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, 7 insertions, 12 deletions

diff --git a/drivers/net/ethernet/qlogic/qede/qede_fp.c b/drivers/net/ethernet/qlogic/qede/qede_fp.c
index 8c47a9d2a965..102d0e0808d5 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_fp.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_fp.c
@@ -345,7 +345,7 @@ int qede_xdp_transmit(struct net_device *dev, int n_frames,
 	struct qede_tx_queue *xdp_tx;
 	struct xdp_frame *xdpf;
 	dma_addr_t mapping;
-	int i, drops = 0;
+	int i, nxmit = 0;
 	u16 xdp_prod;
 
 	if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
@@ -364,18 +364,13 @@ int qede_xdp_transmit(struct net_device *dev, int n_frames,
 
 		mapping = dma_map_single(dmadev, xdpf->data, xdpf->len,
 					 DMA_TO_DEVICE);
-		if (unlikely(dma_mapping_error(dmadev, mapping))) {
-			xdp_return_frame_rx_napi(xdpf);
-			drops++;
-
-			continue;
-		}
+		if (unlikely(dma_mapping_error(dmadev, mapping)))
+			break;
 
 		if (unlikely(qede_xdp_xmit(xdp_tx, mapping, 0, xdpf->len,
-					   NULL, xdpf))) {
-			xdp_return_frame_rx_napi(xdpf);
-			drops++;
-		}
+					   NULL, xdpf)))
+			break;
+		nxmit++;
 	}
 
 	if (flags & XDP_XMIT_FLUSH) {
@@ -387,7 +382,7 @@ int qede_xdp_transmit(struct net_device *dev, int n_frames,
 
 	spin_unlock(&xdp_tx->xdp_tx_lock);
 
-	return n_frames - drops;
+	return nxmit;
 }
 
 int qede_txq_has_work(struct qede_tx_queue *txq)