How to specify node as a mining node or non mining node in geth

As in private network of ethereum there can be nodes who only do mining and the nodes who didn't do mining.so In geth when we create nodes,How to specify nodes that they are mining node or an non mining node?How to set permission for node or specify a node to do mining?

It is upto you basically, if you don't want a node to mine blocks, don't start the miner in that node. If you want to start/stop mining, use miner.start(1) and miner.stop() respectively. To check if any node is mining at that point use eth.mining, returns bool.