+#if PAGETABLE_LEVELS == 4
+pudval_t xen_pud_val(pud_t pud)
+{
+ return pte_mfn_to_pfn(pud.pud);
+}
+
+pud_t xen_make_pud(pudval_t pud)
+{
+ pud = pte_pfn_to_mfn(pud);
+
+ return native_make_pud(pud);
+}
+
+pgd_t *xen_get_user_pgd(pgd_t *pgd)
+{
+ pgd_t *pgd_page = (pgd_t *)(((unsigned long)pgd) & PAGE_MASK);
+ unsigned offset = pgd - pgd_page;
+ pgd_t *user_ptr = NULL;
+
+ if (offset < pgd_index(USER_LIMIT)) {
+ struct page *page = virt_to_page(pgd_page);
+ user_ptr = (pgd_t *)page->private;
+ if (user_ptr)
+ user_ptr += offset;
+ }
+
+ return user_ptr;
+}
+
+static void __xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+ struct mmu_update u;
+
+ u.ptr = virt_to_machine(ptr).maddr;
+ u.val = pgd_val_ma(val);
+ extend_mmu_update(&u);
+}
+
+/*
+ * Raw hypercall-based set_pgd, intended for in early boot before
+ * there's a page structure. This implies:
+ * 1. The only existing pagetable is the kernel's
+ * 2. It is always pinned
+ * 3. It has no user pagetable attached to it
+ */
+void __init xen_set_pgd_hyper(pgd_t *ptr, pgd_t val)
+{
+ preempt_disable();
+
+ xen_mc_batch();
+
+ __xen_set_pgd_hyper(ptr, val);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ preempt_enable();
+}
+
+void xen_set_pgd(pgd_t *ptr, pgd_t val)
+{
+ pgd_t *user_ptr = xen_get_user_pgd(ptr);
+
+ /* If page is not pinned, we can just update the entry
+ directly */
+ if (!page_pinned(ptr)) {
+ *ptr = val;
+ if (user_ptr) {
+ WARN_ON(page_pinned(user_ptr));
+ *user_ptr = val;
+ }
+ return;
+ }
+
+ /* If it's pinned, then we can at least batch the kernel and
+ user updates together. */
+ xen_mc_batch();
+
+ __xen_set_pgd_hyper(ptr, val);
+ if (user_ptr)
+ __xen_set_pgd_hyper(user_ptr, val);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+}
+#endif /* PAGETABLE_LEVELS == 4 */
+