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_owner_priv_1, /* Owner use. If pagecache, fs may use*/ 113 PG_arch_1, 114 PG_reserved, 115 PG_private, /* If pagecache, has fs-private data */ 116 PG_private_2, /* If pagecache, has fs aux data */ 117 PG_mappedtodisk, /* Has blocks allocated on-disk */ 118 PG_reclaim, /* To be reclaimed asap */ 119 PG_swapbacked, /* Page is backed by RAM/swap */ 120 PG_unevictable, /* Page is "unevictable" */ 121 #ifdef CONFIG_MMU 122 PG_mlocked, /* Page is vma mlocked */ 123 #endif 124 #ifdef CONFIG_ARCH_USES_PG_UNCACHED 125 PG_uncached, /* Page has been mapped as uncached */ 126 #endif 127 #ifdef CONFIG_MEMORY_FAILURE 128 PG_hwpoison, /* hardware poisoned page. Don't touch */ 129 #endif 130 #if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT) 131 PG_young, 132 PG_idle, 133 #endif 134 #ifdef CONFIG_ARCH_USES_PG_ARCH_X 135 PG_arch_2, 136 PG_arch_3, 137 #endif 138 __NR_PAGEFLAGS, 139 140 PG_readahead = PG_reclaim, 141 142 /* 143 * Depending on the way an anonymous folio can be mapped into a page 144 * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped 145 * THP), PG_anon_exclusive may be set only for the head page or for 146 * tail pages of an anonymous folio. For now, we only expect it to be 147 * set on tail pages for PTE-mapped THP. 148 */ 149 PG_anon_exclusive = PG_mappedtodisk, 150 151 /* Filesystems */ 152 PG_checked = PG_owner_priv_1, 153 154 /* SwapBacked */ 155 PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ 156 157 /* Two page bits are conscripted by FS-Cache to maintain local caching 158 * state. These bits are set on pages belonging to the netfs's inodes 159 * when those inodes are being locally cached. 160 */ 161 PG_fscache = PG_private_2, /* page backed by cache */ 162 163 /* XEN */ 164 /* Pinned in Xen as a read-only pagetable page. */ 165 PG_pinned = PG_owner_priv_1, 166 /* Pinned as part of domain save (see xen_mm_pin_all()). */ 167 PG_savepinned = PG_dirty, 168 /* Has a grant mapping of another (foreign) domain's page. */ 169 PG_foreign = PG_owner_priv_1, 170 /* Remapped by swiotlb-xen. */ 171 PG_xen_remapped = PG_owner_priv_1, 172 173 /* non-lru isolated movable page */ 174 PG_isolated = PG_reclaim, 175 176 /* Only valid for buddy pages. Used to track pages that are reported */ 177 PG_reported = PG_uptodate, 178 179 #ifdef CONFIG_MEMORY_HOTPLUG 180 /* For self-hosted memmap pages */ 181 PG_vmemmap_self_hosted = PG_owner_priv_1, 182 #endif 183 184 /* 185 * Flags only valid for compound pages. Stored in first tail page's 186 * flags word. Cannot use the first 8 flags or any flag marked as 187 * PF_ANY. 188 */ 189 190 /* At least one page in this folio has the hwpoison flag set */ 191 PG_has_hwpoisoned = PG_error, 192 PG_large_rmappable = PG_workingset, /* anon or file-backed */ 193 }; 194 195 #define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1) 196 197 #ifndef __GENERATING_BOUNDS_H 198 199 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP 200 DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key); 201 202 /* 203 * Return the real head page struct iff the @page is a fake head page, otherwise 204 * return the @page itself. See Documentation/mm/vmemmap_dedup.rst. 205 */ 206 static __always_inline const struct page *page_fixed_fake_head(const struct page *page) 207 { 208 if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) 209 return page; 210 211 /* 212 * Only addresses aligned with PAGE_SIZE of struct page may be fake head 213 * struct page. The alignment check aims to avoid access the fields ( 214 * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly) 215 * cold cacheline in some cases. 216 */ 217 if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) && 218 test_bit(PG_head, &page->flags)) { 219 /* 220 * We can safely access the field of the @page[1] with PG_head 221 * because the @page is a compound page composed with at least 222 * two contiguous pages. 223 */ 224 unsigned long head = READ_ONCE(page[1].compound_head); 225 226 if (likely(head & 1)) 227 return (const struct page *)(head - 1); 228 } 229 return page; 230 } 231 #else 232 static inline const struct page *page_fixed_fake_head(const struct page *page) 233 { 234 return page; 235 } 236 #endif 237 238 static __always_inline int page_is_fake_head(const struct page *page) 239 { 240 return page_fixed_fake_head(page) != page; 241 } 242 243 static inline unsigned long _compound_head(const struct page *page) 244 { 245 unsigned long head = READ_ONCE(page->compound_head); 246 247 if (unlikely(head & 1)) 248 return head - 1; 249 return (unsigned long)page_fixed_fake_head(page); 250 } 251 252 #define compound_head(page) ((typeof(page))_compound_head(page)) 253 254 /** 255 * page_folio - Converts from page to folio. 