[PATCH v1 1/2] net/iavf: remove PHC polling from Rx datapath

[Soumyadeep Hore]

Remove periodic PHC read/update checks from scalar and vector flex
RX paths, keeping timestamp conversion based on queue PHC state.

This avoids hot-path PHC polling overhead and preserves the latency
fix for RX timestamp-enabled traffic.

Signed-off-by: Soumyadeep Hore <soumyadeep.hore at intel.com>
---
 drivers/net/intel/iavf/iavf_rxtx.c            | 34 -------------------
 drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c   | 16 ++-------
 drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c | 16 ++-------
 3 files changed, 4 insertions(+), 62 deletions(-)

diff --git a/drivers/net/intel/iavf/iavf_rxtx.c b/drivers/net/intel/iavf/iavf_rxtx.c
index e621d4bf47..76615f39e8 100644
--- a/drivers/net/intel/iavf/iavf_rxtx.c
+++ b/drivers/net/intel/iavf/iavf_rxtx.c
@@ -1507,16 +1507,6 @@ iavf_recv_pkts_flex_rxd(void *rx_queue,
 	rx_ring = rxq->rx_flex_ring;
 	ptype_tbl = rxq->iavf_vsi->adapter->ptype_tbl;
 
-	if (rxq->offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP) {
-		uint64_t sw_cur_time = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
-
-		if (sw_cur_time - rxq->hw_time_update > 4) {
-			if (iavf_get_phc_time(rxq))
-				PMD_DRV_LOG(ERR, "get physical time failed");
-			rxq->hw_time_update = sw_cur_time;
-		}
-	}
-
 	while (nb_rx < nb_pkts) {
 		rxdp = &rx_ring[rx_id];
 		rx_stat_err0 = rte_le_to_cpu_16(rxdp->wb.status_error0);
@@ -1585,7 +1575,6 @@ iavf_recv_pkts_flex_rxd(void *rx_queue,
 				rte_le_to_cpu_32(rxd.wb.flex_ts.ts_high));
 
 			rxq->phc_time = ts_ns;
-			rxq->hw_time_update = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
 
 			*RTE_MBUF_DYNFIELD(rxm,
 				iavf_timestamp_dynfield_offset,
@@ -1627,16 +1616,6 @@ iavf_recv_scattered_pkts_flex_rxd(void *rx_queue, struct rte_mbuf **rx_pkts,
 	volatile union ci_rx_flex_desc *rxdp;
 	const uint32_t *ptype_tbl = rxq->iavf_vsi->adapter->ptype_tbl;
 
-	if (rxq->offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP) {
-		uint64_t sw_cur_time = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
-
-		if (sw_cur_time - rxq->hw_time_update > 4) {
-			if (iavf_get_phc_time(rxq))
-				PMD_DRV_LOG(ERR, "get physical time failed");
-			rxq->hw_time_update = sw_cur_time;
-		}
-	}
-
 	while (nb_rx < nb_pkts) {
 		rxdp = &rx_ring[rx_id];
 		rx_stat_err0 = rte_le_to_cpu_16(rxdp->wb.status_error0);
@@ -1755,7 +1734,6 @@ iavf_recv_scattered_pkts_flex_rxd(void *rx_queue, struct rte_mbuf **rx_pkts,
 				rte_le_to_cpu_32(rxd.wb.flex_ts.ts_high));
 
 			rxq->phc_time = ts_ns;
-			rxq->hw_time_update = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
 
 			*RTE_MBUF_DYNFIELD(first_seg,
 				iavf_timestamp_dynfield_offset,
@@ -1969,16 +1947,6 @@ iavf_rx_scan_hw_ring_flex_rxd(struct ci_rx_queue *rxq,
 	if (!(stat_err0 & (1 << IAVF_RX_FLEX_DESC_STATUS0_DD_S)))
 		return 0;
 
-	if (rxq->offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP) {
-		uint64_t sw_cur_time = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
-
-		if (sw_cur_time - rxq->hw_time_update > 4) {
-			if (iavf_get_phc_time(rxq))
-				PMD_DRV_LOG(ERR, "get physical time failed");
-			rxq->hw_time_update = sw_cur_time;
-		}
-	}
-
 	/* Scan LOOK_AHEAD descriptors at a time to determine which
 	 * descriptors reference packets that are ready to be received.
 	 */
@@ -2041,8 +2009,6 @@ iavf_rx_scan_hw_ring_flex_rxd(struct ci_rx_queue *rxq,
 					rte_le_to_cpu_32(rxdp[j].wb.flex_ts.ts_high));
 
 				rxq->phc_time = ts_ns;
-				rxq->hw_time_update = rte_get_timer_cycles() /
-					(rte_get_timer_hz() / 1000);
 
