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;
106 kparam_block_sysfs_write(ieee80211_default_rc_algo);
108 alg_name = ieee80211_default_rc_algo;
112 ops = ieee80211_try_rate_control_ops_get(alg_name);
114 request_module("rc80211_%s", alg_name);
115 ops = ieee80211_try_rate_control_ops_get(alg_name);
118 /* try default if specific alg requested but not found */
119 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
121 /* try built-in one if specific alg requested but not found */
122 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
123 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
124 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
129 static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
131 module_put(ops->module);
134 #ifdef CONFIG_MAC80211_DEBUGFS
135 static ssize_t rcname_read(struct file *file, char __user *userbuf,
136 size_t count, loff_t *ppos)
138 struct rate_control_ref *ref = file->private_data;
139 int len = strlen(ref->ops->name);
141 return simple_read_from_buffer(userbuf, count, ppos,
142 ref->ops->name, len);
145 static const struct file_operations rcname_ops = {
147 .open = mac80211_open_file_generic,
148 .llseek = default_llseek,
152 static struct rate_control_ref *rate_control_alloc(const char *name,
153 struct ieee80211_local *local)
155 struct dentry *debugfsdir = NULL;
156 struct rate_control_ref *ref;
158 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
161 kref_init(&ref->kref);
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_release(struct kref *kref)
188 struct rate_control_ref *ctrl_ref;
190 ctrl_ref = container_of(kref, struct rate_control_ref, kref);
191 ctrl_ref->ops->free(ctrl_ref->priv);
193 #ifdef CONFIG_MAC80211_DEBUGFS
194 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
195 ctrl_ref->local->debugfs.rcdir = NULL;
198 ieee80211_rate_control_ops_put(ctrl_ref->ops);
202 static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc)
204 struct sk_buff *skb = txrc->skb;
205 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
206 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
209 fc = hdr->frame_control;
211 return (info->flags & IEEE80211_TX_CTL_NO_ACK) || !ieee80211_is_data(fc);
214 static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
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 <= max_rate_idx; i++) {
226 if (basic_rates & (1 << i)) {
232 /* could not find a basic rate; use original selection */
235 bool rate_control_send_low(struct ieee80211_sta *sta,
237 struct ieee80211_tx_rate_control *txrc)
239 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
241 if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
242 info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
243 info->control.rates[0].count =
244 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
245 1 : txrc->hw->max_rate_tries;
246 if (!sta && txrc->ap)
247 rc_send_low_broadcast(&info->control.rates[0].idx,
248 txrc->bss_conf->basic_rates,
249 txrc->sband->n_bitrates);
254 EXPORT_SYMBOL(rate_control_send_low);
256 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
257 int n_bitrates, u32 mask)
261 /* See whether the selected rate or anything below it is allowed. */
262 for (j = rate->idx; j >= 0; j--) {
263 if (mask & (1 << j)) {
264 /* Okay, found a suitable rate. Use it. */
270 /* Try to find a higher rate that would be allowed */
271 for (j = rate->idx + 1; j < n_bitrates; j++) {
272 if (mask & (1 << j)) {
273 /* Okay, found a suitable rate. Use it. */
280 * Uh.. No suitable rate exists. This should not really happen with
281 * sane TX rate mask configurations. However, should someone manage to
282 * configure supported rates and TX rate mask in incompatible way,
283 * allow the frame to be transmitted with whatever the rate control
288 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
289 struct sta_info *sta,
290 struct ieee80211_tx_rate_control *txrc)
292 struct rate_control_ref *ref = sdata->local->rate_ctrl;
293 void *priv_sta = NULL;
294 struct ieee80211_sta *ista = NULL;
295 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
301 priv_sta = sta->rate_ctrl_priv;
304 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
305 info->control.rates[i].idx = -1;
306 info->control.rates[i].flags = 0;
307 info->control.rates[i].count = 1;
310 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
313 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
316 * Try to enforce the rateidx mask the user wanted. skip this if the
317 * default mask (allow all rates) is used to save some processing for
320 mask = sdata->rc_rateidx_mask[info->band];
321 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
323 /* Filter out rates that the STA does not support */
324 mask &= sta->sta.supp_rates[info->band];
327 * Make sure the rate index selected for each TX rate is
328 * included in the configured mask and change the rate indexes
331 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
332 /* Skip invalid rates */
333 if (info->control.rates[i].idx < 0)
335 /* Rate masking supports only legacy rates for now */
336 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
338 rate_idx_match_mask(&info->control.rates[i],
339 txrc->sband->n_bitrates, mask);
343 BUG_ON(info->control.rates[0].idx < 0);
346 struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
348 kref_get(&ref->kref);
352 void rate_control_put(struct rate_control_ref *ref)
354 kref_put(&ref->kref, rate_control_release);
357 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
360 struct rate_control_ref *ref, *old;
364 if (local->open_count)
367 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
368 if (WARN_ON(!local->ops->set_rts_threshold))
373 ref = rate_control_alloc(name, local);
375 wiphy_warn(local->hw.wiphy,
376 "Failed to select rate control algorithm\n");
380 old = local->rate_ctrl;
381 local->rate_ctrl = ref;
383 rate_control_put(old);
384 sta_info_flush(local, NULL);
387 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
393 void rate_control_deinitialize(struct ieee80211_local *local)
395 struct rate_control_ref *ref;
397 ref = local->rate_ctrl;
402 local->rate_ctrl = NULL;
403 rate_control_put(ref);