256 * @p: The page. 257 * 258 * Every page is part of a folio. This function cannot be called on a 259 * NULL pointer. 260 * 261 * Context: No reference, nor lock is required on @page. If the caller 262 * does not hold a reference, this call may race with a folio split, so 263 * it should re-check the folio still contains this page after gaining 264 * a reference on the folio. 265 * Return: The folio which contains this page. 266 */ 267 #define page_folio(p) (_Generic((p), \ 268 const struct page *: (const struct folio *)_compound_head(p), \ 269 struct page *: (struct folio *)_compound_head(p))) 270 271 /** 272 * folio_page - Return a page from a folio. 273 * @folio: The folio. 274 * @n: The page number to return. 275 * 276 * @n is relative to the start of the folio. This function does not 277 * check that the page number lies within @folio; the caller is presumed 278 * to have a reference to the page. 279 */ 280 #define folio_page(folio, n) nth_page(&(folio)->page, n) 281 282 static __always_inline int PageTail(const struct page *page) 283 { 284 return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page); 285 } 286 287 static __always_inline int PageCompound(const struct page *page) 288 { 289 return test_bit(PG_head, &page->flags) || 290 READ_ONCE(page->compound_head) & 1; 291 } 292 293 #define PAGE_POISON_PATTERN -1l 294 static inline int PagePoisoned(const struct page *page) 295 { 296 return READ_ONCE(page->flags) == PAGE_POISON_PATTERN; 297 } 298 299 #ifdef CONFIG_DEBUG_VM 300 void page_init_poison(struct page *page, size_t size); 301 #else 302 static inline void page_init_poison(struct page *page, size_t size) 303 { 304 } 305 #endif 306 307 static const unsigned long *const_folio_flags(const struct folio *folio, 308 unsigned n) 309 { 310 const struct page *page = &folio->page; 311 312 VM_BUG_ON_PGFLAGS(PageTail(page), page); 313 VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); 314 return &page[n].flags; 315 } 316 317 static unsigned long *folio_flags(struct folio *folio, unsigned n) 318 { 319 struct page *page = &folio->page; 320 321 VM_BUG_ON_PGFLAGS(PageTail(page), page); 322 VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); 323 return &page[n].flags; 324 } 325 326 /* 327 * Page flags policies wrt compound pages 328 * 329 * PF_POISONED_CHECK 330 * check if this struct page poisoned/uninitialized 331 * 332 * PF_ANY: 333 * the page flag is relevant for small, head and tail pages. 334 * 335 * PF_HEAD: 336 * for compound page all operations related to the page flag applied to 337 * head page. 338 * 339 * PF_NO_TAIL: 340 * modifications of the page flag must be done on small or head pages, 341 * checks can be done on tail pages too. 342 * 343 * PF_NO_COMPOUND: 344 * the page flag is not relevant for compound pages. 345 * 346 * PF_SECOND: 347 * the page flag is stored in the first tail page. 348 */ 349 #define PF_POISONED_CHECK(page) ({ \ 350 VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ 351 page; }) 352 #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) 353 #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) 354 #define PF_NO_TAIL(page, enforce) ({ \ 355 VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ 356 PF_POISONED_CHECK(compound_head(page)); }) 357 #define PF_NO_COMPOUND(page, enforce) ({ \ 358 VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ 359 PF_POISONED_CHECK(page); }) 360 #define PF_SECOND(page, enforce) ({ \ 361 VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ 362 PF_POISONED_CHECK(&page[1]); }) 363 364 /* Which page is the flag stored in */ 365 #define FOLIO_PF_ANY 0 366 #define FOLIO_PF_HEAD 0 367 #define FOLIO_PF_NO_TAIL 0 368 #define FOLIO_PF_NO_COMPOUND 0 369 #define FOLIO_PF_SECOND 1 370 371 #define FOLIO_HEAD_PAGE 0 372 #define FOLIO_SECOND_PAGE 1 373 374 /* 375 * Macros to create function definitions for page flags 376 */ 377 #define FOLIO_TEST_FLAG(name, page) \ 378 static __always_inline bool folio_test_##name(const struct folio *folio) \ 379 { return test_bit(PG_##name, const_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_SET_FLAG(name, page) \ 390 static __always_inline void __folio_set_##name(struct folio *folio) \ 391 { __set_bit(PG_##name, folio_flags(folio, page)); } 392 393 #define __FOLIO_CLEAR_FLAG(name, page) \ 394 static __always_inline void __folio_clear_##name(struct folio *folio) \ 395 { __clear_bit(PG_##name, folio_flags(folio, page)); } 396 397 #define FOLIO_TEST_SET_FLAG(name, page) \ 398 static __always_inline bool folio_test_set_##name(struct folio *folio) \ 399 { return test_and_set_bit(PG_##name, folio_flags(folio, page)); } 400 401 #define FOLIO_TEST_CLEAR_FLAG(name, page) \ 402 static __always_inline bool folio_test_clear_##name(struct folio *folio) \ 403 { return