RDMA/hns: Optimize hns_roce_mhop_alloc function.

Move some lines for allocating multi-hop addressing into independent
functions in order to improve readability.

Link: https://lore.kernel.org/r/1562593285-8037-7-git-send-email-oulijun@huawei.comSigned-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/hns/hns_roce_mr.c

@@ -347,31 +347,11 @@ static void hns_roce_loop_free(struct hns_roce_dev *hr_dev,
 	mr->pbl_bt_l0 = NULL;
 	mr->pbl_l0_dma_addr = 0;
 }
-
-/* PBL multi hop addressing */
-static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
-			       struct hns_roce_mr *mr)
+static int pbl_1hop_alloc(struct hns_roce_dev *hr_dev, int npages,
+			       struct hns_roce_mr *mr, u32 pbl_bt_sz)
 {
 	struct device *dev = hr_dev->dev;
-	int mr_alloc_done = 0;
-	int npages_allocated;
-	int i = 0, j = 0;
-	u32 pbl_bt_sz;
-	u32 mhop_num;
-	u64 pbl_last_bt_num;
-	u64 pbl_bt_cnt = 0;
-	u64 bt_idx;
-	u64 size;
-
-	mhop_num = (mr->type == MR_TYPE_FRMR ? 1 : hr_dev->caps.pbl_hop_num);
-	pbl_bt_sz = 1 << (hr_dev->caps.pbl_ba_pg_sz + PAGE_SHIFT);
-	pbl_last_bt_num = (npages + pbl_bt_sz / 8 - 1) / (pbl_bt_sz / 8);
-
-	if (mhop_num == HNS_ROCE_HOP_NUM_0)
-		return 0;
 
-	/* hop_num = 1 */
-	if (mhop_num == 1) {
 	if (npages > pbl_bt_sz / 8) {
 		dev_err(dev, "npages %d is larger than buf_pg_sz!",
 			npages);
@@ -385,45 +365,26 @@ static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
 
 	mr->pbl_size = npages;
 	mr->pbl_ba = mr->pbl_dma_addr;
-		mr->pbl_hop_num = mhop_num;
+	mr->pbl_hop_num = 1;
 	mr->pbl_ba_pg_sz = hr_dev->caps.pbl_ba_pg_sz;
 	mr->pbl_buf_pg_sz = hr_dev->caps.pbl_buf_pg_sz;
 	return 0;
-	}
-
-	mr->pbl_l1_dma_addr = kcalloc(pbl_bt_sz / 8,
-				      sizeof(*mr->pbl_l1_dma_addr),
-				      GFP_KERNEL);
-	if (!mr->pbl_l1_dma_addr)
-		return -ENOMEM;
 
-	mr->pbl_bt_l1 = kcalloc(pbl_bt_sz / 8, sizeof(*mr->pbl_bt_l1),
-				GFP_KERNEL);
-	if (!mr->pbl_bt_l1)
-		goto err_kcalloc_bt_l1;
+}
 
-	if (mhop_num == 3) {
-		mr->pbl_l2_dma_addr = kcalloc(pbl_last_bt_num,
-					      sizeof(*mr->pbl_l2_dma_addr),
-					      GFP_KERNEL);
-		if (!mr->pbl_l2_dma_addr)
-			goto err_kcalloc_l2_dma;
 
-		mr->pbl_bt_l2 = kcalloc(pbl_last_bt_num,
-					sizeof(*mr->pbl_bt_l2),
-					GFP_KERNEL);
-		if (!mr->pbl_bt_l2)
-			goto err_kcalloc_bt_l2;
-	}
+static int pbl_2hop_alloc(struct hns_roce_dev *hr_dev, int npages,
+			       struct hns_roce_mr *mr, u32 pbl_bt_sz)
+{
+	struct device *dev = hr_dev->dev;
+	int npages_allocated;
+	u64 pbl_last_bt_num;
+	u64 pbl_bt_cnt = 0;
+	u64 size;
+	int i;
 
-	/* alloc L0 BT */
-	mr->pbl_bt_l0 = dma_alloc_coherent(dev, pbl_bt_sz,
-					   &(mr->pbl_l0_dma_addr),
-					   GFP_KERNEL);
-	if (!mr->pbl_bt_l0)
-		goto err_dma_alloc_l0;
+	pbl_last_bt_num = (npages + pbl_bt_sz / 8 - 1) / (pbl_bt_sz / 8);
 
-	if (mhop_num == 2) {
 	/* alloc L1 BT */
 	for (i = 0; i < pbl_bt_sz / 8; i++) {
 		if (pbl_bt_cnt + 1 < pbl_last_bt_num) {
@@ -437,7 +398,7 @@ static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
 					    GFP_KERNEL);
 		if (!mr->pbl_bt_l1[i]) {
 			hns_roce_loop_free(hr_dev, mr, 1, i, 0);
-				goto err_dma_alloc_l0;
+			return -ENOMEM;
 		}
 
