0022-net-ena-ensure-Rx-buffer-size-is-at-least-1400B.patch

From 08aaa39c149818d55bb2f31419c355d7310ebe41 Mon Sep 17 00:00:00 2001
From: Michal Krawczyk <mk@semihalf.com>
Date: Wed, 8 Apr 2020 10:28:52 +0200
Subject: [PATCH 22/27] net/ena: ensure Rx buffer size is at least 1400B

[ upstream commit 38364c2687ead97b99402310087c27131a97748c ]

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..

Change-Id: Ib402d3bfad98a3fc4f91095d5c6f90c6069da021
Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
 drivers/net/ena/ena_ethdev.c | 12 +++++++++++-
 drivers/net/ena/ena_ethdev.h |  3 ++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index dd60b7582d..288e53265a 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -1,7 +1,7 @@
 /*-
 * BSD LICENSE
 *
-* Copyright (c) 2015-2016 Amazon.com, Inc. or its affiliates.
+* Copyright (c) 2015-2020 Amazon.com, Inc. or its affiliates.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
@@ -1200,6 +1200,7 @@ static int ena_rx_queue_setup(struct rte_eth_dev *dev,
 	struct ena_adapter *adapter =
 		(struct ena_adapter *)(dev->data->dev_private);
 	struct ena_ring *rxq = NULL;
+	size_t buffer_size;
 	int i;
 
 	rxq = &adapter->rx_ring[queue_idx];
@@ -1224,6 +1225,15 @@ static int ena_rx_queue_setup(struct rte_eth_dev *dev,
 		return -EINVAL;
 	}
 
+	/* ENA isn't supporting buffers smaller than 1400 bytes */
+	buffer_size = rte_pktmbuf_data_room_size(mp) - 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;
+	}
+
 	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 2ce0eb79ec..9d887d4b5b 100644
--- a/drivers/net/ena/ena_ethdev.h
+++ b/drivers/net/ena/ena_ethdev.h
@@ -1,7 +1,7 @@
 /*-
 * BSD LICENSE
 *
-* Copyright (c) 2015-2016 Amazon.com, Inc. or its affiliates.
+* Copyright (c) 2015-2020 Amazon.com, Inc. or its affiliates.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
@@ -49,6 +49,7 @@
 #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