netxen: cache msi register offset

Store msi target status register offset in adapter struct.
This avoids contention on msi_tgt_status table from interrupt
hadlers of different pci function.
Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/netxen/netxen_nic.h

@@ -1257,6 +1257,9 @@ struct netxen_adapter {
 	u32 irq;
 	u32 temp;
 
+	u32 msi_tgt_status;
+	u32 resv4;
+
 	struct netxen_adapter_stats stats;
 
 	struct netxen_recv_context recv_ctx;

drivers/net/netxen/netxen_nic_main.c

@@ -525,6 +525,8 @@ netxen_setup_intr(struct netxen_adapter *adapter)
 request_msi:
 		if (use_msi && !pci_enable_msi(pdev)) {
 			adapter->flags |= NETXEN_NIC_MSI_ENABLED;
+			adapter->msi_tgt_status =
+				msi_tgt_status[adapter->ahw.pci_func];
 			dev_info(&pdev->dev, "using msi interrupts\n");
 		} else
 			dev_info(&pdev->dev, "using legacy interrupts\n");
@@ -1701,7 +1703,7 @@ static irqreturn_t netxen_msi_intr(int irq, void *data)
 
 	/* clear interrupt */
 	adapter->pci_write_immediate(adapter,
-			msi_tgt_status[adapter->ahw.pci_func], 0xffffffff);
+			adapter->msi_tgt_status, 0xffffffff);
 
 	napi_schedule(&sds_ring->napi);
 	return IRQ_HANDLED;