[PATCH v14 15/23] net/dpaa: support Rx/Tx taildrop threshold devarg

[Hemant Agrawal <hemant.agrawal@nxp.com>]

Add a 'drv_rx_taildrop' & drv_tx_taildrop device argument to configure
the Rx frame queue taildrop congestion threshold.

Signed-off-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Signed-off-by: Sachin Saxena <sachin.saxena@nxp.com>
---
 doc/guides/nics/dpaa.rst       | 16 +++++--
 drivers/net/dpaa/dpaa_ethdev.c | 83 ++++++++++++++++++++++++++++++++--
 2 files changed, 92 insertions(+), 7 deletions(-)

diff --git a/doc/guides/nics/dpaa.rst b/doc/guides/nics/dpaa.rst
index c6aab46828..2b6bf7608d 100644
--- a/doc/guides/nics/dpaa.rst
+++ b/doc/guides/nics/dpaa.rst
@@ -272,9 +272,19 @@ Refer to the document :doc:`build_and_test` for details.
       Done
       testpmd>
 
-* Use dev arg option ``recv_err_pkts=1`` to receive all packets including error packets
-  and thus disabling hardware based packet handling at driver level,
-  e.g. ``dpaa:fm1-mac3,recv_err_pkts=1``.
+Device Arguments
+~~~~~~~~~~~~~~~~~
+
+The DPAA PMD supports the following per-port device arguments, passed with
+the ``-a`` EAL option (e.g. ``-a dpaa_bus:fm1-mac3,drv_rx_taildrop=64``):
+
+``recv_err_pkts`` (default disabled)
+   Receive all packets including error packets, disabling hardware based
+   packet handling at driver level. e.g. ``dpaa:fm1-mac3,recv_err_pkts=1``
+
+``drv_rx_taildrop`` / ``drv_tx_taildrop``
+   Configure the Rx / Tx frame queue taildrop congestion threshold. A value
+   of ``0`` disables taildrop.
 
 FMAN Config
 -----------
diff --git a/drivers/net/dpaa/dpaa_ethdev.c b/drivers/net/dpaa/dpaa_ethdev.c
index 7aa1887f98..88a737905d 100644
--- a/drivers/net/dpaa/dpaa_ethdev.c
+++ b/drivers/net/dpaa/dpaa_ethdev.c
@@ -55,6 +55,8 @@
 #define CHECK_INTERVAL          100  /* 100ms */
 #define MAX_REPEAT_TIME         90   /* 9s (90 * 100ms) in total */
 #define DRIVER_RECV_ERR_PKTS      "recv_err_pkts"
+#define DRIVER_RX_TAILDROP        "drv_rx_taildrop"
+#define DRIVER_TX_TAILDROP        "drv_tx_taildrop"
 #define RTE_PRIORITY_103 103
 
 /* Supported Rx offloads */
@@ -2268,6 +2270,53 @@ dpaa_get_devargs(struct rte_devargs *devargs, const char *key)
 	return 1;
 }
 
