wifi: mt76: mt7996: fix key add/remove imbalance

Ensure that a key for a link is only added and removed once.
When bringing up a link, only upload keys for that particular link, instead
of iterating over all of them.

Link: https://patch.msgid.link/20250915075910.47558-7-nbd@nbd.name
Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 90 insertions, 83 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index a81f2133cdc9..d706b8bb244e 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -182,107 +182,96 @@ mt7996_init_bitrate_mask(struct ieee80211_vif *vif, struct mt7996_vif_link *mlin
 static int
 mt7996_set_hw_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		  struct ieee80211_vif *vif, struct ieee80211_sta *sta,
-		  struct ieee80211_key_conf *key)
+		  unsigned int link_id, struct ieee80211_key_conf *key)
 {
 	struct mt7996_dev *dev = mt7996_hw_dev(hw);
+	struct mt7996_sta_link *msta_link;
+	struct mt7996_vif_link *link;
 	int idx = key->keyidx;
-	unsigned int link_id;
-	unsigned long links;
+	u8 *wcid_keyidx;
 
-	if (key->link_id >= 0)
-		links = BIT(key->link_id);
-	else if (sta && sta->valid_links)
-		links = sta->valid_links;
-	else if (vif->valid_links)
-		links = vif->valid_links;
-	else
-		links = BIT(0);
+	link = mt7996_vif_link(dev, vif, link_id);
+	if (!link)
+		return 0;
 
-	for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
-		struct mt7996_sta_link *msta_link;
-		struct mt7996_vif_link *link;
-		u8 *wcid_keyidx;
-		int err;
+	if (!mt7996_vif_link_phy(link))
+		return 0;
 
-		link = mt7996_vif_link(dev, vif, link_id);
-		if (!link)
-			continue;
+	if (sta) {
+		struct mt7996_sta *msta;
 
-		if (sta) {
-			struct mt7996_sta *msta;
+		msta = (struct mt7996_sta *)sta->drv_priv;
+		msta_link = mt76_dereference(msta->link[link_id],
+					     &dev->mt76);
+		if (!msta_link)
+			return 0;
 
-			msta = (struct mt7996_sta *)sta->drv_priv;
-			msta_link = mt76_dereference(msta->link[link_id],
-						     &dev->mt76);
-			if (!msta_link)
-				continue;
+		if (!msta_link->wcid.sta)
+			return -EOPNOTSUPP;
+	} else {
+		msta_link = &link->msta_link;
+	}
+	wcid_keyidx = &msta_link->wcid.hw_key_idx;
 
-			if (!msta_link->wcid.sta)
-				return -EOPNOTSUPP;
-		} else {
-			msta_link = &link->msta_link;
-		}
-		wcid_keyidx = &msta_link->wcid.hw_key_idx;
-
-		switch (key->cipher) {
-		case WLAN_CIPHER_SUITE_AES_CMAC:
-		case WLAN_CIPHER_SUITE_BIP_CMAC_256:
-		case WLAN_CIPHER_SUITE_BIP_GMAC_128:
-		case WLAN_CIPHER_SUITE_BIP_GMAC_256:
-			if (key->keyidx == 6 || key->keyidx == 7) {
-				wcid_keyidx = &msta_link->wcid.hw_key_idx2;
-				key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIE;
-			}
-			break;
-		default:
-			break;
+	switch (key->cipher) {
+	case WLAN_CIPHER_SUITE_AES_CMAC:
+	case WLAN_CIPHER_SUITE_BIP_CMAC_256:
+	case WLAN_CIPHER_SUITE_BIP_GMAC_128:
+	case WLAN_CIPHER_SUITE_BIP_GMAC_256:
+		if (key->keyidx == 6 || key->keyidx == 7) {
+			wcid_keyidx = &msta_link->wcid.hw_key_idx2;
+			key->flags |= IEEE80211_KEY_FLAG_GENERATE_MMIE;
 		}
+		break;
+	default:
+		break;
+	}
 
-		if (cmd == SET_KEY && !sta && !link->mt76.cipher) {
-			struct ieee80211_bss_conf *link_conf;
-
-			link_conf = link_conf_dereference_protected(vif,
-								    link_id);
-			if (!link_conf)
-				link_conf = &vif->bss_conf;
+	if (cmd == SET_KEY && !sta && !link->mt76.cipher) {
+		struct ieee80211_bss_conf *link_conf;
 
-			link->mt76.cipher =
-				mt76_connac_mcu_get_cipher(key->cipher);
-			mt7996_mcu_add_bss_info(link->phy, vif, link_conf,
-						&link->mt76, msta_link, true);
-		}
+		link_conf = link_conf_dereference_protected(vif,
+							    link_id);
+		if (!link_conf)
+			link_conf = &vif->bss_conf;
 
-		if (cmd == SET_KEY)
-			*wcid_keyidx = idx;
-		else if (idx == *wcid_keyidx)
-			*wcid_keyidx = -1;
+		link->mt76.cipher =
+			mt76_connac_mcu_get_cipher(key->cipher);
+		mt7996_mcu_add_bss_info(link->phy, vif, link_conf,
+					&link->mt76, msta_link, true);
+	}
 
