linux-imx

/******************************************************************************

 * gntdev.c

 *

 * Device for accessing (in user-space) pages that have been granted by other

 * domains.

 *

 * Copyright (c) 2006-2007, D G Murray.

 *           (c) 2009 Gerd Hoffmann <kraxel@redhat.com>

 *           (c) 2018 Oleksandr Andrushchenko, EPAM Systems Inc.

 *

 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

​

#undef DEBUG

​

#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/miscdevice.h>

#include <linux/fs.h>

#include <linux/uaccess.h>

#include <linux/sched.h>

#include <linux/sched/mm.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/highmem.h>

#include <linux/refcount.h>

#ifdef CONFIG_XEN_GRANT_DMA_ALLOC

#include <linux/of_device.h>

#endif

​

#include <xen/xen.h>

#include <xen/grant_table.h>

#include <xen/balloon.h>

#include <xen/gntdev.h>

#include <xen/events.h>

#include <xen/page.h>

#include <asm/xen/hypervisor.h>

#include <asm/xen/hypercall.h>

​

#include "gntdev-common.h"

#ifdef CONFIG_XEN_GNTDEV_DMABUF

#include "gntdev-dmabuf.h"

#endif

​

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Derek G. Murray <Derek.Murray@cl.cam.ac.uk>, "

          "Gerd Hoffmann <kraxel@redhat.com>");

MODULE_DESCRIPTION("User-space granted page access driver");

​

static int limit = 1024*1024;

module_param(limit, int, 0644);

MODULE_PARM_DESC(limit, "Maximum number of grants that may be mapped by "

        "the gntdev device");