[SCSI] qla1280: convert to use the data buffer accessors

- remove the unnecessary map_single path.
- convert to use the new accessors for the sg lists and the parameters.

Fixed to missing initialization of sg lists before calling
for_each_sg() by Jes Sorensen - sg list needs to be initialized before
trying to pull the elements out of it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/qla1280.c

@@ -1310,14 +1310,7 @@ qla1280_done(struct scsi_qla_host *ha)
 		}
 
 		/* Release memory used for this I/O */
-		if (cmd->use_sg) {
-			pci_unmap_sg(ha->pdev, cmd->request_buffer,
-					cmd->use_sg, cmd->sc_data_direction);
-		} else if (cmd->request_bufflen) {
-			pci_unmap_single(ha->pdev, sp->saved_dma_handle,
-					cmd->request_bufflen,
-					cmd->sc_data_direction);
-		}
+		scsi_dma_unmap(cmd);
 
 		/* Call the mid-level driver interrupt handler */
 		CMD_HANDLE(sp->cmd) = (unsigned char *)INVALID_HANDLE;
@@ -1406,14 +1399,14 @@ qla1280_return_status(struct response * sts, struct scsi_cmnd *cp)
 		break;
 
 	case CS_DATA_UNDERRUN:
-		if ((cp->request_bufflen - residual_length) <
+		if ((scsi_bufflen(cp) - residual_length) <
 		    cp->underflow) {
 			printk(KERN_WARNING
 			       "scsi: Underflow detected - retrying "
 			       "command.\n");
 			host_status = DID_ERROR;
 		} else {
-			cp->resid = residual_length;
+			scsi_set_resid(cp, residual_length);
 			host_status = DID_OK;
 		}
 		break;
@@ -2775,33 +2768,28 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	struct device_reg __iomem *reg = ha->iobase;
 	struct scsi_cmnd *cmd = sp->cmd;
 	cmd_a64_entry_t *pkt;
-	struct scatterlist *sg = NULL, *s;
 	__le32 *dword_ptr;
 	dma_addr_t dma_handle;
 	int status = 0;
 	int cnt;
 	int req_cnt;
-	u16 seg_cnt;
+	int seg_cnt;
 	u8 dir;
 
 	ENTER("qla1280_64bit_start_scsi:");
 
 	/* Calculate number of entries and segments required. */
 	req_cnt = 1;
-	if (cmd->use_sg) {
-		sg = (struct scatterlist *) cmd->request_buffer;
-		seg_cnt = pci_map_sg(ha->pdev, sg, cmd->use_sg,
-				     cmd->sc_data_direction);
-
+	seg_cnt = scsi_dma_map(cmd);
+	if (seg_cnt > 0) {
 		if (seg_cnt > 2) {
 			req_cnt += (seg_cnt - 2) / 5;
 			if ((seg_cnt - 2) % 5)
 				req_cnt++;
 		}
-	} else if (cmd->request_bufflen) {	/* If data transfer. */
-		seg_cnt = 1;
-	} else {
-		seg_cnt = 0;
+	} else if (seg_cnt < 0) {
+		status = 1;
+		goto out;
 	}
 
 	if ((req_cnt + 2) >= ha->req_q_cnt) {
@@ -2889,15 +2877,19 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	 * Load data segments.
 	 */
 	if (seg_cnt) {	/* If data transfer. */
+		struct scatterlist *sg, *s;
 		int remseg = seg_cnt;
+
+		sg = scsi_sglist(cmd);
+
 		/* Setup packet address segment pointer. */
 		dword_ptr = (u32 *)&pkt->dseg_0_address;
 
-		if (cmd->use_sg) {	/* If scatter gather */
 		/* Load command entry data segments. */
 		for_each_sg(sg, s, seg_cnt, cnt) {
 			if (cnt == 2)
 				break;
+
 			dma_handle = sg_dma_address(s);
 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
 			if (ha->flags.use_pci_vchannel)
@@ -2986,30 +2978,6 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 			qla1280_dump_buffer(5, (char *)pkt,
 					    REQUEST_ENTRY_SIZE);
 		}
-		} else {	/* No scatter gather data transfer */
-			dma_handle = pci_map_single(ha->pdev,
-					cmd->request_buffer,
-					cmd->request_bufflen,
-					cmd->sc_data_direction);
-
-			sp->saved_dma_handle = dma_handle;
-#if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_SGI_SN2)
-			if (ha->flags.use_pci_vchannel)
-				sn_pci_set_vchan(ha->pdev, 
-						(unsigned long *)&dma_handle,
-						 SCSI_BUS_32(cmd));
-#endif
-			*dword_ptr++ = cpu_to_le32(pci_dma_lo32(dma_handle));
-			*dword_ptr++ = cpu_to_le32(pci_dma_hi32(dma_handle));
-			*dword_ptr = cpu_to_le32(cmd->request_bufflen);
-
-			dprintk(5, "qla1280_64bit_start_scsi: No scatter/"
-				"gather command packet data - b %i, t %i, "
-				"l %i \n", SCSI_BUS_32(cmd), SCSI_TCN_32(cmd),
-				SCSI_LUN_32(cmd));
-			qla1280_dump_buffer(5, (char *)pkt,
-					    REQUEST_ENTRY_SIZE);
-		}
 	} else {	/* No data transfer */
 		dprintk(5, "qla1280_64bit_start_scsi: No data, command "
 			"packet data - b %i, t %i, l %i \n",
@@ -3068,12 +3036,11 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	struct device_reg __iomem *reg = ha->iobase;
 	struct scsi_cmnd *cmd = sp->cmd;
 	struct cmd_entry *pkt;
-	struct scatterlist *sg = NULL, *s;
 	__le32 *dword_ptr;
 	int status = 0;
 	int cnt;
 	int req_cnt;
-	uint16_t seg_cnt;
+	int seg_cnt;
 	dma_addr_t dma_handle;
 	u8 dir;
 
