GNU Linux-libre 4.19.211-gnu1
[releases.git] / mm / pgtable-generic.c
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 <asm/tlb.h>
12 #include <asm-generic/pgtable.h>
13
14 /*
15  * If a p?d_bad entry is found while walking page tables, report
16  * the error, before resetting entry to p?d_none.  Usually (but
17  * very seldom) called out from the p?d_none_or_clear_bad macros.
18  */
19
20 void pgd_clear_bad(pgd_t *pgd)
21 {
22         pgd_ERROR(*pgd);
23         pgd_clear(pgd);
24 }
25
26 void p4d_clear_bad(p4d_t *p4d)
27 {
28         p4d_ERROR(*p4d);
29         p4d_clear(p4d);
30 }
31
32 void pud_clear_bad(pud_t *pud)
33 {
34         pud_ERROR(*pud);
35         pud_clear(pud);
36 }
37
38 void pmd_clear_bad(pmd_t *pmd)
39 {
40         pmd_ERROR(*pmd);
41         pmd_clear(pmd);
42 }
43
44 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
45 /*
46  * Only sets the access flags (dirty, accessed), as well as write 
47  * permission. Furthermore, we know it always gets set to a "more
48  * permissive" setting, which allows most architectures to optimize
49  * this. We return whether the PTE actually changed, which in turn
50  * instructs the caller to do things like update__mmu_cache.  This
51  * used to be done in the caller, but sparc needs minor faults to
52  * force that call on sun4c so we changed this macro slightly
53  */
54 int ptep_set_access_flags(struct vm_area_struct *vma,
55                           unsigned long address, pte_t *ptep,
56                           pte_t entry, int dirty)
57 {
58         int changed = !pte_same(*ptep, entry);
59         if (changed) {
60                 set_pte_at(vma->vm_mm, address, ptep, entry);
61                 flush_tlb_fix_spurious_fault(vma, address);
62         }
63         return changed;
64 }
65 #endif
66
67 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
68 int ptep_clear_flush_young(struct vm_area_struct *vma,
69                            unsigned long address, pte_t *ptep)
70 {
71         int young;
72         young = ptep_test_and_clear_young(vma, address, ptep);
73         if (young)
74                 flush_tlb_page(vma, address);
75         return young;
76 }
77 #endif
78
79 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
80 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
81                        pte_t *ptep)
82 {
83         struct mm_struct *mm = (vma)->vm_mm;
84         pte_t pte;
85         pte = ptep_get_and_clear(mm, address, ptep);
86         if (pte_accessible(mm, pte))
87                 flush_tlb_page(vma, address);
88         return pte;
89 }
90 #endif
91
92 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
93
94 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
95 int pmdp_set_access_flags(struct vm_area_struct *vma,
96                           unsigned long address, pmd_t *pmdp,
97                           pmd_t entry, int dirty)
98 {
99         int changed = !pmd_same(*pmdp, entry);
100         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
101         if (changed) {
102                 set_pmd_at(vma->vm_mm, address, pmdp, entry);
103                 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
104         }
105         return changed;
106 }
107 #endif
108
109 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
110 int pmdp_clear_flush_young(struct vm_area_struct *vma,
111                            unsigned long address, pmd_t *pmdp)
112 {
113         int young;
114         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
115         young = pmdp_test_and_clear_young(vma, address, pmdp);
116         if (young)
117                 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
118         return young;
119 }
120 #endif
121
122 #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
123 pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
124                             pmd_t *pmdp)
125 {
126         pmd_t pmd;
127         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
128         VM_BUG_ON(pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) &&
129                            !pmd_devmap(*pmdp));
130         pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
131         flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
132         return pmd;
133 }
134
135 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
136 pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
137                             pud_t *pudp)
138 {
139         pud_t pud;
140
141         VM_BUG_ON(address & ~HPAGE_PUD_MASK);
142         VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp));
143         pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp);
144         flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
145         return pud;
146 }
147 #endif
148 #endif
149
150 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
151 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
152                                 pgtable_t pgtable)
153 {
154         assert_spin_locked(pmd_lockptr(mm, pmdp));
155
156         /* FIFO */
157         if (!pmd_huge_pte(mm, pmdp))
158                 INIT_LIST_HEAD(&pgtable->lru);
159         else
160                 list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
161         pmd_huge_pte(mm, pmdp) = pgtable;
162 }
163 #endif
164
165 #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
166 /* no "address" argument so destroys page coloring of some arch */
167 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
168 {
169         pgtable_t pgtable;
170
171         assert_spin_locked(pmd_lockptr(mm, pmdp));
172
173         /* FIFO */
174         pgtable = pmd_huge_pte(mm, pmdp);
175         pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru,
176                                                           struct page, lru);
177         if (pmd_huge_pte(mm, pmdp))
178                 list_del(&pgtable->lru);
179         return pgtable;
180 }
181 #endif
182
183 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
184 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
185                      pmd_t *pmdp)
186 {
187         pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mknotpresent(*pmdp));
188         flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
189         return old;
190 }
191 #endif
192
193 #ifndef pmdp_collapse_flush
194 pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
195                           pmd_t *pmdp)
196 {
197         /*
198          * pmd and hugepage pte format are same. So we could
199          * use the same function.
200          */
201         pmd_t pmd;
202
203         VM_BUG_ON(address & ~HPAGE_PMD_MASK);
204         VM_BUG_ON(pmd_trans_huge(*pmdp));
205         pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
206
207         /* collapse entails shooting down ptes not pmd */
208         flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
209         return pmd;
210 }
211 #endif
212 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */