[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>

drivers/net/3c515.c

@@ -822,7 +822,7 @@ static int corkscrew_open(struct net_device *dev)
 				break;	/* Bad news!  */
 			skb->dev = dev;	/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
-			vp->rx_ring[i].addr = isa_virt_to_bus(skb->tail);
+			vp->rx_ring[i].addr = isa_virt_to_bus(skb->data);
 		}
 		vp->rx_ring[i - 1].next = isa_virt_to_bus(&vp->rx_ring[0]);	/* Wrap the ring. */
 		outl(isa_virt_to_bus(&vp->rx_ring[0]), ioaddr + UpListPtr);
@@ -1406,7 +1406,7 @@ static int boomerang_rx(struct net_device *dev)
 				break;	/* Bad news!  */
 			skb->dev = dev;	/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
-			vp->rx_ring[entry].addr = isa_virt_to_bus(skb->tail);
+			vp->rx_ring[entry].addr = isa_virt_to_bus(skb->data);
 			vp->rx_skbuff[entry] = skb;
 		}
 		vp->rx_ring[entry].status = 0;	/* Clear complete bit. */

drivers/net/3c59x.c

@@ -1802,7 +1802,7 @@ vortex_open(struct net_device *dev)
 				break;			/* Bad news!  */
 			skb->dev = dev;			/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
-			vp->rx_ring[i].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->tail, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
+			vp->rx_ring[i].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
 		}
 		if (i != RX_RING_SIZE) {
 			int j;
@@ -2632,7 +2632,7 @@ boomerang_rx(struct net_device *dev)
 				pci_dma_sync_single_for_cpu(VORTEX_PCI(vp), dma, PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 				/* 'skb_put()' points to the start of sk_buff data area. */
 				memcpy(skb_put(skb, pkt_len),
-					   vp->rx_skbuff[entry]->tail,
+					   vp->rx_skbuff[entry]->data,
 					   pkt_len);
 				pci_dma_sync_single_for_device(VORTEX_PCI(vp), dma, PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 				vp->rx_copy++;
@@ -2678,7 +2678,7 @@ boomerang_rx(struct net_device *dev)
 			}
 			skb->dev = dev;			/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
-			vp->rx_ring[entry].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->tail, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
+			vp->rx_ring[entry].addr = cpu_to_le32(pci_map_single(VORTEX_PCI(vp), skb->data, PKT_BUF_SZ, PCI_DMA_FROMDEVICE));
 			vp->rx_skbuff[entry] = skb;
 		}
 		vp->rx_ring[entry].status = 0;	/* Clear complete bit. */

drivers/net/8139cp.c

@@ -596,7 +596,7 @@ rx_status_loop:
 
 		mapping =
 		cp->rx_skb[rx_tail].mapping =
-			pci_map_single(cp->pdev, new_skb->tail,
+			pci_map_single(cp->pdev, new_skb->data,
 				       buflen, PCI_DMA_FROMDEVICE);
 		cp->rx_skb[rx_tail].skb = new_skb;
 
@@ -1101,7 +1101,7 @@ static int cp_refill_rx (struct cp_private *cp)
 		skb_reserve(skb, RX_OFFSET);
 
 		cp->rx_skb[i].mapping = pci_map_single(cp->pdev,
-			skb->tail, cp->rx_buf_sz, PCI_DMA_FROMDEVICE);
+			skb->data, cp->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		cp->rx_skb[i].skb = skb;
 
 		cp->rx_ring[i].opts2 = 0;

drivers/net/82596.c

@@ -546,11 +546,11 @@ static inline void init_rx_bufs(struct net_device *dev)
 		rbd->b_next = WSWAPrbd(virt_to_bus(rbd+1));
 		rbd->b_addr = WSWAPrbd(virt_to_bus(rbd));
 		rbd->skb = skb;
-		rbd->v_data = skb->tail;
-		rbd->b_data = WSWAPchar(virt_to_bus(skb->tail));
+		rbd->v_data = skb->data;
+		rbd->b_data = WSWAPchar(virt_to_bus(skb->data));
 		rbd->size = PKT_BUF_SZ;
 #ifdef __mc68000__
-		cache_clear(virt_to_phys(skb->tail), PKT_BUF_SZ);
+		cache_clear(virt_to_phys(skb->data), PKT_BUF_SZ);
 #endif
 	}
 	lp->rbd_head = lp->rbds;
@@ -816,10 +816,10 @@ static inline int i596_rx(struct net_device *dev)
 				rx_in_place = 1;
 				rbd->skb = newskb;
 				newskb->dev = dev;
-				rbd->v_data = newskb->tail;
-				rbd->b_data = WSWAPchar(virt_to_bus(newskb->tail));
+				rbd->v_data = newskb->data;
+				rbd->b_data = WSWAPchar(virt_to_bus(newskb->data));
 #ifdef __mc68000__
-				cache_clear(virt_to_phys(newskb->tail), PKT_BUF_SZ);
+				cache_clear(virt_to_phys(newskb->data), PKT_BUF_SZ);
 #endif
 			}
 			else
@@ -840,7 +840,7 @@ memory_squeeze:
 				skb->protocol=eth_type_trans(skb,dev);
 				skb->len = pkt_len;
 #ifdef __mc68000__
-				cache_clear(virt_to_phys(rbd->skb->tail),
+				cache_clear(virt_to_phys(rbd->skb->data),
 						pkt_len);
 #endif
 				netif_rx(skb);

