net: ena: Use tx_ring instead of xdp_ring for XDP channel TX

When an XDP program is loaded the existing channels in the driver split
into two halves:
- The first half of the channels contain RX and TX rings, these queues
  are used for receiving traffic and sending packets originating from
  kernel.
- The second half of the channels contain only a TX ring. These queues
  are used for sending packets that were redirected using XDP_TX
  or XDP_REDIRECT.

Referring to the queues in the second half of the channels as "xdp_ring"
can be confusing and may give the impression that ENA has the capability
to generate an additional special queue.

This patch ensures that the xdp_ring field is exclusively used to
describe the XDP TX queue that a specific RX queue needs to utilize when
forwarding packets with XDP TX and XDP REDIRECT, preserving the
integrity of the xdp_ring field in ena_ring.

Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20240101190855.18739-6-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 5 insertions, 7 deletions

diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 3c84259e06f9..6ababac9aeeb 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -1746,8 +1746,8 @@ static void ena_del_napi_in_range(struct ena_adapter *adapter,
 	for (i = first_index; i < first_index + count; i++) {
 		netif_napi_del(&adapter->ena_napi[i].napi);
 
-		WARN_ON(!ENA_IS_XDP_INDEX(adapter, i) &&
-			adapter->ena_napi[i].xdp_ring);
+		WARN_ON(ENA_IS_XDP_INDEX(adapter, i) &&
+			adapter->ena_napi[i].rx_ring);
 	}
 }
 
@@ -1762,12 +1762,10 @@ static void ena_init_napi_in_range(struct ena_adapter *adapter,
 		netif_napi_add(adapter->netdev, &napi->napi,
 			       ENA_IS_XDP_INDEX(adapter, i) ? ena_xdp_io_poll : ena_io_poll);
 
-		if (!ENA_IS_XDP_INDEX(adapter, i)) {
+		if (!ENA_IS_XDP_INDEX(adapter, i))
 			napi->rx_ring = &adapter->rx_ring[i];
-			napi->tx_ring = &adapter->tx_ring[i];
-		} else {
-			napi->xdp_ring = &adapter->tx_ring[i];
-		}
+
+		napi->tx_ring = &adapter->tx_ring[i];
 		napi->qid = i;
 	}
 }