arch/x86/include/asm/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_IOMAP         10      /* flag used to indicate IO mapping */
  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_CPA_TEST      _PAGE_BIT_UNUSED1
  23 #define _PAGE_BIT_NX           63       /* No execute: only valid after cpuid check */
  24
  25 #define _PAGE_PRESENT   (_AT(pteval_t, 1) << _PAGE_BIT_PRESENT)
  26 #define _PAGE_RW        (_AT(pteval_t, 1) << _PAGE_BIT_RW)
  27 #define _PAGE_USER      (_AT(pteval_t, 1) << _PAGE_BIT_USER)
  28 #define _PAGE_PWT       (_AT(pteval_t, 1) << _PAGE_BIT_PWT)
  29 #define _PAGE_PCD       (_AT(pteval_t, 1) << _PAGE_BIT_PCD)
  30 #define _PAGE_ACCESSED  (_AT(pteval_t, 1) << _PAGE_BIT_ACCESSED)
  31 #define _PAGE_DIRTY     (_AT(pteval_t, 1) << _PAGE_BIT_DIRTY)
  32 #define _PAGE_PSE       (_AT(pteval_t, 1) << _PAGE_BIT_PSE)
  33 #define _PAGE_GLOBAL    (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL)
  34 #define _PAGE_UNUSED1   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED1)
  35 #define _PAGE_IOMAP     (_AT(pteval_t, 1) << _PAGE_BIT_IOMAP)
  36 #define _PAGE_UNUSED3   (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED3)
  37 #define _PAGE_PAT       (_AT(pteval_t, 1) << _PAGE_BIT_PAT)
  38 #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE)
  39 #define _PAGE_SPECIAL   (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL)
  40 #define _PAGE_CPA_TEST  (_AT(pteval_t, 1) << _PAGE_BIT_CPA_TEST)
  41 #define __HAVE_ARCH_PTE_SPECIAL
  42
  43 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
  44 #define _PAGE_NX        (_AT(pteval_t, 1) << _PAGE_BIT_NX)
  45 #else
  46 #define _PAGE_NX        (_AT(pteval_t, 0))
  47 #endif
  48
  49 /* If _PAGE_PRESENT is clear, we use these: */
  50 #define _PAGE_FILE      _PAGE_DIRTY     /* nonlinear file mapping,
  51                                          * saved PTE; unset:swap */
  52 #define _PAGE_PROTNONE  _PAGE_PSE       /* if the user mapped it with PROT_NONE;
  53                                            pte_present gives true */
  54
  55 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER |        \
  56                          _PAGE_ACCESSED | _PAGE_DIRTY)
  57 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED |    \
  58                          _PAGE_DIRTY)
  59
  60 /* Set of bits not changed in pte_modify */
  61 #define _PAGE_CHG_MASK  (PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |         \
  62                          _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY)
  63
  64 #define _PAGE_CACHE_MASK        (_PAGE_PCD | _PAGE_PWT)
  65 #define _PAGE_CACHE_WB          (0)
  66 #define _PAGE_CACHE_WC          (_PAGE_PWT)
  67 #define _PAGE_CACHE_UC_MINUS    (_PAGE_PCD)
  68 #define _PAGE_CACHE_UC          (_PAGE_PCD | _PAGE_PWT)
  69
  70 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  71 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \
  72                                  _PAGE_ACCESSED | _PAGE_NX)
  73
  74 #define PAGE_SHARED_EXEC        __pgprot(_PAGE_PRESENT | _PAGE_RW |     \
  75                                          _PAGE_USER | _PAGE_ACCESSED)
  76 #define PAGE_COPY_NOEXEC        __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  77                                          _PAGE_ACCESSED | _PAGE_NX)
  78 #define PAGE_COPY_EXEC          __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  79                                          _PAGE_ACCESSED)
  80 #define PAGE_COPY               PAGE_COPY_NOEXEC
  81 #define PAGE_READONLY           __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  82                                          _PAGE_ACCESSED | _PAGE_NX)
