[dpdk-dev] [PATCH v2 33/62] net/cnxk: add MTU set device operation

[Nithin Dabilpuram <ndabilpuram@marvell.com>]

From: Sunil Kumar Kori <skori@marvell.com>

This Patch implements mtu set dev op for cn9k and cn10k platforms.

Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
---
 doc/guides/nics/cnxk.rst              |  1 +
 doc/guides/nics/features/cnxk.ini     |  1 +
 doc/guides/nics/features/cnxk_vec.ini |  1 +
 doc/guides/nics/features/cnxk_vf.ini  |  1 +
 drivers/net/cnxk/cnxk_ethdev.c        | 51 +++++++++++++++++++++++
 drivers/net/cnxk/cnxk_ethdev.h        |  5 ++-
 drivers/net/cnxk/cnxk_ethdev_ops.c    | 77 ++++++++++++++++++++++++++++++++++-
 7 files changed, 135 insertions(+), 2 deletions(-)

diff --git a/doc/guides/nics/cnxk.rst b/doc/guides/nics/cnxk.rst
index 42aa7a5..6cb90a7 100644
--- a/doc/guides/nics/cnxk.rst
+++ b/doc/guides/nics/cnxk.rst
@@ -24,6 +24,7 @@ Features of the CNXK Ethdev PMD are:
 - Receiver Side Scaling (RSS)
 - Inner and Outer Checksum offload
 - Link state information
+- MTU update
 - Scatter-Gather IO support
 - Vector Poll mode driver
 
diff --git a/doc/guides/nics/features/cnxk.ini b/doc/guides/nics/features/cnxk.ini
index 02be26b..6fef725 100644
--- a/doc/guides/nics/features/cnxk.ini
+++ b/doc/guides/nics/features/cnxk.ini
@@ -15,6 +15,7 @@ Runtime Tx queue setup = Y
 Fast mbuf free       = Y
 Free Tx mbuf on demand = Y
 Queue start/stop     = Y
+MTU update           = Y
 TSO                  = Y
 RSS hash             = Y
 Inner RSS            = Y
diff --git a/doc/guides/nics/features/cnxk_vec.ini b/doc/guides/nics/features/cnxk_vec.ini
index 8c63853..79cb1e2 100644
--- a/doc/guides/nics/features/cnxk_vec.ini
+++ b/doc/guides/nics/features/cnxk_vec.ini
@@ -15,6 +15,7 @@ Runtime Tx queue setup = Y
 Fast mbuf free       = Y
 Free Tx mbuf on demand = Y
 Queue start/stop     = Y
+MTU update           = Y
 RSS hash             = Y
 Inner RSS            = Y
 Jumbo frame          = Y
diff --git a/doc/guides/nics/features/cnxk_vf.ini b/doc/guides/nics/features/cnxk_vf.ini
index a1bd49b..5cc9f3f 100644
--- a/doc/guides/nics/features/cnxk_vf.ini
+++ b/doc/guides/nics/features/cnxk_vf.ini
@@ -14,6 +14,7 @@ Runtime Tx queue setup = Y
 Fast mbuf free       = Y
 Free Tx mbuf on demand = Y
 Queue start/stop     = Y
+MTU update           = Y
 TSO                  = Y
 RSS hash             = Y
 Inner RSS            = Y
diff --git a/drivers/net/cnxk/cnxk_ethdev.c b/drivers/net/cnxk/cnxk_ethdev.c
index 4e02be2..6b06ee5 100644
--- a/drivers/net/cnxk/cnxk_ethdev.c
+++ b/drivers/net/cnxk/cnxk_ethdev.c
@@ -37,6 +37,50 @@ nix_get_speed_capa(struct cnxk_eth_dev *dev)
 	return speed_capa;
 }
 