drivers/net/dl2k.c

@@ -547,7 +547,7 @@ rio_timer (unsigned long data)
 				skb_reserve (skb, 2);
 				np->rx_ring[entry].fraginfo =
 				    cpu_to_le64 (pci_map_single
-					 (np->pdev, skb->tail, np->rx_buf_sz,
+					 (np->pdev, skb->data, np->rx_buf_sz,
 					  PCI_DMA_FROMDEVICE));
 			}
 			np->rx_ring[entry].fraginfo |=
@@ -618,7 +618,7 @@ alloc_list (struct net_device *dev)
 		/* Rubicon now supports 40 bits of addressing space. */
 		np->rx_ring[i].fraginfo =
 		    cpu_to_le64 ( pci_map_single (
-			 	  np->pdev, skb->tail, np->rx_buf_sz,
+			 	  np->pdev, skb->data, np->rx_buf_sz,
 				  PCI_DMA_FROMDEVICE));
 		np->rx_ring[i].fraginfo |= cpu_to_le64 (np->rx_buf_sz) << 48;
 	}
@@ -906,7 +906,7 @@ receive_packet (struct net_device *dev)
 				/* 16 byte align the IP header */
 				skb_reserve (skb, 2);
 				eth_copy_and_sum (skb,
-						  np->rx_skbuff[entry]->tail,
+						  np->rx_skbuff[entry]->data,
 						  pkt_len, 0);
 				skb_put (skb, pkt_len);
 				pci_dma_sync_single_for_device(np->pdev,
@@ -950,7 +950,7 @@ receive_packet (struct net_device *dev)
 			skb_reserve (skb, 2);
 			np->rx_ring[entry].fraginfo =
 			    cpu_to_le64 (pci_map_single
-					 (np->pdev, skb->tail, np->rx_buf_sz,
+					 (np->pdev, skb->data, np->rx_buf_sz,
 					  PCI_DMA_FROMDEVICE));
 		}
 		np->rx_ring[entry].fraginfo |=

drivers/net/eepro100.c

@@ -1269,7 +1269,7 @@ speedo_init_rx_ring(struct net_device *dev)
 		if (skb == NULL)
 			break;			/* OK.  Just initially short of Rx bufs. */
 		skb->dev = dev;			/* Mark as being used by this device. */
-		rxf = (struct RxFD *)skb->tail;
+		rxf = (struct RxFD *)skb->data;
 		sp->rx_ringp[i] = rxf;
 		sp->rx_ring_dma[i] =
 			pci_map_single(sp->pdev, rxf,
@@ -1661,7 +1661,7 @@ static inline struct RxFD *speedo_rx_alloc(struct net_device *dev, int entry)
 		sp->rx_ringp[entry] = NULL;
 		return NULL;
 	}
-	rxf = sp->rx_ringp[entry] = (struct RxFD *)skb->tail;
+	rxf = sp->rx_ringp[entry] = (struct RxFD *)skb->data;
 	sp->rx_ring_dma[entry] =
 		pci_map_single(sp->pdev, rxf,
 					   PKT_BUF_SZ + sizeof(struct RxFD), PCI_DMA_FROMDEVICE);
@@ -1808,10 +1808,10 @@ speedo_rx(struct net_device *dev)
 
 #if 1 || USE_IP_CSUM
 				/* Packet is in one chunk -- we can copy + cksum. */
-				eth_copy_and_sum(skb, sp->rx_skbuff[entry]->tail, pkt_len, 0);
+				eth_copy_and_sum(skb, sp->rx_skbuff[entry]->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 #else
-				memcpy(skb_put(skb, pkt_len), sp->rx_skbuff[entry]->tail,
+				memcpy(skb_put(skb, pkt_len), sp->rx_skbuff[entry]->data,
 					   pkt_len);
 #endif
 				pci_dma_sync_single_for_device(sp->pdev, sp->rx_ring_dma[entry],

drivers/net/epic100.c

@@ -1003,7 +1003,7 @@ static void epic_init_ring(struct net_device *dev)
 		skb->dev = dev;			/* Mark as being used by this device. */
 		skb_reserve(skb, 2);	/* 16 byte align the IP header. */
 		ep->rx_ring[i].bufaddr = pci_map_single(ep->pci_dev, 
-			skb->tail, ep->rx_buf_sz, PCI_DMA_FROMDEVICE);
+			skb->data, ep->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		ep->rx_ring[i].rxstatus = cpu_to_le32(DescOwn);
 	}
 	ep->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
@@ -1274,7 +1274,7 @@ static int epic_rx(struct net_device *dev, int budget)
 							    ep->rx_ring[entry].bufaddr,
 							    ep->rx_buf_sz,
 							    PCI_DMA_FROMDEVICE);
-				eth_copy_and_sum(skb, ep->rx_skbuff[entry]->tail, pkt_len, 0);
+				eth_copy_and_sum(skb, ep->rx_skbuff[entry]->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 				pci_dma_sync_single_for_device(ep->pci_dev,
 							       ep->rx_ring[entry].bufaddr,
@@ -1308,7 +1308,7 @@ static int epic_rx(struct net_device *dev, int budget)
 			skb->dev = dev;			/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
 			ep->rx_ring[entry].bufaddr = pci_map_single(ep->pci_dev, 
-				skb->tail, ep->rx_buf_sz, PCI_DMA_FROMDEVICE);
+				skb->data, ep->rx_buf_sz, PCI_DMA_FROMDEVICE);
 			work_done++;
 		}
 		ep->rx_ring[entry].rxstatus = cpu_to_le32(DescOwn);

