Re: [dpdk-dev] [PATCH v2 1/6] ethdev: add descriptor status API

[Olivier Matz <olivier.matz@6wind.com>]

Hi Qiming,

On Tue, 21 Mar 2017 08:32:17 +0000, "Yang, Qiming" <qiming.yang@intel.com> wrote:
> Hi, Olivier
> You need to add your new API in lib/librte_ether/rte_ether_version.map and doc/guides/rel_notes/release_17_05.rst

About rte_ether_version.map, I don't think it's needed since
the functions are static inline. Did you noticed any issue?

About release_17_05.rst, you are right, I can add some words about
this new feature.


Thanks,
Olivier


> 
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier Matz
> > Sent: Wednesday, March 8, 2017 12:00 AM
> > To: dev@dpdk.org; thomas.monjalon@6wind.com; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>; Lu, Wenzhuo <wenzhuo.lu@intel.com>;
> > Zhang, Helin <helin.zhang@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>;
> > adrien.mazarguil@6wind.com; nelio.laranjeiro@6wind.com
> > Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; Richardson, Bruce
> > <bruce.richardson@intel.com>; Venkatesan, Venky
> > <venky.venkatesan@intel.com>; arybchenko@solarflare.com
> > Subject: [dpdk-dev] [PATCH v2 1/6] ethdev: add descriptor status API
> > 
> > Introduce a new API to get the status of a descriptor.
> > 
> > For Rx, it is almost similar to rx_descriptor_done API, except it differentiates
> > "used" descriptors (which are hold by the driver and not returned to the
> > hardware).
> > 
> > For Tx, it is a new API.
> > 
> > The descriptor_done() API, and probably the rx_queue_count() API could be
> > replaced by this new API as soon as it is implemented on all PMDs.
> > 
> > Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
> > ---
> >  doc/guides/nics/features/default.ini |   2 +
> >  lib/librte_ether/rte_ethdev.h        | 125
> > +++++++++++++++++++++++++++++++++++
> >  2 files changed, 127 insertions(+)
> > 
> > diff --git a/doc/guides/nics/features/default.ini
> > b/doc/guides/nics/features/default.ini
> > index 9e363ff..0e6a78d 100644
> > --- a/doc/guides/nics/features/default.ini
> > +++ b/doc/guides/nics/features/default.ini
> > @@ -49,6 +49,8 @@ Inner L3 checksum    =
> >  Inner L4 checksum    =
> >  Packet type parsing  =
> >  Timesync             =
> > +Rx Descriptor Status =
> > +Tx Descriptor Status =
> >  Basic stats          =
> >  Extended stats       =
> >  Stats per queue      =
> > diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
> > index 97f3e2d..904ecbe 100644
> > --- a/lib/librte_ether/rte_ethdev.h
> > +++ b/lib/librte_ether/rte_ethdev.h
> > @@ -1179,6 +1179,12 @@ typedef uint32_t
> > (*eth_rx_queue_count_t)(struct rte_eth_dev *dev,  typedef int
> > (*eth_rx_descriptor_done_t)(void *rxq, uint16_t offset);  /**< @internal
> > Check DD bit of specific RX descriptor */
> > 
> > +typedef int (*eth_rx_descriptor_status_t)(void *rxq, uint16_t offset);
> > +/**< @internal Check the status of a Rx descriptor */
> > +
> > +typedef int (*eth_tx_descriptor_status_t)(void *txq, uint16_t offset);
> > +/**< @internal Check the status of a Tx descriptor */
> > +
> >  typedef int (*eth_fw_version_get_t)(struct rte_eth_dev *dev,
> >  				     char *fw_version, size_t fw_size);  /**<
> > @internal Get firmware information of an Ethernet device. */ @@ -1483,6
> > +1489,10 @@ struct eth_dev_ops {
> >  	eth_queue_release_t        rx_queue_release; /**< Release RX queue.
> > */
> >  	eth_rx_queue_count_t       rx_queue_count;/**< Get Rx queue
> > count. */
> >  	eth_rx_descriptor_done_t   rx_descriptor_done; /**< Check rxd DD
> > bit. */
> > +	eth_rx_descriptor_status_t rx_descriptor_status;
> > +	/**< Check the status of a Rx descriptor. */
> > +	eth_tx_descriptor_status_t tx_descriptor_status;
> > +	/**< Check the status of a Tx descriptor. */
> >  	eth_rx_enable_intr_t       rx_queue_intr_enable;  /**< Enable Rx
> > queue interrupt. */
> >  	eth_rx_disable_intr_t      rx_queue_intr_disable; /**< Disable Rx
> > queue interrupt. */
> >  	eth_tx_queue_setup_t       tx_queue_setup;/**< Set up device TX
> > queue. */
> > @@ -2768,6 +2778,121 @@ rte_eth_rx_descriptor_done(uint8_t port_id,
> > uint16_t queue_id, uint16_t offset)
> >  		dev->data->rx_queues[queue_id], offset);  }
> > 
> > +#define RTE_ETH_RX_DESC_AVAIL    0 /**< Desc available for hw. */
> > +#define RTE_ETH_RX_DESC_DONE     1 /**< Desc done, filled by hw. */
> > +#define RTE_ETH_RX_DESC_UNAVAIL  2 /**< Desc used by driver or hw. */
> > +
> > +/**
> > + * Check the status of a Rx descriptor in the queue
> > + *
