page-flags: define PG_uncached behavior on compound pages
[deliverable/linux.git] / include / linux / page-flags.h
... / ...
CommitLineData
1/*
2 * Macros for manipulating and testing page->flags
3 */
4
5#ifndef PAGE_FLAGS_H
6#define PAGE_FLAGS_H
7
8#include <linux/types.h>
9#include <linux/bug.h>
10#include <linux/mmdebug.h>
11#ifndef __GENERATING_BOUNDS_H
12#include <linux/mm_types.h>
13#include <generated/bounds.h>
14#endif /* !__GENERATING_BOUNDS_H */
15
16/*
17 * Various page->flags bits:
18 *
19 * PG_reserved is set for special pages, which can never be swapped out. Some
20 * of them might not even exist (eg empty_bad_page)...
21 *
22 * The PG_private bitflag is set on pagecache pages if they contain filesystem
23 * specific data (which is normally at page->private). It can be used by
24 * private allocations for its own usage.
25 *
26 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O
27 * and cleared when writeback _starts_ or when read _completes_. PG_writeback
28 * is set before writeback starts and cleared when it finishes.
29 *
30 * PG_locked also pins a page in pagecache, and blocks truncation of the file
31 * while it is held.
32 *
33 * page_waitqueue(page) is a wait queue of all tasks waiting for the page
34 * to become unlocked.
35 *
36 * PG_uptodate tells whether the page's contents is valid. When a read
37 * completes, the page becomes uptodate, unless a disk I/O error happened.
38 *
39 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
40 * file-backed pagecache (see mm/vmscan.c).
41 *
42 * PG_error is set to indicate that an I/O error occurred on this page.
43 *
44 * PG_arch_1 is an architecture specific page state bit. The generic code
45 * guarantees that this bit is cleared for a page when it first is entered into
46 * the page cache.
47 *
48 * PG_highmem pages are not permanently mapped into the kernel virtual address
49 * space, they need to be kmapped separately for doing IO on the pages. The
50 * struct page (these bits with information) are always mapped into kernel
51 * address space...
52 *
53 * PG_hwpoison indicates that a page got corrupted in hardware and contains
54 * data with incorrect ECC bits that triggered a machine check. Accessing is
55 * not safe since it may cause another machine check. Don't touch!
56 */
57
58/*
59 * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
60 * locked- and dirty-page accounting.
61 *
62 * The page flags field is split into two parts, the main flags area
63 * which extends from the low bits upwards, and the fields area which
64 * extends from the high bits downwards.
65 *
66 * | FIELD | ... | FLAGS |
67 * N-1 ^ 0
68 * (NR_PAGEFLAGS)
69 *
70 * The fields area is reserved for fields mapping zone, node (for NUMA) and
71 * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
72 * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
73 */
74enum pageflags {
75 PG_locked, /* Page is locked. Don't touch. */
76 PG_error,
77 PG_referenced,
78 PG_uptodate,
79 PG_dirty,
80 PG_lru,
81 PG_active,
82 PG_slab,
83 PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
84 PG_arch_1,
85 PG_reserved,
86 PG_private, /* If pagecache, has fs-private data */
87 PG_private_2, /* If pagecache, has fs aux data */
88 PG_writeback, /* Page is under writeback */
89 PG_head, /* A head page */
90 PG_swapcache, /* Swap page: swp_entry_t in private */
91 PG_mappedtodisk, /* Has blocks allocated on-disk */
92 PG_reclaim, /* To be reclaimed asap */
93 PG_swapbacked, /* Page is backed by RAM/swap */
94 PG_unevictable, /* Page is "unevictable" */
95#ifdef CONFIG_MMU
96 PG_mlocked, /* Page is vma mlocked */
97#endif
98#ifdef CONFIG_ARCH_USES_PG_UNCACHED
99 PG_uncached, /* Page has been mapped as uncached */
100#endif
101#ifdef CONFIG_MEMORY_FAILURE
102 PG_hwpoison, /* hardware poisoned page. Don't touch */
103#endif
104#ifdef CONFIG_TRANSPARENT_HUGEPAGE
105 PG_compound_lock,
106#endif
107#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
108 PG_young,
109 PG_idle,
110#endif
111 __NR_PAGEFLAGS,
112
113 /* Filesystems */
114 PG_checked = PG_owner_priv_1,
115
116 /* Two page bits are conscripted by FS-Cache to maintain local caching
117 * state. These bits are set on pages belonging to the netfs's inodes
118 * when those inodes are being locally cached.