drivers/net/fealnx.c

@@ -1107,7 +1107,7 @@ static void allocate_rx_buffers(struct net_device *dev)
 
 		skb->dev = dev;	/* Mark as being used by this device. */
 		np->lack_rxbuf->skbuff = skb;
-		np->lack_rxbuf->buffer = pci_map_single(np->pci_dev, skb->tail,
+		np->lack_rxbuf->buffer = pci_map_single(np->pci_dev, skb->data,
 			np->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		np->lack_rxbuf->status = RXOWN;
 		++np->really_rx_count;
@@ -1300,7 +1300,7 @@ static void init_ring(struct net_device *dev)
 		++np->really_rx_count;
 		np->rx_ring[i].skbuff = skb;
 		skb->dev = dev;	/* Mark as being used by this device. */
-		np->rx_ring[i].buffer = pci_map_single(np->pci_dev, skb->tail,
+		np->rx_ring[i].buffer = pci_map_single(np->pci_dev, skb->data,
 			np->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		np->rx_ring[i].status = RXOWN;
 		np->rx_ring[i].control |= RXIC;
@@ -1737,11 +1737,11 @@ static int netdev_rx(struct net_device *dev)
 
 #if ! defined(__alpha__)
 				eth_copy_and_sum(skb, 
-					np->cur_rx->skbuff->tail, pkt_len, 0);
+					np->cur_rx->skbuff->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 #else
 				memcpy(skb_put(skb, pkt_len),
-					np->cur_rx->skbuff->tail, pkt_len);
+					np->cur_rx->skbuff->data, pkt_len);
 #endif
 				pci_dma_sync_single_for_device(np->pci_dev,
 							       np->cur_rx->buffer,

drivers/net/hamachi.c

@@ -1149,7 +1149,7 @@ static void hamachi_tx_timeout(struct net_device *dev)
 		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 @@ static void hamachi_init_ring(struct net_device *dev)
 		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 @@ static int hamachi_rx(struct net_device *dev)
 					    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 @@ static int hamachi_rx(struct net_device *dev)
 			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 @@ static int hamachi_close(struct net_device *dev)
 				   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++)

drivers/net/lance.c

@@ -862,7 +862,7 @@ lance_init_ring(struct net_device *dev, int gfp)
 		lp->rx_skbuff[i] = skb;
 		if (skb) {
 			skb->dev = dev;
-			rx_buff = skb->tail;
+			rx_buff = skb->data;
 		} else
 			rx_buff = kmalloc(PKT_BUF_SZ, GFP_DMA | gfp);
 		if (rx_buff == NULL)

drivers/net/lasi_82596.c

@@ -553,14 +553,14 @@ static inline void init_rx_bufs(struct net_device *dev)
 		if (skb == NULL)
 			panic("%s: alloc_skb() failed", __FILE__);
 		skb_reserve(skb, 2);
-		dma_addr = dma_map_single(lp->dev, skb->tail,PKT_BUF_SZ,
+		dma_addr = dma_map_single(lp->dev, skb->data,PKT_BUF_SZ,
 					  DMA_FROM_DEVICE);
 		skb->dev = dev;
 		rbd->v_next = rbd+1;
 		rbd->b_next = WSWAPrbd(virt_to_dma(lp,rbd+1));
 		rbd->b_addr = WSWAPrbd(virt_to_dma(lp,rbd));
 		rbd->skb = skb;
-		rbd->v_data = skb->tail;
+		rbd->v_data = skb->data;
 		rbd->b_data = WSWAPchar(dma_addr);
 		rbd->size = PKT_BUF_SZ;
 	}
@@ -783,8 +783,8 @@ static inline int i596_rx(struct net_device *dev)
 				rx_in_place = 1;
 				rbd->skb = newskb;
 				newskb->dev = dev;
-				dma_addr = dma_map_single(lp->dev, newskb->tail, PKT_BUF_SZ, DMA_FROM_DEVICE);
-				rbd->v_data = newskb->tail;
+				dma_addr = dma_map_single(lp->dev, newskb->data, PKT_BUF_SZ, DMA_FROM_DEVICE);
+				rbd->v_data = newskb->data;
 				rbd->b_data = WSWAPchar(dma_addr);
 				CHECK_WBACK_INV(rbd, sizeof(struct i596_rbd));
 			}

