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qede: Utilize xmit_more 

This patch uses xmit_more optimization to reduce
number of TX doorbells write per packet.

Signed-off-by: Manish <manish.chopra@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Manish Chopra 2016-06-30 02:35:20 -04:00 committed by David S. Miller
parent c774169d8f
commit 312e06761c
1 changed files with 23 additions and 14 deletions
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37
drivers/net/ethernet/qlogic/qede/qede_main.c
View File

@ -485,6 +485,24 @@ static bool qede_pkt_req_lin(struct qede_dev *edev, struct sk_buff *skb,
} }
#endif #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 */ /* Main transmit function */
static static
netdev_tx_t qede_start_xmit(struct sk_buff *skb, 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))) { if (unlikely(dma_mapping_error(&edev->pdev->dev, mapping))) {
DP_NOTICE(edev, "SKB mapping failed\n"); DP_NOTICE(edev, "SKB mapping failed\n");
qede_free_failed_tx_pkt(edev, txq, first_bd, 0, false); qede_free_failed_tx_pkt(edev, txq, first_bd, 0, false);
qede_update_tx_producer(txq);
return NETDEV_TX_OK; return NETDEV_TX_OK;
} }
nbd++; nbd++;
@ -657,6 +676,7 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb,
if (rc) { if (rc) {
qede_free_failed_tx_pkt(edev, txq, first_bd, nbd, qede_free_failed_tx_pkt(edev, txq, first_bd, nbd,
data_split); data_split);
qede_update_tx_producer(txq);
return NETDEV_TX_OK; return NETDEV_TX_OK;
} }
@ -681,6 +701,7 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb,
if (rc) { if (rc) {
qede_free_failed_tx_pkt(edev, txq, first_bd, nbd, qede_free_failed_tx_pkt(edev, txq, first_bd, nbd,
data_split); data_split);
qede_update_tx_producer(txq);
return NETDEV_TX_OK; return NETDEV_TX_OK;
} }
} }
@ -701,20 +722,8 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb,
txq->tx_db.data.bd_prod = txq->tx_db.data.bd_prod =
cpu_to_le16(qed_chain_get_prod_idx(&txq->tx_pbl)); cpu_to_le16(qed_chain_get_prod_idx(&txq->tx_pbl));
/* wmb makes sure that the BDs data is updated before updating the if (!skb->xmit_more || netif_tx_queue_stopped(netdev_txq))
* producer, otherwise FW may read old data from the BDs. qede_update_tx_producer(txq);
*/
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 (unlikely(qed_chain_get_elem_left(&txq->tx_pbl) if (unlikely(qed_chain_get_elem_left(&txq->tx_pbl)
< (MAX_SKB_FRAGS + 1))) { < (MAX_SKB_FRAGS + 1))) {