mlx4_core: Propagate MR deregistration failures to caller

MR deregistration fails when memory windows are bound to the MR.
Handle such failures by propagating them to the caller ULP.
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/mlx4/mr.c

@@ -68,7 +68,7 @@ struct ib_mr *mlx4_ib_get_dma_mr(struct ib_pd *pd, int acc)
 	return &mr->ibmr;
 
 err_mr:
-	mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);
+	(void) mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);
 
 err_free:
 	kfree(mr);
@@ -163,7 +163,7 @@ struct ib_mr *mlx4_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 	return &mr->ibmr;
 
 err_mr:
-	mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);
+	(void) mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);
 
 err_umem:
 	ib_umem_release(mr->umem);
@@ -177,8 +177,11 @@ struct ib_mr *mlx4_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 int mlx4_ib_dereg_mr(struct ib_mr *ibmr)
 {
 	struct mlx4_ib_mr *mr = to_mmr(ibmr);
+	int ret;
 
-	mlx4_mr_free(to_mdev(ibmr->device)->dev, &mr->mmr);
+	ret = mlx4_mr_free(to_mdev(ibmr->device)->dev, &mr->mmr);
+	if (ret)
+		return ret;
 	if (mr->umem)
 		ib_umem_release(mr->umem);
 	kfree(mr);
@@ -212,7 +215,7 @@ struct ib_mr *mlx4_ib_alloc_fast_reg_mr(struct ib_pd *pd,
 	return &mr->ibmr;
 
 err_mr:
-	mlx4_mr_free(dev->dev, &mr->mmr);
+	(void) mlx4_mr_free(dev->dev, &mr->mmr);
 
 err_free:
 	kfree(mr);
@@ -291,7 +294,7 @@ struct ib_fmr *mlx4_ib_fmr_alloc(struct ib_pd *pd, int acc,
 	return &fmr->ibfmr;
 
 err_mr:
-	mlx4_mr_free(to_mdev(pd->device)->dev, &fmr->mfmr.mr);
+	(void) mlx4_mr_free(to_mdev(pd->device)->dev, &fmr->mfmr.mr);
 
 err_free:
 	kfree(fmr);

drivers/net/ethernet/mellanox/mlx4/en_main.c

@@ -176,7 +176,7 @@ static void mlx4_en_remove(struct mlx4_dev *dev, void *endev_ptr)
 
 	flush_workqueue(mdev->workqueue);
 	destroy_workqueue(mdev->workqueue);
-	mlx4_mr_free(dev, &mdev->mr);
+	(void) mlx4_mr_free(dev, &mdev->mr);
 	iounmap(mdev->uar_map);
 	mlx4_uar_free(dev, &mdev->priv_uar);
 	mlx4_pd_free(dev, mdev->priv_pdn);
@@ -283,7 +283,7 @@ static void *mlx4_en_add(struct mlx4_dev *dev)
 	return mdev;
 
 err_mr:
-	mlx4_mr_free(dev, &mdev->mr);
+	(void) mlx4_mr_free(dev, &mdev->mr);
 err_map:
 	if (!mdev->uar_map)
 		iounmap(mdev->uar_map);

drivers/net/ethernet/mellanox/mlx4/mr.c

@@ -442,7 +442,7 @@ int mlx4_mr_alloc(struct mlx4_dev *dev, u32 pd, u64 iova, u64 size, u32 access,
 }
 EXPORT_SYMBOL_GPL(mlx4_mr_alloc);
 
-static void mlx4_mr_free_reserved(struct mlx4_dev *dev, struct mlx4_mr *mr)
+static int mlx4_mr_free_reserved(struct mlx4_dev *dev, struct mlx4_mr *mr)
 {
 	int err;
 
@@ -450,20 +450,31 @@ static void mlx4_mr_free_reserved(struct mlx4_dev *dev, struct mlx4_mr *mr)
 		err = mlx4_HW2SW_MPT(dev, NULL,
 				     key_to_hw_index(mr->key) &
 				     (dev->caps.num_mpts - 1));
-		if (err)
-			mlx4_warn(dev, "xxx HW2SW_MPT failed (%d)\n", err);
+		if (err) {
+			mlx4_warn(dev, "HW2SW_MPT failed (%d),", err);
+			mlx4_warn(dev, "MR has MWs bound to it.\n");
+			return err;
+		}
 
 		mr->enabled = MLX4_MPT_EN_SW;
 	}
 	mlx4_mtt_cleanup(dev, &mr->mtt);
+
+	return 0;
 }
 
-void mlx4_mr_free(struct mlx4_dev *dev, struct mlx4_mr *mr)
+int mlx4_mr_free(struct mlx4_dev *dev, struct mlx4_mr *mr)
 {
-	mlx4_mr_free_reserved(dev, mr);
+	int ret;
+
+	ret = mlx4_mr_free_reserved(dev, mr);
+	if (ret)
+		return ret;
 	if (mr->enabled)
 		mlx4_mpt_free_icm(dev, key_to_hw_index(mr->key));
 	mlx4_mpt_release(dev, key_to_hw_index(mr->key));
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(mlx4_mr_free);
 
@@ -831,7 +842,7 @@ int mlx4_fmr_alloc(struct mlx4_dev *dev, u32 pd, u32 access, int max_pages,
 	return 0;
 
 err_free:
-	mlx4_mr_free(dev, &fmr->mr);
+	(void) mlx4_mr_free(dev, &fmr->mr);
 	return err;
 }
 EXPORT_SYMBOL_GPL(mlx4_fmr_alloc);
@@ -888,10 +899,14 @@ EXPORT_SYMBOL_GPL(mlx4_fmr_unmap);
 
 int mlx4_fmr_free(struct mlx4_dev *dev, struct mlx4_fmr *fmr)
 {
+	int ret;
+
 	if (fmr->maps)
 		return -EBUSY;
 
-	mlx4_mr_free(dev, &fmr->mr);
+	ret = mlx4_mr_free(dev, &fmr->mr);
+	if (ret)
+		return ret;
 	fmr->mr.enabled = MLX4_MPT_DISABLED;
 
 	return 0;

include/linux/mlx4/device.h

@@ -801,7 +801,7 @@ u64 mlx4_mtt_addr(struct mlx4_dev *dev, struct mlx4_mtt *mtt);
 
 int mlx4_mr_alloc(struct mlx4_dev *dev, u32 pd, u64 iova, u64 size, u32 access,
 		  int npages, int page_shift, struct mlx4_mr *mr);
-void mlx4_mr_free(struct mlx4_dev *dev, struct mlx4_mr *mr);
+int mlx4_mr_free(struct mlx4_dev *dev, struct mlx4_mr *mr);
 int mlx4_mr_enable(struct mlx4_dev *dev, struct mlx4_mr *mr);
 int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt,
 		   int start_index, int npages, u64 *page_list);