  83 #define PAGE_READONLY_EXEC      __pgprot(_PAGE_PRESENT | _PAGE_USER |   \
  84                                          _PAGE_ACCESSED)
  85
  86 #define __PAGE_KERNEL_EXEC                                              \
  87         (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_GLOBAL)
  88 #define __PAGE_KERNEL           (__PAGE_KERNEL_EXEC | _PAGE_NX)
  89
  90 #define __PAGE_KERNEL_RO                (__PAGE_KERNEL & ~_PAGE_RW)
  91 #define __PAGE_KERNEL_RX                (__PAGE_KERNEL_EXEC & ~_PAGE_RW)
  92 #define __PAGE_KERNEL_EXEC_NOCACHE      (__PAGE_KERNEL_EXEC | _PAGE_PCD | _PAGE_PWT)
  93 #define __PAGE_KERNEL_WC                (__PAGE_KERNEL | _PAGE_CACHE_WC)
  94 #define __PAGE_KERNEL_NOCACHE           (__PAGE_KERNEL | _PAGE_PCD | _PAGE_PWT)
  95 #define __PAGE_KERNEL_UC_MINUS          (__PAGE_KERNEL | _PAGE_PCD)
  96 #define __PAGE_KERNEL_VSYSCALL          (__PAGE_KERNEL_RX | _PAGE_USER)
  97 #define __PAGE_KERNEL_VSYSCALL_NOCACHE  (__PAGE_KERNEL_VSYSCALL | _PAGE_PCD | _PAGE_PWT)
  98 #define __PAGE_KERNEL_LARGE             (__PAGE_KERNEL | _PAGE_PSE)
  99 #define __PAGE_KERNEL_LARGE_NOCACHE     (__PAGE_KERNEL | _PAGE_CACHE_UC | _PAGE_PSE)
 100 #define __PAGE_KERNEL_LARGE_EXEC        (__PAGE_KERNEL_EXEC | _PAGE_PSE)
 101
 102 #define __PAGE_KERNEL_IO                (__PAGE_KERNEL | _PAGE_IOMAP)
 103 #define __PAGE_KERNEL_IO_NOCACHE        (__PAGE_KERNEL_NOCACHE | _PAGE_IOMAP)
 104 #define __PAGE_KERNEL_IO_UC_MINUS       (__PAGE_KERNEL_UC_MINUS | _PAGE_IOMAP)
 105 #define __PAGE_KERNEL_IO_WC             (__PAGE_KERNEL_WC | _PAGE_IOMAP)
 106
 107 #define PAGE_KERNEL                     __pgprot(__PAGE_KERNEL)
 108 #define PAGE_KERNEL_RO                  __pgprot(__PAGE_KERNEL_RO)
 109 #define PAGE_KERNEL_EXEC                __pgprot(__PAGE_KERNEL_EXEC)
 110 #define PAGE_KERNEL_RX                  __pgprot(__PAGE_KERNEL_RX)
 111 #define PAGE_KERNEL_WC                  __pgprot(__PAGE_KERNEL_WC)
 112 #define PAGE_KERNEL_NOCACHE             __pgprot(__PAGE_KERNEL_NOCACHE)
 113 #define PAGE_KERNEL_UC_MINUS            __pgprot(__PAGE_KERNEL_UC_MINUS)
 114 #define PAGE_KERNEL_EXEC_NOCACHE        __pgprot(__PAGE_KERNEL_EXEC_NOCACHE)
 115 #define PAGE_KERNEL_LARGE               __pgprot(__PAGE_KERNEL_LARGE)
 116 #define PAGE_KERNEL_LARGE_NOCACHE       __pgprot(__PAGE_KERNEL_LARGE_NOCACHE)
 117 #define PAGE_KERNEL_LARGE_EXEC          __pgprot(__PAGE_KERNEL_LARGE_EXEC)
 118 #define PAGE_KERNEL_VSYSCALL            __pgprot(__PAGE_KERNEL_VSYSCALL)
 119 #define PAGE_KERNEL_VSYSCALL_NOCACHE    __pgprot(__PAGE_KERNEL_VSYSCALL_NOCACHE)
 120
 121 #define PAGE_KERNEL_IO                  __pgprot(__PAGE_KERNEL_IO)
 122 #define PAGE_KERNEL_IO_NOCACHE          __pgprot(__PAGE_KERNEL_IO_NOCACHE)
 123 #define PAGE_KERNEL_IO_UC_MINUS         __pgprot(__PAGE_KERNEL_IO_UC_MINUS)
 124 #define PAGE_KERNEL_IO_WC               __pgprot(__PAGE_KERNEL_IO_WC)
 125
 126 /*         xwr */
 127 #define __P000  PAGE_NONE
 128 #define __P001  PAGE_READONLY
 129 #define __P010  PAGE_COPY
 130 #define __P011  PAGE_COPY
 131 #define __P100  PAGE_READONLY_EXEC
 132 #define __P101  PAGE_READONLY_EXEC
 133 #define __P110  PAGE_COPY_EXEC
 134 #define __P111  PAGE_COPY_EXEC
 135
 136 #define __S000  PAGE_NONE
 137 #define __S001  PAGE_READONLY
 138 #define __S010  PAGE_SHARED
 139 #define __S011  PAGE_SHARED
 140 #define __S100  PAGE_READONLY_EXEC
 141 #define __S101  PAGE_READONLY_EXEC
 142 #define __S110  PAGE_SHARED_EXEC
 143 #define __S111  PAGE_SHARED_EXEC
 144
 145 /*
 146  * early identity mapping  pte attrib macros.
