Re: [PATCH] powerpc/64s: Rewrite __real_pte() as a static inline

[Christophe Leroy]

Le 11/01/2025 à 18:03, Ritesh Harjani a écrit :
> Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
>
> > Rewrite __real_pte() as a static inline in order to avoid
> > following warning/error when building with 4k page size:
> >
> > 	  CC      arch/powerpc/mm/book3s64/hash_tlb.o
> > 	arch/powerpc/mm/book3s64/hash_tlb.c: In function 'hpte_need_flush':
> > 	arch/powerpc/mm/book3s64/hash_tlb.c:49:16: error: variable 'offset' set but not used [-Werror=unused-but-set-variable]
> > 	   49 |         int i, offset;
> > 	      |                ^~~~~~
> > 	cc1: all warnings being treated as errors
> >
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > Closes: https://lore.kernel.org/oe-kbuild-all/202501081741.AYFwybsq-lkp@xxxxxxxxx/
>
> Great. Why not fix the other warning as well which is reported in above
> link, which is...

Just because .... I overlooked the report and missed the second error.

Sent v2 with both fixes now.


> --
>     arch/powerpc/mm/book3s64/hash_native.c: In function 'native_flush_hash_range':
> > > arch/powerpc/mm/book3s64/hash_native.c:786:29: warning: variable 'index' set but not used [-Wunused-but-set-variable]
>       786 |         unsigned long hash, index, hidx, shift, slot;
> --
>
> ...similar to how we fixed this warning by making the macro as static
> inline? That means something like this (not tested)?
>
> -#define __rpte_to_hidx(r,index)        (pte_val(__rpte_to_pte(r)) >> H_PAGE_F_GIX_SHIFT)
> +static inline unsigned long __rpte_to_hidx(real_pte_t r, unsigned long index)
> +{
> +       return pte_val(__rpte_to_pte(r)) >> H_PAGE_F_GIX_SHIFT;
> +}
>
>
> -ritesh
>
>
> > Fixes: ff31e105464d ("powerpc/mm/hash64: Store the slot information at the right offset for hugetlb")
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > ---
> >   arch/powerpc/include/asm/book3s/64/hash-4k.h | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
> > index c3efacab4b94..a7a68ba9c71b 100644
> > --- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
> > +++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
> > @@ -77,7 +77,10 @@
> >   /*
> >    * With 4K page size the real_pte machinery is all nops.
> >    */
> > -#define __real_pte(e, p, o)		((real_pte_t){(e)})
> > +static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep, int offset)
> > +{
> > +	return (real_pte_t){pte};
> > +}
> >   #define __rpte_to_pte(r)	((r).pte)
> >   #define __rpte_to_hidx(r,index)	(pte_val(__rpte_to_pte(r)) >> H_PAGE_F_GIX_SHIFT)
> >   
> > --
> > 2.47.0