| Message ID | 20220329164329.208407-7-david@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages | expand |
On Tue, 29 Mar 2022 18:43:27 +0200 David Hildenbrand <david@redhat.com> wrote: > Let's use bit 52, which is unused. > > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > arch/s390/include/asm/pgtable.h | 23 +++++++++++++++++++++-- > 1 file changed, 21 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h > index 3982575bb586..a397b072a580 100644 > --- a/arch/s390/include/asm/pgtable.h > +++ b/arch/s390/include/asm/pgtable.h > @@ -181,6 +181,8 @@ static inline int is_module_addr(void *addr) > #define _PAGE_SOFT_DIRTY 0x000 > #endif > > +#define _PAGE_SWP_EXCLUSIVE _PAGE_LARGE /* SW pte exclusive swap bit */ > + > /* Set of bits not changed in pte_modify */ > #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_SPECIAL | _PAGE_DIRTY | \ > _PAGE_YOUNG | _PAGE_SOFT_DIRTY) > @@ -826,6 +828,22 @@ static inline int pmd_protnone(pmd_t pmd) > } > #endif > > +#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE > +static inline int pte_swp_exclusive(pte_t pte) > +{ > + return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; > +} > + > +static inline pte_t pte_swp_mkexclusive(pte_t pte) > +{ > + return set_pte_bit(pte, __pgprot(_PAGE_SWP_EXCLUSIVE)); > +} > + > +static inline pte_t pte_swp_clear_exclusive(pte_t pte) > +{ > + return clear_pte_bit(pte, __pgprot(_PAGE_SWP_EXCLUSIVE)); > +} > + > static inline int pte_soft_dirty(pte_t pte) > { > return pte_val(pte) & _PAGE_SOFT_DIRTY; > @@ -1715,14 +1733,15 @@ static inline int has_transparent_hugepage(void) > * Bits 54 and 63 are used to indicate the page type. Bit 53 marks the pte > * as invalid. > * A swap pte is indicated by bit pattern (pte & 0x201) == 0x200 > - * | offset |X11XX|type |S0| > + * | offset |E11XX|type |S0| > * |0000000000111111111122222222223333333333444444444455|55555|55566|66| > * |0123456789012345678901234567890123456789012345678901|23456|78901|23| > * > * Bits 0-51 store the offset. > + * Bit 52 (E) is used to remember PG_anon_exclusive. > * Bits 57-61 store the type. > * Bit 62 (S) is used for softdirty tracking. > - * Bits 52, 55 and 56 (X) are unused. > + * Bits 55 and 56 (X) are unused. > */ > > #define __SWP_OFFSET_MASK ((1UL << 52) - 1) Thanks David! Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 3982575bb586..a397b072a580 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -181,6 +181,8 @@ static inline int is_module_addr(void *addr) #define _PAGE_SOFT_DIRTY 0x000 #endif +#define _PAGE_SWP_EXCLUSIVE _PAGE_LARGE /* SW pte exclusive swap bit */ + /* Set of bits not changed in pte_modify */ #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_SPECIAL | _PAGE_DIRTY | \ _PAGE_YOUNG | _PAGE_SOFT_DIRTY) @@ -826,6 +828,22 @@ static inline int pmd_protnone(pmd_t pmd) } #endif +#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE +static inline int pte_swp_exclusive(pte_t pte) +{ + return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; +} + +static inline pte_t pte_swp_mkexclusive(pte_t pte) +{ + return set_pte_bit(pte, __pgprot(_PAGE_SWP_EXCLUSIVE)); +} + +static inline pte_t pte_swp_clear_exclusive(pte_t pte) +{ + return clear_pte_bit(pte, __pgprot(_PAGE_SWP_EXCLUSIVE)); +} + static inline int pte_soft_dirty(pte_t pte) { return pte_val(pte) & _PAGE_SOFT_DIRTY; @@ -1715,14 +1733,15 @@ static inline int has_transparent_hugepage(void) * Bits 54 and 63 are used to indicate the page type. Bit 53 marks the pte * as invalid. * A swap pte is indicated by bit pattern (pte & 0x201) == 0x200 - * | offset |X11XX|type |S0| + * | offset |E11XX|type |S0| * |0000000000111111111122222222223333333333444444444455|55555|55566|66| * |0123456789012345678901234567890123456789012345678901|23456|78901|23| * * Bits 0-51 store the offset. + * Bit 52 (E) is used to remember PG_anon_exclusive. * Bits 57-61 store the type. * Bit 62 (S) is used for softdirty tracking. - * Bits 52, 55 and 56 (X) are unused. + * Bits 55 and 56 (X) are unused. */ #define __SWP_OFFSET_MASK ((1UL << 52) - 1)
Let's use bit 52, which is unused. Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/s390/include/asm/pgtable.h | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)