Re: [PATCH 3/3] mm: move follow_phys to arch/x86/mm/pat/memtype.c

[David Hildenbrand <david@redhat.com>]

On 25.03.24 00:45, Christoph Hellwig wrote:
> follow_phys is only used by two allers in arch/x86/mm/pat/memtype.c.
> Move it there and hardcode the two arguments that get the same values
> passed by both caller.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   arch/x86/mm/pat/memtype.c | 22 ++++++++++++++++++++--
>   include/linux/mm.h        |  2 --
>   mm/memory.c               | 28 ----------------------------
>   3 files changed, 20 insertions(+), 32 deletions(-)
> 
> diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
> index 0d72183b5dd028..bad99eb5c95b0d 100644
> --- a/arch/x86/mm/pat/memtype.c
> +++ b/arch/x86/mm/pat/memtype.c
> @@ -947,6 +947,24 @@ static void free_pfn_range(u64 paddr, unsigned long size)
>   		memtype_free(paddr, paddr + size);
>   }
>   
> +static int follow_phys(struct vm_area_struct *vma, unsigned long *prot,
> +		resource_size_t *phys)
> +{
> +	pte_t *ptep, pte;
> +	spinlock_t *ptl;
> +
> +	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
> +		return -EINVAL;
> +
> +	if (follow_pte(vma->vm_mm, vma->vm_start, &ptep, &ptl))
> +		return -EINVAL;

I have a patch here that (a) makes follow_pte() consume a VMA instead of 
a MM, and (b) moves the VMA check into follow_pte().

While you're at it, and if you're resending this, you might want to 
include similar changes; otherwise I'll can send this myself later on top.

-- 
Cheers,

David / dhildenb