Commit | Line | Data |
---|---|---|
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 | 8 | #include <linux/types.h> |
187f1882 | 9 | #include <linux/bug.h> |
072bb0aa | 10 | #include <linux/mmdebug.h> |
9223b419 | 11 | #ifndef __GENERATING_BOUNDS_H |
6d777953 | 12 | #include <linux/mm_types.h> |
01fc0ac1 | 13 | #include <generated/bounds.h> |
9223b419 | 14 | #endif /* !__GENERATING_BOUNDS_H */ |
f886ed44 | 15 | |
1da177e4 LT |
16 | /* |
17 | * Various page->flags bits: | |
18 | * | |
19 | * PG_reserved is set for special pages, which can never be swapped out. Some | |
20 | * of them might not even exist (eg empty_bad_page)... | |
21 | * | |
da6052f7 NP |
22 | * The PG_private bitflag is set on pagecache pages if they contain filesystem |
23 | * specific data (which is normally at page->private). It can be used by | |
24 | * private allocations for its own usage. | |
1da177e4 | 25 | * |
da6052f7 NP |
26 | * During initiation of disk I/O, PG_locked is set. This bit is set before I/O |
27 | * and cleared when writeback _starts_ or when read _completes_. PG_writeback | |
28 | * is set before writeback starts and cleared when it finishes. | |
29 | * | |
30 | * PG_locked also pins a page in pagecache, and blocks truncation of the file | |
31 | * while it is held. | |
32 | * | |
33 | * page_waitqueue(page) is a wait queue of all tasks waiting for the page | |
34 | * to become unlocked. | |
1da177e4 LT |
35 | * |
36 | * PG_uptodate tells whether the page's contents is valid. When a read | |
37 | * completes, the page becomes uptodate, unless a disk I/O error happened. | |
38 | * | |
da6052f7 NP |
39 | * PG_referenced, PG_reclaim are used for page reclaim for anonymous and |
40 | * file-backed pagecache (see mm/vmscan.c). | |
1da177e4 LT |
41 | * |
42 | * PG_error is set to indicate that an I/O error occurred on this page. | |
43 | * | |
44 | * PG_arch_1 is an architecture specific page state bit. The generic code | |
45 | * guarantees that this bit is cleared for a page when it first is entered into | |
46 | * the page cache. | |
47 | * | |
48 | * PG_highmem pages are not permanently mapped into the kernel virtual address | |
49 | * space, they need to be kmapped separately for doing IO on the pages. The | |
50 | * struct page (these bits with information) are always mapped into kernel | |
51 | * address space... | |
da6052f7 | 52 | * |
d466f2fc AK |
53 | * PG_hwpoison indicates that a page got corrupted in hardware and contains |
54 | * data with incorrect ECC bits that triggered a machine check. Accessing is | |
55 | * not safe since it may cause another machine check. Don't touch! | |
1da177e4 LT |
56 | */ |
57 | ||
58 | /* | |
59 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
60 | * locked- and dirty-page accounting. |
61 | * | |
62 | * The page flags field is split into two parts, the main flags area | |
63 | * which extends from the low bits upwards, and the fields area which | |
64 | * extends from the high bits downwards. | |
65 | * | |
66 | * | FIELD | ... | FLAGS | | |
9223b419 CL |
67 | * N-1 ^ 0 |
68 | * (NR_PAGEFLAGS) | |
91fc8ab3 | 69 | * |
9223b419 CL |
70 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
71 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like | |
72 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). | |
1da177e4 | 73 | */ |
e2683181 CL |
74 | enum pageflags { |
75 | PG_locked, /* Page is locked. Don't touch. */ | |
76 | PG_error, | |
77 | PG_referenced, | |
78 | PG_uptodate, | |
79 | PG_dirty, | |
80 | PG_lru, | |
81 | PG_active, | |
82 | PG_slab, | |
83 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ | |
e2683181 CL |
84 | PG_arch_1, |
85 | PG_reserved, | |
86 | PG_private, /* If pagecache, has fs-private data */ | |
266cf658 | 87 | PG_private_2, /* If pagecache, has fs aux data */ |
e2683181 | 88 | PG_writeback, /* Page is under writeback */ |
e20b8cca | 89 | PG_head, /* A head page */ |
e2683181 CL |
90 | PG_swapcache, /* Swap page: swp_entry_t in private */ |
91 | PG_mappedtodisk, /* Has blocks allocated on-disk */ | |
92 | PG_reclaim, /* To be reclaimed asap */ | |
b2e18538 | 93 | PG_swapbacked, /* Page is backed by RAM/swap */ |
894bc310 | 94 | PG_unevictable, /* Page is "unevictable" */ |
af8e3354 | 95 | #ifdef CONFIG_MMU |
b291f000 | 96 | PG_mlocked, /* Page is vma mlocked */ |
894bc310 | 97 | #endif |
46cf98cd | 98 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
602c4d11 | 99 | PG_uncached, /* Page has been mapped as uncached */ |
d466f2fc AK |
100 | #endif |
101 | #ifdef CONFIG_MEMORY_FAILURE | |
102 | PG_hwpoison, /* hardware poisoned page. Don't touch */ | |
e9da73d6 | 103 | #endif |
33c3fc71 VD |
104 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
105 | PG_young, | |
106 | PG_idle, | |
f886ed44 | 107 | #endif |
0cad47cf AW |
108 | __NR_PAGEFLAGS, |
109 | ||
110 | /* Filesystems */ | |
111 | PG_checked = PG_owner_priv_1, | |
112 | ||
266cf658 DH |
113 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
114 | * state. These bits are set on pages belonging to the netfs's inodes | |
115 | * when those inodes are being locally cached. | |
116 | */ | |
117 | PG_fscache = PG_private_2, /* page backed by cache */ | |
118 | ||
0cad47cf | 119 | /* XEN */ |
d8ac3dd4 | 120 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 121 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 122 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 123 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
124 | /* Has a grant mapping of another (foreign) domain's page. */ |
125 | PG_foreign = PG_owner_priv_1, | |
8a38082d | 126 | |
9023cb7e | 127 | /* SLOB */ |
9023cb7e | 128 | PG_slob_free = PG_private, |
53f9263b KS |
129 | |
130 | /* Compound pages. Stored in first tail page's flags */ | |
131 | PG_double_map = PG_private_2, | |
e2683181 | 132 | }; |
1da177e4 | 133 | |
9223b419 CL |
134 | #ifndef __GENERATING_BOUNDS_H |
135 | ||
0e6d31a7 KS |
136 | struct page; /* forward declaration */ |
137 | ||
138 | static inline struct page *compound_head(struct page *page) | |
139 | { | |
140 | unsigned long head = READ_ONCE(page->compound_head); | |
141 | ||
142 | if (unlikely(head & 1)) | |
143 | return (struct page *) (head - 1); | |
144 | return page; | |
145 | } | |
146 | ||
4b0f3261 | 147 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
148 | { |
149 | return READ_ONCE(page->compound_head) & 1; | |
150 | } | |
151 | ||
4b0f3261 | 152 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
153 | { |
154 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
155 | } | |
156 | ||
95ad9755 KS |
157 | /* |
158 | * Page flags policies wrt compound pages | |
159 | * | |
160 | * PF_ANY: | |
161 | * the page flag is relevant for small, head and tail pages. | |
162 | * | |
163 | * PF_HEAD: | |
164 | * for compound page all operations related to the page flag applied to | |
165 | * head page. | |
166 | * | |
167 | * PF_NO_TAIL: | |
168 | * modifications of the page flag must be done on small or head pages, | |
169 | * checks can be done on tail pages too. | |
170 | * | |
171 | * PF_NO_COMPOUND: | |
172 | * the page flag is not relevant for compound pages. | |
173 | */ | |
174 | #define PF_ANY(page, enforce) page | |
175 | #define PF_HEAD(page, enforce) compound_head(page) | |
176 | #define PF_NO_TAIL(page, enforce) ({ \ | |
177 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
178 | compound_head(page);}) | |
822cdd11 | 179 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 KS |
180 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
181 | page;}) | |
182 | ||
f94a62e9 CL |
183 | /* |
184 | * Macros to create function definitions for page flags | |
185 | */ | |
95ad9755 | 186 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 187 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 188 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 189 | |
95ad9755 | 190 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 191 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 192 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 193 | |
95ad9755 | 194 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 195 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 196 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 197 | |
95ad9755 | 198 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 199 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 200 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 201 | |
95ad9755 | 202 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 203 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 204 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 205 | |
95ad9755 | 206 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 207 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 208 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 209 | |
95ad9755 | 210 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 211 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 212 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 213 | |
95ad9755 KS |
214 | #define PAGEFLAG(uname, lname, policy) \ |
215 | TESTPAGEFLAG(uname, lname, policy) \ | |
216 | SETPAGEFLAG(uname, lname, policy) \ | |
217 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 218 | |
95ad9755 KS |
219 | #define __PAGEFLAG(uname, lname, policy) \ |
220 | TESTPAGEFLAG(uname, lname, policy) \ | |
221 | __SETPAGEFLAG(uname, lname, policy) \ | |
222 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 223 | |
95ad9755 KS |
224 | #define TESTSCFLAG(uname, lname, policy) \ |
