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From: Joyce Kong <joyce.kong@arm.com>
To: beilei.xing@intel.com, qi.z.zhang@intel.com,
	ruifeng.wang@arm.com, honnappa.nagarahalli@arm.com,
	bruce.richardson@intel.com, helin.zhang@intel.com
Cc: dev@dpdk.org, stable@dpdk.org, nd@arm.com
Subject: [dpdk-dev] [PATCH v2] net/i40e: add logic of processing continuous DD bits for Arm
Date: Wed, 23 Jun 2021 03:43:34 -0500	[thread overview]
Message-ID: <20210623084334.18158-1-joyce.kong@arm.com> (raw)
In-Reply-To: <20210604073405.14880-1-joyce.kong@arm.com>

For Arm platforms, reading descs can get re-ordered, then the
status of DD bits will be discontinuous, so add the logic to
only process continuous descs by checking DD bits.

Fixes: 4861cde46116 ("i40e: new poll mode driver")
Cc: stable@dpdk.org

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
 drivers/net/i40e/i40e_rxtx.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 6c58decec..86e2f083e 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -452,7 +452,7 @@ i40e_rx_scan_hw_ring(struct i40e_rx_queue *rxq)
 	uint16_t pkt_len;
 	uint64_t qword1;
 	uint32_t rx_status;
-	int32_t s[I40E_LOOK_AHEAD], nb_dd;
+	int32_t s[I40E_LOOK_AHEAD], var, nb_dd;
 	int32_t i, j, nb_rx = 0;
 	uint64_t pkt_flags;
 	uint32_t *ptype_tbl = rxq->vsi->adapter->ptype_tbl;
@@ -482,11 +482,22 @@ i40e_rx_scan_hw_ring(struct i40e_rx_queue *rxq)
 					I40E_RXD_QW1_STATUS_SHIFT;
 		}
 
-		rte_smp_rmb();
+		/* This barrier is to order loads of different words in the descriptor */
+		rte_atomic_thread_fence(__ATOMIC_ACQUIRE);
 
 		/* Compute how many status bits were set */
-		for (j = 0, nb_dd = 0; j < I40E_LOOK_AHEAD; j++)
-			nb_dd += s[j] & (1 << I40E_RX_DESC_STATUS_DD_SHIFT);
+		for (j = 0, nb_dd = 0; j < I40E_LOOK_AHEAD; j++) {
+			var = s[j] & (1 << I40E_RX_DESC_STATUS_DD_SHIFT);
+#ifdef RTE_ARCH_ARM
+			/* For Arm platforms, only compute continuous status bits */
+			if (var)
+				nb_dd += 1;
+			else
+				break;
+#else
+			nb_dd += var;
+#endif
+		}
 
 		nb_rx += nb_dd;
 
-- 
2.17.1


  parent reply	other threads:[~2021-06-23  8:44 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-04  7:34 [dpdk-dev] [PATCH v1] net/i40e: remove the SMP barrier in HW scanning func Joyce Kong
2021-06-04 16:12 ` Honnappa Nagarahalli
2021-06-06 14:17 ` Zhang, Qi Z
2021-06-06 18:33   ` Honnappa Nagarahalli
2021-06-07 14:55     ` Zhang, Qi Z
2021-06-07 21:36       ` Honnappa Nagarahalli
2021-06-15  6:30         ` Joyce Kong
2021-06-16 13:29         ` Zhang, Qi Z
2021-06-16 13:37           ` Bruce Richardson
2021-06-16 20:26             ` Honnappa Nagarahalli
2021-06-23  8:43 ` Joyce Kong [this message]
2021-06-30  1:14   ` [dpdk-dev] [PATCH v2] net/i40e: add logic of processing continuous DD bits for Arm Honnappa Nagarahalli
2021-07-05  3:41     ` Joyce Kong
2021-07-06  6:54 ` [dpdk-dev] [PATCH v3 0/2] fixes for i40e hw scan ring Joyce Kong
2021-07-06  6:54   ` [dpdk-dev] [PATCH v3 1/2] net/i40e: add logic of processing continuous DD bits for Arm Joyce Kong
2021-07-09  3:05     ` Zhang, Qi Z
2021-07-06  6:54   ` [dpdk-dev] [PATCH v3 2/2] net/i40e: replace SMP barrier with thread fence Joyce Kong
2021-07-08 12:09     ` Zhang, Qi Z
2021-07-08 13:51       ` Lance Richardson
2021-07-08 14:26         ` Zhang, Qi Z
2021-07-08 14:44           ` Honnappa Nagarahalli
2021-07-13  0:46     ` Zhang, Qi Z

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