test_and_clear_bit(PG_##name, folio_flags(folio, page)); } 404 405 #define FOLIO_FLAG(name, page) \ 406 FOLIO_TEST_FLAG(name, page) \ 407 FOLIO_SET_FLAG(name, page) \ 408 FOLIO_CLEAR_FLAG(name, page) 409 410 #define TESTPAGEFLAG(uname, lname, policy) \ 411 FOLIO_TEST_FLAG(lname, FOLIO_##policy) \ 412 static __always_inline int Page##uname(const struct page *page) \ 413 { return test_bit(PG_##lname, &policy(page, 0)->flags); } 414 415 #define SETPAGEFLAG(uname, lname, policy) \ 416 FOLIO_SET_FLAG(lname, FOLIO_##policy) \ 417 static __always_inline void SetPage##uname(struct page *page) \ 418 { set_bit(PG_##lname, &policy(page, 1)->flags); } 419 420 #define CLEARPAGEFLAG(uname, lname, policy) \ 421 FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \ 422 static __always_inline void ClearPage##uname(struct page *page) \ 423 { clear_bit(PG_##lname, &policy(page, 1)->flags); } 424 425 #define __SETPAGEFLAG(uname, lname, policy) \ 426 __FOLIO_SET_FLAG(lname, FOLIO_##policy) \ 427 static __always_inline void __SetPage##uname(struct page *page) \ 428 { __set_bit(PG_##lname, &policy(page, 1)->flags); } 429 430 #define __CLEARPAGEFLAG(uname, lname, policy) \ 431 __FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \ 432 static __always_inline void __ClearPage##uname(struct page *page) \ 433 { __clear_bit(PG_##lname, &policy(page, 1)->flags); } 434 435 #define TESTSETFLAG(uname, lname, policy) \ 436 FOLIO_TEST_SET_FLAG(lname, FOLIO_##policy) \ 437 static __always_inline int TestSetPage##uname(struct page *page) \ 438 { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } 439 440 #define TESTCLEARFLAG(uname, lname, policy) \ 441 FOLIO_TEST_CLEAR_FLAG(lname, FOLIO_##policy) \ 442 static __always_inline int TestClearPage##uname(struct page *page) \ 443 { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } 444 445 #define PAGEFLAG(uname, lname, policy) \ 446 TESTPAGEFLAG(uname, lname, policy) \ 447 SETPAGEFLAG(uname, lname, policy) \ 448 CLEARPAGEFLAG(uname, lname, policy) 449 450 #define __PAGEFLAG(uname, lname, policy) \ 451 TESTPAGEFLAG(uname, lname, policy) \ 452 __SETPAGEFLAG(uname, lname, policy) \ 453 __CLEARPAGEFLAG(uname, lname, policy) 454 455 #define TESTSCFLAG(uname, lname, policy) \ 456 TESTSETFLAG(uname, lname, policy) \ 457 TESTCLEARFLAG(uname, lname, policy) 458 459 #define FOLIO_TEST_FLAG_FALSE(name) \ 460 static inline bool folio_test_##name(const struct folio *folio) \ 461 { return false; } 462 #define FOLIO_SET_FLAG_NOOP(name) \ 463 static inline void folio_set_##name(struct folio *folio) { } 464 #define FOLIO_CLEAR_FLAG_NOOP(name) \ 465 static inline void folio_clear_##name(struct folio *folio) { } 466 #define __FOLIO_SET_FLAG_NOOP(name) \ 467 static inline void __folio_set_##name(struct folio *folio) { } 468 #define __FOLIO_CLEAR_FLAG_NOOP(name) \ 469 static inline void __folio_clear_##name(struct folio *folio) { } 470 #define FOLIO_TEST_SET_FLAG_FALSE(name) \ 471 static inline bool folio_test_set_##name(struct folio *folio) \ 472 { return false; } 473 #define FOLIO_TEST_CLEAR_FLAG_FALSE(name) \ 474 static inline bool folio_test_clear_##name(struct folio *folio) \ 475 { return false; } 476 477 #define FOLIO_FLAG_FALSE(name) \ 478 FOLIO_TEST_FLAG_FALSE(name) \ 479 FOLIO_SET_FLAG_NOOP(name) \ 480 FOLIO_CLEAR_FLAG_NOOP(name) 481 482 #define TESTPAGEFLAG_FALSE(uname, lname) \ 483 FOLIO_TEST_FLAG_FALSE(lname) \ 484 static inline int Page##uname(const struct page *page) { return 0; } 485 486 #define SETPAGEFLAG_NOOP(uname, lname) \ 487 FOLIO_SET_FLAG_NOOP(lname) \ 488 static inline void SetPage##uname(struct page *page) { } 489 490 #define CLEARPAGEFLAG_NOOP(uname, lname) \ 491 FOLIO_CLEAR_FLAG_NOOP(lname) \ 492 static inline void ClearPage##uname(struct page *page) { } 493 494 #define __CLEARPAGEFLAG_NOOP(uname, lname) \ 495 __FOLIO_CLEAR_FLAG_NOOP(lname) \ 496 static inline void __ClearPage##uname(struct page *page) { } 497 498 #define TESTSETFLAG_FALSE(uname, lname) \ 499 FOLIO_TEST_SET_FLAG_FALSE(lname) \ 500 static inline int TestSetPage##uname(struct page *page) { return 0; } 501 502 #define TESTCLEARFLAG_FALSE(uname, lname) \ 503 FOLIO_TEST_CLEAR_FLAG_FALSE(lname) \ 504 static inline int TestClearPage##uname(struct page *page) { return 0; } 505 506 #define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname) \ 507 SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname) 508 509 #define TESTSCFLAG_FALSE(uname, lname) \ 510 TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname) 511 512 __PAGEFLAG(Locked, locked, PF_NO_TAIL) 513 FOLIO_FLAG(waiters, FOLIO_HEAD_PAGE) 514 PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) 515 FOLIO_FLAG(referenced, FOLIO_HEAD_PAGE) 516 FOLIO_TEST_CLEAR_FLAG(referenced, FOLIO_HEAD_PAGE) 517 __FOLIO_SET_FLAG(referenced, FOLIO_HEAD_PAGE) 