Commit | Line | Data |
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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | /* |
3 | * Macros for manipulating and testing page->flags | |
4 | */ | |
5 | ||
6 | #ifndef PAGE_FLAGS_H | |
7 | #define PAGE_FLAGS_H | |
8 | ||
f886ed44 | 9 | #include <linux/types.h> |
187f1882 | 10 | #include <linux/bug.h> |
072bb0aa | 11 | #include <linux/mmdebug.h> |
9223b419 | 12 | #ifndef __GENERATING_BOUNDS_H |
6d777953 | 13 | #include <linux/mm_types.h> |
01fc0ac1 | 14 | #include <generated/bounds.h> |
9223b419 | 15 | #endif /* !__GENERATING_BOUNDS_H */ |
f886ed44 | 16 | |
1da177e4 LT |
17 | /* |
18 | * Various page->flags bits: | |
19 | * | |
6e2e07cd DH |
20 | * PG_reserved is set for special pages. The "struct page" of such a page |
21 | * should in general not be touched (e.g. set dirty) except by its owner. | |
22 | * Pages marked as PG_reserved include: | |
23 | * - Pages part of the kernel image (including vDSO) and similar (e.g. BIOS, | |
24 | * initrd, HW tables) | |
25 | * - Pages reserved or allocated early during boot (before the page allocator | |
26 | * was initialized). This includes (depending on the architecture) the | |
27 | * initial vmemmap, initial page tables, crashkernel, elfcorehdr, and much | |
28 | * much more. Once (if ever) freed, PG_reserved is cleared and they will | |
29 | * be given to the page allocator. | |
30 | * - Pages falling into physical memory gaps - not IORESOURCE_SYSRAM. Trying | |
31 | * to read/write these pages might end badly. Don't touch! | |
32 | * - The zero page(s) | |
33 | * - Pages not added to the page allocator when onlining a section because | |
34 | * they were excluded via the online_page_callback() or because they are | |
35 | * PG_hwpoison. | |
36 | * - Pages allocated in the context of kexec/kdump (loaded kernel image, | |
37 | * control pages, vmcoreinfo) | |
38 | * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are | |
39 | * not marked PG_reserved (as they might be in use by somebody else who does | |
40 | * not respect the caching strategy). | |
41 | * - Pages part of an offline section (struct pages of offline sections should | |
42 | * not be trusted as they will be initialized when first onlined). | |
43 | * - MCA pages on ia64 | |
44 | * - Pages holding CPU notes for POWER Firmware Assisted Dump | |
45 | * - Device memory (e.g. PMEM, DAX, HMM) | |
46 | * Some PG_reserved pages will be excluded from the hibernation image. | |
47 | * PG_reserved does in general not hinder anybody from dumping or swapping | |
48 | * and is no longer required for remap_pfn_range(). ioremap might require it. | |
49 | * Consequently, PG_reserved for a page mapped into user space can indicate | |
50 | * the zero page, the vDSO, MMIO pages or device memory. | |
1da177e4 | 51 | * |
da6052f7 NP |
52 | * The PG_private bitflag is set on pagecache pages if they contain filesystem |
53 | * specific data (which is normally at page->private). It can be used by | |
54 | * private allocations for its own usage. | |
1da177e4 | 55 | * |
da6052f7 NP |
56 | * During initiation of disk I/O, PG_locked is set. This bit is set before I/O |
57 | * and cleared when writeback _starts_ or when read _completes_. PG_writeback | |
58 | * is set before writeback starts and cleared when it finishes. | |
59 | * | |
60 | * PG_locked also pins a page in pagecache, and blocks truncation of the file | |
61 | * while it is held. | |
62 | * | |
63 | * page_waitqueue(page) is a wait queue of all tasks waiting for the page | |
64 | * to become unlocked. | |
1da177e4 | 65 | * |
9de4f22a HY |
66 | * PG_swapbacked is set when a page uses swap as a backing storage. This are |
67 | * usually PageAnon or shmem pages but please note that even anonymous pages | |
68 | * might lose their PG_swapbacked flag when they simply can be dropped (e.g. as | |
69 | * a result of MADV_FREE). | |
70 | * | |
1da177e4 LT |
71 | * PG_uptodate tells whether the page's contents is valid. When a read |
72 | * completes, the page becomes uptodate, unless a disk I/O error happened. | |
73 | * | |
da6052f7 NP |
74 | * PG_referenced, PG_reclaim are used for page reclaim for anonymous and |
75 | * file-backed pagecache (see mm/vmscan.c). | |
1da177e4 LT |
76 | * |
77 | * PG_error is set to indicate that an I/O error occurred on this page. | |
78 | * | |
79 | * PG_arch_1 is an architecture specific page state bit. The generic code | |
80 | * guarantees that this bit is cleared for a page when it first is entered into | |
81 | * the page cache. | |
82 | * | |
d466f2fc AK |
83 | * PG_hwpoison indicates that a page got corrupted in hardware and contains |
84 | * data with incorrect ECC bits that triggered a machine check. Accessing is | |
