Re: [dpdk-dev] [PATCH 1/2] ethdev: avoid explicit check of valid port state

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

On 4/17/2019 11:59 PM, Thomas Monjalon wrote:
> Some port iterations are manually checking against RTE_ETH_DEV_UNUSED
> instead of using the iterators based on rte_eth_find_next().
> 
> A new macro RTE_ETH_FOREACH_VALID_DEV() is introduced, but kept private
> because there should be no need of iterating over all devices in the API.
> The public iterators have additional filters for ownership, parent device
> or sibling ports.
> 
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
>  drivers/net/mlx5/mlx5.c        |  9 ++-------
>  lib/librte_ethdev/rte_ethdev.c | 25 ++++++++++++-------------

No strong opinion but should we separate patch for driver and the library,
logically both changes RTE_ETH_DEV_UNUSED check with macros, but there is no
dependency, I mean they are individual changes, driver patch will be valid on
its own.

>  2 files changed, 14 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index 9ff50dfbe..4deaada5c 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -1964,14 +1964,9 @@ static int
>  mlx5_pci_remove(struct rte_pci_device *pci_dev)
>  {
>  	uint16_t port_id;
> -	struct rte_eth_dev *port;
>  
> -	for (port_id = 0; port_id < RTE_MAX_ETHPORTS; port_id++) {
> -		port = &rte_eth_devices[port_id];
> -		if (port->state != RTE_ETH_DEV_UNUSED &&
> -				port->device == &pci_dev->device)
> -			rte_eth_dev_close(port_id);
> -	}
> +	RTE_ETH_FOREACH_DEV_OF(port_id, &pci_dev->device)
> +		rte_eth_dev_close(port_id);
>  	return 0;
>  }
>  
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 243beb4dd..cca15efca 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -339,6 +339,11 @@ rte_eth_find_next(uint16_t port_id)
>  	return port_id;
>  }
>  
> +#define RTE_ETH_FOREACH_VALID_DEV(port_id) \
> +	for (port_id = rte_eth_find_next(0); \
> +	     port_id < RTE_MAX_ETHPORTS; \
> +	     port_id = rte_eth_find_next(port_id + 1))
> +

What do you think adding some documentation to the new macro, specially I think
documenting the difference between "RTE_ETH_FOREACH_DEV" and this one can be
good otherwise it may confuse people that "RTE_ETH_FOREACH_DEV" iterates on
invalid devices too?

>  uint16_t
>  rte_eth_find_next_of(uint16_t port_id, const struct rte_device *parent)
>  {
> @@ -584,13 +589,10 @@ rte_eth_is_valid_owner_id(uint64_t owner_id)
>  uint64_t
>  rte_eth_find_next_owned_by(uint16_t port_id, const uint64_t owner_id)
>  {
> +	port_id = rte_eth_find_next(port_id);
>  	while (port_id < RTE_MAX_ETHPORTS &&
> -	       (rte_eth_devices[port_id].state == RTE_ETH_DEV_UNUSED ||
> -	       rte_eth_devices[port_id].data->owner.id != owner_id))
> -		port_id++;
> -
> -	if (port_id >= RTE_MAX_ETHPORTS)
> -		return RTE_MAX_ETHPORTS;
> +			rte_eth_devices[port_id].data->owner.id != owner_id)
> +		port_id = rte_eth_find_next(port_id + 1);
>  
>  	return port_id;
>  }
> @@ -768,9 +770,8 @@ rte_eth_dev_count_total(void)
>  {
>  	uint16_t port, count = 0;
>  
> -	for (port = 0; port < RTE_MAX_ETHPORTS; port++)
> -		if (rte_eth_devices[port].state != RTE_ETH_DEV_UNUSED)
> -			count++;
> +	RTE_ETH_FOREACH_VALID_DEV(port)
> +		count++;
>  
>  	return count;
>  }
> @@ -804,13 +805,11 @@ rte_eth_dev_get_port_by_name(const char *name, uint16_t *port_id)
>  		return -EINVAL;
>  	}
>  
> -	for (pid = 0; pid < RTE_MAX_ETHPORTS; pid++) {
> -		if (rte_eth_devices[pid].state != RTE_ETH_DEV_UNUSED &&
> -		    !strcmp(name, rte_eth_dev_shared_data->data[pid].name)) {
> +	RTE_ETH_FOREACH_VALID_DEV(pid)
> +		if (!strcmp(name, rte_eth_dev_shared_data->data[pid].name)) {
>  			*port_id = pid;
>  			return 0;
>  		}
> -	}
>  
>  	return -ENODEV;
>  }
>