Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * Macros for manipulating and testing page->flags | |
4 | */ | |
5 | ||
6 | #ifndef PAGE_FLAGS_H | |
7 | #define PAGE_FLAGS_H | |
8 | ||
f886ed44 | 9 | #include <linux/types.h> |
187f1882 | 10 | #include <linux/bug.h> |
072bb0aa | 11 | #include <linux/mmdebug.h> |
9223b419 | 12 | #ifndef __GENERATING_BOUNDS_H |
6d777953 | 13 | #include <linux/mm_types.h> |
01fc0ac1 | 14 | #include <generated/bounds.h> |
9223b419 | 15 | #endif /* !__GENERATING_BOUNDS_H */ |
f886ed44 | 16 | |
1da177e4 LT |
17 | /* |
18 | * Various page->flags bits: | |
19 | * | |
20 | * PG_reserved is set for special pages, which can never be swapped out. Some | |
8745808f | 21 | * of them might not even exist... |
1da177e4 | 22 | * |
da6052f7 NP |
23 | * The PG_private bitflag is set on pagecache pages if they contain filesystem |
24 | * specific data (which is normally at page->private). It can be used by | |
25 | * private allocations for its own usage. | |
1da177e4 | 26 | * |
da6052f7 NP |
27 | * During initiation of disk I/O, PG_locked is set. This bit is set before I/O |
28 | * and cleared when writeback _starts_ or when read _completes_. PG_writeback | |
29 | * is set before writeback starts and cleared when it finishes. | |
30 | * | |
31 | * PG_locked also pins a page in pagecache, and blocks truncation of the file | |
32 | * while it is held. | |
33 | * | |
34 | * page_waitqueue(page) is a wait queue of all tasks waiting for the page | |
35 | * to become unlocked. | |
1da177e4 LT |
36 | * |
37 | * PG_uptodate tells whether the page's contents is valid. When a read | |
38 | * completes, the page becomes uptodate, unless a disk I/O error happened. | |
39 | * | |
da6052f7 NP |
40 | * PG_referenced, PG_reclaim are used for page reclaim for anonymous and |
41 | * file-backed pagecache (see mm/vmscan.c). | |
1da177e4 LT |
42 | * |
43 | * PG_error is set to indicate that an I/O error occurred on this page. | |
44 | * | |
45 | * PG_arch_1 is an architecture specific page state bit. The generic code | |
46 | * guarantees that this bit is cleared for a page when it first is entered into | |
47 | * the page cache. | |
48 | * | |
d466f2fc AK |
49 | * PG_hwpoison indicates that a page got corrupted in hardware and contains |
50 | * data with incorrect ECC bits that triggered a machine check. Accessing is | |
51 | * not safe since it may cause another machine check. Don't touch! | |
1da177e4 LT |
52 | */ |
53 | ||
54 | /* | |
55 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
56 | * locked- and dirty-page accounting. |
57 | * | |
58 | * The page flags field is split into two parts, the main flags area | |
59 | * which extends from the low bits upwards, and the fields area which | |
60 | * extends from the high bits downwards. | |
61 | * | |
62 | * | FIELD | ... | FLAGS | | |
9223b419 CL |
63 | * N-1 ^ 0 |
64 | * (NR_PAGEFLAGS) | |
91fc8ab3 | 65 | * |
9223b419 CL |
66 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
67 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like | |
68 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). | |
1da177e4 | 69 | */ |
e2683181 CL |
70 | enum pageflags { |
71 | PG_locked, /* Page is locked. Don't touch. */ | |
72 | PG_error, | |
73 | PG_referenced, | |
74 | PG_uptodate, | |
75 | PG_dirty, | |
76 | PG_lru, | |
77 | PG_active, | |
b91e1302 | 78 | PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ |
e2683181 CL |
79 | PG_slab, |
80 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ | |
e2683181 CL |
81 | PG_arch_1, |
82 | PG_reserved, | |
83 | PG_private, /* If pagecache, has fs-private data */ | |
266cf658 | 84 | PG_private_2, /* If pagecache, has fs aux data */ |
e2683181 | 85 | PG_writeback, /* Page is under writeback */ |
e20b8cca | 86 | PG_head, /* A head page */ |
e2683181 CL |
87 | PG_mappedtodisk, /* Has blocks allocated on-disk */ |
88 | PG_reclaim, /* To be reclaimed asap */ | |
b2e18538 | 89 | PG_swapbacked, /* Page is backed by RAM/swap */ |
894bc310 | 90 | PG_unevictable, /* Page is "unevictable" */ |
af8e3354 | 91 | #ifdef CONFIG_MMU |
b291f000 | 92 | PG_mlocked, /* Page is vma mlocked */ |
894bc310 | 93 | #endif |
46cf98cd | 94 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
602c4d11 | 95 | PG_uncached, /* Page has been mapped as uncached */ |
d466f2fc AK |
96 | #endif |
97 | #ifdef CONFIG_MEMORY_FAILURE | |
98 | PG_hwpoison, /* hardware poisoned page. Don't touch */ | |
e9da73d6 | 99 | #endif |
33c3fc71 VD |
100 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
101 | PG_young, | |
102 | PG_idle, | |
f886ed44 | 103 | #endif |
