[dpdk-dev] [PATCH v2 1/4] eventdev: add eth Tx adapter APIs

[Nikhil Rao]

The ethernet Tx adapter abstracts the transmit stage of an
event driven packet processing application. The transmit
stage may be implemented with eventdev PMD support or use a
rte_service function implemented in the adapter. These APIs
provide a common configuration and control interface and
an transmit API for the eventdev PMD implementation.

The transmit port is specified using mbuf::port. The transmit
queue is specified using the rte_event_eth_tx_adapter_txq_set()
function.

Signed-off-by: Nikhil Rao <nikhil.rao at intel.com>
---

RFC -> V1:
=========

* Move port and tx queue id to mbuf from mbuf private area. (Jerin Jacob)

* Support for PMD transmit function. (Jerin Jacob)

* mbuf change has been replaced with rte_event_eth_tx_adapter_txq_set(). 
The goal is to align with the mbuf change for a qid field. 
(http://mails.dpdk.org/archives/dev/2018-February/090651.html). Once the mbuf
change is available, the function can be replaced with a macro with no impact
to applications.

* Various cleanups (Jerin Jacob)

V2:
==

* Add ethdev port to rte_event_eth_tx_adapter_caps_get() (Pavan Nikhilesh)

* Remove struct rte_event_eth_tx_adapter from rte_event_eth_tx_adapter.h
							(Jerin Jacob)

* Move rte_event_eth_tx_adapter_txq_set() to static inline,
  also add rte_event_eth_tx_adapter_txq_get().

* Remove adapter id from rte_event_eth_tx_adapter_enqueue(), also update
  eventdev PMD callback (Jerin Jacob)

* Fix doxy-api-index.md (Jerin Jacob)

* Rename eventdev_eth_tx_adapter_init_t to eventdev_eth_tx_adapter_create_t,
  Invoke it from rte_event_eth_tx_adapter_create()/create_ext()

* Remove the eventdev_eth_tx_adapter_event_port_get PMD callback, the event
  port is used by the application only in the case of the service function
  implementation.

* Add support for dynamic device (created after the adapter) in the service
  function implementation.

 MAINTAINERS                                    |   5 +
 doc/api/doxy-api-index.md                      |   1 +
 lib/librte_eventdev/rte_event_eth_tx_adapter.h | 479 +++++++++++++++++++++++++
 lib/librte_mbuf/rte_mbuf.h                     |   4 +-
 4 files changed, 488 insertions(+), 1 deletion(-)
 create mode 100644 lib/librte_eventdev/rte_event_eth_tx_adapter.h

Note: 

This patch generates a checkpatch error with the current version
of check-symbol-change.sh. The fix has been posted @
http://mails.dpdk.org/archives/dev/2018-August/109781.html

 lib/librte_eventdev/rte_event_eth_tx_adapter.h | 479 +++++++++++++++++++++++++
 lib/librte_mbuf/rte_mbuf.h                     |   4 +-
 MAINTAINERS                                    |   5 +
 doc/api/doxy-api-index.md                      |   1 +
 4 files changed, 488 insertions(+), 1 deletion(-)
 create mode 100644 lib/librte_eventdev/rte_event_eth_tx_adapter.h

diff --git a/lib/librte_eventdev/rte_event_eth_tx_adapter.h b/lib/librte_eventdev/rte_event_eth_tx_adapter.h
new file mode 100644
index 0000000..837ecbb
--- /dev/null
+++ b/lib/librte_eventdev/rte_event_eth_tx_adapter.h
@@ -0,0 +1,479 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Intel Corporation.
+ */
+
+#ifndef _RTE_EVENT_ETH_TX_ADAPTER_
+#define _RTE_EVENT_ETH_TX_ADAPTER_
+
+/**
+ * @file
+ *
+ * RTE Event Ethernet Tx Adapter
+ *
+ * The event ethernet Tx adapter provides configuration and data path APIs
+ * for the ethernet transmit stage of an event driven packet processing
+ * application. These APIs abstract the implementation of the transmit stage
+ * and allow the application to use eventdev PMD support or a common
+ * implementation.
+ *
+ * In the common implementation, the application enqueues mbufs to the adapter
+ * which runs as a rte_service function. The service function dequeues events
+ * from its event port and transmits the mbufs referenced by these events.
+ *
+ * The ethernet Tx event adapter APIs are:
+ *
+ *  - rte_event_eth_tx_adapter_create()
+ *  - rte_event_eth_tx_adapter_create_ext()
+ *  - rte_event_eth_tx_adapter_free()
+ *  - rte_event_eth_tx_adapter_start()
+ *  - rte_event_eth_tx_adapter_stop()
+ *  - rte_event_eth_tx_adapter_queue_add()
+ *  - rte_event_eth_tx_adapter_queue_del()
+ *  - rte_event_eth_tx_adapter_stats_get()
+ *  - rte_event_eth_tx_adapter_stats_reset()
+ *  - rte_event_eth_tx_adapter_enqueue()
+ *  - rte_event_eth_tx_adapter_event_port_get()
+ *  - rte_event_eth_tx_adapter_service_id_get()
+ *
+ * The application creates the adapter using
+ * rte_event_eth_tx_adapter_create() or rte_event_eth_tx_adapter_create_ext().
+ *
+ * The adapter will use the common implementation when the eventdev PMD
+ * does not have the RTE_EVENT_ETH_TX_ADAPTER_CAP_INTERNAL_PORT capability.
+ * The common implementation uses an event port that is created using the port
+ * configuration parameter passed to rte_event_eth_tx_adapter_create(). The
+ * application can get the port identifier using
+ * rte_event_eth_tx_adapter_event_port_get() and must link an event queue to
+ * this port.
+ *
+ * If the eventdev PMD has the RTE_EVENT_ETH_TX_ADAPTER_CAP_INTERNAL_PORT
+ * flags set, Tx adapter events should be enqueued using the
+ * rte_event_eth_tx_adapter_enqueue() function, else the application should
+ * use rte_event_enqueue_burst().
+ *
+ * Transmit queues can be added and deleted from the adapter using
+ * rte_event_eth_tx_adapter_queue_add()/del() APIs respectively.
+ *
+ * The application can start and stop the adapter using the
+ * rte_event_eth_tx_adapter_start/stop() calls.
+ *
+ * The common adapter implementation uses an EAL service function as described
+ * before and its execution is controlled using the rte_service APIs. The
+ * rte_event_eth_tx_adapter_service_id_get()
+ * function can be used to retrieve the adapter's service function ID.
+ *
+ * The ethernet port and transmit queue index to transmit the mbuf on are
+ * specified using the mbuf port and the struct rte_event_tx_adapter_mbuf_queue
+ * (overlaid on mbuf::hash). The application should use the
+ * rte_event_eth_tx_adapter_txq_set() and rte_event_eth_tx_adapter_txq_get()
+ * functions to access the transmit queue index since it is expected that the
+ * transmit queue will be eventually defined within struct rte_mbuf and using
+ * these macros will help with minimizing application impact due to
+ * a change in how the transmit queue index is specified.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+
+#include <rte_mbuf.h>
+
+#include "rte_eventdev.h"
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * A structure used to specify the Tx queue to the ethernet Tx adapter.
+ */
+struct rte_event_tx_adapter_mbuf_queue {
+	uint32_t resvd1;
+	/**< Reserved */
+	uint16_t resvd2;
+	/**< Reserved */
+	uint16_t txq_id;
+	/**< Transmit queue index */
+};
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Adapter configuration structure
+ *
+ * @see rte_event_eth_tx_adapter_create_ext
+ * @see rte_event_eth_tx_adapter_conf_cb
+ */
+struct rte_event_eth_tx_adapter_conf {
+	uint8_t event_port_id;
+	/**< Event port identifier, the adapter service function dequeues mbuf
+	 * events from this port.
+	 * @see RTE_EVENT_ETH_RX_ADAPTER_CAP_INTERNAL_PORT
+	 */
+	uint32_t max_nb_tx;
+	/**< The adapter can return early if it has processed at least
+	 * max_nb_tx mbufs. This isn't treated as a requirement; batching may
+	 * cause the adapter to process more than max_nb_tx mbufs.
+	 */
+};
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Function type used for adapter configuration callback. The callback is
+ * used to fill in members of the struct rte_event_eth_tx_adapter_conf, this
+ * callback is invoked when creating a RTE service function based
+ * adapter implementation.
+ *
+ * @param id
+ *  Adapter identifier.
+ * @param dev_id
+ *  Event device identifier.
+ * @param [out] conf
+ *  Structure that needs to be populated by this callback.
+ * @param arg
+ *  Argument to the callback. This is the same as the conf_arg passed to the
+ *  rte_event_eth_tx_adapter_create_ext().
+ *
+ * @return
+ *   - 0: Success
+ *   - <0: Error code on failure
+ */
+typedef int (*rte_event_eth_tx_adapter_conf_cb) (uint8_t id, uint8_t dev_id,
+				struct rte_event_eth_tx_adapter_conf *conf,
+				void *arg);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * A structure used to retrieve statistics for an ethernet Tx adapter instance.
+ */
+struct rte_event_eth_tx_adapter_stats {
+	uint64_t tx_retry;
+	/**< Number of transmit retries */
+	uint64_t tx_packets;
+	/**< Number of packets transmitted */
+	uint64_t tx_dropped;
+	/**< Number of packets dropped */
+};
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Create a new ethernet Tx adapter with the specified identifier.
+ *
+ * @param id
+ *  The identifier of the ethernet Tx adapter.
+ * @param dev_id
+ *  The event device identifier.
+ * @param port_config
+ *  Event port configuration, the adapter uses this configuration to
+ *  create an event port if needed.
+ * @return
+ *   - 0: Success
+ *   - <0: Error code on failure
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_create(uint8_t id, uint8_t dev_id,
+				struct rte_event_port_conf *port_config);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Create a new ethernet Tx adapter with the specified identifier.
+ *
+ * @param id
+ *  The identifier of the ethernet Tx adapter.
+ * @param dev_id
+ *  The event device identifier.
+ * @param conf_cb
+ *  Callback function that initializes members of the
+ *  struct rte_event_eth_tx_adapter_conf struct passed into
+ *  it.
+ * @param conf_arg
+ *  Argument that is passed to the conf_cb function.
+ * @return
+ *   - 0: Success
+ *   - <0: Error code on failure
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_create_ext(uint8_t id, uint8_t dev_id,
+				rte_event_eth_tx_adapter_conf_cb conf_cb,
+				void *conf_arg);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Free an ethernet Tx adapter
+ *
+ * @param id
+ *  Adapter identifier.
+ * @return
+ *   - 0: Success
+ *   - <0: Error code on failure, If the adapter still has Tx queues
+ *      added to it, the function returns -EBUSY.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_free(uint8_t id);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Start ethernet Tx adapter
+ *
+ * @param id
+ *  Adapter identifier.
+ * @return
+ *  - 0: Success, Adapter started correctly.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_start(uint8_t id);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Stop ethernet Tx adapter
+ *
+ * @param id
+ *  Adapter identifier.
+ * @return
+ *  - 0: Success.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_stop(uint8_t id);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Add a Tx queue to the adapter.
+ * A queue value of -1 is used to indicate all
+ * queues within the device.
+ *
+ * @param id
+ *  Adapter identifier.
+ * @param eth_dev_id
+ *  Ethernet Port Identifier.
+ * @param queue
+ *  Tx queue index.
+ * @return
+ *  - 0: Success, Queues added successfully.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_queue_add(uint8_t id,
+				uint16_t eth_dev_id,
+				int32_t queue);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Delete a Tx queue from the adapter.
+ * A queue value of -1 is used to indicate all
+ * queues within the device, that have been added to this
+ * adapter.
+ *
+ * @param id
+ *  Adapter identifier.
+ * @param eth_dev_id
+ *  Ethernet Port Identifier.
+ * @param queue
+ *  Tx queue index.
+ * @return
+ *  - 0: Success, Queues deleted successfully.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_queue_del(uint8_t id,
+				uint16_t eth_dev_id,
+				int32_t queue);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Set Tx queue in the mbuf. This queue is used by the  adapter
+ * to transmit the mbuf.
+ *
+ * @param pkt
+ *  Pointer to the mbuf.
+ * @param queue
+ *  Tx queue index.
+ */
+static __rte_always_inline void __rte_experimental
+rte_event_eth_tx_adapter_txq_set(struct rte_mbuf *pkt, uint16_t queue)
+{
+	struct rte_event_tx_adapter_mbuf_queue *mbuf_queue =
+		(struct rte_event_tx_adapter_mbuf_queue *)(&pkt->hash);
+	mbuf_queue->txq_id = queue;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Retrieve Tx queue from the mbuf.
+ *
+ * @param pkt
+ *  Pointer to the mbuf.
+ * @return
+ *  Tx queue identifier.
+ *
+ * @see rte_event_eth_tx_adapter_txq_set()
+ */
+static __rte_always_inline uint16_t __rte_experimental
