[dpdk-dev] [PATCH v12 5/5] net/ice: use WC store to update queue tail registers

From: Radu Nicolau <radu.nicolau@intel.com>
To: dev@dpdk.org
Cc: beilei.xing@intel.com, jia.guo@intel.com,
	bruce.richardson@intel.com, konstantin.ananyev@intel.com,
	jerinjacobk@gmail.com, david.marchand@redhat.com,
	fiona.trahe@intel.com, wei.zhao1@intel.com, ruifeng.wang@arm.com,
	qiming.yang@intel.com, qi.z.zhang@intel.com,
	Radu Nicolau <radu.nicolau@intel.com>
Subject: [dpdk-dev] [PATCH v12 5/5] net/ice: use WC store to update queue tail registers
Date: Wed, 23 Sep 2020 14:22:53 +0000	[thread overview]
Message-ID: <20200923142253.18853-6-radu.nicolau@intel.com> (raw)
In-Reply-To: <20200923142253.18853-1-radu.nicolau@intel.com>

Performance improvement: use a write combining store
instead of a regular mmio write to update queue tail
registers.

Signed-off-by: Radu Nicolau <radu.nicolau@intel.com>
Reviewed-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
---
 doc/guides/rel_notes/release_20_11.rst | 4 ++++
 drivers/net/ice/base/ice_osdep.h       | 1 +
 drivers/net/ice/ice_rxtx.c             | 6 +++---
 drivers/net/ice/ice_rxtx_vec_avx2.c    | 4 ++--
 drivers/net/ice/ice_rxtx_vec_sse.c     | 4 ++--
 5 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/doc/guides/rel_notes/release_20_11.rst b/doc/guides/rel_notes/release_20_11.rst
index caca04208..9d6e07474 100644
--- a/doc/guides/rel_notes/release_20_11.rst
+++ b/doc/guides/rel_notes/release_20_11.rst
@@ -97,6 +97,10 @@ New Features
 
   Updated the Intel ixgbe driver to use write combining stores.
 
+* **Updated Intel ice driver.**
+
+  Updated the Intel ice driver to use write combining stores.
+
 Removed Items
 -------------
 
diff --git a/drivers/net/ice/base/ice_osdep.h b/drivers/net/ice/base/ice_osdep.h
index 9a170b514..c0f1e7725 100644
--- a/drivers/net/ice/base/ice_osdep.h
+++ b/drivers/net/ice/base/ice_osdep.h
@@ -165,6 +165,7 @@ do {									\
 #endif
 
 #define ICE_PCI_REG_WRITE(reg, value) writel(value, reg)
+#define ICE_PCI_REG_WC_WRITE(reg, value) rte_write32_wc(value, reg)
 
 #define ICE_READ_REG(hw, reg)         rd32(hw, reg)
 #define ICE_WRITE_REG(hw, reg, value) wr32(hw, reg, value)
diff --git a/drivers/net/ice/ice_rxtx.c b/drivers/net/ice/ice_rxtx.c
index fef6ad454..6bd5b4a0c 100644
--- a/drivers/net/ice/ice_rxtx.c
+++ b/drivers/net/ice/ice_rxtx.c
@@ -1788,7 +1788,7 @@ ice_recv_scattered_pkts(void *rx_queue,
 		rx_id = (uint16_t)(rx_id == 0 ?
 				   (rxq->nb_rx_desc - 1) : (rx_id - 1));
 		/* write TAIL register */
-		ICE_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+		ICE_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 		nb_hold = 0;
 	}
 	rxq->nb_rx_hold = nb_hold;
@@ -2178,7 +2178,7 @@ ice_recv_pkts(void *rx_queue,
 		rx_id = (uint16_t)(rx_id == 0 ?
 				   (rxq->nb_rx_desc - 1) : (rx_id - 1));
 		/* write TAIL register */
-		ICE_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+		ICE_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 		nb_hold = 0;
 	}
 	rxq->nb_rx_hold = nb_hold;
@@ -2893,7 +2893,7 @@ tx_xmit_pkts(struct ice_tx_queue *txq,
 		txq->tx_tail = 0;
 
 	/* Update the tx tail register */
-	ICE_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
+	ICE_PCI_REG_WC_WRITE(txq->qtx_tail, txq->tx_tail);
 
 	return nb_pkts;
 }
diff --git a/drivers/net/ice/ice_rxtx_vec_avx2.c b/drivers/net/ice/ice_rxtx_vec_avx2.c
index 5969a3048..b72a9e702 100644
--- a/drivers/net/ice/ice_rxtx_vec_avx2.c
+++ b/drivers/net/ice/ice_rxtx_vec_avx2.c
@@ -129,7 +129,7 @@ ice_rxq_rearm(struct ice_rx_queue *rxq)
 			     (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
 
 	/* Update the tail pointer on the NIC */
-	ICE_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+	ICE_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 }
 
 static inline __m256i
@@ -962,7 +962,7 @@ ice_xmit_fixed_burst_vec_avx2(void *tx_queue, struct rte_mbuf **tx_pkts,
 
 	txq->tx_tail = tx_id;
 
-	ICE_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
+	ICE_PCI_REG_WC_WRITE(txq->qtx_tail, txq->tx_tail);
 
 	return nb_pkts;
 }
diff --git a/drivers/net/ice/ice_rxtx_vec_sse.c b/drivers/net/ice/ice_rxtx_vec_sse.c
index c4c9a9126..1afd96ac9 100644
--- a/drivers/net/ice/ice_rxtx_vec_sse.c
+++ b/drivers/net/ice/ice_rxtx_vec_sse.c
@@ -97,7 +97,7 @@ ice_rxq_rearm(struct ice_rx_queue *rxq)
 			   (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
 
 	/* Update the tail pointer on the NIC */
-	ICE_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+	ICE_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 }
 
 static inline void
@@ -689,7 +689,7 @@ ice_xmit_fixed_burst_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
 
 	txq->tx_tail = tx_id;
 
-	ICE_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
+	ICE_PCI_REG_WC_WRITE(txq->qtx_tail, txq->tx_tail);
 
 	return nb_pkts;
 }
-- 
2.17.1