225 | TESTSETFLAG(uname, lname, policy) \ | |
226 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 227 | |
2f3e442c JW |
228 | #define TESTPAGEFLAG_FALSE(uname) \ |
229 | static inline int Page##uname(const struct page *page) { return 0; } | |
230 | ||
8a7a8544 LS |
231 | #define SETPAGEFLAG_NOOP(uname) \ |
232 | static inline void SetPage##uname(struct page *page) { } | |
233 | ||
234 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
235 | static inline void ClearPage##uname(struct page *page) { } | |
236 | ||
237 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
238 | static inline void __ClearPage##uname(struct page *page) { } | |
239 | ||
2f3e442c JW |
240 | #define TESTSETFLAG_FALSE(uname) \ |
241 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
242 | ||
8a7a8544 LS |
243 | #define TESTCLEARFLAG_FALSE(uname) \ |
244 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
245 | ||
2f3e442c JW |
246 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
247 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
248 | ||
249 | #define TESTSCFLAG_FALSE(uname) \ | |
250 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
251 | ||
48c935ad | 252 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
df8c94d1 | 253 | PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) |
8cb38fab KS |
254 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
255 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
256 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
257 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
258 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab KS |
259 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
260 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) | |
261 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
dcb351cd KS |
262 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
263 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 264 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
265 | |
266 | /* Xen */ | |
267 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
268 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
269 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
270 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
271 | ||
de09d31d KS |
272 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
273 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
da5efc40 KS |
274 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
275 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
276 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 277 | |
266cf658 DH |
278 | /* |
279 | * Private page markings that may be used by the filesystem that owns the page | |
280 | * for its own purposes. | |
281 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
282 | */ | |
95ad9755 KS |
283 | PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) |
284 | __CLEARPAGEFLAG(Private, private, PF_ANY) | |
285 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) | |
286 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
287 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 288 | |
6a1e7f77 CL |
289 | /* |
290 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
291 | * risky: they bypass page accounting. | |
292 | */ | |
df8c94d1 KS |
293 | TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND) |
294 | TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND) | |
295 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_COMPOUND) | |
6a1e7f77 | 296 | |
579f8290 | 297 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
df8c94d1 KS |
298 | PAGEFLAG(Reclaim, reclaim, PF_NO_COMPOUND) |
299 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_COMPOUND) | |
300 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
301 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
302 | |
303 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 304 | /* |
6a1e7f77 CL |
305 | * Must use a macro here due to header dependency issues. page_zone() is not |
306 | * available at this point. | |
1da177e4 | 307 | */ |
3ca65c19 | 308 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 309 | #else |
ec7cade8 | 310 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
311 | #endif |
312 | ||
313 | #ifdef CONFIG_SWAP | |
50ea78d6 | 314 | PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) |
6a1e7f77 | 315 | #else |
ec7cade8 | 316 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
317 | #endif |
318 | ||
8cb38fab KS |
319 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
320 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
321 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 322 | |
af8e3354 | 323 | #ifdef CONFIG_MMU |
e4f87d5d KS |
324 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