 				*RTE_MBUF_DYNFIELD(mb,
 					iavf_timestamp_dynfield_offset,
diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
index 2e18be3616..a688ad4230 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
@@ -514,18 +514,10 @@ _iavf_recv_raw_pkts_vec_avx2_flex_rxd(struct ci_rx_queue *rxq,
 	if (!(rxdp->wb.status_error0 &
 			rte_cpu_to_le_32(1 << IAVF_RX_FLEX_DESC_STATUS0_DD_S)))
 		return 0;
-	bool is_tsinit = false;
 	uint8_t inflection_point = 0;
 	__m256i hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, rxq->phc_time);
 	if (rxq->offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP) {
-		uint64_t sw_cur_time = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
-
-		if (unlikely(sw_cur_time - rxq->hw_time_update > 4)) {
-			hw_low_last = _mm256_setzero_si256();
-			is_tsinit = 1;
-		} else {
-			hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, rxq->phc_time);
-		}
+		hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, rxq->phc_time);
 	}
 
 	/* constants used in processing loop */
@@ -1152,10 +1144,8 @@ _iavf_recv_raw_pkts_vec_avx2_flex_rxd(struct ci_rx_queue *rxq,
 					*RTE_MBUF_DYNFIELD(rx_pkts[i + 7],
 						iavf_timestamp_dynfield_offset, uint32_t *) = _mm256_extract_epi32(ts_low1, 7);
 
-					if (unlikely(is_tsinit)) {
+					{
 						uint32_t in_timestamp;
-						if (iavf_get_phc_time(rxq))
-							PMD_DRV_LOG(ERR, "get physical time failed");
 						in_timestamp = *RTE_MBUF_DYNFIELD(rx_pkts[i + 0],
 								iavf_timestamp_dynfield_offset, uint32_t *);
 						rxq->phc_time = iavf_tstamp_convert_32b_64b(rxq->phc_time, in_timestamp);
@@ -1388,8 +1378,6 @@ _iavf_recv_raw_pkts_vec_avx2_flex_rxd(struct ci_rx_queue *rxq,
 				PMD_DRV_LOG(ERR, "invalid inflection point for rx timestamp");
 				break;
 			}
-
-			rxq->hw_time_update = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
 		}
 		if (burst != IAVF_VPMD_DESCS_PER_LOOP_WIDE)
 			break;
diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
index 9a93a0b062..7fc3ba8956 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
@@ -615,18 +615,10 @@ _iavf_recv_raw_pkts_vec_avx512_flex_rxd(struct ci_rx_queue *rxq,
 
 #ifdef IAVF_RX_TS_OFFLOAD
 	uint8_t inflection_point = 0;
-	bool is_tsinit = false;
 	__m256i hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, (uint32_t)rxq->phc_time);
 
 	if (rxq->offloads & RTE_ETH_RX_OFFLOAD_TIMESTAMP) {
-		uint64_t sw_cur_time = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
-
-		if (unlikely(sw_cur_time - rxq->hw_time_update > 4)) {
-			hw_low_last = _mm256_setzero_si256();
-			is_tsinit = 1;
-		} else {
-			hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, (uint32_t)rxq->phc_time);
-		}
+		hw_low_last = _mm256_set_epi32(0, 0, 0, 0, 0, 0, 0, (uint32_t)rxq->phc_time);
 	}
 #endif
 
@@ -1343,11 +1335,9 @@ _iavf_recv_raw_pkts_vec_avx512_flex_rxd(struct ci_rx_queue *rxq,
 					*RTE_MBUF_DYNFIELD(rx_pkts[i + 7],
 						iavf_timestamp_dynfield_offset, uint32_t *) = _mm256_extract_epi32(ts_low1, 7);
 
-					if (unlikely(is_tsinit)) {
+					{
 						uint32_t in_timestamp;
 
-						if (iavf_get_phc_time(rxq))
-							PMD_DRV_LOG(ERR, "get physical time failed");
 						in_timestamp = *RTE_MBUF_DYNFIELD(rx_pkts[i + 0],
 										iavf_timestamp_dynfield_offset, uint32_t *);
 						rxq->phc_time = iavf_tstamp_convert_32b_64b(rxq->phc_time, in_timestamp);
@@ -1584,8 +1574,6 @@ _iavf_recv_raw_pkts_vec_avx512_flex_rxd(struct ci_rx_queue *rxq,
 				PMD_DRV_LOG(ERR, "invalid inflection point for rx timestamp");
 				break;
 			}
-
-			rxq->hw_time_update = rte_get_timer_cycles() / (rte_get_timer_hz() / 1000);
 		}
 #endif
 		if (burst != IAVF_VPMD_DESCS_PER_LOOP_WIDE)
-- 
2.47.1