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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#ifndef PAGE_FLAGS_H#define PAGE_FLAGS_H
#include <linux/types.h>#include <linux/bug.h>#include <linux/mmdebug.h>#ifndef __GENERATING_BOUNDS_H#include <linux/mm_types.h>#include <generated/bounds.h>#endif /* !__GENERATING_BOUNDS_H */
/* * Various page->flags bits: * * PG_reserved is set for special pages. The "struct page" of such a page * should in general not be touched (e.g. set dirty) except by its owner. * Pages marked as PG_reserved include: * - Pages part of the kernel image (including vDSO) and similar (e.g. BIOS, * initrd, HW tables) * - Pages reserved or allocated early during boot (before the page allocator * was initialized). This includes (depending on the architecture) the * initial vmemmap, initial page tables, crashkernel, elfcorehdr, and much * much more. Once (if ever) freed, PG_reserved is cleared and they will * be given to the page allocator. * - Pages falling into physical memory gaps - not IORESOURCE_SYSRAM. Trying * to read/write these pages might end badly. Don't touch! * - The zero page(s) * - Pages allocated in the context of kexec/kdump (loaded kernel image, * control pages, vmcoreinfo) * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are * not marked PG_reserved (as they might be in use by somebody else who does * not respect the caching strategy). * - MCA pages on ia64 * - Pages holding CPU notes for POWER Firmware Assisted Dump * - Device memory (e.g. PMEM, DAX, HMM) * Some PG_reserved pages will be excluded from the hibernation image. * PG_reserved does in general not hinder anybody from dumping or swapping * and is no longer required for remap_pfn_range(). ioremap might require it. * Consequently, PG_reserved for a page mapped into user space can indicate * the zero page, the vDSO, MMIO pages or device memory. * * The PG_private bitflag is set on pagecache pages if they contain filesystem * specific data (which is normally at page->private). It can be used by * private allocations for its own usage. * * During initiation of disk I/O, PG_locked is set. This bit is set before I/O * and cleared when writeback _starts_ or when read _completes_. PG_writeback * is set before writeback starts and cleared when it finishes. * * PG_locked also pins a page in pagecache, and blocks truncation of the file * while it is held. * * page_waitqueue(page) is a wait queue of all tasks waiting for the page * to become unlocked. * * PG_swapbacked is set when a page uses swap as a backing storage. This are * usually PageAnon or shmem pages but please note that even anonymous pages * might lose their PG_swapbacked flag when they simply can be dropped (e.g. as * a result of MADV_FREE). * * PG_referenced, PG_reclaim are used for page reclaim for anonymous and * file-backed pagecache (see mm/vmscan.c). * * PG_arch_1 is an architecture specific page state bit. The generic code * guarantees that this bit is cleared for a page when it first is entered into * the page cache. * * PG_hwpoison indicates that a page got corrupted in hardware and contains * data with incorrect ECC bits that triggered a machine check. Accessing is * not safe since it may cause another machine check. Don't touch! */
/* * Don't use the pageflags directly. Use the PageFoo macros. * * The page flags field is split into two parts, the main flags area * which extends from the low bits upwards, and the fields area which * extends from the high bits downwards. * * | FIELD | ... | FLAGS | * N-1 ^ 0 * (NR_PAGEFLAGS) * * The fields area is reserved for fields mapping zone, node (for NUMA) and * SPARSEMEM section (for variants of SPARSEMEM that require section ids like * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). */enum pageflags { PG_locked, /* Page is locked. Don't touch. */ PG_writeback, /* Page is under writeback */ PG_referenced, PG_uptodate, PG_dirty, PG_lru, PG_head, /* Must be in bit 6 */ PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ PG_active, PG_workingset, PG_owner_priv_1, /* Owner use. If pagecache, fs may use */ PG_owner_2, /* Owner use. If pagecache, fs may use */ PG_arch_1, PG_reserved, PG_private, /* If pagecache, has fs-private data */ PG_private_2, /* If pagecache, has fs aux data */ PG_reclaim, /* To be reclaimed asap */ PG_swapbacked, /* Page is backed by RAM/swap */ PG_unevictable, /* Page is "unevictable" */ PG_dropbehind, /* drop pages on IO completion */#ifdef CONFIG_MMU PG_mlocked, /* Page is vma mlocked */#endif#ifdef CONFIG_MEMORY_FAILURE PG_hwpoison, /* hardware poisoned page. Don't touch */#endif#if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT) PG_young, PG_idle,#endif#ifdef CONFIG_ARCH_USES_PG_ARCH_2 PG_arch_2,#endif#ifdef CONFIG_ARCH_USES_PG_ARCH_3 PG_arch_3,#endif __NR_PAGEFLAGS,
PG_readahead = PG_reclaim,
