Re: [PATCH V5 02/10] perf/amd/iommu: Consolidate and move perf_event_amd_iommu header

[Suravee Suthikulpanit]

Hi

On 03/15/2016 05:53 PM, Peter Zijlstra wrote:
> On Tue, Mar 15, 2016 at 11:40:17AM +0100, Borislav Petkov wrote:
> > On Tue, Mar 15, 2016 at 07:39:31AM +0700, Suravee Suthikulpanit wrote:
> > > What if I just merge the newly introduced arch/x86/include/perf/amd/iommu.h
> > > into the include/linux/amd-iommu.h? I do not see the point of having to
> > > separate things out into two files.
> >
> > Except that this header has x86-specific stuff and include/linux/ is
> > arch-agnostic.
>
> Which would suggest that header is placed wrong, because I would expect
> the amd-iommu to really be rather x86 specific. Or is AMD making ARM
> parts for which this is useful too?

Actually the exposed APIs (in both files) are from the AMD IOMMU driver, 
which is not necessary x86-specific. They mostly use struct pci_dev, 
which is also arch-agnostic. It is correct that the current IOMMU IP is 
only available in x86 systems. However, if AMD plans to use the IOMMU IP 
in the ARM-based processors in the future, putting these into 
include/linux/amd-iommu.h would work better.

Thanks,
Suravee