diff --git a/drivers/scsi/aha1740.c b/drivers/scsi/aha1740.c
index d7af9c6..e4a4f3a 100644
--- a/drivers/scsi/aha1740.c
+++ b/drivers/scsi/aha1740.c
@@ -271,20 +271,8 @@
 				continue;
 			}
 			sgptr = (struct aha1740_sg *) SCtmp->host_scribble;
-			if (SCtmp->use_sg) {
-				/* We used scatter-gather.
-				   Do the unmapping dance. */
-				dma_unmap_sg (&edev->dev,
-					      (struct scatterlist *) SCtmp->request_buffer,
-					      SCtmp->use_sg,
-					      SCtmp->sc_data_direction);
-			} else {
-				dma_unmap_single (&edev->dev,
-						  sgptr->buf_dma_addr,
-						  SCtmp->request_bufflen,
-						  DMA_BIDIRECTIONAL);
-			}
-	    
+			scsi_dma_unmap(SCtmp);
+
 			/* Free the sg block */
 			dma_free_coherent (&edev->dev,
 					   sizeof (struct aha1740_sg),
@@ -349,11 +337,9 @@
 	unchar target = scmd_id(SCpnt);
 	struct aha1740_hostdata *host = HOSTDATA(SCpnt->device->host);
 	unsigned long flags;
-	void *buff = SCpnt->request_buffer;
-	int bufflen = SCpnt->request_bufflen;
 	dma_addr_t sg_dma;
 	struct aha1740_sg *sgptr;
-	int ecbno;
+	int ecbno, nseg;
 	DEB(int i);
 
 	if(*cmd == REQUEST_SENSE) {
@@ -423,24 +409,23 @@
 	}
 	sgptr = (struct aha1740_sg *) SCpnt->host_scribble;
 	sgptr->sg_dma_addr = sg_dma;
-    
-	if (SCpnt->use_sg) {
-		struct scatterlist * sgpnt;
+
+	nseg = scsi_dma_map(SCpnt);
+	BUG_ON(nseg < 0);
+	if (nseg) {
+		struct scatterlist *sg;
 		struct aha1740_chain * cptr;
-		int i, count;
+		int i;
 		DEB(unsigned char * ptr);
 
 		host->ecb[ecbno].sg = 1;  /* SCSI Initiator Command
 					   * w/scatter-gather*/
-		sgpnt = (struct scatterlist *) SCpnt->request_buffer;
 		cptr = sgptr->sg_chain;
-		count = dma_map_sg (&host->edev->dev, sgpnt, SCpnt->use_sg,
-				    SCpnt->sc_data_direction);
-		for(i=0; i < count; i++) {
-			cptr[i].datalen = sg_dma_len (sgpnt + i);
-			cptr[i].dataptr = sg_dma_address (sgpnt + i);
+		scsi_for_each_sg(SCpnt, sg, nseg, i) {
+			cptr[i].datalen = sg_dma_len (sg);
+			cptr[i].dataptr = sg_dma_address (sg);
 		}
-		host->ecb[ecbno].datalen = count*sizeof(struct aha1740_chain);
+		host->ecb[ecbno].datalen = nseg * sizeof(struct aha1740_chain);
 		host->ecb[ecbno].dataptr = sg_dma;
 #ifdef DEBUG
 		printk("cptr %x: ",cptr);
@@ -448,11 +433,8 @@
 		for(i=0;i<24;i++) printk("%02x ", ptr[i]);
 #endif
 	} else {
-		host->ecb[ecbno].datalen = bufflen;
-		sgptr->buf_dma_addr =  dma_map_single (&host->edev->dev,
-						       buff, bufflen,
-						       DMA_BIDIRECTIONAL);
-		host->ecb[ecbno].dataptr = sgptr->buf_dma_addr;
+		host->ecb[ecbno].datalen = 0;
+		host->ecb[ecbno].dataptr = 0;
 	}
 	host->ecb[ecbno].lun = SCpnt->device->lun;
 	host->ecb[ecbno].ses = 1; /* Suppress underrun errors */