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/module.h>
14 #include <linux/slab.h>
16 #include "ieee80211_i.h"
19 struct rate_control_alg {
20 struct list_head list;
21 const 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(const 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(const 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 const struct rate_control_ops *
80 ieee80211_try_rate_control_ops_get(const char *name)
82 struct rate_control_alg *alg;
83 const 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)) {
95 mutex_unlock(&rate_ctrl_mutex);
99 /* Get the rate control algorithm. */
100 static const struct rate_control_ops *
101 ieee80211_rate_control_ops_get(const char *name)
103 const 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 /* try default if specific alg requested but not found */
115 ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
117 /* try built-in one if specific alg requested but not found */
118 if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
119 ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
120 kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
125 #ifdef CONFIG_MAC80211_DEBUGFS
126 static ssize_t rcname_read(struct file *file, char __user *userbuf,
127 size_t count, loff_t *ppos)
129 struct rate_control_ref *ref = file->private_data;
130 int len = strlen(ref->ops->name);
132 return simple_read_from_buffer(userbuf, count, ppos,
133 ref->ops->name, len);
136 static const struct file_operations rcname_ops = {
139 .llseek = default_llseek,
143 static struct rate_control_ref *rate_control_alloc(const char *name,
144 struct ieee80211_local *local)
146 struct dentry *debugfsdir = NULL;
147 struct rate_control_ref *ref;
149 ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
153 ref->ops = ieee80211_rate_control_ops_get(name);
157 #ifdef CONFIG_MAC80211_DEBUGFS
158 debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
159 local->debugfs.rcdir = debugfsdir;
160 debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
163 ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
173 static void rate_control_free(struct rate_control_ref *ctrl_ref)
175 ctrl_ref->ops->free(ctrl_ref->priv);
177 #ifdef CONFIG_MAC80211_DEBUGFS
178 debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
179 ctrl_ref->local->debugfs.rcdir = NULL;
185 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
187 struct sk_buff *skb = txrc->skb;
188 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
189 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
192 fc = hdr->frame_control;
194 return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
195 IEEE80211_TX_CTL_USE_MINRATE)) ||
196 !ieee80211_is_data(fc);
199 static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
200 struct ieee80211_supported_band *sband)
204 if (basic_rates == 0)
205 return; /* assume basic rates unknown and accept rate */
208 if (basic_rates & (1 << *idx))
209 return; /* selected rate is a basic rate */
211 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
212 if (basic_rates & (1 << i)) {
218 /* could not find a basic rate; use original selection */
221 static void __rate_control_send_low(struct ieee80211_hw *hw,
222 struct ieee80211_supported_band *sband,
223 struct ieee80211_sta *sta,
224 struct ieee80211_tx_info *info,
229 ieee80211_chandef_rate_flags(&hw->conf.chandef);
231 if ((sband->band == IEEE80211_BAND_2GHZ) &&
232 (info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
233 rate_flags |= IEEE80211_RATE_ERP_G;
235 info->control.rates[0].idx = 0;
236 for (i = 0; i < sband->n_bitrates; i++) {
237 if (!(rate_mask & BIT(i)))
240 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
243 if (!rate_supported(sta, sband->band, i))
246 info->control.rates[0].idx = i;
249 WARN_ON_ONCE(i == sband->n_bitrates);
251 info->control.rates[0].count =
252 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
253 1 : hw->max_rate_tries;
255 info->control.skip_table = 1;
259 bool rate_control_send_low(struct ieee80211_sta *pubsta,
261 struct ieee80211_tx_rate_control *txrc)
263 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
