[dpdk-dev] [PATCH 01/29] net/ena: check if size of buffer is at least 1400B

[Michal Krawczyk]

Some of the ENA devices can't handle buffers which are smaller than a
1400B. Because of this limitation, size of the buffer is being checked
and limited during the Rx queue setup.

If it's below the allowed value, PMD won't finish it's configuration
successfully..

Signed-off-by: Michal Krawczyk <mk at semihalf.com>
Reviewed-by: Igor Chauskin <igorch at amazon.com>
Reviewed-by: Guy Tzalik <gtzalik at amazon.com>
---
 drivers/net/ena/ena_ethdev.c | 12 ++++++++++++
 drivers/net/ena/ena_ethdev.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index 665afee4f0..a8f8784a9f 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -1282,6 +1282,7 @@ static int ena_rx_queue_setup(struct rte_eth_dev *dev,
 {
 	struct ena_adapter *adapter = dev->data->dev_private;
 	struct ena_ring *rxq = NULL;
+	size_t buffer_size;
 	int i;
 
 	rxq = &adapter->rx_ring[queue_idx];
@@ -1309,6 +1310,17 @@ static int ena_rx_queue_setup(struct rte_eth_dev *dev,
 		return -EINVAL;
 	}
 
+	/* ENA isn't supporting buffers smaller than 1400 bytes */
+	buffer_size = mp->elt_size - sizeof(struct rte_mbuf) -
+		RTE_PKTMBUF_HEADROOM;
+	if (buffer_size < ENA_RX_BUF_MIN_SIZE) {
+		PMD_DRV_LOG(ERR,
+			"Unsupported size of RX buffer: %zu (min size: %d)\n",
+			buffer_size, ENA_RX_BUF_MIN_SIZE);
+		return -EINVAL;
+	}
+	printf("mempool size: %ld\n", buffer_size);
+
 	rxq->port_id = dev->data->port_id;
 	rxq->next_to_clean = 0;
 	rxq->next_to_use = 0;
diff --git a/drivers/net/ena/ena_ethdev.h b/drivers/net/ena/ena_ethdev.h
index af5eeea280..c1457defeb 100644
--- a/drivers/net/ena/ena_ethdev.h
+++ b/drivers/net/ena/ena_ethdev.h
@@ -20,6 +20,7 @@
 #define ENA_MIN_FRAME_LEN	64
 #define ENA_NAME_MAX_LEN	20
 #define ENA_PKT_MAX_BUFS	17
+#define ENA_RX_BUF_MIN_SIZE	1400
 
 #define ENA_MIN_MTU		128
 
-- 
2.20.1