[PATCH] ethdev: remove callback checks from fast path

[PATCH] ethdev: remove callback checks from fast path

[skori]

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.

Removing these NULL checks instead using dummy callbacks.

Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
---
 lib/ethdev/ethdev_driver.c | 47 ++++++++++++++++++++++
 lib/ethdev/ethdev_driver.h | 82 ++++++++++++++++++++++++++++++++++++++
 lib/ethdev/ethdev_pci.h    | 19 +++++++++
 lib/ethdev/rte_ethdev.h    | 20 +---------
 4 files changed, 150 insertions(+), 18 deletions(-)

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;
 }
-- 
2.43.0

Re: [PATCH] ethdev: remove callback checks from fast path

[Stephen Hemminger]

On Tue, 29 Apr 2025 23:41:30 +0530
<skori@marvell.com> wrote:

> @@ -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

I think you could just fix the ETHDEV_DEBUG_TX to just return.
Other ethdev functions skip calling tracing for
the case of errors.

Re: [PATCH] ethdev: remove callback checks from fast path

[Stephen Hemminger]

On Tue, 29 Apr 2025 23:41:30 +0530
<skori@marvell.com> wrote:

>  
> +static inline void
> +rte_eth_set_dummy_fops(struct rte_eth_dev *eth_dev)

Not fastpath, do not add inline here

> +{
> +	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);
> +

What about non PCI ethdev's?
And in PCI devices there is lots of duplicated code already initilizes these.
Needs to be consolidated and documented. Actually the whole probe process needs more documentation.

Also need to make sure secondary process setup is not broken.

RE: [PATCH] ethdev: remove callback checks from fast path

[Morten Brørup]

> From: Sunil Kumar Kori <skori@marvell.com>
> Sent: Tuesday, 29 April 2025 20.12
> 
> rte_eth_fp_ops contains ops for fast path APIs. Each API
> validates availability of callback and then invoke it.
> 
> Removing these NULL checks instead using dummy callbacks.

The description should mention the motivation for this patch: mbuf recycling performance optimization.

A few nits below.

> +RTE_EXPORT_INTERNAL_SYMBOL(rte_eth_rx_queue_count_dummy)
> +uint32_t
> +rte_eth_rx_queue_count_dummy(void *queue __rte_unused)
> +{
> +	return -ENOTSUP;
> +}

Instead of type casting back and forth, change the type of the RX queue count callback [1]:
-typedef uint32_t (*eth_rx_queue_count_t)(void *rxq);
+typedef int (*eth_rx_queue_count_t)(void *rxq);

So it resembles the TX queue count callback, eth_tx_queue_count_t, which already returns int.

[1]: https://elixir.bootlin.com/dpdk/v25.03/source/lib/ethdev/rte_ethdev_core.h#L48

Although my suggestion is formally an API change, I suppose changing from unsigned to signed should be acceptable.

> +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)
> +{
> +

This empty line looks strange. Perhaps add a comment /* No action. */ to indicate that no code is missing here.

> +}

[PATCH v2 1/2] ethdev: remove unnecessary type conversion

[skori]

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

As rte_eth_rx_queue_count() returns signed value to represent
the error cases but internally invoked callback is returning
unsigned value. Hence unnecessary type conversion is done.

To avoid this typecasting from signed to unsigned, fixed
return type of callback functions.

Signed-off-by: Sunil Kumar Kori <skori@marvell.com>
---
 drivers/net/ark/ark_ethdev_rx.c        | 2 +-
 drivers/net/ark/ark_ethdev_rx.h        | 2 +-
 drivers/net/atlantic/atl_ethdev.h      | 2 +-
 drivers/net/atlantic/atl_rxtx.c        | 2 +-
 drivers/net/bnxt/bnxt_ethdev.c         | 2 +-
 drivers/net/cnxk/cnxk_ethdev.h         | 2 +-
 drivers/net/cnxk/cnxk_ethdev_ops.c     | 2 +-
 drivers/net/dpaa/dpaa_ethdev.c         | 2 +-
 drivers/net/dpaa2/dpaa2_ethdev.c       | 2 +-
 drivers/net/enic/enic_ethdev.c         | 2 +-
 drivers/net/hns3/hns3_rxtx.c           | 2 +-
 drivers/net/hns3/hns3_rxtx.h           | 2 +-
 drivers/net/intel/e1000/e1000_ethdev.h | 4 ++--
 drivers/net/intel/e1000/em_rxtx.c      | 2 +-
 drivers/net/intel/e1000/igb_rxtx.c     | 2 +-
 drivers/net/intel/e1000/igc_txrx.c     | 2 +-
 drivers/net/intel/e1000/igc_txrx.h     | 2 +-
 drivers/net/intel/fm10k/fm10k.h        | 2 +-
 drivers/net/intel/fm10k/fm10k_rxtx.c   | 2 +-
 drivers/net/intel/i40e/i40e_rxtx.c     | 2 +-
 drivers/net/intel/i40e/i40e_rxtx.h     | 2 +-
 drivers/net/intel/iavf/iavf_rxtx.c     | 2 +-
 drivers/net/intel/iavf/iavf_rxtx.h     | 2 +-
 drivers/net/intel/ice/ice_rxtx.c       | 2 +-
 drivers/net/intel/ice/ice_rxtx.h       | 2 +-
 drivers/net/intel/ixgbe/ixgbe_ethdev.h | 2 +-
 drivers/net/intel/ixgbe/ixgbe_rxtx.c   | 2 +-
 drivers/net/mlx5/mlx5_rx.c             | 4 ++--
 drivers/net/mlx5/mlx5_rx.h             | 2 +-
 drivers/net/netvsc/hn_rxtx.c           | 2 +-
 drivers/net/netvsc/hn_var.h            | 2 +-
 drivers/net/nfp/nfp_rxtx.c             | 2 +-
 drivers/net/nfp/nfp_rxtx.h             | 2 +-
 drivers/net/ngbe/ngbe_ethdev.h         | 2 +-
 drivers/net/ngbe/ngbe_rxtx.c           | 2 +-
 drivers/net/sfc/sfc_ethdev.c           | 2 +-
 drivers/net/thunderx/nicvf_rxtx.c      | 2 +-
 drivers/net/thunderx/nicvf_rxtx.h      | 2 +-
 drivers/net/txgbe/txgbe_ethdev.h       | 2 +-
 drivers/net/txgbe/txgbe_rxtx.c         | 2 +-
 drivers/net/vhost/rte_eth_vhost.c      | 2 +-
 drivers/net/vmxnet3/vmxnet3_ethdev.h   | 2 +-
 drivers/net/vmxnet3/vmxnet3_rxtx.c     | 2 +-
 lib/ethdev/rte_ethdev.h                | 2 +-
 lib/ethdev/rte_ethdev_core.h           | 2 +-
 45 files changed, 47 insertions(+), 47 deletions(-)

diff --git a/drivers/net/ark/ark_ethdev_rx.c b/drivers/net/ark/ark_ethdev_rx.c
index 80e431f1ae..2fff0ffded 100644
--- a/drivers/net/ark/ark_ethdev_rx.c
+++ b/drivers/net/ark/ark_ethdev_rx.c
@@ -396,7 +396,7 @@ eth_ark_rx_queue_drain(struct ark_rx_queue *queue)
 	}
 }
 
-uint32_t
+int
 eth_ark_dev_rx_queue_count(void *rx_queue)
 {
 	struct ark_rx_queue *queue;
diff --git a/drivers/net/ark/ark_ethdev_rx.h b/drivers/net/ark/ark_ethdev_rx.h
index 2e3400fd2f..12d4f61637 100644
--- a/drivers/net/ark/ark_ethdev_rx.h
+++ b/drivers/net/ark/ark_ethdev_rx.h
@@ -17,7 +17,7 @@ int eth_ark_dev_rx_queue_setup(struct rte_eth_dev *dev,
 			       unsigned int socket_id,
 			       const struct rte_eth_rxconf *rx_conf,
 			       struct rte_mempool *mp);
-uint32_t eth_ark_dev_rx_queue_count(void *rx_queue);
+int eth_ark_dev_rx_queue_count(void *rx_queue);
 int eth_ark_rx_stop_queue(struct rte_eth_dev *dev, uint16_t queue_id);
 int eth_ark_rx_start_queue(struct rte_eth_dev *dev, uint16_t queue_id);
 uint16_t eth_ark_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
diff --git a/drivers/net/atlantic/atl_ethdev.h b/drivers/net/atlantic/atl_ethdev.h
index ed9ef9f0cc..d2f951c146 100644
--- a/drivers/net/atlantic/atl_ethdev.h
+++ b/drivers/net/atlantic/atl_ethdev.h
@@ -66,7 +66,7 @@ int atl_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 		uint16_t nb_tx_desc, unsigned int socket_id,
 		const struct rte_eth_txconf *tx_conf);
 
-uint32_t atl_rx_queue_count(void *rx_queue);
+int atl_rx_queue_count(void *rx_queue);
 
 int atl_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int atl_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
diff --git a/drivers/net/atlantic/atl_rxtx.c b/drivers/net/atlantic/atl_rxtx.c
index 0f367faad5..7b7bf5abbc 100644
--- a/drivers/net/atlantic/atl_rxtx.c
+++ b/drivers/net/atlantic/atl_rxtx.c
@@ -688,7 +688,7 @@ atl_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 
 /* Return Rx queue avail count */
 
-uint32_t
+int
 atl_rx_queue_count(void *rx_queue)
 {
 	struct atl_rx_queue *rxq;
diff --git a/drivers/net/bnxt/bnxt_ethdev.c b/drivers/net/bnxt/bnxt_ethdev.c
index 2f37f5aa10..ec355bab62 100644
--- a/drivers/net/bnxt/bnxt_ethdev.c
+++ b/drivers/net/bnxt/bnxt_ethdev.c
@@ -3407,7 +3407,7 @@ bnxt_dev_led_off_op(struct rte_eth_dev *dev)
 	return bnxt_hwrm_port_led_cfg(bp, false);
 }
 