85 | * not safe since it may cause another machine check. Don't touch! | |
1da177e4 LT |
86 | */ |
87 | ||
88 | /* | |
3b12da6d | 89 | * Don't use the pageflags directly. Use the PageFoo macros. |
91fc8ab3 AW |
90 | * |
91 | * The page flags field is split into two parts, the main flags area | |
92 | * which extends from the low bits upwards, and the fields area which | |
93 | * extends from the high bits downwards. | |
94 | * | |
95 | * | FIELD | ... | FLAGS | | |
9223b419 CL |
96 | * N-1 ^ 0 |
97 | * (NR_PAGEFLAGS) | |
91fc8ab3 | 98 | * |
9223b419 CL |
99 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
100 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like | |
101 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). | |
1da177e4 | 102 | */ |
e2683181 CL |
103 | enum pageflags { |
104 | PG_locked, /* Page is locked. Don't touch. */ | |
e2683181 CL |
105 | PG_referenced, |
106 | PG_uptodate, | |
107 | PG_dirty, | |
108 | PG_lru, | |
109 | PG_active, | |
1899ad18 | 110 | PG_workingset, |
b91e1302 | 111 | PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ |
1899ad18 | 112 | PG_error, |
e2683181 CL |
113 | PG_slab, |
114 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ | |
e2683181 CL |
115 | PG_arch_1, |
116 | PG_reserved, | |
117 | PG_private, /* If pagecache, has fs-private data */ | |
266cf658 | 118 | PG_private_2, /* If pagecache, has fs aux data */ |
e2683181 | 119 | PG_writeback, /* Page is under writeback */ |
e20b8cca | 120 | PG_head, /* A head page */ |
e2683181 CL |
121 | PG_mappedtodisk, /* Has blocks allocated on-disk */ |
122 | PG_reclaim, /* To be reclaimed asap */ | |
b2e18538 | 123 | PG_swapbacked, /* Page is backed by RAM/swap */ |
894bc310 | 124 | PG_unevictable, /* Page is "unevictable" */ |
af8e3354 | 125 | #ifdef CONFIG_MMU |
b291f000 | 126 | PG_mlocked, /* Page is vma mlocked */ |
894bc310 | 127 | #endif |
46cf98cd | 128 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
602c4d11 | 129 | PG_uncached, /* Page has been mapped as uncached */ |
d466f2fc AK |
130 | #endif |
131 | #ifdef CONFIG_MEMORY_FAILURE | |
132 | PG_hwpoison, /* hardware poisoned page. Don't touch */ | |
e9da73d6 | 133 | #endif |
33c3fc71 VD |
134 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
135 | PG_young, | |
136 | PG_idle, | |
4beba948 SP |
137 | #endif |
138 | #ifdef CONFIG_64BIT | |
139 | PG_arch_2, | |
f886ed44 | 140 | #endif |
0cad47cf AW |
141 | __NR_PAGEFLAGS, |
142 | ||
143 | /* Filesystems */ | |
144 | PG_checked = PG_owner_priv_1, | |
145 | ||
6326fec1 NP |
146 | /* SwapBacked */ |
147 | PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ | |
148 | ||
266cf658 DH |
149 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
150 | * state. These bits are set on pages belonging to the netfs's inodes | |
151 | * when those inodes are being locally cached. | |
152 | */ | |
153 | PG_fscache = PG_private_2, /* page backed by cache */ | |
154 | ||
0cad47cf | 155 | /* XEN */ |
d8ac3dd4 | 156 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 157 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 158 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 159 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
160 | /* Has a grant mapping of another (foreign) domain's page. */ |
161 | PG_foreign = PG_owner_priv_1, | |
b877ac98 JG |
162 | /* Remapped by swiotlb-xen. */ |
163 | PG_xen_remapped = PG_owner_priv_1, | |
8a38082d | 164 | |
9023cb7e | 165 | /* SLOB */ |
9023cb7e | 166 | PG_slob_free = PG_private, |
53f9263b KS |
167 | |
168 | /* Compound pages. Stored in first tail page's flags */ | |
e18c45ff | 169 | PG_double_map = PG_workingset, |
bda807d4 MK |
170 | |
171 | /* non-lru isolated movable page */ | |
172 | PG_isolated = PG_reclaim, | |
36e66c55 AD |
173 | |
174 | /* Only valid for buddy pages. Used to track pages that are reported */ | |
175 | PG_reported = PG_uptodate, | |
e2683181 | 176 | }; |
1da177e4 | 177 | |
9223b419 CL |
178 | #ifndef __GENERATING_BOUNDS_H |
179 | ||
0f2317e3 | 180 | static inline unsigned long _compound_head(const struct page *page) |
0e6d31a7 KS |
181 | { |
182 | unsigned long head = READ_ONCE(page->compound_head); | |
183 | ||
184 | if (unlikely(head & 1)) | |
0f2317e3 MWO |
185 | return head - 1; |
186 | return (unsigned long)page; | |
0e6d31a7 KS |
187 | } |
188 | ||
0f2317e3 MWO |
189 | #define compound_head(page) ((typeof(page))_compound_head(page)) |
190 | ||
4b0f3261 | 191 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
192 | { |
193 | return READ_ONCE(page->compound_head) & 1; | |
194 | } | |
195 | ||
4b0f3261 | 196 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
197 | { |
198 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
