1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Macros for manipulating and testing page->flags
4 */
5
6 #ifndef PAGE_FLAGS_H
7 #define PAGE_FLAGS_H
8
9 #include <linux/types.h>
10 #include <linux/bug.h>
11 #include <linux/mmdebug.h>
12 #ifndef __GENERATING_BOUNDS_H
13 #include <linux/mm_types.h>
14 #include <generated/bounds.h>
15 #endif /* !__GENERATING_BOUNDS_H */
16
17 /*
18 * Various page->flags bits:
19 *
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.
51 *
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.
55 *
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.
65 *
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 *
71 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
72 * file-backed pagecache (see mm/vmscan.c).
73 *
74 * PG_error is set to indicate that an I/O error occurred on this page.
75 *
76 * PG_arch_1 is an architecture specific page state bit. The generic code
77 * guarantees that this bit is cleared for a page when it first is entered into
78 * the page cache.
79 *
80 * PG_hwpoison indicates that a page got corrupted in hardware and contains
81 * data with incorrect ECC bits that triggered a machine check. Accessing is
82 * not safe since it may cause another machine check. Don't touch!
83 */
84
85 /*
86 * Don't use the pageflags directly. Use the PageFoo macros.
87 *
88 * The page flags field is split into two parts, the main flags area
89 * which extends from the low bits upwards, and the fields area which
90 * extends from the high bits downwards.
91 *
92 * | FIELD | ... | FLAGS |
93 * N-1 ^ 0
94 * (NR_PAGEFLAGS)
95 *
96 * The fields area is reserved for fields mapping zone, node (for NUMA) and
97 * SPARSEMEM section (for variants of SPARSEMEM that require section ids like
98 * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP).
99 */
100 enum pageflags {
101 PG_locked, /* Page is locked. Don't touch. */
102 PG_writeback, /* Page is under writeback */
103 PG_referenced,
104 PG_uptodate,
105 PG_dirty,
106 PG_lru,
107 PG_head, /* Must be in bit 6 */
108 PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */
109 PG_active,
110 PG_workingset,
111 PG_error,
112 PG_slab,
113 PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/
114 PG_arch_1,
115 PG_reserved,
116 PG_private, /* If pagecache, has fs-private data */
117 PG_private_2, /* If pagecache, has fs aux data */
118 PG_mappedtodisk, /* Has blocks allocated on-disk */
119 PG_reclaim, /* To be reclaimed asap */
120 PG_swapbacked, /* Page is backed by RAM/swap */
121 PG_unevictable, /* Page is "unevictable" */
122 #ifdef CONFIG_MMU
123 PG_mlocked, /* Page is vma mlocked */
124 #endif
125 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
126 PG_uncached, /* Page has been mapped as uncached */
127 #endif
128 #ifdef CONFIG_MEMORY_FAILURE
129 PG_hwpoison, /* hardware poisoned page. Don't touch */
130 #endif
131 #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
132 PG_young,
133 PG_idle,
134 #endif
135 #ifdef CONFIG_ARCH_USES_PG_ARCH_X
136 PG_arch_2,
137 PG_arch_3,
138 #endif
139 #ifdef CONFIG_MEM_PURGEABLE
140 PG_purgeable,
141 #endif
142 #ifdef CONFIG_SECURITY_XPM
143 PG_xpm_readonly,
144 PG_xpm_writetainted,
145 #endif
146 __NR_PAGEFLAGS,
147
148 PG_readahead = PG_reclaim,
149
150 /*
151 * Depending on the way an anonymous folio can be mapped into a page
152 * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped
153 * THP), PG_anon_exclusive may be set only for the head page or for
154 * tail pages of an anonymous folio. For now, we only expect it to be
155 * set on tail pages for PTE-mapped THP.
156 */
157 PG_anon_exclusive = PG_mappedtodisk,
158
159 /* Filesystems */
160 PG_checked = PG_owner_priv_1,
161
162 /* SwapBacked */
163 PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */
164
165 /* Two page bits are conscripted by FS-Cache to maintain local caching
166 * state. These bits are set on pages belonging to the netfs's inodes
167 * when those inodes are being locally cached.
168 */
169 PG_fscache = PG_private_2, /* page backed by cache */
170
171 /* XEN */
172 /* Pinned in Xen as a read-only pagetable page. */
173 PG_pinned = PG_owner_priv_1,
174 /* Pinned as part of domain save (see xen_mm_pin_all()). */
175 PG_savepinned = PG_dirty,
176 /* Has a grant mapping of another (foreign) domain's page. */
177 PG_foreign = PG_owner_priv_1,
178 /* Remapped by swiotlb-xen. */
179 PG_xen_remapped = PG_owner_priv_1,
180
181 /* non-lru isolated movable page */
182 PG_isolated = PG_reclaim,
183
184 /* Only valid for buddy pages. Used to track pages that are reported */
185 PG_reported = PG_uptodate,
186
187 #ifdef CONFIG_MEMORY_HOTPLUG
188 /* For self-hosted memmap pages */
189 PG_vmemmap_self_hosted = PG_owner_priv_1,
190 #endif
191
192 /*
193 * Flags only valid for compound pages. Stored in first tail page's
194 * flags word. Cannot use the first 8 flags or any flag marked as
195 * PF_ANY.