264 struct ieee80211_supported_band *sband = txrc->sband;
265 struct sta_info *sta;
267 bool use_basicrate = false;
269 if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
270 __rate_control_send_low(txrc->hw, sband, pubsta, info,
271 txrc->rate_idx_mask);
273 if (!pubsta && txrc->bss) {
274 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
275 if (mcast_rate > 0) {
276 info->control.rates[0].idx = mcast_rate - 1;
279 use_basicrate = true;
281 sta = container_of(pubsta, struct sta_info, sta);
282 if (ieee80211_vif_is_mesh(&sta->sdata->vif))
283 use_basicrate = true;
287 rc_send_low_basicrate(&info->control.rates[0].idx,
288 txrc->bss_conf->basic_rates,
295 EXPORT_SYMBOL(rate_control_send_low);
297 static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
298 int n_bitrates, u32 mask)
302 /* See whether the selected rate or anything below it is allowed. */
303 for (j = rate->idx; j >= 0; j--) {
304 if (mask & (1 << j)) {
305 /* Okay, found a suitable rate. Use it. */
311 /* Try to find a higher rate that would be allowed */
312 for (j = rate->idx + 1; j < n_bitrates; j++) {
313 if (mask & (1 << j)) {
314 /* Okay, found a suitable rate. Use it. */
322 static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
323 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
328 ridx = rate->idx / 8;
329 rbit = rate->idx % 8;
332 if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
335 /* See whether the selected rate or anything below it is allowed. */
336 for (i = ridx; i >= 0; i--) {
337 for (j = rbit; j >= 0; j--)
338 if (mcs_mask[i] & BIT(j)) {
339 rate->idx = i * 8 + j;
345 /* Try to find a higher rate that would be allowed */
346 ridx = (rate->idx + 1) / 8;
347 rbit = (rate->idx + 1) % 8;
349 for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
350 for (j = rbit; j < 8; j++)
351 if (mcs_mask[i] & BIT(j)) {
352 rate->idx = i * 8 + j;
362 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
363 struct ieee80211_supported_band *sband,
364 enum nl80211_chan_width chan_width,
366 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
368 struct ieee80211_tx_rate alt_rate;
370 /* handle HT rates */
371 if (rate->flags & IEEE80211_TX_RC_MCS) {
372 if (rate_idx_match_mcs_mask(rate, mcs_mask))
375 /* also try the legacy rates. */
377 /* keep protection flags */
378 alt_rate.flags = rate->flags &
379 (IEEE80211_TX_RC_USE_RTS_CTS |
380 IEEE80211_TX_RC_USE_CTS_PROTECT |
381 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
382 alt_rate.count = rate->count;
383 if (rate_idx_match_legacy_mask(&alt_rate,
384 sband->n_bitrates, mask)) {
389 /* handle legacy rates */
390 if (rate_idx_match_legacy_mask(rate, sband->n_bitrates, mask))
393 /* if HT BSS, and we handle a data frame, also try HT rates */
394 switch (chan_width) {
395 case NL80211_CHAN_WIDTH_20_NOHT:
396 case NL80211_CHAN_WIDTH_5:
397 case NL80211_CHAN_WIDTH_10:
404 /* keep protection flags */
405 alt_rate.flags = rate->flags &
406 (IEEE80211_TX_RC_USE_RTS_CTS |
407 IEEE80211_TX_RC_USE_CTS_PROTECT |
408 IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
409 alt_rate.count = rate->count;
411 alt_rate.flags |= IEEE80211_TX_RC_MCS;
413 if (chan_width == NL80211_CHAN_WIDTH_40)
414 alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
416 if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
423 * Uh.. No suitable rate exists. This should not really happen with
424 * sane TX rate mask configurations. However, should someone manage to
425 * configure supported rates and TX rate mask in incompatible way,
426 * allow the frame to be transmitted with whatever the rate control
431 static void rate_fixup_ratelist(struct ieee80211_vif *vif,
432 struct ieee80211_supported_band *sband,
433 struct ieee80211_tx_info *info,
434 struct ieee80211_tx_rate *rates,
437 struct ieee80211_rate *rate;
442 * Set up the RTS/CTS rate as the fastest basic rate
443 * that is not faster than the data rate unless there
444 * is no basic rate slower than the data rate, in which
445 * case we pick the slowest basic rate
447 * XXX: Should this check all retry rates?
