firewire: Use dma_mapping_error() for checking for DMA mapping errors.

Pointed out by Pete Zaitcev.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c
index 024fab4..6481e3d 100644
--- a/drivers/firewire/fw-iso.c
+++ b/drivers/firewire/fw-iso.c
@@ -33,7 +33,7 @@
 		 enum dma_data_direction direction)
 {
 	struct page *page;
-	int i;
+	int i, j;
 	void *p;
 
 	ctx->buffer_size = PAGE_ALIGN(size);
@@ -42,24 +42,33 @@
 
 	ctx->buffer = vmalloc_32_user(ctx->buffer_size);
 	if (ctx->buffer == NULL)
-		return -ENOMEM;
+		goto fail_buffer_alloc;
 
 	ctx->page_count = ctx->buffer_size >> PAGE_SHIFT;
 	ctx->pages =
 	    kzalloc(ctx->page_count * sizeof(ctx->pages[0]), GFP_KERNEL);
-	if (ctx->pages == NULL) {
-		vfree(ctx->buffer);
-		return -ENOMEM;
-	}
+	if (ctx->pages == NULL)
+		goto fail_pages_alloc;
 
 	p = ctx->buffer;
 	for (i = 0; i < ctx->page_count; i++, p += PAGE_SIZE) {
 		page = vmalloc_to_page(p);
 		ctx->pages[i] = dma_map_page(ctx->card->device,
 					     page, 0, PAGE_SIZE, direction);
+		if (dma_mapping_error(ctx->pages[i]))
+			goto fail_mapping;
 	}
 
 	return 0;
+
+ fail_mapping:
+	for (j = 0; j < i; j++)
+		dma_unmap_page(ctx->card->device, ctx->pages[j],
+			       PAGE_SIZE, DMA_TO_DEVICE);
+ fail_pages_alloc:
+	vfree(ctx->buffer);
+ fail_buffer_alloc:
+	return -ENOMEM;
 }
 
 static void destroy_iso_buffer(struct fw_iso_context *ctx)
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index e6fa349..4512edb 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -431,7 +431,7 @@
 						     packet->payload,
 						     packet->payload_length,
 						     DMA_TO_DEVICE);
-		if (packet->payload_bus == 0) {
+		if (dma_mapping_error(packet->payload_bus)) {
 			complete_transmission(packet, RCODE_SEND_ERROR, list);
 			return;
 		}
@@ -590,7 +590,7 @@
 	ctx->descriptor_bus =
 		dma_map_single(ohci->card.device, &ctx->d,
 			       sizeof ctx->d, DMA_TO_DEVICE);
-	if (ctx->descriptor_bus == 0)
+	if (dma_mapping_error(ctx->descriptor_bus))
 		return -ENOMEM;
 
 	ctx->regs = regs;
@@ -1159,16 +1159,14 @@
 	tasklet_init(&ctx->tasklet, tasklet, (unsigned long)ctx);
 
 	ctx->buffer = kmalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
-	if (ctx->buffer == NULL) {
-		spin_lock_irqsave(&ohci->lock, flags);
-		*mask |= 1 << index;
-		spin_unlock_irqrestore(&ohci->lock, flags);
-		return ERR_PTR(-ENOMEM);
-	}
+	if (ctx->buffer == NULL)
+		goto buffer_alloc_failed;
 
 	ctx->buffer_bus =
 	    dma_map_single(card->device, ctx->buffer,
 			   ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+	if (dma_mapping_error(ctx->buffer_bus))
+		goto buffer_map_failed;
 
 	ctx->head_descriptor      = ctx->buffer;
 	ctx->prev_descriptor      = ctx->buffer;
@@ -1187,6 +1185,15 @@
 	ctx->head_descriptor++;
 
 	return &ctx->base;
+
+ buffer_map_failed:
+	kfree(ctx->buffer);
+ buffer_alloc_failed:
+	spin_lock_irqsave(&ohci->lock, flags);
+	*mask |= 1 << index;
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+	return ERR_PTR(-ENOMEM);
 }
 
 static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index fa59e59..2259e22 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -411,13 +411,13 @@
 	orb->base.request_bus =
 		dma_map_single(device->card->device, &orb->request,
 			       sizeof orb->request, DMA_TO_DEVICE);
-	if (orb->base.request_bus == 0)
+	if (dma_mapping_error(orb->base.request_bus))
 		goto out;
 
 	orb->response_bus =
 		dma_map_single(device->card->device, &orb->response,
 			       sizeof orb->response, DMA_FROM_DEVICE);
-	if (orb->response_bus == 0)
+	if (dma_mapping_error(orb->response_bus))
 		goto out;
 
 	orb->request.response.high    = 0;
@@ -963,22 +963,20 @@
 	 * transfer direction not handled. */
 	if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
 		fw_error("Cannot handle DMA_BIDIRECTIONAL - rejecting command");
-		cmd->result = DID_ERROR << 16;
-		done(cmd);
-		return 0;
+		goto fail_alloc;
 	}
 
 	orb = kzalloc(sizeof *orb, GFP_ATOMIC);
 	if (orb == NULL) {
 		fw_notify("failed to alloc orb\n");
-		cmd->result = DID_NO_CONNECT << 16;
-		done(cmd);
-		return 0;
+		goto fail_alloc;
 	}
 
 	orb->base.request_bus =
 		dma_map_single(device->card->device, &orb->request,
 			       sizeof orb->request, DMA_TO_DEVICE);
+	if (dma_mapping_error(orb->base.request_bus))
+		goto fail_mapping;
 
 	orb->unit = unit;
 	orb->done = done;
@@ -1009,9 +1007,7 @@
 		 * could we get the scsi or blk layer to do that by
 		 * reporting our max supported block size? */
 		fw_error("command > 64k\n");
-		cmd->result = DID_ERROR << 16;
-		done(cmd);
-		return 0;
+		goto fail_bufflen;
 	} else if (cmd->request_bufflen > 0) {
 		sbp2_command_orb_map_buffer(orb);
 	}
@@ -1028,6 +1024,16 @@
 		      sd->command_block_agent_address + SBP2_ORB_POINTER);
 
 	return 0;
+
+ fail_bufflen:
+	dma_unmap_single(device->card->device, orb->base.request_bus,
+			 sizeof orb->request, DMA_TO_DEVICE);
+ fail_mapping:
+	kfree(orb);
+ fail_alloc:
+	cmd->result = DID_ERROR << 16;
+	done(cmd);
+	return 0;
 }
 
 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)