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 /*
  14  * If a p?d_bad entry is found while walking page tables, report
  15  * the error, before resetting entry to p?d_none.  Usually (but
  16  * very seldom) called out from the p?d_none_or_clear_bad macros.
  17  */
  18
  19 void pgd_clear_bad(pgd_t *pgd)
  20 {
  21         pgd_ERROR(*pgd);
  22         pgd_clear(pgd);
  23 }
  24
  25 void pud_clear_bad(pud_t *pud)
  26 {
  27         pud_ERROR(*pud);
  28         pud_clear(pud);
  29 }
  30
  31 void pmd_clear_bad(pmd_t *pmd)
  32 {
  33         pmd_ERROR(*pmd);
  34         pmd_clear(pmd);
  35 }
  36
  37 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
  38 /*
  39  * Only sets the access flags (dirty, accessed), as well as write
  40  * permission. Furthermore, we know it always gets set to a "more
  41  * permissive" setting, which allows most architectures to optimize
  42  * this. We return whether the PTE actually changed, which in turn
  43  * instructs the caller to do things like update__mmu_cache.  This
  44  * used to be done in the caller, but sparc needs minor faults to
  45  * force that call on sun4c so we changed this macro slightly
  46  */
  47 int ptep_set_access_flags(struct vm_area_struct *vma,
  48                           unsigned long address, pte_t *ptep,
  49                           pte_t entry, int dirty)
  50 {
  51         int changed = !pte_same(*ptep, entry);
  52         if (changed) {
  53                 set_pte_at(vma->vm_mm, address, ptep, entry);
  54                 flush_tlb_fix_spurious_fault(vma, address);
  55         }
  56         return changed;
  57 }
  58 #endif
  59
  60 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
  61 int pmdp_set_access_flags(struct vm_area_struct *vma,
  62                           unsigned long address, pmd_t *pmdp,
  63                           pmd_t entry, int dirty)
  64 {
  65 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  66         int changed = !pmd_same(*pmdp, entry);
  67         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  68         if (changed) {
  69                 set_pmd_at(vma->vm_mm, address, pmdp, entry);
  70                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
  71         }
  72         return changed;
  73 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
  74         BUG();
  75         return 0;
  76 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
  77 }
  78 #endif
  79
  80 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
  81 int ptep_clear_flush_young(struct vm_area_struct *vma,
  82                            unsigned long address, pte_t *ptep)
  83 {
  84         int young;
  85         young = ptep_test_and_clear_young(vma, address, ptep);
  86         if (young)
  87                 flush_tlb_page(vma, address);
  88         return young;
  89 }
  90 #endif
  91
  92 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
  93 int pmdp_clear_flush_young(struct vm_area_struct *vma,
  94                            unsigned long address, pmd_t *pmdp)
  95 {
  96         int young;
  97 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  98         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
  99 #else
 100         BUG();
 101 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 102         young = pmdp_test_and_clear_young(vma, address, pmdp);
 103         if (young)
 104                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 105         return young;
 106 }
 107 #endif
 108
 109 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 110 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
 111                        pte_t *ptep)
 112 {
 113         struct mm_struct *mm = (vma)->vm_mm;
 114         pte_t pte;
 115         pte = ptep_get_and_clear(mm, address, ptep);
 116         if (pte_accessible(mm, pte))
 117                 flush_tlb_page(vma, address);
 118         return pte;
 119 }
 120 #endif
 121
 122 #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
 123 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 124 pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
 125                             pmd_t *pmdp)
 126 {
 127         pmd_t pmd;
 128         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 129         VM_BUG_ON(!pmd_trans_huge(*pmdp));
 130         pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
 131         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 132         return pmd;
 133 }
 134 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 135 #endif
 136
 137 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
 138 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 139 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
 140                           pmd_t *pmdp)
 141 {
 142         pmd_t pmd = pmd_mksplitting(*pmdp);
 143         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 144         set_pmd_at(vma->vm_mm, address, pmdp, pmd);
 145         /* tlb flush only to serialize against gup-fast */
 146         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 147 }
 148 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 149 #endif
 150
 151 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
 152 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 153 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 154                                 pgtable_t pgtable)
 155 {
 156         assert_spin_locked(pmd_lockptr(mm, pmdp));
 157
 158         /* FIFO */
 159         if (!pmd_huge_pte(mm, pmdp))
 160                 INIT_LIST_HEAD(&pgtable->lru);
 161         else
 162                 list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
 163         pmd_huge_pte(mm, pmdp) = pgtable;
 164 }
 165 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 166 #endif
 167
 168 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
 169 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 170 /* no "address" argument so destroys page coloring of some arch */
 171 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
 172 {
 173         pgtable_t pgtable;
 174
 175         assert_spin_locked(pmd_lockptr(mm, pmdp));
 176
 177         /* FIFO */
 178         pgtable = pmd_huge_pte(mm, pmdp);
 179         if (list_empty(&pgtable->lru))
 180                 pmd_huge_pte(mm, pmdp) = NULL;
 181         else {
 182                 pmd_huge_pte(mm, pmdp) = list_entry(pgtable->lru.next,
 183                                               struct page, lru);
 184                 list_del(&pgtable->lru);
 185         }
 186         return pgtable;
 187 }
 188 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 189 #endif
 190
 191 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
 192 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 193 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
 194                      pmd_t *pmdp)
 195 {
 196         pmd_t entry = *pmdp;
 197         set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(entry));
 198         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 199 }
 200 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 201 #endif
 202
 203 #ifndef pmdp_collapse_flush
 204 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 205 pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
 206                           pmd_t *pmdp)
 207 {
 208         /*
 209          * pmd and hugepage pte format are same. So we could
 210          * use the same function.
 211          */
 212         pmd_t pmd;
 213
 214         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 215         VM_BUG_ON(pmd_trans_huge(*pmdp));
 216         pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
 217         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 218         return pmd;
 219 }
 220 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 221 #endif