v4.19.13 snapshot.
diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h
new file mode 100644
index 0000000..c4d876d
--- /dev/null
+++ b/arch/um/include/asm/pgtable-3level.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2003 PathScale Inc
+ * Derived from include/asm-i386/pgtable.h
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_PGTABLE_3LEVEL_H
+#define __UM_PGTABLE_3LEVEL_H
+
+#define __ARCH_USE_5LEVEL_HACK
+#include <asm-generic/pgtable-nopud.h>
+
+/* PGDIR_SHIFT determines what a third-level page table entry can map */
+
+#ifdef CONFIG_64BIT
+#define PGDIR_SHIFT	30
+#else
+#define PGDIR_SHIFT	31
+#endif
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+/* PMD_SHIFT determines the size of the area a second-level page table can
+ * map
+ */
+
+#define PMD_SHIFT	21
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+
+/*
+ * entries per page directory level
+ */
+
+#define PTRS_PER_PTE 512
+#ifdef CONFIG_64BIT
+#define PTRS_PER_PMD 512
+#define PTRS_PER_PGD 512
+#else
+#define PTRS_PER_PMD 1024
+#define PTRS_PER_PGD 1024
+#endif
+
+#define USER_PTRS_PER_PGD ((TASK_SIZE + (PGDIR_SIZE - 1)) / PGDIR_SIZE)
+#define FIRST_USER_ADDRESS	0UL
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pte_val(e))
+#define pmd_ERROR(e) \
+        printk("%s:%d: bad pmd %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pmd_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd %p(%016lx).\n", __FILE__, __LINE__, &(e), \
+	       pgd_val(e))
+
+#define pud_none(x)	(!(pud_val(x) & ~_PAGE_NEWPAGE))
+#define	pud_bad(x)	((pud_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+#define pud_present(x)	(pud_val(x) & _PAGE_PRESENT)
+#define pud_populate(mm, pud, pmd) \
+	set_pud(pud, __pud(_PAGE_TABLE + __pa(pmd)))
+
+#ifdef CONFIG_64BIT
+#define set_pud(pudptr, pudval) set_64bit((u64 *) (pudptr), pud_val(pudval))
+#else
+#define set_pud(pudptr, pudval) (*(pudptr) = (pudval))
+#endif
+
+static inline int pgd_newpage(pgd_t pgd)
+{
+	return(pgd_val(pgd) & _PAGE_NEWPAGE);
+}
+
+static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEWPAGE; }
+
+#ifdef CONFIG_64BIT
+#define set_pmd(pmdptr, pmdval) set_64bit((u64 *) (pmdptr), pmd_val(pmdval))
+#else
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
+#endif
+
+struct mm_struct;
+extern pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address);
+
+static inline void pud_clear (pud_t *pud)
+{
+	set_pud(pud, __pud(_PAGE_NEWPAGE));
+}
+
+#define pud_page(pud) phys_to_page(pud_val(pud) & PAGE_MASK)
+#define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PAGE_MASK))
+
+/* Find an entry in the second-level page table.. */
+#define pmd_offset(pud, address) ((pmd_t *) pud_page_vaddr(*(pud)) + \
+			pmd_index(address))
+
+static inline unsigned long pte_pfn(pte_t pte)
+{
+	return phys_to_pfn(pte_val(pte));
+}
+
+static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
+{
+	pte_t pte;
+	phys_t phys = pfn_to_phys(page_nr);
+
+	pte_set_val(pte, phys, pgprot);
+	return pte;
+}
+
+static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
+{
+	return __pmd((page_nr << PAGE_SHIFT) | pgprot_val(pgprot));
+}
+
+#endif
+