0cad47cf AW |
104 | __NR_PAGEFLAGS, |
105 | ||
106 | /* Filesystems */ | |
107 | PG_checked = PG_owner_priv_1, | |
108 | ||
6326fec1 NP |
109 | /* SwapBacked */ |
110 | PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ | |
111 | ||
266cf658 DH |
112 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
113 | * state. These bits are set on pages belonging to the netfs's inodes | |
114 | * when those inodes are being locally cached. | |
115 | */ | |
116 | PG_fscache = PG_private_2, /* page backed by cache */ | |
117 | ||
0cad47cf | 118 | /* XEN */ |
d8ac3dd4 | 119 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 120 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 121 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 122 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
123 | /* Has a grant mapping of another (foreign) domain's page. */ |
124 | PG_foreign = PG_owner_priv_1, | |
8a38082d | 125 | |
9023cb7e | 126 | /* SLOB */ |
9023cb7e | 127 | PG_slob_free = PG_private, |
53f9263b KS |
128 | |
129 | /* Compound pages. Stored in first tail page's flags */ | |
130 | PG_double_map = PG_private_2, | |
bda807d4 MK |
131 | |
132 | /* non-lru isolated movable page */ | |
133 | PG_isolated = PG_reclaim, | |
e2683181 | 134 | }; |
1da177e4 | 135 | |
9223b419 CL |
136 | #ifndef __GENERATING_BOUNDS_H |
137 | ||
0e6d31a7 KS |
138 | struct page; /* forward declaration */ |
139 | ||
140 | static inline struct page *compound_head(struct page *page) | |
141 | { | |
142 | unsigned long head = READ_ONCE(page->compound_head); | |
143 | ||
144 | if (unlikely(head & 1)) | |
145 | return (struct page *) (head - 1); | |
146 | return page; | |
147 | } | |
148 | ||
4b0f3261 | 149 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
150 | { |
151 | return READ_ONCE(page->compound_head) & 1; | |
152 | } | |
153 | ||
4b0f3261 | 154 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
155 | { |
156 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
157 | } | |
158 | ||
f165b378 PT |
159 | #define PAGE_POISON_PATTERN -1l |
160 | static inline int PagePoisoned(const struct page *page) | |
161 | { | |
162 | return page->flags == PAGE_POISON_PATTERN; | |
163 | } | |
164 | ||
95ad9755 KS |
165 | /* |
166 | * Page flags policies wrt compound pages | |
167 | * | |
f165b378 PT |
168 | * PF_POISONED_CHECK |
169 | * check if this struct page poisoned/uninitialized | |
170 | * | |
95ad9755 KS |
171 | * PF_ANY: |
172 | * the page flag is relevant for small, head and tail pages. | |
173 | * | |
174 | * PF_HEAD: | |
175 | * for compound page all operations related to the page flag applied to | |
176 | * head page. | |
177 | * | |
62906027 NP |
178 | * PF_ONLY_HEAD: |
179 | * for compound page, callers only ever operate on the head page. | |
180 | * | |
95ad9755 KS |
181 | * PF_NO_TAIL: |
182 | * modifications of the page flag must be done on small or head pages, | |
183 | * checks can be done on tail pages too. | |
184 | * | |
185 | * PF_NO_COMPOUND: | |
186 | * the page flag is not relevant for compound pages. | |
187 | */ | |
f165b378 PT |
188 | #define PF_POISONED_CHECK(page) ({ \ |
189 | VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ | |
190 | page; }) | |
191 | #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) | |
192 | #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) | |
62906027 NP |
193 | #define PF_ONLY_HEAD(page, enforce) ({ \ |
194 | VM_BUG_ON_PGFLAGS(PageTail(page), page); \ | |
f165b378 | 195 | PF_POISONED_CHECK(page); }) |
95ad9755 KS |
196 | #define PF_NO_TAIL(page, enforce) ({ \ |
197 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
f165b378 | 198 | PF_POISONED_CHECK(compound_head(page)); }) |
822cdd11 | 199 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 | 200 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
f165b378 | 201 | PF_POISONED_CHECK(page); }) |
95ad9755 | 202 | |
f94a62e9 CL |
203 | /* |
204 | * Macros to create function definitions for page flags | |
205 | */ | |
95ad9755 | 206 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 207 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 208 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 209 | |
95ad9755 | 210 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 211 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 212 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 213 | |
95ad9755 | 214 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 215 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 216 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 217 | |
