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, | |
bda807d4 MK |
132 | |
133 | /* non-lru isolated movable page */ | |
134 | PG_isolated = PG_reclaim, | |
e2683181 | 135 | }; |
1da177e4 | 136 | |
9223b419 CL |
137 | #ifndef __GENERATING_BOUNDS_H |
138 | ||
0e6d31a7 KS |
139 | struct page; /* forward declaration */ |
140 | ||
141 | static inline struct page *compound_head(struct page *page) | |
142 | { | |
143 | unsigned long head = READ_ONCE(page->compound_head); | |
144 | ||
145 | if (unlikely(head & 1)) | |
146 | return (struct page *) (head - 1); | |
147 | return page; | |
148 | } | |
149 | ||
4b0f3261 | 150 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
151 | { |
152 | return READ_ONCE(page->compound_head) & 1; | |
153 | } | |
154 | ||
4b0f3261 | 155 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
156 | { |
157 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
158 | } | |
159 | ||
95ad9755 KS |
160 | /* |
161 | * Page flags policies wrt compound pages | |
162 | * | |
163 | * PF_ANY: | |
164 | * the page flag is relevant for small, head and tail pages. | |
165 | * | |
166 | * PF_HEAD: | |
167 | * for compound page all operations related to the page flag applied to | |
168 | * head page. | |
169 | * | |
170 | * PF_NO_TAIL: | |
171 | * modifications of the page flag must be done on small or head pages, | |
172 | * checks can be done on tail pages too. | |
173 | * | |
174 | * PF_NO_COMPOUND: | |
175 | * the page flag is not relevant for compound pages. | |
176 | */ | |
177 | #define PF_ANY(page, enforce) page | |
178 | #define PF_HEAD(page, enforce) compound_head(page) | |
179 | #define PF_NO_TAIL(page, enforce) ({ \ | |
180 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
181 | compound_head(page);}) | |
822cdd11 | 182 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 KS |
183 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
184 | page;}) | |
185 | ||
f94a62e9 CL |
186 | /* |
187 | * Macros to create function definitions for page flags | |
188 | */ | |
95ad9755 | 189 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 190 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 191 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 192 | |
95ad9755 | 193 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 194 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 195 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 196 | |
95ad9755 | 197 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 198 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 199 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 200 | |
95ad9755 | 201 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 202 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 203 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 204 | |
95ad9755 | 205 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 206 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 207 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 208 | |
95ad9755 | 209 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 210 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 211 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 212 | |
95ad9755 | 213 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 214 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 215 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 216 | |
95ad9755 KS |
217 | #define PAGEFLAG(uname, lname, policy) \ |
218 | TESTPAGEFLAG(uname, lname, policy) \ | |
219 | SETPAGEFLAG(uname, lname, policy) \ | |
220 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 221 | |
95ad9755 KS |
222 | #define __PAGEFLAG(uname, lname, policy) \ |
223 | TESTPAGEFLAG(uname, lname, policy) \ | |
224 | __SETPAGEFLAG(uname, lname, policy) \ | |
225 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 226 | |
95ad9755 KS |
227 | #define TESTSCFLAG(uname, lname, policy) \ |
228 | TESTSETFLAG(uname, lname, policy) \ | |
229 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 230 | |
2f3e442c JW |
231 | #define TESTPAGEFLAG_FALSE(uname) \ |
232 | static inline int Page##uname(const struct page *page) { return 0; } | |
233 | ||
8a7a8544 LS |
234 | #define SETPAGEFLAG_NOOP(uname) \ |
235 | static inline void SetPage##uname(struct page *page) { } | |
236 | ||
237 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
238 | static inline void ClearPage##uname(struct page *page) { } | |
239 | ||
240 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
241 | static inline void __ClearPage##uname(struct page *page) { } | |
242 | ||
2f3e442c JW |
243 | #define TESTSETFLAG_FALSE(uname) \ |
244 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
245 | ||
8a7a8544 LS |
246 | #define TESTCLEARFLAG_FALSE(uname) \ |
247 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
248 | ||
2f3e442c JW |
249 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
250 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
251 | ||
