Re: [dpdk-dev] [PATCH] ethdev: get rxq interrupt fd

[Stephen Hemminger <stephen@networkplumber.org>]

In general, an API is less error prone if it only does return by value.
What about just returning fd or -1?


On Fri, Sep 28, 2018, 5:55 AM Xiaoyun Li <xiaoyun.li@intel.com> wrote:

> Some users want to use their own epoll instances to control both
> DPDK rxq interrupt fds and their own other fds. So added a function
> to get rxq interrupt fd based on port id and queue id.
>
> Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
> ---
>  lib/librte_ethdev/rte_ethdev.c | 37 ++++++++++++++++++++++++++++++++++
>  lib/librte_ethdev/rte_ethdev.h |  3 +++
>  2 files changed, 40 insertions(+)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.c
> b/lib/librte_ethdev/rte_ethdev.c
> index ef99f7068..c21124e32 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -3433,6 +3433,43 @@ rte_eth_dev_rx_intr_ctl(uint16_t port_id, int epfd,
> int op, void *data)
>         return 0;
>  }
>
> +int
> +rte_eth_dev_rx_intr_ctl_q_get_fd(uint16_t port_id, uint16_t queue_id,
> +                                int *fd)
> +{
> +       struct rte_intr_handle *intr_handle;
> +       struct rte_eth_dev *dev;
> +       unsigned int efd_idx;
> +       uint32_t vec;
> +
> +       RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +
> +       dev = &rte_eth_devices[port_id];
> +
> +       if (queue_id >= dev->data->nb_rx_queues) {
> +               RTE_ETHDEV_LOG(ERR, "Invalid RX queue_id=%u\n", queue_id);
> +               return -EINVAL;
> +       }
> +
> +       if (!dev->intr_handle) {
> +               RTE_ETHDEV_LOG(ERR, "RX Intr handle unset\n");
> +               return -ENOTSUP;
> +       }
> +
> +       intr_handle = dev->intr_handle;
> +       if (!intr_handle->intr_vec) {
> +               RTE_ETHDEV_LOG(ERR, "RX Intr vector unset\n");
> +               return -EPERM;
> +       }
> +
> +       vec = intr_handle->intr_vec[queue_id];
> +       efd_idx = (vec >= RTE_INTR_VEC_RXTX_OFFSET) ?
> +               (vec - RTE_INTR_VEC_RXTX_OFFSET) : vec;
> +       *fd = intr_handle->efds[efd_idx];
> +
> +       return 0;
> +}
> +
>  const struct rte_memzone *
>  rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char
> *ring_name,
>                          uint16_t queue_id, size_t size, unsigned align,
> diff --git a/lib/librte_ethdev/rte_ethdev.h
> b/lib/librte_ethdev/rte_ethdev.h
> index 012577b0a..3670d7249 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -2719,6 +2719,9 @@ int rte_eth_dev_rx_intr_ctl(uint16_t port_id, int
> epfd, int op, void *data);
>  int rte_eth_dev_rx_intr_ctl_q(uint16_t port_id, uint16_t queue_id,
>                               int epfd, int op, void *data);
>
> +int rte_eth_dev_rx_intr_ctl_q_get_fd(uint16_t port_id, uint16_t queue_id,
> +                                    int *fd);
> +
>  /**
>   * Turn on the LED on the Ethernet device.
>   * This function turns on the LED on the Ethernet device.
> --
> 2.17.1
>
>