ACPI: pci_root: pass acpi_pci_root to arch-specific scan

The acpi_pci_root structure contains all the individual items (acpi_device,
domain, bus number) we pass to pci_acpi_scan_root(), so just pass the
single acpi_pci_root pointer directly.

This will make it easier to add _CBA support later.  For _CBA, we need the
entire downstream bus range, not just the base bus number.  We have that in
the acpi_pci_root structure, so passing the pointer makes it available to
the arch-specific code.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/ia64/pci/pci.c

@@ -335,8 +335,11 @@ pcibios_setup_root_windows(struct pci_bus *bus, struct pci_controller *ctrl)
 }
 
 struct pci_bus * __devinit
-pci_acpi_scan_root(struct acpi_device *device, int domain, int bus)
+pci_acpi_scan_root(struct acpi_pci_root *root)
 {
+	struct acpi_device *device = root->device;
+	int domain = root->segment;
+	int bus = root->secondary.start;
 	struct pci_controller *controller;
 	unsigned int windows = 0;
 	struct pci_bus *pbus;

arch/x86/pci/acpi.c

@@ -229,8 +229,11 @@ get_current_resources(struct acpi_device *device, int busnum,
 	return;
 }
 
-struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int domain, int busnum)
+struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 {
+	struct acpi_device *device = root->device;
+	int domain = root->segment;
+	int busnum = root->secondary.start;
 	struct pci_bus *bus;
 	struct pci_sysdata *sd;
 	int node;

drivers/acpi/pci_root.c

@@ -498,7 +498,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 * PCI namespace does not get created until this call is made (and 
 	 * thus the root bridge's pci_dev does not exist).
 	 */
-	root->bus = pci_acpi_scan_root(device, segment, root->secondary.start);
+	root->bus = pci_acpi_scan_root(root);
 	if (!root->bus) {
 		printk(KERN_ERR PREFIX
 			    "Bus %04x:%02x not present in PCI namespace\n",

include/acpi/acpi_drivers.h

@@ -104,8 +104,7 @@ int acpi_pci_bind_root(struct acpi_device *device);
 
 /* Arch-defined function to add a bus to the system */
 
-struct pci_bus *pci_acpi_scan_root(struct acpi_device *device, int domain,
-				   int bus);
+struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root);
 void pci_acpi_crs_quirks(void);
 
 /* --------------------------------------------------------------------------