[PATCH v4 02/13] powerpc/mm: Move setting pte specific flags to pfn_pte

[Christophe Leroy]

Le 02/09/2020 à 13:42, Aneesh Kumar K.V a écrit :
> powerpc used to set the pte specific flags in set_pte_at(). This is
> different from other architectures. To be consistent with other
> architecture update pfn_pte to set _PAGE_PTE on ppc64. Also, drop now
> unused pte_mkpte.
> 
> We add a VM_WARN_ON() to catch the usage of calling set_pte_at()
> without setting _PAGE_PTE bit. We will remove that after a few releases.
> 
> With respect to huge pmd entries, pmd_mkhuge() takes care of adding the
> _PAGE_PTE bit.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>

Reviewed-by: Christophe Leroy <christophe.leroy at csgroup.eu>

Small nit below.

> ---
>   arch/powerpc/include/asm/book3s/64/pgtable.h | 15 +++++++++------
>   arch/powerpc/include/asm/nohash/pgtable.h    |  5 -----
>   arch/powerpc/mm/pgtable.c                    |  5 -----
>   3 files changed, 9 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 079211968987..2382fd516f6b 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -823,6 +818,14 @@ static inline int pte_none(pte_t pte)
>   static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
>   				pte_t *ptep, pte_t pte, int percpu)
>   {
> +
> +	VM_WARN_ON(!(pte_raw(pte) & cpu_to_be64(_PAGE_PTE)));
> +	/*
> +	 * Keep the _PAGE_PTE added till we are sure we handle _PAGE_PTE
> +	 * in all the callers.
> +	 */
> +	 pte = __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_PTE));

Wrong alignment, there is a leading space.

> +
>   	if (radix_enabled())
>   		return radix__set_pte_at(mm, addr, ptep, pte, percpu);
>   	return hash__set_pte_at(mm, addr, ptep, pte, percpu);

Christophe