 147  */
 148 #ifdef CONFIG_X86_64
 149 #define __PAGE_KERNEL_IDENT_LARGE_EXEC  __PAGE_KERNEL_LARGE_EXEC
 150 #else
 151 /*
 152  * For PDE_IDENT_ATTR include USER bit. As the PDE and PTE protection
 153  * bits are combined, this will alow user to access the high address mapped
 154  * VDSO in the presence of CONFIG_COMPAT_VDSO
 155  */
 156 #define PTE_IDENT_ATTR   0x003          /* PRESENT+RW */
 157 #define PDE_IDENT_ATTR   0x067          /* PRESENT+RW+USER+DIRTY+ACCESSED */
 158 #define PGD_IDENT_ATTR   0x001          /* PRESENT (no other attributes) */
 159 #endif
 160
 161 /*
 162  * Macro to mark a page protection value as UC-
 163  */
 164 #define pgprot_noncached(prot)                                  \
 165         ((boot_cpu_data.x86 > 3)                                \
 166          ? (__pgprot(pgprot_val(prot) | _PAGE_CACHE_UC_MINUS))  \
 167          : (prot))
 168
 169 #ifndef __ASSEMBLY__
 170
 171 #define pgprot_writecombine     pgprot_writecombine
 172 extern pgprot_t pgprot_writecombine(pgprot_t prot);
 173
 174 /*
 175  * ZERO_PAGE is a global shared page that is always zero: used
 176  * for zero-mapped memory areas etc..
 177  */
 178 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
 179 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
 180
 181 extern spinlock_t pgd_lock;
 182 extern struct list_head pgd_list;
 183
 184 /*
 185  * The following only work if pte_present() is true.
 186  * Undefined behaviour if not..
 187  */
 188 static inline int pte_dirty(pte_t pte)
 189 {
 190         return pte_flags(pte) & _PAGE_DIRTY;
 191 }
 192
 193 static inline int pte_young(pte_t pte)
 194 {
 195         return pte_flags(pte) & _PAGE_ACCESSED;
 196 }
 197
 198 static inline int pte_write(pte_t pte)
 199 {
 200         return pte_flags(pte) & _PAGE_RW;
 201 }
 202
 203 static inline int pte_file(pte_t pte)
 204 {
 205         return pte_flags(pte) & _PAGE_FILE;
 206 }
 207
 208 static inline int pte_huge(pte_t pte)
 209 {
 210         return pte_flags(pte) & _PAGE_PSE;
 211 }
 212
 213 static inline int pte_global(pte_t pte)
 214 {
 215         return pte_flags(pte) & _PAGE_GLOBAL;
 216 }
 217
 218 static inline int pte_exec(pte_t pte)
 219 {
 220         return !(pte_flags(pte) & _PAGE_NX);
 221 }
 222
 223 static inline int pte_special(pte_t pte)
 224 {
 225         return pte_flags(pte) & _PAGE_SPECIAL;
 226 }
 227
 228 static inline unsigned long pte_pfn(pte_t pte)
 229 {
 230         return (pte_val(pte) & PTE_PFN_MASK) >> PAGE_SHIFT;
 231 }
 232
 233 static inline u64 pte_pa(pte_t pte)
 234 {
 235         return pte_val(pte) & PTE_PFN_MASK;
 236 }
 237
 238 #define pte_page(pte)   pfn_to_page(pte_pfn(pte))
 239
 240 static inline int pmd_large(pmd_t pte)
 241 {
 242         return (pmd_val(pte) & (_PAGE_PSE | _PAGE_PRESENT)) ==
 243                 (_PAGE_PSE | _PAGE_PRESENT);
 244 }
 245
 246 static inline pte_t pte_mkclean(pte_t pte)
 247 {
 248         return __pte(pte_val(pte) & ~_PAGE_DIRTY);
 249 }
 250
 251 static inline pte_t pte_mkold(pte_t pte)
 252 {
 253         return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
 254 }
 255
 256 static inline pte_t pte_wrprotect(pte_t pte)
 257 {
 258         return __pte(pte_val(pte) & ~_PAGE_RW);
 259 }
 260
 261 static inline pte_t pte_mkexec(pte_t pte)
 262 {
 263         return __pte(pte_val(pte) & ~_PAGE_NX);
