On Fri, Mar 18, 2022 at 10:59:10AM +0100, David Hildenbrand wrote: > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index b1e1b74d993c..fd6ddf14c190 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -14,6 +14,7 @@ > * Software defined PTE bits definition. > */ > #define PTE_WRITE (PTE_DBM) /* same as DBM (51) */ > +#define PTE_SWP_EXCLUSIVE (PTE_TABLE_BIT) /* only for swp ptes */ > #define PTE_DIRTY (_AT(pteval_t, 1) << 55) > #define PTE_SPECIAL (_AT(pteval_t, 1) << 56) > #define PTE_DEVMAP (_AT(pteval_t, 1) << 57) > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 94e147e5456c..c78994073cd0 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -402,6 +402,22 @@ static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot) > return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT); > } > > +#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE > +static inline pte_t pte_swp_mkexclusive(pte_t pte) > +{ > + return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE)); > +} > + > +static inline int pte_swp_exclusive(pte_t pte) > +{ > + return pte_val(pte) & PTE_SWP_EXCLUSIVE; > +} > + > +static inline pte_t pte_swp_clear_exclusive(pte_t pte) > +{ > + return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE)); > +} > + > #ifdef CONFIG_NUMA_BALANCING > /* > * See the comment in include/linux/pgtable.h > @@ -908,7 +924,8 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, > > /* > * Encode and decode a swap entry: > - * bits 0-1: present (must be zero) > + * bits 0: present (must be zero) > + * bits 1: remember PG_anon_exclusive It looks fine to me. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>