igb: update napi polling to consolidate function and return correct values

igb is currently not returning the correct values for napi.  In addition it
is doing more work than necessary since it will not exit polling until
work_done is equal to zero.

This patch makes the following changes:
1.  Consolidates msi-x and non-msi polling routines.
2.  Corrects return values for polling routines.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/igb/igb_main.c

@@ -106,7 +106,6 @@ static irqreturn_t igb_intr_msi(int irq, void *);
 static irqreturn_t igb_msix_other(int irq, void *);
 static irqreturn_t igb_msix_rx(int irq, void *);
 static irqreturn_t igb_msix_tx(int irq, void *);
-static int igb_clean_rx_ring_msix(struct napi_struct *, int);
 #ifdef CONFIG_IGB_DCA
 static void igb_update_rx_dca(struct igb_ring *);
 static void igb_update_tx_dca(struct igb_ring *);
@@ -3688,6 +3687,26 @@ static irqreturn_t igb_intr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static inline void igb_rx_irq_enable(struct igb_ring *rx_ring)
+{
+	struct igb_adapter *adapter = rx_ring->adapter;
+	struct e1000_hw *hw = &adapter->hw;
+
+	if (adapter->itr_setting & 3) {
+		if (adapter->num_rx_queues == 1)
+			igb_set_itr(adapter);
+		else
+			igb_update_ring_itr(rx_ring);
+	}
+
+	if (!test_bit(__IGB_DOWN, &adapter->state)) {
+		if (adapter->msix_entries)
+			wr32(E1000_EIMS, rx_ring->eims_value);
+		else
+			igb_irq_enable(adapter);
+	}
+}
+
 /**
  * igb_poll - NAPI Rx polling callback
  * @napi: napi polling structure
@@ -3698,41 +3717,6 @@ static int igb_poll(struct napi_struct *napi, int budget)
 	struct igb_ring *rx_ring = container_of(napi, struct igb_ring, napi);
 	struct igb_adapter *adapter = rx_ring->adapter;
 	struct net_device *netdev = adapter->netdev;
-	int tx_clean_complete, work_done = 0;
-
-	/* this poll routine only supports one tx and one rx queue */
-#ifdef CONFIG_IGB_DCA
-	if (adapter->flags & IGB_FLAG_DCA_ENABLED)
-		igb_update_tx_dca(&adapter->tx_ring[0]);
-#endif
-	tx_clean_complete = igb_clean_tx_irq(&adapter->tx_ring[0]);
-
-#ifdef CONFIG_IGB_DCA
-	if (adapter->flags & IGB_FLAG_DCA_ENABLED)
-		igb_update_rx_dca(&adapter->rx_ring[0]);
-#endif
-	igb_clean_rx_irq_adv(&adapter->rx_ring[0], &work_done, budget);
-
-	/* If no Tx and not enough Rx work done, exit the polling mode */
-	if ((tx_clean_complete && (work_done < budget)) ||
-	    !netif_running(netdev)) {
-		if (adapter->itr_setting & 3)
-			igb_set_itr(adapter);
-		napi_complete(napi);
-		if (!test_bit(__IGB_DOWN, &adapter->state))
-			igb_irq_enable(adapter);
-		return 0;
-	}
-
-	return 1;
-}
-
-static int igb_clean_rx_ring_msix(struct napi_struct *napi, int budget)
-{
-	struct igb_ring *rx_ring = container_of(napi, struct igb_ring, napi);
-	struct igb_adapter *adapter = rx_ring->adapter;
-	struct e1000_hw *hw = &adapter->hw;
-	struct net_device *netdev = adapter->netdev;
 	int work_done = 0;
 
 #ifdef CONFIG_IGB_DCA
@@ -3741,23 +3725,22 @@ static int igb_clean_rx_ring_msix(struct napi_struct *napi, int budget)
 #endif
 	igb_clean_rx_irq_adv(rx_ring, &work_done, budget);
 
-	/* If not enough Rx work done, exit the polling mode */
-	if ((work_done == 0) || !netif_running(netdev)) {
-		napi_complete(napi);
-
-		if (adapter->itr_setting & 3) {
-			if (adapter->num_rx_queues == 1)
-				igb_set_itr(adapter);
-			else
-				igb_update_ring_itr(rx_ring);
-		}
-		if (!test_bit(__IGB_DOWN, &adapter->state))
-			wr32(E1000_EIMS, rx_ring->eims_value);
-
-		return 0;
+	if (rx_ring->buddy) {
+#ifdef CONFIG_IGB_DCA
+		if (adapter->flags & IGB_FLAG_DCA_ENABLED)
+			igb_update_tx_dca(rx_ring->buddy);
+#endif
+		if (!igb_clean_tx_irq(rx_ring->buddy))
+			work_done = budget;
 	}
 
-	return 1;
+	/* If not enough Rx work done, exit the polling mode */
+	if ((work_done < budget) || !netif_running(netdev)) {
+		napi_complete(napi);
+		igb_rx_irq_enable(rx_ring);
+	}
+
+	return work_done;
 }
 
 /**