Re: [PATCH v3 6/9] mm: add hw_pte_val for HW PTE storage

[David Hildenbrand (Arm)]

On 9/22/26 19:12, Muhammad Usama Anjum wrote:
> Atomic PTE updates need an lvalue for the bits stored in an HW PTE.
> pte_val() only accepts a SW PTE value, so it cannot operate directly on
> a distinct hw_pte_t.
> 
> Add hw_pte_val() to expose the underlying pte_val() lvalue. Access the
> wrapper's __pte member when hw_pte_t is distinct, and use pte_val()
> directly when it remains an alias of pte_t.
> 
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
> ---
> Changes in v3:
> - Moved from the arm64 series to generic series as it makes more sense
>   to add this in generic with all other changes. Usually we only add
>   code where its get used. But this whole series wouldn't get used
>   until an arch started using HW PTEs.
> ---
>  include/linux/pgtable_types.h | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/include/linux/pgtable_types.h b/include/linux/pgtable_types.h
> index d6c5a7548550b..ee4eace5c3e1c 100644
> --- a/include/linux/pgtable_types.h
> +++ b/include/linux/pgtable_types.h
> @@ -9,9 +9,13 @@
>  #ifdef CONFIG_ARCH_HAS_HW_PTE_T
>  typedef struct __hw_pte_t { pte_t __pte; } hw_pte_t;
>  #define __pte_from_hw(pte)	((pte).__pte)
> +
> +#define hw_pte_val(x)  pte_val((x).__pte)
>  #else
>  #define hw_pte_t pte_t
>  #define __pte_from_hw(pte)	(pte)
> +
> +#define hw_pte_val(x)  pte_val(x)
>  #endif

I was just about to say: this series doesn't add any users. You should add that
detail to the patch description: "prepare for usage in arch code" or sth like that.

With that

Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>

-- 
Cheers,

David