LXR linux/arch/um/include/asm/pgtable.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4 * Copyright 2003 PathScale, Inc.
   5 * Derived from include/asm-i386/pgtable.h
   6 */
   7
   8#ifndef __UM_PGTABLE_H
   9#define __UM_PGTABLE_H
  10
  11#include <asm/fixmap.h>
  12
  13#define _PAGE_PRESENT   0x001
  14#define _PAGE_NEWPAGE   0x002
  15#define _PAGE_NEWPROT   0x004
  16#define _PAGE_RW        0x020
  17#define _PAGE_USER      0x040
  18#define _PAGE_ACCESSED  0x080
  19#define _PAGE_DIRTY     0x100
  20/* If _PAGE_PRESENT is clear, we use these: */
  21#define _PAGE_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
  22                                   pte_present gives true */
  23
  24#ifdef CONFIG_3_LEVEL_PGTABLES
  25#include <asm/pgtable-3level.h>
  26#else
  27#include <asm/pgtable-2level.h>
  28#endif
  29
  30extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  31
  32/* zero page used for uninitialized stuff */
  33extern unsigned long *empty_zero_page;
  34
  35/* Just any arbitrary offset to the start of the vmalloc VM area: the
  36 * current 8MB value just means that there will be a 8MB "hole" after the
  37 * physical memory until the kernel virtual memory starts.  That means that
  38 * any out-of-bounds memory accesses will hopefully be caught.
  39 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  40 * area for the same reason. ;)
  41 */
  42
  43extern unsigned long end_iomem;
  44
  45#define VMALLOC_OFFSET  (__va_space)
  46#define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  47#define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
  48#define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  49#define MODULES_VADDR   VMALLOC_START
  50#define MODULES_END     VMALLOC_END
  51#define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  52
  53#define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  54#define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  55#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  56#define __PAGE_KERNEL_EXEC                                              \
  57         (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  58#define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  59#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  60#define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  61#define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  62#define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  63#define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
  64
  65/*
  66 * The i386 can't do page protection for execute, and considers that the same
  67 * are read.
  68 * Also, write permissions imply read permissions. This is the closest we can
  69 * get..
  70 */
  71#define __P000  PAGE_NONE
  72#define __P001  PAGE_READONLY
  73#define __P010  PAGE_COPY
  74#define __P011  PAGE_COPY
  75#define __P100  PAGE_READONLY
  76#define __P101  PAGE_READONLY
  77#define __P110  PAGE_COPY
  78#define __P111  PAGE_COPY
  79
  80#define __S000  PAGE_NONE
  81#define __S001  PAGE_READONLY
  82#define __S010  PAGE_SHARED
  83#define __S011  PAGE_SHARED
  84#define __S100  PAGE_READONLY
  85#define __S101  PAGE_READONLY
  86#define __S110  PAGE_SHARED
  87#define __S111  PAGE_SHARED
  88
  89/*
  90 * ZERO_PAGE is a global shared page that is always zero: used
  91 * for zero-mapped memory areas etc..
  92 */
  93#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
  94
  95#define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
  96
  97#define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
  98#define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
  99
 100#define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 101#define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 102
 103#define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 104#define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 105
 106#define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 107#define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 108
 109#define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
 110#define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
 111
 112#define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 113
 114#define pte_page(x) pfn_to_page(pte_pfn(x))
 115
 116#define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 117
 118/*
 119 * =================================
 120 * Flags checking section.
 121 * =================================
 122 */
 123
 124static inline int pte_none(pte_t pte)
 125{
 126        return pte_is_zero(pte);
 127}
 128
 129/*
 130 * The following only work if pte_present() is true.
 131 * Undefined behaviour if not..
 132 */
 133static inline int pte_read(pte_t pte)
 134{
 135        return((pte_get_bits(pte, _PAGE_USER)) &&
 136               !(pte_get_bits(pte, _PAGE_PROTNONE)));
 137}
 138
 139static inline int pte_exec(pte_t pte){
 140        return((pte_get_bits(pte, _PAGE_USER)) &&
 141               !(pte_get_bits(pte, _PAGE_PROTNONE)));
 142}
 143
 144static inline int pte_write(pte_t pte)
 145{
 146        return((pte_get_bits(pte, _PAGE_RW)) &&
 147               !(pte_get_bits(pte, _PAGE_PROTNONE)));
 148}
 149
 150static inline int pte_dirty(pte_t pte)
 151{
 152        return pte_get_bits(pte, _PAGE_DIRTY);
 153}
 154
 155static inline int pte_young(pte_t pte)
 156{
 157        return pte_get_bits(pte, _PAGE_ACCESSED);
 158}
 159
 160static inline int pte_newpage(pte_t pte)
 161{
 162        return pte_get_bits(pte, _PAGE_NEWPAGE);
 163}
 164
 165static inline int pte_newprot(pte_t pte)
 166{
 167        return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 168}
 169
 170/*
 171 * =================================
 172 * Flags setting section.