196 */
197
198 /* At least one page in this folio has the hwpoison flag set */
199 PG_has_hwpoisoned = PG_error,
200 PG_large_rmappable = PG_workingset, /* anon or file-backed */
201 };
202
203 #define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1)
204
205 #ifndef __GENERATING_BOUNDS_H
206
207 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
208 DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key);
209
210 /*
211 * Return the real head page struct iff the @page is a fake head page, otherwise
212 * return the @page itself. See Documentation/mm/vmemmap_dedup.rst.
213 */
page_fixed_fake_head(const struct page * page)214 static __always_inline const struct page *page_fixed_fake_head(const struct page *page)
215 {
216 if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key))
217 return page;
218
219 /*
220 * Only addresses aligned with PAGE_SIZE of struct page may be fake head
221 * struct page. The alignment check aims to avoid access the fields (
222 * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly)
223 * cold cacheline in some cases.
224 */
225 if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) &&
226 test_bit(PG_head, &page->flags)) {
227 /*
228 * We can safely access the field of the @page[1] with PG_head
229 * because the @page is a compound page composed with at least
230 * two contiguous pages.
231 */
232 unsigned long head = READ_ONCE(page[1].compound_head);
233
234 if (likely(head & 1))
235 return (const struct page *)(head - 1);
236 }
237 return page;
238 }
239 #else
page_fixed_fake_head(const struct page * page)240 static inline const struct page *page_fixed_fake_head(const struct page *page)
241 {
242 return page;
243 }
244 #endif
245
page_is_fake_head(struct page * page)246 static __always_inline int page_is_fake_head(struct page *page)
247 {
248 return page_fixed_fake_head(page) != page;
249 }
250
_compound_head(const struct page * page)251 static inline unsigned long _compound_head(const struct page *page)
252 {
253 unsigned long head = READ_ONCE(page->compound_head);
254
255 if (unlikely(head & 1))
256 return head - 1;
257 return (unsigned long)page_fixed_fake_head(page);
258 }
259
260 #define compound_head(page) ((typeof(page))_compound_head(page))
261
262 /**
263 * page_folio - Converts from page to folio.
264 * @p: The page.
265 *
266 * Every page is part of a folio. This function cannot be called on a
267 * NULL pointer.
268 *
269 * Context: No reference, nor lock is required on @page. If the caller
270 * does not hold a reference, this call may race with a folio split, so
271 * it should re-check the folio still contains this page after gaining
272 * a reference on the folio.
273 * Return: The folio which contains this page.
274 */
275 #define page_folio(p) (_Generic((p), \
276 const struct page *: (const struct folio *)_compound_head(p), \
277 struct page *: (struct folio *)_compound_head(p)))
278
279 /**
280 * folio_page - Return a page from a folio.
281 * @folio: The folio.
282 * @n: The page number to return.
283 *
284 * @n is relative to the start of the folio. This function does not
285 * check that the page number lies within @folio; the caller is presumed
286 * to have a reference to the page.
287 */
288 #define folio_page(folio, n) nth_page(&(folio)->page, n)
289
PageTail(struct page * page)290 static __always_inline int PageTail(struct page *page)
291 {
292 return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page);
293 }
294
PageCompound(struct page * page)295 static __always_inline int PageCompound(struct page *page)
296 {
297 return test_bit(PG_head, &page->flags) ||
298 READ_ONCE(page->compound_head) & 1;
299 }
300
301 #define PAGE_POISON_PATTERN -1l
PagePoisoned(const struct page * page)302 static inline int PagePoisoned(const struct page *page)
303 {
304 return READ_ONCE(page->flags) == PAGE_POISON_PATTERN;
305 }
306
307 #ifdef CONFIG_DEBUG_VM
308 void page_init_poison(struct page *page, size_t size);
309 #else
page_init_poison(struct page * page,size_t size)310 static inline void page_init_poison(struct page *page, size_t size)
311 {
312 }
313 #endif
314
folio_flags(struct folio * folio,unsigned n)315 static unsigned long *folio_flags(struct folio *folio, unsigned n)
316 {
317 struct page *page = &folio->page;
318
319 VM_BUG_ON_PGFLAGS(PageTail(page), page);
320 VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page);
321 return &page[n].flags;
322 }
323
324 /*
325 * Page flags policies wrt compound pages
326 *
327 * PF_POISONED_CHECK
328 * check if this struct page poisoned/uninitialized
329 *
330 * PF_ANY:
331 * the page flag is relevant for small, head and tail pages.
332 *
333 * PF_HEAD:
334 * for compound page all operations related to the page flag applied to
335 * head page.
336 *
337 * PF_ONLY_HEAD:
338 * for compound page, callers only ever operate on the head page.
339 *
340 * PF_NO_TAIL:
341 * modifications of the page flag must be done on small or head pages,
342 * checks can be done on tail pages too.
343 *
344 * PF_NO_COMPOUND:
345 * the page flag is not relevant for compound pages.
346 *
347 * PF_SECOND:
348 * the page flag is stored in the first tail page.
