forcedeth: rx skb recycle

This patch removes the code that recycled the skb on error. This will
help in reducing the branches in the main data paths.

Signed-Off-By: Ayaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 75dbd67..0fc0786 100644 (file)
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -1330,36 +1330,32 @@ static int nv_alloc_rx(struct net_device *dev)
                                break;
                }
 
-               if (np->put_rx_ctx->skb == NULL) {
-
-                       skb = dev_alloc_skb(np->rx_buf_sz + NV_RX_ALLOC_PAD);
-                       if (!skb)
-                               return 1;
-
+               skb = dev_alloc_skb(np->rx_buf_sz + NV_RX_ALLOC_PAD);
+               if (skb) {
                        skb->dev = dev;
                        np->put_rx_ctx->skb = skb;
+                       np->put_rx_ctx->dma = pci_map_single(np->pci_dev, skb->data,
+                                                            skb->end-skb->data, PCI_DMA_FROMDEVICE);
+                       np->put_rx_ctx->dma_len = skb->end-skb->data;
+                       if (np->desc_ver == DESC_VER_1 || np->desc_ver == DESC_VER_2) {
+                               np->put_rx.orig->buf = cpu_to_le32(np->put_rx_ctx->dma);
+                               wmb();
+                               np->put_rx.orig->flaglen = cpu_to_le32(np->rx_buf_sz | NV_RX_AVAIL);
+                               if (np->put_rx.orig++ == np->last_rx.orig)
+                                       np->put_rx.orig = np->first_rx.orig;
+                       } else {
+                               np->put_rx.ex->bufhigh = cpu_to_le64(np->put_rx_ctx->dma) >> 32;
+                               np->put_rx.ex->buflow = cpu_to_le64(np->put_rx_ctx->dma) & 0x0FFFFFFFF;
+                               wmb();
+                               np->put_rx.ex->flaglen = cpu_to_le32(np->rx_buf_sz | NV_RX2_AVAIL);
+                               if (np->put_rx.ex++ == np->last_rx.ex)
+                                       np->put_rx.ex = np->first_rx.ex;
+                       }
+                       if (np->put_rx_ctx++ == np->last_rx_ctx)
+                               np->put_rx_ctx = np->first_rx_ctx;
                } else {
-                       skb = np->put_rx_ctx->skb;
-               }
-               np->put_rx_ctx->dma = pci_map_single(np->pci_dev, skb->data,
-                                       skb->end-skb->data, PCI_DMA_FROMDEVICE);
-               np->put_rx_ctx->dma_len = skb->end-skb->data;
-               if (np->desc_ver == DESC_VER_1 || np->desc_ver == DESC_VER_2) {
-                       np->put_rx.orig->buf = cpu_to_le32(np->put_rx_ctx->dma);
-                       wmb();
-                       np->put_rx.orig->flaglen = cpu_to_le32(np->rx_buf_sz | NV_RX_AVAIL);
-                       if (np->put_rx.orig++ == np->last_rx.orig)
-                               np->put_rx.orig = np->first_rx.orig;
-               } else {
-                       np->put_rx.ex->bufhigh = cpu_to_le64(np->put_rx_ctx->dma) >> 32;
-                       np->put_rx.ex->buflow = cpu_to_le64(np->put_rx_ctx->dma) & 0x0FFFFFFFF;
-                       wmb();
-                       np->put_rx.ex->flaglen = cpu_to_le32(np->rx_buf_sz | NV_RX2_AVAIL);
-                       if (np->put_rx.ex++ == np->last_rx.ex)
-                               np->put_rx.ex = np->first_rx.ex;
+                       return 1;
                }
-               if (np->put_rx_ctx++ == np->last_rx_ctx)
-                       np->put_rx_ctx = np->first_rx_ctx;
        }
        return 0;
 }
@@ -1948,6 +1944,8 @@ static int nv_rx_process(struct net_device *dev, int limit)
                pci_unmap_single(np->pci_dev, np->get_rx_ctx->dma,
                                np->get_rx_ctx->dma_len,
                                PCI_DMA_FROMDEVICE);
+               skb = np->get_rx_ctx->skb;
+               np->get_rx_ctx->skb = NULL;
 
