[NET]: Remove gratuitous use of skb->tail in network drivers.
Many drivers use skb->tail unnecessarily.
In these situations, the code roughly looks like:
dev = dev_alloc_skb(...);
[optional] skb_reserve(skb, ...);
... skb->tail ...
But even if the skb_reserve() happens, skb->data equals
skb->tail. So it doesn't make any sense to use anything
other than skb->data in these cases.
Another case was the s2io.c driver directly mucking with
the skb->data and skb->tail pointers. It really just wanted
to do an skb_reserve(), so that's what the code was changed
to do instead.
Another reason I'm making this change as it allows some SKB
cleanups I have planned simpler to merge. In those cleanups,
skb->head, skb->tail, and skb->end pointers are removed, and
replaced with skb->head_room and skb->tail_room integers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/tulip/interrupt.c b/drivers/net/tulip/interrupt.c
index afb5cda..bb35581 100644
--- a/drivers/net/tulip/interrupt.c
+++ b/drivers/net/tulip/interrupt.c
@@ -78,7 +78,7 @@
if (skb == NULL)
break;
- mapping = pci_map_single(tp->pdev, skb->tail, PKT_BUF_SZ,
+ mapping = pci_map_single(tp->pdev, skb->data, PKT_BUF_SZ,
PCI_DMA_FROMDEVICE);
tp->rx_buffers[entry].mapping = mapping;
@@ -199,12 +199,12 @@
tp->rx_buffers[entry].mapping,
pkt_len, PCI_DMA_FROMDEVICE);
#if ! defined(__alpha__)
- eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->tail,
+ eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->data,
pkt_len, 0);
skb_put(skb, pkt_len);
#else
memcpy(skb_put(skb, pkt_len),
- tp->rx_buffers[entry].skb->tail,
+ tp->rx_buffers[entry].skb->data,
pkt_len);
#endif
pci_dma_sync_single_for_device(tp->pdev,
@@ -423,12 +423,12 @@
tp->rx_buffers[entry].mapping,
pkt_len, PCI_DMA_FROMDEVICE);
#if ! defined(__alpha__)
- eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->tail,
+ eth_copy_and_sum(skb, tp->rx_buffers[entry].skb->data,
pkt_len, 0);
skb_put(skb, pkt_len);
#else
memcpy(skb_put(skb, pkt_len),
- tp->rx_buffers[entry].skb->tail,
+ tp->rx_buffers[entry].skb->data,
pkt_len);
#endif
pci_dma_sync_single_for_device(tp->pdev,