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 pte_t pte; 114 pte = ptep_get_and_clear((vma)->vm_mm, address, ptep); 115 if (pte_accessible(pte)) 116 flush_tlb_page(vma, address); 117 return pte; 118 } 119 #endif 120 121 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH 122 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 123 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address, 124 pmd_t *pmdp) 125 { 126 pmd_t pmd; 127 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 128 pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp); 129 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 130 return pmd; 131 } 132 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 133 #endif 134 135 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH 136 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 137 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, 138 pmd_t *pmdp) 139 { 140 pmd_t pmd = pmd_mksplitting(*pmdp); 141 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 142 set_pmd_at(vma->vm_mm, address, pmdp, pmd); 143 /* tlb flush only to serialize against gup-fast */ 144 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 145 } 146 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 147 #endif 148 149 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT 150 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 151 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, 152 pgtable_t pgtable) 153 { 154 assert_spin_locked(&mm->page_table_lock); 155 156 /* FIFO */ 157 if (!mm->pmd_huge_pte) 158 INIT_LIST_HEAD(&pgtable->lru); 159 else 160 list_add(&pgtable->lru, &mm->pmd_huge_pte->lru); 161 mm->pmd_huge_pte = pgtable; 162 } 163 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 164 #endif 165 166 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW 167 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 168 /* no "address" argument so destroys page coloring of some arch */ 169 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) 170 { 171 pgtable_t pgtable; 172 173 assert_spin_locked(&mm->page_table_lock); 174 175 /* FIFO */ 176 pgtable = mm->pmd_huge_pte; 177 if (list_empty(&pgtable->lru)) 178 mm->pmd_huge_pte = NULL; 179 else { 180 mm->pmd_huge_pte = list_entry(pgtable->lru.next, 181 struct page, lru); 182 list_del(&pgtable->lru); 183 } 184 return pgtable; 185 } 186 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 187 #endif 188 189 #ifndef __HAVE_ARCH_PMDP_INVALIDATE 190 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 191 void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, 192 pmd_t *pmdp) 193 { 194 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(*pmdp)); 195 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 196 } 197 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 198 #endif 199