@@ -3083,18 +3050,8 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 		cmd->cmnd[0]);
 
 	/* Calculate number of entries and segments required. */
-	req_cnt = 1;
-	if (cmd->use_sg) {
-		/*
-		 * We must build an SG list in adapter format, as the kernel's
-		 * SG list cannot be used directly because of data field size
-		 * (__alpha__) differences and the kernel SG list uses virtual
-		 * addresses where we need physical addresses.
-		 */
-		sg = (struct scatterlist *) cmd->request_buffer;
-		seg_cnt = pci_map_sg(ha->pdev, sg, cmd->use_sg,
-				     cmd->sc_data_direction);
-
+	seg_cnt = scsi_dma_map(cmd);
+	if (seg_cnt) {
 		/*
 		 * if greater than four sg entries then we need to allocate
 		 * continuation entries
@@ -3106,14 +3063,9 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 		}
 		dprintk(3, "S/G Transfer cmd=%p seg_cnt=0x%x, req_cnt=%x\n",
 			cmd, seg_cnt, req_cnt);
-	} else if (cmd->request_bufflen) {	/* If data transfer. */
-		dprintk(3, "No S/G transfer t=%x cmd=%p len=%x CDB=%x\n",
-			SCSI_TCN_32(cmd), cmd, cmd->request_bufflen,
-			cmd->cmnd[0]);
-		seg_cnt = 1;
-	} else {
-		/* dprintk(1, "No data transfer \n"); */
-		seg_cnt = 0;
+	} else if (seg_cnt < 0) {
+		status = 1;
+		goto out;
 	}
 
 	if ((req_cnt + 2) >= ha->req_q_cnt) {
@@ -3194,11 +3146,14 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	 * Load data segments.
 	 */
 	if (seg_cnt) {
+		struct scatterlist *sg, *s;
 		int remseg = seg_cnt;
+
+		sg = scsi_sglist(cmd);
+
 		/* Setup packet address segment pointer. */
 		dword_ptr = &pkt->dseg_0_address;
 
-		if (cmd->use_sg) {	/* If scatter gather */
 		dprintk(3, "Building S/G data segments..\n");
 		qla1280_dump_buffer(1, (char *)sg, 4 * 16);
 
@@ -3270,16 +3225,6 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 			qla1280_dump_buffer(5, (char *)pkt,
 					    REQUEST_ENTRY_SIZE);
 		}
-		} else {	/* No S/G data transfer */
-			dma_handle = pci_map_single(ha->pdev,
-					cmd->request_buffer,
-					cmd->request_bufflen,
-					cmd->sc_data_direction);
-			sp->saved_dma_handle = dma_handle;
-
-			*dword_ptr++ = cpu_to_le32(pci_dma_lo32(dma_handle));
-			*dword_ptr = cpu_to_le32(cmd->request_bufflen);
-		}
 	} else {	/* No data transfer at all */
 		dprintk(5, "qla1280_32bit_start_scsi: No data, command "
 			"packet data - \n");
@@ -4086,9 +4031,9 @@ __qla1280_print_scsi_cmd(struct scsi_cmnd *cmd)
 	for (i = 0; i < cmd->cmd_len; i++) {
 		printk("0x%02x ", cmd->cmnd[i]);
 	}
-	printk("  seg_cnt =%d\n", cmd->use_sg);
+	printk("  seg_cnt =%d\n", scsi_sg_count(cmd));
 	printk("  request buffer=0x%p, request buffer len=0x%x\n",
-	       cmd->request_buffer, cmd->request_bufflen);
+	       scsi_sglist(cmd), scsi_bufflen(cmd));
 	/* if (cmd->use_sg)
 	   {
 	   sg = (struct scatterlist *) cmd->request_buffer;