95ad9755 | 218 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 219 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 220 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 221 | |
95ad9755 | 222 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 223 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 224 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 225 | |
95ad9755 | 226 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 227 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 228 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 229 | |
95ad9755 | 230 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 231 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 232 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 233 | |
95ad9755 KS |
234 | #define PAGEFLAG(uname, lname, policy) \ |
235 | TESTPAGEFLAG(uname, lname, policy) \ | |
236 | SETPAGEFLAG(uname, lname, policy) \ | |
237 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 238 | |
95ad9755 KS |
239 | #define __PAGEFLAG(uname, lname, policy) \ |
240 | TESTPAGEFLAG(uname, lname, policy) \ | |
241 | __SETPAGEFLAG(uname, lname, policy) \ | |
242 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 243 | |
95ad9755 KS |
244 | #define TESTSCFLAG(uname, lname, policy) \ |
245 | TESTSETFLAG(uname, lname, policy) \ | |
246 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 247 | |
2f3e442c JW |
248 | #define TESTPAGEFLAG_FALSE(uname) \ |
249 | static inline int Page##uname(const struct page *page) { return 0; } | |
250 | ||
8a7a8544 LS |
251 | #define SETPAGEFLAG_NOOP(uname) \ |
252 | static inline void SetPage##uname(struct page *page) { } | |
253 | ||
254 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
255 | static inline void ClearPage##uname(struct page *page) { } | |
256 | ||
257 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
258 | static inline void __ClearPage##uname(struct page *page) { } | |
259 | ||
2f3e442c JW |
260 | #define TESTSETFLAG_FALSE(uname) \ |
261 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
262 | ||
8a7a8544 LS |
263 | #define TESTCLEARFLAG_FALSE(uname) \ |
264 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
265 | ||
2f3e442c JW |
266 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
267 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
268 | ||
269 | #define TESTSCFLAG_FALSE(uname) \ | |
270 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
271 | ||
48c935ad | 272 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
62906027 | 273 | PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) |
df8c94d1 | 274 | PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) |
8cb38fab KS |
275 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
276 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
277 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
278 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
279 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab KS |
280 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
281 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) | |
282 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
dcb351cd KS |
283 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
284 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 285 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
286 | |
287 | /* Xen */ | |
288 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
289 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
290 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
291 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
292 | ||
de09d31d KS |
293 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
294 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
da5efc40 KS |
295 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
296 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
297 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 298 | |
266cf658 DH |
299 | /* |
300 | * Private page markings that may be used by the filesystem that owns the page | |
301 | * for its own purposes. | |
302 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
303 | */ | |
95ad9755 KS |
304 | PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) |
305 | __CLEARPAGEFLAG(Private, private, PF_ANY) | |
306 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) | |
307 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
308 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 309 | |
6a1e7f77 CL |
310 | /* |
311 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
312 | * risky: they bypass page accounting. | |
313 | */ | |
225311a4 HY |
