[E1000] Perform single PCI read per interrupt

* ISR cleanup; performing single PCI read

drivers/net/e1000/e1000_main.c

@@ -1920,82 +1920,45 @@ e1000_intr(int irq, void *data, struct pt_regs *regs)
 {
 	struct net_device *netdev = data;
 	struct e1000_adapter *adapter = netdev->priv;
+	uint32_t icr = E1000_READ_REG(&adapter->hw, ICR);
+	int i;
 
-#ifdef CONFIG_E1000_NAPI
-	if (netif_rx_schedule_prep(netdev)) {
-		/* Disable interrupts and enable polling */
-		atomic_inc(&adapter->irq_sem);
-		E1000_WRITE_REG(&adapter->hw, IMC, ~0);
-		E1000_WRITE_FLUSH(&adapter->hw);
-		__netif_rx_schedule(netdev);
-	}
-#else
-	uint32_t icr;
-	int i = E1000_MAX_INTR;
-
-	while(i && (icr = E1000_READ_REG(&adapter->hw, ICR))) {
+	if(!icr)
+		return;  /* Not our interrupt */
 
 	if(icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
 		adapter->hw.get_link_status = 1;
 		mod_timer(&adapter->watchdog_timer, jiffies);
 	}
 
-		e1000_clean_rx_irq(adapter);
-		e1000_clean_tx_irq(adapter);
-		i--;
-
-	}
-#endif
-}
-
-#ifdef CONFIG_E1000_NAPI
-static int
-e1000_process_intr(struct net_device *netdev)
-{
-	struct e1000_adapter *adapter = netdev->priv;
-	uint32_t icr;
-	int i = E1000_MAX_INTR;
-	int hasReceived = 0;
-
-	while(i && (icr = E1000_READ_REG(&adapter->hw, ICR))) {
-		if (icr & E1000_ICR_RXT0)
-			hasReceived = 1;
- 
-		if (!(icr & ~(E1000_ICR_RXT0)))
+	for(i = 0; i < E1000_MAX_INTR; i++)
+		if(!e1000_clean_rx_irq(adapter) &&
+		   !e1000_clean_tx_irq(adapter))
 			break;
 
-		if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) {
-			adapter->hw.get_link_status = 1;
-			mod_timer(&adapter->watchdog_timer, jiffies);
-		}
- 
-		e1000_clean_tx_irq(adapter);
-		i--;
-	}
-
-	return hasReceived;
 }
-#endif
 
 /**
  * e1000_clean_tx_irq - Reclaim resources after transmit completes
  * @adapter: board private structure
  **/
 
-static void
+static boolean_t
 e1000_clean_tx_irq(struct e1000_adapter *adapter)
 {
 	struct e1000_desc_ring *tx_ring = &adapter->tx_ring;
 	struct net_device *netdev = adapter->netdev;
 	struct pci_dev *pdev = adapter->pdev;
 	struct e1000_tx_desc *tx_desc;
-	int i;
+	int i, cleaned = FALSE;
 
 	i = tx_ring->next_to_clean;
 	tx_desc = E1000_TX_DESC(*tx_ring, i);
 
 	while(tx_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
 
+		cleaned = TRUE;
+
 		if(tx_ring->buffer_info[i].dma) {
 
 			pci_unmap_page(pdev,
@@ -2021,149 +1984,18 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter)
 
 	tx_ring->next_to_clean = i;
 
-	if(netif_queue_stopped(netdev) && netif_carrier_ok(netdev) &&
-	   (E1000_DESC_UNUSED(tx_ring) > E1000_TX_QUEUE_WAKE)) {
-
+	if(cleaned && netif_queue_stopped(netdev) && netif_carrier_ok(netdev))
 		netif_wake_queue(netdev);
-	}
-}
-
-#ifdef CONFIG_E1000_NAPI
-static int
-e1000_poll(struct net_device *netdev, int *budget)
-{
-	struct e1000_adapter *adapter = netdev->priv;
-	struct e1000_desc_ring *rx_ring = &adapter->rx_ring;
-	struct pci_dev *pdev = adapter->pdev;
-	struct e1000_rx_desc *rx_desc;
-	struct sk_buff *skb;
-	unsigned long flags;
-	uint32_t length;
-	uint8_t last_byte;
-	int i;
-	int received = 0;
-	int rx_work_limit = *budget;
-
-	if(rx_work_limit > netdev->quota)
-		rx_work_limit = netdev->quota;
-
-	e1000_process_intr(netdev);
-
-	i = rx_ring->next_to_clean;
-	rx_desc = E1000_RX_DESC(*rx_ring, i);
-
-	while(rx_desc->status & E1000_RXD_STAT_DD) {
-		if(--rx_work_limit < 0)
-			goto not_done;
-
-		pci_unmap_single(pdev,
-		                 rx_ring->buffer_info[i].dma,
-		                 rx_ring->buffer_info[i].length,
-		                 PCI_DMA_FROMDEVICE);
-
-		skb = rx_ring->buffer_info[i].skb;
-		length = le16_to_cpu(rx_desc->length);
-
-		if(!(rx_desc->status & E1000_RXD_STAT_EOP)) {
-
-			/* All receives must fit into a single buffer */
-
-			E1000_DBG("Receive packet consumed multiple buffers\n");
-
-			dev_kfree_skb_irq(skb);
-			rx_desc->status = 0;
-			rx_ring->buffer_info[i].skb = NULL;
-
-			i = (i + 1) % rx_ring->count;
-
-			rx_desc = E1000_RX_DESC(*rx_ring, i);
-			continue;
-		}
 