518 PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) 519 __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) 520 PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) 521 TESTCLEARFLAG(LRU, lru, PF_HEAD) 522 PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) 523 TESTCLEARFLAG(Active, active, PF_HEAD) 524 PAGEFLAG(Workingset, workingset, PF_HEAD) 525 TESTCLEARFLAG(Workingset, workingset, PF_HEAD) 526 PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ 527 528 /* Xen */ 529 PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) 530 TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) 531 PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); 532 PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); 533 PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) 534 TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) 535 536 PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 537 __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 538 __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) 539 PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) 540 __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) 541 __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) 542 543 /* 544 * Private page markings that may be used by the filesystem that owns the page 545 * for its own purposes. 546 * - PG_private and PG_private_2 cause release_folio() and co to be invoked 547 */ 548 PAGEFLAG(Private, private, PF_ANY) 549 PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) 550 PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) 551 TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) 552 553 /* 554 * Only test-and-set exist for PG_writeback. The unconditional operators are 555 * risky: they bypass page accounting. 556 */ 557 TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) 558 TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) 559 PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) 560 561 /* PG_readahead is only used for reads; PG_reclaim is only for writes */ 562 PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) 563 TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) 564 PAGEFLAG(Readahead, readahead, PF_NO_COMPOUND) 565 TESTCLEARFLAG(Readahead, readahead, PF_NO_COMPOUND) 566 567 #ifdef CONFIG_HIGHMEM 568 /* 569 * Must use a macro here due to header dependency issues. page_zone() is not 570 * available at this point. 571 */ 572 #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) 573 #define folio_test_highmem(__f) is_highmem_idx(folio_zonenum(__f)) 574 #else 575 PAGEFLAG_FALSE(HighMem, highmem) 576 #endif 577 578 #ifdef CONFIG_SWAP 579 static __always_inline bool folio_test_swapcache(const struct folio *folio) 580 { 581 return folio_test_swapbacked(folio) && 582 test_bit(PG_swapcache, const_folio_flags(folio, 0)); 583 } 584 585 static __always_inline bool PageSwapCache(const struct page *page) 586 { 587 return folio_test_swapcache(page_folio(page)); 588 } 589 590 SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) 591 CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) 592 #else 593 PAGEFLAG_FALSE(SwapCache, swapcache) 594 #endif 595 596 PAGEFLAG(Unevictable, unevictable, PF_HEAD) 597 __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) 598 TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) 599 600 #ifdef CONFIG_MMU 601 PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) 602 __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) 603 TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) 604 #else 605 PAGEFLAG_FALSE(Mlocked, mlocked) __CLEARPAGEFLAG_NOOP(Mlocked, mlocked) 606 TESTSCFLAG_FALSE(Mlocked, mlocked) 607 #endif 608 609 #ifdef CONFIG_ARCH_USES_PG_UNCACHED 610 PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) 611 #else 612 PAGEFLAG_FALSE(Uncached, uncached) 613 #endif 614 615 #ifdef CONFIG_MEMORY_FAILURE 616 PAGEFLAG(HWPoison, hwpoison, PF_ANY) 617 TESTSCFLAG(HWPoison, hwpoison, PF_ANY) 618 #define __PG_HWPOISON (1UL << PG_hwpoison) 619 #define MAGIC_HWPOISON 0x48575053U /* HWPS */ 620 extern void SetPageHWPoisonTakenOff(struct page *page); 621 extern void ClearPageHWPoisonTakenOff(struct page *page); 622 extern bool take_page_off_buddy(struct page *page); 623 extern bool put_page_back_buddy(struct page *page); 624 #else 625 PAGEFLAG_FALSE(HWPoison, hwpoison) 626 #define __PG_HWPOISON 0 627 #endif 628 629 #ifdef CONFIG_PAGE_IDLE_FLAG 630 #ifdef CONFIG_64BIT 631 FOLIO_TEST_FLAG(young, FOLIO_HEAD_PAGE) 632 FOLIO_SET_FLAG(young, FOLIO_HEAD_PAGE) 633 FOLIO_TEST_CLEAR_FLAG(young, FOLIO_HEAD_PAGE) 634 FOLIO_FLAG(idle, FOLIO_HEAD_PAGE) 635 #endif 636 /* See page_idle.h for !64BIT workaround */ 637 #else /* !CONFIG_PAGE_IDLE_FLAG */ 638 FOLIO_FLAG_FALSE(young) 639 