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Linux/include/asm-generic/pgtable.h

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  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 /*
 11  * On almost all architectures and configurations, 0 can be used as the
 12  * upper ceiling to free_pgtables(): on many architectures it has the same
 13  * effect as using TASK_SIZE.  However, there is one configuration which
 14  * must impose a more careful limit, to avoid freeing kernel pgtables.
 15  */
 16 #ifndef USER_PGTABLES_CEILING
 17 #define USER_PGTABLES_CEILING   0UL
 18 #endif
 19 
 20 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 21 extern int ptep_set_access_flags(struct vm_area_struct *vma,
 22                                  unsigned long address, pte_t *ptep,
 23                                  pte_t entry, int dirty);
 24 #endif
 25 
 26 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
 27 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
 28                                  unsigned long address, pmd_t *pmdp,
 29                                  pmd_t entry, int dirty);
 30 #endif
 31 
 32 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 33 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 34                                             unsigned long address,
 35                                             pte_t *ptep)
 36 {
 37         pte_t pte = *ptep;
 38         int r = 1;
 39         if (!pte_young(pte))
 40                 r = 0;
 41         else
 42                 set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
 43         return r;
 44 }
 45 #endif
 46 
 47 #ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 48 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 49 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 50                                             unsigned long address,
 51                                             pmd_t *pmdp)
 52 {
 53         pmd_t pmd = *pmdp;
 54         int r = 1;
 55         if (!pmd_young(pmd))
 56                 r = 0;
 57         else
 58                 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
 59         return r;
 60 }
 61 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 62 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 63                                             unsigned long address,
 64                                             pmd_t *pmdp)
 65 {
 66         BUG();
 67         return 0;
 68 }
 69 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 70 #endif
 71 
 72 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 73 int ptep_clear_flush_young(struct vm_area_struct *vma,
 74                            unsigned long address, pte_t *ptep);
 75 #endif
 76 
 77 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
 78 int pmdp_clear_flush_young(struct vm_area_struct *vma,
 79                            unsigned long address, pmd_t *pmdp);
 80 #endif
 81 
 82 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
 83 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 84                                        unsigned long address,
 85                                        pte_t *ptep)
 86 {
 87         pte_t pte = *ptep;
 88         pte_clear(mm, address, ptep);
 89         return pte;
 90 }
 91 #endif
 92 
 93 #ifndef __HAVE_ARCH_PMDP_GET_AND_CLEAR
 94 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 95 static inline pmd_t pmdp_get_and_clear(struct mm_struct *mm,
 96                                        unsigned long address,
 97                                        pmd_t *pmdp)
 98 {
 99         pmd_t pmd = *pmdp;
100         pmd_clear(pmdp);
101         return pmd;
102 }
103 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
104 #endif
105 
106 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
107 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
108                                             unsigned long address, pte_t *ptep,
109                                             int full)
110 {
111         pte_t pte;
112         pte = ptep_get_and_clear(mm, address, ptep);
113         return pte;
114 }
115 #endif
116 
117 /*
118  * Some architectures may be able to avoid expensive synchronization
119  * primitives when modifications are made to PTE's which are already
120  * not present, or in the process of an address space destruction.
121  */
122 #ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
123 static inline void pte_clear_not_present_full(struct mm_struct *mm,
124                                               unsigned long address,
125                                               pte_t *ptep,
126                                               int full)
127 {
128         pte_clear(mm, address, ptep);
129 }
130 #endif
131 
132 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
133 extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
134                               unsigned long address,
135                               pte_t *ptep);
136 #endif
137 
138 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
139 extern pmd_t pmdp_clear_flush(struct vm_area_struct *vma,
140                               unsigned long address,
141                               pmd_t *pmdp);
142 #endif
143 
144 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
145 struct mm_struct;
146 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
147 {
148         pte_t old_pte = *ptep;
149         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
150 }
151 #endif
152 
153 #ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
154 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
155 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
156                                       unsigned long address, pmd_t *pmdp)
157 {
158         pmd_t old_pmd = *pmdp;
159         set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
160 }
161 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
162 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
163                                       unsigned long address, pmd_t *pmdp)
164 {
165         BUG();
166 }
167 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
168 #endif
169 
170 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
171 extern void pmdp_splitting_flush(struct vm_area_struct *vma,
172                                  unsigned long address, pmd_t *pmdp);
173 #endif
174 
175 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
176 extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
177                                        pgtable_t pgtable);
178 #endif
179 
180 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
181 extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
182 #endif
183 
184 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
185 extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
186                             pmd_t *pmdp);
187 #endif
188 
189 #ifndef __HAVE_ARCH_PTE_SAME
190 static inline int pte_same(pte_t pte_a, pte_t pte_b)
191 {
192         return pte_val(pte_a) == pte_val(pte_b);
193 }
194 #endif
195 
196 #ifndef __HAVE_ARCH_PMD_SAME
197 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
198 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
199 {
200         return pmd_val(pmd_a) == pmd_val(pmd_b);
201 }
202 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
203 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
204 {
205         BUG();
206         return 0;
207 }
208 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
209 #endif
210 
211 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
212 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
213 #endif
214 
215 #ifndef __HAVE_ARCH_MOVE_PTE
216 #define move_pte(pte, prot, old_addr, new_addr) (pte)
217 #endif
218 
219 #ifndef pte_accessible
220 # define pte_accessible(mm, pte)        ((void)(pte), 1)
221 #endif
222 
223 #ifndef flush_tlb_fix_spurious_fault
224 #define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
225 #endif
226 
227 #ifndef pgprot_noncached
228 #define pgprot_noncached(prot)  (prot)
229 #endif
230 
231 #ifndef pgprot_writecombine
232 #define pgprot_writecombine pgprot_noncached
233 #endif
234 
235 /*
236  * When walking page tables, get the address of the next boundary,
237  * or the end address of the range if that comes earlier.  Although no
238  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
239  */
240 
241 #define pgd_addr_end(addr, end)                                         \
242 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
243         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
244 })
245 
246 #ifndef pud_addr_end
247 #define pud_addr_end(addr, end)                                         \
248 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
249         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
250 })
251 #endif
252 
253 #ifndef pmd_addr_end
254 #define pmd_addr_end(addr, end)                                         \
255 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
256         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
257 })
258 #endif
259 
260 /*
261  * When walking page tables, we usually want to skip any p?d_none entries;
262  * and any p?d_bad entries - reporting the error before resetting to none.
263  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
264  */
265 void pgd_clear_bad(pgd_t *);
266 void pud_clear_bad(pud_t *);
267 void pmd_clear_bad(pmd_t *);
268 
269 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
270 {
271         if (pgd_none(*pgd))
272                 return 1;
273         if (unlikely(pgd_bad(*pgd))) {
274                 pgd_clear_bad(pgd);
275                 return 1;
276         }
277         return 0;
278 }
279 
280 static inline int pud_none_or_clear_bad(pud_t *pud)
281 {
282         if (pud_none(*pud))
283                 return 1;
284         if (unlikely(pud_bad(*pud))) {
285                 pud_clear_bad(pud);
286                 return 1;
287         }
288         return 0;
289 }
290 
291 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
292 {
293         if (pmd_none(*pmd))
294                 return 1;
295         if (unlikely(pmd_bad(*pmd))) {
296                 pmd_clear_bad(pmd);
297                 return 1;
298         }
299         return 0;
300 }
301 
302 static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
303                                              unsigned long addr,
304                                              pte_t *ptep)
305 {
306         /*
307          * Get the current pte state, but zero it out to make it
308          * non-present, preventing the hardware from asynchronously
309          * updating it.
310          */
311         return ptep_get_and_clear(mm, addr, ptep);
312 }
313 
314 static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
315                                              unsigned long addr,
316                                              pte_t *ptep, pte_t pte)
317 {
318         /*
319          * The pte is non-present, so there's no hardware state to
320          * preserve.
321          */
322         set_pte_at(mm, addr, ptep, pte);
323 }
324 
325 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
326 /*
327  * Start a pte protection read-modify-write transaction, which
328  * protects against asynchronous hardware modifications to the pte.
