include/asm-generic/pgtable.h

   1 #ifndef _ASM_GENERIC_PGTABLE_H
   2 #define _ASM_GENERIC_PGTABLE_H
   3
   4 #ifndef __ASSEMBLY__
   5 #ifdef CONFIG_MMU
   6
   7 #include <linux/mm_types.h>
   8 #include <linux/bug.h>
   9
  10 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  11 extern int ptep_set_access_flags(struct vm_area_struct *vma,
  12                                  unsigned long address, pte_t *ptep,
  13                                  pte_t entry, int dirty);
  14 #endif
  15
  16 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
  17 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
  18                                  unsigned long address, pmd_t *pmdp,
  19                                  pmd_t entry, int dirty);
  20 #endif
  21
  22 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  23 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
  24                                             unsigned long address,
  25                                             pte_t *ptep)
  26 {
  27         pte_t pte = *ptep;
  28         int r = 1;
  29         if (!pte_young(pte))
  30                 r = 0;
  31         else
  32                 set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
  33         return r;
  34 }
  35 #endif
  36
  37 #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
  38 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  39 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
  40                                             unsigned long address,
  41                                             pmd_t *pmdp)
  42 {
  43         pmd_t pmd = *pmdp;
  44         int r = 1;
  45         if (!pmd_young(pmd))
  46                 r = 0;
  47         else
  48                 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
  49         return r;
  50 }
  51 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  52 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
  53                                             unsigned long address,
  54                                             pmd_t *pmdp)
  55 {
  56         BUG();
  57         return 0;
  58 }
  59 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  60 #endif
  61
  62 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  63 int ptep_clear_flush_young(struct vm_area_struct *vma,
  64                            unsigned long address, pte_t *ptep);
  65 #endif
  66
  67 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
  68 int pmdp_clear_flush_young(struct vm_area_struct *vma,
  69                            unsigned long address, pmd_t *pmdp);
  70 #endif
  71
  72 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
  73 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
  74                                        unsigned long address,
  75                                        pte_t *ptep)
  76 {
  77         pte_t pte = *ptep;
  78         pte_clear(mm, address, ptep);
  79         return pte;
  80 }
  81 #endif
  82
  83 #ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
  84 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  85 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
  86                                        unsigned long address,
  87                                        pmd_t *pmdp)
  88 {
  89         pmd_t pmd = *pmdp;
  90         pmd_clear(pmdp);
  91         return pmd;
  92 }
  93 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  94 #endif
  95
  96 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
  97 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
  98                                             unsigned long address, pte_t *ptep,
  99                                             int full)
 100 {
 101         pte_t pte;
 102         pte = ptep_get_and_clear(mm, address, ptep);
 103         return pte;
 104 }
 105 #endif
 106
 107 /*
 108  * Some architectures may be able to avoid expensive synchronization
 109  * primitives when modifications are made to PTE's which are already
 110  * not present, or in the process of an address space destruction.
 111  */
 112 #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
 113 static inline void pte_clear_not_present_full(struct mm_struct *mm,
 114                                               unsigned long address,
 115                                               pte_t *ptep,
 116                                               int full)
 117 {
 118         pte_clear(mm, address, ptep);
 119 }
 120 #endif
 121
 122 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 123 extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
 124                               unsigned long address,
 125                               pte_t *ptep);
 126 #endif
 127
 128 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
 129 extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
 130                               unsigned long address,
 131                               pmd_t *pmdp);
 132 #endif
 133
 134 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
 135 struct mm_struct;
 136 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 137 {
 138         pte_t old_pte = *ptep;
 139         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
 140 }
 141 #endif
 142
 143 #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
 144 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 145 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 146                                       unsigned long address, pmd_t *pmdp)
 147 {
 148         pmd_t old_pmd = *pmdp;
 149         set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
 150 }
 151 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 152 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 153                                       unsigned long address, pmd_t *pmdp)
 154 {
 155         BUG();
 156 }
 157 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 158 #endif
