PCI: mobiveil: Use pci_is_root_bus() to check if bus is root bus

Use pci_is_root_bus() rather than tracking the root bus number to
determine if the bus is the root bus or not. This removes storing
duplicated data as well as the need for the host bridge driver to have
to care about the bus numbers in most cases.

Link: https://lore.kernel.org/r/20200722022514.1283916-7-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Karthikeyan Mitran <m.karthikeyan@mobiveil.co.in>
Cc: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/controller/mobiveil/pcie-mobiveil-host.c

@@ -29,18 +29,15 @@
 
 static bool mobiveil_pcie_valid_device(struct pci_bus *bus, unsigned int devfn)
 {
-	struct mobiveil_pcie *pcie = bus->sysdata;
-	struct mobiveil_root_port *rp = &pcie->rp;
-
 	/* Only one device down on each root port */
-	if ((bus->number == rp->root_bus_nr) && (devfn > 0))
+	if (pci_is_root_bus(bus) && (devfn > 0))
 		return false;
 
 	/*
 	 * Do not read more than one device on the bus directly
 	 * attached to RC
 	 */
-	if ((bus->primary == rp->root_bus_nr) && (PCI_SLOT(devfn) > 0))
+	if ((bus->primary == to_pci_host_bridge(bus->bridge)->busnr) && (PCI_SLOT(devfn) > 0))
 		return false;
 
 	return true;
@@ -61,7 +58,7 @@ static void __iomem *mobiveil_pcie_map_bus(struct pci_bus *bus,
 		return NULL;
 
 	/* RC config access */
-	if (bus->number == rp->root_bus_nr)
+	if (pci_is_root_bus(bus))
 		return pcie->csr_axi_slave_base + where;
 
 	/*
@@ -606,7 +603,6 @@ int mobiveil_pcie_host_probe(struct mobiveil_pcie *pcie)
 
 	/* Initialize bridge */
 	bridge->sysdata = pcie;
-	bridge->busnr = rp->root_bus_nr;
 	bridge->ops = &mobiveil_pcie_ops;
 	bridge->map_irq = of_irq_parse_and_map_pci;
 	bridge->swizzle_irq = pci_common_swizzle;

drivers/pci/controller/mobiveil/pcie-mobiveil.h

@@ -149,7 +149,6 @@ struct mobiveil_rp_ops {
 };
 
 struct mobiveil_root_port {
-	char root_bus_nr;
 	void __iomem *config_axi_slave_base;	/* endpoint config base */
 	struct resource *ob_io_res;
 	struct mobiveil_rp_ops *ops;