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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 | * | |
49 | * PG_highmem pages are not permanently mapped into the kernel virtual address | |
50 | * space, they need to be kmapped separately for doing IO on the pages. The | |
51 | * struct page (these bits with information) are always mapped into kernel | |
52 | * address space... | |
da6052f7 | 53 | * |
d466f2fc AK |
54 | * PG_hwpoison indicates that a page got corrupted in hardware and contains |
55 | * data with incorrect ECC bits that triggered a machine check. Accessing is | |
56 | * not safe since it may cause another machine check. Don't touch! | |
1da177e4 LT |
57 | */ |
58 | ||
59 | /* | |
60 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
61 | * locked- and dirty-page accounting. |
62 | * | |
63 | * The page flags field is split into two parts, the main flags area | |
64 | * which extends from the low bits upwards, and the fields area which | |
65 | * extends from the high bits downwards. | |
66 | * | |
67 | * | FIELD | ... | FLAGS | | |
9223b419 CL |
68 | * N-1 ^ 0 |
69 | * (NR_PAGEFLAGS) | |
91fc8ab3 | 70 | * |
9223b419 CL |
71 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
72 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like | |
73 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). | |
1da177e4 | 74 | */ |
e2683181 CL |
75 | enum pageflags { |
76 | PG_locked, /* Page is locked. Don't touch. */ | |
77 | PG_error, | |
78 | PG_referenced, | |
79 | PG_uptodate, | |
80 | PG_dirty, | |
81 | PG_lru, | |
82 | PG_active, | |
b91e1302 | 83 | PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ |
e2683181 CL |
84 | PG_slab, |
85 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ | |
e2683181 CL |
86 | PG_arch_1, |
87 | PG_reserved, | |
88 | PG_private, /* If pagecache, has fs-private data */ | |
266cf658 | 89 | PG_private_2, /* If pagecache, has fs aux data */ |
e2683181 | 90 | PG_writeback, /* Page is under writeback */ |
e20b8cca | 91 | PG_head, /* A head page */ |
e2683181 CL |
92 | PG_mappedtodisk, /* Has blocks allocated on-disk */ |
93 | PG_reclaim, /* To be reclaimed asap */ | |
b2e18538 | 94 | PG_swapbacked, /* Page is backed by RAM/swap */ |
894bc310 | 95 | PG_unevictable, /* Page is "unevictable" */ |
af8e3354 | 96 | #ifdef CONFIG_MMU |
b291f000 | 97 | PG_mlocked, /* Page is vma mlocked */ |
894bc310 | 98 | #endif |
46cf98cd | 99 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
602c4d11 | 100 | PG_uncached, /* Page has been mapped as uncached */ |
d466f2fc AK |
101 | #endif |
102 | #ifdef CONFIG_MEMORY_FAILURE | |
103 | PG_hwpoison, /* hardware poisoned page. Don't touch */ | |
e9da73d6 | 104 | #endif |
33c3fc71 VD |
105 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
106 | PG_young, | |
107 | PG_idle, | |
f886ed44 | 108 | #endif |
0cad47cf AW |
109 | __NR_PAGEFLAGS, |
110 | ||
111 | /* Filesystems */ | |
112 | PG_checked = PG_owner_priv_1, | |
113 | ||
6326fec1 NP |
114 | /* SwapBacked */ |
115 | PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ | |
116 | ||
266cf658 DH |
117 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
118 | * state. These bits are set on pages belonging to the netfs's inodes | |
119 | * when those inodes are being locally cached. | |
120 | */ | |
121 | PG_fscache = PG_private_2, /* page backed by cache */ | |
122 | ||
0cad47cf | 123 | /* XEN */ |
d8ac3dd4 | 124 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 125 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 126 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 127 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
128 | /* Has a grant mapping of another (foreign) domain's page. */ |
129 | PG_foreign = PG_owner_priv_1, | |
8a38082d | 130 | |
9023cb7e | 131 | /* SLOB */ |
9023cb7e | 132 | PG_slob_free = PG_private, |
53f9263b KS |
133 | |
134 | /* Compound pages. Stored in first tail page's flags */ | |
135 | PG_double_map = PG_private_2, | |
bda807d4 MK |
136 | |
137 | /* non-lru isolated movable page */ | |
138 | PG_isolated = PG_reclaim, | |
e2683181 | 139 | }; |
1da177e4 | 140 | |
9223b419 CL |
141 | #ifndef __GENERATING_BOUNDS_H |
142 | ||
0e6d31a7 KS |
143 | struct page; /* forward declaration */ |
144 | ||
145 | static inline struct page *compound_head(struct page *page) | |
146 | { | |
147 | unsigned long head = READ_ONCE(page->compound_head); | |
148 | ||
149 | if (unlikely(head & 1)) | |
150 | return (struct page *) (head - 1); | |
151 | return page; | |
152 | } | |
153 | ||
4b0f3261 | 154 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
155 | { |
156 | return READ_ONCE(page->compound_head) & 1; | |
157 | } | |
158 | ||
4b0f3261 | 159 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
160 | { |
161 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
162 | } | |
163 | ||
95ad9755 KS |
164 | /* |
165 | * Page flags policies wrt compound pages | |
166 | * | |
167 | * PF_ANY: | |
168 | * the page flag is relevant for small, head and tail pages. | |
169 | * | |
170 | * PF_HEAD: | |
171 | * for compound page all operations related to the page flag applied to | |
