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Diffstat (limited to 'include/asm-i386/pgtable-3level.h')
-rw-r--r--include/asm-i386/pgtable-3level.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/asm-i386/pgtable-3level.h b/include/asm-i386/pgtable-3level.h
index 36a5aa63cbbf..dccb1b3337ad 100644
--- a/include/asm-i386/pgtable-3level.h
+++ b/include/asm-i386/pgtable-3level.h
@@ -85,6 +85,26 @@ static inline void pud_clear (pud_t * pud) { }
#define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
pmd_index(address))
+/*
+ * For PTEs and PDEs, we must clear the P-bit first when clearing a page table
+ * entry, so clear the bottom half first and enforce ordering with a compiler
+ * barrier.
+ */
+static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ ptep->pte_low = 0;
+ smp_wmb();
+ ptep->pte_high = 0;
+}
+
+static inline void pmd_clear(pmd_t *pmd)
+{
+ u32 *tmp = (u32 *)pmd;
+ *tmp = 0;
+ smp_wmb();
+ *(tmp + 1) = 0;
+}
+
static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
pte_t res;