[dpdk-dev] [PATCH] ixgbe: fix RX is not working properly when buffer address is not word aligned

[Konstantin Ananyev]

Niantic HW expects Header Buffer Address in the RXD to be word aligned.
So, if mbuf's buf_physaddr is not word aligned then
RX path will not work properly.
Right now, in ixgbe PMD we always setup Packet Buffer Address(PBA) and
Header Buffer Address (HBA) to the same value:
buf_physaddr + RTE_PKTMBUF_HEADROOM.
As ixgbe PMD doesn't support split header feature anyway,
the issue can be fixied just by  always setting HBA in the RXD to zero.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
 drivers/net/ixgbe/ixgbe_rxtx.c     | 8 ++++----
 drivers/net/ixgbe/ixgbe_rxtx_vec.c | 6 ++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index a0c8847..94967c5 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -1183,7 +1183,7 @@ ixgbe_rx_alloc_bufs(struct ixgbe_rx_queue *rxq, bool reset_mbuf)
 
 		/* populate the descriptors */
 		dma_addr = rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mb));
-		rxdp[i].read.hdr_addr = dma_addr;
+		rxdp[i].read.hdr_addr = 0;
 		rxdp[i].read.pkt_addr = dma_addr;
 	}
 
@@ -1414,7 +1414,7 @@ ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		rxe->mbuf = nmb;
 		dma_addr =
 			rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(nmb));
-		rxdp->read.hdr_addr = dma_addr;
+		rxdp->read.hdr_addr = 0;
 		rxdp->read.pkt_addr = dma_addr;
 
 		/*
@@ -1741,7 +1741,7 @@ next_desc:
 			rxe->mbuf = nmb;
 
 			rxm->data_off = RTE_PKTMBUF_HEADROOM;
-			rxdp->read.hdr_addr = dma;
+			rxdp->read.hdr_addr = 0;
 			rxdp->read.pkt_addr = dma;
 		} else
 			rxe->mbuf = NULL;
@@ -3633,7 +3633,7 @@ ixgbe_alloc_rx_queue_mbufs(struct ixgbe_rx_queue *rxq)
 		dma_addr =
 			rte_cpu_to_le_64(RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mbuf));
 		rxd = &rxq->rx_ring[i];
-		rxd->read.hdr_addr = dma_addr;
+		rxd->read.hdr_addr = 0;
 		rxd->read.pkt_addr = dma_addr;
 		rxe[i].mbuf = mbuf;
 	}
diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec.c b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
index 6c1647e..e1750c1 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx_vec.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx_vec.c
@@ -56,6 +56,8 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq)
 			RTE_PKTMBUF_HEADROOM);
 	__m128i dma_addr0, dma_addr1;
 
+	const __m128i hba_msk = _mm_set_epi64x(0, UINT64_MAX);
+
 	rxdp = rxq->rx_ring + rxq->rxrearm_start;
 
 	/* Pull 'n' more MBUFs into the software ring */
@@ -108,6 +110,10 @@ ixgbe_rxq_rearm(struct ixgbe_rx_queue *rxq)
 		dma_addr0 = _mm_add_epi64(dma_addr0, hdr_room);
 		dma_addr1 = _mm_add_epi64(dma_addr1, hdr_room);
 
+		/* set Header Buffer Address to zero */
+		dma_addr0 =  _mm_and_si128(dma_addr0, hba_msk);
+		dma_addr1 =  _mm_and_si128(dma_addr1, hba_msk);
+
 		/* flush desc with pa dma_addr */
 		_mm_store_si128((__m128i *)&rxdp++->read, dma_addr0);
 		_mm_store_si128((__m128i *)&rxdp++->read, dma_addr1);
-- 
1.8.3.1