Re: [PATCH v11 08/11] powerpc: mm: Add pud_pfn() stub

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Le 28/03/2024 à 05:55, Rohan McLure a écrit :
> The page table check feature requires that pud_pfn() be defined
> on each consuming architecture. Since only 64-bit, Book3S platforms
> allow for hugepages at this upper level, and since the calling code is
> gated by a call to pud_user_accessible_page(), which will return zero,
> include this stub as a BUILD_BUG().
> 
> Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
> ---
> v11: pud_pfn() stub has been removed upstream as it has valid users now
> in transparent hugepages. Create a BUG_ON() for other, non Book3S64
> platforms.
> ---
>   arch/powerpc/include/asm/pgtable.h | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
> index 239709a2f68e..ee8c82c0528f 100644
> --- a/arch/powerpc/include/asm/pgtable.h
> +++ b/arch/powerpc/include/asm/pgtable.h
> @@ -211,6 +211,14 @@ static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size)
>   
>   #endif /* CONFIG_PPC64 */
>   
> +#ifndef pud_pfn
> +#define pud_pfn pud_pfn
> +static inline int pud_pfn(pud_t pud)
> +{
> +	BUILD_BUG();

This function must return something.

> +}
> +#endif
> +
>   #endif /* __ASSEMBLY__ */
>   
>   #endif /* _ASM_POWERPC_PGTABLE_H */