From: Jesper Dangaard Brouer <brouer@redhat.com>
Date: Mon, 30 Jul 2018 19:49:08 +0200
Subject: mlx5: handle DMA mapping error case for XDP redirect
Patch-mainline: v4.19-rc1
Git-commit: 39c64d8c876622e766dd2112baf81151dd82da02
References: bsc#1103990 FATE#326006

Commit 58b99ee3e3eb ("net/mlx5e: Add support for XDP_REDIRECT in device-out side")
forgot to return/free the xdp_frame in case the DMA mapping failed, correct this.

Also DMA unmap the frame in case mlx5e_xmit_xdp_frame() fails.

Fixes: 58b99ee3e3eb ("net/mlx5e: Add support for XDP_REDIRECT in device-out side")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c
@@ -283,6 +283,7 @@ int mlx5e_xdp_xmit(struct net_device *de
 		xdpi.dma_addr = dma_map_single(sq->pdev, xdpf->data, xdpf->len,
 					       DMA_TO_DEVICE);
 		if (unlikely(dma_mapping_error(sq->pdev, xdpi.dma_addr))) {
+			xdp_return_frame_rx_napi(xdpf);
 			drops++;
 			continue;
 		}
@@ -290,6 +291,8 @@ int mlx5e_xdp_xmit(struct net_device *de
 		xdpi.xdpf = xdpf;
 
 		if (unlikely(!mlx5e_xmit_xdp_frame(sq, &xdpi))) {
+			dma_unmap_single(sq->pdev, xdpi.dma_addr,
+					 xdpf->len, DMA_TO_DEVICE);
 			xdp_return_frame_rx_napi(xdpf);
 			drops++;
 		}