v4.19.13 snapshot.
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
new file mode 100644
index 0000000..7485398
--- /dev/null
+++ b/arch/um/include/asm/pgtable.h
@@ -0,0 +1,362 @@
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright 2003 PathScale, Inc.
+ * Derived from include/asm-i386/pgtable.h
+ * Licensed under the GPL
+ */
+
+#ifndef __UM_PGTABLE_H
+#define __UM_PGTABLE_H
+
+#include <asm/fixmap.h>
+
+#define _PAGE_PRESENT 0x001
+#define _PAGE_NEWPAGE 0x002
+#define _PAGE_NEWPROT 0x004
+#define _PAGE_RW 0x020
+#define _PAGE_USER 0x040
+#define _PAGE_ACCESSED 0x080
+#define _PAGE_DIRTY 0x100
+/* If _PAGE_PRESENT is clear, we use these: */
+#define _PAGE_PROTNONE 0x010 /* if the user mapped it with PROT_NONE;
+ pte_present gives true */
+
+#ifdef CONFIG_3_LEVEL_PGTABLES
+#include <asm/pgtable-3level.h>
+#else
+#include <asm/pgtable-2level.h>
+#endif
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* zero page used for uninitialized stuff */
+extern unsigned long *empty_zero_page;
+
+#define pgtable_cache_init() do ; while (0)
+
+/* Just any arbitrary offset to the start of the vmalloc VM area: the
+ * current 8MB value just means that there will be a 8MB "hole" after the
+ * physical memory until the kernel virtual memory starts. That means that
+ * any out-of-bounds memory accesses will hopefully be caught.
+ * The vmalloc() routines leaves a hole of 4kB between each vmalloced
+ * area for the same reason. ;)
+ */
+
+extern unsigned long end_iomem;
+
+#define VMALLOC_OFFSET (__va_space)
+#define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
+#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
+#define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
+#define MODULES_VADDR VMALLOC_START
+#define MODULES_END VMALLOC_END
+#define MODULES_LEN (MODULES_VADDR - MODULES_END)
+
+#define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define __PAGE_KERNEL_EXEC \
+ (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
+#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_KERNEL_EXEC __pgprot(__PAGE_KERNEL_EXEC)
+
+/*
+ * The i386 can't do page protection for execute, and considers that the same
+ * are read.
+ * Also, write permissions imply read permissions. This is the closest we can
+ * get..
+ */
+#define __P000 PAGE_NONE
+#define __P001 PAGE_READONLY
+#define __P010 PAGE_COPY
+#define __P011 PAGE_COPY
+#define __P100 PAGE_READONLY
+#define __P101 PAGE_READONLY
+#define __P110 PAGE_COPY
+#define __P111 PAGE_COPY
+
+#define __S000 PAGE_NONE
+#define __S001 PAGE_READONLY
+#define __S010 PAGE_SHARED
+#define __S011 PAGE_SHARED
+#define __S100 PAGE_READONLY
+#define __S101 PAGE_READONLY
+#define __S110 PAGE_SHARED
+#define __S111 PAGE_SHARED
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
+
+#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
+
+#define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
+#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
+
+#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT)
+#define pmd_clear(xp) do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
+
+#define pmd_newpage(x) (pmd_val(x) & _PAGE_NEWPAGE)
+#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
+
+#define pud_newpage(x) (pud_val(x) & _PAGE_NEWPAGE)
+#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
+
+#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
+
+#define pte_page(x) pfn_to_page(pte_pfn(x))
+
+#define pte_present(x) pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
+
+/*
+ * =================================
+ * Flags checking section.
+ * =================================
+ */
+
+static inline int pte_none(pte_t pte)
+{
+ return pte_is_zero(pte);
+}
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_read(pte_t pte)
+{
+ return((pte_get_bits(pte, _PAGE_USER)) &&
+ !(pte_get_bits(pte, _PAGE_PROTNONE)));
+}
+
+static inline int pte_exec(pte_t pte){
+ return((pte_get_bits(pte, _PAGE_USER)) &&
+ !(pte_get_bits(pte, _PAGE_PROTNONE)));
+}
+
+static inline int pte_write(pte_t pte)
+{
+ return((pte_get_bits(pte, _PAGE_RW)) &&
+ !(pte_get_bits(pte, _PAGE_PROTNONE)));
+}
+
+static inline int pte_dirty(pte_t pte)
+{
+ return pte_get_bits(pte, _PAGE_DIRTY);
+}
+
+static inline int pte_young(pte_t pte)
+{
+ return pte_get_bits(pte, _PAGE_ACCESSED);
+}
+
+static inline int pte_newpage(pte_t pte)
+{
+ return pte_get_bits(pte, _PAGE_NEWPAGE);
+}
+
+static inline int pte_newprot(pte_t pte)
+{
+ return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
+}
+
+static inline int pte_special(pte_t pte)
+{
+ return 0;
+}
+
+/*
+ * =================================
+ * Flags setting section.
