Commit 425cc087 authored by Paul Walmsley's avatar Paul Walmsley
Browse files

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 <alex@ghiti.fr>
Signed-off-by: default avatarPaul Walmsley <pjw@kernel.org>
parent 1e6084d5

arch/riscv/include/asm/pgtable.h

+6 −0
Original line number Diff line number Diff line
@@ -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);