Re: [BUGFIX][PATCH] pci: check for 4k resource_size alignment insriov_init

[Ram Pai]

On Sat, Jan 28, 2012 at 12:40:32AM +0530, Vaidyanathan Srinivasan wrote:
> Hi Ram and Jesse,
> 
> I found a trivial issue with page size alignment check on IBM POWER
> box with 64k base page size.  In sriov_init(), changing the check from
> PAGE_SIZE (arch and config dependent) to HW_PAGE_SIZE (always 4k) was
> required to use one of the sriov adapter as PF since the
> resource_size() comes up as 0x8000 and PAGE_SIZE would be 0x10000 for
> pseries boxes.
> 
> I think resource_size() could be less than SystemPageSize, but I would
> like your comments/ack/nack on any consequences of checking for only
> 4k alignment here in a system with larger base page size.

As per the SRIOV specs, the  resource has to be System page size aligned.

PFs are required to support 4-KB, 8-KB, 64-KB, 256-KB, 1-MB, and 4-MB
page sizes. In your case if your adapter's PF is not supporting 64K page size
then I think it is not conforming to the PCI SRIOV spec.

RP

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