+static void
+nix_enable_mseg_on_jumbo(struct cnxk_eth_rxq_sp *rxq)
+{
+	struct rte_pktmbuf_pool_private *mbp_priv;
+	struct rte_eth_dev *eth_dev;
+	struct cnxk_eth_dev *dev;
+	uint32_t buffsz;
+
+	dev = rxq->dev;
+	eth_dev = dev->eth_dev;
+
+	/* Get rx buffer size */
+	mbp_priv = rte_mempool_get_priv(rxq->qconf.mp);
+	buffsz = mbp_priv->mbuf_data_room_size - RTE_PKTMBUF_HEADROOM;
+
+	if (eth_dev->data->dev_conf.rxmode.max_rx_pkt_len > buffsz) {
+		dev->rx_offloads |= DEV_RX_OFFLOAD_SCATTER;
+		dev->tx_offloads |= DEV_TX_OFFLOAD_MULTI_SEGS;
+	}
+}
+
+static int
+nix_recalc_mtu(struct rte_eth_dev *eth_dev)
+{
+	struct rte_eth_dev_data *data = eth_dev->data;
+	struct cnxk_eth_rxq_sp *rxq;
+	uint16_t mtu;
+	int rc;
+
+	rxq = ((struct cnxk_eth_rxq_sp *)data->rx_queues[0]) - 1;
+	/* Setup scatter mode if needed by jumbo */
+	nix_enable_mseg_on_jumbo(rxq);
+
+	/* Setup MTU based on max_rx_pkt_len */
+	mtu = data->dev_conf.rxmode.max_rx_pkt_len - CNXK_NIX_L2_OVERHEAD +
+				CNXK_NIX_MAX_VTAG_ACT_SIZE;
+
+	rc = cnxk_nix_mtu_set(eth_dev, mtu);
+	if (rc)
+		plt_err("Failed to set default MTU size, rc=%d", rc);
+
+	return rc;
+}
+
 uint64_t
 cnxk_nix_rxq_mbuf_setup(struct cnxk_eth_dev *dev)
 {
@@ -973,6 +1017,12 @@ cnxk_nix_dev_start(struct rte_eth_dev *eth_dev)
 	struct cnxk_eth_dev *dev = cnxk_eth_pmd_priv(eth_dev);
 	int rc, i;
 
+	if (eth_dev->data->nb_rx_queues != 0) {
+		rc = nix_recalc_mtu(eth_dev);
+		if (rc)
+			return rc;
+	}
+
 	/* Start rx queues */
 	for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
 		rc = cnxk_nix_rx_queue_start(eth_dev, i);
@@ -1017,6 +1067,7 @@ cnxk_nix_dev_start(struct rte_eth_dev *eth_dev)
 
 /* CNXK platform independent eth dev ops */
 struct eth_dev_ops cnxk_eth_dev_ops = {
+	.mtu_set = cnxk_nix_mtu_set,
 	.mac_addr_set = cnxk_nix_mac_addr_set,
 	.dev_infos_get = cnxk_nix_info_get,
 	.link_update = cnxk_nix_link_update,
diff --git a/drivers/net/cnxk/cnxk_ethdev.h b/drivers/net/cnxk/cnxk_ethdev.h
index 717a8d8..3838573 100644
--- a/drivers/net/cnxk/cnxk_ethdev.h
+++ b/drivers/net/cnxk/cnxk_ethdev.h
@@ -28,7 +28,9 @@
 #define CNXK_NIX_MAX_VTAG_ACT_SIZE (4 * CNXK_NIX_MAX_VTAG_INS)
 
 /* ETH_HLEN+ETH_FCS+2*VLAN_HLEN */
-#define CNXK_NIX_L2_OVERHEAD (RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN + 8)
+#define CNXK_NIX_L2_OVERHEAD (RTE_ETHER_HDR_LEN + \
+			      RTE_ETHER_CRC_LEN + \
+			      CNXK_NIX_MAX_VTAG_ACT_SIZE)
 
