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 | /* | |
89 | * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break | |
91fc8ab3 AW |
90 | * locked- and dirty-page accounting. |
91 | * | |
92 | * The page flags field is split into two parts, the main flags area | |
93 | * which extends from the low bits upwards, and the fields area which | |
94 | * extends from the high bits downwards. | |
95 | * | |
96 | * | FIELD | ... | FLAGS | | |
9223b419 CL |
97 | * N-1 ^ 0 |
98 | * (NR_PAGEFLAGS) | |
91fc8ab3 | 99 | * |
9223b419 CL |
100 | * The fields area is reserved for fields mapping zone, node (for NUMA) and |
101 | * SPARSEMEM section (for variants of SPARSEMEM that require section ids like | |
102 | * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). | |
1da177e4 | 103 | */ |
e2683181 CL |
104 | enum pageflags { |
105 | PG_locked, /* Page is locked. Don't touch. */ | |
e2683181 CL |
106 | PG_referenced, |
107 | PG_uptodate, | |
108 | PG_dirty, | |
109 | PG_lru, | |
110 | PG_active, | |
1899ad18 | 111 | PG_workingset, |
b91e1302 | 112 | PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ |
1899ad18 | 113 | PG_error, |
e2683181 CL |
114 | PG_slab, |
115 | PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ | |
e2683181 CL |
116 | PG_arch_1, |
117 | PG_reserved, | |
118 | PG_private, /* If pagecache, has fs-private data */ | |
266cf658 | 119 | PG_private_2, /* If pagecache, has fs aux data */ |
e2683181 | 120 | PG_writeback, /* Page is under writeback */ |
e20b8cca | 121 | PG_head, /* A head page */ |
e2683181 CL |
122 | PG_mappedtodisk, /* Has blocks allocated on-disk */ |
123 | PG_reclaim, /* To be reclaimed asap */ | |
b2e18538 | 124 | PG_swapbacked, /* Page is backed by RAM/swap */ |
894bc310 | 125 | PG_unevictable, /* Page is "unevictable" */ |
af8e3354 | 126 | #ifdef CONFIG_MMU |
b291f000 | 127 | PG_mlocked, /* Page is vma mlocked */ |
894bc310 | 128 | #endif |
46cf98cd | 129 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
602c4d11 | 130 | PG_uncached, /* Page has been mapped as uncached */ |
d466f2fc AK |
131 | #endif |
132 | #ifdef CONFIG_MEMORY_FAILURE | |
133 | PG_hwpoison, /* hardware poisoned page. Don't touch */ | |
e9da73d6 | 134 | #endif |
33c3fc71 VD |
135 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
136 | PG_young, | |
137 | PG_idle, | |
4beba948 SP |
138 | #endif |
139 | #ifdef CONFIG_64BIT | |
140 | PG_arch_2, | |
f886ed44 | 141 | #endif |
0cad47cf AW |
142 | __NR_PAGEFLAGS, |
143 | ||
144 | /* Filesystems */ | |
145 | PG_checked = PG_owner_priv_1, | |
146 | ||
6326fec1 NP |
147 | /* SwapBacked */ |
148 | PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ | |
149 | ||
266cf658 DH |
150 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
151 | * state. These bits are set on pages belonging to the netfs's inodes | |
152 | * when those inodes are being locally cached. | |
153 | */ | |
154 | PG_fscache = PG_private_2, /* page backed by cache */ | |
155 | ||
0cad47cf | 156 | /* XEN */ |
d8ac3dd4 | 157 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 158 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 159 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 160 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
161 | /* Has a grant mapping of another (foreign) domain's page. */ |
162 | PG_foreign = PG_owner_priv_1, | |
b877ac98 JG |
163 | /* Remapped by swiotlb-xen. */ |
164 | PG_xen_remapped = PG_owner_priv_1, | |
8a38082d | 165 | |
9023cb7e | 166 | /* SLOB */ |
9023cb7e | 167 | PG_slob_free = PG_private, |
53f9263b KS |
168 | |
169 | /* Compound pages. Stored in first tail page's flags */ | |
e18c45ff | 170 | PG_double_map = PG_workingset, |
bda807d4 MK |
171 | |
172 | /* non-lru isolated movable page */ | |
173 | PG_isolated = PG_reclaim, | |
36e66c55 AD |
174 | |
175 | /* Only valid for buddy pages. Used to track pages that are reported */ | |
176 | PG_reported = PG_uptodate, | |
e2683181 | 177 | }; |
1da177e4 | 178 | |
9223b419 CL |
179 | #ifndef __GENERATING_BOUNDS_H |
180 | ||
0e6d31a7 KS |
181 | struct page; /* forward declaration */ |
182 | ||
183 | static inline struct page *compound_head(struct page *page) | |
184 | { | |
185 | unsigned long head = READ_ONCE(page->compound_head); | |
186 | ||
187 | if (unlikely(head & 1)) | |
188 | return (struct page *) (head - 1); | |
189 | return page; | |
190 | } | |
191 | ||
4b0f3261 | 192 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
193 | { |
194 | return READ_ONCE(page->compound_head) & 1; | |
195 | } | |
196 | ||
4b0f3261 | 197 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
198 | { |
