e1000: Add copybreak when using packet split

Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 431b03ee077e..d641fbc7a6e1 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3757,6 +3757,35 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
                 /* Good Receive */
                 skb_put(skb, length);
 
+                {
+                /* this looks ugly, but it seems compiler issues make it
+                   more efficient than reusing j */
+                int l1 = le16_to_cpu(rx_desc->wb.upper.length[0]);
+
+                /* page alloc/put takes too long and effects small packet
+                 * throughput, so unsplit small packets and save the alloc/put*/
+                if (l1 && ((length + l1) < E1000_CB_LENGTH)) {
+                        u8 *vaddr;
+                        /* there is no documentation about how to call 
+                         * kmap_atomic, so we can't hold the mapping
+                         * very long */
+                        pci_dma_sync_single_for_cpu(pdev,
+                                ps_page_dma->ps_page_dma[0],
+                                PAGE_SIZE,
+                                PCI_DMA_FROMDEVICE);
+                        vaddr = kmap_atomic(ps_page->ps_page[0],
+                                            KM_SKB_DATA_SOFTIRQ);
+                        memcpy(skb->tail, vaddr, l1);
+                        kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ);
+                        pci_dma_sync_single_for_device(pdev,
+                                ps_page_dma->ps_page_dma[0],
+                                PAGE_SIZE, PCI_DMA_FROMDEVICE);
+                        skb_put(skb, l1);
+                        length += l1;
+                        goto copydone;
+                } /* if */
+                }
+                
                 for (j = 0; j < adapter->rx_ps_pages; j++) {
                         if (!(length = le16_to_cpu(rx_desc->wb.upper.length[j])))
                                 break;
@@ -3771,6 +3800,7 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
                         skb->data_len += length;
                 }
 
+copydone:
                 e1000_rx_checksum(adapter, staterr,
                                   rx_desc->wb.lower.hi_dword.csum_ip.csum, skb);
                 skb->protocol = eth_type_trans(skb, netdev);