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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e2cda322 AA |
2 | /* |
3 | * mm/pgtable-generic.c | |
4 | * | |
ca5999fd | 5 | * Generic pgtable methods declared in linux/pgtable.h |
e2cda322 AA |
6 | * |
7 | * Copyright (C) 2010 Linus Torvalds | |
8 | */ | |
9 | ||
f95ba941 | 10 | #include <linux/pagemap.h> |
a31acd3e | 11 | #include <linux/hugetlb.h> |
ca5999fd | 12 | #include <linux/pgtable.h> |
0d940a9b HD |
13 | #include <linux/swap.h> |
14 | #include <linux/swapops.h> | |
36090def | 15 | #include <linux/mm_inline.h> |
e2cda322 | 16 | #include <asm/tlb.h> |
e2cda322 | 17 | |
bc4b4448 JK |
18 | /* |
19 | * If a p?d_bad entry is found while walking page tables, report | |
20 | * the error, before resetting entry to p?d_none. Usually (but | |
21 | * very seldom) called out from the p?d_none_or_clear_bad macros. | |
22 | */ | |
23 | ||
24 | void pgd_clear_bad(pgd_t *pgd) | |
25 | { | |
26 | pgd_ERROR(*pgd); | |
27 | pgd_clear(pgd); | |
28 | } | |
29 | ||
f2400abc | 30 | #ifndef __PAGETABLE_P4D_FOLDED |
c2febafc KS |
31 | void p4d_clear_bad(p4d_t *p4d) |
32 | { | |
33 | p4d_ERROR(*p4d); | |
34 | p4d_clear(p4d); | |
35 | } | |
f2400abc | 36 | #endif |
c2febafc | 37 | |
f2400abc | 38 | #ifndef __PAGETABLE_PUD_FOLDED |
bc4b4448 JK |
39 | void pud_clear_bad(pud_t *pud) |
40 | { | |
41 | pud_ERROR(*pud); | |
42 | pud_clear(pud); | |
43 | } | |
f2400abc | 44 | #endif |
bc4b4448 | 45 | |
f2400abc VG |
46 | /* |
47 | * Note that the pmd variant below can't be stub'ed out just as for p4d/pud | |
48 | * above. pmd folding is special and typically pmd_* macros refer to upper | |
49 | * level even when folded | |
50 | */ | |
bc4b4448 JK |
51 | void pmd_clear_bad(pmd_t *pmd) |
52 | { | |
53 | pmd_ERROR(*pmd); | |
54 | pmd_clear(pmd); | |
55 | } | |
56 | ||
e2cda322 AA |
57 | #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS |
58 | /* | |
ca5999fd | 59 | * Only sets the access flags (dirty, accessed), as well as write |
cef23d9d | 60 | * permission. Furthermore, we know it always gets set to a "more |
e2cda322 AA |
61 | * permissive" setting, which allows most architectures to optimize |
62 | * this. We return whether the PTE actually changed, which in turn | |
63 | * instructs the caller to do things like update__mmu_cache. This | |
64 | * used to be done in the caller, but sparc needs minor faults to | |
65 | * force that call on sun4c so we changed this macro slightly | |
66 | */ | |
67 | int ptep_set_access_flags(struct vm_area_struct *vma, | |
68 | unsigned long address, pte_t *ptep, | |
69 | pte_t entry, int dirty) | |
70 | { | |
c33c7948 | 71 | int changed = !pte_same(ptep_get(ptep), entry); |
e2cda322 AA |
72 | if (changed) { |
73 | set_pte_at(vma->vm_mm, address, ptep, entry); | |
99c29133 | 74 | flush_tlb_fix_spurious_fault(vma, address, ptep); |
e2cda322 AA |
75 | } |
76 | return changed; | |
77 | } | |
78 | #endif | |
79 | ||
52585bcc VG |
80 | #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH |
81 | int ptep_clear_flush_young(struct vm_area_struct *vma, | |
82 | unsigned long address, pte_t *ptep) | |
83 | { | |
84 | int young; | |
85 | young = ptep_test_and_clear_young(vma, address, ptep); | |
86 | if (young) | |
87 | flush_tlb_page(vma, address); | |
88 | return young; | |
89 | } | |
90 | #endif | |
91 | ||
92 | #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH | |
93 | pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address, | |
94 | pte_t *ptep) | |
95 | { | |
96 | struct mm_struct *mm = (vma)->vm_mm; | |
