net/mlx5: devcom only supports 2 ports

Devcom API is intended to be used between 2 devices only add this
implied assumption into the code and check when it's no true.
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c

@@ -14,7 +14,7 @@ static LIST_HEAD(devcom_list);
 struct mlx5_devcom_component {
 	struct {
 		void *data;
-	} device[MLX5_MAX_PORTS];
+	} device[MLX5_DEVCOM_PORTS_SUPPORTED];
 
 	mlx5_devcom_event_handler_t handler;
 	struct rw_semaphore sem;
@@ -25,7 +25,7 @@ struct mlx5_devcom_list {
 	struct list_head list;
 
 	struct mlx5_devcom_component components[MLX5_DEVCOM_NUM_COMPONENTS];
-	struct mlx5_core_dev *devs[MLX5_MAX_PORTS];
+	struct mlx5_core_dev *devs[MLX5_DEVCOM_PORTS_SUPPORTED];
 };
 
 struct mlx5_devcom {
@@ -74,13 +74,15 @@ struct mlx5_devcom *mlx5_devcom_register_device(struct mlx5_core_dev *dev)
 
 	if (!mlx5_core_is_pf(dev))
 		return NULL;
+	if (MLX5_CAP_GEN(dev, num_lag_ports) != MLX5_DEVCOM_PORTS_SUPPORTED)
+		return NULL;
 
 	sguid0 = mlx5_query_nic_system_image_guid(dev);
 	list_for_each_entry(iter, &devcom_list, list) {
 		struct mlx5_core_dev *tmp_dev = NULL;
 
 		idx = -1;
-		for (i = 0; i < MLX5_MAX_PORTS; i++) {
+		for (i = 0; i < MLX5_DEVCOM_PORTS_SUPPORTED; i++) {
 			if (iter->devs[i])
 				tmp_dev = iter->devs[i];
 			else
@@ -134,11 +136,11 @@ void mlx5_devcom_unregister_device(struct mlx5_devcom *devcom)
 
 	kfree(devcom);
 
-	for (i = 0; i < MLX5_MAX_PORTS; i++)
+	for (i = 0; i < MLX5_DEVCOM_PORTS_SUPPORTED; i++)
 		if (priv->devs[i])
 			break;
 
-	if (i != MLX5_MAX_PORTS)
+	if (i != MLX5_DEVCOM_PORTS_SUPPORTED)
 		return;
 
 	list_del(&priv->list);
@@ -191,7 +193,7 @@ int mlx5_devcom_send_event(struct mlx5_devcom *devcom,
 
 	comp = &devcom->priv->components[id];
 	down_write(&comp->sem);
-	for (i = 0; i < MLX5_MAX_PORTS; i++)
+	for (i = 0; i < MLX5_DEVCOM_PORTS_SUPPORTED; i++)
 		if (i != devcom->idx && comp->device[i].data) {
 			err = comp->handler(event, comp->device[i].data,
 					    event_data);
@@ -239,7 +241,7 @@ void *mlx5_devcom_get_peer_data(struct mlx5_devcom *devcom,
 		return NULL;
 	}
 
-	for (i = 0; i < MLX5_MAX_PORTS; i++)
+	for (i = 0; i < MLX5_DEVCOM_PORTS_SUPPORTED; i++)
 		if (i != devcom->idx)
 			break;
 

drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.h

@@ -6,6 +6,8 @@
 
 #include <linux/mlx5/driver.h>
 
+#define MLX5_DEVCOM_PORTS_SUPPORTED 2
+
 enum mlx5_devcom_components {
 	MLX5_DEVCOM_ESW_OFFLOADS,