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 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
14 /*
15  * Only sets the access flags (dirty, accessed, and
16  * writable). Furthermore, we know it always gets set to a "more
17  * permissive" setting, which allows most architectures to optimize
18  * this. We return whether the PTE actually changed, which in turn
19  * instructs the caller to do things like update__mmu_cache.  This
20  * used to be done in the caller, but sparc needs minor faults to
21  * force that call on sun4c so we changed this macro slightly
22  */
ptep_set_access_flags(struct vm_area_struct * vma,unsigned long address,pte_t * ptep,pte_t entry,int dirty)23 int ptep_set_access_flags(struct vm_area_struct *vma,
24 			  unsigned long address, pte_t *ptep,
25 			  pte_t entry, int dirty)
26 {
27 	int changed = !pte_same(*ptep, entry);
28 	if (changed) {
29 		set_pte_at(vma->vm_mm, address, ptep, entry);
30 		flush_tlb_page(vma, address);
31 	}
32 	return changed;
33 }
34 #endif
35 
36 #ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
pmdp_set_access_flags(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp,pmd_t entry,int dirty)37 int pmdp_set_access_flags(struct vm_area_struct *vma,
38 			  unsigned long address, pmd_t *pmdp,
39 			  pmd_t entry, int dirty)
40 {
41 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
42 	int changed = !pmd_same(*pmdp, entry);
43 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
44 	if (changed) {
45 		set_pmd_at(vma->vm_mm, address, pmdp, entry);
46 		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
47 	}
48 	return changed;
49 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
50 	BUG();
51 	return 0;
52 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
53 }
54 #endif
55 
56 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
ptep_clear_flush_young(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)57 int ptep_clear_flush_young(struct vm_area_struct *vma,
58 			   unsigned long address, pte_t *ptep)
59 {
60 	int young;
61 	young = ptep_test_and_clear_young(vma, address, ptep);
62 	if (young)
63 		flush_tlb_page(vma, address);
64 	return young;
65 }
66 #endif
67 
68 #ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
pmdp_clear_flush_young(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)69 int pmdp_clear_flush_young(struct vm_area_struct *vma,
70 			   unsigned long address, pmd_t *pmdp)
71 {
72 	int young;
73 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
74 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
75 #else
76 	BUG();
77 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
78 	young = pmdp_test_and_clear_young(vma, address, pmdp);
79 	if (young)
80 		flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
81 	return young;
82 }
83 #endif
84 
85 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
ptep_clear_flush(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)86 pte_t ptep_clear_flush(struct vm_area_struct *vma, unsigned long address,
87 		       pte_t *ptep)
88 {
89 	pte_t pte;
90 	pte = ptep_get_and_clear((vma)->vm_mm, address, ptep);
91 	flush_tlb_page(vma, address);
92 	return pte;
93 }
94 #endif
95 
96 #ifndef __HAVE_ARCH_PMDP_CLEAR_FLUSH
97 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmdp_clear_flush(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)98 pmd_t pmdp_clear_flush(struct vm_area_struct *vma, unsigned long address,
99 		       pmd_t *pmdp)
100 {
101 	pmd_t pmd;
102 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
103 	pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
104 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
105 	return pmd;
106 }
107 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
108 #endif
109 
110 #ifndef __HAVE_ARCH_PMDP_SPLITTING_FLUSH
111 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
pmdp_splitting_flush(struct vm_area_struct * vma,unsigned long address,pmd_t * pmdp)112 pmd_t pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
113 			   pmd_t *pmdp)
114 {
115 	pmd_t pmd = pmd_mksplitting(*pmdp);
116 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
117 	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
118 	/* tlb flush only to serialize against gup-fast */
119 	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
120 }
121 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
122 #endif
123