mlxsw: Narrow the critical section of devl_lock during ports creation/removal

No need to hold the lock for alloc and freecpu. So narrow the critical
section. Follow-up patch is going to benefit from this by adding more
code to the functions which will be out of the critical as well.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/minimal.c

@@ -328,6 +328,7 @@ static void mlxsw_m_port_module_unmap(struct mlxsw_m *mlxsw_m, u8 module)
 static int mlxsw_m_ports_create(struct mlxsw_m *mlxsw_m)
 {
 	unsigned int max_ports = mlxsw_core_max_ports(mlxsw_m->core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_m->core);
 	u8 last_module = max_ports;
 	int i;
 	int err;
@@ -356,6 +357,7 @@ static int mlxsw_m_ports_create(struct mlxsw_m *mlxsw_m)
 	}
 
 	/* Create port objects for each valid entry */
+	devl_lock(devlink);
 	for (i = 0; i < mlxsw_m->max_ports; i++) {
 		if (mlxsw_m->module_to_port[i] > 0 &&
 		    !mlxsw_core_port_is_xm(mlxsw_m->core, i)) {
@@ -366,6 +368,7 @@ static int mlxsw_m_ports_create(struct mlxsw_m *mlxsw_m)
 				goto err_module_to_port_create;
 		}
 	}
+	devl_unlock(devlink);
 
 	return 0;
 
@@ -375,6 +378,7 @@ static int mlxsw_m_ports_create(struct mlxsw_m *mlxsw_m)
 			mlxsw_m_port_remove(mlxsw_m,
 					    mlxsw_m->module_to_port[i]);
 	}
+	devl_unlock(devlink);
 	i = max_ports;
 err_module_to_port_map:
 	for (i--; i > 0; i--)
@@ -387,8 +391,10 @@ static int mlxsw_m_ports_create(struct mlxsw_m *mlxsw_m)
 
 static void mlxsw_m_ports_remove(struct mlxsw_m *mlxsw_m)
 {
+	struct devlink *devlink = priv_to_devlink(mlxsw_m->core);
 	int i;
 
+	devl_lock(devlink);
 	for (i = 0; i < mlxsw_m->max_ports; i++) {
 		if (mlxsw_m->module_to_port[i] > 0) {
 			mlxsw_m_port_remove(mlxsw_m,
@@ -396,6 +402,7 @@ static void mlxsw_m_ports_remove(struct mlxsw_m *mlxsw_m)
 			mlxsw_m_port_module_unmap(mlxsw_m, i);
 		}
 	}
+	devl_unlock(devlink);
 
 	kfree(mlxsw_m->module_to_port);
 	kfree(mlxsw_m->ports);
@@ -424,7 +431,6 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 			struct netlink_ext_ack *extack)
 {
 	struct mlxsw_m *mlxsw_m = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	int err;
 
 	mlxsw_m->core = mlxsw_core;
@@ -440,9 +446,7 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 		return err;
 	}
 
-	devl_lock(devlink);
 	err = mlxsw_m_ports_create(mlxsw_m);
-	devl_unlock(devlink);
 	if (err) {
 		dev_err(mlxsw_m->bus_info->dev, "Failed to create ports\n");
 		return err;
@@ -454,11 +458,8 @@ static int mlxsw_m_init(struct mlxsw_core *mlxsw_core,
 static void mlxsw_m_fini(struct mlxsw_core *mlxsw_core)
 {
 	struct mlxsw_m *mlxsw_m = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 
-	devl_lock(devlink);
 	mlxsw_m_ports_remove(mlxsw_m);
-	devl_unlock(devlink);
 }
 
 static const struct mlxsw_config_profile mlxsw_m_config_profile;

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -1863,12 +1863,15 @@ static bool mlxsw_sp_port_created(struct mlxsw_sp *mlxsw_sp, u16 local_port)
 
 static void mlxsw_sp_ports_remove(struct mlxsw_sp *mlxsw_sp)
 {
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
 	int i;
 
+	devl_lock(devlink);
 	for (i = 1; i < mlxsw_core_max_ports(mlxsw_sp->core); i++)
 		if (mlxsw_sp_port_created(mlxsw_sp, i))
 			mlxsw_sp_port_remove(mlxsw_sp, i);
 	mlxsw_sp_cpu_port_remove(mlxsw_sp);
+	devl_unlock(devlink);
 	kfree(mlxsw_sp->ports);
 	mlxsw_sp->ports = NULL;
 }
@@ -1876,6 +1879,7 @@ static void mlxsw_sp_ports_remove(struct mlxsw_sp *mlxsw_sp)
 static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 {
 	unsigned int max_ports = mlxsw_core_max_ports(mlxsw_sp->core);
+	struct devlink *devlink = priv_to_devlink(mlxsw_sp->core);
 	struct mlxsw_sp_port_mapping *port_mapping;
 	size_t alloc_size;
 	int i;
@@ -1886,6 +1890,7 @@ static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 	if (!mlxsw_sp->ports)
 		return -ENOMEM;
 
+	devl_lock(devlink);
 	err = mlxsw_sp_cpu_port_create(mlxsw_sp);
 	if (err)
 		goto err_cpu_port_create;
@@ -1898,6 +1903,7 @@ static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 		if (err)
 			goto err_port_create;
 	}
+	devl_unlock(devlink);
 	return 0;
 
 err_port_create:
@@ -1906,6 +1912,7 @@ static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 			mlxsw_sp_port_remove(mlxsw_sp, i);
 	mlxsw_sp_cpu_port_remove(mlxsw_sp);
 err_cpu_port_create:
+	devl_unlock(devlink);
 	kfree(mlxsw_sp->ports);
 	mlxsw_sp->ports = NULL;
 	return err;
@@ -2805,7 +2812,6 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 			 struct netlink_ext_ack *extack)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 	int err;
 
 	mlxsw_sp->core = mlxsw_core;
@@ -2966,9 +2972,7 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core,
 		goto err_sample_trigger_init;
 	}
 
-	devl_lock(devlink);
 	err = mlxsw_sp_ports_create(mlxsw_sp);
-	devl_unlock(devlink);
 	if (err) {
 		dev_err(mlxsw_sp->bus_info->dev, "Failed to create ports\n");
 		goto err_ports_create;
@@ -3149,12 +3153,8 @@ static int mlxsw_sp4_init(struct mlxsw_core *mlxsw_core,
 static void mlxsw_sp_fini(struct mlxsw_core *mlxsw_core)
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
-	struct devlink *devlink = priv_to_devlink(mlxsw_core);
 
-	devl_lock(devlink);
 	mlxsw_sp_ports_remove(mlxsw_sp);
-	devl_unlock(devlink);
-
 	rhashtable_destroy(&mlxsw_sp->sample_trigger_ht);
 	mlxsw_sp_port_module_info_fini(mlxsw_sp);
 	mlxsw_sp_dpipe_fini(mlxsw_sp);