[PATCH RFC 1/2] pgtable: add pte_clrhuge() implementation for arm64 and riscv
From: Yin Tirui <hidden>
Date: 2025-09-23 13:37:28
Also in:
linux-mm, linux-riscv, lkml
Subsystem:
arm64 port (aarch64 architecture), risc-v architecture, the rest · Maintainers:
Catalin Marinas, Will Deacon, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
Add pte_clrhuge() helper function for architectures that enable ARCH_SUPPORTS_HUGE_PFNMAP to clear huge page attributes from PTE entries. This function provides the inverse operation of pte_mkhuge() and will be needed for upcoming huge page splitting, where PTE entries derived from huge page mappings need to have their huge page attributes cleared. Signed-off-by: Yin Tirui <redacted> --- arch/arm64/include/asm/pgtable.h | 8 ++++++++ arch/riscv/include/asm/pgtable.h | 5 +++++ 2 files changed, 13 insertions(+)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index abd2dee416b3..244755bad46f 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h@@ -366,6 +366,14 @@ static inline pte_t pte_mkinvalid(pte_t pte) return pte; } +static inline pte_t pte_clrhuge(pte_t pte) +{ + pteval_t mask = PTE_TYPE_MASK & ~PTE_VALID; + pteval_t val = PTE_TYPE_PAGE & ~PTE_VALID; + + return __pte((pte_val(pte) & ~mask) | val); +} + static inline pmd_t pmd_mkcont(pmd_t pmd) { return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 91697fbf1f90..125b241e6d2c 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h@@ -455,6 +455,11 @@ static inline pte_t pte_mkhuge(pte_t pte) return pte; } +static inline pte_t pte_clrhuge(pte_t pte) +{ + return pte; +} + #ifdef CONFIG_RISCV_ISA_SVNAPOT #define pte_leaf_size(pte) (pte_napot(pte) ? \ napot_cont_size(napot_cont_order(pte)) :\
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2.43.0