199 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
200 | } | |
201 | ||
f165b378 PT |
202 | #define PAGE_POISON_PATTERN -1l |
203 | static inline int PagePoisoned(const struct page *page) | |
204 | { | |
205 | return page->flags == PAGE_POISON_PATTERN; | |
206 | } | |
207 | ||
f682a97a AD |
208 | #ifdef CONFIG_DEBUG_VM |
209 | void page_init_poison(struct page *page, size_t size); | |
210 | #else | |
211 | static inline void page_init_poison(struct page *page, size_t size) | |
212 | { | |
213 | } | |
214 | #endif | |
215 | ||
95ad9755 KS |
216 | /* |
217 | * Page flags policies wrt compound pages | |
218 | * | |
f165b378 PT |
219 | * PF_POISONED_CHECK |
220 | * check if this struct page poisoned/uninitialized | |
221 | * | |
95ad9755 KS |
222 | * PF_ANY: |
223 | * the page flag is relevant for small, head and tail pages. | |
224 | * | |
225 | * PF_HEAD: | |
226 | * for compound page all operations related to the page flag applied to | |
227 | * head page. | |
228 | * | |
62906027 NP |
229 | * PF_ONLY_HEAD: |
230 | * for compound page, callers only ever operate on the head page. | |
231 | * | |
95ad9755 KS |
232 | * PF_NO_TAIL: |
233 | * modifications of the page flag must be done on small or head pages, | |
234 | * checks can be done on tail pages too. | |
235 | * | |
236 | * PF_NO_COMPOUND: | |
237 | * the page flag is not relevant for compound pages. | |
a08d93e5 MWO |
238 | * |
239 | * PF_SECOND: | |
240 | * the page flag is stored in the first tail page. | |
95ad9755 | 241 | */ |
f165b378 PT |
242 | #define PF_POISONED_CHECK(page) ({ \ |
243 | VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ | |
244 | page; }) | |
245 | #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) | |
246 | #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) | |
62906027 NP |
247 | #define PF_ONLY_HEAD(page, enforce) ({ \ |
248 | VM_BUG_ON_PGFLAGS(PageTail(page), page); \ | |
f165b378 | 249 | PF_POISONED_CHECK(page); }) |
95ad9755 KS |
250 | #define PF_NO_TAIL(page, enforce) ({ \ |
251 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
f165b378 | 252 | PF_POISONED_CHECK(compound_head(page)); }) |
822cdd11 | 253 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 | 254 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
f165b378 | 255 | PF_POISONED_CHECK(page); }) |
a08d93e5 MWO |
256 | #define PF_SECOND(page, enforce) ({ \ |
257 | VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ | |
258 | PF_POISONED_CHECK(&page[1]); }) | |
95ad9755 | 259 | |
f94a62e9 CL |
260 | /* |
261 | * Macros to create function definitions for page flags | |
262 | */ | |
95ad9755 | 263 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 264 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 265 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 266 | |
95ad9755 | 267 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 268 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 269 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 270 | |
95ad9755 | 271 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 272 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 273 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 274 | |
95ad9755 | 275 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 276 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 277 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 278 | |
95ad9755 | 279 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 280 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 281 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 282 | |
95ad9755 | 283 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 284 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 285 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 286 | |
95ad9755 | 287 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 288 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 289 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 290 | |
95ad9755 KS |
291 | #define PAGEFLAG(uname, lname, policy) \ |
292 | TESTPAGEFLAG(uname, lname, policy) \ | |
293 | SETPAGEFLAG(uname, lname, policy) \ | |
294 | CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 295 | |
95ad9755 KS |
296 | #define __PAGEFLAG(uname, lname, policy) \ |
297 | TESTPAGEFLAG(uname, lname, policy) \ | |
298 | __SETPAGEFLAG(uname, lname, policy) \ | |
299 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 300 | |
95ad9755 KS |
301 | #define TESTSCFLAG(uname, lname, policy) \ |
302 | TESTSETFLAG(uname, lname, policy) \ | |
303 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 304 | |
2f3e442c JW |
