linux-kernel - [PATCH] arm64: mm: Drop duplicate check in pmd_trans

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Message-ID: <20250508035142.189726-1-gshan@redhat.com>
Date: Thu,  8 May 2025 13:51:42 +1000
From: Gavin Shan <gshan@...hat.com>
To: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org,
	catalin.marinas@....com,
	will@...nel.org,
	anshuman.khandual@....com,
	ryan.roberts@....com,
	gshan@...hat.com,
	peterx@...hat.com,
	joey.gouly@....com,
	yangyicong@...ilicon.com,
	shan.gavin@...il.com
Subject: [PATCH] arm64: mm: Drop duplicate check in pmd_trans_huge()

pmd_val(pmd) is inclusive to pmd_present(pmd) since the PMD entry
value isn't zero when pmd_present() returns true. Just drop the
duplicate check done by pmd_val(pmd).

No functional changes intended.

Signed-off-by: Gavin Shan <gshan@...hat.com>
---
Found this by code inspection
---
 arch/arm64/include/asm/pgtable.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index d3b538be1500..2599b9b8666f 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -739,8 +739,7 @@ static inline int pmd_trans_huge(pmd_t pmd)
 	 * If pmd is present-invalid, pmd_table() won't detect it
 	 * as a table, so force the valid bit for the comparison.
 	 */
-	return pmd_val(pmd) && pmd_present(pmd) &&
-	       !pmd_table(__pmd(pmd_val(pmd) | PTE_VALID));
+	return pmd_present(pmd) && !pmd_table(__pmd(pmd_val(pmd) | PTE_VALID));
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
-- 
2.49.0