[dpdk-dev] [PATCH v2] eventdev: update rx timestamp in mbuf using mbuf dynamic field

[Ganapati Kundapura]

Add support to register timestamp dynamic field in mbuf.

Update the timestamp in mbuf for each packet before enqueuing
to event device if the timestamp is not already set.

Adding the timestamp in Rx adapter avoids additional latency
due to the event device.

Signed-off-by: Ganapati Kundapura <ganapati.kundapura at intel.com>

---
v2:
* Removed rte_ prefix from the internal function

v1:
* Add support to register timestamp dynamic field in mbuf
---
---
 lib/eventdev/rte_event_eth_rx_adapter.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/lib/eventdev/rte_event_eth_rx_adapter.c b/lib/eventdev/rte_event_eth_rx_adapter.c
index f2dc695..fd79b28 100644
--- a/lib/eventdev/rte_event_eth_rx_adapter.c
+++ b/lib/eventdev/rte_event_eth_rx_adapter.c
@@ -17,6 +17,7 @@
 #include <rte_service_component.h>
 #include <rte_thash.h>
 #include <rte_interrupts.h>
+#include <rte_mbuf_dyn.h>
 
 #include "rte_eventdev.h"
 #include "eventdev_pmd.h"
@@ -240,6 +241,17 @@ struct eth_rx_queue_info {
 
 static struct rte_event_eth_rx_adapter **event_eth_rx_adapter;
 
+/* Enable dynamic timestamp field in mbuf */
+uint64_t event_eth_rx_timestamp_dynflag;
+int event_eth_rx_timestamp_dynfield_offset = -1;
+
+static inline rte_mbuf_timestamp_t *
+rxa_timestamp_dynfield(struct rte_mbuf *mbuf)
+{
+	return RTE_MBUF_DYNFIELD(mbuf,
+		event_eth_rx_timestamp_dynfield_offset, rte_mbuf_timestamp_t *);
+}
+
 static inline int
 rxa_validate_id(uint8_t id)
 {
@@ -890,8 +902,18 @@ rxa_buffer_mbufs(struct rte_event_eth_rx_adapter *rx_adapter,
 	int do_rss;
 	uint16_t nb_cb;
 	uint16_t dropped;
+	uint64_t ts, ts_mask;
 
 	if (!eth_rx_queue_info->ena_vector) {
+		ts = m->ol_flags & event_eth_rx_timestamp_dynflag ?
+						0 : rte_get_tsc_cycles();
+
+		/* 0xffff ffff ffff ffff if PKT_RX_TIMESTAMP is set,
+		 * otherwise 0
+		 */
+		ts_mask = (uint64_t)(!(m->ol_flags &
+				       event_eth_rx_timestamp_dynflag)) - 1ULL;
+
 		/* 0xffff ffff if PKT_RX_RSS_HASH is set, otherwise 0 */
 		rss_mask = ~(((m->ol_flags & PKT_RX_RSS_HASH) != 0) - 1);
 		do_rss = !rss_mask && !eth_rx_queue_info->flow_id_mask;
@@ -899,6 +921,9 @@ rxa_buffer_mbufs(struct rte_event_eth_rx_adapter *rx_adapter,
 			struct rte_event *ev;
 
 			m = mbufs[i];
+			*rxa_timestamp_dynfield(m) = ts |
+					(*rxa_timestamp_dynfield(m) & ts_mask);
+
 			ev = &buf->events[new_tail];
 
 			rss = do_rss ? rxa_do_softrss(m, rx_adapter->rss_key_be)
@@ -2238,6 +2263,14 @@ rte_event_eth_rx_adapter_create_ext(uint8_t id, uint8_t dev_id,
 	event_eth_rx_adapter[id] = rx_adapter;
 	if (conf_cb == rxa_default_conf_cb)
 		rx_adapter->default_cb_arg = 1;
+
+	if (rte_mbuf_dyn_rx_timestamp_register(
+			&event_eth_rx_timestamp_dynfield_offset,
+			&event_eth_rx_timestamp_dynflag) != 0) {
+		RTE_EDEV_LOG_ERR("Error registering timestamp field in mbuf\n");
+		return -rte_errno;
+	}
+
 	rte_eventdev_trace_eth_rx_adapter_create(id, dev_id, conf_cb,
 		conf_arg);
 	return 0;
-- 
2.6.4