PFN to Base Address

["Bithika Khargharia" <bithika@xxxxxxxxx>]

Hi,

1. Given the PFN, how do I obtain the base physical address for the PFN. 

I use 
             'pfn <<12'.

Is this correct?

2. Does the kernel generate PFN serailly from 0 to TOTAL_PHYS or are there breaks in between?

Thanks
Bithika