vdpa/mlx5: Introduce init/destroy for MR resources

There's currently not a lot of action happening during
the init/destroy of MR resources. But more will be added
in the upcoming patches.

As the mr mutex lock init/destroy has been moved to these
new functions, the lifetime has now shifted away from
mlx5_vdpa_alloc_resources() / mlx5_vdpa_free_resources()
into these new functions. However, the lifetime at the
outer scope remains the same:
mlx5_vdpa_dev_add() / mlx5_vdpa_dev_free()

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Message-Id: <20240830105838.2666587-8-dtatulea@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vdpa/mlx5/core/mlx5_vdpa.h

@@ -138,6 +138,8 @@ int mlx5_vdpa_create_mkey(struct mlx5_vdpa_dev *mvdev, u32 *mkey, u32 *in,
 int mlx5_vdpa_destroy_mkey(struct mlx5_vdpa_dev *mvdev, u32 mkey);
 struct mlx5_vdpa_mr *mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev,
 					 struct vhost_iotlb *iotlb);
+int mlx5_vdpa_init_mr_resources(struct mlx5_vdpa_dev *mvdev);
+void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev);
 void mlx5_vdpa_clean_mrs(struct mlx5_vdpa_dev *mvdev);
 void mlx5_vdpa_get_mr(struct mlx5_vdpa_dev *mvdev,
 		      struct mlx5_vdpa_mr *mr);

drivers/vdpa/mlx5/core/mr.c

@@ -846,3 +846,20 @@ int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid)
 
 	return 0;
 }
+
+int mlx5_vdpa_init_mr_resources(struct mlx5_vdpa_dev *mvdev)
+{
+	struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;
+
+	INIT_LIST_HEAD(&mres->mr_list_head);
+	mutex_init(&mres->lock);
+
+	return 0;
+}
+
+void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev)
+{
+	struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;
+
+	mutex_destroy(&mres->lock);
+}

drivers/vdpa/mlx5/core/resources.c

@@ -256,7 +256,6 @@ int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev)
 		mlx5_vdpa_warn(mvdev, "resources already allocated\n");
 		return -EINVAL;
 	}
-	mutex_init(&mvdev->mres.lock);
 	res->uar = mlx5_get_uars_page(mdev);
 	if (IS_ERR(res->uar)) {
 		err = PTR_ERR(res->uar);
@@ -301,7 +300,6 @@ err_pd:
 err_uctx:
 	mlx5_put_uars_page(mdev, res->uar);
 err_uars:
-	mutex_destroy(&mvdev->mres.lock);
 	return err;
 }
 
@@ -318,7 +316,6 @@ void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev)
 	dealloc_pd(mvdev, res->pdn, res->uid);
 	destroy_uctx(mvdev, res->uid);
 	mlx5_put_uars_page(mvdev->mdev, res->uar);
-	mutex_destroy(&mvdev->mres.lock);
 	res->valid = false;
 }
 

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -3434,6 +3434,7 @@ static void mlx5_vdpa_free(struct vdpa_device *vdev)
 
 	free_fixed_resources(ndev);
 	mlx5_vdpa_clean_mrs(mvdev);
+	mlx5_vdpa_destroy_mr_resources(&ndev->mvdev);
 	if (!is_zero_ether_addr(ndev->config.mac)) {
 		pfmdev = pci_get_drvdata(pci_physfn(mvdev->mdev->pdev));
 		mlx5_mpfs_del_mac(pfmdev, ndev->config.mac);
@@ -3962,12 +3963,14 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
 	if (err)
 		goto err_mpfs;
 
-	INIT_LIST_HEAD(&mvdev->mres.mr_list_head);
+	err = mlx5_vdpa_init_mr_resources(mvdev);
+	if (err)
+		goto err_res;
 
 	if (MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
 		err = mlx5_vdpa_create_dma_mr(mvdev);
 		if (err)
-			goto err_res;
+			goto err_mr_res;
 	}
 
 	err = alloc_fixed_resources(ndev);
@@ -4009,6 +4012,8 @@ err_res2:
 	free_fixed_resources(ndev);
 err_mr:
 	mlx5_vdpa_clean_mrs(mvdev);
+err_mr_res:
+	mlx5_vdpa_destroy_mr_resources(mvdev);
 err_res:
 	mlx5_vdpa_free_resources(&ndev->mvdev);
 err_mpfs: