[PATCH] mm: update comments to pte lock
[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 the pte 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_GET_AND_CLEAR_FULL
105 #define ptep_get_and_clear_full(__mm, __address, __ptep, __full)        \
106 ({                                                                      \
107         pte_t __pte;                                                    \
108         __pte = ptep_get_and_clear((__mm), (__address), (__ptep));      \
109         __pte;                                                          \
110 })
111 #endif
112
113 #ifndef __HAVE_ARCH_PTE_CLEAR_FULL
114 #define pte_clear_full(__mm, __address, __ptep, __full)                 \
115 do {                                                                    \
116         pte_clear((__mm), (__address), (__ptep));                       \
117 } while (0)
118 #endif
119
120 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
121 #define ptep_clear_flush(__vma, __address, __ptep)                      \
122 ({                                                                      \
123         pte_t __pte;                                                    \
124         __pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep);  \
125         flush_tlb_page(__vma, __address);                               \
126         __pte;                                                          \
127 })
128 #endif
129
130 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
131 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
132 {
133         pte_t old_pte = *ptep;
134         set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
135 }
136 #endif
137
138 #ifndef __HAVE_ARCH_PTE_SAME
139 #define pte_same(A,B)   (pte_val(A) == pte_val(B))
140 #endif
141
142 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
143 #define page_test_and_clear_dirty(page) (0)
144 #define pte_maybe_dirty(pte)            pte_dirty(pte)
145 #else
146 #define pte_maybe_dirty(pte)            (1)
147 #endif
148
149 #ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
150 #define page_test_and_clear_young(page) (0)
151 #endif
152
153 #ifndef __HAVE_ARCH_PGD_OFFSET_GATE
154 #define pgd_offset_gate(mm, addr)       pgd_offset(mm, addr)
155 #endif
156
157 #ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
158 #define lazy_mmu_prot_update(pte)       do { } while (0)
159 #endif
160
161 #ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE
162 #define move_pte(pte, prot, old_addr, new_addr) (pte)
163 #else
164 #define move_pte(pte, prot, old_addr, new_addr)                         \
165 ({                                                                      \
166         pte_t newpte = (pte);                                           \
167         if (pte_present(pte) && pfn_valid(pte_pfn(pte)) &&              \
168                         pte_page(pte) == ZERO_PAGE(old_addr))           \
169                 newpte = mk_pte(ZERO_PAGE(new_addr), (prot));           \
170         newpte;                                                         \
171 })
172 #endif
173
174 /*
175  * When walking page tables, get the address of the next boundary,
176  * or the end address of the range if that comes earlier.  Although no
177  * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
178  */
179
180 #define pgd_addr_end(addr, end)                                         \
181 ({      unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;  \
182         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
183 })
184
185 #ifndef pud_addr_end
186 #define pud_addr_end(addr, end)                                         \
187 ({      unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;      \
188         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
189 })
190 #endif
191
192 #ifndef pmd_addr_end
193 #define pmd_addr_end(addr, end)                                         \
194 ({      unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;      \
195         (__boundary - 1 < (end) - 1)? __boundary: (end);                \
196 })
197 #endif
198
199 #ifndef __ASSEMBLY__
200 /*
201  * When walking page tables, we usually want to skip any p?d_none entries;
202  * and any p?d_bad entries - reporting the error before resetting to none.
203  * Do the tests inline, but report and clear the bad entry in mm/memory.c.
204  */
205 void pgd_clear_bad(pgd_t *);
206 void pud_clear_bad(pud_t *);
207 void pmd_clear_bad(pmd_t *);
208
209 static inline int pgd_none_or_clear_bad(pgd_t *pgd)
210 {
211         if (pgd_none(*pgd))
212                 return 1;
213         if (unlikely(pgd_bad(*pgd))) {
214                 pgd_clear_bad(pgd);
215                 return 1;
216         }
217         return 0;
218 }
219
220 static inline int pud_none_or_clear_bad(pud_t *pud)
221 {
222         if (pud_none(*pud))
223                 return 1;
224         if (unlikely(pud_bad(*pud))) {
225                 pud_clear_bad(pud);
226                 return 1;
227         }
228         return 0;
229 }
230
231 static inline int pmd_none_or_clear_bad(pmd_t *pmd)
232 {
233         if (pmd_none(*pmd))
234                 return 1;
235         if (unlikely(pmd_bad(*pmd))) {
236                 pmd_clear_bad(pmd);
237                 return 1;
238         }
239         return 0;
240 }
241 #endif /* !__ASSEMBLY__ */
242
243 #endif /* _ASM_GENERIC_PGTABLE_H */