1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * mm/pgtable-generic.c 4 * 5 * Generic pgtable methods declared in linux/pgtable.h 6 * 7 * Copyright (C) 2010 Linus Torvalds 8 */ 9 10 #include <linux/pagemap.h> 11 #include <linux/hugetlb.h> 12 #include <linux/pgtable.h> 13 #include <linux/mm_inline.h> 14 #include <asm/tlb.h> 15 16 /* 17 * If a p?d_bad entry is found while walking page tables, report 18 * the error, before resetting entry to p?d_none. Usually (but 19 * very seldom) called out from the p?d_none_or_clear_bad macros. 20 */ 21 22 void pgd_clear_bad(pgd_t *pgd) 23 { 24 pgd_ERROR(*pgd); 25 pgd_clear(pgd); 26 } 27 28 #ifndef __PAGETABLE_P4D_FOLDED 29 void p4d_clear_bad(p4d_t *p4d) 30 { 31 p4d_ERROR(*p4d); 32 p4d_clear(p4d); 33 } 34 #endif 35 36 #ifndef __PAGETABLE_PUD_FOLDED 37 void pud_clear_bad(pud_t *pud) 38 { 39 pud_ERROR(*pud); 40 pud_clear(pud); 41 } 42 #endif 43 44 /* 45 * Note that the pmd variant below can't be stub'ed out just as for p4d/pud 46 * above. pmd folding is special and typically pmd_* macros refer to upper 47 * level even when folded 48 */ 49 void pmd_clear_bad(pmd_t *pmd) 50 { 51 pmd_ERROR(*pmd); 52 pmd_clear(pmd); 53 } 54 55 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS 56 /* 57 * Only sets the access flags (dirty, accessed), as well as write 58 * permission. Furthermore, we know it always gets set to a "more 59 * permissive" setting, which allows most architectures to optimize 60 * this. We return whether the PTE actually changed, which in turn 61 * instructs the caller to do things like update__mmu_cache. This 62 * used to be done in the caller, but sparc needs minor faults to 63 * force that call on sun4c so we changed this macro slightly 64 */ 65 int ptep_set_access_flags(struct vm_area_struct *vma, 66 unsigned long address, pte_t *ptep, 67 pte_t entry, int dirty) 68 { 69 int changed = !pte_same(*ptep, entry); 70 if (changed) { 71 set_pte_at(vma->vm_mm, address, ptep, entry); 72 flush_tlb_fix_spurious_fault(vma, address, ptep); 73 } 74 return changed; 75 } 76 #endif 77 78 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH 79 int ptep_clear_flush_young(struct vm_area_struct *vma, 80 unsigned long address, pte_t *ptep) 81 { 82 int young; 83 young = ptep_test_and_clear_young(vma, address, ptep); 84 if (young) 85 flush_tlb_page(vma, address); 86 return young; 87 } 88 #endif 89 90 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH 91 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, 92 pte_t *ptep) 93 { 94 struct mm_struct *mm = (vma)->vm_mm; 95 pte_t pte; 96 pte = ptep_get_and_clear(mm, address, ptep); 97 if (pte_accessible(mm, pte)) 98 flush_tlb_page(vma, address); 99 return pte; 100 } 101 #endif 102 103 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 104 105 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS 106 int pmdp_set_access_flags(struct vm_area_struct *vma, 107 unsigned long address, pmd_t *pmdp, 108 pmd_t entry, int dirty) 109 { 110 int changed = !pmd_same(*pmdp, entry); 111 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 112 if (changed) { 113 set_pmd_at(vma->vm_mm, address, pmdp, entry); 114 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 115 } 116 return changed; 117 } 118 #endif 119 120 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH 121 int pmdp_clear_flush_young(struct vm_area_struct *vma, 122 unsigned long address, pmd_t *pmdp) 123 { 124 int young; 125 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 126 young = pmdp_test_and_clear_young(vma, address, pmdp); 127 if (young) 128 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 129 return young; 130 } 131 #endif 132 133 #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH 134 pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, 135 pmd_t *pmdp) 136 { 137 pmd_t pmd; 138 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 139 VM_BUG_ON(pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) && 140 !pmd_devmap(*pmdp)); 141 pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); 142 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 143 return pmd; 144 } 145 146 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 147 pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, 148 pud_t *pudp) 149 { 150 pud_t pud; 151 152 VM_BUG_ON(address & ~HPAGE_PUD_MASK); 153 VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp)); 154 pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp); 155 flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE); 156 return pud; 157 } 158 #endif 159 #endif 160 161 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT 162 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, 163 pgtable_t pgtable) 164 { 165 assert_spin_locked(pmd_lockptr(mm, pmdp)); 166 167 /* FIFO */ 168 if (!pmd_huge_pte(mm, pmdp)) 169 INIT_LIST_HEAD(&pgtable->lru); 170 else 171 list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru); 172 pmd_huge_pte(mm, pmdp) = pgtable; 173 } 174 #endif 175 176 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW 177 /* no "address" argument so destroys page coloring of some arch */ 178 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) 179 { 180 pgtable_t pgtable; 181 182 assert_spin_locked(pmd_lockptr(mm, pmdp)); 183 184 /* FIFO */ 185 pgtable = pmd_huge_pte(mm, pmdp); 186 pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru, 187 struct page, lru); 188 if (pmd_huge_pte(mm, pmdp)) 189 list_del(&pgtable->lru); 190 return pgtable; 191 } 192 #endif 193 194 #ifndef __HAVE_ARCH_PMDP_INVALIDATE 195 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, 196 pmd_t *pmdp) 197 { 198 pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp)); 199 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 200 return old; 201 } 202 #endif 203 204 #ifndef __HAVE_ARCH_PMDP_INVALIDATE_AD 205 pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address, 206 pmd_t *pmdp) 207 { 208 return pmdp_invalidate(vma, address, pmdp); 209 } 210 #endif 211 212 #ifndef pmdp_collapse_flush 213 pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, 214 pmd_t *pmdp) 215 { 216 /* 217 * pmd and hugepage pte format are same. So we could 218 * use the same function. 219 */ 220 pmd_t pmd; 221 222 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 223 VM_BUG_ON(pmd_trans_huge(*pmdp)); 224 pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); 225 226 /* collapse entails shooting down ptes not pmd */ 227 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); 228 return pmd; 229 } 230 #endif 231 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 232