alx: prepare tx path for multi queue support

This patch prepares the tx path to send data on multiple tx queues. It
introduces per queue register adresses and uses them in the alx_tx_queue
structs.

There are new helper functions for the queue mapping in the tx path.

Based on the downstream driver at github.com/qca/alx

Signed-off-by: Tobias Regnery <tobias.regnery@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/atheros/alx/main.c

@@ -143,6 +143,22 @@ static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t gfp)
 	return count;
 }
 
+static struct alx_tx_queue *alx_tx_queue_mapping(struct alx_priv *alx,
+						 struct sk_buff *skb)
+{
+	unsigned int r_idx = skb->queue_mapping;
+
+	if (r_idx >= alx->num_txq)
+		r_idx = r_idx % alx->num_txq;
+
+	return alx->qnapi[r_idx]->txq;
+}
+
+static struct netdev_queue *alx_get_tx_queue(const struct alx_tx_queue *txq)
+{
+	return netdev_get_tx_queue(txq->netdev, txq->queue_idx);
+}
+
 static inline int alx_tpd_avail(struct alx_tx_queue *txq)
 {
 	if (txq->write_idx >= txq->read_idx)
@@ -153,14 +169,16 @@ static inline int alx_tpd_avail(struct alx_tx_queue *txq)
 static bool alx_clean_tx_irq(struct alx_tx_queue *txq)
 {
 	struct alx_priv *alx;
+	struct netdev_queue *tx_queue;
 	u16 hw_read_idx, sw_read_idx;
 	unsigned int total_bytes = 0, total_packets = 0;
 	int budget = ALX_DEFAULT_TX_WORK;
 
 	alx = netdev_priv(txq->netdev);
+	tx_queue = alx_get_tx_queue(txq);
 
 	sw_read_idx = txq->read_idx;
-	hw_read_idx = alx_read_mem16(&alx->hw, ALX_TPD_PRI0_CIDX);
+	hw_read_idx = alx_read_mem16(&alx->hw, txq->c_reg);
 
 	if (sw_read_idx != hw_read_idx) {
 		while (sw_read_idx != hw_read_idx && budget > 0) {
@@ -180,12 +198,12 @@ static bool alx_clean_tx_irq(struct alx_tx_queue *txq)
 		}
 		txq->read_idx = sw_read_idx;
 
-		netdev_completed_queue(txq->netdev, total_packets, total_bytes);
+		netdev_tx_completed_queue(tx_queue, total_packets, total_bytes);
 	}
 
-	if (netif_queue_stopped(txq->netdev) && netif_carrier_ok(txq->netdev) &&
+	if (netif_tx_queue_stopped(tx_queue) && netif_carrier_ok(alx->dev) &&
 	    alx_tpd_avail(txq) > txq->count / 4)
-		netif_wake_queue(txq->netdev);
+		netif_tx_wake_queue(tx_queue);
 
 	return sw_read_idx == hw_read_idx;
 }
@@ -487,7 +505,7 @@ static void alx_free_txring_buf(struct alx_tx_queue *txq)
 	txq->write_idx = 0;
 	txq->read_idx = 0;
 
-	netdev_reset_queue(txq->netdev);
+	netdev_tx_reset_queue(alx_get_tx_queue(txq));
 }
 
 static void alx_free_rxring_buf(struct alx_rx_queue *rxq)
@@ -714,6 +732,10 @@ static void alx_free_napis(struct alx_priv *alx)
 	}
 }
 
+static const u16 tx_pidx_reg[] = {ALX_TPD_PRI0_PIDX, ALX_TPD_PRI1_PIDX,
+				  ALX_TPD_PRI2_PIDX, ALX_TPD_PRI3_PIDX};
+static const u16 tx_cidx_reg[] = {ALX_TPD_PRI0_CIDX, ALX_TPD_PRI1_CIDX,
+				  ALX_TPD_PRI2_CIDX, ALX_TPD_PRI3_CIDX};
 static const u32 tx_vect_mask[] = {ALX_ISR_TX_Q0, ALX_ISR_TX_Q1,
 				   ALX_ISR_TX_Q2, ALX_ISR_TX_Q3};
 static const u32 rx_vect_mask[] = {ALX_ISR_RX_Q0, ALX_ISR_RX_Q1,
@@ -749,6 +771,8 @@ static int alx_alloc_napis(struct alx_priv *alx)
 			goto err_out;
 
 		np->txq = txq;
+		txq->p_reg = tx_pidx_reg[i];
+		txq->c_reg = tx_cidx_reg[i];
 		txq->queue_idx = i;
 		txq->count = alx->tx_ringsz;
 		txq->netdev = alx->dev;
@@ -1501,16 +1525,17 @@ err_dma:
 	return -ENOMEM;
 }
 
-static netdev_tx_t alx_start_xmit(struct sk_buff *skb,
-				  struct net_device *netdev)
+static netdev_tx_t alx_start_xmit_ring(struct sk_buff *skb,
+				       struct alx_tx_queue *txq)
 {
-	struct alx_priv *alx = netdev_priv(netdev);
-	struct alx_tx_queue *txq = alx->qnapi[0]->txq;
+	struct alx_priv *alx;
 	struct alx_txd *first;
 	int tso;
 
+	alx = netdev_priv(txq->netdev);
+
 	if (alx_tpd_avail(txq) < alx_tpd_req(skb)) {
-		netif_stop_queue(txq->netdev);
+		netif_tx_stop_queue(alx_get_tx_queue(txq));
 		goto drop;
 	}
 
@@ -1526,14 +1551,14 @@ static netdev_tx_t alx_start_xmit(struct sk_buff *skb,
 	if (alx_map_tx_skb(txq, skb) < 0)
 		goto drop;
 
-	netdev_sent_queue(txq->netdev, skb->len);
+	netdev_tx_sent_queue(alx_get_tx_queue(txq), skb->len);
 
 	/* flush updates before updating hardware */
 	wmb();
-	alx_write_mem16(&alx->hw, ALX_TPD_PRI0_PIDX, txq->write_idx);
+	alx_write_mem16(&alx->hw, txq->p_reg, txq->write_idx);
 
 	if (alx_tpd_avail(txq) < txq->count / 8)
-		netif_stop_queue(txq->netdev);
+		netif_tx_stop_queue(alx_get_tx_queue(txq));
 
 	return NETDEV_TX_OK;
 
@@ -1542,6 +1567,13 @@ drop:
 	return NETDEV_TX_OK;
 }
 
+static netdev_tx_t alx_start_xmit(struct sk_buff *skb,
+				  struct net_device *netdev)
+{
+	struct alx_priv *alx = netdev_priv(netdev);
+	return alx_start_xmit_ring(skb, alx_tx_queue_mapping(alx, skb));
+}
+
 static void alx_tx_timeout(struct net_device *dev)
 {
 	struct alx_priv *alx = netdev_priv(dev);