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arm64: mm: Drop redundant check in pmd_trans_huge()

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pmd_val(pmd) is redundant because a positive pmd_present(pmd) ensures
a positive pmd_val(pmd) according to their definitions like below.

  #define pmd_val(x)       ((x).pmd)
  #define pmd_present(pmd) pte_present(pmd_pte(pmd))
  #define pte_present(pte) (pte_valid(pte) || pte_present_invalid(pte))
  #define pte_valid(pte)   (!!(pte_val(pte) & PTE_VALID))
  #define pte_present_invalid(pte) \
          ((pte_val(pte) & (PTE_VALID | PTE_PRESENT_INVALID)) == PTE_PRESENT_INVALID)

pte_present() can't be positive unless either of the flag PTE_VALID or
PTE_PRESENT_INVALID is set. In this case, pmd_val(pmd) should be positive
either.

So lets drop the redundant check pmd_val(pmd) and no functional changes
intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250508085251.204282-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Gavin Shan 2025-05-08 18:52:51 +10:00 committed by Will Deacon
parent 1ef3095b14
commit 13c63ce358
1 changed files with 1 additions and 2 deletions
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3
arch/arm64/include/asm/pgtable.h
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@ -837,8 +837,7 @@ 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 */