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, | |
c275c5c6 PC |
140 | #endif |
141 | #ifdef CONFIG_KASAN_HW_TAGS | |
142 | PG_skip_kasan_poison, | |
f886ed44 | 143 | #endif |
0cad47cf AW |
144 | __NR_PAGEFLAGS, |
145 | ||
146 | /* Filesystems */ | |
147 | PG_checked = PG_owner_priv_1, | |
148 | ||
6326fec1 NP |
149 | /* SwapBacked */ |
150 | PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ | |
151 | ||
266cf658 DH |
152 | /* Two page bits are conscripted by FS-Cache to maintain local caching |
153 | * state. These bits are set on pages belonging to the netfs's inodes | |
154 | * when those inodes are being locally cached. | |
155 | */ | |
156 | PG_fscache = PG_private_2, /* page backed by cache */ | |
157 | ||
0cad47cf | 158 | /* XEN */ |
d8ac3dd4 | 159 | /* Pinned in Xen as a read-only pagetable page. */ |
0cad47cf | 160 | PG_pinned = PG_owner_priv_1, |
d8ac3dd4 | 161 | /* Pinned as part of domain save (see xen_mm_pin_all()). */ |
0cad47cf | 162 | PG_savepinned = PG_dirty, |
d8ac3dd4 JH |
163 | /* Has a grant mapping of another (foreign) domain's page. */ |
164 | PG_foreign = PG_owner_priv_1, | |
b877ac98 JG |
165 | /* Remapped by swiotlb-xen. */ |
166 | PG_xen_remapped = PG_owner_priv_1, | |
8a38082d | 167 | |
9023cb7e | 168 | /* SLOB */ |
9023cb7e | 169 | PG_slob_free = PG_private, |
53f9263b KS |
170 | |
171 | /* Compound pages. Stored in first tail page's flags */ | |
e18c45ff | 172 | PG_double_map = PG_workingset, |
bda807d4 MK |
173 | |
174 | /* non-lru isolated movable page */ | |
175 | PG_isolated = PG_reclaim, | |
36e66c55 AD |
176 | |
177 | /* Only valid for buddy pages. Used to track pages that are reported */ | |
178 | PG_reported = PG_uptodate, | |
e2683181 | 179 | }; |
1da177e4 | 180 | |
41c961b9 MS |
181 | #define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1) |
182 | ||
9223b419 CL |
183 | #ifndef __GENERATING_BOUNDS_H |
184 | ||
0f2317e3 | 185 | static inline unsigned long _compound_head(const struct page *page) |
0e6d31a7 KS |
186 | { |
187 | unsigned long head = READ_ONCE(page->compound_head); | |
188 | ||
189 | if (unlikely(head & 1)) | |
0f2317e3 MWO |
190 | return head - 1; |
191 | return (unsigned long)page; | |
0e6d31a7 KS |
192 | } |
193 | ||
0f2317e3 MWO |
194 | #define compound_head(page) ((typeof(page))_compound_head(page)) |
195 | ||
4b0f3261 | 196 | static __always_inline int PageTail(struct page *page) |
0e6d31a7 KS |
197 | { |
198 | return READ_ONCE(page->compound_head) & 1; | |
199 | } | |
200 | ||
4b0f3261 | 201 | static __always_inline int PageCompound(struct page *page) |
0e6d31a7 KS |
202 | { |
203 | return test_bit(PG_head, &page->flags) || PageTail(page); | |
204 | } | |
205 | ||
f165b378 PT |
206 | #define PAGE_POISON_PATTERN -1l |
207 | static inline int PagePoisoned(const struct page *page) | |
208 | { | |
209 | return page->flags == PAGE_POISON_PATTERN; | |
210 | } | |
211 | ||
f682a97a AD |
212 | #ifdef CONFIG_DEBUG_VM |
213 | void page_init_poison(struct page *page, size_t size); | |
214 | #else | |
215 | static inline void page_init_poison(struct page *page, size_t size) | |
216 | { | |
217 | } | |
218 | #endif | |
219 | ||
95ad9755 KS |
220 | /* |
221 | * Page flags policies wrt compound pages | |
222 | * | |
f165b378 PT |
223 | * PF_POISONED_CHECK |
224 | * check if this struct page poisoned/uninitialized | |
225 | * | |
95ad9755 KS |
226 | * PF_ANY: |
227 | * the page flag is relevant for small, head and tail pages. | |
228 | * | |
229 | * PF_HEAD: | |
230 | * for compound page all operations related to the page flag applied to | |
231 | * head page. | |
232 | * | |
62906027 NP |
233 | * PF_ONLY_HEAD: |
234 | * for compound page, callers only ever operate on the head page. | |
235 | * | |
95ad9755 KS |
236 | * PF_NO_TAIL: |
237 | * modifications of the page flag must be done on small or head pages, | |
238 | * checks can be done on tail pages too. | |
239 | * | |
240 | * PF_NO_COMPOUND: | |
241 | * the page flag is not relevant for compound pages. | |
a08d93e5 MWO |
242 | * |
243 | * PF_SECOND: | |
244 | * the page flag is stored in the first tail page. | |
95ad9755 | 245 | */ |
f165b378 PT |
246 | #define PF_POISONED_CHECK(page) ({ \ |