199 | } | |
200 | ||
f165b378 PT |
201 | #define PAGE_POISON_PATTERN -1l |
202 | static inline int PagePoisoned(const struct page *page) | |
203 | { | |
204 | return page->flags == PAGE_POISON_PATTERN; | |
205 | } | |
206 | ||
f682a97a AD |
207 | #ifdef CONFIG_DEBUG_VM |
208 | void page_init_poison(struct page *page, size_t size); | |
209 | #else | |
210 | static inline void page_init_poison(struct page *page, size_t size) | |
211 | { | |
212 | } | |
213 | #endif | |
214 | ||
95ad9755 KS |
215 | /* |
216 | * Page flags policies wrt compound pages | |
217 | * | |
f165b378 PT |
218 | * PF_POISONED_CHECK |
219 | * check if this struct page poisoned/uninitialized | |
220 | * | |
95ad9755 KS |
221 | * PF_ANY: |
222 | * the page flag is relevant for small, head and tail pages. | |
223 | * | |
224 | * PF_HEAD: | |
225 | * for compound page all operations related to the page flag applied to | |
226 | * head page. | |
227 | * | |
62906027 NP |
228 | * PF_ONLY_HEAD: |
229 | * for compound page, callers only ever operate on the head page. | |
230 | * | |
95ad9755 KS |
231 | * PF_NO_TAIL: |
232 | * modifications of the page flag must be done on small or head pages, | |
233 | * checks can be done on tail pages too. | |
234 | * | |
235 | * PF_NO_COMPOUND: | |
236 | * the page flag is not relevant for compound pages. | |
a08d93e5 MWO |
237 | * |
238 | * PF_SECOND: | |
239 | * the page flag is stored in the first tail page. | |
95ad9755 | 240 | */ |
f165b378 PT |
241 | #define PF_POISONED_CHECK(page) ({ \ |
242 | VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ | |
243 | page; }) | |
244 | #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) | |
245 | #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) | |
62906027 NP |
246 | #define PF_ONLY_HEAD(page, enforce) ({ \ |
247 | VM_BUG_ON_PGFLAGS(PageTail(page), page); \ | |
f165b378 | 248 | PF_POISONED_CHECK(page); }) |
95ad9755 KS |
249 | #define PF_NO_TAIL(page, enforce) ({ \ |
250 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
f165b378 | 251 | PF_POISONED_CHECK(compound_head(page)); }) |
822cdd11 | 252 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 | 253 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
f165b378 | 254 | PF_POISONED_CHECK(page); }) |
a08d93e5 MWO |
255 | #define PF_SECOND(page, enforce) ({ \ |
256 | VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ | |
257 | PF_POISONED_CHECK(&page[1]); }) | |
95ad9755 | 258 | |
f94a62e9 CL |
259 | /* |
260 | * Macros to create function definitions for page flags | |
261 | */ | |
95ad9755 | 262 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 263 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 264 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 265 | |
95ad9755 | 266 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 267 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 268 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 269 | |
95ad9755 | 270 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 271 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 272 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 273 | |
95ad9755 | 274 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 275 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 276 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 277 | |
95ad9755 | 278 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 279 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 280 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 281 | |
95ad9755 | 282 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 283 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 284 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 285 | |
95ad9755 | 286 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 287 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 288 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 289 | |
95ad9755 KS |
290 | #define PAGEFLAG(uname, lname, policy) \ |
291 | TESTPAGEFLAG(uname, lname, policy) \ | |
292 | SETPAGEFLAG(uname, lname, policy) \ | |
293 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 294 | |
95ad9755 KS |
295 | #define __PAGEFLAG(uname, lname, policy) \ |
296 | TESTPAGEFLAG(uname, lname, policy) \ | |
297 | __SETPAGEFLAG(uname, lname, policy) \ | |
298 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 299 | |
95ad9755 KS |
300 | #define TESTSCFLAG(uname, lname, policy) \ |
301 | TESTSETFLAG(uname, lname, policy) \ | |
302 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 303 | |
2f3e442c JW |
304 | #define TESTPAGEFLAG_FALSE(uname) \ |
305 | static inline int Page##uname(const struct page *page) { return 0; } | |
306 | ||
8a7a8544 LS |
307 | #define SETPAGEFLAG_NOOP(uname) \ |