 159
 160 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 161 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
 162                                  unsigned long address, pmd_t *pmdp);
 163 #endif
 164
 165 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 166 extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable);
 167 #endif
 168
 169 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 170 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm);
 171 #endif
 172
 173 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 174 extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 175                             pmd_t *pmdp);
 176 #endif
 177
 178 #ifndef __HAVE_ARCH_PTE_SAME
 179 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 180 {
 181         return pte_val(pte_a) == pte_val(pte_b);
 182 }
 183 #endif
 184
 185 #ifndef __HAVE_ARCH_PMD_SAME
 186 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 187 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 188 {
 189         return pmd_val(pmd_a) == pmd_val(pmd_b);
 190 }
 191 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 192 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 193 {
 194         BUG();
 195         return 0;
 196 }
 197 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 198 #endif
 199
 200 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 201 #define page_test_and_clear_young(pfn) (0)
 202 #endif
 203
 204 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
 205 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
 206 #endif
 207
 208 #ifndef __HAVE_ARCH_MOVE_PTE
 209 #define move_pte(pte, prot, old_addr, new_addr) (pte)
 210 #endif
 211
 212 #ifndef pte_accessible
 213 # define pte_accessible(pte)            ((void)(pte),1)
 214 #endif
 215
 216 #ifndef flush_tlb_fix_spurious_fault
 217 #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
 218 #endif
 219
 220 #ifndef pgprot_noncached
 221 #define pgprot_noncached(prot)  (prot)
 222 #endif
 223
 224 #ifndef pgprot_writecombine
 225 #define pgprot_writecombine pgprot_noncached
 226 #endif
 227
 228 /*
 229  * When walking page tables, get the address of the next boundary,
 230  * or the end address of the range if that comes earlier.  Although no
 231  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
 232  */
 233
 234 #define pgd_addr_end(addr, end)                                         \
 235 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
 236         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 237 })
 238
 239 #ifndef pud_addr_end
 240 #define pud_addr_end(addr, end)                                         \
 241 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
 242         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 243 })
 244 #endif
 245
 246 #ifndef pmd_addr_end
 247 #define pmd_addr_end(addr, end)                                         \
 248 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
 249         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
 250 })
 251 #endif
 252
 253 /*
 254  * When walking page tables, we usually want to skip any p?d_none entries;
 255  * and any p?d_bad entries - reporting the error before resetting to none.
 256  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
 257  */
 258 void pgd_clear_bad(pgd_t *);
 259 void pud_clear_bad(pud_t *);
 260 void pmd_clear_bad(pmd_t *);
 261
 262 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
 263 {
 264         if (pgd_none(*pgd))
 265                 return 1;
 266         if (unlikely(pgd_bad(*pgd))) {
 267                 pgd_clear_bad(pgd);
 268                 return 1;
 269         }
 270         return 0;
 271 }
 272
 273 static inline int pud_none_or_clear_bad(pud_t *pud)
 274 {
 275         if (pud_none(*pud))
 276                 return 1;
 277         if (unlikely(pud_bad(*pud))) {
 278                 pud_clear_bad(pud);
 279                 return 1;
 280         }
 281         return 0;
 282 }
 283
 284 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
 285 {
 286         if (pmd_none(*pmd))
 287                 return 1;
 288         if (unlikely(pmd_bad(*pmd))) {
 289                 pmd_clear_bad(pmd);
 290                 return 1;
 291         }
 292         return 0;
 293 }
 294
 295 static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
 296                                              unsigned long addr,
 297                                              pte_t *ptep)
 298 {
 299         /*
 300          * Get the current pte state, but zero it out to make it
 301          * non-present, preventing the hardware from asynchronously
 302          * updating it.
 303          */
 304         return ptep_get_and_clear(mm, addr, ptep);
 305 }
 306
 307 static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
 308                                              unsigned long addr,
 309                                              pte_t *ptep, pte_t pte)
 310 {
 311         /*
 312          * The pte is non-present, so there's no hardware state to
 313          * preserve.
 314          */
 315         set_pte_at(mm, addr, ptep, pte);
 316 }
 317
 318 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
 319 /*
 320  * Start a pte protection read-modify-write transaction, which
 321  * protects against asynchronous hardware modifications to the pte.
 322  * The intention is not to prevent the hardware from making pte
 323  * updates, but to prevent any updates it may make from being lost.
 324  *
 325  * This does not protect against other software modifications of the
 326  * pte; the appropriate pte lock must be held over the transation.
 327  *
 328  * Note that this interface is intended to be batchable, meaning that
 329  * ptep_modify_prot_commit may not actually update the pte, but merely
 330  * queue the update to be done at some later time.  The update must be
 331  * actually committed before the pte lock is released, however.
