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
  56void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
  57void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
  58
  59static inline void native_set_pte(pte_t *ptep, pte_t pte)
  60{
  61        WRITE_ONCE(*ptep, pte);
  62}
  63
  64static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr,
  65                                    pte_t *ptep)
  66{
  67        native_set_pte(ptep, native_make_pte(0));
  68}
  69
  70static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  71{
  72        native_set_pte(ptep, pte);
  73}
  74
  75static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  76{
  77        WRITE_ONCE(*pmdp, pmd);
  78}
  79
  80static inline void native_pmd_clear(pmd_t *pmd)
  81{
  82        native_set_pmd(pmd, native_make_pmd(0));
  83}
  84
  85static inline pte_t native_ptep_get_and_clear(pte_t *xp)
  86{
  87#ifdef CONFIG_SMP
  88        return native_make_pte(xchg(&xp->pte, 0));
  89#else
  90        /* native_local_ptep_get_and_clear,
  91           but duplicated because of cyclic dependency */
  92        pte_t ret = *xp;
  93        native_pte_clear(NULL, 0, xp);
  94        return ret;
  95#endif
  96}
  97
  98static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
  99{
 100#ifdef CONFIG_SMP
 101        return native_make_pmd(xchg(&xp->pmd, 0));
 102#else
 103        /* native_local_pmdp_get_and_clear,
 104           but duplicated because of cyclic dependency */
 105        pmd_t ret = *xp;
 106        native_pmd_clear(xp);
 107        return ret;
 108#endif
 109}
 110
 111static inline void native_set_pud(pud_t *pudp, pud_t pud)
 112{
 113        WRITE_ONCE(*pudp, pud);
 114}
 115
 116static inline void native_pud_clear(pud_t *pud)
 117{
 118        native_set_pud(pud, native_make_pud(0));
 119}
 120
 121static inline pud_t native_pudp_get_and_clear(pud_t *xp)
 122{
 123#ifdef CONFIG_SMP
 124        return native_make_pud(xchg(&xp->pud, 0));
 125#else
 126        /* native_local_pudp_get_and_clear,
 127         * but duplicated because of cyclic dependency
 128         */
 129        pud_t ret = *xp;
 130
 131        native_pud_clear(xp);
 132        return ret;
 133#endif
 134}
 135
 136static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
 137{
 138        pgd_t pgd;
 139
 140        if (pgtable_l5_enabled() || !IS_ENABLED(CONFIG_PAGE_TABLE_ISOLATION)) {
 141                WRITE_ONCE(*p4dp, p4d);
 142                return;
 143        }
 144
 145        pgd = native_make_pgd(native_p4d_val(p4d));
 146        pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd);
 147        WRITE_ONCE(*p4dp, native_make_p4d(native_pgd_val(pgd)));
 148}
 149
 150static inline void native_p4d_clear(p4d_t *p4d)
 151{
 152        native_set_p4d(p4d, native_make_p4d(0));
 153}
 154
 155static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 156{
 157        WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
 158}
 159
 160static inline void native_pgd_clear(pgd_t *pgd)
 161{
 162        native_set_pgd(pgd, native_make_pgd(0));
 163}
 164
 165extern void sync_global_pgds(unsigned long start, unsigned long end);
 166
 167/*
 168 * Conversion functions: convert a page and protection to a page entry,
 169 * and a page entry and page directory to the page they refer to.
 170 */
 171
 172/*
 173 * Level 4 access.
 174 */
 175#define mk_kernel_pgd(address) __pgd((address) | _KERNPG_TABLE)
 176
 177/* PUD - Level3 access */
 178
 179/* PMD  - Level 2 access */
 180
 181/* PTE - Level 1 access. */
 182
 183/* x86-64 always has all page tables mapped. */
 184#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
 185#define pte_unmap(pte) ((void)(pte))/* NOP */
 186
 187/*
 188 * Encode and de-code a swap entry
 189 *
 190 * |     ...            | 11| 10|  9|8|7|6|5| 4| 3|2| 1|0| <- bit number
 191 * |     ...            |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
 192 * | TYPE (59-63) | ~OFFSET (9-58)  |0|0|X|X| X| X|X|SD|0| <- swp entry
 193 *
 194 * G (8) is aliased and used as a PROT_NONE indicator for
 195 * !present ptes.  We need to start storing swap entries above
 196 * there.  We also need to avoid using A and D because of an
 197 * erratum where they can be incorrectly set by hardware on
 198 * non-present PTEs.
 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 * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
 204 * but also L and G.
 205 *
 206 * The offset is inverted by a binary not operation to make the high
 207 * physical bits set.
 208 */
 209#define SWP_TYPE_BITS           5
 210
 211#define SWP_OFFSET_FIRST_BIT    (_PAGE_BIT_PROTNONE + 1)
 212
 213/* We always extract/encode the offset by shifting it all the way up, and then down again */
 214#define SWP_OFFSET_SHIFT        (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
 215
 216#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
 217
 218/* Extract the high bits for type */
 219#define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
 220
 221/* Shift up (to get rid of type), then down to get value */
 222#define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
 223
 224/*
 225 * Shift the offset up "too far" by TYPE bits, then down again
 226 * The offset is inverted by a binary not operation to make the high
 227 * physical bits set.
 228 */
 229#define __swp_entry(type, offset) ((swp_entry_t) { \
 230        (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
 231        | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
 232
 233#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val((pte)) })
 234#define __pmd_to_swp_entry(pmd)         ((swp_entry_t) { pmd_val((pmd)) })
 235#define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
 236#define __swp_entry_to_pmd(x)           ((pmd_t) { .pmd = (x).val })
 237
 238extern int kern_addr_valid(unsigned long addr);
 239extern void cleanup_highmap(void);
 240
 241#define HAVE_ARCH_UNMAPPED_AREA
 242#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 243
 244#define PAGE_AGP    PAGE_KERNEL_NOCACHE
 245#define HAVE_PAGE_AGP 1
 246
 247/* fs/proc/kcore.c */
 248#define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
 249#define kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
 250
 251#define __HAVE_ARCH_PTE_SAME
 252
 253#define vmemmap ((struct page *)VMEMMAP_START)
 254
 255extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
 256extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
 257
 258#define gup_fast_permitted gup_fast_permitted
 259static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
 260{
 261        if (end >> __VIRTUAL_MASK_SHIFT)
 262                return false;
 263        return true;
 264}
 265
 266#include <asm/pgtable-invert.h>
 267
 268#endif /* !__ASSEMBLY__ */
 269#endif /* _ASM_X86_PGTABLE_64_H */
 270