449 if (!(rates[0].flags & IEEE80211_TX_RC_MCS)) {
450 u32 basic_rates = vif->bss_conf.basic_rates;
451 s8 baserate = basic_rates ? ffs(basic_rates - 1) : 0;
453 rate = &sband->bitrates[rates[0].idx];
455 for (i = 0; i < sband->n_bitrates; i++) {
456 /* must be a basic rate */
457 if (!(basic_rates & BIT(i)))
459 /* must not be faster than the data rate */
460 if (sband->bitrates[i].bitrate > rate->bitrate)
463 if (sband->bitrates[baserate].bitrate <
464 sband->bitrates[i].bitrate)
468 info->control.rts_cts_rate_idx = baserate;
471 for (i = 0; i < max_rates; i++) {
473 * make sure there's no valid rate following
474 * an invalid one, just in case drivers don't
475 * take the API seriously to stop at -1.
481 if (rates[i].idx < 0) {
487 * For now assume MCS is already set up correctly, this
490 if (rates[i].flags & IEEE80211_TX_RC_MCS) {
491 WARN_ON(rates[i].idx > 76);
493 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
494 info->control.use_cts_prot)
496 IEEE80211_TX_RC_USE_CTS_PROTECT;
500 if (rates[i].flags & IEEE80211_TX_RC_VHT_MCS) {
501 WARN_ON(ieee80211_rate_get_vht_mcs(&rates[i]) > 9);
505 /* set up RTS protection if desired */
506 if (info->control.use_rts) {
507 rates[i].flags |= IEEE80211_TX_RC_USE_RTS_CTS;
508 info->control.use_cts_prot = false;
512 if (WARN_ON_ONCE(rates[i].idx >= sband->n_bitrates)) {
517 rate = &sband->bitrates[rates[i].idx];
519 /* set up short preamble */
520 if (info->control.short_preamble &&
521 rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
522 rates[i].flags |= IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
524 /* set up G protection */
525 if (!(rates[i].flags & IEEE80211_TX_RC_USE_RTS_CTS) &&
526 info->control.use_cts_prot &&
527 rate->flags & IEEE80211_RATE_ERP_G)
528 rates[i].flags |= IEEE80211_TX_RC_USE_CTS_PROTECT;
533 static void rate_control_fill_sta_table(struct ieee80211_sta *sta,
534 struct ieee80211_tx_info *info,
535 struct ieee80211_tx_rate *rates,
538 struct ieee80211_sta_rates *ratetbl = NULL;
541 if (sta && !info->control.skip_table)
542 ratetbl = rcu_dereference(sta->rates);
544 /* Fill remaining rate slots with data from the sta rate table. */
545 max_rates = min_t(int, max_rates, IEEE80211_TX_RATE_TABLE_SIZE);
546 for (i = 0; i < max_rates; i++) {
547 if (i < ARRAY_SIZE(info->control.rates) &&
548 info->control.rates[i].idx >= 0 &&
549 info->control.rates[i].count) {
550 if (rates != info->control.rates)
551 rates[i] = info->control.rates[i];
552 } else if (ratetbl) {
553 rates[i].idx = ratetbl->rate[i].idx;
554 rates[i].flags = ratetbl->rate[i].flags;
555 if (info->control.use_rts)
556 rates[i].count = ratetbl->rate[i].count_rts;
557 else if (info->control.use_cts_prot)
558 rates[i].count = ratetbl->rate[i].count_cts;
560 rates[i].count = ratetbl->rate[i].count;
566 if (rates[i].idx < 0 || !rates[i].count)
571 static void rate_control_apply_mask(struct ieee80211_sub_if_data *sdata,
572 struct ieee80211_sta *sta,
573 struct ieee80211_supported_band *sband,
574 struct ieee80211_tx_info *info,
575 struct ieee80211_tx_rate *rates,
578 enum nl80211_chan_width chan_width;
579 u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
586 * Try to enforce the rateidx mask the user wanted. skip this if the
587 * default mask (allow all rates) is used to save some processing for
590 mask = sdata->rc_rateidx_mask[info->band];
591 has_mcs_mask = sdata->rc_has_mcs_mask[info->band];
593 ieee80211_chandef_rate_flags(&sdata->vif.bss_conf.chandef);
594 for (i = 0; i < sband->n_bitrates; i++)
595 if ((rate_flags & sband->bitrates[i].flags) != rate_flags)
