[RFC PATCH 03/10] vfio: Export unmap_mapping_range() wrapper

[Alex Williamson <alex.williamson@redhat.com>]

Allow bus drivers to use vfio pseudo fs mapping to zap all mmaps
across a range of their device files.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/vfio/vfio.c  |    7 +++++++
 include/linux/vfio.h |    2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 067cd843961c..da212425ab30 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -565,6 +565,13 @@ static struct inode *vfio_fs_inode_new(void)
 	return inode;
 }
 
+void vfio_device_unmap_mapping_range(struct vfio_device *device,
+				     loff_t start, loff_t len)
+{
+	unmap_mapping_range(device->inode->i_mapping, start, len, true);
+}
+EXPORT_SYMBOL_GPL(vfio_device_unmap_mapping_range);
+
 /**
  * Device objects - create, release, get, put, search
  */
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index b784463000d4..f435dfca15eb 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -56,6 +56,8 @@ extern void *vfio_del_group_dev(struct device *dev);
 extern struct vfio_device *vfio_device_get_from_dev(struct device *dev);
 extern void vfio_device_put(struct vfio_device *device);
 extern void *vfio_device_data(struct vfio_device *device);
+extern void vfio_device_unmap_mapping_range(struct vfio_device *device,
+					    loff_t start, loff_t len);
 
 /* events for the backend driver notify callback */
 enum vfio_iommu_notify_type {