349 */
350 #define PF_POISONED_CHECK(page) ({ \
351 VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \
352 page; })
353 #define PF_ANY(page, enforce) PF_POISONED_CHECK(page)
354 #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page))
355 #define PF_ONLY_HEAD(page, enforce) ({ \
356 VM_BUG_ON_PGFLAGS(PageTail(page), page); \
357 PF_POISONED_CHECK(page); })
358 #define PF_NO_TAIL(page, enforce) ({ \
359 VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \
360 PF_POISONED_CHECK(compound_head(page)); })
361 #define PF_NO_COMPOUND(page, enforce) ({ \
362 VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \
363 PF_POISONED_CHECK(page); })
364 #define PF_SECOND(page, enforce) ({ \
365 VM_BUG_ON_PGFLAGS(!PageHead(page), page); \
366 PF_POISONED_CHECK(&page[1]); })
367
368 /* Which page is the flag stored in */
369 #define FOLIO_PF_ANY 0
370 #define FOLIO_PF_HEAD 0
371 #define FOLIO_PF_ONLY_HEAD 0
372 #define FOLIO_PF_NO_TAIL 0
373 #define FOLIO_PF_NO_COMPOUND 0
374 #define FOLIO_PF_SECOND 1
375
376 /*
377 * Macros to create function definitions for page flags
378 */
379 #define TESTPAGEFLAG(uname, lname, policy) \
380 static __always_inline bool folio_test_##lname(struct folio *folio) \
381 { return test_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
382 static __always_inline int Page##uname(struct page *page) \
383 { return test_bit(PG_##lname, &policy(page, 0)->flags); }
384
385 #define SETPAGEFLAG(uname, lname, policy) \
386 static __always_inline \
387 void folio_set_##lname(struct folio *folio) \
388 { set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
389 static __always_inline void SetPage##uname(struct page *page) \
390 { set_bit(PG_##lname, &policy(page, 1)->flags); }
391
392 #define CLEARPAGEFLAG(uname, lname, policy) \
393 static __always_inline \
394 void folio_clear_##lname(struct folio *folio) \
395 { clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
396 static __always_inline void ClearPage##uname(struct page *page) \
397 { clear_bit(PG_##lname, &policy(page, 1)->flags); }
398
399 #define __SETPAGEFLAG(uname, lname, policy) \
400 static __always_inline \
401 void __folio_set_##lname(struct folio *folio) \
402 { __set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
403 static __always_inline void __SetPage##uname(struct page *page) \
404 { __set_bit(PG_##lname, &policy(page, 1)->flags); }
405
406 #define __CLEARPAGEFLAG(uname, lname, policy) \
407 static __always_inline \
408 void __folio_clear_##lname(struct folio *folio) \
409 { __clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
410 static __always_inline void __ClearPage##uname(struct page *page) \
411 { __clear_bit(PG_##lname, &policy(page, 1)->flags); }
412
413 #define TESTSETFLAG(uname, lname, policy) \
414 static __always_inline \
415 bool folio_test_set_##lname(struct folio *folio) \
416 { return test_and_set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
417 static __always_inline int TestSetPage##uname(struct page *page) \
418 { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); }
419
420 #define TESTCLEARFLAG(uname, lname, policy) \
421 static __always_inline \
422 bool folio_test_clear_##lname(struct folio *folio) \
423 { return test_and_clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
424 static __always_inline int TestClearPage##uname(struct page *page) \
425 { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); }
426
427 #define PAGEFLAG(uname, lname, policy) \
428 TESTPAGEFLAG(uname, lname, policy) \
429 SETPAGEFLAG(uname, lname, policy) \
430 CLEARPAGEFLAG(uname, lname, policy)
431
432 #define __PAGEFLAG(uname, lname, policy) \
433 TESTPAGEFLAG(uname, lname, policy) \
434 __SETPAGEFLAG(uname, lname, policy) \
435 __CLEARPAGEFLAG(uname, lname, policy)
436
437 #define TESTSCFLAG(uname, lname, policy) \
438 TESTSETFLAG(uname, lname, policy) \
439 TESTCLEARFLAG(uname, lname, policy)
440
441 #define FOLIO_TEST_FLAG_FALSE(name) \
442 static inline bool folio_test_##name(const struct folio *folio) \
443 { return false; }
444 #define FOLIO_SET_FLAG_NOOP(name) \
445 static inline void folio_set_##name(struct folio *folio) { }
446 #define FOLIO_CLEAR_FLAG_NOOP(name) \
447 static inline void folio_clear_##name(struct folio *folio) { }
448 #define __FOLIO_SET_FLAG_NOOP(name) \
449 static inline void __folio_set_##name(struct folio *folio) { }
450 #define __FOLIO_CLEAR_FLAG_NOOP(name) \
451 static inline void __folio_clear_##name(struct folio *folio) { }
452 #define FOLIO_TEST_SET_FLAG_FALSE(name) \
453 static inline bool folio_test_set_##name(struct folio *folio) \
