Re: [PATCH v9 06/10] mm/vmalloc: extract vmap_set_ptes() to consolidate PTE mapping logic

[Uladzislau Rezki]

On Wed, Sep 23, 2026 at 02:28:28PM +0800, Wen Jiang wrote:
> Extract the common PTE mapping logic from vmap_pte_range() into a
> shared helper vmap_set_ptes(). This handles both CONT_PTE and regular
> PTE mappings in a single function, preparing for the next patch which
> will extend vmap_pages_pte_range() to also use this helper.
> 
> No functional change.
> 
> Signed-off-by: Wen Jiang <jiangwen6@xxxxxxxxxx>
> Tested-by: Xueyuan Chen <xueyuan.chen21@xxxxxxxxx>
> Tested-by: Leo Yan <leo.yan@xxxxxxx>
> ---
>  mm/vmalloc.c | 36 +++++++++++++++++++++++++++---------
>  1 file changed, 27 insertions(+), 9 deletions(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index fb757d95bde25..d475e52110e4a 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -92,6 +92,29 @@ struct vfree_deferred {
>  static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
>  
>  /*** Page table manipulation functions ***/
> +
> +/*
> + * Try contiguous mappings at the PTE level for arches which support them, and if
> + * requested by the caller. Fall back to PAGE_SIZE mappings otherwise.
> + *
> + * Return: mapping size.
> + */
> +static __always_inline unsigned long vmap_set_ptes(pte_t *ptep,
> +		unsigned long addr, unsigned long end, u64 pfn,
> +		pgprot_t prot, unsigned int max_page_shift)
> +{
> +	unsigned long size;
> +
> +	size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
> +	if (size != PAGE_SIZE) {
> +		pte_set_huge(ptep, addr, PFN_PHYS(pfn), prot, size);
> +		return size;
> +	}
> +
> +	set_pte_at(&init_mm, addr, ptep, pfn_pte(pfn, prot));
> +	return PAGE_SIZE;
> +}
> +
>  static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
>  			phys_addr_t phys_addr, pgprot_t prot,
>  			unsigned int max_page_shift, pgtbl_mod_mask *mask)
> @@ -100,6 +123,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
>  	u64 pfn;
>  	struct page *page;
>  	unsigned long size;
> +	unsigned int steps;
>  
>  	if (WARN_ON_ONCE(!PAGE_ALIGNED(end - addr)))
>  		return -EINVAL;
> @@ -120,15 +144,9 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
>  			BUG();
>  		}
>  
> -		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
> -		if (size != PAGE_SIZE) {
> -			pte_set_huge(pte, addr, PFN_PHYS(pfn), prot, size);
> -			pfn += PFN_DOWN(size);
> -			continue;
> -		}
> -		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
> -		pfn++;
> -	} while (pte += PFN_DOWN(size), addr += size, addr != end);
> +		size = vmap_set_ptes(pte, addr, end, pfn, prot, max_page_shift);
> +		steps = PFN_DOWN(size);
> +	} while (pte += steps, pfn += steps, addr += size, addr != end);
>
#define PFN_DOWN(x)	((x) >> PAGE_SHIFT) - how many pages covers the size.
Replace steps by nr_pages or nr_ptes?

--
Uladzislau Rezki