diff --git a/drivers/scsi/a3000.c b/drivers/scsi/a3000.c
index bc6eb69..ae9b25a3 100644
--- a/drivers/scsi/a3000.c
+++ b/drivers/scsi/a3000.c
@@ -22,16 +22,15 @@
 #include <linux/stat.h>
 
 
-#define DMA(ptr)	((a3000_scsiregs *)((ptr)->base))
-
 static struct Scsi_Host *a3000_host = NULL;
 
 static int a3000_release(struct Scsi_Host *instance);
 
 static irqreturn_t a3000_intr(int irq, void *dummy)
 {
+	a3000_scsiregs *regs = (a3000_scsiregs *)(a3000_host->base);
+	unsigned int status = regs->ISTR;
 	unsigned long flags;
-	unsigned int status = DMA(a3000_host)->ISTR;
 
 	if (!(status & ISTR_INT_P))
 		return IRQ_NONE;
@@ -48,6 +47,7 @@
 static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
 {
 	struct WD33C93_hostdata *hdata = shost_priv(a3000_host);
+	a3000_scsiregs *regs = (a3000_scsiregs *)(a3000_host->base);
 	unsigned short cntr = CNTR_PDMD | CNTR_INTEN;
 	unsigned long addr = virt_to_bus(cmd->SCp.ptr);
 
@@ -84,10 +84,10 @@
 	/* remember direction */
 	hdata->dma_dir = dir_in;
 
-	DMA(a3000_host)->CNTR = cntr;
+	regs->CNTR = cntr;
 
 	/* setup DMA *physical* address */
-	DMA(a3000_host)->ACR = addr;
+	regs->ACR = addr;
 
 	if (dir_in) {
 		/* invalidate any cache */
@@ -99,7 +99,7 @@
 
 	/* start DMA */
 	mb();			/* make sure setup is completed */
-	DMA(a3000_host)->ST_DMA = 1;
+	regs->ST_DMA = 1;
 	mb();			/* make sure DMA has started before next IO */
 
 	/* return success */
@@ -110,6 +110,7 @@
 		     int status)
 {
 	struct WD33C93_hostdata *hdata = shost_priv(instance);
+	a3000_scsiregs *regs = (a3000_scsiregs *)(instance->base);
 
 	/* disable SCSI interrupts */
 	unsigned short cntr = CNTR_PDMD;
@@ -117,14 +118,14 @@
 	if (!hdata->dma_dir)
 		cntr |= CNTR_DDIR;
 
-	DMA(instance)->CNTR = cntr;
+	regs->CNTR = cntr;
 	mb();			/* make sure CNTR is updated before next IO */
 
 	/* flush if we were reading */
 	if (hdata->dma_dir) {
-		DMA(instance)->FLUSH = 1;
+		regs->FLUSH = 1;
 		mb();		/* don't allow prefetch */
-		while (!(DMA(instance)->ISTR & ISTR_FE_FLG))
+		while (!(regs->ISTR & ISTR_FE_FLG))
 			barrier();
 		mb();		/* no IO until FLUSH is done */
 	}
@@ -133,14 +134,14 @@
 	/* I think that this CINT is only necessary if you are
 	 * using the terminal count features.   HM 7 Mar 1994
 	 */
-	DMA(instance)->CINT = 1;
+	regs->CINT = 1;
 
 	/* stop DMA */
-	DMA(instance)->SP_DMA = 1;
+	regs->SP_DMA = 1;
 	mb();			/* make sure DMA is stopped before next IO */
 
 	/* restore the CONTROL bits (minus the direction flag) */
-	DMA(instance)->CNTR = CNTR_PDMD | CNTR_INTEN;
+	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 	mb();			/* make sure CNTR is updated before next IO */
 
 	/* copy from a bounce buffer, if necessary */
@@ -163,7 +164,8 @@
 
 static int __init a3000_detect(struct scsi_host_template *tpnt)
 {
-	wd33c93_regs regs;
+	wd33c93_regs wdregs;
+	a3000_scsiregs *regs;
 	struct WD33C93_hostdata *hdata;
 
 	if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(A3000_SCSI))
@@ -180,18 +182,20 @@
 
 	a3000_host->base = ZTWO_VADDR(0xDD0000);
 	a3000_host->irq = IRQ_AMIGA_PORTS;
-	DMA(a3000_host)->DAWR = DAWR_A3000;
-	regs.SASR = &(DMA(a3000_host)->SASR);
-	regs.SCMD = &(DMA(a3000_host)->SCMD);
+	regs = (a3000_scsiregs *)(a3000_host->base);
+	regs->DAWR = DAWR_A3000;
+	wdregs.SASR = &regs->SASR;
+	wdregs.SCMD = &regs->SCMD;
 	hdata = shost_priv(a3000_host);
 	hdata->no_sync = 0xff;
 	hdata->fast = 0;
 	hdata->dma_mode = CTRL_DMA;
-	wd33c93_init(a3000_host, regs, dma_setup, dma_stop, WD33C93_FS_12_15);
+	wd33c93_init(a3000_host, wdregs, dma_setup, dma_stop,
+		     WD33C93_FS_12_15);
 	if (request_irq(IRQ_AMIGA_PORTS, a3000_intr, IRQF_SHARED, "A3000 SCSI",
 			a3000_intr))
 		goto fail_irq;
-	DMA(a3000_host)->CNTR = CNTR_PDMD | CNTR_INTEN;
+	regs->CNTR = CNTR_PDMD | CNTR_INTEN;
 
 	return 1;
 
@@ -239,7 +243,9 @@
 
 static int a3000_release(struct Scsi_Host *instance)
 {
-	DMA(instance)->CNTR = 0;
+	a3000_scsiregs *regs = (a3000_scsiregs *)(instance->base);
+
+	regs->CNTR = 0;
 	release_mem_region(0xDD0000, 256);
 	free_irq(IRQ_AMIGA_PORTS, a3000_intr);
 	return 1;