-		if (cmd != SET_KEY && sta)
-			continue;
+	if (cmd == SET_KEY)
+		*wcid_keyidx = idx;
+	else if (idx == *wcid_keyidx)
+		*wcid_keyidx = -1;
 
-		mt76_wcid_key_setup(&dev->mt76, &msta_link->wcid, key);
+	if (cmd != SET_KEY && sta)
+		return 0;
 
-		err = mt7996_mcu_add_key(&dev->mt76, vif, key,
-					 MCU_WMWA_UNI_CMD(STA_REC_UPDATE),
-					 &msta_link->wcid, cmd);
-		if (err)
-			return err;
-	}
+	mt76_wcid_key_setup(&dev->mt76, &msta_link->wcid, key);
 
-	return 0;
+	return mt7996_mcu_add_key(&dev->mt76, vif, key,
+				  MCU_WMWA_UNI_CMD(STA_REC_UPDATE),
+				  &msta_link->wcid, cmd);
 }
 
+struct mt7996_key_iter_data {
+    enum set_key_cmd cmd;
+    unsigned int link_id;
+};
+
 static void
 mt7996_key_iter(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		struct ieee80211_sta *sta, struct ieee80211_key_conf *key,
 		void *data)
 {
-	enum set_key_cmd *cmd = data;
+	struct mt7996_key_iter_data *it = data;
 
 	if (sta)
 		return;
 
-	WARN_ON(mt7996_set_hw_key(hw, *cmd, vif, NULL, key));
+	WARN_ON(mt7996_set_hw_key(hw, it->cmd, vif, NULL, it->link_id, key));
 }
 
 int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
@@ -293,9 +282,12 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 	struct mt7996_vif *mvif = (struct mt7996_vif *)vif->drv_priv;
 	struct mt7996_sta_link *msta_link = &link->msta_link;
 	struct mt7996_phy *phy = mphy->priv;
-	enum set_key_cmd key_cmd = SET_KEY;
 	struct mt7996_dev *dev = phy->dev;
 	u8 band_idx = phy->mt76->band_idx;
+	struct mt7996_key_iter_data it = {
+		.cmd = SET_KEY,
+		.link_id = link_conf->link_id,
+	};
 	struct mt76_txq *mtxq;
 	int mld_idx, idx, ret;
 
@@ -373,7 +365,7 @@ int mt7996_vif_link_add(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 				   CONN_STATE_PORT_SECURE, true);
 	rcu_assign_pointer(dev->mt76.wcid[idx], &msta_link->wcid);
 
-	ieee80211_iter_keys(mphy->hw, vif, mt7996_key_iter, &key_cmd);
+	ieee80211_iter_keys(mphy->hw, vif, mt7996_key_iter, &it);
 
 	if (mvif->mt76.deflink_id == IEEE80211_LINK_UNSPECIFIED)
 		mvif->mt76.deflink_id = link_conf->link_id;
@@ -388,12 +380,15 @@ void mt7996_vif_link_remove(struct mt76_phy *mphy, struct ieee80211_vif *vif,
 	struct mt7996_vif_link *link = container_of(mlink, struct mt7996_vif_link, mt76);
 	struct mt7996_vif *mvif = (struct mt7996_vif *)vif->drv_priv;
 	struct mt7996_sta_link *msta_link = &link->msta_link;
-	enum set_key_cmd key_cmd = DISABLE_KEY;
 	struct mt7996_phy *phy = mphy->priv;
 	struct mt7996_dev *dev = phy->dev;
+	struct mt7996_key_iter_data it = {
+		.cmd = SET_KEY,
+		.link_id = link_conf->link_id,
+	};
 	int idx = msta_link->wcid.idx;
 
-	ieee80211_iter_keys(mphy->hw, vif, mt7996_key_iter, &key_cmd);
+	ieee80211_iter_keys(mphy->hw, vif, mt7996_key_iter, &it);
 
 	mt7996_mcu_add_sta(dev, link_conf, NULL, link, NULL,
 			   CONN_STATE_DISCONNECT, false);
@@ -594,8 +589,9 @@ static int mt7996_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 			  struct ieee80211_key_conf *key)
 {
 	struct mt7996_dev *dev = mt7996_hw_dev(hw);
-	struct mt7996_vif *mvif = (struct mt7996_vif *)vif->drv_priv;
-	int err;
+	unsigned int link_id;
+	unsigned long links;
+	int err = 0;
 
 	/* The hardware does not support per-STA RX GTK, fallback
 	 * to software mode for these.
@@ -629,11 +625,22 @@ static int mt7996_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		return -EOPNOTSUPP;
 	}
 
-	if (!mt7996_vif_link_phy(&mvif->deflink))
-		return 0; /* defer until after link add */
-
 	mutex_lock(&dev->mt76.mutex);
-	err = mt7996_set_hw_key(hw, cmd, vif, sta, key);
+
+	if (key->link_id >= 0)
+		links = BIT(key->link_id);
+	else if (sta && sta->valid_links)
+		links = sta->valid_links;
+	else if (vif->valid_links)
+		links = vif->valid_links;
+	else
+		links = BIT(0);
+
+	for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		err = mt7996_set_hw_key(hw, cmd, vif, sta, link_id, key);
+		if (err)
+			break;
+	}
 	mutex_unlock(&dev->mt76.mutex);
 
 	return err;