Function is_hhdm_range_mapped_now 

pub fn is_hhdm_range_mapped_now(phys_base: u64, size: u64) -> bool

Returns whether the current page tables map the HHDM view of the whole range.

This helper is safe before paging::init() and is intended for early boot allocators that must only touch memory already reachable through the current firmware-provided direct map.