[PATCH v4 2/7] mm: Implement for_each_valid_pfn() for CONFIG_FLATMEM

David Hildenbrand david at redhat.com
Thu Apr 24 14:13:17 PDT 2025


On 23.04.25 15:33, David Woodhouse wrote:
> From: David Woodhouse <dwmw at amazon.co.uk>
> 
> In the FLATMEM case, the default pfn_valid() just checks that the PFN is
> within the range [ ARCH_PFN_OFFSET .. ARCH_PFN_OFFSET + max_mapnr ).
> 
> The for_each_valid_pfn() function can therefore be a simple for() loop
> using those as min/max respectively.
> 
> Signed-off-by: David Woodhouse <dwmw at amazon.co.uk>
> Reviewed-by: Mike Rapoport (Microsoft) <rppt at kernel.org>
> ---
>   include/asm-generic/memory_model.h | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h
> index a3b5029aebbd..74d0077cc5fa 100644
> --- a/include/asm-generic/memory_model.h
> +++ b/include/asm-generic/memory_model.h
> @@ -30,7 +30,15 @@ static inline int pfn_valid(unsigned long pfn)
>   	return pfn >= pfn_offset && (pfn - pfn_offset) < max_mapnr;
>   }
>   #define pfn_valid pfn_valid
> -#endif
> +
> +#ifndef for_each_valid_pfn
> +#define for_each_valid_pfn(pfn, start_pfn, end_pfn)			 \
> +	for ((pfn) = max_t(unsigned long, (start_pfn), ARCH_PFN_OFFSET); \
> +	     (pfn) < min_t(unsigned long, (end_pfn),			 \
> +			   ARCH_PFN_OFFSET + max_mapnr);		 \
> +	     (pfn)++)
> +#endif /* for_each_valid_pfn */
> +#endif /* valid_pfn */

"pfn_valid"

>   
>   #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
>   

Acked-by: David Hildenbrand <david at redhat.com>

-- 
Cheers,

David / dhildenb




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