 332  */
 333 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
 334                                            unsigned long addr,
 335                                            pte_t *ptep)
 336 {
 337         return __ptep_modify_prot_start(mm, addr, ptep);
 338 }
 339
 340 /*
 341  * Commit an update to a pte, leaving any hardware-controlled bits in
 342  * the PTE unmodified.
 343  */
 344 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
 345                                            unsigned long addr,
 346                                            pte_t *ptep, pte_t pte)
 347 {
 348         __ptep_modify_prot_commit(mm, addr, ptep, pte);
 349 }
 350 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
 351 #endif /* CONFIG_MMU */
 352
 353 /*
 354  * A facility to provide lazy MMU batching.  This allows PTE updates and
 355  * page invalidations to be delayed until a call to leave lazy MMU mode
 356  * is issued.  Some architectures may benefit from doing this, and it is
 357  * beneficial for both shadow and direct mode hypervisors, which may batch
 358  * the PTE updates which happen during this window.  Note that using this
 359  * interface requires that read hazards be removed from the code.  A read
 360  * hazard could result in the direct mode hypervisor case, since the actual
 361  * write to the page tables may not yet have taken place, so reads though
 362  * a raw PTE pointer after it has been modified are not guaranteed to be
 363  * up to date.  This mode can only be entered and left under the protection of
 364  * the page table locks for all page tables which may be modified.  In the UP
 365  * case, this is required so that preemption is disabled, and in the SMP case,
 366  * it must synchronize the delayed page table writes properly on other CPUs.
 367  */
 368 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
 369 #define arch_enter_lazy_mmu_mode()      do {} while (0)
 370 #define arch_leave_lazy_mmu_mode()      do {} while (0)
 371 #define arch_flush_lazy_mmu_mode()      do {} while (0)
 372 #endif
 373
 374 /*
 375  * A facility to provide batching of the reload of page tables and
 376  * other process state with the actual context switch code for
 377  * paravirtualized guests.  By convention, only one of the batched
 378  * update (lazy) modes (CPU, MMU) should be active at any given time,
 379  * entry should never be nested, and entry and exits should always be
 380  * paired.  This is for sanity of maintaining and reasoning about the
 381  * kernel code.  In this case, the exit (end of the context switch) is
 382  * in architecture-specific code, and so doesn't need a generic
 383  * definition.
 384  */
 385 #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
 386 #define arch_start_context_switch(prev) do {} while (0)
 387 #endif
 388
 389 #ifndef __HAVE_PFNMAP_TRACKING
 390 /*
 391  * Interfaces that can be used by architecture code to keep track of
 392  * memory type of pfn mappings specified by the remap_pfn_range,
 393  * vm_insert_pfn.
 394  */
 395
 396 /*
 397  * track_pfn_remap is called when a _new_ pfn mapping is being established
 398  * by remap_pfn_range() for physical range indicated by pfn and size.
 399  */
 400 static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
 401                                   unsigned long pfn, unsigned long addr,
 402                                   unsigned long size)
 403 {
 404         return 0;
 405 }
 406
 407 /*
 408  * track_pfn_insert is called when a _new_ single pfn is established
 409  * by vm_insert_pfn().
 410  */
 411 static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
 412                                    unsigned long pfn)
 413 {
 414         return 0;
 415 }
 416
 417 /*
 418  * track_pfn_copy is called when vma that is covering the pfnmap gets
 419  * copied through copy_page_range().
 420  */
 421 static inline int track_pfn_copy(struct vm_area_struct *vma)
 422 {
 423         return 0;
 424 }
 425
 426 /*
 427  * untrack_pfn_vma is called while unmapping a pfnmap for a region.
 428  * untrack can be called for a specific region indicated by pfn and size or
 429  * can be for the entire vma (in which case pfn, size are zero).
 430  */
 431 static inline void untrack_pfn(struct vm_area_struct *vma,
 432                                unsigned long pfn, unsigned long size)
 433 {
 434 }
 435 #else
 436 extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
 437                            unsigned long pfn, unsigned long addr,
 438                            unsigned long size);
 439 extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
 440                             unsigned long pfn);
 441 extern int track_pfn_copy(struct vm_area_struct *vma);
 442 extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
 443                         unsigned long size);
 444 #endif
 445
 446 #ifdef __HAVE_COLOR_ZERO_PAGE
 447 static inline int is_zero_pfn(unsigned long pfn)
 448 {
 449         extern unsigned long zero_pfn;
 450         unsigned long offset_from_zero_pfn = pfn - zero_pfn;
 451         return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
 452 }
 453
 454 #define my_zero_pfn(addr)       page_to_pfn(ZERO_PAGE(addr))
 455
 456 #else
 457 static inline int is_zero_pfn(unsigned long pfn)
 458 {
 459         extern unsigned long zero_pfn;
 460         return pfn == zero_pfn;
 461 }
 462
 463 static inline unsigned long my_zero_pfn(unsigned long addr)
 464 {
 465         extern unsigned long zero_pfn;
 466         return zero_pfn;
 467 }
 468 #endif
 469
 470 #ifdef CONFIG_MMU
 471
 472 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
 473 static inline int pmd_trans_huge(pmd_t pmd)
 474 {
 475         return 0;
 476 }
 477 static inline int pmd_trans_splitting(pmd_t pmd)
 478 {
 479         return 0;
 480 }
 481 #ifndef __HAVE_ARCH_PMD_WRITE
 482 static inline int pmd_write(pmd_t pmd)
 483 {
 484         BUG();
 485         return 0;
 486 }
 487 #endif /* __HAVE_ARCH_PMD_WRITE */
 488 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 489
 490 #ifndef pmd_read_atomic
 491 static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
 492 {
 493         /*
 494          * Depend on compiler for an atomic pmd read. NOTE: this is
 495          * only going to work, if the pmdval_t isn't larger than
 496          * an unsigned long.
 497          */
 498         return *pmdp;
 499 }
 500 #endif
 501
 502 /*
 503  * This function is meant to be used by sites walking pagetables with
 504  * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
 505  * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
 506  * into a null pmd and the transhuge page fault can convert a null pmd
 507  * into an hugepmd or into a regular pmd (if the hugepage allocation
 508  * fails). While holding the mmap_sem in read mode the pmd becomes
 509  * stable and stops changing under us only if it's not null and not a
 510  * transhuge pmd. When those races occurs and this function makes a
 511  * difference vs the standard pmd_none_or_clear_bad, the result is
 512  * undefined so behaving like if the pmd was none is safe (because it
 513  * can return none anyway). The compiler level barrier() is critically
 514  * important to compute the two checks atomically on the same pmdval.
 515  *
 516  * For 32bit kernels with a 64bit large pmd_t this automatically takes
 517  * care of reading the pmd atomically to avoid SMP race conditions
 518  * against pmd_populate() when the mmap_sem is hold for reading by the
 519  * caller (a special atomic read not done by "gcc" as in the generic
 520  * version above, is also needed when THP is disabled because the page
 521  * fault can populate the pmd from under us).
 522  */
 523 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
 524 {
 525         pmd_t pmdval = pmd_read_atomic(pmd);
 526         /*
 527          * The barrier will stabilize the pmdval in a register or on
 528          * the stack so that it will stop changing under the code.
 529          *
 530          * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
 531          * pmd_read_atomic is allowed to return a not atomic pmdval
 532          * (for example pointing to an hugepage that has never been
 533          * mapped in the pmd). The below checks will only care about
 534          * the low part of the pmd with 32bit PAE x86 anyway, with the
 535          * exception of pmd_none(). So the important thing is that if
 536          * the low part of the pmd is found null, the high part will
 537          * be also null or the pmd_none() check below would be
 538          * confused.
 539          */
 540 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 541         barrier();
 542 #endif
 543         if (pmd_none(pmdval))
 544                 return 1;
 545         if (unlikely(pmd_bad(pmdval))) {
 546                 if (!pmd_trans_huge(pmdval))
 547                         pmd_clear_bad(pmd);
 548                 return 1;
 549         }
 550         return 0;
 551 }
 552
 553 /*
 554  * This is a noop if Transparent Hugepage Support is not built into
 555  * the kernel. Otherwise it is equivalent to
 556  * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
 557  * places that already verified the pmd is not none and they want to
 558  * walk ptes while holding the mmap sem in read mode (write mode don't
 559  * need this). If THP is not enabled, the pmd can't go away under the
 560  * code even if MADV_DONTNEED runs, but if THP is enabled we need to
 561  * run a pmd_trans_unstable before walking the ptes after
 562  * split_huge_page_pmd returns (because it may have run when the pmd
 563  * become null, but then a page fault can map in a THP and not a
 564  * regular page).