-static uint32_t
+static int
 bnxt_rx_queue_count_op(void *rx_queue)
 {
 	struct bnxt *bp;
diff --git a/drivers/net/cnxk/cnxk_ethdev.h b/drivers/net/cnxk/cnxk_ethdev.h
index daf80be51b..8583d35ad5 100644
--- a/drivers/net/cnxk/cnxk_ethdev.h
+++ b/drivers/net/cnxk/cnxk_ethdev.h
@@ -705,7 +705,7 @@ void cnxk_nix_txq_info_get(struct rte_eth_dev *eth_dev, uint16_t qid,
 /* Queue status */
 int cnxk_nix_rx_descriptor_status(void *rxq, uint16_t offset);
 int cnxk_nix_tx_descriptor_status(void *txq, uint16_t offset);
-uint32_t cnxk_nix_rx_queue_count(void *rxq);
+int cnxk_nix_rx_queue_count(void *rxq);
 
 /* Lookup configuration */
 const uint32_t *cnxk_nix_supported_ptypes_get(struct rte_eth_dev *eth_dev,
diff --git a/drivers/net/cnxk/cnxk_ethdev_ops.c b/drivers/net/cnxk/cnxk_ethdev_ops.c
index 9970c5ff5c..797e049a6e 100644
--- a/drivers/net/cnxk/cnxk_ethdev_ops.c
+++ b/drivers/net/cnxk/cnxk_ethdev_ops.c
@@ -870,7 +870,7 @@ cnxk_nix_txq_info_get(struct rte_eth_dev *eth_dev, uint16_t qid,
 	memcpy(&qinfo->conf, &txq_sp->qconf.conf.tx, sizeof(qinfo->conf));
 }
 
-uint32_t
+int
 cnxk_nix_rx_queue_count(void *rxq)
 {
 	struct cnxk_eth_rxq_sp *rxq_sp = cnxk_eth_rxq_to_sp(rxq);
diff --git a/drivers/net/dpaa/dpaa_ethdev.c b/drivers/net/dpaa/dpaa_ethdev.c
index 00b57cb715..02ec501228 100644
--- a/drivers/net/dpaa/dpaa_ethdev.c
+++ b/drivers/net/dpaa/dpaa_ethdev.c
@@ -1414,7 +1414,7 @@ int dpaa_eth_tx_queue_setup(struct rte_eth_dev *dev, uint16_t queue_idx,
 	return 0;
 }
 
-static uint32_t
+static int
 dpaa_dev_rx_queue_count(void *rx_queue)
 {
 	struct qman_fq *rxq = rx_queue;
diff --git a/drivers/net/dpaa2/dpaa2_ethdev.c b/drivers/net/dpaa2/dpaa2_ethdev.c
index c53c2d0549..501f7e169d 100644
--- a/drivers/net/dpaa2/dpaa2_ethdev.c
+++ b/drivers/net/dpaa2/dpaa2_ethdev.c
@@ -1047,7 +1047,7 @@ dpaa2_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t rx_queue_id)
 	}
 }
 
-static uint32_t
+static int
 dpaa2_dev_rx_queue_count(void *rx_queue)
 {
 	int32_t ret;
diff --git a/drivers/net/enic/enic_ethdev.c b/drivers/net/enic/enic_ethdev.c
index c216994766..749cc9ca5c 100644
--- a/drivers/net/enic/enic_ethdev.c
+++ b/drivers/net/enic/enic_ethdev.c
@@ -258,7 +258,7 @@ static void enicpmd_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t qid)
 	enic_free_rq(rxq);
 }
 
-static uint32_t enicpmd_dev_rx_queue_count(void *rx_queue)
+static int enicpmd_dev_rx_queue_count(void *rx_queue)
 {
 	struct enic *enic;
 	struct vnic_rq *sop_rq;
diff --git a/drivers/net/hns3/hns3_rxtx.c b/drivers/net/hns3/hns3_rxtx.c
index bb7ffee12c..8be8f55696 100644
--- a/drivers/net/hns3/hns3_rxtx.c
+++ b/drivers/net/hns3/hns3_rxtx.c
@@ -4745,7 +4745,7 @@ hns3_dev_tx_descriptor_status(void *tx_queue, uint16_t offset)
 		return RTE_ETH_TX_DESC_DONE;
 }
 