172 | * head page. | |
173 | * | |
62906027 NP |
174 | * PF_ONLY_HEAD: |
175 | * for compound page, callers only ever operate on the head page. | |
176 | * | |
95ad9755 KS |
177 | * PF_NO_TAIL: |
178 | * modifications of the page flag must be done on small or head pages, | |
179 | * checks can be done on tail pages too. | |
180 | * | |
181 | * PF_NO_COMPOUND: | |
182 | * the page flag is not relevant for compound pages. | |
183 | */ | |
184 | #define PF_ANY(page, enforce) page | |
185 | #define PF_HEAD(page, enforce) compound_head(page) | |
62906027 NP |
186 | #define PF_ONLY_HEAD(page, enforce) ({ \ |
187 | VM_BUG_ON_PGFLAGS(PageTail(page), page); \ | |
188 | page;}) | |
95ad9755 KS |
189 | #define PF_NO_TAIL(page, enforce) ({ \ |
190 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
191 | compound_head(page);}) | |
822cdd11 | 192 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 KS |
193 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
194 | page;}) | |
195 | ||
f94a62e9 CL |
196 | /* |
197 | * Macros to create function definitions for page flags | |
198 | */ | |
95ad9755 | 199 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 200 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 201 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 202 | |
95ad9755 | 203 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 204 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 205 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 206 | |
95ad9755 | 207 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 208 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 209 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 210 | |
95ad9755 | 211 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 212 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 213 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 214 | |
95ad9755 | 215 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 216 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 217 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 218 | |
95ad9755 | 219 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 220 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 221 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 222 | |
95ad9755 | 223 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 224 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 225 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 226 | |
95ad9755 KS |
227 | #define PAGEFLAG(uname, lname, policy) \ |
228 | TESTPAGEFLAG(uname, lname, policy) \ | |
229 | SETPAGEFLAG(uname, lname, policy) \ | |
230 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 231 | |
95ad9755 KS |
232 | #define __PAGEFLAG(uname, lname, policy) \ |
233 | TESTPAGEFLAG(uname, lname, policy) \ | |
234 | __SETPAGEFLAG(uname, lname, policy) \ | |
235 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 236 | |
95ad9755 KS |
237 | #define TESTSCFLAG(uname, lname, policy) \ |
238 | TESTSETFLAG(uname, lname, policy) \ | |
239 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 240 | |
2f3e442c JW |
241 | #define TESTPAGEFLAG_FALSE(uname) \ |
242 | static inline int Page##uname(const struct page *page) { return 0; } | |
243 | ||
8a7a8544 LS |
244 | #define SETPAGEFLAG_NOOP(uname) \ |
245 | static inline void SetPage##uname(struct page *page) { } | |
246 | ||
247 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
248 | static inline void ClearPage##uname(struct page *page) { } | |
249 | ||
250 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
251 | static inline void __ClearPage##uname(struct page *page) { } | |
252 | ||
2f3e442c JW |
253 | #define TESTSETFLAG_FALSE(uname) \ |
254 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
255 | ||
8a7a8544 LS |
256 | #define TESTCLEARFLAG_FALSE(uname) \ |
257 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
258 | ||
2f3e442c JW |
259 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
260 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
261 | ||
262 | #define TESTSCFLAG_FALSE(uname) \ | |
263 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
264 | ||
48c935ad | 265 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
62906027 | 266 | PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) |
df8c94d1 | 267 | PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) |
8cb38fab KS |
268 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
269 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
270 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
271 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
272 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab KS |
273 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
274 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) | |
275 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
dcb351cd KS |
276 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
277 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 278 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
279 | |
280 | /* Xen */ | |
