include/asm-x86/pgtable.h

   1 #ifndef _ASM_X86_PGTABLE_H
   2 #define _ASM_X86_PGTABLE_H
   3
   4 #define FIRST_USER_ADDRESS      0
   5
   6 #define _PAGE_BIT_PRESENT       0       /* is present */
   7 #define _PAGE_BIT_RW            1       /* writeable */
   8 #define _PAGE_BIT_USER          2       /* userspace addressable */
   9 #define _PAGE_BIT_PWT           3       /* page write through */
  10 #define _PAGE_BIT_PCD           4       /* page cache disabled */
  11 #define _PAGE_BIT_ACCESSED      5       /* was accessed (raised by CPU) */
  12 #define _PAGE_BIT_DIRTY         6       /* was written to (raised by CPU) */
  13 #define _PAGE_BIT_FILE          6
  14 #define _PAGE_BIT_PSE           7       /* 4 MB (or 2MB) page */
  15 #define _PAGE_BIT_PAT           7       /* on 4KB pages */
  16 #define _PAGE_BIT_GLOBAL        8       /* Global TLB entry PPro+ */
  17 #define _PAGE_BIT_UNUSED1       9       /* available for programmer */
  18 #define _PAGE_BIT_UNUSED2       10
  19 #define _PAGE_BIT_UNUSED3       11
  20 #define _PAGE_BIT_PAT_LARGE     12      /* On 2MB or 1GB pages */
  21 #define _PAGE_BIT_SPECIAL       _PAGE_BIT_UNUSED1
  22 #define _PAGE_BIT_NX           63       /* No execute: only valid after cpuid check */
  23
  24 #define _PAGE_PRESENT   (_AT(pteval_t, 1) << _PAGE_BIT_PRESENT)
  25 #define _PAGE_RW        (_AT(pteval_t, 1) << _PAGE_BIT_RW)
  26 #define _PAGE_USER      (_AT(pteval_t, 1) << _PAGE_BIT_USER)
  27 #define _PAGE_PWT       (_AT(pteval_t, 1) << _PAGE_BIT_PWT)
  28 #define _PAGE_PCD       (_AT(pteval_t, 1) << _PAGE_BIT_PCD)
  29 #define _PAGE_ACCESSED  (_AT(pteval_t, 1) << _PAGE_BIT_ACCESSED)
  30 #define _PAGE_DIRTY     (_AT(pteval_t, 1) << _PAGE_BIT_DIRTY)
  31 #define _PAGE_PSE       (_AT(pteval_t, 1) << _PAGE_BIT_PSE)
  32 #define _PAGE_GLOBAL    (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL)
  33 #define _PAGE_UNUSED1   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED1)
  34 #define _PAGE_UNUSED2   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED2)
  35 #define _PAGE_UNUSED3   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED3)
  36 #define _PAGE_PAT       (_AT(pteval_t, 1) << _PAGE_BIT_PAT)
  37 #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE)
  38 #define _PAGE_SPECIAL   (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL)
  39 #define __HAVE_ARCH_PTE_SPECIAL
  40
  41 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
  42 #define _PAGE_NX        (_AT(pteval_t, 1) << _PAGE_BIT_NX)
  43 #else
  44 #define _PAGE_NX        (_AT(pteval_t, 0))
  45 #endif
  46
  47 /* If _PAGE_PRESENT is clear, we use these: */
  48 #define _PAGE_FILE      _PAGE_DIRTY     /* nonlinear file mapping,
  49                                          * saved PTE; unset:swap */
  50 #define _PAGE_PROTNONE  _PAGE_PSE       /* if the user mapped it with PROT_NONE;
  51                                            pte_present gives true */
  52
  53 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER |        \
  54                          _PAGE_ACCESSED | _PAGE_DIRTY)
  55 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED |    \
  56                          _PAGE_DIRTY)
  57
  58 /* Set of bits not changed in pte_modify */
  59 #define _PAGE_CHG_MASK  (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |         \
  60                          _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY)
  61
  62 #define _PAGE_CACHE_MASK        (_PAGE_PCD | _PAGE_PWT)
  63 #define _PAGE_CACHE_WB          (0)
  64 #define _PAGE_CACHE_WC          (_PAGE_PWT)
  65 #define _PAGE_CACHE_UC_MINUS    (_PAGE_PCD)
  66 #define _PAGE_CACHE_UC          (_PAGE_PCD | _PAGE_PWT)
  67
  68 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  69 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \
  70                                  _PAGE_ACCESSED | _PAGE_NX)
  71
  72 #define PAGE_SHARED_EXEC        __pgprot(_PAGE_PRESENT | _PAGE_RW |     \
  73                                          _PAGE_USER | _PAGE_ACCESSED)
  74 #define PAGE_COPY_NOEXEC        __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  75                                          _PAGE_ACCESSED | _PAGE_NX)
  76 #define PAGE_COPY_EXEC          __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  77                                          _PAGE_ACCESSED)
  78 #define PAGE_COPY               PAGE_COPY_NOEXEC
  79 #define PAGE_READONLY           __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  80                                          _PAGE_ACCESSED | _PAGE_NX)
  81 #define PAGE_READONLY_EXEC      __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  82                                          _PAGE_ACCESSED)
  83
  84 #define __PAGE_KERNEL_EXEC                                              \
  85         (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
  86 #define __PAGE_KERNEL           (__PAGE_KERNEL_EXEC | _PAGE_NX)
  87
  88 #define __PAGE_KERNEL_RO                (__PAGE_KERNEL & ~_PAGE_RW)
  89 #define __PAGE_KERNEL_RX                (__PAGE_KERNEL_EXEC & ~_PAGE_RW)
  90 #define __PAGE_KERNEL_EXEC_NOCACHE      (__PAGE_KERNEL_EXEC | _PAGE_PCD | _PAGE_PWT)
  91 #define __PAGE_KERNEL_WC                (__PAGE_KERNEL | _PAGE_CACHE_WC)
  92 #define __PAGE_KERNEL_NOCACHE           (__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT)
  93 #define __PAGE_KERNEL_UC_MINUS          (__PAGE_KERNEL | _PAGE_PCD)
  94 #define __PAGE_KERNEL_VSYSCALL          (__PAGE_KERNEL_RX | _PAGE_USER)
  95 #define __PAGE_KERNEL_VSYSCALL_NOCACHE  (__PAGE_KERNEL_VSYSCALL | _PAGE_PCD | _PAGE_PWT)
  96 #define __PAGE_KERNEL_LARGE             (__PAGE_KERNEL | _PAGE_PSE)
  97 #define __PAGE_KERNEL_LARGE_NOCACHE     (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)
  98 #define __PAGE_KERNEL_LARGE_EXEC        (__PAGE_KERNEL_EXEC | _PAGE_PSE)
  99
 100 #define PAGE_KERNEL                     __pgprot(__PAGE_KERNEL)
 101 #define PAGE_KERNEL_RO                  __pgprot(__PAGE_KERNEL_RO)
 102 #define PAGE_KERNEL_EXEC                __pgprot(__PAGE_KERNEL_EXEC)
 103 #define PAGE_KERNEL_RX                  __pgprot(__PAGE_KERNEL_RX)
 104 #define PAGE_KERNEL_WC                  __pgprot(__PAGE_KERNEL_WC)
 105 #define PAGE_KERNEL_NOCACHE             __pgprot(__PAGE_KERNEL_NOCACHE)
 106 #define PAGE_KERNEL_UC_MINUS            __pgprot(__PAGE_KERNEL_UC_MINUS)
 107 #define PAGE_KERNEL_EXEC_NOCACHE        __pgprot(__PAGE_KERNEL_EXEC_NOCACHE)
 108 #define PAGE_KERNEL_LARGE               __pgprot(__PAGE_KERNEL_LARGE)
 109 #define PAGE_KERNEL_LARGE_NOCACHE       __pgprot(__PAGE_KERNEL_LARGE_NOCACHE)
 110 #define PAGE_KERNEL_LARGE_EXEC          __pgprot(__PAGE_KERNEL_LARGE_EXEC)
 111 #define PAGE_KERNEL_VSYSCALL            __pgprot(__PAGE_KERNEL_VSYSCALL)
 112 #define PAGE_KERNEL_VSYSCALL_NOCACHE    __pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)
 113
 114 /*         xwr */
 115 #define __P000  PAGE_NONE
 116 #define __P001  PAGE_READONLY
 117 #define __P010  PAGE_COPY
 118 #define __P011  PAGE_COPY
 119 #define __P100  PAGE_READONLY_EXEC
 120 #define __P101  PAGE_READONLY_EXEC
 121 #define __P110  PAGE_COPY_EXEC
 122 #define __P111  PAGE_COPY_EXEC
 123
 124 #define __S000  PAGE_NONE
 125 #define __S001  PAGE_READONLY
 126 #define __S010  PAGE_SHARED
 127 #define __S011  PAGE_SHARED
 128 #define __S100  PAGE_READONLY_EXEC
 129 #define __S101  PAGE_READONLY_EXEC
 130 #define __S110  PAGE_SHARED_EXEC
 131 #define __S111  PAGE_SHARED_EXEC
 132
 133 #ifndef __ASSEMBLY__
 134
 135 /*
 136  * ZERO_PAGE is a global shared page that is always zero: used
 137  * for zero-mapped memory areas etc..
