ethdev: remove callback checks from fast path

diff --git a/lib/ethdev/ethdev_driver.c b/lib/ethdev/ethdev_driver.c
index ec0c1e1176..75073f98cf 100644
--- a/lib/ethdev/ethdev_driver.c
+++ b/lib/ethdev/ethdev_driver.c
@@ -847,6 +847,53 @@  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_rx_queue_count_dummy)
+uint32_t
+rte_eth_rx_queue_count_dummy(void *queue __rte_unused)
+{
+	return -ENOTSUP;
+}
+
+RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_tx_queue_count_dummy)
+int
+rte_eth_tx_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)
+{
+
+}
+
 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..ec00f16ed3 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -1874,6 +1874,88 @@  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 Rx queue count.
+ *
+ * @param queue
+ *  Pointer to Rx queue
+ */
+__rte_internal
+uint32_t
+rte_eth_rx_queue_count_dummy(void *queue __rte_unused);
+
+/**
+ * @internal
+ * Dummy DPDK callback for Tx queue count.
+ *
+ * @param queue
+ *  Pointer to Tx queue
+ */
+__rte_internal
+int
+rte_eth_tx_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/ethdev_pci.h b/lib/ethdev/ethdev_pci.h
index 2229ffa252..1bd49ab822 100644
--- a/lib/ethdev/ethdev_pci.h
+++ b/lib/ethdev/ethdev_pci.h
@@ -16,6 +16,20 @@ 
 extern "C" {
 #endif
 
+static inline void
+rte_eth_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_rx_queue_count_dummy;
+	eth_dev->tx_queue_count = rte_eth_tx_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;
+}
+
 /**
  * Copy pci device info to the Ethernet device data.
  * Shared memory (eth_dev->data) only updated by primary process, so it is safe
@@ -147,6 +161,11 @@  rte_eth_dev_pci_generic_probe(struct rte_pci_device *pci_dev,
 	if (!eth_dev)
 		return -ENOMEM;
 
+	/* Update fast path ops with dummy callbacks. Driver will update
+	 * them with required callbacks in the init function.
+	 */
+	rte_eth_set_dummy_fops(eth_dev);
+
 	ret = dev_init(eth_dev);
 	if (ret)
 		rte_eth_dev_release_port(eth_dev);
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index ea7f8c4a1a..aa67b69134 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 (int)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.
@@ -7131,14 +7118,11 @@  rte_eth_tx_queue_count(uint16_t port_id, uint16_t queue_id)
 		goto out;
 	}
 #endif
-	if (fops->tx_queue_count == NULL) {
-		rc = -ENOTSUP;
-		goto out;
-	}
-
 	rc = fops->tx_queue_count(qd);
 
+#ifdef RTE_ETHDEV_DEBUG_TX
 out:
+#endif
 	rte_eth_trace_tx_queue_count(port_id, queue_id, rc);
 	return rc;
 }