Subject: Re: Finding Kernel VA that maps given physical address?
To: None <tech-kern@NetBSD.ORG,>
From: Wolfgang Solfrank <>
List: tech-kern
Date: 07/21/1997 17:42:26
> I've figured out how to find the physical address given a kernel VA using
> pmap_extract().  But I haven't found the equivalent mechanism to do the
> reverse translation.  I realize that, in a general case, there might be
> _several_ (or even _many_) kernel VAs that map to the same physical
> address, but I'm pretty sure that that won;t happen in the specific case I
> need to handle.  So it would be just peachy if there were a way to find
> _any_ kernel virtual address that maps to a given physical address.

What makes you think that a given physical address _does_ have a virtual
address in the kernel address space?

Why don't you map the physical address into the kernel address space yourself
where you need it, remembering the virtual address in some driver data
structure in case you don't want to drop the mapping again immediately?
ws@TooLs.DE     (Wolfgang Solfrank, TooLs GmbH) 	+49-228-985800