Query on directly accessing physical memory from a kernel module

[Arjun <cse.syslab@xxxxxxxxx>]

Hi, 

I need help with understanding how physical memory can be accessed from within a kernel module :
Arch is AMD x86_64 , kernel is 2.6.22

Suppose
in a kernel module (or any other kernel code) I wanted to read a byte
from a random address anywhere within the entire physical memory region
(lets say 2 GB of physical memory). How could I do this ?

Do I need to access the page frame lists or can I directly access physical memory using a pointer ?

Thanks
ARN