119 */
120 PG_fscache = PG_private_2, /* page backed by cache */
121
122 /* XEN */
123 /* Pinned in Xen as a read-only pagetable page. */
124 PG_pinned = PG_owner_priv_1,
125 /* Pinned as part of domain save (see xen_mm_pin_all()). */
126 PG_savepinned = PG_dirty,
127 /* Has a grant mapping of another (foreign) domain's page. */
128 PG_foreign = PG_owner_priv_1,
129
130 /* SLOB */
131 PG_slob_free = PG_private,
132};
133
134#ifndef __GENERATING_BOUNDS_H
135
136struct page; /* forward declaration */
137
138static inline struct page *compound_head(struct page *page)
139{
140 unsigned long head = READ_ONCE(page->compound_head);
141
142 if (unlikely(head & 1))
143 return (struct page *) (head - 1);
144 return page;
145}
146
147static inline int PageTail(struct page *page)
148{
149 return READ_ONCE(page->compound_head) & 1;
150}
151
152static inline int PageCompound(struct page *page)
153{
154 return test_bit(PG_head, &page->flags) || PageTail(page);
155}
156
157/*
158 * Page flags policies wrt compound pages
159 *
160 * PF_ANY:
161 * the page flag is relevant for small, head and tail pages.
162 *
163 * PF_HEAD:
164 * for compound page all operations related to the page flag applied to
165 * head page.
166 *
167 * PF_NO_TAIL:
168 * modifications of the page flag must be done on small or head pages,
169 * checks can be done on tail pages too.
170 *
171 * PF_NO_COMPOUND:
172 * the page flag is not relevant for compound pages.
173 */
174#define PF_ANY(page, enforce) page
175#define PF_HEAD(page, enforce) compound_head(page)
176#define PF_NO_TAIL(page, enforce) ({ \
177 VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \
178 compound_head(page);})
179#define PF_NO_COMPOUND(page, enforce) ({ \
180 VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \
181 page;})
182
183/*
184 * Macros to create function definitions for page flags
185 */
186#define TESTPAGEFLAG(uname, lname, policy) \
187static inline int Page##uname(struct page *page) \
188 { return test_bit(PG_##lname, &policy(page, 0)->flags); }
189
190#define SETPAGEFLAG(uname, lname, policy) \
191static inline void SetPage##uname(struct page *page) \
192 { set_bit(PG_##lname, &policy(page, 1)->flags); }
193
194#define CLEARPAGEFLAG(uname, lname, policy) \
195static inline void ClearPage##uname(struct page *page) \
196 { clear_bit(PG_##lname, &policy(page, 1)->flags); }
197
198#define __SETPAGEFLAG(uname, lname, policy) \
199static inline void __SetPage##uname(struct page *page) \
200 { __set_bit(PG_##lname, &policy(page, 1)->flags); }
201
202#define __CLEARPAGEFLAG(uname, lname, policy) \
203static inline void __ClearPage##uname(struct page *page) \
204 { __clear_bit(PG_##lname, &policy(page, 1)->flags); }
205
206#define TESTSETFLAG(uname, lname, policy) \
207static inline int TestSetPage##uname(struct page *page) \
208 { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
209
210#define TESTCLEARFLAG(uname, lname, policy) \
211static inline int TestClearPage##uname(struct page *page) \
212 { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
213
214#define __TESTCLEARFLAG(uname, lname, policy) \
215static inline int __TestClearPage##uname(struct page *page) \
216 { return __test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
217
218#define PAGEFLAG(uname, lname, policy) \
219 TESTPAGEFLAG(uname, lname, policy) \
220 SETPAGEFLAG(uname, lname, policy) \
221 CLEARPAGEFLAG(uname, lname, policy)
222
223#define __PAGEFLAG(uname, lname, policy) \
224 TESTPAGEFLAG(uname, lname, policy) \
225 __SETPAGEFLAG(uname, lname, policy) \
226 __CLEARPAGEFLAG(uname, lname, policy)
227
228#define TESTSCFLAG(uname, lname, policy) \
229 TESTSETFLAG(uname, lname, policy) \
230 TESTCLEARFLAG(uname, lname, policy)
231
232#define TESTPAGEFLAG_FALSE(uname) \
233static inline int Page##uname(const struct page *page) { return 0; }
234
235#define SETPAGEFLAG_NOOP(uname) \
236static inline void SetPage##uname(struct page *page) { }
237
238#define CLEARPAGEFLAG_NOOP(uname) \
239static inline void ClearPage##uname(struct page *page) { }
240
241#define __CLEARPAGEFLAG_NOOP(uname) \
242static inline void __ClearPage##uname(struct page *page) { }
243
244#define TESTSETFLAG_FALSE(uname) \
245static inline int TestSetPage##uname(struct page *page) { return 0; }
246
247#define TESTCLEARFLAG_FALSE(uname) \
248static inline int TestClearPage##uname(struct page *page) { return 0; }
249
250#define __TESTCLEARFLAG_FALSE(uname) \
251static inline int __TestClearPage##uname(struct page *page) { return 0; }
252
253#define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \
254 SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname)
255
256#define TESTSCFLAG_FALSE(uname) \
257 TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname)
258
259__PAGEFLAG(Locked, locked, PF_NO_TAIL)
260PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
261PAGEFLAG(Referenced, referenced, PF_HEAD)
262 TESTCLEARFLAG(Referenced, referenced, PF_HEAD)
263 __SETPAGEFLAG(Referenced, referenced, PF_HEAD)
264PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD)
265 __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD)
266PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD)
267PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD)
268 TESTCLEARFLAG(Active, active, PF_HEAD)
269__PAGEFLAG(Slab, slab, PF_NO_TAIL)
270__PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL)
271PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */
272
273/* Xen */
274PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND)
275 TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND)
276PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND);
277PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND);
278
279PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
280 __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
281PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
282 __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
283 __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
284
285/*
286 * Private page markings that may be used by the filesystem that owns the page
287 * for its own purposes.
288 * - PG_private and PG_private_2 cause releasepage() and co to be invoked
289 */
290PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY)
291 __CLEARPAGEFLAG(Private, private, PF_ANY)
292PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY)
293PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
294 TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
295
296/*
297 * Only test-and-set exist for PG_writeback. The unconditional operators are
298 * risky: they bypass page accounting.
299 */
300TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND)
301 TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND)
302PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_COMPOUND)
303
304/* PG_readahead is only used for reads; PG_reclaim is only for writes */
305PAGEFLAG(Reclaim, reclaim, PF_NO_COMPOUND)
306 TESTCLEARFLAG(Reclaim, reclaim, PF_NO_COMPOUND)
307PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND)
308 TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND)
309
310#ifdef CONFIG_HIGHMEM
311/*
312 * Must use a macro here due to header dependency issues. page_zone() is not
313 * available at this point.
314 */
315#define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))
316#else
317PAGEFLAG_FALSE(HighMem)
318#endif
319
320#ifdef CONFIG_SWAP
321PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND)
322#else
323PAGEFLAG_FALSE(SwapCache)
324#endif
325
326PAGEFLAG(Unevictable, unevictable, PF_HEAD)
327 __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD)
328 TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD)
329
330#ifdef CONFIG_MMU
331PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
332 __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
333 TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL)
334 __TESTCLEARFLAG(Mlocked, mlocked, PF_NO_TAIL)
335#else
336PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked)
337 TESTSCFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked)
338#endif
339
340#ifdef CONFIG_ARCH_USES_PG_UNCACHED
341PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND)
342#else
343PAGEFLAG_FALSE(Uncached)
344#endif
345
346#ifdef CONFIG_MEMORY_FAILURE
347PAGEFLAG(HWPoison, hwpoison, PF_ANY)
348TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
349#define __PG_HWPOISON (1UL << PG_hwpoison)
350#else
351PAGEFLAG_FALSE(HWPoison)
352#define __PG_HWPOISON 0
353#endif
354
355#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT)
356TESTPAGEFLAG(Young, young, PF_ANY)
357SETPAGEFLAG(Young, young, PF_ANY)
358TESTCLEARFLAG(Young, young, PF_ANY)
359PAGEFLAG(Idle, idle, PF_ANY)
360#endif
361
362/*
363 * On an anonymous page mapped into a user virtual memory area,
364 * page->mapping points to its anon_vma, not to a struct address_space;
365 * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h.
366 *
367 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
368 * the PAGE_MAPPING_KSM bit may be set along with the PAGE_MAPPING_ANON bit;
369 * and then page->mapping points, not to an anon_vma, but to a private
370 * structure which KSM associates with that merged page. See ksm.h.
371 *
372 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is currently never used.
373 *
374 * Please note that, confusingly, "page_mapping" refers to the inode
375 * address_space which maps the page from disk; whereas "page_mapped"
376 * refers to user virtual address space into which the page is mapped.
