1 files changed, 337 insertions, 0 deletions
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
new file mode 100644
index 0000000000..e1ece21dbe
--- /dev/null
+++ b/arch/um/include/asm/pgtable.h
@@ -0,0 +1,337 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright 2003 PathScale, Inc.
+ * Derived from include/asm-i386/pgtable.h
+ */
+
+#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 */
+
+/* We borrow bit 10 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE	0x400
+
+#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;
+
+/* 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..
+ */
+
+/*
+ * 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 p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
+#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
+
+#define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
+#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)));
+}
+
+/*
+ * =================================
+ * 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)
+{
+	if (likely(pte_get_bits(pte, _PAGE_RW)))
+		pte_clear_bits(pte, _PAGE_RW);
+	else
+		return pte;
+	return(pte_mknewprot(pte));
+}
+
+static inline pte_t pte_mkread(pte_t pte)
+{
+	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
+		return 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_novma(pte_t pte)
+{
+	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
+		return 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 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 PFN_PTE_SHIFT		PAGE_SHIFT
+
+#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 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))
+
+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)
+#define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
+
+/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ *
+ * Format of swap PTEs:
+ *
+ *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
+ *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ *   <--------------- offset ----------------> E < type -> 0 0 0 1 0
+ *
+ *   E is the exclusive marker that is not stored in swap entries.
+ *   _PAGE_NEWPAGE (bit 1) is always set to 1 in set_pte().
+ */
+#define __swp_type(x)			(((x).val >> 5) & 0x1f)
+#define __swp_offset(x)			((x).val >> 11)
+
+#define __swp_entry(type, offset) \
+	((swp_entry_t) { (((type) & 0x1f) << 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 })
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+	return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
+}
+
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+	pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
+	return pte;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+	pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
+	return pte;
+}
+
+/* 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