arch/arm64/include/asm/pgtable.h

   1 /*
   2  * Copyright (C) 2012 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_PGTABLE_H
  17 #define __ASM_PGTABLE_H
  18
  19 #include <asm/proc-fns.h>
  20
  21 #include <asm/memory.h>
  22 #include <asm/pgtable-hwdef.h>
  23
  24 /*
  25  * Software defined PTE bits definition.
  26  */
  27 #define PTE_VALID               (_AT(pteval_t, 1) << 0)
  28 #define PTE_FILE                (_AT(pteval_t, 1) << 2) /* only when !pte_present() */
  29 #define PTE_DIRTY               (_AT(pteval_t, 1) << 55)
  30 #define PTE_SPECIAL             (_AT(pteval_t, 1) << 56)
  31 #define PTE_WRITE               (_AT(pteval_t, 1) << 57)
  32 #define PTE_PROT_NONE           (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
  33
  34 /*
  35  * VMALLOC and SPARSEMEM_VMEMMAP ranges.
  36  *
  37  * VMEMAP_SIZE: allows the whole VA space to be covered by a struct page array
  38  *      (rounded up to PUD_SIZE).
  39  * VMALLOC_START: beginning of the kernel VA space
  40  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space,
  41  *      fixed mappings and modules
  42  */
  43 #define VMEMMAP_SIZE            ALIGN((1UL << (VA_BITS - PAGE_SHIFT)) * sizeof(struct page), PUD_SIZE)
  44 #define VMALLOC_START           (UL(0xffffffffffffffff) << VA_BITS)
  45 #define VMALLOC_END             (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
  46
  47 #define vmemmap                 ((struct page *)(VMALLOC_END + SZ_64K))
  48
  49 #define FIRST_USER_ADDRESS      0
  50
  51 #ifndef __ASSEMBLY__
  52 extern void __pte_error(const char *file, int line, unsigned long val);
  53 extern void __pmd_error(const char *file, int line, unsigned long val);
  54 extern void __pud_error(const char *file, int line, unsigned long val);
  55 extern void __pgd_error(const char *file, int line, unsigned long val);
  56
  57 #ifdef CONFIG_SMP
  58 #define PROT_DEFAULT            (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
  59 #define PROT_SECT_DEFAULT       (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
  60 #else
  61 #define PROT_DEFAULT            (PTE_TYPE_PAGE | PTE_AF)
  62 #define PROT_SECT_DEFAULT       (PMD_TYPE_SECT | PMD_SECT_AF)
  63 #endif
  64
  65 #define PROT_DEVICE_nGnRE       (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
  66 #define PROT_NORMAL_NC          (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL_NC))
  67 #define PROT_NORMAL             (PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_NORMAL))
  68
  69 #define PROT_SECT_DEVICE_nGnRE  (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
  70 #define PROT_SECT_NORMAL        (PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
  71 #define PROT_SECT_NORMAL_EXEC   (PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
  72
  73 #define _PAGE_DEFAULT           (PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
  74
  75 #define PAGE_KERNEL             __pgprot(_PAGE_DEFAULT | PTE_PXN | PTE_UXN | PTE_DIRTY | PTE_WRITE)
  76 #define PAGE_KERNEL_EXEC        __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
  77
  78 #define PAGE_HYP                __pgprot(_PAGE_DEFAULT | PTE_HYP)
  79 #define PAGE_HYP_DEVICE         __pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
  80
  81 #define PAGE_S2                 __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
  82 #define PAGE_S2_DEVICE          __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_DEVICE_nGnRE) | PTE_S2_RDWR | PTE_UXN)
  83
  84 #define PAGE_NONE               __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_PXN | PTE_UXN)
  85 #define PAGE_SHARED             __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
  86 #define PAGE_SHARED_EXEC        __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_WRITE)
  87 #define PAGE_COPY               __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
  88 #define PAGE_COPY_EXEC          __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
  89 #define PAGE_READONLY           __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN)
  90 #define PAGE_READONLY_EXEC      __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN)
  91
  92 #define __P000  PAGE_NONE
  93 #define __P001  PAGE_READONLY
  94 #define __P010  PAGE_COPY
  95 #define __P011  PAGE_COPY
  96 #define __P100  PAGE_READONLY_EXEC
  97 #define __P101  PAGE_READONLY_EXEC
  98 #define __P110  PAGE_COPY_EXEC
  99 #define __P111  PAGE_COPY_EXEC
 100
 101 #define __S000  PAGE_NONE
 102 #define __S001  PAGE_READONLY
 103 #define __S010  PAGE_SHARED
 104 #define __S011  PAGE_SHARED
 105 #define __S100  PAGE_READONLY_EXEC
 106 #define __S101  PAGE_READONLY_EXEC
 107 #define __S110  PAGE_SHARED_EXEC
 108 #define __S111  PAGE_SHARED_EXEC
 109
 110 /*
 111  * ZERO_PAGE is a global shared page that is always zero: used
 112  * for zero-mapped memory areas etc..