314 | TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) |
315 | TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) | |
e2f0a0db | 316 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) |
6a1e7f77 | 317 | |
579f8290 | 318 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
e2f0a0db KS |
319 | PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) |
320 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) | |
df8c94d1 KS |
321 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) |
322 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
323 | |
324 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 325 | /* |
6a1e7f77 CL |
326 | * Must use a macro here due to header dependency issues. page_zone() is not |
327 | * available at this point. | |
1da177e4 | 328 | */ |
3ca65c19 | 329 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 330 | #else |
ec7cade8 | 331 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
332 | #endif |
333 | ||
334 | #ifdef CONFIG_SWAP | |
6326fec1 NP |
335 | static __always_inline int PageSwapCache(struct page *page) |
336 | { | |
38d8b4e6 HY |
337 | #ifdef CONFIG_THP_SWAP |
338 | page = compound_head(page); | |
339 | #endif | |
6326fec1 NP |
340 | return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); |
341 | ||
342 | } | |
38d8b4e6 HY |
343 | SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) |
344 | CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) | |
6a1e7f77 | 345 | #else |
ec7cade8 | 346 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
347 | #endif |
348 | ||
8cb38fab KS |
349 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
350 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
351 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 352 | |
af8e3354 | 353 | #ifdef CONFIG_MMU |
e4f87d5d KS |
354 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
355 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
356 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 357 | #else |
2f3e442c | 358 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 359 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
360 | #endif |
361 | ||
46cf98cd | 362 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 363 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 364 | #else |
ec7cade8 | 365 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 366 | #endif |
1da177e4 | 367 | |
d466f2fc | 368 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
369 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
370 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc AK |
371 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
372 | #else | |
373 | PAGEFLAG_FALSE(HWPoison) | |
374 | #define __PG_HWPOISON 0 | |
375 | #endif | |
376 | ||
33c3fc71 | 377 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
378 | TESTPAGEFLAG(Young, young, PF_ANY) |
379 | SETPAGEFLAG(Young, young, PF_ANY) | |
380 | TESTCLEARFLAG(Young, young, PF_ANY) | |
381 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
382 | #endif |
383 | ||
e8c6158f KS |
384 | /* |
385 | * On an anonymous page mapped into a user virtual memory area, | |
386 | * page->mapping points to its anon_vma, not to a struct address_space; | |
387 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
388 | * | |
389 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
390 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
391 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
392 | * structure which KSM associates with that merged page. See ksm.h. |
393 | * | |
bda807d4 MK |
394 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
395 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
396 | * |
397 | * Please note that, confusingly, "page_mapping" refers to the inode | |
398 | * address_space which maps the page from disk; whereas "page_mapped" | |
399 | * refers to user virtual address space into which the page is mapped. | |
400 | */ | |
bda807d4 MK |
401 | #define PAGE_MAPPING_ANON 0x1 |
402 | #define PAGE_MAPPING_MOVABLE 0x2 | |
403 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
404 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 405 | |
bda807d4 | 406 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 407 | { |
bda807d4 | 408 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
409 | } |
410 | ||
4b0f3261 | 411 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 412 | { |
822cdd11 | 413 | page = compound_head(page); |
bda807d4 MK |
414 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
415 | } | |
416 | ||
417 | static __always_inline int __PageMovable(struct page *page) | |
418 | { | |
