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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Macros for manipulating and testing page->flags | |
3 | */ | |
4 | ||
5 | #ifndef PAGE_FLAGS_H | |
6 | #define PAGE_FLAGS_H | |
7 | ||
f886ed44 | 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 AA |
103 | #endif |
104 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE | |
105 | PG_compound_lock, | |
33c3fc71 VD |
106 | #endif |
107 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) | |
108 | PG_young, | |
109 | PG_idle, | |
f886ed44 | 110 | #endif |
0cad47cf AW |
111 | __NR_PAGEFLAGS, |
112 | ||
113 | /* Filesystems */ | |
114 | PG_checked = PG_owner_priv_1, | |
115 | ||
266cf658 DH |
116 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
117 | * state. These bits are set on pages belonging to the netfs's inodes | |
118 | * when those inodes are being locally cached. | |
119 | */ | |
120 | PG_fscache = PG_private_2, /* page backed by cache */ | |
121 | ||
0cad47cf | 122 | /* XEN */ |
d8ac3dd4 | 123 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 124 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 125 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 126 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
127 | /* Has a grant mapping of another (foreign) domain's page. */ |
128 | PG_foreign = PG_owner_priv_1, | |
8a38082d | 129 | |
9023cb7e | 130 | /* SLOB */ |
9023cb7e | 131 | PG_slob_free = PG_private, |
e2683181 | 132 | }; |
1da177e4 | 133 | |
9223b419 CL |
134 | #ifndef __GENERATING_BOUNDS_H |
135 | ||
f94a62e9 CL |
136 | /* |
137 | * Macros to create function definitions for page flags | |
138 | */ | |
139 | #define TESTPAGEFLAG(uname, lname) \ | |
67db392d | 140 | static inline int Page##uname(const struct page *page) \ |
f94a62e9 CL |
141 | { return test_bit(PG_##lname, &page->flags); } |
142 | ||
143 | #define SETPAGEFLAG(uname, lname) \ | |
144 | static inline void SetPage##uname(struct page *page) \ | |
145 | { set_bit(PG_##lname, &page->flags); } | |
146 | ||
147 | #define CLEARPAGEFLAG(uname, lname) \ | |
148 | static inline void ClearPage##uname(struct page *page) \ | |
149 | { clear_bit(PG_##lname, &page->flags); } | |
150 | ||
151 | #define __SETPAGEFLAG(uname, lname) \ | |
152 | static inline void __SetPage##uname(struct page *page) \ | |
153 | { __set_bit(PG_##lname, &page->flags); } | |
154 | ||
155 | #define __CLEARPAGEFLAG(uname, lname) \ | |
156 | static inline void __ClearPage##uname(struct page *page) \ | |
157 | { __clear_bit(PG_##lname, &page->flags); } | |
158 | ||
159 | #define TESTSETFLAG(uname, lname) \ | |
160 | static inline int TestSetPage##uname(struct page *page) \ | |
161 | { return test_and_set_bit(PG_##lname, &page->flags); } | |
162 | ||
163 | #define TESTCLEARFLAG(uname, lname) \ | |
164 | static inline int TestClearPage##uname(struct page *page) \ | |
165 | { return test_and_clear_bit(PG_##lname, &page->flags); } | |
166 | ||
451ea25d JW |
167 | #define __TESTCLEARFLAG(uname, lname) \ |
168 | static inline int __TestClearPage##uname(struct page *page) \ | |
169 | { return __test_and_clear_bit(PG_##lname, &page->flags); } | |
f94a62e9 CL |
170 | |
171 | #define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ | |
172 | SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname) | |
173 | ||
174 | #define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ | |
175 | __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname) | |
176 | ||
177 | #define TESTSCFLAG(uname, lname) \ | |
178 | TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname) | |
179 | ||
2f3e442c JW |
180 | #define TESTPAGEFLAG_FALSE(uname) \ |
181 | static inline int Page##uname(const struct page *page) { return 0; } | |
182 | ||
8a7a8544 LS |
183 | #define SETPAGEFLAG_NOOP(uname) \ |
184 | static inline void SetPage##uname(struct page *page) { } | |
185 | ||
186 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
187 | static inline void ClearPage##uname(struct page *page) { } | |
188 | ||
189 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
190 | static inline void __ClearPage##uname(struct page *page) { } | |
191 | ||
2f3e442c JW |
192 | #define TESTSETFLAG_FALSE(uname) \ |