FOLIO_TEST_CLEAR_FLAG_FALSE(young) 640 FOLIO_FLAG_FALSE(idle) 641 #endif 642 643 /* 644 * PageReported() is used to track reported free pages within the Buddy 645 * allocator. We can use the non-atomic version of the test and set 646 * operations as both should be shielded with the zone lock to prevent 647 * any possible races on the setting or clearing of the bit. 648 */ 649 __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) 650 651 #ifdef CONFIG_MEMORY_HOTPLUG 652 PAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY) 653 #else 654 PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) 655 #endif 656 657 /* 658 * On an anonymous page mapped into a user virtual memory area, 659 * page->mapping points to its anon_vma, not to a struct address_space; 660 * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. 661 * 662 * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, 663 * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON 664 * bit; and then page->mapping points, not to an anon_vma, but to a private 665 * structure which KSM associates with that merged page. See ksm.h. 666 * 667 * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable 668 * page and then page->mapping points to a struct movable_operations. 669 * 670 * Please note that, confusingly, "page_mapping" refers to the inode 671 * address_space which maps the page from disk; whereas "page_mapped" 672 * refers to user virtual address space into which the page is mapped. 673 * 674 * For slab pages, since slab reuses the bits in struct page to store its 675 * internal states, the page->mapping does not exist as such, nor do these 676 * flags below. So in order to avoid testing non-existent bits, please 677 * make sure that PageSlab(page) actually evaluates to false before calling 678 * the following functions (e.g., PageAnon). See mm/slab.h. 679 */ 680 #define PAGE_MAPPING_ANON 0x1 681 #define PAGE_MAPPING_MOVABLE 0x2 682 #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) 683 #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) 684 685 /* 686 * Different with flags above, this flag is used only for fsdax mode. It 687 * indicates that this page->mapping is now under reflink case. 688 */ 689 #define PAGE_MAPPING_DAX_SHARED ((void *)0x1) 690 691 static __always_inline bool folio_mapping_flags(const struct folio *folio) 692 { 693 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; 694 } 695 696 static __always_inline bool PageMappingFlags(const struct page *page) 697 { 698 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; 699 } 700 701 static __always_inline bool folio_test_anon(const struct folio *folio) 702 { 703 return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0; 704 } 705 706 static __always_inline bool PageAnon(const struct page *page) 707 { 708 return folio_test_anon(page_folio(page)); 709 } 710 711 static __always_inline bool __folio_test_movable(const struct folio *folio) 712 { 713 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == 714 PAGE_MAPPING_MOVABLE; 715 } 716 717 static __always_inline bool __PageMovable(const struct page *page) 718 { 719 return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == 720 PAGE_MAPPING_MOVABLE; 721 } 722 723 #ifdef CONFIG_KSM 724 /* 725 * A KSM page is one of those write-protected "shared pages" or "merged pages" 726 * which KSM maps into multiple mms, wherever identical anonymous page content 727 * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any 728 * anon_vma, but to that page's node of the stable tree. 729 */ 730 static __always_inline bool folio_test_ksm(const struct folio *folio) 731 { 732 return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == 733 PAGE_MAPPING_KSM; 734 } 735 736 static __always_inline bool PageKsm(const struct page *page) 737 { 738 return folio_test_ksm(page_folio(page)); 739 } 740 #else 741 TESTPAGEFLAG_FALSE(Ksm, ksm) 742 #endif 743 744 u64 stable_page_flags(const struct page *page); 745 746 /** 747 * folio_xor_flags_has_waiters - Change some folio flags. 748 * @folio: The folio. 749 * @mask: Bits set in this word will be changed. 750 * 751 * This must only be used for flags which are changed with the folio 752 * lock held. For example, it is unsafe to use for PG_dirty as that 753 * can be set without the folio lock held. It can also only be used 754 * on flags which are in the range 0-6 as some of the implementations 755 * only affect those bits. 756 * 757 * Return: Whether there are tasks waiting on the folio. 758 */ 759 static inline bool folio_xor_flags_has_waiters(struct folio *folio, 760 unsigned long mask) 761 { 762 return xor_unlock_is_negative_byte(mask, folio_flags(folio, 0)); 763 } 764 765 /** 766 * folio_test_uptodate - Is this folio up to date? 767 * @folio: The folio. 