+rte_event_eth_tx_adapter_txq_get(struct rte_mbuf *pkt)
+{
+	struct rte_event_tx_adapter_mbuf_queue *mbuf_queue =
+		(struct rte_event_tx_adapter_mbuf_queue *)(&pkt->hash);
+	return mbuf_queue->txq_id;
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Retrieve the adapter event port. The adapter creates an event port if
+ * the RTE_EVENT_ETH_TX_ADAPTER_CAP_INTERNAL_PORT is not set in the
+ * ethernet Tx capabilities of the event device.
+ *
+ * @param id
+ *  Adapter Identifier.
+ * @param[out] event_port_id
+ *  Event port pointer.
+ * @return
+ *   - 0: Success.
+ *   - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_event_port_get(uint8_t id, uint8_t *event_port_id);
+
+/**
+ * Enqueue a burst of events objects or an event object supplied in *rte_event*
+ * structure on an  event device designated by its *dev_id* through the event
+ * port specified by *port_id*. This function is supported if the eventdev PMD
+ * has the RTE_EVENT_ETH_TX_ADAPTER_CAP_INTERNAL_PORT capability flag set.
+ *
+ * The *nb_events* parameter is the number of event objects to enqueue which are
+ * supplied in the *ev* array of *rte_event* structure.
+ *
+ * The rte_event_eth_tx_adapter_enqueue() function returns the number of
+ * events objects it actually enqueued. A return value equal to *nb_events*
+ * means that all event objects have been enqueued.
+ *
+ * @param dev_id
+ *  The identifier of the device.
+ * @param port_id
+ *  The identifier of the event port.
+ * @param ev
+ *  Points to an array of *nb_events* objects of type *rte_event* structure
+ *  which contain the event object enqueue operations to be processed.
+ * @param nb_events
+ *  The number of event objects to enqueue, typically number of
+ *  rte_event_port_enqueue_depth() available for this port.
+ *
+ * @return
+ *   The number of event objects actually enqueued on the event device. The
+ *   return value can be less than the value of the *nb_events* parameter when
+ *   the event devices queue is full or if invalid parameters are specified in a
+ *   *rte_event*. If the return value is less than *nb_events*, the remaining
+ *   events at the end of ev[] are not consumed and the caller has to take care
+ *   of them, and rte_errno is set accordingly. Possible errno values include:
+ *   - -EINVAL  The port ID is invalid, device ID is invalid, an event's queue
+ *              ID is invalid, or an event's sched type doesn't match the
+ *              capabilities of the destination queue.
+ *   - -ENOSPC  The event port was backpressured and unable to enqueue
+ *              one or more events. This error code is only applicable to
+ *              closed systems.
+ */
+static inline uint16_t __rte_experimental
+rte_event_eth_tx_adapter_enqueue(uint8_t dev_id,
+				uint8_t port_id,
+				struct rte_event ev[],
+				uint16_t nb_events)
+{
+	const struct rte_eventdev *dev = &rte_eventdevs[dev_id];
+
+#ifdef RTE_LIBRTE_EVENTDEV_DEBUG
+	if (dev_id >= RTE_EVENT_MAX_DEVS ||
+		!rte_eventdevs[dev_id].attached) {
+		rte_errno = -EINVAL;
+		return 0;
+	}
+
+	if (port_id >= dev->data->nb_ports) {
+		rte_errno = -EINVAL;
+		return 0;
+	}
+#endif
+	return dev->txa_enqueue(dev->data->ports[port_id], ev, nb_events);
+}
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Retrieve statistics for an adapter
+ *
+ * @param id
+ *  Adapter identifier.
+ * @param [out] stats
+ *  A pointer to structure used to retrieve statistics for an adapter.
+ * @return
+ *  - 0: Success, statistics retrieved successfully.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_stats_get(uint8_t id,
+				struct rte_event_eth_tx_adapter_stats *stats);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Reset statistics for an adapter.
+ *
+ * @param id
+ *  Adapter identifier.
+ * @return
+ *  - 0: Success, statistics reset successfully.
+ *  - <0: Error code on failure.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_stats_reset(uint8_t id);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Retrieve the service ID of an adapter. If the adapter doesn't use
+ * a rte_service function, this function returns -ESRCH.
+ *
+ * @param id
+ *  Adapter identifier.
+ * @param [out] service_id
+ *  A pointer to a uint32_t, to be filled in with the service id.
+ * @return
+ *  - 0: Success
+ *  - <0: Error code on failure, if the adapter doesn't use a rte_service
+ * function, this function returns -ESRCH.
+ */
+int __rte_experimental
+rte_event_eth_tx_adapter_service_id_get(uint8_t id, uint32_t *service_id);
+
+#ifdef __cplusplus
+}
+#endif
+#endif	/* _RTE_EVENT_ETH_TX_ADAPTER_ */
diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 00793ed..7d1ed18 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -464,7 +464,9 @@ struct rte_mbuf {
 	};
 	uint16_t nb_segs;         /**< Number of segments. */
 