 138  */
 139 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 140 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 141
 142 extern spinlock_t pgd_lock;
 143 extern struct list_head pgd_list;
 144
 145 /*
 146  * The following only work if pte_present() is true.
 147  * Undefined behaviour if not..
 148  */
 149 static inline int pte_dirty(pte_t pte)
 150 {
 151         return pte_flags(pte) & _PAGE_DIRTY;
 152 }
 153
 154 static inline int pte_young(pte_t pte)
 155 {
 156         return pte_flags(pte) & _PAGE_ACCESSED;
 157 }
 158
 159 static inline int pte_write(pte_t pte)
 160 {
 161         return pte_flags(pte) & _PAGE_RW;
 162 }
 163
 164 static inline int pte_file(pte_t pte)
 165 {
 166         return pte_flags(pte) & _PAGE_FILE;
 167 }
 168
 169 static inline int pte_huge(pte_t pte)
 170 {
 171         return pte_flags(pte) & _PAGE_PSE;
 172 }
 173
 174 static inline int pte_global(pte_t pte)
 175 {
 176         return pte_flags(pte) & _PAGE_GLOBAL;
 177 }
 178
 179 static inline int pte_exec(pte_t pte)
 180 {
 181         return !(pte_flags(pte) & _PAGE_NX);
 182 }
 183
 184 static inline int pte_special(pte_t pte)
 185 {
 186         return pte_val(pte) & _PAGE_SPECIAL;
 187 }
 188
 189 static inline int pmd_large(pmd_t pte)
 190 {
 191         return (pmd_val(pte) & (_PAGE_PSE | _PAGE_PRESENT)) ==
 192                 (_PAGE_PSE | _PAGE_PRESENT);
 193 }
 194
 195 static inline pte_t pte_mkclean(pte_t pte)
 196 {
 197         return __pte(pte_val(pte) & ~_PAGE_DIRTY);
 198 }
 199
 200 static inline pte_t pte_mkold(pte_t pte)
 201 {
 202         return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
 203 }
 204
 205 static inline pte_t pte_wrprotect(pte_t pte)
 206 {
 207         return __pte(pte_val(pte) & ~_PAGE_RW);
 208 }
 209
 210 static inline pte_t pte_mkexec(pte_t pte)
 211 {
 212         return __pte(pte_val(pte) & ~_PAGE_NX);
 213 }
 214
 215 static inline pte_t pte_mkdirty(pte_t pte)
 216 {
 217         return __pte(pte_val(pte) | _PAGE_DIRTY);
 218 }
 219
 220 static inline pte_t pte_mkyoung(pte_t pte)
 221 {
 222         return __pte(pte_val(pte) | _PAGE_ACCESSED);
 223 }
 224
 225 static inline pte_t pte_mkwrite(pte_t pte)
 226 {
 227         return __pte(pte_val(pte) | _PAGE_RW);
 228 }
 229
 230 static inline pte_t pte_mkhuge(pte_t pte)
 231 {
 232         return __pte(pte_val(pte) | _PAGE_PSE);
 233 }
 234
 235 static inline pte_t pte_clrhuge(pte_t pte)
 236 {
 237         return __pte(pte_val(pte) & ~_PAGE_PSE);
 238 }
 239
 240 static inline pte_t pte_mkglobal(pte_t pte)
 241 {
 242         return __pte(pte_val(pte) | _PAGE_GLOBAL);
 243 }
 244
 245 static inline pte_t pte_clrglobal(pte_t pte)
 246 {
 247         return __pte(pte_val(pte) & ~_PAGE_GLOBAL);
 248 }
 249
 250 static inline pte_t pte_mkspecial(pte_t pte)
 251 {
 252         return __pte(pte_val(pte) | _PAGE_SPECIAL);
 253 }
 254
 255 extern pteval_t __supported_pte_mask;
 256
 257 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 258 {
 259         return __pte((((phys_addr_t)page_nr << PAGE_SHIFT) |
 260                       pgprot_val(pgprot)) & __supported_pte_mask);
 261 }
 262
 263 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 264 {
 265         return __pmd((((phys_addr_t)page_nr << PAGE_SHIFT) |
 266                       pgprot_val(pgprot)) & __supported_pte_mask);
 267 }
 268
 269 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 270 {
 271         pteval_t val = pte_val(pte);
 272
 273         /*
 274          * Chop off the NX bit (if present), and add the NX portion of
 275          * the newprot (if present):
 276          */
 277         val &= _PAGE_CHG_MASK;
 278         val |= pgprot_val(newprot) & (~_PAGE_CHG_MASK) & __supported_pte_mask;
 279
 280         return __pte(val);
 281 }
 282
 283 /* mprotect needs to preserve PAT bits when updating vm_page_prot */
 284 #define pgprot_modify pgprot_modify
 285 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
 286 {
 287         pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
 288         pgprotval_t addbits = pgprot_val(newprot);