 173 * =================================
 174 */
 175
 176static inline pte_t pte_mknewprot(pte_t pte)
 177{
 178        pte_set_bits(pte, _PAGE_NEWPROT);
 179        return(pte);
 180}
 181
 182static inline pte_t pte_mkclean(pte_t pte)
 183{
 184        pte_clear_bits(pte, _PAGE_DIRTY);
 185        return(pte);
 186}
 187
 188static inline pte_t pte_mkold(pte_t pte)
 189{
 190        pte_clear_bits(pte, _PAGE_ACCESSED);
 191        return(pte);
 192}
 193
 194static inline pte_t pte_wrprotect(pte_t pte)
 195{
 196        if (likely(pte_get_bits(pte, _PAGE_RW)))
 197                pte_clear_bits(pte, _PAGE_RW);
 198        else
 199                return pte;
 200        return(pte_mknewprot(pte));
 201}
 202
 203static inline pte_t pte_mkread(pte_t pte)
 204{
 205        if (unlikely(pte_get_bits(pte, _PAGE_USER)))
 206                return pte;
 207        pte_set_bits(pte, _PAGE_USER);
 208        return(pte_mknewprot(pte));
 209}
 210
 211static inline pte_t pte_mkdirty(pte_t pte)
 212{
 213        pte_set_bits(pte, _PAGE_DIRTY);
 214        return(pte);
 215}
 216
 217static inline pte_t pte_mkyoung(pte_t pte)
 218{
 219        pte_set_bits(pte, _PAGE_ACCESSED);
 220        return(pte);
 221}
 222
 223static inline pte_t pte_mkwrite(pte_t pte)
 224{
 225        if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
 226                return pte;
 227        pte_set_bits(pte, _PAGE_RW);
 228        return(pte_mknewprot(pte));
 229}
 230
 231static inline pte_t pte_mkuptodate(pte_t pte)
 232{
 233        pte_clear_bits(pte, _PAGE_NEWPAGE);
 234        if(pte_present(pte))
 235                pte_clear_bits(pte, _PAGE_NEWPROT);
 236        return(pte);
 237}
 238
 239static inline pte_t pte_mknewpage(pte_t pte)
 240{
 241        pte_set_bits(pte, _PAGE_NEWPAGE);
 242        return(pte);
 243}
 244
 245static inline void set_pte(pte_t *pteptr, pte_t pteval)
 246{
 247        pte_copy(*pteptr, pteval);
 248
 249        /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 250         * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 251         * mapped pages.
 252         */
 253
 254        *pteptr = pte_mknewpage(*pteptr);
 255        if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 256}
 257
 258static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 259                              pte_t *pteptr, pte_t pteval)
 260{
 261        set_pte(pteptr, pteval);
 262}
 263
 264#define __HAVE_ARCH_PTE_SAME
 265static inline int pte_same(pte_t pte_a, pte_t pte_b)
 266{
 267        return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
 268}
 269
 270/*
 271 * Conversion functions: convert a page and protection to a page entry,
 272 * and a page entry and page directory to the page they refer to.
 273 */
 274
 275#define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 276#define __virt_to_page(virt) phys_to_page(__pa(virt))
 277#define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
 278#define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 279
 280#define mk_pte(page, pgprot) \
 281        ({ pte_t pte;                                   \
 282                                                        \
 283        pte_set_val(pte, page_to_phys(page), (pgprot)); \
 284        if (pte_present(pte))                           \
 285                pte_mknewprot(pte_mknewpage(pte));      \
 286        pte;})
 287
 288static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 289{
 290        pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 291        return pte;
 292}
 293
 294/*
 295 * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 296 *
 297 * this macro returns the index of the entry in the pmd page which would
 298 * control the given virtual address
 299 */
 300#define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 301
 302struct mm_struct;
 303extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 304
 305#define update_mmu_cache(vma,address,ptep) do {} while (0)
 306
 307/* Encode and de-code a swap entry */
 308#define __swp_type(x)                   (((x).val >> 5) & 0x1f)
 309#define __swp_offset(x)                 ((x).val >> 11)
 310
 311#define __swp_entry(type, offset) \
 312        ((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
 313#define __pte_to_swp_entry(pte) \
 314        ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 315#define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 316
 317#define kern_addr_valid(addr) (1)
 318
 319/* Clear a kernel PTE and flush it from the TLB */
 320#define kpte_clear_flush(ptep, vaddr)           \
 321do {                                            \
 322        pte_clear(&init_mm, (vaddr), (ptep));   \
 323        __flush_tlb_one((vaddr));               \
 324} while (0)
 325
 326#endif
 327