PCI: xilinx-nwl: Convert PCI scan API to pci_scan_root_bus_bridge()

The introduction of pci_scan_root_bus_bridge() provides a PCI core API to
scan a PCI root bus backed by an already initialized struct pci_host_bridge
object, which simplifies the bus scan interface and makes the PCI scan root
bus interface easier to generalize as members are added to the struct
pci_host_bridge.

Convert PCI xilinx-nwl host code to pci_scan_root_bus_bridge() to improve
the PCI root bus scanning interface.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>

1 files changed, 18 insertions, 10 deletions

diff --git a/drivers/pci/host/pcie-xilinx-nwl.c b/drivers/pci/host/pcie-xilinx-nwl.c
index 26e66e8eebbb..e8a589431008 100644
--- a/drivers/pci/host/pcie-xilinx-nwl.c
+++ b/drivers/pci/host/pcie-xilinx-nwl.c
@@ -791,13 +791,16 @@ static int nwl_pcie_probe(struct platform_device *pdev)
         struct nwl_pcie *pcie;
         struct pci_bus *bus;
         struct pci_bus *child;
+        struct pci_host_bridge *bridge;
         int err;
         resource_size_t iobase = 0;
         LIST_HEAD(res);
 
-        pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
-        if (!pcie)
-                return -ENOMEM;
+        bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
+        if (!bridge)
+                return -ENODEV;
+
+        pcie = pci_host_bridge_priv(bridge);
 
         pcie->dev = dev;
         pcie->ecam_value = NWL_ECAM_VALUE_DEFAULT;
@@ -830,12 +833,11 @@ static int nwl_pcie_probe(struct platform_device *pdev)
                 goto error;
         }
 
-        bus = pci_create_root_bus(dev, pcie->root_busno,
-                                  &nwl_pcie_ops, pcie, &res);
-        if (!bus) {
-                err = -ENOMEM;
-                goto error;
-        }
+        list_splice_init(&res, &bridge->windows);
+        bridge->dev.parent = dev;
+        bridge->sysdata = pcie;
+        bridge->busnr = pcie->root_busno;
+        bridge->ops = &nwl_pcie_ops;
 
         if (IS_ENABLED(CONFIG_PCI_MSI)) {
                 err = nwl_pcie_enable_msi(pcie);
@@ -844,7 +846,13 @@ static int nwl_pcie_probe(struct platform_device *pdev)
                         goto error;
                 }
         }
-        pci_scan_child_bus(bus);
+
+        err = pci_scan_root_bus_bridge(bridge);
+        if (err)
+                goto error;
+
+        bus = bridge->bus;
+
         pci_assign_unassigned_bus_resources(bus);
         list_for_each_entry(child, &bus->children, node)
                 pcie_bus_configure_settings(child);