193 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
194 | ||
8a7a8544 LS |
195 | #define TESTCLEARFLAG_FALSE(uname) \ |
196 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
197 | ||
451ea25d JW |
198 | #define __TESTCLEARFLAG_FALSE(uname) \ |
199 | static inline int __TestClearPage##uname(struct page *page) { return 0; } | |
200 | ||
2f3e442c JW |
201 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
202 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
203 | ||
204 | #define TESTSCFLAG_FALSE(uname) \ | |
205 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
206 | ||
6a1e7f77 CL |
207 | struct page; /* forward declaration */ |
208 | ||
cb240452 | 209 | TESTPAGEFLAG(Locked, locked) |
212260aa | 210 | PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error) |
6a1e7f77 | 211 | PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced) |
2457aec6 | 212 | __SETPAGEFLAG(Referenced, referenced) |
6a1e7f77 CL |
213 | PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty) |
214 | PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru) | |
215 | PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active) | |
894bc310 | 216 | TESTCLEARFLAG(Active, active) |
6a1e7f77 | 217 | __PAGEFLAG(Slab, slab) |
0cad47cf AW |
218 | PAGEFLAG(Checked, checked) /* Used by some filesystems */ |
219 | PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */ | |
220 | PAGEFLAG(SavePinned, savepinned); /* Xen */ | |
d8ac3dd4 | 221 | PAGEFLAG(Foreign, foreign); /* Xen */ |
6a1e7f77 | 222 | PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) |
b2e18538 | 223 | PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked) |
07a42788 | 224 | __SETPAGEFLAG(SwapBacked, swapbacked) |
6a1e7f77 | 225 | |
9023cb7e AW |
226 | __PAGEFLAG(SlobFree, slob_free) |
227 | ||
266cf658 DH |
228 | /* |
229 | * Private page markings that may be used by the filesystem that owns the page | |
230 | * for its own purposes. | |
231 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
232 | */ | |
233 | PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private) | |
234 | __CLEARPAGEFLAG(Private, private) | |
235 | PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2) | |
236 | PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1) | |
237 | ||
6a1e7f77 CL |
238 | /* |
239 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
240 | * risky: they bypass page accounting. | |
241 | */ | |
242 | TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback) | |
6a1e7f77 CL |
243 | PAGEFLAG(MappedToDisk, mappedtodisk) |
244 | ||
579f8290 | 245 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
6a1e7f77 | 246 | PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim) |
579f8290 | 247 | PAGEFLAG(Readahead, reclaim) TESTCLEARFLAG(Readahead, reclaim) |
6a1e7f77 CL |
248 | |
249 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 250 | /* |
6a1e7f77 CL |
251 | * Must use a macro here due to header dependency issues. page_zone() is not |
252 | * available at this point. | |
1da177e4 | 253 | */ |
3ca65c19 | 254 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 255 | #else |
ec7cade8 | 256 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
257 | #endif |
258 | ||
259 | #ifdef CONFIG_SWAP | |
260 | PAGEFLAG(SwapCache, swapcache) | |
261 | #else | |
ec7cade8 | 262 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
263 | #endif |
264 | ||
894bc310 LS |
265 | PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable) |
266 | TESTCLEARFLAG(Unevictable, unevictable) | |
b291f000 | 267 | |
af8e3354 | 268 | #ifdef CONFIG_MMU |
b291f000 | 269 | PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) |
451ea25d | 270 | TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked) |
894bc310 | 271 | #else |
2f3e442c JW |
272 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
273 | TESTSCFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked) | |
894bc310 LS |
274 | #endif |
275 | ||
46cf98cd | 276 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
6a1e7f77 | 277 | PAGEFLAG(Uncached, uncached) |
602c4d11 | 278 | #else |
ec7cade8 | 279 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 280 | #endif |
1da177e4 | 281 | |
d466f2fc AK |
282 | #ifdef CONFIG_MEMORY_FAILURE |
283 | PAGEFLAG(HWPoison, hwpoison) | |