305 | #define TESTPAGEFLAG_FALSE(uname) \ |
306 | static inline int Page##uname(const struct page *page) { return 0; } | |
307 | ||
8a7a8544 LS |
308 | #define SETPAGEFLAG_NOOP(uname) \ |
309 | static inline void SetPage##uname(struct page *page) { } | |
310 | ||
311 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
312 | static inline void ClearPage##uname(struct page *page) { } | |
313 | ||
314 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
315 | static inline void __ClearPage##uname(struct page *page) { } | |
316 | ||
2f3e442c JW |
317 | #define TESTSETFLAG_FALSE(uname) \ |
318 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
319 | ||
8a7a8544 LS |
320 | #define TESTCLEARFLAG_FALSE(uname) \ |
321 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
322 | ||
2f3e442c JW |
323 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
324 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
325 | ||
326 | #define TESTSCFLAG_FALSE(uname) \ | |
327 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
328 | ||
48c935ad | 329 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
62906027 | 330 | PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) |
d72520ad | 331 | PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) |
8cb38fab KS |
332 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
333 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
334 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
335 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
336 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab KS |
337 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
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 | */ | |
95ad9755 KS |
366 | PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) |
367 | __CLEARPAGEFLAG(Private, private, PF_ANY) | |
368 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) | |
369 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
370 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 371 | |
6a1e7f77 CL |
372 | /* |
373 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
374 | * risky: they bypass page accounting. | |
375 | */ | |
225311a4 HY |
376 | TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) |
377 | TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) | |
e2f0a0db | 378 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) |
6a1e7f77 | 379 | |
579f8290 | 380 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
e2f0a0db KS |
381 | PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) |
382 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) | |
df8c94d1 KS |
383 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) |
384 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
385 | |
386 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 387 | /* |
6a1e7f77 CL |
388 | * Must use a macro here due to header dependency issues. page_zone() is not |
389 | * available at this point. | |
1da177e4 | 390 | */ |
3ca65c19 | 391 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 392 | #else |
ec7cade8 | 393 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
394 | #endif |
395 | ||
396 | #ifdef CONFIG_SWAP | |
6326fec1 NP |
397 | static __always_inline int PageSwapCache(struct page *page) |
398 | { | |
38d8b4e6 HY |
399 | #ifdef CONFIG_THP_SWAP |
400 | page = compound_head(page); | |
401 | #endif | |
6326fec1 NP |
402 | return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); |
403 | ||
404 | } | |
38d8b4e6 HY |
405 | SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) |
406 | CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) | |
6a1e7f77 | 407 | #else |
ec7cade8 | 408 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
409 | #endif |
410 | ||
8cb38fab KS |
411 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
412 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
413 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 414 | |
af8e3354 | 415 | #ifdef CONFIG_MMU |
e4f87d5d KS |
416 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
417 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
418 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 419 | #else |
2f3e442c | 420 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 421 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
422 | #endif |
423 | ||
46cf98cd | 424 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 425 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 426 | #else |
ec7cade8 | 427 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 428 | #endif |
1da177e4 | 429 | |
d466f2fc | 430 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