drivers/net/natsemi.c

@@ -1926,7 +1926,7 @@ static void refill_rx(struct net_device *dev)
 				break; /* Better luck next round. */
 			skb->dev = dev; /* Mark as being used by this device. */
 			np->rx_dma[entry] = pci_map_single(np->pci_dev,
-				skb->tail, buflen, PCI_DMA_FROMDEVICE);
+				skb->data, buflen, PCI_DMA_FROMDEVICE);
 			np->rx_ring[entry].addr = cpu_to_le32(np->rx_dma[entry]);
 		}
 		np->rx_ring[entry].cmd_status = cpu_to_le32(np->rx_buf_sz);
@@ -2280,7 +2280,7 @@ static void netdev_rx(struct net_device *dev)
 					buflen,
 					PCI_DMA_FROMDEVICE);
 				eth_copy_and_sum(skb,
-					np->rx_skbuff[entry]->tail, pkt_len, 0);
+					np->rx_skbuff[entry]->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 				pci_dma_sync_single_for_device(np->pci_dev,
 					np->rx_dma[entry],

drivers/net/ns83820.c

@@ -574,7 +574,7 @@ static inline int ns83820_add_rx_skb(struct ns83820 *dev, struct sk_buff *skb)
 
 	dev->rx_info.next_empty = (next_empty + 1) % NR_RX_DESC;
 	cmdsts = REAL_RX_BUF_SIZE | CMDSTS_INTR;
-	buf = pci_map_single(dev->pci_dev, skb->tail,
+	buf = pci_map_single(dev->pci_dev, skb->data,
 			     REAL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 	build_rx_desc(dev, sg, 0, buf, cmdsts, 0);
 	/* update link of previous rx */
@@ -604,7 +604,7 @@ static inline int rx_refill(struct net_device *ndev, int gfp)
 		if (unlikely(!skb))
 			break;
 
-		res = (long)skb->tail & 0xf;
+		res = (long)skb->data & 0xf;
 		res = 0x10 - res;
 		res &= 0xf;
 		skb_reserve(skb, res);

drivers/net/pcnet32.c

@@ -1602,7 +1602,7 @@ pcnet32_init_ring(struct net_device *dev)
 
 	rmb();
 	if (lp->rx_dma_addr[i] == 0)
-	    lp->rx_dma_addr[i] = pci_map_single(lp->pci_dev, rx_skbuff->tail,
+	    lp->rx_dma_addr[i] = pci_map_single(lp->pci_dev, rx_skbuff->data,
 		    PKT_BUF_SZ-2, PCI_DMA_FROMDEVICE);
 	lp->rx_ring[i].base = (u32)le32_to_cpu(lp->rx_dma_addr[i]);
 	lp->rx_ring[i].buf_length = le16_to_cpu(2-PKT_BUF_SZ);
@@ -1983,7 +1983,7 @@ pcnet32_rx(struct net_device *dev)
 			lp->rx_skbuff[entry] = newskb;
 			newskb->dev = dev;
 			lp->rx_dma_addr[entry] =
-			    pci_map_single(lp->pci_dev, newskb->tail,
+			    pci_map_single(lp->pci_dev, newskb->data,
 				    PKT_BUF_SZ-2, PCI_DMA_FROMDEVICE);
 			lp->rx_ring[entry].base = le32_to_cpu(lp->rx_dma_addr[entry]);
 			rx_in_place = 1;
@@ -2020,7 +2020,7 @@ pcnet32_rx(struct net_device *dev)
 						PKT_BUF_SZ-2,
 						PCI_DMA_FROMDEVICE);
 		    eth_copy_and_sum(skb,
-			    (unsigned char *)(lp->rx_skbuff[entry]->tail),
+			    (unsigned char *)(lp->rx_skbuff[entry]->data),
 			    pkt_len,0);
 		    pci_dma_sync_single_for_device(lp->pci_dev,
 						   lp->rx_dma_addr[entry],

drivers/net/r8169.c

@@ -1876,7 +1876,7 @@ static int rtl8169_alloc_rx_skb(struct pci_dev *pdev, struct sk_buff **sk_buff,
 	skb_reserve(skb, NET_IP_ALIGN);
 	*sk_buff = skb;
 
-	mapping = pci_map_single(pdev, skb->tail, rx_buf_sz,
+	mapping = pci_map_single(pdev, skb->data, rx_buf_sz,
 				 PCI_DMA_FROMDEVICE);
 
 	rtl8169_map_to_asic(desc, mapping, rx_buf_sz);
@@ -2336,7 +2336,7 @@ static inline int rtl8169_try_rx_copy(struct sk_buff **sk_buff, int pkt_size,
 		skb = dev_alloc_skb(pkt_size + NET_IP_ALIGN);
 		if (skb) {
 			skb_reserve(skb, NET_IP_ALIGN);
-			eth_copy_and_sum(skb, sk_buff[0]->tail, pkt_size, 0);
+			eth_copy_and_sum(skb, sk_buff[0]->data, pkt_size, 0);
 			*sk_buff = skb;
 			rtl8169_mark_to_asic(desc, rx_buf_sz);
 			ret = 0;

drivers/net/s2io.c

@@ -1699,11 +1699,9 @@ static int fill_rx_buffers(struct s2io_nic *nic, int ring_no)
 #else
 		ba = &nic->ba[ring_no][block_no][off];
 		skb_reserve(skb, BUF0_LEN);
-		tmp = (unsigned long) skb->data;
-		tmp += ALIGN_SIZE;
-		tmp &= ~ALIGN_SIZE;
-		skb->data = (void *) tmp;
-		skb->tail = (void *) tmp;
+		tmp = ((unsigned long) skb->data & ALIGN_SIZE);
+		if (tmp)
+			skb_reserve(skb, (ALIGN_SIZE + 1) - tmp);
 
