v4.19.13 snapshot.
diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
new file mode 100644
index 0000000..7aa0ea9
--- /dev/null
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _ASM_RISCV_PGTABLE_64_H
+#define _ASM_RISCV_PGTABLE_64_H
+
+#include <linux/const.h>
+
+#define PGDIR_SHIFT 30
+/* Size of region mapped by a page global directory */
+#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
+#define PGDIR_MASK (~(PGDIR_SIZE - 1))
+
+#define PMD_SHIFT 21
+/* Size of region mapped by a page middle directory */
+#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
+#define PMD_MASK (~(PMD_SIZE - 1))
+
+/* Page Middle Directory entry */
+typedef struct {
+ unsigned long pmd;
+} pmd_t;
+
+#define pmd_val(x) ((x).pmd)
+#define __pmd(x) ((pmd_t) { (x) })
+
+#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
+
+static inline int pud_present(pud_t pud)
+{
+ return (pud_val(pud) & _PAGE_PRESENT);
+}
+
+static inline int pud_none(pud_t pud)
+{
+ return (pud_val(pud) == 0);
+}
+
+static inline int pud_bad(pud_t pud)
+{
+ return !pud_present(pud);
+}
+
+static inline void set_pud(pud_t *pudp, pud_t pud)
+{
+ *pudp = pud;
+}
+
+static inline void pud_clear(pud_t *pudp)
+{
+ set_pud(pudp, __pud(0));
+}
+
+static inline unsigned long pud_page_vaddr(pud_t pud)
+{
+ return (unsigned long)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT);
+}
+
+#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
+
+static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
+{
+ return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
+}
+
+static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
+{
+ return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
+}
+
+#define pmd_ERROR(e) \
+ pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+
+#endif /* _ASM_RISCV_PGTABLE_64_H */