Re: [PATCH 1/3] powerpc/nohash: remove hash related code from nohash headers.

[Christophe LEROY]

Le 04/05/2018 Ã 13:17, Michael Ellerman a ÃcritÂ:
> kbuild test robot <lkp@xxxxxxxxx> writes:
>
> > Hi Christophe,
> >
> > Thank you for the patch! Yet something to improve:
> >
> > [auto build test ERROR on powerpc/next]
> > [also build test ERROR on v4.17-rc2 next-20180426]
> > [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> >
> > url:    https://github.com/0day-ci/linux/commits/Christophe-Leroy/powerpc-nohash-remove-hash-related-code-from-nohash-headers/20180425-182026
> > base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
> > config: powerpc-ppc64e_defconfig (attached as .config)
> > compiler: powerpc64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
> > reproduce:
> >          wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >          chmod +x ~/bin/make.cross
> >          # save the attached .config to linux build tree
> >          make.cross ARCH=powerpc
> >
> > All errors (new ones prefixed by >>):
> >
> >     In file included from arch/powerpc/include/asm/nohash/pgtable.h:6:0,
> >                      from arch/powerpc/include/asm/pgtable.h:19,
> >                      from include/linux/memremap.h:8,
> >                      from include/linux/mm.h:27,
> >                      from include/linux/mman.h:5,
> >                      from arch/powerpc/kernel/asm-offsets.c:22:
> >     arch/powerpc/include/asm/nohash/64/pgtable.h: In function '__ptep_test_and_clear_young':
> > > > arch/powerpc/include/asm/nohash/64/pgtable.h:214:6: error: implicit declaration of function 'pte_young'; did you mean 'pte_pud'? [-Werror=implicit-function-declaration]
> >       if (pte_young(*ptep))
> >           ^~~~~~~~~
> >           pte_pud
>
> Urk.
>
> There's a circular dependency here.
>
> I fixed it with the patch below, which seems to be the least worst
> solution. Possibly we can clean things up further in future.

Oops, I just sent you a new version of the patch not using pte_young() 
anymore. I'll let you decide what to do.

Christophe

> cheers
>
> diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h
> index 140f8e74b478..987a658b18e1 100644
> --- a/arch/powerpc/include/asm/nohash/32/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h
> @@ -267,6 +267,11 @@ static inline void __ptep_set_access_flags(struct mm_struct *mm,
>   	pte_update(ptep, clr, set);
>   }
>   
> +static inline int pte_young(pte_t pte)
> +{
> +	return pte_val(pte) & _PAGE_ACCESSED;
> +}
> +
>   #define __HAVE_ARCH_PTE_SAME
>   #define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
>   
> diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
> index e8de7cb4d3fb..6ac8381f4c7a 100644
> --- a/arch/powerpc/include/asm/nohash/64/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
> @@ -204,6 +204,11 @@ static inline unsigned long pte_update(struct mm_struct *mm,
>   	return old;
>   }
>   
> +static inline int pte_young(pte_t pte)
> +{
> +	return pte_val(pte) & _PAGE_ACCESSED;
> +}
> +
>   static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
>   					      unsigned long addr, pte_t *ptep)
>   {
> diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
> index 077472640b35..2160be2e4339 100644
> --- a/arch/powerpc/include/asm/nohash/pgtable.h
> +++ b/arch/powerpc/include/asm/nohash/pgtable.h
> @@ -17,7 +17,6 @@ static inline int pte_write(pte_t pte)
>   }
>   static inline int pte_read(pte_t pte)		{ return 1; }
>   static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
> -static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
>   static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
>   static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
>   static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }