From 4329cb8111f2b58e0927e88b9621f5d3fc8ee434 Mon Sep 17 00:00:00 2001
From: Shachar Beiser <shacharbe@mellanox.com>
Date: Sun, 4 Jun 2017 05:25:21 +0000
Subject: [PATCH] net/mlx5: implement drop action in hardware classifier

The current drop action is implemented as a queue tail drop,
requiring to instantiate multiple WQs to maintain high drop rate.
This commit, implements the drop action in hardware classifier.
This enables to reduce the amount of contexts needed for the drop,
without affecting the drop rate.

Signed-off-by: Shachar Beiser <shacharbe@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/Makefile    |  5 +++++
 drivers/net/mlx5/mlx5_flow.c | 23 ++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
index c0799591bf..daf80134bc 100644
--- a/drivers/net/mlx5/Makefile
+++ b/drivers/net/mlx5/Makefile
@@ -100,6 +100,11 @@ mlx5_autoconf.h.new: FORCE
 
 mlx5_autoconf.h.new: $(RTE_SDK)/buildtools/auto-config-h.sh
 	$Q $(RM) -f -- '$@'
+	$Q sh -- '$<' '$@' \
+		HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP \
+		infiniband/verbs_exp.h \
+		enum IBV_EXP_FLOW_SPEC_ACTION_DROP \
+		$(AUTOCONF_OUTPUT)
 	$Q sh -- '$<' '$@' \
 		HAVE_VERBS_IBV_EXP_CQ_COMPRESSED_CQE \
 		infiniband/verbs_exp.h \
diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 8b3957babb..bbfa85c2f0 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -53,7 +53,11 @@
 #include "mlx5_prm.h"
 
 /* Number of Work Queue necessary for the DROP queue. */
+#ifndef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
 #define MLX5_DROP_WQ_N 4
+#else
+#define MLX5_DROP_WQ_N 1
+#endif
 
 static int
 mlx5_flow_create_eth(const struct rte_flow_item *item,
@@ -576,6 +580,10 @@ priv_flow_validate(struct priv *priv,
 	}
 	if (action->mark && !flow->ibv_attr && !action->drop)
 		flow->offset += sizeof(struct ibv_exp_flow_spec_action_tag);
+#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
+	if (!flow->ibv_attr && action->drop)
+		flow->offset += sizeof(struct ibv_exp_flow_spec_action_drop);
+#endif
 	if (!action->queue && !action->drop) {
 		rte_flow_error_set(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE,
 				   NULL, "no valid action");
@@ -993,6 +1001,10 @@ priv_flow_create_action_queue_drop(struct priv *priv,
 				   struct rte_flow_error *error)
 {
 	struct rte_flow *rte_flow;
+#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
+	struct ibv_exp_flow_spec_action_drop *drop;
+	unsigned int size = sizeof(struct ibv_exp_flow_spec_action_drop);
+#endif
 
 	assert(priv->pd);
 	assert(priv->ctx);
@@ -1003,8 +1015,17 @@ priv_flow_create_action_queue_drop(struct priv *priv,
 		return NULL;
 	}
 	rte_flow->drop = 1;
-	rte_flow->ibv_attr = flow->ibv_attr;
 	rte_flow->qp = priv->flow_drop_queue->qp;
+#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
+	drop = (void *)((uintptr_t)flow->ibv_attr + flow->offset);
+	*drop = (struct ibv_exp_flow_spec_action_drop){
+			.type = IBV_EXP_FLOW_SPEC_ACTION_DROP,
+			.size = size,
+	};
+	++flow->ibv_attr->num_of_specs;
+	flow->offset += sizeof(struct ibv_exp_flow_spec_action_drop);
+#endif
+	rte_flow->ibv_attr = flow->ibv_attr;
 	if (!priv->started)
 		return rte_flow;
 	rte_flow->ibv_flow = ibv_exp_create_flow(rte_flow->qp,
-- 
2.20.1