> > + * It should be called in a similar context than the Rx function:
> > + * - on a dataplane core
> > + * - not concurrently on the same queue
> > + *
> > + * Since it's a dataplane function, no check is performed on port_id
> > +and
> > + * queue_id. The caller must therefore ensure that the port is enabled
> > + * and the queue is configured and running.
> > + *
> > + * Note: accessing to a random descriptor in the ring may trigger cache
> > + * misses and have a performance impact.
> > + *
> > + * @param port_id
> > + *  A valid port identifier of the Ethernet device which.
> > + * @param queue_id
> > + *  A valid Rx queue identifier on this port.
> > + * @param offset
> > + *  The offset of the descriptor starting from tail (0 is the next
> > + *  packet to be received by the driver).
> > + *
> > + * @return
> > + *  - (RTE_ETH_RX_DESC_AVAIL): Descriptor is available for the hardware to
> > + *    receive a packet.
> > + *  - (RTE_ETH_RX_DESC_DONE): Descriptor is done, it is filled by hw, but
> > + *    not yet processed by the driver (i.e. in the receive queue).
> > + *  - (RTE_ETH_RX_DESC_UNAVAIL): Descriptor is unavailable, either hold by
> > + *    the driver and not yet returned to hw, or reserved by the hw.
> > + *  - (-EINVAL) bad descriptor offset.
> > + *  - (-ENOTSUP) if the device does not support this function.
> > + *  - (-ENODEV) bad port or queue (only if compiled with debug).
> > + */
> > +static inline int
> > +rte_eth_rx_descriptor_status(uint8_t port_id, uint16_t queue_id,
> > +	uint16_t offset)
> > +{
> > +	struct rte_eth_dev *dev;
> > +	void *rxq;
> > +
> > +#ifdef RTE_LIBRTE_ETHDEV_DEBUG
> > +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV); #endif
> > +	dev = &rte_eth_devices[port_id];
> > +#ifdef RTE_LIBRTE_ETHDEV_DEBUG
> > +	if (queue_id >= dev->data->nb_rx_queues)
> > +		return -ENODEV;
> > +#endif
> > +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops-  
> > >rx_descriptor_status, -ENOTSUP);  
> > +	rxq = dev->data->rx_queues[queue_id];
> > +
> > +	return (*dev->dev_ops->rx_descriptor_status)(rxq, offset); }
> > +
> > +#define RTE_ETH_TX_DESC_FULL    0 /**< Desc filled for hw, waiting xmit.
> > */
> > +#define RTE_ETH_TX_DESC_DONE    1 /**< Desc done, packet is
> > transmitted. */
> > +#define RTE_ETH_TX_DESC_UNAVAIL 2 /**< Desc used by driver or hw. */
> > +
> > +/**
> > + * Check the status of a Tx descriptor in the queue.
> > + *
> > + * It should be called in a similar context than the Tx function:
> > + * - on a dataplane core
> > + * - not concurrently on the same queue
> > + *
> > + * Since it's a dataplane function, no check is performed on port_id
> > +and
> > + * queue_id. The caller must therefore ensure that the port is enabled
> > + * and the queue is configured and running.
> > + *
> > + * Note: accessing to a random descriptor in the ring may trigger cache
> > + * misses and have a performance impact.
> > + *
> > + * @param port_id
> > + *  A valid port identifier of the Ethernet device which.
> > + * @param queue_id
> > + *  A valid Tx queue identifier on this port.
> > + * @param offset
> > + *  The offset of the descriptor starting from tail (0 is the place
> > +where
> > + *  the next packet will be send).
> > + *
> > + * @return
> > + *  - (RTE_ETH_TX_DESC_FULL) Descriptor is being processed by the hw, i.e.
> > + *    in the transmit queue.
> > + *  - (RTE_ETH_TX_DESC_DONE) Hardware is done with this descriptor, it
> > can
> > + *    be reused by the driver.
> > + *  - (RTE_ETH_TX_DESC_UNAVAIL): Descriptor is unavailable, reserved by
> > the
> > + *    driver or the hardware.
> > + *  - (-EINVAL) bad descriptor offset.
> > + *  - (-ENOTSUP) if the device does not support this function.
> > + *  - (-ENODEV) bad port or queue (only if compiled with debug).
> > + */
> > +static inline int rte_eth_tx_descriptor_status(uint8_t port_id,
> > +	uint16_t queue_id, uint16_t offset)
> > +{
> > +	struct rte_eth_dev *dev;
> > +	void *txq;
> > +
> > +#ifdef RTE_LIBRTE_ETHDEV_DEBUG
> > +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV); #endif
> > +	dev = &rte_eth_devices[port_id];
> > +#ifdef RTE_LIBRTE_ETHDEV_DEBUG
> > +	if (queue_id >= dev->data->nb_tx_queues)
> > +		return -ENODEV;
> > +#endif
> > +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops-  
> > >tx_descriptor_status, -ENOTSUP);  
> > +	txq = dev->data->tx_queues[queue_id];
> > +
> > +	return (*dev->dev_ops->tx_descriptor_status)(txq, offset); }
> > +
> >  /**
> >   * Send a burst of output packets on a transmit queue of an Ethernet device.
> >   *
> > --
> > 2.8.1  
>