308 | static inline void SetPage##uname(struct page *page) { } | |
309 | ||
310 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
311 | static inline void ClearPage##uname(struct page *page) { } | |
312 | ||
313 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
314 | static inline void __ClearPage##uname(struct page *page) { } | |
315 | ||
2f3e442c JW |
316 | #define TESTSETFLAG_FALSE(uname) \ |
317 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
318 | ||
8a7a8544 LS |
319 | #define TESTCLEARFLAG_FALSE(uname) \ |
320 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
321 | ||
2f3e442c JW |
322 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
323 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
324 | ||
325 | #define TESTSCFLAG_FALSE(uname) \ | |
326 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
327 | ||
48c935ad | 328 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
62906027 | 329 | PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) |
d72520ad | 330 | PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) |
8cb38fab KS |
331 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
332 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
333 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
334 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
335 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab | 336 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
d25b5bd8 | 337 | TESTCLEARFLAG(LRU, lru, PF_HEAD) |
8cb38fab KS |
338 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) |
339 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
1899ad18 JW |
340 | PAGEFLAG(Workingset, workingset, PF_HEAD) |
341 | TESTCLEARFLAG(Workingset, workingset, PF_HEAD) | |
dcb351cd KS |
342 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
343 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 344 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
345 | |
346 | /* Xen */ | |
347 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
348 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
349 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
350 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
b877ac98 JG |
351 | PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) |
352 | TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) | |
c13985fa | 353 | |
de09d31d KS |
354 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
355 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
d483da5b | 356 | __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
da5efc40 KS |
357 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
358 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
359 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 360 | |
266cf658 DH |
361 | /* |
362 | * Private page markings that may be used by the filesystem that owns the page | |
363 | * for its own purposes. | |
364 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
365 | */ | |
2ee08717 | 366 | PAGEFLAG(Private, private, PF_ANY) |
95ad9755 KS |
367 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) |
368 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
369 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 370 | |
6a1e7f77 CL |
371 | /* |
372 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
373 | * risky: they bypass page accounting. | |
374 | */ | |
225311a4 HY |
375 | TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) |
376 | TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) | |
e2f0a0db | 377 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) |
6a1e7f77 | 378 | |
579f8290 | 379 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
e2f0a0db KS |
380 | PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) |
381 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) | |
df8c94d1 KS |
382 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) |
383 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
384 | |
385 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 386 | /* |
6a1e7f77 CL |
387 | * Must use a macro here due to header dependency issues. page_zone() is not |
388 | * available at this point. | |
1da177e4 | 389 | */ |
3ca65c19 | 390 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 391 | #else |
ec7cade8 | 392 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
393 | #endif |
394 | ||
395 | #ifdef CONFIG_SWAP | |
6326fec1 NP |
396 | static __always_inline int PageSwapCache(struct page *page) |
397 | { | |
38d8b4e6 HY |
398 | #ifdef CONFIG_THP_SWAP |
399 | page = compound_head(page); | |
400 | #endif | |
6326fec1 NP |
401 | return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); |
402 | ||
403 | } | |
38d8b4e6 HY |
