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 = {
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_basicrate(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 */
235 static void __rate_control_send_low(struct ieee80211_hw *hw,
236 struct ieee80211_supported_band *sband,
237 struct ieee80211_sta *sta,
238 struct ieee80211_tx_info *info)
242 ieee80211_chandef_rate_flags(&hw->conf.chandef);
244 if ((sband->band == IEEE80211_BAND_2GHZ) &&
245 (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
246 rate_flags |= IEEE80211_RATE_ERP_G;
248 info->control.rates[0].idx = 0;
249 for (i = 0; i < sband->n_bitrates; i++) {
250 if (!rate_supported(sta, sband->band, i))
253 info->control.rates[0].idx = i;
256 WARN_ON_ONCE(i == sband->n_bitrates);
258 info->control.rates[0].count =
259 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
260 1 : hw->max_rate_tries;
262 info->control.skip_table = 1;
266 bool rate_control_send_low(struct ieee80211_sta *pubsta,
268 struct ieee80211_tx_rate_control *txrc)
270 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
271 struct ieee80211_supported_band *sband = txrc->sband;
272 struct sta_info *sta;
274 bool use_basicrate = false;
276 if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
277 __rate_control_send_low(txrc->hw, sband, pubsta, info);
279 if (!pubsta && txrc->bss) {
280 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
281 if (mcast_rate > 0) {
282 info->control.rates[0].idx = mcast_rate - 1;
285 use_basicrate = true;
287 sta = container_of(pubsta, struct sta_info, sta);
288 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
289 use_basicrate = true;
293 rc_send_low_basicrate(&info->control.rates[0].idx,
294 txrc->bss_conf->basic_rates,
301 EXPORT_SYMBOL(rate_control_send_low);
303 static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
304 int n_bitrates, u32 mask)
308 /* See whether the selected rate or anything below it is allowed. */
309 for (j = rate->idx; j >= 0; j--) {
310 if (mask & (1 << j)) {
311 /* Okay, found a suitable rate. Use it. */
317 /* Try to find a higher rate that would be allowed */
318 for (j = rate->idx + 1; j < n_bitrates; j++) {
319 if (mask & (1 << j)) {
320 /* Okay, found a suitable rate. Use it. */
328 static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
329 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
334 ridx = rate->idx / 8;
335 rbit = rate->idx % 8;
338 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
341 /* See whether the selected rate or anything below it is allowed. */
342 for (i = ridx; i >= 0; i--) {
343 for (j = rbit; j >= 0; j--)
344 if (mcs_mask[i] & BIT(j)) {
345 rate->idx = i * 8 + j;
351 /* Try to find a higher rate that would be allowed */
352 ridx = (rate->idx + 1) / 8;
353 rbit = (rate->idx + 1) % 8;
355 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
356 for (j = rbit; j < 8; j++)
357 if (mcs_mask[i] & BIT(j)) {
358 rate->idx = i * 8 + j;
368 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
369 struct ieee80211_supported_band *sband,
370 enum nl80211_chan_width chan_width,
372 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
374 struct ieee80211_tx_rate alt_rate;
376 /* handle HT rates */
377 if (rate->flags & IEEE80211_TX_RC_MCS) {
378 if (rate_idx_match_mcs_mask(rate, mcs_mask))
381 /* also try the legacy rates. */
383 /* keep protection flags */
384 alt_rate.flags = rate->flags &
385 (IEEE80211_TX_RC_USE_RTS_CTS |
386 IEEE80211_TX_RC_USE_CTS_PROTECT |
387 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
388 alt_rate.count = rate->count;
389 if (rate_idx_match_legacy_mask(&alt_rate,
390 sband->n_bitrates, mask)) {
395 /* handle legacy rates */
396 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
399 /* if HT BSS, and we handle a data frame, also try HT rates */
400 switch (chan_width) {
401 case NL80211_CHAN_WIDTH_20_NOHT:
402 case NL80211_CHAN_WIDTH_5:
403 case NL80211_CHAN_WIDTH_10:
410 /* keep protection flags */
411 alt_rate.flags = rate->flags &
412 (IEEE80211_TX_RC_USE_RTS_CTS |
413 IEEE80211_TX_RC_USE_CTS_PROTECT |
414 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
415 alt_rate.count = rate->count;
417 alt_rate.flags |= IEEE80211_TX_RC_MCS;
419 if (chan_width == NL80211_CHAN_WIDTH_40)
420 alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
422 if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
429 * Uh.. No suitable rate exists. This should not really happen with
430 * sane TX rate mask configurations. However, should someone manage to
431 * configure supported rates and TX rate mask in incompatible way,
432 * allow the frame to be transmitted with whatever the rate control
437 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
438 struct ieee80211_supported_band *sband,
439 struct ieee80211_tx_info *info,
440 struct ieee80211_tx_rate *rates,
443 struct ieee80211_rate *rate;
448 * Set up the RTS/CTS rate as the fastest basic rate
449 * that is not faster than the data rate unless there
450 * is no basic rate slower than the data rate, in which
451 * case we pick the slowest basic rate
453 * XXX: Should this check all retry rates?
455 if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) {
456 u32 basic_rates = vif->bss_conf.basic_rates;
457 s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0;
459 rate = &sband->bitrates[rates[0].idx];
461 for (i = 0; i < sband->n_bitrates; i++) {
462 /* must be a basic rate */
463 if (!(basic_rates & BIT(i)))
465 /* must not be faster than the data rate */
466 if (sband->bitrates[i].bitrate > rate->bitrate)
469 if (sband->bitrates[baserate].bitrate <
470 sband->bitrates[i].bitrate)
474 info->control.rts_cts_rate_idx = baserate;
477 for (i = 0; i < max_rates; i++) {
479 * make sure there's no valid rate following
480 * an invalid one, just in case drivers don't
481 * take the API seriously to stop at -1.