454 { return false; }
455 #define FOLIO_TEST_CLEAR_FLAG_FALSE(name) \
456 static inline bool folio_test_clear_##name(struct folio *folio) \
457 { return false; }
458
459 #define FOLIO_FLAG_FALSE(name) \
460 FOLIO_TEST_FLAG_FALSE(name) \
461 FOLIO_SET_FLAG_NOOP(name) \
462 FOLIO_CLEAR_FLAG_NOOP(name)
463
464 #define TESTPAGEFLAG_FALSE(uname, lname) \
465 FOLIO_TEST_FLAG_FALSE(lname) \
466 static inline int Page##uname(const struct page *page) { return 0; }
467
468 #define SETPAGEFLAG_NOOP(uname, lname) \
469 FOLIO_SET_FLAG_NOOP(lname) \
470 static inline void SetPage##uname(struct page *page) { }
471
472 #define CLEARPAGEFLAG_NOOP(uname, lname) \
473 FOLIO_CLEAR_FLAG_NOOP(lname) \
474 static inline void ClearPage##uname(struct page *page) { }
475
476 #define __CLEARPAGEFLAG_NOOP(uname, lname) \
477 __FOLIO_CLEAR_FLAG_NOOP(lname) \
478 static inline void __ClearPage##uname(struct page *page) { }
479
480 #define TESTSETFLAG_FALSE(uname, lname) \
481 FOLIO_TEST_SET_FLAG_FALSE(lname) \
482 static inline int TestSetPage##uname(struct page *page) { return 0; }
483
484 #define TESTCLEARFLAG_FALSE(uname, lname) \
485 FOLIO_TEST_CLEAR_FLAG_FALSE(lname) \
486 static inline int TestClearPage##uname(struct page *page) { return 0; }
487
488 #define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname) \
489 SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname)
490
491 #define TESTSCFLAG_FALSE(uname, lname) \
492 TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname)
493
494 __PAGEFLAG(Locked, locked, PF_NO_TAIL)
495 PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD)
496 PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL)
497 PAGEFLAG(Referenced, referenced, PF_HEAD)
498 TESTCLEARFLAG(Referenced, referenced, PF_HEAD)
499 __SETPAGEFLAG(Referenced, referenced, PF_HEAD)
500 PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD)
501 __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD)
502 PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD)
503 TESTCLEARFLAG(LRU, lru, PF_HEAD)
504 PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD)
505 TESTCLEARFLAG(Active, active, PF_HEAD)
506 PAGEFLAG(Workingset, workingset, PF_HEAD)
507 TESTCLEARFLAG(Workingset, workingset, PF_HEAD)
508 __PAGEFLAG(Slab, slab, PF_NO_TAIL)
509 PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */
510
511 #ifdef CONFIG_SECURITY_XPM
512 PAGEFLAG(XPMReadonly, xpm_readonly, PF_HEAD)
513 PAGEFLAG(XPMWritetainted, xpm_writetainted, PF_HEAD)
514 #else
515 PAGEFLAG_FALSE(XPMReadonly)
516 PAGEFLAG_FALSE(XPMWritetainted)
517 #endif
518
519 /* Xen */
520 PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND)
521 TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND)
522 PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND);
523 PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND);
PAGEFLAG(XenRemapped,xen_remapped,PF_NO_COMPOUND)524 PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND)
525 TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND)
526
527 PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
528 __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
529 __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)
530 PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
531 __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
532 __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL)
533
534 /*
535 * Private page markings that may be used by the filesystem that owns the page
536 * for its own purposes.
537 * - PG_private and PG_private_2 cause release_folio() and co to be invoked
538 */
539 PAGEFLAG(Private, private, PF_ANY)
540 PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY)
541 PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
542 TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
543
544 /*
545 * Only test-and-set exist for PG_writeback. The unconditional operators are
546 * risky: they bypass page accounting.
547 */
548 TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL)
549 TESTSCFLAG(Writeback, writeback, PF_NO_TAIL)
550 PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL)
551
552 /* PG_readahead is only used for reads; PG_reclaim is only for writes */
553 PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL)
554 TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL)
555 PAGEFLAG(Readahead, readahead, PF_NO_COMPOUND)
556 TESTCLEARFLAG(Readahead, readahead, PF_NO_COMPOUND)
557
558 #ifdef CONFIG_HIGHMEM
559 /*
560 * Must use a macro here due to header dependency issues. page_zone() is not
561 * available at this point.
