From: Leon Romanovsky <leonro@mellanox.com>
Date: Sun, 8 Jul 2018 13:50:20 +0300
Subject: RDMA/mlx5: Melt consecutive calls to alloc_bfreg() in one call
Patch-mainline: v4.19-rc1
Git-commit: ffaf58def01ebdbf2669204e105c5a4f356ba276
References: bsc#1103991 FATE#326007

There is no need for three consecutive calls to alloc_bfreg(). It can be
implemented with one function.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/mlx5_ib.h |    6 ----
 drivers/infiniband/hw/mlx5/qp.c      |   47 ++++++++---------------------------
 2 files changed, 12 insertions(+), 41 deletions(-)

--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -78,12 +78,6 @@ enum {
 	MLX5_REQ_SCAT_DATA64_CQE	= 0x22,
 };
 
-enum mlx5_ib_latency_class {
-	MLX5_IB_LATENCY_CLASS_LOW,
-	MLX5_IB_LATENCY_CLASS_MEDIUM,
-	MLX5_IB_LATENCY_CLASS_HIGH,
-};
-
 enum mlx5_ib_mad_ifc_flags {
 	MLX5_MAD_IFC_IGNORE_MKEY	= 1,
 	MLX5_MAD_IFC_IGNORE_BKEY	= 2,
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -563,32 +563,21 @@ static int alloc_med_class_bfreg(struct
 }
 
 static int alloc_bfreg(struct mlx5_ib_dev *dev,
-		       struct mlx5_bfreg_info *bfregi,
-		       enum mlx5_ib_latency_class lat)
+		       struct mlx5_bfreg_info *bfregi)
 {
-	int bfregn = -EINVAL;
+	int bfregn = -ENOMEM;
 
 	mutex_lock(&bfregi->lock);
-	switch (lat) {
-	case MLX5_IB_LATENCY_CLASS_LOW:
+	if (bfregi->ver >= 2) {
+		bfregn = alloc_high_class_bfreg(dev, bfregi);
+		if (bfregn < 0)
+			bfregn = alloc_med_class_bfreg(dev, bfregi);
+	}
+
+	if (bfregn < 0) {
 		BUILD_BUG_ON(NUM_NON_BLUE_FLAME_BFREGS != 1);
 		bfregn = 0;
 		bfregi->count[bfregn]++;
-		break;
-
-	case MLX5_IB_LATENCY_CLASS_MEDIUM:
-		if (bfregi->ver < 2)
-			bfregn = -ENOMEM;
-		else
-			bfregn = alloc_med_class_bfreg(dev, bfregi);
-		break;
-
-	case MLX5_IB_LATENCY_CLASS_HIGH:
-		if (bfregi->ver < 2)
-			bfregn = -ENOMEM;
-		else
-			bfregn = alloc_high_class_bfreg(dev, bfregi);
-		break;
 	}
 	mutex_unlock(&bfregi->lock);
 
@@ -822,21 +811,9 @@ static int create_user_qp(struct mlx5_ib
 		bfregn = MLX5_CROSS_CHANNEL_BFREG;
 	}
 	else {
-		bfregn = alloc_bfreg(dev, &context->bfregi, MLX5_IB_LATENCY_CLASS_HIGH);
-		if (bfregn < 0) {
-			mlx5_ib_dbg(dev, "failed to allocate low latency BFREG\n");
-			mlx5_ib_dbg(dev, "reverting to medium latency\n");
-			bfregn = alloc_bfreg(dev, &context->bfregi, MLX5_IB_LATENCY_CLASS_MEDIUM);
-			if (bfregn < 0) {
-				mlx5_ib_dbg(dev, "failed to allocate medium latency BFREG\n");
-				mlx5_ib_dbg(dev, "reverting to high latency\n");
-				bfregn = alloc_bfreg(dev, &context->bfregi, MLX5_IB_LATENCY_CLASS_LOW);
-				if (bfregn < 0) {
-					mlx5_ib_warn(dev, "bfreg allocation failed\n");
-					return bfregn;
-				}
-			}
-		}
+		bfregn = alloc_bfreg(dev, &context->bfregi);
+		if (bfregn < 0)
+			return bfregn;
 	}
 
 	mlx5_ib_dbg(dev, "bfregn 0x%x, uar_index 0x%x\n", bfregn, uar_index);