252 | #define TESTSCFLAG_FALSE(uname) \ | |
253 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
254 | ||
48c935ad | 255 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
df8c94d1 | 256 | PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) |
8cb38fab KS |
257 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
258 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
259 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
260 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
261 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab KS |
262 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
263 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) | |
264 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
dcb351cd KS |
265 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
266 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 267 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
268 | |
269 | /* Xen */ | |
270 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
271 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
272 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
273 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
274 | ||
de09d31d KS |
275 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
276 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
da5efc40 KS |
277 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
278 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
279 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 280 | |
266cf658 DH |
281 | /* |
282 | * Private page markings that may be used by the filesystem that owns the page | |
283 | * for its own purposes. | |
284 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
285 | */ | |
95ad9755 KS |
286 | PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) |
287 | __CLEARPAGEFLAG(Private, private, PF_ANY) | |
288 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) | |
289 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
290 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 291 | |
6a1e7f77 CL |
292 | /* |
293 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
294 | * risky: they bypass page accounting. | |
295 | */ | |
df8c94d1 KS |
296 | TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND) |
297 | TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND) | |
298 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_COMPOUND) | |
6a1e7f77 | 299 | |
579f8290 | 300 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
df8c94d1 KS |
301 | PAGEFLAG(Reclaim, reclaim, PF_NO_COMPOUND) |
302 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_COMPOUND) | |
303 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
304 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
305 | |
306 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 307 | /* |
6a1e7f77 CL |
308 | * Must use a macro here due to header dependency issues. page_zone() is not |
309 | * available at this point. | |
1da177e4 | 310 | */ |
3ca65c19 | 311 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 312 | #else |
ec7cade8 | 313 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
314 | #endif |
315 | ||
316 | #ifdef CONFIG_SWAP | |
50ea78d6 | 317 | PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) |
6a1e7f77 | 318 | #else |
ec7cade8 | 319 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
320 | #endif |
321 | ||
8cb38fab KS |
322 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
323 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
324 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 325 | |
af8e3354 | 326 | #ifdef CONFIG_MMU |
e4f87d5d KS |
327 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
328 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
329 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 330 | #else |
2f3e442c | 331 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 332 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
333 | #endif |
334 | ||
46cf98cd | 335 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 336 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 337 | #else |
ec7cade8 | 338 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 339 | #endif |
1da177e4 | 340 | |
d466f2fc | 341 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
342 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
343 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc AK |
344 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
345 | #else | |
346 | PAGEFLAG_FALSE(HWPoison) | |
347 | #define __PG_HWPOISON 0 | |
348 | #endif | |
349 | ||
33c3fc71 | 350 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
351 | TESTPAGEFLAG(Young, young, PF_ANY) |
352 | SETPAGEFLAG(Young, young, PF_ANY) | |
353 | TESTCLEARFLAG(Young, young, PF_ANY) | |
354 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
355 | #endif |
356 | ||
e8c6158f KS |
357 | /* |
358 | * On an anonymous page mapped into a user virtual memory area, | |