562 */
563 #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))
564 #define folio_test_highmem(__f) is_highmem_idx(folio_zonenum(__f))
565 #else
566 PAGEFLAG_FALSE(HighMem, highmem)
567 #endif
568
569 /* Does kmap_local_folio() only allow access to one page of the folio? */
570 #ifdef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP
571 #define folio_test_partial_kmap(f) true
572 #else
573 #define folio_test_partial_kmap(f) folio_test_highmem(f)
574 #endif
575
576 #ifdef CONFIG_SWAP
577 static __always_inline bool folio_test_swapcache(struct folio *folio)
578 {
579 return folio_test_swapbacked(folio) &&
580 test_bit(PG_swapcache, folio_flags(folio, 0));
581 }
582
PageSwapCache(struct page * page)583 static __always_inline bool PageSwapCache(struct page *page)
584 {
585 return folio_test_swapcache(page_folio(page));
586 }
587
588 SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
589 CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL)
590 #else
591 PAGEFLAG_FALSE(SwapCache, swapcache)
592 #endif
593
594 PAGEFLAG(Unevictable, unevictable, PF_HEAD)
595 __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD)
596 TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD)
597
598 #ifdef CONFIG_MMU
599 PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
600 __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL)
601 TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL)
602 #else
603 PAGEFLAG_FALSE(Mlocked, mlocked) __CLEARPAGEFLAG_NOOP(Mlocked, mlocked)
604 TESTSCFLAG_FALSE(Mlocked, mlocked)
605 #endif
606
607 #ifdef CONFIG_ARCH_USES_PG_UNCACHED
608 PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND)
609 #else
610 PAGEFLAG_FALSE(Uncached, uncached)
611 #endif
612
613 #ifdef CONFIG_MEMORY_FAILURE
614 PAGEFLAG(HWPoison, hwpoison, PF_ANY)
615 TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
616 #define __PG_HWPOISON (1UL << PG_hwpoison)
617 #define MAGIC_HWPOISON 0x48575053U /* HWPS */
618 extern void SetPageHWPoisonTakenOff(struct page *page);
619 extern void ClearPageHWPoisonTakenOff(struct page *page);
620 extern bool take_page_off_buddy(struct page *page);
621 extern bool put_page_back_buddy(struct page *page);
622 #else
623 PAGEFLAG_FALSE(HWPoison, hwpoison)
624 #define __PG_HWPOISON 0
625 #endif
626
627 #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT)
TESTPAGEFLAG(Young,young,PF_ANY)628 TESTPAGEFLAG(Young, young, PF_ANY)
629 SETPAGEFLAG(Young, young, PF_ANY)
630 TESTCLEARFLAG(Young, young, PF_ANY)
631 PAGEFLAG(Idle, idle, PF_ANY)
632 #endif
633
634 /*
635 * PageReported() is used to track reported free pages within the Buddy
636 * allocator. We can use the non-atomic version of the test and set
637 * operations as both should be shielded with the zone lock to prevent
638 * any possible races on the setting or clearing of the bit.
639 */
640 __PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
641
642 #ifdef CONFIG_MEMORY_HOTPLUG
643 PAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY)
644 #else
645 PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted)
646 #endif
647
648 #ifdef CONFIG_MEM_PURGEABLE
649 PAGEFLAG(Purgeable, purgeable, PF_ANY)
650 #else
651 PAGEFLAG_FALSE(Purgeable)
652 #endif
653
654 /*
655 * On an anonymous page mapped into a user virtual memory area,
656 * page->mapping points to its anon_vma, not to a struct address_space;
657 * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h.
658 *
659 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled,
660 * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON
661 * bit; and then page->mapping points, not to an anon_vma, but to a private
662 * structure which KSM associates with that merged page. See ksm.h.
663 *
664 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable
665 * page and then page->mapping points to a struct movable_operations.
666 *
667 * Please note that, confusingly, "page_mapping" refers to the inode
668 * address_space which maps the page from disk; whereas "page_mapped"
669 * refers to user virtual address space into which the page is mapped.
670 *
671 * For slab pages, since slab reuses the bits in struct page to store its
672 * internal states, the page->mapping does not exist as such, nor do these
673 * flags below. So in order to avoid testing non-existent bits, please
674 * make sure that PageSlab(page) actually evaluates to false before calling
675 * the following functions (e.g., PageAnon). See mm/slab.h.
676 */
677 #define PAGE_MAPPING_ANON 0x1
678 #define PAGE_MAPPING_MOVABLE 0x2
679 #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
680 #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
681
682 /*
683 * Different with flags above, this flag is used only for fsdax mode. It
684 * indicates that this page->mapping is now under reflink case.
685 */
686 #define PAGE_MAPPING_DAX_SHARED ((void *)0x1)
687
688 static __always_inline bool folio_mapping_flags(struct folio *folio)
689 {
690 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0;
691 }
692
PageMappingFlags(struct page * page)693 static __always_inline int PageMappingFlags(struct page *page)
694 {
695 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
696 }
697
folio_test_anon(struct folio * folio)698 static __always_inline bool folio_test_anon(struct folio *folio)
699 {
700 return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0;
701 }
702
PageAnon(struct page * page)703 static __always_inline bool PageAnon(struct page *page)
704 {
705 return folio_test_anon(page_folio(page));
706 }
707
__folio_test_movable(const struct folio * folio)708 static __always_inline bool __folio_test_movable(const struct folio *folio)
709 {
710 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) ==
711 PAGE_MAPPING_MOVABLE;
712 }
713
__PageMovable(struct page * page)714 static __always_inline int __PageMovable(struct page *page)
715 {
716 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
717 PAGE_MAPPING_MOVABLE;
718 }
719
720 #ifdef CONFIG_KSM
721 /*
722 * A KSM page is one of those write-protected "shared pages" or "merged pages"
723 * which KSM maps into multiple mms, wherever identical anonymous page content
724 * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any
725 * anon_vma, but to that page's node of the stable tree.
726 */
folio_test_ksm(struct folio * folio)727 static __always_inline bool folio_test_ksm(struct folio *folio)
728 {
729 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) ==
730 PAGE_MAPPING_KSM;
731 }
732
PageKsm(struct page * page)733 static __always_inline bool PageKsm(struct page *page)
734 {
735 return folio_test_ksm(page_folio(page));
736 }
737 #else
738 TESTPAGEFLAG_FALSE(Ksm, ksm)
739 #endif
740
741 u64 stable_page_flags(struct page *page);
742
743 /**
744 * folio_test_uptodate - Is this folio up to date?
745 * @folio: The folio.
746 *
747 * The uptodate flag is set on a folio when every byte in the folio is
748 * at least as new as the corresponding bytes on storage. Anonymous
749 * and CoW folios are always uptodate. If the folio is not uptodate,
750 * some of the bytes in it may be; see the is_partially_uptodate()
751 * address_space operation.