 113  */
 114 extern struct page *empty_zero_page;
 115 #define ZERO_PAGE(vaddr)        (empty_zero_page)
 116
 117 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
 118
 119 #define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 120
 121 #define pfn_pte(pfn,prot)       (__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
 122
 123 #define pte_none(pte)           (!pte_val(pte))
 124 #define pte_clear(mm,addr,ptep) set_pte(ptep, __pte(0))
 125 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
 126
 127 /* Find an entry in the third-level page table. */
 128 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 129
 130 #define pte_offset_kernel(dir,addr)     (pmd_page_vaddr(*(dir)) + pte_index(addr))
 131
 132 #define pte_offset_map(dir,addr)        pte_offset_kernel((dir), (addr))
 133 #define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
 134 #define pte_unmap(pte)                  do { } while (0)
 135 #define pte_unmap_nested(pte)           do { } while (0)
 136
 137 /*
 138  * The following only work if pte_present(). Undefined behaviour otherwise.
 139  */
 140 #define pte_present(pte)        (!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
 141 #define pte_dirty(pte)          (!!(pte_val(pte) & PTE_DIRTY))
 142 #define pte_young(pte)          (!!(pte_val(pte) & PTE_AF))
 143 #define pte_special(pte)        (!!(pte_val(pte) & PTE_SPECIAL))
 144 #define pte_write(pte)          (!!(pte_val(pte) & PTE_WRITE))
 145 #define pte_exec(pte)           (!(pte_val(pte) & PTE_UXN))
 146
 147 #define pte_valid_user(pte) \
 148         ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
 149 #define pte_valid_not_user(pte) \
 150         ((pte_val(pte) & (PTE_VALID | PTE_USER)) == PTE_VALID)
 151
 152 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
 153 {
 154         pte_val(pte) &= ~pgprot_val(prot);
 155         return pte;
 156 }
 157
 158 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
 159 {
 160         pte_val(pte) |= pgprot_val(prot);
 161         return pte;
 162 }
 163
 164 static inline pte_t pte_wrprotect(pte_t pte)
 165 {
 166         return clear_pte_bit(pte, __pgprot(PTE_WRITE));
 167 }
 168
 169 static inline pte_t pte_mkwrite(pte_t pte)
 170 {
 171         return set_pte_bit(pte, __pgprot(PTE_WRITE));
 172 }
 173
 174 static inline pte_t pte_mkclean(pte_t pte)
 175 {
 176         return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
 177 }
 178
 179 static inline pte_t pte_mkdirty(pte_t pte)
 180 {
 181         return set_pte_bit(pte, __pgprot(PTE_DIRTY));
 182 }
 183
 184 static inline pte_t pte_mkold(pte_t pte)
 185 {
 186         return clear_pte_bit(pte, __pgprot(PTE_AF));
 187 }
 188
 189 static inline pte_t pte_mkyoung(pte_t pte)
 190 {
 191         return set_pte_bit(pte, __pgprot(PTE_AF));
 192 }
 193
 194 static inline pte_t pte_mkspecial(pte_t pte)
 195 {
 196         return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
 197 }
 198
 199 static inline void set_pte(pte_t *ptep, pte_t pte)
 200 {
 201         *ptep = pte;
 202
 203         /*
 204          * Only if the new pte is valid and kernel, otherwise TLB maintenance
 205          * or update_mmu_cache() have the necessary barriers.
 206          */
 207         if (pte_valid_not_user(pte)) {
 208                 dsb(ishst);
 209                 isb();
 210         }
 211 }
 212
 213 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
 214
 215 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 216                               pte_t *ptep, pte_t pte)
 217 {
 218         if (pte_valid_user(pte)) {
 219                 if (!pte_special(pte) && pte_exec(pte))
 220                         __sync_icache_dcache(pte, addr);
 221                 if (pte_dirty(pte) && pte_write(pte))
 222                         pte_val(pte) &= ~PTE_RDONLY;
 223                 else
 224                         pte_val(pte) |= PTE_RDONLY;
 225         }
 226
 227         set_pte(ptep, pte);
 228 }
 229
 230 /*
 231  * Huge pte definitions.