247 | VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ | |
248 | page; }) | |
249 | #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) | |
250 | #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) | |
62906027 NP |
251 | #define PF_ONLY_HEAD(page, enforce) ({ \ |
252 | VM_BUG_ON_PGFLAGS(PageTail(page), page); \ | |
f165b378 | 253 | PF_POISONED_CHECK(page); }) |
95ad9755 KS |
254 | #define PF_NO_TAIL(page, enforce) ({ \ |
255 | VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ | |
f165b378 | 256 | PF_POISONED_CHECK(compound_head(page)); }) |
822cdd11 | 257 | #define PF_NO_COMPOUND(page, enforce) ({ \ |
95ad9755 | 258 | VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ |
f165b378 | 259 | PF_POISONED_CHECK(page); }) |
a08d93e5 MWO |
260 | #define PF_SECOND(page, enforce) ({ \ |
261 | VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ | |
262 | PF_POISONED_CHECK(&page[1]); }) | |
95ad9755 | 263 | |
f94a62e9 CL |
264 | /* |
265 | * Macros to create function definitions for page flags | |
266 | */ | |
95ad9755 | 267 | #define TESTPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 268 | static __always_inline int Page##uname(struct page *page) \ |
95ad9755 | 269 | { return test_bit(PG_##lname, &policy(page, 0)->flags); } |
f94a62e9 | 270 | |
95ad9755 | 271 | #define SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 272 | static __always_inline void SetPage##uname(struct page *page) \ |
95ad9755 | 273 | { set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 274 | |
95ad9755 | 275 | #define CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 276 | static __always_inline void ClearPage##uname(struct page *page) \ |
95ad9755 | 277 | { clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 278 | |
95ad9755 | 279 | #define __SETPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 280 | static __always_inline void __SetPage##uname(struct page *page) \ |
95ad9755 | 281 | { __set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 282 | |
95ad9755 | 283 | #define __CLEARPAGEFLAG(uname, lname, policy) \ |
4b0f3261 | 284 | static __always_inline void __ClearPage##uname(struct page *page) \ |
95ad9755 | 285 | { __clear_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 286 | |
95ad9755 | 287 | #define TESTSETFLAG(uname, lname, policy) \ |
4b0f3261 | 288 | static __always_inline int TestSetPage##uname(struct page *page) \ |
95ad9755 | 289 | { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } |
f94a62e9 | 290 | |
95ad9755 | 291 | #define TESTCLEARFLAG(uname, lname, policy) \ |
4b0f3261 | 292 | static __always_inline int TestClearPage##uname(struct page *page) \ |
95ad9755 | 293 | { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } |
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 __PAGEFLAG(uname, lname, policy) \ |
301 | TESTPAGEFLAG(uname, lname, policy) \ | |
302 | __SETPAGEFLAG(uname, lname, policy) \ | |
303 | __CLEARPAGEFLAG(uname, lname, policy) | |
f94a62e9 | 304 | |
95ad9755 KS |
305 | #define TESTSCFLAG(uname, lname, policy) \ |
306 | TESTSETFLAG(uname, lname, policy) \ | |
307 | TESTCLEARFLAG(uname, lname, policy) | |
f94a62e9 | 308 | |
2f3e442c JW |
309 | #define TESTPAGEFLAG_FALSE(uname) \ |
310 | static inline int Page##uname(const struct page *page) { return 0; } | |
311 | ||
8a7a8544 LS |
312 | #define SETPAGEFLAG_NOOP(uname) \ |
313 | static inline void SetPage##uname(struct page *page) { } | |
314 | ||
315 | #define CLEARPAGEFLAG_NOOP(uname) \ | |
316 | static inline void ClearPage##uname(struct page *page) { } | |
317 | ||
318 | #define __CLEARPAGEFLAG_NOOP(uname) \ | |
319 | static inline void __ClearPage##uname(struct page *page) { } | |
320 | ||
2f3e442c JW |
321 | #define TESTSETFLAG_FALSE(uname) \ |
322 | static inline int TestSetPage##uname(struct page *page) { return 0; } | |
323 | ||
8a7a8544 LS |
324 | #define TESTCLEARFLAG_FALSE(uname) \ |
325 | static inline int TestClearPage##uname(struct page *page) { return 0; } | |
326 | ||
2f3e442c JW |
327 | #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ |
328 | SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) | |
329 | ||
330 | #define TESTSCFLAG_FALSE(uname) \ | |
