CONFIG_GENERIC_EARLY_IOREMAP (not configurable)

modulename: early_ioremap.ko

configname: CONFIG_GENERIC_EARLY_IOREMAP

Linux Kernel Configuration
└─>Memory Management options
└─>GENERIC_EARLY_IOREMAP
In linux kernel since version 3.15 (release Date: 2014-06-08)  
source code:
mm/early_ioremap.c