ACPI: optimize pci_rootbridge search

acpi_get_pci_rootbridge_handle() walks the ACPI name space
searching for seg, bus and the PCI_ROOT_HID_STRING --
returning the handle as soon as if find the match.

But the current codes always parses through the whole namespace because
the user_function find_pci_rootbridge() returns status=AE_OK when it finds the match.

Make the find_pci_rootbridge() return AE_CTRL_TERMINATE when it finds the match.
This reduces the ACPI namespace walk for acpi_get_pci_rootbridge_handle().

Signed-off-by: Justin Chen <justin.chen@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index 10f160dc75b1..ba8fe83c6298 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -189,8 +189,12 @@ find_pci_rootbridge(acpi_handle handle, u32 lvl, void *context, void **rv)
         bus = tmp;
 
         if (seg == find->seg && bus == find->bus)
+        {
                 find->handle = handle;
-        status = AE_OK;
+                status = AE_CTRL_TERMINATE;
+        }
+        else
+                status = AE_OK;
       exit:
         kfree(buffer.pointer);
         return status;