From: Eran Ben Elisha <eranbe@mellanox.com>
Date: Mon, 20 Nov 2017 09:58:01 +0200
Subject: net/mlx5: Fix mlx5_get_uars_page to return error code
Patch-mainline: v4.15-rc9
Git-commit: 72f36be06138bdc11bdbe1f04e4a3e2637ea438d
References: bsc#1046303 FATE#322944

Change mlx5_get_uars_page to return ERR_PTR in case of
allocation failure. Change all callers accordingly to
check the IS_ERR(ptr) instead of NULL.

Fixes: 59211bd3b632 ("net/mlx5: Split the load/unload flow into hardware and software flows")
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/main.c              |    2 +-
 drivers/net/ethernet/mellanox/mlx5/core/main.c |    3 ++-
 drivers/net/ethernet/mellanox/mlx5/core/uar.c  |   14 ++++++--------
 3 files changed, 9 insertions(+), 10 deletions(-)

--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -4111,7 +4111,7 @@ static void *mlx5_ib_add(struct mlx5_cor
 		goto err_cnt;
 
 	dev->mdev->priv.uar = mlx5_get_uars_page(dev->mdev);
-	if (!dev->mdev->priv.uar)
+	if (IS_ERR(dev->mdev->priv.uar))
 		goto err_cong;
 
 	err = mlx5_alloc_bfreg(dev->mdev, &dev->bfreg, false, false);
--- a/drivers/net/ethernet/mellanox/mlx5/core/main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/main.c
@@ -1128,8 +1128,9 @@ static int mlx5_load_one(struct mlx5_cor
 	}
 
 	dev->priv.uar = mlx5_get_uars_page(dev);
-	if (!dev->priv.uar) {
+	if (IS_ERR(dev->priv.uar)) {
 		dev_err(&pdev->dev, "Failed allocating uar, aborting\n");
+		err = PTR_ERR(dev->priv.uar);
 		goto err_disable_msix;
 	}
 
--- a/drivers/net/ethernet/mellanox/mlx5/core/uar.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/uar.c
@@ -168,18 +168,16 @@ struct mlx5_uars_page *mlx5_get_uars_pag
 	struct mlx5_uars_page *ret;
 
 	mutex_lock(&mdev->priv.bfregs.reg_head.lock);
-	if (list_empty(&mdev->priv.bfregs.reg_head.list)) {
-		ret = alloc_uars_page(mdev, false);
-		if (IS_ERR(ret)) {
-			ret = NULL;
-			goto out;
-		}
-		list_add(&ret->list, &mdev->priv.bfregs.reg_head.list);
-	} else {
+	if (!list_empty(&mdev->priv.bfregs.reg_head.list)) {
 		ret = list_first_entry(&mdev->priv.bfregs.reg_head.list,
 				       struct mlx5_uars_page, list);
 		kref_get(&ret->ref_count);
+		goto out;
 	}
+	ret = alloc_uars_page(mdev, false);
+	if (IS_ERR(ret))
+		goto out;
+	list_add(&ret->list, &mdev->priv.bfregs.reg_head.list);
 out:
 	mutex_unlock(&mdev->priv.bfregs.reg_head.lock);