[PATCH v2 2/2] ethdev: remove callback checks from fast path

[<skori@marvell.com>]

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

rte_eth_fp_ops contains ops for fast path APIs. Each API
validates availability of callback and then invoke it.
These checks impact data path performace.

Hence removing these NULL checks instead using dummy
callbacks.

Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
---
 lib/ethdev/ethdev_driver.c | 55 +++++++++++++++++++++++++++++
 lib/ethdev/ethdev_driver.h | 71 ++++++++++++++++++++++++++++++++++++++
 lib/ethdev/rte_ethdev.h    | 29 ++--------------
 3 files changed, 129 insertions(+), 26 deletions(-)

diff --git a/lib/ethdev/ethdev_driver.c b/lib/ethdev/ethdev_driver.c
index ec0c1e1176..f89562b237 100644
--- a/lib/ethdev/ethdev_driver.c
+++ b/lib/ethdev/ethdev_driver.c
@@ -75,6 +75,20 @@ eth_dev_get(uint16_t port_id)
 	return eth_dev;
 }
 
+static void
+eth_dev_set_dummy_fops(struct rte_eth_dev *eth_dev)
+{
+	eth_dev->rx_pkt_burst = rte_eth_pkt_burst_dummy;
+	eth_dev->tx_pkt_burst = rte_eth_pkt_burst_dummy;
+	eth_dev->tx_pkt_prepare = rte_eth_tx_pkt_prepare_dummy;
+	eth_dev->rx_queue_count = rte_eth_queue_count_dummy;
+	eth_dev->tx_queue_count = rte_eth_queue_count_dummy;
+	eth_dev->rx_descriptor_status = rte_eth_descriptor_status_dummy;
+	eth_dev->tx_descriptor_status = rte_eth_descriptor_status_dummy;
+	eth_dev->recycle_tx_mbufs_reuse = rte_eth_recycle_tx_mbufs_reuse_dummy;
+	eth_dev->recycle_rx_descriptors_refill = rte_eth_recycle_rx_descriptors_refill_dummy;
+}
+
 RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_dev_allocate)
 struct rte_eth_dev *
 rte_eth_dev_allocate(const char *name)
@@ -115,6 +129,7 @@ rte_eth_dev_allocate(const char *name)
 	}
 
 	eth_dev = eth_dev_get(port_id);
+	eth_dev_set_dummy_fops(eth_dev);
 	eth_dev->flow_fp_ops = &rte_flow_fp_default_ops;
 	strlcpy(eth_dev->data->name, name, sizeof(eth_dev->data->name));
 	eth_dev->data->port_id = port_id;
@@ -847,6 +862,46 @@ rte_eth_pkt_burst_dummy(void *queue __rte_unused,
 	return 0;
 }
 
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_tx_pkt_prepare_dummy)
+uint16_t
+rte_eth_tx_pkt_prepare_dummy(void *queue __rte_unused,
+		struct rte_mbuf **pkts __rte_unused,
+		uint16_t nb_pkts)
+{
+	return nb_pkts;
+}
+
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_queue_count_dummy)
+int
+rte_eth_queue_count_dummy(void *queue __rte_unused)
+{
+	return -ENOTSUP;
+}
+
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_descriptor_status_dummy)
+int
+rte_eth_descriptor_status_dummy(void *queue __rte_unused,
+		uint16_t offset __rte_unused)
+{
+	return -ENOTSUP;
+}
+
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_recycle_tx_mbufs_reuse_dummy)
+uint16_t
+rte_eth_recycle_tx_mbufs_reuse_dummy(void *queue __rte_unused,
+		struct rte_eth_recycle_rxq_info *recycle_rxq_info __rte_unused)
+{
+	return 0;
+}
+
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_recycle_rx_descriptors_refill_dummy)
+void
+rte_eth_recycle_rx_descriptors_refill_dummy(void *queue __rte_unused,
+		uint16_t nb __rte_unused)
+{
+	/* No action. */
+}
+
 RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_representor_id_get)
 int
 rte_eth_representor_id_get(uint16_t port_id,
diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index 2b4d2ae9c3..71085bddff 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -1874,6 +1874,77 @@ rte_eth_pkt_burst_dummy(void *queue __rte_unused,
 		struct rte_mbuf **pkts __rte_unused,
 		uint16_t nb_pkts __rte_unused);
 
+/**
+ * @internal
+ * Dummy DPDK callback for Tx packet prepare.
+ *
+ * @param queue
+ *  Pointer to Tx queue
+ * @param pkts
+ *  Packet array
+ * @param nb_pkts
+ *  Number of packets in packet array
+ */
+__rte_internal
+uint16_t
+rte_eth_tx_pkt_prepare_dummy(void *queue __rte_unused,
+		struct rte_mbuf **pkts __rte_unused,
+		uint16_t nb_pkts __rte_unused);
+
+/**
+ * @internal
+ * Dummy DPDK callback for queue count.
+ *
+ * @param queue
+ *  Pointer to Rx/Tx queue
+ */
+__rte_internal
+int
+rte_eth_queue_count_dummy(void *queue __rte_unused);
+
+/**
+ * @internal
+ * Dummy DPDK callback for descriptor status.
+ *
+ * @param queue
+ *  Pointer to Rx/Tx queue
+ * @param offset
+ *  The offset of the descriptor starting from tail (0 is the next
+ *  packet to be received by the driver).
+ */
+__rte_internal
+int
+rte_eth_descriptor_status_dummy(void *queue __rte_unused,
+		uint16_t offset __rte_unused);
+
+/**
+ * @internal
+ * Dummy DPDK callback for recycle Tx mbufs reuse.
+ *
+ * @param queue
+ *  Pointer to Tx queue
+ * @param recycle_rxq_info
+ *  Pointer to recycle Rx queue info
+ */
+__rte_internal
+uint16_t
+rte_eth_recycle_tx_mbufs_reuse_dummy(void *queue __rte_unused,
+		struct rte_eth_recycle_rxq_info *recycle_rxq_info __rte_unused);
+
+/**
+ * @internal
+ * Dummy DPDK callback Rx descriptor refill.
+ *
+ * @param queue
+ *  Pointer Rx queue
+ * @param offset
+ *  number of descriptors to refill
+ */
+__rte_internal
+void
+rte_eth_recycle_rx_descriptors_refill_dummy(void *queue __rte_unused,
+		uint16_t nb __rte_unused);
+
 /**
  * Allocate an unique switch domain identifier.
  *
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index b3031ab9e6..2034680560 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -6399,8 +6399,6 @@ rte_eth_rx_queue_count(uint16_t port_id, uint16_t queue_id)
 		return -EINVAL;
 #endif
 
-	if (p->rx_queue_count == NULL)
-		return -ENOTSUP;
 	return p->rx_queue_count(qd);
 }
 
@@ -6471,8 +6469,6 @@ rte_eth_rx_descriptor_status(uint16_t port_id, uint16_t queue_id,
 	if (qd == NULL)
 		return -ENODEV;
 #endif
-	if (p->rx_descriptor_status == NULL)
-		return -ENOTSUP;
 	return p->rx_descriptor_status(qd, offset);
 }
 
@@ -6542,8 +6538,6 @@ static inline int rte_eth_tx_descriptor_status(uint16_t port_id,
 	if (qd == NULL)
 		return -ENODEV;
 #endif
-	if (p->tx_descriptor_status == NULL)
-		return -ENOTSUP;
 	return p->tx_descriptor_status(qd, offset);
 }
 
@@ -6786,9 +6780,6 @@ rte_eth_tx_prepare(uint16_t port_id, uint16_t queue_id,
 	}
 #endif
 
-	if (!p->tx_pkt_prepare)
-		return nb_pkts;
-
 	return p->tx_pkt_prepare(qd, tx_pkts, nb_pkts);
 }
 
@@ -6985,8 +6976,6 @@ rte_eth_recycle_mbufs(uint16_t rx_port_id, uint16_t rx_queue_id,
 		return 0;
 	}
 #endif
-	if (p1->recycle_tx_mbufs_reuse == NULL)
-		return 0;
 
 #ifdef RTE_ETHDEV_DEBUG_RX
 	if (rx_port_id >= RTE_MAX_ETHPORTS ||
@@ -7010,8 +6999,6 @@ rte_eth_recycle_mbufs(uint16_t rx_port_id, uint16_t rx_queue_id,
 		return 0;
 	}
 #endif
-	if (p2->recycle_rx_descriptors_refill == NULL)
-		return 0;
 
 	/* Copy used *rte_mbuf* buffer pointers from Tx mbuf ring
 	 * into Rx mbuf ring.
@@ -7107,15 +7094,13 @@ rte_eth_tx_queue_count(uint16_t port_id, uint16_t queue_id)
 #ifdef RTE_ETHDEV_DEBUG_TX
 	if (port_id >= RTE_MAX_ETHPORTS || !rte_eth_dev_is_valid_port(port_id)) {
 		RTE_ETHDEV_LOG_LINE(ERR, "Invalid port_id=%u", port_id);
-		rc = -ENODEV;
-		goto out;
+		return -ENODEV;
 	}
 
 	if (queue_id >= RTE_MAX_QUEUES_PER_PORT) {
 		RTE_ETHDEV_LOG_LINE(ERR, "Invalid queue_id=%u for port_id=%u",
 				    queue_id, port_id);
-		rc = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 #endif
 
@@ -7127,18 +7112,10 @@ rte_eth_tx_queue_count(uint16_t port_id, uint16_t queue_id)
 	if (qd == NULL) {
 		RTE_ETHDEV_LOG_LINE(ERR, "Invalid queue_id=%u for port_id=%u",
 				    queue_id, port_id);
-		rc = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
 #endif
-	if (fops->tx_queue_count == NULL) {
-		rc = -ENOTSUP;
-		goto out;
-	}
-
 	rc = fops->tx_queue_count(qd);
-
-out:
 	rte_eth_trace_tx_queue_count(port_id, queue_id, rc);
 	return rc;
 }
-- 
2.43.0