mt76: mt7615: fix slow performance when enable encryption

Fix wrong WCID assignment and add RKV (RX Key of this entry is valid)
flag to check if peer uses the same configuration with previous
handshaking.

If the configuration is mismatch, WTBL indicates a “cipher mismatch”
to stop SEC decryption to prevent the packet from damage.

Suggested-by: YF Luo <yf.luo@mediatek.com>
Suggested-by: Yiwei Chung <yiwei.chung@mediatek.com>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7615/init.c

@@ -62,16 +62,11 @@ static void mt7615_mac_init(struct mt7615_dev *dev)
 		 MT_AGG_ARCR_RATE_DOWN_RATIO_EN |
 		 FIELD_PREP(MT_AGG_ARCR_RATE_DOWN_RATIO, 1) |
 		 FIELD_PREP(MT_AGG_ARCR_RATE_UP_EXTRA_TH, 4)));
-
-	dev->mt76.global_wcid.idx = MT7615_WTBL_RESERVED;
-	dev->mt76.global_wcid.hw_key_idx = -1;
-	rcu_assign_pointer(dev->mt76.wcid[MT7615_WTBL_RESERVED],
-			   &dev->mt76.global_wcid);
 }
 
 static int mt7615_init_hardware(struct mt7615_dev *dev)
 {
-	int ret;
+	int ret, idx;
 
 	mt76_wr(dev, MT_INT_SOURCE_CSR, ~0);
 
@@ -98,6 +93,15 @@ static int mt7615_init_hardware(struct mt7615_dev *dev)
 	mt7615_mcu_ctrl_pm_state(dev, 0);
 	mt7615_mcu_del_wtbl_all(dev);
 
+	/* Beacon and mgmt frames should occupy wcid 0 */
+	idx = mt76_wcid_alloc(dev->mt76.wcid_mask, MT7615_WTBL_STA - 1);
+	if (idx)
+		return -ENOSPC;
+
+	dev->mt76.global_wcid.idx = idx;
+	dev->mt76.global_wcid.hw_key_idx = -1;
+	rcu_assign_pointer(dev->mt76.wcid[idx], &dev->mt76.global_wcid);
+
 	return 0;
 }
 

drivers/net/wireless/mediatek/mt76/mt7615/main.c

@@ -95,7 +95,7 @@ static int mt7615_add_interface(struct ieee80211_hw *hw,
 
 	dev->vif_mask |= BIT(mvif->idx);
 	dev->omac_mask |= BIT(mvif->omac_idx);
-	idx = MT7615_WTBL_RESERVED - 1 - mvif->idx;
+	idx = MT7615_WTBL_RESERVED - mvif->idx;
 	mvif->sta.wcid.idx = idx;
 	mvif->sta.wcid.hw_key_idx = -1;
 

drivers/net/wireless/mediatek/mt76/mt7615/mcu.c

@@ -882,6 +882,7 @@ int mt7615_mcu_set_wtbl_key(struct mt7615_dev *dev, int wcid,
 		if (cipher == MT_CIPHER_NONE && key)
 			return -EOPNOTSUPP;
 
+		req.key.rkv = 1;
 		req.key.cipher_id = cipher;
 		req.key.key_id = key->keyidx;
 		req.key.key_len = key->keylen;