diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 8f08ae53f53e..9f1e4d9c008b 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1269,7 +1269,7 @@ static void imx6_pcie_quirk(struct pci_dev *dev)
 	if (bus->dev.parent->parent->driver != &imx6_pcie_driver.driver)
 		return;
 
-	if (bus->number == pp->root_bus_nr) {
+	if (pci_is_root_bus(bus)) {
 		struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 		struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci);
 
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 790679fdfa48..fcc3586c345b 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -440,7 +440,7 @@ static int ks_pcie_rd_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 
 	reg = CFG_BUS(bus->number) | CFG_DEVICE(PCI_SLOT(devfn)) |
 		CFG_FUNC(PCI_FUNC(devfn));
-	if (bus->parent->number != pp->root_bus_nr)
+	if (!pci_is_root_bus(bus->parent))
 		reg |= CFG_TYPE1;
 	ks_pcie_app_writel(ks_pcie, CFG_SETUP, reg);
 
@@ -457,7 +457,7 @@ static int ks_pcie_wr_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 
 	reg = CFG_BUS(bus->number) | CFG_DEVICE(PCI_SLOT(devfn)) |
 		CFG_FUNC(PCI_FUNC(devfn));
-	if (bus->parent->number != pp->root_bus_nr)
+	if (!pci_is_root_bus(bus->parent))
 		reg |= CFG_TYPE1;
 	ks_pcie_app_writel(ks_pcie, CFG_SETUP, reg);
 
diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 4a16306cec25..9e8a9cfc6d3a 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -473,10 +473,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 		goto err_free_msi;
 	}
 
-	pp->root_bus_nr = pp->busn->start;
-
 	bridge->sysdata = pp;
-	bridge->busnr = pp->root_bus_nr;
+	bridge->busnr = pp->busn->start;
 	bridge->ops = &dw_pcie_ops;
 	bridge->map_irq = of_irq_parse_and_map_pci;
 	bridge->swizzle_irq = pci_common_swizzle;
@@ -528,7 +526,7 @@ static int dw_pcie_access_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 	busdev = PCIE_ATU_BUS(bus->number) | PCIE_ATU_DEV(PCI_SLOT(devfn)) |
 		 PCIE_ATU_FUNC(PCI_FUNC(devfn));
 
-	if (bus->parent->number == pp->root_bus_nr) {
+	if (pci_is_root_bus(bus->parent)) {
 		type = PCIE_ATU_TYPE_CFG0;
 		cpu_addr = pp->cfg0_base;
 		cfg_size = pp->cfg0_size;
@@ -584,13 +582,11 @@ static int dw_pcie_valid_device(struct pcie_port *pp, struct pci_bus *bus,
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 
 	/* If there is no link, then there is no device */
-	if (bus->number != pp->root_bus_nr) {
+	if (!pci_is_root_bus(bus)) {
 		if (!dw_pcie_link_up(pci))
 			return 0;
-	}
-
-	/* Access only one slot on each root port */
-	if (bus->number == pp->root_bus_nr && dev > 0)
+	} else if (dev > 0)
+		/* Access only one slot on each root port */
 		return 0;
 
 	return 1;
@@ -606,7 +602,7 @@ static int dw_pcie_rd_conf(struct pci_bus *bus, u32 devfn, int where,
 		return PCIBIOS_DEVICE_NOT_FOUND;
 	}
 
-	if (bus->number == pp->root_bus_nr)
+	if (pci_is_root_bus(bus))
 		return dw_pcie_rd_own_conf(pp, where, size, val);
 
 	return dw_pcie_rd_other_conf(pp, bus, devfn, where, size, val);
@@ -620,7 +616,7 @@ static int dw_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
 	if (!dw_pcie_valid_device(pp, bus, PCI_SLOT(devfn)))
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
-	if (bus->number == pp->root_bus_nr)
+	if (pci_is_root_bus(bus))
 		return dw_pcie_wr_own_conf(pp, where, size, val);
 
 	return dw_pcie_wr_other_conf(pp, bus, devfn, where, size, val);
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 656e00f8fbeb..fd2146298b58 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -173,7 +173,6 @@ struct dw_pcie_host_ops {
 };
 
 struct pcie_port {
-	u8			root_bus_nr;
 	u64			cfg0_base;
 	void __iomem		*va_cfg0_base;
 	u32			cfg0_size;