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 allocated in the context of kexec/kdump (loaded kernel image, 34 * control pages, vmcoreinfo) 35 * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are 36 * not marked PG_reserved (as they might be in use by somebody else who does 37 * not respect the caching strategy). 38 * - MCA pages on ia64 39 * - Pages holding CPU notes for POWER Firmware Assisted Dump 40 * - Device memory (e.g. PMEM, DAX, HMM) 41 * Some PG_reserved pages will be excluded from the hibernation image. 42 * PG_reserved does in general not hinder anybody from dumping or swapping 43 * and is no longer required for remap_pfn_range(). ioremap might require it. 44 * Consequently, PG_reserved for a page mapped into user space can indicate 45 * the zero page, the vDSO, MMIO pages or device memory. 46 * 47 * The PG_private bitflag is set on pagecache pages if they contain filesystem 48 * specific data (which is normally at page->private). It can be used by 49 * private allocations for its own usage. 50 * 51 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O 52 * and cleared when writeback _starts_ or when read _completes_. PG_writeback 53 * is set before writeback starts and cleared when it finishes. 54 * 55 * PG_locked also pins a page in pagecache, and blocks truncation of the file 56 * while it is held. 57 * 58 * page_waitqueue(page) is a wait queue of all tasks waiting for the page 59 * to become unlocked. 60 * 61 * PG_swapbacked is set when a page uses swap as a backing storage. This are 62 * usually PageAnon or shmem pages but please note that even anonymous pages 63 * might lose their PG_swapbacked flag when they simply can be dropped (e.g. as 64 * a result of MADV_FREE). 65 * 66 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and 67 * file-backed pagecache (see mm/vmscan.c). 68 * 69 * PG_arch_1 is an architecture specific page state bit. The generic code 70 * guarantees that this bit is cleared for a page when it first is entered into 71 * the page cache. 72 * 73 * PG_hwpoison indicates that a page got corrupted in hardware and contains 74 * data with incorrect ECC bits that triggered a machine check. Accessing is 75 * not safe since it may cause another machine check. Don't touch! 76 */ 77 78 /* 79 * Don't use the pageflags directly. Use the PageFoo macros. 80 * 81 * The page flags field is split into two parts, the main flags area 82 * which extends from the low bits upwards, and the fields area which 83 * extends from the high bits downwards. 84 * 85 * | FIELD | ... | FLAGS | 86 * N-1 ^ 0 87 * (NR_PAGEFLAGS) 88 * 89 * The fields area is reserved for fields mapping zone, node (for NUMA) and 90 * SPARSEMEM section (for variants of SPARSEMEM that require section ids like 91 * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). 92 */ 93 enum pageflags { 94 PG_locked, /* Page is locked. Don't touch. */ 95 PG_writeback, /* Page is under writeback */ 96 PG_referenced, 97 PG_uptodate, 98 PG_dirty, 99 PG_lru, 100 PG_head, /* Must be in bit 6 */ 101 PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ 102 PG_active, 103 PG_workingset, 104 PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ 105 PG_arch_1, 106 PG_reserved, 107 PG_private, /* If pagecache, has fs-private data */ 108 PG_private_2, /* If pagecache, has fs aux data */ 109 PG_mappedtodisk, /* Has blocks allocated on-disk */ 110 PG_reclaim, /* To be reclaimed asap */ 111 PG_swapbacked, /* Page is backed by RAM/swap */ 112 PG_unevictable, /* Page is "unevictable" */ 113 #ifdef CONFIG_MMU 114 PG_mlocked, /* Page is vma mlocked */ 115 #endif 116 #ifdef CONFIG_ARCH_USES_PG_UNCACHED 117 PG_uncached, /* Page has been mapped as uncached */ 118 #endif 119 #ifdef CONFIG_MEMORY_FAILURE 120 PG_hwpoison, /* hardware poisoned page. Don't touch */ 121 #endif 122 #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT) 123 PG_young, 124 PG_idle, 125 #endif 126 #ifdef CONFIG_ARCH_USES_PG_ARCH_X 127 PG_arch_2, 128 PG_arch_3, 129 #endif 130 __NR_PAGEFLAGS, 131 132 PG_readahead = PG_reclaim, 133 134 /* 135 * Depending on the way an anonymous folio can be mapped into a page 136 * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped 137 * THP), PG_anon_exclusive may be set only for the head page or for 138 * tail pages of an anonymous folio. For now, we only expect it to be 139 * set on tail pages for PTE-mapped THP. 140 */ 141 PG_anon_exclusive = PG_mappedtodisk, 142 143 /* Filesystems */ 144 PG_checked = PG_owner_priv_1, 145 146 /* SwapBacked */ 147 PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ 148 149 /* Two page bits are conscripted by FS-Cache to maintain local caching 150 * state. These bits are set on pages belonging to the netfs's inodes 151 * when those inodes are being locally cached. 