-uint32_t
+int
 hns3_rx_queue_count(void *rx_queue)
 {
 	/*
diff --git a/drivers/net/hns3/hns3_rxtx.h b/drivers/net/hns3/hns3_rxtx.h
index 0bce89ebaa..d4865faa77 100644
--- a/drivers/net/hns3/hns3_rxtx.h
+++ b/drivers/net/hns3/hns3_rxtx.h
@@ -745,7 +745,7 @@ int hns3_rx_queue_setup(struct rte_eth_dev *dev, uint16_t idx, uint16_t nb_desc,
 int hns3_tx_queue_setup(struct rte_eth_dev *dev, uint16_t idx, uint16_t nb_desc,
 			unsigned int socket_id,
 			const struct rte_eth_txconf *conf);
-uint32_t hns3_rx_queue_count(void *rx_queue);
+int hns3_rx_queue_count(void *rx_queue);
 int hns3_dev_rx_queue_start(struct rte_eth_dev *dev, uint16_t rx_queue_id);
 int hns3_dev_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id);
 int hns3_dev_tx_queue_start(struct rte_eth_dev *dev, uint16_t tx_queue_id);
diff --git a/drivers/net/intel/e1000/e1000_ethdev.h b/drivers/net/intel/e1000/e1000_ethdev.h
index 339ae1f4b6..0907c7c259 100644
--- a/drivers/net/intel/e1000/e1000_ethdev.h
+++ b/drivers/net/intel/e1000/e1000_ethdev.h
@@ -414,7 +414,7 @@ int eth_igb_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 		const struct rte_eth_rxconf *rx_conf,
 		struct rte_mempool *mb_pool);
 
-uint32_t eth_igb_rx_queue_count(void *rx_queue);
+int eth_igb_rx_queue_count(void *rx_queue);
 
 int eth_igb_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int eth_igb_tx_descriptor_status(void *tx_queue, uint16_t offset);
@@ -488,7 +488,7 @@ int eth_em_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 		const struct rte_eth_rxconf *rx_conf,
 		struct rte_mempool *mb_pool);
 
-uint32_t eth_em_rx_queue_count(void *rx_queue);
+int eth_em_rx_queue_count(void *rx_queue);
 
 int eth_em_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int eth_em_tx_descriptor_status(void *tx_queue, uint16_t offset);
diff --git a/drivers/net/intel/e1000/em_rxtx.c b/drivers/net/intel/e1000/em_rxtx.c
index df5fbb7823..b8c4bb80e5 100644
--- a/drivers/net/intel/e1000/em_rxtx.c
+++ b/drivers/net/intel/e1000/em_rxtx.c
@@ -1489,7 +1489,7 @@ eth_em_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 }
 
-uint32_t
+int
 eth_em_rx_queue_count(void *rx_queue)
 {
 #define EM_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/e1000/igb_rxtx.c b/drivers/net/intel/e1000/igb_rxtx.c
index 4276bb6d31..e9ce354255 100644
--- a/drivers/net/intel/e1000/igb_rxtx.c
+++ b/drivers/net/intel/e1000/igb_rxtx.c
@@ -1792,7 +1792,7 @@ eth_igb_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 }
 
-uint32_t
+int
 eth_igb_rx_queue_count(void *rx_queue)
 {
 #define IGB_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/e1000/igc_txrx.c b/drivers/net/intel/e1000/igc_txrx.c
index 9b2eb343ef..f2a6c34094 100644
--- a/drivers/net/intel/e1000/igc_txrx.c
+++ b/drivers/net/intel/e1000/igc_txrx.c
@@ -667,7 +667,7 @@ void eth_igc_rx_queue_release(struct rte_eth_dev *dev, uint16_t qid)
 		igc_rx_queue_release(dev->data->rx_queues[qid]);
 }
 
-uint32_t eth_igc_rx_queue_count(void *rx_queue)
+int eth_igc_rx_queue_count(void *rx_queue)
 {
 	/**
 	 * Check the DD bit of a rx descriptor of each 4 in a group,
diff --git a/drivers/net/intel/e1000/igc_txrx.h b/drivers/net/intel/e1000/igc_txrx.h
index 1e63ddb5aa..972508dcc0 100644
--- a/drivers/net/intel/e1000/igc_txrx.h
+++ b/drivers/net/intel/e1000/igc_txrx.h
@@ -141,7 +141,7 @@ int eth_igc_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 		const struct rte_eth_rxconf *rx_conf,
 		struct rte_mempool *mb_pool);
 
-uint32_t eth_igc_rx_queue_count(void *rx_queue);
+int eth_igc_rx_queue_count(void *rx_queue);
 
 int eth_igc_rx_descriptor_status(void *rx_queue, uint16_t offset);
 
diff --git a/drivers/net/intel/fm10k/fm10k.h b/drivers/net/intel/fm10k/fm10k.h
index 17a7056c45..0eb32ac0d0 100644
--- a/drivers/net/intel/fm10k/fm10k.h
+++ b/drivers/net/intel/fm10k/fm10k.h
@@ -321,7 +321,7 @@ uint16_t fm10k_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 uint16_t fm10k_recv_scattered_pkts(void *rx_queue,
 		struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
 
-uint32_t
+int
 fm10k_dev_rx_queue_count(void *rx_queue);
 
 int
diff --git a/drivers/net/intel/fm10k/fm10k_rxtx.c b/drivers/net/intel/fm10k/fm10k_rxtx.c
index 690142b357..d145b8a2cc 100644
--- a/drivers/net/intel/fm10k/fm10k_rxtx.c
+++ b/drivers/net/intel/fm10k/fm10k_rxtx.c
@@ -364,7 +364,7 @@ fm10k_recv_scattered_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 	return nb_rcv;
 }
 