 565  */
 566 static inline int pmd_trans_unstable(pmd_t *pmd)
 567 {
 568 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 569         return pmd_none_or_trans_huge_or_clear_bad(pmd);
 570 #else
 571         return 0;
 572 #endif
 573 }
 574
 575 #ifdef CONFIG_NUMA_BALANCING
 576 #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
 577 /*
 578  * _PAGE_NUMA works identical to _PAGE_PROTNONE (it's actually the
 579  * same bit too). It's set only when _PAGE_PRESET is not set and it's
 580  * never set if _PAGE_PRESENT is set.
 581  *
 582  * pte/pmd_present() returns true if pte/pmd_numa returns true. Page
 583  * fault triggers on those regions if pte/pmd_numa returns true
 584  * (because _PAGE_PRESENT is not set).
 585  */
 586 #ifndef pte_numa
 587 static inline int pte_numa(pte_t pte)
 588 {
 589         return (pte_flags(pte) &
 590                 (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
 591 }
 592 #endif
 593
 594 #ifndef pmd_numa
 595 static inline int pmd_numa(pmd_t pmd)
 596 {
 597         return (pmd_flags(pmd) &
 598                 (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
 599 }
 600 #endif
 601
 602 /*
 603  * pte/pmd_mknuma sets the _PAGE_ACCESSED bitflag automatically
 604  * because they're called by the NUMA hinting minor page fault. If we
 605  * wouldn't set the _PAGE_ACCESSED bitflag here, the TLB miss handler
 606  * would be forced to set it later while filling the TLB after we
 607  * return to userland. That would trigger a second write to memory
 608  * that we optimize away by setting _PAGE_ACCESSED here.
 609  */
 610 #ifndef pte_mknonnuma
 611 static inline pte_t pte_mknonnuma(pte_t pte)
 612 {
 613         pte = pte_clear_flags(pte, _PAGE_NUMA);
 614         return pte_set_flags(pte, _PAGE_PRESENT|_PAGE_ACCESSED);
 615 }
 616 #endif
 617
 618 #ifndef pmd_mknonnuma
 619 static inline pmd_t pmd_mknonnuma(pmd_t pmd)
 620 {
 621         pmd = pmd_clear_flags(pmd, _PAGE_NUMA);
 622         return pmd_set_flags(pmd, _PAGE_PRESENT|_PAGE_ACCESSED);
 623 }
 624 #endif
 625
 626 #ifndef pte_mknuma
 627 static inline pte_t pte_mknuma(pte_t pte)
 628 {
 629         pte = pte_set_flags(pte, _PAGE_NUMA);
 630         return pte_clear_flags(pte, _PAGE_PRESENT);
 631 }
 632 #endif
 633
 634 #ifndef pmd_mknuma
 635 static inline pmd_t pmd_mknuma(pmd_t pmd)
 636 {
 637         pmd = pmd_set_flags(pmd, _PAGE_NUMA);
 638         return pmd_clear_flags(pmd, _PAGE_PRESENT);
 639 }
 640 #endif
 641 #else
 642 extern int pte_numa(pte_t pte);
 643 extern int pmd_numa(pmd_t pmd);
 644 extern pte_t pte_mknonnuma(pte_t pte);
 645 extern pmd_t pmd_mknonnuma(pmd_t pmd);
 646 extern pte_t pte_mknuma(pte_t pte);
 647 extern pmd_t pmd_mknuma(pmd_t pmd);
 648 #endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
 649 #else
 650 static inline int pmd_numa(pmd_t pmd)
 651 {
 652         return 0;
 653 }
 654
 655 static inline int pte_numa(pte_t pte)
 656 {
 657         return 0;
 658 }
 659
 660 static inline pte_t pte_mknonnuma(pte_t pte)
 661 {
 662         return pte;
 663 }
 664
 665 static inline pmd_t pmd_mknonnuma(pmd_t pmd)
 666 {
 667         return pmd;
 668 }
 669
 670 static inline pte_t pte_mknuma(pte_t pte)
 671 {
 672         return pte;
 673 }
 674
 675 static inline pmd_t pmd_mknuma(pmd_t pmd)
 676 {
 677         return pmd;
 678 }
 679 #endif /* CONFIG_NUMA_BALANCING */
 680
 681 #endif /* CONFIG_MMU */
 682
 683 #endif /* !__ASSEMBLY__ */
 684
 685 #endif /* _ASM_GENERIC_PGTABLE_H */