847ce401 | 284 | TESTSCFLAG(HWPoison, hwpoison) |
d466f2fc AK |
285 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
286 | #else | |
287 | PAGEFLAG_FALSE(HWPoison) | |
288 | #define __PG_HWPOISON 0 | |
289 | #endif | |
290 | ||
33c3fc71 VD |
291 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
292 | TESTPAGEFLAG(Young, young) | |
293 | SETPAGEFLAG(Young, young) | |
294 | TESTCLEARFLAG(Young, young) | |
295 | PAGEFLAG(Idle, idle) | |
296 | #endif | |
297 | ||
e8c6158f KS |
298 | /* |
299 | * On an anonymous page mapped into a user virtual memory area, | |
300 | * page->mapping points to its anon_vma, not to a struct address_space; | |
301 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
302 | * | |
303 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
304 | * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit; | |
305 | * and then page->mapping points, not to an anon_vma, but to a private | |
306 | * structure which KSM associates with that merged page. See ksm.h. | |
307 | * | |
308 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used. | |
309 | * | |
310 | * Please note that, confusingly, "page_mapping" refers to the inode | |
311 | * address_space which maps the page from disk; whereas "page_mapped" | |
312 | * refers to user virtual address space into which the page is mapped. | |
313 | */ | |
314 | #define PAGE_MAPPING_ANON 1 | |
315 | #define PAGE_MAPPING_KSM 2 | |
316 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM) | |
317 | ||
318 | static inline int PageAnon(struct page *page) | |
319 | { | |
320 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; | |
321 | } | |
322 | ||
323 | #ifdef CONFIG_KSM | |
324 | /* | |
325 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
326 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
327 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
328 | * anon_vma, but to that page's node of the stable tree. | |
329 | */ | |
330 | static inline int PageKsm(struct page *page) | |
331 | { | |
332 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
333 | (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); | |
334 | } | |
335 | #else | |
336 | TESTPAGEFLAG_FALSE(Ksm) | |
337 | #endif | |
338 | ||
1a9b5b7f WF |
339 | u64 stable_page_flags(struct page *page); |
340 | ||
0ed361de NP |
341 | static inline int PageUptodate(struct page *page) |
342 | { | |
343 | int ret = test_bit(PG_uptodate, &(page)->flags); | |
344 | ||
345 | /* | |
346 | * Must ensure that the data we read out of the page is loaded | |
347 | * _after_ we've loaded page->flags to check for PageUptodate. | |
348 | * We can skip the barrier if the page is not uptodate, because | |
349 | * we wouldn't be reading anything from it. | |
350 | * | |
351 | * See SetPageUptodate() for the other side of the story. | |
352 | */ | |
353 | if (ret) | |
354 | smp_rmb(); | |
355 | ||
356 | return ret; | |
357 | } | |
358 | ||
359 | static inline void __SetPageUptodate(struct page *page) | |
360 | { | |
361 | smp_wmb(); | |
362 | __set_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
363 | } |
364 | ||
2dcea57a HC |
365 | static inline void SetPageUptodate(struct page *page) |
366 | { | |
0ed361de NP |
367 | /* |
368 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
369 | * so that all previous stores issued in order to bring the page | |
370 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
371 | */ |
372 | smp_wmb(); | |
373 | set_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
374 | } |
375 | ||
6a1e7f77 | 376 | CLEARPAGEFLAG(Uptodate, uptodate) |
1da177e4 | 377 | |
6a1e7f77 | 378 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
379 | int __test_set_page_writeback(struct page *page, bool keep_write); |
380 | ||
381 | #define test_set_page_writeback(page) \ | |
382 | __test_set_page_writeback(page, false) | |
383 | #define test_set_page_writeback_keepwrite(page) \ | |
384 | __test_set_page_writeback(page, true) | |
1da177e4 | 385 | |
6a1e7f77 CL |
386 | static inline void set_page_writeback(struct page *page) |
387 | { | |
388 | test_set_page_writeback(page); | |
389 | } | |
1da177e4 | 390 | |
1c8349a1 NJ |
391 | static inline void set_page_writeback_keepwrite(struct page *page) |