768 * 769 * The uptodate flag is set on a folio when every byte in the folio is 770 * at least as new as the corresponding bytes on storage. Anonymous 771 * and CoW folios are always uptodate. If the folio is not uptodate, 772 * some of the bytes in it may be; see the is_partially_uptodate() 773 * address_space operation. 774 */ 775 static inline bool folio_test_uptodate(const struct folio *folio) 776 { 777 bool ret = test_bit(PG_uptodate, const_folio_flags(folio, 0)); 778 /* 779 * Must ensure that the data we read out of the folio is loaded 780 * _after_ we've loaded folio->flags to check the uptodate bit. 781 * We can skip the barrier if the folio is not uptodate, because 782 * we wouldn't be reading anything from it. 783 * 784 * See folio_mark_uptodate() for the other side of the story. 785 */ 786 if (ret) 787 smp_rmb(); 788 789 return ret; 790 } 791 792 static inline bool PageUptodate(const struct page *page) 793 { 794 return folio_test_uptodate(page_folio(page)); 795 } 796 797 static __always_inline void __folio_mark_uptodate(struct folio *folio) 798 { 799 smp_wmb(); 800 __set_bit(PG_uptodate, folio_flags(folio, 0)); 801 } 802 803 static __always_inline void folio_mark_uptodate(struct folio *folio) 804 { 805 /* 806 * Memory barrier must be issued before setting the PG_uptodate bit, 807 * so that all previous stores issued in order to bring the folio 808 * uptodate are actually visible before folio_test_uptodate becomes true. 809 */ 810 smp_wmb(); 811 set_bit(PG_uptodate, folio_flags(folio, 0)); 812 } 813 814 static __always_inline void __SetPageUptodate(struct page *page) 815 { 816 __folio_mark_uptodate((struct folio *)page); 817 } 818 819 static __always_inline void SetPageUptodate(struct page *page) 820 { 821 folio_mark_uptodate((struct folio *)page); 822 } 823 824 CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) 825 826 void __folio_start_writeback(struct folio *folio, bool keep_write); 827 void set_page_writeback(struct page *page); 828 829 #define folio_start_writeback(folio) \ 830 __folio_start_writeback(folio, false) 831 #define folio_start_writeback_keepwrite(folio) \ 832 __folio_start_writeback(folio, true) 833 834 static __always_inline bool folio_test_head(const struct folio *folio) 835 { 836 return test_bit(PG_head, const_folio_flags(folio, FOLIO_PF_ANY)); 837 } 838 839 static __always_inline int PageHead(const struct page *page) 840 { 841 PF_POISONED_CHECK(page); 842 return test_bit(PG_head, &page->flags) && !page_is_fake_head(page); 843 } 844 845 __SETPAGEFLAG(Head, head, PF_ANY) 846 __CLEARPAGEFLAG(Head, head, PF_ANY) 847 CLEARPAGEFLAG(Head, head, PF_ANY) 848 849 /** 850 * folio_test_large() - Does this folio contain more than one page? 851 * @folio: The folio to test. 852 * 853 * Return: True if the folio is larger than one page. 854 */ 855 static inline bool folio_test_large(const struct folio *folio) 856 { 857 return folio_test_head(folio); 858 } 859 860 static __always_inline void set_compound_head(struct page *page, struct page *head) 861 { 862 WRITE_ONCE(page->compound_head, (unsigned long)head + 1); 863 } 864 865 static __always_inline void clear_compound_head(struct page *page) 866 { 867 WRITE_ONCE(page->compound_head, 0); 868 } 869 870 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 871 static inline void ClearPageCompound(struct page *page) 872 { 873 BUG_ON(!PageHead(page)); 874 ClearPageHead(page); 875 } 876 FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE) 877 #else 878 FOLIO_FLAG_FALSE(large_rmappable) 879 #endif 880 881 #define PG_head_mask ((1UL << PG_head)) 882 883 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 884 /* 885 * PageHuge() only returns true for hugetlbfs pages, but not for 886 * normal or transparent huge pages. 887 * 888 * PageTransHuge() returns true for both transparent huge and 889 * hugetlbfs pages, but not normal pages. PageTransHuge() can only be 890 * called only in the core VM paths where hugetlbfs pages can't exist. 891 */ 892 static inline int PageTransHuge(const struct page *page) 893 { 894 VM_BUG_ON_PAGE(PageTail(page), page); 895 return PageHead(page); 896 } 897 898 /* 899 * PageTransCompound returns true for both transparent huge pages 900 * and hugetlbfs pages, so it should only be called when it's known 901 * that hugetlbfs pages aren't involved. 902 */ 903 static inline int PageTransCompound(const struct page *page) 904 { 905 return PageCompound(page); 906 } 907 908 /* 909 * PageTransTail returns true for both transparent huge pages 910 * and hugetlbfs pages, so it should only be called when it's known 911 * that hugetlbfs pages aren't involved. 