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