392 | { | |
393 | test_set_page_writeback_keepwrite(page); | |
394 | } | |
395 | ||
4e6af67e | 396 | __PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head) |
e20b8cca | 397 | |
1d798ca3 | 398 | static inline int PageTail(struct page *page) |
4e6af67e | 399 | { |
1d798ca3 | 400 | return READ_ONCE(page->compound_head) & 1; |
4e6af67e | 401 | } |
b3acc56b | 402 | |
1d798ca3 | 403 | static inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 404 | { |
1d798ca3 | 405 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
406 | } |
407 | ||
1d798ca3 | 408 | static inline void clear_compound_head(struct page *page) |
6a1e7f77 | 409 | { |
1d798ca3 | 410 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 411 | } |
6d777953 | 412 | |
1d798ca3 | 413 | static inline struct page *compound_head(struct page *page) |
6d777953 | 414 | { |
1d798ca3 KS |
415 | unsigned long head = READ_ONCE(page->compound_head); |
416 | ||
417 | if (unlikely(head & 1)) | |
418 | return (struct page *) (head - 1); | |
419 | return page; | |
6d777953 CL |
420 | } |
421 | ||
1d798ca3 | 422 | static inline int PageCompound(struct page *page) |
6d777953 | 423 | { |
1d798ca3 | 424 | return PageHead(page) || PageTail(page); |
6d777953 | 425 | |
1d798ca3 | 426 | } |
4e6af67e AA |
427 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
428 | static inline void ClearPageCompound(struct page *page) | |
429 | { | |
1d798ca3 KS |
430 | BUG_ON(!PageHead(page)); |
431 | ClearPageHead(page); | |
4e6af67e AA |
432 | } |
433 | #endif | |
434 | ||
1d798ca3 | 435 | #define PG_head_mask ((1L << PG_head)) |
dfa7e20c | 436 | |
e8c6158f KS |
437 | #ifdef CONFIG_HUGETLB_PAGE |
438 | int PageHuge(struct page *page); | |
439 | int PageHeadHuge(struct page *page); | |
7e1f049e | 440 | bool page_huge_active(struct page *page); |
e8c6158f KS |
441 | #else |
442 | TESTPAGEFLAG_FALSE(Huge) | |
443 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
444 | |
445 | static inline bool page_huge_active(struct page *page) | |
446 | { | |
447 | return 0; | |
448 | } | |
e8c6158f KS |
449 | #endif |
450 | ||
7e1f049e | 451 | |
936a5fe6 | 452 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
453 | /* |
454 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
455 | * normal or transparent huge pages. | |
456 | * | |
457 | * PageTransHuge() returns true for both transparent huge and | |
458 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
459 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
460 | */ | |
461 | static inline int PageTransHuge(struct page *page) | |
462 | { | |
309381fe | 463 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
464 | return PageHead(page); |
465 | } | |
466 | ||
385de357 DN |
467 | /* |
468 | * PageTransCompound returns true for both transparent huge pages | |
469 | * and hugetlbfs pages, so it should only be called when it's known | |
470 | * that hugetlbfs pages aren't involved. | |
471 | */ | |
936a5fe6 AA |
472 | static inline int PageTransCompound(struct page *page) |
473 | { | |
474 | return PageCompound(page); | |
475 | } | |
71e3aac0 | 476 | |
385de357 DN |
477 | /* |
478 | * PageTransTail returns true for both transparent huge pages | |
479 | * and hugetlbfs pages, so it should only be called when it's known | |
480 | * that hugetlbfs pages aren't involved. | |
481 | */ | |
482 | static inline int PageTransTail(struct page *page) | |
483 | { | |
484 | return PageTail(page); | |
485 | } | |
486 | ||
936a5fe6 | 487 | #else |
d8c1bdeb KS |
488 | TESTPAGEFLAG_FALSE(TransHuge) |
489 | TESTPAGEFLAG_FALSE(TransCompound) | |
490 | TESTPAGEFLAG_FALSE(TransTail) | |
936a5fe6 AA |
491 | #endif |
492 | ||
e8c6158f KS |
493 | /* |
494 | * PageBuddy() indicate that the page is free and in the buddy system | |
495 | * (see mm/page_alloc.c). | |
496 | * | |
497 | * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to | |
498 | * -2 so that an underflow of the page_mapcount() won't be mistaken | |
499 | * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very | |
500 | * efficiently by most CPU architectures. | |
501 | */ | |
502 | #define PAGE_BUDDY_MAPCOUNT_VALUE (-128) | |
503 | ||
504 | static inline int PageBuddy(struct page *page) | |
505 | { | |
