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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Macros for manipulating and testing page->flags | |
3 | */ | |
4 | ||
5 | #ifndef PAGE_FLAGS_H | |
6 | #define PAGE_FLAGS_H | |
7 | ||
f886ed44 AM |
8 | #include <linux/types.h> |
9 | ||
1da177e4 LT |
10 | /* |
11 | * Various page->flags bits: | |
12 | * | |
13 | * PG_reserved is set for special pages, which can never be swapped out. Some | |
14 | * of them might not even exist (eg empty_bad_page)... | |
15 | * | |
16 | * The PG_private bitflag is set if page->private contains a valid value. | |
17 | * | |
18 | * During disk I/O, PG_locked is used. This bit is set before I/O and | |
19 | * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks | |
20 | * waiting for the I/O on this page to complete. | |
21 | * | |
22 | * PG_uptodate tells whether the page's contents is valid. When a read | |
23 | * completes, the page becomes uptodate, unless a disk I/O error happened. | |
24 | * | |
25 | * For choosing which pages to swap out, inode pages carry a PG_referenced bit, | |
26 | * which is set any time the system accesses that page through the (mapping, | |
27 | * index) hash table. This referenced bit, together with the referenced bit | |
28 | * in the page tables, is used to manipulate page->age and move the page across | |
29 | * the active, inactive_dirty and inactive_clean lists. | |
30 | * | |
31 | * Note that the referenced bit, the page->lru list_head and the active, | |
32 | * inactive_dirty and inactive_clean lists are protected by the | |
33 | * zone->lru_lock, and *NOT* by the usual PG_locked bit! | |
34 | * | |
35 | * PG_error is set to indicate that an I/O error occurred on this page. | |
36 | * | |
37 | * PG_arch_1 is an architecture specific page state bit. The generic code | |
38 | * guarantees that this bit is cleared for a page when it first is entered into | |
39 | * the page cache. | |
40 | * | |
41 | * PG_highmem pages are not permanently mapped into the kernel virtual address | |
42 | * space, they need to be kmapped separately for doing IO on the pages. The | |
43 | * struct page (these bits with information) are always mapped into kernel | |
44 | * address space... | |
45 | */ | |
46 | ||
47 | /* | |
48 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
49 | * locked- and dirty-page accounting. |
50 | * | |
51 | * The page flags field is split into two parts, the main flags area | |
52 | * which extends from the low bits upwards, and the fields area which | |
53 | * extends from the high bits downwards. | |
54 | * | |
55 | * | FIELD | ... | FLAGS | | |
56 | * N-1 ^ 0 | |
57 | * (N-FLAGS_RESERVED) | |
58 | * | |
59 | * The fields area is reserved for fields mapping zone, node and SPARSEMEM | |
60 | * section. The boundry between these two areas is defined by | |
61 | * FLAGS_RESERVED which defines the width of the fields section | |
62 | * (see linux/mmzone.h). New flags must _not_ overlap with this area. | |
1da177e4 LT |
63 | */ |
64 | #define PG_locked 0 /* Page is locked. Don't touch. */ | |
65 | #define PG_error 1 | |
66 | #define PG_referenced 2 | |
67 | #define PG_uptodate 3 | |
68 | ||
69 | #define PG_dirty 4 | |
70 | #define PG_lru 5 | |
71 | #define PG_active 6 | |
72 | #define PG_slab 7 /* slab debug (Suparna wants this) */ | |
73 | ||
cbe37d09 BP |
74 | #define PG_checked 8 /* kill me in 2.5.<early>. */ |
75 | #define PG_arch_1 9 | |
76 | #define PG_reserved 10 | |
77 | #define PG_private 11 /* Has something at ->private */ | |
78 | ||
79 | #define PG_writeback 12 /* Page is under writeback */ | |
80 | #define PG_nosave 13 /* Used for system suspend/resume */ | |
81 | #define PG_compound 14 /* Part of a compound page */ | |
82 | #define PG_swapcache 15 /* Swap page: swp_entry_t in private */ | |
83 | ||
84 | #define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ | |
85 | #define PG_reclaim 17 /* To be reclaimed asap */ | |
86 | #define PG_nosave_free 18 /* Free, should not be written */ | |
676165a8 NP |
87 | #define PG_buddy 19 /* Page is free, on buddy lists */ |
88 | ||
f886ed44 AM |
89 | |
90 | #if (BITS_PER_LONG > 32) | |
91 | /* | |
92 | * 64-bit-only flags build down from bit 31 | |
93 | * | |
94 | * 32 bit -------------------------------| FIELDS | FLAGS | | |
95 | * 64 bit | FIELDS | ?????? FLAGS | | |
96 | * 63 32 0 | |
97 | */ | |
98 | #define PG_uncached 31 /* Page has been mapped as uncached */ | |
99 | #endif | |
1da177e4 | 100 | |
1da177e4 LT |
101 | /* |
102 | * Manipulation of page state flags | |
103 | */ | |
104 | #define PageLocked(page) \ | |
105 | test_bit(PG_locked, &(page)->flags) | |
106 | #define SetPageLocked(page) \ | |
107 | set_bit(PG_locked, &(page)->flags) | |
108 | #define TestSetPageLocked(page) \ | |
109 | test_and_set_bit(PG_locked, &(page)->flags) | |
110 | #define ClearPageLocked(page) \ | |
111 | clear_bit(PG_locked, &(page)->flags) | |
112 | #define TestClearPageLocked(page) \ | |
113 | test_and_clear_bit(PG_locked, &(page)->flags) | |
114 | ||
115 | #define PageError(page) test_bit(PG_error, &(page)->flags) | |
116 | #define SetPageError(page) set_bit(PG_error, &(page)->flags) | |
117 | #define ClearPageError(page) clear_bit(PG_error, &(page)->flags) | |
118 | ||
119 | #define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) | |
120 | #define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) | |
121 | #define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) | |
122 | #define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) | |
123 | ||
124 | #define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) | |
f6ac2354 CL |
125 | #ifdef CONFIG_S390 |
126 | #define SetPageUptodate(_page) \ | |
127 | do { \ | |
128 | struct page *__page = (_page); \ | |
129 | if (!test_and_set_bit(PG_uptodate, &__page->flags)) \ | |
130 | page_test_and_clear_dirty(_page); \ | |
131 | } while (0) | |
132 | #else | |
1da177e4 LT |
133 | #define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) |
134 | #endif | |
135 | #define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) | |
136 | ||
137 | #define PageDirty(page) test_bit(PG_dirty, &(page)->flags) | |
138 | #define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) | |
