Re: [PATCH 08/19] mm: Always define pxx_pgprot()

Peter Xu
2024-08-14T15:43:16Z

On Wed, Aug 14, 2024 at 10:09:15AM -0300, Jason Gunthorpe wrote:
> On Fri, Aug 09, 2024 at 12:08:58PM -0400, Peter Xu wrote:
> > There're:
> >
> > - 8 archs (arc, arm64, include, mips, powerpc, s390, sh, x86) that
> > support pte_pgprot().
> >
> > - 2 archs (x86, sparc) that support pmd_pgprot().
> >
> > - 1 arch (x86) that support pud_pgprot().
> >
> > Always define them to be used in generic code, and then we don't need to
> > fiddle with "#ifdef"s when doing so.
> >
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> > arch/arm64/include/asm/pgtable.h | 1 +
> > arch/powerpc/include/asm/pgtable.h | 1 +
> > arch/s390/include/asm/pgtable.h | 1 +
> > arch/sparc/include/asm/pgtable_64.h | 1 +
> > include/linux/pgtable.h | 12 ++++++++++++
> > 5 files changed, 16 insertions(+)
>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
>
> > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> > index 7a4f5604be3f..b78cc4a6758b 100644
> > --- a/arch/arm64/include/asm/pgtable.h
> > +++ b/arch/arm64/include/asm/pgtable.h
> > @@ -384,6 +384,7 @@ static inline void __sync_cache_and_tags(pte_t pte, unsigned int nr_pages)
> > /*
> > * Select all bits except the pfn
> > */
> > +#define pte_pgprot pte_pgprot
> > static inline pgprot_t pte_pgprot(pte_t pte)
> > {
> > unsigned long pfn = pte_pfn(pte);
>
> Stylistically I've been putting the #defines after the function body,
> I wonder if there is a common pattern..

Right, I see both happening in tree right now and I don't know which is
better. Personally I preferred "before function" as it makes spell checks
easy to match macro/func names, and also cscope indexes both macro and
func, so a jump to any of them would make me look at the entry of func.

I'll keep it as-is for now just to make it easy for me.. but please comment
if we do have a preferred pattern the other way round, then I'll follow.

Thanks,

--
Peter Xu