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 | |