 289         return __pgprot(preservebits | addbits);
 290 }
 291
 292 #define pte_pgprot(x) __pgprot(pte_flags(x) & PTE_FLAGS_MASK)
 293
 294 #define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
 295
 296 #ifndef __ASSEMBLY__
 297 #define __HAVE_PHYS_MEM_ACCESS_PROT
 298 struct file;
 299 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 300                               unsigned long size, pgprot_t vma_prot);
 301 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 302                               unsigned long size, pgprot_t *vma_prot);
 303 #endif
 304
 305 /* Install a pte for a particular vaddr in kernel space. */
 306 void set_pte_vaddr(unsigned long vaddr, pte_t pte);
 307
 308 #ifdef CONFIG_X86_32
 309 extern void native_pagetable_setup_start(pgd_t *base);
 310 extern void native_pagetable_setup_done(pgd_t *base);
 311 #else
 312 static inline void native_pagetable_setup_start(pgd_t *base) {}
 313 static inline void native_pagetable_setup_done(pgd_t *base) {}
 314 #endif
 315
 316 #ifdef CONFIG_PARAVIRT
 317 #include <asm/paravirt.h>
 318 #else  /* !CONFIG_PARAVIRT */
 319 #define set_pte(ptep, pte)              native_set_pte(ptep, pte)
 320 #define set_pte_at(mm, addr, ptep, pte) native_set_pte_at(mm, addr, ptep, pte)
 321
 322 #define set_pte_present(mm, addr, ptep, pte)                            \
 323         native_set_pte_present(mm, addr, ptep, pte)
 324 #define set_pte_atomic(ptep, pte)                                       \
 325         native_set_pte_atomic(ptep, pte)
 326
 327 #define set_pmd(pmdp, pmd)              native_set_pmd(pmdp, pmd)
 328
 329 #ifndef __PAGETABLE_PUD_FOLDED
 330 #define set_pgd(pgdp, pgd)              native_set_pgd(pgdp, pgd)
 331 #define pgd_clear(pgd)                  native_pgd_clear(pgd)
 332 #endif
 333
 334 #ifndef set_pud
 335 # define set_pud(pudp, pud)             native_set_pud(pudp, pud)
 336 #endif
 337
 338 #ifndef __PAGETABLE_PMD_FOLDED
 339 #define pud_clear(pud)                  native_pud_clear(pud)
 340 #endif
 341
 342 #define pte_clear(mm, addr, ptep)       native_pte_clear(mm, addr, ptep)
 343 #define pmd_clear(pmd)                  native_pmd_clear(pmd)
 344
 345 #define pte_update(mm, addr, ptep)              do { } while (0)
 346 #define pte_update_defer(mm, addr, ptep)        do { } while (0)
 347
 348 static inline void __init paravirt_pagetable_setup_start(pgd_t *base)
 349 {
 350         native_pagetable_setup_start(base);
 351 }
 352
 353 static inline void __init paravirt_pagetable_setup_done(pgd_t *base)
 354 {
 355         native_pagetable_setup_done(base);
 356 }
 357 #endif  /* CONFIG_PARAVIRT */
 358
 359 #endif  /* __ASSEMBLY__ */
 360
 361 #ifdef CONFIG_X86_32
 362 # include "pgtable_32.h"
 363 #else
 364 # include "pgtable_64.h"
 365 #endif
 366
 367 /*
 368  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 369  *
 370  * this macro returns the index of the entry in the pgd page which would
 371  * control the given virtual address
 372  */
 373 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 374
 375 /*
 376  * pgd_offset() returns a (pgd_t *)
 377  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 378  */
 379 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index((address)))
 380 /*
 381  * a shortcut which implies the use of the kernel's pgd, instead
 382  * of a process's
 383  */
 384 #define pgd_offset_k(address) pgd_offset(&init_mm, (address))
 385
 386
 387 #define KERNEL_PGD_BOUNDARY     pgd_index(PAGE_OFFSET)
 388 #define KERNEL_PGD_PTRS         (PTRS_PER_PGD - KERNEL_PGD_BOUNDARY)
 389
 390 #ifndef __ASSEMBLY__
 391
 392 enum {
 393         PG_LEVEL_NONE,
 394         PG_LEVEL_4K,
 395         PG_LEVEL_2M,
 396         PG_LEVEL_1G,
 397         PG_LEVEL_NUM
 398 };
 399
 400 #ifdef CONFIG_PROC_FS
 401 extern void update_page_count(int level, unsigned long pages);
 402 #else
 403 static inline void update_page_count(int level, unsigned long pages) { }
 404 #endif
 405
 406 /*
 407  * Helper function that returns the kernel pagetable entry controlling
 408  * the virtual address 'address'. NULL means no pagetable entry present.