419 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
420 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
421 | } |
422 | ||
423 | #ifdef CONFIG_KSM | |
424 | /* | |
425 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
426 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
427 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
428 | * anon_vma, but to that page's node of the stable tree. | |
429 | */ | |
4b0f3261 | 430 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 431 | { |
822cdd11 | 432 | page = compound_head(page); |
e8c6158f | 433 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 434 | PAGE_MAPPING_KSM; |
e8c6158f KS |
435 | } |
436 | #else | |
437 | TESTPAGEFLAG_FALSE(Ksm) | |
438 | #endif | |
439 | ||
1a9b5b7f WF |
440 | u64 stable_page_flags(struct page *page); |
441 | ||
0ed361de NP |
442 | static inline int PageUptodate(struct page *page) |
443 | { | |
d2998c4d KS |
444 | int ret; |
445 | page = compound_head(page); | |
446 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
447 | /* |
448 | * Must ensure that the data we read out of the page is loaded | |
449 | * _after_ we've loaded page->flags to check for PageUptodate. | |
450 | * We can skip the barrier if the page is not uptodate, because | |
451 | * we wouldn't be reading anything from it. | |
452 | * | |
453 | * See SetPageUptodate() for the other side of the story. | |
454 | */ | |
455 | if (ret) | |
456 | smp_rmb(); | |
457 | ||
458 | return ret; | |
459 | } | |
460 | ||
4b0f3261 | 461 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 462 | { |
d2998c4d | 463 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 464 | smp_wmb(); |
df8c94d1 | 465 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
466 | } |
467 | ||
4b0f3261 | 468 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 469 | { |
d2998c4d | 470 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
471 | /* |
472 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
473 | * so that all previous stores issued in order to bring the page | |
474 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
475 | */ |
476 | smp_wmb(); | |
df8c94d1 | 477 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
478 | } |
479 | ||
d2998c4d | 480 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 481 | |
6a1e7f77 | 482 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
483 | int __test_set_page_writeback(struct page *page, bool keep_write); |
484 | ||
485 | #define test_set_page_writeback(page) \ | |
486 | __test_set_page_writeback(page, false) | |
487 | #define test_set_page_writeback_keepwrite(page) \ | |
488 | __test_set_page_writeback(page, true) | |
1da177e4 | 489 | |
6a1e7f77 CL |
490 | static inline void set_page_writeback(struct page *page) |
491 | { | |
492 | test_set_page_writeback(page); | |
493 | } | |
1da177e4 | 494 | |
1c8349a1 NJ |
495 | static inline void set_page_writeback_keepwrite(struct page *page) |
496 | { | |
497 | test_set_page_writeback_keepwrite(page); | |
498 | } | |
499 | ||
95ad9755 | 500 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 501 | |
4b0f3261 | 502 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 503 | { |
1d798ca3 | 504 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
505 | } |
506 | ||
4b0f3261 | 507 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 508 | { |
1d798ca3 | 509 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 510 | } |
6d777953 | 511 | |
4e6af67e AA |
512 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
513 | static inline void ClearPageCompound(struct page *page) | |
514 | { | |
1d798ca3 KS |
515 | BUG_ON(!PageHead(page)); |
516 | ClearPageHead(page); | |
4e6af67e AA |
517 | } |
518 | #endif | |
519 | ||
d2a1a1f0 | 520 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 521 | |
e8c6158f KS |
522 | #ifdef CONFIG_HUGETLB_PAGE |
523 | int PageHuge(struct page *page); | |
524 | int PageHeadHuge(struct page *page); | |
7e1f049e | 525 | bool page_huge_active(struct page *page); |
e8c6158f KS |
526 | #else |
527 | TESTPAGEFLAG_FALSE(Huge) | |
528 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
529 | |
530 | static inline bool page_huge_active(struct page *page) | |
531 | { | |
532 | return 0; | |
533 | } | |
e8c6158f KS |
534 | #endif |
535 | ||
7e1f049e | 536 | |
936a5fe6 | 537 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
538 | /* |
539 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
540 | * normal or transparent huge pages. | |
541 | * | |
542 | * PageTransHuge() returns true for both transparent huge and | |
543 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