281 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
282 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
283 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
284 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
285 | ||
de09d31d KS |
286 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
287 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
da5efc40 KS |
288 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
289 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
290 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 291 | |
266cf658 DH |
292 | /* |
293 | * Private page markings that may be used by the filesystem that owns the page | |
294 | * for its own purposes. | |
295 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
296 | */ | |
95ad9755 KS |
297 | PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) |
298 | __CLEARPAGEFLAG(Private, private, PF_ANY) | |
299 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) | |
300 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
301 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 302 | |
6a1e7f77 CL |
303 | /* |
304 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
305 | * risky: they bypass page accounting. | |
306 | */ | |
225311a4 HY |
307 | TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) |
308 | TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) | |
e2f0a0db | 309 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) |
6a1e7f77 | 310 | |
579f8290 | 311 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
e2f0a0db KS |
312 | PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) |
313 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) | |
df8c94d1 KS |
314 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) |
315 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
316 | |
317 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 318 | /* |
6a1e7f77 CL |
319 | * Must use a macro here due to header dependency issues. page_zone() is not |
320 | * available at this point. | |
1da177e4 | 321 | */ |
3ca65c19 | 322 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 323 | #else |
ec7cade8 | 324 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
325 | #endif |
326 | ||
327 | #ifdef CONFIG_SWAP | |
6326fec1 NP |
328 | static __always_inline int PageSwapCache(struct page *page) |
329 | { | |
38d8b4e6 HY |
330 | #ifdef CONFIG_THP_SWAP |
331 | page = compound_head(page); | |
332 | #endif | |
6326fec1 NP |
333 | return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); |
334 | ||
335 | } | |
38d8b4e6 HY |
336 | SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) |
337 | CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) | |
6a1e7f77 | 338 | #else |
ec7cade8 | 339 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
340 | #endif |
341 | ||
8cb38fab KS |
342 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
343 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
344 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 345 | |
af8e3354 | 346 | #ifdef CONFIG_MMU |
e4f87d5d KS |
347 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
348 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
349 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 350 | #else |
2f3e442c | 351 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 352 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
353 | #endif |
354 | ||
46cf98cd | 355 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 356 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 357 | #else |
ec7cade8 | 358 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 359 | #endif |
1da177e4 | 360 | |
d466f2fc | 361 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
362 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
363 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc AK |
364 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
365 | #else | |
366 | PAGEFLAG_FALSE(HWPoison) | |
367 | #define __PG_HWPOISON 0 | |
368 | #endif | |
369 | ||
33c3fc71 | 370 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
371 | TESTPAGEFLAG(Young, young, PF_ANY) |
372 | SETPAGEFLAG(Young, young, PF_ANY) | |
373 | TESTCLEARFLAG(Young, young, PF_ANY) | |
374 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
375 | #endif |
376 | ||
e8c6158f KS |
377 | /* |
378 | * On an anonymous page mapped into a user virtual memory area, | |
379 | * page->mapping points to its anon_vma, not to a struct address_space; | |
380 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
381 | * | |
382 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
383 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
384 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
385 | * structure which KSM associates with that merged page. See ksm.h. |
386 | * | |
bda807d4 MK |
387 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
388 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
389 | * |
390 | * Please note that, confusingly, "page_mapping" refers to the inode | |
391 | * address_space which maps the page from disk; whereas "page_mapped" | |
