scsi: hisi_sas: Remove unnecessary variable to hold DMA map elements

Use slot->n_elem to store the return value of dma_map_sg() for SSP and SMP
IOs, and remove unnecessary variable n_elem_req.

Link: https://lore.kernel.org/r/1657823002-139010-3-git-send-email-john.garry@huawei.com
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 764e859..bd62e44 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -220,9 +220,10 @@ void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba, struct sas_task *task,
 
                if (!sas_protocol_ata(task->task_proto)) {
                        if (slot->n_elem)
-                               dma_unmap_sg(dev, task->scatter,
-                                            task->num_scatter,
-                                            task->data_dir);
+                               if (task->task_proto & SAS_PROTOCOL_SSP)
+                                       dma_unmap_sg(dev, task->scatter,
+                                                    task->num_scatter,
+                                                    task->data_dir);
                        if (slot->n_elem_dif) {
                                struct sas_ssp_task *ssp_task = &task->ssp_task;
                                struct scsi_cmnd *scsi_cmnd = ssp_task->cmd;
@@ -269,28 +270,23 @@ static void hisi_sas_task_prep_abort(struct hisi_hba *hisi_hba,
 }
 
 static void hisi_sas_dma_unmap(struct hisi_hba *hisi_hba,
-                              struct sas_task *task, int n_elem,
-                              int n_elem_req)
+                              struct sas_task *task, int n_elem)
 {
        struct device *dev = hisi_hba->dev;
 
-       if (!sas_protocol_ata(task->task_proto)) {
+       if (!sas_protocol_ata(task->task_proto) && n_elem) {
                if (task->num_scatter) {
-                       if (n_elem)
-                               dma_unmap_sg(dev, task->scatter,
-                                            task->num_scatter,
-                                            task->data_dir);
+                       dma_unmap_sg(dev, task->scatter, task->num_scatter,
+                                    task->data_dir);
                } else if (task->task_proto & SAS_PROTOCOL_SMP) {
-                       if (n_elem_req)
-                               dma_unmap_sg(dev, &task->smp_task.smp_req,
-                                            1, DMA_TO_DEVICE);
+                       dma_unmap_sg(dev, &task->smp_task.smp_req,
+                                    1, DMA_TO_DEVICE);
                }
        }
 }
 
 static int hisi_sas_dma_map(struct hisi_hba *hisi_hba,
-                           struct sas_task *task, int *n_elem,
-                           int *n_elem_req)
+                           struct sas_task *task, int *n_elem)
 {
        struct device *dev = hisi_hba->dev;
        int rc;
@@ -308,9 +304,9 @@ static int hisi_sas_dma_map(struct hisi_hba *hisi_hba,
                                goto prep_out;
                        }
                } else if (task->task_proto & SAS_PROTOCOL_SMP) {
-                       *n_elem_req = dma_map_sg(dev, &task->smp_task.smp_req,
-                                                1, DMA_TO_DEVICE);
-                       if (!*n_elem_req) {
+                       *n_elem = dma_map_sg(dev, &task->smp_task.smp_req,
+                                            1, DMA_TO_DEVICE);
+                       if (!*n_elem) {
                                rc = -ENOMEM;
                                goto prep_out;
                        }
@@ -332,8 +328,7 @@ static int hisi_sas_dma_map(struct hisi_hba *hisi_hba,
 
 err_out_dma_unmap:
        /* It would be better to call dma_unmap_sg() here, but it's messy */
-       hisi_sas_dma_unmap(hisi_hba, task, *n_elem,
-                          *n_elem_req);
+       hisi_sas_dma_unmap(hisi_hba, task, *n_elem);
 prep_out:
        return rc;
 }
@@ -457,7 +452,7 @@ void hisi_sas_task_deliver(struct hisi_hba *hisi_hba,
 
 static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
 {
-       int n_elem = 0, n_elem_dif = 0, n_elem_req = 0;
+       int n_elem = 0, n_elem_dif = 0;
        struct domain_device *device = task->dev;
        struct asd_sas_port *sas_port = device->port;
        struct hisi_sas_device *sas_dev = device->lldd_dev;
@@ -568,8 +563,7 @@ static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
                return -EINVAL;
        }
 
-       rc = hisi_sas_dma_map(hisi_hba, task, &n_elem,
-                             &n_elem_req);
+       rc = hisi_sas_dma_map(hisi_hba, task, &n_elem);
        if (rc < 0)
                goto prep_out;
 
@@ -605,8 +599,7 @@ err_out_dif_dma_unmap:
        if (!sas_protocol_ata(task->task_proto))
                hisi_sas_dif_dma_unmap(hisi_hba, task, n_elem_dif);
 err_out_dma_unmap:
-       hisi_sas_dma_unmap(hisi_hba, task, n_elem,
-                                  n_elem_req);
+       hisi_sas_dma_unmap(hisi_hba, task, n_elem);
 prep_out:
        dev_err(dev, "task exec: failed[%d]!\n", rc);
        return rc;