544 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
545 | */ | |
546 | static inline int PageTransHuge(struct page *page) | |
547 | { | |
309381fe | 548 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
549 | return PageHead(page); |
550 | } | |
551 | ||
385de357 DN |
552 | /* |
553 | * PageTransCompound returns true for both transparent huge pages | |
554 | * and hugetlbfs pages, so it should only be called when it's known | |
555 | * that hugetlbfs pages aren't involved. | |
556 | */ | |
936a5fe6 AA |
557 | static inline int PageTransCompound(struct page *page) |
558 | { | |
559 | return PageCompound(page); | |
560 | } | |
71e3aac0 | 561 | |
127393fb AA |
562 | /* |
563 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
564 | * guarantees the primary MMU has the entire compound page mapped | |
565 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
566 | * can also map the entire compound page. This allows the secondary | |
567 | * MMUs to call get_user_pages() only once for each compound page and | |
568 | * to immediately map the entire compound page with a single secondary | |
569 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
570 | * will get an update through the MMU notifier invalidation through | |
571 | * split_huge_pmd(). | |
572 | * | |
573 | * Unlike PageTransCompound, this is safe to be called only while | |
574 | * split_huge_pmd() cannot run from under us, like if protected by the | |
575 | * MMU notifier, otherwise it may result in page->_mapcount < 0 false | |
576 | * positives. | |
577 | */ | |
578 | static inline int PageTransCompoundMap(struct page *page) | |
579 | { | |
580 | return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0; | |
581 | } | |
582 | ||
385de357 DN |
583 | /* |
584 | * PageTransTail returns true for both transparent huge pages | |
585 | * and hugetlbfs pages, so it should only be called when it's known | |
586 | * that hugetlbfs pages aren't involved. | |
587 | */ | |
588 | static inline int PageTransTail(struct page *page) | |
589 | { | |
590 | return PageTail(page); | |
591 | } | |
592 | ||
53f9263b KS |
593 | /* |
594 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
595 | * as PMDs. | |
596 | * | |
597 | * This is required for optimization of rmap operations for THP: we can postpone | |
598 | * per small page mapcount accounting (and its overhead from atomic operations) | |
599 | * until the first PMD split. | |
600 | * | |
601 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
602 | * by one. This reference will go away with last compound_mapcount. | |
603 | * | |
604 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
605 | */ | |
606 | static inline int PageDoubleMap(struct page *page) | |
607 | { | |
608 | return PageHead(page) && test_bit(PG_double_map, &page[1].flags); | |
609 | } | |
610 | ||
9a73f61b KS |
611 | static inline void SetPageDoubleMap(struct page *page) |
612 | { | |
613 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
614 | set_bit(PG_double_map, &page[1].flags); | |
615 | } | |
616 | ||
617 | static inline void ClearPageDoubleMap(struct page *page) | |
618 | { | |
619 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
620 | clear_bit(PG_double_map, &page[1].flags); | |
621 | } | |
53f9263b KS |
622 | static inline int TestSetPageDoubleMap(struct page *page) |
623 | { | |
624 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
625 | return test_and_set_bit(PG_double_map, &page[1].flags); | |
626 | } | |
627 | ||
628 | static inline int TestClearPageDoubleMap(struct page *page) | |
629 | { | |
630 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
631 | return test_and_clear_bit(PG_double_map, &page[1].flags); | |
632 | } | |
633 | ||
936a5fe6 | 634 | #else |
d8c1bdeb KS |
635 | TESTPAGEFLAG_FALSE(TransHuge) |
636 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 637 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 638 | TESTPAGEFLAG_FALSE(TransTail) |
9a73f61b | 639 | PAGEFLAG_FALSE(DoubleMap) |
53f9263b KS |
640 | TESTSETFLAG_FALSE(DoubleMap) |
641 | TESTCLEARFLAG_FALSE(DoubleMap) | |
936a5fe6 AA |
642 | #endif |
643 | ||
e8c6158f | 644 | /* |
632c0a1a VD |
645 | * For pages that are never mapped to userspace, page->mapcount may be |
646 | * used for storing extra information about page type. Any value used | |
647 | * for this purpose must be <= -2, but it's better start not too close | |
648 | * to -2 so that an underflow of the page_mapcount() won't be mistaken | |
649 | * for a special page. | |
e8c6158f | 650 | */ |
632c0a1a VD |
651 | #define PAGE_MAPCOUNT_OPS(uname, lname) \ |
