PCI: add pci_create_root_bus() that accepts resource list

pci_create_bus() assigns ioport_resource and iomem_resource as the default
bus resources, i.e., the entire address space.  Architectures fix these
later, typically in pcibios_fixup_bus() or after pci_scan_bus_parented()
returns, but code that runs in the interim sees incorrect resource
information.

This patch adds a new pci_create_root_bus() that sets the bus resources
correctly from a supplied list of resources.

I intend to remove pci_create_bus() after changing all callers.

Based on original patch by Deng-Cheng Zhu.

Reference: http://www.spinics.net/lists/mips/msg41654.html
Reference: https://lkml.org/lkml/2011/8/26/88
Signed-off-by: Deng-Cheng Zhu <dczhu@mips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9daa79901122..eacb1e51e11b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -670,6 +670,9 @@ static inline struct pci_bus * __devinit pci_scan_bus(int bus, struct pci_ops *o
                 pci_bus_add_devices(root_bus);
         return root_bus;
 }
+struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
+                                    struct pci_ops *ops, void *sysdata,
+                                    struct list_head *resources);
 struct pci_bus *pci_create_bus(struct device *parent, int bus,
                                struct pci_ops *ops, void *sysdata);
 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,