mt76: mt76x02: store software PN/IV in wcid

Avoids expensive 64-bit atomic access in the data path

Signed-off-by: Felix Fietkau <[email protected]>

mt76.h

@@ -220,6 +220,8 @@ struct mt76_wcid {
 	u8 rx_key_pn[IEEE80211_NUM_TIDS][6];
 
 	u32 tx_info;
+
+	u64 tx_pn;
 	bool sw_iv;
 
 	u8 packet_id;

mt76x02_mac.c

@@ -352,7 +352,12 @@ void mt76x02_mac_write_txwi(struct mt76x02_dev *dev, struct mt76x02_txwi *txwi,
 		txwi->wcid = 0xff;
 
 	if (wcid && wcid->sw_iv && key) {
-		u64 pn = atomic64_inc_return(&key->tx_pn);
+		u64 pn;
+
+		spin_lock(&dev->mt76.lock);
+		pn = ++wcid->tx_pn;
+		spin_unlock(&dev->mt76.lock);
+
 		ccmp_pn[0] = pn;
 		ccmp_pn[1] = pn >> 8;
 		ccmp_pn[2] = 0;

mt76x02_mmio.c

@@ -421,10 +421,13 @@ static void mt76x02_key_sync(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 
 	wcid = (struct mt76_wcid *) sta->drv_priv;
 
-	if (wcid->hw_key_idx != key->keyidx || wcid->sw_iv)
+	if (wcid->hw_key_idx != key->keyidx)
 	    return;
 
-	mt76x02_mac_wcid_sync_pn(dev, wcid->idx, key);
+	if (wcid->sw_iv)
+		atomic64_set(&key->tx_pn, wcid->tx_pn);
+	else
+		mt76x02_mac_wcid_sync_pn(dev, wcid->idx, key);
 }
 
 static void mt76x02_reset_state(struct mt76x02_dev *dev)

mt76x02_util.c

@@ -433,6 +433,7 @@ int mt76x02_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 		if (key->flags & IEEE80211_KEY_FLAG_RX_MGMT) {
 			key->flags |= IEEE80211_KEY_FLAG_SW_MGMT_TX;
 			wcid->sw_iv = true;
+			wcid->tx_pn = atomic64_read(&key->tx_pn);
 		}
 	} else {
 		if (idx == wcid->hw_key_idx) {