377 */
378#define PAGE_MAPPING_ANON 1
379#define PAGE_MAPPING_KSM 2
380#define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM)
381
382static inline int PageAnon(struct page *page)
383{
384 return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
385}
386
387#ifdef CONFIG_KSM
388/*
389 * A KSM page is one of those write-protected "shared pages" or "merged pages"
390 * which KSM maps into multiple mms, wherever identical anonymous page content
391 * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any
392 * anon_vma, but to that page's node of the stable tree.
393 */
394static inline int PageKsm(struct page *page)
395{
396 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
397 (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM);
398}
399#else
400TESTPAGEFLAG_FALSE(Ksm)
401#endif
402
403u64 stable_page_flags(struct page *page);
404
405static inline int PageUptodate(struct page *page)
406{
407 int ret = test_bit(PG_uptodate, &(page)->flags);
408
409 /*
410 * Must ensure that the data we read out of the page is loaded
411 * _after_ we've loaded page->flags to check for PageUptodate.
412 * We can skip the barrier if the page is not uptodate, because
413 * we wouldn't be reading anything from it.
414 *
415 * See SetPageUptodate() for the other side of the story.
416 */
417 if (ret)
418 smp_rmb();
419
420 return ret;
421}
422
423static inline void __SetPageUptodate(struct page *page)
424{
425 smp_wmb();
426 __set_bit(PG_uptodate, &page->flags);
427}
428
429static inline void SetPageUptodate(struct page *page)
430{
431 /*
432 * Memory barrier must be issued before setting the PG_uptodate bit,
433 * so that all previous stores issued in order to bring the page
434 * uptodate are actually visible before PageUptodate becomes true.
435 */
436 smp_wmb();
437 set_bit(PG_uptodate, &page->flags);
438}
439
440CLEARPAGEFLAG(Uptodate, uptodate, PF_ANY)
441
442int test_clear_page_writeback(struct page *page);
443int __test_set_page_writeback(struct page *page, bool keep_write);
444
445#define test_set_page_writeback(page) \
446 __test_set_page_writeback(page, false)
447#define test_set_page_writeback_keepwrite(page) \
448 __test_set_page_writeback(page, true)
449
450static inline void set_page_writeback(struct page *page)
451{
452 test_set_page_writeback(page);
453}
454
455static inline void set_page_writeback_keepwrite(struct page *page)
456{
457 test_set_page_writeback_keepwrite(page);
458}
459
460__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY)
461
462static inline void set_compound_head(struct page *page, struct page *head)
463{
464 WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
465}
466
467static inline void clear_compound_head(struct page *page)
468{
469 WRITE_ONCE(page->compound_head, 0);
470}
471
472#ifdef CONFIG_TRANSPARENT_HUGEPAGE
473static inline void ClearPageCompound(struct page *page)
474{
475 BUG_ON(!PageHead(page));
476 ClearPageHead(page);
477}
478#endif
479
480#define PG_head_mask ((1L << PG_head))
481
482#ifdef CONFIG_HUGETLB_PAGE
483int PageHuge(struct page *page);
484int PageHeadHuge(struct page *page);
485bool page_huge_active(struct page *page);
486#else
487TESTPAGEFLAG_FALSE(Huge)
488TESTPAGEFLAG_FALSE(HeadHuge)
489
490static inline bool page_huge_active(struct page *page)
491{
492 return 0;
493}
494#endif
495
496
497#ifdef CONFIG_TRANSPARENT_HUGEPAGE
498/*
499 * PageHuge() only returns true for hugetlbfs pages, but not for
500 * normal or transparent huge pages.
501 *
502 * PageTransHuge() returns true for both transparent huge and
503 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be
504 * called only in the core VM paths where hugetlbfs pages can't exist.
505 */
506static inline int PageTransHuge(struct page *page)
507{
508 VM_BUG_ON_PAGE(PageTail(page), page);
509 return PageHead(page);
510}
511
512/*
513 * PageTransCompound returns true for both transparent huge pages
514 * and hugetlbfs pages, so it should only be called when it's known
515 * that hugetlbfs pages aren't involved.
516 */
517static inline int PageTransCompound(struct page *page)
518{
519 return PageCompound(page);
520}
521
522/*
523 * PageTransTail returns true for both transparent huge pages
524 * and hugetlbfs pages, so it should only be called when it's known
525 * that hugetlbfs pages aren't involved.
526 */
527static inline int PageTransTail(struct page *page)
528{
529 return PageTail(page);
530}
531
532#else
533TESTPAGEFLAG_FALSE(TransHuge)
534TESTPAGEFLAG_FALSE(TransCompound)
535TESTPAGEFLAG_FALSE(TransTail)
536#endif
537
538/*
539 * PageBuddy() indicate that the page is free and in the buddy system
540 * (see mm/page_alloc.c).
