From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next 07/11] e1000: perform copybreak ahead of DMA unmap Date: Fri, 12 Sep 2014 05:33:47 -0700 Message-ID: <1410525231-19851-8-git-send-email-jeffrey.t.kirsher@intel.com> References: <1410525231-19851-1-git-send-email-jeffrey.t.kirsher@intel.com> Cc: Florian Westphal , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga02.intel.com ([134.134.136.20]:49791 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754436AbaILMeF (ORCPT ); Fri, 12 Sep 2014 08:34:05 -0400 In-Reply-To: <1410525231-19851-1-git-send-email-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal Currently we unmap the DMA range, then copy to new skb. Change this so we can keep the mapping in case the data is copied. Signed-off-by: Florian Westphal Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/e1000/e1000_main.c | 73 ++++++++++++++++----------- 1 file changed, 43 insertions(+), 30 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index e26a32d..79626ba 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -4077,6 +4077,16 @@ static bool e1000_tbi_should_accept(struct e1000_adapter *adapter, return false; } +static struct sk_buff *e1000_alloc_rx_skb(struct e1000_adapter *adapter, + unsigned int bufsz) +{ + struct sk_buff *skb = netdev_alloc_skb_ip_align(adapter->netdev, bufsz); + + if (unlikely(!skb)) + adapter->alloc_rx_buff_failed++; + return skb; +} + /** * e1000_clean_jumbo_rx_irq - Send received data up the network stack; legacy * @adapter: board private structure @@ -4262,25 +4272,25 @@ next_desc: /* this should improve performance for small packets with large amounts * of reassembly being done in the stack */ -static void e1000_check_copybreak(struct net_device *netdev, - struct e1000_buffer *buffer_info, - u32 length, struct sk_buff **skb) +static struct sk_buff *e1000_copybreak(struct e1000_adapter *adapter, + struct e1000_buffer *buffer_info, + u32 length, const void *data) { - struct sk_buff *new_skb; + struct sk_buff *skb; if (length > copybreak) - return; + return NULL; - new_skb = netdev_alloc_skb_ip_align(netdev, length); - if (!new_skb) - return; + skb = e1000_alloc_rx_skb(adapter, length); + if (!skb) + return NULL; + + dma_sync_single_for_cpu(&adapter->pdev->dev, buffer_info->dma, + length, DMA_FROM_DEVICE); + + memcpy(skb_put(skb, length), data, length); - skb_copy_to_linear_data_offset(new_skb, -NET_IP_ALIGN, - (*skb)->data - NET_IP_ALIGN, - length + NET_IP_ALIGN); - /* save the skb in buffer_info as good */ - buffer_info->skb = *skb; - *skb = new_skb; + return skb; } /** @@ -4318,10 +4328,18 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter, rmb(); /* read descriptor and rx_buffer_info after status DD */ status = rx_desc->status; - skb = buffer_info->skb; - buffer_info->skb = NULL; + length = le16_to_cpu(rx_desc->length); - prefetch(skb->data - NET_IP_ALIGN); + prefetch(buffer_info->skb->data - NET_IP_ALIGN); + skb = e1000_copybreak(adapter, buffer_info, length, + buffer_info->skb->data); + if (!skb) { + skb = buffer_info->skb; + buffer_info->skb = NULL; + dma_unmap_single(&pdev->dev, buffer_info->dma, + buffer_info->length, DMA_FROM_DEVICE); + buffer_info->dma = 0; + } if (++i == rx_ring->count) i = 0; next_rxd = E1000_RX_DESC(*rx_ring, i); @@ -4331,11 +4349,7 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter, cleaned = true; cleaned_count++; - dma_unmap_single(&pdev->dev, buffer_info->dma, - buffer_info->length, DMA_FROM_DEVICE); - buffer_info->dma = 0; - length = le16_to_cpu(rx_desc->length); /* !EOP means multiple descriptors were used to store a single * packet, if thats the case we need to toss it. In fact, we * to toss every packet with the EOP bit clear and the next @@ -4348,8 +4362,7 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter, if (adapter->discarding) { /* All receives must fit into a single buffer */ netdev_dbg(netdev, "Receive packet consumed multiple buffers\n"); - /* recycle */ - buffer_info->skb = skb; + dev_kfree_skb(skb); if (status & E1000_RXD_STAT_EOP) adapter->discarding = false; goto next_desc; @@ -4363,8 +4376,7 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter, } else if (netdev->features & NETIF_F_RXALL) { goto process_skb; } else { - /* recycle */ - buffer_info->skb = skb; + dev_kfree_skb(skb); goto next_desc; } } @@ -4379,9 +4391,10 @@ process_skb: */ length -= 4; - e1000_check_copybreak(netdev, buffer_info, length, &skb); - - skb_put(skb, length); + if (buffer_info->skb == NULL) + skb_put(skb, length); + else /* copybreak skb */ + skb_trim(skb, length); /* Receive Checksum Offload */ e1000_rx_checksum(adapter, @@ -4527,7 +4540,7 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, skb = buffer_info->skb; if (skb) { skb_trim(skb, 0); - goto map_skb; + goto skip; } skb = netdev_alloc_skb_ip_align(netdev, bufsz); @@ -4564,7 +4577,6 @@ static void e1000_alloc_rx_buffers(struct e1000_adapter *adapter, } buffer_info->skb = skb; buffer_info->length = adapter->rx_buffer_len; -map_skb: buffer_info->dma = dma_map_single(&pdev->dev, skb->data, buffer_info->length, @@ -4602,6 +4614,7 @@ map_skb: rx_desc = E1000_RX_DESC(*rx_ring, i); rx_desc->buffer_addr = cpu_to_le64(buffer_info->dma); +skip: if (unlikely(++i == rx_ring->count)) i = 0; buffer_info = &rx_ring->buffer_info[i]; -- 1.9.3