/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MM_PAGE_IDLE_H
#define _LINUX_MM_PAGE_IDLE_H

#include <linux/bitops.h>
#include <linux/page-flags.h>
#include <linux/page_ext.h>

#if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
/*
 * If there is not enough space to store Idle and Young bits in page flags, use
 * page ext flags instead.
 */
static inline bool folio_test_young(const struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);
        bool page_young;

        if (unlikely(!page_ext))
                return false;

        page_young = test_bit(PAGE_EXT_YOUNG, &page_ext->flags);
        page_ext_put(page_ext);

        return page_young;
}

static inline void folio_set_young(struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);

        if (unlikely(!page_ext))
                return;

        set_bit(PAGE_EXT_YOUNG, &page_ext->flags);
        page_ext_put(page_ext);
}

static inline bool folio_test_clear_young(struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);
        bool page_young;

        if (unlikely(!page_ext))
                return false;

        page_young = test_and_clear_bit(PAGE_EXT_YOUNG, &page_ext->flags);
        page_ext_put(page_ext);

        return page_young;
}

static inline bool folio_test_idle(const struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);
        bool page_idle;

        if (unlikely(!page_ext))
                return false;

        page_idle = test_bit(PAGE_EXT_IDLE, &page_ext->flags);
        page_ext_put(page_ext);

        return page_idle;
}

static inline void folio_set_idle(struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);

        if (unlikely(!page_ext))
                return;

        set_bit(PAGE_EXT_IDLE, &page_ext->flags);
        page_ext_put(page_ext);
}

static inline void folio_clear_idle(struct folio *folio)
{
        struct page_ext *page_ext = page_ext_get(&folio->page);

        if (unlikely(!page_ext))
                return;

        clear_bit(PAGE_EXT_IDLE, &page_ext->flags);
        page_ext_put(page_ext);
}
#endif /* CONFIG_PAGE_IDLE_FLAG && !64BIT */
#endif /* _LINUX_MM_PAGE_IDLE_H */