Query on directly accessing physical memory from a kernel module

[Arjun]

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