IB/iser: Generalize map/unmap dma tasks

Avoid code duplication and add the mapping/unmapping of the protection
buffers to the iser_dma_map_task_data/iser_dma_unmap_task_data functions.

Link: https://lore.kernel.org/r/20220308145546.8372-4-mgurtovoy@nvidia.com
Reviewed-by: Sergey Gorenko <sergeygo@nvidia.com>
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Author: mgurtovoy

drivers/infiniband/ulp/iser/iscsi_iser.h

@@ -531,13 +531,12 @@ int  iser_post_recvm(struct iser_conn *iser_conn,
 int  iser_post_send(struct ib_conn *ib_conn, struct iser_tx_desc *tx_desc);
 
 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
-			   struct iser_data_buf *data,
 			   enum iser_data_dir iser_dir,
 			   enum dma_data_direction dma_dir);
 
 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
-			      struct iser_data_buf *data,
-			      enum dma_data_direction dir);
+			      enum iser_data_dir iser_dir,
+			      enum dma_data_direction dma_dir);
 
 int  iser_initialize_task_headers(struct iscsi_task *task,
 			struct iser_tx_desc *tx_desc);

drivers/infiniband/ulp/iser/iser_initiator.c

@@ -52,26 +52,13 @@ static int iser_prepare_read_cmd(struct iscsi_task *task)
 	struct iser_mem_reg *mem_reg;
 	int err;
 	struct iser_ctrl *hdr = &iser_task->desc.iser_header;
-	struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
 
 	err = iser_dma_map_task_data(iser_task,
-				     buf_in,
 				     ISER_DIR_IN,
 				     DMA_FROM_DEVICE);
 	if (err)
 		return err;
 
-	if (scsi_prot_sg_count(iser_task->sc)) {
-		struct iser_data_buf *pbuf_in = &iser_task->prot[ISER_DIR_IN];
-
-		err = iser_dma_map_task_data(iser_task,
-					     pbuf_in,
-					     ISER_DIR_IN,
-					     DMA_FROM_DEVICE);
-		if (err)
-			return err;
-	}
-
 	err = iser_reg_mem_fastreg(iser_task, ISER_DIR_IN, false);
 	if (err) {
 		iser_err("Failed to set up Data-IN RDMA\n");
@@ -106,23 +93,11 @@ static int iser_prepare_write_cmd(struct iscsi_task *task, unsigned int imm_sz,
 	struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 
 	err = iser_dma_map_task_data(iser_task,
-				     buf_out,
 				     ISER_DIR_OUT,
 				     DMA_TO_DEVICE);
 	if (err)
 		return err;
 
-	if (scsi_prot_sg_count(iser_task->sc)) {
-		struct iser_data_buf *pbuf_out = &iser_task->prot[ISER_DIR_OUT];
-
-		err = iser_dma_map_task_data(iser_task,
-					     pbuf_out,
-					     ISER_DIR_OUT,
-					     DMA_TO_DEVICE);
-		if (err)
-			return err;
-	}
-
 	err = iser_reg_mem_fastreg(iser_task, ISER_DIR_OUT,
 				   buf_out->data_len == imm_sz);
 	if (err != 0) {
@@ -740,27 +715,16 @@ void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 
 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 {
-	int prot_count = scsi_prot_sg_count(iser_task->sc);
 
 	if (iser_task->dir[ISER_DIR_IN]) {
 		iser_unreg_mem_fastreg(iser_task, ISER_DIR_IN);
-		iser_dma_unmap_task_data(iser_task,
-					 &iser_task->data[ISER_DIR_IN],
+		iser_dma_unmap_task_data(iser_task, ISER_DIR_IN,
 					 DMA_FROM_DEVICE);
-		if (prot_count)
-			iser_dma_unmap_task_data(iser_task,
-						 &iser_task->prot[ISER_DIR_IN],
-						 DMA_FROM_DEVICE);
 	}
 
 	if (iser_task->dir[ISER_DIR_OUT]) {
 		iser_unreg_mem_fastreg(iser_task, ISER_DIR_OUT);
-		iser_dma_unmap_task_data(iser_task,
-					 &iser_task->data[ISER_DIR_OUT],
+		iser_dma_unmap_task_data(iser_task, ISER_DIR_OUT,
 					 DMA_TO_DEVICE);
-		if (prot_count)
-			iser_dma_unmap_task_data(iser_task,
-						 &iser_task->prot[ISER_DIR_OUT],
-						 DMA_TO_DEVICE);
 	}
 }

drivers/infiniband/ulp/iser/iser_memory.c

@@ -70,10 +70,10 @@ static void iser_reg_desc_put_fr(struct ib_conn *ib_conn,
 }
 
 int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
-			   struct iser_data_buf *data,
 			   enum iser_data_dir iser_dir,
 			   enum dma_data_direction dma_dir)
 {
+	struct iser_data_buf *data = &iser_task->data[iser_dir];
 	struct ib_device *dev;
 
 	iser_task->dir[iser_dir] = 1;
@@ -84,17 +84,40 @@ int iser_dma_map_task_data(struct iscsi_iser_task *iser_task,
 		iser_err("dma_map_sg failed!!!\n");
 		return -EINVAL;
 	}
+
+	if (scsi_prot_sg_count(iser_task->sc)) {
+		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
+
+		pdata->dma_nents = ib_dma_map_sg(dev, pdata->sg, pdata->size, dma_dir);
+		if (unlikely(pdata->dma_nents == 0)) {
+			iser_err("protection dma_map_sg failed!!!\n");
+			goto out_unmap;
+		}
+	}
+
 	return 0;
+
+out_unmap:
+	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
+	return -EINVAL;
 }
 
+
 void iser_dma_unmap_task_data(struct iscsi_iser_task *iser_task,
-			      struct iser_data_buf *data,
-			      enum dma_data_direction dir)
+			      enum iser_data_dir iser_dir,
+			      enum dma_data_direction dma_dir)
 {
+	struct iser_data_buf *data = &iser_task->data[iser_dir];
 	struct ib_device *dev;
 
 	dev = iser_task->iser_conn->ib_conn.device->ib_device;
-	ib_dma_unmap_sg(dev, data->sg, data->size, dir);
+	ib_dma_unmap_sg(dev, data->sg, data->size, dma_dir);
+
+	if (scsi_prot_sg_count(iser_task->sc)) {
+		struct iser_data_buf *pdata = &iser_task->prot[iser_dir];
+
+		ib_dma_unmap_sg(dev, pdata->sg, pdata->size, dma_dir);
+	}
 }
 
 static int iser_reg_dma(struct iser_device *device, struct iser_data_buf *mem,