 264 }
 265
 266 static inline pte_t pte_mkdirty(pte_t pte)
 267 {
 268         return __pte(pte_val(pte) | _PAGE_DIRTY);
 269 }
 270
 271 static inline pte_t pte_mkyoung(pte_t pte)
 272 {
 273         return __pte(pte_val(pte) | _PAGE_ACCESSED);
 274 }
 275
 276 static inline pte_t pte_mkwrite(pte_t pte)
 277 {
 278         return __pte(pte_val(pte) | _PAGE_RW);
 279 }
 280
 281 static inline pte_t pte_mkhuge(pte_t pte)
 282 {
 283         return __pte(pte_val(pte) | _PAGE_PSE);
 284 }
 285
 286 static inline pte_t pte_clrhuge(pte_t pte)
 287 {
 288         return __pte(pte_val(pte) & ~_PAGE_PSE);
 289 }
 290
 291 static inline pte_t pte_mkglobal(pte_t pte)
 292 {
 293         return __pte(pte_val(pte) | _PAGE_GLOBAL);
 294 }
 295
 296 static inline pte_t pte_clrglobal(pte_t pte)
 297 {
 298         return __pte(pte_val(pte) & ~_PAGE_GLOBAL);
 299 }
 300
 301 static inline pte_t pte_mkspecial(pte_t pte)
 302 {
 303         return __pte(pte_val(pte) | _PAGE_SPECIAL);
 304 }
 305
 306 extern pteval_t __supported_pte_mask;
 307
 308 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 309 {
 310         return __pte((((phys_addr_t)page_nr << PAGE_SHIFT) |
 311                       pgprot_val(pgprot)) & __supported_pte_mask);
 312 }
 313
 314 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 315 {
 316         return __pmd((((phys_addr_t)page_nr << PAGE_SHIFT) |
 317                       pgprot_val(pgprot)) & __supported_pte_mask);
 318 }
 319
 320 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 321 {
 322         pteval_t val = pte_val(pte);
 323
 324         /*
 325          * Chop off the NX bit (if present), and add the NX portion of
 326          * the newprot (if present):
 327          */
 328         val &= _PAGE_CHG_MASK;
 329         val |= pgprot_val(newprot) & (~_PAGE_CHG_MASK) & __supported_pte_mask;
 330
 331         return __pte(val);
 332 }
 333
 334 /* mprotect needs to preserve PAT bits when updating vm_page_prot */
 335 #define pgprot_modify pgprot_modify
 336 static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
 337 {
 338         pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
 339         pgprotval_t addbits = pgprot_val(newprot);
 340         return __pgprot(preservebits | addbits);
 341 }
 342
 343 #define pte_pgprot(x) __pgprot(pte_flags(x) & PTE_FLAGS_MASK)
 344
 345 #define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
 346
 347 /* Indicate that x86 has its own track and untrack pfn vma functions */
 348 #define track_pfn_vma_new track_pfn_vma_new
 349 #define track_pfn_vma_copy track_pfn_vma_copy
 350 #define untrack_pfn_vma untrack_pfn_vma
 351
 352 #ifndef __ASSEMBLY__
 353 #define __HAVE_PHYS_MEM_ACCESS_PROT
 354 struct file;
 355 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 356                               unsigned long size, pgprot_t vma_prot);
 357 int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
 358                               unsigned long size, pgprot_t *vma_prot);
 359 #endif
 360
 361 /* Install a pte for a particular vaddr in kernel space. */
 362 void set_pte_vaddr(unsigned long vaddr, pte_t pte);
 363
 364 #ifdef CONFIG_X86_32
 365 extern void native_pagetable_setup_start(pgd_t *base);
 366 extern void native_pagetable_setup_done(pgd_t *base);
 367 #else