 232  */
 233 #define pte_huge(pte)           (!(pte_val(pte) & PTE_TABLE_BIT))
 234 #define pte_mkhuge(pte)         (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
 235
 236 /*
 237  * Hugetlb definitions.
 238  */
 239 #define HUGE_MAX_HSTATE         2
 240 #define HPAGE_SHIFT             PMD_SHIFT
 241 #define HPAGE_SIZE              (_AC(1, UL) << HPAGE_SHIFT)
 242 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
 243 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 244
 245 #define __HAVE_ARCH_PTE_SPECIAL
 246
 247 static inline pte_t pmd_pte(pmd_t pmd)
 248 {
 249         return __pte(pmd_val(pmd));
 250 }
 251
 252 static inline pmd_t pte_pmd(pte_t pte)
 253 {
 254         return __pmd(pte_val(pte));
 255 }
 256
 257 /*
 258  * THP definitions.
 259  */
 260
 261 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 262 #define pmd_trans_huge(pmd)     (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
 263 #define pmd_trans_splitting(pmd)        pte_special(pmd_pte(pmd))
 264 #endif
 265
 266 #define pmd_young(pmd)          pte_young(pmd_pte(pmd))
 267 #define pmd_wrprotect(pmd)      pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 268 #define pmd_mksplitting(pmd)    pte_pmd(pte_mkspecial(pmd_pte(pmd)))
 269 #define pmd_mkold(pmd)          pte_pmd(pte_mkold(pmd_pte(pmd)))
 270 #define pmd_mkwrite(pmd)        pte_pmd(pte_mkwrite(pmd_pte(pmd)))
 271 #define pmd_mkdirty(pmd)        pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 272 #define pmd_mkyoung(pmd)        pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 273 #define pmd_mknotpresent(pmd)   (__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
 274
 275 #define __HAVE_ARCH_PMD_WRITE
 276 #define pmd_write(pmd)          pte_write(pmd_pte(pmd))
 277
 278 #define pmd_mkhuge(pmd)         (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
 279
 280 #define pmd_pfn(pmd)            (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 281 #define pfn_pmd(pfn,prot)       (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
 282 #define mk_pmd(page,prot)       pfn_pmd(page_to_pfn(page),prot)
 283
 284 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 285 #define pud_pfn(pud)            (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 286
 287 #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
 288
 289 static inline int has_transparent_hugepage(void)
 290 {
 291         return 1;
 292 }
 293
 294 #define __pgprot_modify(prot,mask,bits) \
 295         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
 296
 297 /*
 298  * Mark the prot value as uncacheable and unbufferable.
 299  */
 300 #define pgprot_noncached(prot) \
 301         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
 302 #define pgprot_writecombine(prot) \
 303         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
 304 #define __HAVE_PHYS_MEM_ACCESS_PROT
 305 struct file;
 306 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 307                                      unsigned long size, pgprot_t vma_prot);
 308
 309 #define pmd_none(pmd)           (!pmd_val(pmd))
 310 #define pmd_present(pmd)        (pmd_val(pmd))
 311
 312 #define pmd_bad(pmd)            (!(pmd_val(pmd) & 2))
 313
 314 #define pmd_table(pmd)          ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 315                                  PMD_TYPE_TABLE)
 316 #define pmd_sect(pmd)           ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 317                                  PMD_TYPE_SECT)
 318
 319 #ifdef CONFIG_ARM64_64K_PAGES
 320 #define pud_sect(pud)           (0)
 321 #else
 322 #define pud_sect(pud)           ((pud_val(pud) & PUD_TYPE_MASK) == \
 323                                  PUD_TYPE_SECT)
 324 #endif
 325
 326 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 327 {
 328         *pmdp = pmd;
 329         dsb(ishst);
 330         isb();
 331 }
 332
 333 static inline void pmd_clear(pmd_t *pmdp)
 334 {
 335         set_pmd(pmdp, __pmd(0));
 336 }
 337
 338 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 339 {
 340         return __va(pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK);
 341 }
 342
 343 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 344
 345 /*
 346  * Conversion functions: convert a page and protection to a page entry,
 347  * and a page entry and page directory to the page they refer to.
