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>

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)
 {

drivers/pci/hotplug/acpi_pcihp.c

@@ -354,7 +354,7 @@ acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus,
 		status = acpi_run_hpp(handle, hpp);
 		if (ACPI_SUCCESS(status))
 			break;
-		if (acpi_root_bridge(handle))
+		if (acpi_is_root_bridge(handle))
 			break;
 		status = acpi_get_parent(handle, &phandle);
 		if (ACPI_FAILURE(status))
@@ -428,7 +428,7 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
 		status = acpi_run_oshp(handle);
 		if (ACPI_SUCCESS(status))
 			goto got_one;
-		if (acpi_root_bridge(handle))
+		if (acpi_is_root_bridge(handle))
 			break;
 		chandle = handle;
 		status = acpi_get_parent(chandle, &handle);
@@ -449,42 +449,6 @@ int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev, u32 flags)
 }
 EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware);
 
-/* acpi_root_bridge - check to see if this acpi object is a root bridge
- *
- * @handle - the acpi object in question.
- */
-int acpi_root_bridge(acpi_handle handle)
-{
-	acpi_status status;
-	struct acpi_device_info *info;
-	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
-	int i;
-
-	status = acpi_get_object_info(handle, &buffer);
-	if (ACPI_SUCCESS(status)) {
-		info = buffer.pointer;
-		if ((info->valid & ACPI_VALID_HID) &&
-			!strcmp(PCI_ROOT_HID_STRING,
-					info->hardware_id.value)) {
-			kfree(buffer.pointer);
-			return 1;
-		}
-		if (info->valid & ACPI_VALID_CID) {
-			for (i=0; i < info->compatibility_id.count; i++) {
-				if (!strcmp(PCI_ROOT_HID_STRING,
-					info->compatibility_id.id[i].value)) {
-					kfree(buffer.pointer);
-					return 1;
-				}
-			}
-		}
-		kfree(buffer.pointer);
-	}
-	return 0;
-}
-EXPORT_SYMBOL_GPL(acpi_root_bridge);
-
-
 static int is_ejectable(acpi_handle handle)
 {
 	acpi_status status;

drivers/pci/hotplug/acpiphp_glue.c

@@ -1631,7 +1631,7 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
 {
 	int *count = (int *)context;
 
-	if (acpi_root_bridge(handle)) {
+	if (acpi_is_root_bridge(handle)) {
 		acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 				handle_hotplug_event_bridge, NULL);
 			(*count)++;

include/acpi/acpi_bus.h

@@ -369,6 +369,7 @@ struct device *acpi_get_physical_pci_device(acpi_handle);
 
 /* helper */
 acpi_handle acpi_get_child(acpi_handle, acpi_integer);
+int acpi_is_root_bridge(acpi_handle);
 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int, unsigned int);
 #define DEVICE_ACPI_HANDLE(dev) ((acpi_handle)((dev)->archdata.acpi_handle))
 

include/linux/pci_hotplug.h

@@ -226,7 +226,6 @@ struct hotplug_params {
 extern acpi_status acpi_get_hp_params_from_firmware(struct pci_bus *bus,
 				struct hotplug_params *hpp);
 int acpi_get_hp_hw_control_from_firmware(struct pci_dev *dev, u32 flags);
-int acpi_root_bridge(acpi_handle handle);
 int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle);
 int acpi_pci_detect_ejectable(struct pci_bus *pbus);
 #endif