fm10k: Add transmit and receive fastpath and interrupt handlers

This change adds the transmit and receive fastpath and interrupt handlers.
With this code in place the network device is now able to send and receive
frames over the network interface using a single queue.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
CC: Rick Jones <rick.jones2@hp.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/fm10k/fm10k.h

@@ -391,6 +391,11 @@ extern char fm10k_driver_name[];
 extern const char fm10k_driver_version[];
 int fm10k_init_queueing_scheme(struct fm10k_intfc *interface);
 void fm10k_clear_queueing_scheme(struct fm10k_intfc *interface);
+netdev_tx_t fm10k_xmit_frame_ring(struct sk_buff *skb,
+				  struct fm10k_ring *tx_ring);
+void fm10k_tx_timeout_reset(struct fm10k_intfc *interface);
+bool fm10k_check_tx_hang(struct fm10k_ring *tx_ring);
+void fm10k_alloc_rx_buffers(struct fm10k_ring *rx_ring, u16 cleaned_count);
 
 /* PCI */
 void fm10k_mbx_free_irq(struct fm10k_intfc *);

drivers/net/ethernet/intel/fm10k/fm10k_netdev.c

@@ -451,8 +451,66 @@ int fm10k_close(struct net_device *netdev)
 
 static netdev_tx_t fm10k_xmit_frame(struct sk_buff *skb, struct net_device *dev)
 {
-	dev_kfree_skb_any(skb);
-	return NETDEV_TX_OK;
+	struct fm10k_intfc *interface = netdev_priv(dev);
+	unsigned int r_idx = 0;
+	int err;
+
+	if ((skb->protocol ==  htons(ETH_P_8021Q)) &&
+	    !vlan_tx_tag_present(skb)) {
+		/* FM10K only supports hardware tagging, any tags in frame
+		 * are considered 2nd level or "outer" tags
+		 */
+		struct vlan_hdr *vhdr;
+		__be16 proto;
+
+		/* make sure skb is not shared */
+		skb = skb_share_check(skb, GFP_ATOMIC);
+		if (!skb)
+			return NETDEV_TX_OK;
+
+		/* make sure there is enough room to move the ethernet header */
+		if (unlikely(!pskb_may_pull(skb, VLAN_ETH_HLEN)))
+			return NETDEV_TX_OK;
+
+		/* verify the skb head is not shared */
+		err = skb_cow_head(skb, 0);
+		if (err)
+			return NETDEV_TX_OK;
+
+		/* locate vlan header */
+		vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
+
+		/* pull the 2 key pieces of data out of it */
+		__vlan_hwaccel_put_tag(skb,
+				       htons(ETH_P_8021Q),
+				       ntohs(vhdr->h_vlan_TCI));
+		proto = vhdr->h_vlan_encapsulated_proto;
+		skb->protocol = (ntohs(proto) >= 1536) ? proto :
+							 htons(ETH_P_802_2);
+
+		/* squash it by moving the ethernet addresses up 4 bytes */
+		memmove(skb->data + VLAN_HLEN, skb->data, 12);
+		__skb_pull(skb, VLAN_HLEN);
+		skb_reset_mac_header(skb);
+	}
+
+	/* The minimum packet size for a single buffer is 17B so pad the skb
+	 * in order to meet this minimum size requirement.
+	 */
+	if (unlikely(skb->len < 17)) {
+		int pad_len = 17 - skb->len;
+
+		if (skb_pad(skb, pad_len))
+			return NETDEV_TX_OK;
+		__skb_put(skb, pad_len);
+	}
+
+	if (r_idx >= interface->num_tx_queues)
+		r_idx %= interface->num_tx_queues;
+
+	err = fm10k_xmit_frame_ring(skb, interface->tx_ring[r_idx]);
+
+	return err;
 }
 
 static int fm10k_change_mtu(struct net_device *dev, int new_mtu)
@@ -465,6 +523,37 @@ static int fm10k_change_mtu(struct net_device *dev, int new_mtu)
 	return 0;
 }
 
+/**
+ * fm10k_tx_timeout - Respond to a Tx Hang
+ * @netdev: network interface device structure
+ **/
+static void fm10k_tx_timeout(struct net_device *netdev)
+{
+	struct fm10k_intfc *interface = netdev_priv(netdev);
+	bool real_tx_hang = false;
+	int i;
+
+#define TX_TIMEO_LIMIT 16000
+	for (i = 0; i < interface->num_tx_queues; i++) {
+		struct fm10k_ring *tx_ring = interface->tx_ring[i];
+
+		if (check_for_tx_hang(tx_ring) && fm10k_check_tx_hang(tx_ring))
+			real_tx_hang = true;
+	}
+
+	if (real_tx_hang) {
+		fm10k_tx_timeout_reset(interface);
+	} else {
+		netif_info(interface, drv, netdev,
+			   "Fake Tx hang detected with timeout of %d seconds\n",
+			   netdev->watchdog_timeo/HZ);
+
+		/* fake Tx hang - increase the kernel timeout */
+		if (netdev->watchdog_timeo < TX_TIMEO_LIMIT)
+			netdev->watchdog_timeo *= 2;
+	}
+}
+
 static int fm10k_uc_vlan_unsync(struct net_device *netdev,
 				const unsigned char *uc_addr)
 {
@@ -891,6 +980,7 @@ static const struct net_device_ops fm10k_netdev_ops = {
 	.ndo_start_xmit		= fm10k_xmit_frame,
 	.ndo_set_mac_address	= fm10k_set_mac,
 	.ndo_change_mtu		= fm10k_change_mtu,
+	.ndo_tx_timeout		= fm10k_tx_timeout,
 	.ndo_vlan_rx_add_vid	= fm10k_vlan_rx_add_vid,
 	.ndo_vlan_rx_kill_vid	= fm10k_vlan_rx_kill_vid,
 	.ndo_set_rx_mode	= fm10k_set_rx_mode,

drivers/net/ethernet/intel/fm10k/fm10k_pci.c

@@ -661,6 +661,9 @@ static void fm10k_configure_rx_ring(struct fm10k_intfc *interface,
 
 	/* enable queue */
 	fm10k_write_reg(hw, FM10K_RXQCTL(reg_idx), rxqctl);
+
+	/* place buffers on ring for receive data */
+	fm10k_alloc_rx_buffers(ring, fm10k_desc_unused(ring));
 }
 
 /**