506 | return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE; | |
507 | } | |
508 | ||
509 | static inline void __SetPageBuddy(struct page *page) | |
510 | { | |
511 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); | |
512 | atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE); | |
513 | } | |
514 | ||
515 | static inline void __ClearPageBuddy(struct page *page) | |
516 | { | |
517 | VM_BUG_ON_PAGE(!PageBuddy(page), page); | |
518 | atomic_set(&page->_mapcount, -1); | |
519 | } | |
520 | ||
521 | #define PAGE_BALLOON_MAPCOUNT_VALUE (-256) | |
522 | ||
523 | static inline int PageBalloon(struct page *page) | |
524 | { | |
525 | return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE; | |
526 | } | |
527 | ||
528 | static inline void __SetPageBalloon(struct page *page) | |
529 | { | |
530 | VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page); | |
531 | atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE); | |
532 | } | |
533 | ||
534 | static inline void __ClearPageBalloon(struct page *page) | |
535 | { | |
536 | VM_BUG_ON_PAGE(!PageBalloon(page), page); | |
537 | atomic_set(&page->_mapcount, -1); | |
538 | } | |
539 | ||
072bb0aa MG |
540 | /* |
541 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
542 | * were allocated from pfmemalloc reserves. | |
543 | */ | |
544 | static inline int PageSlabPfmemalloc(struct page *page) | |
545 | { | |
309381fe | 546 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
547 | return PageActive(page); |
548 | } | |
549 | ||
550 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
551 | { | |
309381fe | 552 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
553 | SetPageActive(page); |
554 | } | |
555 | ||
556 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
557 | { | |
309381fe | 558 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
559 | __ClearPageActive(page); |
560 | } | |
561 | ||
562 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
563 | { | |
309381fe | 564 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
565 | ClearPageActive(page); |
566 | } | |
567 | ||
af8e3354 | 568 | #ifdef CONFIG_MMU |
33925b25 DH |
569 | #define __PG_MLOCKED (1 << PG_mlocked) |
570 | #else | |
b291f000 | 571 | #define __PG_MLOCKED 0 |
894bc310 LS |
572 | #endif |
573 | ||
e9da73d6 AA |
574 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
575 | #define __PG_COMPOUND_LOCK (1 << PG_compound_lock) | |
576 | #else | |
577 | #define __PG_COMPOUND_LOCK 0 | |
578 | #endif | |
579 | ||
dfa7e20c RA |
580 | /* |
581 | * Flags checked when a page is freed. Pages being freed should not have | |
582 | * these flags set. It they are, there is a problem. | |
583 | */ | |
79f4b7bf | 584 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
266cf658 DH |
585 | (1 << PG_lru | 1 << PG_locked | \ |
586 | 1 << PG_private | 1 << PG_private_2 | \ | |
5f24ce5f | 587 | 1 << PG_writeback | 1 << PG_reserved | \ |
266cf658 | 588 | 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ |
f4c18e6f | 589 | 1 << PG_unevictable | __PG_MLOCKED | \ |
e9da73d6 | 590 | __PG_COMPOUND_LOCK) |
dfa7e20c RA |
591 | |
592 | /* | |
593 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 594 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 595 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
596 | * |
597 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
598 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 599 | */ |
f4c18e6f NH |
600 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
601 | (((1 << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) | |
dfa7e20c | 602 | |
edcf4748 JW |
603 | #define PAGE_FLAGS_PRIVATE \ |
604 | (1 << PG_private | 1 << PG_private_2) | |
266cf658 DH |
605 | /** |
606 | * page_has_private - Determine if page has private stuff | |
607 | * @page: The page to be checked | |
608 | * | |
609 | * Determine if a page has private stuff, indicating that release routines | |
610 | * should be invoked upon it. | |
611 | */ | |
edcf4748 JW |
612 | static inline int page_has_private(struct page *page) |
613 | { | |
614 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
615 | } | |
616 | ||
617 | #endif /* !__GENERATING_BOUNDS_H */ | |
266cf658 | 618 | |
1da177e4 | 619 | #endif /* PAGE_FLAGS_H */ |