[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/hamachi.c b/drivers/net/hamachi.c
index 3d96714..d9df1d9 100644
--- a/drivers/net/hamachi.c
+++ b/drivers/net/hamachi.c
@@ -1149,7 +1149,7 @@
skb->dev = dev; /* Mark as being used by this device. */
skb_reserve(skb, 2); /* 16 byte align the IP header. */
hmp->rx_ring[i].addr = cpu_to_leXX(pci_map_single(hmp->pci_dev,
- skb->tail, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
+ skb->data, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
hmp->rx_ring[i].status_n_length = cpu_to_le32(DescOwn |
DescEndPacket | DescIntr | (hmp->rx_buf_sz - 2));
}
@@ -1210,7 +1210,7 @@
skb->dev = dev; /* Mark as being used by this device. */
skb_reserve(skb, 2); /* 16 byte align the IP header. */
hmp->rx_ring[i].addr = cpu_to_leXX(pci_map_single(hmp->pci_dev,
- skb->tail, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
+ skb->data, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
/* -2 because it doesn't REALLY have that first 2 bytes -KDU */
hmp->rx_ring[i].status_n_length = cpu_to_le32(DescOwn |
DescEndPacket | DescIntr | (hmp->rx_buf_sz -2));
@@ -1509,7 +1509,7 @@
desc->addr,
hmp->rx_buf_sz,
PCI_DMA_FROMDEVICE);
- buf_addr = (u8 *) hmp->rx_skbuff[entry]->tail;
+ buf_addr = (u8 *) hmp->rx_skbuff[entry]->data;
frame_status = le32_to_cpu(get_unaligned((s32*)&(buf_addr[data_size - 12])));
if (hamachi_debug > 4)
printk(KERN_DEBUG " hamachi_rx() status was %8.8x.\n",
@@ -1678,7 +1678,7 @@
skb->dev = dev; /* Mark as being used by this device. */
skb_reserve(skb, 2); /* Align IP on 16 byte boundaries */
desc->addr = cpu_to_leXX(pci_map_single(hmp->pci_dev,
- skb->tail, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
+ skb->data, hmp->rx_buf_sz, PCI_DMA_FROMDEVICE));
}
desc->status_n_length = cpu_to_le32(hmp->rx_buf_sz);
if (entry >= RX_RING_SIZE-1)
@@ -1772,9 +1772,9 @@
readl(ioaddr + RxCurPtr) == (long)&hmp->rx_ring[i] ? '>' : ' ',
i, hmp->rx_ring[i].status_n_length, hmp->rx_ring[i].addr);
if (hamachi_debug > 6) {
- if (*(u8*)hmp->rx_skbuff[i]->tail != 0x69) {
+ if (*(u8*)hmp->rx_skbuff[i]->data != 0x69) {
u16 *addr = (u16 *)
- hmp->rx_skbuff[i]->tail;
+ hmp->rx_skbuff[i]->data;
int j;
for (j = 0; j < 0x50; j++)