/* Anonymous memory (and shmem) */ PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ /* Some filesystems */ PG_checked = PG_owner_priv_1,
/* * Depending on the way an anonymous folio can be mapped into a page * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped * THP), PG_anon_exclusive may be set only for the head page or for * tail pages of an anonymous folio. For now, we only expect it to be * set on tail pages for PTE-mapped THP. */ PG_anon_exclusive = PG_owner_2,
/* * Set if all buffer heads in the folio are mapped. * Filesystems which do not use BHs can use it for their own purpose. */ PG_mappedtodisk = PG_owner_2,
/* Two page bits are conscripted by FS-Cache to maintain local caching * state. These bits are set on pages belonging to the netfs's inodes * when those inodes are being locally cached. */ PG_fscache = PG_private_2, /* page backed by cache */
/* XEN */ /* Pinned in Xen as a read-only pagetable page. */ PG_pinned = PG_owner_priv_1, /* Pinned as part of domain save (see xen_mm_pin_all()). */ PG_savepinned = PG_dirty, /* Has a grant mapping of another (foreign) domain's page. */ PG_foreign = PG_owner_priv_1, /* Remapped by swiotlb-xen. */ PG_xen_remapped = PG_owner_priv_1,
#ifdef CONFIG_MIGRATION /* movable_ops page that is isolated for migration */ PG_movable_ops_isolated = PG_reclaim, /* this is a movable_ops page (for selected typed pages only) */ PG_movable_ops = PG_uptodate,#endif
/* Only valid for buddy pages. Used to track pages that are reported */ PG_reported = PG_uptodate,
#ifdef CONFIG_MEMORY_HOTPLUG /* For self-hosted memmap pages */ PG_vmemmap_self_hosted = PG_owner_priv_1,#endif
/* * Flags only valid for compound pages. Stored in first tail page's * flags word. Cannot use the first 8 flags or any flag marked as * PF_ANY. */
/* At least one page in this folio has the hwpoison flag set */ PG_has_hwpoisoned = PG_active, PG_large_rmappable = PG_workingset, /* anon or file-backed */ PG_partially_mapped = PG_reclaim, /* was identified to be partially mapped */};
#define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1)
#ifndef __GENERATING_BOUNDS_H
/* * For tail pages, if the size of struct page is power-of-2 ->compound_info * encodes the mask that converts the address of the tail page address to * the head page address. * * Otherwise, ->compound_info has direct pointer to head pages. */static __always_inline bool compound_info_has_mask(void){ /* * Limit mask usage to HugeTLB vmemmap optimization (HVO) where it * makes a difference. * * The approach with mask would work in the wider set of conditions, * but it requires validating that struct pages are naturally aligned * for all orders up to the MAX_FOLIO_ORDER, which can be tricky. */ if (!IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)) return false;
return is_power_of_2(sizeof(struct page));}
static __always_inline unsigned long _compound_head(const struct page *page){ unsigned long info = READ_ONCE(page->compound_info); unsigned long mask;
if (!compound_info_has_mask()) { /* Bit 0 encodes PageTail() */ if (info & 1) return info - 1;
return (unsigned long)page; }
/* * If compound_info_has_mask() is true the rest of the info encodes * the mask that converts the address of the tail page to the head page. * * No need to clear bit 0 in the mask as 'page' always has it clear. * * Let's do it in a branchless manner. */
/* Non-tail: -1UL, Tail: 0 */ mask = (info & 1) - 1;
/* Non-tail: -1UL, Tail: info */ mask |= info;
return (unsigned long)page & mask;}
#define compound_head(page) ((typeof(page))_compound_head(page))
static __always_inline void set_compound_head(struct page *tail, const struct page *head, unsigned int order){ unsigned int shift; unsigned long mask;
if (!compound_info_has_mask()) { WRITE_ONCE(tail->compound_info, (unsigned long)head | 1); return; }
/* * If the size of struct page is power-of-2, bits [shift:0] of the * virtual address of compound head are zero. * * Calculate mask that can be applied to the virtual address of * the tail page to get address of the head page. */ shift = order + order_base_2(sizeof(struct page)); mask = GENMASK(BITS_PER_LONG - 1, shift);
/* Bit 0 encodes PageTail() */ WRITE_ONCE(tail->compound_info, mask | 1);}
static __always_inline void clear_compound_head(struct page *page){ WRITE_ONCE(page->compound_info, 0);}
/** * page_folio - Converts from page to folio. * @p: The page. * * Every page is part of a folio. This function cannot be called on a * NULL pointer. * * Context: No reference, nor lock is required on @page. If the caller * does not hold a reference, this call may race with a folio split, so * it should re-check the folio still contains this page after gaining * a reference on the folio. * Return: The folio which contains this page. */#define page_folio(p) (_Generic((p), \ const struct page *: (const struct folio *)_compound_head(p), \ struct page *: (struct folio *)_compound_head(p)))
