[coreboot] pci resource allocation overlaps config_mmconf_base_address

Myles Watson mylesgw at gmail.com
Mon Oct 18 17:43:55 CEST 2010

On Mon, Oct 18, 2010 at 6:48 AM, Arne Georg Gleditsch
<arne.gleditsch at numascale.com> wrote:
> Rudolf Marek <r.marek at assembler.cz> writes:
>> Please can you help here? Also I tried to have a look how the non-posted support
>> could be added but it looks like it must be done somewhat inside the resource
>> allocator. Please can you help with that too? Basically we would need to put
>> some MMIO resources which have non-posted attribute set in resource (this must
>> be done) to be allocated somewhat together so only one MMIO resource would be
>> needed (and we need to modify the northbridge.c of K8 to set the non-posted bit)
> On a similar note: I'm looking at a southbridge that has its own notion
> of what constitutes TOP_OF_DRAM.  Apparently, the IOMMU aperture needs
> to be below this boundary, or DMA transactions towards the aperture are
> terminated with master abort.  From the CPU's side, though, the IOMMU
> aperture should be above TOP_OF_MEM, in order to avoid wasting the DRAM
> behind it, no?  So, as well as being able to allocate posted and
> non-posted memory resources in separate hunks: in this instance it would
> be good to be able to allocate the GART aperture in a third hunk that
> was placed below the other two, so that the SB TOM register could be
> programmed to include it when needed.
> Is this feasible, or should I approach this from a different angle?

It sounds like overkill to include this as a special case for the
resource allocator.  At first glance, the code would seem to be very
simple for that register.  Is this a one-time, one-resource problem?
Are there other hunks that need to be allocated together with it?


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