cdx: Create symbol namespaces for cdx subsystem

Create CDX_BUS and CDX_BUS_CONTROLLER symbol namespace for cdx bus
subsystem. CDX controller modules are required to import symbols from
CDX_BUS_CONTROLLER namespace and other than controller modules to
import from CDX_BUS namespace.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/20231017160505.10640-4-abhijit.gangurde@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: abhijitG-xlnx

drivers/cdx/Makefile

@@ -5,4 +5,6 @@
 # Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
 #
 
+ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=CDX_BUS
+
 obj-$(CONFIG_CDX_BUS) += cdx.o controller/

drivers/cdx/cdx.c

@@ -530,7 +530,7 @@ int cdx_device_add(struct cdx_dev_params *dev_params)
 
 	return ret;
 }
-EXPORT_SYMBOL_GPL(cdx_device_add);
+EXPORT_SYMBOL_NS_GPL(cdx_device_add, CDX_BUS_CONTROLLER);
 
 int cdx_register_controller(struct cdx_controller *cdx)
 {
@@ -555,7 +555,7 @@ int cdx_register_controller(struct cdx_controller *cdx)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(cdx_register_controller);
+EXPORT_SYMBOL_NS_GPL(cdx_register_controller, CDX_BUS_CONTROLLER);
 
 void cdx_unregister_controller(struct cdx_controller *cdx)
 {
@@ -570,7 +570,7 @@ void cdx_unregister_controller(struct cdx_controller *cdx)
 
 	mutex_unlock(&cdx_controller_lock);
 }
-EXPORT_SYMBOL_GPL(cdx_unregister_controller);
+EXPORT_SYMBOL_NS_GPL(cdx_unregister_controller, CDX_BUS_CONTROLLER);
 
 static int __init cdx_bus_init(void)
 {

drivers/cdx/controller/cdx_controller.c

@@ -229,3 +229,4 @@ module_exit(cdx_controller_exit);
 MODULE_AUTHOR("AMD Inc.");
 MODULE_DESCRIPTION("CDX controller for AMD devices");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(CDX_BUS_CONTROLLER);

drivers/vfio/cdx/main.c

@@ -231,3 +231,4 @@ module_driver(vfio_cdx_driver, cdx_driver_register, cdx_driver_unregister);
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("VFIO for CDX devices - User Level meta-driver");
+MODULE_IMPORT_NS(CDX_BUS);