97 | pte_t pte; | |
98 | pte = ptep_get_and_clear(mm, address, ptep); | |
99 | if (pte_accessible(mm, pte)) | |
100 | flush_tlb_page(vma, address); | |
101 | return pte; | |
102 | } | |
103 | #endif | |
104 | ||
bd5e88ad VG |
105 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
106 | ||
e2cda322 AA |
107 | #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS |
108 | int pmdp_set_access_flags(struct vm_area_struct *vma, | |
109 | unsigned long address, pmd_t *pmdp, | |
110 | pmd_t entry, int dirty) | |
111 | { | |
e2cda322 AA |
112 | int changed = !pmd_same(*pmdp, entry); |
113 | VM_BUG_ON(address & ~HPAGE_PMD_MASK); | |
114 | if (changed) { | |
115 | set_pmd_at(vma->vm_mm, address, pmdp, entry); | |
12ebc158 | 116 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
e2cda322 AA |
117 | } |
118 | return changed; | |
e2cda322 AA |
119 | } |
120 | #endif | |
121 | ||
e2cda322 AA |
122 | #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH |
123 | int pmdp_clear_flush_young(struct vm_area_struct *vma, | |
124 | unsigned long address, pmd_t *pmdp) | |
125 | { | |
126 | int young; | |
d8c37c48 | 127 | VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
e2cda322 AA |
128 | young = pmdp_test_and_clear_young(vma, address, pmdp); |
129 | if (young) | |
12ebc158 | 130 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
e2cda322 AA |
131 | return young; |
132 | } | |
133 | #endif | |
134 | ||
8809aa2d | 135 | #ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH |
8809aa2d AK |
136 | pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, |
137 | pmd_t *pmdp) | |
e2cda322 AA |
138 | { |
139 | pmd_t pmd; | |
e2cda322 | 140 | VM_BUG_ON(address & ~HPAGE_PMD_MASK); |
99fa8a48 HD |
141 | VM_BUG_ON(pmd_present(*pmdp) && !pmd_trans_huge(*pmdp) && |
142 | !pmd_devmap(*pmdp)); | |
8809aa2d | 143 | pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); |
12ebc158 | 144 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
e2cda322 AA |
145 | return pmd; |
146 | } | |
a00cc7d9 MW |
147 | |
148 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD | |
149 | pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address, | |
150 | pud_t *pudp) | |
151 | { | |
152 | pud_t pud; | |
153 | ||
154 | VM_BUG_ON(address & ~HPAGE_PUD_MASK); | |
155 | VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp)); | |
156 | pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp); | |
157 | flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE); | |
158 | return pud; | |
159 | } | |
160 | #endif | |
e2cda322 AA |
161 | #endif |
162 | ||
e3ebcf64 | 163 | #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT |
6b0b50b0 AK |
164 | void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, |
165 | pgtable_t pgtable) | |
e3ebcf64 | 166 | { |
c4088ebd | 167 | assert_spin_locked(pmd_lockptr(mm, pmdp)); |
e3ebcf64 GS |
168 | |
169 | /* FIFO */ | |
c389a250 | 170 | if (!pmd_huge_pte(mm, pmdp)) |
e3ebcf64 GS |
171 | INIT_LIST_HEAD(&pgtable->lru); |
172 | else | |
c389a250 KS |
173 | list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru); |
174 | pmd_huge_pte(mm, pmdp) = pgtable; | |
e3ebcf64 | 175 | } |
e3ebcf64 GS |
176 | #endif |
177 | ||
178 | #ifndef __HAVE_ARCH_PGTABLE_WITHDRAW | |
e3ebcf64 | 179 | /* no "address" argument so destroys page coloring of some arch */ |
6b0b50b0 | 180 | pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) |
e3ebcf64 GS |
181 | { |
182 | pgtable_t pgtable; | |
183 | ||
c4088ebd | 184 | assert_spin_locked(pmd_lockptr(mm, pmdp)); |
e3ebcf64 GS |
185 | |