752 */
folio_test_uptodate(struct folio * folio)753 static inline bool folio_test_uptodate(struct folio *folio)
754 {
755 bool ret = test_bit(PG_uptodate, folio_flags(folio, 0));
756 /*
757 * Must ensure that the data we read out of the folio is loaded
758 * _after_ we've loaded folio->flags to check the uptodate bit.
759 * We can skip the barrier if the folio is not uptodate, because
760 * we wouldn't be reading anything from it.
761 *
762 * See folio_mark_uptodate() for the other side of the story.
763 */
764 if (ret)
765 smp_rmb();
766
767 return ret;
768 }
769
PageUptodate(struct page * page)770 static inline int PageUptodate(struct page *page)
771 {
772 return folio_test_uptodate(page_folio(page));
773 }
774
__folio_mark_uptodate(struct folio * folio)775 static __always_inline void __folio_mark_uptodate(struct folio *folio)
776 {
777 smp_wmb();
778 __set_bit(PG_uptodate, folio_flags(folio, 0));
779 }
780
folio_mark_uptodate(struct folio * folio)781 static __always_inline void folio_mark_uptodate(struct folio *folio)
782 {
783 /*
784 * Memory barrier must be issued before setting the PG_uptodate bit,
785 * so that all previous stores issued in order to bring the folio
786 * uptodate are actually visible before folio_test_uptodate becomes true.
787 */
788 smp_wmb();
789 set_bit(PG_uptodate, folio_flags(folio, 0));
790 }
791
__SetPageUptodate(struct page * page)792 static __always_inline void __SetPageUptodate(struct page *page)
793 {
794 __folio_mark_uptodate((struct folio *)page);
795 }
796
SetPageUptodate(struct page * page)797 static __always_inline void SetPageUptodate(struct page *page)
798 {
799 folio_mark_uptodate((struct folio *)page);
800 }
801
802 CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL)
803
804 bool __folio_start_writeback(struct folio *folio, bool keep_write);
805 bool set_page_writeback(struct page *page);
806
807 #define folio_start_writeback(folio) \
808 __folio_start_writeback(folio, false)
809 #define folio_start_writeback_keepwrite(folio) \
810 __folio_start_writeback(folio, true)
811
test_set_page_writeback(struct page * page)812 static inline bool test_set_page_writeback(struct page *page)
813 {
814 return set_page_writeback(page);
815 }
816
folio_test_head(struct folio * folio)817 static __always_inline bool folio_test_head(struct folio *folio)
818 {
819 return test_bit(PG_head, folio_flags(folio, FOLIO_PF_ANY));
820 }
821
PageHead(struct page * page)822 static __always_inline int PageHead(struct page *page)
823 {
824 PF_POISONED_CHECK(page);
825 return test_bit(PG_head, &page->flags) && !page_is_fake_head(page);
826 }
827
__SETPAGEFLAG(Head,head,PF_ANY)828 __SETPAGEFLAG(Head, head, PF_ANY)
829 __CLEARPAGEFLAG(Head, head, PF_ANY)
830 CLEARPAGEFLAG(Head, head, PF_ANY)
831
832 /**
833 * folio_test_large() - Does this folio contain more than one page?
834 * @folio: The folio to test.
835 *
836 * Return: True if the folio is larger than one page.
837 */
838 static inline bool folio_test_large(struct folio *folio)
839 {
840 return folio_test_head(folio);
841 }
842
set_compound_head(struct page * page,struct page * head)843 static __always_inline void set_compound_head(struct page *page, struct page *head)
844 {
845 WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
846 }
847
clear_compound_head(struct page * page)848 static __always_inline void clear_compound_head(struct page *page)
849 {
850 WRITE_ONCE(page->compound_head, 0);
851 }
852
853 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
ClearPageCompound(struct page * page)854 static inline void ClearPageCompound(struct page *page)
855 {
856 BUG_ON(!PageHead(page));
857 ClearPageHead(page);
858 }
PAGEFLAG(LargeRmappable,large_rmappable,PF_SECOND)859 PAGEFLAG(LargeRmappable, large_rmappable, PF_SECOND)
860 #else
861 TESTPAGEFLAG_FALSE(LargeRmappable, large_rmappable)
862 #endif
863
864 #define PG_head_mask ((1UL << PG_head))
865
866 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
867 /*
868 * PageHuge() only returns true for hugetlbfs pages, but not for
869 * normal or transparent huge pages.
870 *
871 * PageTransHuge() returns true for both transparent huge and
872 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be
873 * called only in the core VM paths where hugetlbfs pages can't exist.
874 */
875 static inline int PageTransHuge(struct page *page)
876 {
877 VM_BUG_ON_PAGE(PageTail(page), page);
878 return PageHead(page);
879 }
880
881 /*
882 * PageTransCompound returns true for both transparent huge pages
883 * and hugetlbfs pages, so it should only be called when it's known
884 * that hugetlbfs pages aren't involved.
885 */
PageTransCompound(struct page * page)886 static inline int PageTransCompound(struct page *page)
887 {
888 return PageCompound(page);
889 }
890
891 /*
892 * PageTransTail returns true for both transparent huge pages
893 * and hugetlbfs pages, so it should only be called when it's known
894 * that hugetlbfs pages aren't involved.