404 | SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) |
405 | CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) | |
6a1e7f77 | 406 | #else |
ec7cade8 | 407 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
408 | #endif |
409 | ||
8cb38fab KS |
410 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
411 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
412 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 413 | |
af8e3354 | 414 | #ifdef CONFIG_MMU |
e4f87d5d KS |
415 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
416 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
417 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 418 | #else |
2f3e442c | 419 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 420 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
421 | #endif |
422 | ||
46cf98cd | 423 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 424 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 425 | #else |
ec7cade8 | 426 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 427 | #endif |
1da177e4 | 428 | |
d466f2fc | 429 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
430 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
431 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc | 432 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
06be6ff3 | 433 | extern bool take_page_off_buddy(struct page *page); |
d466f2fc AK |
434 | #else |
435 | PAGEFLAG_FALSE(HWPoison) | |
436 | #define __PG_HWPOISON 0 | |
437 | #endif | |
438 | ||
33c3fc71 | 439 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
440 | TESTPAGEFLAG(Young, young, PF_ANY) |
441 | SETPAGEFLAG(Young, young, PF_ANY) | |
442 | TESTCLEARFLAG(Young, young, PF_ANY) | |
443 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
444 | #endif |
445 | ||
36e66c55 AD |
446 | /* |
447 | * PageReported() is used to track reported free pages within the Buddy | |
448 | * allocator. We can use the non-atomic version of the test and set | |
449 | * operations as both should be shielded with the zone lock to prevent | |
450 | * any possible races on the setting or clearing of the bit. | |
451 | */ | |
452 | __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) | |
453 | ||
e8c6158f KS |
454 | /* |
455 | * On an anonymous page mapped into a user virtual memory area, | |
456 | * page->mapping points to its anon_vma, not to a struct address_space; | |
457 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
458 | * | |
459 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
460 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
461 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
462 | * structure which KSM associates with that merged page. See ksm.h. |
463 | * | |
bda807d4 MK |
464 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
465 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
466 | * |
467 | * Please note that, confusingly, "page_mapping" refers to the inode | |
468 | * address_space which maps the page from disk; whereas "page_mapped" | |
469 | * refers to user virtual address space into which the page is mapped. | |
470 | */ | |
bda807d4 MK |
471 | #define PAGE_MAPPING_ANON 0x1 |
472 | #define PAGE_MAPPING_MOVABLE 0x2 | |
473 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
474 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 475 | |
bda807d4 | 476 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 477 | { |
bda807d4 | 478 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
479 | } |
480 | ||
4b0f3261 | 481 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 482 | { |
822cdd11 | 483 | page = compound_head(page); |
bda807d4 MK |
484 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
485 | } | |
486 | ||
487 | static __always_inline int __PageMovable(struct page *page) | |
488 | { | |
489 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
490 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
491 | } |
492 | ||
493 | #ifdef CONFIG_KSM | |
494 | /* | |
495 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
496 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
497 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
498 | * anon_vma, but to that page's node of the stable tree. | |
499 | */ | |
4b0f3261 | 500 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 501 | { |
822cdd11 | 502 | page = compound_head(page); |
e8c6158f | 503 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 504 | PAGE_MAPPING_KSM; |
e8c6158f KS |
505 | } |
506 | #else | |
507 | TESTPAGEFLAG_FALSE(Ksm) | |
508 | #endif | |
509 | ||
1a9b5b7f WF |
510 | u64 stable_page_flags(struct page *page); |
511 | ||
0ed361de NP |
512 | static inline int PageUptodate(struct page *page) |
513 | { | |
