Re: [dpdk-dev] [PATCH v3 01/10] bus: add bus iterator to find a particular bus

[Jan Blunck <jblunck@infradead.org>]

On Thu, Jun 8, 2017 at 1:53 AM, Gaetan Rivet <gaetan.rivet@6wind.com> wrote:
> From: Jan Blunck <jblunck@infradead.org>
>
> Signed-off-by: Jan Blunck <jblunck@infradead.org>
> Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
> ---
>  lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  1 +
>  lib/librte_eal/common/eal_common_bus.c          | 11 ++++++++
>  lib/librte_eal/common/include/rte_bus.h         | 34 +++++++++++++++++++++++++
>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>  4 files changed, 47 insertions(+)
>
> diff --git a/lib/librte_eal/bsdapp/eal/rte_eal_version.map b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> index 2e48a73..ed09ab2 100644
> --- a/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/bsdapp/eal/rte_eal_version.map
> @@ -162,6 +162,7 @@ DPDK_17.02 {
>  DPDK_17.05 {
>         global:
>
> +       rte_bus_find;
>         rte_cpu_is_supported;
>         rte_log_dump;
>         rte_log_register;
> diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
> index 8f9baf8..a54aeb4 100644
> --- a/lib/librte_eal/common/eal_common_bus.c
> +++ b/lib/librte_eal/common/eal_common_bus.c
> @@ -145,3 +145,14 @@ rte_bus_dump(FILE *f)
>                 }
>         }
>  }
> +
> +struct rte_bus *
> +rte_bus_find(rte_bus_cmp_t cmp, const void *data)
> +{
> +       struct rte_bus *bus = NULL;
> +
> +       TAILQ_FOREACH(bus, &rte_bus_list, next)
> +               if (cmp(bus, data) == 0)
> +                       break;
> +       return bus;
> +}
> diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> index 7c36969..16bcfd9 100644
> --- a/lib/librte_eal/common/include/rte_bus.h
> +++ b/lib/librte_eal/common/include/rte_bus.h
> @@ -141,6 +141,40 @@ int rte_bus_probe(void);
>  void rte_bus_dump(FILE *f);
>
>  /**
> + * Bus comparison function.
> + *
> + * @param bus
> + *     Bus under test.
> + *
> + * @param data
> + *     Data to compare against.
> + *
> + * @return
> + *     0 if the bus matches the data.
> + *     !0 if the bus does not match.
> + *     <0 if ordering is possible and the bus is lower than the data.
> + *     >0 if ordering is possible and the bus is greater than the data.
> + */
> +typedef int (*rte_bus_cmp_t)(const struct rte_bus *bus, const void *data);

Gaetan,

Thanks for doing the adjustments. I believe we should also pass the
starting pointer down to the bus implementation to enable continuation
of a search after the given starting pointer. Does this make sense?

> +
> +/**
> + * Bus iterator to find a particular bus.
> + *
> + * If the callback returns non-zero this function will stop iterating over
> + * any more buses.
> + *
> + * @param cmp
> + *     Comparison function.
> + *
> + * @param data
> + *      Data to pass to cmp callback
> + *
> + * @return
> + *      A pointer to a rte_bus structure or NULL in case no bus matches
> + */
> +struct rte_bus *rte_bus_find(rte_bus_cmp_t cmp, const void *data);
> +
> +/**
>   * Helper for Bus registration.
>   * The constructor has higher priority than PMD constructors.
>   */
> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> index 670bab3..6efa517 100644
> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> @@ -166,6 +166,7 @@ DPDK_17.02 {
>  DPDK_17.05 {
>         global:
>
> +       rte_bus_find;
>         rte_cpu_is_supported;
>         rte_intr_free_epoll_fd;
>         rte_log_dump;
> --
> 2.1.4
>