On 2016-04-14 03:36, Marc Zyngier wrote:
On 14/04/16 08:20, Tomasz Nowicki wrote:
On 13.04.2016 23:18, Sinan Kaya wrote:
On 4/13/2016 11:52 AM, Marc Zyngier wrote:
Sure. Please see:
http://infocenter.arm.com/help/topic/com.arm.doc.den0049a/DEN0049A_IO_Remapping_Table.pdf
3.1.1.5 PCI root complex node
PCI Segment number -> The PCI segment number, as in MCFG and as
returned by _SEG in the namespace.
So IORT spec states that pci_segment_number corresponds to the
segment
number from MCFG table and _SEG method. Here is my patch which
makes
sure pci_domain_nr(bus) is set properly:
https://lkml.org/lkml/2016/2/16/418
Lovely. So this series is actually dependent on the PCI one. I guess
we
need to solve that one first, because IORT seems pretty pointless if
we
don't have PCI support. What's the plan?
Would it be OK to split the PCI specific section of the patch and
continue
review? PCI is a user of the IORT table. Not the other way around.
I need to disagree. What would be the use case for patches w/o "PCI
part" ?
Quite. PCI (as a subsystem) doesn't need IORT at all, thank you very
much. GIC (implementing MSI) and SMMU (implementing DMA) do, by virtue
of RID/SID/DID being translated all over the place.
So by the look of it, the dependency chain is GIC+SMMU->IORT->PCI.
The GIC changes here are pretty mechanical, and not that interesting.
The stuff that needs sorting quickly is PCI, because all this work is
pointless if we don't have it.
At the risk of sounding like a stuck record: What's the plan?
Thanks,
M.
My answer is based on the spec definition. The spec defines named
components for other peripherals that are behind iommu and can
potentially implement msi.
You could have used a basic device like platform sata to take care of
basic iort and smmu support.
You can then come back and implement PCIe support.
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