From 425cc087fbaf267be7683b95481b46a058d63e49 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Mon, 17 Nov 2025 21:19:27 -0700 Subject: [PATCH] riscv: mm: ptep_get_and_clear(): avoid atomic ops when !CONFIG_SMP When !CONFIG_SMP, there's no need for atomic operations in ptep_get_and_clear(), so, similar to x86, let's not use atomics in this case. Cc: Alexandre Ghiti Signed-off-by: Paul Walmsley --- arch/riscv/include/asm/pgtable.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 1df8a6adb407e..ebab8ecd78b20 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -660,7 +660,13 @@ extern int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long a static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long address, pte_t *ptep) { +#ifdef CONFIG_SMP pte_t pte = __pte(atomic_long_xchg((atomic_long_t *)ptep, 0)); +#else + pte_t pte = *ptep; + + set_pte(ptep, __pte(0)); +#endif page_table_check_pte_clear(mm, pte); -- 2.47.3