hamachi PCI DMA fix from 2.4

hamachi PCI DMA fix from 2.4

[davej]

Maintainer fix that went into 2.4 last August with the comments
"Get hamachi net driver RX working again.
 Apparently the PCI DMA conversion still has a bug or two left in it..."

diff -urpN --exclude-from=/home/davej/.exclude bk-linus/drivers/net/hamachi.c linux-2.5/drivers/net/hamachi.c
--- bk-linus/drivers/net/hamachi.c	2003-04-22 00:40:42.000000000 +0100
+++ linux-2.5/drivers/net/hamachi.c	2003-04-22 01:23:14.000000000 +0100
@@ -207,8 +207,10 @@ KERN_INFO "   Further modifications by K
 /* Condensed bus+endian portability operations. */
 #if ADDRLEN == 64
 #define cpu_to_leXX(addr)	cpu_to_le64(addr)
+#define desc_to_virt(addr) bus_to_virt(le64_to_cpu(addr))
 #else 
 #define cpu_to_leXX(addr)	cpu_to_le32(addr)
+#define desc_to_virt(addr) bus_to_virt(le32_to_cpu(addr))
 #endif   
 
 
@@ -1497,7 +1499,7 @@ static int hamachi_rx(struct net_device 
 			break;
 		pci_dma_sync_single(hmp->pci_dev, desc->addr, hmp->rx_buf_sz, 
 			PCI_DMA_FROMDEVICE);
-		buf_addr = (u8 *)hmp->rx_ring + entry*sizeof(*desc);
+		buf_addr = desc_to_virt(desc->addr);
 		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",