PCI: add struct pci_host_bridge_window with CPU/bus address offset

Some PCI host bridges apply an address offset, so bus addresses on PCI are
different from CPU addresses.  This patch adds a way for architectures to
tell the PCI core about this offset.  For example:

    LIST_HEAD(resources);
    pci_add_resource_offset(&resources, host->io_space, host->io_offset);
    pci_add_resource_offset(&resources, host->mem_space, host->mem_offset);
    pci_scan_root_bus(parent, bus, ops, sysdata, &resources);

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 2c946b3bbf77..419f78f96375 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -368,9 +368,16 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
         return (pdev->error_state != pci_channel_io_normal);
 }
 
+struct pci_host_bridge_window {
+        struct list_head list;
+        struct resource *res;           /* host bridge aperture (CPU address) */
+        resource_size_t offset;         /* bus address + offset = CPU address */
+};
+
 struct pci_host_bridge {
         struct list_head list;
         struct pci_bus *bus;            /* root bus */
+        struct list_head windows;       /* pci_host_bridge_windows */
 };
 
 /*
@@ -901,6 +908,8 @@ void pci_release_selected_regions(struct pci_dev *, int);
 
 /* drivers/pci/bus.c */
 void pci_add_resource(struct list_head *resources, struct resource *res);
+void pci_add_resource_offset(struct list_head *resources, struct resource *res,
+                             resource_size_t offset);
 void pci_free_resource_list(struct list_head *resources);
 void pci_bus_add_resource(struct pci_bus *bus, struct resource *res, unsigned int flags);
 struct resource *pci_bus_resource_n(const struct pci_bus *bus, int n);