392 | * refers to user virtual address space into which the page is mapped. | |
393 | */ | |
bda807d4 MK |
394 | #define PAGE_MAPPING_ANON 0x1 |
395 | #define PAGE_MAPPING_MOVABLE 0x2 | |
396 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
397 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 398 | |
bda807d4 | 399 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 400 | { |
bda807d4 | 401 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
402 | } |
403 | ||
4b0f3261 | 404 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 405 | { |
822cdd11 | 406 | page = compound_head(page); |
bda807d4 MK |
407 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
408 | } | |
409 | ||
410 | static __always_inline int __PageMovable(struct page *page) | |
411 | { | |
412 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
413 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
414 | } |
415 | ||
416 | #ifdef CONFIG_KSM | |
417 | /* | |
418 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
419 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
420 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
421 | * anon_vma, but to that page's node of the stable tree. | |
422 | */ | |
4b0f3261 | 423 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 424 | { |
822cdd11 | 425 | page = compound_head(page); |
e8c6158f | 426 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 427 | PAGE_MAPPING_KSM; |
e8c6158f KS |
428 | } |
429 | #else | |
430 | TESTPAGEFLAG_FALSE(Ksm) | |
431 | #endif | |
432 | ||
1a9b5b7f WF |
433 | u64 stable_page_flags(struct page *page); |
434 | ||
0ed361de NP |
435 | static inline int PageUptodate(struct page *page) |
436 | { | |
d2998c4d KS |
437 | int ret; |
438 | page = compound_head(page); | |
439 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
440 | /* |
441 | * Must ensure that the data we read out of the page is loaded | |
442 | * _after_ we've loaded page->flags to check for PageUptodate. | |
443 | * We can skip the barrier if the page is not uptodate, because | |
444 | * we wouldn't be reading anything from it. | |
445 | * | |
446 | * See SetPageUptodate() for the other side of the story. | |
447 | */ | |
448 | if (ret) | |
449 | smp_rmb(); | |
450 | ||
451 | return ret; | |
452 | } | |
453 | ||
4b0f3261 | 454 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 455 | { |
d2998c4d | 456 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 457 | smp_wmb(); |
df8c94d1 | 458 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
459 | } |
460 | ||
4b0f3261 | 461 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 462 | { |
d2998c4d | 463 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
464 | /* |
465 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
466 | * so that all previous stores issued in order to bring the page | |
467 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
468 | */ |
469 | smp_wmb(); | |
df8c94d1 | 470 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
471 | } |
472 | ||
d2998c4d | 473 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 474 | |
6a1e7f77 | 475 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
476 | int __test_set_page_writeback(struct page *page, bool keep_write); |
477 | ||
478 | #define test_set_page_writeback(page) \ | |
479 | __test_set_page_writeback(page, false) | |
480 | #define test_set_page_writeback_keepwrite(page) \ | |
481 | __test_set_page_writeback(page, true) | |
1da177e4 | 482 | |
6a1e7f77 CL |
483 | static inline void set_page_writeback(struct page *page) |
484 | { | |
485 | test_set_page_writeback(page); | |
486 | } | |
1da177e4 | 487 | |
1c8349a1 NJ |
488 | static inline void set_page_writeback_keepwrite(struct page *page) |
489 | { | |
490 | test_set_page_writeback_keepwrite(page); | |
491 | } | |
492 | ||
95ad9755 | 493 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 494 | |
4b0f3261 | 495 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 496 | { |
1d798ca3 | 497 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
498 | } |
499 | ||
4b0f3261 | 500 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 501 | { |
1d798ca3 | 502 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 503 | } |
6d777953 | 504 | |
4e6af67e AA |
505 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
506 | static inline void ClearPageCompound(struct page *page) | |
507 | { | |
1d798ca3 KS |
508 | BUG_ON(!PageHead(page)); |
509 | ClearPageHead(page); | |
4e6af67e AA |
510 | } |
511 | #endif | |
512 | ||
d2a1a1f0 | 513 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 514 | |
e8c6158f KS |
515 | #ifdef CONFIG_HUGETLB_PAGE |
516 | int PageHuge(struct page *page); | |
517 | int PageHeadHuge(struct page *page); | |
7e1f049e | 518 | bool page_huge_active(struct page *page); |
e8c6158f KS |
519 | #else |
520 | TESTPAGEFLAG_FALSE(Huge) | |
521 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
522 | |
523 | static inline bool page_huge_active(struct page *page) | |
524 | { | |
525 | return 0; | |
526 | } | |
e8c6158f KS |
527 | #endif |
528 | ||
7e1f049e | 529 | |
936a5fe6 | 530 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
