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), as well as write
  16  * permission. 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_fix_spurious_fault(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 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  74         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  75 #else
  76         BUG();
  77 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  78         young = pmdp_test_and_clear_young(vma, address, pmdp);
  79         if (young)
  80                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  81         return young;
  82 }
  83 #endif
  84
  85 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
  86 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
  87                        pte_t *ptep)
  88 {
  89         pte_t pte;
  90         pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
  91         if (pte_accessible(pte))
  92                 flush_tlb_page(vma, address);
  93         return pte;
  94 }
  95 #endif
  96
  97 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
  98 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  99 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
 100                        pmd_t *pmdp)
 101 {
 102         pmd_t pmd;
 103         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 104         pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
 105         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 106         return pmd;
 107 }
 108 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 109 #endif
 110
 111 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 112 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 113 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 114                           pmd_t *pmdp)
 115 {
 116         pmd_t pmd = pmd_mksplitting(*pmdp);
 117         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 118         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
 119         /* tlb flush only to serialize against gup-fast */
 120         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 121 }
 122 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 123 #endif
 124
 125 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 126 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 127 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 128                                 pgtable_t pgtable)
 129 {
 130         assert_spin_locked(&mm->page_table_lock);
 131
 132         /* FIFO */
 133         if (!mm->pmd_huge_pte)
 134                 INIT_LIST_HEAD(&pgtable->lru);
 135         else
 136                 list_add(&pgtable->lru, &mm->pmd_huge_pte->lru);
 137         mm->pmd_huge_pte = pgtable;
 138 }
 139 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 140 #endif
 141
 142 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 143 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 144 /* no "address" argument so destroys page coloring of some arch */
 145 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 146 {
 147         pgtable_t pgtable;
 148
 149         assert_spin_locked(&mm->page_table_lock);
 150
 151         /* FIFO */
 152         pgtable = mm->pmd_huge_pte;
 153         if (list_empty(&pgtable->lru))
 154                 mm->pmd_huge_pte = NULL;
 155         else {
 156                 mm->pmd_huge_pte = list_entry(pgtable->lru.next,
 157                                               struct page, lru);
 158                 list_del(&pgtable->lru);
 159         }
 160         return pgtable;
 161 }
 162 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 163 #endif
 164
 165 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 166 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 167 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 168                      pmd_t *pmdp)
 169 {
 170         set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp));
 171         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 172 }
 173 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 174 #endif