/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Macros for manipulating and testing page->flags
 */

#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

#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key);

/*
 * Return the real head page struct iff the @page is a fake head page, otherwise
 * return the @page itself. See Documentation/mm/vmemmap_dedup.rst.
 */
static __always_inline const struct page *page_fixed_fake_head(const struct page *page)
{
        if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key))
                return page;

        /*
         * Only addresses aligned with PAGE_SIZE of struct page may be fake head
         * struct page. The alignment check aims to avoid access the fields (
         * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly)
         * cold cacheline in some cases.
         */
        if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) &&
            test_bit(PG_head, &page->flags.f)) {
                /*
                 * We can safely access the field of the @page[1] with PG_head
                 * because the @page is a compound page composed with at least
                 * two contiguous pages.
                 */
                unsigned long head = READ_ONCE(page[1].compound_head);

                if (likely(head & 1))
                        return (const struct page *)(head - 1);
        }
        return page;
}

static __always_inline bool page_count_writable(const struct page *page, int u)
{
        if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key))
                return true;

        /*
         * The refcount check is ordered before the fake-head check to prevent
         * the following race:
         *   CPU 1 (HVO)                     CPU 2 (speculative PFN walker)
         *
         *   page_ref_freeze()
         *   synchronize_rcu()
         *                                   rcu_read_lock()
         *                                   page_is_fake_head() is false
         *   vmemmap_remap_pte()
         *   XXX: struct page[] becomes r/o
         *
         *   page_ref_unfreeze()
         *                                   page_ref_count() is not zero
         *
         *                                   atomic_add_unless(&page->_refcount)
         *                                   XXX: try to modify r/o struct page[]
         *
         * The refcount check also prevents modification attempts to other (r/o)
         * tail pages that are not fake heads.
         */
        if (atomic_read_acquire(&page->_refcount) == u)
                return false;

        return page_fixed_fake_head(page) == page;
}
#else
static inline const struct page *page_fixed_fake_head(const struct page *page)
{
        return page;
}

static inline bool page_count_writable(const struct page *page, int u)
{
        return true;
}
#endif

static __always_inline int page_is_fake_head(const struct page *page)
{
        return page_fixed_fake_head(page) != page;
}

static __always_inline unsigned long _compound_head(const struct page *page)
{
        unsigned long head = READ_ONCE(page->compound_head);

        if (unlikely(head & 1))
                return head - 1;
        return (unsigned long)page_fixed_fake_head(page);
}

#define compound_head(page)     ((typeof(page))_compound_head(page))

/**
 * 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_head) & 1 || page_is_fake_head(page);
}

static __always_inline int PageCompound(const struct page *page)
{
        return test_bit(PG_head, &page->flags.f) ||
               READ_ONCE(page->compound_head) & 1;
}

#define PAGE_POISON_PATTERN     -1l
static inline int PagePoisoned(const struct page *page)
{
        return READ_ONCE(page->flags.f) == PAGE_POISON_PATTERN;
}

#ifdef CONFIG_DEBUG_VM
void page_init_poison(struct page *page, size_t size);
#else
static 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_head & 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_head & 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))
#else
PAGEFLAG_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_SWAP
static __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)
#else
FOLIO_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_MMU
FOLIO_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)
#else
FOLIO_FLAG_FALSE(mlocked)
        __FOLIO_CLEAR_FLAG_NOOP(mlocked)
        FOLIO_TEST_CLEAR_FLAG_FALSE(mlocked)
        FOLIO_TEST_SET_FLAG_FALSE(mlocked)
#endif

#ifdef CONFIG_MEMORY_FAILURE
PAGEFLAG(HWPoison, hwpoison, PF_ANY)
TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
#define __PG_HWPOISON (1UL << PG_hwpoison)
#else
PAGEFLAG_FALSE(HWPoison, hwpoison)
#define __PG_HWPOISON 0
#endif

#ifdef CONFIG_PAGE_IDLE_FLAG
#ifdef CONFIG_64BIT
FOLIO_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_HOTPLUG
PAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY)
#else
PAGEFLAG_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 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;
}
#else
FOLIO_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) && !page_is_fake_head(page);
}

__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);
}

static __always_inline void set_compound_head(struct page *page, struct page *head)
{
        WRITE_ONCE(page->compound_head, (unsigned long)head + 1);
}

static __always_inline void clear_compound_head(struct page *page)
{
        WRITE_ONCE(page->compound_head, 0);
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static 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)
#else
FOLIO_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);
}
#else
TESTPAGEFLAG_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)
#else
FOLIO_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_PAGE
FOLIO_TYPE_OPS(hugetlb, hugetlb)
#else
FOLIO_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 */