 368 static inline void native_pagetable_setup_start(pgd_t *base) {}
 369 static inline void native_pagetable_setup_done(pgd_t *base) {}
 370 #endif
 371
 372 struct seq_file;
 373 extern void arch_report_meminfo(struct seq_file *m);
 374
 375 #ifdef CONFIG_PARAVIRT
 376 #include <asm/paravirt.h>
 377 #else  /* !CONFIG_PARAVIRT */
 378 #define set_pte(ptep, pte)              native_set_pte(ptep, pte)
 379 #define set_pte_at(mm, addr, ptep, pte) native_set_pte_at(mm, addr, ptep, pte)
 380
 381 #define set_pte_present(mm, addr, ptep, pte)                            \
 382         native_set_pte_present(mm, addr, ptep, pte)
 383 #define set_pte_atomic(ptep, pte)                                       \
 384         native_set_pte_atomic(ptep, pte)
 385
 386 #define set_pmd(pmdp, pmd)              native_set_pmd(pmdp, pmd)
 387
 388 #ifndef __PAGETABLE_PUD_FOLDED
 389 #define set_pgd(pgdp, pgd)              native_set_pgd(pgdp, pgd)
 390 #define pgd_clear(pgd)                  native_pgd_clear(pgd)
 391 #endif
 392
 393 #ifndef set_pud
 394 # define set_pud(pudp, pud)             native_set_pud(pudp, pud)
 395 #endif
 396
 397 #ifndef __PAGETABLE_PMD_FOLDED
 398 #define pud_clear(pud)                  native_pud_clear(pud)
 399 #endif
 400
 401 #define pte_clear(mm, addr, ptep)       native_pte_clear(mm, addr, ptep)
 402 #define pmd_clear(pmd)                  native_pmd_clear(pmd)
 403
 404 #define pte_update(mm, addr, ptep)              do { } while (0)
 405 #define pte_update_defer(mm, addr, ptep)        do { } while (0)
 406
 407 static inline void __init paravirt_pagetable_setup_start(pgd_t *base)
 408 {
 409         native_pagetable_setup_start(base);
 410 }
 411
 412 static inline void __init paravirt_pagetable_setup_done(pgd_t *base)
 413 {
 414         native_pagetable_setup_done(base);
 415 }
 416 #endif  /* CONFIG_PARAVIRT */
 417
 418 #endif  /* __ASSEMBLY__ */
 419
 420 #ifdef CONFIG_X86_32
 421 # include "pgtable_32.h"
 422 #else
 423 # include "pgtable_64.h"
 424 #endif
 425
 426 /*
 427  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 428  *
 429  * this macro returns the index of the entry in the pgd page which would
 430  * control the given virtual address
 431  */
 432 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 433
 434 /*
 435  * pgd_offset() returns a (pgd_t *)
 436  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 437  */
 438 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index((address)))
 439 /*
 440  * a shortcut which implies the use of the kernel's pgd, instead
 441  * of a process's
 442  */
 443 #define pgd_offset_k(address) pgd_offset(&init_mm, (address))
 444
 445
 446 #define KERNEL_PGD_BOUNDARY     pgd_index(PAGE_OFFSET)
 447 #define KERNEL_PGD_PTRS         (PTRS_PER_PGD - KERNEL_PGD_BOUNDARY)
 448
 449 #ifndef __ASSEMBLY__
 450
 451 enum {
 452         PG_LEVEL_NONE,
 453         PG_LEVEL_4K,
 454         PG_LEVEL_2M,
 455         PG_LEVEL_1G,
 456         PG_LEVEL_NUM
 457 };
 458
 459 #ifdef CONFIG_PROC_FS
 460 extern void update_page_count(int level, unsigned long pages);
 461 #else
 462 static inline void update_page_count(int level, unsigned long pages) { }
 463 #endif
 464
 465 /*
 466  * Helper function that returns the kernel pagetable entry controlling
 467  * the virtual address 'address'. NULL means no pagetable entry present.