359 | * page->mapping points to its anon_vma, not to a struct address_space; | |
360 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
361 | * | |
362 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
363 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
364 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
365 | * structure which KSM associates with that merged page. See ksm.h. |
366 | * | |
bda807d4 MK |
367 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
368 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
369 | * |
370 | * Please note that, confusingly, "page_mapping" refers to the inode | |
371 | * address_space which maps the page from disk; whereas "page_mapped" | |
372 | * refers to user virtual address space into which the page is mapped. | |
373 | */ | |
bda807d4 MK |
374 | #define PAGE_MAPPING_ANON 0x1 |
375 | #define PAGE_MAPPING_MOVABLE 0x2 | |
376 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
377 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 378 | |
bda807d4 | 379 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 380 | { |
bda807d4 | 381 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
382 | } |
383 | ||
4b0f3261 | 384 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 385 | { |
822cdd11 | 386 | page = compound_head(page); |
bda807d4 MK |
387 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
388 | } | |
389 | ||
390 | static __always_inline int __PageMovable(struct page *page) | |
391 | { | |
392 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
393 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
394 | } |
395 | ||
396 | #ifdef CONFIG_KSM | |
397 | /* | |
398 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
399 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
400 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
401 | * anon_vma, but to that page's node of the stable tree. | |
402 | */ | |
4b0f3261 | 403 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 404 | { |
822cdd11 | 405 | page = compound_head(page); |
e8c6158f | 406 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 407 | PAGE_MAPPING_KSM; |
e8c6158f KS |
408 | } |
409 | #else | |
410 | TESTPAGEFLAG_FALSE(Ksm) | |
411 | #endif | |
412 | ||
1a9b5b7f WF |
413 | u64 stable_page_flags(struct page *page); |
414 | ||
0ed361de NP |
415 | static inline int PageUptodate(struct page *page) |
416 | { | |
d2998c4d KS |
417 | int ret; |
418 | page = compound_head(page); | |
419 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
420 | /* |
421 | * Must ensure that the data we read out of the page is loaded | |
422 | * _after_ we've loaded page->flags to check for PageUptodate. | |
423 | * We can skip the barrier if the page is not uptodate, because | |
424 | * we wouldn't be reading anything from it. | |
425 | * | |
426 | * See SetPageUptodate() for the other side of the story. | |
427 | */ | |
428 | if (ret) | |
429 | smp_rmb(); | |
430 | ||
431 | return ret; | |
432 | } | |
433 | ||
4b0f3261 | 434 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 435 | { |
d2998c4d | 436 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 437 | smp_wmb(); |
df8c94d1 | 438 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
439 | } |
440 | ||
4b0f3261 | 441 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 442 | { |
d2998c4d | 443 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
444 | /* |
445 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
446 | * so that all previous stores issued in order to bring the page | |
447 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
448 | */ |
449 | smp_wmb(); | |
df8c94d1 | 450 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
451 | } |
452 | ||
d2998c4d | 453 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 454 | |
6a1e7f77 | 455 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
456 | int __test_set_page_writeback(struct page *page, bool keep_write); |
457 | ||
458 | #define test_set_page_writeback(page) \ | |
459 | __test_set_page_writeback(page, false) | |
460 | #define test_set_page_writeback_keepwrite(page) \ | |
461 | __test_set_page_writeback(page, true) | |
1da177e4 | 462 | |
6a1e7f77 CL |
463 | static inline void set_page_writeback(struct page *page) |
464 | { | |
465 | test_set_page_writeback(page); | |
466 | } | |
1da177e4 | 467 | |
1c8349a1 NJ |
468 | static inline void set_page_writeback_keepwrite(struct page *page) |
469 | { | |
470 | test_set_page_writeback_keepwrite(page); | |
471 | } | |
472 | ||
95ad9755 | 473 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 474 | |
4b0f3261 | 475 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 476 | { |
1d798ca3 | 477 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
478 | } |
479 | ||
4b0f3261 | 480 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 481 | { |
1d798ca3 | 482 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 483 | } |
6d777953 | 484 | |
4e6af67e AA |
