qlcnic: fix register access

For certain set of register, base window addresses are not defined.
In such cases window should not set.
Return with error for such cases to avoid NMI.
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/qlcnic/qlcnic_hw.c

@@ -766,7 +766,7 @@ qlcnic_pci_get_crb_addr_2M(struct qlcnic_adapter *adapter,
  * Out: 'off' is 2M pci map addr
  * side effect: lock crb window
  */
-static void
+static int
 qlcnic_pci_set_crbwindow_2M(struct qlcnic_adapter *adapter, ulong off)
 {
 	u32 window;
@@ -775,6 +775,10 @@ qlcnic_pci_set_crbwindow_2M(struct qlcnic_adapter *adapter, ulong off)
 	off -= QLCNIC_PCI_CRBSPACE;
 
 	window = CRB_HI(off);
+	if (window == 0) {
+		dev_err(&adapter->pdev->dev, "Invalid offset 0x%lx\n", off);
+		return -EIO;
+	}
 
 	writel(window, addr);
 	if (readl(addr) != window) {
@@ -782,7 +786,9 @@ qlcnic_pci_set_crbwindow_2M(struct qlcnic_adapter *adapter, ulong off)
 			dev_warn(&adapter->pdev->dev,
 				"failed to set CRB window to %d off 0x%lx\n",
 				window, off);
+		return -EIO;
 	}
+	return 0;
 }
 
 int
@@ -803,11 +809,12 @@ qlcnic_hw_write_wx_2M(struct qlcnic_adapter *adapter, ulong off, u32 data)
 		/* indirect access */
 		write_lock_irqsave(&adapter->ahw.crb_lock, flags);
 		crb_win_lock(adapter);
-		qlcnic_pci_set_crbwindow_2M(adapter, off);
-		writel(data, addr);
+		rv = qlcnic_pci_set_crbwindow_2M(adapter, off);
+		if (!rv)
+			writel(data, addr);
 		crb_win_unlock(adapter);
 		write_unlock_irqrestore(&adapter->ahw.crb_lock, flags);
-		return 0;
+		return rv;
 	}
 
 	dev_err(&adapter->pdev->dev,
@@ -821,7 +828,7 @@ qlcnic_hw_read_wx_2M(struct qlcnic_adapter *adapter, ulong off)
 {
 	unsigned long flags;
 	int rv;
-	u32 data;
+	u32 data = -1;
 	void __iomem *addr = NULL;
 
 	rv = qlcnic_pci_get_crb_addr_2M(adapter, off, &addr);
@@ -833,8 +840,8 @@ qlcnic_hw_read_wx_2M(struct qlcnic_adapter *adapter, ulong off)
 		/* indirect access */
 		write_lock_irqsave(&adapter->ahw.crb_lock, flags);
 		crb_win_lock(adapter);
-		qlcnic_pci_set_crbwindow_2M(adapter, off);
-		data = readl(addr);
+		if (!qlcnic_pci_set_crbwindow_2M(adapter, off))
+			data = readl(addr);
 		crb_win_unlock(adapter);
 		write_unlock_irqrestore(&adapter->ahw.crb_lock, flags);
 		return data;