[dpdk-dev] [PATCH v3 03/11] rawdev: add buffer stream IO support

[Shreyansh Jain <shreyansh.jain@nxp.com>]

Introduce handlers for raw buffer enqueue and dequeue. A raw buffer
is essentially a void object which is transparently passed via the
library onto the driver.

Using a context field as argument, any arbitrary meta information
can be passed by application to the driver/implementation. This can
be any data on which driver needs to define the operation semantics.
For example, passing along a queue identifier can suggest the driver
the queue context to perform I/O on.

Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
---
 lib/librte_rawdev/rte_rawdev.c           | 30 +++++++++++++++++
 lib/librte_rawdev/rte_rawdev.h           | 58 ++++++++++++++++++++++++++++++++
 lib/librte_rawdev/rte_rawdev_pmd.h       | 58 ++++++++++++++++++++++++++++++++
 lib/librte_rawdev/rte_rawdev_version.map |  2 ++
 4 files changed, 148 insertions(+)

diff --git a/lib/librte_rawdev/rte_rawdev.c b/lib/librte_rawdev/rte_rawdev.c
index 08dd982a4..a6d937c34 100644
--- a/lib/librte_rawdev/rte_rawdev.c
+++ b/lib/librte_rawdev/rte_rawdev.c
@@ -203,6 +203,36 @@ rte_rawdev_set_attr(uint16_t dev_id,
 	return (*dev->dev_ops->attr_set)(dev, attr_name, attr_value);
 }
 
+int __rte_experimental
+rte_rawdev_enqueue_buffers(uint16_t dev_id,
+			   struct rte_rawdev_buf **buffers,
+			   unsigned int count,
+			   rte_rawdev_obj_t context)
+{
+	struct rte_rawdev *dev;
+
+	RTE_RAWDEV_VALID_DEVID_OR_ERR_RET(dev_id, -EINVAL);
+	dev = &rte_rawdevs[dev_id];
+
+	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->enqueue_bufs, -ENOTSUP);
+	return (*dev->dev_ops->enqueue_bufs)(dev, buffers, count, context);
+}
+
+int __rte_experimental
+rte_rawdev_dequeue_buffers(uint16_t dev_id,
+			   struct rte_rawdev_buf **buffers,
+			   unsigned int count,
+			   rte_rawdev_obj_t context)
+{
+	struct rte_rawdev *dev;
+
+	RTE_RAWDEV_VALID_DEVID_OR_ERR_RET(dev_id, -EINVAL);
+	dev = &rte_rawdevs[dev_id];
+
+	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dequeue_bufs, -ENOTSUP);
+	return (*dev->dev_ops->dequeue_bufs)(dev, buffers, count, context);
+}
+
 int __rte_experimental
 rte_rawdev_dump(uint16_t dev_id, FILE *f)
 {
diff --git a/lib/librte_rawdev/rte_rawdev.h b/lib/librte_rawdev/rte_rawdev.h
index bfcbe1270..b4f9aee37 100644
--- a/lib/librte_rawdev/rte_rawdev.h
+++ b/lib/librte_rawdev/rte_rawdev.h
@@ -350,6 +350,64 @@ rte_rawdev_set_attr(uint16_t dev_id,
 		    const char *attr_name,
 		    const uint64_t attr_value);
 
