cryptodev: support session private data setting

The application may want to store private data along with the
rte_cryptodev that is transparent to the rte_cryptodev layer.
For e.g., If an eventdev based application is submitting a
rte_cryptodev_sym_session operation and wants to indicate event
information required to construct a new event that will be
enqueued to eventdev after completion of the rte_cryptodev_sym_session
operation. This patch provides a mechanism for the application
to associate this information with the rte_cryptodev_sym_session session.
The application can set the private data using
rte_cryptodev_sym_session_set_private_data() and retrieve it using
rte_cryptodev_sym_session_get_private_data().

Signed-off-by: Abhinandan Gujjar <abhinandan.gujjar@intel.com>
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
Acked-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>

lib/librte_cryptodev/rte_cryptodev.c

@@ -1099,8 +1099,10 @@ rte_cryptodev_sym_session_create(struct rte_mempool *mp)
 		return NULL;
 	}
 
-	/* Clear device session pointer */
-	memset(sess, 0, (sizeof(void *) * nb_drivers));
+	/* Clear device session pointer.
+	 * Include the flag indicating presence of private data
+	 */
+	memset(sess, 0, (sizeof(void *) * nb_drivers) + sizeof(uint8_t));
 
 	return sess;
 }
@@ -1204,9 +1206,10 @@ rte_cryptodev_get_header_session_size(void)
 {
 	/*
 	 * Header contains pointers to the private data
-	 * of all registered drivers
+	 * of all registered drivers, and a flag which
+	 * indicates presence of private data
 	 */
-	return (sizeof(void *) * nb_drivers);
+	return ((sizeof(void *) * nb_drivers) + sizeof(uint8_t));
 }
 
 unsigned int
@@ -1238,6 +1241,38 @@ rte_cryptodev_get_private_session_size(uint8_t dev_id)
 
 }
 
+int __rte_experimental
+rte_cryptodev_sym_session_set_private_data(
+					struct rte_cryptodev_sym_session *sess,
+					void *data,
+					uint16_t size)
+{
+	uint16_t off_set = sizeof(void *) * nb_drivers;
+	uint8_t *private_data_present = (uint8_t *)sess + off_set;
+
+	if (sess == NULL)
+		return -EINVAL;
+
+	*private_data_present = 1;
+	off_set += sizeof(uint8_t);
+	rte_memcpy((uint8_t *)sess + off_set, data, size);
+	return 0;
+}
+
+void * __rte_experimental
+rte_cryptodev_sym_session_get_private_data(
+					struct rte_cryptodev_sym_session *sess)
+{
+	uint16_t off_set = sizeof(void *) * nb_drivers;
+	uint8_t *private_data_present = (uint8_t *)sess + off_set;
+
+	if (sess == NULL || !*private_data_present)
+		return NULL;
+
+	off_set += sizeof(uint8_t);
+	return (uint8_t *)sess + off_set;
+}
+
 /** Initialise rte_crypto_op mempool element */
 static void
 rte_crypto_op_init(struct rte_mempool *mempool,

lib/librte_cryptodev/rte_cryptodev.h

@@ -1037,6 +1037,38 @@ int rte_cryptodev_driver_id_get(const char *name);
  */
 const char *rte_cryptodev_driver_name_get(uint8_t driver_id);
 
+/**
+ * Set private data for a session.
+ *
+ * @param	sess		Session pointer allocated by
+ *				*rte_cryptodev_sym_session_create*.
+ * @param	data		Pointer to the private data.
+ * @param	size		Size of the private data.
+ *
+ * @return
+ *  - On success, zero.
+ *  - On failure, a negative value.
+ */
+int __rte_experimental
+rte_cryptodev_sym_session_set_private_data(
+					struct rte_cryptodev_sym_session *sess,
+					void *data,
+					uint16_t size);
+
+/**
+ * Get private data of a session.
+ *
+ * @param	sess		Session pointer allocated by
+ *				*rte_cryptodev_sym_session_create*.
+ *
+ * @return
+ *  - On success return pointer to private data.
+ *  - On failure returns NULL.
+ */
+void * __rte_experimental
+rte_cryptodev_sym_session_get_private_data(
+					struct rte_cryptodev_sym_session *sess);
+
 #ifdef __cplusplus
 }
 #endif

lib/librte_cryptodev/rte_cryptodev_version.map

@@ -85,3 +85,10 @@ DPDK_17.11 {
 	rte_cryptodev_pmd_parse_input_args;
 
 } DPDK_17.08;
+
+EXPERIMENTAL {
+        global:
+
+	rte_cryptodev_sym_session_get_private_data;
+	rte_cryptodev_sym_session_set_private_data;
+} DPDK_17.11;