scsi: hisi_sas: Relocate some code to reduce complexity

Relocate the codes related to dma_map/unmap in hisi_sas_task_prep() to
reduce complexity, with a view to add DIF/DIX support.

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 c39c91c877145f0027182219a3a07ca0b86b2a3b..95350fdb393baca3dffb2374fc8655c15811739f 100644 (file)
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -296,6 +296,90 @@ static void hisi_sas_task_prep_abort(struct hisi_hba *hisi_hba,
                        device_id, abort_flag, tag_to_abort);
 }
 
+static void hisi_sas_dma_unmap(struct hisi_hba *hisi_hba,
+                              struct sas_task *task, int n_elem,
+                              int n_elem_req, int n_elem_resp)
+{
+       struct device *dev = hisi_hba->dev;
+
+       if (!sas_protocol_ata(task->task_proto)) {
+               if (task->num_scatter) {
+                       if (n_elem)
+                               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);
+                       if (n_elem_resp)
+                               dma_unmap_sg(dev, &task->smp_task.smp_resp,
+                                            1, DMA_FROM_DEVICE);
+               }
+       }
+}
+
+static int hisi_sas_dma_map(struct hisi_hba *hisi_hba,
+                           struct sas_task *task, int *n_elem,
+                           int *n_elem_req, int *n_elem_resp)
+{
+       struct device *dev = hisi_hba->dev;
+       int rc;
+
+       if (sas_protocol_ata(task->task_proto)) {
+               *n_elem = task->num_scatter;
+       } else {
+               unsigned int req_len, resp_len;
+
+               if (task->num_scatter) {
+                       *n_elem = dma_map_sg(dev, task->scatter,
+                                            task->num_scatter, task->data_dir);
+                       if (!*n_elem) {
+                               rc = -ENOMEM;
+                               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) {
+                               rc = -ENOMEM;
+                               goto prep_out;
+                       }
+                       req_len = sg_dma_len(&task->smp_task.smp_req);
+                       if (req_len & 0x3) {
+                               rc = -EINVAL;
+                               goto err_out_dma_unmap;
+                       }
+                       *n_elem_resp = dma_map_sg(dev, &task->smp_task.smp_resp,
+                                                 1, DMA_FROM_DEVICE);
+                       if (!*n_elem_resp) {
+                               rc = -ENOMEM;
+                               goto err_out_dma_unmap;
+                       }
+                       resp_len = sg_dma_len(&task->smp_task.smp_resp);
+                       if (resp_len & 0x3) {
+                               rc = -EINVAL;
+                               goto err_out_dma_unmap;
+                       }
+               }
+       }
+
+       if (*n_elem > HISI_SAS_SGE_PAGE_CNT) {
+               dev_err(dev, "task prep: n_elem(%d) > HISI_SAS_SGE_PAGE_CNT",
+                       *n_elem);
+               rc = -EINVAL;
+               goto err_out_dma_unmap;
+       }
+       return 0;
+
+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, *n_elem_resp);
+prep_out:
+       return rc;
+}
+
 static int hisi_sas_task_prep(struct sas_task *task,
                              struct hisi_sas_dq **dq_pointer,
                              bool is_tmf, struct hisi_sas_tmf_task *tmf,
@@ -338,49 +422,10 @@ static int hisi_sas_task_prep(struct sas_task *task,
                return -ECOMM;
        }
 
-       if (!sas_protocol_ata(task->task_proto)) {
-               unsigned int req_len, resp_len;
-
-               if (task->num_scatter) {
-                       n_elem = dma_map_sg(dev, task->scatter,
-                                           task->num_scatter, task->data_dir);
-                       if (!n_elem) {
-                               rc = -ENOMEM;
-                               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) {
-                               rc = -ENOMEM;
-                               goto prep_out;
-                       }
-                       req_len = sg_dma_len(&task->smp_task.smp_req);
-                       if (req_len & 0x3) {
-                               rc = -EINVAL;
-                               goto err_out_dma_unmap;
-                       }
-                       n_elem_resp = dma_map_sg(dev, &task->smp_task.smp_resp,
-                                                1, DMA_FROM_DEVICE);
-                       if (!n_elem_resp) {
-                               rc = -ENOMEM;
-                               goto err_out_dma_unmap;
-                       }
-                       resp_len = sg_dma_len(&task->smp_task.smp_resp);
-                       if (resp_len & 0x3) {
-                               rc = -EINVAL;
-                               goto err_out_dma_unmap;
-                       }
-               }
-       } else
-               n_elem = task->num_scatter;
-
-       if (n_elem > HISI_SAS_SGE_PAGE_CNT) {
-               dev_err(dev, "task prep: n_elem(%d) > HISI_SAS_SGE_PAGE_CNT",
-                       n_elem);
-               rc = -EINVAL;
-               goto err_out_dma_unmap;
-       }
+       rc = hisi_sas_dma_map(hisi_hba, task, &n_elem,
+                             &n_elem_req, &n_elem_resp);
+       if (rc < 0)
+               goto prep_out;
 
        if (hisi_hba->hw->slot_index_alloc)
                rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device);
@@ -465,19 +510,8 @@ static int hisi_sas_task_prep(struct sas_task *task,
 err_out_tag:
        hisi_sas_slot_index_free(hisi_hba, slot_idx);
 err_out_dma_unmap:
-       if (!sas_protocol_ata(task->task_proto)) {
-               if (task->num_scatter) {
-                       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);
-                       if (n_elem_resp)
-                               dma_unmap_sg(dev, &task->smp_task.smp_resp,
-                                            1, DMA_FROM_DEVICE);
-               }
-       }
+       hisi_sas_dma_unmap(hisi_hba, task, n_elem,
+                          n_elem_req, n_elem_resp);
 prep_out:
        dev_err(dev, "task prep: failed[%d]!\n", rc);
        return rc;