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[PATCH] sky2: optimize for 32 bit dma

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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>
This commit is contained in:
Stephen Hemminger 2006-01-17 13:43:16 -08:00 committed by Jeff Garzik
parent dc4d5ea221
commit a036119f97
1 changed files with 2 additions and 2 deletions
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4
drivers/net/sky2.c
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@ -745,7 +745,7 @@ static inline struct sky2_rx_le *sky2_next_rx(struct sky2_port *sky2)
/* 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 @@ static int sky2_xmit_frame(struct sk_buff *skb, struct net_device *dev)
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);