+/**
+ * Enqueue a stream of buffers to the device.
+ *
+ * Rather than specifying a queue, this API passes along an opaque object
+ * to the driver implementation. That object can be a queue or any other
+ * contextual information necessary for the device to enqueue buffers.
+ *
+ * @param dev_id
+ *   The identifier of the device to configure.
+ * @param bufs
+ *   Collection of buffers for enqueueing
+ * @param count
+ *   Count of buffers to enqueue
+ * @param context
+ *   Opaque context information.
+ * @return
+ *   >=0 for buffers enqueued
+ *  !0 for failure.
+ *  Whether partial enqueue is failure or success is defined between app
+ *  and driver implementation.
+ */
+int __rte_experimental
+rte_rawdev_enqueue_buffers(uint16_t dev_id,
+			   struct rte_rawdev_buf **buffers,
+			   unsigned int count,
+			   rte_rawdev_obj_t context);
+
+/**
+ * Dequeue a stream of buffers from the device.
+ *
+ * Rather than specifying a queue, this API passes along an opaque object
+ * to the driver implementation. That object can be a queue or any other
+ * contextual information necessary for the device to dequeue buffers.
+ *
+ * Application should have allocated enough space to store `count` response
+ * buffers.
+ * Releasing buffers dequeued is responsibility of the application.
+ *
+ * @param dev_id
+ *   The identifier of the device to configure.
+ * @param bufs
+ *   Collection of buffers dequeued
+ * @param count
+ *   Max buffers expected to be dequeued
+ * @param context
+ *   Opaque context information.
+ * @return
+ *   >=0 for buffers dequeued
+ *  !0 for failure.
+ *  Whether partial enqueue is failure or success is defined between app
+ *  and driver implementation.
+ */
+int __rte_experimental
+rte_rawdev_dequeue_buffers(uint16_t dev_id,
+			   struct rte_rawdev_buf **buffers,
+			   unsigned int count,
+			   rte_rawdev_obj_t context);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_rawdev/rte_rawdev_pmd.h b/lib/librte_rawdev/rte_rawdev_pmd.h
index aa67c4f39..da891dc4d 100644
--- a/lib/librte_rawdev/rte_rawdev_pmd.h
+++ b/lib/librte_rawdev/rte_rawdev_pmd.h
@@ -248,6 +248,58 @@ typedef int (*rawdev_queue_setup_t)(struct rte_rawdev *dev,
 typedef int (*rawdev_queue_release_t)(struct rte_rawdev *dev,
 				      uint16_t queue_id);
 
+/**
+ * Enqueue an array of raw buffers to the device.
+ *
+ * Buffer being used is opaque - it can be obtained from mempool or from
+ * any other source. Interpretation of buffer is responsibility of driver.
+ *
+ * @param dev
+ *   Raw device pointer
+ * @param bufs
+ *   array of buffers
+ * @param count
+ *   number of buffers passed
+ * @context
+ *   an opaque object representing context of the call; for example, an
+ *   application can pass information about the queues on which enqueue needs
+ *   to be done. Or, the enqueue operation might be passed reference to an
+ *   object containing a callback (agreed upon between applicatio and driver).
+ *
+ * @return
+ *   >=0 Count of buffers successfully enqueued (0: no buffers enqueued)
+ *   <0 Error count in case of error
+ */
+typedef int (*rawdev_enqueue_bufs_t)(struct rte_rawdev *dev,
+				     struct rte_rawdev_buf **buffers,
+				     unsigned int count,
+				     rte_rawdev_obj_t context);
+
+/**
+ * Dequeue an array of raw buffers from the device.
+ *
+ * @param dev
+ *   Raw device pointer
+ * @param bufs
+ *   array of buffers
+ * @param count
+ *   Max buffers expected to be dequeued
+ * @context
+ *   an opaque object representing context of the call. Based on this object,
+ *   the application and driver can coordinate for dequeue operation involving
+ *   agreed upon semantics. For example, queue information/id on which Dequeue
+ *   needs to be performed.
+ * @return
+ *   >0, ~0: Count of buffers returned
+ *   <0: Error
+ *   Whether short dequeue is success or failure is decided between app and
+ *   driver.
+ */
+typedef int (*rawdev_dequeue_bufs_t)(struct rte_rawdev *dev,
+				     struct rte_rawdev_buf **buffers,
+				     unsigned int count,
+				     rte_rawdev_obj_t context);
+
 /**
  * Dump internal information
  *
@@ -321,6 +373,12 @@ struct rte_rawdev_ops {
 	/**< Release an raw queue. */
 	rawdev_queue_release_t queue_release;
 
+	/**< Enqueue an array of raw buffers to device. */
+	rawdev_enqueue_bufs_t enqueue_bufs;
+	/**< Dequeue an array of raw buffers from device. */
+	/** TODO: Callback based enqueue and dequeue support */
+	rawdev_dequeue_bufs_t dequeue_bufs;
+
 	/* Dump internal information */
 	rawdev_dump_t dump;
 
diff --git a/lib/librte_rawdev/rte_rawdev_version.map b/lib/librte_rawdev/rte_rawdev_version.map
index d63476e47..bafe2c5de 100644
--- a/lib/librte_rawdev/rte_rawdev_version.map
+++ b/lib/librte_rawdev/rte_rawdev_version.map
@@ -4,6 +4,8 @@ EXPERIMENTAL {
 	rte_rawdev_close;
 	rte_rawdev_configure;
 	rte_rawdev_count;
+	rte_rawdev_dequeue_buffers;
+	rte_rawdev_enqueue_buffers;
 	rte_rawdev_get_attr;
 	rte_rawdev_get_dev_id;
 	rte_rawdev_info_get;
-- 
2.14.1