i40e: Ioremap changes

For future device support we do not want to map the whole CSR space since some
of it is mapped by other drivers with different mapping methods.

Note: As a side effect, the flash region (if exposed through the memory map)
gets unmapped too since it follows the future use region.

Change-ID: Ic729a2eacd692984220b1a415ff4fa0f98ea419a
Signed-off-by: NAnjali Singhai Jain <anjali.singhai@intel.com>
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: NJim Young <james.m.young@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -72,6 +72,7 @@
 
 #define I40E_MAX_NUM_DESCRIPTORS      4096
 #define I40E_MAX_REGISTER     0x800000
+#define I40E_MAX_CSR_SPACE (4 * 1024 * 1024 - 64 * 1024)
 #define I40E_DEFAULT_NUM_DESCRIPTORS  512
 #define I40E_REQ_DESCRIPTOR_MULTIPLE  32
 #define I40E_MIN_NUM_DESCRIPTORS      64

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -9459,6 +9459,7 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct i40e_pf *pf;
 	struct i40e_hw *hw;
 	static u16 pfs_found;
+	u32 ioremap_len;
 	u16 link_status;
 	int err = 0;
 	u32 len;
@@ -9507,8 +9508,11 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	hw = &pf->hw;
 	hw->back = pf;
-	hw->hw_addr = ioremap(pci_resource_start(pdev, 0),
-			      pci_resource_len(pdev, 0));
+
+	ioremap_len = min_t(int, pci_resource_len(pdev, 0),
+			    I40E_MAX_CSR_SPACE);
+
+	hw->hw_addr = ioremap(pci_resource_start(pdev, 0), ioremap_len);
 	if (!hw->hw_addr) {
 		err = -EIO;
 		dev_info(&pdev->dev, "ioremap(0x%04x, 0x%04x) failed: 0x%x\n",