+ * =================================
+ */
+
+static inline pte_t pte_mknewprot(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_NEWPROT);
+ return(pte);
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+ pte_clear_bits(pte, _PAGE_DIRTY);
+ return(pte);
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+ pte_clear_bits(pte, _PAGE_ACCESSED);
+ return(pte);
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+ pte_clear_bits(pte, _PAGE_RW);
+ return(pte_mknewprot(pte));
+}
+
+static inline pte_t pte_mkread(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_USER);
+ return(pte_mknewprot(pte));
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_DIRTY);
+ return(pte);
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_ACCESSED);
+ return(pte);
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_RW);
+ return(pte_mknewprot(pte));
+}
+
+static inline pte_t pte_mkuptodate(pte_t pte)
+{
+ pte_clear_bits(pte, _PAGE_NEWPAGE);
+ if(pte_present(pte))
+ pte_clear_bits(pte, _PAGE_NEWPROT);
+ return(pte);
+}
+
+static inline pte_t pte_mknewpage(pte_t pte)
+{
+ pte_set_bits(pte, _PAGE_NEWPAGE);
+ return(pte);
+}
+
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+ return(pte);
+}
+
+static inline void set_pte(pte_t *pteptr, pte_t pteval)
+{
+ pte_copy(*pteptr, pteval);
+
+ /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
+ * fix_range knows to unmap it. _PAGE_NEWPROT is specific to
+ * mapped pages.
+ */
+
+ *pteptr = pte_mknewpage(*pteptr);
+ if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
+}
+#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+
+#define __HAVE_ARCH_PTE_SAME
+static inline int pte_same(pte_t pte_a, pte_t pte_b)
+{
+ return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+
+#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
+#define __virt_to_page(virt) phys_to_page(__pa(virt))
+#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
+#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
+
+#define mk_pte(page, pgprot) \
+ ({ pte_t pte; \
+ \
+ pte_set_val(pte, page_to_phys(page), (pgprot)); \
+ if (pte_present(pte)) \
+ pte_mknewprot(pte_mknewpage(pte)); \
+ pte;})
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+ pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
+ return pte;
+}
+
+/*
+ * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
+ *
+ * this macro returns the index of the entry in the pgd page which would
+ * control the given virtual address
+ */
+#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+
+/*
+ * pgd_offset() returns a (pgd_t *)
+ * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
+ */
+#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
+
+/*
+ * a shortcut which implies the use of the kernel's pgd, instead
+ * of a process's
+ */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+/*
+ * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
+ *
+ * this macro returns the index of the entry in the pmd page which would
+ * control the given virtual address
+ */
+#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+
+#define pmd_page_vaddr(pmd) \
+ ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
+
+/*
+ * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
+ *
+ * this macro returns the index of the entry in the pte page which would
+ * control the given virtual address
+ */
+#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset_kernel(dir, address) \
+ ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(address))
+#define pte_offset_map(dir, address) \
+ ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
+#define pte_unmap(pte) do { } while (0)
+
+struct mm_struct;
+extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
+
+#define update_mmu_cache(vma,address,ptep) do ; while (0)
+
+/* Encode and de-code a swap entry */
+#define __swp_type(x) (((x).val >> 5) & 0x1f)
+#define __swp_offset(x) ((x).val >> 11)
+
+#define __swp_entry(type, offset) \
+ ((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
+#define __pte_to_swp_entry(pte) \
+ ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
+#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+
+#define kern_addr_valid(addr) (1)
+
+#include <asm-generic/pgtable.h>
+
+/* Clear a kernel PTE and flush it from the TLB */
+#define kpte_clear_flush(ptep, vaddr) \
+do { \
+ pte_clear(&init_mm, (vaddr), (ptep)); \
+ __flush_tlb_one((vaddr)); \
+} while (0)
+
+#endif