331 | TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) | |
332 | ||
48c935ad | 333 | __PAGEFLAG(Locked, locked, PF_NO_TAIL) |
62906027 | 334 | PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) |
d72520ad | 335 | PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) |
8cb38fab KS |
336 | PAGEFLAG(Referenced, referenced, PF_HEAD) |
337 | TESTCLEARFLAG(Referenced, referenced, PF_HEAD) | |
338 | __SETPAGEFLAG(Referenced, referenced, PF_HEAD) | |
df8c94d1 KS |
339 | PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) |
340 | __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) | |
8cb38fab | 341 | PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) |
d25b5bd8 | 342 | TESTCLEARFLAG(LRU, lru, PF_HEAD) |
8cb38fab KS |
343 | PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) |
344 | TESTCLEARFLAG(Active, active, PF_HEAD) | |
1899ad18 JW |
345 | PAGEFLAG(Workingset, workingset, PF_HEAD) |
346 | TESTCLEARFLAG(Workingset, workingset, PF_HEAD) | |
dcb351cd KS |
347 | __PAGEFLAG(Slab, slab, PF_NO_TAIL) |
348 | __PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) | |
df8c94d1 | 349 | PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ |
c13985fa KS |
350 | |
351 | /* Xen */ | |
352 | PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
353 | TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) | |
354 | PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); | |
355 | PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); | |
b877ac98 JG |
356 | PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) |
357 | TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) | |
c13985fa | 358 | |
de09d31d KS |
359 | PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
360 | __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) | |
d483da5b | 361 | __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) |
da5efc40 KS |
362 | PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) |
363 | __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
364 | __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) | |
95ad9755 | 365 | |
266cf658 DH |
366 | /* |
367 | * Private page markings that may be used by the filesystem that owns the page | |
368 | * for its own purposes. | |
369 | * - PG_private and PG_private_2 cause releasepage() and co to be invoked | |
370 | */ | |
2ee08717 | 371 | PAGEFLAG(Private, private, PF_ANY) |
95ad9755 KS |
372 | PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) |
373 | PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
374 | TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) | |
266cf658 | 375 | |
6a1e7f77 CL |
376 | /* |
377 | * Only test-and-set exist for PG_writeback. The unconditional operators are | |
378 | * risky: they bypass page accounting. | |
379 | */ | |
225311a4 HY |
380 | TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) |
381 | TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) | |
e2f0a0db | 382 | PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) |
6a1e7f77 | 383 | |
579f8290 | 384 | /* PG_readahead is only used for reads; PG_reclaim is only for writes */ |
e2f0a0db KS |
385 | PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) |
386 | TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) | |
df8c94d1 KS |
387 | PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) |
388 | TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) | |
6a1e7f77 CL |
389 | |
390 | #ifdef CONFIG_HIGHMEM | |
1da177e4 | 391 | /* |
6a1e7f77 CL |
392 | * Must use a macro here due to header dependency issues. page_zone() is not |
393 | * available at this point. | |
1da177e4 | 394 | */ |
3ca65c19 | 395 | #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) |
6a1e7f77 | 396 | #else |
ec7cade8 | 397 | PAGEFLAG_FALSE(HighMem) |
6a1e7f77 CL |
398 | #endif |
399 | ||
400 | #ifdef CONFIG_SWAP | |
6326fec1 NP |
401 | static __always_inline int PageSwapCache(struct page *page) |
402 | { | |
38d8b4e6 HY |
403 | #ifdef CONFIG_THP_SWAP |
404 | page = compound_head(page); | |
405 | #endif | |
6326fec1 NP |
406 | return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); |
407 | ||
408 | } | |
38d8b4e6 HY |