186 | /* FIFO */ | |
c389a250 | 187 | pgtable = pmd_huge_pte(mm, pmdp); |
14669347 GT |
188 | pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru, |
189 | struct page, lru); | |
190 | if (pmd_huge_pte(mm, pmdp)) | |
e3ebcf64 | 191 | list_del(&pgtable->lru); |
e3ebcf64 GS |
192 | return pgtable; |
193 | } | |
e3ebcf64 | 194 | #endif |
46dcde73 GS |
195 | |
196 | #ifndef __HAVE_ARCH_PMDP_INVALIDATE | |
d52605d7 | 197 | pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address, |
46dcde73 GS |
198 | pmd_t *pmdp) |
199 | { | |
86ec2da0 | 200 | pmd_t old = pmdp_establish(vma, address, pmdp, pmd_mkinvalid(*pmdp)); |
12ebc158 | 201 | flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE); |
d52605d7 | 202 | return old; |
46dcde73 | 203 | } |
46dcde73 | 204 | #endif |
f28b6ff8 | 205 | |
4f831457 NA |
206 | #ifndef __HAVE_ARCH_PMDP_INVALIDATE_AD |
207 | pmd_t pmdp_invalidate_ad(struct vm_area_struct *vma, unsigned long address, | |
208 | pmd_t *pmdp) | |
209 | { | |
210 | return pmdp_invalidate(vma, address, pmdp); | |
211 | } | |
212 | #endif | |
213 | ||
f28b6ff8 | 214 | #ifndef pmdp_collapse_flush |
f28b6ff8 AK |
215 | pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, |
216 | pmd_t *pmdp) | |
217 | { | |
8809aa2d AK |
218 | /* |
219 | * pmd and hugepage pte format are same. So we could | |
220 | * use the same function. | |
221 | */ | |
f28b6ff8 AK |
222 | pmd_t pmd; |
223 | ||
224 | VM_BUG_ON(address & ~HPAGE_PMD_MASK); | |
225 | VM_BUG_ON(pmd_trans_huge(*pmdp)); | |
8809aa2d | 226 | pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); |
6a6ac72f VG |
227 | |
228 | /* collapse entails shooting down ptes not pmd */ | |
229 | flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE); | |
f28b6ff8 AK |
230 | return pmd; |
231 | } | |
f28b6ff8 | 232 | #endif |
bd5e88ad | 233 | #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |
0d940a9b HD |
234 | |
235 | pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp) | |
236 | { | |
237 | pmd_t pmdval; | |
238 | ||
239 | /* rcu_read_lock() to be added later */ | |
240 | pmdval = pmdp_get_lockless(pmd); | |
241 | if (pmdvalp) | |
242 | *pmdvalp = pmdval; | |
243 | if (unlikely(pmd_none(pmdval) || is_pmd_migration_entry(pmdval))) | |
244 | goto nomap; | |
245 | if (unlikely(pmd_trans_huge(pmdval) || pmd_devmap(pmdval))) | |
246 | goto nomap; | |
247 | if (unlikely(pmd_bad(pmdval))) { | |
248 | pmd_clear_bad(pmd); | |
249 | goto nomap; | |
250 | } | |
251 | return __pte_map(&pmdval, addr); | |
252 | nomap: | |
253 | /* rcu_read_unlock() to be added later */ | |
254 | return NULL; | |
255 | } | |
256 | ||
257 | pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd, | |
258 | unsigned long addr, spinlock_t **ptlp) | |
259 | { | |
260 | pmd_t pmdval; | |
261 | pte_t *pte; | |
262 | ||
263 | pte = __pte_offset_map(pmd, addr, &pmdval); | |
264 | if (likely(pte)) | |
265 | *ptlp = pte_lockptr(mm, &pmdval); | |
266 | return pte; | |
267 | } | |
268 | ||
269 | pte_t *__pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd, | |
270 | unsigned long addr, spinlock_t **ptlp) | |
271 | { | |
272 | spinlock_t *ptl; | |
273 | pmd_t pmdval; | |
274 | pte_t *pte; | |
275 | again: | |
276 | pte = __pte_offset_map(pmd, addr, &pmdval); | |
277 | if (unlikely(!pte)) | |
278 | return pte; | |
279 | ptl = pte_lockptr(mm, &pmdval); | |
280 | spin_lock(ptl); | |
281 | if (likely(pmd_same(pmdval, pmdp_get_lockless(pmd)))) { | |
282 | *ptlp = ptl; | |
283 | return pte; | |
284 | } | |
285 | pte_unmap_unlock(pte, ptl); | |
286 | goto again; | |
287 | } |