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 <linux/pagemap.h>
  10 #include <asm/tlb.h>
  11 #include <asm-generic/pgtable.h>
  12
  13 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  14 /*
  15  * Only sets the access flags (dirty, accessed, and
  16  * writable). Furthermore, we know it always gets set to a "more
  17  * permissive" setting, which allows most architectures to optimize
  18  * this. We return whether the PTE actually changed, which in turn
  19  * instructs the caller to do things like update__mmu_cache.  This
  20  * used to be done in the caller, but sparc needs minor faults to
  21  * force that call on sun4c so we changed this macro slightly
  22  */
  23 int ptep_set_access_flags(struct vm_area_struct *vma,
  24                           unsigned long address, pte_t *ptep,
  25                           pte_t entry, int dirty)
  26 {
  27         int changed = !pte_same(*ptep, entry);
  28         if (changed) {
  29                 set_pte_at(vma->vm_mm, address, ptep, entry);
  30                 flush_tlb_page(vma, address);
  31         }
  32         return changed;
  33 }
  34 #endif
  35
  36 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
  37 int pmdp_set_access_flags(struct vm_area_struct *vma,
  38                           unsigned long address, pmd_t *pmdp,
  39                           pmd_t entry, int dirty)
  40 {
  41 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  42         int changed = !pmd_same(*pmdp, entry);
  43         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  44         if (changed) {
  45                 set_pmd_at(vma->vm_mm, address, pmdp, entry);
  46                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  47         }
  48         return changed;
  49 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  50         BUG();
  51         return 0;
  52 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  53 }
  54 #endif
  55
  56 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  57 int ptep_clear_flush_young(struct vm_area_struct *vma,
  58                            unsigned long address, pte_t *ptep)
  59 {
  60         int young;
  61         young = ptep_test_and_clear_young(vma, address, ptep);
  62         if (young)
  63                 flush_tlb_page(vma, address);
  64         return young;
  65 }
  66 #endif
  67
  68 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
  69 int pmdp_clear_flush_young(struct vm_area_struct *vma,
  70                            unsigned long address, pmd_t *pmdp)
  71 {
  72         int young;
  73 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
  74         BUG();
  75 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  76         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  77         young = pmdp_test_and_clear_young(vma, address, pmdp);
  78         if (young)
  79                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  80         return young;
  81 }
  82 #endif
  83
  84 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
  85 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
  86                        pte_t *ptep)
  87 {
  88         pte_t pte;
  89         pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
  90         flush_tlb_page(vma, address);
  91         return pte;
  92 }
  93 #endif
  94
  95 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
  96 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  97 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
  98                        pmd_t *pmdp)
  99 {
 100         pmd_t pmd;
 101         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 102         pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
 103         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 104         return pmd;
 105 }
 106 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 107 #endif
 108
 109 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 110 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 111 pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 112                            pmd_t *pmdp)
 113 {
 114         pmd_t pmd = pmd_mksplitting(*pmdp);
 115         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 116         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
 117         /* tlb flush only to serialize against gup-fast */
 118         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 119 }
 120 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 121 #endif