ravb: Factorise ravb_ring_free function

R-Car uses extended descriptor in RX, whereas RZ/G2L uses normal
descriptor. Factorise ravb_ring_free function so that it can
support later SoC.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/renesas/ravb.h

@@ -980,6 +980,7 @@ struct ravb_ptp {
 };
 
 struct ravb_hw_info {
+	void (*rx_ring_free)(struct net_device *ndev, int q);
 	const char (*gstrings_stats)[ETH_GSTRING_LEN];
 	size_t gstrings_size;
 	netdev_features_t net_hw_features;

drivers/net/ethernet/renesas/ravb_main.c

@@ -216,15 +216,15 @@ static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only)
 	return free_num;
 }
 
-/* Free skb's and DMA buffers for Ethernet AVB */
-static void ravb_ring_free(struct net_device *ndev, int q)
+static void ravb_rx_ring_free(struct net_device *ndev, int q)
 {
 	struct ravb_private *priv = netdev_priv(ndev);
-	unsigned int num_tx_desc = priv->num_tx_desc;
 	unsigned int ring_size;
 	unsigned int i;
 
-	if (priv->rx_ring[q]) {
+	if (!priv->rx_ring[q])
+		return;
+
 	for (i = 0; i < priv->num_rx_ring[q]; i++) {
 		struct ravb_ex_rx_desc *desc = &priv->rx_ring[q][i];
 
@@ -240,7 +240,18 @@ static void ravb_ring_free(struct net_device *ndev, int q)
 	dma_free_coherent(ndev->dev.parent, ring_size, priv->rx_ring[q],
 			  priv->rx_desc_dma[q]);
 	priv->rx_ring[q] = NULL;
-	}
+}
+
+/* Free skb's and DMA buffers for Ethernet AVB */
+static void ravb_ring_free(struct net_device *ndev, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	const struct ravb_hw_info *info = priv->info;
+	unsigned int num_tx_desc = priv->num_tx_desc;
+	unsigned int ring_size;
+	unsigned int i;
+
+	info->rx_ring_free(ndev, q);
 
 	if (priv->tx_ring[q]) {
 		ravb_tx_free(ndev, q, false);
@@ -1937,6 +1948,7 @@ static int ravb_mdio_release(struct ravb_private *priv)
 }
 
 static const struct ravb_hw_info ravb_gen3_hw_info = {
+	.rx_ring_free = ravb_rx_ring_free,
 	.gstrings_stats = ravb_gstrings_stats,
 	.gstrings_size = sizeof(ravb_gstrings_stats),
 	.net_hw_features = NETIF_F_RXCSUM,
@@ -1950,6 +1962,7 @@ static const struct ravb_hw_info ravb_gen3_hw_info = {
 };
 
 static const struct ravb_hw_info ravb_gen2_hw_info = {
+	.rx_ring_free = ravb_rx_ring_free,
 	.gstrings_stats = ravb_gstrings_stats,
 	.gstrings_size = sizeof(ravb_gstrings_stats),
 	.net_hw_features = NETIF_F_RXCSUM,