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 21void pgd_clear_bad(pgd_t *pgd) 22{ 23 pgd_ERROR(*pgd); 24 pgd_clear(pgd); 25} 26 27#ifndef __PAGETABLE_P4D_FOLDED 28void p4d_clear_bad(p4d_t *p4d) 29{ 30 p4d_ERROR(*p4d); 31 p4d_clear(p4d); 32} 33#endif 34 35#ifndef __PAGETABLE_PUD_FOLDED 36void 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 */ 48void 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 */ 64int 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 78int 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 90pte_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 105int 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 120int 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 133pmd_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 146pud_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 161void 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 */ 177pgtable_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 194pmd_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 204pmd_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