541 *
542 * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
543 * -2 so that an underflow of the page_mapcount() won't be mistaken
544 * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
545 * efficiently by most CPU architectures.
546 */
547#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
548
549static inline int PageBuddy(struct page *page)
550{
551 return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
552}
553
554static inline void __SetPageBuddy(struct page *page)
555{
556 VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
557 atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
558}
559
560static inline void __ClearPageBuddy(struct page *page)
561{
562 VM_BUG_ON_PAGE(!PageBuddy(page), page);
563 atomic_set(&page->_mapcount, -1);
564}
565
566#define PAGE_BALLOON_MAPCOUNT_VALUE (-256)
567
568static inline int PageBalloon(struct page *page)
569{
570 return atomic_read(&page->_mapcount) == PAGE_BALLOON_MAPCOUNT_VALUE;
571}
572
573static inline void __SetPageBalloon(struct page *page)
574{
575 VM_BUG_ON_PAGE(atomic_read(&page->_mapcount) != -1, page);
576 atomic_set(&page->_mapcount, PAGE_BALLOON_MAPCOUNT_VALUE);
577}
578
579static inline void __ClearPageBalloon(struct page *page)
580{
581 VM_BUG_ON_PAGE(!PageBalloon(page), page);
582 atomic_set(&page->_mapcount, -1);
583}
584
585/*
586 * If network-based swap is enabled, sl*b must keep track of whether pages
587 * were allocated from pfmemalloc reserves.
588 */
589static inline int PageSlabPfmemalloc(struct page *page)
590{
591 VM_BUG_ON_PAGE(!PageSlab(page), page);
592 return PageActive(page);
593}
594
595static inline void SetPageSlabPfmemalloc(struct page *page)
596{
597 VM_BUG_ON_PAGE(!PageSlab(page), page);
598 SetPageActive(page);
599}
600
601static inline void __ClearPageSlabPfmemalloc(struct page *page)
602{
603 VM_BUG_ON_PAGE(!PageSlab(page), page);
604 __ClearPageActive(page);
605}
606
607static inline void ClearPageSlabPfmemalloc(struct page *page)
608{
609 VM_BUG_ON_PAGE(!PageSlab(page), page);
610 ClearPageActive(page);
611}
612
613#ifdef CONFIG_MMU
614#define __PG_MLOCKED (1 << PG_mlocked)
615#else
616#define __PG_MLOCKED 0
617#endif
618
619#ifdef CONFIG_TRANSPARENT_HUGEPAGE
620#define __PG_COMPOUND_LOCK (1 << PG_compound_lock)
621#else
622#define __PG_COMPOUND_LOCK 0
623#endif
624
625/*
626 * Flags checked when a page is freed. Pages being freed should not have
627 * these flags set. It they are, there is a problem.
628 */
629#define PAGE_FLAGS_CHECK_AT_FREE \
630 (1 << PG_lru | 1 << PG_locked | \
631 1 << PG_private | 1 << PG_private_2 | \
632 1 << PG_writeback | 1 << PG_reserved | \
633 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \
634 1 << PG_unevictable | __PG_MLOCKED | \
635 __PG_COMPOUND_LOCK)
636
637/*
638 * Flags checked when a page is prepped for return by the page allocator.
639 * Pages being prepped should not have these flags set. It they are set,
640 * there has been a kernel bug or struct page corruption.
641 *
642 * __PG_HWPOISON is exceptional because it needs to be kept beyond page's
643 * alloc-free cycle to prevent from reusing the page.
644 */
645#define PAGE_FLAGS_CHECK_AT_PREP \
646 (((1 << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON)
647
648#define PAGE_FLAGS_PRIVATE \
649 (1 << PG_private | 1 << PG_private_2)
650/**
651 * page_has_private - Determine if page has private stuff
652 * @page: The page to be checked
653 *
654 * Determine if a page has private stuff, indicating that release routines
655 * should be invoked upon it.
656 */
657static inline int page_has_private(struct page *page)
658{
659 return !!(page->flags & PAGE_FLAGS_PRIVATE);
660}
661
662#undef PF_ANY
663#undef PF_HEAD
664#undef PF_NO_TAIL
665#undef PF_NO_COMPOUND
666#endif /* !__GENERATING_BOUNDS_H */
667
668#endif /* PAGE_FLAGS_H */
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