PCI Hotplug: acpiphp: get pci_bus from acpi handle correctly

We cannot simply call acpi_get_pci_dev() on any random ACPI handle
and hope that it works, because a PCI root bridge may not have
an associated struct pci_dev.

This is allowed per the PCI specification, and is referred to as a
non-materialized bridge.

So, depending on the type of PCI bridge that the handle points to,
use the appropriate interface to return the struct pci_bus correctly.

Reviewed-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 17 insertions, 11 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 0cb0f830a993..2e5f25969e11 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -62,6 +62,22 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus);
 static void acpiphp_set_hpp_values(acpi_handle handle, struct pci_bus *bus);
 static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);
 
+static struct pci_bus *pci_bus_from_handle(acpi_handle handle)
+{
+        struct pci_bus *pbus;
+        struct acpi_pci_root *root;
+
+        root = acpi_pci_find_root(handle);
+        if (root)
+                pbus = root->bus;
+        else {
+                struct pci_dev *pdev = acpi_get_pci_dev(handle);
+                pbus = pdev->subordinate;
+                pci_dev_put(pdev);
+        }
+        return pbus;
+}
+
 /* callback routine to check for the existence of a pci dock device */
 static acpi_status
 is_pci_dock_device(acpi_handle handle, u32 lvl, void *context, void **rv)
@@ -1387,16 +1403,7 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus)
 /* Program resources in newly inserted bridge */
 static int acpiphp_configure_bridge (acpi_handle handle)
 {
-        struct pci_dev *dev;
-        struct pci_bus *bus;
-
-        dev = acpi_get_pci_dev(handle);
-        if (!dev) {
-                err("cannot get PCI domain and bus number for bridge\n");
-                return -EINVAL;
-        }
-
-        bus = dev->bus;
+        struct pci_bus *bus = pci_bus_from_handle(handle);
 
         pci_bus_size_bridges(bus);
         pci_bus_assign_resources(bus);
@@ -1404,7 +1411,6 @@ static int acpiphp_configure_bridge (acpi_handle handle)
         acpiphp_set_hpp_values(handle, bus);
         pci_enable_bridges(bus);
         acpiphp_configure_ioapics(handle);
-        pci_dev_put(dev);
         return 0;
 }