[PATCH] sky2: optimize for 32 bit dma
Small optimization, if dma addresses are 32 bits, then high
bits are always zero.
Signed-off-by: Stephen Hemminger <shemminger@osdl.or>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 3c5d004..92ea915c 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -745,7 +745,7 @@
/* Return high part of DMA address (could be 32 or 64 bit) */
static inline u32 high32(dma_addr_t a)
{
- return (a >> 16) >> 16;
+ return sizeof(a) > sizeof(u32) ? (a >> 16) >> 16 : 0;
}
/* Build description to hardware about buffer */
@@ -1225,7 +1225,7 @@
mapping = pci_map_page(hw->pdev, frag->page, frag->page_offset,
frag->size, PCI_DMA_TODEVICE);
- addr64 = (mapping >> 16) >> 16;
+ addr64 = high32(mapping);
if (addr64 != sky2->tx_addr64) {
le = get_tx_le(sky2);
le->tx.addr = cpu_to_le32(addr64);
