[dpdk-dev] [PATCH v4] net/i40e: add interface to choose latest vector path

[Xiaoyun Li <xiaoyun.li@intel.com>]

Right now, vector path is limited to only use on later platform.
This patch adds a devarg use-latest-vec to allow the users to
use the latest vector path that the platform supported. Namely,
using AVX2 vector path on broadwell is possible.

Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
---
v4:
 * Polish the codes.
v3:
 * Polish the doc and commit log.
v2:
 * Correct the calling of the wrong function last time.
 * Fix seg fault bug.
---
 doc/guides/nics/i40e.rst               |   8 ++
 doc/guides/rel_notes/release_18_11.rst |   4 +
 drivers/net/i40e/i40e_ethdev.c         |  46 ++++++++++-
 drivers/net/i40e/i40e_ethdev.h         |   3 +
 drivers/net/i40e/i40e_rxtx.c           | 103 ++++++++++++++++---------
 5 files changed, 128 insertions(+), 36 deletions(-)

diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst
index 65d87f869..643e6a062 100644
--- a/doc/guides/nics/i40e.rst
+++ b/doc/guides/nics/i40e.rst
@@ -163,6 +163,14 @@ Runtime Config Options
   Currently hot-plugging of representor ports is not supported so all required
   representors must be specified on the creation of the PF.
 
+- ``Use latest vector`` (default ``disable``)
+
+  Vector path was limited to use only on later platform. But users may want the
+  latest vector path. For example, VPP users may want to use AVX2 vector path on HSW/BDW
+  because it can get better perf. So ``devargs`` parameter ``use-latest-vec`` is
+  introduced, for example::
+    -w 84:00.0,use-latest-vec=1
+
 Driver compilation and testing
 ------------------------------
 
diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index 3ae6b3f58..34af591a2 100644
--- a/doc/guides/rel_notes/release_18_11.rst
+++ b/doc/guides/rel_notes/release_18_11.rst
@@ -54,6 +54,10 @@ New Features
      Also, make sure to start the actual text at the margin.
      =========================================================
 
+* **Added a devarg to use the latest vector path.**
+  A new devarg ``use-latest-vec`` was introduced to allow users to choose
+  the latest vector path that the platform supported. For example, VPP users
+  can use AVX2 vector path on BDW/HSW to get better performance.
 
 API Changes
 -----------
diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 85a6a867f..72377d0b6 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -44,6 +44,7 @@
 #define ETH_I40E_FLOATING_VEB_LIST_ARG	"floating_veb_list"
 #define ETH_I40E_SUPPORT_MULTI_DRIVER	"support-multi-driver"
 #define ETH_I40E_QUEUE_NUM_PER_VF_ARG	"queue-num-per-vf"
+#define ETH_I40E_USE_LATEST_VEC	"use-latest-vec"
 
 #define I40E_CLEAR_PXE_WAIT_MS     200
 
@@ -408,6 +409,7 @@ static const char *const valid_keys[] = {
 	ETH_I40E_FLOATING_VEB_LIST_ARG,
 	ETH_I40E_SUPPORT_MULTI_DRIVER,
 	ETH_I40E_QUEUE_NUM_PER_VF_ARG,
+	ETH_I40E_USE_LATEST_VEC,
 	NULL};
 
 static const struct rte_pci_id pci_id_i40e_map[] = {
@@ -1201,6 +1203,46 @@ i40e_aq_debug_write_global_register(struct i40e_hw *hw,
 	return i40e_aq_debug_write_register(hw, reg_addr, reg_val, cmd_details);
 }
 