895 */
PageTransTail(struct page * page)896 static inline int PageTransTail(struct page *page)
897 {
898 return PageTail(page);
899 }
900 #else
901 TESTPAGEFLAG_FALSE(TransHuge, transhuge)
902 TESTPAGEFLAG_FALSE(TransCompound, transcompound)
903 TESTPAGEFLAG_FALSE(TransCompoundMap, transcompoundmap)
904 TESTPAGEFLAG_FALSE(TransTail, transtail)
905 #endif
906
907 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
908 /*
909 * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the
910 * compound page.
911 *
912 * This flag is set by hwpoison handler. Cleared by THP split or free page.
913 */
PAGEFLAG(HasHWPoisoned,has_hwpoisoned,PF_SECOND)914 PAGEFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
915 TESTSCFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND)
916 #else
917 PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned)
918 TESTSCFLAG_FALSE(HasHWPoisoned, has_hwpoisoned)
919 #endif
920
921 /*
922 * For pages that are never mapped to userspace (and aren't PageSlab),
923 * page_type may be used. Because it is initialised to -1, we invert the
924 * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and
925 * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and
926 * low bits so that an underflow or overflow of _mapcount won't be
927 * mistaken for a page type value.
928 */
929
930 #define PAGE_TYPE_BASE 0xf0000000
931 /* Reserve 0x0000007f to catch underflows of _mapcount */
932 #define PAGE_MAPCOUNT_RESERVE -128
933 #define PG_buddy 0x00000080
934 #define PG_offline 0x00000100
935 #define PG_table 0x00000200
936 #define PG_guard 0x00000400
937 #define PG_hugetlb 0x00000800
938
939 #define PageType(page, flag) \
940 ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
941 #define folio_test_type(folio, flag) \
942 ((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE)
943
944 static inline int page_type_has_type(unsigned int page_type)
945 {
946 return (int)page_type < PAGE_MAPCOUNT_RESERVE;
947 }
948
page_has_type(struct page * page)949 static inline int page_has_type(struct page *page)
950 {
951 return page_type_has_type(page->page_type);
952 }
953
954 #define FOLIO_TYPE_OPS(lname, fname) \
955 static __always_inline bool folio_test_##fname(const struct folio *folio)\
956 { \
957 return folio_test_type(folio, PG_##lname); \
958 } \
959 static __always_inline void __folio_set_##fname(struct folio *folio) \
960 { \
961 VM_BUG_ON_FOLIO(!folio_test_type(folio, 0), folio); \
962 folio->page.page_type &= ~PG_##lname; \
963 } \
964 static __always_inline void __folio_clear_##fname(struct folio *folio) \
965 { \
966 VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \
967 folio->page.page_type |= PG_##lname; \
968 }
969
970 #define PAGE_TYPE_OPS(uname, lname, fname) \
971 FOLIO_TYPE_OPS(lname, fname) \
972 static __always_inline int Page##uname(const struct page *page) \
973 { \
974 return PageType(page, PG_##lname); \
975 } \
976 static __always_inline void __SetPage##uname(struct page *page) \
977 { \
978 VM_BUG_ON_PAGE(!PageType(page, 0), page); \
979 page->page_type &= ~PG_##lname; \
980 } \
981 static __always_inline void __ClearPage##uname(struct page *page) \
982 { \
983 VM_BUG_ON_PAGE(!Page##uname(page), page); \
984 page->page_type |= PG_##lname; \
985 }
986
987 /*
988 * PageBuddy() indicates that the page is free and in the buddy system
989 * (see mm/page_alloc.c).
990 */
991 PAGE_TYPE_OPS(Buddy, buddy, buddy)
992
993 /*
994 * PageOffline() indicates that the page is logically offline although the
995 * containing section is online. (e.g. inflated in a balloon driver or
996 * not onlined when onlining the section).
997 * The content of these pages is effectively stale. Such pages should not
998 * be touched (read/write/dump/save) except by their owner.
999 *
1000 * If a driver wants to allow to offline unmovable PageOffline() pages without
1001 * putting them back to the buddy, it can do so via the memory notifier by
1002 * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the
1003 * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline()
1004 * pages (now with a reference count of zero) are treated like free pages,
1005 * allowing the containing memory block to get offlined. A driver that
1006 * relies on this feature is aware that re-onlining the memory block will
1007 * require to re-set the pages PageOffline() and not giving them to the
1008 * buddy via online_page_callback_t.
1009 *
1010 * There are drivers that mark a page PageOffline() and expect there won't be
1011 * any further access to page content. PFN walkers that read content of random
1012 * pages should check PageOffline() and synchronize with such drivers using
1013 * page_offline_freeze()/page_offline_thaw().
1014 */
1015 PAGE_TYPE_OPS(Offline, offline, offline)
1016
1017 extern void page_offline_freeze(void);
1018 extern void page_offline_thaw(void);
1019 extern void page_offline_begin(void);
1020 extern void page_offline_end(void);
1021
1022 /*
1023 * Marks pages in use as page tables.
1024 */
PAGE_TYPE_OPS(Table,table,pgtable)1025 PAGE_TYPE_OPS(Table, table, pgtable)
1026
1027 /*
1028 * Marks guardpages used with debug_pagealloc.