485 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
486 | static inline void ClearPageCompound(struct page *page) | |
487 | { | |
1d798ca3 KS |
488 | BUG_ON(!PageHead(page)); |
489 | ClearPageHead(page); | |
4e6af67e AA |
490 | } |
491 | #endif | |
492 | ||
d2a1a1f0 | 493 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 494 | |
e8c6158f KS |
495 | #ifdef CONFIG_HUGETLB_PAGE |
496 | int PageHuge(struct page *page); | |
497 | int PageHeadHuge(struct page *page); | |
7e1f049e | 498 | bool page_huge_active(struct page *page); |
e8c6158f KS |
499 | #else |
500 | TESTPAGEFLAG_FALSE(Huge) | |
501 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
502 | |
503 | static inline bool page_huge_active(struct page *page) | |
504 | { | |
505 | return 0; | |
506 | } | |
e8c6158f KS |
507 | #endif |
508 | ||
7e1f049e | 509 | |
936a5fe6 | 510 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
511 | /* |
512 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
513 | * normal or transparent huge pages. | |
514 | * | |
515 | * PageTransHuge() returns true for both transparent huge and | |
516 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
517 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
518 | */ | |
519 | static inline int PageTransHuge(struct page *page) | |
520 | { | |
309381fe | 521 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
522 | return PageHead(page); |
523 | } | |
524 | ||
385de357 DN |
525 | /* |
526 | * PageTransCompound returns true for both transparent huge pages | |
527 | * and hugetlbfs pages, so it should only be called when it's known | |
528 | * that hugetlbfs pages aren't involved. | |
529 | */ | |
936a5fe6 AA |
530 | static inline int PageTransCompound(struct page *page) |
531 | { | |
532 | return PageCompound(page); | |
533 | } | |
71e3aac0 | 534 | |
127393fb AA |
535 | /* |
536 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
537 | * guarantees the primary MMU has the entire compound page mapped | |
538 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
539 | * can also map the entire compound page. This allows the secondary | |
540 | * MMUs to call get_user_pages() only once for each compound page and | |
541 | * to immediately map the entire compound page with a single secondary | |
542 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
543 | * will get an update through the MMU notifier invalidation through | |
544 | * split_huge_pmd(). | |
545 | * | |
546 | * Unlike PageTransCompound, this is safe to be called only while | |
547 | * split_huge_pmd() cannot run from under us, like if protected by the | |
548 | * MMU notifier, otherwise it may result in page->_mapcount < 0 false | |
549 | * positives. | |
550 | */ | |
551 | static inline int PageTransCompoundMap(struct page *page) | |
552 | { | |
553 | return PageTransCompound(page) && atomic_read(&page->_mapcount) < 0; | |
554 | } | |
555 | ||
385de357 DN |
556 | /* |
557 | * PageTransTail returns true for both transparent huge pages | |
558 | * and hugetlbfs pages, so it should only be called when it's known | |
559 | * that hugetlbfs pages aren't involved. | |
560 | */ | |
561 | static inline int PageTransTail(struct page *page) | |
562 | { | |
563 | return PageTail(page); | |
564 | } | |
565 | ||
53f9263b KS |
566 | /* |
567 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
568 | * as PMDs. | |
569 | * | |
570 | * This is required for optimization of rmap operations for THP: we can postpone | |
571 | * per small page mapcount accounting (and its overhead from atomic operations) | |
572 | * until the first PMD split. | |
573 | * | |
574 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
575 | * by one. This reference will go away with last compound_mapcount. | |
576 | * | |
577 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
578 | */ | |
579 | static inline int PageDoubleMap(struct page *page) | |
580 | { | |
581 | return PageHead(page) && test_bit(PG_double_map, &page[1].flags); | |
582 | } | |
583 | ||
584 | static inline int TestSetPageDoubleMap(struct page *page) | |
585 | { | |
586 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
587 | return test_and_set_bit(PG_double_map, &page[1].flags); | |
588 | } | |
589 | ||
590 | static inline int TestClearPageDoubleMap(struct page *page) | |
591 | { | |
592 | VM_BUG_ON_PAGE(!PageHead(page), page); | |
593 | return test_and_clear_bit(PG_double_map, &page[1].flags); | |
594 | } | |
595 | ||
936a5fe6 | 596 | #else |
d8c1bdeb KS |
597 | TESTPAGEFLAG_FALSE(TransHuge) |
598 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 599 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 600 | TESTPAGEFLAG_FALSE(TransTail) |
53f9263b KS |
601 | TESTPAGEFLAG_FALSE(DoubleMap) |
602 | TESTSETFLAG_FALSE(DoubleMap) | |
603 | TESTCLEARFLAG_FALSE(DoubleMap) | |
936a5fe6 AA |
604 | #endif |
605 | ||
e8c6158f | 606 | /* |
632c0a1a VD |
607 | * For pages that are never mapped to userspace, page->mapcount may be |