431 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
432 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc | 433 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
d4ae9916 | 434 | extern bool set_hwpoison_free_buddy_page(struct page *page); |
06be6ff3 | 435 | extern bool take_page_off_buddy(struct page *page); |
d466f2fc AK |
436 | #else |
437 | PAGEFLAG_FALSE(HWPoison) | |
d4ae9916 NH |
438 | static inline bool set_hwpoison_free_buddy_page(struct page *page) |
439 | { | |
440 | return 0; | |
441 | } | |
d466f2fc AK |
442 | #define __PG_HWPOISON 0 |
443 | #endif | |
444 | ||
33c3fc71 | 445 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
446 | TESTPAGEFLAG(Young, young, PF_ANY) |
447 | SETPAGEFLAG(Young, young, PF_ANY) | |
448 | TESTCLEARFLAG(Young, young, PF_ANY) | |
449 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
450 | #endif |
451 | ||
36e66c55 AD |
452 | /* |
453 | * PageReported() is used to track reported free pages within the Buddy | |
454 | * allocator. We can use the non-atomic version of the test and set | |
455 | * operations as both should be shielded with the zone lock to prevent | |
456 | * any possible races on the setting or clearing of the bit. | |
457 | */ | |
458 | __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) | |
459 | ||
e8c6158f KS |
460 | /* |
461 | * On an anonymous page mapped into a user virtual memory area, | |
462 | * page->mapping points to its anon_vma, not to a struct address_space; | |
463 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
464 | * | |
465 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
466 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
467 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
468 | * structure which KSM associates with that merged page. See ksm.h. |
469 | * | |
bda807d4 MK |
470 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
471 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
472 | * |
473 | * Please note that, confusingly, "page_mapping" refers to the inode | |
474 | * address_space which maps the page from disk; whereas "page_mapped" | |
475 | * refers to user virtual address space into which the page is mapped. | |
476 | */ | |
bda807d4 MK |
477 | #define PAGE_MAPPING_ANON 0x1 |
478 | #define PAGE_MAPPING_MOVABLE 0x2 | |
479 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
480 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 481 | |
bda807d4 | 482 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 483 | { |
bda807d4 | 484 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
485 | } |
486 | ||
4b0f3261 | 487 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 488 | { |
822cdd11 | 489 | page = compound_head(page); |
bda807d4 MK |
490 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
491 | } | |
492 | ||
493 | static __always_inline int __PageMovable(struct page *page) | |
494 | { | |
495 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
496 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
497 | } |
498 | ||
499 | #ifdef CONFIG_KSM | |
500 | /* | |
501 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
502 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
503 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
504 | * anon_vma, but to that page's node of the stable tree. | |
505 | */ | |
4b0f3261 | 506 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 507 | { |
822cdd11 | 508 | page = compound_head(page); |
e8c6158f | 509 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 510 | PAGE_MAPPING_KSM; |
e8c6158f KS |
511 | } |
512 | #else | |
513 | TESTPAGEFLAG_FALSE(Ksm) | |
514 | #endif | |
515 | ||
1a9b5b7f WF |
516 | u64 stable_page_flags(struct page *page); |
517 | ||
0ed361de NP |
518 | static inline int PageUptodate(struct page *page) |
519 | { | |
d2998c4d KS |
520 | int ret; |
521 | page = compound_head(page); | |
522 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
523 | /* |
524 | * Must ensure that the data we read out of the page is loaded | |
525 | * _after_ we've loaded page->flags to check for PageUptodate. | |
526 | * We can skip the barrier if the page is not uptodate, because | |
527 | * we wouldn't be reading anything from it. | |
528 | * | |
529 | * See SetPageUptodate() for the other side of the story. | |
530 | */ | |
531 | if (ret) | |
532 | smp_rmb(); | |
533 | ||
534 | return ret; | |
535 | } | |
536 | ||
4b0f3261 | 537 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 538 | { |
d2998c4d | 539 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 540 | smp_wmb(); |
df8c94d1 | 541 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