 		memset(rxdp, 0, sizeof(RxD_t));
 		rxdp->Buffer2_ptr = pci_map_single

drivers/net/sb1250-mac.c

@@ -963,11 +963,11 @@ static int sbdma_add_rcvbuffer(sbmacdma_t *d,struct sk_buff *sb)
 	/*
 	 * Do not interrupt per DMA transfer.
 	 */
-	dsc->dscr_a = virt_to_phys(sb_new->tail) |
+	dsc->dscr_a = virt_to_phys(sb_new->data) |
 		V_DMA_DSCRA_A_SIZE(NUMCACHEBLKS(pktsize+ETHER_ALIGN)) |
 		0;
 #else
-	dsc->dscr_a = virt_to_phys(sb_new->tail) |
+	dsc->dscr_a = virt_to_phys(sb_new->data) |
 		V_DMA_DSCRA_A_SIZE(NUMCACHEBLKS(pktsize+ETHER_ALIGN)) |
 		M_DMA_DSCRA_INTERRUPT;
 #endif

drivers/net/sis900.c

@@ -1154,7 +1154,7 @@ sis900_init_rx_ring(struct net_device *net_dev)
 		sis_priv->rx_skbuff[i] = skb;
 		sis_priv->rx_ring[i].cmdsts = RX_BUF_SIZE;
                 sis_priv->rx_ring[i].bufptr = pci_map_single(sis_priv->pci_dev,
-                        skb->tail, RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
+                        skb->data, RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 	}
 	sis_priv->dirty_rx = (unsigned int) (i - NUM_RX_DESC);
 
@@ -1776,7 +1776,7 @@ static int sis900_rx(struct net_device *net_dev)
 			sis_priv->rx_skbuff[entry] = skb;
 			sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
                 	sis_priv->rx_ring[entry].bufptr = 
-				pci_map_single(sis_priv->pci_dev, skb->tail, 
+				pci_map_single(sis_priv->pci_dev, skb->data, 
 					RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 			sis_priv->dirty_rx++;
 		}
@@ -1809,7 +1809,7 @@ static int sis900_rx(struct net_device *net_dev)
 			sis_priv->rx_skbuff[entry] = skb;
 			sis_priv->rx_ring[entry].cmdsts = RX_BUF_SIZE;
                 	sis_priv->rx_ring[entry].bufptr =
-				pci_map_single(sis_priv->pci_dev, skb->tail,
+				pci_map_single(sis_priv->pci_dev, skb->data,
 					RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
 		}
 	}

drivers/net/starfire.c

@@ -1286,7 +1286,7 @@ static void init_ring(struct net_device *dev)
 		np->rx_info[i].skb = skb;
 		if (skb == NULL)
 			break;
-		np->rx_info[i].mapping = pci_map_single(np->pci_dev, skb->tail, np->rx_buf_sz, PCI_DMA_FROMDEVICE);
+		np->rx_info[i].mapping = pci_map_single(np->pci_dev, skb->data, np->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		skb->dev = dev;			/* Mark as being used by this device. */
 		/* Grrr, we cannot offset to correctly align the IP header. */
 		np->rx_ring[i].rxaddr = cpu_to_dma(np->rx_info[i].mapping | RxDescValid);
@@ -1572,7 +1572,7 @@ static int __netdev_rx(struct net_device *dev, int *quota)
 			pci_dma_sync_single_for_cpu(np->pci_dev,
 						    np->rx_info[entry].mapping,
 						    pkt_len, PCI_DMA_FROMDEVICE);
-			eth_copy_and_sum(skb, np->rx_info[entry].skb->tail, pkt_len, 0);
+			eth_copy_and_sum(skb, np->rx_info[entry].skb->data, pkt_len, 0);
 			pci_dma_sync_single_for_device(np->pci_dev,
 						       np->rx_info[entry].mapping,
 						       pkt_len, PCI_DMA_FROMDEVICE);
@@ -1696,7 +1696,7 @@ static void refill_rx_ring(struct net_device *dev)
 			if (skb == NULL)
 				break;	/* Better luck next round. */
 			np->rx_info[entry].mapping =
-				pci_map_single(np->pci_dev, skb->tail, np->rx_buf_sz, PCI_DMA_FROMDEVICE);
+				pci_map_single(np->pci_dev, skb->data, np->rx_buf_sz, PCI_DMA_FROMDEVICE);
 			skb->dev = dev;	/* Mark as being used by this device. */
 			np->rx_ring[entry].rxaddr =
 				cpu_to_dma(np->rx_info[entry].mapping | RxDescValid);

drivers/net/sundance.c

@@ -1028,7 +1028,7 @@ static void init_ring(struct net_device *dev)
 		skb->dev = dev;		/* Mark as being used by this device. */
 		skb_reserve(skb, 2);	/* 16 byte align the IP header. */
 		np->rx_ring[i].frag[0].addr = cpu_to_le32(
-			pci_map_single(np->pci_dev, skb->tail, np->rx_buf_sz,
+			pci_map_single(np->pci_dev, skb->data, np->rx_buf_sz,
 				PCI_DMA_FROMDEVICE));
 		np->rx_ring[i].frag[0].length = cpu_to_le32(np->rx_buf_sz | LastFrag);
 	}
@@ -1341,7 +1341,7 @@ static void rx_poll(unsigned long data)
 							    np->rx_buf_sz,
 							    PCI_DMA_FROMDEVICE);
 
