ice: allow 3k MTU for XDP

At this point ice driver is able to work on order 1 pages that are split
onto two 3k buffers. Let's reflect that when user is setting new MTU
size and XDP is present on interface.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ice/ice_main.c

@@ -4658,6 +4658,18 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 	dev_err(dev, "Rebuild failed, unload and reload driver\n");
 }
 
+/**
+ * ice_max_xdp_frame_size - returns the maximum allowed frame size for XDP
+ * @vsi: Pointer to VSI structure
+ */
+static int ice_max_xdp_frame_size(struct ice_vsi *vsi)
+{
+	if (PAGE_SIZE >= 8192 || test_bit(ICE_FLAG_LEGACY_RX, vsi->back->flags))
+		return ICE_RXBUF_2048 - XDP_PACKET_HEADROOM;
+	else
+		return ICE_RXBUF_3072;
+}
+
 /**
  * ice_change_mtu - NDO callback to change the MTU
  * @netdev: network interface device structure
@@ -4678,11 +4690,11 @@ static int ice_change_mtu(struct net_device *netdev, int new_mtu)
 	}
 
 	if (ice_is_xdp_ena_vsi(vsi)) {
-		int frame_size = ICE_RXBUF_2048 - XDP_PACKET_HEADROOM;
+		int frame_size = ice_max_xdp_frame_size(vsi);
 
 		if (new_mtu + ICE_ETH_PKT_HDR_PAD > frame_size) {
 			netdev_err(netdev, "max MTU for XDP usage is %d\n",
-				   frame_size);
+				   frame_size - ICE_ETH_PKT_HDR_PAD);
 			return -EINVAL;
 		}
 	}