 348  */
 349 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page),prot)
 350
 351 #if CONFIG_ARM64_PGTABLE_LEVELS > 2
 352
 353 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
 354
 355 #define pud_none(pud)           (!pud_val(pud))
 356 #define pud_bad(pud)            (!(pud_val(pud) & 2))
 357 #define pud_present(pud)        (pud_val(pud))
 358
 359 static inline void set_pud(pud_t *pudp, pud_t pud)
 360 {
 361         *pudp = pud;
 362         dsb(ishst);
 363         isb();
 364 }
 365
 366 static inline void pud_clear(pud_t *pudp)
 367 {
 368         set_pud(pudp, __pud(0));
 369 }
 370
 371 static inline pmd_t *pud_page_vaddr(pud_t pud)
 372 {
 373         return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
 374 }
 375
 376 /* Find an entry in the second-level page table. */
 377 #define pmd_index(addr)         (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 378
 379 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 380 {
 381         return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
 382 }
 383
 384 #endif  /* CONFIG_ARM64_PGTABLE_LEVELS > 2 */
 385
 386 #if CONFIG_ARM64_PGTABLE_LEVELS > 3
 387
 388 #define pud_ERROR(pud)          __pud_error(__FILE__, __LINE__, pud_val(pud))
 389
 390 #define pgd_none(pgd)           (!pgd_val(pgd))
 391 #define pgd_bad(pgd)            (!(pgd_val(pgd) & 2))
 392 #define pgd_present(pgd)        (pgd_val(pgd))
 393
 394 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
 395 {
 396         *pgdp = pgd;
 397         dsb(ishst);
 398 }
 399
 400 static inline void pgd_clear(pgd_t *pgdp)
 401 {
 402         set_pgd(pgdp, __pgd(0));
 403 }
 404
 405 static inline pud_t *pgd_page_vaddr(pgd_t pgd)
 406 {
 407         return __va(pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK);
 408 }
 409
 410 /* Find an entry in the frst-level page table. */
 411 #define pud_index(addr)         (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
 412
 413 static inline pud_t *pud_offset(pgd_t *pgd, unsigned long addr)
 414 {
 415         return (pud_t *)pgd_page_vaddr(*pgd) + pud_index(addr);
 416 }
 417
 418 #endif  /* CONFIG_ARM64_PGTABLE_LEVELS > 3 */
 419
 420 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 421
 422 /* to find an entry in a page-table-directory */
 423 #define pgd_index(addr)         (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 424
 425 #define pgd_offset(mm, addr)    ((mm)->pgd+pgd_index(addr))
 426
 427 /* to find an entry in a kernel page-table-directory */
 428 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 429
 430 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 431 {
 432         const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
 433                               PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
 434         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 435         return pte;
 436 }
 437
 438 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 439 {
 440         return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
 441 }
 442
 443 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 444 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
 445
 446 /*
 447  * Encode and decode a swap entry:
 448  *      bits 0-1:       present (must be zero)
 449  *      bit  2:         PTE_FILE
 450  *      bits 3-8:       swap type
 451  *      bits 9-57:      swap offset
 452  */
 453 #define __SWP_TYPE_SHIFT        3
 454 #define __SWP_TYPE_BITS         6
 455 #define __SWP_OFFSET_BITS       49
 456 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 457 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 458 #define __SWP_OFFSET_MASK       ((1UL << __SWP_OFFSET_BITS) - 1)
 459
 460 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 461 #define __swp_offset(x)         (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
 462 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 463
 464 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 465 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 466
 467 /*
 468  * Ensure that there are not more swap files than can be encoded in the kernel
 469  * PTEs.
 470  */
 471 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 472
 473 /*
 474  * Encode and decode a file entry:
 475  *      bits 0-1:       present (must be zero)
 476  *      bit  2:         PTE_FILE
 477  *      bits 3-57:      file offset / PAGE_SIZE
 478  */
 479 #define pte_file(pte)           (pte_val(pte) & PTE_FILE)
 480 #define pte_to_pgoff(x)         (pte_val(x) >> 3)
 481 #define pgoff_to_pte(x)         __pte(((x) << 3) | PTE_FILE)
 482
 483 #define PTE_FILE_MAX_BITS       55
 484
 485 extern int kern_addr_valid(unsigned long addr);
 486
 487 #include <asm-generic/pgtable.h>
 488
 489 #define pgtable_cache_init() do { } while (0)
 490
 491 #endif /* !__ASSEMBLY__ */
 492
 493 #endif /* __ASM_PGTABLE_H */