How to handle SCU at runtime on Cortex-A9

[Altera_Forum]

Hi there, 

I'm working on altera cyclone V SoC equipped with a Dual Core Cortex-A9. It runs Linux socfpga 3.13. I'm trying to disable (and enable) the SCU at runtime, but I have a segmantation fault: unable to handle kernel paging requet at virtual address FFFEF1000. I think that the conversion from virtual to physical address deny me to access a the SCU Control Register. Obviously, I cannot disable the MMU because I cannot flush caches. Can anyone help me? How can I proceed?  Thanks in advance. MI