Re: [dpdk-dev] [PATCH] ethdev: add siblings iterator

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 11/30/2018 12:27 AM, Thomas Monjalon wrote:
> If multiple ports share the same hardware device (rte_device),
> they are siblings and can be found thanks to the new function
> and loop macro.
> 
> The ownership is not checked because siblings may have
> different owners.

Looks good on its own, but I think now we require an implementation of any new
API, so it can be good to have:
- a sample implementation of this new API and the macro
- an unit test for the API and the macro

> 
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
>  lib/librte_ethdev/rte_ethdev.c           | 15 +++++++++++++++
>  lib/librte_ethdev/rte_ethdev.h           | 23 +++++++++++++++++++++++
>  lib/librte_ethdev/rte_ethdev_version.map |  1 +
>  3 files changed, 39 insertions(+)
> 
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 5f858174b..11e0ade6e 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -341,6 +341,21 @@ rte_eth_find_next(uint16_t port_id)
>  	return port_id;
>  }
>  
> +uint16_t __rte_experimental

I think __rte_experimental tag only in header file is sufficient

> +rte_eth_find_next_sibling(uint16_t port_id, uint16_t ref)
> +{
> +	while (port_id < RTE_MAX_ETHPORTS &&
> +			rte_eth_devices[port_id].state == RTE_ETH_DEV_UNUSED &&
> +			rte_eth_devices[port_id].device !=
> +				rte_eth_devices[ref].device)
> +		port_id++;
> +
> +	if (port_id >= RTE_MAX_ETHPORTS)
> +		return RTE_MAX_ETHPORTS;
> +
> +	return port_id;
> +}
> +
>  static void
>  rte_eth_dev_shared_data_prepare(void)
>  {
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 1960f3a2d..647e6634d 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -1383,6 +1383,29 @@ uint16_t rte_eth_find_next(uint16_t port_id);
>  #define RTE_ETH_FOREACH_DEV(p) \
>  	RTE_ETH_FOREACH_DEV_OWNED_BY(p, RTE_ETH_DEV_NO_OWNER)
>  
> +/**
> + * Iterates over sibling ethdev ports (i.e. sharing the same rte_device).
> + *
> + * @param port_id_start
> + *   The id of the next possible valid sibling port.
> + * @param ref
> + *   The id of a reference port to compare rte_device with.
> + * @return
> + *   Next sibling port id (or ref itself), RTE_MAX_ETHPORTS if there is none.
> + */
> +__rte_experimental
> +uint16_t rte_eth_find_next_sibling(uint16_t port_id_start, uint16_t ref);
> +
> +/**
> + * Macro to iterate over all ethdev ports sharing the same rte_device
> + * as the specified port.
> + * Note: the specified port is part of the loop iterations.
> + */
> +#define RTE_ETH_FOREACH_DEV_SIBLING(p, ref) \
> +	for (p = rte_eth_find_next_sibling(0, ref); \
> +		p < RTE_MAX_ETHPORTS; \
> +		p = rte_eth_find_next_sibling(p + 1, ref))
> +
>  
>  /**
>   * @warning
> diff --git a/lib/librte_ethdev/rte_ethdev_version.map b/lib/librte_ethdev/rte_ethdev_version.map
> index 92ac3de25..a0c930d04 100644
> --- a/lib/librte_ethdev/rte_ethdev_version.map
> +++ b/lib/librte_ethdev/rte_ethdev_version.map
> @@ -245,6 +245,7 @@ EXPERIMENTAL {
>  	rte_eth_dev_owner_set;
>  	rte_eth_dev_owner_unset;
>  	rte_eth_dev_rx_intr_ctl_q_get_fd;
> +	rte_eth_find_next_sibling;
>  	rte_eth_switch_domain_alloc;
>  	rte_eth_switch_domain_free;
>  	rte_flow_conv;
>