152 */ 153 PG_fscache = PG_private_2, /* page backed by cache */ 154 155 /* XEN */ 156 /* Pinned in Xen as a read-only pagetable page. */ 157 PG_pinned = PG_owner_priv_1, 158 /* Pinned as part of domain save (see xen_mm_pin_all()). */ 159 PG_savepinned = PG_dirty, 160 /* Has a grant mapping of another (foreign) domain's page. */ 161 PG_foreign = PG_owner_priv_1, 162 /* Remapped by swiotlb-xen. */ 163 PG_xen_remapped = PG_owner_priv_1, 164 165 /* non-lru isolated movable page */ 166 PG_isolated = PG_reclaim, 167 168 /* Only valid for buddy pages. Used to track pages that are reported */ 169 PG_reported = PG_uptodate, 170 171 #ifdef CONFIG_MEMORY_HOTPLUG 172 /* For self-hosted memmap pages */ 173 PG_vmemmap_self_hosted = PG_owner_priv_1, 174 #endif 175 176 /* 177 * Flags only valid for compound pages. Stored in first tail page's 178 * flags word. Cannot use the first 8 flags or any flag marked as 179 * PF_ANY. 180 */ 181 182 /* At least one page in this folio has the hwpoison flag set */ 183 PG_has_hwpoisoned = PG_active, 184 PG_large_rmappable = PG_workingset, /* anon or file-backed */ 185 }; 186 187 #define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1) 188 189 #ifndef __GENERATING_BOUNDS_H 190 191 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP 192 DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key); 193 194 /* 195 * Return the real head page struct iff the @page is a fake head page, otherwise 196 * return the @page itself. See Documentation/mm/vmemmap_dedup.rst. 197 */ 198 static __always_inline const struct page *page_fixed_fake_head(const struct page *page) 199 { 200 if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) 201 return page; 202 203 /* 204 * Only addresses aligned with PAGE_SIZE of struct page may be fake head 205 * struct page. The alignment check aims to avoid access the fields ( 206 * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly) 207 * cold cacheline in some cases. 208 */ 209 if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) && 210 test_bit(PG_head, &page->flags)) { 211 /* 212 * We can safely access the field of the @page[1] with PG_head 213 * because the @page is a compound page composed with at least 214 * two contiguous pages. 215 */ 216 unsigned long head = READ_ONCE(page[1].compound_head); 217 218 if (likely(head & 1)) 219 return (const struct page *)(head - 1); 220 } 221 return page; 222 } 223 #else 224 static inline const struct page *page_fixed_fake_head(const struct page *page) 225 { 226 return page; 227 } 228 #endif 229 230 static __always_inline int page_is_fake_head(const struct page *page) 231 { 232 return page_fixed_fake_head(page) != page; 233 } 234 235 static __always_inline unsigned long _compound_head(const struct page *page) 236 { 237 unsigned long head = READ_ONCE(page->compound_head); 238 239 if (unlikely(head & 1)) 240 return head - 1; 241 return (unsigned long)page_fixed_fake_head(page); 242 } 243 244 #define compound_head(page) ((typeof(page))_compound_head(page)) 245 246 /** 247 * page_folio - Converts from page to folio. 248 * @p: The page. 249 * 250 * Every page is part of a folio. This function cannot be called on a 251 * NULL pointer. 252 * 253 * Context: No reference, nor lock is required on @page. If the caller 254 * does not hold a reference, this call may race with a folio split, so 255 * it should re-check the folio still contains this page after gaining 256 * a reference on the folio. 257 * Return: The folio which contains this page. 258 */ 259 #define page_folio(p) (_Generic((p), \ 260 const struct page *: (const struct folio *)_compound_head(p), \ 261 struct page *: (struct folio *)_compound_head(p))) 262 263 /** 264 * folio_page - Return a page from a folio. 265 * @folio: The folio. 266 * @n: The page number to return. 267 * 268 * @n is relative to the start of the folio. This function does not 269 * check that the page number lies within @folio; the caller is presumed 270 * to have a reference to the page. 271 */ 272 #define folio_page(folio, n) nth_page(&(folio)->page, n) 273 274 static __always_inline int PageTail(const struct page *page) 275 { 276 return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page); 277 } 278 279 static __always_inline int PageCompound(const struct page *page) 280 { 281 return test_bit(PG_head, &page->flags) || 282 READ_ONCE(page->compound_head) & 1; 283 } 284 285 #define PAGE_POISON_PATTERN -1l 286 static inline int PagePoisoned(const struct page *page) 287 { 288 return READ_ONCE(page->flags) == PAGE_POISON_PATTERN; 289 } 290 291 #ifdef CONFIG_DEBUG_VM 292 void page_init_poison(struct page *page, size_t size); 293 #else 294 static inline void page_init_poison(struct page *page, size_t size) 295 { 296 } 297 #endif 298 299 static const unsigned long *const_folio_flags(const struct folio *folio, 300 unsigned n) 301 { 302 const struct page *page = &folio->page; 303 304 VM_BUG_ON_PGFLAGS(PageTail(page), page); 305 VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); 306 return &page[n].flags; 307 } 308 309 static unsigned long *folio_flags(struct folio *folio, unsigned n) 310 { 311 struct page *page = &folio->page; 312 313 VM_BUG_ON_PGFLAGS(PageTail(page), page); 314 VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); 315 return &page[n].flags; 316 } 317 318 /* 319 * Page flags policies wrt compound pages 320 * 321 * PF_POISONED_CHECK 322 * check if this struct page poisoned/uninitialized 323 * 324 * PF_ANY: 325 * the page flag is relevant for small, head and tail pages. 