mlxsw: spectrum: Don't sleep during ndo_get_phys_port_name()

When rtnl_fill_ifinfo() is called for a certain netdevice it queries its
various parameters such as switch id and physical port name. The
function might get called in an atomic context, which means the
underlying driver must not sleep during the query operation.

Don't query the device and sleep during ndo_get_phys_port_name(), but
instead store the needed parameters in port creation time.

Fixes: 2bf9a58675c5 ("mlxsw: spectrum: Add support for physical port names")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index cc62d4c..6f9e3dd 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -313,9 +313,9 @@
 	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(sspr), sspr_pl);
 }
 
-static int __mlxsw_sp_port_module_info_get(struct mlxsw_sp *mlxsw_sp,
-					   u8 local_port, u8 *p_module,
-					   u8 *p_width, u8 *p_lane)
+static int mlxsw_sp_port_module_info_get(struct mlxsw_sp *mlxsw_sp,
+					 u8 local_port, u8 *p_module,
+					 u8 *p_width, u8 *p_lane)
 {
 	char pmlp_pl[MLXSW_REG_PMLP_LEN];
 	int err;
@@ -330,16 +330,6 @@
 	return 0;
 }
 
-static int mlxsw_sp_port_module_info_get(struct mlxsw_sp *mlxsw_sp,
-					 u8 local_port, u8 *p_module,
-					 u8 *p_width)
-{
-	u8 lane;
-
-	return __mlxsw_sp_port_module_info_get(mlxsw_sp, local_port, p_module,
-					       p_width, &lane);
-}
-
 static int mlxsw_sp_port_module_map(struct mlxsw_sp *mlxsw_sp, u8 local_port,
 				    u8 module, u8 width, u8 lane)
 {
@@ -957,17 +947,11 @@
 					    size_t len)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port = netdev_priv(dev);
-	u8 module, width, lane;
+	u8 module = mlxsw_sp_port->mapping.module;
+	u8 width = mlxsw_sp_port->mapping.width;
+	u8 lane = mlxsw_sp_port->mapping.lane;
 	int err;
 
-	err = __mlxsw_sp_port_module_info_get(mlxsw_sp_port->mlxsw_sp,
-					      mlxsw_sp_port->local_port,
-					      &module, &width, &lane);
-	if (err) {
-		netdev_err(dev, "Failed to retrieve module information\n");
-		return err;
-	}
-
 	if (!mlxsw_sp_port->split)
 		err = snprintf(name, len, "p%d", module + 1);
 	else
@@ -1690,7 +1674,7 @@
 }
 
 static int mlxsw_sp_port_create(struct mlxsw_sp *mlxsw_sp, u8 local_port,
-				bool split, u8 module, u8 width)
+				bool split, u8 module, u8 width, u8 lane)
 {
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	struct net_device *dev;
@@ -1705,6 +1689,9 @@
 	mlxsw_sp_port->mlxsw_sp = mlxsw_sp;
 	mlxsw_sp_port->local_port = local_port;
 	mlxsw_sp_port->split = split;
+	mlxsw_sp_port->mapping.module = module;
+	mlxsw_sp_port->mapping.width = width;
+	mlxsw_sp_port->mapping.lane = lane;
 	bytes = DIV_ROUND_UP(VLAN_N_VID, BITS_PER_BYTE);
 	mlxsw_sp_port->active_vlans = kzalloc(bytes, GFP_KERNEL);
 	if (!mlxsw_sp_port->active_vlans) {
@@ -1895,8 +1882,8 @@
 
 static int mlxsw_sp_ports_create(struct mlxsw_sp *mlxsw_sp)
 {
+	u8 module, width, lane;
 	size_t alloc_size;
-	u8 module, width;
 	int i;
 	int err;
 
@@ -1907,13 +1894,14 @@
 
 	for (i = 1; i < MLXSW_PORT_MAX_PORTS; i++) {
 		err = mlxsw_sp_port_module_info_get(mlxsw_sp, i, &module,
-						    &width);
+						    &width, &lane);
 		if (err)
 			goto err_port_module_info_get;
 		if (!width)
 			continue;
 		mlxsw_sp->port_to_module[i] = module;
-		err = mlxsw_sp_port_create(mlxsw_sp, i, false, module, width);
+		err = mlxsw_sp_port_create(mlxsw_sp, i, false, module, width,
+					   lane);
 		if (err)
 			goto err_port_create;
 	}
@@ -1955,7 +1943,7 @@
 
 	for (i = 0; i < count; i++) {
 		err = mlxsw_sp_port_create(mlxsw_sp, base_port + i, true,
-					   module, width);
+					   module, width, i * width);
 		if (err)
 			goto err_port_create;
 	}
@@ -2004,7 +1992,7 @@
 		module = mlxsw_sp->port_to_module[local_port];
 
 		mlxsw_sp_port_create(mlxsw_sp, local_port, false, module,
-				     width);
+				     width, 0);
 	}
 }
 
@@ -2024,18 +2012,14 @@
 		return -EINVAL;
 	}
 
+	module = mlxsw_sp_port->mapping.module;
+	cur_width = mlxsw_sp_port->mapping.width;
+
 	if (count != 2 && count != 4) {
 		netdev_err(mlxsw_sp_port->dev, "Port can only be split into 2 or 4 ports\n");
 		return -EINVAL;
 	}
 
-	err = mlxsw_sp_port_module_info_get(mlxsw_sp, local_port, &module,
-					    &cur_width);
-	if (err) {
-		netdev_err(mlxsw_sp_port->dev, "Failed to get port's width\n");
-		return err;
-	}
-
 	if (cur_width != MLXSW_PORT_MODULE_MAX_WIDTH) {
 		netdev_err(mlxsw_sp_port->dev, "Port cannot be split further\n");
 		return -EINVAL;
@@ -2077,10 +2061,9 @@
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_core_driver_priv(mlxsw_core);
 	struct mlxsw_sp_port *mlxsw_sp_port;
-	u8 module, cur_width, base_port;
+	u8 cur_width, base_port;
 	unsigned int count;
 	int i;
-	int err;
 
 	mlxsw_sp_port = mlxsw_sp->ports[local_port];
 	if (!mlxsw_sp_port) {
@@ -2094,12 +2077,7 @@
 		return -EINVAL;
 	}
 
-	err = mlxsw_sp_port_module_info_get(mlxsw_sp, local_port, &module,
-					    &cur_width);
-	if (err) {
-		netdev_err(mlxsw_sp_port->dev, "Failed to get port's width\n");
-		return err;
-	}
+	cur_width = mlxsw_sp_port->mapping.width;
 	count = cur_width == 1 ? 4 : 2;
 
 	base_port = mlxsw_sp_cluster_base_port_get(local_port);
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
index e2c022d..13b30ea 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.h
@@ -229,6 +229,11 @@
 		struct ieee_maxrate *maxrate;
 		struct ieee_pfc *pfc;
 	} dcb;
+	struct {
+		u8 module;
+		u8 width;
+		u8 lane;
+	} mapping;
 	/* 802.1Q bridge VLANs */
 	unsigned long *active_vlans;
 	unsigned long *untagged_vlans;