Linux kernel mirror (for testing)
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linux
1/*
2 * mm/pgtable-generic.c
3 *
4 * Generic pgtable methods declared in asm-generic/pgtable.h
5 *
6 * Copyright (C) 2010 Linus Torvalds
7 */
8
9#include <linux/pagemap.h>
10#include <asm/tlb.h>
11#include <asm-generic/pgtable.h>
12
13/*
14 * If a p?d_bad entry is found while walking page tables, report
15 * the error, before resetting entry to p?d_none. Usually (but
16 * very seldom) called out from the p?d_none_or_clear_bad macros.
17 */
18
19void pgd_clear_bad(pgd_t *pgd)
20{
21 pgd_ERROR(*pgd);
22 pgd_clear(pgd);
23}
24
25void pud_clear_bad(pud_t *pud)
26{
27 pud_ERROR(*pud);
28 pud_clear(pud);
29}
30
31void pmd_clear_bad(pmd_t *pmd)
32{
33 pmd_ERROR(*pmd);
34 pmd_clear(pmd);
35}
36
37#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
38/*
39 * Only sets the access flags (dirty, accessed), as well as write
40 * permission. Furthermore, we know it always gets set to a "more
41 * permissive" setting, which allows most architectures to optimize
42 * this. We return whether the PTE actually changed, which in turn
43 * instructs the caller to do things like update__mmu_cache. This
44 * used to be done in the caller, but sparc needs minor faults to
45 * force that call on sun4c so we changed this macro slightly
46 */
47int ptep_set_access_flags(struct vm_area_struct *vma,
48 unsigned long address, pte_t *ptep,
49 pte_t entry, int dirty)
50{
51 int changed = !pte_same(*ptep, entry);
52 if (changed) {
53 set_pte_at(vma->vm_mm, address, ptep, entry);
54 flush_tlb_fix_spurious_fault(vma, address);
55 }
56 return changed;
57}
58#endif
59
60#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
61int pmdp_set_access_flags(struct vm_area_struct *vma,
62 unsigned long address, pmd_t *pmdp,
63 pmd_t entry, int dirty)
64{
65#ifdef CONFIG_TRANSPARENT_HUGEPAGE
66 int changed = !pmd_same(*pmdp, entry);
67 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
68 if (changed) {
69 set_pmd_at(vma->vm_mm, address, pmdp, entry);
70 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
71 }
72 return changed;
73#else /* CONFIG_TRANSPARENT_HUGEPAGE */
74 BUG();
75 return 0;
76#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
77}
78#endif
79
80#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
81int 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_PMDP_CLEAR_YOUNG_FLUSH
93int pmdp_clear_flush_young(struct vm_area_struct *vma,
94 unsigned long address, pmd_t *pmdp)
95{
96 int young;
97#ifdef CONFIG_TRANSPARENT_HUGEPAGE
98 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
99#else
100 BUG();
101#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
102 young = pmdp_test_and_clear_young(vma, address, pmdp);
103 if (young)
104 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
105 return young;
106}
107#endif
108
109#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
110pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
111 pte_t *ptep)
112{
113 struct mm_struct *mm = (vma)->vm_mm;
114 pte_t pte;
115 pte = ptep_get_and_clear(mm, address, ptep);
116 if (pte_accessible(mm, pte))
117 flush_tlb_page(vma, address);
118 return pte;
119}
120#endif
121
122#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
123#ifdef CONFIG_TRANSPARENT_HUGEPAGE
124pmd_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_trans_huge(*pmdp));
130 pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
131 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
132 return pmd;
133}
134#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
135#endif
136
137#ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
138#ifdef CONFIG_TRANSPARENT_HUGEPAGE
139void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
140 pmd_t *pmdp)
141{
142 pmd_t pmd = pmd_mksplitting(*pmdp);
143 VM_BUG_ON(address & ~HPAGE_PMD_MASK);
144 set_pmd_at(vma->vm_mm, address, pmdp, pmd);
145 /* tlb flush only to serialize against gup-fast */
146 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
147}
148#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
149#endif
150
151#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
152#ifdef CONFIG_TRANSPARENT_HUGEPAGE
153void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
154 pgtable_t pgtable)
155{
156 assert_spin_locked(pmd_lockptr(mm, pmdp));
157
158 /* FIFO */
159 if (!pmd_huge_pte(mm, pmdp))
160 INIT_LIST_HEAD(&pgtable->lru);
161 else
162 list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
163 pmd_huge_pte(mm, pmdp) = pgtable;
164}
165#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
166#endif
167
168#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
169#ifdef CONFIG_TRANSPARENT_HUGEPAGE
170/* no "address" argument so destroys page coloring of some arch */
171pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
172{
173 pgtable_t pgtable;
174
175 assert_spin_locked(pmd_lockptr(mm, pmdp));
176
177 /* FIFO */
178 pgtable = pmd_huge_pte(mm, pmdp);
179 if (list_empty(&pgtable->lru))
180 pmd_huge_pte(mm, pmdp) = NULL;
181 else {
182 pmd_huge_pte(mm, pmdp) = list_entry(pgtable->lru.next,
183 struct page, lru);
184 list_del(&pgtable->lru);
185 }
186 return pgtable;
187}
188#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
189#endif
190
191#ifndef __HAVE_ARCH_PMDP_INVALIDATE
192#ifdef CONFIG_TRANSPARENT_HUGEPAGE
193void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
194 pmd_t *pmdp)
195{
196 pmd_t entry = *pmdp;
197 set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(entry));
198 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
199}
200#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
201#endif
202
203#ifndef pmdp_collapse_flush
204#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
218 return pmd;
219}
220#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
221#endif