409 | SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) |
410 | CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) | |
6a1e7f77 | 411 | #else |
ec7cade8 | 412 | PAGEFLAG_FALSE(SwapCache) |
6a1e7f77 CL |
413 | #endif |
414 | ||
8cb38fab KS |
415 | PAGEFLAG(Unevictable, unevictable, PF_HEAD) |
416 | __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) | |
417 | TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) | |
b291f000 | 418 | |
af8e3354 | 419 | #ifdef CONFIG_MMU |
e4f87d5d KS |
420 | PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) |
421 | __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
422 | TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) | |
894bc310 | 423 | #else |
2f3e442c | 424 | PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) |
685eaade | 425 | TESTSCFLAG_FALSE(Mlocked) |
894bc310 LS |
426 | #endif |
427 | ||
46cf98cd | 428 | #ifdef CONFIG_ARCH_USES_PG_UNCACHED |
b9d41817 | 429 | PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) |
602c4d11 | 430 | #else |
ec7cade8 | 431 | PAGEFLAG_FALSE(Uncached) |
6a1e7f77 | 432 | #endif |
1da177e4 | 433 | |
d466f2fc | 434 | #ifdef CONFIG_MEMORY_FAILURE |
95ad9755 KS |
435 | PAGEFLAG(HWPoison, hwpoison, PF_ANY) |
436 | TESTSCFLAG(HWPoison, hwpoison, PF_ANY) | |
d466f2fc | 437 | #define __PG_HWPOISON (1UL << PG_hwpoison) |
06be6ff3 | 438 | extern bool take_page_off_buddy(struct page *page); |
d466f2fc AK |
439 | #else |
440 | PAGEFLAG_FALSE(HWPoison) | |
441 | #define __PG_HWPOISON 0 | |
442 | #endif | |
443 | ||
33c3fc71 | 444 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) |
95ad9755 KS |
445 | TESTPAGEFLAG(Young, young, PF_ANY) |
446 | SETPAGEFLAG(Young, young, PF_ANY) | |
447 | TESTCLEARFLAG(Young, young, PF_ANY) | |
448 | PAGEFLAG(Idle, idle, PF_ANY) | |
33c3fc71 VD |
449 | #endif |
450 | ||
c275c5c6 PC |
451 | #ifdef CONFIG_KASAN_HW_TAGS |
452 | PAGEFLAG(SkipKASanPoison, skip_kasan_poison, PF_HEAD) | |
453 | #else | |
454 | PAGEFLAG_FALSE(SkipKASanPoison) | |
455 | #endif | |
456 | ||
36e66c55 AD |
457 | /* |
458 | * PageReported() is used to track reported free pages within the Buddy | |
459 | * allocator. We can use the non-atomic version of the test and set | |
460 | * operations as both should be shielded with the zone lock to prevent | |
461 | * any possible races on the setting or clearing of the bit. | |
462 | */ | |
463 | __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) | |
464 | ||
e8c6158f KS |
465 | /* |
466 | * On an anonymous page mapped into a user virtual memory area, | |
467 | * page->mapping points to its anon_vma, not to a struct address_space; | |
468 | * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. | |
469 | * | |
470 | * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, | |
bda807d4 MK |
471 | * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON |
472 | * bit; and then page->mapping points, not to an anon_vma, but to a private | |
e8c6158f KS |
473 | * structure which KSM associates with that merged page. See ksm.h. |
474 | * | |
bda807d4 MK |
475 | * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable |
476 | * page and then page->mapping points a struct address_space. | |
e8c6158f KS |
477 | * |
478 | * Please note that, confusingly, "page_mapping" refers to the inode | |
479 | * address_space which maps the page from disk; whereas "page_mapped" | |
480 | * refers to user virtual address space into which the page is mapped. | |
481 | */ | |
bda807d4 MK |
482 | #define PAGE_MAPPING_ANON 0x1 |
483 | #define PAGE_MAPPING_MOVABLE 0x2 | |
484 | #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
485 | #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) | |
e8c6158f | 486 | |
bda807d4 | 487 | static __always_inline int PageMappingFlags(struct page *page) |
17514574 | 488 | { |
bda807d4 | 489 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; |
17514574 MG |
490 | } |
491 | ||
4b0f3261 | 492 | static __always_inline int PageAnon(struct page *page) |
e8c6158f | 493 | { |
822cdd11 | 494 | page = compound_head(page); |
bda807d4 MK |
495 | return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; |
496 | } | |
497 | ||
498 | static __always_inline int __PageMovable(struct page *page) | |
