Re: [dpdk-dev] [PATCH v5 3/9] dmadev: add device iterator

[fengchengwen]

On 2021/9/17 21:54, Bruce Richardson wrote:
> Add a function and wrapper macro to iterate over all dma devices.
> 
> Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
> ---
>  lib/dmadev/rte_dmadev.c | 13 +++++++++++++
>  lib/dmadev/rte_dmadev.h | 18 ++++++++++++++++++
>  lib/dmadev/version.map  |  1 +
>  3 files changed, 32 insertions(+)
> 
> diff --git a/lib/dmadev/rte_dmadev.c b/lib/dmadev/rte_dmadev.c
> index ed342e0d32..ba189f3539 100644
> --- a/lib/dmadev/rte_dmadev.c
> +++ b/lib/dmadev/rte_dmadev.c
> @@ -55,6 +55,19 @@ rte_dma_dev_max(size_t dev_max)
>       return 0;
>  }
> 
> +uint16_t
> +rte_dma_next_dev(uint16_t start_dev_id)
> +{
> +     uint16_t dev_id = start_dev_id;
> +     while (dev_id < dma_devices_max && rte_dma_devices[dev_id].state == 
> RTE_DMA_DEV_UNUSED)
> +             dev_id++;
> +
> +     if (dev_id < dma_devices_max)
> +             return dev_id;
> +
> +     return UINT16_MAX;
> +}

Now dev_id is int16_t, so the input parameter should be int16_t and return -1 
when non next. e.g.

int16_t
rte_dma_next_dev(int16_t start_dev_id)
{
        int16_t dev_id = start_dev_id;
        while (dev_id < dma_devices_max && rte_dma_devices[dev_id].state == 
RTE_DMA_DEV_UNUSED)
                dev_id++;

        if (dev_id < dma_devices_max)
                return dev_id;

        return -1;
}

> +
>  static int
>  dma_check_name(const char *name)
>  {
> diff --git a/lib/dmadev/rte_dmadev.h b/lib/dmadev/rte_dmadev.h
> index be4bb18ee6..d262b8ed8d 100644
> --- a/lib/dmadev/rte_dmadev.h
> +++ b/lib/dmadev/rte_dmadev.h
> @@ -219,6 +219,24 @@ bool rte_dma_is_valid(int16_t dev_id);
>  __rte_experimental
>  uint16_t rte_dma_count_avail(void);
> 
> +/**
> + * Iterates over valid dmadev instances.
> + *
> + * @param start_dev_id
> + *   The id of the next possible dmadev.
> + * @return
> + *   Next valid dmadev, UINT16_MAX if there is none.
> + */
> +__rte_experimental
> +uint16_t rte_dma_next_dev(uint16_t start_dev_id);
> +
> +/** Utility macro to iterate over all available dmadevs */
> +#define RTE_DMA_FOREACH_DEV(p) \
> +     for (p = rte_dma_next_dev(0); \
> +          (uint16_t)p < UINT16_MAX; \
> +          p = rte_dma_next_dev(p + 1))

#define RTE_DMA_FOREACH_DEV(p) \
        for (p = rte_dma_next_dev(0); \
             p != -1; \
             p = rte_dma_next_dev(p + 1))

> +
> +
>  /** DMA device support memory-to-memory transfer.
>   *
>   * @see struct rte_dma_info::dev_capa
> diff --git a/lib/dmadev/version.map b/lib/dmadev/version.map
> index 66420c4ede..0ab570a1be 100644
> --- a/lib/dmadev/version.map
> +++ b/lib/dmadev/version.map
> @@ -15,6 +15,7 @@ EXPERIMENTAL {
>       rte_dma_get_dev_id;
>       rte_dma_info_get;
>       rte_dma_is_valid;
> +     rte_dma_next_dev;
>       rte_dma_start;
>       rte_dma_stats_get;
>       rte_dma_stats_reset;
> --
> 2.30.2
> 
> .
>