[dpdk-dev,7/9] pci: add a helper for device name

  eal is a better place than ethdev for naming resources.
Add a helper here, and make use of it in ethdev hotplug code.

Signed-off-by: David Marchand <david.marchand@6wind.com>
---
 lib/librte_eal/common/include/rte_pci.h | 28 ++++++++++++++++++++++++++++
 lib/librte_ether/rte_ethdev.c           | 22 ++--------------------
 2 files changed, 30 insertions(+), 20 deletions(-)
  

On Fri, 29 Jan 2016 15:08:34 +0100
David Marchand <david.marchand@6wind.com> wrote:

> eal is a better place than ethdev for naming resources.
> Add a helper here, and make use of it in ethdev hotplug code.
> 
> Signed-off-by: David Marchand <david.marchand@6wind.com>
> ---
>  lib/librte_eal/common/include/rte_pci.h | 28 ++++++++++++++++++++++++++++
>  lib/librte_ether/rte_ethdev.c           | 22 ++--------------------
>  2 files changed, 30 insertions(+), 20 deletions(-)
> 
> diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
> index 334c12e..9edd5f5 100644
> --- a/lib/librte_eal/common/include/rte_pci.h
> +++ b/lib/librte_eal/common/include/rte_pci.h
> @@ -309,6 +309,34 @@ eal_parse_pci_DomBDF(const char *input, struct rte_pci_addr *dev_addr)
>  }
>  #undef GET_PCIADDR_FIELD
>  
> +/**
> + * Utility function to write a pci device name, this device name can later be
> + * used to retrieve the corresponding rte_pci_addr using above functions.
> + *
> + * @param addr
> + *	The PCI Bus-Device-Function address
> + * @param output
> + *	The output buffer string
> + * @param size
> + *	The output buffer size
> + * @return
> + *  0 on success, negative on error.
> + */
> +static inline int
> +eal_pci_device_name(const struct rte_pci_addr *addr,
> +		    char *output, int size)

"size_t size" (or unsigned int) seems to be better to me.

> +{
> +	int ret;
> +
> +	ret = snprintf(output, size, PCI_PRI_FMT,
> +		       addr->domain, addr->bus,
> +		       addr->devid, addr->function);
> +	if (ret < 0 || ret >= size)
> +		return -1;

The return value is not checked (below). I think, such functions
are usually missing error checking as nobody expects them to fail.
Wouldn't it be better to panic here?

> +
> +	return 0;
> +}
> +
>  /* Compare two PCI device addresses. */
>  /**
>   * Utility function to compare two PCI device addresses.
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index 17e4f4d..5ba7479 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -214,20 +214,6 @@ rte_eth_dev_allocate(const char *name, enum rte_eth_dev_type type)
>  	return eth_dev;
>  }
>  
> -static int
> -rte_eth_dev_create_unique_device_name(char *name, size_t size,
> -		struct rte_pci_device *pci_dev)
> -{
> -	int ret;
> -
> -	ret = snprintf(name, size, "%d:%d.%d",
> -			pci_dev->addr.bus, pci_dev->addr.devid,
> -			pci_dev->addr.function);
> -	if (ret < 0)
> -		return ret;
> -	return 0;
> -}
> -
>  int
>  rte_eth_dev_release_port(struct rte_eth_dev *eth_dev)
>  {
> @@ -251,9 +237,7 @@ rte_eth_dev_pci_probe(struct rte_pci_driver *pci_drv,
>  
>  	eth_drv = (struct eth_driver *)pci_drv;
>  
> -	/* Create unique Ethernet device name using PCI address */
> -	rte_eth_dev_create_unique_device_name(ethdev_name,
> -			sizeof(ethdev_name), pci_dev);
> +	eal_pci_device_name(&pci_dev->addr, ethdev_name, sizeof(ethdev_name));
>  
>  	eth_dev = rte_eth_dev_allocate(ethdev_name, RTE_ETH_DEV_PCI);
>  	if (eth_dev == NULL)
> @@ -304,9 +288,7 @@ rte_eth_dev_pci_remove(struct rte_pci_device *pci_dev)
>  	if (pci_dev == NULL)
>  		return -EINVAL;
>  
> -	/* Create unique Ethernet device name using PCI address */
> -	rte_eth_dev_create_unique_device_name(ethdev_name,
> -			sizeof(ethdev_name), pci_dev);
> +	eal_pci_device_name(&pci_dev->addr, ethdev_name, sizeof(ethdev_name));
>  
>  	eth_dev = rte_eth_dev_allocated(ethdev_name);
>  	if (eth_dev == NULL)
  

On Wed, Feb 10, 2016 at 12:10 PM, Jan Viktorin <viktorin@rehivetech.com> wrote:
> On Fri, 29 Jan 2016 15:08:34 +0100
> David Marchand <david.marchand@6wind.com> wrote:
>
>> eal is a better place than ethdev for naming resources.
>> Add a helper here, and make use of it in ethdev hotplug code.
>>
>> Signed-off-by: David Marchand <david.marchand@6wind.com>
>> ---
>>  lib/librte_eal/common/include/rte_pci.h | 28 ++++++++++++++++++++++++++++
>>  lib/librte_ether/rte_ethdev.c           | 22 ++--------------------
>>  2 files changed, 30 insertions(+), 20 deletions(-)
>>
>> diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
>> index 334c12e..9edd5f5 100644
>> --- a/lib/librte_eal/common/include/rte_pci.h
>> +++ b/lib/librte_eal/common/include/rte_pci.h
>> @@ -309,6 +309,34 @@ eal_parse_pci_DomBDF(const char *input, struct rte_pci_addr *dev_addr)
>>  }
>>  #undef GET_PCIADDR_FIELD
>>
>> +/**
>> + * Utility function to write a pci device name, this device name can later be
>> + * used to retrieve the corresponding rte_pci_addr using above functions.
>> + *
>> + * @param addr
>> + *   The PCI Bus-Device-Function address
>> + * @param output
>> + *   The output buffer string
>> + * @param size
>> + *   The output buffer size
>> + * @return
>> + *  0 on success, negative on error.
>> + */
>> +static inline int
>> +eal_pci_device_name(const struct rte_pci_addr *addr,
>> +                 char *output, int size)
>
> "size_t size" (or unsigned int) seems to be better to me.

Yes.

>
>> +{
>> +     int ret;
>> +
>> +     ret = snprintf(output, size, PCI_PRI_FMT,
>> +                    addr->domain, addr->bus,
>> +                    addr->devid, addr->function);
>> +     if (ret < 0 || ret >= size)
>> +             return -1;
>
> The return value is not checked (below). I think, such functions
> are usually missing error checking as nobody expects them to fail.
> Wouldn't it be better to panic here?

assert or panic, yes.