 468  * NOTE: the return type is pte_t but if the pmd is PSE then we return it
 469  * as a pte too.
 470  */
 471 extern pte_t *lookup_address(unsigned long address, unsigned int *level);
 472
 473 /* local pte updates need not use xchg for locking */
 474 static inline pte_t native_local_ptep_get_and_clear(pte_t *ptep)
 475 {
 476         pte_t res = *ptep;
 477
 478         /* Pure native function needs no input for mm, addr */
 479         native_pte_clear(NULL, 0, ptep);
 480         return res;
 481 }
 482
 483 static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
 484                                      pte_t *ptep , pte_t pte)
 485 {
 486         native_set_pte(ptep, pte);
 487 }
 488
 489 #ifndef CONFIG_PARAVIRT
 490 /*
 491  * Rules for using pte_update - it must be called after any PTE update which
 492  * has not been done using the set_pte / clear_pte interfaces.  It is used by
 493  * shadow mode hypervisors to resynchronize the shadow page tables.  Kernel PTE
 494  * updates should either be sets, clears, or set_pte_atomic for P->P
 495  * transitions, which means this hook should only be called for user PTEs.
 496  * This hook implies a P->P protection or access change has taken place, which
 497  * requires a subsequent TLB flush.  The notification can optionally be delayed
 498  * until the TLB flush event by using the pte_update_defer form of the
 499  * interface, but care must be taken to assure that the flush happens while
 500  * still holding the same page table lock so that the shadow and primary pages
 501  * do not become out of sync on SMP.
 502  */
 503 #define pte_update(mm, addr, ptep)              do { } while (0)
 504 #define pte_update_defer(mm, addr, ptep)        do { } while (0)
 505 #endif
 506
 507 /*
 508  * We only update the dirty/accessed state if we set
 509  * the dirty bit by hand in the kernel, since the hardware
 510  * will do the accessed bit for us, and we don't want to
 511  * race with other CPU's that might be updating the dirty
 512  * bit at the same time.
 513  */
 514 struct vm_area_struct;
 515
 516 #define  __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 517 extern int ptep_set_access_flags(struct vm_area_struct *vma,
 518                                  unsigned long address, pte_t *ptep,
 519                                  pte_t entry, int dirty);
 520
 521 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 522 extern int ptep_test_and_clear_young(struct vm_area_struct *vma,
 523                                      unsigned long addr, pte_t *ptep);
 524
 525 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 526 extern int ptep_clear_flush_young(struct vm_area_struct *vma,
 527                                   unsigned long address, pte_t *ptep);
 528
 529 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 530 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 531                                        pte_t *ptep)
 532 {
 533         pte_t pte = native_ptep_get_and_clear(ptep);
 534         pte_update(mm, addr, ptep);
 535         return pte;
 536 }
 537
 538 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
 539 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 540                                             unsigned long addr, pte_t *ptep,
 541                                             int full)
 542 {
 543         pte_t pte;
 544         if (full) {
 545                 /*
 546                  * Full address destruction in progress; paravirt does not
 547                  * care about updates and native needs no locking
 548                  */
 549                 pte = native_local_ptep_get_and_clear(ptep);
 550         } else {
 551                 pte = ptep_get_and_clear(mm, addr, ptep);
 552         }
 553         return pte;
 554 }
 555
 556 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 557 static inline void ptep_set_wrprotect(struct mm_struct *mm,
 558                                       unsigned long addr, pte_t *ptep)
 559 {
 560         clear_bit(_PAGE_BIT_RW, (unsigned long *)&ptep->pte);
 561         pte_update(mm, addr, ptep);
 562 }
 563
 564 /*
 565  * clone_pgd_range(pgd_t *dst, pgd_t *src, int count);
 566  *
 567  *  dst - pointer to pgd range anwhere on a pgd page
 568  *  src - ""
 569  *  count - the number of pgds to copy.
 570  *
 571  * dst and src can be on the same page, but the range must not overlap,
 572  * and must not cross a page boundary.
 573  */
 574 static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count)
 575 {
 576        memcpy(dst, src, count * sizeof(pgd_t));
 577 }
 578
 579
 580 #include <asm-generic/pgtable.h>
 581 #endif  /* __ASSEMBLY__ */
 582
 583 #endif /* _ASM_X86_PGTABLE_H */