[SCSI] mesh: 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: Paul Mackerras <paulus@samba.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/mesh.c

@@ -421,7 +421,7 @@ static void mesh_start_cmd(struct mesh_state *ms, struct scsi_cmnd *cmd)
 		for (i = 0; i < cmd->cmd_len; ++i)
 			printk(" %x", cmd->cmnd[i]);
 		printk(" use_sg=%d buffer=%p bufflen=%u\n",
-		       cmd->use_sg, cmd->request_buffer, cmd->request_bufflen);
+		       scsi_sg_count(cmd), scsi_sglist(cmd), scsi_bufflen(cmd));
 	}
 #endif
 	if (ms->dma_started)
@@ -602,13 +602,16 @@ static void mesh_done(struct mesh_state *ms, int start_next)
 			cmd->result += (cmd->SCp.Message << 8);
 		if (DEBUG_TARGET(cmd)) {
 			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
-			       cmd->result, ms->data_ptr, cmd->request_bufflen);
+			       cmd->result, ms->data_ptr, scsi_bufflen(cmd));
+#if 0
+			/* needs to use sg? */
 			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
 			    && cmd->request_buffer != 0) {
 				unsigned char *b = cmd->request_buffer;
 				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
 				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
 			}
+#endif
 		}
 		cmd->SCp.this_residual -= ms->data_ptr;
 		mesh_completed(ms, cmd);
@@ -1265,15 +1268,18 @@ static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
 	dcmds = ms->dma_cmds;
 	dtot = 0;
 	if (cmd) {
-		cmd->SCp.this_residual = cmd->request_bufflen;
-		if (cmd->use_sg > 0) {
-			int nseg;
+		int nseg;
+
+		cmd->SCp.this_residual = scsi_bufflen(cmd);
+
+		nseg = scsi_dma_map(cmd);
+		BUG_ON(nseg < 0);
+
+		if (nseg) {
 			total = 0;
-			scl = (struct scatterlist *) cmd->request_buffer;
 			off = ms->data_ptr;
-			nseg = pci_map_sg(ms->pdev, scl, cmd->use_sg,
-					  cmd->sc_data_direction);
-			for (i = 0; i <nseg; ++i, ++scl) {
+
+			scsi_for_each_sg(cmd, scl, nseg, i) {
 				u32 dma_addr = sg_dma_address(scl);
 				u32 dma_len = sg_dma_len(scl);
 				
@@ -1292,16 +1298,6 @@ static void set_dma_cmds(struct mesh_state *ms, struct scsi_cmnd *cmd)
 				dtot += dma_len - off;
 				off = 0;
 			}
-		} else if (ms->data_ptr < cmd->request_bufflen) {
-			dtot = cmd->request_bufflen - ms->data_ptr;
-			if (dtot > 0xffff)
-				panic("mesh: transfer size >= 64k");
-			st_le16(&dcmds->req_count, dtot);
-			/* XXX Use pci DMA API here ... */
-			st_le32(&dcmds->phy_addr,
-				virt_to_phys(cmd->request_buffer) + ms->data_ptr);
-			dcmds->xfer_status = 0;
-			++dcmds;
 		}
 	}
 	if (dtot == 0) {
@@ -1356,18 +1352,14 @@ static void halt_dma(struct mesh_state *ms)
 		dumplog(ms, ms->conn_tgt);
 		dumpslog(ms);
 #endif /* MESH_DBG */
-	} else if (cmd && cmd->request_bufflen != 0 &&
-		   ms->data_ptr > cmd->request_bufflen) {
+	} else if (cmd && scsi_bufflen(cmd) &&
+		   ms->data_ptr > scsi_bufflen(cmd)) {
 		printk(KERN_DEBUG "mesh: target %d overrun, "
 		       "data_ptr=%x total=%x goes_out=%d\n",
-		       ms->conn_tgt, ms->data_ptr, cmd->request_bufflen,
+		       ms->conn_tgt, ms->data_ptr, scsi_bufflen(cmd),
 		       ms->tgts[ms->conn_tgt].data_goes_out);
 	}
-	if (cmd->use_sg != 0) {
-		struct scatterlist *sg;
-		sg = (struct scatterlist *)cmd->request_buffer;
-		pci_unmap_sg(ms->pdev, sg, cmd->use_sg, cmd->sc_data_direction);
-	}
+	scsi_dma_unmap(cmd);
 	ms->dma_started = 0;
 }