CONFIG_CRC64 (not configurable)

modulename: crc64.ko

configname: CONFIG_CRC64

Linux Kernel Configuration
└─>Library routines
└─>CRC64
In linux kernel since version 3.10 (release Date: 2013-06-30)  
The CRC64 library functions. Select this if your module uses any of
the functions from <linux/crc64.h>.

source code:
lib/crc64.c