-				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
+				eth_copy_and_sum(skb, np->rx_skbuff[entry]->data, pkt_len, 0);
 				pci_dma_sync_single_for_device(np->pci_dev,
 							       desc->frag[0].addr,
 							       np->rx_buf_sz,
@@ -1400,7 +1400,7 @@ static void refill_rx (struct net_device *dev)
 			skb->dev = dev;		/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
 			np->rx_ring[entry].frag[0].addr = cpu_to_le32(
-				pci_map_single(np->pci_dev, skb->tail,
+				pci_map_single(np->pci_dev, skb->data,
 					np->rx_buf_sz, PCI_DMA_FROMDEVICE));
 		}
 		/* Perhaps we need not reset this field. */

drivers/net/tulip/de2104x.c

@@ -446,13 +446,13 @@ static void de_rx (struct de_private *de)
 
 			mapping =
 			de->rx_skb[rx_tail].mapping =
-				pci_map_single(de->pdev, copy_skb->tail,
+				pci_map_single(de->pdev, copy_skb->data,
 					       buflen, PCI_DMA_FROMDEVICE);
 			de->rx_skb[rx_tail].skb = copy_skb;
 		} else {
 			pci_dma_sync_single_for_cpu(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
 			skb_reserve(copy_skb, RX_OFFSET);
-			memcpy(skb_put(copy_skb, len), skb->tail, len);
+			memcpy(skb_put(copy_skb, len), skb->data, len);
 
 			pci_dma_sync_single_for_device(de->pdev, mapping, len, PCI_DMA_FROMDEVICE);
 
@@ -1269,7 +1269,7 @@ static int de_refill_rx (struct de_private *de)
 		skb->dev = de->dev;
 
 		de->rx_skb[i].mapping = pci_map_single(de->pdev,
-			skb->tail, de->rx_buf_sz, PCI_DMA_FROMDEVICE);
+			skb->data, de->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		de->rx_skb[i].skb = skb;
 
 		de->rx_ring[i].opts1 = cpu_to_le32(DescOwn);

drivers/net/tulip/dmfe.c

@@ -945,8 +945,8 @@ static void dmfe_rx_packet(struct DEVICE *dev, struct dmfe_board_info * db)
 
 				/* Received Packet CRC check need or not */
 				if ( (db->dm910x_chk_mode & 1) &&
-					(cal_CRC(skb->tail, rxlen, 1) !=
-					(*(u32 *) (skb->tail+rxlen) ))) { /* FIXME (?) */
+					(cal_CRC(skb->data, rxlen, 1) !=
+					(*(u32 *) (skb->data+rxlen) ))) { /* FIXME (?) */
 					/* Found a error received packet */
 					dmfe_reuse_skb(db, rxptr->rx_skb_ptr);
 					db->dm910x_chk_mode = 3;
@@ -959,7 +959,7 @@ static void dmfe_rx_packet(struct DEVICE *dev, struct dmfe_board_info * db)
 						/* size less than COPY_SIZE, allocate a rxlen SKB */
 						skb->dev = dev;
 						skb_reserve(skb, 2); /* 16byte align */
-						memcpy(skb_put(skb, rxlen), rxptr->rx_skb_ptr->tail, rxlen);
+						memcpy(skb_put(skb, rxlen), rxptr->rx_skb_ptr->data, rxlen);
 						dmfe_reuse_skb(db, rxptr->rx_skb_ptr);
 					} else {
 						skb->dev = dev;
@@ -1252,7 +1252,7 @@ static void dmfe_reuse_skb(struct dmfe_board_info *db, struct sk_buff * skb)
 
 	if (!(rxptr->rdes0 & cpu_to_le32(0x80000000))) {
 		rxptr->rx_skb_ptr = skb;
-		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->tail, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
+		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->data, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
 		wmb();
 		rxptr->rdes0 = cpu_to_le32(0x80000000);
 		db->rx_avail_cnt++;
@@ -1463,7 +1463,7 @@ static void allocate_rx_buffer(struct dmfe_board_info *db)
 		if ( ( skb = dev_alloc_skb(RX_ALLOC_SIZE) ) == NULL )
 			break;
 		rxptr->rx_skb_ptr = skb; /* FIXME (?) */
-		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->tail, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
+		rxptr->rdes2 = cpu_to_le32( pci_map_single(db->pdev, skb->data, RX_ALLOC_SIZE, PCI_DMA_FROMDEVICE) );
 		wmb();
 		rxptr->rdes0 = cpu_to_le32(0x80000000);
 		rxptr = rxptr->next_rx_desc;

drivers/net/tulip/interrupt.c

@@ -78,7 +78,7 @@ int tulip_refill_rx(struct net_device *dev)
 			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 @@ int tulip_poll(struct net_device *dev, int *budget)
 								   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 @@ static int tulip_rx(struct net_device *dev)
 							    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,

