[PATCH v3 3/3] PCI: ARM: add support for generic PCI host controller

On Tue, Feb 18, 2014 at 07:32:33PM +0000, Arnd Bergmann wrote:

On Tuesday 18 February 2014 19:09:29 Will Deacon wrote:

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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