unsigned long mask_addr;
void __iomem *mask_addr;
static void vsc_intr_mask_update(struct ata_port *ap, u8 ctl){	unsigned long mask_addr;	u8 mask;	mask_addr = (unsigned long) ap->host_set->mmio_base +		VSC_SATA_INT_MASK_OFFSET + ap->port_no;	mask = readb(mask_addr);	if (ctl & ATA_NIEN)		mask |= 0x80;	else		mask &= 0x7F;	writeb(mask, mask_addr);}