[PATCH 01/13] net/iavf: remove unnecessary alignment calls

[Bruce Richardson]

When we have a context descriptor on Tx of a packet from the vector
paths, that means that we always have 32-bytes being written per
descriptor/per packet, so the stores are always 32-bit aligned. This
means we can use aligned stores for each single descriptor store, and
that we never need to do an initial descriptor write for alignment when
doing a burst of descriptors.

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c   | 9 ++-------
 drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c | 9 ++-------
 2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
index 7217f32cef..9b62ef53d3 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx2.c
@@ -1933,7 +1933,8 @@ ctx_vtx1(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 	__m256i ctx_data_desc = _mm256_set_epi64x(high_data_qw, pkt->buf_iova + pkt->data_off,
 							high_ctx_qw, low_ctx_qw);
 
-	_mm256_storeu_si256(RTE_CAST_PTR(__m256i *, txdp), ctx_data_desc);
+	/* tx_id is always even in ctx mode, so txdp is always 32-byte aligned */
+	_mm256_store_si256(RTE_CAST_PTR(__m256i *, txdp), ctx_data_desc);
 }
 
 static __rte_always_inline void
@@ -1944,12 +1945,6 @@ ctx_vtx(volatile struct ci_tx_desc *txdp,
 	uint64_t hi_data_qw_tmpl = (IAVF_TX_DESC_DTYPE_DATA |
 					((uint64_t)flags  << IAVF_TXD_QW1_CMD_SHIFT));
 
-	/* if unaligned on 32-bit boundary, do one to align */
-	if (((uintptr_t)txdp & 0x1F) != 0 && nb_pkts != 0) {
-		ctx_vtx1(txdp, *pkt, flags, offload, vlan_flag, ptype_lldp_enabled);
-		nb_pkts--; txdp++; pkt++;
-	}
-
 	for (; nb_pkts > 1; txdp += 4, pkt += 2, nb_pkts -= 2) {
 		uint64_t hi_ctx_qw1 = IAVF_TX_DESC_DTYPE_CONTEXT;
 		uint64_t hi_ctx_qw0 = IAVF_TX_DESC_DTYPE_CONTEXT;
diff --git a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
index bf0245e8f4..4609c2245a 100644
--- a/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
+++ b/drivers/net/intel/iavf/iavf_rxtx_vec_avx512.c
@@ -2078,7 +2078,8 @@ ctx_vtx1(volatile struct ci_tx_desc *txdp, struct rte_mbuf *pkt,
 	__m256i ctx_data_desc = _mm256_set_epi64x(high_data_qw, pkt->buf_iova + pkt->data_off,
 							high_ctx_qw, low_ctx_qw);
 
-	_mm256_storeu_si256(RTE_CAST_PTR(__m256i *, txdp), ctx_data_desc);
+	/* tx_id is always even in ctx mode, so txdp is always 32-byte aligned */
+	_mm256_store_si256(RTE_CAST_PTR(__m256i *, txdp), ctx_data_desc);
 }
 
 static __rte_always_inline void
@@ -2088,12 +2089,6 @@ ctx_vtx(volatile struct ci_tx_desc *txdp,
 {
 	uint64_t hi_data_qw_tmpl = (CI_TX_DESC_DTYPE_DATA | (flags << CI_TXD_QW1_CMD_S));
 
-	/* if unaligned on 32-bit boundary, do one to align */
-	if (((uintptr_t)txdp & 0x1F) != 0 && nb_pkts != 0) {
-		ctx_vtx1(txdp, *pkt, flags, offload, vlan_flag, lldp_enabled);
-		nb_pkts--; txdp++; pkt++;
-	}
-
 	for (; nb_pkts > 1; txdp += 4, pkt += 2, nb_pkts -= 2) {
 		uint64_t hi_ctx_qw1 = IAVF_TX_DESC_DTYPE_CONTEXT;
 		uint64_t hi_ctx_qw0 = IAVF_TX_DESC_DTYPE_CONTEXT;
-- 
2.53.0