531 | /* |
532 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
533 | * normal or transparent huge pages. | |
534 | * | |
535 | * PageTransHuge() returns true for both transparent huge and | |
536 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
537 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
538 | */ | |
539 | static inline int PageTransHuge(struct page *page) | |
540 | { | |
309381fe | 541 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
542 | return PageHead(page); |
543 | } | |
544 | ||
385de357 DN |
545 | /* |
546 | * PageTransCompound returns true for both transparent huge pages | |
547 | * and hugetlbfs pages, so it should only be called when it's known | |
548 | * that hugetlbfs pages aren't involved. | |
549 | */ | |
936a5fe6 AA |
550 | static inline int PageTransCompound(struct page *page) |
551 | { | |
552 | return PageCompound(page); | |
553 | } | |
71e3aac0 | 554 | |
127393fb AA |
555 | /* |
556 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
557 | * guarantees the primary MMU has the entire compound page mapped | |
558 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
559 | * can also map the entire compound page. This allows the secondary | |
560 | * MMUs to call get_user_pages() only once for each compound page and | |
561 | * to immediately map the entire compound page with a single secondary | |
562 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
563 | * will get an update through the MMU notifier invalidation through | |
564 | * split_huge_pmd(). | |
565 | * | |
566 | * Unlike PageTransCompound, this is safe to be called only while | |
567 | * split_huge_pmd() cannot run from under us, like if protected by the | |
95bb9fd7 | 568 | * MMU notifier, otherwise it may result in page->_mapcount check false |
127393fb | 569 | * positives. |
95bb9fd7 YS |
570 | * |
571 | * We have to treat page cache THP differently since every subpage of it | |
572 | * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE | |
573 | * mapped in the current process so comparing subpage's _mapcount to | |
574 | * compound_mapcount to filter out PTE mapped case. | |
127393fb AA |
575 | */ |
576 | static inline int PageTransCompoundMap(struct page *page) | |
577 | { | |
95bb9fd7 YS |
578 | struct page *head; |
579 | ||
580 | if (!PageTransCompound(page)) | |
581 | return 0; | |
582 | ||
583 | if (PageAnon(page)) | |
584 | return atomic_read(&page->_mapcount) < 0; | |
585 | ||
586 | head = compound_head(page); | |
587 | /* File THP is PMD mapped and not PTE mapped */ | |
588 | return atomic_read(&page->_mapcount) == | |
589 | atomic_read(compound_mapcount_ptr(head)); | |
127393fb AA |
590 | } |
591 | ||
385de357 DN |
592 | /* |
593 | * PageTransTail returns true for both transparent huge pages | |
594 | * and hugetlbfs pages, so it should only be called when it's known | |
595 | * that hugetlbfs pages aren't involved. | |
596 | */ | |
597 | static inline int PageTransTail(struct page *page) | |
598 | { | |
599 | return PageTail(page); | |
600 | } | |
601 | ||
53f9263b KS |
602 | /* |
603 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
604 | * as PMDs. | |
605 | * | |
606 | * This is required for optimization of rmap operations for THP: we can postpone | |
607 | * per small page mapcount accounting (and its overhead from atomic operations) | |
608 | * until the first PMD split. | |
609 | * | |
610 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
611 | * by one. This reference will go away with last compound_mapcount. | |
612 | * | |
613 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
614 | */ | |
615 | static inline int PageDoubleMap(struct page *page) | |
616 | { | |
617 | return PageHead(page) && test_bit(PG_double_map, &page[1].flags); | |
618 | } | |
619 | ||
9a73f61b KS |
620 | static inline void SetPageDoubleMap(struct page *page) |
621 | { | |
622 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
623 | set_bit(PG_double_map, &page[1].flags); | |
624 | } | |
625 | ||
626 | static inline void ClearPageDoubleMap(struct page *page) | |
627 | { | |
628 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
629 | clear_bit(PG_double_map, &page[1].flags); | |
630 | } | |
53f9263b KS |
631 | static inline int TestSetPageDoubleMap(struct page *page) |
632 | { | |
633 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
634 | return test_and_set_bit(PG_double_map, &page[1].flags); | |
635 | } | |
636 | ||
637 | static inline int TestClearPageDoubleMap(struct page *page) | |
638 | { | |
639 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
640 | return test_and_clear_bit(PG_double_map, &page[1].flags); | |
641 | } | |
642 | ||
936a5fe6 | 643 | #else |
d8c1bdeb KS |
644 | TESTPAGEFLAG_FALSE(TransHuge) |
645 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 646 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 647 | TESTPAGEFLAG_FALSE(TransTail) |
9a73f61b | 648 | PAGEFLAG_FALSE(DoubleMap) |
53f9263b KS |
649 | TESTSETFLAG_FALSE(DoubleMap) |
650 | TESTCLEARFLAG_FALSE(DoubleMap) | |
936a5fe6 AA |
651 | #endif |
652 | ||