542 | } |
543 | ||
4b0f3261 | 544 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 545 | { |
d2998c4d | 546 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
547 | /* |
548 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
549 | * so that all previous stores issued in order to bring the page | |
550 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
551 | */ |
552 | smp_wmb(); | |
df8c94d1 | 553 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
554 | } |
555 | ||
d2998c4d | 556 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 557 | |
6a1e7f77 | 558 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
559 | int __test_set_page_writeback(struct page *page, bool keep_write); |
560 | ||
561 | #define test_set_page_writeback(page) \ | |
562 | __test_set_page_writeback(page, false) | |
563 | #define test_set_page_writeback_keepwrite(page) \ | |
564 | __test_set_page_writeback(page, true) | |
1da177e4 | 565 | |
6a1e7f77 CL |
566 | static inline void set_page_writeback(struct page *page) |
567 | { | |
568 | test_set_page_writeback(page); | |
569 | } | |
1da177e4 | 570 | |
1c8349a1 NJ |
571 | static inline void set_page_writeback_keepwrite(struct page *page) |
572 | { | |
573 | test_set_page_writeback_keepwrite(page); | |
574 | } | |
575 | ||
95ad9755 | 576 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 577 | |
4b0f3261 | 578 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 579 | { |
1d798ca3 | 580 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
581 | } |
582 | ||
4b0f3261 | 583 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 584 | { |
1d798ca3 | 585 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 586 | } |
6d777953 | 587 | |
4e6af67e AA |
588 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
589 | static inline void ClearPageCompound(struct page *page) | |
590 | { | |
1d798ca3 KS |
591 | BUG_ON(!PageHead(page)); |
592 | ClearPageHead(page); | |
4e6af67e AA |
593 | } |
594 | #endif | |
595 | ||
d2a1a1f0 | 596 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 597 | |
e8c6158f KS |
598 | #ifdef CONFIG_HUGETLB_PAGE |
599 | int PageHuge(struct page *page); | |
600 | int PageHeadHuge(struct page *page); | |
7e1f049e | 601 | bool page_huge_active(struct page *page); |
e8c6158f KS |
602 | #else |
603 | TESTPAGEFLAG_FALSE(Huge) | |
604 | TESTPAGEFLAG_FALSE(HeadHuge) | |
7e1f049e NH |
605 | |
606 | static inline bool page_huge_active(struct page *page) | |
607 | { | |
608 | return 0; | |
609 | } | |
e8c6158f KS |
610 | #endif |
611 | ||
7e1f049e | 612 | |
936a5fe6 | 613 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
614 | /* |
615 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
616 | * normal or transparent huge pages. | |
617 | * | |
618 | * PageTransHuge() returns true for both transparent huge and | |
619 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
620 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
621 | */ | |
622 | static inline int PageTransHuge(struct page *page) | |
623 | { | |
309381fe | 624 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
625 | return PageHead(page); |
626 | } | |
627 | ||
385de357 DN |
628 | /* |
629 | * PageTransCompound returns true for both transparent huge pages | |
630 | * and hugetlbfs pages, so it should only be called when it's known | |
631 | * that hugetlbfs pages aren't involved. | |
632 | */ | |
936a5fe6 AA |
633 | static inline int PageTransCompound(struct page *page) |
634 | { | |
635 | return PageCompound(page); | |
636 | } | |
71e3aac0 | 637 | |
127393fb AA |
638 | /* |
639 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
640 | * guarantees the primary MMU has the entire compound page mapped | |
641 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
642 | * can also map the entire compound page. This allows the secondary | |
643 | * MMUs to call get_user_pages() only once for each compound page and | |
644 | * to immediately map the entire compound page with a single secondary | |
645 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
646 | * will get an update through the MMU notifier invalidation through | |
647 | * split_huge_pmd(). | |
648 | * | |
649 | * Unlike PageTransCompound, this is safe to be called only while | |
650 | * split_huge_pmd() cannot run from under us, like if protected by the | |
169226f7 | 651 | * MMU notifier, otherwise it may result in page->_mapcount check false |
127393fb | 652 | * positives. |
169226f7 YS |
653 | * |
654 | * We have to treat page cache THP differently since every subpage of it | |
655 | * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE | |
656 | * mapped in the current process so comparing subpage's _mapcount to | |
657 | * compound_mapcount to filter out PTE mapped case. | |
127393fb AA |
658 | */ |
659 | static inline int PageTransCompoundMap(struct page *page) | |
660 | { | |
169226f7 YS |
661 | struct page *head; |
662 | ||
663 | if (!PageTransCompound(page)) | |
664 | return 0; | |
665 | ||
666 | if (PageAnon(page)) | |
667 | return atomic_read(&page->_mapcount) < 0; | |
668 | ||
669 | head = compound_head(page); | |
670 | /* File THP is PMD mapped and not PTE mapped */ | |
671 | return atomic_read(&page->_mapcount) == | |
672 | atomic_read(compound_mapcount_ptr(head)); | |
127393fb AA |
673 | } |
674 | ||
385de357 DN |
675 | /* |
676 | * PageTransTail returns true for both transparent huge pages | |
677 | * and hugetlbfs pages, so it should only be called when it's known | |
678 | * that hugetlbfs pages aren't involved. | |
679 | */ | |
680 | static inline int PageTransTail(struct page *page) | |
681 | { | |
682 | return PageTail(page); | |
683 | } | |
684 | ||
53f9263b KS |
685 | /* |
686 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
687 | * as PMDs. | |
688 | * | |
689 | * This is required for optimization of rmap operations for THP: we can postpone | |
690 | * per small page mapcount accounting (and its overhead from atomic operations) | |
691 | * until the first PMD split. | |
692 | * | |
693 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
694 | * by one. This reference will go away with last compound_mapcount. | |
695 | * | |
696 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
697 | */ | |
a08d93e5 MWO |
698 | PAGEFLAG(DoubleMap, double_map, PF_SECOND) |
699 | TESTSCFLAG(DoubleMap, double_map, PF_SECOND) | |
936a5fe6 | 700 | #else |
d8c1bdeb KS |
701 | TESTPAGEFLAG_FALSE(TransHuge) |
702 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 703 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 704 | TESTPAGEFLAG_FALSE(TransTail) |
9a73f61b | 705 | PAGEFLAG_FALSE(DoubleMap) |
a08d93e5 | 706 | TESTSCFLAG_FALSE(DoubleMap) |
936a5fe6 AA |
707 | #endif |
708 | ||
e8c6158f | 709 | /* |
6e292b9b MW |
710 | * For pages that are never mapped to userspace (and aren't PageSlab), |
711 | * page_type may be used. Because it is initialised to -1, we invert the | |
712 | * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and | |
713 | * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and | |
714 | * low bits so that an underflow or overflow of page_mapcount() won't be | |
715 | * mistaken for a page type value. | |
e8c6158f | 716 | */ |
6e292b9b MW |
717 | |
718 | #define PAGE_TYPE_BASE 0xf0000000 | |
719 | /* Reserve 0x0000007f to catch underflows of page_mapcount */ | |
144552ff | 720 | #define PAGE_MAPCOUNT_RESERVE -128 |
6e292b9b | 721 | #define PG_buddy 0x00000080 |
ca215086 | 722 | #define PG_offline 0x00000100 |
6e292b9b | 723 | #define PG_kmemcg 0x00000200 |
1d40a5ea | 724 | #define PG_table 0x00000400 |
3972f6bb | 725 | #define PG_guard 0x00000800 |
6e292b9b MW |
726 | |
727 | #define PageType(page, flag) \ | |
728 | ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) | |
729 | ||
144552ff AY |
730 | static inline int page_has_type(struct page *page) |
731 | { | |
732 | return (int)page->page_type < PAGE_MAPCOUNT_RESERVE; | |
733 | } | |
734 | ||
6e292b9b | 735 | #define PAGE_TYPE_OPS(uname, lname) \ |
632c0a1a VD |
736 | static __always_inline int Page##uname(struct page *page) \ |
737 | { \ | |
6e292b9b | 738 | return PageType(page, PG_##lname); \ |
632c0a1a VD |
739 | } \ |
740 | static __always_inline void __SetPage##uname(struct page *page) \ | |
741 | { \ | |
6e292b9b MW |
742 | VM_BUG_ON_PAGE(!PageType(page, 0), page); \ |
743 | page->page_type &= ~PG_##lname; \ | |
632c0a1a VD |
744 | } \ |
745 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
746 | { \ | |
747 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
6e292b9b | 748 | page->page_type |= PG_##lname; \ |
e8c6158f KS |
749 | } |
750 | ||
632c0a1a | 751 | /* |
6e292b9b | 752 | * PageBuddy() indicates that the page is free and in the buddy system |
632c0a1a VD |
753 | * (see mm/page_alloc.c). |
754 | */ | |
6e292b9b | 755 | PAGE_TYPE_OPS(Buddy, buddy) |
e8c6158f | 756 | |
632c0a1a | 757 | /* |
ca215086 DH |
758 | * PageOffline() indicates that the page is logically offline although the |
759 | * containing section is online. (e.g. inflated in a balloon driver or | |
760 | * not onlined when onlining the section). | |
761 | * The content of these pages is effectively stale. Such pages should not | |
762 | * be touched (read/write/dump/save) except by their owner. | |