608 | * used for storing extra information about page type. Any value used | |
609 | * for this purpose must be <= -2, but it's better start not too close | |
610 | * to -2 so that an underflow of the page_mapcount() won't be mistaken | |
611 | * for a special page. | |
e8c6158f | 612 | */ |
632c0a1a VD |
613 | #define PAGE_MAPCOUNT_OPS(uname, lname) \ |
614 | static __always_inline int Page##uname(struct page *page) \ | |
615 | { \ | |
616 | return atomic_read(&page->_mapcount) == \ | |
617 | PAGE_##lname##_MAPCOUNT_VALUE; \ | |
618 | } \ | |
619 | static __always_inline void __SetPage##uname(struct page *page) \ | |
620 | { \ | |
621 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); \ | |
622 | atomic_set(&page->_mapcount, PAGE_##lname##_MAPCOUNT_VALUE); \ | |
623 | } \ | |
624 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
625 | { \ | |
626 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
627 | atomic_set(&page->_mapcount, -1); \ | |
e8c6158f KS |
628 | } |
629 | ||
632c0a1a VD |
630 | /* |
631 | * PageBuddy() indicate that the page is free and in the buddy system | |
632 | * (see mm/page_alloc.c). | |
633 | */ | |
634 | #define PAGE_BUDDY_MAPCOUNT_VALUE (-128) | |
635 | PAGE_MAPCOUNT_OPS(Buddy, BUDDY) | |
e8c6158f | 636 | |
632c0a1a VD |
637 | /* |
638 | * PageBalloon() is set on pages that are on the balloon page list | |
639 | * (see mm/balloon_compaction.c). | |
640 | */ | |
641 | #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) | |
642 | PAGE_MAPCOUNT_OPS(Balloon, BALLOON) | |
e8c6158f | 643 | |
4949148a VD |
644 | /* |
645 | * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on | |
646 | * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. | |
647 | */ | |
648 | #define PAGE_KMEMCG_MAPCOUNT_VALUE (-512) | |
649 | PAGE_MAPCOUNT_OPS(Kmemcg, KMEMCG) | |
650 | ||
832fc1de NH |
651 | extern bool is_free_buddy_page(struct page *page); |
652 | ||
bda807d4 MK |
653 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
654 | ||
072bb0aa MG |
655 | /* |
656 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
657 | * were allocated from pfmemalloc reserves. | |
658 | */ | |
659 | static inline int PageSlabPfmemalloc(struct page *page) | |
660 | { | |
309381fe | 661 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
662 | return PageActive(page); |
663 | } | |
664 | ||
665 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
666 | { | |
309381fe | 667 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
668 | SetPageActive(page); |
669 | } | |
670 | ||
671 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
672 | { | |
309381fe | 673 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
674 | __ClearPageActive(page); |
675 | } | |
676 | ||
677 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
678 | { | |
309381fe | 679 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
680 | ClearPageActive(page); |
681 | } | |
682 | ||
af8e3354 | 683 | #ifdef CONFIG_MMU |
d2a1a1f0 | 684 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 685 | #else |
b291f000 | 686 | #define __PG_MLOCKED 0 |
894bc310 LS |
687 | #endif |
688 | ||
dfa7e20c RA |
689 | /* |
690 | * Flags checked when a page is freed. Pages being freed should not have | |
691 | * these flags set. It they are, there is a problem. | |
692 | */ | |
79f4b7bf | 693 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
d2a1a1f0 YZ |
694 | (1UL << PG_lru | 1UL << PG_locked | \ |
695 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
696 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
697 | 1UL << PG_slab | 1UL << PG_swapcache | 1UL << PG_active | \ | |
698 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
699 | |
700 | /* | |
701 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 702 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 703 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
704 | * |
705 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
706 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 707 | */ |
f4c18e6f | 708 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
d2a1a1f0 | 709 | (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) |
dfa7e20c | 710 | |
edcf4748 | 711 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 712 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
713 | /** |
714 | * page_has_private - Determine if page has private stuff | |
715 | * @page: The page to be checked | |
716 | * | |
717 | * Determine if a page has private stuff, indicating that release routines | |
718 | * should be invoked upon it. | |
719 | */ | |
edcf4748 JW |
720 | static inline int page_has_private(struct page *page) |
721 | { | |
722 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
723 | } | |
724 | ||
95ad9755 KS |
725 | #undef PF_ANY |
726 | #undef PF_HEAD | |
727 | #undef PF_NO_TAIL | |
728 | #undef PF_NO_COMPOUND | |
edcf4748 | 729 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 730 | |
1da177e4 | 731 | #endif /* PAGE_FLAGS_H */ |