isci: fix dma_unmap_sg usage

One bug and a cleanup:
1/ Fix cases where we were unmapping invalid addresses (smp requests were
being unmapped)

[ 604.662770] ------------[ cut here ]------------
[ 604.668026] WARNING: at lib/dma-debug.c:800 check_unmap+0x418/0x740()
[ 604.675315] Hardware name: SandyBridge Platform
[ 604.680465] isci 0000:03:00.0: DMA-API: device driver tries to free an invalid DMA memory address

2/ The unmap routine is too large to be an inline function, and
isci_request_io_request_get_next_sge is unused.

Signed-off-by: Dan Williams <[e-mail]>

drivers/scsi/isci/request.c

···
 		break;
 	}
 
-	isci_request_unmap_sgl(request, isci_host->pdev);
+	switch (task->task_proto) {
+	case SAS_PROTOCOL_SSP:
+		if (task->data_dir == DMA_NONE)
+			break;
+		if (task->num_scatter == 0)
+			/* 0 indicates a single dma address */
+			dma_unmap_single(&isci_host->pdev->dev,
+					 request->zero_scatter_daddr,
+					 task->total_xfer_len, task->data_dir);
+		else  /* unmap the sgl dma addresses */
+			dma_unmap_sg(&isci_host->pdev->dev, task->scatter,
+				     request->num_sg_entries, task->data_dir);
+		break;
+	default:
+		break;
+	}
 
 	/* Put the completed request on the correct list */
 	isci_task_save_for_upper_layer_completion(isci_host, request, response,

drivers/scsi/isci/request.h

···
 struct isci_request *isci_request_alloc_tmf(struct isci_host *ihost,
 					    struct isci_tmf *isci_tmf,
 					    gfp_t gfp_flags);
-
 int isci_request_execute(struct isci_host *ihost, struct isci_remote_device *idev,
 			 struct sas_task *task, gfp_t gfp_flags);
-
-/**
- * isci_request_unmap_sgl() - This function unmaps the DMA address of a given
- *    sgl
- * @request: This parameter points to the isci_request object
- * @*pdev: This Parameter is the pci_device struct for the controller
- *
- */
-static inline void
-isci_request_unmap_sgl(struct isci_request *request, struct pci_dev *pdev)
-{
-	struct sas_task *task = isci_request_access_task(request);
-
-	dev_dbg(&request->isci_host->pdev->dev,
-		"%s: request = %p, task = %p,\n"
-		"task->data_dir = %d, is_sata = %d\n ",
-		__func__,
-		request,
-		task,
-		task->data_dir,
-		sas_protocol_ata(task->task_proto));
-
-	if ((task->data_dir != PCI_DMA_NONE) &&
-	    !sas_protocol_ata(task->task_proto)) {
-		if (task->num_scatter == 0)
-			/* 0 indicates a single dma address */
-			dma_unmap_single(
-				&pdev->dev,
-				request->zero_scatter_daddr,
-				task->total_xfer_len,
-				task->data_dir
-				);
-
-		else  /* unmap the sgl dma addresses */
-			dma_unmap_sg(
-				&pdev->dev,
-				task->scatter,
-				request->num_sg_entries,
-				task->data_dir
-				);
-	}
-}
-
-/**
- * isci_request_io_request_get_next_sge() - This function is called by the sci
- *    core to retrieve the next sge for a given request.
- * @request: This parameter is the isci_request object.
- * @current_sge_address: This parameter is the last sge retrieved by the sci
- *    core for this request.
- *
- * pointer to the next sge for specified request.
- */
-static inline void *
-isci_request_io_request_get_next_sge(struct isci_request *request,
-				     void *current_sge_address)
-{
-	struct sas_task *task = isci_request_access_task(request);
-	void *ret = NULL;
-
-	dev_dbg(&request->isci_host->pdev->dev,
-		"%s: request = %p, "
-		"current_sge_address = %p, "
-		"num_scatter = %d\n",
-		__func__,
-		request,
-		current_sge_address,
-		task->num_scatter);
-
-	if (!current_sge_address)	/* First time through.. */
-		ret = task->scatter;    /* always task->scatter */
-	else if (task->num_scatter == 0) /* Next element, if num_scatter == 0 */
-		ret = NULL;              /* there is only one element. */
-	else
-		ret = sg_next(current_sge_address);     /* sg_next returns NULL
-							 * for the last element
-							 */
-
-	dev_dbg(&request->isci_host->pdev->dev,
-		"%s: next sge address = %p\n",
-		__func__,
-		ret);
-
-	return ret;
-}
-
-void
-isci_terminate_pending_requests(struct isci_host *ihost,
-				struct isci_remote_device *idev);
+void isci_terminate_pending_requests(struct isci_host *ihost,
+				     struct isci_remote_device *idev);
 enum sci_status
 scic_task_request_construct(struct scic_sds_controller *scic,
 			    struct scic_sds_remote_device *sci_dev,