326 * 327 * PF_HEAD: 328 * for compound page all operations related to the page flag applied to 329 * head page. 330 * 331 * PF_NO_TAIL: 332 * modifications of the page flag must be done on small or head pages, 333 * checks can be done on tail pages too. 334 * 335 * PF_NO_COMPOUND: 336 * the page flag is not relevant for compound pages. 337 * 338 * PF_SECOND: 339 * the page flag is stored in the first tail page. 340 */ 341 #define PF_POISONED_CHECK(page) ({ \ 342 VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ 343 page; }) 344 #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) 345 #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) 346 #define PF_NO_TAIL(page, enforce) ({ \ 347 VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ 348 PF_POISONED_CHECK(compound_head(page)); }) 349 #define PF_NO_COMPOUND(page, enforce) ({ \ 350 VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ 351 PF_POISONED_CHECK(page); }) 352 #define PF_SECOND(page, enforce) ({ \ 353 VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ 354 PF_POISONED_CHECK(&page[1]); }) 355 356 /* Which page is the flag stored in */ 357 #define FOLIO_PF_ANY 0 358 #define FOLIO_PF_HEAD 0 359 #define FOLIO_PF_NO_TAIL 0 360 #define FOLIO_PF_NO_COMPOUND 0 361 #define FOLIO_PF_SECOND 1 362 363 #define FOLIO_HEAD_PAGE 0 364 #define FOLIO_SECOND_PAGE 1 365 366 /* 367 * Macros to create function definitions for page flags 368 */ 369 #define FOLIO_TEST_FLAG(name, page) \ 370 static __always_inline bool folio_test_##name(const struct folio *folio) \ 371 { return test_bit(PG_##name, const_folio_flags(folio, page)); } 372 373 #define FOLIO_SET_FLAG(name, page) \ 374 static __always_inline void folio_set_##name(struct folio *folio) \ 375 { set_bit(PG_##name, folio_flags(folio, page)); } 376 377 #define FOLIO_CLEAR_FLAG(name, page) \ 378 static __always_inline void folio_clear_##name(struct folio *folio) \ 379 { clear_bit(PG_##name, folio_flags(folio, page)); } 380 381 #define __FOLIO_SET_FLAG(name, page) \ 382 static __always_inline void __folio_set_##name(struct folio *folio) \ 383 { __set_bit(PG_##name, folio_flags(folio, page)); } 384 385 #define __FOLIO_CLEAR_FLAG(name, page) \ 386 static __always_inline void __folio_clear_##name(struct folio *folio) \ 387 { __clear_bit(PG_##name, folio_flags(folio, page)); } 388 389 #define FOLIO_TEST_SET_FLAG(name, page) \ 390 static __always_inline bool folio_test_set_##name(struct folio *folio) \ 391 { return test_and_set_bit(PG_##name, folio_flags(folio, page)); } 392 393 #define FOLIO_TEST_CLEAR_FLAG(name, page) \ 394 static __always_inline bool folio_test_clear_##name(struct folio *folio) \ 395 { return test_and_clear_bit(PG_##name, folio_flags(folio, page)); } 396 397 #define FOLIO_FLAG(name, page) \ 398 FOLIO_TEST_FLAG(name, page) \ 399 FOLIO_SET_FLAG(name, page) \ 400 FOLIO_CLEAR_FLAG(name, page) 401 402 #define TESTPAGEFLAG(uname, lname, policy) \ 403 FOLIO_TEST_FLAG(lname, FOLIO_##policy) \ 404 static __always_inline int Page##uname(const struct page *page) \ 405 { return test_bit(PG_##lname, &policy(page, 0)->flags); } 406 407 #define SETPAGEFLAG(uname, lname, policy) \ 408 FOLIO_SET_FLAG(lname, FOLIO_##policy) \ 409 static __always_inline void SetPage##uname(struct page *page) \ 410 { set_bit(PG_##lname, &policy(page, 1)->flags); } 411 412 #define CLEARPAGEFLAG(uname, lname, policy) \ 413 FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \ 414 static __always_inline void ClearPage##uname(struct page *page) \ 415 { clear_bit(PG_##lname, &policy(page, 1)->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 TESTSETFLAG(uname, lname, policy) \ 428 FOLIO_TEST_SET_FLAG(lname, FOLIO_##policy) \ 429 static __always_inline int TestSetPage##uname(struct page *page) \ 430 { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } 431 432 #define TESTCLEARFLAG(uname, lname, policy) \ 433 FOLIO_TEST_CLEAR_FLAG(lname, FOLIO_##policy) \ 434 static __always_inline int TestClearPage##uname(struct page *page) \ 435 { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } 436 437 #define PAGEFLAG(uname, lname, policy) \ 438 TESTPAGEFLAG(uname, lname, policy) \ 439 SETPAGEFLAG(uname, lname, policy) \ 440 CLEARPAGEFLAG(uname, lname, policy) 441 442 #define __PAGEFLAG(uname, lname, policy) \ 443 TESTPAGEFLAG(uname, lname, policy) \ 444 __SETPAGEFLAG(uname, lname, policy) \ 445 __CLEARPAGEFLAG(uname, lname, policy) 446 447 #define TESTSCFLAG(uname, lname, policy) \ 448 TESTSETFLAG(uname, lname, policy) \ 449 TESTCLEARFLAG(uname, lname, policy) 450 451 #define FOLIO_TEST_FLAG_FALSE(name) \ 452 static inline bool folio_test_##name(const struct folio *folio) \ 453 { return false; } 454 #define FOLIO_SET_FLAG_NOOP(name) \ 455 static inline void folio_set_##name(struct folio *folio) { } 456 #define FOLIO_CLEAR_FLAG_NOOP(name) \ 457 static inline void folio_clear_##name(struct folio *folio) { } 458 #define __FOLIO_SET_FLAG_NOOP(name) \ 459 static inline void __folio_set_##name(struct folio *folio) { } 460 #define __FOLIO_CLEAR_FLAG_NOOP(name) \ 461 static inline void __folio_clear_##name(struct folio *folio) { } 462 #define FOLIO_TEST_SET_FLAG_FALSE(name) \ 463 static inline bool folio_test_set_##name(struct folio *folio) \ 464 { return false; } 465 #define FOLIO_TEST_CLEAR_FLAG_FALSE(name) \ 466 static inline bool folio_test_clear_##name(struct folio *folio) \ 467 { return false; } 468 469 #define FOLIO_FLAG_FALSE(name) \ 470 FOLIO_TEST_FLAG_FALSE(name) \ 471 FOLIO_SET_FLAG_NOOP(name) \ 472 FOLIO_CLEAR_FLAG_NOOP(name) 473 474 #define TESTPAGEFLAG_FALSE(uname, lname) \ 475 FOLIO_TEST_FLAG_FALSE(lname) \ 476 static inline int Page##uname(const struct page *page) { return 0; } 477 478 #define SETPAGEFLAG_NOOP(uname, lname) \ 479 FOLIO_SET_FLAG_NOOP(lname) \ 480 static inline void SetPage##uname(struct page *page) { } 481 482 #define CLEARPAGEFLAG_NOOP(uname, lname) \ 483 FOLIO_CLEAR_FLAG_NOOP(lname) \ 484 static inline void ClearPage##uname(struct page *page) { } 485 486 #define __CLEARPAGEFLAG_NOOP(uname, lname) \ 487 __FOLIO_CLEAR_FLAG_NOOP(lname) \ 488 static inline void __ClearPage##uname(struct page *page) { } 489 490 #define TESTSETFLAG_FALSE(uname, lname) \ 491 FOLIO_TEST_SET_FLAG_FALSE(lname) \ 492 static inline int TestSetPage##uname(struct page *page) { return 0; } 493 494 #define TESTCLEARFLAG_FALSE(uname, lname) \ 495 FOLIO_TEST_CLEAR_FLAG_FALSE(lname) \ 496 static inline int TestClearPage##uname(struct page *page) { return 0; } 497 498 #define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname) \ 499 SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname) 500 501 #define TESTSCFLAG_FALSE(uname, lname) \ 502 TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname) 503 504 __PAGEFLAG(Locked, locked, PF_NO_TAIL) 505 FOLIO_FLAG(waiters, FOLIO_HEAD_PAGE) 506 FOLIO_FLAG(referenced, FOLIO_HEAD_PAGE) 507 FOLIO_TEST_CLEAR_FLAG(referenced, FOLIO_HEAD_PAGE) 508 __FOLIO_SET_FLAG(referenced, FOLIO_HEAD_PAGE) 509 PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) 510 __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) 511 PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) 512 TESTCLEARFLAG(LRU, lru, PF_HEAD) 513 FOLIO_FLAG(active, FOLIO_HEAD_PAGE) 514 __FOLIO_CLEAR_FLAG(active, FOLIO_HEAD_PAGE) 515 FOLIO_TEST_CLEAR_FLAG(active, FOLIO_HEAD_PAGE) 516 PAGEFLAG(Workingset, workingset, PF_HEAD) 517 TESTCLEARFLAG(Workingset, workingset, PF_HEAD) 518 PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ 519 520 /* Xen */ 521 PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) 522 TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) 523 PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); 524 PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); 525 PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) 526 TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) 527 528 PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 529 __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 530 __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 531 FOLIO_FLAG(swapbacked, FOLIO_HEAD_PAGE) 532 __FOLIO_CLEAR_FLAG(swapbacked, FOLIO_HEAD_PAGE) 533 __FOLIO_SET_FLAG(swapbacked, FOLIO_HEAD_PAGE) 534 535 /* 536 * Private page markings that may be used by the filesystem that owns the page 537 * for its own purposes. 538 * - PG_private and PG_private_2 cause release_folio() and co to be invoked 539 */ 540 PAGEFLAG(Private, private, PF_ANY) 541 PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) 542 PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) 543 TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) 544 545 /* 546 * Only test-and-set exist for PG_writeback. The unconditional operators are 547 * risky: they bypass page accounting. 548 */ 549 TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) 550 TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) 551 PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) 552 553 /* PG_readahead is only used for reads; PG_reclaim is only for writes */ 554 PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) 555 TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) 556 FOLIO_FLAG(readahead, FOLIO_HEAD_PAGE) 557 FOLIO_TEST_CLEAR_FLAG(readahead, FOLIO_HEAD_PAGE) 558 559 #ifdef CONFIG_HIGHMEM 560 /* 561 * Must use a macro here due to header dependency issues. page_zone() is not 562 * available at this point. 563 */ 564 #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) 565 #define folio_test_highmem(__f) is_highmem_idx(folio_zonenum(__f)) 566 #else 567 PAGEFLAG_FALSE(HighMem, highmem) 568 #endif 569 570 #ifdef CONFIG_SWAP 571 static __always_inline bool folio_test_swapcache(const struct folio *folio) 572 { 573 return folio_test_swapbacked(folio) && 574 test_bit(PG_swapcache, const_folio_flags(folio, 0)); 575 } 576 577 FOLIO_SET_FLAG(swapcache, FOLIO_HEAD_PAGE) 578 FOLIO_CLEAR_FLAG(swapcache, FOLIO_HEAD_PAGE) 579 #else 580 FOLIO_FLAG_FALSE(swapcache) 581 #endif 582 583 FOLIO_FLAG(unevictable, FOLIO_HEAD_PAGE) 584 __FOLIO_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE) 585 FOLIO_TEST_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE) 586 587 #ifdef CONFIG_MMU 588 FOLIO_FLAG(mlocked, FOLIO_HEAD_PAGE) 589 __FOLIO_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) 590 FOLIO_TEST_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) 591 FOLIO_TEST_SET_FLAG(mlocked, FOLIO_HEAD_PAGE) 592 #else 593 FOLIO_FLAG_FALSE(mlocked) 594 __FOLIO_CLEAR_FLAG_NOOP(mlocked) 595 FOLIO_TEST_CLEAR_FLAG_FALSE(mlocked) 