499 | { | |
500 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == | |
501 | PAGE_MAPPING_MOVABLE; | |
e8c6158f KS |
502 | } |
503 | ||
504 | #ifdef CONFIG_KSM | |
505 | /* | |
506 | * A KSM page is one of those write-protected "shared pages" or "merged pages" | |
507 | * which KSM maps into multiple mms, wherever identical anonymous page content | |
508 | * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any | |
509 | * anon_vma, but to that page's node of the stable tree. | |
510 | */ | |
4b0f3261 | 511 | static __always_inline int PageKsm(struct page *page) |
e8c6158f | 512 | { |
822cdd11 | 513 | page = compound_head(page); |
e8c6158f | 514 | return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == |
bda807d4 | 515 | PAGE_MAPPING_KSM; |
e8c6158f KS |
516 | } |
517 | #else | |
518 | TESTPAGEFLAG_FALSE(Ksm) | |
519 | #endif | |
520 | ||
1a9b5b7f WF |
521 | u64 stable_page_flags(struct page *page); |
522 | ||
0ed361de NP |
523 | static inline int PageUptodate(struct page *page) |
524 | { | |
d2998c4d KS |
525 | int ret; |
526 | page = compound_head(page); | |
527 | ret = test_bit(PG_uptodate, &(page)->flags); | |
0ed361de NP |
528 | /* |
529 | * Must ensure that the data we read out of the page is loaded | |
530 | * _after_ we've loaded page->flags to check for PageUptodate. | |
531 | * We can skip the barrier if the page is not uptodate, because | |
532 | * we wouldn't be reading anything from it. | |
533 | * | |
534 | * See SetPageUptodate() for the other side of the story. | |
535 | */ | |
536 | if (ret) | |
537 | smp_rmb(); | |
538 | ||
539 | return ret; | |
540 | } | |
541 | ||
4b0f3261 | 542 | static __always_inline void __SetPageUptodate(struct page *page) |
0ed361de | 543 | { |
d2998c4d | 544 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de | 545 | smp_wmb(); |
df8c94d1 | 546 | __set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
547 | } |
548 | ||
4b0f3261 | 549 | static __always_inline void SetPageUptodate(struct page *page) |
2dcea57a | 550 | { |
d2998c4d | 551 | VM_BUG_ON_PAGE(PageTail(page), page); |
0ed361de NP |
552 | /* |
553 | * Memory barrier must be issued before setting the PG_uptodate bit, | |
554 | * so that all previous stores issued in order to bring the page | |
555 | * uptodate are actually visible before PageUptodate becomes true. | |
0ed361de NP |
556 | */ |
557 | smp_wmb(); | |
df8c94d1 | 558 | set_bit(PG_uptodate, &page->flags); |
0ed361de NP |
559 | } |
560 | ||
d2998c4d | 561 | CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) |
1da177e4 | 562 | |
6a1e7f77 | 563 | int test_clear_page_writeback(struct page *page); |
1c8349a1 NJ |
564 | int __test_set_page_writeback(struct page *page, bool keep_write); |
565 | ||
566 | #define test_set_page_writeback(page) \ | |
567 | __test_set_page_writeback(page, false) | |
568 | #define test_set_page_writeback_keepwrite(page) \ | |
569 | __test_set_page_writeback(page, true) | |
1da177e4 | 570 | |
6a1e7f77 CL |
571 | static inline void set_page_writeback(struct page *page) |
572 | { | |
573 | test_set_page_writeback(page); | |
574 | } | |
1da177e4 | 575 | |
1c8349a1 NJ |
576 | static inline void set_page_writeback_keepwrite(struct page *page) |
577 | { | |
578 | test_set_page_writeback_keepwrite(page); | |
579 | } | |
580 | ||
95ad9755 | 581 | __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) |
e20b8cca | 582 | |
4b0f3261 | 583 | static __always_inline void set_compound_head(struct page *page, struct page *head) |
ad4b3fb7 | 584 | { |
1d798ca3 | 585 | WRITE_ONCE(page->compound_head, (unsigned long)head + 1); |
ad4b3fb7 CD |
586 | } |
587 | ||
4b0f3261 | 588 | static __always_inline void clear_compound_head(struct page *page) |
6a1e7f77 | 589 | { |
1d798ca3 | 590 | WRITE_ONCE(page->compound_head, 0); |
6a1e7f77 | 591 | } |
6d777953 | 592 | |
4e6af67e AA |
593 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
594 | static inline void ClearPageCompound(struct page *page) | |
595 | { | |
1d798ca3 KS |
596 | BUG_ON(!PageHead(page)); |
597 | ClearPageHead(page); | |
4e6af67e AA |
598 | } |
599 | #endif | |
600 | ||
d2a1a1f0 | 601 | #define PG_head_mask ((1UL << PG_head)) |