/** * folio_page - Return a page from a folio. * @folio: The folio. * @n: The page number to return. * * @n is relative to the start of the folio. This function does not * check that the page number lies within @folio; the caller is presumed * to have a reference to the page. */#define folio_page(folio, n) (&(folio)->page + (n))
static __always_inline int PageTail(const struct page *page){ return READ_ONCE(page->compound_info) & 1;}
static __always_inline int PageCompound(const struct page *page){ return test_bit(PG_head, &page->flags.f) || READ_ONCE(page->compound_info) & 1;}
#define PAGE_POISON_PATTERN -1lstatic inline int PagePoisoned(const struct page *page){ return READ_ONCE(page->flags.f) == PAGE_POISON_PATTERN;}
#ifdef CONFIG_DEBUG_VMvoid page_init_poison(struct page *page, size_t size);#elsestatic inline void page_init_poison(struct page *page, size_t size){}#endif
static const unsigned long *const_folio_flags(const struct folio *folio, unsigned n){ const struct page *page = &folio->page;
VM_BUG_ON_PGFLAGS(page->compound_info & 1, page); VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page); return &page[n].flags.f;}
static unsigned long *folio_flags(struct folio *folio, unsigned n){ struct page *page = &folio->page;
VM_BUG_ON_PGFLAGS(page->compound_info & 1, page); VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags.f), page); return &page[n].flags.f;}
/* * Page flags policies wrt compound pages * * PF_POISONED_CHECK * check if this struct page poisoned/uninitialized * * PF_ANY: * the page flag is relevant for small, head and tail pages. * * PF_HEAD: * for compound page all operations related to the page flag applied to * head page. * * PF_NO_TAIL: * modifications of the page flag must be done on small or head pages, * checks can be done on tail pages too. * * PF_NO_COMPOUND: * the page flag is not relevant for compound pages. * * PF_SECOND: * the page flag is stored in the first tail page. */#define PF_POISONED_CHECK(page) ({ \ VM_BUG_ON_PGFLAGS(PagePoisoned(page), page); \ page; })#define PF_ANY(page, enforce) PF_POISONED_CHECK(page)#define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page))#define PF_NO_TAIL(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ PF_POISONED_CHECK(compound_head(page)); })#define PF_NO_COMPOUND(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ PF_POISONED_CHECK(page); })#define PF_SECOND(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ PF_POISONED_CHECK(&page[1]); })
/* Which page is the flag stored in */#define FOLIO_PF_ANY 0#define FOLIO_PF_HEAD 0#define FOLIO_PF_NO_TAIL 0#define FOLIO_PF_NO_COMPOUND 0#define FOLIO_PF_SECOND 1
#define FOLIO_HEAD_PAGE 0#define FOLIO_SECOND_PAGE 1
/* * Macros to create function definitions for page flags */#define FOLIO_TEST_FLAG(name, page) \static __always_inline bool folio_test_##name(const struct folio *folio) \{ return test_bit(PG_##name, const_folio_flags(folio, page)); }
#define FOLIO_SET_FLAG(name, page) \static __always_inline void folio_set_##name(struct folio *folio) \{ set_bit(PG_##name, folio_flags(folio, page)); }
#define FOLIO_CLEAR_FLAG(name, page) \static __always_inline void folio_clear_##name(struct folio *folio) \{ clear_bit(PG_##name, folio_flags(folio, page)); }
#define __FOLIO_SET_FLAG(name, page) \static __always_inline void __folio_set_##name(struct folio *folio) \{ __set_bit(PG_##name, folio_flags(folio, page)); }
#define __FOLIO_CLEAR_FLAG(name, page) \static __always_inline void __folio_clear_##name(struct folio *folio) \{ __clear_bit(PG_##name, folio_flags(folio, page)); }
#define FOLIO_TEST_SET_FLAG(name, page) \static __always_inline bool folio_test_set_##name(struct folio *folio) \{ return test_and_set_bit(PG_##name, folio_flags(folio, page)); }
#define FOLIO_TEST_CLEAR_FLAG(name, page) \static __always_inline bool folio_test_clear_##name(struct folio *folio) \{ return test_and_clear_bit(PG_##name, folio_flags(folio, page)); }
#define FOLIO_FLAG(name, page) \FOLIO_TEST_FLAG(name, page) \FOLIO_SET_FLAG(name, page) \FOLIO_CLEAR_FLAG(name, page)
#define TESTPAGEFLAG(uname, lname, policy) \FOLIO_TEST_FLAG(lname, FOLIO_##policy) \static __always_inline int Page##uname(const struct page *page) \{ return test_bit(PG_##lname, &policy(page, 0)->flags.f); }
