flush_dcache_range equivalent in arm64

Hello everyone!

I am trying writing a module that needs to flush the data cache base on an address range, and I found dcache_clean_inval_poc calls within the  arm/include/asm/cacheflush.h, but compiling the kernel for arm64 gives me errors since this function is not exported globally. 

I do see on other archteictures implementing flush_dcache_range, such as powerpc. I am curious to see if arm64 already has a function like that and I just missed it? If not, does it need to be implemented? or Is there a reason why that it has not been implemented?