Re: [PATCH v3 1/9] mm: introduce hw_pte_t for PTE table storage

[Zi Yan]

On 22 Sep 2026, at 13:12, Muhammad Usama Anjum wrote:

> pte_t is used both for software PTE values and for entries stored in a PTE
> table, so pte_t * does not distinguish a pointer to a software PTE
> value from a pointer to table storage.
>
> Introduce hw_pte_t as the generic name for a PTE table element. Define it
> as a macro alias of pte_t by default. When an architecture selects
> ARCH_HAS_HW_PTE_T, define it as a structure containing a pte_t instead.
> This preserves the representation while allowing converted architectures
> to enforce the distinction at compile time.
>
> Name the generic wrapper structure __hw_pte_t so architectures can
> forward-declare it when pgtable_t must be defined before the generic
> hw_pte_t typedef is visible. This avoids header-order dependencies.
>
> Keep the C type definitions behind an __ASSEMBLY__ check because
> architecture assembly sources can include this header indirectly. Include
> asm/page.h so consumers such as linux/vmalloc.h retain the page definitions
> they previously obtained from that header.
>
> Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
> Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
> ---
> Changes since v1:
> - Name the generic wrapper structure __hw_pte_t so architectures can
>   forward-declare it, and explain why this is required.
> - Use software PTE value terminology.
>
> Changes since RFC v1:
> - Add the ARCH_HAS_HW_PTE_T opt-in and generic wrapper definition.
> - Exclude the C type definitions from assembly sources.
> - Update the description for the new opt-in model.
> ---
>  MAINTAINERS                   |  1 +
>  include/linux/pgtable_types.h | 17 +++++++++++++++++
>  mm/Kconfig                    |  3 +++
>  3 files changed, 21 insertions(+)
>
LGTM.

Acked-by: Zi Yan <ziy@xxxxxxxxxx>

Best Regards,
Yan, Zi