linux/arch/x86/include/asm/pgtable_64.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_X86_PGTABLE_64_H
   3#define _ASM_X86_PGTABLE_64_H
   4
   5#include <linux/const.h>
   6#include <asm/pgtable_64_types.h>
   7
   8#ifndef __ASSEMBLY__
   9
  10/*
  11 * This file contains the functions and defines necessary to modify and use
  12 * the x86-64 page table tree.
  13 */
  14#include <asm/processor.h>
  15#include <linux/bitops.h>
  16#include <linux/threads.h>
  17#include <asm/fixmap.h>
  18
  19extern p4d_t level4_kernel_pgt[512];
  20extern p4d_t level4_ident_pgt[512];
  21extern pud_t level3_kernel_pgt[512];
  22extern pud_t level3_ident_pgt[512];
  23extern pmd_t level2_kernel_pgt[512];
  24extern pmd_t level2_fixmap_pgt[512];
  25extern pmd_t level2_ident_pgt[512];
  26extern pte_t level1_fixmap_pgt[512 * FIXMAP_PMD_NUM];
  27extern pgd_t init_top_pgt[];
  28
  29#define swapper_pg_dir init_top_pgt
  30
  31extern void paging_init(void);
  32static inline void sync_initial_page_table(void) { }
  33
  34#define pte_ERROR(e)                                    \
  35        pr_err("%s:%d: bad pte %p(%016lx)\n",           \
  36               __FILE__, __LINE__, &(e), pte_val(e))
  37#define pmd_ERROR(e)                                    \
  38        pr_err("%s:%d: bad pmd %p(%016lx)\n",           \
  39               __FILE__, __LINE__, &(e), pmd_val(e))
  40#define pud_ERROR(e)                                    \
  41        pr_err("%s:%d: bad pud %p(%016lx)\n",           \
  42               __FILE__, __LINE__, &(e), pud_val(e))
  43
  44#if CONFIG_PGTABLE_LEVELS >= 5
  45#define p4d_ERROR(e)                                    \
  46        pr_err("%s:%d: bad p4d %p(%016lx)\n",           \
  47               __FILE__, __LINE__, &(e), p4d_val(e))
  48#endif
  49
  50#define pgd_ERROR(e)                                    \
  51        pr_err("%s:%d: bad pgd %p(%016lx)\n",           \
  52               __FILE__, __LINE__, &(e), pgd_val(e))
  53
  54struct mm_struct;
  55
  56#define mm_p4d_folded mm_p4d_folded
  57static inline bool mm_p4d_folded(struct mm_struct *mm)
  58{
  59        return !pgtable_l5_enabled();
  60}
  61
  62void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
  63void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
  64
  65static inline void native_set_pte(pte_t *ptep, pte_t pte)
  66{
  67        WRITE_ONCE(*ptep, pte);
  68}
  69
  70static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr,
  71                                    pte_t *ptep)
  72{
  73        native_set_pte(ptep, native_make_pte(0));
  74}
  75
  76static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  77{
  78        native_set_pte(ptep, pte);
  79}
  80
  81static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  82{
  83        WRITE_ONCE(*pmdp, pmd);
  84}
  85
  86static inline void native_pmd_clear(pmd_t *pmd)
  87{
  88        native_set_pmd(pmd, native_make_pmd(0));
  89}
  90
  91static inline pte_t native_ptep_get_and_clear(pte_t *xp)
  92{
  93#ifdef CONFIG_SMP
  94        return native_make_pte(xchg(&xp->pte, 0));
  95#else
  96        /* native_local_ptep_get_and_clear,
  97           but duplicated because of cyclic dependency */
  98        pte_t ret = *xp;
  99        native_pte_clear(NULL, 0, xp);
 100        return ret;
 101#endif
 102}
 103
 104static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
 105{
 106#ifdef CONFIG_SMP
 107        return native_make_pmd(xchg(&xp->pmd, 0));
 108#else
 109        /* native_local_pmdp_get_and_clear,
 110           but duplicated because of cyclic dependency */
 111        pmd_t ret = *xp;
 112        native_pmd_clear(xp);
 113        return ret;
 114#endif
 115}
 116
 117static inline void native_set_pud(pud_t *pudp, pud_t pud)
 118{
 119        WRITE_ONCE(*pudp, pud);
 120}
 121
 122static inline void native_pud_clear(pud_t *pud)
 123{
 124        native_set_pud(pud, native_make_pud(0));
 125}
 126
 127static inline pud_t native_pudp_get_and_clear(pud_t *xp)
 128{
 129#ifdef CONFIG_SMP
 130        return native_make_pud(xchg(&xp->pud, 0));
 131#else
 132        /* native_local_pudp_get_and_clear,
 133         * but duplicated because of cyclic dependency
 134         */
 135        pud_t ret = *xp;
 136
 137        native_pud_clear(xp);
 138        return ret;
 139#endif
 140}
 141
 142static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
 143{
 144        pgd_t pgd;
 145
 146        if (pgtable_l5_enabled() || !IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) {
 147                WRITE_ONCE(*p4dp, p4d);
 148                return;
 149        }
 150
 151        pgd = native_make_pgd(native_p4d_val(p4d));
 152        pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd);
 153        WRITE_ONCE(*p4dp, native_make_p4d(native_pgd_val(pgd)));
 154}
 155
 156static inline void native_p4d_clear(p4d_t *p4d)
 157{
 158        native_set_p4d(p4d, native_make_p4d(0));
 159}
 160
 161static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 162{
 163        WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
 164}
 165
 166static inline void native_pgd_clear(pgd_t *pgd)
 167{
 168        native_set_pgd(pgd, native_make_pgd(0));
 169}
 170
 171/*
 172 * Conversion functions: convert a page and protection to a page entry,
 173 * and a page entry and page directory to the page they refer to.
