[PATCH v3 3/3] PCI: ARM: add support for generic PCI host controller
Will Deacon
will.deacon at arm.com
Tue Feb 18 14:36:54 EST 2014
On Tue, Feb 18, 2014 at 07:32:33PM +0000, Arnd Bergmann wrote:
> On Tuesday 18 February 2014 19:09:29 Will Deacon wrote:
> >
> > > Regarding the 0x6200.. There are two conflicting issues there
> > > - You really don't want to let the PCI core assign resources to that
> > > range, it probably won't work.
> >
> > Right, with kvmtool we don't support resource assignment (the BARs are fixed)
> > so everything is PCI_PROBE_ONLY.
>
> Ok, I looked at the source now and can confirm:
>
> * 0x0-0x1000 are used for lots of legacy ISA devices.
> * PCI devices get assigned IO addresses in 0x400 steps starting at 0x6200.
> * There are three PCI drivers doing this: VESA, PCI-SHMEM and virtio-pci.
>
> Regarding the PCI_PROBE_ONLY flag, how do you set that? Should we
> have a standard DT property for that? On PowerPC we already specified
> "linux,pci-probe-only" and "linux,pci-assign-all-buses", which seems
> reasonable to use in architecture independent code as well.
For arch/arm/ it's done on the command line (pci=firmware) but yes, for the
generic driver it sounds like a good idea to put this in the device-tree.
I'll look at adding the ppc properties in the next version.
Cheers,
Will
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