From 70b33fb0ddec827cbbd14cdc664fc27b2ef4a6b6 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Fri, 17 Oct 2014 15:32:25 +0100 Subject: sfc: add support for skb->xmit_more Don't ring the doorbell, and don't do PIO. This will also prevent TX Push, because there will be more than one buffer waiting when the doorbell is rung. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/tx.c | 43 +++++++++++++++++++------------------------ 1 file changed, 19 insertions(+), 24 deletions(-) (limited to 'drivers/net/ethernet/sfc/tx.c') diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index 320609842211..ee84a90e371c 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -132,15 +132,6 @@ unsigned int efx_tx_max_skb_descs(struct efx_nic *efx) return max_descs; } -/* Get partner of a TX queue, seen as part of the same net core queue */ -static struct efx_tx_queue *efx_tx_queue_partner(struct efx_tx_queue *tx_queue) -{ - if (tx_queue->queue & EFX_TXQ_TYPE_OFFLOAD) - return tx_queue - EFX_TXQ_TYPE_OFFLOAD; - else - return tx_queue + EFX_TXQ_TYPE_OFFLOAD; -} - static void efx_tx_maybe_stop_queue(struct efx_tx_queue *txq1) { /* We need to consider both queues that the net core sees as one */ @@ -344,6 +335,7 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) struct efx_nic *efx = tx_queue->efx; struct device *dma_dev = &efx->pci_dev->dev; struct efx_tx_buffer *buffer; + unsigned int old_insert_count = tx_queue->insert_count; skb_frag_t *fragment; unsigned int len, unmap_len = 0; dma_addr_t dma_addr, unmap_addr = 0; @@ -351,7 +343,7 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) unsigned short dma_flags; int i = 0; - EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); + EFX_BUG_ON_PARANOID(tx_queue->write_count > tx_queue->insert_count); if (skb_shinfo(skb)->gso_size) return efx_enqueue_skb_tso(tx_queue, skb); @@ -369,9 +361,8 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) /* Consider using PIO for short packets */ #ifdef EFX_USE_PIO - if (skb->len <= efx_piobuf_size && tx_queue->piobuf && - efx_nic_tx_is_empty(tx_queue) && - efx_nic_tx_is_empty(efx_tx_queue_partner(tx_queue))) { + if (skb->len <= efx_piobuf_size && !skb->xmit_more && + efx_nic_may_tx_pio(tx_queue)) { buffer = efx_enqueue_skb_pio(tx_queue, skb); dma_flags = EFX_TX_BUF_OPTION; goto finish_packet; @@ -439,13 +430,14 @@ finish_packet: netdev_tx_sent_queue(tx_queue->core_txq, skb->len); + efx_tx_maybe_stop_queue(tx_queue); + /* Pass off to hardware */ - efx_nic_push_buffers(tx_queue); + if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) + efx_nic_push_buffers(tx_queue); tx_queue->tx_packets++; - efx_tx_maybe_stop_queue(tx_queue); - return NETDEV_TX_OK; dma_err: @@ -458,7 +450,7 @@ finish_packet: dev_kfree_skb_any(skb); /* Work backwards until we hit the original insert pointer value */ - while (tx_queue->insert_count != tx_queue->write_count) { + while (tx_queue->insert_count != old_insert_count) { unsigned int pkts_compl = 0, bytes_compl = 0; --tx_queue->insert_count; buffer = __efx_tx_queue_get_insert_buffer(tx_queue); @@ -989,12 +981,13 @@ static int efx_tso_put_header(struct efx_tx_queue *tx_queue, /* Remove buffers put into a tx_queue. None of the buffers must have * an skb attached. */ -static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue) +static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue, + unsigned int insert_count) { struct efx_tx_buffer *buffer; /* Work backwards until we hit the original insert pointer value */ - while (tx_queue->insert_count != tx_queue->write_count) { + while (tx_queue->insert_count != insert_count) { --tx_queue->insert_count; buffer = __efx_tx_queue_get_insert_buffer(tx_queue); efx_dequeue_buffer(tx_queue, buffer, NULL, NULL); @@ -1258,13 +1251,14 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, struct sk_buff *skb) { struct efx_nic *efx = tx_queue->efx; + unsigned int old_insert_count = tx_queue->insert_count; int frag_i, rc; struct tso_state state; /* Find the packet protocol and sanity-check it */ state.protocol = efx_tso_check_protocol(skb); - EFX_BUG_ON_PARANOID(tx_queue->write_count != tx_queue->insert_count); + EFX_BUG_ON_PARANOID(tx_queue->write_count > tx_queue->insert_count); rc = tso_start(&state, efx, skb); if (rc) @@ -1308,11 +1302,12 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, netdev_tx_sent_queue(tx_queue->core_txq, skb->len); - /* Pass off to hardware */ - efx_nic_push_buffers(tx_queue); - efx_tx_maybe_stop_queue(tx_queue); + /* Pass off to hardware */ + if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) + efx_nic_push_buffers(tx_queue); + tx_queue->tso_bursts++; return NETDEV_TX_OK; @@ -1336,6 +1331,6 @@ static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, dma_unmap_single(&efx->pci_dev->dev, state.header_dma_addr, state.header_unmap_len, DMA_TO_DEVICE); - efx_enqueue_unwind(tx_queue); + efx_enqueue_unwind(tx_queue, old_insert_count); return NETDEV_TX_OK; } -- cgit v1.2.3-59-g8ed1b