596 FOLIO_TEST_SET_FLAG_FALSE(mlocked) 597 #endif 598 599 #ifdef CONFIG_ARCH_USES_PG_UNCACHED 600 PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) 601 #else 602 PAGEFLAG_FALSE(Uncached, uncached) 603 #endif 604 605 #ifdef CONFIG_MEMORY_FAILURE 606 PAGEFLAG(HWPoison, hwpoison, PF_ANY) 607 TESTSCFLAG(HWPoison, hwpoison, PF_ANY) 608 #define __PG_HWPOISON (1UL << PG_hwpoison) 609 #else 610 PAGEFLAG_FALSE(HWPoison, hwpoison) 611 #define __PG_HWPOISON 0 612 #endif 613 614 #ifdef CONFIG_PAGE_IDLE_FLAG 615 #ifdef CONFIG_64BIT 616 FOLIO_TEST_FLAG(young, FOLIO_HEAD_PAGE) 617 FOLIO_SET_FLAG(young, FOLIO_HEAD_PAGE) 618 FOLIO_TEST_CLEAR_FLAG(young, FOLIO_HEAD_PAGE) 619 FOLIO_FLAG(idle, FOLIO_HEAD_PAGE) 620 #endif 621 /* See page_idle.h for !64BIT workaround */ 622 #else /* !CONFIG_PAGE_IDLE_FLAG */ 623 FOLIO_FLAG_FALSE(young) 624 FOLIO_TEST_CLEAR_FLAG_FALSE(young) 625 FOLIO_FLAG_FALSE(idle) 626 #endif 627 628 /* 629 * PageReported() is used to track reported free pages within the Buddy 630 * allocator. We can use the non-atomic version of the test and set 631 * operations as both should be shielded with the zone lock to prevent 632 * any possible races on the setting or clearing of the bit. 633 */ 634 __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) 635 636 #ifdef CONFIG_MEMORY_HOTPLUG 637 PAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY) 638 #else 639 PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) 640 #endif 641 642 /* 643 * On an anonymous folio mapped into a user virtual memory area, 644 * folio->mapping points to its anon_vma, not to a struct address_space; 645 * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. 646 * 647 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, 648 * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON 649 * bit; and then folio->mapping points, not to an anon_vma, but to a private 650 * structure which KSM associates with that merged page. See ksm.h. 651 * 652 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable 653 * page and then folio->mapping points to a struct movable_operations. 654 * 655 * Please note that, confusingly, "folio_mapping" refers to the inode 656 * address_space which maps the folio from disk; whereas "folio_mapped" 657 * refers to user virtual address space into which the folio is mapped. 658 * 659 * For slab pages, since slab reuses the bits in struct page to store its 660 * internal states, the folio->mapping does not exist as such, nor do 661 * these flags below. So in order to avoid testing non-existent bits, 662 * please make sure that folio_test_slab(folio) actually evaluates to 663 * false before calling the following functions (e.g., folio_test_anon). 664 * See mm/slab.h. 665 */ 666 #define PAGE_MAPPING_ANON 0x1 667 #define PAGE_MAPPING_MOVABLE 0x2 668 #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) 669 #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) 670 671 /* 672 * Different with flags above, this flag is used only for fsdax mode. It 673 * indicates that this page->mapping is now under reflink case. 674 */ 675 #define PAGE_MAPPING_DAX_SHARED ((void *)0x1) 676 677 static __always_inline bool folio_mapping_flags(const struct folio *folio) 678 { 679 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; 680 } 681 682 static __always_inline bool PageMappingFlags(const struct page *page) 683 { 684 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; 685 } 686 687 static __always_inline bool folio_test_anon(const struct folio *folio) 688 { 689 return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0; 690 } 691 692 static __always_inline bool PageAnon(const struct page *page) 693 { 694 return folio_test_anon(page_folio(page)); 695 } 696 697 static __always_inline bool __folio_test_movable(const struct folio *folio) 698 { 699 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == 700 PAGE_MAPPING_MOVABLE; 701 } 702 703 static __always_inline bool __PageMovable(const struct page *page) 704 { 705 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == 706 PAGE_MAPPING_MOVABLE; 707 } 708 709 #ifdef CONFIG_KSM 710 /* 711 * A KSM page is one of those write-protected "shared pages" or "merged pages" 712 * which KSM maps into multiple mms, wherever identical anonymous page content 713 * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any 714 * anon_vma, but to that page's node of the stable tree. 715 */ 716 static __always_inline bool folio_test_ksm(const struct folio *folio) 717 { 718 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == 719 PAGE_MAPPING_KSM; 720 } 721 722 static __always_inline bool PageKsm(const struct page *page) 723 { 724 return folio_test_ksm(page_folio(page)); 725 } 726 #else 727 TESTPAGEFLAG_FALSE(Ksm, ksm) 728 #endif 729 730 u64 stable_page_flags(const struct page *page); 731 732 /** 733 * folio_xor_flags_has_waiters - Change some folio flags. 734 * @folio: The folio. 735 * @mask: Bits set in this word will be changed. 736 * 737 * This must only be used for flags which are changed with the folio 738 * lock held. For example, it is unsafe to use for PG_dirty as that 739 * can be set without the folio lock held. It can also only be used 740 * on flags which are in the range 0-6 as some of the implementations 741 * only affect those bits. 742 * 743 * Return: Whether there are tasks waiting on the folio. 