-uint32_t
+int
 fm10k_dev_rx_queue_count(void *rx_queue)
 {
 #define FM10K_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/i40e/i40e_rxtx.c b/drivers/net/intel/i40e/i40e_rxtx.c
index c3ff2e05c3..835d8c8017 100644
--- a/drivers/net/intel/i40e/i40e_rxtx.c
+++ b/drivers/net/intel/i40e/i40e_rxtx.c
@@ -2255,7 +2255,7 @@ i40e_rx_queue_release(void *rxq)
 	rte_free(q);
 }
 
-uint32_t
+int
 i40e_dev_rx_queue_count(void *rx_queue)
 {
 #define I40E_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/i40e/i40e_rxtx.h b/drivers/net/intel/i40e/i40e_rxtx.h
index 2f32fc5686..a98906da95 100644
--- a/drivers/net/intel/i40e/i40e_rxtx.h
+++ b/drivers/net/intel/i40e/i40e_rxtx.h
@@ -183,7 +183,7 @@ int i40e_tx_done_cleanup(void *txq, uint32_t free_cnt);
 int i40e_alloc_rx_queue_mbufs(struct i40e_rx_queue *rxq);
 void i40e_rx_queue_release_mbufs(struct i40e_rx_queue *rxq);
 
-uint32_t i40e_dev_rx_queue_count(void *rx_queue);
+int i40e_dev_rx_queue_count(void *rx_queue);
 int i40e_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int i40e_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
 
diff --git a/drivers/net/intel/iavf/iavf_rxtx.c b/drivers/net/intel/iavf/iavf_rxtx.c
index 533e0c78a2..3bf86e20cd 100644
--- a/drivers/net/intel/iavf/iavf_rxtx.c
+++ b/drivers/net/intel/iavf/iavf_rxtx.c
@@ -4318,7 +4318,7 @@ iavf_dev_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 }
 
 /* Get the number of used descriptors of a rx queue */
-uint32_t
+int
 iavf_dev_rxq_count(void *rx_queue)
 {
 #define IAVF_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/iavf/iavf_rxtx.h b/drivers/net/intel/iavf/iavf_rxtx.h
index 823a6efa9a..575dc4eb44 100644
--- a/drivers/net/intel/iavf/iavf_rxtx.h
+++ b/drivers/net/intel/iavf/iavf_rxtx.h
@@ -641,7 +641,7 @@ void iavf_dev_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 			  struct rte_eth_rxq_info *qinfo);
 void iavf_dev_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 			  struct rte_eth_txq_info *qinfo);
-uint32_t iavf_dev_rxq_count(void *rx_queue);
+int iavf_dev_rxq_count(void *rx_queue);
 int iavf_dev_rx_desc_status(void *rx_queue, uint16_t offset);
 int iavf_dev_tx_desc_status(void *tx_queue, uint16_t offset);
 
diff --git a/drivers/net/intel/ice/ice_rxtx.c b/drivers/net/intel/ice/ice_rxtx.c
index 40ac01e782..29a7609efc 100644
--- a/drivers/net/intel/ice/ice_rxtx.c
+++ b/drivers/net/intel/ice/ice_rxtx.c
@@ -1581,7 +1581,7 @@ ice_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 	qinfo->conf.tx_deferred_start = txq->tx_deferred_start;
 }
 
-uint32_t
+int
 ice_rx_queue_count(void *rx_queue)
 {
 #define ICE_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/intel/ice/ice_rxtx.h b/drivers/net/intel/ice/ice_rxtx.h
index 276d40b57f..ef1a4068d7 100644
--- a/drivers/net/intel/ice/ice_rxtx.h
+++ b/drivers/net/intel/ice/ice_rxtx.h
@@ -235,7 +235,7 @@ uint16_t ice_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
 void ice_set_tx_function_flag(struct rte_eth_dev *dev,
 			      struct ci_tx_queue *txq);
 void ice_set_tx_function(struct rte_eth_dev *dev);
-uint32_t ice_rx_queue_count(void *rx_queue);
+int ice_rx_queue_count(void *rx_queue);
 void ice_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 		      struct rte_eth_rxq_info *qinfo);
 void ice_txq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
diff --git a/drivers/net/intel/ixgbe/ixgbe_ethdev.h b/drivers/net/intel/ixgbe/ixgbe_ethdev.h
index 8ad841ea2c..3597ec0e90 100644
--- a/drivers/net/intel/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/intel/ixgbe/ixgbe_ethdev.h
@@ -601,7 +601,7 @@ int  ixgbe_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 		uint16_t nb_tx_desc, unsigned int socket_id,
 		const struct rte_eth_txconf *tx_conf);
 
-uint32_t ixgbe_dev_rx_queue_count(void *rx_queue);
+int ixgbe_dev_rx_queue_count(void *rx_queue);
 
 int ixgbe_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int ixgbe_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
diff --git a/drivers/net/intel/ixgbe/ixgbe_rxtx.c b/drivers/net/intel/ixgbe/ixgbe_rxtx.c
index 77773d56ef..7754094930 100644
--- a/drivers/net/intel/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/intel/ixgbe/ixgbe_rxtx.c
@@ -3346,7 +3346,7 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 }
 
