[PATCH mlx5-next 3/7] vfio/pci_core: Make the region->release() function optional

[Leon Romanovsky]

From: Yishai Hadas <yishaih@xxxxxxxxxx>

Make the region->release() function optional as in some cases there is
nothing to do by driver as part of it.

This is needed for coming patch from this series once we add
mlx5_vfio_cpi driver to support live migration but we don't need a
migration release function.

Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>
---
 drivers/vfio/pci/vfio_pci_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 68198e0f2a63..3ddc3adb24de 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -341,7 +341,8 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
 	vdev->virq_disabled = false;
 
 	for (i = 0; i < vdev->num_regions; i++)
-		vdev->region[i].ops->release(vdev, &vdev->region[i]);
+		if (vdev->region[i].ops->release)
+			vdev->region[i].ops->release(vdev, &vdev->region[i]);
 
 	vdev->num_regions = 0;
 	kfree(vdev->region);
-- 
2.31.1