[PATCH v3 3/4] ethdev: add mbuf dynfield for incomplete IP reassembly

[Akhil Goyal <gakhil@marvell.com>]

Hardware IP reassembly may be incomplete for multiple reasons like
reassembly timeout reached, duplicate fragments, etc.
To save application cycles to process these packets again, a new
mbuf dynflag is added to show that the mbuf received is not
reassembled properly.

Now if this dynflag is set, application can retrieve corresponding
chain of mbufs using mbuf dynfield set by the PMD. Now, it will be
up to application to either drop those fragments or wait for more time.

Signed-off-by: Akhil Goyal <gakhil@marvell.com>
---
 lib/ethdev/ethdev_driver.h |  8 ++++++++
 lib/ethdev/rte_ethdev.c    | 28 ++++++++++++++++++++++++++++
 lib/ethdev/rte_ethdev.h    | 21 +++++++++++++++++++++
 lib/ethdev/version.map     |  1 +
 4 files changed, 58 insertions(+)

diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index a310001648..7499a4fbf5 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -1689,6 +1689,14 @@ int
 rte_eth_hairpin_queue_peer_unbind(uint16_t cur_port, uint16_t cur_queue,
 				  uint32_t direction);
 
+/**
+ * @internal
+ * Register mbuf dynamic field and flag for IP reassembly incomplete case.
+ */
+__rte_internal
+int
+rte_eth_ip_reass_dynfield_register(int *field_offset, int *flag);
+
 
 /*
  * Legacy ethdev API used internally by drivers.
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 6e9a8cf33b..3c68a951c0 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -6553,6 +6553,34 @@ rte_eth_ip_reassembly_conf_set(uint16_t port_id,
 		       (*dev->dev_ops->ip_reassembly_conf_set)(dev, conf));
 }
 
+int
+rte_eth_ip_reass_dynfield_register(int *field_offset, int *flag_offset)
+{
+	static const struct rte_mbuf_dynfield field_desc = {
+		.name = RTE_ETH_IP_REASS_DYNFIELD_NAME,
+		.size = sizeof(rte_eth_ip_reass_dynfield_t),
+		.align = __alignof__(rte_eth_ip_reass_dynfield_t),
+	};
+	static const struct rte_mbuf_dynflag ip_reass_dynflag = {
+		.name = RTE_ETH_IP_REASS_INCOMPLETE_DYNFLAG_NAME,
+	};
+	int offset;
+
+	offset = rte_mbuf_dynfield_register(&field_desc);
+	if (offset < 0)
+		return -1;
+	if (field_offset != NULL)
+		*field_offset = offset;
+
+	offset = rte_mbuf_dynflag_register(&ip_reass_dynflag);
+	if (offset < 0)
+		return -1;
+	if (flag_offset != NULL)
+		*flag_offset = offset;
+
+	return 0;
+}
+
 RTE_LOG_REGISTER_DEFAULT(rte_eth_dev_logtype, INFO);
 
 RTE_INIT(ethdev_init_telemetry)
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index e3532591f4..e3e6368a1d 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -5264,6 +5264,27 @@ __rte_experimental
 int rte_eth_ip_reassembly_conf_set(uint16_t port_id,
 				   struct rte_eth_ip_reass_params *conf);
 
+#define RTE_ETH_IP_REASS_DYNFIELD_NAME "rte_eth_ip_reass_dynfield"
+#define RTE_ETH_IP_REASS_INCOMPLETE_DYNFLAG_NAME "rte_eth_ip_reass_incomplete_dynflag"
+
+/**
+ * In case of IP reassembly offload failure, ol_flags in mbuf will be set
+ * with RTE_MBUF_F_RX_IPREASSEMBLY_INCOMPLETE and packets will be returned
+ * without alteration. The application can retrieve the attached fragments
+ * using mbuf dynamic field.
+ */
+typedef struct {
+	/**
+	 * Next fragment packet. Application should fetch dynamic field of
+	 * each fragment until a NULL is received and nb_frags is 0.
+	 */
+	struct rte_mbuf *next_frag;
+	/** Time spent(in ms) by HW in waiting for further fragments. */
+	uint16_t time_spent_ms;
+	/** Number of more fragments attached in mbuf dynamic fields. */
+	uint16_t nb_frags;
+} rte_eth_ip_reass_dynfield_t;
+
 
 #include <rte_ethdev_core.h>
 
diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
index ad829dd47e..8b7578471a 100644
--- a/lib/ethdev/version.map
+++ b/lib/ethdev/version.map
@@ -283,6 +283,7 @@ INTERNAL {
 	rte_eth_hairpin_queue_peer_bind;
 	rte_eth_hairpin_queue_peer_unbind;
 	rte_eth_hairpin_queue_peer_update;
+	rte_eth_ip_reass_dynfield_register;
 	rte_eth_representor_id_get;
 	rte_eth_switch_domain_alloc;
 	rte_eth_switch_domain_free;
-- 
2.25.1