ACPI: Introduce acpi_is_root_bridge()

Returns whether an ACPI CA node is a PCI root bridge or not.

This API is generically useful, and shouldn't just be a hotplug function.

The implementation becomes much simpler as well.

Signed-off-by: Alex Chiang <achiang@hp.com>
Acked-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ca8dba3b40b9..888cb9f5c5fb 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -142,6 +142,30 @@ acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 
 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
 
+/**
+ * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge
+ * @handle - the ACPI CA node in question.
+ *
+ * Note: we could make this API take a struct acpi_device * instead, but
+ * for now, it's more convenient to operate on an acpi_handle.
+ */
+int acpi_is_root_bridge(acpi_handle handle)
+{
+        int ret;
+        struct acpi_device *device;
+
+        ret = acpi_bus_get_device(handle, &device);
+        if (ret)
+                return 0;
+
+        ret = acpi_match_device_ids(device, root_device_ids);
+        if (ret)
+                return 0;
+        else
+                return 1;
+}
+EXPORT_SYMBOL_GPL(acpi_is_root_bridge);
+
 static acpi_status
 get_root_bridge_busnr_callback(struct acpi_resource *resource, void *data)
 {