2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/jiffies.h>
11 #include <linux/init.h>
12 #include <linux/netdevice.h>
13 #include <linux/types.h>
14 #include <linux/slab.h>
15 #include <linux/skbuff.h>
16 #include <linux/compiler.h>
17 #include <linux/module.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "ieee80211_rate.h"
25 /* This is a minimal implementation of TX rate controlling that can be used
26 * as the default when no improved mechanisms are available. */
28 #define RATE_CONTROL_NUM_DOWN 20
29 #define RATE_CONTROL_NUM_UP 15
31 #define RATE_CONTROL_EMERG_DEC 2
32 #define RATE_CONTROL_INTERVAL (HZ / 20)
33 #define RATE_CONTROL_MIN_TX 10
35 static void rate_control_rate_inc(struct ieee80211_local *local,
38 struct ieee80211_sub_if_data *sdata;
39 struct ieee80211_supported_band *sband;
40 int i = sta->txrate_idx;
44 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
45 /* forced unicast rate - do not change STA rate */
49 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
50 maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
52 if (i > sband->n_bitrates)
53 i = sband->n_bitrates - 2;
55 while (i + 1 < sband->n_bitrates) {
57 if (rate_supported(sta, sband->band, i) &&
58 (maxrate < 0 || i <= maxrate)) {
66 static void rate_control_rate_dec(struct ieee80211_local *local,
69 struct ieee80211_sub_if_data *sdata;
70 struct ieee80211_supported_band *sband;
71 int i = sta->txrate_idx;
74 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
75 /* forced unicast rate - do not change STA rate */
79 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
80 if (i > sband->n_bitrates)
81 i = sband->n_bitrates;
85 if (rate_supported(sta, sband->band, i)) {
92 struct global_rate_control {
96 struct sta_rate_control {
97 unsigned long last_rate_change;
101 unsigned long avg_rate_update;
105 #ifdef CONFIG_MAC80211_DEBUGFS
106 struct dentry *tx_avg_rate_sum_dentry;
107 struct dentry *tx_avg_rate_num_dentry;
112 static void rate_control_simple_tx_status(void *priv, struct net_device *dev,
114 struct ieee80211_tx_status *status)
116 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
117 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
118 struct sta_info *sta;
119 struct sta_rate_control *srctrl;
123 sta = sta_info_get(local, hdr->addr1);
128 srctrl = sta->rate_ctrl_priv;
129 srctrl->tx_num_xmit++;
130 if (status->excessive_retries) {
131 srctrl->tx_num_failures++;
132 sta->tx_retry_failed++;
133 sta->tx_num_consecutive_failures++;
134 sta->tx_num_mpdu_fail++;
136 sta->tx_num_consecutive_failures = 0;
137 sta->tx_num_mpdu_ok++;
139 sta->tx_retry_count += status->retry_count;
140 sta->tx_num_mpdu_fail += status->retry_count;
142 if (time_after(jiffies,
143 srctrl->last_rate_change + RATE_CONTROL_INTERVAL) &&
144 srctrl->tx_num_xmit > RATE_CONTROL_MIN_TX) {
146 srctrl->last_rate_change = jiffies;
148 per_failed = (100 * sta->tx_num_mpdu_fail) /
149 (sta->tx_num_mpdu_fail + sta->tx_num_mpdu_ok);
150 /* TODO: calculate average per_failed to make adjusting
151 * parameters easier */
153 if (net_ratelimit()) {
154 printk(KERN_DEBUG "MPDU fail=%d ok=%d per_failed=%d\n",
155 sta->tx_num_mpdu_fail, sta->tx_num_mpdu_ok,
161 * XXX: Make these configurable once we have an
162 * interface to the rate control algorithms
164 if (per_failed > RATE_CONTROL_NUM_DOWN) {
165 rate_control_rate_dec(local, sta);
166 } else if (per_failed < RATE_CONTROL_NUM_UP) {
167 rate_control_rate_inc(local, sta);
169 srctrl->tx_avg_rate_sum += status->control.tx_rate->bitrate;
170 srctrl->tx_avg_rate_num++;
171 srctrl->tx_num_failures = 0;
172 srctrl->tx_num_xmit = 0;
173 } else if (sta->tx_num_consecutive_failures >=
174 RATE_CONTROL_EMERG_DEC) {
175 rate_control_rate_dec(local, sta);
178 if (time_after(jiffies, srctrl->avg_rate_update + 60 * HZ)) {
179 srctrl->avg_rate_update = jiffies;
180 if (srctrl->tx_avg_rate_num > 0) {
181 #ifdef CONFIG_MAC80211_VERBOSE_DEBUG
182 DECLARE_MAC_BUF(mac);
183 printk(KERN_DEBUG "%s: STA %s Average rate: "
185 dev->name, print_mac(mac, sta->addr),
186 srctrl->tx_avg_rate_sum /
187 srctrl->tx_avg_rate_num,
188 srctrl->tx_avg_rate_sum,
189 srctrl->tx_avg_rate_num);
190 #endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
191 srctrl->tx_avg_rate_sum = 0;
192 srctrl->tx_avg_rate_num = 0;
202 rate_control_simple_get_rate(void *priv, struct net_device *dev,
203 struct ieee80211_supported_band *sband,
205 struct rate_selection *sel)
207 struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
208 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
209 struct ieee80211_sub_if_data *sdata;
210 struct sta_info *sta;
216 sta = sta_info_get(local, hdr->addr1);
218 /* Send management frames and broadcast/multicast data using lowest
220 fc = le16_to_cpu(hdr->frame_control);
221 if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
222 is_multicast_ether_addr(hdr->addr1) || !sta) {
223 sel->rate = rate_lowest(local, sband, sta);
228 /* If a forced rate is in effect, select it. */
229 sdata = IEEE80211_DEV_TO_SUB_IF(dev);
230 if (sdata->bss && sdata->bss->force_unicast_rateidx > -1)
231 sta->txrate_idx = sdata->bss->force_unicast_rateidx;
233 rateidx = sta->txrate_idx;
235 if (rateidx >= sband->n_bitrates)
236 rateidx = sband->n_bitrates - 1;
238 sta->last_txrate_idx = rateidx;
242 sel->rate = &sband->bitrates[rateidx];
246 static void rate_control_simple_rate_init(void *priv, void *priv_sta,
247 struct ieee80211_local *local,
248 struct sta_info *sta)
250 struct ieee80211_supported_band *sband;
252 sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
254 /* TODO: This routine should consider using RSSI from previous packets
255 * as we need to have IEEE 802.1X auth succeed immediately after assoc..
