Re: [PATCH 3/6] pci, thunder: Add PCIe host controller devicetree bindings

[Sunil Kovvuri]

On Wed, Sep 24, 2014 at 9:36 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Wednesday 24 September 2014 17:37:45 Robert Richter wrote:
>>
>> +       pcie0@0x8480,00000000 {
>
> The name should be pci, not pci0.

Thanks, will change.

>
>> +               compatible = "cavium,thunder-pcie";
>> +               device_type = "pci";
>> +               msi-parent = <&its>;
>> +               bus-range = <0 255>;
>> +               #size-cells = <2>;
>> +               #address-cells = <3>;
>> +               reg = <0x8480 0x00000000 0 0x10000000>;  /* Configuration space */
>> +               ranges = <0x03000000 0x8010 0x00000000 0x8010 0x00000000 0x70 0x00000000>, /* mem ranges */
>> +                       <0x03000000 0x8300 0x00000000 0x8300 0x00000000 0x80 0x00000000>,
>> +                       <0x03000000 0x87e0 0x00000000 0x87e0 0x00000000 0x01 0x00000000>;
>> +        };
>
> If you claim the entire 0-255 bus range, I think you should also
> specify a domain, otherwise it's not predictable which domain you
> get.
>
> The interrupt-map and interrupt-map-mask properties are required for PCI,
> otherwise you can't do LSI interrupts.

This PCI controller supports only MSIx interrupts which are edge triggered.

>
> If your hardware can support it, you should also list I/O space and prefetchable
> memory spaces. Can you explain why you have multiple non-prefetchable ranges?

Our hardware is an ECAM based host controller and doesn't support I/O
and prefetchable memory spaces.
All on-board PCI devices connected to this PCI controller have fixed resources
and doesn't have to be allocated/reassigned. Some of these devices are
SRIOV based.
Kernel's SRIOV (pci/iov.c) is expecting 'resource->parent' hierarchy
to be set, otherwise doesn't
enable SRIOV device. So, here multiple non-prefetchable ranges of root bus
aid in resource claiming and setting res->parent hierarchy.

We do call "pci_claim_resource" in controller driver code.
"[PATCH 1/6] pci, thunder: Add support for Thunder PCIe host controller."

>
>         Arnd
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