Re: mmap and ppc460gt

[vb <vb@vsbe.com>]

On Wed, Aug 27, 2008 at 5:11 PM, Roland Dreier <rdreier@cisco.com> wrote:
>  > The problem now is that that PCI register space gets mapped with
>  > caching enabled (by looking at the TLB contents), so I still can't
>  > control the device. I did some search and indeed UIO device driver
>  > came up, I'll read the article. I was wondering  though if there is a
>  > simpler way to modify cache attributes of a region. mmap() doesn't
>  > seem to provide an interface for that, is there some other function to
>  > call to configure 'cache inhibit' attribute for a region?
>
> The issue would be related to phys_mem_access_prot() not doing the right
> thing in this case.  In fact it looks like the arch/powerpc
> page_is_ram() implementation has the same bug that I fixed a long time
> ago for arch/ppc in 8b150478 ("[PATCH] ppc: make phys_mem_access_prot()
> work with pfns instead of addresses").  I'll send a patch a little later
> that you can try out.
>

Ronald, I will appreciate the patch that very much!

TIA,
/vb


>  - R.
>