[SCSI] 3w-xxxx: 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.

Jens Axboe <jens.axboe@oracle.com> did the for_each_sg cleanup.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Adam Radford <linuxraid@amcc.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/3w-xxxx.c

@@ -1273,57 +1273,24 @@ static int tw_map_scsi_sg_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
 	int use_sg;
 
 	dprintk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data()\n");
-	
-	if (cmd->use_sg == 0)
-		return 0;
 
-	use_sg = pci_map_sg(pdev, cmd->request_buffer, cmd->use_sg, DMA_BIDIRECTIONAL);
-	
-	if (use_sg == 0) {
+	use_sg = scsi_dma_map(cmd);
+	if (use_sg < 0) {
 		printk(KERN_WARNING "3w-xxxx: tw_map_scsi_sg_data(): pci_map_sg() failed.\n");
 		return 0;
 	}
 
 	cmd->SCp.phase = TW_PHASE_SGLIST;
 	cmd->SCp.have_data_in = use_sg;
-	
+
 	return use_sg;
 } /* End tw_map_scsi_sg_data() */
 
-static u32 tw_map_scsi_single_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
-{
-	dma_addr_t mapping;
-
-	dprintk(KERN_WARNING "3w-xxxx: tw_map_scsi_single_data()\n");
-
-	if (cmd->request_bufflen == 0)
-		return 0;
-
-	mapping = pci_map_page(pdev, virt_to_page(cmd->request_buffer), offset_in_page(cmd->request_buffer), cmd->request_bufflen, DMA_BIDIRECTIONAL);
-
-	if (mapping == 0) {
-		printk(KERN_WARNING "3w-xxxx: tw_map_scsi_single_data(): pci_map_page() failed.\n");
-		return 0;
-	}
-
-	cmd->SCp.phase = TW_PHASE_SINGLE;
-	cmd->SCp.have_data_in = mapping;
-
-	return mapping;
-} /* End tw_map_scsi_single_data() */
-
 static void tw_unmap_scsi_data(struct pci_dev *pdev, struct scsi_cmnd *cmd)
 {
 	dprintk(KERN_WARNING "3w-xxxx: tw_unmap_scsi_data()\n");
 
-	switch(cmd->SCp.phase) {
-		case TW_PHASE_SINGLE:
-			pci_unmap_page(pdev, cmd->SCp.have_data_in, cmd->request_bufflen, DMA_BIDIRECTIONAL);
-			break;
-		case TW_PHASE_SGLIST:
-			pci_unmap_sg(pdev, cmd->request_buffer, cmd->use_sg, DMA_BIDIRECTIONAL);
-			break;
-	}
+	scsi_dma_unmap(cmd);
 } /* End tw_unmap_scsi_data() */
 
 /* This function will reset a device extension */
@@ -1499,27 +1466,16 @@ static void tw_transfer_internal(TW_Device_Extension *tw_dev, int request_id,
 	void *buf;
 	unsigned int transfer_len;
 	unsigned long flags = 0;
+	struct scatterlist *sg = scsi_sglist(cmd);
 
-	if (cmd->use_sg) {
-		struct scatterlist *sg =
-			(struct scatterlist *)cmd->request_buffer;
-		local_irq_save(flags);
-		buf = kmap_atomic(sg->page, KM_IRQ0) + sg->offset;
-		transfer_len = min(sg->length, len);
-	} else {
-		buf = cmd->request_buffer;
-		transfer_len = min(cmd->request_bufflen, len);
-	}
+	local_irq_save(flags);
+	buf = kmap_atomic(sg->page, KM_IRQ0) + sg->offset;
+	transfer_len = min(sg->length, len);
 
 	memcpy(buf, data, transfer_len);
-	
-	if (cmd->use_sg) {
-		struct scatterlist *sg;
 
-		sg = (struct scatterlist *)cmd->request_buffer;
-		kunmap_atomic(buf - sg->offset, KM_IRQ0);
-		local_irq_restore(flags);
-	}
+	kunmap_atomic(buf - sg->offset, KM_IRQ0);
+	local_irq_restore(flags);
 }
 
 /* This function is called by the isr to complete an inquiry command */
@@ -1764,19 +1720,20 @@ static int tw_scsiop_read_write(TW_Device_Extension *tw_dev, int request_id)
 {
 	TW_Command *command_packet;
 	unsigned long command_que_value;
-	u32 lba = 0x0, num_sectors = 0x0, buffaddr = 0x0;
+	u32 lba = 0x0, num_sectors = 0x0;
 	int i, use_sg;
 	struct scsi_cmnd *srb;
-	struct scatterlist *sglist;
+	struct scatterlist *sglist, *sg;
 
 	dprintk(KERN_NOTICE "3w-xxxx: tw_scsiop_read_write()\n");
 
-	if (tw_dev->srb[request_id]->request_buffer == NULL) {
+	srb = tw_dev->srb[request_id];
+
+	sglist = scsi_sglist(srb);
+	if (!sglist) {
 		printk(KERN_WARNING "3w-xxxx: tw_scsiop_read_write(): Request buffer NULL.\n");
 		return 1;
 	}
-	sglist = (struct scatterlist *)tw_dev->srb[request_id]->request_buffer;
-	srb = tw_dev->srb[request_id];
 
 	/* Initialize command packet */
 	command_packet = (TW_Command *)tw_dev->command_packet_virtual_address[request_id];
@@ -1819,33 +1776,18 @@ static int tw_scsiop_read_write(TW_Device_Extension *tw_dev, int request_id)
 	command_packet->byte8.io.lba = lba;
 	command_packet->byte6.block_count = num_sectors;
 
-	/* Do this if there are no sg list entries */
-	if (tw_dev->srb[request_id]->use_sg == 0) {    
-		dprintk(KERN_NOTICE "3w-xxxx: tw_scsiop_read_write(): SG = 0\n");
-		buffaddr = tw_map_scsi_single_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
-		if (buffaddr == 0)
-			return 1;
+	use_sg = tw_map_scsi_sg_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
+	if (!use_sg)
+		return 1;
 
-		command_packet->byte8.io.sgl[0].address = buffaddr;
-		command_packet->byte8.io.sgl[0].length = tw_dev->srb[request_id]->request_bufflen;
+	scsi_for_each_sg(tw_dev->srb[request_id], sg, use_sg, i) {
+		command_packet->byte8.io.sgl[i].address = sg_dma_address(sg);
+		command_packet->byte8.io.sgl[i].length = sg_dma_len(sg);
 		command_packet->size+=2;
 	}
 
-	/* Do this if we have multiple sg list entries */
-	if (tw_dev->srb[request_id]->use_sg > 0) {
-		use_sg = tw_map_scsi_sg_data(tw_dev->tw_pci_dev, tw_dev->srb[request_id]);
-		if (use_sg == 0)
-			return 1;
-
-		for (i=0;i<use_sg; i++) {
-			command_packet->byte8.io.sgl[i].address = sg_dma_address(&sglist[i]);
-			command_packet->byte8.io.sgl[i].length = sg_dma_len(&sglist[i]);
-			command_packet->size+=2;
-		}
-	}
-
 	/* Update SG statistics */
-	tw_dev->sgl_entries = tw_dev->srb[request_id]->use_sg;
+	tw_dev->sgl_entries = scsi_sg_count(tw_dev->srb[request_id]);
 	if (tw_dev->sgl_entries > tw_dev->max_sgl_entries)
 		tw_dev->max_sgl_entries = tw_dev->sgl_entries;