+/*
+ * Since this is only called on user PTEs, and the page fault handler
+ * must handle the already racy situation of simultaneous page faults,
+ * we are justified in merely clearing the PTE present bit, followed
+ * by a set. The ordering here is important.
+ */
+static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+{
+ ptep->pte_low = 0;
+ smp_wmb();
+ ptep->pte_high = pte.pte_high;
+ smp_wmb();
+ ptep->pte_low = pte.pte_low;
+}
+