744 */ 745 static inline bool folio_xor_flags_has_waiters(struct folio *folio, 746 unsigned long mask) 747 { 748 return xor_unlock_is_negative_byte(mask, folio_flags(folio, 0)); 749 } 750 751 /** 752 * folio_test_uptodate - Is this folio up to date? 753 * @folio: The folio. 754 * 755 * The uptodate flag is set on a folio when every byte in the folio is 756 * at least as new as the corresponding bytes on storage. Anonymous 757 * and CoW folios are always uptodate. If the folio is not uptodate, 758 * some of the bytes in it may be; see the is_partially_uptodate() 759 * address_space operation. 760 */ 761 static inline bool folio_test_uptodate(const struct folio *folio) 762 { 763 bool ret = test_bit(PG_uptodate, const_folio_flags(folio, 0)); 764 /* 765 * Must ensure that the data we read out of the folio is loaded 766 * _after_ we've loaded folio->flags to check the uptodate bit. 767 * We can skip the barrier if the folio is not uptodate, because 768 * we wouldn't be reading anything from it. 769 * 770 * See folio_mark_uptodate() for the other side of the story. 771 */ 772 if (ret) 773 smp_rmb(); 774 775 return ret; 776 } 777 778 static inline bool PageUptodate(const struct page *page) 779 { 780 return folio_test_uptodate(page_folio(page)); 781 } 782 783 static __always_inline void __folio_mark_uptodate(struct folio *folio) 784 { 785 smp_wmb(); 786 __set_bit(PG_uptodate, folio_flags(folio, 0)); 787 } 788 789 static __always_inline void folio_mark_uptodate(struct folio *folio) 790 { 791 /* 792 * Memory barrier must be issued before setting the PG_uptodate bit, 793 * so that all previous stores issued in order to bring the folio 794 * uptodate are actually visible before folio_test_uptodate becomes true. 795 */ 796 smp_wmb(); 797 set_bit(PG_uptodate, folio_flags(folio, 0)); 798 } 799 800 static __always_inline void __SetPageUptodate(struct page *page) 801 { 802 __folio_mark_uptodate((struct folio *)page); 803 } 804 805 static __always_inline void SetPageUptodate(struct page *page) 806 { 807 folio_mark_uptodate((struct folio *)page); 808 } 809 810 CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) 811 812 void __folio_start_writeback(struct folio *folio, bool keep_write); 813 void set_page_writeback(struct page *page); 814 815 #define folio_start_writeback(folio) \ 816 __folio_start_writeback(folio, false) 817 #define folio_start_writeback_keepwrite(folio) \ 818 __folio_start_writeback(folio, true) 819 820 static __always_inline bool folio_test_head(const struct folio *folio) 821 { 822 return test_bit(PG_head, const_folio_flags(folio, FOLIO_PF_ANY)); 823 } 824 825 static __always_inline int PageHead(const struct page *page) 826 { 827 PF_POISONED_CHECK(page); 828 return test_bit(PG_head, &page->flags) && !page_is_fake_head(page); 829 } 830 831 __SETPAGEFLAG(Head, head, PF_ANY) 832 __CLEARPAGEFLAG(Head, head, PF_ANY) 833 CLEARPAGEFLAG(Head, head, PF_ANY) 834 835 /** 836 * folio_test_large() - Does this folio contain more than one page? 837 * @folio: The folio to test. 838 * 839 * Return: True if the folio is larger than one page. 840 */ 841 static inline bool folio_test_large(const struct folio *folio) 842 { 843 return folio_test_head(folio); 844 } 845 846 static __always_inline void set_compound_head(struct page *page, struct page *head) 847 { 848 WRITE_ONCE(page->compound_head, (unsigned long)head + 1); 849 } 850 851 static __always_inline void clear_compound_head(struct page *page) 852 { 853 WRITE_ONCE(page->compound_head, 0); 854 } 855 856 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 857 static inline void ClearPageCompound(struct page *page) 858 { 859 BUG_ON(!PageHead(page)); 860 ClearPageHead(page); 861 } 862 FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE) 863 #else 864 FOLIO_FLAG_FALSE(large_rmappable) 865 #endif 866 867 #define PG_head_mask ((1UL << PG_head)) 868 869 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 870 /* 871 * PageHuge() only returns true for hugetlbfs pages, but not for 872 * normal or transparent huge pages. 873 * 874 * PageTransHuge() returns true for both transparent huge and 875 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be 876 * called only in the core VM paths where hugetlbfs pages can't exist. 877 */ 878 static inline int PageTransHuge(const struct page *page) 879 { 880 VM_BUG_ON_PAGE(PageTail(page), page); 881 return PageHead(page); 882 } 883 884 /* 885 * PageTransCompound returns true for both transparent huge pages 886 * and hugetlbfs pages, so it should only be called when it's known 887 * that hugetlbfs pages aren't involved. 888 */ 889 static inline int PageTransCompound(const struct page *page) 890 { 891 return PageCompound(page); 892 } 893 894 /* 895 * PageTransTail returns true for both transparent huge pages 896 * and hugetlbfs pages, so it should only be called when it's known 897 * that hugetlbfs pages aren't involved. 