dfa7e20c | 602 | |
e8c6158f KS |
603 | #ifdef CONFIG_HUGETLB_PAGE |
604 | int PageHuge(struct page *page); | |
605 | int PageHeadHuge(struct page *page); | |
606 | #else | |
607 | TESTPAGEFLAG_FALSE(Huge) | |
608 | TESTPAGEFLAG_FALSE(HeadHuge) | |
609 | #endif | |
610 | ||
7e1f049e | 611 | |
936a5fe6 | 612 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
71e3aac0 AA |
613 | /* |
614 | * PageHuge() only returns true for hugetlbfs pages, but not for | |
615 | * normal or transparent huge pages. | |
616 | * | |
617 | * PageTransHuge() returns true for both transparent huge and | |
618 | * hugetlbfs pages, but not normal pages. PageTransHuge() can only be | |
619 | * called only in the core VM paths where hugetlbfs pages can't exist. | |
620 | */ | |
621 | static inline int PageTransHuge(struct page *page) | |
622 | { | |
309381fe | 623 | VM_BUG_ON_PAGE(PageTail(page), page); |
71e3aac0 AA |
624 | return PageHead(page); |
625 | } | |
626 | ||
385de357 DN |
627 | /* |
628 | * PageTransCompound returns true for both transparent huge pages | |
629 | * and hugetlbfs pages, so it should only be called when it's known | |
630 | * that hugetlbfs pages aren't involved. | |
631 | */ | |
936a5fe6 AA |
632 | static inline int PageTransCompound(struct page *page) |
633 | { | |
634 | return PageCompound(page); | |
635 | } | |
71e3aac0 | 636 | |
127393fb AA |
637 | /* |
638 | * PageTransCompoundMap is the same as PageTransCompound, but it also | |
639 | * guarantees the primary MMU has the entire compound page mapped | |
640 | * through pmd_trans_huge, which in turn guarantees the secondary MMUs | |
641 | * can also map the entire compound page. This allows the secondary | |
642 | * MMUs to call get_user_pages() only once for each compound page and | |
643 | * to immediately map the entire compound page with a single secondary | |
644 | * MMU fault. If there will be a pmd split later, the secondary MMUs | |
645 | * will get an update through the MMU notifier invalidation through | |
646 | * split_huge_pmd(). | |
647 | * | |
648 | * Unlike PageTransCompound, this is safe to be called only while | |
649 | * split_huge_pmd() cannot run from under us, like if protected by the | |
169226f7 | 650 | * MMU notifier, otherwise it may result in page->_mapcount check false |
127393fb | 651 | * positives. |
169226f7 YS |
652 | * |
653 | * We have to treat page cache THP differently since every subpage of it | |
654 | * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE | |
655 | * mapped in the current process so comparing subpage's _mapcount to | |
656 | * compound_mapcount to filter out PTE mapped case. | |
127393fb AA |
657 | */ |
658 | static inline int PageTransCompoundMap(struct page *page) | |
659 | { | |
169226f7 YS |
660 | struct page *head; |
661 | ||
662 | if (!PageTransCompound(page)) | |
663 | return 0; | |
664 | ||
665 | if (PageAnon(page)) | |
666 | return atomic_read(&page->_mapcount) < 0; | |
667 | ||
668 | head = compound_head(page); | |
669 | /* File THP is PMD mapped and not PTE mapped */ | |
670 | return atomic_read(&page->_mapcount) == | |
671 | atomic_read(compound_mapcount_ptr(head)); | |
127393fb AA |
672 | } |
673 | ||
385de357 DN |
674 | /* |
675 | * PageTransTail returns true for both transparent huge pages | |
676 | * and hugetlbfs pages, so it should only be called when it's known | |
677 | * that hugetlbfs pages aren't involved. | |
678 | */ | |
679 | static inline int PageTransTail(struct page *page) | |
680 | { | |
681 | return PageTail(page); | |
682 | } | |
683 | ||
53f9263b KS |
684 | /* |
685 | * PageDoubleMap indicates that the compound page is mapped with PTEs as well | |
686 | * as PMDs. | |
687 | * | |
688 | * This is required for optimization of rmap operations for THP: we can postpone | |
689 | * per small page mapcount accounting (and its overhead from atomic operations) | |
690 | * until the first PMD split. | |
691 | * | |
692 | * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up | |
693 | * by one. This reference will go away with last compound_mapcount. | |
694 | * | |
695 | * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). | |
696 | */ | |
a08d93e5 MWO |
