Re: [Qemu-devel] [PATCH v3 07/10] ppc/pnv: add XSCOM infrastructure

[David Gibson]

On Fri, Sep 16, 2016 at 08:11:45AM +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2016-09-15 at 14:45 +0200, Cédric Le Goater wrote:
> >  - The PCB translation is too much of a constraint for a specific
> >    XSCOM address space, unless someone can explain me how to address 8
> >    bytes at 0xb0021 and another 8 different bytes at 0xb0022. I don't
> >    think the address space and the memory regions were designed with
> >    this in mind. Please advise !
> 
> I'd say just dispatch pcb_addr << 3 to the memory regions (which is
> also the P9 translation iirc).

Yes, I think that's the way to go.

That also means on P9 you can potentially just map the scom address
space directly into address_space_memory, instead of requiring a
redispatcher to do the address mangling.

> Just add a quirk to the ADU/XSCOM dispatch object to do the additional
> unmangling needed on P7/P8
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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