path: root/mm/pgtable-generic.c (plain)
blob: 71c5f9109f2a84fce41b0fcfce07f9e7d8ba16d1

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
19	void pgd_clear_bad(pgd_t *pgd)
20	{
21	pgd_ERROR(*pgd);
22	pgd_clear(pgd);
23	}
24
25	void pud_clear_bad(pud_t *pud)
26	{
27	pud_ERROR(*pud);
28	pud_clear(pud);
29	}
30
31	void 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	*/
47	int 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_PTEP_CLEAR_YOUNG_FLUSH
61	int ptep_clear_flush_young(struct vm_area_struct *vma,
62	unsigned long address, pte_t *ptep)
63	{
64	int young;
65	young = ptep_test_and_clear_young(vma, address, ptep);
66	if (young)
67	flush_tlb_page(vma, address);
68	return young;
69	}
70	#endif
71
72	#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
73	pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
74	pte_t *ptep)
75	{
76	struct mm_struct *mm = (vma)->vm_mm;
77	pte_t pte;
78	pte = ptep_get_and_clear(mm, address, ptep);
79	if (pte_accessible(mm, pte))
80	flush_tlb_page(vma, address);
81	return pte;
82	}
83	#endif
84
85	#ifdef CONFIG_TRANSPARENT_HUGEPAGE
86
87	#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
88	int pmdp_set_access_flags(struct vm_area_struct *vma,
89	unsigned long address, pmd_t *pmdp,
90	pmd_t entry, int dirty)
91	{
92	int changed = !pmd_same(*pmdp, entry);
93	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
94	if (changed) {
95	set_pmd_at(vma->vm_mm, address, pmdp, entry);
96	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
97	}
98	return changed;
99	}
100	#endif
101
102	#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
103	int pmdp_clear_flush_young(struct vm_area_struct *vma,
104	unsigned long address, pmd_t *pmdp)
105	{
106	int young;
107	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
108	young = pmdp_test_and_clear_young(vma, address, pmdp);
109	if (young)
110	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
111	return young;
112	}
113	#endif
114
115	#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
116	pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
117	pmd_t *pmdp)
118	{
119	pmd_t pmd;
120	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
121	VM_BUG_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
122	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
123	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
124	return pmd;
125	}
126	#endif
127
128	#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
129	void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
130	pgtable_t pgtable)
131	{
132	assert_spin_locked(pmd_lockptr(mm, pmdp));
133
134	/* FIFO */
135	if (!pmd_huge_pte(mm, pmdp))
136	INIT_LIST_HEAD(&pgtable->lru);
137	else
138	list_add(&pgtable->lru, &pmd_huge_pte(mm, pmdp)->lru);
139	pmd_huge_pte(mm, pmdp) = pgtable;
140	}
141	#endif
142
143	#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
144	/* no "address" argument so destroys page coloring of some arch */
145	pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
146	{
147	pgtable_t pgtable;
148
149	assert_spin_locked(pmd_lockptr(mm, pmdp));
150
151	/* FIFO */
152	pgtable = pmd_huge_pte(mm, pmdp);
153	pmd_huge_pte(mm, pmdp) = list_first_entry_or_null(&pgtable->lru,
154	struct page, lru);
155	if (pmd_huge_pte(mm, pmdp))
156	list_del(&pgtable->lru);
157	return pgtable;
158	}
159	#endif
160
161	#ifndef __HAVE_ARCH_PMDP_INVALIDATE
162	void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
163	pmd_t *pmdp)
164	{
165	pmd_t entry = *pmdp;
166	set_pmd_at(vma->vm_mm, address, pmdp, pmd_mknotpresent(entry));
167	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
168	}
169	#endif
170
171	#ifndef pmdp_collapse_flush
172	pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address,
173	pmd_t *pmdp)
174	{
175	/*
176	* pmd and hugepage pte format are same. So we could
177	* use the same function.
178	*/
179	pmd_t pmd;
180
181	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
182	VM_BUG_ON(pmd_trans_huge(*pmdp));
183	pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
184
185	/* collapse entails shooting down ptes not pmd */
186	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
187	return pmd;
188	}
189	#endif
190	#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
191