wifi: mac80211: allow rate_control_rate_init() for links

Andrei previously fixed an issue in the client where the NSS
for links other than the primary/assoc/deflink isn't set. The
same issue appears to exist on the AP side, because there's
only a call to rate_control_rate_init() for the deflink, and
not any other links.

Rework the code a bit to do rate_control_rate_init() for links,
even if it really doesn't work with software rate control yet,
it does other things as well.

Also add rate_control_rate_init_all_links() to actually do it
properly when moving to ASSOC state in cfg80211.

Change the explicit call to ieee80211_sta_init_nss() to instead
be rate_control_rate_init() now in the client code, but also
add a call to rate_control_rate_init() when a link is added in
AP mode and the STA is already associated.

This should fix the NSS initialization issue, and perhaps pave
the way for actual software rate scaling a bit, in case anyone
cares in the future, but that of course needs a lot more than
just the init call.

We still need to fix the rate control _update_ as well, and the
sta_rc_update() driver method especially, but that will be in a
different patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://patch.msgid.link/20241007144851.c693274a908f.I0376da02e9f5a30eaa1b5d0d01371ff09506d453@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/cfg.c

@@ -1720,7 +1720,7 @@ static int sta_apply_auth_flags(struct ieee80211_local *local,
 		 * before drv_sta_state() is called.
 		 */
 		if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
-			rate_control_rate_init(sta);
+			rate_control_rate_init_all_links(sta);
 
 		ret = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
 		if (ret)
@@ -2149,7 +2149,7 @@ static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
 	 */
 	if (!test_sta_flag(sta, WLAN_STA_TDLS_PEER) &&
 	    test_sta_flag(sta, WLAN_STA_ASSOC))
-		rate_control_rate_init(sta);
+		rate_control_rate_init_all_links(sta);
 
 	return sta_info_insert(sta);
 }
@@ -5063,6 +5063,13 @@ ieee80211_add_link_station(struct wiphy *wiphy, struct net_device *dev,
 		return ret;
 	}
 
+	if (test_sta_flag(sta, WLAN_STA_ASSOC)) {
+		struct link_sta_info *link_sta;
+
+		link_sta = sdata_dereference(sta->link[params->link_id], sdata);
+		rate_control_rate_init(link_sta);
+	}
+
 	/* ieee80211_sta_activate_link frees the link upon failure */
 	return ieee80211_sta_activate_link(sta, params->link_id);
 }

net/mac80211/ibss.c

@@ -569,7 +569,7 @@ static struct sta_info *ieee80211_ibss_finish_sta(struct sta_info *sta)
 	if (!sta->sdata->u.ibss.control_port)
 		sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
 
-	rate_control_rate_init(sta);
+	rate_control_rate_init(&sta->deflink);
 
 	/* If it fails, maybe we raced another insertion? */
 	if (sta_info_insert_rcu(sta))
@@ -1068,7 +1068,7 @@ static void ieee80211_update_sta_info(struct ieee80211_sub_if_data *sdata,
 
 		/* Force rx_nss recalculation */
 		sta->sta.deflink.rx_nss = 0;
-		rate_control_rate_init(sta);
+		rate_control_rate_init(&sta->deflink);
 		if (sta->sta.deflink.rx_nss != rx_nss)
 			changed |= IEEE80211_RC_NSS_CHANGED;
 

net/mac80211/mesh_plink.c

@@ -487,7 +487,7 @@ static void mesh_sta_info_init(struct ieee80211_sub_if_data *sdata,
 	}
 
 	if (!test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
-		rate_control_rate_init(sta);
+		rate_control_rate_init(&sta->deflink);
 	else
 		rate_control_rate_update(local, sband, sta, 0, changed);
 out:

net/mac80211/mlme.c

@@ -5750,7 +5750,7 @@ static bool ieee80211_assoc_success(struct ieee80211_sub_if_data *sdata,
 	/* links might have changed due to rejected ones, set them again */
 	ieee80211_vif_set_links(sdata, valid_links, dormant_links);
 