912 */ 913 static inline int PageTransTail(const struct page *page) 914 { 915 return PageTail(page); 916 } 917 #else 918 TESTPAGEFLAG_FALSE(TransHuge, transhuge) 919 TESTPAGEFLAG_FALSE(TransCompound, transcompound) 920 TESTPAGEFLAG_FALSE(TransCompoundMap, transcompoundmap) 921 TESTPAGEFLAG_FALSE(TransTail, transtail) 922 #endif 923 924 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE) 925 /* 926 * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the 927 * compound page. 928 * 929 * This flag is set by hwpoison handler. Cleared by THP split or free page. 930 */ 931 PAGEFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND) 932 TESTSCFLAG(HasHWPoisoned, has_hwpoisoned, PF_SECOND) 933 #else 934 PAGEFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) 935 TESTSCFLAG_FALSE(HasHWPoisoned, has_hwpoisoned) 936 #endif 937 938 /* 939 * For pages that are never mapped to userspace, 940 * page_type may be used. Because it is initialised to -1, we invert the 941 * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and 942 * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and 943 * low bits so that an underflow or overflow of _mapcount won't be 944 * mistaken for a page type value. 945 */ 946 947 #define PAGE_TYPE_BASE 0xf0000000 948 /* Reserve 0x0000007f to catch underflows of _mapcount */ 949 #define PAGE_MAPCOUNT_RESERVE -128 950 #define PG_buddy 0x00000080 951 #define PG_offline 0x00000100 952 #define PG_table 0x00000200 953 #define PG_guard 0x00000400 954 #define PG_hugetlb 0x00000800 955 #define PG_slab 0x00001000 956 957 #define PageType(page, flag) \ 958 ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) 959 #define folio_test_type(folio, flag) \ 960 ((folio->page.page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) 961 962 static inline int page_type_has_type(unsigned int page_type) 963 { 964 return (int)page_type < PAGE_MAPCOUNT_RESERVE; 965 } 966 967 static inline int page_has_type(const struct page *page) 968 { 969 return page_type_has_type(page->page_type); 970 } 971 972 #define FOLIO_TYPE_OPS(lname, fname) \ 973 static __always_inline bool folio_test_##fname(const struct folio *folio)\ 974 { \ 975 return folio_test_type(folio, PG_##lname); \ 976 } \ 977 static __always_inline void __folio_set_##fname(struct folio *folio) \ 978 { \ 979 VM_BUG_ON_FOLIO(!folio_test_type(folio, 0), folio); \ 980 folio->page.page_type &= ~PG_##lname; \ 981 } \ 982 static __always_inline void __folio_clear_##fname(struct folio *folio) \ 983 { \ 984 VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ 985 folio->page.page_type |= PG_##lname; \ 986 } 987 988 #define PAGE_TYPE_OPS(uname, lname, fname) \ 989 FOLIO_TYPE_OPS(lname, fname) \ 990 static __always_inline int Page##uname(const struct page *page) \ 991 { \ 992 return PageType(page, PG_##lname); \ 993 } \ 994 static __always_inline void __SetPage##uname(struct page *page) \ 995 { \ 996 VM_BUG_ON_PAGE(!PageType(page, 0), page); \ 997 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 1005 /* 1006 * PageBuddy() indicates that the page is free and in the buddy system 1007 * (see mm/page_alloc.c). 1008 */ 1009 PAGE_TYPE_OPS(Buddy, buddy, buddy) 1010 1011 /* 1012 * PageOffline() indicates that the page is logically offline although the 1013 * containing section is online. (e.g. inflated in a balloon driver or 1014 * not onlined when onlining the section). 1015 * The content of these pages is effectively stale. Such pages should not 1016 * be touched (read/write/dump/save) except by their owner. 1017 * 1018 * If a driver wants to allow to offline unmovable PageOffline() pages without 1019 * putting them back to the buddy, it can do so via the memory notifier by 1020 * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the 1021 * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() 1022 * pages (now with a reference count of zero) are treated like free pages, 1023 * allowing the containing memory block to get offlined. A driver that 1024 * relies on this feature is aware that re-onlining the memory block will 1025 * require to re-set the pages PageOffline() and not giving them to the 1026 * buddy via online_page_callback_t. 1027 * 1028 * There are drivers that mark a page PageOffline() and expect there won't be 1029 * any further access to page content. PFN walkers that read content of random 1030 * pages should check PageOffline() and synchronize with such drivers using 1031 * page_offline_freeze()/page_offline_thaw(). 1032 */ 1033 PAGE_TYPE_OPS(Offline, offline, offline) 1034 1035 extern void page_offline_freeze(void); 1036 extern void page_offline_thaw(void); 1037 extern void page_offline_begin(void); 1038 extern void page_offline_end(void); 1039 1040 /* 1041 * Marks pages in use as page tables. 1042 */ 1043 PAGE_TYPE_OPS(Table, table, pgtable) 1044 1045 /* 1046 * Marks guardpages used with debug_pagealloc. 