256 * Until that method is implemented, we will use the lowest supported rate
257 * as a workaround, */
258 sta->txrate_idx = rate_lowest_index(local, sband, sta);
262 static void * rate_control_simple_alloc(struct ieee80211_local *local)
264 struct global_rate_control *rctrl;
266 rctrl = kzalloc(sizeof(*rctrl), GFP_ATOMIC);
272 static void rate_control_simple_free(void *priv)
274 struct global_rate_control *rctrl = priv;
279 static void rate_control_simple_clear(void *priv)
284 static void * rate_control_simple_alloc_sta(void *priv, gfp_t gfp)
286 struct sta_rate_control *rctrl;
288 rctrl = kzalloc(sizeof(*rctrl), gfp);
294 static void rate_control_simple_free_sta(void *priv, void *priv_sta)
296 struct sta_rate_control *rctrl = priv_sta;
300 #ifdef CONFIG_MAC80211_DEBUGFS
302 static int open_file_generic(struct inode *inode, struct file *file)
304 file->private_data = inode->i_private;
308 static ssize_t sta_tx_avg_rate_sum_read(struct file *file,
309 char __user *userbuf,
310 size_t count, loff_t *ppos)
312 struct sta_rate_control *srctrl = file->private_data;
315 sprintf(buf, "%d\n", srctrl->tx_avg_rate_sum);
316 return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
319 static const struct file_operations sta_tx_avg_rate_sum_ops = {
320 .read = sta_tx_avg_rate_sum_read,
321 .open = open_file_generic,
324 static ssize_t sta_tx_avg_rate_num_read(struct file *file,
325 char __user *userbuf,
326 size_t count, loff_t *ppos)
328 struct sta_rate_control *srctrl = file->private_data;
331 sprintf(buf, "%d\n", srctrl->tx_avg_rate_num);
332 return simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
335 static const struct file_operations sta_tx_avg_rate_num_ops = {
336 .read = sta_tx_avg_rate_num_read,
337 .open = open_file_generic,
340 static void rate_control_simple_add_sta_debugfs(void *priv, void *priv_sta,
343 struct sta_rate_control *srctrl = priv_sta;
345 srctrl->tx_avg_rate_num_dentry =
346 debugfs_create_file("rc_simple_sta_tx_avg_rate_num", 0400,
347 dir, srctrl, &sta_tx_avg_rate_num_ops);
348 srctrl->tx_avg_rate_sum_dentry =
349 debugfs_create_file("rc_simple_sta_tx_avg_rate_sum", 0400,
350 dir, srctrl, &sta_tx_avg_rate_sum_ops);
353 static void rate_control_simple_remove_sta_debugfs(void *priv, void *priv_sta)
355 struct sta_rate_control *srctrl = priv_sta;
357 debugfs_remove(srctrl->tx_avg_rate_sum_dentry);
358 debugfs_remove(srctrl->tx_avg_rate_num_dentry);
362 static struct rate_control_ops mac80211_rcsimple = {
364 .tx_status = rate_control_simple_tx_status,
365 .get_rate = rate_control_simple_get_rate,
366 .rate_init = rate_control_simple_rate_init,
367 .clear = rate_control_simple_clear,
368 .alloc = rate_control_simple_alloc,
369 .free = rate_control_simple_free,
370 .alloc_sta = rate_control_simple_alloc_sta,
371 .free_sta = rate_control_simple_free_sta,
372 #ifdef CONFIG_MAC80211_DEBUGFS
373 .add_sta_debugfs = rate_control_simple_add_sta_debugfs,
374 .remove_sta_debugfs = rate_control_simple_remove_sta_debugfs,
378 MODULE_LICENSE("GPL");
379 MODULE_DESCRIPTION("Simple rate control algorithm");
381 int __init rc80211_simple_init(void)
383 return ieee80211_rate_control_register(&mac80211_rcsimple);
386 void rc80211_simple_exit(void)
388 ieee80211_rate_control_unregister(&mac80211_rcsimple);
391 #ifdef CONFIG_MAC80211_RC_SIMPLE_MODULE
392 module_init(rc80211_simple_init);
393 module_exit(rc80211_simple_exit);