[dpdk-dev] [PATCH 01/22] eal: introduce one device scan

[Shreyansh Jain]

On 6/7/2018 6:08 PM, Qi Zhang wrote:
> When hot plug a new device, it is not necessary to scan everything
> on the bus since the devname and devargs are already there. So new
> rte_bus ops "scan_one" is introduced, bus driver can implement this
> function to simply the hotplug process.
              ^^^^^^^^^
              simplify

> 
> Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
> ---
>   lib/librte_eal/common/eal_common_dev.c  | 17 +++++++++++++----
>   lib/librte_eal/common/include/rte_bus.h |  4 ++++
>   2 files changed, 17 insertions(+), 4 deletions(-)
> 
> diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
> index 61cb3b162..1ad033536 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -147,11 +147,20 @@ int __rte_experimental rte_eal_hotplug_add(const char *busname, const char *devn
>   	if (ret)
>   		goto err_devarg;
>   
> -	ret = bus->scan();
> -	if (ret)
> -		goto err_devarg;
> +	/**
> +	 * if bus support to scan specific device by devargs,
> +	 * we don't need to scan all devices on the bus.
> +	 */
> +	if (bus->scan_one) {
> +		dev = bus->scan_one(da);
> +	} else {
> +		ret = bus->scan();
> +		if (ret)
> +			goto err_devarg;
> +
> +		dev = bus->find_device(NULL, cmp_detached_dev_name, devname);
> +	}
>   
> -	dev = bus->find_device(NULL, cmp_detached_dev_name, devname);
>   	if (dev == NULL) {
>   		RTE_LOG(ERR, EAL, "Cannot find unplugged device (%s)\n",
>   			devname);
> diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> index eb9eded4e..b15cff892 100644
> --- a/lib/librte_eal/common/include/rte_bus.h
> +++ b/lib/librte_eal/common/include/rte_bus.h
> @@ -83,6 +83,7 @@ enum rte_iova_mode {
>    */
>   typedef int (*rte_bus_scan_t)(void);
>   
> +typedef struct rte_device *(*rte_bus_scan_one_t)(struct rte_devargs *);

You should add comments over the declaration, just like the other 
similar declarations.
And, a new line should be here.

>   /**
>    * Implementation specific probe function which is responsible for linking
>    * devices on that bus with applicable drivers.
> @@ -95,6 +96,8 @@ typedef int (*rte_bus_scan_t)(void);
>    */
>   typedef int (*rte_bus_probe_t)(void);
>   
> +
> +

And please remove the extra lines added above in next version of patch.

>   /**
>    * Device iterator to find a device on a bus.
>    *
> @@ -204,6 +207,7 @@ struct rte_bus {
>   	TAILQ_ENTRY(rte_bus) next;   /**< Next bus object in linked list */
>   	const char *name;            /**< Name of the bus */
>   	rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
> +	rte_bus_scan_one_t scan_one; /**< Scan one device by devargs */

I think you mean "Scan one device using devargs" rather than "Scan one 
device by devargs".

>   	rte_bus_probe_t probe;       /**< Probe devices on bus */
>   	rte_bus_find_device_t find_device; /**< Find a device on the bus */
>   	rte_bus_plug_t plug;         /**< Probe single device for drivers */
>