#define SETPAGEFLAG(uname, lname, policy) \FOLIO_SET_FLAG(lname, FOLIO_##policy) \static __always_inline void SetPage##uname(struct page *page) \{ set_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define CLEARPAGEFLAG(uname, lname, policy) \FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \static __always_inline void ClearPage##uname(struct page *page) \{ clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define __SETPAGEFLAG(uname, lname, policy) \__FOLIO_SET_FLAG(lname, FOLIO_##policy) \static __always_inline void __SetPage##uname(struct page *page) \{ __set_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define __CLEARPAGEFLAG(uname, lname, policy) \__FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \static __always_inline void __ClearPage##uname(struct page *page) \{ __clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define TESTSETFLAG(uname, lname, policy) \FOLIO_TEST_SET_FLAG(lname, FOLIO_##policy) \static __always_inline int TestSetPage##uname(struct page *page) \{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define TESTCLEARFLAG(uname, lname, policy) \FOLIO_TEST_CLEAR_FLAG(lname, FOLIO_##policy) \static __always_inline int TestClearPage##uname(struct page *page) \{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags.f); }
#define PAGEFLAG(uname, lname, policy) \ TESTPAGEFLAG(uname, lname, policy) \ SETPAGEFLAG(uname, lname, policy) \ CLEARPAGEFLAG(uname, lname, policy)
#define __PAGEFLAG(uname, lname, policy) \ TESTPAGEFLAG(uname, lname, policy) \ __SETPAGEFLAG(uname, lname, policy) \ __CLEARPAGEFLAG(uname, lname, policy)
#define TESTSCFLAG(uname, lname, policy) \ TESTSETFLAG(uname, lname, policy) \ TESTCLEARFLAG(uname, lname, policy)
#define FOLIO_TEST_FLAG_FALSE(name) \static inline bool folio_test_##name(const struct folio *folio) \{ return false; }#define FOLIO_SET_FLAG_NOOP(name) \static inline void folio_set_##name(struct folio *folio) { }#define FOLIO_CLEAR_FLAG_NOOP(name) \static inline void folio_clear_##name(struct folio *folio) { }#define __FOLIO_SET_FLAG_NOOP(name) \static inline void __folio_set_##name(struct folio *folio) { }#define __FOLIO_CLEAR_FLAG_NOOP(name) \static inline void __folio_clear_##name(struct folio *folio) { }#define FOLIO_TEST_SET_FLAG_FALSE(name) \static inline bool folio_test_set_##name(struct folio *folio) \{ return false; }#define FOLIO_TEST_CLEAR_FLAG_FALSE(name) \static inline bool folio_test_clear_##name(struct folio *folio) \{ return false; }
#define FOLIO_FLAG_FALSE(name) \FOLIO_TEST_FLAG_FALSE(name) \FOLIO_SET_FLAG_NOOP(name) \FOLIO_CLEAR_FLAG_NOOP(name)
#define TESTPAGEFLAG_FALSE(uname, lname) \FOLIO_TEST_FLAG_FALSE(lname) \static inline int Page##uname(const struct page *page) { return 0; }
#define SETPAGEFLAG_NOOP(uname, lname) \FOLIO_SET_FLAG_NOOP(lname) \static inline void SetPage##uname(struct page *page) { }
#define CLEARPAGEFLAG_NOOP(uname, lname) \FOLIO_CLEAR_FLAG_NOOP(lname) \static inline void ClearPage##uname(struct page *page) { }
#define __CLEARPAGEFLAG_NOOP(uname, lname) \__FOLIO_CLEAR_FLAG_NOOP(lname) \static inline void __ClearPage##uname(struct page *page) { }
#define TESTSETFLAG_FALSE(uname, lname) \FOLIO_TEST_SET_FLAG_FALSE(lname) \static inline int TestSetPage##uname(struct page *page) { return 0; }
#define TESTCLEARFLAG_FALSE(uname, lname) \FOLIO_TEST_CLEAR_FLAG_FALSE(lname) \static inline int TestClearPage##uname(struct page *page) { return 0; }
#define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname) \ SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname)
#define TESTSCFLAG_FALSE(uname, lname) \ TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname)
__PAGEFLAG(Locked, locked, PF_NO_TAIL)FOLIO_FLAG(waiters, FOLIO_HEAD_PAGE)FOLIO_FLAG(referenced, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(referenced, FOLIO_HEAD_PAGE) __FOLIO_SET_FLAG(referenced, FOLIO_HEAD_PAGE)PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD)PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) TESTCLEARFLAG(LRU, lru, PF_HEAD)FOLIO_FLAG(active, FOLIO_HEAD_PAGE) __FOLIO_CLEAR_FLAG(active, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(active, FOLIO_HEAD_PAGE)PAGEFLAG(Workingset, workingset, PF_HEAD) TESTCLEARFLAG(Workingset, workingset, PF_HEAD)PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */
/* Xen */PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND)PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND);PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND);PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) TESTCLEARFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND)
PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND)FOLIO_FLAG(swapbacked, FOLIO_HEAD_PAGE) __FOLIO_CLEAR_FLAG(swapbacked, FOLIO_HEAD_PAGE) __FOLIO_SET_FLAG(swapbacked, FOLIO_HEAD_PAGE)
/* * Private page markings that may be used by the filesystem that owns the page * for its own purposes. * - PG_private and PG_private_2 cause release_folio() and co to be invoked */PAGEFLAG(Private, private, PF_ANY)FOLIO_FLAG(private_2, FOLIO_HEAD_PAGE)
/* owner_2 can be set on tail pages for anon memory */FOLIO_FLAG(owner_2, FOLIO_HEAD_PAGE)
/* * Only test-and-set exist for PG_writeback. The unconditional operators are * risky: they bypass page accounting. */TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) TESTSCFLAG(Writeback, writeback, PF_NO_TAIL)FOLIO_FLAG(mappedtodisk, FOLIO_HEAD_PAGE)
