drivers/net: fix vector Rx comments

[ upstream commit 4f76ac9 ]

For the loop to process packets in Rx vector path, some notes for the
code are wrong, fix these errors.

Fixes: 7092be8 ("fm10k: add vector Rx")
Fixes: c3def6a ("net/i40e: implement vector PMD for altivec")
Fixes: ae0eb31 ("net/i40e: implement vector PMD for ARM")
Fixes: 9ed94e5 ("i40e: add vector Rx")
Fixes: 319c421 ("net/avf: enable SSE Rx Tx")
Fixes: 1162f5a ("net/iavf: support flexible Rx descriptor in SSE path")
Fixes: c68a52b ("net/ice: support vector SSE in Rx")
Fixes: cf4b470 ("ixgbe: improve slow-path perf with vector scattered Rx")

Suggested-by: Ruifeng Wang <ruifeng.wang@arm.com>
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>

drivers/net/fm10k/fm10k_rxtx_vec.c

@@ -472,7 +472,7 @@ fm10k_recv_raw_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 		mbp1 = _mm_loadu_si128((__m128i *)&mbufp[pos]);
 
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs0[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
 		rte_compiler_barrier();
 
@@ -484,9 +484,9 @@ fm10k_recv_raw_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&mbufp[pos+2]);
 #endif
 
+		/* A.1 load desc[2-0] */
 		descs0[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs0[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
 		rte_compiler_barrier();
 		descs0[0] = _mm_loadu_si128((__m128i *)(rxdp));

drivers/net/i40e/i40e_rxtx_vec_altivec.c

@@ -281,22 +281,22 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 						  * in one XMM reg.
 						  */
 
-		/* B.1 load 1 mbuf point */
+		/* B.1 load 2 mbuf point */
 		mbp1 = *(vector unsigned long *)&sw_ring[pos];
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] = *(vector unsigned long *)(rxdp + 3);
 		rte_compiler_barrier();
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
 		*(vector unsigned long *)&rx_pkts[pos] = mbp1;
 
-		/* B.1 load 1 mbuf point */
+		/* B.1 load 2 mbuf point */
 		mbp2 = *(vector unsigned long *)&sw_ring[pos + 2];
 
+		/* A.1 load desc[2-0] */
 		descs[2] = *(vector unsigned long *)(rxdp + 2);
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs[1] = *(vector unsigned long *)(rxdp + 1);
 		rte_compiler_barrier();
 		descs[0] = *(vector unsigned long *)(rxdp);

drivers/net/i40e/i40e_rxtx_vec_neon.c

@@ -279,20 +279,20 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 
 		int32x4_t len_shl = {0, 0, 0, PKTLEN_SHIFT};
 
-		/* B.1 load 1 mbuf point */
+		/* B.1 load 2 mbuf point */
 		mbp1 = vld1q_u64((uint64_t *)&sw_ring[pos]);
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] =  vld1q_u64((uint64_t *)(rxdp + 3));
 
 		/* B.2 copy 2 mbuf point into rx_pkts  */
 		vst1q_u64((uint64_t *)&rx_pkts[pos], mbp1);
 
-		/* B.1 load 1 mbuf point */
+		/* B.1 load 2 mbuf point */
 		mbp2 = vld1q_u64((uint64_t *)&sw_ring[pos + 2]);
 
+		/* A.1 load desc[2-0] */
 		descs[2] =  vld1q_u64((uint64_t *)(rxdp + 2));
-		/* B.1 load 2 mbuf point */
 		descs[1] =  vld1q_u64((uint64_t *)(rxdp + 1));
 		descs[0] =  vld1q_u64((uint64_t *)(rxdp));
 

drivers/net/i40e/i40e_rxtx_vec_sse.c

@@ -462,7 +462,7 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* B.1 load 2 (64 bit) or 4 (32 bit) mbuf points */
 		mbp1 = _mm_loadu_si128((__m128i *)&sw_ring[pos]);
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
 		rte_compiler_barrier();
 
@@ -474,9 +474,9 @@ _recv_raw_pkts_vec(struct i40e_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos+2]);
 #endif
 
+		/* A.1 load desc[2-0] */
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
 		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));

drivers/net/iavf/iavf_rxtx_vec_sse.c

@@ -341,7 +341,7 @@ _recv_raw_pkts_vec(struct iavf_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* B.1 load 2 (64 bit) or 4 (32 bit) mbuf points */
 		mbp1 = _mm_loadu_si128((__m128i *)&sw_ring[pos]);
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
 		rte_compiler_barrier();
 
@@ -353,9 +353,9 @@ _recv_raw_pkts_vec(struct iavf_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos + 2]);
 #endif
 
+		/* A.1 load desc[2-0] */
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
 		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));

drivers/net/ice/ice_rxtx_vec_sse.c

@@ -366,7 +366,7 @@ _ice_recv_raw_pkts_vec(struct ice_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		/* B.1 load 2 (64 bit) or 4 (32 bit) mbuf points */
 		mbp1 = _mm_loadu_si128((__m128i *)&sw_ring[pos]);
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
 		rte_compiler_barrier();
 
@@ -378,9 +378,9 @@ _ice_recv_raw_pkts_vec(struct ice_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos + 2]);
 #endif
 
+		/* A.1 load desc[2-0] */
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
 		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));

drivers/net/ixgbe/ixgbe_rxtx_vec_sse.c

@@ -454,7 +454,7 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp1 = _mm_loadu_si128((__m128i *)&sw_ring[pos]);
 
 		/* Read desc statuses backwards to avoid race condition */
-		/* A.1 load 4 pkts desc */
+		/* A.1 load desc[3] */
 		descs[3] = _mm_loadu_si128((__m128i *)(rxdp + 3));
 		rte_compiler_barrier();
 
@@ -466,9 +466,9 @@ _recv_raw_pkts_vec(struct ixgbe_rx_queue *rxq, struct rte_mbuf **rx_pkts,
 		mbp2 = _mm_loadu_si128((__m128i *)&sw_ring[pos+2]);
 #endif
 
+		/* A.1 load desc[2-0] */
 		descs[2] = _mm_loadu_si128((__m128i *)(rxdp + 2));
 		rte_compiler_barrier();
-		/* B.1 load 2 mbuf point */
 		descs[1] = _mm_loadu_si128((__m128i *)(rxdp + 1));
 		rte_compiler_barrier();
 		descs[0] = _mm_loadu_si128((__m128i *)(rxdp));