329  * The intention is not to prevent the hardware from making pte
330  * updates, but to prevent any updates it may make from being lost.
331  *
332  * This does not protect against other software modifications of the
333  * pte; the appropriate pte lock must be held over the transation.
334  *
335  * Note that this interface is intended to be batchable, meaning that
336  * ptep_modify_prot_commit may not actually update the pte, but merely
337  * queue the update to be done at some later time.  The update must be
338  * actually committed before the pte lock is released, however.
339  */
340 static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
341                                            unsigned long addr,
342                                            pte_t *ptep)
343 {
344         return __ptep_modify_prot_start(mm, addr, ptep);
345 }
346 
347 /*
348  * Commit an update to a pte, leaving any hardware-controlled bits in
349  * the PTE unmodified.
350  */
351 static inline void ptep_modify_prot_commit(struct mm_struct *mm,
352                                            unsigned long addr,
353                                            pte_t *ptep, pte_t pte)
354 {
355         __ptep_modify_prot_commit(mm, addr, ptep, pte);
356 }
357 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
358 #endif /* CONFIG_MMU */
359 
360 /*
361  * A facility to provide lazy MMU batching.  This allows PTE updates and
362  * page invalidations to be delayed until a call to leave lazy MMU mode
363  * is issued.  Some architectures may benefit from doing this, and it is
364  * beneficial for both shadow and direct mode hypervisors, which may batch
365  * the PTE updates which happen during this window.  Note that using this
366  * interface requires that read hazards be removed from the code.  A read
367  * hazard could result in the direct mode hypervisor case, since the actual
368  * write to the page tables may not yet have taken place, so reads though
369  * a raw PTE pointer after it has been modified are not guaranteed to be
370  * up to date.  This mode can only be entered and left under the protection of
371  * the page table locks for all page tables which may be modified.  In the UP
372  * case, this is required so that preemption is disabled, and in the SMP case,
373  * it must synchronize the delayed page table writes properly on other CPUs.
374  */
375 #ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
376 #define arch_enter_lazy_mmu_mode()      do {} while (0)
377 #define arch_leave_lazy_mmu_mode()      do {} while (0)
378 #define arch_flush_lazy_mmu_mode()      do {} while (0)
379 #endif
380 
381 /*
382  * A facility to provide batching of the reload of page tables and
383  * other process state with the actual context switch code for
384  * paravirtualized guests.  By convention, only one of the batched
385  * update (lazy) modes (CPU, MMU) should be active at any given time,
386  * entry should never be nested, and entry and exits should always be
387  * paired.  This is for sanity of maintaining and reasoning about the
388  * kernel code.  In this case, the exit (end of the context switch) is
389  * in architecture-specific code, and so doesn't need a generic
390  * definition.
391  */
392 #ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
393 #define arch_start_context_switch(prev) do {} while (0)
394 #endif
395 
396 #ifndef CONFIG_HAVE_ARCH_SOFT_DIRTY
397 static inline int pte_soft_dirty(pte_t pte)
398 {
399         return 0;
400 }
401 
402 static inline int pmd_soft_dirty(pmd_t pmd)
403 {
404         return 0;
405 }
406 
407 static inline pte_t pte_mksoft_dirty(pte_t pte)
408 {
409         return pte;
410 }
411 
412 static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
413 {
414         return pmd;
415 }
416 
417 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
418 {
419         return pte;
420 }
421 
422 static inline int pte_swp_soft_dirty(pte_t pte)
423 {
424         return 0;
425 }
426 
427 static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
428 {
429         return pte;
430 }
431 
432 static inline pte_t pte_file_clear_soft_dirty(pte_t pte)
433 {
434        return pte;
435 }
436 
437 static inline pte_t pte_file_mksoft_dirty(pte_t pte)
438 {
439        return pte;
440 }
441 
442 static inline int pte_file_soft_dirty(pte_t pte)
443 {
444        return 0;
445 }
446 #endif
447 
448 #ifndef __HAVE_PFNMAP_TRACKING
449 /*
450  * Interfaces that can be used by architecture code to keep track of
451  * memory type of pfn mappings specified by the remap_pfn_range,
452  * vm_insert_pfn.
