[RFC V1 11/16] arm64/mm: Route all pgtable atomics to central helpers

[David Hildenbrand (Arm)]

On 2/24/26 06:11, Anshuman Khandual wrote:
> Route all cmpxchg() operations performed on various page table entries to a
> new ptdesc_cmpxchg_relaxed() helper. Similarly route all xchg() operations
> performed on page table entries to a new ptdesc_xchg_relaxed() helper.
> 
> Currently these helpers just forward to the same APIs that were previously
> called direct, but in future we will change the routing for D128 which is
> too long to use the standard APIs.
> 
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>
> Cc: Ryan Roberts <ryan.roberts at arm.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-kernel at vger.kernel.org
> Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
> ---
>  arch/arm64/include/asm/pgtable.h | 23 +++++++++++++++++------
>  arch/arm64/mm/fault.c            |  2 +-
>  2 files changed, 18 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index 42124d2f323d..cf69ce68f951 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -87,6 +87,17 @@ static inline void arch_leave_lazy_mmu_mode(void)
>  #define ptdesc_get(x)		READ_ONCE(x)
>  #define ptdesc_set(x, val)	WRITE_ONCE(x, val)
>  
> +static inline ptdesc_t ptdesc_cmpxchg_relaxed(ptdesc_t *ptep, ptdesc_t old,
> +					      ptdesc_t new)
> +{
> +	return cmpxchg_relaxed(ptep, old, new);
> +}
> +
> +static inline ptdesc_t ptdesc_xchg_relaxed(ptdesc_t *ptep, ptdesc_t new)
> +{
> +	return xchg_relaxed(ptep, new);
> +}
> +

We really want the rename of ptdesc_t before this change.

-- 
Cheers,

David