Hi Tom,
Adding ethdev maintainers and Oliver as the author of the new API.
Saturday, October 27, 2018 6:11 PM, Tom Barbette:
> Subject: [PATCH v4] mlx5: Support for rte_eth_rx_queue_count
>
I have a more basic question.
The rte_eth_rx_queue_count is a very old API, more or less from the beginning
of DPDK.
We progressed from then and a newer API to check the descriptor status was
introduced @DPDK17.05 : rte_eth_rx_descriptor_status, see commit[1].
There is also a plan to deprecate it once all drivers will support the new API.
With the new API you can check the number of available descriptors on a similar
way.
So my question is, is the new API enough for your functionality? If not, what
it is missing? I would prefer to improve the new one instead of starting to
support the old one.
[1]
commit b1b700ce7d6fe0db9152f73e8e00394fc2756e60
Author: Olivier Matz <olivier.m...@6wind.com>
Date: Wed Mar 29 10:36:28 2017 +0200
ethdev: add descriptor status API
Introduce a new API to get the status of a descriptor.
For Rx, it is almost similar to rx_descriptor_done API, except it
differentiates "used" descriptors (which are hold by the driver and not
returned to the hardware).
For Tx, it is a new API.
The descriptor_done() API, and probably the rx_queue_count() API could
be replaced by this new API as soon as it is implemented on all PMDs.
Signed-off-by: Olivier Matz <olivier.m...@6wind.com>
Reviewed-by: Andrew Rybchenko <arybche...@solarflare.com>
> This patch adds support for the rx_queue_count API in mlx5 driver
>
> Changes in v2:
> * Fixed styling issues
> * Fix missing return
>
> Changes in v3:
> * Fix styling comments and checks as per Yongseok Koh
> <ys...@mellanox.com> comments. Thanks !
>
> Changes in v4:
> * Fix compiling issue because of a line that disappeared in v3
>
> Signed-off-by: Tom Barbette <barbe...@kth.se>
> ---
> drivers/net/mlx5/mlx5.c | 1 +
> drivers/net/mlx5/mlx5_rxtx.c | 78
> ++++++++++++++++++++++++++++++++++++++------
> drivers/net/mlx5/mlx5_rxtx.h | 1 +
> 3 files changed, 70 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c index
> ec63bc6..6fccadd 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -375,6 +375,7 @@ const struct eth_dev_ops mlx5_dev_ops = {
> .filter_ctrl = mlx5_dev_filter_ctrl,
> .rx_descriptor_status = mlx5_rx_descriptor_status,
> .tx_descriptor_status = mlx5_tx_descriptor_status,
> + .rx_queue_count = mlx5_rx_queue_count,
> .rx_queue_intr_enable = mlx5_rx_intr_enable,
> .rx_queue_intr_disable = mlx5_rx_intr_disable,
> .is_removed = mlx5_is_removed,
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 2d14f8a..2126205 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -417,20 +417,17 @@ mlx5_tx_descriptor_status(void *tx_queue,
> uint16_t offset) }
>
> /**
> - * DPDK callback to check the status of a rx descriptor.
> + * Internal function to compute the number of used descriptors in an RX
> + queue
> *
> - * @param rx_queue
> - * The rx queue.
> - * @param[in] offset
> - * The index of the descriptor in the ring.
> + * @param rxq
> + * The Rx queue.
> *
> * @return
> - * The status of the tx descriptor.
> + * The number of used rx descriptor.
> */
> -int
> -mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset)
> +static uint32_t
> +rx_queue_count(struct mlx5_rxq_data *rxq)
> {
> - struct mlx5_rxq_data *rxq = rx_queue;
> struct rxq_zip *zip = &rxq->zip;
> volatile struct mlx5_cqe *cqe;
> const unsigned int cqe_n = (1 << rxq->cqe_n); @@ -461,12 +458,73
> @@ mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset)
> cqe = &(*rxq->cqes)[cq_ci & cqe_cnt];
> }
> used = RTE_MIN(used, (1U << rxq->elts_n) - 1);
> - if (offset < used)
> + return used;
> +}
> +
> +/**
> + * DPDK callback to check the status of a rx descriptor.
> + *
> + * @param rx_queue
> + * The Rx queue.
> + * @param[in] offset
> + * The index of the descriptor in the ring.
> + *
> + * @return
> + * The status of the tx descriptor.
> + */
> +int
> +mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset) {
> + struct mlx5_rxq_data *rxq = rx_queue;
> + struct mlx5_rxq_ctrl *rxq_ctrl =
> + container_of(rxq, struct mlx5_rxq_ctrl, rxq);
> + struct rte_eth_dev *dev = ETH_DEV(rxq_ctrl->priv);
> +
> + if (dev->rx_pkt_burst != mlx5_rx_burst) {
> + rte_errno = ENOTSUP;
> + return -rte_errno;
> + }
> + if (offset >= (1 << rxq->elts_n)) {
> + rte_errno = EINVAL;
> + return -rte_errno;
> + }
> + if (offset < rx_queue_count(rxq))
> return RTE_ETH_RX_DESC_DONE;
> return RTE_ETH_RX_DESC_AVAIL;
> }
>
> /**
> + * DPDK callback to get the number of used descriptors in a RX queue
> + *
> + * @param dev
> + * Pointer to the device structure.
> + *
> + * @param rx_queue_id
> + * The Rx queue.
> + *
> + * @return
> + * The number of used rx descriptor.
> + * -EINVAL if the queue is invalid
> + */
> +uint32_t
> +mlx5_rx_queue_count(struct rte_eth_dev *dev, uint16_t rx_queue_id) {
> + struct priv *priv = dev->data->dev_private;
> + struct mlx5_rxq_data *rxq;
> +
> + if (dev->rx_pkt_burst != mlx5_rx_burst) {
> + rte_errno = ENOTSUP;
> + return -rte_errno;
> + }
> + rxq = (*priv->rxqs)[rx_queue_id];
> + if (!rxq) {
> + rte_errno = EINVAL;
> + return -rte_errno;
> + }
> + return rx_queue_count(rxq);
> +}
> +
> +/**
> * DPDK callback for TX.
> *
> * @param dpdk_txq
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index 48ed2b2..c82059b 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -345,6 +345,7 @@ uint16_t removed_rx_burst(void *dpdk_rxq, struct
> rte_mbuf **pkts,
> uint16_t pkts_n);
> int mlx5_rx_descriptor_status(void *rx_queue, uint16_t offset); int
> mlx5_tx_descriptor_status(void *tx_queue, uint16_t offset);
> +uint32_t mlx5_rx_queue_count(struct rte_eth_dev *dev, uint16_t
> +rx_queue_id);
>
> /* Vectorized version of mlx5_rxtx.c */ int
> mlx5_check_raw_vec_tx_support(struct rte_eth_dev *dev);
> --
> 2.7.4
