arch/x86/include/asm/pgtable_64.h

   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
  19 extern p4d_t level4_kernel_pgt[512];
  20 extern p4d_t level4_ident_pgt[512];
  21 extern pud_t level3_kernel_pgt[512];
  22 extern pud_t level3_ident_pgt[512];
  23 extern pmd_t level2_kernel_pgt[512];
  24 extern pmd_t level2_fixmap_pgt[512];
  25 extern pmd_t level2_ident_pgt[512];
  26 extern pte_t level1_fixmap_pgt[512 * FIXMAP_PMD_NUM];
  27 extern pgd_t init_top_pgt[];
  28
  29 #define swapper_pg_dir init_top_pgt
  30
  31 extern void paging_init(void);
  32 static 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
  54 struct mm_struct;
  55
  56 #define mm_p4d_folded mm_p4d_folded
  57 static inline bool mm_p4d_folded(struct mm_struct *mm)
  58 {
  59         return !pgtable_l5_enabled();
  60 }
  61
  62 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
  63 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
  64
  65 static inline void native_set_pte(pte_t *ptep, pte_t pte)
  66 {
  67         WRITE_ONCE(*ptep, pte);
  68 }
  69
  70 static 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
  76 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  77 {
  78         native_set_pte(ptep, pte);
  79 }
  80
  81 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  82 {
  83         WRITE_ONCE(*pmdp, pmd);
  84 }
  85
  86 static inline void native_pmd_clear(pmd_t *pmd)
  87 {
  88         native_set_pmd(pmd, native_make_pmd(0));
  89 }
  90
  91 static 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
 104 static 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
 117 static inline void native_set_pud(pud_t *pudp, pud_t pud)
 118 {
 119         WRITE_ONCE(*pudp, pud);
 120 }
 121
 122 static inline void native_pud_clear(pud_t *pud)
 123 {
 124         native_set_pud(pud, native_make_pud(0));
 125 }
 126
 127 static 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
 142 static 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
 156 static inline void native_p4d_clear(p4d_t *p4d)
 157 {
 158         native_set_p4d(p4d, native_make_p4d(0));
 159 }
 160
 161 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 162 {
 163         WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
 164 }
 165
 166 static 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
 241 extern int kern_addr_valid(unsigned long addr);
 242 extern 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
 258 extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
 259 extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
 260
 261 #define gup_fast_permitted gup_fast_permitted
 262 static 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 */