net/ena: flush Rx buffers memory pool cache

[ upstream commit 4387e81 ]

As the refill called as part of ena_start(), we end up the refill
progress with stuck buffers at the caller core cache.

Calling to flush the cache results with invalidate this cache and free
those stuck buffers.

Fixes: 1173fca ("ena: add polling-mode driver")

Signed-off-by: Ido Segev <idose@amazon.com>
Reviewed-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>

drivers/net/ena/ena_ethdev.c

@@ -1182,6 +1182,10 @@ static int ena_queue_start(struct ena_ring *ring)
 		PMD_INIT_LOG(ERR, "Failed to populate rx ring !");
 		return ENA_COM_FAULT;
 	}
+	/* Flush per-core RX buffers pools cache as they can be used on other
+	 * cores as well.
+	 */
+	rte_mempool_cache_flush(NULL, ring->mb_pool);
 
 	return 0;
 }