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

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@kernel.org>
Signed-off-by: Muhammad Usama Anjum <redacted>
---
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@nvidia.com>

Best Regards,
Yan, Zi