST_HEAD(rate_ctrl_algs);
24 static DEFINE_MUTEX(rate_ctrl_mutex);
26 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
27 module_param(ieee80211_default_rc_algo, charp, 0644);
28 MODULE_PARM_DESC(ieee80211_default_rc_algo,
29 "Default rate control algorithm for mac80211 to use");
31 int ieee80211_rate_control_register(struct rate_control_ops *ops)
33 struct rate_control_alg *alg;
38 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 */
43 mutex_unlock(&rate_ctrl_mutex);
48 alg = kzalloc(sizeof(*alg), GFP_KERNEL);
50 mutex_unlock(&rate_ctrl_mutex);
55 list_add_tail(&alg->list, &rate_ctrl_algs);
56 mutex_unlock(&rate_ctrl_mutex);
60 EXPORT_SYMBOL(ieee80211_rate_control_register);
62 void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
64 struct rate_control_alg *alg;
66 mutex_lock(&rate_ctrl_mutex);
67 list_for_each_entry(alg, &rate_ctrl_algs, list) {
68 if (alg->ops == ops) {
74 mutex_unlock(&rate_ctrl_mutex);
76 EXPORT_SYMBOL(ieee80211_rate_control_unregister);
78 static struct rate_control_ops *
79 ieee80211_try_rate_control_ops_get(const char *name)
81 struct rate_control_alg *alg;
82 struct rate_control_ops *ops = NULL;
87 mutex_lock(&rate_ctrl_mutex);
88 list_for_each_entry(alg, &rate_ctrl_algs, list) {
89 if (!strcmp(alg->ops->name, name))
90 if (try_module_get(alg->ops->module)) {
95 mutex_unlock(&rate_ctrl_mutex);
99 /* Get the rate control algorithm. */
100 static struct rate_control_ops *
101 ieee80211_rate_control_ops_get(const char *name)
103 struct rate_control_ops *ops;
104 const char *alg_name;
107 alg_name = ieee80211_default_rc_algo;
111 ops = ieee80211_try_rate_control_ops_get(alg_name);
113 request_module("rc80211_%s", alg_name);
114 ops = ieee80211_try_rate_control_ops_get(alg_name);
117 /* try default if specific alg requested but not found */
118 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
120 /* try built-in one if specific alg requested but not found */
121 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
122 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
127 static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
129 module_put(ops->module);
132 #ifdef CONFIG_MAC80211_DEBUGFS
133 static ssize_t rcname_read(struct file *file, char __user *userbuf,
134 size_t count, loff_t *ppos)
136 struct rate_control_ref *ref = file->private_data;
137 int len = strlen(ref->ops->name);
139 return simple_read_from_buffer(userbuf, count, ppos,
140 ref->ops->name, len);
143 static const struct file_operations rcname_ops = {
145 .open = mac80211_open_file_generic,
149 static struct rate_control_ref *rate_control_alloc(const char *name,
150 struct ieee80211_local *local)
152 struct dentry *debugfsdir = NULL;
153 struct rate_control_ref *ref;
155 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
158 kref_init(&ref->kref);
160 ref->ops = ieee80211_rate_control_ops_get(name);
164 #ifdef CONFIG_MAC80211_DEBUGFS
165 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
166 local->debugfs.rcdir = debugfsdir;
167 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
170 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
176 ieee80211_rate_control_ops_put(ref->ops);
183 static void rate_control_release(struct kref *kref)
185 struct rate_control_ref *ctrl_ref;
187 ctrl_ref = container_of(kref, struct rate_control_ref, kref);
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(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) || !ieee80211_is_data(fc));
211 static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
215 if (basic_rates == 0)
216 return; /* assume basic rates unknown and accept rate */
219 if (basic_rates & (1 << *idx))
220 return; /* selected rate is a basic rate */
222 for (i = *idx + 1; i <= max_rate_idx; i++) {
223 if (basic_rates & (1 << i)) {
229 /* could not find a basic rate; use original selection */
232 bool rate_control_send_low(struct ieee80211_sta *sta,
234 struct ieee80211_tx_rate_control *txrc)
236 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
238 if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
239 info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
240 info->control.rates[0].count =
241 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
242 1 : txrc->hw->max_rate_tries;
243 if (!sta && txrc->ap)
244 rc_send_low_broadcast(&info->control.rates[0].idx,
245 txrc->bss_conf->basic_rates,
246 txrc->sband->n_bitrates);
251 EXPORT_SYMBOL(rate_control_send_low);
253 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
254 int n_bitrates, u32 mask)
258 /* See whether the selected rate or anything below it is allowed. */
259 for (j = rate->idx; j >= 0; j--) {
260 if (mask & (1 << j)) {
261 /* Okay, found a suitable rate. Use it. */
267 /* Try to find a higher rate that would be allowed */
268 for (j = rate->idx + 1; j < n_bitrates; j++) {
269 if (mask & (1 << j)) {
270 /* Okay, found a suitable rate. Use it. */
277 * Uh.. No suitable rate exists. This should not really happen with
278 * sane TX rate mask configurations. However, should someone manage to
279 * configure supported rates and TX rate mask in incompatible way,
280 * allow the frame to be transmitted with whatever the rate control
285 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
286 struct sta_info *sta,
287 struct ieee80211_tx_rate_control *txrc)
289 struct rate_control_ref *ref = sdata->local->rate_ctrl;
290 void *priv_sta = NULL;
291 struct ieee80211_sta *ista = NULL;
292 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
298 priv_sta = sta->rate_ctrl_priv;
301 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
302 info->control.rates[i].idx = -1;
303 info->control.rates[i].flags = 0;
304 info->control.rates[i].count = 1;
307 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
310 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
313 * Try to enforce the rateidx mask the user wanted. skip this if the
314 * default mask (allow all rates) is used to save some processing for
317 mask = sdata->rc_rateidx_mask[info->band];
318 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
320 /* Filter out rates that the STA does not support */
321 mask &= sta->sta.supp_rates[info->band];
324 * Make sure the rate index selected for each TX rate is
325 * included in the configured mask and change the rate indexes
328 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
329 /* Rate masking supports only legacy rates for now */
330 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
332 rate_idx_match_mask(&info->control.rates[i],
333 txrc->sband->n_bitrates, mask);
337 BUG_ON(info->control.rates[0].idx < 0);
340 struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
342 kref_get(&ref->kref);
346 void rate_control_put(struct rate_control_ref *ref)
348 kref_put(&ref->kref, rate_control_release);
351 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
354 struct rate_control_ref *ref, *old;
358 if (local->open_count)
361 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
362 if (WARN_ON(!local->ops->set_rts_threshold))
367 ref = rate_control_alloc(name, local);
369 printk(KERN_WARNING "%s: Failed to select rate control "
370 "algorithm\n", wiphy_name(local->hw.wiphy));
374 old = local->rate_ctrl;
375 local->rate_ctrl = ref;
377 rate_control_put(old);
378 sta_info_flush(local, NULL);
381 printk(KERN_DEBUG "%s: Selected rate control "
382 "algorithm '%s'\n", wiphy_name(local->hw.wiphy),
388 void rate_control_deinitialize(struct ieee80211_local *local)
390 struct rate_control_ref *ref;
392 ref = local->rate_ctrl;
397 local->rate_ctrl = NULL;
398 rate_control_put(ref);