From 432aa7ed75b3adaef6040d2cbe745fdd1c899415 Mon Sep 17 00:00:00 2001 From: Matt Carlson Date: Thu, 19 May 2011 12:12:45 +0000 Subject: [PATCH] tg3: Cleanup transmit error path This patch consolidates the skb cleanup code into a function named tg3_skb_error_unmap(). The modification addresses a long-standing bug where pci_unmap_single() was incorrectly being called instead of pci_unmap_page() in tigon3_dma_hwbug_workaround(). Signed-off-by: Matt Carlson Reviewed-by: Michael Chan Signed-off-by: David S. Miller --- drivers/net/tg3.c | 98 ++++++++++++++++++----------------------------- 1 file changed, 38 insertions(+), 60 deletions(-) diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index 4c441682a291..b2b1ba168c88 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -5758,16 +5758,39 @@ static void tg3_set_txd(struct tg3_napi *tnapi, int entry, txd->vlan_tag = vlan_tag << TXD_VLAN_TAG_SHIFT; } +static void tg3_skb_error_unmap(struct tg3_napi *tnapi, + struct sk_buff *skb, int last) +{ + int i; + u32 entry = tnapi->tx_prod; + struct ring_info *txb = &tnapi->tx_buffers[entry]; + + pci_unmap_single(tnapi->tp->pdev, + dma_unmap_addr(txb, mapping), + skb_headlen(skb), + PCI_DMA_TODEVICE); + for (i = 0; i <= last; i++) { + skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; + + entry = NEXT_TX(entry); + txb = &tnapi->tx_buffers[entry]; + + pci_unmap_page(tnapi->tp->pdev, + dma_unmap_addr(txb, mapping), + frag->size, PCI_DMA_TODEVICE); + } +} + /* Workaround 4GB and 40-bit hardware DMA bugs. */ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi, - struct sk_buff *skb, u32 last_plus_one, - u32 *start, u32 base_flags, u32 mss) + struct sk_buff *skb, + u32 base_flags, u32 mss) { struct tg3 *tp = tnapi->tp; struct sk_buff *new_skb; dma_addr_t new_addr = 0; - u32 entry = *start; - int i, ret = 0; + u32 entry = tnapi->tx_prod; + int ret = 0; if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5701) new_skb = skb_copy(skb, GFP_ATOMIC); @@ -5783,14 +5806,12 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi, ret = -1; } else { /* New SKB is guaranteed to be linear. */ - entry = *start; new_addr = pci_map_single(tp->pdev, new_skb->data, new_skb->len, PCI_DMA_TODEVICE); /* Make sure the mapping succeeded */ if (pci_dma_mapping_error(tp->pdev, new_addr)) { ret = -1; dev_kfree_skb(new_skb); - new_skb = NULL; /* Make sure new skb does not cross any 4G boundaries. * Drop the packet if it does. @@ -5801,39 +5822,16 @@ static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi, PCI_DMA_TODEVICE); ret = -1; dev_kfree_skb(new_skb); - new_skb = NULL; } else { + tnapi->tx_buffers[entry].skb = new_skb; + dma_unmap_addr_set(&tnapi->tx_buffers[entry], + mapping, new_addr); + tg3_set_txd(tnapi, entry, new_addr, new_skb->len, base_flags, 1 | (mss << 1)); - *start = NEXT_TX(entry); } } - /* Now clean up the sw ring entries. */ - i = 0; - while (entry != last_plus_one) { - int len; - - if (i == 0) - len = skb_headlen(skb); - else - len = skb_shinfo(skb)->frags[i-1].size; - - pci_unmap_single(tp->pdev, - dma_unmap_addr(&tnapi->tx_buffers[entry], - mapping), - len, PCI_DMA_TODEVICE); - if (i == 0) { - tnapi->tx_buffers[entry].skb = new_skb; - dma_unmap_addr_set(&tnapi->tx_buffers[entry], mapping, - new_addr); - } else { - tnapi->tx_buffers[entry].skb = NULL; - } - entry = NEXT_TX(entry); - i++; - } - dev_kfree_skb(skb); return ret; @@ -5889,11 +5887,11 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct tg3 *tp = netdev_priv(dev); u32 len, entry, base_flags, mss; - int would_hit_hwbug; + int i = -1, would_hit_hwbug; dma_addr_t mapping; struct tg3_napi *tnapi; struct netdev_queue *txq; - unsigned int i, last; + unsigned int last; txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); tnapi = &tp->napi[skb_get_queue_mapping(skb)]; @@ -6074,20 +6072,15 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) } if (would_hit_hwbug) { - u32 last_plus_one = entry; - u32 start; - - start = entry - 1 - skb_shinfo(skb)->nr_frags; - start &= (TG3_TX_RING_SIZE - 1); + tg3_skb_error_unmap(tnapi, skb, i); /* If the workaround fails due to memory/mapping * failure, silently drop this packet. */ - if (tigon3_dma_hwbug_workaround(tnapi, skb, last_plus_one, - &start, base_flags, mss)) + if (tigon3_dma_hwbug_workaround(tnapi, skb, base_flags, mss)) goto out_unlock; - entry = start; + entry = NEXT_TX(tnapi->tx_prod); } /* Packets are ready, update Tx producer idx local and on card. */ @@ -6113,24 +6106,9 @@ out_unlock: return NETDEV_TX_OK; dma_error: - last = i; - entry = tnapi->tx_prod; - tnapi->tx_buffers[entry].skb = NULL; - pci_unmap_single(tp->pdev, - dma_unmap_addr(&tnapi->tx_buffers[entry], mapping), - skb_headlen(skb), - PCI_DMA_TODEVICE); - for (i = 0; i <= last; i++) { - skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; - entry = NEXT_TX(entry); - - pci_unmap_page(tp->pdev, - dma_unmap_addr(&tnapi->tx_buffers[entry], - mapping), - frag->size, PCI_DMA_TODEVICE); - } - + tg3_skb_error_unmap(tnapi, skb, i); dev_kfree_skb(skb); + tnapi->tx_buffers[tnapi->tx_prod].skb = NULL; return NETDEV_TX_OK; } -- 2.39.5