453  */
454 
455 /*
456  * track_pfn_remap is called when a _new_ pfn mapping is being established
457  * by remap_pfn_range() for physical range indicated by pfn and size.
458  */
459 static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
460                                   unsigned long pfn, unsigned long addr,
461                                   unsigned long size)
462 {
463         return 0;
464 }
465 
466 /*
467  * track_pfn_insert is called when a _new_ single pfn is established
468  * by vm_insert_pfn().
469  */
470 static inline int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
471                                    unsigned long pfn)
472 {
473         return 0;
474 }
475 
476 /*
477  * track_pfn_copy is called when vma that is covering the pfnmap gets
478  * copied through copy_page_range().
479  */
480 static inline int track_pfn_copy(struct vm_area_struct *vma)
481 {
482         return 0;
483 }
484 
485 /*
486  * untrack_pfn_vma is called while unmapping a pfnmap for a region.
487  * untrack can be called for a specific region indicated by pfn and size or
488  * can be for the entire vma (in which case pfn, size are zero).
489  */
490 static inline void untrack_pfn(struct vm_area_struct *vma,
491                                unsigned long pfn, unsigned long size)
492 {
493 }
494 #else
495 extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
496                            unsigned long pfn, unsigned long addr,
497                            unsigned long size);
498 extern int track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
499                             unsigned long pfn);
500 extern int track_pfn_copy(struct vm_area_struct *vma);
501 extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
502                         unsigned long size);
503 #endif
504 
505 #ifdef __HAVE_COLOR_ZERO_PAGE
506 static inline int is_zero_pfn(unsigned long pfn)
507 {
508         extern unsigned long zero_pfn;
509         unsigned long offset_from_zero_pfn = pfn - zero_pfn;
510         return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
511 }
512 
513 #define my_zero_pfn(addr)       page_to_pfn(ZERO_PAGE(addr))
514 
515 #else
516 static inline int is_zero_pfn(unsigned long pfn)
517 {
518         extern unsigned long zero_pfn;
519         return pfn == zero_pfn;
520 }
521 
522 static inline unsigned long my_zero_pfn(unsigned long addr)
523 {
524         extern unsigned long zero_pfn;
525         return zero_pfn;
526 }
527 #endif
528 
529 #ifdef CONFIG_MMU
530 
531 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
532 static inline int pmd_trans_huge(pmd_t pmd)
533 {
534         return 0;
535 }
536 static inline int pmd_trans_splitting(pmd_t pmd)
537 {
538         return 0;
539 }
540 #ifndef __HAVE_ARCH_PMD_WRITE
541 static inline int pmd_write(pmd_t pmd)
542 {
543         BUG();
544         return 0;
545 }
546 #endif /* __HAVE_ARCH_PMD_WRITE */
547 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
548 
549 #ifndef pmd_read_atomic
550 static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
551 {
552         /*
553          * Depend on compiler for an atomic pmd read. NOTE: this is
554          * only going to work, if the pmdval_t isn't larger than
555          * an unsigned long.
556          */
557         return *pmdp;
558 }
559 #endif
560 
561 #ifndef pmd_move_must_withdraw
562 static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl,
563                                          spinlock_t *old_pmd_ptl)
564 {
565         /*
566          * With split pmd lock we also need to move preallocated
567          * PTE page table if new_pmd is on different PMD page table.
568          */
569         return new_pmd_ptl != old_pmd_ptl;
570 }
571 #endif
572 
573 /*
574  * This function is meant to be used by sites walking pagetables with
575  * the mmap_sem hold in read mode to protect against MADV_DONTNEED and
576  * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
577  * into a null pmd and the transhuge page fault can convert a null pmd
578  * into an hugepmd or into a regular pmd (if the hugepage allocation
579  * fails). While holding the mmap_sem in read mode the pmd becomes
580  * stable and stops changing under us only if it's not null and not a
581  * transhuge pmd. When those races occurs and this function makes a
582  * difference vs the standard pmd_none_or_clear_bad, the result is
583  * undefined so behaving like if the pmd was none is safe (because it
584  * can return none anyway). The compiler level barrier() is critically
585  * important to compute the two checks atomically on the same pmdval.