 		*(mr->pbl_bt_l0 + i) = mr->pbl_l1_dma_addr[i];
@@ -446,7 +407,39 @@ static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
 		if (pbl_bt_cnt >= pbl_last_bt_num)
 			break;
 	}
-	} else if (mhop_num == 3) {
+
+	mr->l0_chunk_last_num = i + 1;
+
+	return 0;
+}
+
+static int pbl_3hop_alloc(struct hns_roce_dev *hr_dev, int npages,
+			       struct hns_roce_mr *mr, u32 pbl_bt_sz)
+{
+	struct device *dev = hr_dev->dev;
+	int mr_alloc_done = 0;
+	int npages_allocated;
+	u64 pbl_last_bt_num;
+	u64 pbl_bt_cnt = 0;
+	u64 bt_idx;
+	u64 size;
+	int i;
+	int j = 0;
+
+	pbl_last_bt_num = (npages + pbl_bt_sz / 8 - 1) / (pbl_bt_sz / 8);
+
+	mr->pbl_l2_dma_addr = kcalloc(pbl_last_bt_num,
+				      sizeof(*mr->pbl_l2_dma_addr),
+				      GFP_KERNEL);
+	if (!mr->pbl_l2_dma_addr)
+		return -ENOMEM;
+
+	mr->pbl_bt_l2 = kcalloc(pbl_last_bt_num,
+				sizeof(*mr->pbl_bt_l2),
+				GFP_KERNEL);
+	if (!mr->pbl_bt_l2)
+		goto err_kcalloc_bt_l2;
+
 	/* alloc L1, L2 BT */
 	for (i = 0; i < pbl_bt_sz / 8; i++) {
 		mr->pbl_bt_l1[i] = dma_alloc_coherent(dev, pbl_bt_sz,
@@ -491,17 +484,10 @@ static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
 		if (mr_alloc_done)
 			break;
 	}
-	}
 
 	mr->l0_chunk_last_num = i + 1;
-	if (mhop_num == 3)
 	mr->l1_chunk_last_num = j + 1;
 
-	mr->pbl_size = npages;
-	mr->pbl_ba = mr->pbl_l0_dma_addr;
-	mr->pbl_hop_num = hr_dev->caps.pbl_hop_num;
-	mr->pbl_ba_pg_sz = hr_dev->caps.pbl_ba_pg_sz;
-	mr->pbl_buf_pg_sz = hr_dev->caps.pbl_buf_pg_sz;
 
 	return 0;
 
@@ -513,6 +499,65 @@ static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
 	kfree(mr->pbl_l2_dma_addr);
 	mr->pbl_l2_dma_addr = NULL;
 
+	return -ENOMEM;
+}
+
+
+/* PBL multi hop addressing */
+static int hns_roce_mhop_alloc(struct hns_roce_dev *hr_dev, int npages,
+			       struct hns_roce_mr *mr)
+{
+	struct device *dev = hr_dev->dev;
+	u32 pbl_bt_sz;
+	u32 mhop_num;
+
+	mhop_num = (mr->type == MR_TYPE_FRMR ? 1 : hr_dev->caps.pbl_hop_num);
+	pbl_bt_sz = 1 << (hr_dev->caps.pbl_ba_pg_sz + PAGE_SHIFT);
+
+	if (mhop_num == HNS_ROCE_HOP_NUM_0)
+		return 0;
+
+	/* hop_num = 1 */
+	if (mhop_num == 1)
+		return pbl_1hop_alloc(hr_dev, npages, mr, pbl_bt_sz);
+
+	mr->pbl_l1_dma_addr = kcalloc(pbl_bt_sz / 8,
+				      sizeof(*mr->pbl_l1_dma_addr),
+				      GFP_KERNEL);
+	if (!mr->pbl_l1_dma_addr)
+		return -ENOMEM;
+
+	mr->pbl_bt_l1 = kcalloc(pbl_bt_sz / 8, sizeof(*mr->pbl_bt_l1),
+				GFP_KERNEL);
+	if (!mr->pbl_bt_l1)
+		goto err_kcalloc_bt_l1;
+
+	/* alloc L0 BT */
+	mr->pbl_bt_l0 = dma_alloc_coherent(dev, pbl_bt_sz,
+					   &(mr->pbl_l0_dma_addr),
+					   GFP_KERNEL);
+	if (!mr->pbl_bt_l0)
+		goto err_kcalloc_l2_dma;
+
+	if (mhop_num == 2) {
+		if (pbl_2hop_alloc(hr_dev, npages, mr, pbl_bt_sz))
+			goto err_kcalloc_l2_dma;
+	}
+
+	if (mhop_num == 3) {
+		if (pbl_3hop_alloc(hr_dev, npages, mr, pbl_bt_sz))
+			goto err_kcalloc_l2_dma;
+	}
+
+
+	mr->pbl_size = npages;
+	mr->pbl_ba = mr->pbl_l0_dma_addr;
+	mr->pbl_hop_num = hr_dev->caps.pbl_hop_num;
+	mr->pbl_ba_pg_sz = hr_dev->caps.pbl_ba_pg_sz;
+	mr->pbl_buf_pg_sz = hr_dev->caps.pbl_buf_pg_sz;
+
+	return 0;
+
 err_kcalloc_l2_dma:
 	kfree(mr->pbl_bt_l1);
 	mr->pbl_bt_l1 = NULL;