-		if(rx_desc->errors & E1000_RXD_ERR_FRAME_ERR_MASK) {
-
-			last_byte = *(skb->data + length - 1);
-
-			if(TBI_ACCEPT(&adapter->hw, rx_desc->status,
-			              rx_desc->errors, length, last_byte)) {
-
-				spin_lock_irqsave(&adapter->stats_lock, flags);
-
-				e1000_tbi_adjust_stats(&adapter->hw,
-				                       &adapter->stats,
-				                       length, skb->data);
-
-				spin_unlock_irqrestore(&adapter->stats_lock,
-				                       flags);
-				length--;
-			} else {
-
-				dev_kfree_skb_irq(skb);
-				rx_desc->status = 0;
-				rx_ring->buffer_info[i].skb = NULL;
-
-				i = (i + 1) % rx_ring->count;
-
-				rx_desc = E1000_RX_DESC(*rx_ring, i);
-				continue;
-			}
-		}
-
-		/* Good Receive */
-		skb_put(skb, length - ETHERNET_FCS_SIZE);
-
-		/* Receive Checksum Offload */
-		e1000_rx_checksum(adapter, rx_desc, skb);
-
-		skb->protocol = eth_type_trans(skb, netdev);
-		if(adapter->vlgrp && (rx_desc->status & E1000_RXD_STAT_VP)) {
-			vlan_hwaccel_rx(skb, adapter->vlgrp,
-				(rx_desc->special & E1000_RXD_SPC_VLAN_MASK));
-		} else {
-			netif_receive_skb(skb);
-		}
-		netdev->last_rx = jiffies;
-
-		rx_desc->status = 0;
-		rx_ring->buffer_info[i].skb = NULL;
-
-		i = (i + 1) % rx_ring->count;
-
-		rx_desc = E1000_RX_DESC(*rx_ring, i);
-		received++;
-	}
-
-	if(!received)
-		received = 1;
-
-	e1000_alloc_rx_buffers(adapter);
-	
-	rx_ring->next_to_clean = i;
-	netdev->quota -= received;
-	*budget -= received;
-
-	netif_rx_complete(netdev);
-
-	e1000_irq_enable(adapter);
-	return 0;
-
-not_done:
-
-	e1000_alloc_rx_buffers(adapter);
-	
-	rx_ring->next_to_clean = i;
-	netdev->quota -= received;
-	*budget -= received;
-
-	return 1;
+	return cleaned;
 }
-#else
+
 /**
  * e1000_clean_rx_irq - Send received data up the network stack,
  * @adapter: board private structure
  **/
 
-static void
+static boolean_t
 e1000_clean_rx_irq(struct e1000_adapter *adapter)
 {
 	struct e1000_desc_ring *rx_ring = &adapter->rx_ring;
@@ -2174,13 +2006,15 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter)
 	unsigned long flags;
 	uint32_t length;
 	uint8_t last_byte;
-	int i;
+	int i, cleaned = FALSE;
 
 	i = rx_ring->next_to_clean;
 	rx_desc = E1000_RX_DESC(*rx_ring, i);
 
 	while(rx_desc->status & E1000_RXD_STAT_DD) {
 
+		cleaned = TRUE;
+
 		pci_unmap_single(pdev,
 		                 rx_ring->buffer_info[i].dma,
 		                 rx_ring->buffer_info[i].length,
@@ -2260,8 +2094,9 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter)
 	rx_ring->next_to_clean = i;
 
 	e1000_alloc_rx_buffers(adapter);
+
+	return cleaned;
 }
-#endif
 
 /**
  * e1000_alloc_rx_buffers - Replace used receive buffers