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