drivers/net/tulip/tulip_core.c

@@ -625,7 +625,7 @@ static void tulip_init_ring(struct net_device *dev)
 		tp->rx_buffers[i].skb = skb;
 		if (skb == NULL)
 			break;
-		mapping = pci_map_single(tp->pdev, skb->tail,
+		mapping = pci_map_single(tp->pdev, skb->data,
 					 PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 		tp->rx_buffers[i].mapping = mapping;
 		skb->dev = dev;			/* Mark as being used by this device. */

drivers/net/tulip/winbond-840.c

@@ -849,7 +849,7 @@ static void init_rxtx_rings(struct net_device *dev)
 		if (skb == NULL)
 			break;
 		skb->dev = dev;			/* Mark as being used by this device. */
-		np->rx_addr[i] = pci_map_single(np->pci_dev,skb->tail,
+		np->rx_addr[i] = pci_map_single(np->pci_dev,skb->data,
 					skb->len,PCI_DMA_FROMDEVICE);
 
 		np->rx_ring[i].buffer1 = np->rx_addr[i];
@@ -1269,7 +1269,7 @@ static int netdev_rx(struct net_device *dev)
 				pci_dma_sync_single_for_cpu(np->pci_dev,np->rx_addr[entry],
 							    np->rx_skbuff[entry]->len,
 							    PCI_DMA_FROMDEVICE);
-				eth_copy_and_sum(skb, np->rx_skbuff[entry]->tail, pkt_len, 0);
+				eth_copy_and_sum(skb, np->rx_skbuff[entry]->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 				pci_dma_sync_single_for_device(np->pci_dev,np->rx_addr[entry],
 							       np->rx_skbuff[entry]->len,
@@ -1315,7 +1315,7 @@ static int netdev_rx(struct net_device *dev)
 				break;			/* Better luck next round. */
 			skb->dev = dev;			/* Mark as being used by this device. */
 			np->rx_addr[entry] = pci_map_single(np->pci_dev,
-							skb->tail,
+							skb->data,
 							skb->len, PCI_DMA_FROMDEVICE);
 			np->rx_ring[entry].buffer1 = np->rx_addr[entry];
 		}

drivers/net/tulip/xircom_tulip_cb.c

@@ -899,7 +899,7 @@ static void xircom_init_ring(struct net_device *dev)
 			break;
 		skb->dev = dev;			/* Mark as being used by this device. */
 		tp->rx_ring[i].status = Rx0DescOwned;	/* Owned by Xircom chip */
-		tp->rx_ring[i].buffer1 = virt_to_bus(skb->tail);
+		tp->rx_ring[i].buffer1 = virt_to_bus(skb->data);
 	}
 	tp->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
 
@@ -1291,7 +1291,7 @@ xircom_rx(struct net_device *dev)
 			if (skb == NULL)
 				break;
 			skb->dev = dev;			/* Mark as being used by this device. */
-			tp->rx_ring[entry].buffer1 = virt_to_bus(skb->tail);
+			tp->rx_ring[entry].buffer1 = virt_to_bus(skb->data);
 			work_done++;
 		}
 		tp->rx_ring[entry].status = Rx0DescOwned;

drivers/net/typhoon.c

@@ -1661,7 +1661,7 @@ typhoon_alloc_rx_skb(struct typhoon *tp, u32 idx)
 #endif
 
 	skb->dev = tp->dev;
-	dma_addr = pci_map_single(tp->pdev, skb->tail,
+	dma_addr = pci_map_single(tp->pdev, skb->data,
 				  PKT_BUF_SZ, PCI_DMA_FROMDEVICE);
 
 	/* Since no card does 64 bit DAC, the high bits will never
@@ -1721,7 +1721,7 @@ typhoon_rx(struct typhoon *tp, struct basic_ring *rxRing, volatile u32 * ready,
 			pci_dma_sync_single_for_cpu(tp->pdev, dma_addr,
 						    PKT_BUF_SZ,
 						    PCI_DMA_FROMDEVICE);
-			eth_copy_and_sum(new_skb, skb->tail, pkt_len, 0);
+			eth_copy_and_sum(new_skb, skb->data, pkt_len, 0);
 			pci_dma_sync_single_for_device(tp->pdev, dma_addr,
 						       PKT_BUF_SZ,
 						       PCI_DMA_FROMDEVICE);

drivers/net/via-rhine.c

@@ -990,7 +990,7 @@ static void alloc_rbufs(struct net_device *dev)
 		skb->dev = dev;                 /* Mark as being used by this device. */
 
 		rp->rx_skbuff_dma[i] =
-			pci_map_single(rp->pdev, skb->tail, rp->rx_buf_sz,
+			pci_map_single(rp->pdev, skb->data, rp->rx_buf_sz,
 				       PCI_DMA_FROMDEVICE);
 
 		rp->rx_ring[i].addr = cpu_to_le32(rp->rx_skbuff_dma[i]);
@@ -1518,7 +1518,7 @@ static void rhine_rx(struct net_device *dev)
 							    PCI_DMA_FROMDEVICE);
 
