Re: [Xen-devel] [PATCH v2 2/4] xen/arm: Add GSER region to ThunderX platform mapping

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Tue, 2015-03-17 at 18:32 +0530, Vijay Kilari wrote:
> Hi Ian,
> 
> On Thu, Mar 5, 2015 at 10:40 PM, Ian Campbell <ian.campbell@xxxxxxxxxx> wrote:
> > On Thu, 2015-03-05 at 16:46 +0000, Ian Campbell wrote:
> >> On Wed, 2015-03-04 at 11:36 +0530, vijay.kilari@xxxxxxxxx wrote:
> >> > From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxxxxxxxxxx>
> >> >
> >> > Add GSER region to thunderx platfrom specific mappings.
> >> > This region is not mentioned in DT. This is required by
> >> > PCI driver to detect and configure pci devices attached.
> >> >
> >> > In future we can remove this mapping, if pci driver
> >> > in Dom does not require this.
> >>
> >> How do we know what the PCI driver in dom0 needs? I don't think we can,
> >> so we can in effect never remove this specific mapping, which is a
> >> shame.
> >>
> >> Unless you have some scheme in mind which would allow us to do so?
> >>
> >> IMHO by far the best solution would be to add this device to the DTB so
> >> that it is correctly mapped. I'm not quite sure what that will look like
> >> since thne mainline DTB doesn't have the PCI node at all.
> >
> > Looking at a more recent DTB which I have access to it seems like
> > 0x87e090000000 is correctly covered by a ranges entry on the PCI
> > controller node.
> 
> Where did you find recent DTB?.  AFAIK, this region does not fall
> under any pci controller range.

It was in the tree you guys sent me a little while back.
ThunderX_Release_v0.3.tar.gz IIRC.

thunder-88xx-2n.dtsi in that contains a PCI node "pcie0:
pcie0@0x8480,00000000" with ranges containing this entry:
                         <0x03000000 0x87e0 0x00000000 0x87e0 0x00000000 0x01 
0x00000000>,

Which covers the range from 0x87e000000000 to 0xe7f00000000, i.e.
covering this region at 0x87e090000000.

> > So I think all which is needed is a) to use this updated DTB and b) my
> > series "xen: arm: Parse PCI DT nodes' ranges and interrupt-map" from
> > last October which, as it happens, I've been working on bringing up to
> > date yesterday and today (one more thing to clean up before I repost).
> 
> Because it is not covered under any PCI ranges, your patch series
> still does not help.
> Infact, this is common region for SERDES configuration so cannot bind
> to any particular pci controller range.

Even if that turns out to be the case then surely this regions needs to
be defined somehow in the DT else how could it be discovered.

Ian.


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