487 if (rates[i].idx < 0) {
493 * For now assume MCS is already set up correctly, this
496 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
497 WARN_ON(rates[i].idx > 76);
499 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
500 info->control.use_cts_prot)
502 IEEE80211_TX_RC_USE_CTS_PROTECT;
506 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
507 WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
511 /* set up RTS protection if desired */
512 if (info->control.use_rts) {
513 rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
514 info->control.use_cts_prot = false;
518 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
523 rate = &sband->bitrates[rates[i].idx];
525 /* set up short preamble */
526 if (info->control.short_preamble &&
527 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
528 rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
530 /* set up G protection */
531 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
532 info->control.use_cts_prot &&
533 rate->flags & IEEE80211_RATE_ERP_G)
534 rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
539 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
540 struct ieee80211_tx_info *info,
541 struct ieee80211_tx_rate *rates,
544 struct ieee80211_sta_rates *ratetbl = NULL;
547 if (sta && !info->control.skip_table)
548 ratetbl = rcu_dereference(sta->rates);
550 /* Fill remaining rate slots with data from the sta rate table. */
551 max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
552 for (i = 0; i < max_rates; i++) {
553 if (i < ARRAY_SIZE(info->control.rates) &&
554 info->control.rates[i].idx >= 0 &&
555 info->control.rates[i].count) {
556 if (rates != info->control.rates)
557 rates[i] = info->control.rates[i];
558 } else if (ratetbl) {
559 rates[i].idx = ratetbl->rate[i].idx;
560 rates[i].flags = ratetbl->rate[i].flags;
561 if (info->control.use_rts)
562 rates[i].count = ratetbl->rate[i].count_rts;
563 else if (info->control.use_cts_prot)
564 rates[i].count = ratetbl->rate[i].count_cts;
566 rates[i].count = ratetbl->rate[i].count;
572 if (rates[i].idx < 0 || !rates[i].count)
577 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
578 struct ieee80211_sta *sta,
579 struct ieee80211_supported_band *sband,
580 struct ieee80211_tx_info *info,
581 struct ieee80211_tx_rate *rates,
584 enum nl80211_chan_width chan_width;
585 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
592 * Try to enforce the rateidx mask the user wanted. skip this if the
593 * default mask (allow all rates) is used to save some processing for
596 mask = sdata->rc_rateidx_mask[info->band];
597 has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
599 ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
600 for (i = 0; i < sband->n_bitrates; i++)
601 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
604 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
608 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
611 memset(mcs_mask, 0xff, sizeof(mcs_mask));
614 /* Filter out rates that the STA does not support */
615 mask &= sta->supp_rates[info->band];
616 for (i = 0; i < sizeof(mcs_mask); i++)
617 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
621 * Make sure the rate index selected for each TX rate is
622 * included in the configured mask and change the rate indexes
625 chan_width = sdata->vif.bss_conf.chandef.width;
626 for (i = 0; i < max_rates; i++) {
627 /* Skip invalid rates */
628 if (rates[i].idx < 0)
631 rate_idx_match_mask(&rates[i], sband, chan_width, mask,
636 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
637 struct ieee80211_sta *sta,
639 struct ieee80211_tx_rate *dest,
642 struct ieee80211_sub_if_data *sdata;
643 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
644 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
645 struct ieee80211_supported_band *sband;
647 rate_control_fill_sta_table(sta, info, dest, max_rates);
652 sdata = vif_to_sdata(vif);
653 sband = sdata->local->hw.wiphy->bands[info->band];
655 if (ieee80211_is_data(hdr->frame_control))
656 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
659 __rate_control_send_low(&sdata->local->hw, sband, sta, info);
662 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
664 EXPORT_SYMBOL(ieee80211_get_tx_rates);
666 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
667 struct sta_info *sta,
668 struct ieee80211_tx_rate_control *txrc)
670 struct rate_control_ref *ref = sdata->local->rate_ctrl;
671 void *priv_sta = NULL;
672 struct ieee80211_sta *ista = NULL;
673 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
676 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
678 priv_sta = sta->rate_ctrl_priv;
681 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
682 info->control.rates[i].idx = -1;
683 info->control.rates[i].flags = 0;
684 info->control.rates[i].count = 0;
687 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
690 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
692 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
695 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
697 ARRAY_SIZE(info->control.rates));
700 int rate_control_set_rates(struct ieee80211_hw *hw,
701 struct ieee80211_sta *pubsta,
702 struct ieee80211_sta_rates *rates)
704 struct ieee80211_sta_rates *old;
707 * mac80211 guarantees that this function will not be called
708 * concurrently, so the following RCU access is safe, even without
709 * extra locking. This can not be checked easily, so we just set
710 * the condition to true.
712 old = rcu_dereference_protected(pubsta->rates, true);
713 rcu_assign_pointer(pubsta->rates, rates);
715 kfree_rcu(old, rcu_head);
719 EXPORT_SYMBOL(rate_control_set_rates);
721 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
724 struct rate_control_ref *ref;
728 if (local->open_count)
731 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
732 if (WARN_ON(!local->ops->set_rts_threshold))
737 ref = rate_control_alloc(name, local);
739 wiphy_warn(local->hw.wiphy,
740 "Failed to select rate control algorithm\n");
744 WARN_ON(local->rate_ctrl);
745 local->rate_ctrl = ref;
747 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
753 void rate_control_deinitialize(struct ieee80211_local *local)
755 struct rate_control_ref *ref;
757 ref = local->rate_ctrl;
762 local->rate_ctrl = NULL;
763 rate_control_free(ref);