 				eth_copy_and_sum(skb,
-						 rp->rx_skbuff[entry]->tail,
+						 rp->rx_skbuff[entry]->data,
 						 pkt_len, 0);
 				skb_put(skb, pkt_len);
 				pci_dma_sync_single_for_device(rp->pdev,
@@ -1561,7 +1561,7 @@ static void rhine_rx(struct net_device *dev)
 				break;	/* Better luck next round. */
 			skb->dev = dev;	/* Mark as being used by this device. */
 			rp->rx_skbuff_dma[entry] =
-				pci_map_single(rp->pdev, skb->tail,
+				pci_map_single(rp->pdev, skb->data,
 					       rp->rx_buf_sz,
 					       PCI_DMA_FROMDEVICE);
 			rp->rx_ring[entry].addr = cpu_to_le32(rp->rx_skbuff_dma[entry]);

drivers/net/via-velocity.c

@@ -1335,7 +1335,7 @@ static inline int velocity_rx_copy(struct sk_buff **rx_skb, int pkt_size,
 			if (vptr->flags & VELOCITY_FLAGS_IP_ALIGN)
 				skb_reserve(new_skb, 2);
 
-			memcpy(new_skb->data, rx_skb[0]->tail, pkt_size);
+			memcpy(new_skb->data, rx_skb[0]->data, pkt_size);
 			*rx_skb = new_skb;
 			ret = 0;
 		}
@@ -1456,9 +1456,9 @@ static int velocity_alloc_rx_buf(struct velocity_info *vptr, int idx)
 	 *	Do the gymnastics to get the buffer head for data at
 	 *	64byte alignment.
 	 */
-	skb_reserve(rd_info->skb, (unsigned long) rd_info->skb->tail & 63);
+	skb_reserve(rd_info->skb, (unsigned long) rd_info->skb->data & 63);
 	rd_info->skb->dev = vptr->dev;
-	rd_info->skb_dma = pci_map_single(vptr->pdev, rd_info->skb->tail, vptr->rx_buf_sz, PCI_DMA_FROMDEVICE);
+	rd_info->skb_dma = pci_map_single(vptr->pdev, rd_info->skb->data, vptr->rx_buf_sz, PCI_DMA_FROMDEVICE);
 	
 	/*
 	 *	Fill in the descriptor to match

drivers/net/wan/hdlc_cisco.c

@@ -72,7 +72,7 @@ static void cisco_keepalive_send(struct net_device *dev, u32 type,
 	}
 	skb_reserve(skb, 4);
 	cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
-	data = (cisco_packet*)skb->tail;
+	data = (cisco_packet*)skb->data;
 
 	data->type = htonl(type);
 	data->par1 = htonl(par1);

drivers/net/yellowfin.c

@@ -786,7 +786,7 @@ static void yellowfin_init_ring(struct net_device *dev)
 		skb->dev = dev;		/* Mark as being used by this device. */
 		skb_reserve(skb, 2);	/* 16 byte align the IP header. */
 		yp->rx_ring[i].addr = cpu_to_le32(pci_map_single(yp->pci_dev,
-			skb->tail, yp->rx_buf_sz, PCI_DMA_FROMDEVICE));
+			skb->data, yp->rx_buf_sz, PCI_DMA_FROMDEVICE));
 	}
 	yp->rx_ring[i-1].dbdma_cmd = cpu_to_le32(CMD_STOP);
 	yp->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
@@ -1111,7 +1111,7 @@ static int yellowfin_rx(struct net_device *dev)
 		pci_dma_sync_single_for_cpu(yp->pci_dev, desc->addr,
 			yp->rx_buf_sz, PCI_DMA_FROMDEVICE);
 		desc_status = le32_to_cpu(desc->result_status) >> 16;
-		buf_addr = rx_skb->tail;
+		buf_addr = rx_skb->data;
 		data_size = (le32_to_cpu(desc->dbdma_cmd) - 
 			le32_to_cpu(desc->result_status)) & 0xffff;
 		frame_status = le16_to_cpu(get_unaligned((s16*)&(buf_addr[data_size - 2])));
@@ -1185,7 +1185,7 @@ static int yellowfin_rx(struct net_device *dev)
 					break;
 				skb->dev = dev;
 				skb_reserve(skb, 2);	/* 16 byte align the IP header */
-				eth_copy_and_sum(skb, rx_skb->tail, pkt_len, 0);
+				eth_copy_and_sum(skb, rx_skb->data, pkt_len, 0);
 				skb_put(skb, pkt_len);
 				pci_dma_sync_single_for_device(yp->pci_dev, desc->addr,
 											   yp->rx_buf_sz,
@@ -1211,7 +1211,7 @@ static int yellowfin_rx(struct net_device *dev)
 			skb->dev = dev;	/* Mark as being used by this device. */
 			skb_reserve(skb, 2);	/* Align IP on 16 byte boundaries */
 			yp->rx_ring[entry].addr = cpu_to_le32(pci_map_single(yp->pci_dev,
-				skb->tail, yp->rx_buf_sz, PCI_DMA_FROMDEVICE));
+				skb->data, yp->rx_buf_sz, PCI_DMA_FROMDEVICE));
 		}
 		yp->rx_ring[entry].dbdma_cmd = cpu_to_le32(CMD_STOP);
 		yp->rx_ring[entry].result_status = 0;	/* Clear complete bit. */