-uint32_t
+int
 ixgbe_dev_rx_queue_count(void *rx_queue)
 {
 #define IXGBE_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/mlx5/mlx5_rx.c b/drivers/net/mlx5/mlx5_rx.c
index b0b0ce250e..2064601377 100644
--- a/drivers/net/mlx5/mlx5_rx.c
+++ b/drivers/net/mlx5/mlx5_rx.c
@@ -73,7 +73,7 @@ mlx5_lro_update_hdr(uint8_t *__rte_restrict padd,
  * @return
  *   The number of used Rx descriptor.
  */
-static uint32_t
+static int
 rx_queue_count(struct mlx5_rxq_data *rxq)
 {
 	struct rxq_zip *zip = &rxq->zip;
@@ -259,7 +259,7 @@ mlx5_rx_burst_mode_get(struct rte_eth_dev *dev,
  *   The number of used rx descriptor.
  *   -EINVAL if the queue is invalid
  */
-uint32_t
+int
 mlx5_rx_queue_count(void *rx_queue)
 {
 	struct mlx5_rxq_data *rxq = rx_queue;
diff --git a/drivers/net/mlx5/mlx5_rx.h b/drivers/net/mlx5/mlx5_rx.h
index 6380895502..d7a259a8f9 100644
--- a/drivers/net/mlx5/mlx5_rx.h
+++ b/drivers/net/mlx5/mlx5_rx.h
@@ -312,7 +312,7 @@ void mlx5_mprq_buf_free(struct mlx5_mprq_buf *buf);
 uint16_t mlx5_rx_burst_mprq(void *dpdk_rxq, struct rte_mbuf **pkts,
 			    uint16_t pkts_n);
 int mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset);
-uint32_t mlx5_rx_queue_count(void *rx_queue);
+int mlx5_rx_queue_count(void *rx_queue);
 void mlx5_rxq_info_get(struct rte_eth_dev *dev, uint16_t queue_id,
 		       struct rte_eth_rxq_info *qinfo);
 int mlx5_rx_burst_mode_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
diff --git a/drivers/net/netvsc/hn_rxtx.c b/drivers/net/netvsc/hn_rxtx.c
index 9d3948e03d..dc5bc1340a 100644
--- a/drivers/net/netvsc/hn_rxtx.c
+++ b/drivers/net/netvsc/hn_rxtx.c
@@ -1056,7 +1056,7 @@ hn_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t qid)
  * Get the number of used descriptor in a rx queue
  * For this device that means how many packets are pending in the ring.
  */
-uint32_t
+int
 hn_dev_rx_queue_count(void *rx_queue)
 {
 	struct hn_rx_queue *rxq = rx_queue;
diff --git a/drivers/net/netvsc/hn_var.h b/drivers/net/netvsc/hn_var.h
index 0f638bc5fd..ff176d0fef 100644
--- a/drivers/net/netvsc/hn_var.h
+++ b/drivers/net/netvsc/hn_var.h
@@ -224,7 +224,7 @@ int	hn_dev_rx_queue_setup(struct rte_eth_dev *dev,
 void	hn_dev_rx_queue_info(struct rte_eth_dev *dev, uint16_t queue_id,
 			     struct rte_eth_rxq_info *qinfo);
 void	hn_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t qid);
-uint32_t hn_dev_rx_queue_count(void *rx_queue);
+int	hn_dev_rx_queue_count(void *rx_queue);
 int	hn_dev_rx_queue_status(void *rxq, uint16_t offset);
 void	hn_dev_free_queues(struct rte_eth_dev *dev);
 
diff --git a/drivers/net/nfp/nfp_rxtx.c b/drivers/net/nfp/nfp_rxtx.c
index e0c1fb0987..37f4334b00 100644
--- a/drivers/net/nfp/nfp_rxtx.c
+++ b/drivers/net/nfp/nfp_rxtx.c
@@ -199,7 +199,7 @@ nfp_net_rx_freelist_setup(struct rte_eth_dev *dev)
 	return 0;
 }
 
-uint32_t
+int
 nfp_net_rx_queue_count(void *rx_queue)
 {
 	uint32_t idx;
diff --git a/drivers/net/nfp/nfp_rxtx.h b/drivers/net/nfp/nfp_rxtx.h
index 4e0ed9da38..dfab90f186 100644
--- a/drivers/net/nfp/nfp_rxtx.h
+++ b/drivers/net/nfp/nfp_rxtx.h
@@ -220,7 +220,7 @@ nfp_net_mbuf_alloc_failed(struct nfp_net_rxq *rxq)
 void nfp_net_rx_cksum(struct nfp_net_rxq *rxq, struct nfp_net_rx_desc *rxd,
 		struct rte_mbuf *mb);
 int nfp_net_rx_freelist_setup(struct rte_eth_dev *dev);
-uint32_t nfp_net_rx_queue_count(void *rx_queue);
+int nfp_net_rx_queue_count(void *rx_queue);
 uint16_t nfp_net_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		uint16_t nb_pkts);
 void nfp_net_rx_queue_release(struct rte_eth_dev *dev, uint16_t queue_idx);
diff --git a/drivers/net/ngbe/ngbe_ethdev.h b/drivers/net/ngbe/ngbe_ethdev.h
index 37c6459f51..e1e9865d7c 100644
--- a/drivers/net/ngbe/ngbe_ethdev.h
+++ b/drivers/net/ngbe/ngbe_ethdev.h
@@ -204,7 +204,7 @@ int  ngbe_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 		uint16_t nb_tx_desc, unsigned int socket_id,
 		const struct rte_eth_txconf *tx_conf);
 
