Re: [rfc] hw resource debugging checks

[Arjan van de Ven]

On Sun, 13 Apr 2008 12:29:30 -0700
"Yinghai Lu" <yhlu.kernel@xxxxxxxxx> wrote:

> On Sun, Apr 13, 2008 at 11:29 AM, Andi Kleen <andi@xxxxxxxxxxxxxx>
> wrote:
> > > even I could talk to BIOS
> >  > engineers everyday and tell them how to fix the problem in
> >  > BIOS,  some still can not be fixed because of the legacy BIOS
> >  > framework or big mess.
> >
> >  ... so you opt to create the big mess in the kernel. Great.
> >
> >  And it does not even fixes a real problem, but getting
> >  mmconfig or the numa bus discovery to work is not really a too
> > serious issue anyways. At best it is the icing on the cake to enable
> >  some relatively obscure functionality and be a little more
> >  efficient, but nothing really fundamental.
> >
> >  But for those things just expecting a working modern BIOS is quite
> >  reasonable.
> 
> it does fix real problem. when big system with several HT links, and
> every link some pcie slots.
> you fully load pci-e cards (with pci bridge). BIOS will stop assign
> io/mmio resource to left device if it run out of io port range.
> (though it is supposed to go on to allocate mmio to left devices) (
> modern pcie device only need mmio with drivers)
> 
> With pre set range allocation in NB pci conf, kernel could allocate
> the resource in every peer root bus ranges.
> (the code for assign resource to device that is not assigned resource
> by BIOS --- already in kernel)
> 

there is a really big difference between assigning PCI device resources
and doing a whole thing like MMCFG from scratch.

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