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