ARM/PCI: 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 ARM bios32 code to pci_scan_root_bus_bridge() to improve the PCI
root bus scanning interface.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[bhelgaas: fold in warning fix from Arnd Bergmann <arnd@arndb.de>:
http://lkml.kernel.org/r/20170621215323.3921382-1-arnd@arndb.de]
[bhelgaas: set bridge->ops for mv78xx0]
[bhelgaas: fold in fixes from Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>:
http://lkml.kernel.org/r/20170701135457.GB8977@red-moon]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Andrew Lunn <andrew@lunn.ch>

1 files changed, 25 insertions, 14 deletions

diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index b259956365a0..4c7621ac389c 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -458,10 +458,14 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 	int nr, busnr;
 
 	for (nr = busnr = 0; nr < hw->nr_controllers; nr++) {
-		sys = kzalloc(sizeof(struct pci_sys_data), GFP_KERNEL);
-		if (WARN(!sys, "PCI: unable to allocate sys data!"))
+		struct pci_host_bridge *bridge;
+
+		bridge = pci_alloc_host_bridge(sizeof(struct pci_sys_data));
+		if (WARN(!bridge, "PCI: unable to allocate bridge!"))
 			break;
 
+		sys = pci_host_bridge_priv(bridge);
+
 		sys->busnr   = busnr;
 		sys->swizzle = hw->swizzle;
 		sys->map_irq = hw->map_irq;
@@ -473,7 +477,6 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 		ret = hw->setup(nr, sys);
 
 		if (ret > 0) {
-			struct pci_host_bridge *host_bridge;
 
 			ret = pcibios_init_resource(nr, sys, hw->io_optional);
 			if (ret)  {
@@ -482,25 +485,33 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 			}
 
 			if (hw->scan)
-				sys->bus = hw->scan(nr, sys);
-			else
-				sys->bus = pci_scan_root_bus_msi(parent,
-					sys->busnr, hw->ops, sys,
-					&sys->resources, hw->msi_ctrl);
+				ret = hw->scan(nr, bridge);
+			else {
+				list_splice_init(&sys->resources,
+						 &bridge->windows);
+				bridge->dev.parent = parent;
+				bridge->sysdata = sys;
+				bridge->busnr = sys->busnr;
+				bridge->ops = hw->ops;
+				bridge->msi = hw->msi_ctrl;
+				bridge->align_resource =
+						hw->align_resource;
+
+				ret = pci_scan_root_bus_bridge(bridge);
+			}
 
-			if (WARN(!sys->bus, "PCI: unable to scan bus!")) {
-				kfree(sys);
+			if (WARN(ret < 0, "PCI: unable to scan bus!")) {
+				pci_free_host_bridge(bridge);
 				break;
 			}
 
+			sys->bus = bridge->bus;
+
 			busnr = sys->bus->busn_res.end + 1;
 
 			list_add(&sys->node, head);
-
-			host_bridge = pci_find_host_bridge(sys->bus);
-			host_bridge->align_resource = hw->align_resource;
 		} else {
-			kfree(sys);
+			pci_free_host_bridge(bridge);
 			if (ret < 0)
 				break;
 		}