325 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
326 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 327 | #else |
2f3e442c | 328 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 329 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
330 | #endif |
331 | ||
46cf98cd | 332 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 333 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 334 | #else |
ec7cade8 | 335 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 336 | #endif |
1da177e4 | 337 | |
d466f2fc | 338 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
339 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
340 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc AK |
341 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
342 | #else | |
343 | PAGEFLAG_FALSE(HWPoison) | |
344 | #define __PG_HWPOISON 0 | |
345 | #endif | |
346 | ||
33c3fc71 | 347 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
348 | TESTPAGEFLAG(Young, young, PF_ANY) |
349 | SETPAGEFLAG(Young, young, PF_ANY) | |
350 | TESTCLEARFLAG(Young, young, PF_ANY) | |
351 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
352 | #endif |
353 | ||
e8c6158f KS |
354 | /* |
355 | * On an anonymous page mapped into a user virtual memory area, | |
356 | * page->mapping points to its anon_vma, not to a struct address_space; | |
357 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
358 | * | |
359 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
360 | * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit; | |
361 | * and then page->mapping points, not to an anon_vma, but to a private | |
362 | * structure which KSM associates with that merged page. See ksm.h. | |
363 | * | |
364 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used. | |
365 | * | |
366 | * Please note that, confusingly, "page_mapping" refers to the inode | |
367 | * address_space which maps the page from disk; whereas "page_mapped" | |
368 | * refers to user virtual address space into which the page is mapped. | |
369 | */ | |
370 | #define PAGE_MAPPING_ANON 1 | |
371 | #define PAGE_MAPPING_KSM 2 | |
372 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) | |
373 | ||
4b0f3261 | 374 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 375 | { |
822cdd11 | 376 | page = compound_head(page); |
e8c6158f KS |
377 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
378 | } | |
379 | ||
380 | #ifdef CONFIG_KSM | |
381 | /* | |
382 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
383 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
384 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
385 | * anon_vma, but to that page's node of the stable tree. | |
386 | */ | |
4b0f3261 | 387 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 388 | { |
822cdd11 | 389 | page = compound_head(page); |
e8c6158f KS |
390 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
391 | (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); | |
392 | } | |
393 | #else | |
394 | TESTPAGEFLAG_FALSE(Ksm) | |
395 | #endif | |
396 | ||
1a9b5b7f WF |
397 | u64 stable_page_flags(struct page *page); |
398 | ||
0ed361de NP |
399 | static inline int PageUptodate(struct page *page) |
400 | { | |
d2998c4d KS |
401 | int ret; |
402 | page = compound_head(page); | |
403 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
404 | /* |
405 | * Must ensure that the data we read out of the page is loaded | |
406 | * _after_ we've loaded page->flags to check for PageUptodate. | |
407 | * We can skip the barrier if the page is not uptodate, because | |
408 | * we wouldn't be reading anything from it. | |
409 | * | |
410 | * See SetPageUptodate() for the other side of the story. | |
411 | */ | |
412 | if (ret) | |
413 | smp_rmb(); | |
414 | ||
415 | return ret; | |
416 | } | |
417 | ||
4b0f3261 | 418 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 419 | { |
d2998c4d | 420 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 421 | smp_wmb(); |
df8c94d1 | 422 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
423 | } |
424 | ||
4b0f3261 | 425 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 426 | { |
d2998c4d | 427 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
428 | /* |
429 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
430 | * so that all previous stores issued in order to bring the page | |
431 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
432 | */ |
433 | smp_wmb(); | |
df8c94d1 | 434 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
435 | } |
436 | ||
d2998c4d | 437 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 438 | |
6a1e7f77 | 439 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
440 | int __test_set_page_writeback(struct page *page, bool keep_write); |
