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, 23 insertions, 9 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3a30023a123c..3f07cb6bae32 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1562,12 +1562,15 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
                 struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {
-        int error, i;
+        int error;
         struct pci_host_bridge *bridge;
         struct pci_bus *b, *b2;
         struct device *dev;
-        struct pci_bus_resource *bus_res, *n;
+        struct pci_host_bridge_window *window, *n;
         struct resource *res;
+        resource_size_t offset;
+        char bus_addr[64];
+        char *fmt;
 
         bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
         if (!bridge)
@@ -1617,19 +1620,30 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
         b->number = b->secondary = bus;
 
         bridge->bus = b;
-
-        /* Add initial resources to the bus */
-        list_for_each_entry_safe(bus_res, n, resources, list)
-                list_move_tail(&bus_res->list, &b->resources);
+        INIT_LIST_HEAD(&bridge->windows);
 
         if (parent)
                 dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
         else
                 printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev));
 
-        pci_bus_for_each_resource(b, res, i) {
-                if (res)
-                        dev_info(&b->dev, "root bus resource %pR\n", res);
+        /* Add initial resources to the bus */
+        list_for_each_entry_safe(window, n, resources, list) {
+                list_move_tail(&window->list, &bridge->windows);
+                res = window->res;
+                offset = window->offset;
+                pci_bus_add_resource(b, res, 0);
+                if (offset) {
+                        if (resource_type(res) == IORESOURCE_IO)
+                                fmt = " (bus address [%#06llx-%#06llx])";
+                        else
+                                fmt = " (bus address [%#010llx-%#010llx])";
+                        snprintf(bus_addr, sizeof(bus_addr), fmt,
+                                 (unsigned long long) (res->start - offset),
+                                 (unsigned long long) (res->end - offset));
+                } else
+                        bus_addr[0] = '\0';
+                dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr);
         }
 
         down_write(&pci_bus_sem);