d2998c4d KS |
514 | int ret; |
515 | page = compound_head(page); | |
516 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
517 | /* |
518 | * Must ensure that the data we read out of the page is loaded | |
519 | * _after_ we've loaded page->flags to check for PageUptodate. | |
520 | * We can skip the barrier if the page is not uptodate, because | |
521 | * we wouldn't be reading anything from it. | |
522 | * | |
523 | * See SetPageUptodate() for the other side of the story. | |
524 | */ | |
525 | if (ret) | |
526 | smp_rmb(); | |
527 | ||
528 | return ret; | |
529 | } | |
530 | ||
4b0f3261 | 531 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 532 | { |
d2998c4d | 533 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 534 | smp_wmb(); |
df8c94d1 | 535 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
536 | } |
537 | ||
4b0f3261 | 538 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 539 | { |
d2998c4d | 540 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
541 | /* |
542 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
543 | * so that all previous stores issued in order to bring the page | |
544 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
545 | */ |
546 | smp_wmb(); | |
df8c94d1 | 547 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
548 | } |
549 | ||
d2998c4d | 550 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 551 | |
6a1e7f77 | 552 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
553 | int __test_set_page_writeback(struct page *page, bool keep_write); |
554 | ||
555 | #define test_set_page_writeback(page) \ | |
556 | __test_set_page_writeback(page, false) | |
557 | #define test_set_page_writeback_keepwrite(page) \ | |
558 | __test_set_page_writeback(page, true) | |
1da177e4 | 559 | |
6a1e7f77 CL |
560 | static inline void set_page_writeback(struct page *page) |
561 | { | |
562 | test_set_page_writeback(page); | |
563 | } | |
1da177e4 | 564 | |
1c8349a1 NJ |
565 | static inline void set_page_writeback_keepwrite(struct page *page) |
566 | { | |
567 | test_set_page_writeback_keepwrite(page); | |
568 | } | |
569 | ||
95ad9755 | 570 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 571 | |
4b0f3261 | 572 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 573 | { |
1d798ca3 | 574 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
575 | } |
576 | ||
4b0f3261 | 577 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 578 | { |
1d798ca3 | 579 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 580 | } |
6d777953 | 581 | |
4e6af67e AA |
582 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
583 | static inline void ClearPageCompound(struct page *page) | |
584 | { | |
1d798ca3 KS |
585 | BUG_ON(!PageHead(page)); |
586 | ClearPageHead(page); | |
4e6af67e AA |
587 | } |
588 | #endif | |
589 | ||
d2a1a1f0 | 590 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 591 | |
e8c6158f KS |
592 | #ifdef CONFIG_HUGETLB_PAGE |
593 | int PageHuge(struct page *page); | |
594 | int PageHeadHuge(struct page *page); | |
595 | #else | |
596 | TESTPAGEFLAG_FALSE(Huge) | |
597 | TESTPAGEFLAG_FALSE(HeadHuge) | |
598 | #endif | |
599 | ||
7e1f049e | 600 | |
936a5fe6 | 601 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
602 | /* |
603 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
604 | * normal or transparent huge pages. | |
605 | * | |
606 | * PageTransHuge() returns true for both transparent huge and | |
607 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
608 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
609 | */ | |
610 | static inline int PageTransHuge(struct page *page) | |
611 | { | |
309381fe | 612 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
613 | return PageHead(page); |
614 | } | |
615 | ||
385de357 DN |
616 | /* |
617 | * PageTransCompound returns true for both transparent huge pages | |
618 | * and hugetlbfs pages, so it should only be called when it's known | |
619 | * that hugetlbfs pages aren't involved. | |
620 | */ | |
936a5fe6 AA |
621 | static inline int PageTransCompound(struct page *page) |
622 | { | |
623 | return PageCompound(page); | |
624 | } | |
71e3aac0 | 625 | |
127393fb AA |
626 | /* |
627 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
628 | * guarantees the primary MMU has the entire compound page mapped | |
629 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
630 | * can also map the entire compound page. This allows the secondary | |
631 | * MMUs to call get_user_pages() only once for each compound page and | |
632 | * to immediately map the entire compound page with a single secondary | |
633 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
634 | * will get an update through the MMU notifier invalidation through | |