441 | ||
442 | #define test_set_page_writeback(page) \ | |
443 | __test_set_page_writeback(page, false) | |
444 | #define test_set_page_writeback_keepwrite(page) \ | |
445 | __test_set_page_writeback(page, true) | |
1da177e4 | 446 | |
6a1e7f77 CL |
447 | static inline void set_page_writeback(struct page *page) |
448 | { | |
449 | test_set_page_writeback(page); | |
450 | } | |
1da177e4 | 451 | |
1c8349a1 NJ |
452 | static inline void set_page_writeback_keepwrite(struct page *page) |
453 | { | |
454 | test_set_page_writeback_keepwrite(page); | |
455 | } | |
456 | ||
95ad9755 | 457 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 458 | |
4b0f3261 | 459 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 460 | { |
1d798ca3 | 461 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
462 | } |
463 | ||
4b0f3261 | 464 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 465 | { |
1d798ca3 | 466 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 467 | } |
6d777953 | 468 | |
4e6af67e AA |
469 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
470 | static inline void ClearPageCompound(struct page *page) | |
471 | { | |
1d798ca3 KS |
472 | BUG_ON(!PageHead(page)); |
473 | ClearPageHead(page); | |
4e6af67e AA |
474 | } |
475 | #endif | |
476 | ||
1d798ca3 | 477 | #define PG_head_mask ((1L << PG_head)) |
dfa7e20c | 478 | |
e8c6158f KS |
479 | #ifdef CONFIG_HUGETLB_PAGE |
480 | int PageHuge(struct page *page); | |
481 | int PageHeadHuge(struct page *page); | |
7e1f049e | 482 | bool page_huge_active(struct page *page); |
e8c6158f KS |
483 | #else |
484 | TESTPAGEFLAG_FALSE(Huge) | |
485 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
486 | |
487 | static inline bool page_huge_active(struct page *page) | |
488 | { | |
489 | return 0; | |
490 | } | |
e8c6158f KS |
491 | #endif |
492 | ||
7e1f049e | 493 | |
936a5fe6 | 494 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
495 | /* |
496 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
497 | * normal or transparent huge pages. | |
498 | * | |
499 | * PageTransHuge() returns true for both transparent huge and | |
500 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
501 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
502 | */ | |
503 | static inline int PageTransHuge(struct page *page) | |
504 | { | |
309381fe | 505 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
506 | return PageHead(page); |
507 | } | |
508 | ||
385de357 DN |
509 | /* |
510 | * PageTransCompound returns true for both transparent huge pages | |
511 | * and hugetlbfs pages, so it should only be called when it's known | |
512 | * that hugetlbfs pages aren't involved. | |
513 | */ | |
936a5fe6 AA |
514 | static inline int PageTransCompound(struct page *page) |
515 | { | |
516 | return PageCompound(page); | |
517 | } | |
71e3aac0 | 518 | |
385de357 DN |
519 | /* |
520 | * PageTransTail returns true for both transparent huge pages | |
521 | * and hugetlbfs pages, so it should only be called when it's known | |
522 | * that hugetlbfs pages aren't involved. | |
523 | */ | |
524 | static inline int PageTransTail(struct page *page) | |
525 | { | |
526 | return PageTail(page); | |
527 | } | |
528 | ||
53f9263b KS |
529 | /* |
530 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
531 | * as PMDs. | |
532 | * | |
533 | * This is required for optimization of rmap operations for THP: we can postpone | |
534 | * per small page mapcount accounting (and its overhead from atomic operations) | |
535 | * until the first PMD split. | |
536 | * | |
537 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
538 | * by one. This reference will go away with last compound_mapcount. | |
539 | * | |
540 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
541 | */ | |
542 | static inline int PageDoubleMap(struct page *page) | |
543 | { | |
544 | return PageHead(page) && test_bit(PG_double_map, &page[1].flags); | |
545 | } | |
546 | ||
547 | static inline int TestSetPageDoubleMap(struct page *page) | |
548 | { | |
549 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
550 | return test_and_set_bit(PG_double_map, &page[1].flags); | |
551 | } | |
552 | ||
553 | static inline int TestClearPageDoubleMap(struct page *page) | |
554 | { | |
555 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
556 | return test_and_clear_bit(PG_double_map, &page[1].flags); | |
557 | } | |
558 | ||
936a5fe6 | 559 | #else |
d8c1bdeb KS |
560 | TESTPAGEFLAG_FALSE(TransHuge) |
561 | TESTPAGEFLAG_FALSE(TransCompound) | |
562 | TESTPAGEFLAG_FALSE(TransTail) | |
53f9263b KS |
563 | TESTPAGEFLAG_FALSE(DoubleMap) |
564 | TESTSETFLAG_FALSE(DoubleMap) | |
565 | TESTCLEARFLAG_FALSE(DoubleMap) | |
936a5fe6 AA |
566 | #endif |
567 | ||
e8c6158f KS |
568 | /* |
