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authorHeiko Carstens <hca@linux.ibm.com>2022-02-10 18:08:29 +0300
committerVasily Gorbik <gor@linux.ibm.com>2022-03-01 23:05:10 +0300
commite2aaae2d3677563c1bb6cd15fbddd701381823be (patch)
tree7c4682cfe521a2d01aada62439692294799bb682 /arch/s390/include
parentf0003a9e4c18ae71308fb6b24de8248ac6180777 (diff)
downloadlinux-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.h25
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)