net:fec: move skb allocation earlier

Move the skb allocation before we sync the buffer for CPU access.  In
order to do this, we need to detect whether the packet contains a VLAN
header so we can adjust the packet size appropriately.

This allows us to tidy the code a little in the following patches.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 24 insertions, 21 deletions

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index c0f166538738..791d6f519256 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -977,7 +977,6 @@ fec_enet_rx(struct net_device *ndev, int budget)
 	ushort	pkt_len;
 	__u8 *data;
 	int	pkt_received = 0;
-	bool	vlan_packet_rcvd = false;
 	u16	vlan_tag;
 	unsigned int index = fep->rx_next;
 
@@ -1053,13 +1052,6 @@ fec_enet_rx(struct net_device *ndev, int budget)
 		pkt_len = bdp->bd.cbd_datlen - 4;
 		ndev->stats.rx_bytes += pkt_len;
 
-		data = fep->rx_skbuff[index]->data;
-		dma_sync_single_for_cpu(&fep->pdev->dev, bdp->bd.cbd_bufaddr,
-					FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
-
-		if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
-			swap_buffer(data, pkt_len);
-
 		if (fep->flags & FEC_FLAG_BUFDESC_EX) {
 			cbd_esc = bdp->ebd.cbd_esc;
 			if (!(fep->flags & FEC_FLAG_RX_VLAN))
@@ -1068,32 +1060,43 @@ fec_enet_rx(struct net_device *ndev, int budget)
 			cbd_esc = 0;
 		}
 
+		/*
+		 * Detect the presence of the VLANG tag, and just
+		 * the packet length appropriately.
+		 */
+		if (cbd_esc & BD_ENET_RX_VLAN)
+			pkt_len -= VLAN_HLEN;
+
+		/* This does 16 byte alignment, exactly what we need. */
+		skb = netdev_alloc_skb(ndev, pkt_len + NET_IP_ALIGN);
+		if (unlikely(!skb)) {
+			ndev->stats.rx_dropped++;
+			goto rx_processing_done;
+		}
+
+		data = fep->rx_skbuff[index]->data;
+		dma_sync_single_for_cpu(&fep->pdev->dev, bdp->bd.cbd_bufaddr,
+					FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);
+
+		if (fep->quirks & FEC_QUIRK_SWAP_FRAME)
+			swap_buffer(data, pkt_len);
+
 		/* If this is a VLAN packet remove the VLAN Tag */
-		vlan_packet_rcvd = false;
 		if (cbd_esc & BD_ENET_RX_VLAN) {
 			/* Push and remove the vlan tag */
 			struct vlan_hdr *vlan_header =
 					(struct vlan_hdr *) (data + ETH_HLEN);
 			vlan_tag = ntohs(vlan_header->h_vlan_TCI);
-			pkt_len -= VLAN_HLEN;
-
-			vlan_packet_rcvd = true;
 		}
 
-		/* This does 16 byte alignment, exactly what we need.
-		 */
-		skb = netdev_alloc_skb(ndev, pkt_len + NET_IP_ALIGN);
-
-		if (unlikely(!skb)) {
-			ndev->stats.rx_dropped++;
-		} else {
+		{
 			int payload_offset = (2 * ETH_ALEN);
 			skb_reserve(skb, NET_IP_ALIGN);
 			skb_put(skb, pkt_len);	/* Make room */
 
 			/* Extract the frame data without the VLAN header. */
 			skb_copy_to_linear_data(skb, data, (2 * ETH_ALEN));
-			if (vlan_packet_rcvd)
+			if (cbd_esc & BD_ENET_RX_VLAN)
 				payload_offset = (2 * ETH_ALEN) + VLAN_HLEN;
 			skb_copy_to_linear_data_offset(skb, (2 * ETH_ALEN),
 						       data + payload_offset,
@@ -1116,7 +1119,7 @@ fec_enet_rx(struct net_device *ndev, int budget)
 			}
 
 			/* Handle received VLAN packets */
-			if (vlan_packet_rcvd)
+			if (cbd_esc & BD_ENET_RX_VLAN)
 				__vlan_hwaccel_put_tag(skb,
 						       htons(ETH_P_8021Q),
 						       vlan_tag);