qlge: Enhance nested VLAN (Q-in-Q) handling.

o Adapter doesn’t handle packets with nested VLAN tags in
Rx path. User can turn off VLAN tag stripping in the hardware
and let the stack handle stripping of VLAN tags in the Rx path.

o Users can enable or disable hardware VLAN acceleration using ethtool
Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qlge/qlge_main.c

@@ -96,8 +96,10 @@ static DEFINE_PCI_DEVICE_TABLE(qlge_pci_tbl) = {
 
 MODULE_DEVICE_TABLE(pci, qlge_pci_tbl);
 
-static int ql_wol(struct ql_adapter *qdev);
-static void qlge_set_multicast_list(struct net_device *ndev);
+static int ql_wol(struct ql_adapter *);
+static void qlge_set_multicast_list(struct net_device *);
+static int ql_adapter_down(struct ql_adapter *);
+static int ql_adapter_up(struct ql_adapter *);
 
 /* This hardware semaphore causes exclusive access to
  * resources shared between the NIC driver, MPI firmware,
@@ -1464,6 +1466,29 @@ static void ql_categorize_rx_err(struct ql_adapter *qdev, u8 rx_err,
 	}
 }
 
+/**
+ * ql_update_mac_hdr_len - helper routine to update the mac header length
+ * based on vlan tags if present
+ */
+static void ql_update_mac_hdr_len(struct ql_adapter *qdev,
+				  struct ib_mac_iocb_rsp *ib_mac_rsp,
+				  void *page, size_t *len)
+{
+	u16 *tags;
+
+	if (qdev->ndev->features & NETIF_F_HW_VLAN_CTAG_RX)
+		return;
+	if (ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) {
+		tags = (u16 *)page;
+		/* Look for stacked vlan tags in ethertype field */
+		if (tags[6] == ETH_P_8021Q &&
+		    tags[8] == ETH_P_8021Q)
+			*len += 2 * VLAN_HLEN;
+		else
+			*len += VLAN_HLEN;
+	}
+}
+
 /* Process an inbound completion from an rx ring. */
 static void ql_process_mac_rx_gro_page(struct ql_adapter *qdev,
 					struct rx_ring *rx_ring,
@@ -1523,6 +1548,7 @@ static void ql_process_mac_rx_page(struct ql_adapter *qdev,
 	void *addr;
 	struct bq_desc *lbq_desc = ql_get_curr_lchunk(qdev, rx_ring);
 	struct napi_struct *napi = &rx_ring->napi;
+	size_t hlen = ETH_HLEN;
 
 	skb = netdev_alloc_skb(ndev, length);
 	if (!skb) {
@@ -1540,25 +1566,28 @@ static void ql_process_mac_rx_page(struct ql_adapter *qdev,
 		goto err_out;
 	}
 
+	/* Update the MAC header length*/
+	ql_update_mac_hdr_len(qdev, ib_mac_rsp, addr, &hlen);
+
 	/* The max framesize filter on this chip is set higher than
 	 * MTU since FCoE uses 2k frames.
 	 */
-	if (skb->len > ndev->mtu + ETH_HLEN) {
+	if (skb->len > ndev->mtu + hlen) {
 		netif_err(qdev, drv, qdev->ndev,
 			  "Segment too small, dropping.\n");
 		rx_ring->rx_dropped++;
 		goto err_out;
 	}
-	memcpy(skb_put(skb, ETH_HLEN), addr, ETH_HLEN);
+	memcpy(skb_put(skb, hlen), addr, hlen);
 	netif_printk(qdev, rx_status, KERN_DEBUG, qdev->ndev,
 		     "%d bytes of headers and data in large. Chain page to new skb and pull tail.\n",
 		     length);
 	skb_fill_page_desc(skb, 0, lbq_desc->p.pg_chunk.page,
-				lbq_desc->p.pg_chunk.offset+ETH_HLEN,
-				length-ETH_HLEN);
-	skb->len += length-ETH_HLEN;
-	skb->data_len += length-ETH_HLEN;
-	skb->truesize += length-ETH_HLEN;
+				lbq_desc->p.pg_chunk.offset + hlen,
+				length - hlen);
+	skb->len += length - hlen;
+	skb->data_len += length - hlen;
+	skb->truesize += length - hlen;
 
 	rx_ring->rx_packets++;
 	rx_ring->rx_bytes += skb->len;
@@ -1576,7 +1605,7 @@ static void ql_process_mac_rx_page(struct ql_adapter *qdev,
 				(ib_mac_rsp->flags3 & IB_MAC_IOCB_RSP_V4)) {
 			/* Unfragmented ipv4 UDP frame. */
 			struct iphdr *iph =
-				(struct iphdr *) ((u8 *)addr + ETH_HLEN);
+				(struct iphdr *)((u8 *)addr + hlen);
 			if (!(iph->frag_off &
 				htons(IP_MF|IP_OFFSET))) {
 				skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -1727,6 +1756,7 @@ static struct sk_buff *ql_build_rx_skb(struct ql_adapter *qdev,
 	struct sk_buff *skb = NULL;
 	u32 length = le32_to_cpu(ib_mac_rsp->data_len);
 	u32 hdr_len = le32_to_cpu(ib_mac_rsp->hdr_len);
+	size_t hlen = ETH_HLEN;
 
