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diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
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+++ b/include/linux/balloon_compaction.h
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+/*
+ * include/linux/balloon_compaction.h
+ *
+ * Common interface definitions for making balloon pages movable by compaction.
+ *
+ * Despite being perfectly possible to perform ballooned pages migration, they
+ * make a special corner case to compaction scans because balloon pages are not
+ * enlisted at any LRU list like the other pages we do compact / migrate.
+ *
+ * As the page isolation scanning step a compaction thread does is a lockless
+ * procedure (from a page standpoint), it might bring some racy situations while
+ * performing balloon page compaction. In order to sort out these racy scenarios
+ * and safely perform balloon's page compaction and migration we must, always,
+ * ensure following these three simple rules:
+ *
+ *   i. when updating a balloon's page ->mapping element, strictly do it under
+ *      the following lock order, independently of the far superior
+ *      locking scheme (lru_lock, balloon_lock):
+ *	    +-page_lock(page);
+ *	      +--spin_lock_irq(&b_dev_info->pages_lock);
+ *	            ... page->mapping updates here ...
+ *
+ *  ii. before isolating or dequeueing a balloon page from the balloon device
+ *      pages list, the page reference counter must be raised by one and the
+ *      extra refcount must be dropped when the page is enqueued back into
+ *      the balloon device page list, thus a balloon page keeps its reference
+ *      counter raised only while it is under our special handling;
+ *
+ * iii. after the lockless scan step have selected a potential balloon page for
+ *      isolation, re-test the PageBalloon mark and the PagePrivate flag
+ *      under the proper page lock, to ensure isolating a valid balloon page
+ *      (not yet isolated, nor under release procedure)
+ *
+ *  iv. isolation or dequeueing procedure must clear PagePrivate flag under
+ *      page lock together with removing page from balloon device page list.
+ *
+ * The functions provided by this interface are placed to help on coping with
+ * the aforementioned balloon page corner case, as well as to ensure the simple
+ * set of exposed rules are satisfied while we are dealing with balloon pages
+ * compaction / migration.
+ *
+ * Copyright (C) 2012, Red Hat, Inc.  Rafael Aquini <aquini@redhat.com>
+ */
+#ifndef _LINUX_BALLOON_COMPACTION_H
+#define _LINUX_BALLOON_COMPACTION_H
+#include <linux/pagemap.h>
+#include <linux/page-flags.h>
+#include <linux/migrate.h>
+#include <linux/gfp.h>
+#include <linux/err.h>
+
+/*
+ * Balloon device information descriptor.
+ * This struct is used to allow the common balloon compaction interface
+ * procedures to find the proper balloon device holding memory pages they'll
+ * have to cope for page compaction / migration, as well as it serves the
+ * balloon driver as a page book-keeper for its registered balloon devices.
+ */
+struct balloon_dev_info {
+	unsigned long isolated_pages;	/* # of isolated pages for migration */
+	spinlock_t pages_lock;		/* Protection to pages list */
+	struct list_head pages;		/* Pages enqueued & handled to Host */
+	int (*migratepage)(struct balloon_dev_info *, struct page *newpage,
+			struct page *page, enum migrate_mode mode);
+};
+
+extern struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info);
+extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info);
+
+static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
+{
+	balloon->isolated_pages = 0;
+	spin_lock_init(&balloon->pages_lock);
+	INIT_LIST_HEAD(&balloon->pages);
+	balloon->migratepage = NULL;
+}
+
+#ifdef CONFIG_BALLOON_COMPACTION
+extern bool balloon_page_isolate(struct page *page);
+extern void balloon_page_putback(struct page *page);
+extern int balloon_page_migrate(struct page *newpage,
+				struct page *page, enum migrate_mode mode);
+
+/*
+ * __is_movable_balloon_page - helper to perform @page PageBalloon tests
+ */
+static inline bool __is_movable_balloon_page(struct page *page)
+{
+	return PageBalloon(page);
+}
+
+/*
+ * balloon_page_movable - test PageBalloon to identify balloon pages
+ *			  and PagePrivate to check that the page is not
+ *			  isolated and can be moved by compaction/migration.
+ *
+ * As we might return false positives in the case of a balloon page being just
+ * released under us, this need to be re-tested later, under the page lock.
+ */
+static inline bool balloon_page_movable(struct page *page)
+{
+	return PageBalloon(page) && PagePrivate(page);
+}
+
+/*
+ * isolated_balloon_page - identify an isolated balloon page on private
+ *			   compaction/migration page lists.
+ */
+static inline bool isolated_balloon_page(struct page *page)
+{
+	return PageBalloon(page);
+}
+
+/*
+ * balloon_page_insert - insert a page into the balloon's page list and make
+ *			 the page->private assignment accordingly.
+ * @balloon : pointer to balloon device
+ * @page    : page to be assigned as a 'balloon page'
+ *
+ * Caller must ensure the page is locked and the spin_lock protecting balloon
+ * pages list is held before inserting a page into the balloon device.
+ */
+static inline void balloon_page_insert(struct balloon_dev_info *balloon,
+				       struct page *page)
+{
+	__SetPageBalloon(page);
+	SetPagePrivate(page);
+	set_page_private(page, (unsigned long)balloon);
+	list_add(&page->lru, &balloon->pages);
+}
+
+/*
+ * balloon_page_delete - delete a page from balloon's page list and clear
+ *			 the page->private assignement accordingly.
+ * @page    : page to be released from balloon's page list
+ *
+ * Caller must ensure the page is locked and the spin_lock protecting balloon
+ * pages list is held before deleting a page from the balloon device.
+ */
+static inline void balloon_page_delete(struct page *page)
+{
+	__ClearPageBalloon(page);
+	set_page_private(page, 0);
+	if (PagePrivate(page)) {
+		ClearPagePrivate(page);
+		list_del(&page->lru);
+	}
+}
+
+/*
+ * balloon_page_device - get the b_dev_info descriptor for the balloon device
+ *			 that enqueues the given page.
+ */
+static inline struct balloon_dev_info *balloon_page_device(struct page *page)
+{
+	return (struct balloon_dev_info *)page_private(page);
+}
+
+static inline gfp_t balloon_mapping_gfp_mask(void)
+{
+	return GFP_HIGHUSER_MOVABLE;
+}
+
+#else /* !CONFIG_BALLOON_COMPACTION */
+
+static inline void balloon_page_insert(struct balloon_dev_info *balloon,
+				       struct page *page)
+{
+	__SetPageBalloon(page);
+	list_add(&page->lru, &balloon->pages);
+}
+
+static inline void balloon_page_delete(struct page *page)
+{
+	__ClearPageBalloon(page);
+	list_del(&page->lru);
+}
+
+static inline bool __is_movable_balloon_page(struct page *page)
+{
+	return false;
+}
+
+static inline bool balloon_page_movable(struct page *page)
+{
+	return false;
+}
+
+static inline bool isolated_balloon_page(struct page *page)
+{
+	return false;
+}
+
+static inline bool balloon_page_isolate(struct page *page)
+{
+	return false;
+}
+
+static inline void balloon_page_putback(struct page *page)
+{
+	return;
+}
+
+static inline int balloon_page_migrate(struct page *newpage,
+				struct page *page, enum migrate_mode mode)
+{
+	return 0;
+}
+
+static inline gfp_t balloon_mapping_gfp_mask(void)
+{
+	return GFP_HIGHUSER;
+}
+
+#endif /* CONFIG_BALLOON_COMPACTION */
+#endif /* _LINUX_BALLOON_COMPACTION_H */