-	/** Input port (16 bits to support more than 256 virtual ports). */
+	/** Input port (16 bits to support more than 256 virtual ports).
+	 * The event eth Tx adapter uses this field to specify the output port.
+	 */
 	uint16_t port;
 
 	uint64_t ol_flags;        /**< Offload features. */
diff --git a/MAINTAINERS b/MAINTAINERS
index 227e32c..13f378a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -391,6 +391,11 @@ F: lib/librte_eventdev/*crypto_adapter*
 F: test/test/test_event_crypto_adapter.c
 F: doc/guides/prog_guide/event_crypto_adapter.rst
 
+Eventdev Ethdev Tx Adapter API - EXPERIMENTAL
+M: Nikhil Rao <nikhil.rao at intel.com>
+T: git://dpdk.org/next/dpdk-next-eventdev
+F: lib/librte_eventdev/*eth_tx_adapter*
+
 Raw device API - EXPERIMENTAL
 M: Shreyansh Jain <shreyansh.jain at nxp.com>
 M: Hemant Agrawal <hemant.agrawal at nxp.com>
diff --git a/doc/api/doxy-api-index.md b/doc/api/doxy-api-index.md
index 9265907..911a902 100644
--- a/doc/api/doxy-api-index.md
+++ b/doc/api/doxy-api-index.md
@@ -24,6 +24,7 @@ The public API headers are grouped by topics:
   [event_eth_rx_adapter]   (@ref rte_event_eth_rx_adapter.h),
   [event_timer_adapter]    (@ref rte_event_timer_adapter.h),
   [event_crypto_adapter]   (@ref rte_event_crypto_adapter.h),
+  [event_eth_tx_adapter]   (@ref rte_event_eth_tx_adapter.h),
   [rawdev]             (@ref rte_rawdev.h),
   [metrics]            (@ref rte_metrics.h),
   [bitrate]            (@ref rte_bitrate.h),
-- 
1.8.3.1