697 | PAGEFLAG(DoubleMap, double_map, PF_SECOND) |
698 | TESTSCFLAG(DoubleMap, double_map, PF_SECOND) | |
936a5fe6 | 699 | #else |
d8c1bdeb KS |
700 | TESTPAGEFLAG_FALSE(TransHuge) |
701 | TESTPAGEFLAG_FALSE(TransCompound) | |
127393fb | 702 | TESTPAGEFLAG_FALSE(TransCompoundMap) |
d8c1bdeb | 703 | TESTPAGEFLAG_FALSE(TransTail) |
9a73f61b | 704 | PAGEFLAG_FALSE(DoubleMap) |
a08d93e5 | 705 | TESTSCFLAG_FALSE(DoubleMap) |
936a5fe6 AA |
706 | #endif |
707 | ||
0daa322b DH |
708 | /* |
709 | * Check if a page is currently marked HWPoisoned. Note that this check is | |
710 | * best effort only and inherently racy: there is no way to synchronize with | |
711 | * failing hardware. | |
712 | */ | |
713 | static inline bool is_page_hwpoison(struct page *page) | |
714 | { | |
715 | if (PageHWPoison(page)) | |
716 | return true; | |
717 | return PageHuge(page) && PageHWPoison(compound_head(page)); | |
718 | } | |
719 | ||
e8c6158f | 720 | /* |
6e292b9b MW |
721 | * For pages that are never mapped to userspace (and aren't PageSlab), |
722 | * page_type may be used. Because it is initialised to -1, we invert the | |
723 | * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and | |
724 | * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and | |
725 | * low bits so that an underflow or overflow of page_mapcount() won't be | |
726 | * mistaken for a page type value. | |
e8c6158f | 727 | */ |
6e292b9b MW |
728 | |
729 | #define PAGE_TYPE_BASE 0xf0000000 | |
730 | /* Reserve 0x0000007f to catch underflows of page_mapcount */ | |
144552ff | 731 | #define PAGE_MAPCOUNT_RESERVE -128 |
6e292b9b | 732 | #define PG_buddy 0x00000080 |
ca215086 | 733 | #define PG_offline 0x00000100 |
18b2db3b RG |
734 | #define PG_table 0x00000200 |
735 | #define PG_guard 0x00000400 | |
6e292b9b MW |
736 | |
737 | #define PageType(page, flag) \ | |
738 | ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) | |
739 | ||
144552ff AY |
740 | static inline int page_has_type(struct page *page) |
741 | { | |
742 | return (int)page->page_type < PAGE_MAPCOUNT_RESERVE; | |
743 | } | |
744 | ||
6e292b9b | 745 | #define PAGE_TYPE_OPS(uname, lname) \ |
632c0a1a VD |
746 | static __always_inline int Page##uname(struct page *page) \ |
747 | { \ | |
6e292b9b | 748 | return PageType(page, PG_##lname); \ |
632c0a1a VD |
749 | } \ |
750 | static __always_inline void __SetPage##uname(struct page *page) \ | |
751 | { \ | |
6e292b9b MW |
752 | VM_BUG_ON_PAGE(!PageType(page, 0), page); \ |
753 | page->page_type &= ~PG_##lname; \ | |
632c0a1a VD |
754 | } \ |
755 | static __always_inline void __ClearPage##uname(struct page *page) \ | |
756 | { \ | |
757 | VM_BUG_ON_PAGE(!Page##uname(page), page); \ | |
6e292b9b | 758 | page->page_type |= PG_##lname; \ |
e8c6158f KS |
759 | } |
760 | ||
632c0a1a | 761 | /* |
6e292b9b | 762 | * PageBuddy() indicates that the page is free and in the buddy system |
632c0a1a VD |
763 | * (see mm/page_alloc.c). |
764 | */ | |
6e292b9b | 765 | PAGE_TYPE_OPS(Buddy, buddy) |
e8c6158f | 766 | |
632c0a1a | 767 | /* |
ca215086 DH |
768 | * PageOffline() indicates that the page is logically offline although the |
769 | * containing section is online. (e.g. inflated in a balloon driver or | |
770 | * not onlined when onlining the section). | |
771 | * The content of these pages is effectively stale. Such pages should not | |
772 | * be touched (read/write/dump/save) except by their owner. | |
aa218795 DH |
773 | * |
774 | * If a driver wants to allow to offline unmovable PageOffline() pages without | |
775 | * putting them back to the buddy, it can do so via the memory notifier by | |
776 | * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the | |
777 | * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() | |
778 | * pages (now with a reference count of zero) are treated like free pages, | |
779 | * allowing the containing memory block to get offlined. A driver that | |
780 | * relies on this feature is aware that re-onlining the memory block will | |
781 | * require to re-set the pages PageOffline() and not giving them to the | |
782 | * buddy via online_page_callback_t. | |
82840451 DH |
783 | * |
784 | * There are drivers that mark a page PageOffline() and expect there won't be | |