/* PG_readahead is only used for reads; PG_reclaim is only for writes */PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL)FOLIO_FLAG(readahead, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(readahead, FOLIO_HEAD_PAGE)
FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(dropbehind, FOLIO_HEAD_PAGE) __FOLIO_SET_FLAG(dropbehind, FOLIO_HEAD_PAGE)
#ifdef CONFIG_HIGHMEM/* * Must use a macro here due to header dependency issues. page_zone() is not * available at this point. */#define PageHighMem(__p) is_highmem_idx(page_zonenum(__p))#define folio_test_highmem(__f) is_highmem_idx(folio_zonenum(__f))#elsePAGEFLAG_FALSE(HighMem, highmem)#endif#define PhysHighMem(__p) (PageHighMem(phys_to_page(__p)))
/* Does kmap_local_folio() only allow access to one page of the folio? */#ifdef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP#define folio_test_partial_kmap(f) true#else#define folio_test_partial_kmap(f) folio_test_highmem(f)#endif
#ifdef CONFIG_SWAPstatic __always_inline bool folio_test_swapcache(const struct folio *folio){ return folio_test_swapbacked(folio) && test_bit(PG_swapcache, const_folio_flags(folio, 0));}
FOLIO_SET_FLAG(swapcache, FOLIO_HEAD_PAGE)FOLIO_CLEAR_FLAG(swapcache, FOLIO_HEAD_PAGE)#elseFOLIO_FLAG_FALSE(swapcache)#endif
FOLIO_FLAG(unevictable, FOLIO_HEAD_PAGE) __FOLIO_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE)
#ifdef CONFIG_MMUFOLIO_FLAG(mlocked, FOLIO_HEAD_PAGE) __FOLIO_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) FOLIO_TEST_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) FOLIO_TEST_SET_FLAG(mlocked, FOLIO_HEAD_PAGE)#elseFOLIO_FLAG_FALSE(mlocked) __FOLIO_CLEAR_FLAG_NOOP(mlocked) FOLIO_TEST_CLEAR_FLAG_FALSE(mlocked) FOLIO_TEST_SET_FLAG_FALSE(mlocked)#endif
#ifdef CONFIG_MEMORY_FAILUREPAGEFLAG(HWPoison, hwpoison, PF_ANY)TESTSCFLAG(HWPoison, hwpoison, PF_ANY)#define __PG_HWPOISON (1UL << PG_hwpoison)#elsePAGEFLAG_FALSE(HWPoison, hwpoison)#define __PG_HWPOISON 0#endif
#ifdef CONFIG_PAGE_IDLE_FLAG#ifdef CONFIG_64BITFOLIO_TEST_FLAG(young, FOLIO_HEAD_PAGE)FOLIO_SET_FLAG(young, FOLIO_HEAD_PAGE)FOLIO_TEST_CLEAR_FLAG(young, FOLIO_HEAD_PAGE)FOLIO_FLAG(idle, FOLIO_HEAD_PAGE)#endif/* See page_idle.h for !64BIT workaround */#else /* !CONFIG_PAGE_IDLE_FLAG */FOLIO_FLAG_FALSE(young)FOLIO_TEST_CLEAR_FLAG_FALSE(young)FOLIO_FLAG_FALSE(idle)#endif
/* * PageReported() is used to track reported free pages within the Buddy * allocator. We can use the non-atomic version of the test and set * operations as both should be shielded with the zone lock to prevent * any possible races on the setting or clearing of the bit. */__PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
#ifdef CONFIG_MEMORY_HOTPLUGPAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY)#elsePAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted)#endif
/* * On an anonymous folio mapped into a user virtual memory area, * folio->mapping points to its anon_vma, not to a struct address_space; * with the FOLIO_MAPPING_ANON bit set to distinguish it. See rmap.h. * * On an anonymous folio in a VM_MERGEABLE area, if CONFIG_KSM is enabled, * the FOLIO_MAPPING_ANON_KSM bit may be set along with the FOLIO_MAPPING_ANON * bit; and then folio->mapping points, not to an anon_vma, but to a private * structure which KSM associates with that merged folio. See ksm.h. * * Please note that, confusingly, "folio_mapping" refers to the inode * address_space which maps the folio from disk; whereas "folio_mapped" * refers to user virtual address space into which the folio is mapped. * * For slab pages, since slab reuses the bits in struct page to store its * internal states, the folio->mapping does not exist as such, nor do * these flags below. So in order to avoid testing non-existent bits, * please make sure that folio_test_slab(folio) actually evaluates to * false before calling the following functions (e.g., folio_test_anon). * See mm/slab.h. */#define FOLIO_MAPPING_ANON 0x1#define FOLIO_MAPPING_ANON_KSM 0x2#define FOLIO_MAPPING_KSM (FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM)#define FOLIO_MAPPING_FLAGS (FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM)
static __always_inline bool folio_test_anon(const struct folio *folio){ return ((unsigned long)folio->mapping & FOLIO_MAPPING_ANON) != 0;}
static __always_inline bool folio_test_lazyfree(const struct folio *folio){ return folio_test_anon(folio) && !folio_test_swapbacked(folio);}
static __always_inline bool PageAnonNotKsm(const struct page *page){ unsigned long flags = (unsigned long)page_folio(page)->mapping;
return (flags & FOLIO_MAPPING_FLAGS) == FOLIO_MAPPING_ANON;}
