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Message-Id: <1410525231-19851-8-git-send-email-jeffrey.t.kirsher@intel.com>
Date: Fri, 12 Sep 2014 05:33:47 -0700
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: Florian Westphal <fw@...len.de>, netdev@...r.kernel.org,
nhorman@...hat.com, sassmann@...hat.com, jogreene@...hat.com,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 07/11] e1000: perform copybreak ahead of DMA unmap
From: Florian Westphal <fw@...len.de>
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 <fw@...len.de>
Tested-by: Aaron Brown <aaron.f.brown@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
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
--
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