mm/pgtable-generic.c

   1 /*
   2  *  mm/pgtable-generic.c
   3  *
   4  *  Generic pgtable methods declared in asm-generic/pgtable.h
   5  *
   6  *  Copyright (C) 2010  Linus Torvalds
   7  */
   8
   9 #include <asm/tlb.h>
  10 #include <asm-generic/pgtable.h>
  11
  12 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  13 /*
  14  * Only sets the access flags (dirty, accessed, and
  15  * writable). Furthermore, we know it always gets set to a "more
  16  * permissive" setting, which allows most architectures to optimize
  17  * this. We return whether the PTE actually changed, which in turn
  18  * instructs the caller to do things like update__mmu_cache.  This
  19  * used to be done in the caller, but sparc needs minor faults to
  20  * force that call on sun4c so we changed this macro slightly
  21  */
  22 int ptep_set_access_flags(struct vm_area_struct *vma,
  23                           unsigned long address, pte_t *ptep,
  24                           pte_t entry, int dirty)
  25 {
  26         int changed = !pte_same(*ptep, entry);
  27         if (changed) {
  28                 set_pte_at(vma->vm_mm, address, ptep, entry);
  29                 flush_tlb_page(vma, address);
  30         }
  31         return changed;
  32 }
  33 #endif
  34
  35 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
  36 int pmdp_set_access_flags(struct vm_area_struct *vma,
  37                           unsigned long address, pmd_t *pmdp,
  38                           pmd_t entry, int dirty)
  39 {
  40 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  41         int changed = !pmd_same(*pmdp, entry);
  42         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  43         if (changed) {
  44                 set_pmd_at(vma->vm_mm, address, pmdp, entry);
  45                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  46         }
  47         return changed;
  48 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  49         BUG();
  50         return 0;
  51 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  52 }
  53 #endif
  54
  55 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  56 int ptep_clear_flush_young(struct vm_area_struct *vma,
  57                            unsigned long address, pte_t *ptep)
  58 {
  59         int young;
  60         young = ptep_test_and_clear_young(vma, address, ptep);
  61         if (young)
  62                 flush_tlb_page(vma, address);
  63         return young;
  64 }
  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 {
  71         int young;
  72 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
  73         BUG();
  74 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  75         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  76         young = pmdp_test_and_clear_young(vma, address, pmdp);
  77         if (young)
  78                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  79         return young;
  80 }
  81 #endif
  82
  83 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
  84 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
  85                        pte_t *ptep)
  86 {
  87         pte_t pte;
  88         pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
  89         flush_tlb_page(vma, address);
  90         return pte;
  91 }
  92 #endif
  93
  94 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
  95 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  96 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
  97                        pmd_t *pmdp)
  98 {
  99         pmd_t pmd;
 100         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 101         pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
 102         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 103         return pmd;
 104 }
 105 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 106 #endif
 107
 108 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 109 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 110 pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 111                            pmd_t *pmdp)
 112 {
 113         pmd_t pmd = pmd_mksplitting(*pmdp);
 114         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 115         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
 116         /* tlb flush only to serialize against gup-fast */
 117         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 118 }
 119 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 120 #endif