static __always_inline bool PageAnon(const struct page *page){ return folio_test_anon(page_folio(page));}#ifdef CONFIG_KSM/* * A KSM page is one of those write-protected "shared pages" or "merged pages" * which KSM maps into multiple mms, wherever identical anonymous page content * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any * anon_vma, but to that page's node of the stable tree. */static __always_inline bool folio_test_ksm(const struct folio *folio){ return ((unsigned long)folio->mapping & FOLIO_MAPPING_FLAGS) == FOLIO_MAPPING_KSM;}#elseFOLIO_TEST_FLAG_FALSE(ksm)#endif
u64 stable_page_flags(const struct page *page);
/** * folio_xor_flags_has_waiters - Change some folio flags. * @folio: The folio. * @mask: Bits set in this word will be changed. * * This must only be used for flags which are changed with the folio * lock held. For example, it is unsafe to use for PG_dirty as that * can be set without the folio lock held. It can also only be used * on flags which are in the range 0-6 as some of the implementations * only affect those bits. * * Return: Whether there are tasks waiting on the folio. */static inline bool folio_xor_flags_has_waiters(struct folio *folio, unsigned long mask){ return xor_unlock_is_negative_byte(mask, folio_flags(folio, 0));}
/** * folio_test_uptodate - Is this folio up to date? * @folio: The folio. * * The uptodate flag is set on a folio when every byte in the folio is * at least as new as the corresponding bytes on storage. Anonymous * and CoW folios are always uptodate. If the folio is not uptodate, * some of the bytes in it may be; see the is_partially_uptodate() * address_space operation. */static inline bool folio_test_uptodate(const struct folio *folio){ bool ret = test_bit(PG_uptodate, const_folio_flags(folio, 0)); /* * Must ensure that the data we read out of the folio is loaded * _after_ we've loaded folio->flags to check the uptodate bit. * We can skip the barrier if the folio is not uptodate, because * we wouldn't be reading anything from it. * * See folio_mark_uptodate() for the other side of the story. */ if (ret) smp_rmb();
return ret;}
static inline bool PageUptodate(const struct page *page){ return folio_test_uptodate(page_folio(page));}
static __always_inline void __folio_mark_uptodate(struct folio *folio){ smp_wmb(); __set_bit(PG_uptodate, folio_flags(folio, 0));}
static __always_inline void folio_mark_uptodate(struct folio *folio){ /* * Memory barrier must be issued before setting the PG_uptodate bit, * so that all previous stores issued in order to bring the folio * uptodate are actually visible before folio_test_uptodate becomes true. */ smp_wmb(); set_bit(PG_uptodate, folio_flags(folio, 0));}
static __always_inline void __SetPageUptodate(struct page *page){ __folio_mark_uptodate((struct folio *)page);}
static __always_inline void SetPageUptodate(struct page *page){ folio_mark_uptodate((struct folio *)page);}
CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL)
void __folio_start_writeback(struct folio *folio, bool keep_write);void set_page_writeback(struct page *page);
#define folio_start_writeback(folio) \ __folio_start_writeback(folio, false)
static __always_inline bool folio_test_head(const struct folio *folio){ return test_bit(PG_head, const_folio_flags(folio, FOLIO_PF_ANY));}
static __always_inline int PageHead(const struct page *page){ PF_POISONED_CHECK(page); return test_bit(PG_head, &page->flags.f);}
__SETPAGEFLAG(Head, head, PF_ANY)__CLEARPAGEFLAG(Head, head, PF_ANY)CLEARPAGEFLAG(Head, head, PF_ANY)
/** * folio_test_large() - Does this folio contain more than one page? * @folio: The folio to test. * * Return: True if the folio is larger than one page. */static inline bool folio_test_large(const struct folio *folio){ return folio_test_head(folio);}
#ifdef CONFIG_TRANSPARENT_HUGEPAGEstatic inline void ClearPageCompound(struct page *page){ BUG_ON(!PageHead(page)); ClearPageHead(page);}FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE)FOLIO_FLAG(partially_mapped, FOLIO_SECOND_PAGE)#elseFOLIO_FLAG_FALSE(large_rmappable)FOLIO_FLAG_FALSE(partially_mapped)#endif
#define PG_head_mask ((1UL << PG_head))
#ifdef CONFIG_TRANSPARENT_HUGEPAGE/* * PageTransCompound returns true for both transparent huge pages * and hugetlbfs pages, so it should only be called when it's known * that hugetlbfs pages aren't involved. */static inline int PageTransCompound(const struct page *page){ return PageCompound(page);}#elseTESTPAGEFLAG_FALSE(TransCompound, transcompound)#endif
#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE)/* * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the * compound page. * * This flag is set by hwpoison handler. Cleared by THP split or free page. */FOLIO_FLAG(has_hwpoisoned, FOLIO_SECOND_PAGE)#elseFOLIO_FLAG_FALSE(has_hwpoisoned)#endif