aa218795 DH |
763 | * |
764 | * If a driver wants to allow to offline unmovable PageOffline() pages without | |
765 | * putting them back to the buddy, it can do so via the memory notifier by | |
766 | * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the | |
767 | * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() | |
768 | * pages (now with a reference count of zero) are treated like free pages, | |
769 | * allowing the containing memory block to get offlined. A driver that | |
770 | * relies on this feature is aware that re-onlining the memory block will | |
771 | * require to re-set the pages PageOffline() and not giving them to the | |
772 | * buddy via online_page_callback_t. | |
632c0a1a | 773 | */ |
ca215086 | 774 | PAGE_TYPE_OPS(Offline, offline) |
e8c6158f | 775 | |
4949148a VD |
776 | /* |
777 | * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on | |
778 | * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. | |
779 | */ | |
6e292b9b | 780 | PAGE_TYPE_OPS(Kmemcg, kmemcg) |
4949148a | 781 | |
1d40a5ea MW |
782 | /* |
783 | * Marks pages in use as page tables. | |
784 | */ | |
785 | PAGE_TYPE_OPS(Table, table) | |
786 | ||
3972f6bb VB |
787 | /* |
788 | * Marks guardpages used with debug_pagealloc. | |
789 | */ | |
790 | PAGE_TYPE_OPS(Guard, guard) | |
791 | ||
832fc1de NH |
792 | extern bool is_free_buddy_page(struct page *page); |
793 | ||
bda807d4 MK |
794 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
795 | ||
072bb0aa MG |
796 | /* |
797 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
798 | * were allocated from pfmemalloc reserves. | |
799 | */ | |
800 | static inline int PageSlabPfmemalloc(struct page *page) | |
801 | { | |
309381fe | 802 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
803 | return PageActive(page); |
804 | } | |
805 | ||
806 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
807 | { | |
309381fe | 808 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
809 | SetPageActive(page); |
810 | } | |
811 | ||
812 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
813 | { | |
309381fe | 814 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
815 | __ClearPageActive(page); |
816 | } | |
817 | ||
818 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
819 | { | |
309381fe | 820 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
821 | ClearPageActive(page); |
822 | } | |
823 | ||
af8e3354 | 824 | #ifdef CONFIG_MMU |
d2a1a1f0 | 825 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 826 | #else |
b291f000 | 827 | #define __PG_MLOCKED 0 |
894bc310 LS |
828 | #endif |
829 | ||
dfa7e20c RA |
830 | /* |
831 | * Flags checked when a page is freed. Pages being freed should not have | |
832 | * these flags set. It they are, there is a problem. | |
833 | */ | |
6326fec1 NP |
834 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
835 | (1UL << PG_lru | 1UL << PG_locked | \ | |
836 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
837 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
838 | 1UL << PG_slab | 1UL << PG_active | \ | |
839 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
840 | |
841 | /* | |
842 | * Flags checked when a page is prepped for return by the page allocator. | |
f4c18e6f | 843 | * Pages being prepped should not have these flags set. It they are set, |
79f4b7bf | 844 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
845 | * |
846 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
847 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 848 | */ |
f4c18e6f | 849 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
d2a1a1f0 | 850 | (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) |
dfa7e20c | 851 | |
edcf4748 | 852 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 853 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
854 | /** |
855 | * page_has_private - Determine if page has private stuff | |
856 | * @page: The page to be checked | |
857 | * | |
858 | * Determine if a page has private stuff, indicating that release routines | |
859 | * should be invoked upon it. | |
860 | */ | |
edcf4748 JW |
861 | static inline int page_has_private(struct page *page) |
862 | { | |
863 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
864 | } | |
865 | ||
95ad9755 KS |
866 | #undef PF_ANY |
867 | #undef PF_HEAD | |
62906027 | 868 | #undef PF_ONLY_HEAD |
95ad9755 KS |
869 | #undef PF_NO_TAIL |
870 | #undef PF_NO_COMPOUND | |
a08d93e5 | 871 | #undef PF_SECOND |
edcf4748 | 872 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 873 | |
1da177e4 | 874 | #endif /* PAGE_FLAGS_H */ |