586  *
587  * For 32bit kernels with a 64bit large pmd_t this automatically takes
588  * care of reading the pmd atomically to avoid SMP race conditions
589  * against pmd_populate() when the mmap_sem is hold for reading by the
590  * caller (a special atomic read not done by "gcc" as in the generic
591  * version above, is also needed when THP is disabled because the page
592  * fault can populate the pmd from under us).
593  */
594 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
595 {
596         pmd_t pmdval = pmd_read_atomic(pmd);
597         /*
598          * The barrier will stabilize the pmdval in a register or on
599          * the stack so that it will stop changing under the code.
600          *
601          * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
602          * pmd_read_atomic is allowed to return a not atomic pmdval
603          * (for example pointing to an hugepage that has never been
604          * mapped in the pmd). The below checks will only care about
605          * the low part of the pmd with 32bit PAE x86 anyway, with the
606          * exception of pmd_none(). So the important thing is that if
607          * the low part of the pmd is found null, the high part will
608          * be also null or the pmd_none() check below would be
609          * confused.
610          */
611 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
612         barrier();
613 #endif
614         if (pmd_none(pmdval) || pmd_trans_huge(pmdval))
615                 return 1;
616         if (unlikely(pmd_bad(pmdval))) {
617                 pmd_clear_bad(pmd);
618                 return 1;
619         }
620         return 0;
621 }
622 
623 /*
624  * This is a noop if Transparent Hugepage Support is not built into
625  * the kernel. Otherwise it is equivalent to
626  * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
627  * places that already verified the pmd is not none and they want to
628  * walk ptes while holding the mmap sem in read mode (write mode don't
629  * need this). If THP is not enabled, the pmd can't go away under the
630  * code even if MADV_DONTNEED runs, but if THP is enabled we need to
631  * run a pmd_trans_unstable before walking the ptes after
632  * split_huge_page_pmd returns (because it may have run when the pmd
633  * become null, but then a page fault can map in a THP and not a
634  * regular page).
635  */
636 static inline int pmd_trans_unstable(pmd_t *pmd)
637 {
638 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
639         return pmd_none_or_trans_huge_or_clear_bad(pmd);
640 #else
641         return 0;
642 #endif
643 }
644 
645 #ifdef CONFIG_NUMA_BALANCING
646 #ifdef CONFIG_ARCH_USES_NUMA_PROT_NONE
647 /*
648  * _PAGE_NUMA works identical to _PAGE_PROTNONE (it's actually the
649  * same bit too). It's set only when _PAGE_PRESET is not set and it's
650  * never set if _PAGE_PRESENT is set.
651  *
652  * pte/pmd_present() returns true if pte/pmd_numa returns true. Page
653  * fault triggers on those regions if pte/pmd_numa returns true
654  * (because _PAGE_PRESENT is not set).
655  */
656 #ifndef pte_numa
657 static inline int pte_numa(pte_t pte)
658 {
659         return (pte_flags(pte) &
660                 (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
661 }
662 #endif
663 
664 #ifndef pmd_numa
665 static inline int pmd_numa(pmd_t pmd)
666 {
667         return (pmd_flags(pmd) &
668                 (_PAGE_NUMA|_PAGE_PRESENT)) == _PAGE_NUMA;
669 }
670 #endif
671 
672 /*
673  * pte/pmd_mknuma sets the _PAGE_ACCESSED bitflag automatically
674  * because they're called by the NUMA hinting minor page fault. If we
675  * wouldn't set the _PAGE_ACCESSED bitflag here, the TLB miss handler
676  * would be forced to set it later while filling the TLB after we
677  * return to userland. That would trigger a second write to memory
678  * that we optimize away by setting _PAGE_ACCESSED here.