785 | * any further access to page content. PFN walkers that read content of random | |
786 | * pages should check PageOffline() and synchronize with such drivers using | |
787 | * page_offline_freeze()/page_offline_thaw(). | |
632c0a1a | 788 | */ |
ca215086 | 789 | PAGE_TYPE_OPS(Offline, offline) |
e8c6158f | 790 | |
82840451 DH |
791 | extern void page_offline_freeze(void); |
792 | extern void page_offline_thaw(void); | |
793 | extern void page_offline_begin(void); | |
794 | extern void page_offline_end(void); | |
795 | ||
1d40a5ea MW |
796 | /* |
797 | * Marks pages in use as page tables. | |
798 | */ | |
799 | PAGE_TYPE_OPS(Table, table) | |
800 | ||
3972f6bb VB |
801 | /* |
802 | * Marks guardpages used with debug_pagealloc. | |
803 | */ | |
804 | PAGE_TYPE_OPS(Guard, guard) | |
805 | ||
832fc1de NH |
806 | extern bool is_free_buddy_page(struct page *page); |
807 | ||
bda807d4 MK |
808 | __PAGEFLAG(Isolated, isolated, PF_ANY); |
809 | ||
072bb0aa MG |
810 | /* |
811 | * If network-based swap is enabled, sl*b must keep track of whether pages | |
812 | * were allocated from pfmemalloc reserves. | |
813 | */ | |
814 | static inline int PageSlabPfmemalloc(struct page *page) | |
815 | { | |
309381fe | 816 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
817 | return PageActive(page); |
818 | } | |
819 | ||
820 | static inline void SetPageSlabPfmemalloc(struct page *page) | |
821 | { | |
309381fe | 822 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
823 | SetPageActive(page); |
824 | } | |
825 | ||
826 | static inline void __ClearPageSlabPfmemalloc(struct page *page) | |
827 | { | |
309381fe | 828 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
829 | __ClearPageActive(page); |
830 | } | |
831 | ||
832 | static inline void ClearPageSlabPfmemalloc(struct page *page) | |
833 | { | |
309381fe | 834 | VM_BUG_ON_PAGE(!PageSlab(page), page); |
072bb0aa MG |
835 | ClearPageActive(page); |
836 | } | |
837 | ||
af8e3354 | 838 | #ifdef CONFIG_MMU |
d2a1a1f0 | 839 | #define __PG_MLOCKED (1UL << PG_mlocked) |
33925b25 | 840 | #else |
b291f000 | 841 | #define __PG_MLOCKED 0 |
894bc310 LS |
842 | #endif |
843 | ||
dfa7e20c RA |
844 | /* |
845 | * Flags checked when a page is freed. Pages being freed should not have | |
4be408ce | 846 | * these flags set. If they are, there is a problem. |
dfa7e20c | 847 | */ |
6326fec1 NP |
848 | #define PAGE_FLAGS_CHECK_AT_FREE \ |
849 | (1UL << PG_lru | 1UL << PG_locked | \ | |
850 | 1UL << PG_private | 1UL << PG_private_2 | \ | |
851 | 1UL << PG_writeback | 1UL << PG_reserved | \ | |
852 | 1UL << PG_slab | 1UL << PG_active | \ | |
853 | 1UL << PG_unevictable | __PG_MLOCKED) | |
dfa7e20c RA |
854 | |
855 | /* | |
856 | * Flags checked when a page is prepped for return by the page allocator. | |
4be408ce | 857 | * Pages being prepped should not have these flags set. If they are set, |
79f4b7bf | 858 | * there has been a kernel bug or struct page corruption. |
f4c18e6f NH |
859 | * |
860 | * __PG_HWPOISON is exceptional because it needs to be kept beyond page's | |
861 | * alloc-free cycle to prevent from reusing the page. | |
dfa7e20c | 862 | */ |
f4c18e6f | 863 | #define PAGE_FLAGS_CHECK_AT_PREP \ |
41c961b9 | 864 | (PAGEFLAGS_MASK & ~__PG_HWPOISON) |
dfa7e20c | 865 | |
edcf4748 | 866 | #define PAGE_FLAGS_PRIVATE \ |
d2a1a1f0 | 867 | (1UL << PG_private | 1UL << PG_private_2) |
266cf658 DH |
868 | /** |
869 | * page_has_private - Determine if page has private stuff | |
870 | * @page: The page to be checked | |
871 | * | |
872 | * Determine if a page has private stuff, indicating that release routines | |
873 | * should be invoked upon it. | |
874 | */ | |
edcf4748 JW |
875 | static inline int page_has_private(struct page *page) |
876 | { | |
877 | return !!(page->flags & PAGE_FLAGS_PRIVATE); | |
878 | } | |
879 | ||
95ad9755 KS |
880 | #undef PF_ANY |
881 | #undef PF_HEAD | |
62906027 | 882 | #undef PF_ONLY_HEAD |
95ad9755 KS |
883 | #undef PF_NO_TAIL |
884 | #undef PF_NO_COMPOUND | |
a08d93e5 | 885 | #undef PF_SECOND |
edcf4748 | 886 | #endif /* !__GENERATING_BOUNDS_H */ |
266cf658 | 887 | |
1da177e4 | 888 | #endif /* PAGE_FLAGS_H */ |