598 if (mask == (1 << sband->n_bitrates) - 1 && !has_mcs_mask)
602 memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
605 memset(mcs_mask, 0xff, sizeof(mcs_mask));
608 /* Filter out rates that the STA does not support */
609 mask &= sta->supp_rates[info->band];
610 for (i = 0; i < sizeof(mcs_mask); i++)
611 mcs_mask[i] &= sta->ht_cap.mcs.rx_mask[i];
615 * Make sure the rate index selected for each TX rate is
616 * included in the configured mask and change the rate indexes
619 chan_width = sdata->vif.bss_conf.chandef.width;
620 for (i = 0; i < max_rates; i++) {
621 /* Skip invalid rates */
622 if (rates[i].idx < 0)
625 rate_idx_match_mask(&rates[i], sband, chan_width, mask,
630 void ieee80211_get_tx_rates(struct ieee80211_vif *vif,
631 struct ieee80211_sta *sta,
633 struct ieee80211_tx_rate *dest,
636 struct ieee80211_sub_if_data *sdata;
637 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
638 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
639 struct ieee80211_supported_band *sband;
641 rate_control_fill_sta_table(sta, info, dest, max_rates);
646 sdata = vif_to_sdata(vif);
647 sband = sdata->local->hw.wiphy->bands[info->band];
649 if (ieee80211_is_data(hdr->frame_control))
650 rate_control_apply_mask(sdata, sta, sband, info, dest, max_rates);
653 __rate_control_send_low(&sdata->local->hw, sband, sta, info,
654 sdata->rc_rateidx_mask[info->band]);
657 rate_fixup_ratelist(vif, sband, info, dest, max_rates);
659 EXPORT_SYMBOL(ieee80211_get_tx_rates);
661 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
662 struct sta_info *sta,
663 struct ieee80211_tx_rate_control *txrc)
665 struct rate_control_ref *ref = sdata->local->rate_ctrl;
666 void *priv_sta = NULL;
667 struct ieee80211_sta *ista = NULL;
668 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
671 if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
673 priv_sta = sta->rate_ctrl_priv;
676 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
677 info->control.rates[i].idx = -1;
678 info->control.rates[i].flags = 0;
679 info->control.rates[i].count = 0;
682 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
685 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
687 if (sdata->local->hw.flags & IEEE80211_HW_SUPPORTS_RC_TABLE)
690 ieee80211_get_tx_rates(&sdata->vif, ista, txrc->skb,
692 ARRAY_SIZE(info->control.rates));
695 int rate_control_set_rates(struct ieee80211_hw *hw,
696 struct ieee80211_sta *pubsta,
697 struct ieee80211_sta_rates *rates)
699 struct ieee80211_sta_rates *old;
702 * mac80211 guarantees that this function will not be called
703 * concurrently, so the following RCU access is safe, even without
704 * extra locking. This can not be checked easily, so we just set
705 * the condition to true.
707 old = rcu_dereference_protected(pubsta->rates, true);
708 rcu_assign_pointer(pubsta->rates, rates);
710 kfree_rcu(old, rcu_head);
714 EXPORT_SYMBOL(rate_control_set_rates);
716 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
719 struct rate_control_ref *ref;
723 if (local->open_count)
726 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
727 if (WARN_ON(!local->ops->set_rts_threshold))
732 ref = rate_control_alloc(name, local);
734 wiphy_warn(local->hw.wiphy,
735 "Failed to select rate control algorithm\n");
739 WARN_ON(local->rate_ctrl);
740 local->rate_ctrl = ref;
742 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
748 void rate_control_deinitialize(struct ieee80211_local *local)
750 struct rate_control_ref *ref;
752 ref = local->rate_ctrl;
757 local->rate_ctrl = NULL;
758 rate_control_free(ref);