-uint32_t ngbe_dev_rx_queue_count(void *rx_queue);
+int ngbe_dev_rx_queue_count(void *rx_queue);
 
 int ngbe_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int ngbe_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
diff --git a/drivers/net/ngbe/ngbe_rxtx.c b/drivers/net/ngbe/ngbe_rxtx.c
index a372bf2963..a62e5d2cf3 100644
--- a/drivers/net/ngbe/ngbe_rxtx.c
+++ b/drivers/net/ngbe/ngbe_rxtx.c
@@ -2442,7 +2442,7 @@ ngbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 }
 
-uint32_t
+int
 ngbe_dev_rx_queue_count(void *rx_queue)
 {
 #define NGBE_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index 82fbdbae9c..a82d172a1c 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -1357,7 +1357,7 @@ sfc_tx_queue_info_get(struct rte_eth_dev *dev, uint16_t ethdev_qid,
  * The function is used by the secondary process as well. It must not
  * use any process-local pointers from the adapter data.
  */
-static uint32_t
+static int
 sfc_rx_queue_count(void *rx_queue)
 {
 	struct sfc_dp_rxq *dp_rxq = rx_queue;
diff --git a/drivers/net/thunderx/nicvf_rxtx.c b/drivers/net/thunderx/nicvf_rxtx.c
index cab5532417..3992da765a 100644
--- a/drivers/net/thunderx/nicvf_rxtx.c
+++ b/drivers/net/thunderx/nicvf_rxtx.c
@@ -649,7 +649,7 @@ nicvf_recv_pkts_multiseg_cksum_vlan_strip(void *rx_queue,
 			NICVF_RX_OFFLOAD_CKSUM | NICVF_RX_OFFLOAD_VLAN_STRIP);
 }
 
-uint32_t
+int
 nicvf_dev_rx_queue_count(void *rx_queue)
 {
 	struct nicvf_rxq *rxq;
diff --git a/drivers/net/thunderx/nicvf_rxtx.h b/drivers/net/thunderx/nicvf_rxtx.h
index 4b83e33f4d..17e406e6dd 100644
--- a/drivers/net/thunderx/nicvf_rxtx.h
+++ b/drivers/net/thunderx/nicvf_rxtx.h
@@ -83,7 +83,7 @@ nicvf_mbuff_init_mseg_update(struct rte_mbuf *pkt, const uint64_t mbuf_init,
 	*(uint64_t *)(&pkt->rearm_data) = init.value;
 }
 
-uint32_t nicvf_dev_rx_queue_count(void *rx_queue);
+int nicvf_dev_rx_queue_count(void *rx_queue);
 uint32_t nicvf_dev_rbdr_refill(struct rte_eth_dev *dev, uint16_t queue_idx);
 
 uint16_t nicvf_recv_pkts_no_offload(void *rxq, struct rte_mbuf **rx_pkts,
diff --git a/drivers/net/txgbe/txgbe_ethdev.h b/drivers/net/txgbe/txgbe_ethdev.h
index 302ea9f037..967961bf95 100644
--- a/drivers/net/txgbe/txgbe_ethdev.h
+++ b/drivers/net/txgbe/txgbe_ethdev.h
@@ -451,7 +451,7 @@ int  txgbe_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 		uint16_t nb_tx_desc, unsigned int socket_id,
 		const struct rte_eth_txconf *tx_conf);
 
-uint32_t txgbe_dev_rx_queue_count(void *rx_queue);
+int txgbe_dev_rx_queue_count(void *rx_queue);
 
 int txgbe_dev_rx_descriptor_status(void *rx_queue, uint16_t offset);
 int txgbe_dev_tx_descriptor_status(void *tx_queue, uint16_t offset);
diff --git a/drivers/net/txgbe/txgbe_rxtx.c b/drivers/net/txgbe/txgbe_rxtx.c
index 4e4b78fb43..205c702849 100644
--- a/drivers/net/txgbe/txgbe_rxtx.c
+++ b/drivers/net/txgbe/txgbe_rxtx.c
@@ -2873,7 +2873,7 @@ txgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
 	return 0;
 }
 
-uint32_t
+int
 txgbe_dev_rx_queue_count(void *rx_queue)
 {
 #define TXGBE_RXQ_SCAN_INTERVAL 4
diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index 44bf2e3241..87c91e2f96 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -1407,7 +1407,7 @@ eth_link_update(struct rte_eth_dev *dev __rte_unused,
 	return 0;
 }
 
