bpf, devmap: Move drop error path to devmap for XDP_REDIRECT

We want to change the current ndo_xdp_xmit drop semantics because it will
allow us to implement better queue overflow handling. This is working
towards the larger goal of a XDP TX queue-hook. Move XDP_REDIRECT error
path handling from each XDP ethernet driver to devmap code. According to
the new APIs, the driver running the ndo_xdp_xmit pointer, will break tx
loop whenever the hw reports a tx error and it will just return to devmap
caller the number of successfully transmitted frames. It will be devmap
responsibility to free dropped frames.

Move each XDP ndo_xdp_xmit capable driver to the new APIs:

- veth
- virtio-net
- mvneta
- mvpp2
- socionext
- amazon ena
- bnxt
- freescale (dpaa2, dpaa)
- xen-frontend
- qede
- ice
- igb
- ixgbe
- i40e
- mlx5
- ti (cpsw, cpsw-new)
- tun
- sfc

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Shay Agroskin <shayagr@amazon.com>
Link: https://lore.kernel.org/bpf/ed670de24f951cfd77590decf0229a0ad7fd12f6.1615201152.git.lorenzo@kernel.org

1 files changed, 6 insertions, 7 deletions

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 1767c60056c5..ec706d614cac 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -3744,7 +3744,7 @@ mvpp2_xdp_xmit(struct net_device *dev, int num_frame,
 	       struct xdp_frame **frames, u32 flags)
 {
 	struct mvpp2_port *port = netdev_priv(dev);
-	int i, nxmit_byte = 0, nxmit = num_frame;
+	int i, nxmit_byte = 0, nxmit = 0;
 	struct mvpp2_pcpu_stats *stats;
 	u16 txq_id;
 	u32 ret;
@@ -3762,12 +3762,11 @@ mvpp2_xdp_xmit(struct net_device *dev, int num_frame,
 
 	for (i = 0; i < num_frame; i++) {
 		ret = mvpp2_xdp_submit_frame(port, txq_id, frames[i], true);
-		if (ret == MVPP2_XDP_TX) {
-			nxmit_byte += frames[i]->len;
-		} else {
-			xdp_return_frame_rx_napi(frames[i]);
-			nxmit--;
-		}
+		if (ret != MVPP2_XDP_TX)
+			break;
+
+		nxmit_byte += frames[i]->len;
+		nxmit++;
 	}
 
 	if (likely(nxmit > 0))