652 | static __always_inline int Page##uname(struct page *page) \ | |
653 | { \ | |
654 | return atomic_read(&page->_mapcount) == \ | |
655 | PAGE_##lname##_MAPCOUNT_VALUE; \ | |
656 | } \ | |
657 | static __always_inline void __SetPage##uname(struct page *page) \ | |
658 | { \ | |
659 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); \ | |
660 | atomic_set(&page->_mapcount, PAGE_##lname##_MAPCOUNT_VALUE); \ | |
661 | } \ | |
662 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
663 | { \ | |
664 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
665 | atomic_set(&page->_mapcount, -1); \ | |
e8c6158f KS |
666 | } |
667 | ||
632c0a1a VD |
668 | /* |
669 | * PageBuddy() indicate that the page is free and in the buddy system | |
670 | * (see mm/page_alloc.c). | |
671 | */ | |
672 | #define PAGE_BUDDY_MAPCOUNT_VALUE (-128) | |
673 | PAGE_MAPCOUNT_OPS(Buddy, BUDDY) | |
e8c6158f | 674 | |
632c0a1a VD |
675 | /* |
676 | * PageBalloon() is set on pages that are on the balloon page list | |
677 | * (see mm/balloon_compaction.c). | |
678 | */ | |
679 | #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) | |
680 | PAGE_MAPCOUNT_OPS(Balloon, BALLOON) | |
e8c6158f | 681 | |
4949148a VD |
682 | /* |
683 | * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on | |
684 | * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. | |
685 | */ | |
686 | #define PAGE_KMEMCG_MAPCOUNT_VALUE (-512) | |
687 | PAGE_MAPCOUNT_OPS(Kmemcg, KMEMCG) | |
688 | ||
832fc1de NH |
689 | extern bool is_free_buddy_page(struct page *page); |
690 | ||
bda807d4 MK |
691 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
692 | ||
072bb0aa MG |
693 | /* |
694 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
695 | * were allocated from pfmemalloc reserves. | |
696 | */ | |
697 | static inline int PageSlabPfmemalloc(struct page *page) | |
698 | { | |
309381fe | 699 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
700 | return PageActive(page); |
701 | } | |
702 | ||
703 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
704 | { | |
309381fe | 705 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
706 | SetPageActive(page); |
707 | } | |
708 | ||
709 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
710 | { | |
309381fe | 711 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
712 | __ClearPageActive(page); |
713 | } | |
714 | ||
715 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
716 | { | |
309381fe | 717 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
718 | ClearPageActive(page); |
719 | } | |
720 | ||
af8e3354 | 721 | #ifdef CONFIG_MMU |
d2a1a1f0 | 722 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 723 | #else |
b291f000 | 724 | #define __PG_MLOCKED 0 |
894bc310 LS |
725 | #endif |
726 | ||
dfa7e20c RA |
727 | /* |
728 | * Flags checked when a page is freed. Pages being freed should not have | |
729 | * these flags set. It they are, there is a problem. | |
730 | */ | |
6326fec1 NP |
731 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
732 | (1UL << PG_lru | 1UL << PG_locked | \ | |
733 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
734 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
735 | 1UL << PG_slab | 1UL << PG_active | \ | |
736 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
737 | |
738 | /* | |
739 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 740 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 741 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
742 | * |
743 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
744 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 745 | */ |
f4c18e6f | 746 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
d2a1a1f0 | 747 | (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) |
dfa7e20c | 748 | |
edcf4748 | 749 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 750 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
751 | /** |
752 | * page_has_private - Determine if page has private stuff | |
753 | * @page: The page to be checked | |
754 | * | |
755 | * Determine if a page has private stuff, indicating that release routines | |
756 | * should be invoked upon it. | |
757 | */ | |
edcf4748 JW |
758 | static inline int page_has_private(struct page *page) |
759 | { | |
760 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
761 | } | |
762 | ||
95ad9755 KS |
763 | #undef PF_ANY |
764 | #undef PF_HEAD | |
62906027 | 765 | #undef PF_ONLY_HEAD |
95ad9755 KS |
766 | #undef PF_NO_TAIL |
767 | #undef PF_NO_COMPOUND | |
edcf4748 | 768 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 769 | |
1da177e4 | 770 | #endif /* PAGE_FLAGS_H */ |