898 */ 899 static inline int PageTransTail(const struct page *page) 900 { 901 return PageTail(page); 902 } 903 #else 904 TESTPAGEFLAG_FALSE(TransHuge, transhuge) 905 TESTPAGEFLAG_FALSE(TransCompound, transcompound) 906 TESTPAGEFLAG_FALSE(TransCompoundMap, transcompoundmap) 907 TESTPAGEFLAG_FALSE(TransTail, transtail) 908 #endif 909 910 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 911 /* 912 * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the 913 * compound page. 914 * 915 * This flag is set by hwpoison handler. Cleared by THP split or free page. 916 */ 917 PAGEFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND) 918 TESTSCFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND) 919 #else 920 PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) 921 TESTSCFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) 922 #endif 923 924 /* 925 * For pages that do not use mapcount, page_type may be used. 926 * The low 24 bits of pagetype may be used for your own purposes, as long 927 * as you are careful to not affect the top 8 bits. The low bits of 928 * pagetype will be overwritten when you clear the page_type from the page. 929 */ 930 enum pagetype { 931 /* 0x00-0x7f are positive numbers, ie mapcount */ 932 /* Reserve 0x80-0xef for mapcount overflow. */ 933 PGTY_buddy = 0xf0, 934 PGTY_offline = 0xf1, 935 PGTY_table = 0xf2, 936 PGTY_guard = 0xf3, 937 PGTY_hugetlb = 0xf4, 938 PGTY_slab = 0xf5, 939 PGTY_zsmalloc = 0xf6, 940 PGTY_unaccepted = 0xf7, 941 942 PGTY_mapcount_underflow = 0xff 943 }; 944 945 static inline bool page_type_has_type(int page_type) 946 { 947 return page_type < (PGTY_mapcount_underflow << 24); 948 } 949 950 /* This takes a mapcount which is one more than page->_mapcount */ 951 static inline bool page_mapcount_is_type(unsigned int mapcount) 952 { 953 return page_type_has_type(mapcount - 1); 954 } 955 956 static inline bool page_has_type(const struct page *page) 957 { 958 return page_mapcount_is_type(data_race(page->page_type)); 959 } 960 961 #define FOLIO_TYPE_OPS(lname, fname) \ 962 static __always_inline bool folio_test_##fname(const struct folio *folio) \ 963 { \ 964 return data_race(folio->page.page_type >> 24) == PGTY_##lname; \ 965 } \ 966 static __always_inline void __folio_set_##fname(struct folio *folio) \ 967 { \ 968 VM_BUG_ON_FOLIO(data_race(folio->page.page_type) != UINT_MAX, \ 969 folio); \ 970 folio->page.page_type = (unsigned int)PGTY_##lname << 24; \ 971 } \ 972 static __always_inline void __folio_clear_##fname(struct folio *folio) \ 973 { \ 974 VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ 975 folio->page.page_type = UINT_MAX; \ 976 } 977 978 #define PAGE_TYPE_OPS(uname, lname, fname) \ 979 FOLIO_TYPE_OPS(lname, fname) \ 980 static __always_inline int Page##uname(const struct page *page) \ 981 { \ 982 return data_race(page->page_type >> 24) == PGTY_##lname; \ 983 } \ 984 static __always_inline void __SetPage##uname(struct page *page) \ 985 { \ 986 VM_BUG_ON_PAGE(data_race(page->page_type) != UINT_MAX, page); \ 987 page->page_type = (unsigned int)PGTY_##lname << 24; \ 988 } \ 989 static __always_inline void __ClearPage##uname(struct page *page) \ 990 { \ 991 VM_BUG_ON_PAGE(!Page##uname(page), page); \ 992 page->page_type = UINT_MAX; \ 993 } 994 995 /* 996 * PageBuddy() indicates that the page is free and in the buddy system 997 * (see mm/page_alloc.c). 998 */ 999 PAGE_TYPE_OPS(Buddy, buddy, buddy) 1000 1001 /* 1002 * PageOffline() indicates that the page is logically offline although the 1003 * containing section is online. (e.g. inflated in a balloon driver or 1004 * not onlined when onlining the section). 1005 * The content of these pages is effectively stale. Such pages should not 1006 * be touched (read/write/dump/save) except by their owner. 1007 * 1008 * When a memory block gets onlined, all pages are initialized with a 1009 * refcount of 1 and PageOffline(). generic_online_page() will 1010 * take care of clearing PageOffline(). 1011 * 1012 * If a driver wants to allow to offline unmovable PageOffline() pages without 1013 * putting them back to the buddy, it can do so via the memory notifier by 1014 * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the 1015 * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() 1016 * pages (now with a reference count of zero) are treated like free (unmanaged) 1017 * pages, allowing the containing memory block to get offlined. A driver that 1018 * relies on this feature is aware that re-onlining the memory block will 1019 * require not giving them to the buddy via generic_online_page(). 1020 * 1021 * Memory offlining code will not adjust the managed page count for any 1022 * PageOffline() pages, treating them like they were never exposed to the 1023 * buddy using generic_online_page(). 1024 * 1025 * There are drivers that mark a page PageOffline() and expect there won't be 1026 * any further access to page content. PFN walkers that read content of random 1027 * pages should check PageOffline() and synchronize with such drivers using 1028 * page_offline_freeze()/page_offline_thaw(). 1029 */ 1030 PAGE_TYPE_OPS(Offline, offline, offline) 1031 1032 extern void page_offline_freeze(void); 1033 extern void page_offline_thaw(void); 1034 extern void page_offline_begin(void); 1035 extern void page_offline_end(void); 1036 1037 /* 1038 * Marks pages in use as page tables. 