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 222