                {
                        int j;
@@ -1955,39 +1953,46 @@ static int nv_rx_process(struct net_device *dev, int limit)
                        for (j=0; j<64; j++) {
                                if ((j%16) == 0)
                                        dprintk("\n%03x:", j);
-                               dprintk(" %02x", ((unsigned char*)np->get_rx_ctx->skb->data)[j]);
+                               dprintk(" %02x", ((unsigned char*)skb->data)[j]);
                        }
                        dprintk("\n");
                }
                /* look at what we actually got: */
                if (np->desc_ver == DESC_VER_1) {
-                       if (!(flags & NV_RX_DESCRIPTORVALID))
+                       if (!(flags & NV_RX_DESCRIPTORVALID)) {
+                               dev_kfree_skb(skb);
                                goto next_pkt;
+                       }
 
                        if (flags & NV_RX_ERROR) {
                                if (flags & NV_RX_MISSEDFRAME) {
                                        np->stats.rx_missed_errors++;
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & (NV_RX_ERROR1|NV_RX_ERROR2|NV_RX_ERROR3)) {
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX_CRCERR) {
                                        np->stats.rx_crc_errors++;
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX_OVERFLOW) {
                                        np->stats.rx_over_errors++;
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX_ERROR4) {
-                                       len = nv_getlen(dev, np->get_rx_ctx->skb->data, len);
+                                       len = nv_getlen(dev, skb->data, len);
                                        if (len < 0) {
                                                np->stats.rx_errors++;
+                                               dev_kfree_skb(skb);
                                                goto next_pkt;
                                        }
                                }
@@ -1999,28 +2004,34 @@ static int nv_rx_process(struct net_device *dev, int limit)
                                }
                        }
                } else {
-                       if (!(flags & NV_RX2_DESCRIPTORVALID))
+                       if (!(flags & NV_RX2_DESCRIPTORVALID)) {
+                               dev_kfree_skb(skb);
                                goto next_pkt;
+                       }
 
                        if (flags & NV_RX2_ERROR) {
                                if (flags & (NV_RX2_ERROR1|NV_RX2_ERROR2|NV_RX2_ERROR3)) {
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX2_CRCERR) {
                                        np->stats.rx_crc_errors++;
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX2_OVERFLOW) {
                                        np->stats.rx_over_errors++;
                                        np->stats.rx_errors++;
+                                       dev_kfree_skb(skb);
                                        goto next_pkt;
                                }
                                if (flags & NV_RX2_ERROR4) {
-                                       len = nv_getlen(dev, np->get_rx_ctx->skb->data, len);
+                                       len = nv_getlen(dev, skb->data, len);
                                        if (len < 0) {
                                                np->stats.rx_errors++;
+                                               dev_kfree_skb(skb);
                                                goto next_pkt;
                                        }
                                }
@@ -2037,16 +2048,13 @@ static int nv_rx_process(struct net_device *dev, int limit)
                                    flags == NV_RX2_CHECKSUMOK2 ||
                                    flags == NV_RX2_CHECKSUMOK3) {
                                        dprintk(KERN_DEBUG "%s: hw checksum hit!.\n", dev->name);
-                                       np->get_rx_ctx->skb->ip_summed = CHECKSUM_UNNECESSARY;
+                                       skb->ip_summed = CHECKSUM_UNNECESSARY;
                                } else {
                                        dprintk(KERN_DEBUG "%s: hwchecksum miss!.\n", dev->name);
                                }
                        }
                }
                /* got a valid packet - forward it to the network core */
-               skb = np->get_rx_ctx->skb;
-               np->get_rx_ctx->skb = NULL;
-
                skb_put(skb, len);
                skb->protocol = eth_type_trans(skb, dev);
                dprintk(KERN_DEBUG "%s: nv_rx_process: %d bytes, proto %d accepted.\n",