1047 */ 1048 PAGE_TYPE_OPS(Guard, guard, guard) 1049 1050 FOLIO_TYPE_OPS(slab, slab) 1051 1052 /** 1053 * PageSlab - Determine if the page belongs to the slab allocator 1054 * @page: The page to test. 1055 * 1056 * Context: Any context. 1057 * Return: True for slab pages, false for any other kind of page. 1058 */ 1059 static inline bool PageSlab(const struct page *page) 1060 { 1061 return folio_test_slab(page_folio(page)); 1062 } 1063 1064 #ifdef CONFIG_HUGETLB_PAGE 1065 FOLIO_TYPE_OPS(hugetlb, hugetlb) 1066 #else 1067 FOLIO_TEST_FLAG_FALSE(hugetlb) 1068 #endif 1069 1070 /** 1071 * PageHuge - Determine if the page belongs to hugetlbfs 1072 * @page: The page to test. 1073 * 1074 * Context: Any context. 1075 * Return: True for hugetlbfs pages, false for anon pages or pages 1076 * belonging to other filesystems. 1077 */ 1078 static inline bool PageHuge(const struct page *page) 1079 { 1080 return folio_test_hugetlb(page_folio(page)); 1081 } 1082 1083 /* 1084 * Check if a page is currently marked HWPoisoned. Note that this check is 1085 * best effort only and inherently racy: there is no way to synchronize with 1086 * failing hardware. 1087 */ 1088 static inline bool is_page_hwpoison(const struct page *page) 1089 { 1090 const struct folio *folio; 1091 1092 if (PageHWPoison(page)) 1093 return true; 1094 folio = page_folio(page); 1095 return folio_test_hugetlb(folio) && PageHWPoison(&folio->page); 1096 } 1097 1098 bool is_free_buddy_page(const struct page *page); 1099 1100 PAGEFLAG(Isolated, isolated, PF_ANY); 1101 1102 static __always_inline int PageAnonExclusive(const struct page *page) 1103 { 1104 VM_BUG_ON_PGFLAGS(!PageAnon(page), page); 1105 /* 1106 * HugeTLB stores this information on the head page; THP keeps it per 1107 * page 1108 */ 1109 if (PageHuge(page)) 1110 page = compound_head(page); 1111 return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1112 } 1113 1114 static __always_inline void SetPageAnonExclusive(struct page *page) 1115 { 1116 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); 1117 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1118 set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1119 } 1120 1121 static __always_inline void ClearPageAnonExclusive(struct page *page) 1122 { 1123 VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page); 1124 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1125 clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1126 } 1127 1128 static __always_inline void __ClearPageAnonExclusive(struct page *page) 1129 { 1130 VM_BUG_ON_PGFLAGS(!PageAnon(page), page); 1131 VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); 1132 __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); 1133 } 1134 1135 #ifdef CONFIG_MMU 1136 #define __PG_MLOCKED (1UL << PG_mlocked) 1137 #else 1138 #define __PG_MLOCKED 0 1139 #endif 1140 1141 /* 1142 * Flags checked when a page is freed. Pages being freed should not have 1143 * these flags set. If they are, there is a problem. 1144 */ 1145 #define PAGE_FLAGS_CHECK_AT_FREE \ 1146 (1UL << PG_lru | 1UL << PG_locked | \ 1147 1UL << PG_private | 1UL << PG_private_2 | \ 1148 1UL << PG_writeback | 1UL << PG_reserved | \ 1149 1UL << PG_active | \ 1150 1UL << PG_unevictable | __PG_MLOCKED | LRU_GEN_MASK) 1151 1152 /* 1153 * Flags checked when a page is prepped for return by the page allocator. 1154 * Pages being prepped should not have these flags set. If they are set, 1155 * there has been a kernel bug or struct page corruption. 1156 * 1157 * __PG_HWPOISON is exceptional because it needs to be kept beyond page's 1158 * alloc-free cycle to prevent from reusing the page. 1159 */ 1160 #define PAGE_FLAGS_CHECK_AT_PREP \ 1161 ((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK) 1162 1163 /* 1164 * Flags stored in the second page of a compound page. They may overlap 1165 * the CHECK_AT_FREE flags above, so need to be cleared. 1166 */ 1167 #define PAGE_FLAGS_SECOND \ 1168 (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ 1169 1UL << PG_large_rmappable) 1170 1171 #define PAGE_FLAGS_PRIVATE \ 1172 (1UL << PG_private | 1UL << PG_private_2) 1173 /** 1174 * page_has_private - Determine if page has private stuff 1175 * @page: The page to be checked 1176 * 1177 * Determine if a page has private stuff, indicating that release routines 1178 * should be invoked upon it. 1179 */ 1180 static inline int page_has_private(const struct page *page) 1181 { 1182 return !!(page->flags & PAGE_FLAGS_PRIVATE); 1183 } 1184 1185 static inline bool folio_has_private(const struct folio *folio) 1186 { 1187 return page_has_private(&folio->page); 1188 } 1189 1190 #undef PF_ANY 1191 #undef PF_HEAD 1192 #undef PF_NO_TAIL 1193 #undef PF_NO_COMPOUND 1194 #undef PF_SECOND 1195 #endif /* !__GENERATING_BOUNDS_H */ 1196 1197 #endif /* PAGE_FLAGS_H */ 1198