e8c6158f | 653 | /* |
632c0a1a VD |
654 | * For pages that are never mapped to userspace, page->mapcount may be |
655 | * used for storing extra information about page type. Any value used | |
656 | * for this purpose must be <= -2, but it's better start not too close | |
657 | * to -2 so that an underflow of the page_mapcount() won't be mistaken | |
658 | * for a special page. | |
e8c6158f | 659 | */ |
632c0a1a VD |
660 | #define PAGE_MAPCOUNT_OPS(uname, lname) \ |
661 | static __always_inline int Page##uname(struct page *page) \ | |
662 | { \ | |
663 | return atomic_read(&page->_mapcount) == \ | |
664 | PAGE_##lname##_MAPCOUNT_VALUE; \ | |
665 | } \ | |
666 | static __always_inline void __SetPage##uname(struct page *page) \ | |
667 | { \ | |
668 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); \ | |
669 | atomic_set(&page->_mapcount, PAGE_##lname##_MAPCOUNT_VALUE); \ | |
670 | } \ | |
671 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
672 | { \ | |
673 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
674 | atomic_set(&page->_mapcount, -1); \ | |
e8c6158f KS |
675 | } |
676 | ||
632c0a1a VD |
677 | /* |
678 | * PageBuddy() indicate that the page is free and in the buddy system | |
679 | * (see mm/page_alloc.c). | |
680 | */ | |
681 | #define PAGE_BUDDY_MAPCOUNT_VALUE (-128) | |
682 | PAGE_MAPCOUNT_OPS(Buddy, BUDDY) | |
e8c6158f | 683 | |
632c0a1a VD |
684 | /* |
685 | * PageBalloon() is set on pages that are on the balloon page list | |
686 | * (see mm/balloon_compaction.c). | |
687 | */ | |
688 | #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) | |
689 | PAGE_MAPCOUNT_OPS(Balloon, BALLOON) | |
e8c6158f | 690 | |
4949148a VD |
691 | /* |
692 | * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on | |
693 | * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. | |
694 | */ | |
695 | #define PAGE_KMEMCG_MAPCOUNT_VALUE (-512) | |
696 | PAGE_MAPCOUNT_OPS(Kmemcg, KMEMCG) | |
697 | ||
832fc1de NH |
698 | extern bool is_free_buddy_page(struct page *page); |
699 | ||
bda807d4 MK |
700 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
701 | ||
072bb0aa MG |
702 | /* |
703 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
704 | * were allocated from pfmemalloc reserves. | |
705 | */ | |
706 | static inline int PageSlabPfmemalloc(struct page *page) | |
707 | { | |
309381fe | 708 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
709 | return PageActive(page); |
710 | } | |
711 | ||
712 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
713 | { | |
309381fe | 714 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
715 | SetPageActive(page); |
716 | } | |
717 | ||
718 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
719 | { | |
309381fe | 720 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
721 | __ClearPageActive(page); |
722 | } | |
723 | ||
724 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
725 | { | |
309381fe | 726 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
727 | ClearPageActive(page); |
728 | } | |
729 | ||
af8e3354 | 730 | #ifdef CONFIG_MMU |
d2a1a1f0 | 731 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 732 | #else |
b291f000 | 733 | #define __PG_MLOCKED 0 |
894bc310 LS |
734 | #endif |
735 | ||
dfa7e20c RA |
736 | /* |
737 | * Flags checked when a page is freed. Pages being freed should not have | |
738 | * these flags set. It they are, there is a problem. | |
739 | */ | |
6326fec1 NP |
740 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
741 | (1UL << PG_lru | 1UL << PG_locked | \ | |
742 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
743 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
744 | 1UL << PG_slab | 1UL << PG_active | \ | |
745 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
746 | |
747 | /* | |
748 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 749 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 750 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
751 | * |
752 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
753 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 754 | */ |
f4c18e6f | 755 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
d2a1a1f0 | 756 | (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) |
dfa7e20c | 757 | |
edcf4748 | 758 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 759 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
760 | /** |
761 | * page_has_private - Determine if page has private stuff | |
762 | * @page: The page to be checked | |
763 | * | |
764 | * Determine if a page has private stuff, indicating that release routines | |
765 | * should be invoked upon it. | |
766 | */ | |
edcf4748 JW |
767 | static inline int page_has_private(struct page *page) |
768 | { | |
769 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
770 | } | |
771 | ||
95ad9755 KS |
772 | #undef PF_ANY |
773 | #undef PF_HEAD | |
62906027 | 774 | #undef PF_ONLY_HEAD |
95ad9755 KS |
775 | #undef PF_NO_TAIL |
776 | #undef PF_NO_COMPOUND | |
edcf4748 | 777 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 778 | |
1da177e4 | 779 | #endif /* PAGE_FLAGS_H */ |