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charset=UTF-8 Content-Transfer-Encoding: 7bit X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 3/2/26 05:34, Anshuman Khandual wrote: > > > On 28/02/26 4:47 PM, Mike Rapoport wrote: >> Hi Anshuman, >> >> On Tue, Feb 24, 2026 at 10:41:46AM +0530, Anshuman Khandual wrote: >>> Define arm64 platform specific implementations for new pXdp_get() helpers. >>> These resolve into READ_ONCE(), thus ensuring required single copy atomic >>> semantics for the page table entry reads. >>> >>> In future this infrastructure can be used for D128 to maintain single copy >>> atomicity semantics with inline asm blocks. >>> >>> Cc: Catalin Marinas >>> Cc: Will Deacon >>> Cc: Ryan Roberts >>> Cc: Mark Rutland >>> Cc: linux-arm-kernel@lists.infradead.org >>> Cc: linux-kernel@vger.kernel.org >>> Signed-off-by: Anshuman Khandual >>> --- >>> arch/arm64/include/asm/pgtable.h | 28 +++++++++++++++++++++++++++- >>> 1 file changed, 27 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >>> index 257af1c3015d..804ef49aea88 100644 >>> --- a/arch/arm64/include/asm/pgtable.h >>> +++ b/arch/arm64/include/asm/pgtable.h >>> @@ -84,6 +84,32 @@ static inline void arch_leave_lazy_mmu_mode(void) >>> arch_flush_lazy_mmu_mode(); >>> } >>> >>> +#define ptdesc_get(x) READ_ONCE(x) >> >> This will be confusing with 'struct ptdesc' APIs, maybe ptent_get()? > > Created 'ptdesc_t' earlier on arm64 platform as an unified data type, which could > represent page table entries including their protection fields and masks for any > level. > > typedef u64 ptdesc_t; > > typedef ptdesc_t pteval_t; > typedef ptdesc_t pmdval_t; > typedef ptdesc_t pudval_t; > typedef ptdesc_t p4dval_t; > typedef ptdesc_t pgdval_t; > > But now it conflicts with generic 'struct ptdesc'. Agreed that overall renaming is > required. Probably ptent_t along with ptent_get/set() could be an option. But that > is probably orthogonal to the series and can be done later in a separate patch. We often refer to *ptep as ptent. Can we find something that does not contain "pte" to avoid confusion with pteval_t ? We often refer to the set of functions as "pXX" or "pxx". pxxval_t would certainly be an option, but it would be the first "official" such occurrence. -- Cheers, David