 409  * NOTE: the return type is pte_t but if the pmd is PSE then we return it
 410  * as a pte too.
 411  */
 412 extern pte_t *lookup_address(unsigned long address, unsigned int *level);
 413
 414 /* local pte updates need not use xchg for locking */
 415 static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
 416 {
 417         pte_t res = *ptep;
 418
 419         /* Pure native function needs no input for mm, addr */
 420         native_pte_clear(NULL, 0, ptep);
 421         return res;
 422 }
 423
 424 static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
 425                                      pte_t *ptep , pte_t pte)
 426 {
 427         native_set_pte(ptep, pte);
 428 }
 429
 430 #ifndef CONFIG_PARAVIRT
 431 /*
 432  * Rules for using pte_update - it must be called after any PTE update which
 433  * has not been done using the set_pte / clear_pte interfaces.  It is used by
 434  * shadow mode hypervisors to resynchronize the shadow page tables.  Kernel PTE
 435  * updates should either be sets, clears, or set_pte_atomic for P->P
 436  * transitions, which means this hook should only be called for user PTEs.
 437  * This hook implies a P->P protection or access change has taken place, which
 438  * requires a subsequent TLB flush.  The notification can optionally be delayed
 439  * until the TLB flush event by using the pte_update_defer form of the
 440  * interface, but care must be taken to assure that the flush happens while
 441  * still holding the same page table lock so that the shadow and primary pages
 442  * do not become out of sync on SMP.
 443  */
 444 #define pte_update(mm, addr, ptep)              do { } while (0)
 445 #define pte_update_defer(mm, addr, ptep)        do { } while (0)
 446 #endif
 447
 448 /*
 449  * We only update the dirty/accessed state if we set
 450  * the dirty bit by hand in the kernel, since the hardware
 451  * will do the accessed bit for us, and we don't want to
 452  * race with other CPU's that might be updating the dirty
 453  * bit at the same time.
 454  */
 455 struct vm_area_struct;
 456
 457 #define  __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 458 extern int ptep_set_access_flags(struct vm_area_struct *vma,
 459                                  unsigned long address, pte_t *ptep,
 460                                  pte_t entry, int dirty);
 461
 462 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 463 extern int ptep_test_and_clear_young(struct vm_area_struct *vma,
 464                                      unsigned long addr, pte_t *ptep);
 465
 466 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 467 extern int ptep_clear_flush_young(struct vm_area_struct *vma,
 468                                   unsigned long address, pte_t *ptep);
 469
 470 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 471 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 472                                        pte_t *ptep)
 473 {
 474         pte_t pte = native_ptep_get_and_clear(ptep);
 475         pte_update(mm, addr, ptep);
 476         return pte;
 477 }
 478
 479 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
 480 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 481                                             unsigned long addr, pte_t *ptep,
 482                                             int full)
 483 {
 484         pte_t pte;
 485         if (full) {
 486                 /*
 487                  * Full address destruction in progress; paravirt does not
 488                  * care about updates and native needs no locking
 489                  */
 490                 pte = native_local_ptep_get_and_clear(ptep);
 491         } else {
 492                 pte = ptep_get_and_clear(mm, addr, ptep);
 493         }
 494         return pte;
 495 }
 496
 497 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 498 static inline void ptep_set_wrprotect(struct mm_struct *mm,
 499                                       unsigned long addr, pte_t *ptep)
 500 {
 501         clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
 502         pte_update(mm, addr, ptep);
 503 }
 504
 505 /*
 506  * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
 507  *
 508  *  dst - pointer to pgd range anwhere on a pgd page
 509  *  src - ""
 510  *  count - the number of pgds to copy.
 511  *
 512  * dst and src can be on the same page, but the range must not overlap,
 513  * and must not cross a page boundary.
 514  */
 515 static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
 516 {
 517        memcpy(dst, src, count * sizeof(pgd_t));
 518 }
 519
 520
 521 #include <asm-generic/pgtable.h>
 522 #endif  /* __ASSEMBLY__ */
 523
 524 #endif  /* _ASM_X86_PGTABLE_H */