/* * For pages that do not use mapcount, page_type may be used. * The low 24 bits of pagetype may be used for your own purposes, as long * as you are careful to not affect the top 8 bits. The low bits of * pagetype will be overwritten when you clear the page_type from the page. */enum pagetype { /* 0x00-0x7f are positive numbers, ie mapcount */ /* Reserve 0x80-0xef for mapcount overflow. */ PGTY_buddy = 0xf0, PGTY_offline = 0xf1, PGTY_table = 0xf2, PGTY_guard = 0xf3, PGTY_hugetlb = 0xf4, PGTY_slab = 0xf5, PGTY_zsmalloc = 0xf6, PGTY_unaccepted = 0xf7, PGTY_large_kmalloc = 0xf8,
PGTY_mapcount_underflow = 0xff};
static inline bool page_type_has_type(int page_type){ return page_type < (PGTY_mapcount_underflow << 24);}
/* This takes a mapcount which is one more than page->_mapcount */static inline bool page_mapcount_is_type(unsigned int mapcount){ return page_type_has_type(mapcount - 1);}
static inline bool page_has_type(const struct page *page){ return page_type_has_type(data_race(page->page_type));}
#define FOLIO_TYPE_OPS(lname, fname) \static __always_inline bool folio_test_##fname(const struct folio *folio) \{ \ return data_race(folio->page.page_type >> 24) == PGTY_##lname; \} \static __always_inline void __folio_set_##fname(struct folio *folio) \{ \ if (folio_test_##fname(folio)) \ return; \ VM_BUG_ON_FOLIO(data_race(folio->page.page_type) != UINT_MAX, \ folio); \ folio->page.page_type = (unsigned int)PGTY_##lname << 24; \} \static __always_inline void __folio_clear_##fname(struct folio *folio) \{ \ if (folio->page.page_type == UINT_MAX) \ return; \ VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ folio->page.page_type = UINT_MAX; \}
#define PAGE_TYPE_OPS(uname, lname, fname) \FOLIO_TYPE_OPS(lname, fname) \static __always_inline int Page##uname(const struct page *page) \{ \ return data_race(page->page_type >> 24) == PGTY_##lname; \} \static __always_inline void __SetPage##uname(struct page *page) \{ \ if (Page##uname(page)) \ return; \ VM_BUG_ON_PAGE(data_race(page->page_type) != UINT_MAX, page); \ page->page_type = (unsigned int)PGTY_##lname << 24; \} \static __always_inline void __ClearPage##uname(struct page *page) \{ \ if (page->page_type == UINT_MAX) \ return; \ VM_BUG_ON_PAGE(!Page##uname(page), page); \ page->page_type = UINT_MAX; \}
/* * PageBuddy() indicates that the page is free and in the buddy system * (see mm/page_alloc.c). */PAGE_TYPE_OPS(Buddy, buddy, buddy)
/* * PageOffline() indicates that the page is logically offline although the * containing section is online. (e.g. inflated in a balloon driver or * not onlined when onlining the section). * The content of these pages is effectively stale. Such pages should not * be touched (read/write/dump/save) except by their owner. * * When a memory block gets onlined, all pages are initialized with a * refcount of 1 and PageOffline(). generic_online_page() will * take care of clearing PageOffline(). * * If a driver wants to allow to offline unmovable PageOffline() pages without * putting them back to the buddy, it can do so via the memory notifier by * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() * pages (now with a reference count of zero) are treated like free (unmanaged) * pages, allowing the containing memory block to get offlined. A driver that * relies on this feature is aware that re-onlining the memory block will * require not giving them to the buddy via generic_online_page(). * * Memory offlining code will not adjust the managed page count for any * PageOffline() pages, treating them like they were never exposed to the * buddy using generic_online_page(). * * There are drivers that mark a page PageOffline() and expect there won't be * any further access to page content. PFN walkers that read content of random * pages should check PageOffline() and synchronize with such drivers using * page_offline_freeze()/page_offline_thaw(). */PAGE_TYPE_OPS(Offline, offline, offline)
extern void page_offline_freeze(void);extern void page_offline_thaw(void);extern void page_offline_begin(void);extern void page_offline_end(void);
/* * Marks pages in use as page tables. */PAGE_TYPE_OPS(Table, table, pgtable)
/* * Marks guardpages used with debug_pagealloc. */PAGE_TYPE_OPS(Guard, guard, guard)
PAGE_TYPE_OPS(Slab, slab, slab)
#ifdef CONFIG_HUGETLB_PAGEFOLIO_TYPE_OPS(hugetlb, hugetlb)#elseFOLIO_TEST_FLAG_FALSE(hugetlb)#endif
PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc)
/* * Mark pages that has to be accepted before touched for the first time. * * Serialized with zone lock. */PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted)PAGE_TYPE_OPS(LargeKmalloc, large_kmalloc, large_kmalloc)
/** * PageHuge - Determine if the page belongs to hugetlbfs * @page: The page to test. * * Context: Any context. * Return: True for hugetlbfs pages, false for anon pages or pages * belonging to other filesystems. */static inline bool PageHuge(const struct page *page){ return folio_test_hugetlb(page_folio(page));}
