netxen: improve msi support

Recent netxen firmware has new scheme of generating MSI interrupts, it
raises interrupt and blocks itself, waiting for driver to unmask. This
reduces chance of spurious interrupts.

The driver will be able to deal with older firmware as well.

Signed-off-by: Dhananjay Phadke <dhananjay@netxen.com>
Tested-by: Vernon Mauery <mauery@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/netxen/netxen_nic_main.c b/drivers/net/netxen/netxen_nic_main.c
index 9737eae..cd665da 100644
--- a/drivers/net/netxen/netxen_nic_main.c
+++ b/drivers/net/netxen/netxen_nic_main.c
@@ -149,33 +149,31 @@
 
 #define	ADAPTER_LIST_SIZE 12
 
+static uint32_t msi_tgt_status[4] = {
+	ISR_INT_TARGET_STATUS, ISR_INT_TARGET_STATUS_F1,
+	ISR_INT_TARGET_STATUS_F2, ISR_INT_TARGET_STATUS_F3
+};
+
+static uint32_t sw_int_mask[4] = {
+	CRB_SW_INT_MASK_0, CRB_SW_INT_MASK_1,
+	CRB_SW_INT_MASK_2, CRB_SW_INT_MASK_3
+};
+
 static void netxen_nic_disable_int(struct netxen_adapter *adapter)
 {
-	uint32_t	mask = 0x7ff;
+	u32 mask = 0x7ff;
 	int retries = 32;
+	int port = adapter->portnum;
+	int pci_fn = adapter->ahw.pci_func;
 
-	DPRINTK(1, INFO, "Entered ISR Disable \n");
-
-	switch (adapter->portnum) {
-	case 0:
-		writel(0x0, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_0));
-		break;
-	case 1:
-		writel(0x0, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_1));
-		break;
-	case 2:
-		writel(0x0, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_2));
-		break;
-	case 3:
-		writel(0x0, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_3));
-		break;
+	if (adapter->msi_mode != MSI_MODE_MULTIFUNC) {
+		writel(0x0, NETXEN_CRB_NORMALIZE(adapter, sw_int_mask[port]));
 	}
 
 	if (adapter->intr_scheme != -1 &&
 	    adapter->intr_scheme != INTR_SCHEME_PERPORT)
 		writel(mask,PCI_OFFSET_SECOND_RANGE(adapter, ISR_INT_MASK));
 
-	/* Window = 0 or 1 */
 	if (!(adapter->flags & NETXEN_NIC_MSI_ENABLED)) {
 		do {
 			writel(0xffffffff,
@@ -190,14 +188,18 @@
 			printk(KERN_NOTICE "%s: Failed to disable interrupt completely\n",
 					netxen_nic_driver_name);
 		}
+	} else {
+		if (adapter->msi_mode == MSI_MODE_MULTIFUNC) {
+			writel(0xffffffff, PCI_OFFSET_SECOND_RANGE(adapter,
+						msi_tgt_status[pci_fn]));
+		}
 	}
-
-	DPRINTK(1, INFO, "Done with Disable Int\n");
 }
 
 static void netxen_nic_enable_int(struct netxen_adapter *adapter)
 {
 	u32 mask;
+	int port = adapter->portnum;
 
 	DPRINTK(1, INFO, "Entered ISR Enable \n");
 
@@ -218,20 +220,7 @@
 		writel(mask, PCI_OFFSET_SECOND_RANGE(adapter, ISR_INT_MASK));
 	}
 
-	switch (adapter->portnum) {
-	case 0:
-		writel(0x1, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_0));
-		break;
-	case 1:
-		writel(0x1, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_1));
-		break;
-	case 2:
-		writel(0x1, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_2));
-		break;
-	case 3:
-		writel(0x1, NETXEN_CRB_NORMALIZE(adapter, CRB_SW_INT_MASK_3));
-		break;
-	}
+	writel(0x1, NETXEN_CRB_NORMALIZE(adapter, sw_int_mask[port]));
 
 	if (!(adapter->flags & NETXEN_NIC_MSI_ENABLED)) {
 		mask = 0xbff;
@@ -401,6 +390,7 @@
 
 	/* this will be read from FW later */
 	adapter->intr_scheme = -1;
+	adapter->msi_mode = -1;
 
 	/* This will be reset for mezz cards  */
 	adapter->portnum = pci_func_id;