Re: [PATCH v8 09/14] bus: introduce device plug/unplug functionality

["Gaëtan Rivet" <gaetan.rivet@6wind.com>]

On Fri, Jun 30, 2017 at 08:19:38PM +0200, Jan Blunck wrote:
> This allows the buses to plug and probe specific devices. This is meant to
> be a building block for hotplug support.
> 
> Signed-off-by: Jan Blunck <jblunck@infradead.org>
> ---
>  lib/librte_eal/common/eal_common_bus.c  |  2 ++
>  lib/librte_eal/common/include/rte_bus.h | 32 ++++++++++++++++++++++++++++++++
>  2 files changed, 34 insertions(+)
> 
> diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
> index bf2b138..87b0c6e 100644
> --- a/lib/librte_eal/common/eal_common_bus.c
> +++ b/lib/librte_eal/common/eal_common_bus.c
> @@ -51,6 +51,8 @@ rte_bus_register(struct rte_bus *bus)
>  	RTE_VERIFY(bus->scan);
>  	RTE_VERIFY(bus->probe);
>  	RTE_VERIFY(bus->find_device);
> +	/* Buses supporting driver plug also require unplug. */
> +	RTE_VERIFY(!bus->plug || bus->unplug);
>  
>  	TAILQ_INSERT_TAIL(&rte_bus_list, bus, next);
>  	RTE_LOG(DEBUG, EAL, "Registered [%s] bus.\n", bus->name);
> diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> index 509292d..34ea9d5 100644
> --- a/lib/librte_eal/common/include/rte_bus.h
> +++ b/lib/librte_eal/common/include/rte_bus.h
> @@ -108,6 +108,36 @@ typedef struct rte_device *
>  			 const void *data);
>  
>  /**
> + * Implementation specific probe function which is responsible for linking
> + * devices on that bus with applicable drivers.
> + *
> + * @param dev
> + *	Device pointer that was returned by a previous call to find_device.
> + *
> + * @param devargs
> + *	Device declaration.
> + *
> + * @return
> + *	The pointer to a valid rte_device usable by the bus on success.
> + *	NULL on error. rte_errno is then set.
> + */
> +typedef int (*rte_bus_plug_t)(struct rte_device *dev,

This typedef does not match its doc.
If it is the doc that is right, the PCI and vdev implementation should
be fixed as well.

> +			      const char *devargs);
> +
> +/**
> + * Implementation specific remove function which is responsible for unlinking
> + * devices on that bus from assigned driver.
> + *
> + * @param dev
> + *	Device pointer that was returned by a previous call to find_device.
> + *
> + * @return
> + *	0 on success.
> + *	!0 on error. rte_errno is then set.
> + */
> +typedef int (*rte_bus_unplug_t)(struct rte_device *dev);
> +
> +/**
>   * A structure describing a generic bus.
>   */
>  struct rte_bus {
> @@ -116,6 +146,8 @@ struct rte_bus {
>  	rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
>  	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 */
> +	rte_bus_unplug_t unplug;     /**< Remove single device from driver */
>  };
>  
>  /**
> -- 
> 2.9.4
> 

-- 
Gaëtan Rivet
6WIND