139 | #define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) | |
140 | #define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) | |
242e5468 | 141 | #define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags) |
1da177e4 LT |
142 | #define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
143 | ||
1da177e4 | 144 | #define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
8d438f96 NP |
145 | #define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
146 | #define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags) | |
67453911 | 147 | #define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags) |
1da177e4 LT |
148 | |
149 | #define PageActive(page) test_bit(PG_active, &(page)->flags) | |
150 | #define SetPageActive(page) set_bit(PG_active, &(page)->flags) | |
151 | #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) | |
67453911 | 152 | #define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags) |
1da177e4 LT |
153 | |
154 | #define PageSlab(page) test_bit(PG_slab, &(page)->flags) | |
f205b2fe NP |
155 | #define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags) |
156 | #define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags) | |
1da177e4 LT |
157 | |
158 | #ifdef CONFIG_HIGHMEM | |
cbe37d09 | 159 | #define PageHighMem(page) is_highmem(page_zone(page)) |
1da177e4 LT |
160 | #else |
161 | #define PageHighMem(page) 0 /* needed to optimize away at compile time */ | |
162 | #endif | |
163 | ||
164 | #define PageChecked(page) test_bit(PG_checked, &(page)->flags) | |
165 | #define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) | |
166 | #define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) | |
167 | ||
168 | #define PageReserved(page) test_bit(PG_reserved, &(page)->flags) | |
169 | #define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) | |
170 | #define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) | |
171 | #define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) | |
172 | ||
173 | #define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) | |
174 | #define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) | |
175 | #define PagePrivate(page) test_bit(PG_private, &(page)->flags) | |
176 | #define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) | |
177 | #define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) | |
178 | ||
179 | #define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) | |
180 | #define SetPageWriteback(page) \ | |
181 | do { \ | |
182 | if (!test_and_set_bit(PG_writeback, \ | |
183 | &(page)->flags)) \ | |
ce866b34 | 184 | inc_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
185 | } while (0) |
186 | #define TestSetPageWriteback(page) \ | |
187 | ({ \ | |
188 | int ret; \ | |
189 | ret = test_and_set_bit(PG_writeback, \ | |
190 | &(page)->flags); \ | |
191 | if (!ret) \ | |
ce866b34 | 192 | inc_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
193 | ret; \ |
194 | }) | |
195 | #define ClearPageWriteback(page) \ | |
196 | do { \ | |
197 | if (test_and_clear_bit(PG_writeback, \ | |
198 | &(page)->flags)) \ | |
ce866b34 | 199 | dec_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
200 | } while (0) |
201 | #define TestClearPageWriteback(page) \ | |
202 | ({ \ | |
203 | int ret; \ | |
204 | ret = test_and_clear_bit(PG_writeback, \ | |
205 | &(page)->flags); \ | |
206 | if (ret) \ | |
ce866b34 | 207 | dec_zone_page_state(page, NR_WRITEBACK); \ |
1da177e4 LT |
208 | ret; \ |
209 | }) | |
210 | ||
211 | #define PageNosave(page) test_bit(PG_nosave, &(page)->flags) | |
212 | #define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) | |
213 | #define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) | |
214 | #define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) | |
215 | #define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) | |
216 | ||
217 | #define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) | |
218 | #define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) | |
219 | #define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) | |
220 | ||
676165a8 NP |
221 | #define PageBuddy(page) test_bit(PG_buddy, &(page)->flags) |
222 | #define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags) | |
223 | #define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags) | |
224 | ||
1da177e4 LT |
225 | #define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
226 | #define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) | |
227 | #define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) | |
228 | ||
229 | #define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) | |
230 | #define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) | |
231 | #define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) | |
232 | #define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) | |
233 | ||
1da177e4 | 234 | #define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
5e9dace8 NP |
235 | #define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags) |
236 | #define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags) | |
1da177e4 LT |
237 | |
238 | #ifdef CONFIG_SWAP | |
239 | #define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) | |
240 | #define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) | |
241 | #define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) | |
242 | #else | |
243 | #define PageSwapCache(page) 0 | |
244 | #endif | |
245 | ||
246 | #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) | |
247 | #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) | |
248 | #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) | |
249 | ||
250 | struct page; /* forward declaration */ | |
251 | ||
252 | int test_clear_page_dirty(struct page *page); | |
253 | int test_clear_page_writeback(struct page *page); | |
254 | int test_set_page_writeback(struct page *page); | |
255 | ||
256 | static inline void clear_page_dirty(struct page *page) | |
257 | { | |
258 | test_clear_page_dirty(page); | |
259 | } | |
260 | ||
261 | static inline void set_page_writeback(struct page *page) | |
262 | { | |
263 | test_set_page_writeback(page); | |
264 | } | |
265 | ||
266 | #endif /* PAGE_FLAGS_H */ |