635 | * split_huge_pmd(). | |
636 | * | |
637 | * Unlike PageTransCompound, this is safe to be called only while | |
638 | * split_huge_pmd() cannot run from under us, like if protected by the | |
169226f7 | 639 | * MMU notifier, otherwise it may result in page->_mapcount check false |
127393fb | 640 | * positives. |
169226f7 YS |
641 | * |
642 | * We have to treat page cache THP differently since every subpage of it | |
643 | * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE | |
644 | * mapped in the current process so comparing subpage's _mapcount to | |
645 | * compound_mapcount to filter out PTE mapped case. | |
127393fb AA |
646 | */ |
647 | static inline int PageTransCompoundMap(struct page *page) | |
648 | { | |
169226f7 YS |
649 | struct page *head; |
650 | ||
651 | if (!PageTransCompound(page)) | |
652 | return 0; | |
653 | ||
654 | if (PageAnon(page)) | |
655 | return atomic_read(&page->_mapcount) < 0; | |
656 | ||
657 | head = compound_head(page); | |
658 | /* File THP is PMD mapped and not PTE mapped */ | |
659 | return atomic_read(&page->_mapcount) == | |
660 | atomic_read(compound_mapcount_ptr(head)); | |
127393fb AA |
661 | } |
662 | ||
385de357 DN |
663 | /* |
664 | * PageTransTail returns true for both transparent huge pages | |
665 | * and hugetlbfs pages, so it should only be called when it's known | |
666 | * that hugetlbfs pages aren't involved. | |
667 | */ | |
668 | static inline int PageTransTail(struct page *page) | |
669 | { | |
670 | return PageTail(page); | |
671 | } | |
672 | ||
53f9263b KS |
673 | /* |
674 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
675 | * as PMDs. | |
676 | * | |
677 | * This is required for optimization of rmap operations for THP: we can postpone | |
678 | * per small page mapcount accounting (and its overhead from atomic operations) | |
679 | * until the first PMD split. | |
680 | * | |
681 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
682 | * by one. This reference will go away with last compound_mapcount. | |
683 | * | |
684 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
685 | */ | |
a08d93e5 MWO |
686 | PAGEFLAG(DoubleMap, double_map, PF_SECOND) |
687 | TESTSCFLAG(DoubleMap, double_map, PF_SECOND) | |
936a5fe6 | 688 | #else |
d8c1bdeb KS |
689 | TESTPAGEFLAG_FALSE(TransHuge) |
690 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 691 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 692 | TESTPAGEFLAG_FALSE(TransTail) |
9a73f61b | 693 | PAGEFLAG_FALSE(DoubleMap) |
a08d93e5 | 694 | TESTSCFLAG_FALSE(DoubleMap) |
936a5fe6 AA |
695 | #endif |
696 | ||
e8c6158f | 697 | /* |
6e292b9b MW |
698 | * For pages that are never mapped to userspace (and aren't PageSlab), |
699 | * page_type may be used. Because it is initialised to -1, we invert the | |
700 | * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and | |
701 | * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and | |
702 | * low bits so that an underflow or overflow of page_mapcount() won't be | |
703 | * mistaken for a page type value. | |
e8c6158f | 704 | */ |
6e292b9b MW |
705 | |
706 | #define PAGE_TYPE_BASE 0xf0000000 | |
707 | /* Reserve 0x0000007f to catch underflows of page_mapcount */ | |
144552ff | 708 | #define PAGE_MAPCOUNT_RESERVE -128 |
6e292b9b | 709 | #define PG_buddy 0x00000080 |
ca215086 | 710 | #define PG_offline 0x00000100 |
18b2db3b RG |
711 | #define PG_table 0x00000200 |
712 | #define PG_guard 0x00000400 | |
6e292b9b MW |
713 | |
714 | #define PageType(page, flag) \ | |
715 | ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) | |
716 | ||
144552ff AY |
717 | static inline int page_has_type(struct page *page) |
718 | { | |
719 | return (int)page->page_type < PAGE_MAPCOUNT_RESERVE; | |
720 | } | |
721 | ||
6e292b9b | 722 | #define PAGE_TYPE_OPS(uname, lname) \ |
632c0a1a VD |
723 | static __always_inline int Page##uname(struct page *page) \ |
724 | { \ | |
6e292b9b | 725 | return PageType(page, PG_##lname); \ |
632c0a1a VD |
726 | } \ |
727 | static __always_inline void __SetPage##uname(struct page *page) \ | |
728 | { \ | |
6e292b9b MW |
729 | VM_BUG_ON_PAGE(!PageType(page, 0), page); \ |
730 | page->page_type &= ~PG_##lname; \ | |
632c0a1a VD |
731 | } \ |
732 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
733 | { \ | |
734 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
6e292b9b | 735 | page->page_type |= PG_##lname; \ |
e8c6158f KS |
736 | } |
737 | ||
632c0a1a | 738 | /* |
6e292b9b | 739 | * PageBuddy() indicates that the page is free and in the buddy system |
632c0a1a VD |
740 | * (see mm/page_alloc.c). |
741 | */ | |
6e292b9b | 742 | PAGE_TYPE_OPS(Buddy, buddy) |
e8c6158f | 743 | |
632c0a1a | 744 | /* |
ca215086 DH |
