ACPI: Introduce acpi_is_root_bridge()

[firefly-linux-kernel-4.4.55.git] / drivers / acpi / pci_root.c

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ca8dba3b40b95ef3237e81b5292fcfb7f08eb395..888cb9f5c5fbf563354af0f89a75da6af8f0202c 100644 (file)
--- 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)
 {