Re: [dpdk-dev] [PATCH v8 07/14] ethdev: Add functions that will be used by port hotplug functions

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

2015-02-16 13:14, Tetsuya Mukawa:
> The patch adds following functions.
> 
> - rte_eth_dev_save()
>   The function is used for saving current rte_eth_dev structures.
> - rte_eth_dev_get_changed_port()
>   The function receives the rte_eth_dev structures, then compare
>   these with current values to know which port is actually
>   attached or detached.
> - rte_eth_dev_get_addr_by_port()
>   The function returns a pci address of an ethdev specified by port
>   identifier.
> - rte_eth_dev_get_port_by_addr()
>   The function returns a port identifier of an ethdev specified by
>   pci address.
> - rte_eth_dev_get_name_by_port()
>   The function returns a unique identifier name of an ethdev
>   specified by port identifier.
> - Add rte_eth_dev_check_detachable()
>   The function returns whether a PMD supports detach function.
> 
> Also, the patch changes scope of rte_eth_dev_allocated() to global.
> This function will be called by virtual PMDs to support port hotplug.
> So change scope of the function to global.
> 
> v8:
> - Add size parameter to rte_eth_dev_save().
> - Add missing symbol in version map.
>   (Thanks to Qiu, Michael and Iremonger, Bernard)
> v7:
> - Add pt_driver checking to rte_eth_dev_check_detachable().
>   (Thanks to Qiu, Michael)
> v5:
> - Fix return value of below functions.
>   rte_eth_dev_get_changed_port().
>   rte_eth_dev_get_port_by_addr().
> v4:
> - Add parameter checking.
> v3:
> - Fix if-condition bug while comparing pci addresses.
> - Add error checking codes.
> Reported-by: Mark Enright <menrigh@brocade.com>
> 
> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
> ---
>  lib/librte_ether/rte_ethdev.c          | 99 +++++++++++++++++++++++++++++++++-
>  lib/librte_ether/rte_ethdev.h          | 83 ++++++++++++++++++++++++++++
>  lib/librte_ether/rte_ether_version.map |  6 +++
>  3 files changed, 187 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 58d8072..3869a96 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -206,7 +206,7 @@ rte_eth_dev_data_alloc(void)
>  				RTE_MAX_ETHPORTS * sizeof(*rte_eth_dev_data));
>  }
>  
> -static struct rte_eth_dev *
> +struct rte_eth_dev *
>  rte_eth_dev_allocated(const char *name)
>  {
>  	unsigned i;
> @@ -426,6 +426,103 @@ rte_eth_dev_count(void)
>  	return (nb_ports);
>  }
>  
> +int
> +rte_eth_dev_save(struct rte_eth_dev *devs, size_t size)
> +{
> +	if ((devs == NULL) ||
> +	    (size != sizeof(struct rte_eth_dev) * RTE_MAX_ETHPORTS))
> +		return -EINVAL;
> +
> +	/* save current rte_eth_devices */
> +	memcpy(devs, rte_eth_devices, size);
> +	return 0;
> +}

Why creating a function for a memcpy?

> +
> +int
> +rte_eth_dev_get_changed_port(struct rte_eth_dev *devs, uint8_t *port_id)
> +{
> +	if ((devs == NULL) || (port_id == NULL))
> +		return -EINVAL;
> +
> +	/* check which port was attached or detached */
> +	for (*port_id = 0; *port_id < RTE_MAX_ETHPORTS; (*port_id)++, devs++) {
> +		if (rte_eth_devices[*port_id].attached ^ devs->attached)
> +			return 0;
> +	}
> +	return -ENODEV;
> +}

It seems weird to require this function.
Functions which are attaching a new port should return the port_id.

> +
> +int
> +rte_eth_dev_get_addr_by_port(uint8_t port_id, struct rte_pci_addr *addr)
> +{
> +	if (rte_eth_dev_validate_port(port_id, TRACE) == DEV_INVALID)
> +		return -EINVAL;
> +
> +	if (addr == NULL) {
> +		PMD_DEBUG_TRACE("Null pointer is specified\n");
> +		return -EINVAL;
> +	}
> +
> +	*addr = rte_eth_devices[port_id].pci_dev->addr;
> +	return 0;
> +}

Again, I'm not sure this function is needed.

> +
> +int
> +rte_eth_dev_get_port_by_addr(struct rte_pci_addr *addr, uint8_t *port_id)
> +{
> +	struct rte_pci_addr *tmp;
> +
> +	if ((addr == NULL) || (port_id == NULL)) {
> +		PMD_DEBUG_TRACE("Null pointer is specified\n");
> +		return -EINVAL;
> +	}
> +
> +	for (*port_id = 0; *port_id < RTE_MAX_ETHPORTS; (*port_id)++) {
> +		if (!rte_eth_devices[*port_id].attached)
> +			continue;
> +		if (!rte_eth_devices[*port_id].pci_dev)
> +			continue;
> +		tmp = &rte_eth_devices[*port_id].pci_dev->addr;
> +		if (eal_compare_pci_addr(tmp, addr) == 0)
> +			return 0;
> +	}
> +	return -ENODEV;
> +}
> +
> +int
> +rte_eth_dev_get_name_by_port(uint8_t port_id, char *name)
> +{
> +	char *tmp;
> +
> +	if (rte_eth_dev_validate_port(port_id, TRACE) == DEV_INVALID)
> +		return -EINVAL;
> +
> +	if (name == NULL) {
> +		PMD_DEBUG_TRACE("Null pointer is specified\n");
> +		return -EINVAL;
> +	}
> +
> +	/* shouldn't check 'rte_eth_devices[i].data',
> +	 * because it might be overwritten by VDEV PMD */

I don't understand the comment.