 	/*
 	 * Handle the header buffer if present.
@@ -1853,9 +1883,10 @@ static struct sk_buff *ql_build_rx_skb(struct ql_adapter *qdev,
 			skb->data_len += length;
 			skb->truesize += length;
 			length -= length;
-			__pskb_pull_tail(skb,
-				(ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) ?
-				VLAN_ETH_HLEN : ETH_HLEN);
+			ql_update_mac_hdr_len(qdev, ib_mac_rsp,
+					      lbq_desc->p.pg_chunk.va,
+					      &hlen);
+			__pskb_pull_tail(skb, hlen);
 		}
 	} else {
 		/*
@@ -1910,8 +1941,9 @@ static struct sk_buff *ql_build_rx_skb(struct ql_adapter *qdev,
 			length -= size;
 			i++;
 		}
-		__pskb_pull_tail(skb, (ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) ?
-				VLAN_ETH_HLEN : ETH_HLEN);
+		ql_update_mac_hdr_len(qdev, ib_mac_rsp, lbq_desc->p.pg_chunk.va,
+				      &hlen);
+		__pskb_pull_tail(skb, hlen);
 	}
 	return skb;
 }
@@ -2003,7 +2035,7 @@ static void ql_process_mac_split_rx_intr(struct ql_adapter *qdev,
 	rx_ring->rx_packets++;
 	rx_ring->rx_bytes += skb->len;
 	skb_record_rx_queue(skb, rx_ring->cq_id);
-	if ((ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) && (vlan_id != 0))
+	if (vlan_id != 0xffff)
 		__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_id);
 	if (skb->ip_summed == CHECKSUM_UNNECESSARY)
 		napi_gro_receive(&rx_ring->napi, skb);
@@ -2017,7 +2049,8 @@ static unsigned long ql_process_mac_rx_intr(struct ql_adapter *qdev,
 					struct ib_mac_iocb_rsp *ib_mac_rsp)
 {
 	u32 length = le32_to_cpu(ib_mac_rsp->data_len);
-	u16 vlan_id = (ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) ?
+	u16 vlan_id = ((ib_mac_rsp->flags2 & IB_MAC_IOCB_RSP_V) &&
+			(qdev->ndev->features & NETIF_F_HW_VLAN_CTAG_RX)) ?
 			((le16_to_cpu(ib_mac_rsp->vlan_id) &
 			IB_MAC_IOCB_RSP_VLAN_MASK)) : 0xffff;
 
@@ -2310,9 +2343,39 @@ static void qlge_vlan_mode(struct net_device *ndev, netdev_features_t features)
 	}
 }
 
+/**
+ * qlge_update_hw_vlan_features - helper routine to reinitialize the adapter
+ * based on the features to enable/disable hardware vlan accel
+ */
+static int qlge_update_hw_vlan_features(struct net_device *ndev,
+					netdev_features_t features)
+{
+	struct ql_adapter *qdev = netdev_priv(ndev);
+	int status = 0;
+
+	status = ql_adapter_down(qdev);
+	if (status) {
+		netif_err(qdev, link, qdev->ndev,
+			  "Failed to bring down the adapter\n");
+		return status;
+	}
+
+	/* update the features with resent change */
+	ndev->features = features;
+
+	status = ql_adapter_up(qdev);
+	if (status) {
+		netif_err(qdev, link, qdev->ndev,
+			  "Failed to bring up the adapter\n");
+		return status;
+	}
+	return status;
+}
+
 static netdev_features_t qlge_fix_features(struct net_device *ndev,
 	netdev_features_t features)
 {
+	int err;
 	/*
 	 * Since there is no support for separate rx/tx vlan accel
 	 * enable/disable make sure tx flag is always in same state as rx.
@@ -2322,6 +2385,11 @@ static netdev_features_t qlge_fix_features(struct net_device *ndev,
 	else
 		features &= ~NETIF_F_HW_VLAN_CTAG_TX;
 
+	/* Update the behavior of vlan accel in the adapter */
+	err = qlge_update_hw_vlan_features(ndev, features);
+	if (err)
+		return err;
+
 	return features;
 }
 
@@ -3704,8 +3772,12 @@ static int ql_adapter_initialize(struct ql_adapter *qdev)
 	ql_write32(qdev, SYS, mask | value);
 
 	/* Set the default queue, and VLAN behavior. */
-	value = NIC_RCV_CFG_DFQ | NIC_RCV_CFG_RV;
-	mask = NIC_RCV_CFG_DFQ_MASK | (NIC_RCV_CFG_RV << 16);
+	value = NIC_RCV_CFG_DFQ;
+	mask = NIC_RCV_CFG_DFQ_MASK;
+	if (qdev->ndev->features & NETIF_F_HW_VLAN_CTAG_RX) {
+		value |= NIC_RCV_CFG_RV;
+		mask |= (NIC_RCV_CFG_RV << 16);
+	}
 	ql_write32(qdev, NIC_RCV_CFG, (mask | value));
 
 	/* Set the MPI interrupt to enabled. */
@@ -4692,11 +4764,15 @@ static int qlge_probe(struct pci_dev *pdev,
 
 	qdev = netdev_priv(ndev);
 	SET_NETDEV_DEV(ndev, &pdev->dev);
-	ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
-		NETIF_F_TSO | NETIF_F_TSO_ECN |
-		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_RXCSUM;
-	ndev->features = ndev->hw_features |
-		NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_VLAN_CTAG_FILTER;
+	ndev->hw_features = NETIF_F_SG |
+			    NETIF_F_IP_CSUM |
+			    NETIF_F_TSO |
+			    NETIF_F_TSO_ECN |
+			    NETIF_F_HW_VLAN_CTAG_TX |
+			    NETIF_F_HW_VLAN_CTAG_RX |
+			    NETIF_F_HW_VLAN_CTAG_FILTER |
+			    NETIF_F_RXCSUM;
+	ndev->features = ndev->hw_features;
 	ndev->vlan_features = ndev->hw_features;
 
 	if (test_bit(QL_DMA64, &qdev->flags))