[PATCH] Refactor sys_reboot into reusable parts
[linux-2.6.git] / include / asm-generic / pgtable.h
1 #ifndef _ASM_GENERIC_PGTABLE_H
2 #define _ASM_GENERIC_PGTABLE_H
3
4 #ifndef __HAVE_ARCH_PTEP_ESTABLISH
5 /*
6  * Establish a new mapping:
7  *  - flush the old one
8  *  - update the page tables
9  *  - inform the TLB about the new one
10  *
11  * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock.
12  *
13  * Note: the old pte is known to not be writable, so we don't need to
14  * worry about dirty bits etc getting lost.
15  */
16 #ifndef __HAVE_ARCH_SET_PTE_ATOMIC
17 #define ptep_establish(__vma, __address, __ptep, __entry)               \
18 do {                                                                    \
19         set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);       \
20         flush_tlb_page(__vma, __address);                               \
21 } while (0)
22 #else /* __HAVE_ARCH_SET_PTE_ATOMIC */
23 #define ptep_establish(__vma, __address, __ptep, __entry)               \
24 do {                                                                    \
25         set_pte_atomic(__ptep, __entry);                                \
26         flush_tlb_page(__vma, __address);                               \
27 } while (0)
28 #endif /* __HAVE_ARCH_SET_PTE_ATOMIC */
29 #endif
30
31 #ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
32 /*
33  * Largely same as above, but only sets the access flags (dirty,
34  * accessed, and writable). Furthermore, we know it always gets set
35  * to a "more permissive" setting, which allows most architectures
36  * to optimize this.
37  */
38 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
39 do {                                                                      \
40         set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry);         \
41         flush_tlb_page(__vma, __address);                                 \
42 } while (0)
43 #endif
44
45 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
46 #define ptep_test_and_clear_young(__vma, __address, __ptep)             \
47 ({                                                                      \
48         pte_t __pte = *(__ptep);                                        \
49         int r = 1;                                                      \
50         if (!pte_young(__pte))                                          \
51                 r = 0;                                                  \
52         else                                                            \
53                 set_pte_at((__vma)->vm_mm, (__address),                 \
54                            (__ptep), pte_mkold(__pte));                 \
55         r;                                                              \
56 })
57 #endif
58
59 #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
60 #define ptep_clear_flush_young(__vma, __address, __ptep)                \
61 ({                                                                      \
62         int __young;                                                    \
63         __young = ptep_test_and_clear_young(__vma, __address, __ptep);  \
64         if (__young)                                                    \
65                 flush_tlb_page(__vma, __address);                       \
66         __young;                                                        \
67 })
68 #endif
69
70 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
71 #define ptep_test_and_clear_dirty(__vma, __address, __ptep)             \
72 ({                                                                      \
73         pte_t __pte = *__ptep;                                          \
74         int r = 1;                                                      \
75         if (!pte_dirty(__pte))                                          \
76                 r = 0;                                                  \
77         else                                                            \
78                 set_pte_at((__vma)->vm_mm, (__address), (__ptep),       \
79                            pte_mkclean(__pte));                         \
80         r;                                                              \
81 })
82 #endif
83
84 #ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
85 #define ptep_clear_flush_dirty(__vma, __address, __ptep)                \
86 ({                                                                      \
87         int __dirty;                                                    \
88         __dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep);  \
89         if (__dirty)                                                    \
90                 flush_tlb_page(__vma, __address);                       \
91         __dirty;                                                        \
92 })
93 #endif
94
95 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
96 #define ptep_get_and_clear(__mm, __address, __ptep)                     \
97 ({                                                                      \
98         pte_t __pte = *(__ptep);                                        \
99         pte_clear((__mm), (__address), (__ptep));                       \
100         __pte;                                                          \
101 })
102 #endif
103
104 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
105 #define ptep_clear_flush(__vma, __address, __ptep)                      \
106 ({                                                                      \
107         pte_t __pte;                                                    \
108         __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
109         flush_tlb_page(__vma, __address);                               \
110         __pte;                                                          \
111 })
112 #endif
113
114 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
115 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
116 {
117         pte_t old_pte = *ptep;
118         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
119 }
120 #endif
121
122 #ifndef __HAVE_ARCH_PTE_SAME
123 #define pte_same(A,B)   (pte_val(A) == pte_val(B))
124 #endif
125
126 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
127 #define page_test_and_clear_dirty(page) (0)
128 #define pte_maybe_dirty(pte)            pte_dirty(pte)
129 #else
130 #define pte_maybe_dirty(pte)            (1)
131 #endif
132
133 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
134 #define page_test_and_clear_young(page) (0)
135 #endif
136
137 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
138 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
139 #endif
140
141 #ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
142 #define lazy_mmu_prot_update(pte)       do { } while (0)
143 #endif
144
145 /*
146  * When walking page tables, get the address of the next boundary,
147  * or the end address of the range if that comes earlier.  Although no
148  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
149  */
150
151 #define pgd_addr_end(addr, end)                                         \
152 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
153         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
154 })
155
156 #ifndef pud_addr_end
157 #define pud_addr_end(addr, end)                                         \
158 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
159         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
160 })
161 #endif
162
163 #ifndef pmd_addr_end
164 #define pmd_addr_end(addr, end)                                         \
165 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
166         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
167 })
168 #endif
169
170 #ifndef __ASSEMBLY__
171 /*
172  * When walking page tables, we usually want to skip any p?d_none entries;
173  * and any p?d_bad entries - reporting the error before resetting to none.
174  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
175  */
176 void pgd_clear_bad(pgd_t *);
177 void pud_clear_bad(pud_t *);
178 void pmd_clear_bad(pmd_t *);
179
180 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
181 {
182         if (pgd_none(*pgd))
183                 return 1;
184         if (unlikely(pgd_bad(*pgd))) {
185                 pgd_clear_bad(pgd);
186                 return 1;
187         }
188         return 0;
189 }
190
191 static inline int pud_none_or_clear_bad(pud_t *pud)
192 {
193         if (pud_none(*pud))
194                 return 1;
195         if (unlikely(pud_bad(*pud))) {
196                 pud_clear_bad(pud);
197                 return 1;
198         }
199         return 0;
200 }
201
202 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
203 {
204         if (pmd_none(*pmd))
205                 return 1;
206         if (unlikely(pmd_bad(*pmd))) {
207                 pmd_clear_bad(pmd);
208                 return 1;
209         }
210         return 0;
211 }
212 #endif /* !__ASSEMBLY__ */
213
214 #endif /* _ASM_GENERIC_PGTABLE_H */