> +	tmp = rte_eth_dev_data[port_id].name;
> +	strncpy(name, tmp, strlen(tmp) + 1);

tmp seems useless.
strncpy with strlen should be equivalent to strcpy.

> +	return 0;
> +}
> +
> +int
> +rte_eth_dev_check_detachable(uint8_t port_id)

Why not "is_detachable" instead of "check_detachable"?

> +{
> +	uint32_t drv_flags;
> +
> +	if (port_id >= RTE_MAX_ETHPORTS) {
> +		PMD_DEBUG_TRACE("Invalid port_id=%d\n", port_id);
> +		return -EINVAL;
> +	}
> +
> +	drv_flags = rte_eth_devices[port_id].driver->pci_drv.drv_flags;
> +	return !(drv_flags & RTE_PCI_DRV_DETACHABLE);
> +}
> +
>  static int
>  rte_eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>  {
> diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
> index 91d9e86..6651890 100644
> --- a/lib/librte_ether/rte_ethdev.h
> +++ b/lib/librte_ether/rte_ethdev.h
> @@ -1616,6 +1616,89 @@ extern struct rte_eth_dev rte_eth_devices[];
>  extern uint8_t rte_eth_dev_count(void);
>  
>  /**
> + * Function for internal use by port hotplug functions.
> + * Copies current ethdev structures to the specified pointer.
> + *
> + * @param	devs	The pointer to the ethdev structures
> + * @param	size	The size of ethdev structures
> + * @return
> + *   - 0 on success, negative on error
> + */
> +extern int rte_eth_dev_save(struct rte_eth_dev *devs, size_t size);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Compare the specified ethdev structures with currents. Then
> + * if there is a port which status is changed, fill the specified pointer
> + * with the port id of that port.
> + * @param	devs	The pointer to the ethdev structures
> + * @param	port_id	The pointer to the port id
> + * @return
> + *   - 0 on success, negative on error
> + */
> +extern int rte_eth_dev_get_changed_port(
> +		struct rte_eth_dev *devs, uint8_t *port_id);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Returns a pci address of a ethdev specified by port identifier.
> + * @param	port_id
> + *   The port identifier of the Ethernet device
> + * @param	addr
> + *   The pointer to the pci address
> + * @return
> + *   - 0 on success, negative on error
> + */
> +extern int rte_eth_dev_get_addr_by_port(
> +		uint8_t port_id, struct rte_pci_addr *addr);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Returns a port identifier of a ethdev specified by pci address.
> + * @param	addr
> + *   The pointer to the pci address of the Ethernet device.
> + * @param	port_id
> + *   The pointer to the port identifier
> + * @return
> + *   - 0 on success, negative on error
> + */
> +extern int rte_eth_dev_get_port_by_addr(
> +		struct rte_pci_addr *addr, uint8_t *port_id);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Returns a unique identifier name of a ethdev specified by port identifier.
> + * @param	port_id
> + *   The port identifier.
> + * @param	name
> + *  The pointer to the Unique identifier name for each Ethernet device
> + * @return
> + *   - 0 on success, negative on error
> + */
> +extern int rte_eth_dev_get_name_by_port(uint8_t port_id, char *name);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Check whether or not, a PMD that is handling the ethdev specified by port
> + * identifier can support detach function.
> + * @param	port_id
> + *   The port identifier
> + * @return
> + *   - 0 on supporting detach function, negative on not supporting
> + */
> +extern int rte_eth_dev_check_detachable(uint8_t port_id);
> +
> +/**
> + * Function for internal use by port hotplug functions.
> + * Returns a ethdev slot specified by the unique identifier name.
> + * @param	name
> + *  The pointer to the Unique identifier name for each Ethernet device
> + * @return
> + *   - The pointer to the ethdev slot, on success. NULL on error
> + */
> +extern struct rte_eth_dev *rte_eth_dev_allocated(const char *name);
> +
> +/**
>   * Function for internal use by dummy drivers primarily, e.g. ring-based
>   * driver.
>   * Allocates a new ethdev slot for an ethernet device and returns the pointer
> diff --git a/lib/librte_ether/rte_ether_version.map b/lib/librte_ether/rte_ether_version.map
> index 7316530..fc5dc27 100644
> --- a/lib/librte_ether/rte_ether_version.map
> +++ b/lib/librte_ether/rte_ether_version.map
> @@ -109,6 +109,12 @@ DPDK_2.0 {
>  	rte_eth_tx_queue_setup;
>  	rte_eth_xstats_get;
>  	rte_eth_xstats_reset;
> +	rte_eth_dev_check_detachable;
> +	rte_eth_dev_get_name_by_port;
> +	rte_eth_dev_get_addr_by_port;
> +	rte_eth_dev_get_port_by_addr;
> +	rte_eth_dev_get_changed_port;
> +	rte_eth_dev_save;
>  
>  	local: *;
>  };
>