[dpdk-dev] [PATCH 1/7] net/ice: change RSS hash parsing in AVX path

[Guinan Sun <guinanx.sun@intel.com>]

From: Junyu Jiang <junyux.jiang@intel.com>

Change RSS hash parsing from Flex Rx descriptor in AVX data path.

Signed-off-by: Junyu Jiang <junyux.jiang@intel.com>
---
 drivers/net/ice/ice_rxtx_vec_avx2.c | 98 +++++++++++++++++++++++++++--
 1 file changed, 94 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ice/ice_rxtx_vec_avx2.c b/drivers/net/ice/ice_rxtx_vec_avx2.c
index be50677c2..07d129e3f 100644
--- a/drivers/net/ice/ice_rxtx_vec_avx2.c
+++ b/drivers/net/ice/ice_rxtx_vec_avx2.c
@@ -191,8 +191,8 @@ _ice_recv_raw_pkts_vec_avx2(struct ice_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 	const __m256i shuf_msk =
 		_mm256_set_epi8
 			(/* first descriptor */
-			 15, 14,
-			 13, 12,	/* octet 12~15, 32 bits rss */
+			 0xFF, 0xFF,
+			 0xFF, 0xFF,	/* rss hash parsed separately */
 			 11, 10,	/* octet 10~11, 16 bits vlan_macip */
 			 5, 4,		/* octet 4~5, 16 bits data_len */
 			 0xFF, 0xFF,	/* skip hi 16 bits pkt_len, zero out */
@@ -200,8 +200,8 @@ _ice_recv_raw_pkts_vec_avx2(struct ice_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 			 0xFF, 0xFF,	/* pkt_type set as unknown */
 			 0xFF, 0xFF,	/*pkt_type set as unknown */
 			 /* second descriptor */
-			 15, 14,
-			 13, 12,	/* octet 12~15, 32 bits rss */
+			 0xFF, 0xFF,
+			 0xFF, 0xFF,	/* rss hash parsed separately */
 			 11, 10,	/* octet 10~11, 16 bits vlan_macip */
 			 5, 4,		/* octet 4~5, 16 bits data_len */
 			 0xFF, 0xFF,	/* skip hi 16 bits pkt_len, zero out */
@@ -461,6 +461,96 @@ _ice_recv_raw_pkts_vec_avx2(struct ice_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* merge flags */
 		const __m256i mbuf_flags = _mm256_or_si256(l3_l4_flags,
 				rss_vlan_flags);
+
+#ifndef RTE_LIBRTE_ICE_16BYTE_RX_DESC
+		/**
+		 * needs to load 2nd 16B of each desc for RSS hash parsing,
+		 * will cause performance drop to get into this context.
+		 */
+		if (rxq->vsi->adapter->eth_dev->data->dev_conf.rxmode.offloads &
+				DEV_RX_OFFLOAD_RSS_HASH) {
+			/* load bottom half of every 32B desc */
+			const __m128i raw_desc_bh7 =
+				_mm_load_si128
+					((void *)(&rxdp[7].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh6 =
+				_mm_load_si128
+					((void *)(&rxdp[6].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh5 =
+				_mm_load_si128
+					((void *)(&rxdp[5].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh4 =
+				_mm_load_si128
+					((void *)(&rxdp[4].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh3 =
+				_mm_load_si128
+					((void *)(&rxdp[3].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh2 =
+				_mm_load_si128
+					((void *)(&rxdp[2].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh1 =
+				_mm_load_si128
+					((void *)(&rxdp[1].wb.status_error1));
+			rte_compiler_barrier();
+			const __m128i raw_desc_bh0 =
+				_mm_load_si128
+					((void *)(&rxdp[0].wb.status_error1));
+
+			__m256i raw_desc_bh6_7 =
+				_mm256_inserti128_si256
+					(_mm256_castsi128_si256(raw_desc_bh6),
+					raw_desc_bh7, 1);
+			__m256i raw_desc_bh4_5 =
+				_mm256_inserti128_si256
+					(_mm256_castsi128_si256(raw_desc_bh4),
+					raw_desc_bh5, 1);
+			__m256i raw_desc_bh2_3 =
+				_mm256_inserti128_si256
+					(_mm256_castsi128_si256(raw_desc_bh2),
+					raw_desc_bh3, 1);
+			__m256i raw_desc_bh0_1 =
+				_mm256_inserti128_si256
+					(_mm256_castsi128_si256(raw_desc_bh0),
+					raw_desc_bh1, 1);
+
+			/**
+			 * to shift the 32b RSS hash value to the
+			 * highest 32b of each 128b before mask
+			 */
+			__m256i rss_hash6_7 =
+				_mm256_slli_epi64(raw_desc_bh6_7, 32);
+			__m256i rss_hash4_5 =
+				_mm256_slli_epi64(raw_desc_bh4_5, 32);
+			__m256i rss_hash2_3 =
+				_mm256_slli_epi64(raw_desc_bh2_3, 32);
+			__m256i rss_hash0_1 =
+				_mm256_slli_epi64(raw_desc_bh0_1, 32);
+
+			__m256i rss_hash_msk =
+				_mm256_set_epi32(0xFFFFFFFF, 0, 0, 0,
+						 0xFFFFFFFF, 0, 0, 0);
+
+			rss_hash6_7 = _mm256_and_si256
+					(rss_hash6_7, rss_hash_msk);
+			rss_hash4_5 = _mm256_and_si256
+					(rss_hash4_5, rss_hash_msk);
+			rss_hash2_3 = _mm256_and_si256
+					(rss_hash2_3, rss_hash_msk);
+			rss_hash0_1 = _mm256_and_si256
+					(rss_hash0_1, rss_hash_msk);
+
+			mb6_7 = _mm256_or_si256(mb6_7, rss_hash6_7);
+			mb4_5 = _mm256_or_si256(mb4_5, rss_hash4_5);
+			mb2_3 = _mm256_or_si256(mb2_3, rss_hash2_3);
+			mb0_1 = _mm256_or_si256(mb0_1, rss_hash0_1);
+		} /* if() on RSS hash parsing */
+#endif
 		/**
 		 * At this point, we have the 8 sets of flags in the low 16-bits
 		 * of each 32-bit value in vlan0.
-- 
2.17.1