 174 */
 175
 176/* PGD - Level 4 access */
 177
 178/* PUD - Level 3 access */
 179
 180/* PMD - Level 2 access */
 181
 182/* PTE - Level 1 access */
 183
 184/*
 185 * Encode and de-code a swap entry
 186 *
 187 * |     ...            | 11| 10|  9|8|7|6|5| 4| 3|2| 1|0| <- bit number
 188 * |     ...            |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
 189 * | TYPE (59-63) | ~OFFSET (9-58)  |0|0|X|X| X| X|F|SD|0| <- swp entry
 190 *
 191 * G (8) is aliased and used as a PROT_NONE indicator for
 192 * !present ptes.  We need to start storing swap entries above
 193 * there.  We also need to avoid using A and D because of an
 194 * erratum where they can be incorrectly set by hardware on
 195 * non-present PTEs.
 196 *
 197 * SD Bits 1-4 are not used in non-present format and available for
 198 * special use described below:
 199 *
 200 * SD (1) in swp entry is used to store soft dirty bit, which helps us
 201 * remember soft dirty over page migration
 202 *
 203 * F (2) in swp entry is used to record when a pagetable is
 204 * writeprotected by userfaultfd WP support.
 205 *
 206 * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
 207 * but also L and G.
 208 *
 209 * The offset is inverted by a binary not operation to make the high
 210 * physical bits set.
 211 */
 212#define SWP_TYPE_BITS           5
 213
 214#define SWP_OFFSET_FIRST_BIT    (_PAGE_BIT_PROTNONE + 1)
 215
 216/* We always extract/encode the offset by shifting it all the way up, and then down again */
 217#define SWP_OFFSET_SHIFT        (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
 218
 219#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
 220
 221/* Extract the high bits for type */
 222#define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
 223
 224/* Shift up (to get rid of type), then down to get value */
 225#define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
 226
 227/*
 228 * Shift the offset up "too far" by TYPE bits, then down again
 229 * The offset is inverted by a binary not operation to make the high
 230 * physical bits set.
 231 */
 232#define __swp_entry(type, offset) ((swp_entry_t) { \
 233        (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
 234        | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
 235
 236#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val((pte)) })
 237#define __pmd_to_swp_entry(pmd)         ((swp_entry_t) { pmd_val((pmd)) })
 238#define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
 239#define __swp_entry_to_pmd(x)           ((pmd_t) { .pmd = (x).val })
 240
 241extern int kern_addr_valid(unsigned long addr);
 242extern void cleanup_highmap(void);
 243
 244#define HAVE_ARCH_UNMAPPED_AREA
 245#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 246
 247#define PAGE_AGP    PAGE_KERNEL_NOCACHE
 248#define HAVE_PAGE_AGP 1
 249
 250/* fs/proc/kcore.c */
 251#define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
 252#define kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
 253
 254#define __HAVE_ARCH_PTE_SAME
 255
 256#define vmemmap ((struct page *)VMEMMAP_START)
 257
 258extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
 259extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
 260
 261#define gup_fast_permitted gup_fast_permitted
 262static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
 263{
 264        if (end >> __VIRTUAL_MASK_SHIFT)
 265                return false;
 266        return true;
 267}
 268
 269#include <asm/pgtable-invert.h>
 270
 271#endif /* !__ASSEMBLY__ */
 272#endif /* _ASM_X86_PGTABLE_64_H */
 273