Re: [dpdk-dev] [PATCH v8 06/14] eal, ethdev: Add a function and function pointers to close ether device

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-02-16 13:14, Tetsuya Mukawa:
> The patch adds function pointer to rte_pci_driver and eth_driver
> structure. These function pointers are used when ports are detached.
> Also, the patch adds rte_eth_dev_uninit(). So far, it's not called
> by anywhere, but it will be called when port hotplug function is
> implemented.
> 
> v6:
> - Fix rte_eth_dev_uninit() to handle a return value of uninit
>   function of PMD.
> v4:
> - Add parameter checking.
> - Change function names.
> 
> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
> ---
>  lib/librte_eal/common/include/rte_pci.h |  7 +++++
>  lib/librte_ether/rte_ethdev.c           | 47 +++++++++++++++++++++++++++++++++
>  lib/librte_ether/rte_ethdev.h           | 24 +++++++++++++++++
>  3 files changed, 78 insertions(+)
> 
> diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
> index 4814cd7..87ca4cf 100644
> --- a/lib/librte_eal/common/include/rte_pci.h
> +++ b/lib/librte_eal/common/include/rte_pci.h
> @@ -189,12 +189,19 @@ struct rte_pci_driver;
>  typedef int (pci_devinit_t)(struct rte_pci_driver *, struct rte_pci_device *);
>  
>  /**
> + * Uninitialisation function for the driver called during hotplugging.
> + */
> +typedef int (pci_devuninit_t)(
> +		struct rte_pci_driver *, struct rte_pci_device *);
> +
> +/**
>   * A structure describing a PCI driver.
>   */
>  struct rte_pci_driver {
>  	TAILQ_ENTRY(rte_pci_driver) next;       /**< Next in list. */
>  	const char *name;                       /**< Driver name. */
>  	pci_devinit_t *devinit;                 /**< Device init. function. */
> +	pci_devuninit_t *devuninit;             /**< Device uninit function. */
>  	struct rte_pci_id *id_table;            /**< ID table, NULL terminated. */
>  	uint32_t drv_flags;                     /**< Flags contolling handling of device. */
>  };
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 2463d18..58d8072 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -326,6 +326,52 @@ rte_eth_dev_init(struct rte_pci_driver *pci_drv,
>  	return diag;
>  }
>  
> +static int
> +rte_eth_dev_uninit(struct rte_pci_driver *pci_drv,
> +		 struct rte_pci_device *pci_dev)

There's something strange here: this is an uninit of an ethdev but the parameter
is a pci_dev.
The driver parameter shouldn't be needed.

> +{
> +	struct eth_driver *eth_drv;
> +	struct rte_eth_dev *eth_dev;
> +	char ethdev_name[RTE_ETH_NAME_MAX_LEN];
> +	int ret;
> +
> +	if ((pci_drv == NULL) || (pci_dev == NULL))
> +		return -EINVAL;
> +
> +	/* Create unique Ethernet device name using PCI address */
> +	snprintf(ethdev_name, RTE_ETH_NAME_MAX_LEN, "%d:%d.%d",
> +			pci_dev->addr.bus, pci_dev->addr.devid,
> +			pci_dev->addr.function);

You should call a function common to init and uninit to generate
the same unique name.

> +
> +	eth_dev = rte_eth_dev_allocated(ethdev_name);
> +	if (eth_dev == NULL)
> +		return -ENODEV;
> +
> +	eth_drv = (struct eth_driver *)pci_drv;
> +
> +	/* Invoke PMD device uninit function */
> +	if (*eth_drv->eth_dev_uninit) {
> +		ret = (*eth_drv->eth_dev_uninit)(eth_drv, eth_dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* free ether device */
> +	rte_eth_dev_free(eth_dev);
> +
> +	/* init user callbacks */
> +	TAILQ_INIT(&(eth_dev->callbacks));

Please comment more why you are resetting callbacks.
An init in an uninit function seems weird ;)

> +
> +	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
> +		rte_free(eth_dev->data->dev_private);
> +
> +	eth_dev->pci_dev = NULL;
> +	eth_dev->driver = NULL;
> +	eth_dev->data = NULL;
> +
> +	return 0;
> +}
> +
>  /**
>   * Register an Ethernet [Poll Mode] driver.
>   *
> @@ -344,6 +390,7 @@ void
>  rte_eth_driver_register(struct eth_driver *eth_drv)
>  {
>  	eth_drv->pci_drv.devinit = rte_eth_dev_init;
> +	eth_drv->pci_drv.devuninit = rte_eth_dev_uninit;
>  	rte_eal_pci_register(&eth_drv->pci_drv);
>  }
>  
> diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
> index fbe7ac1..91d9e86 100644
> --- a/lib/librte_ether/rte_ethdev.h
> +++ b/lib/librte_ether/rte_ethdev.h
> @@ -1678,6 +1678,27 @@ typedef int (*eth_dev_init_t)(struct eth_driver  *eth_drv,
>  
>  /**
>   * @internal
> + * Finalization function of an Ethernet driver invoked for each matching
> + * Ethernet PCI device detected during the PCI closing phase.
> + *
> + * @param eth_drv
> + *   The pointer to the [matching] Ethernet driver structure supplied by
> + *   the PMD when it registered itself.
> + * @param eth_dev
> + *   The *eth_dev* pointer is the address of the *rte_eth_dev* structure
> + *   associated with the matching device and which have been [automatically]
> + *   allocated in the *rte_eth_devices* array.
> + * @return
> + *   - 0: Success, the device is properly finalized by the driver.
> + *        In particular, the driver MUST free the *dev_ops* pointer
> + *        of the *eth_dev* structure.
> + *   - <0: Error code of the device initialization failure.
> + */
> +typedef int (*eth_dev_uninit_t)(struct eth_driver  *eth_drv,
> +				  struct rte_eth_dev *eth_dev);
> +
> +/**
> + * @internal
>   * The structure associated with a PMD Ethernet driver.
>   *
>   * Each Ethernet driver acts as a PCI driver and is represented by a generic
> @@ -1687,11 +1708,14 @@ typedef int (*eth_dev_init_t)(struct eth_driver  *eth_drv,
>   *
>   * - The *eth_dev_init* function invoked for each matching PCI device.
>   *
> + * - The *eth_dev_uninit* function invoked for each matching PCI device.
> + *
>   * - The size of the private data to allocate for each matching device.
>   */
>  struct eth_driver {
>  	struct rte_pci_driver pci_drv;    /**< The PMD is also a PCI driver. */
>  	eth_dev_init_t eth_dev_init;      /**< Device init function. */
> +	eth_dev_uninit_t eth_dev_uninit;  /**< Device uninit function. */
>  	unsigned int dev_private_size;    /**< Size of device private data. */
>  };
>  
>