From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manish Chopra Subject: [PATCH net-next 3/5] qede: Utilize xmit_more Date: Thu, 30 Jun 2016 02:35:20 -0400 Message-ID: <1467268522-24589-4-git-send-email-manish.chopra@qlogic.com> References: <1467268522-24589-1-git-send-email-manish.chopra@qlogic.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , , To: Return-path: Received: from mx0a-0016ce01.pphosted.com ([67.231.148.157]:34727 "EHLO mx0b-0016ce01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751837AbcF3HTw (ORCPT ); Thu, 30 Jun 2016 03:19:52 -0400 In-Reply-To: <1467268522-24589-1-git-send-email-manish.chopra@qlogic.com> Sender: netdev-owner@vger.kernel.org List-ID: This patch uses xmit_more optimization to reduce number of TX doorbells write per packet. Signed-off-by: Manish Signed-off-by: Yuval Mintz --- drivers/net/ethernet/qlogic/qede/qede_main.c | 37 +++++++++++++++++----------- 1 file changed, 23 insertions(+), 14 deletions(-) diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c index ab811e2..2c27b3b 100644 --- a/drivers/net/ethernet/qlogic/qede/qede_main.c +++ b/drivers/net/ethernet/qlogic/qede/qede_main.c @@ -485,6 +485,24 @@ static bool qede_pkt_req_lin(struct qede_dev *edev, struct sk_buff *skb, } #endif +static inline void qede_update_tx_producer(struct qede_tx_queue *txq) +{ + /* wmb makes sure that the BDs data is updated before updating the + * producer, otherwise FW may read old data from the BDs. + */ + wmb(); + barrier(); + writel(txq->tx_db.raw, txq->doorbell_addr); + + /* mmiowb is needed to synchronize doorbell writes from more than one + * processor. It guarantees that the write arrives to the device before + * the queue lock is released and another start_xmit is called (possibly + * on another CPU). Without this barrier, the next doorbell can bypass + * this doorbell. This is applicable to IA64/Altix systems. + */ + mmiowb(); +} + /* Main transmit function */ static netdev_tx_t qede_start_xmit(struct sk_buff *skb, @@ -543,6 +561,7 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb, if (unlikely(dma_mapping_error(&edev->pdev->dev, mapping))) { DP_NOTICE(edev, "SKB mapping failed\n"); qede_free_failed_tx_pkt(edev, txq, first_bd, 0, false); + qede_update_tx_producer(txq); return NETDEV_TX_OK; } nbd++; @@ -657,6 +676,7 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb, if (rc) { qede_free_failed_tx_pkt(edev, txq, first_bd, nbd, data_split); + qede_update_tx_producer(txq); return NETDEV_TX_OK; } @@ -681,6 +701,7 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb, if (rc) { qede_free_failed_tx_pkt(edev, txq, first_bd, nbd, data_split); + qede_update_tx_producer(txq); return NETDEV_TX_OK; } } @@ -701,20 +722,8 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb, txq->tx_db.data.bd_prod = cpu_to_le16(qed_chain_get_prod_idx(&txq->tx_pbl)); - /* wmb makes sure that the BDs data is updated before updating the - * producer, otherwise FW may read old data from the BDs. - */ - wmb(); - barrier(); - writel(txq->tx_db.raw, txq->doorbell_addr); - - /* mmiowb is needed to synchronize doorbell writes from more than one - * processor. It guarantees that the write arrives to the device before - * the queue lock is released and another start_xmit is called (possibly - * on another CPU). Without this barrier, the next doorbell can bypass - * this doorbell. This is applicable to IA64/Altix systems. - */ - mmiowb(); + if (!skb->xmit_more || netif_tx_queue_stopped(netdev_txq)) + qede_update_tx_producer(txq); if (unlikely(qed_chain_get_elem_left(&txq->tx_pbl) < (MAX_SKB_FRAGS + 1))) { -- 2.7.2