linux-imx

/*

 * Virtio balloon implementation, inspired by Dor Laor and Marcelo

 * Tosatti's implementations.

 *

 *  Copyright 2008 Rusty Russell IBM Corporation

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

​

#include <linux/virtio.h>

#include <linux/virtio_balloon.h>

#include <linux/swap.h>

#include <linux/workqueue.h>

#include <linux/delay.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/balloon_compaction.h>

#include <linux/wait.h>

#include <linux/mm.h>

#include <linux/mount.h>

#include <linux/magic.h>

​

/*

 * Balloon device works in 4K page units.  So each page is pointed to by

 * multiple balloon pages.  All memory counters in this driver are in balloon

 * page units.

 */

#define VIRTIO_BALLOON_PAGES_PER_PAGE (unsigned)(PAGE_SIZE >> VIRTIO_BALLOON_PFN_SHIFT)

#define VIRTIO_BALLOON_ARRAY_PFNS_MAX 256

#define VIRTBALLOON_OOM_NOTIFY_PRIORITY 80

​

#define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \

                         __GFP_NOMEMALLOC)

/* The order of free page blocks to report to host */

#define VIRTIO_BALLOON_FREE_PAGE_ORDER (MAX_ORDER - 1)

/* The size of a free page block in bytes */

#define VIRTIO_BALLOON_FREE_PAGE_SIZE \

    (1 << (VIRTIO_BALLOON_FREE_PAGE_ORDER + PAGE_SHIFT))

​

#ifdef CONFIG_BALLOON_COMPACTION

static struct vfsmount *balloon_mnt;

#endif

​

enum virtio_balloon_vq {

    VIRTIO_BALLOON_VQ_INFLATE,

    VIRTIO_BALLOON_VQ_DEFLATE,

    VIRTIO_BALLOON_VQ_STATS,

    VIRTIO_BALLOON_VQ_FREE_PAGE,

    VIRTIO_BALLOON_VQ_MAX

};

​