569 | * PageBuddy() indicate that the page is free and in the buddy system | |
570 | * (see mm/page_alloc.c). | |
571 | * | |
572 | * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to | |
573 | * -2 so that an underflow of the page_mapcount() won't be mistaken | |
574 | * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very | |
575 | * efficiently by most CPU architectures. | |
576 | */ | |
577 | #define PAGE_BUDDY_MAPCOUNT_VALUE (-128) | |
578 | ||
579 | static inline int PageBuddy(struct page *page) | |
580 | { | |
581 | return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE; | |
582 | } | |
583 | ||
584 | static inline void __SetPageBuddy(struct page *page) | |
585 | { | |
586 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); | |
587 | atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE); | |
588 | } | |
589 | ||
590 | static inline void __ClearPageBuddy(struct page *page) | |
591 | { | |
592 | VM_BUG_ON_PAGE(!PageBuddy(page), page); | |
593 | atomic_set(&page->_mapcount, -1); | |
594 | } | |
595 | ||
832fc1de NH |
596 | extern bool is_free_buddy_page(struct page *page); |
597 | ||
e8c6158f KS |
598 | #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) |
599 | ||
600 | static inline int PageBalloon(struct page *page) | |
601 | { | |
602 | return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE; | |
603 | } | |
604 | ||
605 | static inline void __SetPageBalloon(struct page *page) | |
606 | { | |
607 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); | |
608 | atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE); | |
609 | } | |
610 | ||
611 | static inline void __ClearPageBalloon(struct page *page) | |
612 | { | |
613 | VM_BUG_ON_PAGE(!PageBalloon(page), page); | |
614 | atomic_set(&page->_mapcount, -1); | |
615 | } | |
616 | ||
072bb0aa MG |
617 | /* |
618 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
619 | * were allocated from pfmemalloc reserves. | |
620 | */ | |
621 | static inline int PageSlabPfmemalloc(struct page *page) | |
622 | { | |
309381fe | 623 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
624 | return PageActive(page); |
625 | } | |
626 | ||
627 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
628 | { | |
309381fe | 629 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
630 | SetPageActive(page); |
631 | } | |
632 | ||
633 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
634 | { | |
309381fe | 635 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
636 | __ClearPageActive(page); |
637 | } | |
638 | ||
639 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
640 | { | |
309381fe | 641 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
642 | ClearPageActive(page); |
643 | } | |
644 | ||
af8e3354 | 645 | #ifdef CONFIG_MMU |
33925b25 DH |
646 | #define __PG_MLOCKED (1 << PG_mlocked) |
647 | #else | |
b291f000 | 648 | #define __PG_MLOCKED 0 |
894bc310 LS |
649 | #endif |
650 | ||
dfa7e20c RA |
651 | /* |
652 | * Flags checked when a page is freed. Pages being freed should not have | |
653 | * these flags set. It they are, there is a problem. | |
654 | */ | |
79f4b7bf | 655 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
266cf658 DH |
656 | (1 << PG_lru | 1 << PG_locked | \ |
657 | 1 << PG_private | 1 << PG_private_2 | \ | |
5f24ce5f | 658 | 1 << PG_writeback | 1 << PG_reserved | \ |
266cf658 | 659 | 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ |
3ac808fd | 660 | 1 << PG_unevictable | __PG_MLOCKED) |
dfa7e20c RA |
661 | |
662 | /* | |
663 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 664 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 665 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
666 | * |
667 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
668 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 669 | */ |
f4c18e6f NH |
670 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
671 | (((1 << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) | |
dfa7e20c | 672 | |
edcf4748 JW |
673 | #define PAGE_FLAGS_PRIVATE \ |
674 | (1 << PG_private | 1 << PG_private_2) | |
266cf658 DH |
675 | /** |
676 | * page_has_private - Determine if page has private stuff | |
677 | * @page: The page to be checked | |
678 | * | |
679 | * Determine if a page has private stuff, indicating that release routines | |
680 | * should be invoked upon it. | |
681 | */ | |
edcf4748 JW |
682 | static inline int page_has_private(struct page *page) |
683 | { | |
684 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
685 | } | |
686 | ||
95ad9755 KS |
687 | #undef PF_ANY |
688 | #undef PF_HEAD | |
689 | #undef PF_NO_TAIL | |
690 | #undef PF_NO_COMPOUND | |
edcf4748 | 691 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 692 | |
1da177e4 | 693 | #endif /* PAGE_FLAGS_H */ |