 #define CNXK_NIX_RX_MIN_DESC	    16
 #define CNXK_NIX_RX_MIN_DESC_ALIGN  16
@@ -203,6 +205,7 @@ extern struct eth_dev_ops cnxk_eth_dev_ops;
 int cnxk_nix_probe(struct rte_pci_driver *pci_drv,
 		   struct rte_pci_device *pci_dev);
 int cnxk_nix_remove(struct rte_pci_device *pci_dev);
+int cnxk_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu);
 int cnxk_nix_mac_addr_set(struct rte_eth_dev *eth_dev,
 			  struct rte_ether_addr *addr);
 int cnxk_nix_info_get(struct rte_eth_dev *eth_dev,
diff --git a/drivers/net/cnxk/cnxk_ethdev_ops.c b/drivers/net/cnxk/cnxk_ethdev_ops.c
index 87cf4ee..21b55c4 100644
--- a/drivers/net/cnxk/cnxk_ethdev_ops.c
+++ b/drivers/net/cnxk/cnxk_ethdev_ops.c
@@ -20,7 +20,8 @@ cnxk_nix_info_get(struct rte_eth_dev *eth_dev, struct rte_eth_dev_info *devinfo)
 	devinfo->max_tx_queues = RTE_MAX_QUEUES_PER_PORT;
 	devinfo->max_mac_addrs = dev->max_mac_entries;
 	devinfo->max_vfs = pci_dev->max_vfs;
-	devinfo->max_mtu = devinfo->max_rx_pktlen - CNXK_NIX_L2_OVERHEAD;
+	devinfo->max_mtu = devinfo->max_rx_pktlen -
+				(RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN);
 	devinfo->min_mtu = devinfo->min_rx_bufsize - CNXK_NIX_L2_OVERHEAD;
 
 	devinfo->rx_offload_capa = dev->rx_offload_capa;
@@ -98,3 +99,77 @@ cnxk_nix_mac_addr_set(struct rte_eth_dev *eth_dev, struct rte_ether_addr *addr)
 exit:
 	return rc;
 }
+
+int
+cnxk_nix_mtu_set(struct rte_eth_dev *eth_dev, uint16_t mtu)
+{
+	uint32_t old_frame_size, frame_size = mtu + CNXK_NIX_L2_OVERHEAD;
+	struct cnxk_eth_dev *dev = cnxk_eth_pmd_priv(eth_dev);
+	struct rte_eth_dev_data *data = eth_dev->data;
+	struct roc_nix *nix = &dev->nix;
+	int rc = -EINVAL;
+	uint32_t buffsz;
+
+	/* Check if MTU is within the allowed range */
+	if ((frame_size - RTE_ETHER_CRC_LEN) < NIX_MIN_HW_FRS) {
+		plt_err("MTU is lesser than minimum");
+		goto exit;
+	}
+
+	if ((frame_size - RTE_ETHER_CRC_LEN) >
+	    ((uint32_t)roc_nix_max_pkt_len(nix))) {
+		plt_err("MTU is greater than maximum");
+		goto exit;
+	}
+
+	buffsz = data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM;
+	old_frame_size = data->mtu + CNXK_NIX_L2_OVERHEAD;
+
+	/* Refuse MTU that requires the support of scattered packets
+	 * when this feature has not been enabled before.
+	 */
+	if (data->dev_started && frame_size > buffsz &&
+	    !(dev->rx_offloads & DEV_RX_OFFLOAD_SCATTER)) {
+		plt_err("Scatter offload is not enabled for mtu");
+		goto exit;
+	}
+
+	/* Check <seg size> * <max_seg>  >= max_frame */
+	if ((dev->rx_offloads & DEV_RX_OFFLOAD_SCATTER)	&&
+	    frame_size > (buffsz * CNXK_NIX_RX_NB_SEG_MAX)) {
+		plt_err("Greater than maximum supported packet length");
+		goto exit;
+	}
+
+	frame_size -= RTE_ETHER_CRC_LEN;
+
+	/* Update mtu on Tx */
+	rc = roc_nix_mac_mtu_set(nix, frame_size);
+	if (rc) {
+		plt_err("Failed to set MTU, rc=%d", rc);
+		goto exit;
+	}
+
+	/* Sync same frame size on Rx */
+	rc = roc_nix_mac_max_rx_len_set(nix, frame_size);
+	if (rc) {
+		/* Rollback to older mtu */
+		roc_nix_mac_mtu_set(nix,
+				    old_frame_size - RTE_ETHER_CRC_LEN);
+		plt_err("Failed to max Rx frame length, rc=%d", rc);
+		goto exit;
+	}
+
+	frame_size += RTE_ETHER_CRC_LEN;
+
+	if (frame_size > RTE_ETHER_MAX_LEN)
+		dev->rx_offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
+	else
+		dev->rx_offloads &= ~DEV_RX_OFFLOAD_JUMBO_FRAME;
+
+	/* Update max_rx_pkt_len */
+	data->dev_conf.rxmode.max_rx_pkt_len = frame_size;
+
+exit:
+	return rc;
+}
-- 
2.8.4