diff options
| author | Heiko Carstens <hca@linux.ibm.com> | 2022-02-10 18:08:29 +0300 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2022-03-01 23:05:10 +0300 |
| commit | e2aaae2d3677563c1bb6cd15fbddd701381823be (patch) | |
| tree | 7c4682cfe521a2d01aada62439692294799bb682 /arch/s390/include | |
| parent | f0003a9e4c18ae71308fb6b24de8248ac6180777 (diff) | |
| download | linux-e2aaae2d3677563c1bb6cd15fbddd701381823be.tar.xz | |
s390/mm: add set_pXd()/set_pte() helper functions
Add set_pXd()/set_pte() helper functions which must be used to update
page table entries. The new helpers use WRITE_ONCE() to make sure that
a page table entry is written to only once.
Without this the compiler could otherwise generate code which writes
several times to a page table entry when updating its contents from
invalid to valid, which could lead to surprising results especially
for multithreaded processes...
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/include')
| -rw-r--r-- | arch/s390/include/asm/pgtable.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index 008a6c856fa4..2aa8057c7ef8 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -881,6 +881,31 @@ static inline pgprot_t pte_pgprot(pte_t pte) * pgd/pmd/pte modification functions */ +static inline void set_pgd(pgd_t *pgdp, pgd_t pgd) +{ + WRITE_ONCE(*pgdp, pgd); +} + +static inline void set_p4d(p4d_t *p4dp, p4d_t p4d) +{ + WRITE_ONCE(*p4dp, p4d); +} + +static inline void set_pud(pud_t *pudp, pud_t pud) +{ + WRITE_ONCE(*pudp, pud); +} + +static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) +{ + WRITE_ONCE(*pmdp, pmd); +} + +static inline void set_pte(pte_t *ptep, pte_t pte) +{ + WRITE_ONCE(*ptep, pte); +} + static inline void pgd_clear(pgd_t *pgd) { if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1) |