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 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
  57 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
  58
  59 static inline void native_set_pte(pte_t *ptep, pte_t pte)
  60 {
  61         WRITE_ONCE(*ptep, pte);
  62 }
  63
  64 static 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
  70 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
  71 {
  72         native_set_pte(ptep, pte);
  73 }
  74
  75 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
  76 {
  77         WRITE_ONCE(*pmdp, pmd);
  78 }
  79
  80 static inline void native_pmd_clear(pmd_t *pmd)
  81 {
  82         native_set_pmd(pmd, native_make_pmd(0));
  83 }
  84
  85 static 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
  98 static 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
 111 static inline void native_set_pud(pud_t *pudp, pud_t pud)
 112 {
 113         WRITE_ONCE(*pudp, pud);
 114 }
 115
 116 static inline void native_pud_clear(pud_t *pud)
 117 {
 118         native_set_pud(pud, native_make_pud(0));
 119 }
 120
 121 static 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
 136 static 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
 150 static inline void native_p4d_clear(p4d_t *p4d)
 151 {
 152         native_set_p4d(p4d, native_make_p4d(0));
 153 }
 154
 155 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 156 {
 157         WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
 158 }
 159
 160 static inline void native_pgd_clear(pgd_t *pgd)
 161 {
 162         native_set_pgd(pgd, native_make_pgd(0));
 163 }
 164
 165 extern 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|F|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 Bits 1-4 are not used in non-present format and available for
 201  * special use described below:
 202  *
 203  * SD (1) in swp entry is used to store soft dirty bit, which helps us
 204  * remember soft dirty over page migration
 205  *
 206  * F (2) in swp entry is used to record when a pagetable is
 207  * writeprotected by userfaultfd WP support.
 208  *
 209  * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
 210  * but also L and G.
 211  *
 212  * The offset is inverted by a binary not operation to make the high
 213  * physical bits set.
 214  */
 215 #define SWP_TYPE_BITS           5
 216
 217 #define SWP_OFFSET_FIRST_BIT    (_PAGE_BIT_PROTNONE + 1)
 218
 219 /* We always extract/encode the offset by shifting it all the way up, and then down again */
 220 #define SWP_OFFSET_SHIFT        (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
 221
 222 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
 223
 224 /* Extract the high bits for type */
 225 #define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
 226
 227 /* Shift up (to get rid of type), then down to get value */
 228 #define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
 229
 230 /*
 231  * Shift the offset up "too far" by TYPE bits, then down again
 232  * The offset is inverted by a binary not operation to make the high
 233  * physical bits set.
 234  */
 235 #define __swp_entry(type, offset) ((swp_entry_t) { \
 236         (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
 237         | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
 238
 239 #define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val((pte)) })
 240 #define __pmd_to_swp_entry(pmd)         ((swp_entry_t) { pmd_val((pmd)) })
 241 #define __swp_entry_to_pte(x)           ((pte_t) { .pte = (x).val })
 242 #define __swp_entry_to_pmd(x)           ((pmd_t) { .pmd = (x).val })
 243
 244 extern int kern_addr_valid(unsigned long addr);
 245 extern void cleanup_highmap(void);
 246
 247 #define HAVE_ARCH_UNMAPPED_AREA
 248 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 249
 250 #define PAGE_AGP    PAGE_KERNEL_NOCACHE
 251 #define HAVE_PAGE_AGP 1
 252
 253 /* fs/proc/kcore.c */
 254 #define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
 255 #define kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
 256
 257 #define __HAVE_ARCH_PTE_SAME
 258
 259 #define vmemmap ((struct page *)VMEMMAP_START)
 260
 261 extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
 262 extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
 263
 264 #define gup_fast_permitted gup_fast_permitted
 265 static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
 266 {
 267         if (end >> __VIRTUAL_MASK_SHIFT)
 268                 return false;
 269         return true;
 270 }
 271
 272 #include <asm/pgtable-invert.h>
 273
 274 #endif /* !__ASSEMBLY__ */
 275 #endif /* _ASM_X86_PGTABLE_64_H */