kernel_arpi/include/linux/mm_inline.h

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

#include <linux/huge_mm.h>
#include <linux/swap.h>
#include <linux/string.h>

/**
 * page_is_file_lru - should the page be on a file LRU or anon LRU?
 * @page: the page to test
 *
 * Returns 1 if @page is a regular filesystem backed page cache page or a lazily
 * freed anonymous page (e.g. via MADV_FREE).  Returns 0 if @page is a normal
 * anonymous page, a tmpfs page or otherwise ram or swap backed page.  Used by
 * functions that manipulate the LRU lists, to sort a page onto the right LRU
 * list.
 *
 * We would like to get this info without a page flag, but the state
 * needs to survive until the page is last deleted from the LRU, which
 * could be as far down as __page_cache_release.
 */
static inline int page_is_file_lru(struct page *page)
{
	return !PageSwapBacked(page);
}

static __always_inline void update_lru_size(struct lruvec *lruvec,
				enum lru_list lru, enum zone_type zid,
				int nr_pages)
{
	struct pglist_data *pgdat = lruvec_pgdat(lruvec);

	__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
	__mod_zone_page_state(&pgdat->node_zones[zid],
				NR_ZONE_LRU_BASE + lru, nr_pages);
#ifdef CONFIG_MEMCG
	mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
#endif
}

/**
 * __clear_page_lru_flags - clear page lru flags before releasing a page
 * @page: the page that was on lru and now has a zero reference
 */
static __always_inline void __clear_page_lru_flags(struct page *page)
{
	VM_BUG_ON_PAGE(!PageLRU(page), page);

	__ClearPageLRU(page);

	/* this shouldn't happen, so leave the flags to bad_page() */
	if (PageActive(page) && PageUnevictable(page))
		return;

	__ClearPageActive(page);
	__ClearPageUnevictable(page);
}

/**
 * page_lru - which LRU list should a page be on?
 * @page: the page to test
 *
 * Returns the LRU list a page should be on, as an index
 * into the array of LRU lists.
 */
static __always_inline enum lru_list page_lru(struct page *page)
{
	enum lru_list lru;

	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);

	if (PageUnevictable(page))
		return LRU_UNEVICTABLE;

	lru = page_is_file_lru(page) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
	if (PageActive(page))
		lru += LRU_ACTIVE;

	return lru;
}

static __always_inline void add_page_to_lru_list(struct page *page,
				struct lruvec *lruvec)
{
	enum lru_list lru = page_lru(page);

	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
	list_add(&page->lru, &lruvec->lists[lru]);
}

static __always_inline void add_page_to_lru_list_tail(struct page *page,
				struct lruvec *lruvec)
{
	enum lru_list lru = page_lru(page);

	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
	list_add_tail(&page->lru, &lruvec->lists[lru]);
}

static __always_inline void del_page_from_lru_list(struct page *page,
				struct lruvec *lruvec)
{
	list_del(&page->lru);
	update_lru_size(lruvec, page_lru(page), page_zonenum(page),
			-thp_nr_pages(page));
}

#ifdef CONFIG_ANON_VMA_NAME
/*
 * mmap_lock should be read-locked when calling anon_vma_name(). Caller should
 * either keep holding the lock while using the returned pointer or it should
 * raise anon_vma_name refcount before releasing the lock.
 */
extern struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma);
extern struct anon_vma_name *anon_vma_name_alloc(const char *name);
extern void anon_vma_name_free(struct kref *kref);

/* mmap_lock should be read-locked */
static inline void anon_vma_name_get(struct anon_vma_name *anon_name)
{
	if (anon_name)
		kref_get(&anon_name->kref);
}

static inline void anon_vma_name_put(struct anon_vma_name *anon_name)
{
	if (anon_name)
		kref_put(&anon_name->kref, anon_vma_name_free);
}

static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
				     struct vm_area_struct *new_vma)
{
	struct anon_vma_name *anon_name = anon_vma_name(orig_vma);

	if (anon_name) {
		anon_vma_name_get(anon_name);
		new_vma->anon_name = anon_name;
	}
}

static inline void free_anon_vma_name(struct vm_area_struct *vma)
{
	/*
	 * Not using anon_vma_name because it generates a warning if mmap_lock
	 * is not held, which might be the case here.
	 */
	if (!vma->vm_file)
		anon_vma_name_put(vma->anon_name);
}

static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
				    struct anon_vma_name *anon_name2)
{
	if (anon_name1 == anon_name2)
		return true;

	return anon_name1 && anon_name2 &&
		!strcmp(anon_name1->name, anon_name2->name);
}
#else /* CONFIG_ANON_VMA_NAME */
static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma)
{
	return NULL;
}

static inline struct anon_vma_name *anon_vma_name_alloc(const char *name)
{
	return NULL;
}

static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}
static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}
static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
				     struct vm_area_struct *new_vma) {}
static inline void free_anon_vma_name(struct vm_area_struct *vma) {}

static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
				    struct anon_vma_name *anon_name2)
{
	return true;
}

#endif  /* CONFIG_ANON_VMA_NAME */

#endif