-static uint32_t
+static int
 eth_rx_queue_count(void *rx_queue)
 {
 	struct vhost_queue *vq;
diff --git a/drivers/net/vmxnet3/vmxnet3_ethdev.h b/drivers/net/vmxnet3/vmxnet3_ethdev.h
index fd150d12c5..75dafa664f 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethdev.h
+++ b/drivers/net/vmxnet3/vmxnet3_ethdev.h
@@ -212,7 +212,7 @@ int  vmxnet3_dev_rx_queue_setup(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 				const struct rte_eth_rxconf *rx_conf,
 				struct rte_mempool *mb_pool);
 
-uint32_t vmxnet3_dev_rx_queue_count(void *rx_queue);
+int vmxnet3_dev_rx_queue_count(void *rx_queue);
 
 int  vmxnet3_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 				uint16_t nb_tx_desc, unsigned int socket_id,
diff --git a/drivers/net/vmxnet3/vmxnet3_rxtx.c b/drivers/net/vmxnet3/vmxnet3_rxtx.c
index e226641fdf..552b8a9823 100644
--- a/drivers/net/vmxnet3/vmxnet3_rxtx.c
+++ b/drivers/net/vmxnet3/vmxnet3_rxtx.c
@@ -1055,7 +1055,7 @@ vmxnet3_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts, uint16_t nb_pkts)
 	return nb_rx;
 }
 
-uint32_t
+int
 vmxnet3_dev_rx_queue_count(void *rx_queue)
 {
 	const vmxnet3_rx_queue_t *rxq;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index ea7f8c4a1a..b3031ab9e6 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -6401,7 +6401,7 @@ rte_eth_rx_queue_count(uint16_t port_id, uint16_t queue_id)
 
 	if (p->rx_queue_count == NULL)
 		return -ENOTSUP;
-	return (int)p->rx_queue_count(qd);
+	return p->rx_queue_count(qd);
 }
 
 /**@{@name Rx hardware descriptor states
diff --git a/lib/ethdev/rte_ethdev_core.h b/lib/ethdev/rte_ethdev_core.h
index e55fb42996..4ffae4921a 100644
--- a/lib/ethdev/rte_ethdev_core.h
+++ b/lib/ethdev/rte_ethdev_core.h
@@ -45,7 +45,7 @@ typedef uint16_t (*eth_tx_prep_t)(void *txq,
 
 
 /** @internal Get number of used descriptors on a receive queue. */
-typedef uint32_t (*eth_rx_queue_count_t)(void *rxq);
+typedef int (*eth_rx_queue_count_t)(void *rxq);
 
 /** @internal Check the status of a Rx descriptor */
 typedef int (*eth_rx_descriptor_status_t)(void *rxq, uint16_t offset);
-- 
2.43.0

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

[skori]

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

RE: [PATCH v2 1/2] ethdev: remove unnecessary type conversion

[Morten Brørup]

> From: Sunil Kumar Kori <skori@marvell.com>
> Sent: Monday, 12 May 2025 17.07
> 
> As rte_eth_rx_queue_count() returns signed value to represent
> the error cases but internally invoked callback is returning
> unsigned value. Hence unnecessary type conversion is done.
> 
> To avoid this typecasting from signed to unsigned, fixed
> return type of callback functions.
> 
> Signed-off-by: Sunil Kumar Kori <skori@marvell.com>

Note for other reviewers:
The tx_queue_count callback already returns int, and doesn't need to be updated.

Acked-by: Morten Brørup <mb@smartsharesystems.com>

> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index ea7f8c4a1a..b3031ab9e6 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -6401,7 +6401,7 @@ rte_eth_rx_queue_count(uint16_t port_id, uint16_t
> queue_id)
> 
>  	if (p->rx_queue_count == NULL)
>  		return -ENOTSUP;
> -	return (int)p->rx_queue_count(qd);
> +	return p->rx_queue_count(qd);
>  }
> 
>  /**@{@name Rx hardware descriptor states
> diff --git a/lib/ethdev/rte_ethdev_core.h
> b/lib/ethdev/rte_ethdev_core.h
> index e55fb42996..4ffae4921a 100644
> --- a/lib/ethdev/rte_ethdev_core.h
> +++ b/lib/ethdev/rte_ethdev_core.h
> @@ -45,7 +45,7 @@ typedef uint16_t (*eth_tx_prep_t)(void *txq,
> 
> 
>  /** @internal Get number of used descriptors on a receive queue. */
> -typedef uint32_t (*eth_rx_queue_count_t)(void *rxq);
> +typedef int (*eth_rx_queue_count_t)(void *rxq);
> 
>  /** @internal Check the status of a Rx descriptor */
>  typedef int (*eth_rx_descriptor_status_t)(void *rxq, uint16_t offset);
> --
> 2.43.0

For the ethdev library changes:
Reviewed-by: Morten Brørup <mb@smartsharesystems.com>

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

[Morten Brørup]

> From: Sunil Kumar Kori <skori@marvell.com>
> Sent: Monday, 12 May 2025 17.07
> 
> 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>
> ---

Acked-by: Morten Brørup <mb@smartsharesystems.com>