/* * Check if a page is currently marked HWPoisoned. Note that this check is * best effort only and inherently racy: there is no way to synchronize with * failing hardware. */static inline bool is_page_hwpoison(const struct page *page){ const struct folio *folio;
if (PageHWPoison(page)) return true; folio = page_folio(page); return folio_test_hugetlb(folio) && PageHWPoison(&folio->page);}
static inline bool folio_contain_hwpoisoned_page(struct folio *folio){ return folio_test_hwpoison(folio) || (folio_test_large(folio) && folio_test_has_hwpoisoned(folio));}
bool is_free_buddy_page(const struct page *page);
#ifdef CONFIG_MIGRATION/* * This page is migratable through movable_ops (for selected typed pages * only). * * Page migration of such pages might fail, for example, if the page is * already isolated by somebody else, or if the page is about to get freed. * * While a subsystem might set selected typed pages that support page migration * as being movable through movable_ops, it must never clear this flag. * * This flag is only cleared when the page is freed back to the buddy. * * Only selected page types support this flag (see page_movable_ops()) and * the flag might be used in other context for other pages. Always use * page_has_movable_ops() instead. */TESTPAGEFLAG(MovableOps, movable_ops, PF_NO_TAIL);SETPAGEFLAG(MovableOps, movable_ops, PF_NO_TAIL);/* * A movable_ops page has this flag set while it is isolated for migration. * This flag primarily protects against concurrent migration attempts. * * Once migration ended (success or failure), the flag is cleared. The * flag is managed by the migration core. */PAGEFLAG(MovableOpsIsolated, movable_ops_isolated, PF_NO_TAIL);#else /* !CONFIG_MIGRATION */TESTPAGEFLAG_FALSE(MovableOps, movable_ops);SETPAGEFLAG_NOOP(MovableOps, movable_ops);PAGEFLAG_FALSE(MovableOpsIsolated, movable_ops_isolated);#endif /* CONFIG_MIGRATION */
/** * page_has_movable_ops - test for a movable_ops page * @page: The page to test. * * Test whether this is a movable_ops page. Such pages will stay that * way until freed. * * Returns true if this is a movable_ops page, otherwise false. */static inline bool page_has_movable_ops(const struct page *page){ return PageMovableOps(page) && (PageOffline(page) || PageZsmalloc(page));}
static __always_inline int PageAnonExclusive(const struct page *page){ VM_BUG_ON_PGFLAGS(!PageAnon(page), page); /* * HugeTLB stores this information on the head page; THP keeps it per * page */ if (PageHuge(page)) page = compound_head(page); return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);}
static __always_inline void SetPageAnonExclusive(struct page *page){ VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page); VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);}
static __always_inline void ClearPageAnonExclusive(struct page *page){ VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page); VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);}
static __always_inline void __ClearPageAnonExclusive(struct page *page){ VM_BUG_ON_PGFLAGS(!PageAnon(page), page); VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags.f);}
#ifdef CONFIG_MMU#define __PG_MLOCKED (1UL << PG_mlocked)#else#define __PG_MLOCKED 0#endif
/* * Flags checked when a page is freed. Pages being freed should not have * these flags set. If they are, there is a problem. */#define PAGE_FLAGS_CHECK_AT_FREE \ (1UL << PG_lru | 1UL << PG_locked | \ 1UL << PG_private | 1UL << PG_private_2 | \ 1UL << PG_writeback | 1UL << PG_reserved | \ 1UL << PG_active | \ 1UL << PG_unevictable | __PG_MLOCKED | LRU_GEN_MASK)
/* * Flags checked when a page is prepped for return by the page allocator. * Pages being prepped should not have these flags set. If they are set, * there has been a kernel bug or struct page corruption. * * __PG_HWPOISON is exceptional because it needs to be kept beyond page's * alloc-free cycle to prevent from reusing the page. */#define PAGE_FLAGS_CHECK_AT_PREP \ ((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK)
/* * Flags stored in the second page of a compound page. They may overlap * the CHECK_AT_FREE flags above, so need to be cleared. */#define PAGE_FLAGS_SECOND \ (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ 1UL << PG_large_rmappable | 1UL << PG_partially_mapped)
#define PAGE_FLAGS_PRIVATE \ (1UL << PG_private | 1UL << PG_private_2)/** * folio_has_private - Determine if folio has private stuff * @folio: The folio to be checked * * Determine if a folio has private stuff, indicating that release routines * should be invoked upon it. */static inline int folio_has_private(const struct folio *folio){ return !!(folio->flags.f & PAGE_FLAGS_PRIVATE);}
#undef PF_ANY#undef PF_HEAD#undef PF_NO_TAIL#undef PF_NO_COMPOUND#undef PF_SECOND#endif /* !__GENERATING_BOUNDS_H */
#endif /* PAGE_FLAGS_H */