pasemi_mac: Add SKB reuse / copy-break

Add a copy-break and recycle the SKB in the driver for small packets.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 24 insertions, 7 deletions

diff --git a/drivers/net/pasemi_mac.c b/drivers/net/pasemi_mac.c
index 2bf13cf55358..216bb4a2c633 100644
--- a/drivers/net/pasemi_mac.c
+++ b/drivers/net/pasemi_mac.c
@@ -279,8 +279,8 @@ static void pasemi_mac_free_rx_resources(struct net_device *dev)
         for (i = 0; i < RX_RING_SIZE; i++) {
                 info = &RX_DESC_INFO(mac, i);
                 dp = &RX_DESC(mac, i);
-                if (info->dma) {
-                        if (info->skb) {
+                if (info->skb) {
+                        if (info->dma) {
                                 pci_unmap_single(mac->dma_pdev,
                                                  info->dma,
                                                  info->skb->len,
@@ -329,12 +329,14 @@ static void pasemi_mac_replenish_rx_ring(struct net_device *dev)
                 struct sk_buff *skb;
                 dma_addr_t dma;
 
-                skb = dev_alloc_skb(BUF_SIZE);
+                /* skb might still be in there for recycle on short receives */
+                if (info->skb)
+                        skb = info->skb;
+                else
+                        skb = dev_alloc_skb(BUF_SIZE);
 
-                if (!skb) {
-                        count = i - start;
+                if (unlikely(!skb))
                         break;
-                }
 
                 dma = pci_map_single(mac->dma_pdev, skb->data, skb->len,
                                      PCI_DMA_FROMDEVICE);
@@ -442,13 +444,28 @@ static int pasemi_mac_clean_rx(struct pasemi_mac *mac, int limit)
 
                 BUG_ON(!info);
                 BUG_ON(info->dma != dma);
+                skb = info->skb;
 
                 pci_unmap_single(mac->dma_pdev, info->dma, info->skb->len,
                                  PCI_DMA_FROMDEVICE);
+                info->dma = 0;
 
-                skb = info->skb;
 
                 len = (dp->macrx & XCT_MACRX_LLEN_M) >> XCT_MACRX_LLEN_S;
+                if (len < 256) {
+                        struct sk_buff *new_skb =
+                            netdev_alloc_skb(mac->netdev, len + NET_IP_ALIGN);
+                        if (new_skb) {
+                                skb_reserve(new_skb, NET_IP_ALIGN);
+                                memcpy(new_skb->data - NET_IP_ALIGN,
+                                        skb->data - NET_IP_ALIGN,
+                                        len + NET_IP_ALIGN);
+                                /* save the skb in buffer_info as good */
+                                skb = new_skb;
+                        }
+                        /* else just continue with the old one */
+                } else
+                        info->skb = NULL;
 
                 skb_put(skb, len);