+static int
+i40e_parse_latest_vec(struct rte_eth_dev *dev)
+{
+	struct i40e_adapter *ad =
+		I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
+	int kvargs_count, use_latest_vec;
+	struct rte_kvargs *kvlist;
+
+	ad->use_latest_vec = false;
+
+	if (!dev->device->devargs)
+		return 0;
+
+	kvlist = rte_kvargs_parse(dev->device->devargs->args, valid_keys);
+	if (!kvlist)
+		return -EINVAL;
+
+	kvargs_count = rte_kvargs_count(kvlist, ETH_I40E_USE_LATEST_VEC);
+	if (!kvargs_count) {
+		rte_kvargs_free(kvlist);
+		return 0;
+	}
+
+	if (kvargs_count > 1)
+		PMD_DRV_LOG(WARNING, "More than one argument \"%s\" and only "
+			    "the first one is used !",
+			    ETH_I40E_USE_LATEST_VEC);
+
+	use_latest_vec = atoi((&kvlist->pairs[0])->value);
+
+	rte_kvargs_free(kvlist);
+
+	if (use_latest_vec != 0 && use_latest_vec != 1)
+		PMD_DRV_LOG(WARNING, "Value should be 0 or 1, set it as 1!");
+
+	ad->use_latest_vec = (bool)use_latest_vec;
+
+	return 0;
+}
+
 static int
 eth_i40e_dev_init(struct rte_eth_dev *dev, void *init_params __rte_unused)
 {
@@ -1263,6 +1305,7 @@ eth_i40e_dev_init(struct rte_eth_dev *dev, void *init_params __rte_unused)
 
 	/* Check if need to support multi-driver */
 	i40e_support_multi_driver(dev);
+	i40e_parse_latest_vec(dev);
 
 	/* Make sure all is clean before doing PF reset */
 	i40e_clear_hw(hw);
@@ -12527,4 +12570,5 @@ RTE_PMD_REGISTER_PARAM_STRING(net_i40e,
 			      ETH_I40E_FLOATING_VEB_ARG "=1"
 			      ETH_I40E_FLOATING_VEB_LIST_ARG "=<string>"
 			      ETH_I40E_QUEUE_NUM_PER_VF_ARG "=1|2|4|8|16"
-			      ETH_I40E_SUPPORT_MULTI_DRIVER "=1");
+			      ETH_I40E_SUPPORT_MULTI_DRIVER "=1"
+			      ETH_I40E_USE_LATEST_VEC "=1");
diff --git a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h
index 3fffe5a55..140c92b84 100644
--- a/drivers/net/i40e/i40e_ethdev.h
+++ b/drivers/net/i40e/i40e_ethdev.h
@@ -1078,6 +1078,9 @@ struct i40e_adapter {
 	uint64_t pctypes_tbl[I40E_FLOW_TYPE_MAX] __rte_cache_min_aligned;
 	uint64_t flow_types_mask;
 	uint64_t pctypes_mask;
+
+	/* For devargs */
+	bool use_latest_vec;
 };
 
 /**
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 2a28ee348..e9fa7ed90 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -2909,6 +2909,34 @@ i40e_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	qinfo->conf.offloads = txq->offloads;
 }
 
