diff options
| author | Gavin Shan <gshan@redhat.com> | 2025-05-08 11:52:51 +0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2025-05-16 17:10:13 +0300 |
| commit | 13c63ce358832e01575d3b186210966e17f9ff68 (patch) | |
| tree | ddb45d1a13b65a6ccec6c1f80d69b2b2510d5ce9 | |
| parent | 1ef3095b14057c6898468e90184bd0942977fbad (diff) | |
| download | linux-13c63ce358832e01575d3b186210966e17f9ff68.tar.xz | |
arm64: mm: Drop redundant check in pmd_trans_huge()
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>
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 43457940a388..8c6d7e7fbe82 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -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 */ |