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, 1 insertions, 14 deletions

diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 1665529a7271..0c6650d2e239 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -412,14 +412,6 @@ err:
 	return NETDEV_TX_OK;
 }
 
-static void efx_xdp_return_frames(int n,  struct xdp_frame **xdpfs)
-{
-	int i;
-
-	for (i = 0; i < n; i++)
-		xdp_return_frame_rx_napi(xdpfs[i]);
-}
-
 /* Transmit a packet from an XDP buffer
  *
  * Returns number of packets sent on success, error code otherwise.
@@ -492,12 +484,7 @@ int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs,
 	if (flush && i > 0)
 		efx_nic_push_buffers(tx_queue);
 
-	if (i == 0)
-		return -EIO;
-
-	efx_xdp_return_frames(n - i, xdpfs + i);
-
-	return i;
+	return i == 0 ? -EIO : i;
 }
 
 /* Initiate a packet transmission.  We use one channel per CPU