[dpdk-dev] [PATCH v3 07/28] ethdev: Add functions to know which port is attached or detached

[Qiu, Michael]

On 12/11/2014 11:12 AM, Tetsuya Mukawa wrote:
> Hi Michael,
>
> (2014/12/09 23:39), Qiu, Michael wrote:
>> On 2014/12/9 14:32, Tetsuya Mukawa wrote:
>>> The patch adds rte_eth_dev_save() and rte_eth_dev_get_changed_port().
>>> rte_eth_dev_save() is used for saving current rte_eth_dev structures.
>>> rte_eth_dev_get_changed_port() receives the rte_eth_dev structures, then
>>> compare these with current values to know which port is actually
>>> attached or detached.
>>>
>>> Signed-off-by: Tetsuya Mukawa <mukawa at igel.co.jp>
>>> ---
>>>  lib/librte_ether/rte_ethdev.c | 21 +++++++++++++++++++++
>>>  lib/librte_ether/rte_ethdev.h | 21 +++++++++++++++++++++
>>>  2 files changed, 42 insertions(+)
>>>
>>> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
>>> index 51697e1..6a3700e 100644
>>> --- a/lib/librte_ether/rte_ethdev.c
>>> +++ b/lib/librte_ether/rte_ethdev.c
>>> @@ -416,6 +416,27 @@ rte_eth_dev_count(void)
>>>  	return (nb_ports);
>>>  }
>>>  
>>> +void
>>> +rte_eth_dev_save(struct rte_eth_dev *devs)
>>> +{
>>> +	if (devs == NULL)
>>> +		return;
>>> +
>>> +	/* save current rte_eth_devices */
>>> +	memcpy(devs, rte_eth_devices,
>>> +			sizeof(struct rte_eth_dev) * RTE_MAX_ETHPORTS);
>>> +}
>>> +
>>> +int
>>> +rte_eth_dev_get_changed_port(struct rte_eth_dev *devs, uint8_t *port_id)
>>> +{
>>> +	/* 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;
>> Can we have more than one port changed?
>> If so, your logic should do little modify.
> The port hotplug APIs cannot attach or detach multiple port at the same
> time.

What I mean is can we first detach one port, then another? If it legal
to do this, here will always return the port with the min port_id.

Thanks,
Michael
> And the APIs are not thread safe. DPDK application should have lock
> properly if multiple threads call the APIs.
> Because of this, we don't need to take care of such a case.
>
>> Thanks,
>> Michael
>>> +	return 1;
>>> +}
>>> +
>>>  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 b329e11..03c8850 100644
>>> --- a/lib/librte_ether/rte_ethdev.h
>>> +++ b/lib/librte_ether/rte_ethdev.h
>>> @@ -1642,6 +1642,27 @@ 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
>>> + */
>>> +extern void rte_eth_dev_save(struct rte_eth_dev *devs);
>>> +
>>> +/**
>>> + * 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 dummy drivers primarily, e.g. ring-based
>>>   * driver.
>>>   * Allocates a new ethdev slot for an ethernet device and returns the pointer
>
>