mlxsw: spectrum_buffers: Query shared buffer size from firmware

Instead of hard coding the size of the shared buffer in the driver,
query it from the firmware, as it may change in future devices.
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>

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

@@ -536,12 +536,15 @@ static int mlxsw_sp_sb_mms_init(struct mlxsw_sp *mlxsw_sp)
 	return 0;
 }
 
-#define MLXSW_SP_SB_SIZE (16 * 1024 * 1024)
-
 int mlxsw_sp_buffers_init(struct mlxsw_sp *mlxsw_sp)
 {
+	u64 sb_size;
 	int err;
 
+	if (!MLXSW_CORE_RES_VALID(mlxsw_sp->core, MAX_BUFFER_SIZE))
+		return -EIO;
+	sb_size = MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_BUFFER_SIZE);
+
 	err = mlxsw_sp_sb_ports_init(mlxsw_sp);
 	if (err)
 		return err;
@@ -554,8 +557,7 @@ int mlxsw_sp_buffers_init(struct mlxsw_sp *mlxsw_sp)
 	err = mlxsw_sp_sb_mms_init(mlxsw_sp);
 	if (err)
 		goto err_sb_mms_init;
-	err = devlink_sb_register(priv_to_devlink(mlxsw_sp->core), 0,
-				  MLXSW_SP_SB_SIZE,
+	err = devlink_sb_register(priv_to_devlink(mlxsw_sp->core), 0, sb_size,
 				  MLXSW_SP_SB_POOL_COUNT,
 				  MLXSW_SP_SB_POOL_COUNT,
 				  MLXSW_SP_SB_TC_COUNT,