HHDM_BASE

kernel_vmem::info

Constant HHDM_BASE 

Source 
pub const HHDM_BASE: u64 = 0xffff_8880_0000_0000; // 18_446_612_682_070_032_384u64
Expand description

A simple Higher Half Direct Map (HHDM) base. Anything you map at HHDM_BASE + pa lets the kernel access physical memory via a fixed offset.