679  */
680 #ifndef pte_mknonnuma
681 static inline pte_t pte_mknonnuma(pte_t pte)
682 {
683         pteval_t val = pte_val(pte);
684 
685         val &= ~_PAGE_NUMA;
686         val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
687         return __pte(val);
688 }
689 #endif
690 
691 #ifndef pmd_mknonnuma
692 static inline pmd_t pmd_mknonnuma(pmd_t pmd)
693 {
694         pmdval_t val = pmd_val(pmd);
695 
696         val &= ~_PAGE_NUMA;
697         val |= (_PAGE_PRESENT|_PAGE_ACCESSED);
698 
699         return __pmd(val);
700 }
701 #endif
702 
703 #ifndef pte_mknuma
704 static inline pte_t pte_mknuma(pte_t pte)
705 {
706         pteval_t val = pte_val(pte);
707 
708         val &= ~_PAGE_PRESENT;
709         val |= _PAGE_NUMA;
710 
711         return __pte(val);
712 }
713 #endif
714 
715 #ifndef ptep_set_numa
716 static inline void ptep_set_numa(struct mm_struct *mm, unsigned long addr,
717                                  pte_t *ptep)
718 {
719         pte_t ptent = *ptep;
720 
721         ptent = pte_mknuma(ptent);
722         set_pte_at(mm, addr, ptep, ptent);
723         return;
724 }
725 #endif
726 
727 #ifndef pmd_mknuma
728 static inline pmd_t pmd_mknuma(pmd_t pmd)
729 {
730         pmdval_t val = pmd_val(pmd);
731 
732         val &= ~_PAGE_PRESENT;
733         val |= _PAGE_NUMA;
734 
735         return __pmd(val);
736 }
737 #endif
738 
739 #ifndef pmdp_set_numa
740 static inline void pmdp_set_numa(struct mm_struct *mm, unsigned long addr,
741                                  pmd_t *pmdp)
742 {
743         pmd_t pmd = *pmdp;
744 
745         pmd = pmd_mknuma(pmd);
746         set_pmd_at(mm, addr, pmdp, pmd);
747         return;
748 }
749 #endif
750 #else
751 extern int pte_numa(pte_t pte);
752 extern int pmd_numa(pmd_t pmd);
753 extern pte_t pte_mknonnuma(pte_t pte);
754 extern pmd_t pmd_mknonnuma(pmd_t pmd);
755 extern pte_t pte_mknuma(pte_t pte);
756 extern pmd_t pmd_mknuma(pmd_t pmd);
757 extern void ptep_set_numa(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
758 extern void pmdp_set_numa(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp);
759 #endif /* CONFIG_ARCH_USES_NUMA_PROT_NONE */
760 #else
761 static inline int pmd_numa(pmd_t pmd)
762 {
763         return 0;
764 }
765 
766 static inline int pte_numa(pte_t pte)
767 {
768         return 0;
769 }
770 
771 static inline pte_t pte_mknonnuma(pte_t pte)
772 {
773         return pte;
774 }
775 
776 static inline pmd_t pmd_mknonnuma(pmd_t pmd)
777 {
778         return pmd;
779 }
780 
781 static inline pte_t pte_mknuma(pte_t pte)
782 {
783         return pte;
784 }
785 
786 static inline void ptep_set_numa(struct mm_struct *mm, unsigned long addr,
787                                  pte_t *ptep)
788 {
789         return;
790 }
791 
792 
793 static inline pmd_t pmd_mknuma(pmd_t pmd)
794 {
795         return pmd;
796 }
797 
798 static inline void pmdp_set_numa(struct mm_struct *mm, unsigned long addr,
799                                  pmd_t *pmdp)
800 {
801         return ;
802 }
803 #endif /* CONFIG_NUMA_BALANCING */
804 
805 #endif /* CONFIG_MMU */
806 
807 #endif /* !__ASSEMBLY__ */
808 
809 #ifndef io_remap_pfn_range
810 #define io_remap_pfn_range remap_pfn_range
811 #endif
812 
813 #endif /* _ASM_GENERIC_PGTABLE_H */
814 

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