-	rate_control_rate_init(sta);
+	rate_control_rate_init_all_links(sta);
 
 	if (ifmgd->flags & IEEE80211_STA_MFP_ENABLED) {
 		set_sta_flag(sta, WLAN_STA_MFP);

net/mac80211/ocb.c

@@ -4,7 +4,7 @@
  *
  * Copyright: (c) 2014 Czech Technical University in Prague
  *            (c) 2014 Volkswagen Group Research
- * Copyright (C) 2022 - 2023 Intel Corporation
+ * Copyright (C) 2022 - 2024 Intel Corporation
  * Author:    Rostislav Lisovy <rostislav.lisovy@fel.cvut.cz>
  * Funded by: Volkswagen Group Research
  */
@@ -96,7 +96,7 @@ static struct sta_info *ieee80211_ocb_finish_sta(struct sta_info *sta)
 	sta_info_move_state(sta, IEEE80211_STA_ASSOC);
 	sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
 
-	rate_control_rate_init(sta);
+	rate_control_rate_init(&sta->deflink);
 
 	/* If it fails, maybe we raced another insertion? */
 	if (sta_info_insert_rcu(sta))

net/mac80211/rate.c

@@ -28,8 +28,9 @@ module_param(ieee80211_default_rc_algo, charp, 0644);
 MODULE_PARM_DESC(ieee80211_default_rc_algo,
 		 "Default rate control algorithm for mac80211 to use");
 
-void rate_control_rate_init(struct sta_info *sta)
+void rate_control_rate_init(struct link_sta_info *link_sta)
 {
+	struct sta_info *sta = link_sta->sta;
 	struct ieee80211_local *local = sta->sdata->local;
 	struct rate_control_ref *ref = sta->rate_ctrl;
 	struct ieee80211_sta *ista = &sta->sta;
@@ -37,11 +38,15 @@ void rate_control_rate_init(struct sta_info *sta)
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_chanctx_conf *chanctx_conf;
 
-	ieee80211_sta_init_nss(&sta->deflink);
+	ieee80211_sta_init_nss(link_sta);
 
 	if (!ref)
 		return;
 
+	/* SW rate control isn't supported with MLO right now */
+	if (WARN_ON(ieee80211_vif_is_mld(&sta->sdata->vif)))
+		return;
+
 	rcu_read_lock();
 
 	chanctx_conf = rcu_dereference(sta->sdata->vif.bss_conf.chanctx_conf);
@@ -67,6 +72,21 @@ void rate_control_rate_init(struct sta_info *sta)
 	set_sta_flag(sta, WLAN_STA_RATE_CONTROL);
 }
 
+void rate_control_rate_init_all_links(struct sta_info *sta)
+{
+	int link_id;
+
+	for (link_id = 0; link_id < ARRAY_SIZE(sta->link); link_id++) {
+		struct link_sta_info *link_sta;
+
+		link_sta = sdata_dereference(sta->link[link_id], sta->sdata);
+		if (!link_sta)
+			continue;
+
+		rate_control_rate_init(link_sta);
+	}
+}
+
 void rate_control_tx_status(struct ieee80211_local *local,
 			    struct ieee80211_tx_status *st)
 {

net/mac80211/rate.h

@@ -3,7 +3,7 @@
  * Copyright 2002-2005, Instant802 Networks, Inc.
  * Copyright 2005, Devicescape Software, Inc.
  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
- * Copyright (C) 2022 Intel Corporation
+ * Copyright (C) 2022, 2024 Intel Corporation
  */
 
 #ifndef IEEE80211_RATE_H
@@ -29,7 +29,8 @@ void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 void rate_control_tx_status(struct ieee80211_local *local,
 			    struct ieee80211_tx_status *st);
 
-void rate_control_rate_init(struct sta_info *sta);
+void rate_control_rate_init(struct link_sta_info *link_sta);
+void rate_control_rate_init_all_links(struct sta_info *sta);
 void rate_control_rate_update(struct ieee80211_local *local,
 			      struct ieee80211_supported_band *sband,
 			      struct sta_info *sta,