1029 */
1030 PAGE_TYPE_OPS(Guard, guard, guard)
1031
1032 #ifdef CONFIG_HUGETLB_PAGE
1033 FOLIO_TYPE_OPS(hugetlb, hugetlb)
1034 #else
1035 FOLIO_TEST_FLAG_FALSE(hugetlb)
1036 #endif
1037
1038 /**
1039 * PageHuge - Determine if the page belongs to hugetlbfs
1040 * @page: The page to test.
1041 *
1042 * Context: Any context.
1043 * Return: True for hugetlbfs pages, false for anon pages or pages
1044 * belonging to other filesystems.
1045 */
1046 static inline bool PageHuge(const struct page *page)
1047 {
1048 return folio_test_hugetlb(page_folio(page));
1049 }
1050
1051 /*
1052 * Check if a page is currently marked HWPoisoned. Note that this check is
1053 * best effort only and inherently racy: there is no way to synchronize with
1054 * failing hardware.
1055 */
is_page_hwpoison(struct page * page)1056 static inline bool is_page_hwpoison(struct page *page)
1057 {
1058 if (PageHWPoison(page))
1059 return true;
1060 return PageHuge(page) && PageHWPoison(compound_head(page));
1061 }
1062
1063 extern bool is_free_buddy_page(struct page *page);
1064
1065 PAGEFLAG(Isolated, isolated, PF_ANY);
1066
PageAnonExclusive(struct page * page)1067 static __always_inline int PageAnonExclusive(struct page *page)
1068 {
1069 VM_BUG_ON_PGFLAGS(!PageAnon(page), page);
1070 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
1071 return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
1072 }
1073
SetPageAnonExclusive(struct page * page)1074 static __always_inline void SetPageAnonExclusive(struct page *page)
1075 {
1076 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page);
1077 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
1078 set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
1079 }
1080
ClearPageAnonExclusive(struct page * page)1081 static __always_inline void ClearPageAnonExclusive(struct page *page)
1082 {
1083 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page);
1084 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
1085 clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
1086 }
1087
__ClearPageAnonExclusive(struct page * page)1088 static __always_inline void __ClearPageAnonExclusive(struct page *page)
1089 {
1090 VM_BUG_ON_PGFLAGS(!PageAnon(page), page);
1091 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
1092 __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
1093 }
1094
1095 #ifdef CONFIG_MMU
1096 #define __PG_MLOCKED (1UL << PG_mlocked)
1097 #else
1098 #define __PG_MLOCKED 0
1099 #endif
1100
1101 #ifdef CONFIG_SECURITY_XPM
1102 #define __XPM_PAGE_FLAGS (1UL << PG_xpm_readonly | 1UL << PG_xpm_writetainted)
1103 #else
1104 #define __XPM_PAGE_FLAGS 0
1105 #endif
1106
1107 /*
1108 * Flags checked when a page is freed. Pages being freed should not have
1109 * these flags set. If they are, there is a problem.
1110 */
1111 #define PAGE_FLAGS_CHECK_AT_FREE \
1112 (1UL << PG_lru | 1UL << PG_locked | \
1113 1UL << PG_private | 1UL << PG_private_2 | \
1114 1UL << PG_writeback | 1UL << PG_reserved | \
1115 1UL << PG_slab | 1UL << PG_active | \
1116 __XPM_PAGE_FLAGS | \
1117 1UL << PG_unevictable | __PG_MLOCKED | LRU_GEN_MASK)
1118
1119 /*
1120 * Flags checked when a page is prepped for return by the page allocator.
1121 * Pages being prepped should not have these flags set. If they are set,
1122 * there has been a kernel bug or struct page corruption.
1123 *
1124 * __PG_HWPOISON is exceptional because it needs to be kept beyond page's
1125 * alloc-free cycle to prevent from reusing the page.
1126 */
1127 #define PAGE_FLAGS_CHECK_AT_PREP \
1128 ((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK)
1129
1130 /*
1131 * Flags stored in the second page of a compound page. They may overlap
1132 * the CHECK_AT_FREE flags above, so need to be cleared.
1133 */
1134 #define PAGE_FLAGS_SECOND \
1135 (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \
1136 1UL << PG_large_rmappable)
1137
1138 #define PAGE_FLAGS_PRIVATE \
1139 (1UL << PG_private | 1UL << PG_private_2)
1140 /**
1141 * page_has_private - Determine if page has private stuff
1142 * @page: The page to be checked
1143 *
1144 * Determine if a page has private stuff, indicating that release routines
1145 * should be invoked upon it.
1146 */
page_has_private(struct page * page)1147 static inline int page_has_private(struct page *page)
1148 {
1149 return !!(page->flags & PAGE_FLAGS_PRIVATE);
1150 }
1151
folio_has_private(struct folio * folio)1152 static inline bool folio_has_private(struct folio *folio)
1153 {
1154 return page_has_private(&folio->page);
1155 }
1156
1157 #undef PF_ANY
1158 #undef PF_HEAD
1159 #undef PF_ONLY_HEAD
1160 #undef PF_NO_TAIL
1161 #undef PF_NO_COMPOUND
1162 #undef PF_SECOND
1163 #endif /* !__GENERATING_BOUNDS_H */
1164
1165 #endif /* PAGE_FLAGS_H */
1166