RDMA/hns: Refactor mtr find

hns_roce_mtr_find() is a collection of multiple functions, and the
return value is also difficult to understand, which is not conducive
to modification and maintenance.

Separate the function of obtaining MTR root BA from this function.
And some adjustments has been made to improve readability.

Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
Link: https://lore.kernel.org/r/20240113085935.2838701-2-huangjunxian6@hisilicon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

1 files changed, 57 insertions, 29 deletions

diff --git a/drivers/infiniband/hw/hns/hns_roce_mr.c b/drivers/infiniband/hw/hns/hns_roce_mr.c
index 91cd580480fe..9537a2c00bb6 100644
--- a/drivers/infiniband/hw/hns/hns_roce_mr.c
+++ b/drivers/infiniband/hw/hns/hns_roce_mr.c
@@ -809,47 +809,53 @@ int hns_roce_mtr_map(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
 	return ret;
 }
 
-int hns_roce_mtr_find(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
-		      u32 offset, u64 *mtt_buf, int mtt_max, u64 *base_addr)
+static int hns_roce_get_direct_addr_mtt(struct hns_roce_hem_cfg *cfg,
+					u32 start_index, u64 *mtt_buf,
+					int mtt_cnt)
 {
-	struct hns_roce_hem_cfg *cfg = &mtr->hem_cfg;
-	int mtt_count, left;
-	u32 start_index;
+	int mtt_count;
 	int total = 0;
-	__le64 *mtts;
 	u32 npage;
 	u64 addr;
 
-	if (!mtt_buf || mtt_max < 1)
-		goto done;
-
-	/* no mtt memory in direct mode, so just return the buffer address */
-	if (cfg->is_direct) {
-		start_index = offset >> HNS_HW_PAGE_SHIFT;
-		for (mtt_count = 0; mtt_count < cfg->region_count &&
-		     total < mtt_max; mtt_count++) {
-			npage = cfg->region[mtt_count].offset;
-			if (npage < start_index)
-				continue;
+	if (mtt_cnt > cfg->region_count)
+		return -EINVAL;
 
-			addr = cfg->root_ba + (npage << HNS_HW_PAGE_SHIFT);
-			mtt_buf[total] = addr;
+	for (mtt_count = 0; mtt_count < cfg->region_count && total < mtt_cnt;
+	     mtt_count++) {
+		npage = cfg->region[mtt_count].offset;
+		if (npage < start_index)
+			continue;
 
-			total++;
-		}
+		addr = cfg->root_ba + (npage << HNS_HW_PAGE_SHIFT);
+		mtt_buf[total] = addr;
 
-		goto done;
+		total++;
 	}
 
-	start_index = offset >> cfg->buf_pg_shift;
-	left = mtt_max;
+	if (!total)
+		return -ENOENT;
+
+	return 0;
+}
+
+static int hns_roce_get_mhop_mtt(struct hns_roce_dev *hr_dev,
+				 struct hns_roce_mtr *mtr, u32 start_index,
+				 u64 *mtt_buf, int mtt_cnt)
+{
+	int left = mtt_cnt;
+	int total = 0;
+	int mtt_count;
+	__le64 *mtts;
+	u32 npage;
+
 	while (left > 0) {
 		mtt_count = 0;
 		mtts = hns_roce_hem_list_find_mtt(hr_dev, &mtr->hem_list,
 						  start_index + total,
 						  &mtt_count);
 		if (!mtts || !mtt_count)
-			goto done;
+			break;
 
 		npage = min(mtt_count, left);
 		left -= npage;
@@ -857,11 +863,33 @@ int hns_roce_mtr_find(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
 			mtt_buf[total++] = le64_to_cpu(mtts[mtt_count]);
 	}
 
-done:
-	if (base_addr)
-		*base_addr = cfg->root_ba;
+	if (!total)
+		return -ENOENT;
+
+	return 0;
+}
+
+int hns_roce_mtr_find(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
+		      u32 offset, u64 *mtt_buf, int mtt_max)
+{
+	struct hns_roce_hem_cfg *cfg = &mtr->hem_cfg;
+	u32 start_index;
+	int ret;
+
+	if (!mtt_buf || mtt_max < 1)
+		return -EINVAL;
 
-	return total;
+	/* no mtt memory in direct mode, so just return the buffer address */
+	if (cfg->is_direct) {
+		start_index = offset >> HNS_HW_PAGE_SHIFT;
+		ret = hns_roce_get_direct_addr_mtt(cfg, start_index,
+						   mtt_buf, mtt_max);
+	} else {
+		start_index = offset >> cfg->buf_pg_shift;
+		ret = hns_roce_get_mhop_mtt(hr_dev, mtr, start_index,
+					    mtt_buf, mtt_max);
+	}
+	return ret;
 }
 
 static int mtr_init_buf_cfg(struct hns_roce_dev *hr_dev,