CONFIG_OF_RESERVED_MEM (not configurable)

modulename: of_reserved_mem.ko

configname: CONFIG_OF_RESERVED_MEM

Linux Kernel Configuration
└─>Device Drivers
└─>Device Tree and Open Firmware support
└─>OF_RESERVED_MEM
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Helpers to allow for reservation of memory regions

source code: