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