+static eth_rx_burst_t
+i40e_get_latest_rx_vec(bool scatter)
+{
+#ifdef RTE_ARCH_X86
+	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2))
+		return scatter ? i40e_recv_scattered_pkts_vec_avx2 :
+				 i40e_recv_pkts_vec_avx2;
+#endif
+	return scatter ? i40e_recv_scattered_pkts_vec :
+			 i40e_recv_pkts_vec;
+}
+
+static eth_rx_burst_t
+i40e_get_recommend_rx_vec(bool scatter)
+{
+#ifdef RTE_ARCH_X86
+	/*
+	 * since AVX frequency can be different to base frequency, limit
+	 * use of AVX2 version to later plaforms, not all those that could
+	 * theoretically run it.
+	 */
+	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F))
+		return scatter ? i40e_recv_scattered_pkts_vec_avx2 :
+				 i40e_recv_pkts_vec_avx2;
+#endif
+	return scatter ? i40e_recv_scattered_pkts_vec :
+			 i40e_recv_pkts_vec;
+}
 void __attribute__((cold))
 i40e_set_rx_function(struct rte_eth_dev *dev)
 {
@@ -2948,19 +2976,12 @@ i40e_set_rx_function(struct rte_eth_dev *dev)
 			PMD_INIT_LOG(DEBUG, "Using Vector Scattered Rx "
 					    "callback (port=%d).",
 				     dev->data->port_id);
-
-			dev->rx_pkt_burst = i40e_recv_scattered_pkts_vec;
-#ifdef RTE_ARCH_X86
-			/*
-			 * since AVX frequency can be different to base
-			 * frequency, limit use of AVX2 version to later
-			 * plaforms, not all those that could theoretically
-			 * run it.
-			 */
-			if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F))
+			if (ad->use_latest_vec)
 				dev->rx_pkt_burst =
-					i40e_recv_scattered_pkts_vec_avx2;
-#endif
+					i40e_get_latest_rx_vec(true);
+			else
+				dev->rx_pkt_burst =
+					i40e_get_recommend_rx_vec(true);
 		} else {
 			PMD_INIT_LOG(DEBUG, "Using a Scattered with bulk "
 					   "allocation callback (port=%d).",
@@ -2978,18 +2999,10 @@ i40e_set_rx_function(struct rte_eth_dev *dev)
 				    "burst size no less than %d (port=%d).",
 			     RTE_I40E_DESCS_PER_LOOP,
 			     dev->data->port_id);
-
-		dev->rx_pkt_burst = i40e_recv_pkts_vec;
-#ifdef RTE_ARCH_X86
-		/*
-		 * since AVX frequency can be different to base
-		 * frequency, limit use of AVX2 version to later
-		 * plaforms, not all those that could theoretically
-		 * run it.
-		 */
-		if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F))
-			dev->rx_pkt_burst = i40e_recv_pkts_vec_avx2;
-#endif
+		if (ad->use_latest_vec)
+			dev->rx_pkt_burst = i40e_get_latest_rx_vec(false);
+		else
+			dev->rx_pkt_burst = i40e_get_recommend_rx_vec(false);
 	} else if (ad->rx_bulk_alloc_allowed) {
 		PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions are "
 				    "satisfied. Rx Burst Bulk Alloc function "
@@ -3049,6 +3062,31 @@ i40e_set_tx_function_flag(struct rte_eth_dev *dev, struct i40e_tx_queue *txq)
 				txq->queue_id);
 }
 
+static eth_tx_burst_t
+i40e_get_latest_tx_vec(void)
+{
+#ifdef RTE_ARCH_X86
+	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2))
+		return i40e_xmit_pkts_vec_avx2;
+#endif
+	return i40e_xmit_pkts_vec;
+}
+
+static eth_tx_burst_t
+i40e_get_recommend_tx_vec(void)
+{
+#ifdef RTE_ARCH_X86
+	/*
+	 * since AVX frequency can be different to base frequency, limit
+	 * use of AVX2 version to later plaforms, not all those that could
+	 * theoretically run it.
+	 */
+	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F))
+		return i40e_xmit_pkts_vec_avx2;
+#endif
+	return i40e_xmit_pkts_vec;
+}
+
 void __attribute__((cold))
 i40e_set_tx_function(struct rte_eth_dev *dev)
 {
@@ -3073,17 +3111,12 @@ i40e_set_tx_function(struct rte_eth_dev *dev)
 	if (ad->tx_simple_allowed) {
 		if (ad->tx_vec_allowed) {
 			PMD_INIT_LOG(DEBUG, "Vector tx finally be used.");
-			dev->tx_pkt_burst = i40e_xmit_pkts_vec;
-#ifdef RTE_ARCH_X86
-			/*
-			 * since AVX frequency can be different to base
-			 * frequency, limit use of AVX2 version to later
-			 * plaforms, not all those that could theoretically
-			 * run it.
-			 */
-			if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512F))
-				dev->tx_pkt_burst = i40e_xmit_pkts_vec_avx2;
-#endif
+			if (ad->use_latest_vec)
+				dev->tx_pkt_burst =
+					i40e_get_latest_tx_vec();
+			else
+				dev->tx_pkt_burst =
+					i40e_get_recommend_tx_vec();
 		} else {
 			PMD_INIT_LOG(DEBUG, "Simple tx finally be used.");
 			dev->tx_pkt_burst = i40e_xmit_pkts_simple;
-- 
2.17.1