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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));
139 /* Below assumes pmd_present() is true */
140 VM_BUG_ON(!pmd_trans_huge(*pmdp) && !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
147pud_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
162void 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 */
178pgtable_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
195pmd_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 pmdp_collapse_flush
205pmd_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
218 /* collapse entails shooting down ptes not pmd */
219 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
220 return pmd;
221}
222#endif
223#endif /* CONFIG_TRANSPARENT_HUGEPAGE */