xref: /linux/mm/pgtable-generic.c (revision 394d83c17fac2b7bcf05cb99d1e945135767bb6b)
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 <asm/tlb.h>
10 #include <asm-generic/pgtable.h>
11 
12 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
13 /*
14  * Only sets the access flags (dirty, accessed, and
15  * writable). Furthermore, we know it always gets set to a "more
16  * permissive" setting, which allows most architectures to optimize
17  * this. We return whether the PTE actually changed, which in turn
18  * instructs the caller to do things like update__mmu_cache.  This
19  * used to be done in the caller, but sparc needs minor faults to
20  * force that call on sun4c so we changed this macro slightly
21  */
22 int ptep_set_access_flags(struct vm_area_struct *vma,
23 			  unsigned long address, pte_t *ptep,
24 			  pte_t entry, int dirty)
25 {
26 	int changed = !pte_same(*ptep, entry);
27 	if (changed) {
28 		set_pte_at(vma->vm_mm, address, ptep, entry);
29 		flush_tlb_page(vma, address);
30 	}
31 	return changed;
32 }
33 #endif
34 
35 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
36 int pmdp_set_access_flags(struct vm_area_struct *vma,
37 			  unsigned long address, pmd_t *pmdp,
38 			  pmd_t entry, int dirty)
39 {
40 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
41 	int changed = !pmd_same(*pmdp, entry);
42 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
43 	if (changed) {
44 		set_pmd_at(vma->vm_mm, address, pmdp, entry);
45 		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
46 	}
47 	return changed;
48 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
49 	BUG();
50 	return 0;
51 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
52 }
53 #endif
54 
55 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
56 int ptep_clear_flush_young(struct vm_area_struct *vma,
57 			   unsigned long address, pte_t *ptep)
58 {
59 	int young;
60 	young = ptep_test_and_clear_young(vma, address, ptep);
61 	if (young)
62 		flush_tlb_page(vma, address);
63 	return young;
64 }
65 #endif
66 
67 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
68 int pmdp_clear_flush_young(struct vm_area_struct *vma,
69 			   unsigned long address, pmd_t *pmdp)
70 {
71 	int young;
72 #ifndef CONFIG_TRANSPARENT_HUGEPAGE
73 	BUG();
74 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
75 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
76 	young = pmdp_test_and_clear_young(vma, address, pmdp);
77 	if (young)
78 		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
79 	return young;
80 }
81 #endif
82 
83 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
84 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
85 		       pte_t *ptep)
86 {
87 	pte_t pte;
88 	pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
89 	flush_tlb_page(vma, address);
90 	return pte;
91 }
92 #endif
93 
94 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
95 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
96 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
97 		       pmd_t *pmdp)
98 {
99 	pmd_t pmd;
100 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
101 	pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
102 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
103 	return pmd;
104 }
105 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
106 #endif
107 
108 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
109 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
110 pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
111 			   pmd_t *pmdp)
112 {
113 	pmd_t pmd = pmd_mksplitting(*pmdp);
114 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
115 	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
116 	/* tlb flush only to serialize against gup-fast */
117 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
118 }
119 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
120 #endif
121