1039 */ 1040 PAGE_TYPE_OPS(Table, table, pgtable) 1041 1042 /* 1043 * Marks guardpages used with debug_pagealloc. 1044 */ 1045 PAGE_TYPE_OPS(Guard, guard, guard) 1046 1047 FOLIO_TYPE_OPS(slab, slab) 1048 1049 /** 1050 * PageSlab - Determine if the page belongs to the slab allocator 1051 * @page: The page to test. 1052 * 1053 * Context: Any context. 1054 * Return: True for slab pages, false for any other kind of page. 1055 */ 1056 static inline bool PageSlab(const struct page *page) 1057 { 1058 return folio_test_slab(page_folio(page)); 1059 } 1060 1061 #ifdef CONFIG_HUGETLB_PAGE 1062 FOLIO_TYPE_OPS(hugetlb, hugetlb) 1063 #else 1064 FOLIO_TEST_FLAG_FALSE(hugetlb) 1065 #endif 1066 1067 PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc) 1068 1069 /* 1070 * Mark pages that has to be accepted before touched for the first time. 1071 * 1072 * Serialized with zone lock. 1073 */ 1074 PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted) 1075 1076 /** 1077 * PageHuge - Determine if the page belongs to hugetlbfs 1078 * @page: The page to test. 1079 * 1080 * Context: Any context. 1081 * Return: True for hugetlbfs pages, false for anon pages or pages 1082 * belonging to other filesystems. 1083 */ 1084 static inline bool PageHuge(const struct page *page) 1085 { 1086 return folio_test_hugetlb(page_folio(page)); 1087 } 1088 1089 /* 1090 * Check if a page is currently marked HWPoisoned. Note that this check is 1091 * best effort only and inherently racy: there is no way to synchronize with 1092 * failing hardware. 1093 */ 1094 static inline bool is_page_hwpoison(const struct page *page) 1095 { 1096 const struct folio *folio; 1097 1098 if (PageHWPoison(page)) 1099 return true; 1100 folio = page_folio(page); 1101 return folio_test_hugetlb(folio) && PageHWPoison(&folio->page); 1102 } 1103 1104 bool is_free_buddy_page(const struct page *page); 1105 1106 PAGEFLAG(Isolated, isolated, PF_ANY); 1107 1108 static __always_inline int PageAnonExclusive(const struct page *page) 1109 { 1110 VM_BUG_ON_PGFLAGS(!PageAnon(page), page); 1111 /* 1112 * HugeTLB stores this information on the head page; THP keeps it per 1113 * page 1114 */ 1115 if (PageHuge(page)) 1116 page = compound_head(page); 1117 return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1118 } 1119 1120 static __always_inline void SetPageAnonExclusive(struct page *page) 1121 { 1122 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); 1123 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1124 set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1125 } 1126 1127 static __always_inline void ClearPageAnonExclusive(struct page *page) 1128 { 1129 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); 1130 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1131 clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1132 } 1133 1134 static __always_inline void __ClearPageAnonExclusive(struct page *page) 1135 { 1136 VM_BUG_ON_PGFLAGS(!PageAnon(page), page); 1137 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1138 __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1139 } 1140 1141 #ifdef CONFIG_MMU 1142 #define __PG_MLOCKED (1UL << PG_mlocked) 1143 #else 1144 #define __PG_MLOCKED 0 1145 #endif 1146 1147 /* 1148 * Flags checked when a page is freed. Pages being freed should not have 1149 * these flags set. If they are, there is a problem. 1150 */ 1151 #define PAGE_FLAGS_CHECK_AT_FREE \ 1152 (1UL << PG_lru | 1UL << PG_locked | \ 1153 1UL << PG_private | 1UL << PG_private_2 | \ 1154 1UL << PG_writeback | 1UL << PG_reserved | \ 1155 1UL << PG_active | \ 1156 1UL << PG_unevictable | __PG_MLOCKED | LRU_GEN_MASK) 1157 1158 /* 1159 * Flags checked when a page is prepped for return by the page allocator. 1160 * Pages being prepped should not have these flags set. If they are set, 1161 * there has been a kernel bug or struct page corruption. 1162 * 1163 * __PG_HWPOISON is exceptional because it needs to be kept beyond page's 1164 * alloc-free cycle to prevent from reusing the page. 1165 */ 1166 #define PAGE_FLAGS_CHECK_AT_PREP \ 1167 ((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK) 1168 1169 /* 1170 * Flags stored in the second page of a compound page. They may overlap 1171 * the CHECK_AT_FREE flags above, so need to be cleared. 1172 */ 1173 #define PAGE_FLAGS_SECOND \ 1174 (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ 1175 1UL << PG_large_rmappable) 1176 1177 #define PAGE_FLAGS_PRIVATE \ 1178 (1UL << PG_private | 1UL << PG_private_2) 1179 /** 1180 * page_has_private - Determine if page has private stuff 1181 * @page: The page to be checked 1182 * 1183 * Determine if a page has private stuff, indicating that release routines 1184 * should be invoked upon it. 1185 */ 1186 static inline int page_has_private(const struct page *page) 1187 { 1188 return !!(page->flags & PAGE_FLAGS_PRIVATE); 1189 } 1190 1191 static inline bool folio_has_private(const struct folio *folio) 1192 { 1193 return page_has_private(&folio->page); 1194 } 1195 1196 #undef PF_ANY 1197 #undef PF_HEAD 1198 #undef PF_NO_TAIL 1199 #undef PF_NO_COMPOUND 1200 #undef PF_SECOND 1201 #endif /* !__GENERATING_BOUNDS_H */ 1202 1203 #endif /* PAGE_FLAGS_H */ 1204