diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index 24ca19a28ba7..1cd55c3686f3 100755
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -23,6 +23,10 @@
 #define VMD_MEMBAR1	2
 #define VMD_MEMBAR2	4
 
+#define VMD_RESTRICT_0_BUS_START 0
+#define VMD_RESTRICT_1_BUS_START 128
+#define VMD_RESTRICT_2_BUS_START 224
+
 #define PCI_REG_VMCAP		0x40
 #define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
 #define PCI_REG_VMCONFIG	0x44
@@ -34,6 +38,13 @@
 #define MB2_SHADOW_OFFSET	0x2000
 #define MB2_SHADOW_SIZE		16
 
+enum vmd_resource {
+	VMD_RES_CFGBAR = 0, /* VMD Bus0 Config BAR */
+	VMD_RES_MBAR_1, /* VMD Bus0 Resource MemBAR 1 */
+	VMD_RES_MBAR_2, /* VMD Bus0 Resource MemBAR 2 */
+	VMD_RES_COUNT
+};
+
 enum vmd_features {
 	/*
 	 * Device may contain registers which hint the physical location of the
@@ -132,7 +143,7 @@ struct vmd_dev {
 	struct vmd_irq_list	*irqs;
 
 	struct pci_sysdata	sysdata;
-	struct resource		resources[3];
+	struct resource		resources[VMD_RES_COUNT];
 	struct irq_domain	*irq_domain;
 	struct pci_bus		*bus;
 	u8			busn_start;
@@ -516,7 +527,7 @@ static inline void vmd_acpi_end(void) { }
 
 static void vmd_domain_reset(struct vmd_dev *vmd)
 {
-	u16 bus, max_buses = resource_size(&vmd->resources[0]);
+	u16 bus, max_buses = resource_size(&vmd->resources[VMD_RES_CFGBAR]);
 	u8 dev, functions, fn, hdr_type;
 	char __iomem *base;
 
@@ -564,8 +575,8 @@ static void vmd_domain_reset(struct vmd_dev *vmd)
 
 static void vmd_attach_resources(struct vmd_dev *vmd)
 {
-	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
-	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
+	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[VMD_RES_MBAR_1];
+	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[VMD_RES_MBAR_2];
 }
 
 static void vmd_detach_resources(struct vmd_dev *vmd)
@@ -655,13 +666,13 @@ static int vmd_get_bus_number_start(struct vmd_dev *vmd)
 
 		switch (BUS_RESTRICT_CFG(reg)) {
 		case 0:
-			vmd->busn_start = 0;
+			vmd->busn_start = VMD_RESTRICT_0_BUS_START;
 			break;
 		case 1:
-			vmd->busn_start = 128;
+			vmd->busn_start = VMD_RESTRICT_1_BUS_START;
 			break;
 		case 2:
-			vmd->busn_start = 224;
+			vmd->busn_start = VMD_RESTRICT_2_BUS_START;
 			break;
 		default:
 			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
@@ -782,7 +793,7 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
 {
 	struct resource *res = &vmd->dev->resource[VMD_CFGBAR];
 
-	vmd->resources[0] = (struct resource){
+	vmd->resources[VMD_RES_CFGBAR] = (struct resource){
 		.name = "VMD CFGBAR",
 		.start = vmd->busn_start,
 		.end = vmd->busn_start + (resource_size(res) >> 20) - 1,
@@ -801,7 +812,8 @@ static void vmd_configure_cfgbar(struct vmd_dev *vmd)
  *
  * Function fills resource buffer inside the VMD structure.
  */
-static void vmd_configure_membar(struct vmd_dev *vmd, u8 resource_number,
+static void vmd_configure_membar(struct vmd_dev *vmd,
+				 enum vmd_resource resource_number,
 				 u8 membar_number, resource_size_t start_offset,
 				 resource_size_t end_offset)
 {
@@ -837,9 +849,11 @@ static int vmd_create_bus(struct vmd_dev *vmd, struct pci_sysdata *sd,
 {
 	LIST_HEAD(resources);
 
-	pci_add_resource(&resources, &vmd->resources[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
-	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
+	pci_add_resource(&resources, &vmd->resources[VMD_RES_CFGBAR]);
+	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_1],
+				offset[0]);
+	pci_add_resource_offset(&resources, &vmd->resources[VMD_RES_MBAR_2],
+				offset[1]);
 
 	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
 				       &vmd_ops, sd, &resources);
@@ -1091,8 +1105,8 @@ static void vmd_remove(struct pci_dev *dev)
 	pci_remove_root_bus(vmd->bus);
 
 	/* CFGBAR is static, does not require releasing memory */
-	kfree(vmd->resources[1].name);
-	kfree(vmd->resources[2].name);
+	kfree(vmd->resources[VMD_RES_MBAR_1].name);
+	kfree(vmd->resources[VMD_RES_MBAR_2].name);
 
 	vmd_cleanup_srcu(vmd);
 	vmd_detach_resources(vmd);
