RDMA/mlx5: Create ODP EQ only when ODP MR is created

There is no need to create the ODP EQ if the user doesn't use ODP MRs.
Hence, create it only when the first ODP MR is created. This EQ will be
destroyed only when the device is unloaded.
This will decrease the number of EQs created per device. for example: If
we creates 1K devices (SF/VF/etc'), than we will decrease the num of EQs
by 1K.

Link: https://lore.kernel.org/r/20210314125418.179716-1-leon@kernel.org
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 19 insertions, 10 deletions

diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index 3008d1539ad4..a0b9111b508a 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -1531,20 +1531,24 @@ enum {
 	MLX5_IB_NUM_PF_DRAIN	= 64,
 };
 
-static int
-mlx5_ib_create_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
+int mlx5r_odp_create_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
 {
 	struct mlx5_eq_param param = {};
-	int err;
+	int err = 0;
 
+	mutex_lock(&dev->odp_eq_mutex);
+	if (eq->core)
+		goto unlock;
 	INIT_WORK(&eq->work, mlx5_ib_eq_pf_action);
 	spin_lock_init(&eq->lock);
 	eq->dev = dev;
 
 	eq->pool = mempool_create_kmalloc_pool(MLX5_IB_NUM_PF_DRAIN,
 					       sizeof(struct mlx5_pagefault));
-	if (!eq->pool)
-		return -ENOMEM;
+	if (!eq->pool) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	eq->wq = alloc_workqueue("mlx5_ib_page_fault",
 				 WQ_HIGHPRI | WQ_UNBOUND | WQ_MEM_RECLAIM,
@@ -1555,7 +1559,7 @@ mlx5_ib_create_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
 	}
 
 	eq->irq_nb.notifier_call = mlx5_ib_eq_pf_int;
-	param = (struct mlx5_eq_param) {
+	param = (struct mlx5_eq_param){
 		.irq_index = 0,
 		.nent = MLX5_IB_NUM_PF_EQE,
 	};
@@ -1571,21 +1575,27 @@ mlx5_ib_create_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
 		goto err_eq;
 	}
 
+	mutex_unlock(&dev->odp_eq_mutex);
 	return 0;
 err_eq:
 	mlx5_eq_destroy_generic(dev->mdev, eq->core);
 err_wq:
+	eq->core = NULL;
 	destroy_workqueue(eq->wq);
 err_mempool:
 	mempool_destroy(eq->pool);
+unlock:
+	mutex_unlock(&dev->odp_eq_mutex);
 	return err;
 }
 
 static int
-mlx5_ib_destroy_pf_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
+mlx5_ib_odp_destroy_eq(struct mlx5_ib_dev *dev, struct mlx5_ib_pf_eq *eq)
 {
 	int err;
 
+	if (!eq->core)
+		return 0;
 	mlx5_eq_disable(dev->mdev, eq->core, &eq->irq_nb);
 	err = mlx5_eq_destroy_generic(dev->mdev, eq->core);
 	cancel_work_sync(&eq->work);
@@ -1642,8 +1652,7 @@ int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
 		}
 	}
 
-	ret = mlx5_ib_create_pf_eq(dev, &dev->odp_pf_eq);
-
+	mutex_init(&dev->odp_eq_mutex);
 	return ret;
 }
 
@@ -1652,7 +1661,7 @@ void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *dev)
 	if (!(dev->odp_caps.general_caps & IB_ODP_SUPPORT))
 		return;
 
-	mlx5_ib_destroy_pf_eq(dev, &dev->odp_pf_eq);
+	mlx5_ib_odp_destroy_eq(dev, &dev->odp_pf_eq);
 }
 
 int mlx5_ib_odp_init(void)