745 | * PageOffline() indicates that the page is logically offline although the |
746 | * containing section is online. (e.g. inflated in a balloon driver or | |
747 | * not onlined when onlining the section). | |
748 | * The content of these pages is effectively stale. Such pages should not | |
749 | * be touched (read/write/dump/save) except by their owner. | |
aa218795 DH |
750 | * |
751 | * If a driver wants to allow to offline unmovable PageOffline() pages without | |
752 | * putting them back to the buddy, it can do so via the memory notifier by | |
753 | * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the | |
754 | * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() | |
755 | * pages (now with a reference count of zero) are treated like free pages, | |
756 | * allowing the containing memory block to get offlined. A driver that | |
757 | * relies on this feature is aware that re-onlining the memory block will | |
758 | * require to re-set the pages PageOffline() and not giving them to the | |
759 | * buddy via online_page_callback_t. | |
632c0a1a | 760 | */ |
ca215086 | 761 | PAGE_TYPE_OPS(Offline, offline) |
e8c6158f | 762 | |
1d40a5ea MW |
763 | /* |
764 | * Marks pages in use as page tables. | |
765 | */ | |
766 | PAGE_TYPE_OPS(Table, table) | |
767 | ||
3972f6bb VB |
768 | /* |
769 | * Marks guardpages used with debug_pagealloc. | |
770 | */ | |
771 | PAGE_TYPE_OPS(Guard, guard) | |
772 | ||
832fc1de NH |
773 | extern bool is_free_buddy_page(struct page *page); |
774 | ||
bda807d4 MK |
775 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
776 | ||
072bb0aa MG |
777 | /* |
778 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
779 | * were allocated from pfmemalloc reserves. | |
780 | */ | |
781 | static inline int PageSlabPfmemalloc(struct page *page) | |
782 | { | |
309381fe | 783 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
784 | return PageActive(page); |
785 | } | |
786 | ||
787 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
788 | { | |
309381fe | 789 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
790 | SetPageActive(page); |
791 | } | |
792 | ||
793 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
794 | { | |
309381fe | 795 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
796 | __ClearPageActive(page); |
797 | } | |
798 | ||
799 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
800 | { | |
309381fe | 801 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
802 | ClearPageActive(page); |
803 | } | |
804 | ||
af8e3354 | 805 | #ifdef CONFIG_MMU |
d2a1a1f0 | 806 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 807 | #else |
b291f000 | 808 | #define __PG_MLOCKED 0 |
894bc310 LS |
809 | #endif |
810 | ||
dfa7e20c RA |
811 | /* |
812 | * Flags checked when a page is freed. Pages being freed should not have | |
4be408ce | 813 | * these flags set. If they are, there is a problem. |
dfa7e20c | 814 | */ |
6326fec1 NP |
815 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
816 | (1UL << PG_lru | 1UL << PG_locked | \ | |
817 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
818 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
819 | 1UL << PG_slab | 1UL << PG_active | \ | |
820 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
821 | |
822 | /* | |
823 | * Flags checked when a page is prepped for return by the page allocator. | |
4be408ce | 824 | * Pages being prepped should not have these flags set. If they are set, |
79f4b7bf | 825 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
826 | * |
827 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
828 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 829 | */ |
f4c18e6f | 830 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
d2a1a1f0 | 831 | (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) |
dfa7e20c | 832 | |
edcf4748 | 833 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 834 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
835 | /** |
836 | * page_has_private - Determine if page has private stuff | |
837 | * @page: The page to be checked | |
838 | * | |
839 | * Determine if a page has private stuff, indicating that release routines | |
840 | * should be invoked upon it. | |
841 | */ | |
edcf4748 JW |
842 | static inline int page_has_private(struct page *page) |
843 | { | |
844 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
845 | } | |
846 | ||
95ad9755 KS |
847 | #undef PF_ANY |
848 | #undef PF_HEAD | |
62906027 | 849 | #undef PF_ONLY_HEAD |
95ad9755 KS |
850 | #undef PF_NO_TAIL |
851 | #undef PF_NO_COMPOUND | |
a08d93e5 | 852 | #undef PF_SECOND |
edcf4748 | 853 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 854 | |
1da177e4 | 855 | #endif /* PAGE_FLAGS_H */ |