+static int
+parse_int_devarg_handler(__rte_unused const char *key, const char *value,
+			 void *opaque)
+{
+	char *end;
+	long val;
+
+	errno = 0;
+	val = strtol(value, &end, 0);
+	if (errno != 0 || end == value || *end != '\0')
+		return -EINVAL;
+
+	*(long *)opaque = val;
+	return 0;
+}
+
+/*
+ * Fetch an integer valued device argument.
+ * Returns 1 and stores the parsed value in *val if the key is present and
+ * valid, 0 if the key is absent, and a negative errno on parse error.
+ */
+static int
+dpaa_get_devargs_int(struct rte_devargs *devargs, const char *key, long *val)
+{
+	struct rte_kvargs *kvlist;
+	int ret;
+
+	if (!devargs)
+		return 0;
+
+	kvlist = rte_kvargs_parse(devargs->args, NULL);
+	if (!kvlist)
+		return 0;
+
+	if (!rte_kvargs_count(kvlist, key)) {
+		rte_kvargs_free(kvlist);
+		return 0;
+	}
+
+	ret = rte_kvargs_process(kvlist, key, parse_int_devarg_handler, val);
+	rte_kvargs_free(kvlist);
+	if (ret < 0)
+		return ret;
+
+	return 1;
+}
+
 /* Initialise a network interface */
 static int
 dpaa_dev_init(struct rte_eth_dev *eth_dev)
@@ -2288,6 +2337,7 @@ dpaa_dev_init(struct rte_eth_dev *eth_dev)
 	int8_t dev_vspids[DPAA_MAX_NUM_PCD_QUEUES];
 	int8_t vsp_id = -1;
 	struct rte_device *dev = eth_dev->device;
+	long td_val = 0;
 #ifdef RTE_LIBRTE_DPAA_DEBUG_DRIVER
 	char *penv;
 #endif
@@ -2362,13 +2412,36 @@ dpaa_dev_init(struct rte_eth_dev *eth_dev)
 
 	memset(cgrid, 0, sizeof(cgrid));
 	memset(cgrid_tx, 0, sizeof(cgrid_tx));
+	td_threshold = CGR_RX_PERFQ_THRESH;
+	td_tx_threshold = 0;
+
+	/* If "drv_rx_taildrop" devarg is set, use that value; if 0, it means
+	 * Rx tail drop is disabled.
+	 */
+	if (dpaa_get_devargs_int(dev->devargs, DRIVER_RX_TAILDROP,
+				 &td_val) == 1) {
+		td_threshold = (unsigned int)td_val;
+		DPAA_PMD_DEBUG("Rx tail drop threshold configured: %u",
+			       td_threshold);
+		/* if a very large value is being configured */
+		if (td_threshold > UINT16_MAX)
+			td_threshold = CGR_RX_PERFQ_THRESH;
+	}
 
-	/* if DPAA_TX_TAILDROP_THRESHOLD is set, use that value; if 0, it means
+	/* If "drv_tx_taildrop" devarg is set, use that value; if 0, it means
 	 * Tx tail drop is disabled.
 	 */
-	if (getenv("DPAA_TX_TAILDROP_THRESHOLD")) {
+	if (dpaa_get_devargs_int(dev->devargs, DRIVER_TX_TAILDROP,
+				 &td_val) == 1) {
+		td_tx_threshold = (unsigned int)td_val;
+		DPAA_PMD_DEBUG("Tx tail drop threshold configured: %u",
+			       td_tx_threshold);
+		/* if a very large value is being configured */
+		if (td_tx_threshold > UINT16_MAX)
+			td_tx_threshold = CGR_RX_PERFQ_THRESH;
+	} else if (getenv("DPAA_TX_TAILDROP_THRESHOLD")) {
 		td_tx_threshold = atoi(getenv("DPAA_TX_TAILDROP_THRESHOLD"));
-		DPAA_PMD_DEBUG("Tail drop threshold env configured: %u",
+		DPAA_PMD_DEBUG("Tx tail drop threshold env configured: %u",
 			       td_tx_threshold);
 		/* if a very large value is being configured */
 		if (td_tx_threshold > UINT16_MAX)
@@ -2791,5 +2864,7 @@ static struct rte_dpaa_driver rte_dpaa_pmd = {
 
 RTE_PMD_REGISTER_DPAA(net_dpaa, rte_dpaa_pmd);
 RTE_PMD_REGISTER_PARAM_STRING(net_dpaa,
-		DRIVER_RECV_ERR_PKTS "=<int>");
+		DRIVER_RECV_ERR_PKTS "=<int> "
+		DRIVER_RX_TAILDROP "=<int> "
+		DRIVER_TX_TAILDROP "=<int>");
 RTE_LOG_REGISTER_DEFAULT(dpaa_logtype_pmd, NOTICE);
-- 
2.25.1