vfio/fsl-mc: Add per device reset support

Currently when a fsl-mc device is reset, the entire DPRC container
is reset which is very inefficient because the devices within a
container will be reset multiple times.
Add support for individually resetting a device.
Signed-off-by: Diana Craciun <diana.craciun@oss.nxp.com>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Link: https://lore.kernel.org/r/20210922110530.24736-2-diana.craciun@oss.nxp.comSigned-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/fsl-mc/vfio_fsl_mc.c

@@ -65,6 +65,34 @@ static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
 	kfree(vdev->regions);
 }
 
+static int vfio_fsl_mc_reset_device(struct vfio_fsl_mc_device *vdev)
+{
+	struct fsl_mc_device *mc_dev = vdev->mc_dev;
+	int ret = 0;
+
+	if (is_fsl_mc_bus_dprc(vdev->mc_dev)) {
+		return dprc_reset_container(mc_dev->mc_io, 0,
+					mc_dev->mc_handle,
+					mc_dev->obj_desc.id,
+					DPRC_RESET_OPTION_NON_RECURSIVE);
+	} else {
+		u16 token;
+
+		ret = fsl_mc_obj_open(mc_dev->mc_io, 0, mc_dev->obj_desc.id,
+				      mc_dev->obj_desc.type,
+				      &token);
+		if (ret)
+			goto out;
+		ret = fsl_mc_obj_reset(mc_dev->mc_io, 0, token);
+		if (ret) {
+			fsl_mc_obj_close(mc_dev->mc_io, 0, token);
+			goto out;
+		}
+		ret = fsl_mc_obj_close(mc_dev->mc_io, 0, token);
+	}
+out:
+	return ret;
+}
 
 static void vfio_fsl_mc_close_device(struct vfio_device *core_vdev)
 {
@@ -78,9 +106,7 @@ static void vfio_fsl_mc_close_device(struct vfio_device *core_vdev)
 	vfio_fsl_mc_regions_cleanup(vdev);
 
 	/* reset the device before cleaning up the interrupts */
-	ret = dprc_reset_container(mc_cont->mc_io, 0, mc_cont->mc_handle,
-				   mc_cont->obj_desc.id,
-				   DPRC_RESET_OPTION_NON_RECURSIVE);
+	ret = vfio_fsl_mc_reset_device(vdev);
 
 	if (WARN_ON(ret))
 		dev_warn(&mc_cont->dev,
@@ -203,18 +229,7 @@ static long vfio_fsl_mc_ioctl(struct vfio_device *core_vdev,
 	}
 	case VFIO_DEVICE_RESET:
 	{
-		int ret;
-		struct fsl_mc_device *mc_dev = vdev->mc_dev;
-
-		/* reset is supported only for the DPRC */
-		if (!is_fsl_mc_bus_dprc(mc_dev))
-			return -ENOTTY;
-
-		ret = dprc_reset_container(mc_dev->mc_io, 0,
-					   mc_dev->mc_handle,
-					   mc_dev->obj_desc.id,
-					   DPRC_RESET_OPTION_NON_RECURSIVE);
-		return ret;
+		return vfio_fsl_mc_reset_device(vdev);
 
 	}
 	default: